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CROSS REFERENCE
[0001] This application is a continuation of U.S. Ser. No. 09/643,354 filed on Aug. 22, 2000, which claims the benefit of U.S. Serial Nos. 60/151,577, 60/151,607, 60/151,498, 60/151,602, 60/151,603, 60/151,529, 60/151,489, 60/151,604, 60/151,606, 60/151,589, 60/151,497, 60/151,590 and 60/151,578 all filed on Aug. 30, 1999.
FIELD OF INVENTION
[0002] This invention is related to a process for the production of purified 2,6-naphthalene dicarboxylic acid (hereafter referred to as 2,6-NDA) from a crude 2,6-NDA disproportionation product. More particularly, this invention is related to a novel method of separating and recycling byproducts in a process for producing 2,6-NDA from a disproportionation product that utilizes reverse osmosis and is industrially advantageous.
BACKGROUND OF THE INVENTION
[0003] Aromatic carboxylic acids are highly useful organic compounds. They are useful as intermediates for the preparation of other organic compounds, and as monomers for the preparation of polymeric materials. In particular, the naphthalene carboxylic acids are used for preparing photographic chemicals and dyestuffs. Naphthalene dicarboxylic acids can also be used to prepare a variety of polyester and polyamide compositions. 2,6-NDA is a particularly useful aromatic carboxylic acid which can be reacted with ethylene glycol to prepare poly(ethylene-2,6-naphthalate). Polyesters prepared from 2,6-NDA have excellent heat resistance, gas barrier, and mechanical properties. Therefore, much research in the art has focused on methods of preparing 2,6-NDA. The production of 2,6-NDA from disproportionation product is described, for example, in U.S. Pat. Nos. 2,823,231 and 2,849,482.
[0004] Production of high purity 2,6-NDA from disproportionation product requires many process steps to separate impurities from the dipotassium salt of 2,6-NDA hereafter referred to as 2,6-K2NDA, which is the 2,6-NDA precursor. The impurities include naphthalene, zinc oxide, and several naphthalene mono- and dicarboxylic acid salts. This complexity results in numerous byproduct streams that must be recycled to make the process less costly.
[0005] There have been different approaches to the separation of the dialkali metal salt products of disproportionation reactions and conversion of them into 2,6-NDA.
[0006] In U.S. Pat. No. 2,823,231, the method used to separate the dialkali metal salts of 2,6-naphthalene dicarboxylic acid comprises dissolving the disproportionation conversion product mixture in water, filtering off insoluble impurities from the resulting solution, acidifying the filtrate with mineral or organic acid, such as sulfuric or hydrochloric acid, and separating the precipitated naphthalene-2,6-dicarboxylic acid from the acid solution. In U.S. Pat. No. 2,823,231 the dialkali metal salt of naphthalene 2,6-dicarboxylic acid formed is converted into free naphthalene 2,6-dicarboxylic acid by acidification of said dialkali metal salt with a strong mineral acid.
[0007] U.S. Pat. No. 2,849,482 teaches acidifying an aqueous solution of the crude reaction product of the disproportionation or converting the crude alkali metal salt directly into the dichloride or into esters of naphthalene-2,6-naphthalene dicarboxylic acid in accordance with known methods.
[0008] In U.S. Pat. No. 3,631,096, to Phillips, salts formed by the reaction can be transformed into the corresponding free acids by acidifying the solution with organic or inorganic acids or by introducing carbon dioxide into the solution at atmospheric or elevated pressure, and then separating the free acids from the acidified solution. The individual reaction products may be separated from each other and isolated in pure form by methods that are based upon their different solubilities or volatilities and may thereafter, if desired, be transformed into their derivatives. The salt mixture produced by the reaction may also be transformed directly into derivatives of the acids, for example, into their esters or halides, and these derivatives may be purified, if desired, by fractional distillation.
[0009] U.S. Pat. No. 3,671,578, to Teijin, discloses that the monoalkali salt of 2,6-naphthalene dicarboxylic acid is easily disproportionated when heated in water or water-containing organic solvent, to form free dicarboxylic acid and by-product dialkali salt, and the former acid is precipitated.
[0010] In U.S. Pat. No. 3,952,052, to Phillips, there is disclosed a process for separating a disproportionation reaction product by forming a slurry comprising alkali metal salts of aromatic polycarboxylic acid and dispersant and a gaseous effluent, and then lowering the pressure, flashing the dispersant, and recovering said alkali metal salts of said polycarboxylic acids as solids from said separation zone.
[0011] U.S. Pat. No. 3,888,921, to Teijin Ltd., discloses a method for purifying a dialkali salt of crude 2,6-naphthalene dicarboxylic acid comprising precipitating 40 to 97 mol percent of the dialkali 2,6-naphthalene dicarboxylate dissolved in an aqueous solution substantially as monoalkali salt of 2,6-naphthalenedicarboxylic acid while maintaining the pH of said aqueous solution at a value not lower than 6.3, and separating the precipitate, and converting the separated precipitate to 2,6-naphthalene dicarboxylic acid.
[0012] Canadian Patent 864587 discloses a process for the preparation of 2,6-NDA which comprises heating a monoalkali salt of 2,6-NDA in water or water-containing organic solvent causing disproportionation thereof into 2,6-NDA and a dialkali salt and separating the 2,6-NDA by a method that includes dissolving a rearrangement reaction product containing dialkali salt of 2,6-naphthalene dicarboxylic acid in warm water, filtering off the insoluble matter therefrom, concentrating the remaining solution, whereby the filtrate is concentrated to such a degree that the precipitation yield of the dialkali salt precipitated when the concentrated liquid is cooled to room temperature reaches at least 70% and the purity of said precipitate exceeds 99%, passing gaseous carbon dioxide through the aqueous solution of the precipitate recovered from the concentrated liquid, and recovering the resulting precipitate, and the mother liquour containing the side product dialkali salt of 2,6-naphthalene dicarboxylic acid is recycled into the carbon dioxide reaction step.
[0013] U.S. Pat. No. 5,175,354 discloses a reaction step wherein 2,6-naphthalene dicarboxylic acid potassium salts are allowed to react with benzene-carboxylic acids in the presence of water to yield 2,6-NDA and benzene-carboxylic acid potassium salts and a separation step wherein the crystallized 2,6-NDA is separated from the benzene-carboxylic acid potassium salts dissolved in the aqueous solution and provides 2,6-NDA.
[0014] None of these references suggest the idea of incorporating reverse osmosis membranes into a process for purifying 2,6-NDA.
[0015] There is a need in the art for alternative methods of separating the desired product and efficiently recycling byproducts. The purification process of the present invention provides an efficient way of separating and recycling byproducts which is advantageous.
SUMMARY OF THE INVENTION
[0016] In accordance with the foregoing the present invention comprises a process for purifying 2,6-naphthalene dicarboxylic acid produced by disproportionation and more efficiently recycling byproduct dipotassium salts which comprises:
[0017] a) Dissolving the disproportionation product of potassium naphthoate comprising the dipotassium salt of 2,6-NDA (K2NDA) in water, removing any residual disproportionation reaction medium, centrifuging the solution to remove the disproportionation catalyst, and removing acid salts other than 2,6-NDA by crystallization and/or carbon adsorption;
[0018] b) Contacting said aqueous solution of 2,6-K2NDA with carbon dioxide to form as a precipitate the monopotassium salt of 2,6-NDA (KHNDA) and an aqueous solution containing 2,3-KHNDA, K2NDA, and potassium bicarbonate;
[0019] c) Separating said monopotassium salt as a solid from said stream containing 2,3-KHNDA, K2NDA and potassium bicarbonate;
[0020] d) Disproportionating said monopotassium salt (KHNDA) to form solid 2,6-NDA and an aqueous solution containing K2NDA and potassium bicarbonate;
[0021] e) Separating said 2,6-NDA;
[0022] f) Concentrating said aqueous solution containing K2NDA and potassium bicarbonate from step (d) by reverse osmosis; and
[0023] e) Recycling concentrated K2NDA to step (b) and pure water to step (d).
BRIEF DESCRIPTION OF THE DRAWING
[0024] The drawing is a process flow diagram illustrating the use of the process of the present invention as part of an integrated process for producing 2,6-naphthalene dicarboxylic acid.
DETAILED DESCRIPTION OF THE INVENTION
[0025] The novel process of the present invention for producing high purity 2,6-NDA begins with a disproportionation reaction product. This type reaction is described, for example, in U.S. Pat. Nos. 2,823,231 and 2,849,482.
[0026] The present invention is advantageously used in conjunction with a process for the production of 2,6-NDA by disproportionation of potassium naphthoate as described in copending U.S. Patent Application Ser. No. 60/151,577 (Attorney's Docket #TH1432), incorporated by reference herein in the entirety. In that application the disproportionation effluent solids (in naphthalene) consist primarily of 2,6 K2NDA, 2,3 K2NDA (isomer intermediate), unreacted KNA, catalyst, and trace coke. After leaving the disproportionation reactor the solvent is flashed.
[0027] Next, the solid product comprising dipotassium salts of 2,6-NDA, K2NDA (2,6-and 2,3-isomers), unreacted KNA, catalyst, heavy by-products, any residual solvent, and trace coke enter a water wash. The organic salts are dissolved and the liquid is directed to a decanter and centrifuge to remove residual solvent, catalyst and coke particles. The ZnO catalyst is regenerated and recycled.
[0028] The next step in the process is crystallization of the dipotassium salt. The dipotassium salt of naphthalene dicarboxylic acid resulting from the disproportionation reaction contains at least 15% unconverted feed and intermediates. The liquid carrying the dipotassium salts of NDA, K2NDA (2,6-and 2,3-isomers), KHCO 3 , and unreacted KNA, flows to a two-stage evaporative crystallization section, where the disalt of 2,6 NDA (2,6 K2NDA) is selectively precipitated.
[0029] The crystallization section rejects a mother liquor stream containing KHCO3, unreacted KNA, and 2,3 K2NDA. Recovery of 2,6 K2NDA is approximately 90%, and the purity of the K2NDA leaving the second crystallizer is 99.9%+.
[0030] The purified K2NDA slurry is then redissolved with additional clean water and optionally treated with a solid adsorbing agent. Examples of solid adsorbing agents include activated carbon, alumina, magnesia or ion exchange resins. The use of activated carbon is especially preferred. The amount of the solid adsorbent to be used depends upon the amounts of impurities contained therein. A suitable amount of adsorbent would be in the range of 0.1 to 10 percent by weight, preferably 0.5 to 5 percent by weight, based on the K2NDA. By subjecting an aqueous solution of the dipotassium salt to a solid adsorbent, most residual trace impurities that could affect the color of the final product can be removed.
[0031] Next, the monopotassium salt of 2,6-NDA (KHNDA) is selectively precipitated from an aqueous solution of K2NDA (about 20%) by reacting said aqueous solution at 0-200 psi CO 2 pressure, and 0-50° C. for about 30 minutes. The reaction produces the solid mono-potassium salt of 2,6-NDA, 2,6-KHNDA, and also 2,3-KHNDA and potassium bicarbonate. 2,3-KHNDA is rejected from the 2,6-KHNDA crystals.
[0032] The CO 2 precipitation step effectively separates 2,6-KHNDA from 2,3-KHNDA, which remains in solution due to its higher solubility. Examples 1-8 demonstrate this separation. The rejection of the 2,3-KHNDA is beneficial because, as a result, 2,3-KHNDA does not interfere with the separation of the 2,6-NDA from the K2NDA and the reverse osmosis of the present invention that takes place after the disproportionation of the 2,6-KHNDA.
[0033] Yields of 2,6-KHNDA better than 80% have been demonstrated at only 1 atm CO 2 pressure. The fact that the precipitation can be done effectively at modest pressure allows for centrifugation of the product without releasing pressure. The centrate also contains dissolved potassium bicarbonate and 2,3-KHNDA.
[0034] KHNDA solids are then diluted to 5-10% and disproportionated by reacting for less than an hour, preferably about 20 to 30 minutes at 150° C., under about 50 Psi CO 2 pressure. The reactor effluent from this step is separated to give a 2, 6-NDA solid, and a centrate containing predominantly 2,6-K2NDA and KHCO 3 .
[0035] This centrate stream from the disproportionation of the monosalt, KHNDA, is the primary focus of the present invention. According to the present invention the K2NDA in the centrate stream would be very useful if recycled to the CO 2 precipitation step, however it has to be concentrated because the optimal salt concentration in the CO2 precipitation step is about 20 wt %, whereas it is less than 10 wt % in the KHNDA disproportionation step. Concentrating this solution by evaporating off water is very energy intensive and costly.
[0036] It has been discovered in the present invention that when the solid 2,6-NDA produced in the disproportionation of KHNDA is separated out, the remaining solution containing K2NDA and potassium bicarbonate can be concentrated via reverse osmosis and recycled to the CO 2 precipitation step very efficiently and economically. The reverse osmosis step produces a pure water stream that can be recycled to the disproportionation step, and a concentrated K2NDA solution that can be recycled to the CO 2 precipitation step. Any potassium present in forms such as potassium carbonate or potassium bicarbonate is also separated by the membrane for recycle.
[0037] The dipotassium salt should be concentrated to a wt % in the range of 10-30 wt % salt. In the examples of the present invention the target was 20 wt % salt.
[0038] The reverse osmosis membranes that are suitable for use in the process are those characterized by high flux and high salt rejection, hydrolytic stability, resistance to compaction under pressure, and resistance to chemical attack.
[0039] The membranes employed in the examples were thin film composite membranes. These membranes consist of three layers: a support web, a microporous polysulfone layer with controlled pore diameters, and an ultrathin polyamide coating which is the selective layer. The support web provides the major structural support; the interlayer provides a smooth surface for the selective layer. The selective layer is on the order of 0.2 microns and can withstand high pressures due to the support provided by the interlayer. Examples of suitable membranes are FT-30 and HP-31, commercially available from Rochem Environmental, Inc.
[0040] In the present invention it is necessary to increase pressure in conjunction with the use of the membranes to achieve the desired concentration of the K2NDA. Suitable pressure is a pressure higher than the osmotic pressure of the solution. Good results were observed where a pressure in the range of 800 to 2000 psig was used. In some cases it is advantageous to use a pressure on the lower end of the range until most of the water is recovered, say 60-80%, and then employ a higher pressure. Examples 9-13 and 14-19 set forth data obtained for tests at low pressure and two-stage (low to high) pressure, respectively.
[0041] It has been found that the 2,6-NDA produced by this process is of high purity and contains only low levels of potassium. It has also been found that potassium can be removed to even lower levels by washing the 2,6-NDA with water.
DETAILED DESCRIPTION OF THE DRAWING
[0042] The drawing is a flow diagram showing one embodiment of the process of the present invention as part of a purification section for producing 2,6-NDA. It is understood the drawing is only intended as an illustration and not intended to limit the scope of the invention.
[0043] Referring to the Figure, solid product comprising dipotassium salts of NDA, K2NDA (2,6 and 2,3 isomers), unreacted KNA, catalyst, heavy by-products, and trace coke from which most of the reaction medium from the disproportionation reaction has been removed, represented by 1 enters water wash 2 where the organic salts are dissolved. Steam and 25% naphthalene can enter the water wash via 3 from another section of the process. The entire integrated process is discussed in detail in copending Ser. No. 60/151,577 (Attorney's Docket #TH1432), incorporated by reference herein in its entirety. The liquid is then directed to a decanter 4 to remove any residual solvent, catalyst and coke particles. Naphthalene and some solids exit the process at 5 , while an aqueous solution of crude K2NDA also containing solid ZnO catalyst is directed to a centrifuge 6 . ZnO catalyst exits the centrifuge through 7 and is recycled. The liquid carrying the mixed organic salts, including the crude K2NDA is directed through 8 to a two-stage evaporative crystallization section, 9 and 10 .
[0044] In the evaporative crystallization section 2 , 6 -K2NDA is selectively precipitated from crude K2NDA product, rejecting KNA, 2,3-K2NDA, and KHCO 3 . First, the crude K2NDA stream 8 and a recycle stream 11 containing KHCO 3 are added to evaporative crystallizer 9 . In evaporative crystallizer 9 , 2,6-K2NDA is selectively precipitated as water is evaporated. The water vapor exits the crystallizer, and is condensed by overhead exchanger 12 . The water is then routed through line 13 to other portions of the finishing section in order to provide a dilution medium. The contents of the first evaporative crystallizer 9 exit through 14 to centrifuge 15 . In centrifuge 15 , mother liquor containing KNA, 2,3-K2NDA, and KHCO 3 are rejected, exit at 16 , and are recycled back to the salt formation reactor in another section of the integrated process. The K2NDA solids are combined with recycle stream 17 containing KHCO 3 and 2,6-K2NDA and added to the second stage evaporative crystallizer 10 . In 10 2,6-K2NDA is again selectively precipitated as water evaporates and exits the crystallizer. The water is condensed by overhead exchanger 18 and is directed into line 13 . The purified K2NDA slurry leaves the second stage evaporative crystallizer through 19 and is directed to centrifuge 20 . In centrifuge 20 mother liquor containing KHCO 3 is separated from purified 2,6-K2NDA and recycled back to the first stage evaporative crystallizer 9 through 11 .
[0045] The purified solid 2,6-K2NDA is dissolved with water from overhead line 13 and transported through line 21 to an activated carbon guard bed 22 . The 2,6-K2NDA solution then passes through the activated carbon guard bed 22 to remove residual trace impurities that could affect the color of the final product.
[0046] The 2,6-K2NDA solution exits the activated carbon bed 22 via line 23 and is directed to the C 02 precipitation reactor 24 . CO 2 is added to reactor 24 through line 25 . In reactor 24 the monopotassium salt of 2,6-NDA, KHNDA, is selectively precipitated from the 2,6-K2NDA solution. The KHNDA is then directed out of the reactor through line 26 to centrifuge 27 . The mother liquor, containing KHCO 3 and unreacted 2,6-K2NDA, is separated from the solid KHNDA and is recycled back to the second stage evaporative crystallizer 10 via line 17 . The solid KHNDA is slurried with water from recycle line 28 and directed through line 29 to disproportionation reactor 30 . CO 2 is added to reactor 30 through line 31 . The KHNDA is reacted in the presence of 50 psig CO 2 and about 150° C. in disproportionation reactor 30 to form solid 2,6-NDA and 2,6-K2NDA. The reactor effluent from this step is directed through 32 to centrifuge 33 .
[0047] This is the point where the present invention provides a very efficient method of making the process more economical. The solid 2,6-NDA is separated from the mother liquor and exits through 35 to a section for further purification and reduction of potassium levels. The centrate containing predominantly 2,6-K2NDA is directed through 34 to a two-stage reverse osmosis section, 36 & 38 . In 36 the K2NDA feed enters a reverse osmosis stage operated at a lower pressure. Concentrate exits at 37 and is directed to a second reverse osmosis stage 38 operated at higher pressure, and permeate (water) exits at 39 and connects with a water recycle line which is directed back to the disproportionation step. The concentrate from 38 exits into line 25 which recycles back to the CO 2 precipitation step and water from the second stage reverse osmosis exits at 40 .
[0048] The present invention will be more clearly understood from the following examples. It is understood that these examples are presented only to illustrate some embodiments of the invention and are not intended to limit the scope thereof.
EXAMPLES 1-8
[0049] Examples 1-8 were performed to investigate the separation of 2,3-KHNDA from 2,6-KHNDA in the CO 2 precipitation step. In these experiments, aqueous solutions containing 5% molar 2,3-K2NDA based on 2,6-K2NDA were contacted with CO 2 at 100° C. and various CO 2 pressures. The results in Table 1 show that the precipitate obtained by this process contained essentially no 2,3-NDA impurity.
TABLE 1 (Separation of 2,3 - NDA from 2,6 - NDA) Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Ex. 8 Initial solution weight (g) 50 50 59 52 50 50 50 52 % K2NDA in initial solution 20 20 20 20 20 20 20 20 2,3/2,6 molar ratio 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 CO 3 /2,6 molar ratio 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 CO 2 pressure (psig) 400 400 400 400 200 200 200 200 Contact time (hr) 1 1 1 1 1 1 1 1 Temperature (° C.) 100 100 100 100 100 100 100 100 Precipitate weight (g) 6.5 7.48 6.5 7.6 5.41 5.23 4.95 6.58 2,6 - NDA in precipitate 80.8 78 79 79.8 79.5 79.5 80.2 80.1 (% w) 2,3 - NDA in precipitate 135 160 125 <60 <60 <60 <60 45 (ppm) K in precipitate (% w) 13.7 14.9 14.5 13.8 14.2 14.2 13.6 14 2,3/2,6 molar ratio in 2 × 10 −4 2 × 10 −4 2 × 10 −4 <8 × 10 −5 <8 × 10 −5 <8 × 10 −5 <8 × 10 −5 <6 × 10 −5 product
EXAMPLES 9-13
[0050] Reverse osmosis experiments were carried out using a 3 wt % solution of 2,6-K2NDA. The pH and conductivity of the test solution were 9.2 and 16,100 μS/cm, respectively. A Rochem Disc Tube TM (DT) module, scaled down to 110th of the standard 169 membrane module was used for all examples. Examples 9-13 were performed at low pressure using an FT30 membrane. In the low pressure test, the system was operated below 900 psig. Examples 14-19 were carried out using an FT-30 membrane in a low pressure module and an HP31 membrane in a high pressure module. The low pressure module was operated below 900 psig up to a 75% water recovery, and then a switch was made to the high pressure module operated below 1800 psig. The initial feed volume was 62 liters. Based on the calculated feed concentration of 3 wt %, a volume reduction requirement of 85% was assumed to achieve the goal of 20 wt % K2NDA in the resulting stream. The results obtained are set forth in Tables 2 and 3 and clearly show excellent salt rejection achieved. The flux rates obtained in these examples after normalization with respect to temperature and pressure range from about 25 to about 70 gal/sq.ft-day.
TABLE 2 (Results of low pressure reverse osmosis test) Ex. 9 Ex. 10 Ex. 11 Ex. 12 Ex. 13 % recovery 0 25 50 75 85 K2NDA in feed 28000 35000 53000 107000 155000 (ppm) K2NDA in 30 37 58 99 264 permeate (ppm) % rejection 99.9 99.9 99.9 99.9 99.8 Pressure (psig) 500 525 525 750 850 Flux (gal/sq. 32.7 37.6 31.8 24.1 11.1 ft. - day) Temperature 73 83 94 98 102 (° F.)
[0051] [0051] TABLE 3 (Results of low pressure/high pressure reverse osmosis test) Ex. 14 Ex. 15 Ex. 16 Ex. 17 Ex. 18 Ex. 19 % recovery 0 25 50 75 75 85 K2NDA in 27000 35000 57000 103000 105000 178000 feed (ppm) K2NDA in 59 81 168 399 151 495 permeate (ppm) % rejection 99.8 99.8 99.7 99.6 99.9 99.7 Pressure (psig) 500 525 525 680 1000 1400 Flux (gal/sq. 27.5 30.3 26 18.8 37.6 23.1 ft - day) Temperature 76 90 94 102 106 115 (° F.)
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Disclosed is a process for purifying 2,6-naphthalene dicarboxylic acid produced by disproportionation and more efficiently recycling byproduct dipotassium salts which includes the steps of:
a) Contacting an aqueous solution containing the disalt of 2,6-NDA(2,6-K2NDA) with carbon dioxide to form as a precipitate the monopotassium salt of 2,6-NDA (KHNDA) and an aqueous solution containing 2,3-KHNDA, K2NDA, and potassium bicarbonate;
b) Disproportionating said monopotassium salt (KHNDA) to form 2,6-NDA and an aqueous solution containing K2NDA, and potassium bicarbonate;
c) Separating said 2,6-NDA and concentrating said aqueous solution containing K2NDA and potassium bicarbonate by reverse osmosis.
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CROSS REFERENCE TO RELATED PATENT APPLICATIONS
This disclosure incorporates by reference the following pending U.S. patent applications: (1) Ser. No. 14/515,142, title: Satellite Operating System, Architecture, Testing and Radio Communication System filed on Oct. 15, 2014; (2) Ser. No. 14/514,836, title: Back-Plane Connector for Cubesat filed on Oct. 15, 2014; and (3) Ser. No. 14/514,573, title: Novel Satellite Communication System filed on Oct. 15, 2014. The contents of these three applications are incorporated by reference herein as if each was restated in full.
FIELD OF THE INVENTION
The inventions herein are directed to novel on-board computers implemented with hardware interfaces and connectors for communicating with peripherals. In particular, the present invention is directed to on-board computers implemented on satellite systems, such as small factor satellites (known in the art as “cubesats”).
BACKGROUND
A growing interest in low earth orbit satellites having a small form factor has led to an increase in both launches of the vehicles and the recognition that earlier techniques for control thereof are inadequate. Due to their smaller size, cubesats generally cost less to build and deploy into orbit above the Earth. As a result, cubesats present opportunities for educational institutions, governments, and commercial entities to launch and deploy cubesats for a variety of purposes with fewer costs compared to traditional, large satellites.
To maximize the cubesat's usage and optimize its performance, it is desirable to configure the cubesat to accommodate a wide spectrum of peripherals of different types. As such, there is a need for a computer architecture that offers a rich interface to the cubesat so as to enhance the cubesat communications with various peripherals. Select embodiments of the disclosed technology address these needs.
SUMMARY
The disclosed technology relates to an on-board computer implemented in a small form factor satellite. The on-board computer may include a processor and a memory storing system initiation or “boot” information. The on-board computer may also include a backplane having a plurality of connectors. The connectors may physically connect the processor to a plurality of peripherals external to the on-board computer. Further, the on-board computer may include a plurality of hardware interfaces. The hardware interfaces may facilitate communication between the processor and a plurality of peripherals external to the on-board computer, but within the small form factor satellite. The hardware interfaces may include a multimedia card interface, a general-purpose input output, an Ethernet interface, a controller area network interface, an inter-integrated circuit, a serial peripheral interface, a universal asynchronous receiver/transmitter, and a video interface.
Another aspect of the disclosed technology relates to a cubesat communications system. The system may include an on-board computer implemented on a hardware platform. The on-board computer may include a processor and a memory storing selected “boot” information. The on-board computer may include a hardware interface implemented on the selected hardware platform. The hardware interface may facilitate communication between the processor and one or more peripherals external to the on-board computer. The on-board computer may include a backplane having a connector, connecting the processor to the peripheral.
Various aspects of the described illustrative embodiments may be combined with aspects of certain other embodiments to realize yet further combinations. It is to be understood that one or more features of any one illustration may be combined with one or more features of the other arrangements disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
The following Detailed Description of the technology is better understood when read in conjunction with the appended drawings. For the purposes of illustration, there is shown in the drawings exemplary embodiments, but the subject matter is not limited to the specific elements and instrumentalities disclosed. Components in the figures are shown for illustration purposes only, and may not be drawn to scale.
FIG. 1 illustrates an example terrestrial and orbital communication network according to one aspect of the disclosed technology.
FIG. 2 is a schematic drawing of a satellite according to one aspect of the disclosed technology.
FIG. 3 is a block diagram of satellite architecture according to one aspect of the disclosed technology.
FIG. 4 is a block diagram of the on-board computer according to one aspect of the disclosed technology.
DETAILED DESCRIPTION
In the following detailed description, numerous specific details are set forth by way of examples in order to provide a thorough understanding of the relevant teachings. However, it should be apparent to those skilled in the art that the present teachings may be practiced without such details. In other instances, well known methods, procedures, components, and/or circuitry have been described at a relatively high-level, without detail, in order to avoid unnecessarily obscuring aspects of the present teachings.
1. Satellite Overview
The present application relates to, but not limited to, a terrestrial and orbital communication network having a constellation of satellites. FIG. 1 illustrates an exemplary terrestrial and orbital communication network 100 covering at least a portion of a planet 110 , such as the Earth. The network 100 may include a constellation of satellites 120 each configured to collect data from a point on the planet from time to time or on a regular basis. The satellite 120 may analyze the collected data to monitor maritime activities, including but not limited to tracking ship or oceangoing vessels, detecting illegal, unreported and unregulated fishing or pirate activities, monitoring trade transit, and detecting oil spill, among other possibilities.
The satellite 120 may be a cubesat having a small form factor. For instance, the size of the satellite 120 may be relatively small, in general not exceeding 10 cm×10 cm×30 cm and 10 kg of mass. In one embodiment, the satellite 120 may be based on an industry standard, developed in 2001 by Stanford University and California Polytechnic Institute and described in the document “CubeSat Design Specification.” Cubesats may be launched and deployed using a common deployment system. For example, cubesats may be launched and deployed from a mechanism called a Poly-PicoSatellite Orbital Deployer (P-POD). P-PODs may be mounted to a launch vehicle and carry cubesats into orbit. P-PODs may deploy cubesats once a proper signal is received from the launch vehicle.
FIG. 2 is a schematic drawing of a satellite according to one aspect of the disclosed technology. As shown in FIG. 2 , the satellite 120 may include one or more solar panels 122 . The solar panels 122 may be configured to provide energy to one or more components contained within the satellite 120 . The satellite 120 may also include one or more antennas 124 that may extend when fully deployed.
FIG. 3 illustrates an architecture design of the satellite 120 according to one aspect of the disclosed technology. As shown in FIG. 3 , the satellite 120 may include an on-board computer (OBC) 200 that acts as a central computer, a power distribution unit (PDU) 300 that routes and regulates power throughout the satellite 120 , and a communications system 400 configured to handle radio communications of the satellite 120 . The satellite 120 may also include an automatic identification system (AIS) 500 . The OBC 200 , the PDU 300 , the communications system 400 , and the AIS 500 may communicate with one another via a controller area network (CAN) bus 600 .
As shown in FIG. 3 , the OBC 200 may include a System on Module (SOM) board processor 210 and a USB/FTDI connector 220 . The PDU 300 may include a microcontroller (MCU) 310 and a CAN transceiver 320 . The communications system 400 may include a MCU 410 , radios such as a UHF/VHF radio 420 and an S-band radio 430 , and a CAN transceiver 440 . The AIS 500 may include a MCU 510 and a CAN transceiver 520 .
In addition, the satellite 120 may also include one or more other systems, subsystems, components, devices, parts or peripherals. For example, the satellite 120 may include one or more sun sensors 710 , one or more cameras such as a camera 720 and an infrared camera 730 , a sensor printed circuit board (PCB) 740 , RS 232 750 , and an attitude detection/control system (ADCS) 760 directly or indirectly coupled to the OBC 200 . The satellite 120 may include an electrical power source (EPS) 810 , a UHF antenna system 820 , a VNF antenna system 830 , and one or more batteries (BPX) 840 , all of which may be coupled to the PDU 300 via an inter-integrated circuit (I 2 C) 850 . Each antenna system may have one or more microcontrollers configured to perform a deployment of the antennas. Each antenna may have four antenna elements that may be deployed individually.
The satellite 120 may also include a GPS radio occultation receiver, such as a GPS radio occultation sensor (GPS-RO) receiver 910 , coupled to the communications system 400 .
Detailed discussions of the OBC 200 are provided herein.
2. On-Board Computer
The OBC 200 may act as a central computer for the satellite 120 .
FIG. 4 is a block diagram of the OBC 200 according to one aspect of the disclosed technology. As illustrated in FIG. 4 , the OBC 200 may include a system on chip or system on module 210 , such as a SOM board. The OBC 200 may also include one or more hardware interfaces 230 and a backplane 260 . The OBC 200 may run at a speed between 500 MHz and 1 GHz. Detailed discussions of some components of the OBC 200 are provided herein.
2.1 SOM Board
The SOM board 210 may include a general purpose central processing unit (CPU) powered by a processor 212 .
As shown in FIG. 4 , the SOM board 210 may include one or more physical storage mediums, including but not limited to one or more of the following: a NOR flash 214 , a NAND flash 215 and a SDRAM 216 . The NOR flash 214 may have a size up to 128 MB, and may act as a boot memory. The NAND flash 215 may also act as a boot memory. The NAND flash 215 may be of various sizes, including, but not limited to, 128 MB, 256 MB, 512 MB, and 1024 MB. The SDRAM 216 may be a DDR2 SDRAM memory bank. The SDRAM 216 may be of various sizes such as 128 MB or 256 MB. Upon deployment of the satellite 120 , software may be loaded from the memory.
In addition, the SOM board 210 may include general purpose connectors, such as pitch stacking connectors, for custom expansions. Further, the SOM board 210 may include one or more of the following: a power supply unit, a non-volatile memory which may provide additional storage area for user-specific usage, a computer clock, and a touch screen controller
2.2 Interface
As shown in FIG. 4 , the OBC 200 may be implemented with one or more hardware interfaces 230 to interface with one or more payloads, systems, subsystems, apparatus, devices, components, parts, or peripherals, which may be collectively referred to as peripherals 250 . The interfaces 230 and the peripherals 250 may be arranged in a manner surrounding the SOM board 210 . Example interfaces implemented by the OBC 200 may include, but not limited to, one or more multimedia card (MMC) interfaces 232 and 234 , a general-purpose input/output (GPIO) 236 for interface with a camera, an Ethernet interface 238 for debugging, a controller area network (CAN) interface 239 for a Cubesat Space Protocol (CSP) bus, an I 2 C 240 for interface with one or more low-level sensors, a serial peripheral interface (SPI) 242 for a high-speed radio, one or more universal asynchronous receivers/transmitters (UART) 244 for interface with one or more peripherals, one or more FTDI UART 245 , and a video interface 246 for receiving or transmitting high band width data. Details with regard to each interface are provided herein.
An MMC interface 232 or 234 may be implemented by one or more MMC host controllers integrated in the processor 212 of the OBC 200 . The MMC interface may be coupled to a secure digital (SD) card, e.g., a multimedia card, to store system memory. Alternatively, the MMC interface may interface to a camera, such as a high-definition personal camera, that captures still photos or videos. Such a camera may work automatically with minimum intervention, or remotely controlled. In one embodiment, the OBC 200 may include two MMC interfaces 232 and 234 .
The GPIO 236 may include a generic pin on an integrated circuit, and its behavior may be controlled by a user at run time. The GPIO interface 236 may be configured to be coupled to a camera, such as a high-definition personal camera, to capture still photos or videos. Such a camera may work automatically with minimum intervention, or remotely controlled.
The Ethernet interface 238 may be implemented by an Ethernet physical layer that provides interface signals. The Ethernet interface 238 may be configured to serve for debugging purposes.
The CAN interface 239 may be implemented by a CAN controller integrated in the processor 212 . The CAN controller may be a high end CAN controller (HECC). The HECC may be connected to an on-board physical layer. Signal lines such as CANH and CANL may be routed to a connector. The CAN interface 239 may serve as a CSP bus. The CAN interface 239 may connect the OBC 200 with the PDU 300 , the communications system 400 , and the AIS 500 .
The OBC 200 may include one or more I 2 C 240 for interface with one or more low-level sensors. Such low-level sensors may include, but not limited to, a light sensor 186 , a thermopile sensor 187 for temperature measurement, a thermopile array 188 for temperature measurement, an accelerator 189 , a gyroscope such as a digital output MEMS gyroscope 190 , a magnetic sensor 191 , and a temperature sensor 192 . In one example, the OBC 200 may include two I 2 C.
The OBC 200 may include an SPI 242 for interface with a radio 193 such as a high-speed radio. The SPI 242 may include an optional low-voltage differential signaling (LVDS) level shifting. The OBC 200 may include an SPI channel, and may have a port that provides 3 chip selects such as MCSPI 1 _CS 0 , MCSPI 1 _CS 1 , and MCSPI 1 _CS 2 .
The OBC 200 may include one or more UARTs 244 for communication with one or more systems. A UART 244 may be an individual or part of an integrated circuit used for serial communications over a computer or peripheral device serial port. The UART 244 may take bytes of data and transmit the individual bits in a sequential fashion. The UART 244 may be used in conjunction with communication standards such as RS- 232 . The OBC 200 may be connected to one or more systems over the UART 244 in different ways. UART ports may be routed to connectors of the OBC 200 . In one example, the OBC 200 may include four UARTs. In one embodiment, the OBC 200 may include one or more direct MCU UART channels. Such channels may serve one or more of the following functions: debug port, GPS-RO sensor UART, and ADCS UART.
In another embodiment, the OBC 200 may include one or more FTDI UART 245 channels. In this embodiment, four extra UART ports may be created through a MCU's USB 1 port using a USB-4xUART chip. The whole FTDI circuit may be switched on/off through a GPIO pin. One or more FTDI UART channels may serve one or more of the following functions: UART on the backplane for infrared camera (IR Camera) 730 , debug port for the PDU 300 , debug port for the communications system 400 , extra connector, and generic UART.
The OBC 200 may include a video interface 246 for high band width data. For example, the video interface 246 may be a parallel video interface having a port configured to interface with an infrared camera 730 In one embodiment, the OBC 200 may not directly interface with the UHF/VHF radio 420 and the S-band radio 430 .
2.3 Connectors
The backplane 260 may serve as a backbone for connecting one or more printed circuit boards or peripherals 250 to the OBC 200 . The backplane 260 may include one or more electrical connectors and parallel signal traces that connect one or more printed circuit boards or peripherals 250 to the OBC 200 . Each pin of each connector may be linked to the same relative pin of all the other connectors to form a common computer bus.
According to one embodiment, the OBC 200 may have a top side with one or more of the following connectors: USB micro connector 261 , backplane connector 262 , and SOM board connectors 263 , Camera MMC connector 264 , MCU FTDI UART 3 265 , MCU JTAG 266 , Ethernet breakout 267 , IR Camera breakout 268 , USB host 269 , Camera GPIO connector 270 , Debug/bootstrap UART 3 breakout/FTDI UART breakout 271 , FTDI UART breakout 272 , I 2 C breakout 273 , serial peripheral interface (SPI) connector 274 , CAN breakout 275 , USB power jumper 276 , power breakout 277 , CAN termination jumper 278 , UART breakout 279 , CPU UART 280 , CPU ICSP 281 , and LED power jumper 282 .
The USB micro connector 261 may be configured to connect to an FTDI USB to 4x serial port converter. The USB micro connector 261 may be connected to one or more ports with the following connections: Debug UART, GPS-RO sensor UART, ADCS UART, and infrared camera UART.
The Camera MMC connector 264 may have one or more of the following pins: command (e.g., MMC_CMD), Serial Clock (e.g., MMC_SCK), Data (e.g., MMC_DAT 0 , MMC_DAT 1 , MMC_DAT 2 and MMC_DAT 3 ), ground (e.g., GND), and power supply (e.g., 3.3V).
The MCU FTDI UART 3 265 may have one or more pins associated with one or more of the following functions: transmit data (e.g., MCU-FTDI-TXD 1 ), receive data (e.g., MCU-FTDI-RXD 1 ), and ground (e.g., GND).
The MCU JTAG 266 may have one or more pins associated with one or more of the following functions: test clock (e.g., TCK), test data in (e.g., TDI), test data out (e.g., TDO), test mode select (e.g., TMS), rest (e.g., RST), power supply (e.g., 3.3V), and ground (e.g., GND).
The Ethernet breakout 267 may have one or more pins associated with one or more of the following functions: receive data (e.g., RX+ and RX−), transmit data (e.g., TX+ and TX−), light emitting diode (e.g., LED 1 and LED 2 ), and ground (e.g., GND).
The IR Camera breakout 268 may have one or more pins associated with one or more of the following functions: horizontal sync (e.g., HSYNC), vertical sync (e.g., VSYNC), processor clock (e.g., PCLK), data (e.g., DATA 0 , DATA 1 , DATA 2 , DATA 3 , DATA 4 , DATA 5 , DATA 6 and DATA 7 ), and ground (e.g., GND).
The USB host 269 may have one or more pins associated with one or more of the following functions: power supply (e.g., 5V), ground (e.g., GND), and USB data (e.g., USB 2 − and USB2+).
The Camera GPIO connector 270 may have one or more pins associated with one or more of the following functions: power supply (e.g., 3.3V coming from Camera), ground (e.g., GND), and camera data
The Debug/bootstrap UART 3 breakout/FTDI UART breakout 271 may have one or more pins associated with one or more of the following functions: receive data (e.g., MCU-FTDI-TXD 2 ), transmit data (e.g., MCU-FTDI-RXD 2 ), and ground (e.g., GND).
The FTDI UART breakout 272 may have one or more pins associated with one or more of the following functions: receive data (e.g., MCU-FTDI-TXD 3 ), transmit data (e.g., MCU-FTDI-RXD 3 ), and ground (GND).
The I 2 C breakout 273 may have one or more pins associated with one or more of the following functions: serial clock line (e.g., SCL 0 and SCL 1 ), serial data line (e.g., SDA 0 and SDA 1 ), and ground (e.g., GND).
The SPI connector 274 may have one or more pins associated with one or more of the following functions: serial clock (e.g., SPI SCK LVDS+, SPI SCK LVDS− and SPI SCK), ground (e.g., GND), master OUT slave IN (e.g., SPI MOSI, SPI MOSI LVDS+ and SPI MOSI LVDS−), and master IN slave OUT (e.g., SPI MISO, SPI MISO LVDS+ and SPI MISO LVDS−), chip select (e.g., SPI CS 1 and SPI CS 2 ), and high speed general-purpose input/output (e.g., HS GPIO 0 and HS GPIO 1 ).
The CAN breakout 275 may have one or more pins associated with one or more of the following functions: high voltage signal (e.g., CANH) and low voltage signal (e.g., CANL).
The USB power jumper 276 may have one or more pins associated with the following function: power supply (e.g., 5V USB and 5V).
The power breakout 277 may have one or more pins associated with one or more of the following functions: power supply (e.g., 5V and 3.3V), battery voltage (e.g., VBAT), and ground (e.g., GND).
The CAN termination jumper 278 may have one or more pins associated with one or more of the following functions: high voltage signal (e.g., CANH) and low voltage signal (e.g., CANL).
The UART breakout 279 may have one or more pins associated with one or more of the following functions: receive data (e.g., ADCS_RX and GPS-RO sensor_RX) and transmit data (e.g., ADCS_TX and GPS-RO sensor_TX).
The CPU UART 280 may have one or more pins associated with one or more of the following functions: receive data (e.g., RX) and transmit data (e.g., TX).
The LED power jumper 282 may have one or more pins associated with the following function: ground (e.g., GND and LED_GND).
According to one embodiment, the OBC 200 may have a bottom side with one or more of secure digital (SD) connectors 283 . For instance, SD 1 283 may connect to MMC 1 on the SOM board 210 directly. SD 2 284 may connect to MMC 2 on the SOM board 210 through a multiplexer, e.g., camera SD mux.
The OBC 200 may have many advantages. For example, the OBC 200 may have a small form factor with inexpensive connectors. The OBC 200 may offer high flexibility, great performances, low power consumption and a rich interface set. The OBC 200 may work in extreme environmental conditions. For example, the OBC 200 may work in an extended temperature range from −40° C. to +85° C.
While certain implementations of the disclosed technology have been described in connection with what is presently considered to be the most practical and various implementations, it is to be understood that the disclosed technology is not to be limited to the disclosed implementations, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. For example, the disclosed technology may be implemented in an aerospace device or system, including but not limited to, satellite communication systems of all sizes, and aircrafts including airplanes, jets, and air balloon, among other possibilities. The disclosed technology may serve multiple purposes, including monitoring maritime activities, monitoring trade transit, general aviation, commercial and private purposes including transport and cargo services, and military purposes, among other possibilities.
Certain implementations of the disclosed technology are described above with reference to block and flow diagrams of systems and methods and/or computer program products according to example implementations of the disclosed technology. It will be understood that one or more blocks of the block diagrams and flow diagrams, and combinations of blocks in the block diagrams and flow diagrams, respectively, can be implemented by computer-executable program instructions. Likewise, some blocks of the block diagrams and flow diagrams may not necessarily need to be performed in the order presented, or may not necessarily need to be performed at all, according to some implementations of the disclosed technology.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means that implement one or more functions specified in the flow diagram block or blocks.
Implementations of the disclosed technology may provide for a computer program product, comprising a computer-usable medium having a computer-readable program code or program instructions embodied therein, said computer-readable program code adapted to be executed to implement one or more functions specified in the flow diagram block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational elements or steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions that execute on the computer or other programmable apparatus provide elements or steps for implementing the functions specified in the flow diagram block or blocks.
Accordingly, blocks of the block diagrams and flow diagrams support combinations of means for performing the specified functions, combinations of elements or steps for performing the specified functions and program instruction means for performing the specified functions. It will also be understood that each block of the block diagrams and flow diagrams, and combinations of blocks in the block diagrams and flow diagrams, can be implemented by special-purpose, hardware-based computer systems that perform the specified functions, elements or steps, or combinations of special-purpose hardware and computer instructions.
This written description uses examples to disclose certain implementations of the disclosed technology, including the best mode, and also to enable any person skilled in the art to practice certain implementations of the disclosed technology, including making and using any devices or systems and performing any incorporated methods. The patentable scope of certain implementations of the disclosed technology is defined in the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
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A cubesat communications system includes an on-board computer implemented on a hardware platform. The on-board computer may include a system on module having a processor and a memory storing “boot” information. The on-board computer may also include a plurality of hardware interfaces implemented on the hardware platform to facilitate communication between the processor and a plurality of peripherals external to the on-board computer. The on-board computer may have a backplane having a plurality of connectors connecting the processor to the peripherals.
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BACKGROUND OF THE INVENTION
This invention relates to a pump, especially to a submersible pump.
In submersible pumps, the rotor is connected to the motor by a drive shaft surrounded by a first, internal, pipe in turn surrounded by a second, external, pipe. A seal is provided below a lowermost bearing, immediately adjacent to the rotor. The lowermost bearing is disposed in the internal pipe at a considerable distance from the rotor. Owing to this relatively large distance between the lowermost bearing and the rotor, the section of the drive shaft in that region at the end of the internal pipe is subjected to relatively large shocks. The seal, which generally takes the form of a slip ring seal, is also subjected to considerable stresses and can fail at an early time.
An object of the present invention is to provide an improved pump particularly of the submersible type.
Another, more particular, object of the present invention is to provide such a pump wherein a seal located in a region about a lowermost bearing is subjected to a minimum of wear and tear during pump operation.
SUMMARY OF THE INVENTION
A pump in accordance with the present invention comprises a rotor connected to a motor by a drive shaft surrounded by a first pipe which extends from the motor towards the rotor. A plurality of bearings is provided for supporting the shaft in the first pipe, one of the bearings being disposed in a region about the rotor proximately to an end of the first pipe. A seal for the first pipe has a radial position between the shaft and the first pipe and an axial position between the bearing near the rotor and another bearing adjacent to that first bearing. A second pipe surrounds the first pipe and is radially spaced therefrom to form a transport channel for effluent moved by rotation of the rotor. The second pipe is provided with an outlet communicating with the transport channel and is further provided with an opening. A reduced-pressure chamber is provided in the first pipe in a region about the rotor proximately to an end of the first pipe, the seal being disposed in the reduced-pressure chamber. The chamber is connected to the opening in the second pipe, whereby the chamber can be subjected to reduced pressure to evacuate leakage material from the chamber through the opening in the second, external, pipe.
In a pump in accordance with the present invention, the lowermost bearing is located below the seal (i.e., between the seal and the rotor) and is therefore but a small distance from the rotor. The lowest section of the pump shaft is optimally supported and guided, inasmuch as the distance between the lowest shaft section and the rotor is small. The lowest shaft section accordingly runs very quietly and experiences little or no shock disturbances. The shock load placed on the seal is likewise considerably reduced, whereby the seal can have a long operating life. Should the material being pumped enter the reduced-pressure chamber, the leakage cannot rise further in the first, internal, pipe but is led to the opening in the external pipe. Because the seal is located in the reduced-pressure chamber, the seal need not be pressure proof.
The principle of the invention applies to submersible pumps, drum pumps and centrifugal pumps.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a side elevational view, partially in cross-section, of a first embodiment of a pump in accordance with the present invention.
FIG. 2 is a side elevational view, partially in cross-section, of a second embodiment of a pump in accordance with the present invention.
FIG. 3 is partially a side elevational view and partially a longitudinal cross-sectional view of a lower portion of a third embodiment of a pump in accordance with the present invention.
FIG. 4 is partially a side elevational view and partially a longitudinal cross-sectional view of a lower end of a fourth embodiment of a pump in accordance with the present invention.
FIG. 5 is partially a side elevational view and partially a longitudinal cross-sectional view of a lower end of a fifth embodiment of a pump in accordance with the present invention.
DETAILED DESCRIPTION
As illustrated in FIG. 1, a submersible pump, particularly a drum pump, has a motor 1 with a motor shaft (not illustrated) connected via a coupling 2 to a pump shaft 3. Pump shaft 3 is surrounded by a first, internal, pipe 4 which extends from motor 1 towards a rotor 6 fixed to the free end of pump shaft 3. Pump shaft 3 is rotatably supported in internal pipe 4 by a plurality of bearings 5 distributed over the length of the pump shaft.
Internal pipe 4 surrounded by a second, external, pipe 8 which is spaced in a radial direction from the internal pipe to form a transport or uptake channel 7 for guiding effluent material moved by the rotation of rotor 6. The effluent material exits uptake channel 7 via an outlet 9 formed in external pipe 8. Internal pipe 4 is supported in the external pipe by centering pieces 10 distributed over the length thereof. Centering pieces 10 are formed so that effluent material can be delivered to outlet 9 without difficulty.
A bearing 5', preferably a friction bearing, is provided immediately adjacent to rotor 6 at the lower end of pipe 4. An adjacent bearing 5, likewise preferably a friction bearing, is disposed in pipe 4 at a slight distance from lowermost bearing 5'. To prevent effluent material which might possibly leak past bearing 5', exemplarily between bearing 5' and pipe 4, from moving upwardly inside pipe 4 a reduced-pressure chamber 11 is provided on a side of bearing 5' opposite rotor 6. Should effluent material leak into chamber 11, the leakage is prevented from rising in pipe 4 by reduced pressure in chamber 11. Chamber 11 advantageously communicates with a vacuum source 35 via conduits or ducts 12 extending from internal pipe 4 to outlet openings 13 in external pipe 8. All effluent material entering reduced-pressure chamber 11 flows to the outside under the evacuation force exerted by vacuum source 35.
As an additional safety feature, a seal 14 is located in reduced-pressure chamber 11 at a radial position between shaft 3 and internal pipe 4 and at an axial position between lowermost bearing 5' and the bearing 5 adjacent thereto. More specifically, seal 14 is axially disposed between conduits or ducts 12 and the second bearing 5.
A shaft section 15 between lowermost bearing 5' and the adjacent bearing 5 is subjected to only very small shocks during rotation of pump shaft 3 because shaft section 15 is optimally guided by the two bearings. Because the two bearings are placed closely adjacent to rotor 6, shock in the region of shaft section 15 is reduced to a minimum. Accordingly, seal 14 is stressed only slightly and can optimally fulfill its sealing function.
Lower shaft section 15 rotates smoothly and quietly for the additional reason that bearing 5' is disposed immediately adjacent to rotor 6. The lever arm between bearing 5' and rotor 6 is therefore small, reducing noisy vibration.
Inasmuch as seal 14 is located in reduced-pressure chamber 11, the seal need not be pressure roof. The reduction of pressure in chamber 11 prevents leakage material from rising inside pipe 4, the leakage material being guided through ducts 12 to openings 13.
Because bearing 5' comes into contact with the effluent material being pumped, that bearing preferably consists of corrosion resistant material. Bearing 5' is exemplarily fabricated from coal or hard carbides such as silicon carbide. Alternatively, ceramic materials such as aluminum oxide can be used for bearing 5'. A particularly resistant material advantageously used for the lowermost bearing is a polytetrafluoroethylene-compound material.
In the event that lowermost bearing 5' need not be corrosion resistant, the bearing can consist exemplarily of bronze.
Inasmuch as no effluent material can pass beyond the second bearing 5, owing to reduced-pressure chamber 11 and seal 14, the portion of pump shaft 3 located above the second bearing 5 can be of a material of lower quality than the material of shaft section 15. Shaft section 15 must comprise a resistant and high-quality material, because that portion of pump shaft 3 can come into contact with leakage of the material being pumped. Shaft section 15 must be constructed in a special way depending on the type of seal 14. If seal 14 exemplarily takes the form of a lip seal, shaft section 15 must have a hard surface to minimize wear and tear of the lip seal. Shaft section 15 can in such a case be hardened or, alternatively, be provided with an oxide or a metallic coating, the coating being applied using any of the many known methods for applying such coatings, which ensures a good sliding fit or engagement of the lip seal. The surface of shaft section 15 should be formed, in the case that a lip seal is used, with a low degree of roughness to facilitate smooth sliding of the lip seal as well as to provide a minimum of wear and tear. Shaft section 15 need be provided with a hard surface only if the pump is intended to operate continuously. If, on the contrary, the pump is to be operated only intermittently, shaft section 15 need not be provided with a hard surface.
As illustrated in FIG. 2, a centrifugal pump has a pump shaft 3a attached at a lower or free end to a rotor 16 in the form of a pump cover. A lowermost bearing 5a' in an internal pipe 4a surrounding pump shaft 3a is axially secured by a guard ring 17. Two lip seals 18 and 19 are provided in a pressure reduction chamber 11a which communicates via outlet conduits or ducts 12a with outlet openings 13a in an external pipe 8a surrounding internal pipe 4a. Seals 14a, 18 and 19 are disposed above outlet ducts 12a, i.e., have axial positions between ducts 12a and a second bearing 5a. Lip seal 18 is clamped by a spacer ring against a setoff or shoulder 21 in internal pipe 4a. Lip seal 19 in turn is clamped against spacer ring 20 by a clamp ring 22 screwed into internal pipe 4a. Both lip seals 18 and 19 engage pump shaft 3a, thereby sealing it. Additional seal 14a is disposed in the area between lip seal 18 and bearing 5a. A shaft section 15a between lowermost bearing 5a' and the second lowermost bearing 5a experiences only small shocks inasmuch as the shaft section is rotatably supported by bearings 5a and 5a' in pipe 4a at a small distance from pump cover 16. Seals 14a, 18 and 19 can consist of an elastomere material, preferably polytetrafluoroethylene, which has a high resistance to chemically reactive materials as well as to mechanical wear and tear.
As depicted in FIG. 3, a pump in accordance with the present invention may include an internal pipe 4b provided at a lower end with a lowermost bearing 5b'. Between lowermost bearing 5b' and an adjacent bearing 5b, two lip seals 18b and 19b, as well as an additional seal 14b, are provided. Upper lip seal 18b is clamped between a shoulder 21b on the inside of pipe 4b and a spacer ring 20b. Spacer ring 20b separates upper lip seal 18b from lower lip seal 19b. Lower lip seal 19b is clamped against spacer ring 20b by a clamp ring 22b screwed into pipe 4b. The pump has a rotor 6b attached to the lower end of a pump shaft 3b. Seals 14b, 18b and 19b are located in a pressure reduction chamber connected via outlet ducts 12b to outlet openings 13b in an external pipe 8b surrounding internal pipe 4b. The pump of FIG. 3 corresponds for the remaining part to the embodiment of FIG. 2. A shaft section 15b between lowermost bearings 5b and 5b' is subjected to only small shocks, whereby seals 14b, 18b and 19b are minimally stressed and subjected to little wear and tear.
A rotor 6c of the pump embodiment of FIG. 4 is fastened to the lower end of a pump shaft 3c. A lowermost shaft section 15c is rotatably supported by only one bearing 15c' fastened at the free end of an internal pipe 4c in a force or friction lock fit. A pressure reduction chamber 11c is connected via ducts 12c to outlet openings 13c in an external pipe 8c surrounding internal pipe 4c. A seal 11c disposed in pressure reduction chamber 11c includes a slip ring 23 which lies against a sealing surface 25 of another sealing ring 26. Slipring 23 is pressed against sealing ring 26 by the force exerted by a pressure spring 24. Sealing ring 26 fits tightly in internal pipe 4c and rests axially against a shoulder 27 of internal pipe 4c. Sealing ring 26 is provided on an outside surface with an O-ring seal 28 which seals ring 26 against internal pipe 4c. Pressure spring 24 rests against a lowermost bearing 5 c' and against slipring 23, while slippering 23 is connected in a torsion-proof manner to pump shaft 3c. The remaining components of the pump of FIG. 4 are essentially identical to corresponding components of the pump embodiment of FIG. 3. Owing to the support through bearing 5c', shaft section 15c is subjected to only slight shocks and the sensitive slip ring seal 14c is stressed minimally so that a long operating life of the seal is ensured while effecting optimal sealing.
The embodiment of FIG. 5 differs from the embodiment of FIG. 4 only in that a bearing 5d is provided above a slipring seal 14d. In this way, shaft section 15d of pump shaft 3d is supported more effectively to reduce shocks to a minimum.
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A pump has a rotor-carrying pump shaft rotatably supported within an internal pipe by a plurality of spaced bearings. A lowermost bearing is located in the vicinity of the rotor near the end of the internal pipe. Adjacent to the lowermost bearing is a seal provided in a reduced-pressure chamber within the internal pipe, the chamber being closed off at the lower end by the bearing juxtaposed to the rotor. The reduced-pressure chamber is connected to an outlet opening in an external pipe which surrounds the internal pipe and is spaced therefrom to provide a transport channel for effluent material being moved by the rotating rotor.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to television systems.
[0003] 2. Description of the Related Art
[0004] Televisions and computers have become ubiquitous, and since both usually entail a visual display, efforts have been made to integrate both functions into a single system. In this way, a consumer need not purchase and operate two separate systems, which can burden some consumers who, while familiar with operating a television and its remote control, might not be familiar with operating, e.g., an Internet computer.
[0005] To the extent that attempts have been made to combine television with Internet features, it has generally been with the focus of producing what might be thought of as a “lean forward” system. That is, hybrid TV/computers have typically been more oriented toward productivity, generally thought of as a computer system characteristic, and less toward entertainment (“lean back”), generally regarded as a television system characteristic. It is not just the dichotomy between productivity and entertainment that distinguishes a “lean forward” experience from a “lean back” experience, however. As contemplated herein, “lean forward” activities often are experienced by only a single person, while “lean back” activities are often group experiences. Moreover, “lean back” activities can extend to purchasing products that are advertised on TV, as opposed to, e.g., making products for sale. In any case, with the above-mentioned critical observation of the present invention in mind, it can readily be appreciated that the differences between a system designed for “lean forward” experiences and a system designed for “lean back” experiences can be both subtle and profound.
[0006] An example of a “lean forward” system is the system known as “WebTV”, with preselected Web pages being accessible through the television using a computer keyboard with its attendant complexity. To access the pages, the consumer must access a central site by means of the keyboard, and then be redirected to a desired Web page. In terms of currently expected speeds of Internet access, this consumes an undue amount of time. Furthermore, it requires browser or browser-like operations that must be executed by a consumer. All of these features—use of a keyboard, knowledgeable use of a browser, and wait time for Web page access—are not per se unacceptable for a lean forward experience, but would severely detract from a lean back experience.
[0007] For instance, in the context of lean back, entertainment- and group-oriented experiences, consumers are accustomed to using a much simpler input device than a computer keyboard, namely, a remote control. Moreover, a user interface that is simpler than a Web browser, e.g., an electronic program guide (EPG), is preferred. Also, waiting for entertainment to load or otherwise be prepared for playing is distracting in a lean-back, group-oriented experience. But as exemplified above by the WebTV system, current systems that attempt to integrate television and computers essentially do so by grafting a TV onto what is essentially an underlying, lean forward computer system, and consequently provide less than optimum lean back experiences. As an example, in a group lean back experience, viewers might wish to obtain interesting information via a TV in addition to conventional TV broadcasts. The object of the present invention is to provide a TV system that accommodates lean back experiences better than existing systems.
SUMMARY OF THE INVENTION
[0008] The invention provides a way to provide broadcast content to a TV viewer without passing the content through conventional TV gateways such as broadcasters, cable, or satellite.
[0009] Accordingly, a system for presenting content on a TV includes a receiver TV presenting broadcast TV content, and a receiver such as an AM radio receiver or pager receiver as examples. A data cache receives cache content via the receiver, and a processor communicates with the data cache and presents the cache content on the TV.
[0010] In a preferred implementation, the processor presents the cache content in response to a viewer-generated signal. In another implementation, the processor automatically presents the cache content in accordance with at least one cache content presentation rule. A sender TV can send the cache content to the receiver TV peer-to-peer, or the content can originate at a server in a server-to-client architecture.
[0011] In another aspect, a system for presenting content on a TV includes a receiver TV presenting broadcast TV content. The system further includes a cache content receiver and a data cache that receives cache content via the receiver. A processor communicates with the data cache and presents the cache content on the TV.
[0012] In still another aspect, a method for presenting TV content and cache content on a TV simultaneously with each other is disclosed. The method includes receiving a TV signal and presenting it on a TV, and also receiving cache content and storing the cache content in a data cache. In response to a cache content presentation rule or a viewer-generated signal, cache content from the data cache is presented on the TV along with the TV content.
[0013] In yet another aspect, a system for presenting out of band content on a TV includes receiver TV means for displaying television signals. Out of band content receiver means are associated with the receiver TV means for presenting out of band content on the TV. The out of band content is not a television signal although the TV signal may be co-opted to deliver the content.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which:
[0015] [0015]FIG. 1 is a block diagram of the system of the present invention; and
[0016] [0016]FIG. 2 is a flow chart of the present logic.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] This invention provides a way for TV viewers to avail themselves of out of TV band content without the content passing through conventional TV gateways such as broadcast, cable, or satellite.
[0018] Referring initially to FIG. 1, a system is shown, generally designated 10 . As shown, the system 10 includes a TV 12 that conventionally receives televised content at a content receiver 14 (e.g., an antenna, cable receiver, satellite dish, set-top box, etc.) for display of the content on a monitor 16 and associated speakers 17 .
[0019] While the embodiment below discusses a TV 12 with a single housing that is shown separate from the microprocessor and database, it is to be understood that the term “television” encompasses any apparatus that has a television tuner and the below-described capability in a single housing or in separate housings that cooperate together. For instance, the term “TV” encompasses the television system shown in FIG. 1, as well as a conventional television in combination with a set-top box that functions in accordance with the present invention. In the latter example, the set-top box might include, e.g., the microprocessor discussed below.
[0020] In the preferred non-limiting embodiment shown, the TV 12 includes a housing 18 that holds a conventional television tuner which receives the TV signals. A remote control device 20 can also be provided. Moreover, a microprocessor 26 communicates with the TV circuitry for presenting out of band data on the monitor 16 /speakers 17 in accordance with the disclosure below. As intimated above, the microprocessor 26 can be located in the housing 18 or it can be disposed elsewhere, such as in a set-top box or in the remote control device 20 or other component. In any case, the microprocessor 26 executes the logic set forth herein. The microprocessor 26 can also access a database 30 of content cache, with the database 30 being contained in computer memory, or on a hard disk drive, optical drive, solid state storage, tape drive, removable flash memory, or any other suitable data storage medium and potentially accessible to a network such as the Internet.
[0021] It is to be understood that the microprocessor 26 controls certain functions of the TV 12 in accordance with the logic below. The flow charts herein illustrate the structure of the logic modules of the present invention as embodied in computer program software. Those skilled in the art will appreciate that the flow charts illustrate the structures of logic elements, such as computer program code elements or electronic logic circuits, that function according to this invention. Manifestly, the invention is practiced in its essential embodiment by a machine component that renders the logic elements in a form that instructs a digital processing apparatus (that is, a computer or microprocessor) to perform a sequence of function steps corresponding to those shown. Internal logic could be as simple as a state machine.
[0022] In other words, the present logic may be established as a computer program that is executed by a processor within, e.g., the present microprocessors/servers as a series of computer-executable instructions. In addition to residing on hard disk drives, these instructions may reside, for example, in RAM of the appropriate computer, or the instructions may be stored on magnetic tape, electronic read-only memory, or other appropriate data storage device.
[0023] As also shown in FIG. 1, the content cache database 30 receives non-conventional content (relative to conventional TV content) via an out of band content receiver 32 . In one preferred, non-limiting embodiment, the out of band content receiver is a broadcast receiver such as an AM radio receiver or pager receiver, as opposed to a POTS line/Internet content receiver. For instance, the out of band content receiver 32 can be a Radio Data Service (RDS) receiver. In any case, the out of band content receiver 32 can be mounted on or incorporated into the TV 12 or associated system 10 component such as but not limited to a set top box, VCR, TiVO-type device, etc.
[0024] [0024]FIG. 1 shows that the content receiver 32 receives out of band content from a source 34 . The source 34 can be another TV, in which case the out of band content is sent peer-to-peer. Alternatively, the source 34 can be server associated with a radio station transmitter.
[0025] The logic of the present invention can be seen in reference to FIG. 2. Commencing at block 36 , the out of band content is received by the receiver 32 via a non-conventional (for TV) broadcast path, and then it is cached at block 38 in the cache content database 30 . At block 40 , the content is displayed by superimposing it on the TV channel being displayed at the same time. The display of the cache content can be in response to a viewer command entered by means of, e.g., the remote control device 20 , or it can be presented in accordance with one or more display rules. For example, it might be desired that whenever a viewer activates a pay per view purchase from their cable or satellite system, cache content is presented that includes an independent presentation, e.g., a leader of a movie that has been selected.
[0026] While the particular SYSTEM AND METHOD FOR ALTERNATE CONTENT DELIVERY as herein shown and described in detail is fully capable of attaining the above-described objects of the invention, it is to be understood that it is the presently preferred embodiment of the present invention and is thus representative of the subject matter which is broadly contemplated by the present invention, that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular means “at least one”. All structural and functional equivalents to the elements of the above-described preferred embodiment that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase “means for”.
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A system and method for presenting out of band content on a TV includes an out of TV band receiver such as a radio that receives content peer to peer from other TVs, or from a server. The content is cached at the receiving TV and is played on the TV automatically in response to a predetermined rule being satisfied, or on demand from the viewer, giving the appearance of a real time connection.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process and a system for detecting an object in relation to a surface, said surface is not necessarily flat. In accordance with the present invention an object is defined as: a material element devoid of life and/or a person or animal. The object in accordance with the invention may be static and/or in movement. The surface in accordance with the invention may be a virtual surface or a real surface transparent or not.
2. Discussion of Background
It is necessary to detect presence and determine the position of an object in relation to a surface in a number of industrial applications, notably in order to make it possible to assess whether the object is moving in relation to this surface. The study of this relative movement gives information on the object and/or the surface.
In order to present the problem posed and resolved by the present invention in the framework of a concrete industrial application, the specific case of electronic surveillance, designed to detect an intruder moving in a defined environment, will be developed hereinafter. These electronic surveillance systems make it possible to distinguish between persons behaving abnormally in relation to those behaving normally.
More specifically, the process and the system according to the invention are applicable to the surveillance of a swimming pool in order to prevent drawings.
The patent SP2 FR 96 10442 submitted on Aug. 26, 1996 on behalf of Poséidon describes this type of surveillance system for a swimming pool while referring to the previous art. Large extracts of it will be incorporated here. Surveillance of swimming pools is either non-existent, or carried out by means of human surveillance. Such surveillance is a difficult task and requires sustained attention and causing nervous fatigue in people, notably in lifeguards, who are responsible for it. In fact, in addition to the inherent limitations of any system based on human intervention, for example a reduction of vigilance due to tiredness or momentary distraction, the surveillance of swimming pools is made extremely delicate because of the reflection of light on the surface of turbulent water, a phenomenon which makes it difficult visually to locate an immobile body or a body sinking passively, at a few metres depth. The surveillance problem in swimming pools mainly arises for swimming pools that are open to the public.
In general, a swimmer in distress sinks to the bottom but, more rarely, it occurs that he floats unconsciously in a characteristic position just below the surface of the water.
An experienced lifeguard has two to three minutes to save a drowning person from the loss of consciousness, which marks the beginning of drowning. If this period is adhered to, the person drowning will not generally experience any after-effects of the accident, after a possible stay in the hospital to clean the lungs. In general, if the help is provided in three to five minutes after the loss of consciousness, however this period varies for each individual, the drowning person may still be saved, but certainly risks irreversible injuries, notably brain damage. Over five minutes, the risk of death becomes considerable.
U.S. Pat. No. 5,043,705 already proposed the use of sonar to carry out surveillance in a swimming pool. According to this system, a sonar transceiver is at least installed in the bottom of the swimming pool and a horizontal section is watched using this machine. The implementation of such a system does present inconveniences. In effect, the signal obtained with a sonar includes the echoes from the swimming pool walls and it is extremely difficult to eliminate the noise signal received in this way in order to detect the signal corresponding to the submerged body of a person drowning. In addition, the sonar essentially makes it possible to locate the body of a drowning person through the volume of air which he holds; if a person in distress has lungs filled with water, the signal obtained will not conform in any way with that which may be expected and might not even be located by processing the signal. Consequently it may be established that such a system is not likely to be satisfactory.
The patent application WO 95/34056 also proposed the implementation of cameras applicable in the field of visible waves for the surveillance of a swimming pool. These cameras are installed so that the zone observed is situated in a volume near and parallel to the bottom of the swimming pool.
In this system the cameras only observe a section of water parallel to the bottom, which implies multiplication of the cameras if the bottom is not flat and leaves the majority of the volume of the swimming pool unwatched. In addition, this system does not make it possible to detect an immobile body floating just below the surface of the water. This system consequently cannot be satisfactory.
A surveillance system for a swimming pool is described in patent application SP2 (FR 96 10442 Poséidon) which consists of:
means of detection (notably video cameras positioned in waterproof compartments) appropriate for giving images of bodies submerged in the water of the swimming pool in the form of electrical signals, these means of detection are planned in the sides of the swimming pool and places judiciously chosen to sweep at least a fraction of the water volume in the swimming pool; means of digitisation of the electrical signals obtained; means of temporarily and permanently storing the digital image data at successive moments; means of comparison between digitised images of the same body at successive moments; means of estimating the nature of a body (human body or not), of the trajectory and changes in attitude of the body according to these successive images; and means for making decisions appropriate for setting off an alarm in the event of a suspicious trajectory or movement of the body being observed.
The means of comparison of the digitised images between successive moments are appropriate only to take forms into consideration, of which the dimensions at least correspond to those of a child, in order to eliminate false alarms being caused by foreign bodies. In addition, these means of comparison are implemented in order to isolate a form and follow its trajectory at successive moments.
The means of estimating are appropriate to determine the slow nature of a movement and/or the immobility of a human body in the swimming pool by means of the results of the means of comparison.
The means for making decisions are appropriate for setting off an alarm if the slow nature of a movement or the almost-immobility of a body in the swimming pool continues over a defined period, in particular over 15 seconds.
One or numerous control screens are positioned by the lifeguards' chairs or in the offices of the persons responsible for surveillance of the swimming pool, screens on which the images are shown of a zone considered suspect. The alarm may be given through a sound and/or visual warning, in particular with an indication of the zone of the swimming pool in which a suspicious event is taking place.
No matter how perfected they are, such systems cannot always make it possible to distinguish an object in front of the bottom. In fact, in the event that a single camera is used, it is not always possible to distinguish a shadow of a body of a swimmer passively floating, moving along the bottom. Admittedly, in the event that numerous cameras are used to observe the same object from numerous points of view, the parallax effect should, in principle, make it possible to distinguish a dense object situated in front of the bottom of a bi-dimensional mark situated on the bottom. In any event numerous conditions must be met in order for the parallax effect to adequately sensitive. On the one hand, it is desirable for the viewpoints to be close to the object being observed. This first condition implies that numerous cameras will be used for surveillance over a large zone in relation to the dimensions of the objects that one hopes to detect. In correlation, this type of system is consequently particularly costly. On the other hand, it is desirable that the depiction of colours perceived by each camera is identical. Now, in order for this to be the case it is essential for the opto-electronic characteristics of the video cameras to be the same, which is not always the case. In addition the optical route between the object and each camera may cross environments with different refraction or transparency indexes. This is notably the case when the body being observed is submerged in a swimming pool with a turbulent surface. The depiction of the colours of the object being observed by each camera is not the same. Consequently the geometric correlations that make it possible to establish that the images (their outlines and grey scale nuances) produced by each camera come from the same dense object situated in front of a coloured bottom, can not longer be verified with certainty. Consequently confusion is possible between a shade of colour (for example a shadow being carried) on the bottom of the swimming pool and a dense object close to the bottom. Consequently, the result is that errors in detection and false initiation of the alarm systems.
The present invention is intended to avoid the inconveniences of the processes and systems known as yet, no matter how efficient they are.
SUMMARY OF THE INVENTION
The process and the system according to the invention were originally conceived for surveillance in swimming pools and the prevention of incidents of drowning. In any event, it quickly became apparent that the image processing techniques consisting of analysing the image of a dense object in a general way in relation to a surface, could be applied to surfaces including virtual surfaces and objects located before or behind such surfaces. Due to this fact they are appropriate for application in fields other than the surveillance of swimming pools.
Process
The present invention relates to a process for detecting an object in relation to a surface, notably a virtual surface, said surface is not necessarily flat.
The process according to the invention includes a step for realising a computer-generated image associated to the viewpoint being considered for each viewpoint by means of a geometric conversion at least including a projection in perspective of said object on said surface from at least two distinct viewpoints.
Further in the description the computer-generated image associated to the viewpoint considered is defined as the image obtained by the application of the geometric conversion at the scene being observed from said viewpoint whether or not there is an object.
In addition said process includes a stage for distinguishing between the computer-generated images for detecting a presence and determining the position of said object in relation to said surface.
In order to distinguish between the different computer-generated images said process additionally includes the following stages:
the stage for breaking said surface down into a mosaic of fields (Zi) each including a centre (Ci). the stage for associating a specific direction (Di) to each centre (Ci) and each viewpoint.
In this way each computer-generated image is broken down in virtual fields (zi) each consisting of as many specific virtual directions (di)as there are viewpoints.
The process according to the invention also includes the following stages in order to distinguish between the computer-generated images:
the stage of selecting at least a couple of computer-generated images associated to at least a couple of viewpoints, the stage of choosing zones situated according to each of the specific virtual directions (di) of each virtual field (zi) on each computer-generated image of the couple selected, the stage of comparing said zones in searching for opposing differences from one computer-generated image to another.
If opposing differences appear as a result of the search it is possible to conclude that there is an object.
Preferably, in order to determine whether an object is before and/or behind said surface, zones of comparison are selected for each of the specific virtual directions (di) on one side and/or the other side of said centres (ci) of said virtual fields (zi) in relation to each of the viewpoints.
Preferably, in order to determine whether said object extends to further or less far in relation to said surface, zones of comparison more or less distant from said centres (ci) of the virtual fields (zi) are chosen for each of the specific virtual directions (di).
Preferably, the process according to the invention also includes the stage of deducing the position of said object along the surface in relation to the position of the fields on the surface (zi) for which opposing differences have been found.
Preferably, in order to realise each of said computer-generated images associated to a viewpoint being considered,
radioactive emissions and/or electromagnetic rays (notably lights) and/or mechanical vibrations emitted from said object are captured in each viewpoint in such a way as to produce a signal, said signal is digitised in order to obtain digital data, said computer-generated images are calculated on the basis of the data obtained in this way.
Preferably an optical camera and/or a sonar is/are implemented at each viewpoint in order to capture the electromagnetic rays, notably lights, and/or mechanical vibrations, notably ultrasounds.
Preferably, when said computer-generated images show different coloured zones, in order to search for the opposing differences in each computer-generated image of the selected couple, inversions of colour contrasts between the zones situated along each of the specific virtual directions (di) of each field (zi) are searched for.
According to a realisation variant, the invention also relates to a process more specifically intended to detect an object in front of a bottom, in this case said bottom constitutes said surface.
In the event of this realisation variant, said geometric conversion also includes a projection, on a surface of reference (notably a flat surface) associated in the viewpoint being considered, with the virtual image resulting from the projection in perspective of said object on said bottom from said viewpoint being considered. Favourably, the projection on the surface of reference is an orthogonal projection. Equally in the event of this realisation variant, said computer-generated image associated to the viewpoint being considered consists of:
the image realised by means of the application of said geometric conversion on said object, and in addition to the superposition, on said surface of reference, the image realised through the application of said geometric conversion on a virtual representation consisting of sections of the bottom not masked by said projection of the object in perspective.
Preferably, data relating to the computer-generated image on said surface of reference is calculated on the basis of said digitised data in order to realise said computer-generated image on a surface of reference, in the event of this realisation variant.
The invention is also intended for an application implementing the aforementioned technical features and intended for the surveillance of bodies in a swimming pool. In the event of this application, said bottom consists of the bottom and/or sides of the swimming pool. In the event that, after discrimination of the computer-generated images, it is concluded that there is a body in the swimming pool:
the procedure for discrimination in order to distinguish a body with a suspicious trajectory, notably an immobile body sinking passively from a body with a normal trajectory is reiterated, an alarm signal is emitted if the body has a suspicious trajectory for an abnormally long period of time.
Preferably this application relates to the event in which the body is situated close to the bottom.
Preferably in the event of this application:
at least two viewpoints are located in the sides of the swimming pool in positions appropriate for sweeping at least a fraction of the volume of water in the swimming pool, said surface of reference is roughly parallel to the surface of the water in the swimming pool.
System
The invention also relates to a system for detecting an object in relation to a surface, notably a virtual surface, said surface not necessarily being flat.
The system according to the invention consists of means of detection and the first means of calculation of a central processing unit in order to realise a computer-associated image associated to the viewpoint being considered by means of a geometric conversion consisting of at least a projection in perspective of said object on said surface from at least two distinct viewpoints.
In addition said system includes means for discriminating between the computer-generated images. The said means for discriminating make it possible to detect the presence and determine the position of said object in relation to said surface. Preferably, said means of discrimination include means of division in order to break down said surface into a mosaic of fields (Zi) each including a centre (Ci) and as many specific directions (Di) as there are viewpoints. Each computer-generated image is also broken down into virtual fields (zi) each including as many specific virtual directions (di) as there are viewpoints.
In addition said means of discrimination include discrimination between computer-generated images:
means of selection in order to select at least a couple of computer-generated images associated with at least a couple of viewpoints, means for choosing zones situated according to each of the specific virtual directions (di) of each virtual field (zi) on each computer-generated image of the couple selected, means of comparison for comparing said zones by searching for opposing differences of one computer-generated image to the other.
The presence of an object is the conclusion if opposing differences appear during the search.
Preferably, in order to determine whether an object is before and/or behind said surface, said means for choosing the zones on each of the specific virtual directions (di) choose the zones of comparison on one side and/or the other of said centres (ci) of said virtual fields (zi) in relation to each of the viewpoints.
Preferably, in order to determine whether said object extends further or less far in relation to said surface, said means for choosing the zones on each of the specific virtual directions (di) choose zones of comparison that are more or less distant from said centres (ci) of the virtual fields (zi).
Preferably, the means of discrimination to discriminate between the computer-generated images defining the position of said object along the surface in relation to the position on the surface of the fields (zi) for which opposing differences have been found.
Preferably, in order to realise each of said computer-generated images associated to a viewpoint being considered, said system includes sensors, at each viewpoint. The said sensors include means for capturing radioactive emissions and/or electromagnetic rays (notably lights) and/or mechanical vibrations emitted from said object, so as to produce a signal. The said system also includes:
means for digitisation in order to digitise said signal and in order to obtain digitised data, means for calculation in order to calculate said computer-generated images on the basis of data obtained in this way.
Preferably, said sensors for capturing electromagnetic rays, notably lights, and/or mechanical vibrations, notably ultrasounds, are optical cameras and/or sonars situated at each viewpoint.
Preferably, said means of discrimination including the means for studying the inversions of the colour contrasts between the zones situated according to each of the specific virtual directions (di) of each field (zi) in order to study the opposing differences on each computer-generated image of the couple selected if said computer-generated images show different coloured zones.
According to a realisation variant the invention also relates to a system more particularly intended to detect an object in front of a bottom, in this case said bottom consists of said surface.
In the event of this realisation variant, said geometric conversion also includes a projection, on a surface of reference (notably a flat surface) associated in the viewpoint being considered, with the virtual image resulting from the projection in perspective of said object on said bottom from said viewpoint being considered. Favourably, the projection on the surface of reference is an orthogonal projection. Equally in the event of this realisation variant, said computer-generated image associated to the viewpoint being considered consists of:
the image realised by means of the application of said geometric conversion on said object, and in addition to the superposition, on said surface of reference, the image realised through the application of said geometric conversion on a virtual representation consisting of sections of the bottom not masked by said projection of the object in perspective.
Preferably, data relating to the computer-generated image on said surface of reference is calculated on the basis of said digitised data in order to realise said computer-generated image on a surface of reference, in the event of this realisation variant.
The invention is also intended for an application implementing the aforementioned technical features and intended for the surveillance of bodies in a swimming pool. In the event of this application, said bottom consists of the bottom and/or sides of the swimming pool. In the event that, after discrimination of the computer-generated images, it is concluded that there is a body in the swimming pool, said system also includes:
means for reiteration in order to reiterate the procedure for discrimination and in order to distinguish a body with a suspicious trajectory, notably an immobile body or a body sinking passively from a body with a normal trajectory, means of emission in order to emit an alarm signal if the body has a suspicious trajectory for an abnormally long period of time.
Preferably this application relates to the event in which the body is situated close to the bottom.
Preferably in the event of this application:
at least two viewpoints are located in the sides of the swimming pool in positions appropriate for sweeping at least a fraction of the volume of water in the swimming pool, said surface of reference is roughly parallel to the surface of the water in the swimming pool.
BRIEF DESCRIPTION OF THE DRAWINGS
Other characteristics and advantages of the invention become apparent on reading the description of the realisation variants of the invention, given as an indicative and unrestrictive example, and from:
FIG. 1 which represents a perspective view of an object situated in front of a bottom and of the projection in perspective of the object and the virtual representation of the bottom from a first viewpoint,
FIG. 2 which represents a perspective view of the same object situated in front of the same bottom and of the projection in perspective of the object and the virtual representation of the bottom from a second viewpoint,
FIG. 3 which represents a perspective view of an object situated in front of a bottom and on which the virtual fields Zi are shown, their centre Ci and the specific directions 3D i and 4D i associated with viewpoints 3 and 4 .
FIG. 3 b which represents a perspective view of an object situated in front of a bottom after orthogonal projection on a first level of reference associated to a first viewpoint and on a second level of reference associated to a second viewpoint,
FIG. 4 which represents a perspective view of computer-generated images in the event that there is no object in front of the bottom.
FIGS. 5 a and 5 b which represent the views below the two levels of reference represented in FIG. 3 b,
FIG. 6 which represents a perspective view of a swimming pool in which a body is submerged close to the bottom,
FIG. 7 which represents a schematic view of opto-electronic systems according to a realisation variation of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the event of the realisation variation represented in referring to FIGS. 1 to 7 , the surface in relation to which the position of an object is detected and determined, is an opaque bottom. The detailed description which follows may be applied by a tradesman in the event of an object situated in front of or behind a transparent surface or a virtual surface.
An object 1 is represented in front of a bottom 2 in FIGS. 1 , 2 , 3 a and 3 b . Bottom 2 , is bumpy, and defined by a “square” outline in the form of a “lip”, it shows a “coloured mark” 50 contrasted in relation to the bottom. The following is realised by means of a geometric conversion including a projection in perspective on said bottom 2 from at least two distinct viewpoints 3 , 4 and for each of these:
a projection in perspective 3 a , 4 a of the object on said bottom and a virtual representation 3 b 1 , 3 b 2 ; 4 b 1 , 4 b 2 of the sections of the bottom not masked by said projection of the object in perspective.
The reference 3 b 1 (respectively 4 b 2 ) shows the section of the bottom (not masked), seen from viewpoint 3 (respect. 4 ), which includes a “colour mark”.
The reference 3 b 2 (respectively 4 b 2 ) shows the section of the bottom (not masked), seen from viewpoint 3 (respect. 4 ), which does not include a “colour mark”.
The virtual representation 3 b , 4 b of sections of the bottom not masked by said projection in perspective of object 1 is the union of zones 3 b 1 and 3 b 2 (viewpoint 3 ) and zones 4 b 1 and 4 b 2 (viewpoint 4 ).
The FIG. 3 a shows the paving of the bottom consisting of virtual fields Zi each including a centre Ci and two specific directions 3 D i (resp. 3 D 1 ) and 4 D i (resp. 4 D 1 ) obtained by joining viewpoints 3 and 4 to centre Ci (resp. C 1 ) of field Zi (resp. Z 1 ) being considered. The centre C 1 has been shown on field Z 1 situated at the top left as well as the specific associated directions 3 D 1 and 4 D 1 .
In the event that the geometric conversion only consists of the projection in perspective described above, the computer-generated image, according to the present invention (classified as 3 c , 4 c hereinafter) consists of projections in perspective 3 a and 4 a of the object on said bottom.
FIG. 3 b shows how the computer-generated image 3 c , 4 c is realised in the event that the geometric conversion includes an orthogonal projection 6 on the surfaces of reference 3 e , 4 e associated with viewpoints 3 and 4 after an operation of projection in perspective.
In the example of realisation represented in FIG. 3 , each computer-generated image (respectively 3 c and 4 c ) is obtained by means of an orthogonal projection 6 and superposition of each projection in perspective (respectively 3 a and 4 a ) and each virtual representation of the bottom (respectively 3 b and 4 b ) on flat surfaces or reference (respectively 3 e and 4 e ). The orthogonal projections, according to direction 6 , the virtual projections 3 a and 4 a are respectively classified 3 o , 4 o , on FIG. 3 b . It should be stated that each virtual representation 3 b , 4 b of the sections of the bottom not masked by said projection in perspective 3 a , 4 a of the object on the bottom, consists of sections 3 b 1 , 3 b 2 , 4 b 1 , 4 b 2 defined above.
FIGS. 1 to 3 are geometric constructions for convenience of the description. In fact, as it will now be described, physical means and means of calculation are implemented in order to realise each of said computer-generated images 3 c , 4 c of the object and the bottom associated to a viewpoint being considered 3 , 4 . In the first place, radioactive emissions and/or electromagnetic rays (notably light) and/or mechanical vibrations, notably ultrasounds, emitted from the object and the bottom, so as to produce a signal are captured in each viewpoint 3 , 4 . In the event of the realisation variation relating to the surveillance of swimming pools represented in FIG. 6 , an opto-electronic camera 31 , 41 is implemented at each viewpoint 3 , 4 in order to capture the rays of light emitted by the object and the bottom, which is situated in a box 32 , 42 as described in the patent application SP2 (FR 96 10442 Poséidon) and for which the description is incorporated here as a reference. The output signal of the camera is representative of the image of object 1 and of the bottom 2 produced by the opto-electronic camera.
It is also possible to use a sonar in each viewpoint 3 , 4 and to capture the echo emitted by the different sections of body 1 and bottom 2 and to produce a representative signal of their form and content.
In the known way, the signal produced by the camera and/or the sonar is digitised then the digitised data obtained in this way is used to calculate said computer-generated images. If bottom 2 is flat and/or if an analytical representation of the bottom is known, it is possible directly to calculate the virtual projections 3 a , 4 a of the object on the bottom 2 and/or the virtual representations 3 b , 4 b of the sections of the bottom not masked by said virtual projections. Then, it is possible subsequently to calculate the computer-generated images 3 c and 4 c by means of orthogonal projection 6 of the virtual projections 3 a , 4 a and the virtual representations 3 b , 4 b on the levels of reference 3 e and 4 e , for which an analytical representation is also known. If the bottom is not flat as that shown in FIGS. 1 to 4 , said bottom is sampled beforehand, notably by drawing up a topographical plan of it, in order to obtain a digital model.
The specific virtual directions 3 di and 4 di of each of the virtual fields zi of the computer-generated images associated to the virtual fields Zi of the mosaic forming the bottom are obtained by means of orthogonal projection on the levels of reference 3 e and 4 e of specific directions 3 D i and 4 D i defined above.
If there is no object 1 in front of the bottom (case as shown in FIG. 4 ), the computer-generated images 3 c and 4 c are reduced to virtual projections of the bottom 2 on the levels of reference 3 e and 4 e . The two virtual projections 3 c and 4 c are similar.
If there is an object 1 in front of the bottom (case shown in FIGS. 5 a and 5 b ), the computer-generated images 3 c and 4 c are not similar. They comprise of distinct zones 3 o , 4 o which extend along the specific virtual directions ( 3 di , FIG. 5 a ) and ( 4 di , FIG. 5 b ) associated to the field(s) Zi situated directly below the object (in orthogonal projection on the levels of reference 3 e and 4 e ). These zones correspond to the virtual projections 3 a and 4 a of the object on the bottom 2 .
Proceed as follows in order to distinguish between the computer-generated images 3 c , 4 c and in order to determine the presence of an object 1 in relation to surface 2 : Select a couple of computer-generated images 3 c , 4 c associated to at least a couple of viewpoints 3 , 4 . Study (see FIG. 5 a and 5 b ) each computer-generated image 3 c , 4 c of the couple selected choosing zones 3 fi , 3 gi (level of reference 3 e ), 4 fi , 4 gi (level of reference 4 e ) situated along each of the specific virtual directions 3 di , 4 di of each virtual field zi. Then compare 3 hi , 4 hi of said zones 3 fi , 3 gi , 4 fi , 4 gi by searching out opposing differences of a computer-generated image 3 c with the other 4 c.
More particularly in the event that the computer-generated imaged 3 c , 4 c present zones 3 fi , 3 gi , 4 fi, 4 gi of different colours, proceed as following in order to search out opposing differences in each computer-generated image 3 c , 4 c of the couple selected. Inversions of colour contrasts between zones 3 fi , 3 gi, 4 fi , 4 gi situated along each of the specific virtual directions 3 di , 4 di of each field zi are sought. Computer-generated images presenting zones of different colours are notably obtained when video cameras are used.
If opposing differences between one computer-generated image and another appear for a certain number n of fields zi (n may be equal to 1), for example if 3 fi is grey while 3 gi is not and if 4 fi is not grey while 4 gi is, it must a fortiori be concluded that there is an object in front of the bottom. In analysing the colour contrasts along the specific virtual directions 3 di and 4 di , in seeking the inversion of contrasts it is possible to deduce whether or not there is an object 1 in front of the bottom. In any event, searching out the opposing differences may relate to other elements that the colours and shades of grey. It may also be possible to find opposing differences in the forms, in the surroundings of the outlines.
An application of the process and system according to the invention to the surveillance of bodies 1 in a swimming pool 61 was represented in referring to FIG. 6 . Elements may be recognised in FIG. 6 which have already been described in reference to FIGS. 1 to 5 ; it bears the same references. For example, the bottom 3 is the bottom of swimming pool 61 and/or its sides 62 . Object 1 is the body of a swimmer in distress. In the event of this application, proceed as described above in order to distinguish the computer-generated images and to determine whether there is a body in front of the bottom, more particularly close to it. Then, reiterate the procedure of discrimination in order to distinguish a body with a suspicious trajectory from a body with a normal trajectory, by carrying out an analysis of movements, notably an immobile body or a body sinking impassively. An alarm signal is emitted if the body has a suspicious trajectory for an abnormally long period of time.
In the event of the application of the process and the system according to the invention for the surveillance of a swimming pool, the two optical cameras 31 and 41 located in boxes 32 and 42 associated to viewpoints 3 and 4 , are situated in the sides 62 forming a 90° angle between them. Such a situation is appropriate to sweep at least a fraction of the volume of water in the swimming pool. In this regard we refer to the patent application SP2 (FR 96 10442 Poséidon) incorporated here by reference. The levels of reference 3 e and 4 e are roughly parallel to the surface 63 of the water in the swimming pool.
Now a schematic view of the opto-electronic systems and the means of calculation according to a realisation variant of the invention will be described here while referring to FIG. 7 .
Cables 33 , 43 which cross boxes 32 , 42 containing cameras 31 , 41 , are coax cables, connected to a micro computer 72 , for example of the “IBM compatible” type constructed around a PENTIUM microprocessor, by means of a multiplex system 71 . A continuous power supply is established on each cable 33 , 43 intended to supply the corresponding camera 31 , 41 . The said camera 31 , 41 sends a modulation, which constitutes the signal to be processed through the cable 33 , 43 . Before input into the multiplex system 71 , the separation of the continuous component must be assured thanks to the demodulation means which supply the signal emitted by the camera of the “CCD” type, solely by means of a multiplex system. The microcomputer 72 includes a central processing unit 73 , means for temporary storage, or RAM (Random Access Memory), means for permanent storage, or hard disk 75 , and a remote control card 76 which is able to control the alarm systems 77 . In addition, the microcomputer 72 is connected to a control screen E, said screen is a touch screen which allows control of operation. The microcomputer 72 is configured as “multimedia” and is equipped with a video capture card 78 , which converts these into digital images.
Thanks to the multiplex system it is possible to process cameras 31 and 41 with the same video capture card 78 . It should be noted that the number of cameras processed by the same card may be greater than two.
The central processing unit 73 makes it possible to carry out various calculations making it possible to produce computer-generates images 3 c , 4 c . The central processing unit 73 also carries out the calculations which make it possible to distinguish between the computer-generated images 3 c , 4 c , according to whether or not there is an object in front of the bottom, by applying the procedures described above.
The storage means 74 , 75 of the digital data of computer-generated images at successive moments t, (t+Dt) have been provided. These storage means 74 , 75 consist of the microcomputer 72 's memory systems, notably the internal RAM memory 74 and the hard disk 75 of the computer. The means of comparison between the computer-generated images at successive moments t and (t+Dt) have been provided. The means of comparison are formed by the central processing unit 73 of the computer and appropriate software stored in an areas of the internal RAM 74 . The time interval Dt between two moments t and (t+Dt) taking into consideration is adequate in order, in the event of a normal movement of a swimmer, the differences between the two successive images translate such a movement. However, the interval of time Dt is also as small as possible in order to make it possible to set off the alarm without any delay in the event of a suspicious situation. This interval Dt may be a few tenths of a second. The means of comparison, between two moments t and (t+Dt), calculate the difference between the matrices of the two computer-generated images. The means of comparison make it possible to obtain the zones of change between two images at successive moments in this way, in other words the zones of movements between two moments being considered. The central processing unit 73 combined with appropriate software, also constitutes means of estimating the nature of a body 1 , for which the computer-generated image is obtained (human body or not), of the trajectory and of the changes of attitude of this body. In addition the central unit 73 and the software are provided to constitute the means for making decisions appropriate for setting off an alarm in the event of a suspicious trajectory or movements of the body being observed. The fact that the matrix of the initial image is known (empty swimming pool), makes it possible to count and follow the different forms moving in the swimming pool captured by the cameras individually.
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The invention relates to a method for detecting an object ( 1 ) in relation to a surface ( 2 ). A synthetic image ( 3 c, 4 c ) is produced from at least two distinct viewpoints ( 3, 4 ), for each of said viewpoints, by means of a geometrical transformation comprising at least one perspective projection ( 3 a, 4 a ) of the object on the surface ( 2 ), each synthetic image being associated with the viewpoint concerned. By discriminating between the synthetic images, it is possible to detect the presence of and determine the position of the object ( 1 ) in relation to the surface ( 2 ), by searching for contrast inversions. The invention can be used for surveying a swimming pool.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a remote power source control, and more particularly to a method and apparatus for turning on and off remote power sources of a plurality of information processing apparatuses connected to a network or networks by using remote power source controllers operated by auxiliary power sources of the information processing apparatuses.
2. Description of the Related Art
Distributed processing systems having a plurality of computers connected by a network are widely used. In such a distributed processing system, a host has a function of managing and operating remote computers. One example of such a function of a host is to perform a power source control for remote computers.
As the technology concerning remote power source controls, there are known a centralized power-off scheme in which a server machine transmits a special command to a client machine to turn off the power source of the client machine, reference being made to JP-A-4-284520, a power source stop controlling means in which upon reception of a command inputted from an operation terminal, a machine checks its operation state and if the state is a command accepting state, the power source is turned off, reference being made to JP-A-4-289906, and a terminal equipment in which when a power source control signal is detected from packet data received from a communication line, the terminal equipment controls a power source control unit to turn on or off its power source, reference being made to JP-A-4-343115.
The above-described prior art, however, has have the following problems. The prior art of JP-A-4-284520 pertains only to a power-off control of a client machine by a server machine, and does not consider how security is protected.
Similar to the first prior art, the prior art of JP-A-4-289906 pertains only to a power-off control and requires a command input from an operation terminal. The prior art of JP-A-4-343115 is applicable only to a power control of a terminal equipment. Since this prior art uses a type field of an EtherNet frame, a specific control method is required to be used, and in addition, machines from different vendors are difficult to interconnect. Furthermore, if power is being supplied to a terminal equipment, the power source is turned off, whereas if power is not being supplied to the terminal equipment, the power source is turned on. It is therefore necessary to provide the power source control unit with a logic circuit for operation state judgement. Still further, since a method of supplying power to an EtherNet controller is unspecified, there may be some problem about a power-on control. In addition, security means is not taken into consideration.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a remote power source control method and apparatus capable of controlling remote power sources independently of network architectures and types and providing security checks.
According to one aspect of the present invention achieving the above object, there is provided a remote power source control apparatus for a system having a plurality of network interconnected information processing apparatuses, wherein each of the plurality of information processing apparatuses includes a main power source, an auxiliary power source, and a remote power source controller always operated by the auxiliary power source, and the remote power source controller includes means for transmitting and receiving data between networks and means for controlling a power-on or power-off of the main power source of the information processing apparatus receiving the data in accordance with the received data.
According to a second aspect of the invention, the remote power source controller includes means for checking whether the data has been transmitted from an authorized user.
According to a third aspect of the invention, a first information processing apparatus constitutes a power source controlling apparatus and second to n-th (n is a positive integer) information processing apparatuses constitute power source controlled apparatuses, wherein the remote power source controller of the first information processing apparatus includes means for storing a control program predefining a power-on or power-off order of main power sources of the second to n-th information processing apparatuses, if there is any restriction on the power-on or power-off order.
According to a fourth aspect of the invention, the plurality of information processing apparatuses constitute a server or servers and clients, the server controls the main power source of the client, or the client controls the main power source of the server, or a first server controls the main power source of a second server, or a first client controls the main power source of a second client.
According to a fifth aspect of the invention, the plurality of information processing apparatuses constitute a multiprocessor system interconnected to other information processing apparatuses via a network or networks, one of the other information processing apparatuses controls the main power source of a first information processing apparatus of the multiprocessor system, and the first information processing apparatus controls the main power sources of the remaining information processing apparatuses of the multiprocessor system.
A plurality of information processing apparatuses are interconnected by a network or networks, and the remote power source controller of each information processing apparatus is always powered by an auxiliary power source. When an information processing apparatus A operating as a power source controlling apparatus instructs via a network an information processing apparatus B operating as a power source controlled apparatus to turn on or off the main power source of the information processing apparatus B, the information processing apparatus A transmits power control instruction data. The information processing apparatus B checks a user ID and a password transmitted from the information processing apparatus A, and thereafter turns on the main power source thereof. The remote power source control method of the invention is applicable to various types of networks such as a client/server model and tandem connected networks.
The other objects, features, and advantages of the invention will become apparent from the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a system configuration according to an embodiment of the invention.
FIG. 2 is a block diagram showing the structure of a remote power source controller.
FIG. 3 is a schematic diagram of the remote power source controller realized by using an LSI chip.
FIG. 4 is a table for designating a power-on order.
FIG. 5 shows a power source control sequence using the Telnet protocol according to an embodiment of the invention.
FIG. 6 shows a power control sequence using an IP multicast address according to another embodiment of the invention.
FIG. 7 shows a power control sequence used for tandem connected networks.
FIG. 8 shows the contents of a routing table used for tandem connected networks.
FIG. 9 is a diagram showing a network in which a server controls the main power source of a client.
FIG. 10 is a diagram showing a network in which a client controls the main power source of a server.
FIG. 11 is a diagram showing a network in which a server controls the main power source of another server.
FIG. 12 is a diagram showing a network in which a client controls the main power source of another client.
FIG. 13 is a diagram showing a cluster system configuration in which a particular information processing apparatus can control the main power sources of all other information processing apparatuses.
FIG. 14 is a diagram showing a cluster system configuration in which an information processing apparatus whose main power source has been controlled, sequentially relays the power control to other information processing apparatuses.
FIG. 15 is a diagram showing a cluster system configuration in which the main power sources of information processing apparatuses belonging to a same group are controlled collectively by using an IP multicast address.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the invention will be described with reference to the accompanying drawings. FIG. 1 shows a system configuration according to an embodiment of the invention. Referring to FIG. 1, information processing apparatuses 10, 11, 12 are connected to a network 20 such as a LAN. The information processing apparatus 10 has a main power source 300 and an auxiliary power source 310 which supply power to the information processing apparatus 10.
The auxiliary power source 310 always and continuously supplies power to a remote power source controller 200, and as shown in FIG. 1, supplies power to only the remote power source controller 200. The main power source 300 supplies power to all devices of the information processing apparatus 10 not supplied with power by the auxiliary power source 310. That is, as shown in FIG. 1, the main power source 300 supplies power to all of the devices of the information processing apparatus 10 except the auxiliary power source 310 and the remote power source controller 200. The main power source 300 can be turned on in response to a power-on signal from the remote power source controller 200, or may be turned on in response to a depression of a panel switch.
Each element or device in the information processing apparatus 10 will be explained. A main processor 100 is a dominant element of the information processing apparatus 10. A processor memory controller 80 controls an access from the main processor 100 to a main memory 90 and accesses from a LAN controller 30 and a SCSI (small computer system interface) controller 31 to the main memory 90.
The LAN controller 30 and SCSI controller 31 are connected to an I/O bus 50 which is connected via a bus connector 60 to a system bus 70. The system bus 70 is used for accessing the main memory 90 via the processor memory controller 80. The LAN controller 30 controls an access to the network 20, and the SCSI controller 31 controls an access to, for example, a hard disk drive 40.
FIG. 2 is a block diagram showing the structure of the remote power source controller 200. Referring to FIG. 2, a network controller 210 controls an access to the network 20. Data received from the network 20 is stored in a RAM 220, and data is transmitted from the RAM 220 to the network 20. A processor 250 instructs the network controller 210 to receive and transmit data. In response to this instruction, the network controller 210 performs a data reception or transmission operation. An access controller 230 controls an access to the RAM 220 and a flash ROM 221 from the processor 250, and an access to the RAM 220 from the network controller 210.
The RAM 220 and the flash ROM 221 are connected via a memory bus 225 to the access controller 230, and the processor 250 and an EPROM 240 are connected via a processor bus 231 to the access controller 230. All programs which run on the processor 250 are stored in EPROM 240. The flash ROM 221 stores IP (Internet Protocol) addresses conforming with RFC (Requests For Comments), MAC (Media Access Control) addresses conforming with IEEE, and other data.
A main power source controller 260 is connected to the access controller 230 and accessed by the processor 250. The main power source controller 260 controls a power-on and a power-off of the main power source 310.
FIG. 3 is a schematic diagram of the remote power source controller 200 realized by using a one-chip power source controller LSI 270 made of gate arrays.
FIG. 4 is a table 400 for designating a power source turn-on order. This power source turn-on order table 400 is stored in the flash ROM 221. For example, assuming that the information processing apparatus 12 shown in FIG. 1 instructs other information processing apparatuses to turn on their main power sources, that the information processing apparatuses 11 and 10 are instructed to turn on their power sources in this order, the power source turn-on order table 400 of the information processing apparatus 12 has the IP addresses of the information processing apparatuses 11 and 10 stored in the address fields 400a and 400b, respectively. The end address field 400n stores an identifier representing the end of the table. Referring to the table 400, the information processing apparatus 12 turns on first the main power source of the information processing apparatus 11, and then the main power source of the information processing apparatus 10. If there is any restriction on a power source turn-off order, a similar power source turn-off table is prepared.
FIG. 5 shows a power source control sequence using the Telnet protocol according to an embodiment of the invention. When a power source controlling apparatus 500 instructs a power source controlled apparatus 510 to turn on or off its power source, a telnet command conforming with the RFC is used (the Telnet protocol runs on TCP/IP (Transmission Control Protocol/Internet Protocol) conforming with the RFC).
The power source controlled apparatus 510 is, for example, the information processing apparatus 10 shown in FIGS. 1 and 2, and the power source controlling apparatus 500 is, for example, the information processing apparatus 12 shown in FIG. 1. A telnet command sent from the power source controlling apparatus 500 to the power source controlled apparatus 510 is received by the network controller 210 and stored in the RAM 220. The processor 250 at the power source controlled apparatus 510 analyzes the data stored in the RAM 220 and requests the user ID of the power source controlling apparatus 500.
The power source controlling apparatus 500 then transmits the user ID. Upon reception of this user ID transmitted from the power source controlling apparatus 500, the power source controlled apparatus 510 checks the user ID by referring to a table (hereinafter called a user table) stored in the flash ROM 221. This user table stores data indicating whether each power source controlling apparatus has been authorized to perform a power source control. If the power source controlling apparatus 500 has been authorized, the power source controlled apparatus 510 requests the password of the power source controlling apparatus 500, whereas if the apparatus 500 has not been authorized, an error message is transmitted back to the power source controlling apparatus 500.
The authorized power source controlling apparatus 500 transmits the password. Upon reception of this password, the power source controlled apparatus 510 checks the password in the manner similar to checking the user ID. If the password is correct, then the control enters the Telnet mode, whereas if not correct, an error message is transmitted back to the power source controlling apparatus 500.
In response to a power-on command or a power-off command transmitted from the power source controlling apparatus 500 to the power source controlled apparatus 510, the power source controlled apparatus 510 performs a power-on or power-off operation.
FIG. 6 shows a power control sequence using an IP multicast address according to another embodiment of the invention.
Each of the main power sources of a plurality of power source controlled apparatuses a 510 and b 511 may be controlled by a power source controlling apparatus 500 using the Telnet protocol in the manner described in FIG. 5. However, in this embodiment, an IP multicast address is used to perform the power control of only those power source controlled apparatuses belonging to one group represented by the multicast address.
The power control may be performed by using broadcast addresses. With this method, however, the power control instruction is supplied to all the apparatuses connected to the network, including the apparatuses not intended to be power controlled. This can be avoided by using an IP multicast address.
In the sequence shown in FIG. 6, the power source controlling apparatus 500 transmits a multicast address to the power source controlled apparatuses a 510 and b 511, which send back their IP addresses and supplemental information to the power source controlling apparatus 500. This supplemental information includes information on whether the power source is turned on or off. In this manner, even if there is a power source controlled apparatus which does not want to perform the power control, the power source controlling apparatus can check the status of its power source.
FIG. 7 shows a power control sequence used for tandem connected networks. FIG. 8 shows an example of a routing table for tandem connected networks. If a plurality of networks are tandem connected by gateways, it is necessary to use not only the IP address of a power source controlled apparatus a 510 but also the IP address of another power source controlled apparatus belonging to a network remoter than the network of the power source controlled apparatus a 510.
The routing table shown in FIG. 8 includes destination IP addresses, gateways, the number of tandem connected networks, and interfaces, and is stored in the flash ROM 221 of the power source controlled apparatus a 510. By using this table, it becomes possible to identify the IP address of a power source controlled apparatus of a network remoter than the network of the power source controlled apparatus a 510.
The power source controlling apparatus 500 first instructs the power source controlled apparatus a 510 to turn on its main power source. After the power-on of the power source controlled apparatus a 510, the IP address of a power source controlled apparatus of a network remoter than that of the power source controlled apparatus a 510 is passed via the RAM 220 shown in FIG. 2 to the program running on the main processor 100 shown in FIG. 1 of the power source controlled apparatus a 510. The program receiving the IP address operates in accordance with the power control sequence shown in FIG. 5 or 6 to turn on or off a power source controlled apparatus b 511 or another power source controlled apparatus.
FIG. 9 is a diagram showing a network in which a server controls the main power source of a client. A server 600 corresponds to a power source controlling apparatus, and clients 700 and 701 correspond to power source controlled apparatuses. Power is turned on or off in accordance with the power control sequence shown in FIG. 5 or 6.
FIG. 10 is a diagram showing a network in which a client controls the main power source of a server. A client 700 corresponds to a power source controlling apparatus and a server 600 corresponds to a power source controlled apparatus. Power is turned on or off in accordance with the power control sequence shown in FIG. 5 or 6.
FIG. 11 is a diagram showing a network in which a server 600 controls the main power source of another server 601, and FIG. 12 is a diagram showing a network in which a client 700 controls the main power source of another client 701. In both the cases, power is turned on or off in accordance with the power control sequence shown in FIG. 5 or 6.
FIG. 13 is a diagram showing a cluster system configuration in which a particular information processing apparatus controls the main power sources of all other information processing apparatuses. A cluster system is a multiprocessor system having a plurality of information processing apparatuses connected to a network. The multiprocessor system shown in FIG. 13 is constituted by a plurality of information processing apparatuses 800, 801, . . . , 802 loosely connected together by a connection device 803.
As shown in FIG. 13, after the power source of the first information processing apparatus 800 has been controlled by a power source controlling apparatus (information processing apparatus) 900, the first information processing apparatus 800 becomes a power source controlling apparatus. This power source controlling apparatus refers to the power source turn-on order table shown in FIG. 4 to first instruct the second information processing apparatus 801 to turn on its main power source and to thereafter instruct the third and other information processing apparatuses up to and including the last information providing apparatus 802 to turn on their main power sources. Power is turned on in accordance with the power control sequence shown in FIG. 5 or 6.
FIG. 14 is a diagram showing a cluster system configuration in which an information processing apparatus whose main power source has been controlled sequentially relays the power control to other information processing apparatuses. Specifically, the main power source of a first information processing apparatus 800 is first controlled by a power source controlling apparatus (information processing apparatus) 900. The first information processing apparatus 800 controls the main power source of a second information processing apparatus 801, and the second information processing apparatus 801 controls the main power source of the next information processing apparatus. In this manner, the main power sources of all of the information processing apparatuses up to and including the last information processing apparatus 802 are controlled. For this multi-stage sequential power control, the power control sequence shown in FIG. 7 is used.
FIG. 15 is a diagram showing a cluster system in which the main power sources of information processing apparatuses belonging to a same group are controlled collectively by using an IP multicast address. The main power sources of information processing apparatuses 800, 801, . . . , 802 belonging to a same group are controlled by using an IP multicast address in accordance with the power control sequence shown in FIG. 6.
In the cluster systems shown in FIGS. 13 to 15, they can be handled as if each is a single system.
The present invention is not limited to the above embodiments, but various modifications are possible. For example, instead of providing the remote power source controller operated by an auxiliary power source in each information processing apparatus, it may be provided in another device such as a router. A timer may be connected to the processor bus of the remote power source controller to enable power control to be performed both by the timer and by the remote power source controller. With this arrangement, even if control data cannot be received from the network, the power can be controlled by using the timer. The power control only by the timer may be used. The invention is not limited only to the networks described above, but other various networks may be used for the power control, such as networks operating as open systems via a route of LAN-WAN (wide area network) LAN, a route of WAN-LAN, or other routes.
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Remote power source control for a system having a plurality of information processing apparatuses interconnected by a network or networks capable of controlling remote power sources irrespective of different types of networks and providing security checks. Each information processing apparatus is provided with a remote power source controller which is always operated by an auxiliary power source. In instructing a power control of a remote information processing apparatus, control data is transferred between the remote information processing apparatus and a local information processing apparatus. The remote information processing apparatus checks a user ID and a password transmitted from the local processing apparatus prior to controlling its main power source.
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FIELD OF THE INVENTION
The invention relates generally to the field of magneto-optic recording and erasing and, more particularly, to such recording and erasing utilizing a motorless bias-field device for selectively inverting a bias field for permitting such recording and erasure.
BACKGROUND OF THE INVENTION
In the magneto-optic recording process, a vertically magnetizable recording layer is initially sensitized by simultaneously subjecting it to a uniform magnetic field and a temperature which exceeds its Curie temperature. The magnetic field, being directed perpendicular to the recording layer, serves to uniformly align all of the magnetic domains therewith. Once all the magnetic domains are facing in the same direction, the recording layer is ready to record information. Such recording is effected by subjecting the recording layer to a magnetic field of reverse polarity while scanning the layer with an intensity-modulated laser beam.
During the recording process, a laser beam intensity is switched between high and low levels, representing the digital (binary) information being recorded. Only the high level is sufficiently intense to raise the temperature of the irradiated portion of the recording layer to above its Curie temperature; thus, digital information is recorded at the point of incidence of the laser as the more intensely irradiated magnetic domains flip in orientation to align themselves with the magnetic bias field. Playback of the recorded information is commonly achieved by scanning the information tracks with a plane-polarized beam of radiation and monitoring the reflected beam for shifts in the plane of polarization, as produced by the well known Kerr effect. To erase the recorded information, the polarity of the applied external magnetic field is reversed, and the recording layer is scanned with a beam of sufficient intensity to again heat the recording layer to above its Curie temperature. After this erasure step, all of the irradiated magnetic domains will again face in the same direction.
Various schemes have been proposed to achieve the magnetic field inversions required in switching between the record and erase modes of the magneto-optic recording process. In the disclosures of U.S. Pat. Nos. 5,020,042 and 5,291,345, for example, the field inversion apparatus consists of a magnetic field producing coil surrounding a cylindrical bipolar magnet. One pole of the magnet is placed adjacent the recording medium for inducing its particular magnetization to the recording medium, and when the coil is energized, the field that the coil creates imparts a torque to the magnet forcing it to rotate for causing the other pole of the magnet to be adjacent the recording medium.
Although the presently known and utilized device is satisfactory, it is not without drawbacks. The coils are not energy efficient because they consume a substantial amount of energy.
Consequently, a need exists in the construction and mode of operating the bias-field device.
SUMMARY OF THE INVENTION
The present invention is directed to overcoming one or more of the problems set forth above. Briefly summarized, according to one aspect of the present invention, the invention resides in a bias-field device for a magneto-optical system having a magneto-optical recording element which includes a conductive substrate and which moves through a magnetic field created by the bias-field device so that information is selectively recorded on or erased from the recording element, the device comprising: (a) a rotatable magnet that rotates so that when the recording element rotates the conductive substrate creates a magnetic coupling with the magnet for causing said magnet to rotate; and (b) an escapement mechanism that releases and latches said magnet for permitting said magnet to be selectively rotated.
It is an object of the present invention to provide a bias-field device for overcoming the above-described drawbacks.
It is also an object of the present invention to provide an energy efficient and motorless bias field device.
It is an advantage of the present invention to provide a cost efficient bias-field device.
It is a further advantage of the present invention to provide a bi-directional bias-field device for selectively inverting the magnetic bias field.
These and other aspects, objects, features and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims, and by reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a portion of the bias field device of the present invention in the presence of a conductive media substrate;
FIG. 2 is an exploded view of the bias-field device of the present invention illustrating its assembly;
FIG. 3 is a perspective view of the bias-field device of the present invention; and
FIG. 4 is a side view of the escapement mechanism of the bias-field device.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, there is illustrated a magneto-optic recording element as shown in the form of a disk 10 which is adapted to be rotated about its central axis x. The essential features of the recording element are a vertically magnetizable recording layer 20 and a supporting substrate 30. The supporting substrate is made of a conductive material, preferably aluminum. During the recording step, the recording layer 20 is selectively heated by a beam of radiation, as provided by a laser source 35. The beam intensity is modulated by an information source (not shown) representing certain digital information which is to be recorded. The information source functions to switch the beam intensity of the laser source 35 between high and low levels, only the high level being sufficient to heat the recording layer 20 to at least its Curie temperature. A bias field device (only the magnet of which is shown in FIG. 1) includes a magnet 50 both having north and south poles oriented along their cross-sectional dimension, and is radially disposed with respect to the rotating disk 10 for providing a magnetic bias-field at recording layer 20. Although the preferred embodiment illustrates a magnet with one north and one south pole, the magnet may include a plurality of north and south poles. The magnet 50 is mounted for rotational movement, as will be described in detail below, so that the direction of the field under the desired location on the recording medium 10 may be switched from the downward direction in which one pole of magnet 50 (for example the north pole) is beneath the write/erase spot on recording layer 20 to an upward direction in which the magnet 50 is rotated so that south pole of magnet 50 is beneath the write/erase spot on recording layer 20. The reversal of poles of magnet 50 will cause magnetic domains in the recording element to flip orientations, e.g., from upward to downward, whenever the laser beam intensity is at its high level. In this manner, the digital information provided by the laser source 35 is magnetically recorded in the recording layer 20.
To erase the previously recorded information in the recording layer 20, the direction of the magnetic bias field is inverted. After such field inversion, the laser source 35 scans the recording element while its intensity is maintained at its high level. While so radiated, all of the magnetic domains align themselves with the bias field thereby providing a uniformly sensitized disk or track which is again ready to record information.
Referring to FIGS. 2 and 3, there are illustrated two views of the bias field device 60 of the present invention. The bias field device 60 includes a housing 70 having two retaining members 80 each having a hollowed-out interior portion 90 for partially enclosing the magnet 50. Each retaining member 80 includes two semi circular-shaped, hollowed out portions 100 that each respectively align with a corresponding hollowed out portion 100 on the other retaining member 80 which, when aligned together, form a bore through which two necks 110 of the magnet 50 respectively extend. The neck 110b includes a disk 120 having two lip portions 130 extending therefrom, which lip portions 130 interact with a escapement plate 140, as will be described in detail hereinbelow. The other neck 110a includes a ring 150 which matingly fits against the exterior portion of an end of the housing 70.
An escapement mechanism 160 includes the plate 140 having three prongs 170 positioned on its interior portion against which the lip portions 130 rest for inhibiting rotation of the magnet 50, as will be discussed in detail below. A solenoid 180 is attached to the plate 140 and includes a movable shaft 190 which is retracted when it is energized with direct current by a current source (not shown). A bracket 200 is attached to the shaft 190 at one of its ends and to the plate 140 at its other for providing structural attachment between the solenoid 180 and plate 140. Two deformable springs 210 are respectively attached to a side of the housing 70 at one of their ends and to the plate 140 at their other end.
The springs 210 are respectively attached to the housing 70 via two attachments devices 220. One attachment device 220a includes two support members 230 which are placed abutting each other, and each support member 230 includes two holes 240 therethrough which are respectively in alignment with the holes (240a and 240d; 240b and 240c) in the other support member and in alignment with two holes 250 in the spring. The spring 210a is placed against the housing 70, and with the two support members 230a and 230b disposed on the other side of the spring 210a, a screw 260 is inserted into each triplicate set of aligned holes (240a, 240d, 250b aligned together; 240b, 240c, and 250a aligned together) for attaching the spring 210a to the housing 70. The spring 210a further includes two holes 270 at its other end into which two screws are inserted therethrough and eventually into a pair of holes (not shown) in the plate 140 for attaching the bracket 200 to the plate 140. The bracket 200 also includes a hole 290 which is in registry with a pair of holes 300 (only one of which is shown) in the shaft 190, and a pin 305 is placed into the aligned holes 300 and 290 for attaching the bracket 200 to the shaft 190.
The other attachment device 220b also includes two support plates 310 between which the spring 210b rests and the plates 310 and spring 210 also include a triplicate set of aligned holes (320b, 340a, 320c; 320a, 340b and 320d)as in the other attachment device. With plate 310b resting against the housing 70, a screw 350 is inserted into each triplicate set of aligned holes for attaching the spring 210b on the housing 70. The spring 210b also includes two holes 360 which are respectively in alignment with two holes 370 in a support structure 380, and a screw 390 is inserted into each pair of aligned holes (360a and 370a; 360b and 370b) for permitting each screw 390 to be respectively placed in a pair of holes 400 in the plate 140 for attaching the spring 210b to the plate 140.
Referring to FIGS. 3 and 4, there is illustrated the operation of the escapement mechanism 160. For purposes of illustration, the disk 10 is rotating in the direction illustrated by the arrow which causes the conductive substrate 30 to induce a force on the magnet 50 as illustrated by the arrows. When rotation of the magnet 50 is not desired, the shaft 190 of the solenoid 180 is fully extended outwardly so that the prong 170a contacts the lip portion 130a thereby prohibiting rotation, as illustrated by the lip portion 130a in solid lines. When rotation of the magnet 50 is desired, the solenoid 180 is energized so that the shaft 190 is retracted for permitting the lip portion 130a to rotate, as illustrated by the dashed lines. The opposite lip portion 130b rotates until it contacts the prong 170b, as also illustrated by the dashed lines. This permits control of rotation of the magnet 50 so that approximately one hundred eighty degree rotation of the magnet 50 is permitted and so that multiple rotations of the magnet 50 are eliminated. The solenoid 180 is then de-energized so that the prongs 170 return to their original position. This permits the lip portion 130b to rotate until it contacts the prong 170a so that it is disposed in the original position of lip portion 130a, and lip portion 130a rotates to the original position of lip portion 130b. The hereinabove described process permits the opposite polarity pole of the magnet 50 to be adjacent the disk. This process is repeated when the original polarity of the magnet 50 pole is desired to be adjacent the disk 10.
It is instructive to note that, when the disk 10 rotates in the opposite direction, the induced rotation on the magnet 50 is in the opposite direction from that illustrated by the arrows. In this case, the lip portion 130b is prohibited from rotation by the prong 170a, and the one hundred eighty degree rotation of the magnet is permitted by retracting the shaft 180, as discussed hereinabove. It is readily apparent to those skilled in the art that the interaction of the prongs 170 and lip portions 130 are in a different configuration from rotation in the opposite direction for prohibiting, permitting and controlling rotation of the magnet 50. It is instructive to note that the disk 120 may be divided into two distinct disks for the purposes of achieving precisely one hundred eighty degree rotation.
The preferred embodiment has been illustrated utilizing a two pole magnet. As those skilled in the art will recognize, if a plurality of poles are utilized, the quantity of lip portions 130 would be correspondingly increased according to the number of poles, and the rotation between positions would be correspondingly less than one hundred eighty degrees.
The invention has been described with reference to a preferred embodiment. However, it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the invention.
Parts List
10 disk
20 recording layer
30 substrate
35 laser source
50 magnet
60 bias field device
70 housing
80 retaining members
90 interior portion
100 hollowed out portions
110 two necks
110a neck
110b neck
120 disk
130 lip portions
130a lip portion
130b lip portion
140 escapement plate
150 ring
160 escapement mechanism
170 prongs
170a prong
170b prong
180 solenoid
190 shaft
200 bracket
210 springs
210a spring
210b spring
220 attachment devices
220a attachment device
220b attachment device
230 support members
230a support members
Parts List (cont'd)
230b support members
240 two holes
240a hole
240b holes
240c hole
240d hole
250 two holes
250a hole
250b hole
260 pin
270 two holes
280 screws
290 hole
300 pair of holes
305 pin
310 support plates
310b plate
320a hole
320b hole
320c hole
320d hole
340a hole
340b hole
350 screw
360 two holes
360a hole
36b hole
370 two holes
370a hole
370b hole
380 support structure
390 screw
400 pair of holes
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A bias-field device for a magneto-optical system having a magneto-optical recording element which includes a conductive substrate and which moves through a magnetic field created by the bias-field device so that information is selectively recorded on or erased from the recording element, the device comprises: a rotatable magnet that rotates so that when the recording element rotates the conductive substrate creates a magnetic coupling with the magnet for causing the magnet to rotate; and an escapement mechanism that releases and latches the magnet for permitting the magnet to be selectively rotated.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an interpolation method performed in the transmission of sound in a packet-switching network.
[0003] 2. Description of the Related Art
[0004] In the transmission of audit signals via VoIP (Voice over Internet Protocol), packet loss often occurs. The occurrence of the packet loss causes the intermittence of sound, and thus substantially deteriorates the sound quality. To prevent such deterioration of the sound quality, a concealment process has been performed which conceals the loss of an audio signal by performing interpolation for the lost packet. Specifically, the interpolation process for the lost packet is based on ITU-T (International Telecommunication Union Telecommunication Standardization Sector) Recommendation G.711 Appendix 1. The interpolation process based on G.711 Appendix 1 is a process of performing interpolation for the packet loss by calculating the period of a signal immediately preceding the lost packet and repeating the signal with the calculated period while gradually reducing the amplitude of the signal.
[0005] In conventional interpolation processes for the packet loss, such as the one based on G.711 Appendix 1, however, there is an issue of abnormal sound occurring due to an unnatural period generated when the signal immediately preceding the packet loss is a signal having a small periodicity, such as the signal of a consonant, background noise, and so forth. An example of the conventional interpolation processes is disclosed in the publication of International Patent Application Publication No. 2004-068098.
SUMMARY
[0006] According to an aspect of an embodiment, a method for interpolating a partial loss of an audio signal including a sound signal component and a background noise component in transmission thereof, the method comprising the steps of: calculating frequency characteristic of the background noise in the audio signal; extracting the sound signal component from the audio signal; generating pseudo noise by applying the frequency characteristic of the background noise included in the audio signal to white noise; and generating an interpolation signal by combining the pseudo noise with the extracted sound signal component included in the audio signal to supersede the partial loss of the audio signal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a configuration diagram of an information processing device according to one of embodiments of the present invention;
[0008] FIG. 2 is a configuration diagram of an information processing device according to another one of the present embodiments;
[0009] FIG. 3 is a configuration diagram of an information processing device according to another one of the present embodiments;
[0010] FIG. 4 is a configuration diagram of an information processing device according to another one of the present embodiments;
[0011] FIG. 5 is a configuration diagram of an information processing device according to another one of the present embodiments;
[0012] FIG. 6 is a configuration diagram of an information processing device according to another one of the present embodiments;
[0013] FIG. 7 is a configuration diagram of an information processing device according to another one of the present embodiments;
[0014] FIG. 8 is a flowchart of an interpolation process performed by the information processing devices according to the present embodiments;
[0015] FIG. 9 is a flowchart illustrating a processing procedure for calculating the frequency characteristic of background noise performed by analysis unit according to the present embodiments;
[0016] FIG. 10 is a flowchart of a procedure for calculating a sound component performed by the analysis unit according to one of the present embodiments;
[0017] FIG. 11 is a flowchart of a procedure for calculating the envelope of sound and the sound source of the sound performed by the analysis unit according to another one of the present embodiments;
[0018] FIG. 12 is a flowchart of a procedure for calculating the envelope pattern of the sound performed by the analysis unit according to another one of the present embodiments;
[0019] FIG. 13 is a flowchart of a procedure for generating pseudo sound performed by pseudo sound generation unit according to one of the present embodiments;
[0020] FIG. 14 is a schematic diagram illustrating a connection relationship between repeating signal segments according to one of the present embodiments;
[0021] FIG. 15 is a flowchart of a procedure for generating the pseudo sound performed by pseudo sound generation unit according to another one of the present embodiments;
[0022] FIG. 16 is a flowchart of a procedure for generating the pseudo sound performed by pseudo sound generation unit according to another one of the present embodiments;
[0023] FIG. 17 is a flowchart illustrating a procedure for generating pseudo noise performed by pseudo noise generation unit according to one of the present embodiments;
[0024] FIG. 18 is a flowchart of a procedure for generating the pseudo noise performed by pseudo noise generation unit according to another one of the present embodiments;
[0025] FIG. 19 is a flowchart of a procedure for generating an output signal performed by output signal generation unit according to the present embodiments;
[0026] FIG. 20 is a flowchart illustrating a first procedure for calculating the amplitude coefficient performed by output signal generation unit according to the present embodiments;
[0027] FIG. 21 is a flowchart illustrating a second procedure for calculating the amplitude coefficient performed by the output signal generation unit according to the present embodiments; and
[0028] FIG. 22 is a flowchart illustrating a process for determining the deterioration of the pseudo sound performed by the output signal generation unit according to the present embodiments.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] In embodiments of the present invention, information processing devices 100 to 700 perform interpolation for an audio signal lost by a transmission error occurring in VoIP or the like. Functional configurations of the information processing devices 100 to 700 are illustrated in FIGS. 1 to 7 .
[0030] The information processing devices 100 to 700 calculate pseudo sound of sound included in an input signal and pseudo noise imitating background noise included in the input signal. The information processing devices 100 to 700 perform interpolation for a packet loss by using an interpolation signal formed by the combination of the pseudo sound and the pseudo noise. Further, the information processing devices 100 to 700 can separately control the pseudo sound and the pseudo noise. Accordingly, the information processing devices 100 to 700 can generate an interpolation signal having high sound quality. The signal loss for which the interpolation is performed by the information processing devices 100 to 700 according to the present embodiments includes, for example, a packet loss caused by congestion of a network, an error occurring on a network line, and an encoding error occurring in encoding an audio signal.
[0031] With reference to FIGS. 1 to 7 , an overview of functions of the information processing devices 100 to 700 will be described below.
Configuration Diagram of Information Processing Device 100
[0032] FIG. 1 is a configuration diagram of the information processing device 100 according to one of the present embodiments.
[0033] The information processing device 100 is constituted by analysis unit 101 , pseudo sound generation unit 102 , pseudo noise generation unit 103 , and output signal generation unit 104 . Furthermore, the information processing device 100 includes a receiving unit for receiving an audio signal and an output unit for outputting an interpolation signal, and the receiving unit and the output unit are not shown in FIG. 1 . Information processing device 200 to 700 includes a receiving unit and an output unit as well and each receiving unit and output unit are not shown in FIGS. 1 to 7 . The information processing device 100 is also able to perform a process for interpolating the audio signal in a firmware executed on a CPU mounted on the information processing device 100 . The information processing devices 200 to 700 are able to perform a process for interpolating the audio signal in a firmware executed on a CPU as well.
[0034] The analysis unit 101 calculates the feature quantity of sound and the feature quantity of noise on the basis of error information and an input signal of a normal section input from outside the information processing device 100 . Herein, the error information refers to the information representing the section in which the packet loss has occurred in the transmission of sound. The feature quantity of the sound includes, for example, a sound component of the audio signal, the envelope of the sound component, and the pattern of change in the envelope of the sound component. Further, the feature quantity of the background noise includes, for example, the frequency characteristic of the background noise. Specific examples of the feature quantity of the sound and the feature quantity of the background noise will be described in the description of the information processing devices 200 to 700 illustrated in FIGS. 2 to 7 .
[0035] Then, the analysis unit 101 inputs the feature quantity of the sound to the pseudo sound generation unit 102 . The pseudo sound generation unit 102 generates the pseudo sound on the basis of the feature quantity of the sound.
[0036] Further, the analysis unit 101 inputs the feature quantity of the noise to the pseudo noise generation unit 103 . The pseudo noise generation unit 103 generates the pseudo noise on the basis of the feature quantity of the noise.
[0037] The pseudo sound generation unit 102 inputs the pseudo sound to the output signal generation unit 104 . The pseudo noise generation unit 103 inputs the pseudo noise to the output signal generation unit 104 . Further, the analysis unit 101 inputs the feature quantity of the sound and the feature quantity of the noise to the output signal generation unit 104 . The output signal generation unit 104 acquires the error information and the input signal from outside the information processing device 100 . Then, the output signal generation unit 104 generates an output signal. Configuration diagram of information processing device 200
[0038] FIG. 2 is a configuration diagram of the information processing device 200 according to one of the present embodiments.
[0039] The information processing device 200 is constituted by analysis unit 201 , pseudo sound generation unit 202 , pseudo noise generation unit 203 , and output signal generation unit 204 .
[0040] The analysis unit 201 calculates the feature quantity of the sound and the feature quantity of the noise on the basis of the error information and the input signal of the normal section input from outside the information processing device 200 .
[0041] Then, the analysis unit 201 inputs the feature quantity of the sound to the pseudo sound generation unit 202 . The pseudo sound generation unit 202 generates the pseudo sound on the basis of the feature quantity of the sound.
[0042] Further, the analysis unit 201 inputs the frequency characteristic of the background noise to the pseudo noise generation unit 203 . The frequency characteristic of the background noise include, for example, the power spectrum, the impulse response, and the filter coefficient of the background noise. Herein, the analysis unit 201 calculates the frequency characteristic of the background noise in accordance with a processing procedure illustrated in FIG. 9 . The pseudo noise generation unit 203 generates the pseudo noise on the basis of the frequency characteristic of the background noise. For example, the pseudo noise generation unit 203 generates white noise. Then, the pseudo noise generation unit 203 generates the pseudo noise by applying the frequency characteristic of the background noise to the white noise. Alternatively, the pseudo noise generation unit 203 may be configured to previously hold the white noise. Herein, the pseudo noise generation unit 203 generates the pseudo noise in accordance with a processing procedure illustrated in FIG. 17 .
[0043] The pseudo sound generation unit 202 inputs the pseudo sound to the output signal generation unit 204 . The pseudo noise generation unit 203 inputs the pseudo noise to the output signal generation unit 204 . Further, the analysis unit 201 inputs the feature quantity of the sound and the feature quantity of the noise to the output signal generation unit 204 . The output signal generation unit 204 acquires the error information and the input signal from outside the information processing device 200 . Then, the output signal generation unit 204 generates the output signal.
Configuration Diagram of Information Processing Device 300
[0044] FIG. 3 is a configuration diagram of the information processing device 300 according to one of the present embodiments.
[0045] In the information processing device 300 , analysis unit 301 specifically calculates the power spectrum of the background noise as the feature quantity of the noise.
[0046] The information processing device 300 is constituted by the analysis unit 301 , pseudo sound generation unit 302 , pseudo noise generation unit 303 , and output signal generation unit 304 .
[0047] The analysis unit 301 calculates the feature quantity of the sound and the power spectrum of the background noise on the basis of the error information and the input signal of the normal section input from outside the information processing device 300 . The analysis unit 301 calculates the power spectrum of the background noise in accordance with the processing procedure illustrated in FIG. 9 .
[0048] Then, the analysis unit 301 inputs the feature quantity of the sound to the pseudo sound generation unit 302 . The pseudo sound generation unit 302 generates the pseudo sound on the basis of the feature quantity of the sound.
[0049] Further, the analysis unit 301 inputs the power spectrum of the background noise to the pseudo noise generation unit 303 . The pseudo noise generation unit 303 generates the pseudo noise by providing a random phase to the power spectrum of the background noise and calculating a signal of the time domain through frequency-to-time conversion. Specifically, the pseudo noise generation unit 303 generates the pseudo noise in accordance with a processing procedure illustrated in FIG. 18 .
[0050] The pseudo sound generation unit 302 inputs the pseudo sound to the output signal generation unit 304 . The pseudo noise generation unit 303 inputs the pseudo noise to the output signal generation unit 304 . Further, the analysis unit 301 inputs the feature quantity of the sound and the feature quantity of the noise to the output signal generation unit 304 . The output signal generation unit 304 acquires the error information and the input signal from outside the information processing device 300 . Then, the output signal generation unit 304 generates the output signal.
Configuration Diagram of Information Processing Device 400
[0051] FIG. 4 is a configuration diagram of the information processing device 400 according to one of the present embodiments.
[0052] In the information processing device 400 according to the present embodiment, analysis unit 401 calculates the periodicity of the input signal.
[0053] The information processing device 400 is constituted by the analysis unit 401 , pseudo sound generation unit 402 , pseudo noise generation unit 403 , and output signal generation unit 404 . The information processing device 400 generates the pseudo sound by repeating the input signal with the length of an integral multiple of the period of the input signal.
[0054] The analysis unit 401 calculates the periodicity of the input signal and the feature quantity of the noise on the basis of the error information and the input signal of the normal section input from outside the information processing device 400 .
[0055] Then, the analysis unit 401 inputs the input signal and the periodicity of the input signal to the pseudo sound generation unit 402 . The analysis unit 401 calculates the autocorrelation coefficient of the input signal from Formula (F3). The analysis unit 401 calculates, as the period, the length of a displacement position of the signal for maximizing the autocorrelation coefficient. The procedure for calculating the periodicity will be described later.
[0056] On the basis of the input signal and the periodicity of the input signal, the pseudo sound generation unit 402 generates the pseudo sound by repeating the input signal with the length of the integral multiple of the period. Further, the analysis unit 401 inputs the feature quantity of the noise to the pseudo noise generation unit 403 . The pseudo noise generation unit 403 generates the pseudo noise on the basis of the feature quantity of the noise.
[0057] The pseudo sound generation unit 402 inputs the pseudo sound to the output signal generation unit 404 . The pseudo noise generation unit 403 inputs the pseudo noise to the output signal generation unit 404 . Further, the analysis unit 401 inputs the periodicity of the input signal and the feature quantity of the noise to the output signal generation unit 404 . The output signal generation unit 404 acquires the error information and the input signal from outside the information processing device 400 . Then, the output signal generation unit 404 generates the output signal.
Configuration Diagram of Information Processing Device 500
[0058] FIG. 5 is a configuration diagram of the information processing device 500 according to one of the present embodiments.
[0059] The information processing device 500 is constituted by analysis unit 501 , pseudo sound generation unit 502 , pseudo noise generation unit 503 , and output signal generation unit 504 .
[0060] The information processing device 500 generates the pseudo sound by repeating the sound component included in the input signal with the length of an integral multiple of the period of the sound component.
[0061] The analysis unit 501 calculates the sound component included in the input signal, the periodicity of the sound component, and the feature quantity of the noise on the basis of the error information and the input signal of the normal section input from outside the information processing device 500 .
[0062] Then, the analysis unit 501 inputs the sound component and the periodicity of the sound component to the pseudo sound generation unit 502 . The pseudo sound generation unit 502 generates the pseudo sound by repeating the sound component with the length of the integral multiple of the period of the sound component. The analysis unit 501 calculates the sound component in accordance with a procedure for calculating the sound component illustrated in FIG. 10 . Further, the analysis unit 501 calculates the autocorrelation coefficient of the sound component from Formula (F3). The analysis unit 501 calculates, as the period of the sound component, the length of a displacement position of the signal for maximizing the autocorrelation coefficient.
[0063] Further, the analysis unit 501 inputs the feature quantity of the noise to the pseudo noise generation unit 503 . The pseudo noise generation unit 503 generates the pseudo noise on the basis of the feature quantity of the noise.
[0064] The pseudo sound generation unit 502 inputs the pseudo sound to the output signal generation unit 504 . The pseudo noise generation unit 503 inputs the pseudo noise to the output signal generation unit 504 . Further, the analysis unit 501 inputs the periodicity of the sound component and the feature quantity of the noise to the output signal generation unit 504 . The output signal generation unit 504 acquires the error information and the input signal from outside the information processing device 500 . Then, the output signal generation unit 504 generates the output signal.
Configuration Diagram of Information Processing Device 600
[0065] FIG. 6 is a configuration diagram of the information processing device 600 according to one of the present embodiments.
[0066] The information processing device 600 is constituted by analysis unit 601 , pseudo sound generation unit 602 , pseudo noise generation unit 603 , and output signal generation unit 604 .
[0067] The information processing device 600 generates the pseudo sound by repeating the sound source of the sound included in the input signal with the length of an integral multiple of the period of the sound source and applying the envelope of the sound to the sound source. The analysis unit 601 calculates the envelope of the sound and the sound source of the sound in accordance with a procedure for calculating the envelope of the sound and the sound source of the sound, which is illustrated in FIG. 11 .
[0068] The analysis unit 601 calculates the envelope of the sound included in the input signal, the sound source of the sound, the periodicity of the sound source of the sound, and feature quantity of the noise on the basis of the error information and the input signal of the normal section input from outside the information processing device 600 .
[0069] Then, the analysis unit 601 inputs the envelope of the sound, the sound source of the sound, and the periodicity of the sound source of the sound to the pseudo sound generation unit 602 . The pseudo sound generation unit 602 generates the pseudo sound by repeating the sound source of the sound included in the input signal with the length of the integral multiple of the period of the sound source of the sound and applying the envelope of the sound to the sound source. Further, the analysis unit 601 inputs the feature quantity of the noise to the pseudo noise generation unit 603 . The pseudo noise generation unit 603 generates the pseudo noise on the basis of the feature quantity of the noise.
[0070] The pseudo sound generation unit 602 inputs the pseudo sound to the output signal generation unit 604 . The pseudo noise generation unit 603 inputs the pseudo noise to the output signal generation unit 604 . Further, the analysis unit 601 inputs the periodicity of the sound source of the sound and the feature quantity of the noise to the output signal generation unit 604 . The output signal generation unit 604 acquires the error information and the input signal from outside the information processing device 600 . Then, the output signal generation unit 604 generates the output signal.
Configuration Diagram of Information Processing Device 700
[0071] FIG. 7 is a configuration diagram of the information processing device 700 according to one of the present embodiments.
[0072] The information processing device 700 is constituted by analysis unit 701 , pseudo sound generation unit 702 , pseudo noise generation unit 703 , and output signal generation unit 704 .
[0073] The information processing device 700 generates the pseudo sound by repeating the sound source of the sound included in the input signal with the length of an integral multiple of the period of the sound source of the sound and applying to the sound source the pattern of change in the envelope of the sound.
[0074] The analysis unit 701 calculates the pattern of change in the envelope of the sound included in the input signal, the sound source of the sound, the periodicity of the sound source of the sound, and the feature quantity of the noise on the basis of the error information and the input signal of the normal section input from outside the information processing device 700 . The analysis unit 701 calculates the envelope of the sound and the sound source of the sound in accordance with the procedure for calculating the envelope of the sound and the sound source of the sound, which is illustrated in FIG. 11 . Further, the analysis unit 701 calculates the pattern of change in the envelope of the sound in accordance with a procedure for calculating the pattern of change in the envelope of the sound, which is illustrated in FIG. 12 .
[0075] Then, the analysis unit 701 inputs the pattern of change in the envelope of the sound, the sound source of the sound, and the periodicity of the sound source of the sound to the pseudo sound generation unit 702 . The pseudo sound generation unit 702 generates the pseudo sound by repeating the sound source of the sound included in the input signal with the length of the integral multiple of the period of the sound source of the sound and applying to the sound source the pattern of change in the envelope of the sound. Further, the analysis unit 701 inputs the feature quantity of the noise to the pseudo noise generation unit 703 . The pseudo noise generation unit 703 generates the pseudo noise on the basis of the feature quantity of the noise.
[0076] The pseudo sound generation unit 702 inputs the pseudo sound to the output signal generation unit 704 . The pseudo noise generation unit 703 inputs the pseudo noise to the output signal generation unit 704 . Further, the analysis unit 701 inputs the periodicity of the sound source of the sound and the feature quantity of the noise to the output signal generation unit 704 . The output signal generation unit 704 acquires the error information and the input signal from outside the information processing device 700 . Then, the output signal generation unit 704 generates the output signal.
Procedure of Interpolation Process by Information Processing Devices 100 to 700
[0077] FIG. 8 is a flowchart of the interpolation process performed by the information processing devices 100 to 700 illustrated in FIGS. 1 to 7 . The flowchart of the interpolation process illustrates schematic process steps performed by the information processing devices 100 to 700 .
[0078] The information processing devices 100 to 700 are devices for performing the interpolation for the signal loss occurring in the transmission of sound through digital signals. Particularly, the information processing devices 100 to 700 according to the present embodiments are devices for performing the interpolation for the packet loss occurring in the transmission of sound in a packet switching network. Further, the information processing devices 100 to 700 receive the input signal frame by frame.
[0079] The information processing devices 100 to 700 receive the error information and the input signal of the current frame input to the information processing devices 100 to 700 (Step 801 ). The input signal is a frame-by-frame digital signal representing the sound and the background noise.
[0080] The information processing devices 100 to 700 determine the presence or absence of an error in the current frame on the basis of the error information (Step 802 ). The error information is the information representing the section in which the packet loss has occurred. The presence of the error indicates that the packet loss has occurred in the input signal, i.e., the packet is “absent.”
[0081] If the information processing devices 100 to 700 determine the absence of the error in the current frame (NO at Step 802 ), the information processing devices 100 to 700 analyze the input signal (Step 803 ). More specifically, the analysis unit 101 to 701 included in the information processing devices 100 to 700 analyze the input signal to calculate the feature quantity of the sound and the feature quantity of the background noise. The information processing devices 100 to 700 generate the pseudo sound and the pseudo noise (Steps 804 and 805 ). Then, the information processing devices 100 to 700 generate the output signal by combining together the pseudo sound and the pseudo noise (Step 806 ).
[0082] If the information processing devices 100 to 700 determine the presence of the error in the current frame (YES at Step 802 ), the information processing devices 100 to 700 generate the pseudo sound (Step 804 ). Then, the information processing devices 100 to 700 generate the pseudo noise (Step 805 ). The information processing devices 100 to 700 generate the output signal by combining (superimposing) together the pseudo sound and the pseudo noise (Step 806 ).
[0083] The information processing devices 100 to 700 generate the pseudo sound and the pseudo noise irrespective of the presence or absence of the packet loss (the presence or absence of the error). Then, if the packet loss is absent, the information processing devices 100 to 700 output the input signal as the output signal (see Step 1905 in FIG. 19 ). Frequency characteristic of background noise
[0084] FIG. 9 is a flowchart illustrating the processing procedure for calculating the frequency characteristic of the background noise performed by the analysis unit 101 to 701 according to the present embodiments.
[0085] The analysis unit 101 to 701 perform the detection of the sound in the input signal (Step 901 ). Specifically, the analysis unit 101 to 701 perform the detection of the sound in the input signal by comparing the power of the frame with the average power of the noise. Then, the analysis unit 101 to 701 determine whether or not the sound has been detected (Step 902 ). If the analysis unit 101 to 701 have detected the sound (YES at Step 902 ), the analysis unit 101 to 701 calculate the power spectrum of the background noise (Step 905 ). The calculation of the power spectrum of the background noise is also performed when the analysis unit 101 to 701 have not detected the sound (NO at Step 902 ). In this case, the analysis unit 101 to 701 perform time-to-frequency conversion on the input signal (Step 903 ). Specifically, the analysis unit 101 to 701 perform fast Fourier transform or the like. The time-to-frequency conversion is conversion in which the input signal is decomposed for each frequency and converted from the time domain to the frequency domain. Similarly, the frequency-to-time conversion described later is conversion for converting the input signal from the frequency domain to the time domain. The analysis unit 101 to 701 calculate the power spectrum of the input signal (the current frame) from Formula (F1) (Step 904 ). Herein, p i , re i , and im i represent the power spectrum (dB) of the i-th band, the real part (dB) of the spectrum of the i-th band, and the imaginary part (dB) of the spectrum of the i-th band, respectively.
[0086] Formula 1
[0000] p i =p i =10 log 10 re i 2 +im i 2 (F1)
[0087] Then, the analysis unit 101 to 701 calculate the power spectrum of the background noise (Step 905 ). The analysis unit 101 calculates the power spectrum of the background noise of the current frame by weighting and averaging the power spectrum of the current frame and the power spectrum of the background noise of the preceding frame. If the analysis unit 101 to 701 have detected the sound (YES at Step 902 ), the power spectrum of the background noise of the current frame is calculated to be equal to the power spectrum of the background noise of the preceding frame. Herein, n i , prev_n i , and coef represent the power spectrum (dB) of the background noise of the i-th band, the power spectrum (dB) of the background noise of the i-th band in the preceding frame, and the weighting factor of the current frame, respectively.
[0088] Formula 2
[0000] n i =prev — n i *(1−coef)+ p 1 *coef (F2)
[0089] Alternatively, the analysis unit 101 to 701 may determine the frequency characteristic of the background noise by using an adaptation algorithm, such as a learning identification method. That is, the analysis unit 101 to 701 may calculate the frequency characteristic of the background noise as the filter coefficient learned to minimize the error between the filtered white noise and the background noise.
Procedure for Calculating Periodicity
[0090] The periodicity calculated by the analysis unit 101 to 701 is the periodicity of the input signal, the signal of the sound component, or the sound source of the sound. In the present embodiments, the periodicity refers to the period of the target signal (the input signal, the signal of the sound component, or the sound source of the sound) and the strength of the periodicity. In the present embodiments, the strength of the periodicity is represented by the value of the maximum autocorrelation coefficient. The analysis unit 101 to 701 calculate the autocorrelation coefficient of the target signal from Formula (F3). Then, the analysis unit 101 to 701 calculate, as the period, the length of a displacement position of the signal for maximizing the autocorrelation coefficient. Herein, the period and the periodicity are represented as a_max and MAX(corr(a)), respectively. Further, x, M, and a represent the target signal for which the periodicity is calculated, the length (the sample) of the section for which the correlation coefficient is calculated, and the start position of the signal for which the correlation coefficient is calculated, respectively. Further, corr(a), a_max, and i represent the correlation coefficient obtained when the displacement position is represented by the value a, the value of a corresponding to the maximum correlation coefficient (the position maximizing the autocorrelation coefficient), and the index (the sample) of the signal, respectively.
[0091] Formula 3
[0000]
corr
(
a
)
=
∑
i
=
0
M
-
1
x
(
i
-
a
)
x
(
i
)
∑
i
=
0
M
-
1
x
(
i
-
a
)
2
∑
i
=
0
M
-
1
x
(
i
)
2
(
F3
)
Procedure for Calculating Sound Component
[0092] The analysis unit 501 illustrated in FIG. 5 calculates the sound component of the input signal. FIG. 10 is a flowchart of the procedure for calculating the sound component performed by the analysis unit 501 according to one of the present embodiments. Description will be made below of the procedure for calculating the sound component of the input signal performed by the analysis unit 501 .
[0093] The analysis unit 501 receives the input signal input to the information processing device 500 , and performs the detection of the sound and the calculation of the power spectrum of the background noise (Step 1001 ). The detection of the sound and the calculation of the power spectrum of the background noise are performed in accordance with the processing procedure for calculating the frequency characteristic of the background noise illustrated in FIG. 9 .
[0094] Then, the analysis unit 501 determines whether or not the sound has been detected in the current frame (Step 1002 ). If the analysis unit 501 has detected the sound in the current frame (YES at Step 1002 ), the analysis unit 501 performs the time-to-frequency conversion on the input signal (Step 1003 ). The analysis unit 501 calculates the power spectrum of the input signal (Step 1004 ). The power spectrum of the input signal is calculated from Formula (F1) The analysis unit 501 calculates the power spectrum of the sound (Step 1005 ). The analysis unit 501 calculates the power spectrum of the sound by subtracting the power spectrum of the background noise calculated at Step 1001 from the power spectrum of the input signal calculated at Step 1004 . Alternatively, the analysis unit 501 may be configured to calculate the power spectrum of the sound component by calculating the SNR (signal-to-noise ratio) from the ratio between the power spectrum of the input signal and the power spectrum of the background noise and determining the ratio of the sound component included in the input signal in accordance with the SNR.
[0095] The analysis unit 501 performs the frequency-to-time conversion on the power spectrum of the sound (Step 1006 ). In the present embodiment, inverse Fourier transform is performed as the frequency-to-time conversion. Accordingly, the analysis unit 501 obtains, as the sound component, the signal converted to the time domain.
[0096] Further, if the analysis unit 501 has not detected the sound in the current frame (NO at Step 1002 ), the analysis unit 501 completes the process of calculating the sound component of the input signal.
Procedure for Calculating Envelope of Sound and Sound Source of Sound
[0097] The analysis unit 601 and 701 illustrated in FIGS. 6 and 7 calculate the envelope of the sound in the input signal and the sound source of the sound. FIG. 11 is a flowchart of the procedure for calculating the envelope of the sound and the sound source of the sound performed by the analysis unit 601 and 701 each according to one of the present embodiments.
[0098] The analysis unit 601 and 701 receive the input signal input to the information processing devices 600 and 700 , respectively (Step 1101 ). The analysis unit 601 and 701 perform the time-to-frequency conversion on the input signal (Step 1102 ). Then, the analysis unit 601 and 701 calculate the logarithmic power spectrum of the input signal (Step 1103 ).
[0099] The analysis unit 601 and 701 perform the frequency-to-time conversion on the logarithmic power spectrum of the input signal (Step 1104 ). The analysis unit 601 and 701 extract high quefrency components and low quefrency components from a signal obtained through the frequency-to-time conversion performed on the logarithmic power spectrum of the input signal (Step 1105 ). The dimension of the quefrencies is time.
[0100] Then, the analysis unit 601 and 701 perform the time-to-frequency conversion on the high quefrency components to calculate the envelope of the sound (Step 1106 ). Further, the analysis unit 601 and 701 perform the time-to-frequency conversion on the low quefrency components to calculate the sound source of the sound (Step 1107 ).
Procedure for Calculating Envelope Pattern of Sound
[0101] The analysis unit 701 illustrated in FIG. 7 calculates the envelope pattern of the sound of the input signal. FIG. 12 is a flowchart of the procedure for calculating the envelope pattern of the sound performed by the analysis unit 701 according to one of the present embodiments.
[0102] The analysis unit 701 calculates the envelope spectrum of the input signal, and performs the detection of the sound (Step 1201 ).
[0103] The analysis unit 701 calculates formants and antiformants (Step 1202 ). The formants represent the maximum points of the envelope spectrum, while the antiformants represent the minimum points of the envelope spectrum.
[0104] The analysis unit 701 determines whether or not the current frame is the target section for which the envelope pattern is to be recorded (Step 1203 ). If the total number of the formants and the antiformants included in the current frame is equal to or less than a threshold value in a section, or if the sound has not been detected in a section, the analysis unit 701 determines that the section is not the recording target section. That is, the analysis unit 701 determines, as the recording target section, the section in which the total number of the formants and the antiformants included in the current frame is greater than the threshold value.
[0105] If the analysis unit 701 determines that the current frame is the recording target section (YES at Step 1203 ), the analysis unit 701 stores the formants and the antiformants in a memory (Step 1204 ). In the present example, the analysis unit 701 has the memory for storing the formants and the antiformants.
[0106] Meanwhile, if the analysis unit 701 determines that the current frame is not the recording target section (NO at Step 1203 ), the analysis unit 701 clears the stored formants and antiformants from the memory (Step 1205 ).
First Procedure for Generating Pseudo Sound
[0107] FIG. 13 is a flowchart of a procedure for generating the pseudo sound performed by the pseudo sound generation unit 102 to 502 each according to one of the present embodiments. Further, FIG. 14 is a schematic diagram illustrating a connection relationship between repeating signal segments according to one of the present embodiments. Herein, M represents the length (the sample) of the section for which the correlation coefficient is calculated, while L represents the overlapping length.
[0108] The pseudo sound generation unit 102 to 502 receive the target signal to be repeated from the analysis unit 101 to 501 , respectively (Step 1301 ). The target signal to be repeated is the input signal of the normal section or the signal of the sound component of the normal section. The normal section refers to the section in which the error has not occurred, i.e., the section in which the packet loss has not occurred.
[0109] With the use of Formula (F3), the pseudo sound generation unit 102 to 502 calculate the autocorrelation coefficient of the target signal to be repeated (Step 1302 ). To calculate the periodicity of the pseudo sound (the period and the strength of the periodicity of the pseudo sound), the pseudo sound generation unit 102 to 502 calculate the autocorrelation coefficient of the target signal to be repeated.
[0110] Then, the pseudo sound generation unit 102 to 502 calculate the maximum position of the calculated autocorrelation coefficient (Step 1303 ). The maximum position of the autocorrelation coefficient is represented as a_max, and corresponds to the period.
[0111] The pseudo sound generation unit 102 to 502 calculate a signal segment to be repeated (Step 1304 ). Herein, the signal segment to be repeated is a segment extending to the end of the target signal from the position ahead of an autocorrelation coefficient start position by the distance of a sample corresponding to the value a_max+L.
[0112] The pseudo sound generation unit 102 to 502 connect and repeat the repeating signal segments (Step 1305 ). Herein, the pseudo sound generation unit 102 to 502 sequentially connect the repeating signal segments such that a sample corresponding to the value L is overlapped between the adjacent repeating signal segments. With the repeating signal segments connected together with the overlapped portions, the pseudo sound for preventing the occurrence of the abnormal sound can be generated. With the use of Formula (F4), the pseudo sound generation unit 102 to 502 calculate a signal OL reflecting the result of the overlapping of the connected signal segments. Herein, Sl(j) represents a chronologically earlier (left-side) signal to be connected, and Sr(j) represents a chronologically later (right-side) signal to be connected. Further, j represents the number designating a sample, and ranges from zero to L- 1 .
[0113] Formula 4
[0000]
OL
(
j
)
=
(
L
-
j
L
)
Sl
(
j
)
+
j
L
Sr
(
j
)
(
F4
)
[0114] The pseudo sound generation unit 102 to 502 calculate a signal length obtained as the result of the repeating (the result of the connection) of the repeating signal segments, and determine whether or not the signal length has exceeded a predetermined threshold value (Step 1306 ).
[0115] If the pseudo sound generation unit 102 to 502 determine that the signal length obtained as the result of the repeating has exceeded the predetermined threshold value (YES at Step 1306 ), the pseudo sound generation unit 102 to 502 complete the process of generating the pseudo sound. Meanwhile, if the pseudo sound generation unit 102 to 502 determine that the signal length obtained as the result of the repeating has not exceeded the predetermined threshold value (NO at Step 1306 ), the pseudo sound generation unit 102 to 502 continue to connect the repeating signal segments (Step 1305 ).
Second Procedure for Generating Pseudo Sound
[0116] FIG. 15 is a flowchart of a procedure for generating the pseudo sound performed by the pseudo sound generation unit 602 according to one of the present embodiments.
[0117] The pseudo sound generation unit 602 receives the envelope of the sound. Further, the pseudo sound generation unit 602 receives the sound source of the sound and the periodicity of the sound source (Step 1501 ).
[0118] The pseudo sound generation unit 602 repeats the sound source to generate one frame of the sound source (Step 1502 ). The pseudo sound generation unit 602 repeats the sound source in accordance with the processing flow illustrated in FIG. 13 to generate one frame of the sound source. The pseudo sound generation unit 602 applies the envelope to the repeated sound source to generate the pseudo sound (Step 1503 ). Herein, the pseudo sound generation unit 602 employs the following method as the method for applying the envelope to the repeated sound source. The pseudo sound generation unit 602 performs the time-to-frequency conversion on the repeated sound source to calculate an amplitude spectrum O(k). Then, the pseudo sound generation unit 602 multiplies the calculated amplitude spectrum O(k) by an amplitude spectrum E(k) of the envelope to calculate an amplitude spectrum S(k) of the pseudo sound (see Formula (F5)). Herein, S(k), O(k), and E(k) represent the amplitude spectrum of the pseudo sound of the k-th band, the amplitude spectrum of the repeated sound source of the k-th band, and the amplitude spectrum of the envelope of the k-th band, respectively. The pseudo sound generation unit 602 returns S(k) to the time domain through the frequency-to-time conversion.
[0119] Formula 5
[0000] S ( k )= O ( k )* E ( k ) (F5)
[0000] Third procedure for Generating Pseudo Sound
[0120] FIG. 16 is a flowchart of a procedure for generating the pseudo sound performed by the pseudo sound generation unit 702 according to one of the present embodiments.
[0121] The pseudo sound generation unit 702 receives from the analysis unit 701 the envelope of the sound and the pattern of change in the envelope of the sound. Further, the pseudo sound generation unit 702 receives the sound source of the sound and the periodicity of the sound source (Step 1601 ).
[0122] The pseudo sound generation unit 702 repeats the sound source in accordance with the processing flow illustrated in FIG. 13 to generate one frame of the sound source (Step 1602 ).
[0123] The pseudo sound generation unit 702 calculates the information of change in the envelope from the pattern of change in the envelope of the sound (Step 1603 ). The pseudo sound generation unit 702 calculates the information of change according to the following method. On the basis of envelope information at a time t and a time t+1, the pseudo sound generation unit 702 calculates the information of change in the envelope occurring between the time t and the time t+1. Herein, the envelope information represents the frequency (Hz) and the amplitude (db) of each of the formants and the antiformants. The frequency and the amplitude of the first formant at the time t are assumed to be F 1 x and F 1 y , respectively. Further, the frequency and the amplitude of the first formant at the time t+1 are assumed to be (F 1 x +Δx) and (F 1 y +Δy), respectively. Accordingly, the information of change in the first formant (px, py) is represented as px=Δx/x and py=Δy/y. In a similar manner, the information of change is calculated for the other formants and antiformants. Then, the information of change in all formants and antiformants is integrated to represent the information of change in the envelope.
[0124] The pseudo sound generation unit 702 updates the envelope of the sound by using the information of change in the envelope (Step 1604 ). The pseudo sound generation unit 702 calculates the formants and antiformants of the envelope of the sound. The pseudo sound generation unit 702 updates the formants and antiformants by applying the corresponding information of change to each of the formants and antiformants. Then, the pseudo sound generation unit 702 calculates the width corresponding to each of the formants and antiformants. The width of each of the formants is the difference between two frequencies which are located on the right side and left side of the formant, respectively, and at which the power spectrum first falls below the power spectrum of the formant by a predetermined value. Herein, the predetermined value is 3 dB, for example. Similarly, the width of each of the antiformants is the difference between two frequencies which are located on the right side and left side of the antiformant, respectively, and at which the power spectrum first exceeds the power spectrum of the antiformant by a predetermined value. Specifically, when the frequency and the amplitude of the first formant are F 1 _cur_x and F 1 _cur_y, respectively, the frequency F 1 _cur_x′ and the amplitude F 1 _cur_y′ of the updated first formant can be represented as F 1 _cur_x′=F 1 _cur_x*px and F 1 _cur_y′=F 1 _cur_y*py, respectively. The other formants and antiformants can be updated in a similar manner. The pseudo sound generation unit 702 calculates the envelope of the sound by applying a quadratic curve to each of the formants and antiformants. The quadratic curve applied to each of the formants by the pseudo sound generation unit 702 is a quadratic curve having maximum coordinates (fx, fy) and passing through coordinates (fx+0.5 WF, fy−3). Herein, (fx, fy) and WF (Hz) represent the position and the width of the formant, respectively. Further, the x-axis and the y-axis represent the frequency (Hz) and the power (dB), respectively. Similarly, the quadratic curve applied to each of the antiformants by the pseudo sound generation unit 702 is a quadratic curve having minimum coordinates (ux, uy) and passing through coordinates (ux+0.5 UF, uy+3). Herein, (ux, uy) and UF (Hz) represent the position and the width of the antiformant, respectively. Further, the pseudo sound generation unit 702 interpolates the quadratic curve corresponding to the formant and the quadratic curve corresponding to the antiformant to calculate the envelope of the border between the formant and the antiformant.
[0125] The pseudo sound generation unit 702 applies the updated envelope to the repeated sound source to generate the pseudo sound (Step 1605 ). The pseudo sound generation unit 702 generates the pseudo sound by employing a method similar to the method employed by the pseudo sound generation unit 602 . That is, the pseudo sound generation unit 702 calculates the amplitude spectrum O(k) by performing the time-to-frequency conversion on the repeated sound source. The pseudo sound generation unit 702 multiplies the calculated amplitude spectrum O(k) by the amplitude spectrum E(k) of the envelope to calculate the amplitude spectrum S(k) of the pseudo sound (see Formula (F5)). Then, the pseudo sound generation unit 702 returns S(k) to the time domain through the frequency-to-time conversion to generate the pseudo sound.
First Procedure for Generating Pseudo Noise
[0126] FIG. 17 is a flowchart illustrating the procedure for generating the pseudo noise performed by the pseudo noise generation unit 203 according to one of the present embodiments.
[0127] The pseudo noise generation unit 203 generates the white noise (Step 1701 ).
[0128] With the use of Formula (F6), the pseudo noise generation unit 203 applies to the white noise the filter coefficient representing the frequency characteristic of the background noise, to thereby generate the pseudo noise (Step 1702 ). Herein, y(n), w(n), h(m), n, and m represent the pseudo noise, the white noise, the filter coefficient, the number of samples, and the filter order ranging from zero to p−1, respectively.
[0129] Formula 6
[0000]
y
(
n
)
=
∑
m
=
0
p
-
1
h
(
m
)
w
(
n
-
m
)
(
F6
)
Second Procedure for Generating Pseudo Noise
[0130] FIG. 18 is a flowchart of the procedure for generating the pseudo noise performed by the pseudo noise generation unit 303 according to one of the present embodiments.
[0131] The pseudo noise generation unit 303 receives the power spectrum of the background noise from the analysis unit 301 (Step 1801 ).
[0132] The pseudo noise generation unit 303 randomizes the phase of the spectrum of the background noise (Step 1802 ). Specifically, the pseudo noise generation unit 303 randomizes the phase of the background noise while maintaining the magnitude of the amplitude spectrum of the background noise. The amplitude spectrum, the real part of the spectrum of each band, and the imaginary part of the spectrum of each band are represented as s(i), re(i), and im(i), respectively. The pseudo noise generation unit 303 replaces re(i) and im(i) with random numbers re′(i) and im′(i), respectively, and multiplies the random numbers re′(i) and im′(i) by a coefficient to maintain the magnitude of the amplitude spectrum, to thereby calculate the spectrum of the phase-randomized background noise ((αre′(i), αim′(i)). Accordingly, the pseudo amplitude spectrum can be calculated from Formula (F7).
[0133] Formula 7
[0000] s ( i )=√{square root over ((α re ′( i )) 2 +(α im′ ( i )) 2 )}{square root over ((α re ′( i )) 2 +(α im′ ( i )) 2 )} (F7)
[0134] Then, the pseudo noise generation unit 303 returns the spectrum of the phase-randomized background noise ((αre′(i), αim′(i)) to the time domain through the frequency-to-time conversion to generate the pseudo noise (Step 1803 ).
Procedure for Generating Output Signal
[0135] FIG. 19 is a flowchart of a procedure for generating the output signal performed by the output signal generation unit 104 to 704 according to the present embodiments.
[0136] The output signal generation unit 104 to 704 receive the error information, the input signal, the pseudo sound, the pseudo noise, the feature quantity of the sound, and the feature quantity of the noise (Step 1901 ).
[0137] The output signal generation unit 104 to 704 determine the presence or absence of the error on the basis of the information received at Step 1901 (Step 1902 ).
[0138] If the output signal generation unit 104 to 704 determine the presence of the error in the current frame (YES at Step 1902 ), the output signal generation unit 104 to 704 calculate the amplitude coefficient of each of the pseudo sound and the pseudo noise (Step 1903 ). The output signal generation unit 104 to 704 generate the output signal by superimposing together the pseudo sound and the pseudo noise (Step 1904 ).
[0139] If the output signal generation unit 104 to 704 determine the absence of the error in the current frame (NO at Step 1902 ), the output signal generation unit 104 to 704 determine the input signal as the output signal (Step 1905 ).
First Procedure for Calculating Amplitude Coefficient
[0140] FIG. 20 is a flowchart illustrating a first procedure for calculating the amplitude coefficient performed by the output signal generation unit 104 to 704 according to the present embodiments.
[0141] The output signal generation unit 104 to 704 determine whether or not the current frame is an error start frame (Step 2001 ). The error start frame refers to the frame in which the frame loss (the packet loss) has first occurred in a section in which the frame loss has occurred. If the output signal generation unit 104 to 704 determine that the current frame is the error start frame (YES at Step 2001 ), the output signal generation unit 104 to 704 perform the sound detection process on the input signal (Step 2002 ). The sound detection process is the process of determining the sound according to whether or not the power of the input signal has exceeded a threshold value. Meanwhile, if the output signal generation unit 104 to 704 determine that the current frame is not the error start frame (NO at Step 2001 ), the output signal generation unit 104 to 704 determine the presence or absence of the sound in the current frame (Step 2003 ).
[0142] At Step 2003 , the output signal generation unit 104 to 704 determine whether or not the sound has been detected (Step 2003 ). If the output signal generation unit 104 to 704 have detected the sound (YES at Step 2003 ), the output signal generation unit 104 to 704 calculate the amplitude coefficient of the pseudo sound and the amplitude coefficient of the pseudo noise as 1−i/R and i/R, respectively (Step 2004 ). Herein, R and i represent the number of samples required to adjust the amplitude of the pseudo sound to zero and the number of samples appearing after the start of the error, respectively. The value R is a preset value which has been previously determined. Meanwhile, if the output signal generation unit 104 to 704 have not detected the sound (NO at Step 2003 ), the output signal generation unit 104 to 704 calculate the amplitude coefficient of the pseudo sound and the amplitude coefficient of the pseudo noise as zero and one, respectively (Step 2005 ).
[0143] The output signal generation unit 104 to 704 generate the output signal by adding together the pseudo sound multiplied by the amplitude coefficient therefor and the pseudo noise multiplied by the amplitude coefficient therefor (Step 2006 ). Herein, the output signal generation unit 104 to 704 perform adjustment such that the intra-frame average amplitude of the input signal immediately preceding the error becomes equal to the intra-frame average amplitude of the output signal obtained by adding together the pseudo sound multiplied by the amplitude coefficient therefor and the pseudo noise multiplied by the amplitude coefficient therefor.
Second Procedure for Calculating Amplitude Coefficient
[0144] FIG. 21 is a flowchart illustrating a second procedure for calculating the amplitude coefficient performed by the output signal generation unit 104 to 704 according to the present embodiments.
[0145] The output signal generation unit 104 to 704 determine whether or not the current frame is the error start frame (Step 2101 ). If the output signal generation unit 104 to 704 determine that the current frame is the error start frame (YES at Step 2101 ), the output signal generation unit 104 to 704 perform the sound detection process on the input signal (Step 2102 ). The sound detection process according to the present embodiment is also the process of determining the sound according to whether or not the power of the input signal has exceeded the threshold value. Meanwhile, if the output signal generation unit 104 to 704 determine that the current frame is not the error start frame (NO at Step 2101 ), the output signal generation unit 104 to 704 determine the presence or absence of the sound in the current frame.
[0146] The output signal generation unit 104 to 704 determine whether or not the sound has been detected (Step 2103 ). If the output signal generation unit 104 to 704 have detected the sound (YES at Step 2103 ), the output signal generation unit 104 to 704 perform a deterioration determination process on the pseudo sound (Step 2104 ).
[0147] The output signal generation unit 104 to 704 determine whether or not the pseudo sound has been deteriorated (Step 2105 ). If the output signal generation unit 104 to 704 determine that the pseudo sound has not been deteriorated (NO at Step 2105 ), the output signal generation unit 104 to 704 calculate the amplitude coefficient of the pseudo sound and the amplitude coefficient of the pseudo noise as 0.5 and 0.5, respectively (Step 2106 ). If the output signal generation unit 104 to 704 determine that the pseudo sound has been deteriorated (YES at Step 2105 ), the output signal generation unit 104 to 704 calculate the amplitude coefficient of the pseudo sound and the amplitude coefficient of the pseudo noise as 1−i/Q and i/Q, respectively (Step 2107 ). Herein, Q and i represent the number of samples required to adjust the amplitude of the pseudo sound to zero after the determination of the deterioration of the pseudo sound and the number of samples appearing after the determination of the deterioration of the pseudo sound, respectively. Further, the amplitude coefficient of the pseudo sound may be weighted as follows by the periodicity of the input signal, the periodicity of the sound component, or the periodicity of the sound source. For example, the amplitude coefficient of the pseudo sound may be weighted as (1−i/Q)*MAX(corr(a)).
[0148] At Step 2103 , if the output signal generation unit 104 to 704 have not detected the sound (NO at Step 2103 ), the output signal generation unit 104 to 704 calculate the amplitude coefficient of the pseudo sound and the amplitude coefficient of the pseudo noise as zero and one, respectively (Step 2108 ).
[0149] The output signal generation unit 104 to 704 generate the output signal by adding together the pseudo sound multiplied by the amplitude coefficient therefor and the pseudo noise multiplied by the amplitude coefficient therefor (Step 2109 ). Herein, the output signal generation unit 104 to 704 perform adjustment such that the intra-frame average amplitude of the input signal immediately preceding the error becomes equal to the intra-frame average amplitude of the output signal obtained by adding together the pseudo sound multiplied by the amplitude coefficient therefor and the pseudo noise multiplied by the amplitude coefficient therefor.
Procedure for Determining Deterioration of Pseudo Sound
[0150] FIG. 22 is a flowchart illustrating the process of determining the deterioration of the pseudo sound performed by the output signal generation unit 104 to 704 according to the present embodiments.
[0151] The output signal generation unit 104 to 704 calculate the magnitude P 1 (dB) of the repeating period component of the input signal (Step 2201 ). The output signal generation unit 104 to 704 calculate the power spectrum of the input signal by performing the time-to-frequency conversion on the input signal. Then, on the basis of the power spectrum of the input signal, the output signal generation unit 104 to 704 calculate the magnitude (the power) P 1 of the repeating period component of the input signal.
[0152] The output signal generation unit 104 to 704 calculate the magnitude P 2 (dB) of the repeating period component of the pseudo sound (Step 2202 ). The output signal generation unit 104 to 704 calculate the power spectrum of the pseudo sound by performing the time-to-frequency conversion on the pseudo sound. Then, on the basis of the power spectrum of the pseudo sound, the output signal generation unit 104 to 704 calculate the magnitude (the power) P 2 of the repeating period component of the pseudo sound.
[0153] The output signal generation unit 104 to 704 subtract the magnitude P 1 of the repeating period component of the input signal from the magnitude P 2 of the repeating period component of the pseudo sound to calculate the value P 2 −P 1 . Then, the output signal generation unit 104 to 704 determine whether or not the value P 2 −P 1 has exceeded a preset predetermined threshold value (Step 2203 ). If the output signal generation unit 104 to 704 determine that the value P 2 −P 1 has not exceeded the preset predetermined threshold value (NO at Step 2203 ), the output signal generation unit 104 to 704 determine that the pseudo sound has not been deteriorated (Step 2204 ). Meanwhile, if the output signal generation unit 104 to 704 determine that the value P 2 −P 1 has exceeded the preset predetermined threshold value (YES at Step 2203 ), the output signal generation unit 104 to 704 determine that the pseudo sound has been deteriorated (Step 2205 ).
Functions of Information Processing Devices 100 to 700
[0154] The information processing devices 100 to 700 according to the present embodiments separately generate the pseudo sound and the pseudo noise on the basis of the feature quantity of the sound included in the input signal and the feature quantity of the noise included in the input signal. Accordingly, even if the signal immediately preceding the packet loss is a signal having a small periodicity, such as the signal of a consonant, background noise, and so forth, it is possible to perform interpolation for the packet loss while reducing the deterioration of the sound quality caused by abnormal sound and so forth generated by the occurrence of an unnatural period.
[0155] In the above-described manner, the information processing devices 100 to 700 according to the present embodiments analyze the input signal to calculate the feature quantity of the sound included in the input signal and the feature quantity of the background noise included in the input signal. The information processing devices 100 to 700 separately generate the pseudo sound and the pseudo noise by using the feature quantity of the sound and the feature quantity of the background noise. Further, the information processing devices 100 to 700 generate the output signal by distributing the pseudo sound and the pseudo noise in accordance with the characteristics of the input signal. Accordingly, it is possible to perform interpolation which suppresses the deterioration of the sound quality and thus provides high sound quality.
[0156] Further, the information processing device 200 according to one of the present embodiments generates the pseudo noise by using the frequency characteristic of the background noise. Accordingly, it is possible to generate the pseudo noise without causing discontinuation of the sound quality and the power of the pseudo noise from the sound quality and the power of the background noise superimposed on the input signal.
[0157] Further, the information processing device 400 calculates the periodicity of the input signal. Therefore, the distribution of the pseudo sound can be determined in accordance with the periodicity of the input signal. Accordingly, particularly when the periodicity of the input signal is small, the information processing device 400 can suppress abnormal sound attributed to the repetition of the target signal.
[0158] Further, the information processing device 500 according to one of the present embodiments calculates the periodicity of the sound component of the input signal. Therefore, the distribution of the pseudo sound can be determined in accordance with the periodicity of the sound component of the input signal. Accordingly, particularly when the periodicity of the sound component of the input signal is small, the information processing device 500 can suppress abnormal sound attributed to the repetition of the target signal (the sound component of the input signal). Further, the information processing device 500 repeats only the sound component of the input signal. Therefore, abnormal sound attributed to the periodic repetition of the superimposed noise can be suppressed.
[0159] Further, the information processing devices 600 and 700 calculate the periodicity of the sound source of the sound. Therefore, the distribution of the pseudo sound can be determined in accordance with the periodicity of the sound source of the sound. Accordingly, when the periodicity of the sound source of the sound is small, the information processing devices 600 and 700 can suppress abnormal sound attributed to the repetition of the target signal.
[0160] Further, the information processing device 700 calculates the pattern of change in the envelope of the sound. Therefore, the pseudo sound can be generated with the use of the pattern of change in the envelope of the sound. Accordingly, the information processing device 700 can generate more natural pseudo sound, and thus can perform high-quality interpolation.
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According to an aspect of an embodiment, a method for interpolating a partial loss of an audio signal including a sound signal component and a background noise component in transmission thereof, the method comprising the steps of: calculating frequency characteristic of the background noise in the audio signal; extracting the sound signal component from the audio signal; generating pseudo noise by applying the frequency characteristic of the background noise included in the audio signal to white noise; and generating an interpolation signal by combining the pseudo noise with the extracted sound signal component included in the audio signal to supersede the partial loss of the audio signal.
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BACKGROUND OF THE INVENTION
The perception that nitric oxide (NO), a chemically active gas, plays an essential role in human and animal physiology was first demonstrated in 1987 with the publication of Nitric Oxide Accounts for the Biological Activity of Endothelium Derived Relaxing Factor ; Palmer, R. M., Ferridge, A. G., Moncada, S; Nature 1987; 327:524-526. The authors demonstrated that the endothelial-derived relaxation factor (EDRF) was indeed nitric oxide. Many research publications have since defined more clearly the multiple and complex roles of NO in human, animal and plant physiology. Synthesized endogenously in humans, animals and plants, NO plays many very important physiological roles. For example, research reports have shown that NO may be effective in the treatment of sickle cell anemia.
Nitric oxide, in conjunction with ventilatory support and other appropriate agents, is used for the treatment of term and near-term (greater than 34 weeks) neonates with hypoxic respiratory failure associated with clinical or echocardiographic evidence of pulmonary hypertension, where it improves oxygenation and reduces the need for extracorporeal membrane oxygenation. It has also been reported to be useful as a selective pulmonary vasodilator in patients with adult respiratory distress syndrome. Lack of systemic vasodilatory effects with nitric oxide is an advantage over other vasodilators (e.g., epoprostenol (prostacyclin), nitroprusside).
Among the increasing range of pathologies which can be successfully treated with gaseous NO is anal disease. Anal fissure (or fissure-in-ano), anal ulcer, acute hemorrhoidal disease, and levator spasm (proctalgia fugax) are common, benign conditions of the anal canal which affect men and women. An anal fissure or ulcer is a tear or ulcer of the mucosa or lining tissue of the distal anal canal. An anal fissure/ulcer can be associated with other systemic or local diseases, but it is more frequently present as an isolated finding. The typical, idiopathic fissure or ulcer is confined to the anal mucosa, and usually lies in the posterior midline, distal to the dentate line. The person with an anal fissure or ulcer suffers from anal pain and bleeding, more pronounced during and after bowel movements.
Hemorrhoids are specialized vascular areas lying subjacent to the anal mucosa. Symptomatic hemorrhoidal disease is manifest by bleeding, thrombosis or prolapse of the hemorrhoidal tissues. Men and women are affected. Most commonly, internal hemorrhoidal tissue bulges into the anal canal during defecation causing bleeding. As the tissue enlarges, prolapse pain, thrombosis, and bleeding can ensue. Thrombosis of internal or external hemorrhoids is another cause of pain and bleeding.
Levator spasm (or proctalgia fugax) is a condition of unknown etiology affecting women more frequently than men. This syndrome is characterized by spasticity of the levator ani muscle, a portion of the anal sphincter complex. The patient suffering from levator spasm complains of severe, episodic rectal pain. Physical exam may reveal spasm of the puborectalis muscle. Pain may be reproduced by direct pressure on this muscle. Bleeding is not associated with this condition.
The underlying causes of these problems are poorly understood. However, all of these disorders are associated with a relative or absolute degree of anal sphincter hypertonicity. In the case of anal fissure/ulcer the abnormality appears to be an as yet unidentified problem of the internal and sphincter muscle. The internal sphincter is a specialized, involuntary muscle arising from the inner circular muscular layer of the rectum. Intra-anal pressure measurements obtained from people suffering from typical anal fissure/ulcer disease show an exaggerated pressure response to a variety of stimuli. The abnormally high intra-anal pressure is generated by the internal sphincter muscle. The abnormally elevated intra-anal pressure is responsible for non-healing of the fissure/ulcer and the associated pain. U.S. Pat. No. 5,504,117 teaches methods to treat anal pathologies by the topical application of preparations that stimulate the production of endogenous nitric oxide synthase (NOS) which, in turn, causes NO to be generated in endothelial tissue and in the nervous system, by the catalytic action of NOS upon L-Argenine.
Although safe NO dosage values are at present still evolving, the Occupational Safety and Health Administration (OSHA) has set the time-weighted average inhalation limit for NO at 25 ppm for 10 hours and NOsub2 not to exceed 5 ppm. NIOSH Recommendations for Occupational Safety and Health Standards: Morbidity and Mortality Weekly Report, Vol. 37, No. S-7, p. 21(1988). The Environmental Protection Agency (EPA) has stated that a health-based national (maximum ambient) air quality standard for NOsub2 is 0.053 ppm (measured as an annual average).
When exposed to oxygen, NO gas will, depending on environmental conditions, undergo oxidation to NOsub2, also to higher oxides of nitrogen. Gaseous nitrogen dioxide, if inhaled in sufficient concentration (for example, as little as 10 ppm for ten minutes), is toxic to lung tissue and can produce pulmonary edema and this concentration and exposure time, or more, could result in death. Standards with regard to nitrogen dioxide toxicity have not been firmly established. Nitrogen dioxide is a deep lung irritant that can produce pulmonary edema and death if inhaled at high concentrations. The effects of NOsub2 depend on the level and duration of exposure. Exposure to moderate NOsub2 levels, 50 ppm for example, may produce cough, hemoptysis, dyspnea, and chest pain. Exposure to higher concentrations of NOsub2 (greater than 100 ppm) can produce pulmonary edema, that may be fatal or may lead to bronchiolitis obliterans. Some studies suggest that chronic exposure to nitrogen dioxide may predispose to the development of chronic lung diseases, including infection and chronic obstructive pulmonary diseases.
It is common practice in therapeutic NO inhalation procedures both to monitor and also to remove NOsub2 before it can be inhaled by a subject to whom NO is being applied. For example, the NO respiratory gas mixture may be transported through a soda lime mixture to scavenge nitrogen dioxide. However, NO gas in the therapeutic concentration range (i.e. 1 ppm to as much as 100 ppm) can be administered safely, for short time periods, in dry normal air (21% oxygen) without the formation of toxic concentrations of NOsub2. Moreover, the present invention may include intra-capsular means to adsorb NOsub2.
Historically, NO gas is commercially manufactured using the Ostwald process (U.S. Pat. Nos. 4,774,069, 5,478,549) in which ammonia is catalytically converted to NO and Nitrous Oxide at a temperature above 800 degrees centigrade. This process thus involves the mass production of NO at high temperatures in an industrial setting. The therapeutic advantages of NO over other pulmonary and cardiovascular drugs have led researchers to attempt the design of an instrument that can deliver variable concentrations of NO accurately. For example, U.S. Pat. No. 5,396,882 describes a process for generating NO in an electric arc discharge in air where the electrodes are separated by an air gap in an arc chamber. The application of a high voltage across the air gap produces a localized plasma that breaks down oxygen and nitrogen molecules and generates a mixture of NO, ozone, and other NOx species. The concentration of NO in this system can be varied by adjusting the operating current. The gas mixture is then purified and mixed with air in order to obtain therapeutically significant concentrations of NO prior to administration to a patient. However, the quantification of generated NO by this system is purely empirical making the instrument extremely susceptible to the slightest fluctuations in the internal and external parameters such as ambient humidity and the surface area of the electrodes in the arc chamber.
Although inhalation of nitric oxide gas has been shown to be effective for treatment of pulmonary hypertension, there are several drawbacks and limitations of this particular mode of therapy. For example, current art therapy requires large and heavy gas tanks, expensive monitoring equipment, and a trained anesthesiologist to operate the tanks and equipment so as to deliver NO gas to a patient with safety. Therefore, NO inhalation therapy is at present limited to hospitals or similar clinical facilities. Thus there is a great needed for a more flexible, portable and less expensive means with which NO may be delivered safely in an organ specific manner without causing systemic vasodilation.
For over a century, nitroglycerin has been used as a vasodilating agent in the treatment of cardiovascular disease. Nitroglycerin, or glyceryl trinitrate, is an organic nitrate ester which when administered to a subject is converted biologically to nitric oxide by stimulating an enzyme, nitric oxide synthase (NOS), which in turn, catalyzes the production of endogenous NO from L-argenine. However, the effectiveness of nitroglycerin is greatly diminished because the recipient of therapeutic administration of nitroglycerin rapidly develops a tolerance to the beneficial effects of nitroglycerin. Therefore, onset of nitroglycerin tolerance significantly limits the therapeutic value of nitroglycerin because increased nitroglycerin dosages have little or no effect on vasorelaxation or vasodilatation. A further limitation may result from the fact that nitroglycerin is physiologically non specific. That is, vascular response to the drug will be generally distributed over the entire circulatory system.
SUMMARY OF THE INVENTION
The present invention teaches new and novel methods and means with which NO can be rapidly delivered to alveolar vascular tissue so as to bring about a rapid increase in the concentration of NO in lung and heart vascular epithelia. The effect is to cause rapid dilation of blood vessels in the lung and heart and to a considerably lesser degree, in more distal blood vessels through which blood circulates owing to the rapid absorption of NO by red blood cells.
The present invention features methods for prevention and treatment of asthma attacks and other forms of bronchial constriction, acute respiratory failure, or reversible pulmonary vasoconstriction (i.e., acute or chronic pulmonary vasoconstriction which has a reversible component). An affected subject may be identified, for example, by acute physical distress symptoms or by traditional diagnostic procedures. The subject will then inhale a therapeutically-effective concentration of gaseous nitric oxide so as to achieve therapeutic relief.
The present invention teaches methods and devices that produce NO from the inside of portable and disposable capsules containing NO under pressure and from chemical reagents which, when appropriately combined or activated, generate a controlled outflow of pure NO gas to the capsule exterior in free air. It is essential that the concentration of gas inhaled from the above mentioned capsular NO source be large enough to effect therapeutically beneficial results and at the same time not exceed a safe NO concentration maximum for gas inhalation. Both exposure time and gas concentration values together dictate what safe dosage may be.
The present invention teaches the principles of new devices and new procedures that will provide effective therapeutic application of inhaled NO during coronary and respiratory emergencies such as angina, thrombosis in heart and lung blood vessels; also hypertension in lung vasculature, as well as reversible asthma attacks.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawings in which:
FIG. 1 is a schematic, cross-sectional view of a first embodiment of a NO storage and delivery system in accordance with the invention;
FIG. 2 is a schematic, cross-sectional view of a second embodiment of a NO storage and delivery system in accordance with the invention;
FIG. 3 is a schematic, cross-sectional view of a third embodiment of a NO storage and delivery system in accordance with the invention; and
FIG. 4 is a schematic, cross-sectional view of a fourth embodiment of a NO storage and delivery system in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A number of compounds have been developed that are capable of delivering nitric oxide in a pharmacologically useful way. Such compounds include compounds that release nitric oxide after being metabolized and compounds that release nitric oxide spontaneously in aqueous solutions. Compounds capable of releasing NO upon being metabolized include the widely used nitrovasodilators glyceryl trinitrate (nitroglycerin) and sodium nitroprusside (SNP). These compounds are relatively stable but they release or cause the release of NO upon activation.
Many nitric oxide-nucleophile complexes also have been described. Some of these compounds, known as NONOates, evolve nitric oxide upon heating or hydrolysis. These compounds, unlike nitroglycerin or SNP, release NO without requiring activation. NONOates have reproducible half-lives ranging from 2 seconds to 20 hours. Nitricoxide/nucleophile complexes (NONOates) that release nitric oxide in aqueous solution are disclosed in U.S. Pat. Nos. 5,389,675, 5,366, 977, and 5,250, 550. The nitric oxide-releasing functional group is R-[NONO], where R is an organic or inorganic moiety bonded to the [NONO].
NO may be generated from S-nitrosothiols (RSNO) in presence of catalyst Cu(1), as outlined in the reaction below:
2RSN0→2NO+RS−SR (1)
The concentration of generated NO is equal to the original RSNO concentration after the addition of the catalyst Cu(I).
NO may be generated chemically. In a first example, based on the reaction of nitrite with iodide in an acidic medium as in the reaction:
2KNO 2 +2KI+2H 2 SO 4 →2NO+I 2 +2H 2 O+2K 2 SO 4 (2)
The concentration of NO is determined by the nitrite and iodide concentrations. Ascorbic acid may be used above to replace KI as a reductant.
In a second example, at room temperature, vanadium (III) rapidly reduces nitrite to nitric oxide in an acidic solution. Vanadium (III), as a reductant is oxidized to vanadium (IV):
NO 2 —+2H + +e →NO+H 2 O (3)
The NO storage and delivery system 10 shown in FIG. 1 employs a gas impermeable capsule 12 as the storage vessel for a gas source 14 composed of compressed NO gas. NO gas is injected into the capsule 12 under pressure in an anaerobic environment. The internal gas-filled cavity 16 has preferably a 1 to 5 ml inner volume. Internal NO gas pressure is typically 15 to 30 psi. The capsule casing is impermeable to gas leakage.
Gas is released from the capsule 12 via an opening 18 extending through the capsule wall and an applicator sleeve 20 enclosing the opening 18 and extending outwardly from the capsule 12 . Gas release can be effected, for example, by removal of a gas-tight cap 22 from the neck 24 of the applicator sleeve 20 . Alternative capsule sealing methods can be easily implemented by conventional art means.
A miniature pressure controller 26 within the sleeve 20 limits the exit pressure of the stored gas so as to release NO gas at a constant pressure which is less than that of the initial internal capsule gas pressure. An outlet filter 28 downstream of the pressure controller 26 restricts the rate of gas outflow. For example, gas release pressure regulated at 5 psi would be adequate to assure constant gas outflow for periods of time which can be made to range from a few seconds to hours. The flow rate of exiting gas can be limited to a few micro liters per minute. Prior to use, the capsule 12 is stored in a sterile bag that is gas and moisture impermeable to prevent environmental and bacterial infiltration.
As an alternative to charging the capsule 12 from an external pressurized NO gas source, the NO gas source 14 can be a NO bearing polymer. The polymer material is sealed within the capsule cavity 16 and slowly decomposes to release the NO gas stored therein, and thus constitutes the intra capsular NO gas supply 14 . The polymer material is initially loaded into the capsule 12 in an oxygen-free environment. If NONOate is to be the NO source 14 , de-aerated water must be applied to initiate NO release.
FIG. 2 illustrates a second embodiment of the system 10 ′ having a NO gas source 30 in which NO gas is created by activation of stored chemical reagents 32 , 34 . Capsule 36 is flexible and gas impermeable. The gas source 30 comprises stored reagents 32 and 34 , which are physically isolated by a breakable divider 38 , for example a glass tube, containing reagent 32 . Bending capsule 38 breaks reagent vessel 38 causing chemical reagents 32 and 34 to mix, resulting in the rapid formation of NO gas within the capsule 36 . The known stoichiometry of the chemical reaction and the volume of the capsule interior allows accurate prediction of the resulting intra capsular NO gas pressure. A single example of several feasible chemical reactions is illustrated in equation (1) above. In this example, reagent 32 is a solution of potassium nitrite and reagent 34 is a mixture of potassium iodide and sufric acid.
Compressed NO gas flows out of the capsule 36 via a check valve 40 comprised, for example, by a ball 42 and spring 44 . The outflow filter 46 controls the gas outflow rate and also filters water vapor from the fluid reagents in the capsule 36 . The filter 46 may be treated with a nitrogen dioxide adsorbent so as to insure that, if present, virtually no nitrogen dioxide will be present in the generated gas. Prior to use, the capsule 36 is stored in a sterile bag that is gas and moisture impermeable to prevent environmental and bacterial infiltration.
The embodiment 10 ″ shown is FIG. 3 is similar in form and function to the embodiment 10 ′ of FIG. 2 except that outlet filter 46 of FIG. 2 is replaced by a NO gas permeable capped tube 48 which delivers a diffuse gentle flow of NO into the nostrils or, alternatively, other body cavities of subject humans or animals for therapeutic effect. Internal tubular gas pressure and the gas permeability of the capped tube 48 both determine the rate of the resulting NO gas outflow. Prior to use, the capsule 36 is stored in a sterile bag that is gas and moisture impermeable to prevent environmental and bacterial infiltration.
The embodiment 10 ′″ illustrated in FIG. 4 has an ovoid or lozenge shaped capsule 50 . The capsule 50 is impermeable to acid or water or other interior reagents 32 , 34 employed therein. The capsule 50 is also NO gas permeable and flexible. Active chemical reagents 32 ′ and 34 ′ are similar in function to reagents 32 and 34 of FIG. 2 . Reagent 32 ′ is contained in a breakable compartment 38 ′ or tube as in FIG. 2 . In use, the capsule 50 is activated by applying sufficient force to break the reagents tube 38 ′ which initiates a NO gas producing reaction as discussed above. After activation, the capsule 50 may be lubricated with a gas permeable fluid 52 such as silicone and gently inserted into the appropriate body cavity of a subject requiring NO gas therapy as discussed above. Upon completion of the NO treatment, the capsule 50 may be withdrawn by using the attached cord 54 . For respiratory therapy, the capsule 50 may be held under the nostrils for the duration of the treatment. Prior to use, the capsule 50 is stored in sterile bags that are gas and moisture impermeable to prevent environmental or bacterial infiltration and possible contamination.
It should be appreciated that by using a system 10 , 10 ′, 10 ″, 10 ″Δ in accordance with the invention, pure NO gas is generated for inhalation proximal to or within the nostrils of the subject and transported to the lungs by the tidal action of the subject's respiration. The concentration of nitric oxide gas is diluted by the respiratory tidal volume of the user. Consequently, the user's own respiration performs the dual function of transporting and diluting the NO gas. Moreover, negligible nitrogen dioxide formation occurs within the time interval in which NO gas is transported by the respiratory tidal volume to the lung alveoli. Theoretical analysis and experimental results indicate the NO 2 concentration is much less than 1 ppm for the time periods used by the inventive methods of the present invention. It should also be appreciated that the subject system 10 , 10 ′, 10 ″, 10 ′″ does not require an expensive and complex gas mixing and delivery system because the subject's own respiration safely delivers NO gas at low ppm concentration levels to the subject's lungs. It should further be appreciated that the subject system 10 , 10 ′, 10 ″, 10 ′″ does not utilize industrial NO gas tanks, which are expensive, heavy and potentially dangerous.
The above disclosed embodiments are generally single use systems with the amount of pressurized NO gas or reagents sized accordingly. It should be appreciated that once the reagents of embodiments 10 ′, 10 ″, and 10 ′″ are mixed together, the resulting reaction will continue to completion. Further, the absence of a gas-tight cap 22 on the applicator sleeve of the second embodiment 10 ′ and the permeable nature of the capped tube 48 of the third embodiment 10 ″, and the capsule 50 of the fourth embodiment 10 ′″ preclude retention of the NO gas within the capsule 36 , 36 ′, 50 after the reagents 32 , 32 ′, 34 , 34 ′ have been mixed. While it is possible that the gas-tight cap 22 of the first embodiment 10 may be replaced before all of the pressurized NO gas is dispensed through the applicator sleeve 20 , the escaping NO gas will interfere with such replacement and there is no way of assuring that the remaining amount of NO gas will be therapeutically useful.
While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.
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A storage and delivery system for directly applying nitric oxide to a user includes a portable and disposable capsule and a source of nitric oxide gas disposed within the cavity. Gas flow control apparatus controls the flow of nitric oxide gas from the cavity. Gas flow initiation apparatus allows the user to initiate the flow of nitric oxide gas. The encapsulated nitric oxide gas is applied by positioning the capsule proximate to the objective site of the user and initiating flow of the nitric oxide gas.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a safety device used in systems for circulating a conductive fluid, especially ink-jet recovery circuits in continuous ink-jet printers.
2. Description of the Prior Art
A frequent problem lies in the need to check whether a flow of conductive fluid split-up in the form of drops within a pipe of small diameter is taking place under acceptable conditions which are conducive to good operation of the installation or on the contrary whether any irregularities have developed and justify remedial measures.
A problem of this nature arises particularly in the field of ink-jet printers. In fact, among the different ink-jet printing techniques, a certain number are based on the use of a continuous stream of ink drops from which part of the stream is withdrawn for the purpose of printing characters. The other drops are recycled in a special circuit known as a recirculation circuit. Now a key function of this device is the so-called "dump" zone for collecting the unused stream of drops to be recycled. Taking into account the nature of the inks employed which are capable by definition of very rapid drying and also taking into account the small cross-sectional area of the collecting element, blockage may eventually occur. Another potential danger lies in the possibility of failure of the pumping means. In all cases there is a risk of overflow of ink which would have a damaging effect on the installation. In order to avoid the consequences which would result from an operational fault condition of this type, it is a desirable objective to provide means for detecting such a fault condition in order to take the necessary steps without delay. And this is precisely the aim of the present invention.
SUMMARY OF THE INVENTION
In accordance with the invention, a sensor is adapted to cooperate with an electronic circuit in order to detect the appearance of a fault condition in the circulation of a conductive fluid within a pipe of small diameter. The sensor accordingly delivers a signal which can serve to initate a sequence for ensuring correct operation while meeting safety requirements, for example by completely stopping the machine.
The invention is more specifically concerned with a safety device applied to a system for circulating a conductive fluid of the type comprising a pipe for delivering the fluid to a pump. The distinctive feature of the invention lies in the fact that it permits measurement of the level of turbulence within the pipe by measuring variations in conductivity of the fluid arising from variations in cross-sectional area of said fluid within a pipe segment of predetermined length L and formed of insulating material.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features of the invention will be more apparent upon consideration of the following description and accompanying drawings, wherein:
FIG. 1 is a schematic representation of a sensor which is intended to cooperate with an electronic circuit in order to constitute a safety device in accordance with the invention;
FIG. 2 shows one example of construction of an electronic circuit of this type;
FIG. 3 is a schematic representation of a device for recirculation of the ink stream in a continuous ink-jet printer.
DETAILED DESCRIPTION OF THE INVENTION
For the sake of enhanced clarity, the same elements are designated by the same references in all the figures.
As stated earlier, the non-limitative example chosen for the purpose of illustrating the invention relates to the circuit for recirculating the ink stream not employed for printing, in an ink-jet printer. The recovered ink stream is collected by a pipe which cooperates with a pumping means as will be explained hereinafter and returns the ink to the supply tank for subsequent reuse. The pipe under consideration has a diameter of the order of one millimeter and receives a stream of spaced drops having a diameter which is from five to ten times smaller.
If the flow were perfect and non-turbulent, air would circulate at the center of the tube and the ink entrained by friction would circulate at the periphery. But the action of gravity, friction forces, the substantial difference in viscosity between air and ink as well as other parameters in fact produce turbulent flow.
The present Applicant has found by experiment that a characteristic flow pattern corresponds to normal recirculation. In fact, the cross-sectional area of ink as it flows within the pipe is very irregular. For a given length of piping, there is therefore a variation in conductivity, the frequency of which indicates the quality of flow of fluid at this level. Experimentally, the present Applicant has found, for example, that with a tube 2 mm in diameter and a vacuum of approximately 200 millibars, the variation in conductivity takes place with a spectrum having a large number of components which vary between 40 and 100 Hz.
In accordance with the invention, a sensor 100 as illustrated schematically in FIG. 1 is interposed in the recirculation pipe. This sensor consists of a pipe segment made up of two conductive elements 20 and 21 which delimit an insulating element 22 having a length L which will hereinafter be designated as an insulating segment. The conductive elements are connected to the remainder of the insulating pipe 23 and 24 in a conventional manner. The combination of the two conductive elements 20 and 21 and of the insulating segment 22 constitutes a sensor 100 which is adapted to cooperate with an electronic circuit 101 shown in FIG. 2. The design function of said sensor as contemplated by the invention is to measure the variations in conductivity of the fluid and the frequency of such variations, the measurement being performed at the level of said insulating segment 22. A comparison is then made with a reference signal which makes it possible to obtain an output logical signal having a level 0 to 1 which can be employed as the control signal of a safety device.
One example of construction of an electronic circuit 101 of this type is illustrated schematically in FIG. 2. This circuit essentially consists of four elements or subassemblies A, B, C, D, the functions of which are described hereunder.
These subassemblies are essentially as follows:
A: a generator for producing voltage which is a function of the variations in conductivity of the fluid segment contained in the insulating segment 22 of the sensor 100;
B: a bandpass filter for delivering a filtered signal;
C: a voltage-amplifying peak detector;
D: a comparator.
The first subassembly A comprises the sensor described earlier and the variation in conductivity which occurs at the level of the insulating segment 22 is indicated by the conventional representation of a variable resistance (a). The conductive element 200 is connected to ground M. This variation in conductivity (a) is converted to a variation in voltage by means of the load resistor 32. An amplifier 33 produces a substantial drop in the impedance applied to its input 31. The signal 34 at the output of the amplifier 33 has a voltage equal in value to that of the signal 31 and is filtered in subassembly B of the circuit 101 by means of a bandpass filter constituted by the resistors R1 and R2 and the capacitors C1 and C2, said bandpass filter being in turn followed by an amplifier 35. The resultant filtered signal 36 is applied to the input of subassembly C of the circuit 101 which performs the function of peak detector and voltage amplifier. This circuit element or subassembly C comprises three resistors R4, R5, R6, a capacitor C3, a diode D1 and an amplifier 37. Said subassembly generates a direct-current voltage 38 which is a function of the peak values of the signal 36 and therefore of the rapid variations in conductivity of the fluid which circulates within the insulating segment 22. Subassembly D is a comparator composed of an operator 40, the function of which is to compare the signal 38 with an adjustable reference signal 39 in order to deliver an output signal S.
When the flow of fluid within the insulating segment 22 is satisfactory, the entire safety device constituted by the combination of sensor 100 and of circuit 101 generates a signal having a logic level "1" at the output S. If the flow is either zero or non-turbulent as a result of low vacuum within the pipe, the output S of the device generates a signal having a logic level "0". This signal S which is representative of the state of turbulence of the fluid can serve as a control signal for a safety device.
A safety device in accordance with the invention as applied to an ink-jet printer is represented schematically in FIG. 3. A printer of this type essentially comprises an ink reservoir 11 and a first pump 12 for putting this ink under pressure. The ink is then directed via a supply line (fe) to the device 13 for forming the jet 14 consisting of a succession of calibrated ink drops. These drops are charged electrostatically by means of charging electrodes 15 before passing between two deflecting plates 16 in order to be deflected and directed to a substrate to be printed (not shown in the drawings). The unused drops are collected by a recirculation trough 17 and returned via a recirculation pipe (f2) to the ink reservoir 11 by second pumping means such as a recirculating pump 19.
In accordance with the invention, a safety device 1 formed by the combination of a sensor 100 and an associated electronic circuit 101 is interposed in the recirculation circuit (f2) between the collecting trough 17 and the recirculating pump 19. The schematic diagram shows the insulating segment 22 having a length L which is rigidly fixed to the conductive elements 21 and 20 on each side of said segment. The element 20 is connected to ground M and the element 21 is connected to the input of the electronic circuit 101 comprising four circuit subassemblies A, B, C, D, the structure and functions of which have been defined earlier. The ink used for the formation of drops which are intended to be charged electrostatically is conductive by nature. At the level of the recovery pipe (f2) which connects the collecting trough 17 to the pump 19, a turbulent flow must take place in order to ensure correct operation. The level of optimum turbulence is known in the case of each application as a function of the different parameters which characterize the printer such as type of ink, size of drops, dimension of piping, and so on. For example, in the case of a tube 2 mm in diameter and a vacuum of approximately 200 millibars, the variation in conductivity takes place within a spectrum comprising a large number of components ranging from 40 to 100 Hz. As has been stated earlier, the safety device 1 has the function of performing measurements in order to determine whether the level of turbulence satisfies these criteria within the recirculation pipe (f2). Should this be the case, the output signal S is at level 1; otherwise it is at level 0. Arrangements can then be made to overcome this operational fault and to prevent any danger of ink overflow.
In an alternative embodiment of the invention, the first conductive portion of the sensor 100 is constituted by the ink-drop collecting trough 17 itself. This is conducive to a response time of minimum duration between the appearance of a fault condition and activation of safety system circuits.
A safety device of this type serves to protect the integrity of equipment and its environment. Indeed an overflow of unrecovered ink to be recirculated has a damaging effect and must be avoided as far as possible.
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A safety device for the conductive-fluid circulation system of an ink-jet printer consists of a sensor and an associated electronic circuit inserted between an ink-drop recovery trough and a recirculating pump. The level of turbulence of the fluid flow within a pipe segment of insulating material located between two conductive pipe segments is determined by the sensor by measuring the variation in conductivity in relation to variations in cross-sectional area of fluid within the insulating pipe segment and by delivering a control logic signal.
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This invention claims priority of U.S. provisional application No. 60/080,887 filed on Apr. 7, 1998, the complete disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to non-swiveling, motion furniture that reclines from an erect position to one or more reclined positions, especially low-leg motion furniture.
2. Description of the Related Art
On most reclining chairs, the base is supported from the floor by glides provided on the underside of the base. For such chairs, the actual supporting glides and feet attached thereto, if any, are commonly hidden from view. False showy feet are sometimes attached to the arm frames of the chairs, although such false showy feet are typically spaced from or barely contact the ground so as not to constitute part of the supporting structure.
Another type of reclining chair known in the art is the high-leg-style recliners, which are characterized by relatively tall legs supporting the arm frame from the floor. The base of the mechanism is supported at an elevated level between the arm frames. One such exceptional high-leg recliner is the subject of U.S. Pat. No. 5,013,084 to May, issued May 7, 1991, the complete disclosure of which is incorporated herein by reference. A commercial version of the mechanism depicted in that patent is known as the Action Industries Inc. high leg recliner 2700 mechanism.
As shown by this sequence of movements depicted in FIGS. 2-4 of the '084 patent, movement of the chair from the fully erect position (depicted in FIG. 2 of the '084 patent) to the partially or fully reclining positions (respectively depicted in FIGS. 3 and 4 of the '084 patent) requires that the primary ottoman pivot downward far below the base of the chair and behind the secondary ottoman, before being pivoted upwardly and forwardly to the extended positions.
Apparently, there is a segment of the potential market for reclining chairs which is under served. This segment is composed of potential customers who like some decorative wood showing at the lower corners of their upholstered chairs, but do not want a high-leg-style recliner. However, substitution of the reclining assembly disclosed by the '084 patent into a low-leg-style recliner is not possible, since the proximity of the floor to the chair base would cause the floor to obstruct the pivotal movement of the ottoman into its extended position.
SUMMARY OF THE INVENTION
A low-leg reclining chair disclosed herein includes a base, right and left sides, a seat, a back, and an ottoman having first and second sections. The seat, back, and first and second sections of the ottoman are interconnected by a reclining mechanism that permits movement of the seat, back and ottoman between a fully erect position and at least one reclining position. In the fully erect position, the primary section remains exposed along the chair beneath the seat with the secondary section tucked therebehind. In the reclining position, both the primary and secondary sections are fully extended with the secondary section positioned between the primary section and the seat.
BRIEF DESCRIPTION OF THE DRAWINGS
The following drawings assist in elucidating the principles of this invention. In such drawings:
FIG. 1 is a schematic of a side elevation view of one side mechanism, particularly showing the inboard side of a right side mechanism in its fully erect position and adapted for three-way operation;
FIG. 2 is a schematic of a side elevation view of the mechanism of FIG. 1 in its TV position; and
FIG. 3 is a schematic of a side elevation view of the mechanism of FIGS. 1 and 2 in its fully reclined position.
DETAILED DESCRIPTION OF THE INVENTION
Although it is difficult to draw a distinct definitional line between a short-leg recliner chair and a high-leg recliner chair, a good working definition is that a high-leg recliner has at least five inches of leg protruding downwards to the floor from the lower edge of the ottoman when the chair is fully erect, and an overall style that permits a five-foot six-inch tall person to see the floor under the center of the chair when the chair is fully erect and the person is standing across the room, e.g., at a distance of fifteen feet from the chair. Often, although not essentially, a high-leg recliner has exposed wood legs, often including longitudinal (i.e., front to back) and/or transverse horizontal rungs interconnecting vertically intermediate sites on the legs and/or one another. Also, often, although not essentially, a short-leg recliner has a depending skirt around the lower margin of the upholstered frame.
For convenience in description in referring to the chair and mechanisms, the term "inboard" refers to towards the longitudinal median of the chair; "outboard" refers to the laterally, transversally outwards direction away from the longitudinal median. The terms "right" and "left" are used assuming the perspective of an occupant of the chair.
Although the chair 100 shown in FIG. 1 incorporates reclining mechanism 102, the reclining mechanism 102 is hidden by upholstery and other chair structure in FIG. 1. The chair 100 is shown in its fully-erect position in FIG. 1. In this position, the chair back is up, and the ottoman is stowed.
The chair 100 includes an upholstered base frame 104 which includes left generally vertical side 106 and right generally vertical side (not shown) topped by generally horizontal, longitudinally extending arms 108 (in this instance upholstered, rolled arms), and a set of depending legs 110 for supporting the chair 100 on a floor.
The chair base frame 104 is shown being upholstered, as arc the other components (apart from the mechanisms 102, which will be described below). Conventional upholstery of cloth and/or leather may be used, as may be synthetic sheets and composites such as "vinyl" upholstery. The mechanisms of the invention impose no particular limitations on the materials that the chair can be made of, as it is believed a person of ordinary skill in the art will readily understand. Preferred materials used for manufacturing the chair (apart from the mechanisms) include particle board, wood, mechanical fasteners, adhesive, batting, foamed plastic, chair springs, non-woven fiber, cloth and miscellaneous hardware. The mechanisms are preferably predominately made of links cut and bent from steel plate and painted matte black, these being interpivoted, connected and stopped by steel pins and rivets, with bushings of lubricous plastic sheet material interposed between members of joints. Springs are made of spring steel.
The chair 104 further includes a seat 112 and a back 114. It is conventional for recliner chairs to have two-part ottomans (which some people would call a leg-rest or a foot-rest), i.e., a primary ottoman 116 (the one that is exposed in FIG. 1) and a secondary ottoman 118 which, in the fully-erect position of the chair may be hidden in back of the primary ottoman 116.
The chair back 114 need not have wings 120, but wings 120 on such chairs arc a popular feature. In some low-leg recliners, the seat comprises an underlying support attached to the side mechanisms and surmounted by a loose cushion. In other instances, the support structure and cushion are built into a unitary assembly which is mounted as a whole to the side mechanisms.
In the chair 100 provided with the mechanism of the present invention, there is preferably no hand crank or motor for operating the chair. Rather, the fully-erect chair is operated by an occupant by pushing forwards on the arms 108 relative to the seat 112 to extend the ottomans 116 and 118 and move the seat 112 somewhat forwards relative to the base 104 to achieve the TV position. In instances where the chair 100 is a three-position chair, full recline is achieved from the TV position, by the occupant by pushing back with his or her shoulders on the upper part of the chair back 114, causing the chair 100 back to tilt down relative to the base 104 (and also lowering the seat relative to the base104), thereby lowering the chair/occupant composite center of gravity as reclining of the back 114 shifts the composite center of gravity rearwardly, thereby preserving tolerable stability.
The mechanism 102 shown in FIGS. 1-3 is a right side mechanism. The chair 100 is provided with both a left side mechanism and a right side mechanism, one being a mirror image of the other, each being comparably mounted to the chair parts and the two cooperating as the chair is operated.
The mechanism 102 includes a long, upper longitudinal link 122, which, like all the links to be described is preferably stamped, bent and punched or drilled from metal plate. The links are preferably planar, except that many of the links have one or more shallow-S double bends in them, where necessary to prevent the links from interfering with position or intended loci of movement of one another. Thus, for instance, the forward end portion of the link 122 jogs inboard by one thickness at 124 and the rear portion thereof jogs inboard by three thicknesses at 126, both compared with the central portion of the long link 122. The rear portion of the link 122 is shaped as an upwardly projecting spur 128.
The central portion of the long link 122 is shown provided with a series of holes 130 to receive fasteners for fastening the mechanism to a respective side of the seat 112 of the chair 100.
The mechanism 102 further includes a base-mounting bracket 132 which is provided by a link folded along a longitudinal axis so as to have an outboard vertically-oriented, longitudinally-extending flange 134 which extends throughout approximately the rear eighty percent of the bracket 132, and a generally horizontally, inboard-extending flange at the lower extent of the flange 134, which extends throughout approximately the foremost two-thirds of the bracket 132. The flange 136 is provided with a series of holes 136 to receive fasteners for fastening a respective side 106 of the base frame 104 to the mechanism 102. The flange 134 is located inboard of the central portion of the long frame-mounting link 122 by about seven link thicknesses.
The feature indicated on the flange 134 is not a slot; rather it is an outboard-facing groove embossed in the link, which causes a corresponding low ridge extending along the inboard face of the flange 134, the purpose of such embossment being to impart improved anti-bending strength to this link. (Other links are shown having similar embossments, as will be briefly pointed out as the respective links are described in the description below.)
The link shown located furthest outboard on the mechanism 102 is the flat, V-shaped back-mounting link 140, located on the outboard side of the spur 128 of the seat-mounting link 122. The link 140 is shown provided through the thickness thereof with a series of vertically spaced holes 142 for receiving fasteners for securing the link to a respective edge of the chair back 114.
At its forward end (when in the closed position shown in FIG. 1, equating to the fully erect position of the chair), the mechanism 102 has a primary ottoman mounting bracket 144 in the form of a link folded along a line which is substantially vertical when the mechanism 102 is in its closed position, so as to have at its forward margin a face provided with a series of vertically spaced openings for mounting a corresponding end of the primary ottoman 116 thereto.
By preference, the chair 100 further includes a secondary ottoman 118, and, for mounting it, the mechanism preferably includes a secondary ottoman mounting link 146.
The links and brackets by which the mechanism 102 unites the chair 100 into a unitary structure carried on the chair base have all been introduced above; the remainder of the description relates how the links and brackets of a mechanism 102 are interconnected and how they interact in use. Unless the contrary appears, all of the rivets, pivot joints and pins described below have transverse horizontally-extending main axes (i.e., their own longitudinal axes extend crosswise of the chair and are horizontal). Even if not specifically mentioned, any of the pivot joints can include washer-like bushings, e.g., made of a lubricous synthetic plastic material such as nylon, between the interpivoted parts and/or between the pivot pin head and/or upset tail and the respective adjacent part. And any stop pin or mounting pin may be a plain metal pin, or, where cushioning or noise-reduction is a consideration, a metal pin sleeved with a tubular bushing of lubricous synthetic plastic material such as nylon.
A multiple-link lazy tongs-type linkage 150 is provided at the front end of the seat-mounting link 122 for mounting the primary ottoman-mounting bracket 144 and secondary ottoman-mounting link 146.
The linkage 150 is shown comprising upper and lower forward links 152, 154 and upper and lower rear links 156, 158.
The front ends of the upper and lower forward links 152, 154 are connected one above the other (in the closed position of the mechanism in FIG. 1) to the longitudinal flange of the primary ottoman mounting bracket 144 by respective pivot joints 160, 162.
The rear ends of the upper and lower rear links 156, 158 are connected one in front of and above the other to the forward portion of the seat-mounting link 122 by respective pivot joints 164, 166.
A pivot joint 168 is provided where the upper forward link 152 crosses the upper rear link 156, located approximately eighty percent down from the upper ends of these links. The lower end of the lower front link 154 is connected to the lower end of the upper rear link 156 by a pivot joint 170, and the lower end of the upper front link 152 is connected to the lower end of the lower rear link 158 by a pivot joint 172. In the preferred embodiment, the upper rear link 156 is flat, the central approximately eighty percent of the lower front link 154 is jogged outboards by about two link thicknesses, and the upper approximately twenty percent of the upper and lower rear links 156 and 158 are jogged outboards by about three link thicknesses.
An inboard-extending pin 174 provided on the upper rear link 156 about one-third back from its front end is available to engage the upper edge of the upper front link 152 at 176 and 178 to provide respective stops limiting retraction and extension of the lazy tongs linkage as the primary ottoman is stowed and deployed.
The secondary ottoman mounting link 146 is connected to upper front link 152 at joint 180 and to lower front link 154 at joint 182, which (as depicted in the fully erect position of FIG. 1) is vertically below joint 180. Accordingly, as the primary ottoman 116 is extended from its stowed, on edge, location under the front lip of the seat 112, the secondary ottoman-mounting link 146 pivots the secondary ottoman 118 through approximately ninety degrees back towards the seat 112 (clockwise in the figures). The secondary ottoman 118 is thereby moved from a vertically oriented position behind the primary ottoman 116 (see FIG. 1) to a horizontal position (see FIGS. 2 and 3) substantially horizontal and coplanar with primary ottoman 116, with joint 182 positioned slightly higher than joint 180.
The seat-mounting link 122 is shown provided with front and rear depending links 198, 200 respectively connected at their upper ends to the central portion of the link 122 about one-third back from the front end of the link 122 by a pivot joint 202, and to the base of the spur 128 near the rear end of the link 122 by a pivot joint 204.
The front depending link 198 has a depending toe 206 projecting forwards. The lower sixty percent of the link 198 is jogged inboards about four link thicknesses compared to the upper twenty percent thereof. The toe 206 includes joint 208.
An ottoman lazy tongs operator link 210 has a rear, lower end connected to the toe 206 of the front depending link 198 by the pivot joint 208, and a front, upper end connected to a site on the lower rear link 158 of the lazy tongs about forty percent of the way down from the upper end of that link, by a pivot joint 212.
Accordingly, when the front depending link 198 swings forwards about its upper end 202, the operator link 210 has its rear, lower end pushed towards the pivot joints by which the upper and lower rear links 156 and 158 are connected to the base-mounting link 122, thereby extending the lazy tongs and thrusting the ottoman 116. The reverse happens as the front depending link swings 198 rearwards about its upper end 202.
The back-mounting link 140 is a generally V-shaped link the rear leg of which is shown being somewhat less tall than the forward leg thereof. One of the holes for mounting the back is shown provided at the upper end of the forward leg, and the other is shown provided about forty percent up the rear leg from the lower end. The back-mounting link 140 is shown connected near its lower end, in the region where its legs join, to the spur 128 of the seat-mounting link 122, near the upper end of the spur 128, by a pivot joint 141.
About three-quarters of an inch about the joint 141, the link 140 is provided with an inboard-projecting pin 143 which is available to engage the rear edge of the spur 128 above the joint 141 as the chair 100 is erected for defining the location of the back in the fully-erect position of the chair and helping to maintain the back tightly in place in the closed position of the mechanism.
The mechanism 102 further includes an operator link 220 for the back-mounting link 140. The operator link 220 has an upper end connected to the upper end of the rear leg of the back-mounting link 140 by a pivot joint 222, and a lower end connected to the rear end of the vertical, longitudinal flange of the base-mounting bracket 132 by a pivot joint 224. Accordingly, when the base-mounting bracket 132 translates forwards relative to the seat-mounting link 122, and the latter tips upwards to the front slightly as the mechanism opens from the fully closed (FIG. 1) to the TV position (FIG. 2), the operator link 220 mainly merely pivots forwards around its upper end, but also is pulled slightly downwards in a translational sense, so that the back-mounting link 140 tilts slightly to the rear, thus slightly tilting the back of the chair 100.
The upper ten percent of the operator link 220 is jogged about five link-thicknesses outboards relative to the lowest two-thirds of that link. An impressed stiffening ridge is also present at 222.
If the chair 100 is provided to have a third, fully-reclined position (FIG. 3), in achieving this position from the TV position (by means hereinafter more fully described), the front of the seat-mounting link 122 raises about one and a quarter inches, and the rear of the seat-mounting link 122 raises about one half of an inch and the seat-mounting link 122 swings rearwards about one-quarter of an inch. This action, in combination, pulls downwards and forwards on the back-mounting link operating link 220, causing the latter to rotate rearwardly about its connection to the spur 128 by about fifteen degrees, thereby reclining the chair back.
The remaining structure of the mechanism 102 mounts the base-mounting bracket 132 to the seat-mounting bracket and operates the base-mounting bracket 132 in relation to the seat-mounting bracket, also causing operation of ottoman and chair back as has been described above. The remaining structure of the mechanism 102 is the most difficult to visualize because it is, in general, sandwiched between the longitudinal flange of the base-mounting bracket 132 and the seat-mounting link 122.
The upper end of the rear depending link 200 is shown provided with a rearwardly-extending prong 230. The base link 122 is shown provided at the base of the spur 128, behind and below the pivot joint 204 connecting the upper end of the rear depending link 200 to the seat-mounting link 122, with an inboards-extending pin 232. The pin 232 engages the lower edge of the prong 230 to limit forwards swinging of the rear depending link 200 (and therefore the front depending link 198 and the seat-mounting bracket) relative to the seat-mounting link 122, as the mechanism 102 opens from the closed to the TV position thereof.
A longitudinally short control link 234 is connected by its upper, rear end to the vertical longitudinal flange of the base-mounting bracket 132 about twenty-five percent forwards from the rear end of the base-mounting bracket 132 and about one-fourth of an inch below the inboards-extending flange of the base-mounting bracket 132, by a pivot joint 236. The link 234 is about two inches long. Its forward, lower end is jogged outboards relative to its rear, upper end by about three link thicknesses. That outer portion is provided with a slot 238, elongated along the length of the link 234, and a sliding, pivotal connection is made between such portion and the lower end of the rear depending link 200 by a pivot joint 240 which can slide along the slot 238.
When the mechanism 102 is closed, the link 234 projects downwards and slightly forwards and the pivot joint 240 is located at the upper end of the slot 238. As the mechanism opens from the closed position (FIG. 1) to the TV position (FIG. 2), the link 234 pivots forwards about fifty degrees about its upper end as the pivot joint 240 slides to bottom of the slot 238. As the mechanism 102 moves from the TV position to the fully-reclined position, the link rotates approximately seventy degrees further in the same direction (so that the control link projects upwards and forwards at about a forty-five degree angle) and the pivot joint 240 slides back to the same end of the slot it occupied in the closed (FIG. 1) position. (Because the control link has rotated so much between its FIG. 1 and FIG. 3 positions that it has become generally inverted, the lower end of the slot 238 in FIG. 1 will be called its outer end, and the upper end of the slot 238 in FIG. 1 will be called its inner end, both relative to the pivot joint 236.)
The mechanism 102 further includes three boomerang (or arcuate)-shaped links, namely a forward long one 242, which is concave upwards, a rear long one 244, which is concave downwards, and, under the rear half of the rear long arcuate link, a rear short arcuate link 246, which is concave upwards.
The forward upwardly-concave arcuate link 242 is connected in its central elbow region to the vertical longitudinal flange of the base-mounting bracket 132 near the fold line of the base-mounting bracket 132, about one-third of the way back from the front end of the base-mounting bracket 132, by a pivot joint 248. The front end portion (about three-quarters of an inch) of the link 242 is jogged outboards by about two link thicknesses, and about the same amount of the rear end portion is jogged outboards by about one link thickness.
The front end of the link 242 is connected to the base of the upright standard of the front depending link 198 by a pivot joint 250.
In the closed position (and in the TV position), an inboards-projecting pin 252 provided on the front arm of the link 242 about two-thirds of the way forwards along that arm from the pivot joint 248, engages on a recessed upper edge region of the vertical longitudinal flange of the seat-mounting bracket.
In the fully-reclined position (FIG. 3), an upper edge portion of the link 242, forwardly of the pivot joint 248, engages an outboards-extending pin provided on the vertical, longitudinal flange of the base-mounting bracket for limiting tilting-down of the back and raising of the seat, both relative to the base-mounting link 122.
The rear upwardly-concave link 246 is connected at its central bend to the vertical, longitudinal flange of the base-mounting bracket at the rear end of the latter, below the connection of the lower end of the back-operating link to that flange, by a pivot joint 254.
The forward end of the rear upwardly-concave link 246 is connected to the rear depending link 200 about forty percent of the way up from the lower end of the latter, by a pivot joint 256.
The link 246 remains immobile as the mechanism moves between its fully closed (FIG. 1) and TV (FIG. 2) positions, with an outboards-projecting pin 258 on the vertical, longitudinal flange of the base-mounting bracket 132 engaging the lower edge of the link 246 approximately midway between the pivot joints 248 and 256.
The mechanism 102 is shown provided with aligned openings 260, 262 through the vertical, longitudinal flange of the base-mounting bracket 132 above the pin 258 and through the link 246. For restricting the chair 100 to having only a fully-erect and a TV position, a rivet can be installed through the aligned openings 260, 262, as well.
The rear, concave-downwards link 244 has its rear end connected to the rear end of the link 246 by a pivot joint 266 and its front end connected to the rear end of the forward concave-upwards link 242 by a pivot joint 267. The links 242, 244, 246, and 247 remain immobile as the mechanism 102 moves between its closed (FIG. 1) and TV (FIG. 2) positions.
As the mechanism 102 moves from the TV position (FIG. 2) to the fully-reclined position (FIG. 3), the forward, upwardly-arcuate link 242 rocks towards the rear about its central pivot joint, thus raising the front of the seat-mounting link 122 relative to the base-mounting bracket 1322, shifting the rear, downwardly-concave link 244 rearwards, thereby raising the rear of the seat-mounting link 122.
The raising of the rear of the seat-mounting link pulls down the lower end of the back-operating link, thereby fully reclining the chair back.
When the mechanism is in its TV position (FIG. 2), the ottoman can be retracted by the occupant by pulling backwards with his or her heels on the front edge of the primary ottoman 116, while pushing forwards on the arms 108 the chair. However, when the chair 102 is in its fully-reclined position, the pivotal connection of the front end of the rear upwardly-concave link to the intermediate location on the rear depending link forces the pivot joint at the lower end of the rear depending link along the slot in which it is mounted, to the inner end of that slot, and the angular orientation of the link in which the slot is provided then prevents the rear depending link from swinging about its upper end pivot joint, thus preventing the ottoman from being retracted. In other words, the ottoman-mounting lazy tongs is locked in an extended condition so long as the chair back is fully reclined.
In the preferred embodiment, the seat-mounting link is about sixteen inches long (as projected onto a horizontal, longitudinally-extending line, i.e., not adding five more inches for the distance up the spur 128, but only the about two inches that the spur projects rearwards of its own base on the link 122).
Erecting the chair from a reclined position, to a TV position, and to a fully-erect position involves a reversal of the steps explained above. The weight of the person, concentrating on the seat, pushes the seat down, pulling up the back, whereupon ottoman retraction is assisted by the person's heels.
It should now be apparent that the mechanism for low-leg reclining chair as described hereinabove, possesses each of the attributes set forth in the specification under the heading "Summary of the Invention" hereinbefore. Because it can be modified to some extent without departing from the principles thereof as they have been outlined and explained in this specification, the present invention should be understood as encompassing all such modifications as are within the spirit and scope of the following claims.
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A low-leg reclining chair disclosed includes a base, right and left sides, a seat, a back, an ottoman having a primary section and a secondary section. The seat, back and the primary and secondary sections of the ottoman are interconnected by reclining mechanisms mounted as mirror-image duplicates of each other on the sides of the chair. The reclining mechanisms permit movement of the seat, back and ottoman between a fully erect position, in which the primary section remains exposed along the chair beneath the seat with the secondary section concealed behind the primary section, and at least one reclining position, in which both the primary and secondary sections are extended with the secondary section positioned between the primary section and the seat. The reclining mechanisms include a multiple-link linkage subassembly having upper and lower forward links that interconnect the primary and secondary sections to a seat-mounting link. The secondary section is connected to the multiple-link linkage subassembly with a one-piece secondary ottoman-mounting link that is simultaneously pivotally connected to the upper forward and lower forward links.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 595,374, filed Mar. 30, 1984, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to a method for producing synthetic hydrotalcite.
Hydrotalcite is a naturally occurring mineral having the formula 6 MgO.Al 2 O 3 .CO 2 .12 H 2 O or Mg 6 Al 2 (OH) 16 CO 3 .4 H 2 O. Known deposits of natural hydrotalcite are very limited and total only about 2,000 or 3,000 tons in the whole world. Natural hydrotalcite has been found in Snarum, Norway and in the Ural Mountains. Typical occurrences are in the form of serpentines, in talc schists, and as an alteration product of spinel where, in some cases, hydrotalcite has formed as pseudomorphs after spinel.
The upper stability temperature of hydrotalcite is lower than the lower limit for spinel. Spinel and hydrotalcite theoretically never would appear together in stable condition. If equilibrium has been established, the spinel would be completely changed to hydrotalcite. However, naturally occurring hydrotalcite is intermeshed with spinel and other materials.
Natural hydrotalcite is not present as pure product and always contains other minerals such as penninite and muscovite and potentially undesirable minerals such as heavy metals. Conventional practice recognizes that it is practically impossible to remove such impurities from a natural hydrotalcite.
Previous attempts to synthesize hydrotalcite have included adding dry ice or ammonium carbonate (a) to a mixture of magnesium oxide and alpha-alumina or (b) to a thermal decomposition product from a mixture of magnesium nitrate and aluminum nitrate and thereafter maintaining the system at temperatures below 325° C. at elevated pressures of 2,000-20,000 psi. Such a process is not practical for industrial scale production of synthetic hydrotalcite by reason of the high pressures. Furthermore, the high pressure process forms substances other than hydrotalcite, such as brucite, boehmite, diaspore, and hydromagnesite.
Ross and Kodama have reported a synthetic mineral prepared by titrating a mixed solution of MgCl 2 and AlCl 3 with NaOH in a CO 2 free system and then dialyzing the suspension for 30 days at 60° C. to form a hydrated Mg-Al carbonate hydroxide. The mineral product has been associated with the formula Mg 6 Al 2 CO 3 (OH) 16 .4 H 2 O while having the properties of manasseite and hydrotalcite. X-ray diffraction powder patterns have indicated that the mineral more closely resembles manasseite than hydrotalcite, while the differential thermal analysis curve of the precipitate has been characterized as similar to that given for hydrotalcite.
Kerchle, U.S. Pat. No. 4,458,026, discloses a preparation of Mg/Al/carbonate hydrotalcite which involves the addition of mixed magnesium/aluminum nitrates, sulphates or chlorides as an aqueous solution to a solution of a stoichiometric amount of sodium hydroxide and carbonate at about 25°-35° C. with stirring over a several-hour period producing a slurry. The slurry is then heated for about 18 hours at about 50°-200° C. (preferably 60°-75° C.) to allow a limited amount of crystallization to take place. After filtering the solids, and washing and drying, the dry solids are recovered.
Kumura et al. U.S. 3,650,704, reports a synthetic hydrotalcite preparation by adding an aqueous solution of aluminum sulfate and sodium carbonate to a suspension of magnesium hydroxide. The suspension then can be washed with water until the presence of sulfate radical becomes no longer observable. The suspension is heated at 85° C. for three hours and dried. The magnesium component starting material is reported as any member of the group consisting of magnesium oxide, magnesium hydroxide, magnesium carbonate, and water-soluble magnesium salts, e.g., such as mineral acid salts including magnesium chloride, magnesium nitrate, magnesium sulfate, magnesium dicarbonate, and bittern.
It is an object of the present invention to produce synthetic hydrotalcite in high purity.
It is another object of this invention to produce hydrotalcite in high yield at atmospheric pressure.
SUMMARY OF THE INVENTION
The present invention includes a method for producing hydrotalcite including reacting an activated magnesia with an aqueous solution of aluminate, carbonate, and hydroxyl ions. The method can be carried out at atmospheric pressure to form hydrotalcite in high purity and high yield. Activated magnesia is formed by heating a magnesium compound such as magnesium carbonate or magnesium hydroxide to a temperature between about 500°-900° C.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graphical depiction of a powder X-ray diffraction pattern obtained from synthetic hydrotalcite produced by the method of the present invention.
FIG. 2 is a graphical depiction of the differential thermal analysis of synthetic hydrotalcite obtained by the method of the present invention.
FIG. 3 is a photographic representation of synthetic hydrotalcite obtained by the method of the present invention.
DETAILED DESCRIPTION
The present invention produces synthetic hydrotalcite by reacting activated magnesia with an aqueous solution of aluminate, carbonate, and hydroxyl ions. The magnesia must be activated to produce hydrotalcite in high purity. Otherwise, i.e., in the event that an unactivated magnesia is used, the resulting product will include substantial amounts of mineral forms other than hydrotalcite.
The activated magnesia can be formed by activating magnesium compounds such as magnesium carbonate or magnesium hydroxide at temperatures of between about 500°-900° C. Below 500° C, the magnesium salt will not activate sufficiently and will contain inhibiting amounts of the starting material. Above 900° C, the resulting magnesium oxide takes on a form which is insufficiently active. The insufficiently active magnesia could be characterized as dead burnt. Such a form of magnesia will not form hydrotalcite predominantly over other mineral forms. The insufficiently active form of magnesia which is nonspecific to forming hydrotalcite will be avoided by heating the magnesium salt starting materials to elevated activating temperatures, but which must not exceed about 900° C., to form the activated magnesia or magnesium oxide (MgO).
The activated magnesium oxide is added to a solution containing ions of aluminate, carbonate, and hydroxl. Preferably the activated magnesium oxide is added to an aqueous solution having a pH above about 13. For example, a suitable solution may contain alkali hydroxide, alkali carbonate, and aluminum oxide. Industrial Bayer process liquor used for the production of alumina from bauxite is a suitable solution containing sodium hydroxide, sodium carbonate, and aluminate ions. A Bayer process liquor containing excess alumina also is suitable.
By way of example, 5-25 grams per liter of activated MgO can be added to 120-250 g/1 NaOH (expressed as Na2C03) ' 20-100 g/1 Na 2 CO 3 , and 50-150 g/l Al 2 O 3 in an aqueous solution. The mixture should be agitated at a temperature of about 80°-100° C. for 20-120 minutes.
It has been found that magnesium compounds other than the activated magnesia of the present invention produce less than desirable results. For example, MgSO 4 , MgCl 2 , or MgNO 3 added to Bayer liquor yields Mg(OH) 2 and Al(OH) 3 . Similarly, Mg(OH) 2 added to Bayer liquor remains mostly unreacted.
The process of the present invention produces hydrotalcite in high yield. By high yield is meant a conversion yield greater than about 75% and preferably greater than about 90%.
The mineral produced by the method of the present invention can be analyzed by powder X-ray diffraction. The product formed by Example 2 of this specification was analyzed in powder form in a Siemens X-ray diffractometer having Model No. D-500 supplied by Siemens AG (W. Germany). The resulting X-ray diffraction pattern is depicted in FIG. 1. The diffraction pattern indicates that the product is hydrotalcite at high purity. The dÅ spacing obtained by X-ray diffraction is shown in Table I for the mineral obtained from the method of Example 2 and is compared to (1) the ASTM standard for hydrotalcite and (2) natural hydrotalcite as reported by Roy et al. American Journal of Science, Vol. 251, at page 353. By these indications, the process of the present invention produces hydrotalcite in high purity.
High purity in the context of the present invention is established by the absence of diffraction lines attributable to compounds other than hydrotalcite. The absence of diffraction lines indicates that such other compounds are not present in any significant amount. By way of contrasting example, the material produced in Example 1 described hereinbelow using a non-activated magnesium oxide contains lines or peaks indicating the presence of compounds other than hydrotalcite. These lines are observed in the data in Table I for the dÅ spacing of the product from Example 1.
TABLE I__________________________________________________________________________X-RAY DIFFRACTION Natural HydrotalciteASTM (22-700) (Snarum, Norway) Example 1 Example 2dÅ I/I Max. dÅ I/I Max. dÅ I/I Max. dÅ I/I Max.__________________________________________________________________________7.84 100 7.63 100 12.4676 4.3 8.8729 3.73.90 60 3.82 50 12.3128 4.8 7.7348 99.22.60 40 2.56 10 12.1094 4.2 7.6746 100.02.33 25 2.283 5 11.8579 5.5 6.0944 5.01.990 30 1.941 10 11.5907 4.2 6.0194 4.71.950 6 1.524 5 11.3070 4.7 5.9257 5.91.541 35 1.495 5 11.1268 4.2 4.0786 8.61.498 25 10.9421 4.2 3.9498 30.01.419 8 10.5889 4.1 3.8387 60.91.302 6 4.7678 45.7 3.8192 64.51.265 10 4.6131 6.9 2.6644 4.01.172 2 4.5742 6.0 2.5765 80.10.994 4 4.5429 3.9 2.5204 25.20.976 6 4.5093 5.3 2.5102 21.7 4.4645 4.9 2.4960 14.9 4.4154 3.3 2.4840 13.0 4.3161 3.3 2.4643 10.8 4.2944 3.0 2.4526 11.4 4.2552 3.2 2.4364 10.0 4.2163 5.9 2.0677 3.7 4.1814 5.4 2.0530 5.7 4.1349 7.4 2.0477 3.3 4.1009 6.9 2.0467 3.9 4.0676 9.7 2.0401 4.9 3.9759 13.9 2.0318 7.4 2.7284 5.4 2.0221 6.7 2.6458 4.1 2.0191 6.6 2.5774 30.4 2.0041 12.4 2.4920 7.3 1.9976 10.3 2.4800 6.6 1.5239 38.8 2.4660 8.0 1.5115 18.4 2.4372 19.9 1.4963 34.1 2.3703 100.0 1.3209 2.0 2.3191 15.5 1.3180 2.8 2.2869 17.1 1.3161 4.1 1.9616 5.2 1.3114 4.1 1.9465 9.7 1.3099 3.3 1.9372 8.3 1.2771 4.1 1.9302 8.2 1.2722 5.2 1.9244 7.3 1.2692 4.3 1.8194 5.0 1.2689 5.6 1.7953 27.1 1.2662 6.8 1.5740 29.2 1.2632 4.1 1.5614 3.0 1.5557 4.2 1.5347 4.7 1.5225 18.2 1.5102 7.9 1.4918 87.7 1.3745 4.9 1.3719 5.2 1.3692 3.0 1.3176 2.2 1.3121 7.8 1.3089 8.4__________________________________________________________________________
The product of Example 2 was analyzed by differential thermal analysis (DTA). FIG. 2 presents a graphical illustration of the DTA for the product of Example 2 which represents hydrotalcite in a high purity.
The synthetic hydrotalcite produced by the present invention is a highly porous mineral. A photograph by scanning electron micrograph was taken of the product of the process carried out in Example 2 and is presented as FIG. 3. The photograph illustrates the mineral product at a 5,000X magnification. The mineral can be seen to have a high surface area and high porosity.
Synthetic hydrotalcite produced by the process of the present invention has utility in one aspect in purification applications such as a filter aid. The synthetic hydrotalcite is adaptable in other aspects as a fire retardant material which releases water and CO 2 on heating. Other applications include a filler material for paper or as a drying, bleaching, or absorbent material after activation by heating to over about 500° C. Synthetic hydrotalcite produced by the process of the present invention also is useful in purification and catalytic applications by virtue of an anion exchange capability wherein carbonate anion can be replaced with other anions without destroying the structure of the compound .
EXAMPLE 1
Magnesium carbonate in an amount of 25 grams was heated to about 1,100° C. for about 45 minutes and allowed to cool. The resulting magnesium oxide was added to a Bayer liquor prepared by digesting Suriname bauxite in a ratio of about 0.65 (defined as Al 2 O 3 /caustic expressed as Na 2 CO 3 , as used in industrial practice) at blow off and then filtered. One liter of Bayer liquor was heated to about 95° C. Ten grams of the magnesium compound treated at 1,100° C. were added. The mixture was agitated for one-half hour and then filtered. The residue was washed and dried at 105° C. overnight.
The resulting product weighed about 16.7 grams which indicates a yield of less than 67%. The product of this Example 1 was analyzed by powder X-ray diffraction and was found to contain predominant amounts of Mg(OH)2 and MgO.
EXAMPLE 2
Activated magnesia was produced by heating 25 grams magnesium carbonate to about 600° C. for 45 minutes. The heating period of 45 minutes was selected to facilitate complete activation. For varying amounts and temperatures, the heating period should be adjusted to achieve an active product. Typical heating periods will range from about 30 to about 120 minutes.
Ten grams of the activated MgO were added to one liter of the same Bayer liquor used in Example 1. The mixture was heated to about 95° C. and agitated for about one-half hour. The mixture was filtered, and the residue was washed and dried at 105° C. overnight. The resulting precipitate had a white appearance, weighed about 22.5 grams, and had a refractive index of 1.50. The precipitate was a fine, free-flowing crystalline powder insoluble in water and organic solvents.
The precipitate was analyzed by powder X-ray diffraction and found to be hydrotalcite in high purity.
The 22.5 grams compares to a theoretical yield of 24.95 grams and indicates a high yield conversion of over 90%.
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Disclosed is a method for producing hydrotalcite in high yield including reacting activated magnesia with an aqueous solution containing aluminate, carbonate, and hydroxyl ions. The method further includes a first step of heating magnesium carbonate or magnesium hydroxide to a temperature between about 500°-900° C. to form activated magnesia or magnesium oxide. The method is suited to producing synthetic hydrotalcite from industrial Bayer liquor.
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BACKROUND OF THE INVENTION
This invention relates generally to a process for the high pressure plasma hydrogenation of silicon tetrachloride, and more specifically to a boron catalyzed reaction for the hydrogenation of silicon tetrachloride.
Most silicon produced today for the semiconductor industry is made by a process wherein trichlorosilane is reduced with hydrogen to deposit polycrystalline silicon on a heated substrate. A large portion of the trichlorosilane used in the reaction is not converted to elemental silicon, however, but instead is converted to silicon tetrachloride. Despite its silicon content, silicon tetrachloride is essentially a low value waste by-product of the reaction. The cost of producing silicon is thus increased by the low efficiency of available silicon usage. One way to reduce the overall cost of producing silicon is to recycle the silicon tetrachloride and convert it into a more usable silicon bearing reactant.
One process for the hydrogenation of silicon tetrachloride to produce trichlorosilane and dichlorosilane is described in U.S. Pat. No. 4,309,259. That patent describes a process whereby silicon tetrachloride is hydrogenated in the presence of a high pressure plasma (HPP) to produce the more valuable silicon bearing compounds in a reaction represented by the equation ##EQU1## The SiCl 4 hydrogenation (conversion) efficiency of this process depends mainly on the H 2 SiCl 4 ratio in the process input gas stream and on the RF power of the HPP plasma. Increasing the H 2 /SiCl 4 ratio in the reactor input gases increases the SiCl 4 conversion efficiency. The maximum usable H 2 /SiCl 4 ratio (and thus the maximum SiCl 4 conversion efficiency), however, is determined by the onset of chlorosilane polymer formation at high H 2 /Sil 4 ratios. The chlorosilane polymers are oily, shock sensitive, hazardous materials which are highly undesirable because of safety considerations. Even very small amounts of polymer formation must be avoided because the polymer deposits on reactor walls and process piping and with time gradually builds up to dangerous levels.
For a given SiCl 4 feed rate and H 2 /SiCl 4 ratio, conversion efficiency increases initially with an increase in RF power, reaches a maximum, and then decreases with further increases in RF power. With a particular high pressure plasma reactor apparatus and with a H 2 /SiCl 4 ratio of 4.2, an RF power level of 1.7 KW, and a SiCl 4 feed rate of 10.7 gm/min, a conversion efficiency of 49.9% is achieved without any noticeable polymer formation. In this reaction the chlorosilane composition in the output of the HPP reactor is measured to be 50.1% SiCl 4 , 41.3% SiHCl 3 , and 8.6% SiH 2 Cl 2 . The 49.9% conversion efficiency is very high and very cost effective compared to alternate technologies for hydrogenating SiCl 4 .
Despite the high conversion efficiency of the HPP hydrogenation reaction described in U.S. Pat. No. 4,309,259, however, there is a need for a process for the hydrogenation of silicon tetrachloride which achieves still higher conversion efficiencies, decreases the RF power requirement, and increases the SiH 2 Cl 2 content of the reaction. It is therefore an object of this invention to provide an improved process for the catalyzed hydrogenation of silicon tetrachloride.
It is a further object of this invention to provide a process for the hydrogenation of SiCl 4 which produces enhanced quantities of SiHCl 2 .
BRIEF SUMMARY OF THE INVENTION
The foregoing and other objects and advantages of the invention are achieved through the use of a catalyzed high pressure plasma hydrogenation reaction. Hydrogen and silicon tetrachloride are reacted in the presence of a high pressure plasma and further in the presence of a boron or aluminum catalyst to produce dichlorosilane and trichlorosilane. The boron catalyst can be in the form, for example, of diborane or boron trichloride. The aluminum catalyst can be in the form, for example, of aluminum trichloride.
BRIEF DESCRIPTION OF THE DRAWING
The sole FIGURE illustrates HPP apparatus for practice of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The sole FIGURE illustrates apparatus in which the hydrogenation process, in accordance with the invention, can be practiced. Similar apparatus is described in more detail in U.S. Pat. No. 4,309,259. The deposition apparatus includes means for generating a high pressure RF plasma. By high pressure plasma (HPP) is meant a plasma generated at pressures greater than about 100 torr (about 13.3 KPa), and preferably at pressures near 1 atmosphere. The apparatus includes an RF generator 10 and an impedance matching module 12. As explained more fully in U.S. Pat. No. 4,309,259, the impedance matching module can be, for example, a π network wherein the inductor is a hollow coil through which reactant gases can pass. When the impedance matching module is properly tuned, a high voltage exists at the output of the module. This high voltage, capable of generating a plasma, is coupled to a high pressure plasma nozzle 14. Reactants pass through the coil to the HPP nozzle where a plasma is generated by the high voltage. The high pressure plasma nozzle is positioned within a reaction chamber 16 within which the ambient can be controlled. Reaction chamber 16, for example, can be a quartz tube sealed at the ends by end caps 18. In the practice of the invention, reactants including silicon tetrachloride 20, hydrogen 22, a catalyst such as boron from source 24 and an inert gas 26 such as helium are coupled to a gas control system 28. The gas control system provides for the control and metering of each of the reactant gases. From the gas control system the proper mixture of gases is conveyed to the impedance matching module and then to the HPP nozzle 14.
In practice of the invention, the system is first flushed with an inert gas such as helium. Hydrogen is then flowed through the system and the high pressure plasma is generated. After generating the plasma and properly adjusting the impedance matching module, silicon tetrachloride and a boron or aluminum catalyst is added to the plasma stream. Preferably the catalyst is boron in the form of B 2 H 6 or BCl 3 . Effluent from the reaction is conveyed from the reaction chamber and is collected at 30 for separation, purification, removal of the catalyst material, and the like.
The following non-limiting examples represent best modes contemplated by the inventors and serve to further illustrate the invention.
EXAMPLE I
Silicon tetrachloride was hydrogenated in apparatus as depicted in the FIGURE. The SiCl 4 feed rate was maintained at 12 gm/min. The RF power was adjusted to 1.3 KW and the hydrogen flow rate was adjusted to vary the H 2 /SiCl 4 ratio. Experiments were run with and without the addition of B 2 H 6 to the reactant gas flow. The B 2 H 6 flow was measured in terms of parts per million (ppm) of the total reactant gas flow. The effluent from the reactor was collected and analyzed by gas chromatography. Results of the experiment are shown in Table 1.
Table 1 shows the effect of trace amounts of B 2 H 6 on the hydrogenation of SiCl 4 as the H 2 /SiCl 4 ratio is varied. In each instance the SiCl 4 conversion efficiency is enhanced by the addition of B 2 H 6 to the reaction. In addition, the conversion of SiCl 4 to SiH 2 Cl 2 is enhanced, with the SiH 2 Cl 2 representing more than 25% of the effluent for H 2 /SiCl 4 ratios of 10.1 with 6.4 ppm of B 2 H 6 . No polymer formation was observed even at a H 2 /SiCl 4 ratio of 10.1 with the addition of 6.4 ppm of B 2 H 6 . Considerable polymer formation was observed, however, under similar conditions without the B 2 H 6 . In the absence of B 2 H 6 , polymer formation was observed for H 2 /SiCl 4 ratios greater than 6. Mass spectroscopic analysis of the HPP reactor effluent gases indicates that the B 2 H 6 is converted to BCl 3 in the HPP plasma.
EXAMPLE II
Hydrogenation reactions were carried out in the apparatus as illustrated in the FIGURE using a H 2 /SiCl 4 ratio of 5.19, an RF power of 1.5 KW, and a SiCl 4 feed rate of 12 gm/min. The amount of B 2 H 6 added to the input reactants was varied to show the effect of boron concentration on silicon tetrachloride hydrogenation. Results of the reactions are shown in Table 2.
In the range of concentrations of boron (5 ppm to 15 ppm) shown in Table 2, concentration is not a major influence on the catalytic activity of boron on the SiCl 4 hydrogenation. In further reactions, B 2 H 6 concentrations from 0.1 ppm to 35 ppm have exhibited the catalytic property with little concentration dependence.
TABLE 1__________________________________________________________________________HPPREACTOREFFLUENT H.sub.2 /SiCl.sub.4 5.19 6.07 7.08 8.01 10.1COMPOSITION C.sub.B.sbsb.2.sub.H.sbsb.6 .sub.(PPM) 0 10.2 0 8.9 0 7.8 0 7.0 6.4__________________________________________________________________________SiH.sub.2 Cl.sub.2 (%) 1.6 6.6 2.3 10.1 2.6 13.5 3.5 22.3 25.3SiHCl.sub.3 (%) 33.9 41.0 41.1 42.6 43.5 40.3 41.5 27.4 28.5SiCl.sub.4 Conv. Efficiency (%) 35.3 47.6 43.4 52.7 46.1 53.8 45.0 49.7 53.08__________________________________________________________________________
TABLE 2______________________________________HPPREACTOREFFLUENTCOMPO-SITION C.sub.B.sbsb.2.sub.H.sbsb.6 .sub.(PPM) 15.0 10.0 5.0 0.0______________________________________SiH.sub.2 Cl.sub.2 (%) 4.9 5.0 5.8 2.2SiHCl.sub.3 (%) 42.4 44.4 45.5 44.7SiCl.sub.4 Conv. Efficiency (%) 47.3 49.4 51.3 46.9______________________________________
Although the inventors do not wish to be bound by any particular theory, it is believed that the boron acts as a catalyst in (a) enhancing the conversion to SiH 2 Cl 2 and (b) eliminating polymer formation. The use of trace quantities of catalyst allows the use of higher H 2 /SiCl 4 ratios by eliminating polymer formation. This in turn increases the SiH 2 Cl 2 content in the HPP reactor effluent gas stream and increases the SiCl 4 conversion efficiency. At the same time, the catalyst decreases the RF plasma power requirement for the SiCl 4 hydrogenation process.
Thus it is apparent that there has been provided, in accordance with the invention, an improved SiCl 4 hydrogenation process which fully meets the objects and advantages set out above. While the invention has been described and illustrated with respect to specific embodiments thereof, it is not intended that the invention be limited to these illustrative embodiments. Those skilled in the art will realize, after review of the foregoing detailed description, that variations and modifications departing from these embodiments are possible without departing from the spirit and scope of the invention. Other HPP apparatus than that described in U.S. Pat. No. 4,309,259, for example, can be utilized in practicing the process. While that patent discloses apparatus including a dual flow HPP nozzle, the process can be carried out using a single flow nozzle of graphite or the like. Accordingly, it is intended to encompass all such variations and modifications as fall within the scope of the appended claims.
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An improved process is disclosed for the high pressure plasma hydrogenation of silicon tetrachloride. Hydrogen and silicon tetrachloride are reacted in the presence of a high pressure plasma and further in the presence of a boron catalyst to form trichlorosilane and dichlorosilane. By adding the boron catalyst the overall conversion efficiency is increased and the dichlorosilane content in the reaction effluent is increased.
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BACKGROUND OF INVENTION
1. Field of the Invention
The invention relates to a camshaft adjuster for vehicles, especially motor vehicles, comprising an oscillating motor having a rotor that is fixedly connected to the camshaft and rotatable relative to a stator surrounding the rotor.
2. Description of the Related Art
Camshaft adjusters are known that have an oscillating motor that is connected at the end of a camshaft by means of a central screw. By hydraulically loading the rotor of the oscillating motor, a rotatory movement relative to the stator results and, in this way, an adjustment of the camshaft relative to the crankshaft is achieved. The supply of hydraulic medium is realized either directly through the camshaft or by means of a rotary lead-through in the oscillating motor. It is also known to fasten the rotary lead-through behind the oscillating motor by means of the central screw on the camshaft. The camshaft adjuster has a complex configuration and requires a correspondingly complex assembly.
SUMMARY OF INVENTION
It is an object of the present invention to configure the camshaft adjuster of the aforementioned kind such that, while providing a simple configuration, an inexpensive assembly is ensured without this negatively affecting the proper function of the camshaft adjuster.
In accordance with the present invention, this is achieved in that the camshaft comprises at least one connecting part that acts by positive-engagement and/or force transmission and on which the base member of the rotor is fixedly mounted, wherein the base member has a diameter that is different than the diameter of the circle circumscribing the cams of the camshaft.
In the camshaft adjuster according to the invention, the rotor is fixedly connected by means of a positive-engagement and/or force transmission part to the camshaft. Because of the configuration according to the invention, the camshaft adjuster has only a minimal number of components, and this leads to a simple and inexpensive assembly.
Advantageously, the inner diameter of the base member of the rotor is greater than the diameter of the circle that circumscribes the cams of the camshaft. Accordingly, the oscillating motor can be pushed axially across the cams onto the positive-engagement and/or force transmission part. The camshaft requires therefore only two bearing locations.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective illustration, partially in section, of a camshaft adjuster according to the invention.
FIG. 2 is a perspective illustration of a camshaft of the camshaft adjuster according to FIG. 1 provided with a positive-engagement part for receiving a rotor of the camshaft adjuster.
FIG. 3 is a second embodiment of a camshaft adjuster according to the invention in an illustration similar to FIG. 1 .
FIG. 4 shows the second embodiment of FIG. 3 in an illustration similar to FIG. 2 .
FIG. 5 shows a third embodiment of the camshaft adjuster according to the invention in an illustration similar to FIG. 1 .
FIG. 6 shows the third embodiment of the camshaft adjuster in an illustration similar to FIG. 2 .
FIG. 7 shows a fourth embodiment of the camshaft adjuster according to the invention in an illustration similar to FIG. 1 .
FIG. 8 shows the fourth embodiment of the camshaft adjuster in an illustration similar to FIG. 2 .
FIG. 9 shows a fifth embodiment of the camshaft adjuster according to the invention in an illustration similar to FIG. 1 .
FIG. 10 shows the fifth embodiment of the camshaft adjuster in an illustration similar to FIG. 2 .
FIG. 11 shows a sixth embodiment of the camshaft adjuster according to the invention in an illustration similar to FIG. 1 .
FIG. 12 shows the sixth embodiment of the camshaft adjuster in an illustration similar to FIG. 2 .
FIG. 13 shows a seventh embodiment of the camshaft adjuster according to the invention in an illustration similar to FIG. 1 .
FIG. 14 shows the seventh embodiment of the camshaft adjuster in an illustration similar to FIG. 2 .
FIG. 15 shows an eighth embodiment of the camshaft adjuster according to the invention in an illustration similar to FIG. 1 .
FIG. 16 shows the eighth embodiment of the camshaft adjuster in an illustration similar to FIG. 2 .
FIG. 17 shows a ninth embodiment of the camshaft adjuster according to the invention in an illustration similar to FIG. 1 .
FIG. 18 shows the ninth embodiment of the camshaft adjuster in an illustration similar to FIG. 2 .
FIG. 19 shows a tenth embodiment of the camshaft adjuster according to the invention in an illustration similar to FIG. 1 .
FIG. 20 shows the tenth embodiment of the camshaft adjuster in an illustration similar to FIG. 2 .
FIG. 21 shows in axial section of a camshaft embodied as a hollow shaft with an insert.
DETAILED DESCRIPTION
The camshaft adjuster according to FIGS. 1 and 2 has an oscillating motor 1 comprising a stator 2 and a rotor 3 . The stator 2 has a cylindrical outer wall 4 and webs 5 projecting radially inwardly from the wall 4 at a uniform spacing to one another. The rotor 3 is mounted fixedly on the camshaft 6 and has an annular base member 7 that is fastened fixedly on the camshaft 6 . Web-shaped vanes 8 project from the base member 7 radially outwardly and are spaced at a uniform spacing to one another. The end faces 9 of the vanes 8 rest areally on the inner side 10 of the outer wall 4 of the stator 2 . The stator webs 5 rest with their end faces 11 areally on the cylindrical outer side 12 of the base member 7 of the rotor 3 . The spacing of neighboring stator webs 5 from one another is greater than the width of the rotor vanes 8 . The stator webs 5 delimit pressure chambers 13 that are divided by the rotor vanes 8 into two pressure chambers 14 and 15 . A pressure medium can be introduced into the pressure chambers 14 , 15 in a way known in the art so that the rotor vanes 8 can be pressure-loaded alternatingly on one or the other side. Accordingly, the rotor 3 is rotated relative to the stator 2 . The maximum rotational travel of the rotor 3 relative to the stator 2 is achieved when the rotor vanes 8 rest against the stator webs 5 .
On the radial outer ends of the sidewalls 16 , 17 of each stator web 5 , a recess in the form of a groove 18 , 19 is provided that extends across the axial width of the stator webs 5 . In the grooves 18 , 19 , dirt particles, for example, are collected that are contained within the pressure medium. Moreover, the pressure medium that is contained in the grooves 18 , 19 provides a damping action when the rotor vanes 8 come to rest against the sidewalls 16 , 17 of the stator webs 5 . The stator webs 5 can have very different shapes. For example, the sidewalls 16 , 17 of the stator webs 5 can be plane. The sidewalls 16 , 17 can also have a different course. For example, the cross-sectional width of the stator webs 5 can taper irregularly radially inwardly. The stator 2 itself is provided, as is known in the art, with a chain wheel or pulley 25 across which a chain or belt is guided that is, in turn, guided across a chain wheel or pulley that is mounted on the crankshaft.
The camshaft 6 has a positive-engagement connecting part 20 that has a non-round cross-section. In the illustrated embodiment of FIGS. 1 and 2 , the positive-engagement connecting part 20 has a pentagon-shaped cross-section wherein the circumferential surfaces 21 of the positive-engagement connecting part 20 have a rounded transition into one another. The base member 7 of the rotor has an inner wall 22 whose contour is matched to the contour of the positive-engagement connecting part 20 . The rotor 3 is pushed onto the positive-engagement connecting part 20 wherein as a result of the non-round cross-section a proper fixed connection between the rotor 3 and the camshaft 6 is achieved so that the parts cannot rotate relative to one another.
The cams that are arranged on the camshaft 6 are positioned, as is known in the art, angularly displaced relative to one another. The circumcircle of the cam profiles is smaller than the smallest diameter of the positive-engagement connecting part 20 . In this way, it is possible to push the rotor 3 across the cams of the camshaft 6 onto the positive-engagement connecting part 20 . In this way, a central drive is enabled in a simple way. By means of the positive-engagement connecting part 20 , the supply of the pressure medium that is to be introduced into the pressure chambers 14 , 15 of the oscillating motor 1 can be realized. The corresponding bores in the positive-engagement connecting part 20 for supplying the pressure medium are not illustrated in FIGS. 1 and 2 . In place of such bores, it is also possible to provide annular grooves on the positive-engagement connecting part 20 .
The rotor 3 is fastened with its base member 7 in a suitable way on the positive-engagement connecting part 20 , preferably by press-fit. A cylindrical collar 23 adjoins the positive-engagement connecting part 20 . The collar 23 projects radially past the positive-engagement connecting part 20 and serves as an abutment or axial stop for the base member 7 of the rotor 3 . By means of this collar 23 , the rotor 3 can moved into its mounting position in a simple way during mounting.
As illustrated in FIG. 1 , the base member 7 of the rotor has an axial annular projection 24 with which the base member 7 rest against the collar 23 of the camshaft 6 . On this projection 24 a chain wheel 25 is supported that is fixedly connected to the stator 2 . The chain wheel or pulley 25 can also be formed as a monolithic part of the stator 2 . The chain wheel or pulley 25 closes off the pressure chambers 14 , 15 in the axial direction. On the opposite side, a cover plate (not illustrated) is provided that is fastened on the stator 2 and closes off the pressure chambers axially on the other side.
In the embodiment according to FIGS. 3 and 4 , the camshaft 6 is extended axially past the positive-engagement connecting part 20 . On the projecting cylindrical part 26 of the camshaft 6 , an axial securing element 27 is secured by press-fit whose outer diameter is greater than the greatest outer diameter of the positive-engagement part 20 . The axial securing element 27 is formed as an annular disk and has on its circumference four grooves 24 that are spaced at an angular spacing of 90 E relative to one another and serve as positive-engagement openings for a tool with which the axial securing element 27 can be placed onto the camshaft part 26 . As described in the preceding embodiment, the rotor 3 is moved across the cams of the camshaft 6 onto the positive-engagement connecting part 20 and is secured thereon by press-fit. The part 26 projects past the rotor 3 in the axial direction. The axial securing element 27 is fastened on the part 26 . For example, it can be pressed onto this projecting part 26 . It is also possible to provide the projecting part 26 with a thread so that the axial securing element 27 is screwed onto the part 26 . In the mounted position, the axial securing element rests against the cover plate (not illustrated) that is pushed by the axial securing element 27 against the stator 2 .
The oscillating motor 1 is in other respects of the same configuration as in the preceding embodiment.
In the embodiment according to FIGS. 5 and 6 , the axial securing element 27 is formed by a spring ring or securing ring that is inserted into an annular groove 29 near the free end of the projecting part 26 of the camshaft 6 .
In the mounted position, the part 26 of the camshaft 6 projects past the cover plate (not illustrated) of the oscillating motor. Into the annular groove 29 a spring ring or securing ring 27 is inserted so that the oscillating motor 1 is properly axially secured on the positive-engagement connecting part 20 of the camshaft 6 .
In the oscillating motor according to FIGS. 7 and 8 , a spring ring or securing ring is used as the axial securing element 27 that is provided in the annular groove 29 near the free end of the axially projecting end of the camshaft 6 .
The positive-engagement connecting part 20 , in contrast to the preceding embodiment, is substantially cylindrical. The positive-engagement connecting part 20 has on its outer wall 30 at least one positive-engagement element 31 that is formed as a projection on the outer wall 30 . This positive-engagement element 31 has a substantially rectangular contour and extends from the collar 23 in the direction toward the annular groove 29 . As illustrated in FIG. 8 , the axially extending positive-engagement element 31 has a sufficient spacing from the annular groove 29 so that, when mounting the oscillating motor 1 , the spring ring or securing ring 27 can be inserted simply into the annular groove 29 .
The inner wall 22 of the base member 7 of the rotor 3 has for receiving the positive locking element 31 a matching groove-shaped depression 32 that is engaged positively by the positive-engagement element 31 . By means of this positive-engagement connection 31 , 32 , the rotor 3 is connected fixedly to the camshaft 6 . Since the rotor 3 is not secured by press-fit on the positive-engagement connecting part 20 , a problem-free mounting of the rotor 3 is ensured. It can be easily pushed onto the positive-engagement connecting part 20 . The axial securing action is realized by the spring ring or securing ring 27 that can be inserted without problems into the annular groove 29 of the camshaft part 26 .
On the outer wall 30 of the positive-engagement connecting part 20 additional positive-engagement elements 31 can be provided should this be necessary.
FIGS. 9 and 10 show an oscillating motor where the annular projection 24 of the base member 7 of the rotor has an inner wall 33 with a non-round cross-section. The rotor is seated with this projection 24 on the positive-engagement element 20 of the camshaft 6 . In contrast to the preceding embodiments, the positive-engagement connecting part 20 is formed as a collar that has only minimal axial width. The positive-engagement connecting part 20 has the same contour as the positive-engagement connecting part 20 of the preceding embodiment. The positive-engagement connecting part 20 adjoins directly the collar 23 that projects radially past the positive-engagement connecting part 20 . The part 26 that is positioned on the other end of the positive-engagement connecting part 20 is cylindrical and has at its free end an annular groove 29 that receives the spring ring or securing ring 27 as an axial securing element.
In this configuration, the rotor 3 can also be pushed across the cams of the camshaft 6 to such an extent that it engages with its projection 24 the positive-engagement connecting part 20 . In this way, the rotor 3 is connected in a simple way fixedly to the camshaft 6 . The camshaft projects with its part 26 so far axially past the rotor 3 or the cover plate (not illustrated) that the spring ring or safety ring 27 can be inserted into the annular groove 29 .
The rotor 3 is then properly secured axially on the camshaft 6 . In other respects, the oscillating motor 1 is of the same configuration as in the preceding embodiments.
FIGS. 11 and 12 show an oscillating motor 1 whose rotor 3 is pushed onto the positive-engagement connecting part 20 of the camshaft 6 . The positive-engagement connecting part 20 is identical to the embodiment of FIGS. 1 and 2 . As a result of the non-round cross-section of this positive-engagement connecting part 20 , the rotor 3 is fixedly fastened on the camshaft 6 . For axially securing the rotor 3 or the oscillating motor 1 on the camshaft 6 , the axial securing element 27 as well as a groove nut 24 are provided. The axial securing element 27 in this embodiment is a securing disk that rests against the end face of the cover plate (not illustrated) and is secured by means of the groove nut 34 . It is screwed onto a tapered threaded end of the camshaft 6 . The rotor 3 is positioned axially secured between the collar 23 and the annular disk 27 .
In other respects, the camshaft adjuster is of the same configuration as in the embodiment of FIGS. 1 and 2 .
The camshaft adjuster according to FIGS. 13 and 14 comprises the positive-engagement connecting part 20 with the positive-engagement element 31 in accordance with the embodiment of FIGS. 7 and 8 . The camshaft 6 is provided in accordance with the preceding embodiment with a threaded end onto which the groove nut 34 is screwed. By means of the nut, the axial securing element 27 in the form of the annular disk is secured; the annular disk rests against the cover plate (not illustrated) or the rotor 3 of the oscillating motor 1 and axially secures it between the collar 23 and the axial securing element 27 in the mounted position. In other respects, the oscillating motor is identical to the embodiment of FIGS. 11 and 12 .
The camshaft adjuster according to FIGS. 15 and 16 is similarly configured as the embodiment of FIGS. 3 and 4 . In accordance with this embodiment, the axial securing element 27 is positioned on the projecting part 26 of the camshaft adjuster 6 . Instead of the positive-engagement connecting part 20 , the camshaft 6 has a cylindrical part 35 on which the rotor 3 is secured with press-fit. The fixed connection between the rotor 3 and the camshaft 6 is realized in this case by force transmission (friction). Onto the free end of the part 26 of the camshaft 6 , the axial securing element 27 is placed in the same way as described in connection with FIGS. 3 and 4 . The rotor 3 is thus axially secured between the collar 23 of the camshaft 6 and the axial securing element 27 on the camshaft 6 .
In the embodiment according to FIGS. 17 and 18 , the camshaft 6 has the positive-engagement connecting part 20 with positive-engagement element 31 in accordance with the embodiment of FIGS. 7 and 8 . The part 26 that projects axially past the positive-engagement connecting part 20 , in contrast to the embodiment of FIGS. 7 and 8 , is not provided with an annular groove 29 but has a continuous cylindrical configuration. On this projecting part 26 , the axial securing element 27 is fastened that is identical to that of the embodiment of FIGS. 3 and 4 . The axial securing element 27 in the embodiment of FIGS. 17 and 18 can be attached in the same way as explained in connection with the embodiment of FIGS. 3 and 4 . The rotor 3 of the oscillating motor 1 is axially secured between the collar 23 of the camshaft 6 and the axial securing element 27 .
In the embodiment of FIGS. 19 and 20 , the camshaft 6 is provided with an axially projecting force transmission part 36 projecting past the collar 23 and configured to be of a truncated-cone shape. The base member 7 of the rotor 3 of the oscillating motor 1 is fastened on the part 36 by means of press-fit. The inner wall 22 of the rotor base member 7 is positioned on a conical surface.
Because of the force transmission between the rotor base member 7 and the force transmission part 36 of the camshaft 6 , a proper fixed connection between the rotor 3 and the camshaft 6 is achieved. It is possible without problems to axially secure the rotor 3 by means of an axial securing element on the camshaft 6 . The provided axial securing element 27 can be configured in accordance with the preceding embodiments.
In the described embodiments, the camshaft 6 requires only two bearing locations. In particular, only a minimal number of components is required because a rotary lead-through for the pressure medium in the oscillating motor 1 is obsolete. The central screw required in the known camshaft adjusters for attachment of the oscillating motor to the camshaft is also no longer needed. The camshaft adjuster according to the described embodiments can therefore be produced simply and inexpensively. The supply of pressure medium into the pressure chambers 14 , 15 is realized through the camshaft 6 . In this way, radial bores for supply of pressure medium are not necessary. However, when the camshaft 6 is of a hollow configuration, an insert 37 with oil channels must be inserted as illustrated in FIG. 21 . The insert 37 rests against the inner wall 38 of the hollow camshaft 6 and has two axially extending bores 39 and 40 through which the pressure medium can be introduced into the pressure chambers 14 , 15 of the oscillating motor 1 . The two bores 39 , 40 open into a first end face 41 of the insert 37 and are connected, as is known in the art, to the valve unit with which the supply of pressure medium to the pressure chambers 14 , 15 is controlled.
Radial bores 42 , 43 that are spaced from one another open into the bore 39 ; they are provided at the bottom of an annular groove 44 , 45 in the wall surface 46 of the insert 37 , respectively.
The radial bores 47 , 48 open in the annular groove 44 , 45 into the camshaft 6 .
Radial bores 49 , 50 that are spaced from one another open into the axial bore 40 of the insert 37 ; they are provided at the bottom of two annular grooves 51 , 52 in the wall surface 46 of the insert 37 , respectively. Radial bores 53 , 54 of the camshaft 6 open into the annular groove 51 , 52 .
When employing a hollow camshaft 6 with the insert 37 , the constructive length can be reduced.
The axial securing of the oscillating motor 1 is realized in the described embodiments by means of the axial securing element 27 or by means of a press-fit connection.
In the embodiments in which the positive-engagement connecting part 20 has a polygonal or non-round cross-section ( FIGS. 1 through 6 , 9 through 12 ), it is advantageous when the number of corners corresponds to the number of rotor vanes 8 . In this way, a uniform stress distribution is ensured in the rotor 3 .
While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.
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A camshaft adjuster for motor vehicles has an oscillating motor having a rotor that is fixedly connected to a camshaft and further having a stator surrounding the rotor. The rotor is rotatable relative to the stator. At least one connecting part acting by at least one of positive engagement and force transmission is provided on a camshaft having cams. The rotor has a base member that is fixedly mounted on the connecting part. The base member has a diameter that is different from a diameter of a circle circumscribing the cams of the camshaft.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] Various methods, systems and apparatus relating to the present invention are disclosed in the following U.S. patent/patent applications filed by the applicant or assignee of the present invention:
FND001US FND002US FND003US FND004US FND005US FND006US FND007US FND008US FND009US FND010US FND011US FND012US FND013US FND014US FND015US FND016US FND017US MNN001US MNN002US MNN003US MNN004US MNN005US MNN006US MNN007US MNN008US MNN009US MNN010US MNN011US MNN012US MNN013US MNN014US MNN015US MNN016US MNN017US MNN018US MNN019US MPN001US MPN002US MPN003US MPN004US FNE001US FNE002US FNE003US FNE004US FNE005US FNE006US FNE007US FNE008US FNE009US MNN020US MNN021US
CO-PENDING APPLICATIONS
[0002] The following applications have been filed by the Applicant simultaneously with the present application:
09/517539 6566858 09/112762 6331946 6246970 6442525 09/517384 09/505951 6374354 09/517608 09/505147 10/203564 6757832 6334190 6745331 09/517541 10/203559 10/203560 10/636263 10/636283 10/866608 10/902889 10/902833 10/940653 10/942858 10/727181 10/727162 10/727163 10/727245 10/727204 10/727233 10/727280 10/727157 10/727178 10/727210 10/727257 10/727238 10/727251 10/727159 10/727180 10/727179 10/727192 10/727274 10/727164 10/727161 10/727198 10/727158 10/754536 10/754938 10/727227 10/727160 10/934720 11/212,702 10/296522 6795215 10/296535 09/575109 10/296525 09/575110 09/607985 6398332 6394573 6622923 6747760 10/189459 10/884881 10/943941 10/949294 11/039866 11/123011 11/123010 11/144769 11/148237 10/922846 10/922845 10/854521 10/854522 10/854488 10/854487 10/854503 10/854504 10/854509 10/854510 10/854496 10/854497 10/854495 10/854498 10/854511 10/854512 10/854525 10/854526 10/854516 10/854508 10/854507 10/854515 10/854506 10/854505 10/854493 10/854494 10/854489 10/854490 10/854492 10/854491 10/854528 10/854523 10/854527 10/854524 10/854520 10/854514 10/854519 10/854513 10/854499 10/854501 10/854500 10/854502 10/854518 10/854517 10/934628 PLT046US 10/728804 10/728952 10/728806 10/728834 10/729790 10/728884 10/728970 10/728784 10/728783 10/728925 10/728842 10/728803 10/728780 10/728779 10/773189 10/773204 10/773198 10/773199 10/773190 10/773201 10/773191 10/773183 10/773195 10/773196 10/773186 10/773200 10/773185 10/773192 10/773197 10/773203 10/773187 10/773202 10/773188 10/773194 10/773193 10/773184 11/008118 11/060751 11/060805 11/188017 6623101 6406129 6505916 6457809 6550895 6457812 10/296434 6428133 6746105 10/407212 10/407207 10/683064 10/683041 6750901 6476863 6788336 11/097308 11/097309 11/097335 11/097299 11/097310 11/097213 11/210687 11/097212 11/212637 10/760272 10/760273 10/760187 10/760182 10/760188 10/760218 10/760217 10/760216 10/760233 10/760246 10/760212 10/760243 10/760201 10/760185 10/760253 10/760255 10/760209 10/760208 10/760194 10/760238 10/760234 10/760235 10/760183 10/760189 10/760262 10/760232 10/760231 10/760200 10/760190 10/760191 10/760227 10/760207 10/760181 10/815625 10/815624 10/815628 10/913375 10/913373 10/913374 10/913372 10/913377 10/913378 10/913380 10/913379 10/913376 10/913381 10/986402 11/172816 11/172815 11/172814 11/003786 11/003354 11/003616 11/003418 11/003334 11/003600 11/003404 11/003419 11/003700 11/003601 11/003618 11/003615 11/003337 11/003698 11/003420 11/003682 11/003699 11/071473 11/003463 11/003701 11/003683 11/003614 11/003702 11/003684 11/003619 11/003617 10/760254 10/760210 10/760202 10/760197 10/760198 10/760249 10/760263 10/760196 10/760247 10/760223 10/760264 10/760244 10/760245 10/760222 10/760248 10/760236 10/760192 10/760203 10/760204 10/760205 10/760206 10/760267 10/760270 10/760259 10/760271 10/760275 10/760274 10/760268 10/760184 10/760195 10/760186 10/760261 10/760258 11/014764 11/014763 11/014748 11/014747 11/014761 11/014760 11/014757 11/014714 11/014713 11/014762 11/014724 11/014723 11/014756 11/014736 11/014759 11/014758 11/014725 11/014739 11/014738 11/014737 11/014726 11/014745 11/014712 11/014715 11/014751 11/014735 11/014734 11/014719 11/014750 11/014749 11/014746 11/014769 11/014729 11/014743 11/014733 11/014754 11/014755 11/014765 11/014766 11/014740 11/014720 11/014753 11/014752 11/014744 11/014741 11/014768 11/014767 11/014718 11/014717 11/014716 11/014732 11/014742 11/097268 11/097185 11/097184 09/575197 09/575195 09/575159 09/575132 09/575123 09/575148 09/575130 09/575165 09/575153 09/575118 09/575131 09/575116 09/575144 09/575139 09/575186 6681045 6728000 09/575145 09/575192 09/575181 09/575193 09/575156 09/575183 6789194 09/575150 6789191 6644642 6502614 6622999 6669385 6549935 09/575187 6727996 6591884 6439706 6760119 09/575198 6290349 6428155 6785016 09/575174 09/575163 6737591 09/575154 09/575129 09/575124 09/575188 09/575189 09/575162 09/575172 09/575170 09/575171 09/575161
[0003] The disclosures of these co-pending applications are incorporated herein by reference. The above applications have been identified by their filing docket number, which will be substituted with the corresponding application number, once assigned.
[0000] The disclosures of these applications and patents are incorporated herein by reference.
FIELD OF THE INVENTION
[0004] The present invention relates to the field of inkjet printers and discloses an inkjet printing system using printheads manufactured with micro-electromechanical systems (MEMS) techniques.
BACKGROUND OF THE INVENTION
[0005] The present invention involves the ejection of ink drops by way of forming gas or vapor bubbles in a bubble forming liquid. This principle is generally described in U.S. Pat. No. 3,747,120 (Stemme). Each pixel in the printed image is derived ink drops ejected from one or more ink nozzles. In recent years, inkjet printing has become increasing popular primarily due to its inexpensive and versatile nature. Many different aspects and techniques for inkjet printing are described in detail in the above cross referenced documents.
[0006] Clogging is one of the principle causes of nozzle failure. Nozzles can clog from dried ink and contaminants in the ink. However, paper dust attaching to the exterior of the nozzle plate is another cause of clogging. The airborne paper dust adheres to the nozzle plate by ‘stiction’ as it is known. Capping and maintenance cycles help to clean paper dust away, but often the stiction between the dust particle and the nozzle plate and the too strong.
SUMMARY OF THE INVENTION
[0007] Accordingly, the present invention provides a method of forming a low-stiction nozzle plate for an inkjet printhead, said nozzle plate having a plurality of nozzle apertures defined therein, each nozzle aperture having a respective nozzle rim, said method comprising the steps of:
(a) providing a partially-fabricated printhead comprising a plurality of inkjet nozzle assemblies sealed with roof material; (b) etching partially into said roof material to define simultaneously said nozzle rims and a plurality of stiction-reducing formations; and (c) etching through said roof material to define said nozzle apertures, thereby forming said nozzle plate.
[0011] Preferably the formations are columnar projections of equal length extending normal to the plane of the nozzle plate.
[0012] In a first aspect the present invention provides a method of fabricating a suspended beam in a MEMS process, said method comprising the steps of:
(a) etching a pit in a substrate, said pit having a base and sidewalls; (b) depositing sacrificial material on a surface of said substrate so as to fill said pit; (c) removing said sacrificial material from a perimeter region within said pit and from said substrate surface surrounding said pit; (d) reflowing remaining sacrificial material within said pit such that said remaining sacrificial material contacts said sidewalls; (e) depositing beam material on said substrate surface and on said reflowed sacrificial material; and (f) removing said reflowed sacrificial material to form said suspended beam.
[0019] Optionally, said suspended beam is substantially planar.
[0020] Optionally, all parts of said suspended beam have substantially the same thickness.
[0021] Optionally, said suspended beam is an actuator for an inkjet nozzle.
[0022] Optionally, said actuator is a heater element.
[0023] Optionally, said heater element is suspended between a pair of electrodes.
[0024] Optionally, said substrate is a silicon wafer.
[0025] Optionally, said silicon wafer comprises at least one surface oxide layer.
[0026] Optionally, said sacrificial material is photoresist.
[0027] Optionally, said photoresist is removed by exposure through a mask followed by development.
[0028] Optionally, said perimeter region comprises an area adjacent at least two of said sidewalls.
[0029] Optionally, said perimeter region comprises an area adjacent all of said sidewalls.
[0030] Optionally, removal of said sacrificial material from said perimeter region results in a space of less than 1 micron between said remaining sacrificial material and at least two of said sidewalls.
[0031] Optionally, removal of said sacrificial material from said perimeter region results in a space of less than 1 micron between said remaining sacrificial material and all of said sidewalls.
[0032] Optionally, said reflowing is performed by heating said sacrificial material.
[0033] Optionally, said sacrificial material is treated to prevent further reflow prior to deposition of beam material.
[0034] Optionally, said treatment comprises UV curing.
[0035] Optionally, said beam material is etched into a predetermined configuration after deposition.
[0036] Optionally, further MEMS process steps are performed after deposition of said beam material and prior to said removal of said reflowed sacrificial material.
[0037] Optionally, said further MEMS process steps comprise forming an inkjet nozzle containing said suspended beam.
[0038] In a second aspect the present invention provides a method of fabricating a plurality of inkjet nozzles on a substrate, each nozzle comprising a nozzle chamber having a roof spaced apart from said substrate and sidewalls extending from said roof to said substrate, one of said sidewalls having a chamber entrance for receiving ink from an ink conduit extending along a row of nozzles, said ink conduit receiving ink from a plurality of ink inlets defined in said substrate, said method comprising the steps of:
(a) providing a substrate having a plurality of trenches corresponding to said ink inlets; (b) depositing sacrificial material on said substrate so as fill said trenches and form a scaffold on said substrate; (c) defining openings in said sacrificial material, said openings being positioned to form said chamber sidewalls and said ink conduit when filled with roof material; (d) depositing roof material over said sacrificial material to form simultaneously said nozzle chambers and said ink conduit; (e) etching nozzle apertures through said roof material, each nozzle chamber having at least one nozzle aperture; and (f) removing said sacrificial material.
[0045] Optionally, each nozzle chamber contains an actuator for ejecting ink through said nozzle aperture.
[0046] Optionally, said actuator is formed prior to fabrication of said nozzle chamber.
[0047] Optionally, said substrate is a silicon wafer.
[0048] Optionally, said silicon wafer comprises at least one surface oxide layer.
[0049] Optionally, said sacrificial material is photoresist.
[0050] Optionally, said openings are defined by exposing said photoresist through a mask followed by development.
[0051] Optionally, said photoresist is UV cured prior to deposition of said roof material, thereby preventing reflow of said photoresist during deposition.
[0052] Optionally, said photoresist is removed by plasma ashing.
[0053] In a further aspect there is provided a method further comprising the step of etching ink supply channels from an opposite backside of said substrate, said ink supply channels being in fluid communication with said ink inlets.
[0054] Optionally, each ink inlet has at least one priming feature extending from a respective rim thereof, and said method further comprises defining at least one opening corresponding to said at least one priming feature in said photoresist.
[0055] Optionally, said at least one priming feature comprises a column of roof material extending from said rim.
[0056] Optionally, each ink inlet has a plurality of priming features positioned about a respective rim thereof.
[0057] Optionally, said plurality of priming features together form a columnar cage extending from said rim.
[0058] Optionally, said chamber entrance includes at least one filter structure, and said method further comprises defining at least one opening corresponding to said at least one priming feature in said photoresist.
[0059] Optionally, said at least one filter structure comprises a column of roof material extending from said substrate to said roof.
[0060] Optionally, each chamber entrance includes a plurality of filter structures arranged across said entrance.
[0061] Optionally, each chamber entrance includes a plurality of rows of filter structures arranged across said entrance.
[0062] Optionally, said rows of filter structures are staggered.
[0063] In a third aspect there is provided a method of fabricating a plurality of inkjet nozzles on a substrate, each nozzle comprising a nozzle chamber having a roof spaced apart from said substrate and sidewalls extending from said roof to said substrate, said chamber having an entrance for receiving ink from at least one ink inlet defined in said substrate, said at least one ink inlet having at least one priming feature extending from a respective rim thereof, said method comprising the steps of:
(a) providing a substrate having a plurality of trenches corresponding to said ink inlets; (b) depositing sacrificial material on said substrate so as fill said trenches and form a scaffold on said substrate; (c) defining openings in said sacrificial material, said openings being positioned to form said chamber sidewalls and said at least one priming feature when filled with roof material; (d) depositing roof material over said sacrificial material to form simultaneously said nozzle chambers and said at least one priming feature; (e) etching nozzle apertures through said roof material, each nozzle chamber having at least one nozzle aperture; and (f) removing said sacrificial material.
[0070] Optionally, said at least one priming feature comprises a column of roof material extending from said rim.
[0071] Optionally, each ink inlet has a plurality of priming features positioned about a respective rim thereof.
[0072] Optionally, said plurality of priming features together form a columnar cage extending from said rim.
[0073] Optionally, each nozzle chamber contains an actuator for ejecting ink through said nozzle aperture.
[0074] Optionally, said actuator is formed prior to fabrication of said nozzle chamber.
[0075] Optionally, said substrate is a silicon wafer.
[0076] Optionally, said silicon wafer comprises at least one surface oxide layer.
[0077] Optionally, said sacrificial material is photoresist.
[0078] Optionally, said openings are defined by exposing said photoresist through a mask followed by development.
[0079] Optionally, said photoresist is UV cured prior to deposition of said roof material, thereby preventing reflow of said photoresist during deposition.
[0080] Optionally, said photoresist is removed by plasma ashing.
[0081] In a further aspect there is provided a method further comprising the step of etching ink supply channels from an opposite backside of said substrate, said ink supply channels being in fluid communication with said ink inlets.
[0082] Optionally, said chamber entrance is defined in one of said sidewalls of said nozzle chamber.
[0083] Optionally, said chamber entrance receives ink from an ink conduit extending along a row of nozzles, whereby step (c) further comprises defining further openings in said sacrificial material, said further openings being positioned to form said ink conduit when filled with roof material.
[0084] Optionally, said ink conduit receives ink from said at least one ink inlet.
[0085] In a fourth aspect the present invention provides a method of fabricating a plurality of inkjet nozzles on a substrate, each nozzle comprising a nozzle chamber having a roof spaced apart from said substrate and sidewalls extending from said roof to said substrate, one of said sidewalls having a chamber entrance for receiving ink from at least one ink inlet defined in said substrate, said chamber entrance including at least one filter structure, said method comprising the steps of:
(a) providing a substrate having a plurality of trenches corresponding to said ink inlets; (b) depositing sacrificial material on said substrate so as fill said trenches and form a scaffold on said substrate; (c) defining openings in said sacrificial material, said openings being positioned to form said chamber sidewalls and said at least one filter structure when filled with roof material; (d) depositing roof material over said sacrificial material to form simultaneously said nozzle chambers and said at least one filter structure; (e) etching nozzle apertures through said roof material, each nozzle chamber having at least one nozzle aperture; and (f) removing said sacrificial material.
[0092] Optionally, said filter structure comprises a column of roof material extending from said substrate to said roof.
[0093] Optionally, each chamber entrance includes a plurality of filter structures arranged across said entrance.
[0094] Optionally, each chamber entrance includes a plurality of rows of filter structures arranged across said entrance.
[0095] Optionally, said rows of filter structures are staggered.
[0096] Optionally, each nozzle chamber contains an actuator for ejecting ink through said nozzle aperture.
[0097] Optionally, said actuator is formed prior to fabrication of said nozzle chamber.
[0098] Optionally, said substrate is a silicon wafer.
[0099] Optionally, said silicon wafer comprises at least one surface oxide layer.
[0100] Optionally, said sacrificial material is photoresist.
[0101] Optionally, said openings are defined by exposing said photoresist through a mask followed by development.
[0102] Optionally, said photoresist is UV cured prior to deposition of said roof material, thereby preventing reflow of said photoresist during deposition.
[0103] Optionally, said photoresist is removed by plasma ashing.
[0104] In a further aspect there is provided a method further comprising the step of etching ink supply channels from an opposite backside of said substrate, said ink supply channels being in fluid communication with said ink inlets.
[0105] Optionally, said chamber entrance receives ink from an ink conduit extending along a row of nozzles, whereby step (c) further comprises defining further openings in said sacrificial material, said further openings being positioned to form said ink conduit when filled with roof material.
[0106] Optionally, said ink conduit receives ink from said at least one ink inlet.
[0107] In a fifth aspect the present invention provides a method of forming a low-stiction nozzle plate for an inkjet printhead, said nozzle plate having a plurality of nozzle apertures defined therein, each nozzle aperture having a respective nozzle rim, said method comprising the steps of:
(a) providing a partially-fabricated printhead comprising a plurality of inkjet nozzle assemblies sealed with roof material; (b) etching partially into said roof material to define simultaneously said nozzle rims and a plurality of stiction-reducing formations; and (c) etching through said roof material to define said nozzle apertures, thereby forming said nozzle plate.
[0111] Optionally, each nozzle rim comprises at least one projection around a perimeter of each nozzle aperture.
[0112] Optionally, each nozzle rim comprises a plurality of coaxial projections around a perimeter of each nozzle aperture.
[0113] Optionally, said at least one rim projection projects at least 1 micron from said nozzle plate.
[0114] Optionally, each stiction-reducing formation comprises a columnar projection on said nozzle plate.
[0115] Optionally, each columnar projection projects at least 1 micron from said nozzle plate.
[0116] Optionally, each columnar projection is spaced apart from an adjacent columnar projection by less than 2 microns.
[0117] Optionally, each stiction-reducing formation comprises an elongate wall projection on said nozzle plate.
[0118] Optionally, each wall projection projects at least 1 micron from said nozzle plate.
[0119] Optionally, said wall projections are positioned for minimizing color-mixing of inks on said nozzle plate.
[0120] Optionally, said wall projections extend along said nozzle plate parallel with rows of nozzles, each nozzle in a row ejecting the same colored ink.
[0121] Optionally, the positions of said nozzle rims and said stiction-reducing formations are defined by photolithographic masking.
[0122] Optionally, at least half of the surface area of said nozzle plate is tiled with stiction-reducing formations.
[0123] Optionally, said inkjet nozzle assemblies are formed on a silicon substrate and said nozzle plate is spaced apart from said substrate.
[0124] Optionally, said nozzle plate is comprised of silicon nitride, silicon oxide, silicon oxynitride or aluminium nitride.
[0125] Optionally, said nozzle assemblies are sealed by CVD or PECVD deposition of said roof material.
[0126] Optionally, said roof material is deposited onto a sacrificial scaffold.
[0127] Optionally, each inkjet nozzle assembly has at least one nozzle aperture associated therewith for ejection of ink.
[0128] Optionally, said nozzle plate is subsequently treated with a hydrophobizing material.
[0129] The printhead according to the invention comprises a plurality of nozzles, as well as a chamber and one or more heater elements corresponding to each nozzle. The smallest repeating units of the printhead will have an ink supply inlet feeding ink to one or more chambers. The entire nozzle array is formed by repeating these individual units. Such an individual unit is referred to herein as a “unit cell”.
[0130] Also, the term “ink” is used to signify any ejectable liquid, and is not limited to conventional inks containing colored dyes. Examples of non-colored inks include fixatives, infra-red absorber inks, functionalized chemicals, adhesives, biological fluids, medicaments, water and other solvents, and so on. The ink or ejectable liquid also need not necessarily be a strictly a liquid, and may contain a suspension of solid particles.
BRIEF DESCRIPTION OF THE DRAWINGS
[0131] Preferred embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings, in which:
[0132] FIG. 1 shows a partially fabricated unit cell of the MEMS nozzle array on a printhead according to the present invention, the unit cell being section along A-A of FIG. 3 ;
[0133] FIG. 2 shows a perspective of the partially fabricated unit cell of FIG. 1 ;
[0134] FIG. 3 shows the mark associated with the etch of the heater element trench;
[0135] FIG. 4 is a sectioned view of the unit cell after the etch of the trench;
[0136] FIG. 5 is a perspective view of the unit cell shown in FIG. 4 ;
[0137] FIG. 6 is the mask associated with the deposition of sacrificial photoresist shown in FIG. 7 ;
[0138] FIG. 7 shows the unit cell after the deposition of sacrificial photoresist trench, with partial enlargements of the gaps between the edges of the sacrificial material and the side walls of the trench;
[0139] FIG. 8 is a perspective of the unit cell shown in FIG. 7 ;
[0140] FIG. 9 shows the unit cell following the reflow of the sacrificial photoresist to close the gaps along the side walls of the trench;
[0141] FIG. 10 is a perspective of the unit cell shown in FIG. 9 ;
[0142] FIG. 11 is a section view showing the deposition of the heater material layer;
[0143] FIG. 12 is a perspective of the unit cell shown in FIG. 11 ;
[0144] FIG. 13 is the mask associated with the metal etch of the heater material shown in FIG. 14 ;
[0145] FIG. 14 is a section view showing the metal etch to shape the heater actuators;
[0146] FIG. 15 is a perspective of the unit cell shown in FIG. 14 ;
[0147] FIG. 16 is the mask associated with the etch shown in FIG. 17 ;
[0148] FIG. 17 shows the deposition of the photoresist layer and subsequent etch of the ink inlet to the passivation layer on top of the CMOS drive layers;
[0149] FIG. 18 is a perspective of the unit cell shown in FIG. 17 ;
[0150] FIG. 19 shows the oxide etch through the passivation and CMOS layers to the underlying silicon wafer;
[0151] FIG. 20 is a perspective of the unit cell shown in FIG. 19 ;
[0152] FIG. 21 is the deep anisotropic etch of the ink inlet into the silicon wafer;
[0153] FIG. 22 is a perspective of the unit cell shown in FIG. 21 ;
[0154] FIG. 23 is the mask associated with the photoresist etch shown in FIG. 24 ;
[0155] FIG. 24 shows the photoresist etch to form openings for the chamber roof and side walls;
[0156] FIG. 25 is a perspective of the unit cell shown in FIG. 24 ;
[0157] FIG. 26 shows the deposition of the side wall and risk material;
[0158] FIG. 27 is a perspective of the unit cell shown in FIG. 26 ;
[0159] FIG. 28 is the mask associated with the nozzle rim etch shown in FIG. 29 ;
[0160] FIG. 29 shows the etch of the roof layer to form the nozzle aperture rim;
[0161] FIG. 30 is a perspective of the unit cell shown in FIG. 29 ;
[0162] FIG. 31 is the mask associated with the nozzle aperture etch shown in FIG. 32 ;
[0163] FIG. 32 shows the etch of the roof material to form the elliptical nozzle apertures;
[0164] FIG. 33 is a perspective of the unit cell shown in FIG. 32 ;
[0165] FIG. 34 shows the oxygen plasma release etch of the first and second sacrificial layers;
[0166] FIG. 35 is a perspective of the unit cell shown in FIG. 34 ;
[0167] FIG. 36 shows the unit cell after the release etch, as well as the opposing side of the wafer;
[0168] FIG. 37 is a perspective of the unit cell shown in FIG. 36 ;
[0169] FIG. 38 is the mask associated with the reverse etch shown in FIG. 39 ;
[0170] FIG. 39 shows the reverse etch of the ink supply channel into the wafer;
[0171] FIG. 40 is a perspective of unit cell shown in FIG. 39 ;
[0172] FIG. 41 shows the thinning of the wafer by backside etching;
[0173] FIG. 42 is a perspective of the unit cell shown in FIG. 41 ;
[0174] FIG. 43 is a partial perspective of the array of nozzles on the printhead according to the present invention;
[0175] FIG. 44 shows the plan view of a unit cell;
[0176] FIG. 45 shows a perspective of the unit cell shown in FIG. 44 ;
[0177] FIG. 46 is schematic plan view of two unit cells with the roof layer removed but certain roof layer features shown in outline only;
[0178] FIG. 47 is schematic plan view of two unit cells with the roof layer removed but the nozzle openings shown in outline only;
[0179] FIG. 48 is a partial schematic plan view of unit cells with ink inlet apertures in the sidewall of the chambers;
[0180] FIG. 49 is schematic plan view of a unit cells with the roof layer removed but the nozzle openings shown in outline only;
[0181] FIG. 50 is a partial plan view of the nozzle plate with stiction reducing formations and a particle of paper dust;
[0182] FIG. 51 is a partial plan view of the nozzle plate with residual ink gutters;
[0183] FIG. 52 is a partial section view showing the deposition of SAC1 photoresist in accordance with prior art techniques used to avoid stringers;
[0184] FIG. 53 is a partial section view showing the depositon of a layer of heater material onto the SAC1 photoresist scaffold deposited in FIG. 52 ; and,
[0185] FIG. 54 is a partial schematic plan view of a unit cell with multiple nozzles and actuators in each of the chambers.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0186] In the description than follows, corresponding reference numerals relate to corresponding parts. For convenience, the features indicated by each reference numeral are listed below.
MNN MPN Series Parts List
[0000]
1 . Nozzle Unit Cell
2 . Silicon Wafer
3 . Topmost Aluminium Metal Layer in the CMOS metal layers
4 . Passivation Layer
5 . CVD Oxide Layer
6 . Ink Inlet Opening in Topmost Aluminium Metal Layer 3.
7 . Pit Opening in Topmost Aluminium Metal Layer 3.
8 . Pit
9 . Electrodes
10 . SAC1 Photoresist Layer
11 . Heater Material (TiAlN)
12 . Thermal Actuator
13 . Photoresist Layer
14 . Ink Inlet Opening Etched Through Photo Resist Layer
15 . Ink Inlet Passage
16 . SAC2 Photoresist Layer
17 . Chamber Side Wall Openings
18 . Front Channel Priming Feature
19 . Barrier Formation at Ink Inlet
20 . Chamber Roof Layer
21 . Roof
22 . Sidewalls
23 . Ink Conduit
24 . Nozzle Chambers
25 . Elliptical Nozzle Rim
25 ( a ) Inner Lip 25 ( b ) Outer Lip
26 . Nozzle Aperture
27 . Ink Supply Channel
28 . Contacts
29 . Heater Element.
30 . Bubble cage
32 . bubble retention structure
34 . ink permeable structure
36 . bleed hole
38 . ink chamber
40 . dual row filter
42 . paper dust
44 . ink gutters
46 . gap between SAC1 and trench sidewall
48 . trench sidewall
50 . raised lip of SAC1 around edge of trench
52 . thinner inclined section of heater material
54 . cold spot between series connected heater elements
56 . nozzle plate
58 . columnar projections
60 . sidewall ink opening
62 . ink refill opening
MEMS Manufacturing Process
[0235] The MEMS manufacturing process builds up nozzle structures on a silicon wafer after the completion of CMOS processing. FIG. 2 is a cutaway perspective view of a nozzle unit cell 100 after the completion of CMOS processing and before MEMS processing.
[0236] During CMOS processing of the wafer, four metal layers are deposited onto a silicon wafer 2 , with the metal layers being interspersed between interlayer dielectric (ILD) layers. The four metal layers are referred to as M 1 , M 2 , M 3 and M 4 layers and are built up sequentially on the wafer during CMOS processing. These CMOS layers provide all the drive circuitry and logic for operating the printhead.
[0237] In the completed printhead, each heater element actuator is connected to the CMOS via a pair of electrodes defined in the outermost M 4 layer. Hence, the M 4 CMOS layer is the foundation for subsequent MEMS processing of the wafer. The M 4 layer also defines bonding pads along a longitudinal edge of each printhead integrated circuit. These bonding pads (not shown) allow the CMOS to be connected to a microprocessor via wire bonds extending from the bonding pads.
[0238] FIGS. 1 and 2 show the aluminium M 4 layer 3 having a passivation layer 4 deposited thereon. (Only MEMS features of the M 4 layer are shown in these Figures; the main CMOS features of the M 4 layer are positioned outside the nozzle unit cell). The M 4 layer 3 has a thickness of 1 micron and is itself deposited on a 2 micron layer of CVD oxide 5 . As shown in FIGS. 1 and 2 , the M 4 layer 3 has an ink inlet opening 6 and pit openings 7 . These openings define the positions of the ink inlet and pits formed subsequently in the MEMS process.
[0239] Before MEMS processing of the unit cell 1 begins, bonding pads along a longitudinal edge of each printhead integrated circuit are defined by etching through the passivation layer 4 . This etch reveals the M 4 layer 3 at the bonding pad positions. The nozzle unit cell 1 is completely masked with photoresist for this step and, hence, is unaffected by the etch.
[0240] Turning to FIGS. 3 to 5 , the first stage of MEMS processing etches a pit 8 through the passivation layer 4 and the CVD oxide layer 5 . This etch is defined using a layer of photoresist (not shown) exposed by the dark tone pit mask shown in FIG. 3 . The pit 8 has a depth of 2 microns, as measured from the top of the M 4 layer 3 . At the same time as etching the pit 8 , electrodes 9 are defined on either side of the pit by partially revealing the M 4 layer 3 through the passivation layer 4 . In the completed nozzle, a heater element is suspended across the pit 8 between the electrodes 9 .
[0241] In the next step (FIGS. 6 to 8 ), the pit 8 is filled with a first sacrificial layer (“SAC1”) of photoresist 10 . A 2 micron layer of high viscosity photoresist is first spun onto the wafer and then exposed using the dark tone mask shown in FIG. 6 . The SAC1 photoresist 10 forms a scaffold for subsequent deposition of the heater material across the electrodes 9 on either side of the pit 8 . Consequently, it is important the SAC1 photoresist 10 has a planar upper surface that is flush with the upper surface of the electrodes 9 . At the same time, the SAC1 photoresist must completely fill the pit 8 to avoid ‘stringers’ of conductive heater material extending across the pit and shorting out the electrodes 9 .
[0242] Typically, when filling trenches with photoresist, it is necessary to expose the photoresist outside the perimeter of the trench in order to ensure that photoresist fills against the walls of the trench and, therefore, avoid ‘stringers’ in subsequent deposition steps. However, this technique results in a raised (or spiked) rim of photoresist around the perimeter of the trench. This is undesirable because in a subsequent deposition step, material is deposited unevenly onto the raised rim—vertical or angled surfaces on the rim will receive less deposited material than the horizontal planar surface of the photoresist filling the trench. The result is ‘resistance hotspots ’ in regions where material is thinly deposited.
[0243] As shown in FIG. 7 , the present process deliberately exposes the SAC1 photoresist 10 inside the perimeter walls of the pit 8 (e.g. within 0.5 microns) using the mask shown in FIG. 6 . This ensures a planar upper surface of the SAC1 photoresist 10 and avoids any spiked regions of photoresist around the perimeter rim of the pit 8 .
[0244] After exposure of the SAC1 photoresist 10 , the photoresist is reflowed by heating. Reflowing the photoresist allows it to flow to the walls of the pit 8 , filling it exactly. FIGS. 9 and 10 show the SAC1 photoresist 10 after reflow. The photoresist has a planar upper surface and meets flush with the upper surface of the M 4 layer 3 , which forms the electrodes 9 . Following reflow, the SAC1 photoresist 10 is U.V. cured and/or hardbaked to avoid any reflow during the subsequent deposition step of heater material.
[0245] FIGS. 11 and 12 show the unit cell after deposition of the 0.5 microns of heater material 11 onto the SAC1 photoresist 10 . Due to the reflow process described above, the heater material 11 is deposited evenly and in a planar layer over the electrodes 9 and the SAC1 photoresist 10 . The heater material may be comprised of any suitable conductive material, such as TiAl, TiN, TiAlN, TiAlSiN etc. A typical heater material deposition process may involve sequential deposition of a 100 Å seed layer of TiAl, a 2500 Ålayer of TiAlN, a further 100 Å seed layer of TiAl and finally a further 2500 Ålayer of TiAlN.
[0246] Referring to FIGS. 13 to 15 , in the next step, the layer of heater material 11 is etched to define the thermal actuator 12 . Each actuator 12 has contacts 28 that establish an electrical connection to respective electrodes 9 on either side of the SAC1 photoresist 10 . A heater element 29 spans between its corresponding contacts 28 .
[0247] This etch is defined by a layer of photoresist (not shown) exposed using the dark tone mask shown in FIG. 13 . As shown in FIG. 15 , the heater element 12 is a linear beam spanning between the pair of electrodes 9 . However, the heater element 12 may alternatively adopt other configurations, such as those described in Applicant's U.S. Pat. No. 6,755,509, the content of which is herein incorporated by reference. For example, heater element 29 configurations having a central void may be advantageous for minimizing the deleterious effects of cavitation forces on the heater material when a bubble collapses during ink ejection. Other forms of cavitation protection may be adopted such as ‘bubble venting’ and the use of self passivating materials. These cavitation management techniques are discussed in detail in U.S. patent application Ser. No. (our docket MTC001US).
[0248] In the next sequence of steps, an ink inlet for the nozzle is etched through the passivation layer 4 , the oxide layer 5 and the silicon wafer 2 . During CMOS processing, each of the metal layers had an ink inlet opening (see, for example, opening 6 in the M 4 layer 3 in FIG. 1 ) etched therethrough in preparation for this ink inlet etch. These metal layers, together with the interspersed ILD layers, form a seal ring for the ink inlet, preventing ink from seeping into the CMOS layers.
[0249] Referring to FIGS. 16 to 18 , a relatively thick layer of photoresist 13 is spun onto the wafer and exposed using the dark tone mask shown in FIG. 16 . The thickness of photoresist 13 required will depend on the selectivity of the deep reactive ion etch (DRIE) used to etch the ink inlet. With an ink inlet opening 14 defined in the photoresist 13 , the wafer is ready for the subsequent etch steps.
[0250] In the first etch step ( FIGS. 19 and 20 ), the dielectric layers (passivation layer 4 and oxide layer 5 ) are etched through to the silicon wafer below. Any standard oxide etch (e.g. O 2 /C 4 F 8 plasma) may be used.
[0251] In the second etch step ( FIGS. 21 and 22 ), an ink inlet 15 is etched through the silicon wafer 2 to a depth of 25 microns, using the same photoresist mask 13 . Any standard anisotropic DRIE, such as the Bosch etch (see U.S. Pat. Nos. 6,501,893 and 6,284,148) may be used for this etch. Following etching of the ink inlet 15 , the photoresist layer 13 is removed by plasma ashing.
[0252] In the next step, the ink inlet 15 is plugged with photoresist and a second sacrificial layer (“SAC2”) of photoresist 16 is built up on top of the SAC1 photoresist 10 and passivation layer 4 . The SAC2 photoresist 16 will serve as a scaffold for subsequent deposition of roof material, which forms a roof and sidewalls for each nozzle chamber. Referring to FIGS. 23 to 25 , a ˜6 micron layer of high viscosity photoresist is spun onto the wafer and exposed using the dark tone mask shown in FIG. 23 .
[0253] As shown in FIGS. 23 and 25 , the mask exposes sidewall openings 17 in the SAC2 photoresist 16 corresponding to the positions of chamber sidewalls and sidewalls for an ink conduit. In addition, openings 18 and 19 are exposed adjacent the plugged inlet 15 and nozzle chamber entrance respectively. These openings 18 and 19 will be filled with roof material in the subsequent roof deposition step and provide unique advantages in the present nozzle design. Specifically, the openings 18 filled with roof material act as priming features, which assist in drawing ink from the inlet 15 into each nozzle chamber. This is described in greater detail below. The openings 19 filled with roof material act as filter structures and fluidic cross talk barriers. These help prevent air bubbles from entering the nozzle chambers and diffuses pressure pulses generated by the thermal actuator 12 .
[0254] Referring to FIGS. 26 and 27 , the next stage deposits 3 microns of roof material 20 onto the SAC2 photoresist 16 by PECVD. The roof material 20 fills the openings 17 , 18 and 19 in the SAC2 photoresist 16 to form nozzle chambers 24 having a roof 21 and sidewalls 22 . An ink conduit 23 for supplying ink into each nozzle chamber is also formed during deposition of the roof material 20 . In addition, any priming features and filter structures (not shown in FIGS. 26 and 27 ) are formed at the same time. The roofs 21 , each corresponding to a respective nozzle chamber 24 , span across adjacent nozzle chambers in a row to form a continuous nozzle plate. The roof material 20 may be comprised of any suitable material, such as silicon nitride, silicon oxide, silicon oxynitride, aluminium nitride etc.
[0255] Referring to FIGS. 28 to 30 , the next stage defines an elliptical nozzle rim 25 in the roof 21 by etching away 2 microns of roof material 20 . This etch is defined using a layer of photoresist (not shown) exposed by the dark tone rim mask shown in FIG. 28 . The elliptical rim 25 comprises two coaxial rim lips 25 a and 25 b , positioned over their respective thermal actuator 12 .
[0256] Referring to FIGS. 31 to 33 , the next stage defines an elliptical nozzle aperture 26 in the roof 21 by etching all the way through the remaining roof material 20 , which is bounded by the rim 25 . This etch is defined using a layer of photoresist (not shown) exposed by the dark tone roof mask shown in FIG. 31 . The elliptical nozzle aperture 26 is positioned over the thermal actuator 12 , as shown in FIG. 33 .
[0257] With all the MEMS nozzle features now fully formed, the next stage removes the SAC1 and SAC2 photoresist layers 10 and 16 by O 2 plasma ashing (FIGS. 34 to 35 ). After ashing, the thermal actuator 12 is suspended in a single plane over the pit 8 . The coplanar deposition of the contacts 28 and the heater element 29 provides an efficient electrical connection with the electrodes 9 .
[0258] FIGS. 36 and 37 show the entire thickness (150 microns) of the silicon wafer 2 after ashing the SAC1 and SAC2 photoresist layers 10 and 16 .
[0259] Referring to FIGS. 38 to 40 , once frontside MEMS processing of the wafer is completed, ink supply channels 27 are etched from the backside of the wafer to meet with the ink inlets 15 using a standard anisotropic DRIE. This backside etch is defined using a layer of photoresist (not shown) exposed by the dark tone mask shown in FIG. 38 . The ink supply channel 27 makes a fluidic connection between the backside of the wafer and the ink inlets 15 .
[0260] Finally, and referring to FIGS. 41 and 42 , the wafer is thinned 135 microns by backside etching. FIG. 43 shows three adjacent rows of nozzles in a cutaway perspective view of a completed printhead integrated circuit. Each row of nozzles has a respective ink supply channel 27 extending along its length and supplying ink to a plurality of ink inlets 15 in each row. The ink inlets, in turn, supply ink to the ink conduit 23 for each row, with each nozzle chamber receiving ink from a common ink conduit for that row.
[0000] Features and Advantages of Particular Embodiments
[0261] Discussed below, under appropriate sub-headings, are certain specific features of embodiments of the invention, and the advantages of these features. The features are to be considered in relation to all of the drawings pertaining to the present invention unless the context specifically excludes certain drawings, and relates to those drawings specifically referred to.
[0000] Low Loss Electrodes
[0262] As shown in FIGS. 41 and 42 , the heater element 29 is suspended within the chamber. This ensures that the heater element is immersed in ink when the chamber is primed. Completely immersing the heater element in ink dramatically improves the printhead efficiency. Much less heat dissipates into the underlying wafer substrate so more of the input energy is used to generate the bubble that ejects the ink.
[0263] To suspend the heater element, the contacts may be used to support the element at its raised position. Essentially, the contacts at either end of the heater element can have vertical or inclined sections to connect the respective electrodes on the CMOS drive to the element at an elevated position. However, heater material deposited on vertical or inclined surfaces is thinner than on horizontal surfaces. To avoid undesirable resistive losses from the thinner sections, the contact portion of the thermal actuator needs to be relatively large. Larger contacts occupy a significant area of the wafer surface and limit the nozzle packing density.
[0264] To immerse the heater, the present invention etches a pit or trench 8 between the electrodes 9 to drop the level of the chamber floor. As discussed above, a layer of sacrificial photoresist (SAC) 10 (see FIG. 9 ) is deposited in the trench to provide a scaffold for the heater element. However, depositing SAC 10 in the trench 8 and simply covering it with a layer of heater material, can lead to stringers forming in the gaps 46 between the SAC 10 and the sidewalls 48 of the trench 8 (as previously described in relation to FIG. 7 ). The gaps form because it is difficult to precisely match the mask with the sides of the trench 8 . Usually, when the masked photoresist is exposed, the gaps 46 form between the sides of the pit and the SAC. When the heater material layer is deposited, it fills these gaps to form ‘stringers’ (as they are known). The stringers remain in the trench 8 after the metal etch (that shapes the heater element) and the release etch (to finally remove the SAC). The stringers can short circuit the heater so that it fails to generate a bubble.
[0265] Turning now to FIG. 52 and 53 , the traditional technique for avoiding stringers is illustrated. By making the UV mask that exposes the SAC slightly bigger than the trench 8 , the SAC 10 will be deposited over the side walls 48 so that no gaps form. Unfortunately, this produces a raised lip 50 around top of the trench. When the heater material layer 11 is deposited (see FIG. 53 ), it is thinner on the vertical or inclined surfaces 52 of the lip 50 . After the metal etch and release etch, these thin lip formations 52 remain and cause ‘hotspots’ because the localized thinning increases resistance. These hotspots affect the operation of the heater and typically reduce heater life.
[0266] As discussed above, the Applicant has found that reflowing the SAC 10 closes the gaps 46 so that the scaffold between the electrodes 9 is completely flat. This allows the entire thermal actuator 12 to be planar. The planar structure of the thermal actuator, with contacts directly deposited onto the CMOS electrodes 9 and suspended heater element 29 , avoids hotspots caused by vertical or inclined surfaces so that the contacts can be much smaller structures without acceptable increases in resistive losses. Low resistive losses preserves the efficient operation of a suspended heater element and the small contact size is convenient for close nozzle packing on the printhead.
[0000] Multiple Nozzles for each Chamber
[0267] Referring to FIG. 49 , the unit cell shown has two separate ink chambers 38 , each chamber having heater element 29 extending between respective pairs of contacts 28 . Ink permeable structures 34 are positioned in the ink refill openings so that ink can enter the chambers, but upon actuation, the structures 34 provide enough hydraulic resistance to reduce any reverse flow or fluidic cross talk to an acceptable level.
[0268] Ink is fed from the reverse side of the wafer through the ink inlet 15 . Priming features 18 extend into the inlet opening so that an ink meniscus does not pin itself to the peripheral edge of the opening and stop the ink flow. Ink from the inlet 15 fills the lateral ink conduit 23 which supplies both chambers 38 of the unit cell.
[0269] Instead of a single nozzle per chamber, each chamber 38 has two nozzles 25 . When the heater element 29 actuates (forms a bubble), two drops of ink are ejected; one from each nozzle 25 . Each individual drop of ink has less volume than the single drop ejected if the chamber had only one nozzle. By ejecting multiple drops from a single chamber simultaneously improves the print quality.
[0270] With every nozzle, there is a degree of misdirection in the ejected drop. Depending on the degree of misdirection, this can be detrimental to print quality. By giving the chamber multiple nozzles, each nozzle ejects drops of smaller volume, and having different misdirections. Several small drops misdirected in different directions are less detrimental to print quality than a single relatively large misdirected drop. The Applicant has found that the eye averages the misdirections of each small drop and effectively ‘sees’ a dot from a single drop with a significantly less overall misdirection.
[0271] A multi nozzle chamber can also eject drops more efficiently than a single nozzle chamber. The heater element 29 is an elongate suspended beam of TiAlN and the bubble it forms is likewise elongated. The pressure pulse created by an elongate bubble will cause ink to eject through a centrally disposed nozzle. However, some of the energy from the pressure pulse is dissipated in hydraulic losses associated with the mismatch between the geometry of the bubble and that of the nozzle.
[0272] Spacing several nozzles 25 along the length of the heater element 29 reduces the geometric discrepancy between the bubble shape and the nozzle configuration through which the ink ejects. This in turn reduces hydraulic resistance to ink ejection and thereby improves printhead efficiency.
[0000] Ink Chamber Re-Filled Via Adjacent Ink Chamber
[0273] Referring to FIG. 46 , two opposing unit cells are shown. In this embodiment, unit cell has four ink chambers 38 . The chambers are defined by the sidewalls 22 and the ink permeable structures 34 . Each chamber has its own heater element 29 . The heater elements 29 are arranged in pairs that are connected in series. Between each pair is ‘cold spot’ 54 with lower resistance and or greater heat sinking. This ensures that bubbles do not nucleate at the cold spots 54 and thus the cold spots become the common contact between the outer contacts 28 for each heater element pair.
[0274] The ink permeable structures 34 allow ink to refill the chambers 38 after drop ejection but baffle the pressure pulse from each heater element 29 to reduce the fluidic cross talk between adjacent chambers. It will be appreciated that this embodiment has many parallels with that shown in FIG. 49 discussed above. However, the present embodiment effectively divides the relatively long chambers of FIG. 49 into two separate chambers. This further aligns the geometry of the bubble formed by the heater element 29 with the shape of the nozzle 25 to reduce hydraulic losses during drop ejection. This is achieved without reducing the nozzle density but it does add some complexity to the fabrication process.
[0275] The conduits (ink inlets 15 and supply conduits 23 ) for distributing ink to every ink chamber in the array can occupy a significant proportion of the wafer area. This can be a limiting factor for nozzle density on the printhead. By making some ink chambers part of the ink flow path to other ink chambers, while keeping each chamber sufficiently free of fluidic cross talk, reduces the amount of wafer area lost to ink supply conduits.
[0000] Ink Chamber with Multiple Actuators and Respective Nozzles
[0276] Referring to FIG. 54 , the unit cell shown has two chambers 38 ; each chamber has two heater elements 29 and two nozzles 25 . The effective reduction in drop misdirection by using multiple nozzles per chamber is discussed above in relation to the embodiment shown in FIG. 49 . The additional benefits of dividing a single elongate chamber into separate chambers, each with their own actuators, is described above with reference to the embodiment shown in FIG. 46 . The present embodiment uses multiple nozzles and multiple actuators in each chamber to achieve much of the advantages of the FIG. 46 embodiment with a markedly less complicated design. With a simplified design, the overall dimensions of the unit cell are reduced thereby permitting greater nozzle densities. In the embodiment shown, the footprint of the unit cell is 64 μm long by 16 μm wide.
[0277] The ink permeable structure 34 is a single column at the ink refill opening to each chamber 38 instead of three spaced columns as with the FIG. 46 embodiment. The single column has a cross section profiled to be less resistive to refill flow, but more resistive to sudden back flow from the actuation pressure pulse. Both heater elements in each chamber can be deposited simultaneously, together with the contacts 28 and the cold spot feature 54 . Both chambers 38 are supplied with ink from a common ink inlet 15 and supply conduit 23 . These features also allow the footprint to be reduced and they are discussed in more detail below. The priming features 18 have been made integral with one of the chamber sidewalls 22 and a wall ink conduit 23 . The dual purpose nature of these features simplifies the fabrication and helps to keep the design compact.
[0000] Multiple Chambers and Multiple Nozzles for each Drive Circuit
[0278] In FIG. 54 , the actuators are connected in series and therefore fire in unison from the same drive signal to simplify the CMOS drive circuitry. In the FIG. 46 unit cell, actuators in adjacent nozzles are connected in series within the same drive circuit. Of course, the actuators in adjacent chambers could also be connected in parallel. In contrast, were the actuators in each chamber to be in separate circuits, the CMOS drive circuitry would be more complex and the dimensions of the unit cell footprint would increase. In printhead designs where the drop misdirection is addressed by substituting multiple smaller drops, combining several actuators and their respective nozzles into a common drive circuit is an efficient implementation both in terms of printhead IC fabrication and nozzles density.
[0000] High Density Thermal Inkjet Printhead
[0279] Reduction in the unit cell width enables the printhead to have nozzles patterns that previously would have required the nozzle density to be reduced. Of course, a lower nozzle density has a corresponding influence on printhead size and/or print quality.
[0280] Traditionally, the nozzle rows are arranged in pairs with the actuators for each row extending in opposite directions. The rows are staggered with respect to each other so that the printing resolution (dots per inch) is twice the nozzle pitch (nozzles per inch) along each row. By configuring the components of the unit cell such that the overall width of the unit is reduced, the same number of nozzles can be arranged into a single row instead of two staggered and opposing rows without sacrificing any print resolution (d.p.i.). The embodiments shown in the accompanying figures achieve a nozzle pitch of more than 1000 nozzles per inch in each linear row. At this nozzle pitch, the print resolution of the printhead is better than photographic (1600 dpi) when two opposing staggered rows are considered, and there is sufficient capacity for nozzle redundancy, dead nozzle compensation and so on which ensures the operation life of the printhead remains satisfactory. As discussed above, the embodiment shown in FIG. 54 has a footprint that is 16 μm wide and therefore the nozzle pitch along one row is about 1600 nozzles per inch. Accordingly, two offset staggered rows yield a resolution of about 3200 d.p.i.
[0281] With the realisation of the particular benefits associated with a narrower unit cell, the Applicant has focussed on identifying and combining a number of features to reduce the relevant dimensions of structures in the printhead. For example, elliptical nozzles, shifting the ink inlet from the chamber, finer geometry logic and shorter drive FETs (field effect transistors) are features developed by the Applicant to derive some of the embodiments shown. Each contributing feature necessitated a departure from conventional wisdom in the field, such as reducing the FET drive voltage from the widely used traditional 5V to 2.5V in order to decrease transistor length.
[0000] Reduced Stiction Printhead Surface
[0282] Static friction, or “stiction” as it has become known, allows dust particles to“stick” to nozzle plates and thereby clog nozzles. FIG. 50 shows a portion of the nozzle plate 56 . For clarity, the nozzle apertures 26 and the nozzle rims 25 are also shown. The exterior surface of the nozzle plate is patterned with columnar projections 58 extending a short distance from the plate surface. The nozzle plate could also be patterned with other surface formations such as closely spaced ridges, corrugations or bumps. However, it is easy to create a suitable UV mask for the pattern columnar projections shown, and it is a simple matter to etch the columns into the exterior surface.
[0283] By reducing the co-efficient of static friction, there is less likelihood that paper dust or other contaminants will clog the nozzles in the nozzle plate. Patterning the exterior of the nozzle plate with raised formations limits the surface area that dust particles contact. If the particles can only contact the outer extremities of each formation, the friction between the particles and the nozzle plate is minimal so attachment is much less likely. If the particles do attach, they are more likely to be removed by printhead maintenance cycles.
[0000] Inlet Priming Feature
[0284] Referring to FIG. 47 , two unit cells are shown extending in opposite directions to each other. The ink inlet passage 15 supplies ink to the four chambers 38 via the lateral ink conduit 23 . Distributing ink through micron-scale conduits, such as the ink inlet 15 , to individual MEMS nozzles in an inkjet printhead is complicated by factors that do not arise in macro-scale flow. A meniscus can form and, depending on the geometry of the aperture, it can ‘pin’ itself to the lip of the aperture quite strongly. This can be useful in printheads, such as bleed holes that vent trapped air bubbles but retain the ink, but it can also be problematic if stops ink flow to some chambers. This will most likely occur when initially priming the printhead with ink. If the ink meniscus pins at the ink inlet opening, the chambers supplied by that inlet will stay unprimed.
[0285] To guard against this, two priming features 18 are formed so that they extend through the plane of the inlet aperture 15 . The priming features 18 are columns extending from the interior of the nozzle plate (not shown) to the periphery of the inlet 15 . A part of each column 18 is within the periphery so that the surface tension of an ink meniscus at the ink inlet will form at the priming features 18 so as to draw the ink out of the inlet. This ‘unpins’ the meniscus from that section of the periphery and the flow toward the ink chambers.
[0286] The priming features 18 can take many forms, as long as they present a surface that extends transverse to the plane of the aperture. Furthermore, the priming feature can be an integral part of other nozzles features as shown in FIG. 54 .
[0000] Side Entry Ink Chamber
[0287] Referring to FIG. 48 , several adjacent unit cells are shown. In this embodiment, the elongate heater elements 29 extend parallel to the ink distribution conduit 23 . Accordingly, the elongate ink chambers 38 are likewise aligned with the ink conduit 23 . Sidewall openings 60 connect the chambers 38 to the ink conduit 23 . Configuring the ink chambers so that they have side inlets reduces the ink refill times. The inlets are wider and therefore refill flow rates are higher. The sidewall openings 60 have ink permeable structures 34 to keep fluidic cross talk to an acceptable level.
[0000] Inlet Filter for Ink Chamber
[0288] Referring again to FIG. 47 , the ink refill opening to each chamber 38 has a filter structure 40 to trap air bubbles or other contaminants. Air bubbles and solid contaminants in ink are detrimental to the MEMS nozzle structures. The solid contaminants can obvious clog the nozzle openings, while air bubbles, being highly compressible, can absorb the pressure pulse from the actuator if they get trapped in the ink chamber. This effectively disables the ejection of ink from the affected nozzle. By providing a filter structure 40 in the form of rows of obstructions extending transverse to the flow direction through the opening, each row being spaced such that they are out of registration with the obstructions in an adjacent row with respect to the flow direction, the contaminants are not likely to enter the chamber 38 while the ink refill flow rate is not overly retarded. The rows are offset with respect to each other and the induced turbulence has minimal effect on the nozzle refill rate but the air bubbles or other contaminants follow a relatively tortuous flow path which increases the chance of them being retained by the obstructions 40 . The embodiment shown uses two rows of obstructions 40 in the form of columns extending between the wafer substrate and the nozzle plate.
[0000] Intercolour Surface Barriers in Multi Colour Inkjet Printhead
[0289] Turning now to FIG. 51 , the exterior surface of the nozzle 56 is shown for a unit cell such as that shown in FIG. 46 described above. The nozzle apertures 26 are positioned directly above the heater elements (not shown) and a series of square-edged ink gutters 44 are formed in the nozzle plate 56 above the ink conduit 23 (see FIG. 46 ).
[0290] Inkjet printers often have maintenance stations that cap the printhead when it's not in use. To remove excess ink from the nozzle plate, the capper can be disengaged so that it peels off the exterior surface of the nozzle plate. This promotes the formation of a meniscus between the capper surface and the exterior of the nozzle plate. Using contact angle hysteresis, which relates to the angle that the surface tension in the meniscus contacts the surface (for more detail, see the Applicant's co-pending U.S. Ser. No. (our docket FND007US) incorporated herein by reference), the majority of ink wetting the exterior of the nozzle plate can be collected and drawn along by the meniscus between the capper and nozzle plate. The ink is conveniently deposited as a large bead at the point where the capper fully disengages from the nozzle plate. Unfortunately, some ink remains on the nozzle plate. If the printhead is a multi-colour printhead, the residual ink left in or around a given nozzle aperture, may be a different colour than that ejected by the nozzle because the meniscus draws ink over the whole surface of the nozzle plate. The contamination of ink in one nozzle by ink from another nozzle can create visible artefacts in the print.
[0291] Gutter formations 44 running transverse to the direction that the capper is peeled away from the nozzle plate will remove and retain some of the ink in the meniscus. While the gutters do not collect all the ink in the meniscus, they do significantly reduce the level of nozzle contamination of with different coloured ink.
[0000] Bubble Trap
[0292] Air bubbles entrained in the ink are very bad for printhead operation. Air, or rather gas in general, is highly compressible and can absorb the pressure pulse from the actuator. If a trapped bubble simply compresses in response to the actuator, ink will not eject from the nozzle. Trapped bubbles can be purged from the printhead with a forced flow of ink, but the purged ink needs blotting and the forced flow could well introduce fresh bubbles.
[0293] The embodiment shown in FIG. 46 has a bubble trap at the ink inlet 15 . The trap is formed by a bubble retention structure 32 and a vent 36 formed in the roof layer. The bubble retention structure is a series of columns 32 spaced around the periphery of the inlet 15 . As discussed above, the ink priming features 18 have a dual purpose and conveniently form part of the bubble retaining structure. In use, the ink permeable trap directs gas bubbles to the vent where they vent to atmosphere. By trapping the bubbles at the ink inlets and directing them to a small vent, they are effectively removed from the ink flow without any ink leakage.
[0000] Multiple Ink Inlet Flow Paths
[0294] Supplying ink to the nozzles via conduits extending from one side of the wafer to the other allows more of the wafer area (on the ink ejection side) to have nozzles instead of complex ink distribution systems. However, deep etched, micron-scale holes through a wafer are prone to clogging from contaminants or air bubbles. This starves the nozzle(s) supplied by the affected inlet.
[0295] As best shown in FIG. 48 , printheads according to the present invention have at least two ink inlets 15 supplying each chamber 38 via an ink conduit 23 between the nozzle plate and underlying wafer.
[0296] Introducing an ink conduit 23 that supplies several of the chambers 38 , and is in itself supplied by several ink inlets 15 , reduces the chance that nozzles will be starved of ink by inlet clogging. If one inlet 15 is clogged, the ink conduit will draw more ink from the other inlets in the wafer.
[0297] Although the invention is described above with reference to specific embodiments, it will be understood by those skilled in the art that the invention may be embodied in many other forms.
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A method of forming a low-stiction nozzle plate for an inkjet printhead, said nozzle plate having a plurality of nozzle apertures defined therein, each nozzle aperture having a respective nozzle rim, said method comprising the steps of: (a) providing a partially-fabricated printhead comprising a plurality of inkjet nozzle assemblies sealed with roof material; (b) etching partially into said roof material to define simultaneously said nozzle rims and a plurality of stiction-reducing formations; and (c) etching through said roof material to define said nozzle apertures, thereby forming said nozzle plate.
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TECHNICAL FIELD
The present invention relates to an apparatus and method for placing labels in position for being sewn onto a moving textile web, such as a towel, and more particularly relates to placing labels into the folds of a hem before the hem is sewn.
BACKGROUND ART
Manufacturers of web-like textile products, such as towel, blankets and sheets, usually sew an identifying label into a hem of the product. Many manufacturers utilize automatic equipment which moves the product past a folding device and then a sewing machine to form and sew the hem. The label can be inserted manually into the folds of the hem before sewing, or one of several automatic label injecting machines can be used. In general, the problems faced when automating the label injection process include the difficulty of withdrawing one label at a time from a supply of labels, presenting the label in proper orientation to the textile product during the formation of the folds of the hem, and preventing the motion of the product from disorienting the label before it can be sewn in place.
U.S. Pat. No. 4,157l,692 discloses a label dispensing system which removes from a vertical stack contained in a housing by bowing the bottom label down to a suction head which grasps the label. Then the suction head moves in an arc lying in a plane perpendicular to the path of a towel through about 180 degrees, to a positioning suspending the label over the path of the towel. When an approaching towel is detected, a separate clamp traps the label against the towel as the suction is terminated, and the suction head returns to a position below the stack of labels.
This system requires many moving parts, first to assure that only one label is acquired by the suction head, and also because the suction cannot simply deposit the label on the towel. The transverse relative movement of the suction head could tend to catch the label on the towel, causing the label to be misaligned. Thus, the head must suspend the label above the towel. Nor can the suction head simply drop the label onto the towel, because the movement of the towel could cause misalignment. Even if the towel were stopped for placement of the label, an inefficient step leading to increased cost, the label could float out of alignment.
Other swinging suction head systems have turned the arc of the suction head into the plane parallel to the path of the towel, but many of the same problems are still encountered. In one such system, the label dispenser is slightly inclined to the horizontal, and the suction head is operated to move into the magazine to engage the next label, pull it out of the magazine, and swing it down to the path of the towel. The label passes through a slot in the hemming track that folds the edge of the towel in a hem. This system requires complex control apparatus to precisely time the movement of the suction head.
Another automatic label handling system is disclosed in U.S. Pat. No. 4,505,467, according to which a suction head pulls a label off the bottom of an inclined dispenser holding a plurality of labels. A fork moving in the plane of the label then pushes the label off the suction head, after which it drops into an inclined chute where it is trapped by belts and fed down onto the towel. Another belt picks up the label in a conventional manner and holds it on the towel along the path to the sewing needle. It may be seen that this device depends upon the fork sliding the label off the suction head without folding or buckling the label, and releasing the label to let it free fall into the chute, all without changing the orientation of the label. Again, a relatively large number of moving parts is required, and it appears they must be carefully aligned to result in the label reaching the towel in proper alignment with the hem. IN practice, problems have arisen with one version of this system in which the belts in the chute were driven by the movement of the towel. The belts in the chute tended to lose synchronization of speed and to turn the labels travelling down to the towel.
Other label handling systems are shown in U.S. Pat. Nos. 4,305,338; 4,590,872; and 4,682,446. These systems position labels for sewing, but do not relate to inserting labels in hems.
Thus, there has long been a need in the art for a label injector capable of selecting a single label from a supply of labels and placing the label with consistent accuracy into the hem of a moving towel or other textile item, without slowing down the production rate of towels being hemmed. There has also been a need for such a label injector which has few moving parts, and can easily be moved away from the path of the towels to permit access to the injector and to other parts for maintenance.
SUMMARY OF THE INVENTION
The present invention addresses the problems in the prior art by providing a label injection system in which an applicator member grasps a label and moves it into contact with a moving workpiece, such as a towel, for sewing into a hem, without disrupting the orientation of the label. The system is consistently accurate in selection of one label at a time, and in placement of the labels on the workpiece, although it is less complex than prior, less consistent, devices.
Generally described, the present invention provides an apparatus for placing labels or the like onto a moving workpiece, comprising a magazine containing a plurality of the labels; an applicator wheel positioned between the magazine and the workpiece and rotatable about an axis perpendicular to the direction of movement of the workpiece, the applicator wheel including means for removing a label from the magazine and retaining the label on the applicator wheel; means for rotating the applicator wheel relative to the workpiece while the label is retained on the applicator wheel until the label is located between the applicator wheel and the workpiece; and means for releasing the label from the applicator wheel, whereby the label is placed upon the workpiece.
In the preferred embodiment of the invention, the wheel may define a peripheral surface for receiving the label, and the means for removing and retaining the label may comprise means for creating suction through an opening in the peripheral surface toward the interior of the wheel. Preferably, the peripheral surface defines a flattened portion surrounding the opening and a shoulder along the trailing edge of the flattened portion. The peripheral surface may further define a circumferential groove and a belt positioned in the groove, the belt crossing the opening and extending above the peripheral surface to engage the label. There is no need to stop the workpiece as the label is applied, because the peripheral surface can be moved at substantially the same speed as the workpiece.
In the preferred embodiment, the means for removing and retaining the label comprises means for creating suction through an opening in the peripheral surface toward the interior of the wheel. The means for creating suction can comprise a hollow axle with which the wheel rotates, a radial bore connecting the interior of the axle with the opening, and means for passing air through the axle across the entrance to the radial bore. The operation of the apparatus can be activated responsive to detection of an approaching workpiece.
The present invention also provides an apparatus for sequentially removing labels or the like, comprising a magazine containing a plurality of the labels, the magazine including a withdrawal opening and a lip extending partly across the withdrawal opening in the path of the labels; a suction head positioned adjacent to the withdrawal opening, the suction head being capable of grasping the label present at the withdrawal opening; and means for moving the magazine away from the suction head, such that the label grasped by the suction head is pulled from behind the lip and removed from the magazine. This feature of the invention assists greatly in assuring that one label at a time is removed from the magazine.
The present invention also provides a method of placing labels or the like onto a moving workpiece, generally comprising the steps of withdrawing a label from a magazine by applying suction to the label from an opening on the peripheral surface of a wheel positioned between the magazine and the workpiece; retaining the label on the wheel; moving the wheel relative to the workpiece while the label is retained on the peripheral surface until the label is positioned between the wheel and the workpiece; and releasing the label from the wheel, whereby the label is placed upon the workpiece.
Thus it is an object of the present invention to provide an improved apparatus and method for placing labels or the like onto a workpiece, such as a towel, or other textile web, for attachment to the workpiece.
It is a further object of the present invention to provide a label injector which accurately places labels into the hem of a moving textile web or other workpiece.
It is a further object of the present invention to provide a label injector which transfers a label from a label magazine to a textile web without passing the label between different parts of the injector or releasing the label prior to its placement on the textile web.
It is a further object of the present invention to provide a label injector which consistently retrieves a single label from a magazine and consistently places the label in the proper orientation on a moving textile web.
It is a further object of the present invention to provide a label injector which can be accessed easily for maintenance, removed easily when necessary, and replaced without any need to readjust the injector relative to the sewing apparatus on which it is mounted.
Other objects, features, and advantages of the present invention will become apparent upon reading the following detailed description of embodiments of the invention, when taken in conjunction with the accompanying drawing and the appended claims.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a pictorial view of a label injector embodying the present invention.
FIG. 2 is a vertical cross sectional view of the apparatus of FIG. 1, taken along line 2--2 of FIG. 1.
FIG. 3 is an isolated pictorial view of the applicator or vacuum wheel of the label injector of FIG. 1.
FIG. 4 is a front plan view of the label injector of FIG. 1, showing its relationship to the workpiece being hemmed.
FIG. 5 is a rear plan view of the label injector of FIG. 1.
FIG. 6 is a schematic representation of the pneumatic control circuit of the present invention, also showing the interior detail of the applicator wheel and hollow axle.
FIG. 7 is a schematic representation of the electrical control circuit of the present invention.
FIGS. 8A, 8B, and 8C show in sequence the manner in which a label is removed from the magazine by the applicator wheel.
FIG. 9 is an isolated side view of the magazine and applicator wheel of the label injector of FIG. 2, showing the wheel in position to release a label onto the workpiece.
FIG. 10 is a side view of another embodiment of the present invention according to which a belt surrounds the applicator wheel.
FIG. 11 is an isolated pictorial view of the applicator wheel of the embodiment of the invention shown in FIG. 10.
FIG. 12 is a vertical cross sectional view of a alternate embodiment of a label magazine which can be used with the present invention.
DETAILED DESCRIPTION
Referring now in more detail to the drawing, in which like numerals refer to like parts throughout the several views, FIG. 1 shows a label injector apparatus 10 embodying the present invention. The label injector 10 is positioned upstream of a sewing machine needle 12 above a table 14, along which a towel 15, or other workpiece, is being moved toward the sewing machine needle.
The label injector 10 includes a frame 18 which supports and allows adjustment of the moving parts of the label injector. The frame, shown in FIGS. 1-5, includes a horizontal mounting plate 20, which is rigidly clamped by means (not shown) to the structure of the table 14. A vertical mounting plate 22 defining a vertical slot therein is welded to the front edge of the horizontal mounting plate 20, and extends upwardly. A length of angle iron 23 is connected to the vertical plate 22 by a bolt 24. It will be seen that by loosening the bolt 24, the height of the angle 23 can be adjusted along the slotted plate 22, and the tilt of the angle 23 can be adjusted by rotation about the bolt 24. To stabilize the tilt position of the angle 23, a pair of set screws 25 and 26 at opposite ends of the angle 23 are tapped through the angle 23 until they engage the top surface of the horizontal plate 20.
The angle 23 defines a horizontal slot 28 near its center, and a vertical support member 30 is adjustably mounted to the angle by means of a bolt 31 passing through the slot 28 and threaded into a tapped hole in the vertical member 30. A magazine support member 33 is pivotally attached to the vertical member 30 by a conventional pivot joint 34 which can be locked in position by a locking screw 35. The support member 33 preferably is a vertically oriented angle ion defining a flange 37 which extends rearwardly in a plane at right angles to the length of the angle 23. A pneumatic cylinder 38 is mounted on the flange 37 with a piston rod 39 extending downwardly from the cylinder 38 and being biased in the down position by a spring 40 shown in FIG. 6. The cylinder 38 is provided with air pressure through a supply line 43 in a manner described below. A pair of vertical slots 36 are provided in the magazine support member 33. The front surface of the support member is preferably coated with a friction-reducing material such as Teflon tape.
A label magazine 45 includes a back wall 46, a pair of side walls 47, and a pair of front flanges 48, which together form an elongate, upstanding channel in which labels 52 can be stacked. In the embodiment shown in FIG. 1 a pair of inwardly directed lips 49 are mounted at the bottom of the side walls 47, to prevent the labels from falling out of the magazine 45. The magazine 45 is slidably attached to the magazine support member 33 by a pair of mounting screws 50 passing through the slot 36 into tapped holes in the support member 33, but not tightly binding the magazine against the support member. The vertical position of the piston rod 39, which is removably connected to the back wall 48 by a horizontal screw 41 which passes from the interior of the magazine 45 through the back wall 48 and passes through a ring 42 attached to the end of the piston rod 39. As will be explained in detail below, the operation of the piston rod reciprocates the magazine vertically along the slots 36 during operation of the label injector 10, preferably a distance of about one-half inch.
It may thus be seen that the magazine 45 may be moved horizontally along the slot 28 and tilted from side to side by rotation about the bolt 31 independently of the tilting of the angle 23, and locked by the bolt 31. It may also be tilted front to back about the pivot joint 34 and held in position by the locking screw 35.
The walls of the magazine 45 are preferably made of a smooth material such as plexiglass or stainless steel, so that the labels 52 will not bind as they make their way down the magazine. A follower 53 may be place on top of stack of labels 52 in the magazine to maintain the orientation of the labels and provide some weight forcing the bottom label against the lips 49. This assists in assuring that only one label at a time is retrieved by the suction apparatus described below.
A pair of mounting brackets 55 and 56 extend downwardly from the angel 23 on opposite sides of the magazine 45. At the bottom of the bracket 55, a conventional pneumatic rotary actuator 60 is mounted. The rotary actuator 60 may be, for example, that sold under the brand name FESTO DSR16-182. The function of the device is to rotate a shaft 61 through a certain arc (which is adjustable ) and to return the shaft to its original position. The rotary actuator 60 is supplied with air under pressure through two air lines 62 and 63 for providing rotary motion in opposite directions.
A bearing 65 is mounted at the bottom of the other bracket 56. Journalled in the bearing 65 is a hollow axle 66, which extends to a coupling 67 which joins the axle 66 to the shaft 61 of the rotary actuator 60. At its central portion, the axle 66 passes through an applicator wheel 70, which defines an axial bore 71 for receiving the axle 66. The rotary actuator 60 causes the wheel 70 and axle 66 to move together as the axle turns within the bearing 65.
The applicator wheel 70 also defines a pair of radial bores 72, shown in FIG. 6, which communicate with the axial bore 71 at one end, and extend while diverging in the shape of a "V" to a pair of openings 73 in the peripheral surface 75 of the wheel 70. An exemplary wheel, without limitation thereto, might have a diameter of three inches, a peripheral surface one inch wide, and two bores 72 each having a diameter of three-eights of an inch.
As shown in FIGS. 1, 2, 4, and 5, the applicator wheel 70 is positioned between the bottom of the magazine 45 and the top of the workpiece 15. The wheel is offset from the center of the magazine toward the center of the workpiece. A flattened area or suction platform 80 is formed surrounding the location of the openings 73 in the peripheral surface 75, creating a shoulder 81 at the trailing edge of the platform 80, as best shown in FIG. 3. Preferably, the platform 80 is coated with a friction enhancing substance 82, such as silicon carbide powder placed in a layer of a conventional adhesive. The purpose of the substance 82 is to inhibit sliding of a label 52 being held on the platform 80. The rotary actuator is set so that at one extreme of travel of the wheel 70 (counterclockwise or upward rotation as viewed in FIG. 3), the platform 80 an the openings 73 are directly under the magazine 45. In a manner described below, such is created in the radial bores 72, causing the bottom label 52 to be pulled from the magazine onto the platform 80.
The mounting plate 20 of the label injector 10 is positioned so that the wheel 70 is located just inside a hem folding track or cams 83 of conventional construction. The cam 83 gradually guides the edge of the towel first upwardly and then over onto itself in a manner well known to those skilled in the art. A slot 84 is provided in the cam 83 at the intersection of the peripheral surface of the wheel 70 with the plane of the cam 83. The slot 84 allows the portion of a label extending laterally from the surface of the wheel to be carried within the fold being formed by the cam just before the material of the towel is folded over itself.
A skirt 78, formed of smooth, flexible metal or plastic, is attached to the front of the magazine and closely follows the contour of the wheel 70 to a position generally under the wheel. The skirt 78 passes through the slot 84 in the folding cam 83 and terminates short of the down position of the platform 80 as shown in FIG. 9. The skirt is not essential to the operation of the invention, although it tends to improve the consistency of performance.
The interior of the axle 66 and the applicator wheel 70 is shown in FIG. 6. The axle 66 defines a longitudinal passageway 85 which is divided into three sections. An entrance section 86 is adjacent to the bearing 65, and receives a pneumatic fitting 87 threaded into a tapped opening at the end of the entrance section 86. The fitting 87 is connected to an air line 88 which supplies positive air pressure to the passageway 85. Such air passes into a venturi throat 90 at the other end of the entrance section 86. The venturi throat opens into an exit section 91, which defines a radial opening 92 positioned to communicate with the radial bore 72 of the applicator wheel 70. As noted above, the end of the axle 66 is attached to the coupling 67. The coupling 67 is hollow, and the exit section 91 communicates with the interior chamber 94 of the coupling 67. Several exhaust openings 95 are formed in the coupling connecting the chamber 94 with the exterior.
Thus, it will be seen the pressurized air forced into the entrance section 86 is regulated by the venturi 90 and passes around the radial bores 72. The air exiting the venturi throat expands, adding to the negative pressure created in the radial bores and at the openings 73. The air passes on through the exit section 91, into the chamber 94, and out the openings 95 to atmospheric pressure. In the preferred embodiment, the entrance section may be 1.75 inches long and 5/16 inch in diameter, the venturi section 1/2 inch long and 7/64 inch in diameter, and the exit section 2.25 inches long and 3/8 inch in diameter. The radial bores may be approximately 3/8 inch in diameter, and separated by about 3/16 inch at the platform 80. The bridge of material of the platform separating the openings 73 prevents labels from being sucked into the bores 72. Those skilled in the art will realize that such dimensions may be varied according to the available air supply, the nature of the labels, and the construction of the magazine. It will also be apparent that a vacuum pump could be connected to the radial bores 72 to provide suction at the openings 73.
Referring now to FIG. 2, a belt 99 passes around a pulley 98, positioned above the path of the workpiece between the wheel 70 and the sewing machine 12. The lower run of the belt 99 extends closely adjacent to the path of the workpiece through and beyond the point at which the sewing machine sews a hem stitch into the workpiece. Thus, the belt 99 holds down a label released onto the workpiece from the wheel 70.
An infrared scanner 102 of conventional construction is positioned between the wheel 70 and the sewing machine 12, and is capable of detecting the passing of the leading edge of the workpiece. The scanner 102 may be mounted from the structure of the table 14 or attached to a bar (not shown) mounted on the label injector mounting plate 20. Preferably, the position of the scanner is made adjustable.
A normally closed reset limit switch 104 is positioned to be struck by a projection 105 on the rotary actuator 60 when the wheel 70 has travelled downwardly a distance sufficient to orient the platform 80 over the workpiece. The opening of the limit switch 104 results in the return of the wheel to tis original position through the operation of a control circuit described below.
The label injector 10 is operated using two control circuits, one of which is the pneumatic control circuit 110 shown in FIG. 6. A source of pressurized air at 60-80 PSI, preferably 80 PSI, is connected to the air lines 43, 62, 63, and 88. The line 43, connected to the cylinder 38, includes a solenoid operated valve 112 and a metering valve 113. The lines 62 and 63, connected to the down and up ports, respectively, of the rotary actuator 60, include solenoid operated valves 114 and 115, and metering valves 116 and 117. The line 88 includes a solenoid operated valve 118. The solenoid valves operate the piston rod to move the magazine, switch the rotary actuator position, and turn the suction on and off. Details of the operation are set out below.
An electrical control circuit 120, shown in FIG. 7, operates the solenoid valves. A 24 volt power supply 122 is turned on and off by a power switch 123, supplying power to the infrared scanner 102, solenoid valve 115 (rotary actuator up), and to a three pole, double throw relay 125 when the scanner detects a workpiece and closes contacts 102a. The relay may be, for example, a Potter & Brumfield Model AMF KRP A14BN relay. Energization of the relay 125 closes contacts 125a, operating solenoid valves 118 (suction on) and 112 (magazine up). Activation of the scanner 102 also closes contacts 102a and energizes a time delay relay 126, which times out and provides a signal after about 0.3 seconds. Timing out the relay 126 closes contacts 126a, operating solenoid valve 114, providing air pressure to the down port of the rotary actuator. Timing out of the relay 126 also opens normally closed contacts 126b, which deactivates solenoid valve 116, terminating air to the up port of the rotary actuator.
The relay 125 is also connected to the power supply in parallel through contacts 125c, and the normally closed limit switch 104. Thus, the closing of the scanner contacts 102a energizing the relay 125 is immediately followed by closing of the contacts 125c, which maintain power to the relay until motion of the rotary actuator 60 opens the limit switch 104, deactivating the relay 125. At this event, the relay contacts 125a, 125b, and 125c reverse, and the suction is turned off. Furthermore, deactivation of the relay 125 also resets the time delay relay 126, opening contacts 126a and closing normally closed contacts 126b. This causes the wheel 70 to return to its up position under the magazine. When the workpiece clears the scanner 102, the contacts 102a and 102b open, leaving the circuit in its original state.
In operation of the label injector 10, the operator may load the magazine 45 by sliding a stack of labels 52 down the magazine until they engage the lips 49. The follower weight 53 is placed on top of the stack of labels. The operator then turns on the power switch 123 and feeds the workpiece 15, such as a towel, into the hemming apparatus in a conventional manner. As the towel passes under the scanner 102, the scanner sends a signal closing contacts 102a and 102b. The relay 125 is energized, as well as the time delay relay 126. This results in switching of the valve 118 to allow pressurized air to flow through the axle 66, creating a vacuum at the openings 73 at the air escapes the venturi section 90 and flows past the opening 92 in the axle. The lowermost label 52 of the stack is pulled partially out of the magazine 45 against the platform 890 on the applicator wheel 70. Since the wheel 70 is offset with respect to the magazine, the label extends laterally beyond the peripheral surface of the wheel toward the edge of the towel being hemmed. The position of the components at this point in operation of the system is shown in FIG. 8A.
At the same time, the valve 112 is switched, supplying air to the piston 38, raising the piston rod 39 and the magazine 45 about one half inch. As shown in FIG. 8B, the upward motion of the magazine extracts the label 52 from the lips 49 of the magazine. This procedure has been found to extract only one label at a time in a very consistent manner. The skirt 78 is sufficiently flexible that is not removed from the folding cam 83 during upward motion of the magazine to which the skirt is attached.
Following the extraction of a label, the time delay relay 126 times out, and the switching of contacts 126a and 126b causes valves 114 and 116 to switch. Air is cut off from the up port of the rotary actuator 60 and is supplied to the down port, resulting in the rotation of the applicator wheel 70 toward the front as shown in FIG. 8C. The wheel 70 rotates through an angle of about 180 degrees to the position shown in FIG. 9. During motion of the wheel, the label is positioned against the shoulder 81 of the platform 80 formed in the wheel, and the roughened surface 82 of the platform tends to prevent movement of the label relative to the wheel as the label travels under the skirt 78. As the label approaches the folding cam 83, the extending end of the label passes through the slot 84 in the cam 83, clears the end of the skirt 78, and is in position to be folded into the hem being formed by the cam. The skirt 78 prevents the pile or loop material of the towel from disorienting the label as it passes under the wheel.
When the wheel 70 reaches the position shown in FIG. 9, with the label positioned above the web of the towel 15 and within the folded hem, the projection 105 on the moving portion of the rotary actuator 60 trips the limit switch 104. This deenergize the relay 125. Opening of the contacts 125a switches back the valve 112 to allow the magazine to move back to its original down position, and switches back the valve 118 to remove the vacuum from the openings 73. The label 52 is thus released onto the towel 115. Opening of the contacts 125b resets the time delay relay. Upon the opening of the contacts 126a and closing of the contacts 126b, the air pressure is removed from the down port of the rotary actuator 60 and connected to the up port. The wheel 70 thereby rotates back up to position the platform 80 under the magazine. The limit switch 104 is released and once again closes.
The movement of the towel 15, which has not slowed or stopped during the insertion of the label, continues as the wheel rotates back to its starting position. After the label is released, it is immediately trapped within the hem as the towel material is folded across the label by the shape of the cam 83. The label is carried within the hem until it is pressed against the towel by the belt 99 and subsequently sewn into the hem at the sewing machine 12. When the trailing end of the towel clears the scanner 102, the scanner resets, opening the contacts 102a and 102b. Now the injector system is ready to place a label on the next towel inserted by the operator.
Referring now to FIGS. 10 and 11, a second embodiment 160 of a label injector according to the present invention is shown. The mounting structure, magazine construction, vacuum system, and control systems are similar to those described above in connection with the first embodiment. A peripheral groove 177 is formed in the peripheral surface around the circumference of a wheel 170. A belt 197, preferably having a round cross section, is received in the peripheral groove 177 of the wheel 170. The belt 197 wraps around the side of the wheel facing away from the sewing machine 12, and also passes around a double pulley 198 positioned above the path of the workpiece between the wheel 170 and the sewing machine 12, in place of the pulley 98 previously described. Thus, the horizontal run of the belt 197 between the bottom of the wheel 170 and the pulley 198 passes closely adjacent to the path of the workpiece 15 on the table 14. At the pulley 198, the hold down function of the belt 197 is transferred to the belt 97 described above.
As shown in FIG. 11, the wheel 170 according to the second embodiment has only one radial bore and one surface opening 173. The belt 197 crosses the opening 173 and serves to prevent labels from being sucked into the opening. During operation, the belt helps to position the label on the moving wheel 170, the holds the label on the towel immediately after the label is released from the suction platform of the wheel. As the wheel returns upwardly, it slips within the belt.
FIG. 12 shows an alternate embodiment of a label magazine 145 for use with thicker labels 152, particularly those labels that have been folded into a double thickness prior to insertion into the magazine. Most prior label injectors cannot successfully handle such labels. The magazine 145 includes a back wall 146 and side walls 147 which are angled downwardly toward the front of the magazine. Front corner flanges 148, longer than the back wall 146, retain the labels within the magazine. A follower 153 having an angled bottom portion is placed on the stack of labels. No bottom lips corresponding to the lips 49 in the first embodiment are utilized.
As shown in FIG. 12, the magazine 145 is positioned forward of the center of the applicator 70, and the labels 152 rest directly on the peripheral surface of the wheel 70 at an angle. When the suction is turned on, the bottom label is adhered to the platform of the wheel, and the shoulder assists in separating the bottom label from those above. The thickness of the labels is such that only one label will be removed. The magazine is not raised during label extraction as was the ease with the first embodiment described above. As the wheel turns, the remaining labels 152 are held within the magazine by the passing smooth surface of the wheel 70. When the platform returns, the shoulder slips past the trailing edge of the next label, when then lies on the platform until the next towel is fed through the apparatus.
It will thus be seen that the present invention provides a greatly improved method and apparatus for placing labels into the hem of towels moving through a hemming apparatus. The label injector of the invention consistently extracts a single label and accurately places it into the hem being formed. The label injector can easily be removed from the production line without altering its internal adjustments, and itself has few moving parts. The label is transferred positively onto the moving towel without exchange between various transfer elements as was common in the prior art. Little opportunity exists for the label to become disoriented during the transfer process.
While this invention has been described in detail with particular reference to preferred embodiments thereof, it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinbefore and as defined in the appended claims.
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A label injector for placing labels in the hems of towels, or the like, is disclosed. The labels are extracted from a vertical magazine onto the surface of a wheel by a combination of suction into openings on the surface of the wheel and upward movement of the magazine. The wheel is then rotated until the extracted label passes through a slot in the adjacent hemming track into the hem being folded. Suction is terminated, releasing the label, and the wheel is returned to its original orientation to receive another label. Other embodiments disclose a magazine for double thickness labels, and an applicator carrying a belt in a peripheral groove to assist in moving the labels.
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BACKGROUND OF THE INVENTION
For many years it has been realized by various persons that walls and studs made primarily of wood have serious drawbacks. One reason for this is the high cost of lumber. Other reasons include labor costs, lack of resistance to termites, etc. Despite the need for moving away from wooden studs and associated building components, a satisfactory building system, that is non-wooden, has not been achieved in conventional housing.
To be satisfactory, it is necessary that the building system include components that can be readily handled by one worker. It is necessary that the system be such that workers--who are normally accustomed to wooden walls--can adapt to it with ease. And, it is highly necessary that the components of the system be manufacturable at low cost but with high strength and high quality. It is necessary that the contractor on the job be able to obtain a reasonable profit margin while still delivering to the home owner a very well-built wall and house.
SUMMARY OF THE INVENTION
In accordance with the present invention, a highly elongate load-bearing metal panel and stucco substrate is provided, and is such that one worker can readily handle it while erecting a wall in a house. By "highly elongate" is meant that the panel has a length at least several times its width, and is sufficiently long to extend at least the great majority of the distance between the floor and ceiling of a conventional dwelling house. Stated more definitely, the panel is typically about 16 inches wide, and about 7 or 8 feet long.
Each panel has at opposite edges thereof elements that nest with corresponding elements of other panels to form strong load-bearing studs that are integral with the panels. ("Integral" is hereby defined to mean formed from the same piece of sheet metal.) Stated otherwise, the edge portions of adjacent panels overlap and lock with each other and combine to form a load-bearing stud. Accordingly, there is such a stud at both edges of each panel.
The stucco substrate is an integral part of each panel, being formed by slitting a sheet metal web and then expanding it to form the substrate. The hole size of the substrate is conventional for stucco, namely about 1/2 inch. The substrate may be referred to herein as metal lath for stucco, or as metal lath substrate.
The stucco substrate, that is to say the metal lath, extends the great majority of the distance between the stud portions of each panel. Such distance is typically about 14 inches.
The stud portions of the panels are generally channel shaped, each being adapted to nest and interlock with the stud portion of an adjacent panel.
Insulation is provided in each panel and forms a component thereof. The foam is preferably sandwiched between layers of material, one layer being adjacent the stud portion and the other layer being spaced a short distance from the metal lath. The layers confine the foam while it is foamed in place after manufacture of the metal elements or portions of the panels. Spacing of one layer from the metal lath permits the stucco to penetrate through the lath and achieve a "key" shape such that the stucco may not pull away from the lath.
The panels are pre-manufactured at the factory and then shipped to the house site. A base element is mounted on the (typically) concrete slab floor of the house under construction. A first pre-manufactured panel is stood up with its lower end in the base, and then held in place as by a brace. Then, a second pre-manufactured panel is stood up adjacent the first one in such manner that the channel-shaped adjacent stud portions of the two panels nest and interlock. Such nested stud portions are secured together by screws. This procedure is continued for (typically) about 10 feet, following which a cap element is placed over the upper ends of the interlocked panels. Thereafter, at a suitable stage in the building process, stucco is applied to the exteriors of the panels, and wall board (plaster board or dry wall) is secured by screws to the studs on the interiors of the panels.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of one load-bearing structural panel and substrate incorporating the present invention;
FIG. 2 is a rear elevational view thereof;
FIG. 3 is an isometric view at the upper end of the panel as the panel is shown in FIG. 1, and looking downwardly;
FIG. 4 is an isometric view of a portion of a house incorporating a wall constructed of the present panels, the corner of the house being broken away in order to show the panels in assembled condition;
FIG. 5 is a horizontal sectional view on line 5--5 of FIG. 4; and
FIG. 6 is vertical sectional view on line 6--6 of FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1-3, there is shown at 10 a single highly elongate load-bearing metal panel and stucco substrate embodying the present invention. As above indicated, such panel 10 is at least several times as long (vertical) as it is wide (horizontal). Stated more specifically, it is at least about five times as long as it is wide. Preferably, the width of the panel is about 16 inches while the length is about 7-8 feet.
Each panel 10 has stud portions 11,12 at the edges thereof, and has a web 13, the great majority of which is expanded metal, such web extending almost the entire distance between the stud portions. The expanded metal web 13 is so constructed as to be a proper substrate (metal lath) for stucco.
Stud portions 11,12 connect to opposite edges of web 13 by flanges 15,16 that are perpendicular to the web. Thus, the panel 10 is channel-shaped in section, with flange 15 connecting the web to stud portion 11, and with flange 16 connecting the web to stud portion 12. Foam insulation, indicated at 17, is provided in the channel-shaped panel 10 as described below.
Each panel 10 is roll formed of light gauge galvanized sheet steel. The width of the panel at this time is on the order of 17 inches. Then, the web portion of the panel is slit with slits that are sized and located such that upon expansion of the web there will be formed the stucco substrate (metal lath). The hole size is about 1/2 inch. Then, the webs are expanded to form the lath having the desired proper hole size for stucco.
Preferably, the web is not entirely expanded metal. Instead, there is an expanded metal center portion 19 that extends almost the entire distance between the two corners 20,21 where the web meets flanges 15,16. Solid strips of the sheet steel remain immediately adjacent the corners 20,21 between such corners and the expanded metal 19. These strips 22 are preferably narrow, such as about 1 inch. In the preferred embodiment the distance between corners 20,21 of each panel is 16 inches.
Referring next to stud portion 11, this has a web 24 that is parallel to web 13 and extends toward flange 16. At the inner edge of web 24 is a flange 25 that extends toward web 13 and is parallel to flange 15; it terminates at an edge 26 that is spaced a sufficient distance from web 24 that flange 25 cooperates effectively with the opposed portion of flange 15 (and other portions) to create the desired structural strength.
The stud portion 12 is adapted to fit over stud portion 11 in nesting relationship. Stud portion 12 has a web 27 that is parallel to web 13 but extends outwardly, in a direction away from stud portion 11. At the outer edge of web 27 is a flange 28 that terminates in an edge 29. Edge 29 is disposed approximately the same distance from web 27 that edge 26 is spaced from web 24.
Referring next to the insulating foam 17, such insulating foam 17 is foamed in place at the manufacturing site, after the web 13 has been slit and expanded. This may be done, for example, by providing two parallel walls 31,32 of corrugated cardboard. Wall 31 is disposed inwardly adjacent flange edge 26 and held in place by it as well as by movable support means (not shown). Wall 32 is disposed inwardly adjacent but spaced slightly from web 13, being held by support means (not shown) that extend through the openings in web 13. The cardboard remains in place and is part of each panel 10.
It is pointed out that the described panel may be made much longer than is stated above and employed for one, two or more stories of a dwelling or a commercial building, in the latter case extending from story to story to provide a fast but effective construction operation.
Description of the Building Wall (and Associated Buildinq Components) Incorporating the Present Invention and Employing the Described Load-Bearing Metal Panel
Referring next to FIGS. 4-6 in particular, there is shown a corner portion of a house containing walls and panels constructed in accordance with the present invention. Such house has a subfloor, for example the concrete slab indicated at 34 in FIG. 6. A wooden runner 36 is secured horizontally to slab 34 (FIG. 6) and a sheet metal bottom track 37 is mounted over the runner. (Alternatively, no runner 36 is used; the metal track is attached directly to the slab or to second-story floor.) Bottom track 37 has a web portion 38 that is nailed to the upper surface of runner 36 parallel thereto and seated thereon. It also has a vertical interior portion 39 that is bent upwardly from the inner edge of the web. At the outer edge of web 38 is a downwardly and outwardly extending exterior portion 40.
The worker typically begins at an extreme corner, where there is provided a corner post 42 (FIG. 4) formed of wood. (Alternatively, a break-formed metal panel--having a right-angle bend--is employed as a corner post.) The first of many of the load-bearing metal panels, all identical to the one described in detail above relative to FIGS. 1-3, is then disposed in erect relationship adjacent the corner post 42. The lower end of the panel, which is indicted at 10a, is seated on web portion 38 of bottom track 37. Panel 10a is then screwed or otherwise secured to corner post 42. A second panel, shown at 10b, is then erected adjacent panel 10a, with the stud portion 12 of panel 10b nested loosely over the stud portion 11 of panel 10a. A plurality of self-tapping screws 43 (FIG. 5) are extended in vertically-spaced relationship (one at top, and one at bottom) through the webs 24,25 of both stud portions 11,12.
It is emphasized that the nested and interlocked stud portions 11 and 12, and which are screwed to each other by screws 43, cooperate with the closely adjacent flanges 15,16 (of panels 10a and 10b) to provide load-bearing studs. Stated otherwise, all of the elements 11,12,15,16, and 43 cooperate with each other to form strong studs that achieve the necessary structural support.
As the next step, panel 10c is erected adjacent panel 10b and secured thereto by interlocking of stud portions and by vertically-spaced screws 43 (FIG. 5). Alternatively, screws 43 may be omitted. This procedure is repeated for (typically) about 10 feet of panels, namely about seven panels, following which a top track 44 is mounted over all of the erected panels. As best shown in FIG. 6, top track 44 has a horizontal web portion 46 that seats over the panel ends. It also has flanges 47,48 that extend downwardly from web 46 adjacent the fronts and backs of the panels. The top track 44 is secured to the stud portions 11,12 by self-tapping screws.
The described procedure is repeated around all of the exterior walls of the building. At the various corners, corner posts 42 may be employed and/or the present structural panel may be bent at a right angle to form a corner through the expanded metal web 19.
As the next steps, small sections 50 of metal lath are secured by screws 51 over the exteriors of the edge portions of the panels, as shown in FIG. 5. This covers the solid strips 22 and the small cracks between the adjacent panels. Other sections of metal lath (not shown) may be provided over track portions 40 and 47. There are many possible joint details to cover the interlocking portion of the panels.
Stucco 53 (FIG. 5) is then applied to the substrate (metal lath) at the exterior of the house, as best shown in FIG. 5. The stucco passes in part through the openings in the expanded metal 19, and goes into the small space between the metal web and the cardboard 32 (without necessarily filling such space). This creates a "key" action by which the stucco hangs tightly onto the metal lath in very secure relationship.
Conventional-sized sheets of wallboard 54 (plaster board or dry wall) are secured by screws 55 to the stud portions 12. Here it is emphasized that these are conventional full-size drywall sheets (or in some cases support for plaster) and that they are vertically oriented.
The house is finished in the conventional manner by structural elements including trusses over the described walls, and further including the roof (FIG. 4) and various other conventional elements.
In summary, therefore, the present wall formed from the described panels rapidly provides a strong and inexpensive construction having a high degree of thermal insulation capability, and that has the various features outlined above (as well as other).
The foregoing detailed description is to be clearly understood as given by way of illustration and example only, the spirit and scope of this invention being limited solely by the appended claims.
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A load bearing-metal panel and stucco substrate cooperates with adjacent panels to form load bearing studs that are interconnected by a metal lath stucco substrate to which stucco can be applied, each panel being generally in the form of a channel in which insulation can be placed, whereby a wall structure can be formed by adjacent placement and interconnection of panels.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims priority from U.S. Provisional Patent Application No. 60/140,996 filed Jun. 29, 1999 titled Safety Crossing Gate.
FIELD OF THE INVENTION
This invention relates to the field of gates for highway-rail grade crossings and in particular to a gate which deploys a secondary arm as, or after, a primary gate arm is lowered so as to cover both lanes of a highway crossing a railway grade.
BACKGROUND OF THE INVENTION
A highway-rail grade crossing presents a unique and potentially dangerous traffic obstacle for inexperienced motorists. The fact is that many drivers do not cross railroad tracks often enough to be familiar with the warning devices including safety gates which are there for their own safety. Such drivers are often unaware that trains cannot stop nearly as quickly as motor vehicles in order to avoid a collision. Other drivers for whatever reason, including impatience, simply ignore all warning signs and attempt to defeat railroad crossing warning devices in order to cross over before a train arrives. Combined, driver inattention and impatience are the most common factors contributing to collisions between motor vehicles and trains at highway-rail grade crossings according to Operation Lifesaver, a non-profit public education program having the object of eliminating collisions, deaths and injuries at highway-rail intersections and on railroad rights of way.
Operation Lifesaver reports that thousands of people are seriously injured and hundreds are killed in about 4,000 highway-rail grade crossing crashes each year involving collisions between motor vehicles and trains. Also according to Operation Lifesaver, this translates into a collision between a person or a vehicle and a train approximately every 100 minutes in the United States, thus making it 40 times more likely that a motorist will die in a collision with a train than a collision with another motor vehicle. It is important to keep in mind that, again according to Operation Lifesaver, there are approximately 270,000 highway-rail grade crossings in the United States and that over 50% of crashes at public grade crossings occur where active warning devices such as gates, lights and/or bells exist. In 1996, collisions at public highway-rail crossings between trains and automobiles accounted for approximately 40 percent of all forms of collisions with trains at such crossings.
Many railroad public crossings at grade, specifically highway crossings used by automobiles, have protection gates that are actuated automatically by an approaching train. The gates rotate down into a horizontal position from a vertical position to prevent vehicles from entering onto the tracks as the train approaches and passes by. In many instances these gates only span across half the roadway, usually a single lane. Thus one-half of the roadway is left open. Vehicles often will, rather than wait for an approaching train to pass, go around the lowered gate and proceed into the path of the approaching train if the driver of the vehicle thinks he or she can get over the crossing before the train arrives.
When applicant inquired of those who maintain these gates as to the reason for the gates only spanning half the roadway, he was informed that in a situation where a vehicle arrives at the crossing to find the gates moving down and successfully goes under the gate in that vehicles lane, the vehicle may then still proceed straight ahead to clear the crossing without being immediately blocked on the other side of the track by a lowered gate intended to prevent traffic crossing from the opposite direction.
Consequently, it is an object of the present invention to provide a secondary section of gate of sufficient length to span the half of the roadway not blocked by a primary gate, the secondary gate rotatably mounted at the tip or free end of the primary gate and rotatable 180 degrees into a lowered position by means of a small motor and gearbox.
In the prior art, Applicant is aware of the following United States patents which deal with improvements to single arm railway crossing gates so as to deal with the problem of vehicles striking the gates, none of which teach the use of a secondary gate extension: U.S. Pat. No. 2,874,493 which issued Feb. 24, 1959 to Mandel for an Automatic Signal and Barrier Device for Railroad Crossings, U.S. Pat. No. 3,994,457 which issued Nov. 30, 1976 to Teasel for a Crossing Gate, U.S. Pat. No. 5,469,660 which issued Nov. 28, 1995 to Tamenne for a Self-Restoring Railroad Highway Crossing Gate Device, and U.S. Pat. No. 5,884,432 which issued Mar. 23, 1999 to DeLillo for a Breakaway Assembly for Vehicle Barrier Device.
Applicant is also aware of U.S. Pat. No. 4,666,108 which issued on May 19, 1987 to Fox for an Extensible Railroad Grade Crossing Gate Arm and U.S. Pat. No. 5,671,563 which issued Sep. 30, 1997 to Marcum for a Vehicle Control Arm Device. Both Marcum and Fox disclose the use of a secondary gate arm extension, Marcum providing a breakaway end section addressing the problem of the gate being struck and damaged by vehicles, Fox disclosing a telescoping second arm member telescopically inserted in a first arm member. Neither Fox nor Marcum teach nor suggest the advantages of the present invention as set out herein.
SUMMARY OF THE INVENTION
Consequently, it is an object of the present invention to provide a secondary section of gate of sufficient length to span the half of the roadway not blocked by a primary gate, the secondary gate rotatably mounted at the tip or free end of the primary gate and rotatable 180 degrees over the primary gate into a lowered position by means of a small motor and gearbox. Rotating the secondary gate in a generally vertical plane over the primary gate provides oncoming car traffic with a large, moving and highly visible cue that the approach of the train is imminent.
When not actuated the secondary section of gate would normally be in a retracted position beside or on top of the primary gate. The secondary section of gate is rotated into an extended position after the primary gate is rotated down, so as to approach, its fully lowered position. The lowering of the secondary gate is timed to include enough delay so that a vehicle which drives under a primary gate on one side of a crossing as the primary gate is lowering would have sufficient time to proceed across the crossing and under the secondary gate section on the other side before the secondary section on the other side is rotated into its horizontal, extended position. The timing of the delay is adjusted to allow time for a vehicle to clear, depending on the size, i.e. number of tracks across the crossing. Prior art sensors, known to one skilled in the art, may be employed to detect a vehicle's presence in the crossing to help coordinate the delay. Secondary gate sections thus effectively block vehicles from going around the tip or free end of the primary gate and into the path of an oncoming train during the critical seconds before a collision would be inevitable.
In one embodiment, not intended to be limiting, the secondary gate section is fitted with a double acting spring-type hinge, advantageously near the end mounted to the tip of the primary gate. The hinge allows the secondary gate to be pushed aside by a vehicle in circumstances which would otherwise result in a collision. The spring then urges the secondary gate back into position. Alternatively the secondary gate may be rigid, and it may be mounted to the primary gate in a similar manner to how the primary gate is now mounted to the gate actuating mechanism, for example a Safetran™ Model S-40 gate actuating mechanism, so as to break away when ran into by a vehicle.
The secondary gate section may be of the same type of material (for example, wood, aluminum or fiberglass) as the primary gate, have the same dimensions (although length may vary) and have lights mounted in the same manner as the primary gate.
The rotation assembly for rotation actuation of the secondary gate may be a small motor and gearbox which is capable of rotating a drive shaft 180 degrees. Rotation of the shaft is controlled by relays and limit switches. The motor and gearbox may be mounted at the free end of the primary gate. Materials needed for installation and actuation of the secondary gate section are readily available commercially. The materials include rotation motor/gearboxes, relays, timers, mounting brackets, bearings, limit switches, circuit breakers, wiring, as would be known to one skilled in the art.
In summary, the safety crossing gate for a railway crossing of the present invention includes a secondary gate rotatably mounted or mountable to a primary crossing gate. The secondary gate may be mounted on either side, i.e. either in front of, or behind, the primary crossing gate. The secondary gate is a rigid elongated member having first and second opposite ends. The second end of the secondary gate is rotatably mounted or mountable to a free end of the primary crossing gate by a rotatable coupling mounted or mountable to the second end of secondary gate and the free end of the primary crossing gate so as to allow selectively actuable rotation of the first end of the secondary gate relative to the primary crossing gate in a generally vertical plane containing the primary crossing gate when the secondary gate is rotatably mounted to the primary crossing gate by the rotatable coupling.
A selectively operable actuator is mounted or mountable to the secondary gate and the primary gate for selectively actuable rotation of the secondary gate relative to, and only above, the primary crossing gate about the rotatable coupling when the secondary gate is mounted to the primary crossing gate and the primary crossing gate is rotatably mounted to a gate actuating mechanism housing. The secondary gate is rotatable only above the primary crossing gate in the vertical plane between an extended position extending from and generally parallel to the primary crossing gate and retracted position rotated upwardly at least substantially 90 degrees from the extended position.
The secondary gate is rotatable only above said primary crossing gate so as to allow delayed actuation of the secondary gate after deployment of the primary crossing gate into a horizontal position blocking a first lane of a roadway entering the railway crossing. The delayed actuation allows vehicles to escape from the railway crossing after the deployment of the primary crossing but before the delayed actuation of the secondary gate into the extended position. The extended position of the secondary gate blocks a second lane of the roadway adjacent the first lane.
The rotatable coupling may be a shaft mounted or mountable, so as to extend between, the second end and the free end. The actuator may be an electric motor mounted or mountable to the shaft. The motor may also be mounted or mountable to the free end of the primary crossing gate. A distal end of the shaft is journalled through an aperture in the free end of the primary crossing gate and is rigidly mounted or mountable to the second end of the secondary gate. The shaft is freely rotatable in the aperture in the free end of the primary crossing gate.
In one embodiment the second end and the free end are hollow and have open ends. In this embodiment first and second rigid inserts are snugly and slidably mounted or mountable so as to be journalled into the open ends of the second end and the free end respectively. In this embodiment the rotatable coupling may be a shaft mounted or mountable, so as to extend between, the first and second inserts. If the actuator is an electric motor, it may be mounted or mountable to the shaft and to the second insert. A distal end of the shaft is journalled through an aperture in the second insert and is rigidly mounted or mountable to the first insert. The shaft is freely rotatable in the aperture in the second insert.
The delayed actuation of the secondary gate into the extended position by the actuator may be time delayed by an electronic time delay means, for example a time delayed electrical actuation signal to the motor, so as to allow time for a vehicle to depart from a danger zone in the railway crossing and pass by the secondary gate before the secondary gate is fully deployed into the extended position. The retraction of the secondary gate may commence once the train enters the crossing so that the secondary gate is retracting as the train is passing by. Once the train has passed through the crossing entirely, the primary gate may be raised in the usual fashion. In this manner, the secondary gate does not add to the delay experienced by waiting car traffic.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is, in perspective view, a conventional railway crossing gate having a secondary gate according to the present invention mounted thereon.
FIG. 2 is a partially cut-away enlarged view taken from FIG. 1 .
FIG. 3 is an exploded view of the rotation motor secondary gate actuator assembly.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
As illustrated in FIGS. 1-3, a secondary gate 10 according to one embodiment of the present invention is rotatably mounted at its base end 12 to the free end 14 of primary gate 16 . Base end 12 is mounted, for example by means of drive shaft 18 to rotation motor 20 as better described below.
Primary gate 16 is rigidly mounted at its base end 22 to support arm 24 . Support arm 24 is pivotally mounted to gate actuating mechanism housing 26 and may support counter weight 28 on the side of gate actuating mechanism housing 26 opposite to primary gate 16 . Gate actuating mechanism housing 26 is bolted to a concrete foundation buried in the ground or shoulder beside roadway 30 .
With the approach of a train, gate actuating mechanism housing 26 is automatically triggered so as to rotate primary gate 16 downwardly from a vertical position (not shown) in direction A into a horizontal position so as to block an incoming traffic lane 32 , that is, so that primary gate 16 extends across lane 32 so as to place free end 14 generally above or extended slightly beyond roadway center line 34 .
The electronic control that instigates downward rotation of primary gate 16 in direction A will also actuate rotation motor 20 . The electronic control includes a timer 26 a (shown diagrammatically in dotted outline). It is mounted in the gate actuating mechanism housing 26 . The electronic control is electrically connected to motor 20 . Depending on the desired time delay, secondary gate 10 is rotated in direction B relative to primary gate 16 either as primary 16 is being lowered in direction A or after primary gate 16 has been lowered into its horizontal resting position. Secondary gate 10 when in its stowed or retracted position lies adjacent to, and parallel with, primary gate 16 . In FIG. 1, secondary gate 10 is shown in its retracted position in dotted outline and indicated by reference numeral 10 ′. Secondary gate 10 is deployed by rotation about axis C—C in direction B so as to pass through intermediate positions as indicated by reference numerals 10 ″. The object of introducing a delay in deploying secondary gate 10 relative to the deployment of primary gate 16 , is to allow time for a vehicle coming in the opposite direction, namely direction D, which has passed under a primary gate on the opposite side of the railway crossing, to exit the railway crossing danger area 36 along outgoing traffic lane 38 unimpeded by the lowering of the secondary gate 10 . This avoids trapping a vehicle between primary and secondary crossing gates which have been simultaneously lowered on either side of area 36 .
In the event that a vehicle stalls while in area 36 , and consequently both primary and secondary gates are lowered in front of and behind the vehicle, in order to avoid a collision with an oncoming train, the vehicle has no choice but to drive through the barricade. This dangerous and foreseeable situation is provided for in the present invention by either the use of conventional shear pins at the base end of one or both gate sections and/or, as better seen in FIG. 2, by incorporation of springloaded hinge 40 in base end 12 of the secondary gate 10 . Hinge 40 allows for a vehicle striking secondary gate 10 in direction D to swing the secondary gate away from the vehicle in direction E as better seen in FIG. 2 . Secondary gate 10 may thus fold about hinge 40 out of the path of a vehicle passing in direction D thereby allowing the vehicle to escape from area 36 .
In an alternative embodiment, hinge 40 is a double acting hinge allowing secondary gate 10 to fold, not only in direction E out of collinearity with base end 12 , but also in a direction opposite to direction out of collinearity with base end 12 . In this embodiment, a double acting hinge 40 allows a vehicle which has approached primary gate 16 in direction F along incoming traffic lane 32 to fold back secondary gate 10 about hinge 40 in the event that the vehicle decides to try and beat secondary gate 10 as it is rotating in direction B and is unsuccessful so as to strike secondary gate 10 . In either embodiment, whether hinge 40 is a single acting hinge or a double acting hinge, hinge 40 is of a known design which provides a return biasing force so as to return the free end of secondary gate 10 into its collinear position collinear with base end 12 .
In the preferred embodiment, secondary gate 10 is provided with signal lamps 42 . Signal lamps 42 may be electrically connected in the electrical circuit for signal lamps 44 on primary gate 16 by means of wiring conduit (not known) passing along primary gate 16 , and secondary gate 10 . Thus as signal lamps 44 flash or are otherwise illuminated, so too are signal lamps 42 .
As better seen in the exploded view of FIG. 3, rotation motor 20 , which may be a small electrical motor and/or gearbox as would be known to one skilled in the art, is mounted to free end 14 on primary gate 16 . Specifically, the embodiment of FIG. 3 is directed to a retrofit of the present invention where primary gate 16 is a conventional hollow aluminum beam such as often presently used and supplied commercially by Safetran™. In the retrofit embodiment of the present invention, it is convenient to also use a hollow aluminum beam as the secondary gate 10 so that the same supply of aluminum beam sections used for the primary gate may also be used for the secondary gate. Alternatively, secondary gate 10 may be a hollow fiberglass beam.
Because the aluminum or fiberglass beams are hollow, it is convenient to use inserts such as primary insert 46 and secondary insert 48 which may be machined or formed of metal or perhaps wood or perhaps plastic or the like. Inserts 46 and 48 have corresponding tangs 47 and 49 respectively as shown in dotted outline in FIG. 3 . The tangs are snugly journalled into the respective primary and secondary gates by sliding the tangs into the hollow openings at free end 14 and base end 12 respectively. Inserts 46 and 48 may be notched as illustrated and would be secured within the ends of the gates by appropriate methods known in the art such as by bolting, welding or the like. Insert 48 may also be lengthened at end 48 a , that is, at the end opposite to tang 49 . Such lengthening provides an attachment point for counterweights to offset the weight of secondary gate 10 as needed. Further, insert 48 may also have a rigid tab 48 b mounted on the side facing rotation motor 20 which will act to limit the travel of secondary gate 10 to not more than a horizontal position when in its deployed position.
Insert 46 provides a rigid mounting platform to which rotation motor 20 may be bolted by means of bolts 52 . Rotation motor 20 is bolted onto insert 46 so as to journal the rotation motors output shaft 18 through corresponding bore holes 58 and 60 in inserts 46 and 48 respectively.
Output shaft 18 is long enough to extend through insert 46 through bore hole 58 , and through bore hole 60 so as to extend, once assembled, from the side of insert 48 opposite rotation motor 20 . Output shaft 18 is rigidly mounted to insert 48 , for example, by means of split collar 66 . Split collar 66 is rigidly mounted to insert 48 , for example, by means of bolts 70 .
Thus, actuation of rotation motor 20 , rotates drive shaft 18 , for example, in direction B about axis C—C so as to deploy secondary gate 10 from its stowed position adjacent primary gate 16 .
In one preferred embodiment, self centering rests 72 are mounted along primary gate 16 . Self centering rest 72 have upwardly opening flared flanges 72 a so as to capture therebetween secondary gate 10 as secondary gate 10 is rotated in a direction opposite to direction B from its deployed position into its stowed position resting within channel cavity 74 in self centering rests 72 . Rubber stops (not shown) or the like may be provided within self-centering rests 72 or along the corresponding side of primary gate 16 so as to provide a spacer between the two gate sections and also to provide for dampening of any oscillatory motion of secondary gate 10 which otherwise might cause impact which may eventually damage secondary gate 10 . Rotation motor 20 may be electrically powered by means of electrical wiring (not shown) running along and within the hollow aluminum beam of primary gate 16 . Limit switches or sensors (not shown) may also be employed to disengage rotation motor 20 when secondary gate 10 is fully deployed or fully stowed.
As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.
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The safety crossing gate for a railway crossing of the present invention includes a secondary gate rotatably mounted or mountable to a primary crossing gate. The secondary gate is a rigid elongated member having first and second opposite ends. The second end of the secondary gate is rotatably mounted or mountable to a free end of the primary crossing gate by a rotatable coupling mounted or mountable to the second end of secondary gate and the free end of the primary crossing gate so as to allow selectively actuable rotation of the first end of the secondary gate relative to the primary crossing gate in a generally vertical plane containing the primary crossing gate when the secondary gate is rotatably mounted to the primary crossing gate by the rotatable coupling.
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BACKGROUND OF THE INVENTION
The present invention generally relates to travelling suction cleaning apparatus for removing lint, dust and other light material from room and machine surfaces in textile mills. More particularly, the present invention pertains to travelling suction cleaning apparatus having mobile lint collection chambers and means for automatically removing the accumulated lint from the collection chambers.
One example of a prior art travelling suction cleaning apparatus is shown and described in U.S. Pat. No. 3,011,202 issued Dec. 5, 1961 to G. B. Holtzclaw. Several travelling suction cleaners are supported on several transversely spaced, endless trackways. The trackways are supported above respective rows of spinning machines in a room of a textile mill. The Holtzclaw patent discloses a travelling cleaner unit having a lint collection box having a hinged discharge door that faces laterally of the direction of travel of the cleaner. Waste removal chambers are located adjacent the ends of the trackways on which the cleaners move, and the waste removal chambers are all connected to a common ductway that leads to a suction collecting unit. As a travelling cleaner is driven around the end of its trackway, the discharge door of the collection box thereof is momentarily aligned with the mouth of the removed chamber; and the hinged door is then opened for a short time so that the accumulated lint may be blown from the collection box into the waste removal chamber.
Another example of a textile machine cleaning apparatus that is provided with means for automatically removing the lint from a travelling cleaner is described in U.S. Pat. No. 3,372,425 granted Mar. 12, 1968 to R. L. Black, Jr. The Black patent discloses a travelling suction cleaner that includes two substantially cylindrical collection chambers located on the same side of the support trackway. Each chamber has a exhaust filter therein for stripping lint from intake air. Conduit means are provided for interconnecting the lint collection chambers with a vertical lint discharge passageway. As the travelling cleaner is brought to a stop at a lint removal station, a discharge tube is lowered into abutment with the discharge passageway. Partial vacuum is then applied to remove the lint from the collection chambers through the discharge tube into a lint withdrawal duct that leads to a central collecting unit.
Yet another example of a suction cleaning apparatus for textile mills is shown in U.S. Pat. No. 3,299,463 granted Jan. 24, 1967 to L. R. McEachern. The McEachern patent discloses a pneumatic collection system including collection hoods that are mounted adjacent crane trackways above the paths of travel of air inlet and suction chambers. The hoods are disposed to be closely adjacent the filter screens when the cleaner units are moved below the hoods. A single main collection station is provided and includes a suction fan connected to all of the hoods by a conduit structure. The collection station also includes apparatus for removing lint from the air flowing from the several hoods.
As indicated hereinafter, the cleaning apparatus of the present invention is similar to and constitutes an improvement over the cleaning apparatus described in U.S. Pat. No. 3,245,103 granted Apr. 12, 1966 to J. F. King, Jr. The King Patent is owned by the assignee of the present invention. The cleaning apparatus of the present invention is also similar to and an improvement over the "Bahnson Combo-Jet Travelling Cleaner" that is manufactured and sold by the assignee of the present application; such cleaner is disclosed in the Envirotech Catalog 40-A, which Catalog is entitled, "Bahnson Combo-Jet Travelling Cleaner" and is marked with the date of March, 1978. The travelling cleaner shown in these two references includes a pair of transversly spaced collection chambers confined partially within cylindrical canisters located on opposite sides of the trackway. Lint is sucked into the collection chambers through suction trunks that respectively depend from the canisters. To remove the lint from the collection chambers, the canisters are provided with access doors at the bottoms of the canisters. In operation, when the lint is to be removed, the travelling cleaner is brought to a stop and the accumulated mass of lint is removed manually by opening the access doors and pulling the lint into an underlying receptacle.
SUMMARY OF THE INVENTION
According to the present invention, a travelling suction apparatus for cleaning textile rooms is provided with an automatic lint removal arrangement adapted to rapidly remove a substantial portion of the accumulated lint from the collection chambers of a travelling cleaner while the cleaner is moving on the associated trackway. Generally, each travelling cleaner includes at least one lint collection chamber, an annular lint screen or filter within the lint collection chamber that is open at both ends and a lint removal opening formed in the chamber walls near one open end of the screen. A lint removal hood is provided at a lint removal station located along the length of the trackway, and the hood is connected to a central lint collecting unit. As the travelling cleaner arrives at the lint removal station, the discharge opening is opened and exposed to the lint removal hood so that a substantial portion of the lint may be withdrawn from within the screen and into the hood.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view illustrating a travelling cleaner unit of the present invention as supported on the trackway.
FIG. 2 is an enlarged side elevational view of the upper housing portion of the travelling cleaner unit with the suction and blower tubes thereof being removed for the sake of clarity.
FIG. 3 is an elevational view of the trailing end of the travelling cleaner unit.
FIG. 4 is a top plan view of the travelling cleaner unit.
FIG. 5 is a reduced scale top plan view that illustrates the leveling frame and lint withdrawal hoods of the cleaning apparatus.
FIG. 6 is a side elevation of the leveling frame and lint withdrawal hoods.
FIG. 7 is a schematic view that illustrates the central collector unit and common duct of the improved travelling suction cleaning apparatus.
FIG. 8 is a fragmentary side elevational view that is broken away to illustrate one of the conical screens in the travelling cleaner unit, wherein the cleaner unit is moving under the lint removal hood and the doors above and below the screen are being held open.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now more particularly to FIG. 1, the travelling cleaning apparatus of the present invention includes several cleaner units CU which are driven on separate endless trackways TW. Only a single trackway and cleaner unit are shown herein, the others being of essentially the same construction. The cleaner unit CU is driven along the trackway longitudinally of a textile machine such as a spinning frame. The cleaner unit is designed to keep the spinning frame and adjacent floor area reasonably free from lint accumulations. The cleaner unit CU is propelled along the trackway TW by a motorized tractor TR which is schematically shown in FIG. 7. The basic features of the cleaner unit and tractor are described in the aforementioned, commonly owned U.S. Pat. No. 3,245,103 to J. F. King, and the disclosure of the King patent is incorporated herein by reference. It is also noted that the cleaner unit is similar to the cleaner unit disclosed in the aforementioned Catalog 40-A.
In accordance with the present improvement, leveling frames LF (FIGS. 5-8) are provided at lint collection stations LCS respectively located along the trackways TW. As shall be described hereinafter in detail, each leveling frame includes transversely spaced lint removal hoods HD1 and HD2 which are connected to a common duct DUC. The common duct is connected to a central collector unit CCU that includes a suction fan FN. As a cleaner unit CU arrives at a lint removal hood, the lint collection chambers of the cleaner unit are opened and exposed to a partial vacuum induced by the hoods so that the lint is removed from the cleaner unit while the cleaner unit is moving along the trackway. The lint removed from the several cleaner units is all stored in the central cleaner unit. Such central storage of course reduces the waste disposal problems associated with the entire textile room cleaning apparatus.
Referring again to FIG. 1, the cleaner unit CU includes a right suction trunk 12, a left suction trunk 13, a right blower trunk 14 and a left blower trunk 15. The terms, right and left, are used herein with reference to the direction of travel of the cleaner unit and as would be seen by one looking at the trailing or rear end of the cleaner unit. The trunks 12-15 depend from a cleaner housing 16 that extends transversly above the trackway TW. The right blower trunk is arranged across from the left suction trunk and the left blower trunk is arranged across from the right suction trunk. This arrangement is described in the King U.S. Pat. No. 3,245,103. The suction trunks 12 and 13 are respectively connected to the bottom ends of right and left canisters 17 and 18. The canisters are removeably attached by latches 21 to the underside of the housing 16. Referring to FIG. 8, a frustoconical screen 22 is contained within each canister; the screen is supported uprightly in the respective canister with its smaller end upwardly disposed. The screen strips lint that is carried in the air drawn into the suction trunks. As shown in FIG. 1, the intake opening 23 for the respective suction trunk is formed in the bottom of the respectve canister to direct the lint-laden air into the relatively large diameter lower end of the associated lint-stripping screen 22.
The cleaner unit CU includes a centrally located blower (not illustrated) that is located below the blower cover plate 24 shown in FIG. 4. As depicted by arrows in FIG. 8, the lint-laden air is drawn into the interior of the conical screen 22 and the cleaned air is circulated by the blower toward the center of the housing. The cleaned air is redirected by the blower from the center of the housing into the intakes to the blower trunks 14 and 15. The screens 22 thus define the lint collection chambers of the cleaner unit.
In the past, the lint accumulated within the screens in the canisters 17 and 18 was removed manually by opening access doors 19 and 20 in the bottoms canisters 17 and 18, respectively. The cleaner unit of the present invention includes the access doors 19 and 20 formed in the right and left canisters 17 and 18, respectively. Such doors are spring-biased into closed positions to seal the lower ends of the canisters. The access doors provide easy access to the interiors of the canisters to enable inspection and any manual cleaning the screens as may be felt necessary at such time. It is contemplated that such manual cleaning would only be done on an infrequent basis as a part of a periodic maintenance program because the lint within the canisters is, as made manifest herein, automatically extracted at the lint collection station LCS.
Now referring to FIGS. 4-6 and 8, the cleaner unit CU is provided with lint removal doors 25 and 27 situated directly over the screens 22 supported within the right and left canisters 17 and 18, respectively. Such doors 25 and 26 are of identical construction, and so the construction of the right door 25 only will be described. Door 25 includes a rectangular lid that has downwardly extending flanges at its edges. A sheet of soft rubber is contained within the lid to normally form an air-tight seal with the upper end of the associated lint-stripping screen 22. The lid is pivotably attached by a hinge 28 to the top wall of the cleaner unit housing 16 so that the lid thus rotates about a hinge pin 29. The hinge is so connected to the cleaner housing that the hinge pin 29 extends transversely of the direction of travel of the cleaner unit. The lids are hinged to the housing proximal the trailing ends of the discharge openings formed by the upper ends of the screens so that the lids may be pivoted counter to the direction of travel of the cleaner unit. The doors are biased into the closed positions by springs 31 (FIG. 4). The lint removal doors 25 and 26 each have a Z-shaped latch or hook 30 that is attached to the leading end of the lid 27. Also, each of the lint-removal doors has a flat, rigid strip or bar 31 extending transversely of the direction of travel of the cleaner unit CU.
The cleaner unit CU further includes means enabling the bottom access doors 19 and 20 to be opened at the lint collection station LCS. Such means comprises two bellcrank operated, pushrod mechanisms 35 associated with the right access door 19 and a similar mechanism 36 for the left access door 20. Referring to FIG. 2, each access door opening mechanism includes a bellcrank 37, a pushrod 38, a pushrod guide bracket 39 and an angle iron 40 that is attached to the right access door 19. The bellcrank 37 is mounted to the trailing or rear side wall of the cleaner housing 16 by a bracket 41, with the bellcrank being pivoted on a 42 pin. The bellcrank is pivotably mounted to the housing to pivot about an axis that is, again, transverse to the direction of travel of the cleaner unit. One arm of each bellcrank extends a selected distance above the cleaner unit housing 16, and the pushrod 38 is connected to the other arm of each bellcrank. The pushrod is received in oversized holes in the respective guide bracket 39 (FIG. 3) which is mounted to the side wall of the right canister 17 to vertically guide the pushrod. The free lower ends of the pushrods bear against the outwardly projecting ends of the respective angle irons 40. As shall be explained later, the upstanding arms of the bellcranks are depressed by cam rails at the lint removal station LCS to thus lower the pushrods and open the access doors 19 and 20 by limited amounts.
As is best illustrated in FIG. 4, flat skid members 43 and 44 are mounted to the right and left sides of the top wall of the blower housing 16. Such skid members ride against the leveling frame LF at the lint collection station LCS, as also is described later.
The mounting of the screen 22 within the associated canister 17 or 18 will now be described with reference to FIG. 8. The conical screen 22 is substantially tapered. For example, it may have a diameter of about 19.5 in. at its lower end and of about 6 in. at its upper end and have a height of about 13 in. Each screen has a imperforate ring 46 affixed at its lower end that is supported on a circular flange 47 mounted within the canister above the bottom wall thereof. A cylindrical collar 49 is affixed to the small diameter upper end of each screen. The collar 49 projects upwardly through a discharge opening formed in the top wall of the cleaner unit housing 16. The rubber pads within the lids of the lint removal doors 25 and 26 normally form substantially air-tight seals with the circular upper edges of the collars 49 of the respective screens.
The leveling frame LF includes a steel framework which is shown in FIGS. 5 and 6. The framework is rigidly suspended by supports from the ceiling of the textile room at the lint collection station LCS at a selected height above the trackway TW. The frame includes skid rails 51 and 52 extending longitudinally thereof parallel to the trackway TW and centered over the trackway. The skid rails 51 and 52 are spaced apart so that they bear against the skid members 43 and 44 affixed to the top wall of the cleaner unit CU. The frame LF is horizontally mounted to the room ceiling to level the cleaner unit CU as it moves thereunder. The leveling frame stabilzes the cleaner unit when the access doors 19 and 20 and the lint removal doors 25 and 26 are opened.
When the cleaner unit CU arrives at the lint collection station LCS, the latches 30 of the lint removal doors 25 and 26 are engaged by lifting mechanisms 54 and 55, respectively. The two lifting mechanisms are identical and are suspended from longitudinally spaced cross-members of leveling frame LF. The latching mechanisms 54 and 55 are mounted to the leveling frame to simultaneously engage and pivot open the associated lint removal doors 25 and 26, respectively. Each of the lifting mechanisms 54 and 55 includes a vertically depending latch bar 57 that has a forwardly projecting flange 58 at its lower end. The flanged latch bar is held at a height such that its lower end engages the forwardly projecting, upper portion of the Z-shaped hook 30 of the respective lint removal door. Each latch bar 57 is pivotably mounted to a support bar 59 for pivoting about an axis that is transverse of the direction of travel of the cleaner unit. Bars 59 are pivotably attached to the leveling frame and are supported at their outer ends (which extend counter to the cleaner units direction of travel) by eye-bolts 60 which permit the height of the latch bars 57 to be precisely adjusted. The cleaner unit CU is first leveled by the leveling frame LF skid rails 51 and 52; and as it proceeds forwardly, the latch bars engage simultaneously the hooks 30 of the associated lint removal doors. As the doors are swung open, latch bars 57 of course pivot in the direction of travel of the cleaner unit.
With continued forward travel of the cleaner unit CU, the end portions of transversely projecting slide strip 31 of the associated partially opened lint removal door 25, 26 become engaged against the upstream ends pair of longitudinally extending, transversely spaced, horizontal cam rails 62 and 63. The cam rails are transversely spaced to engage the undersides of the end of the door strips to first cam the door downwardly counter to the direction of travel; and once the door is swung completely open as shown in FIG. 8, the cam rails hold the spring-biased doors open as they are carried under the respective hoods to hold the lint removal door completely open as the associated canister is carried under the lint removal hood HD1, HD2. It is noted that the cam rails 62 and 63 also support the respective hood HD1, HD2. As soon as the door strips 31 clear the downstream ends of the rails 62, 63, the doors swing back into their normally closed, positions against the screens. The cam rails are suspended from the leveling by rails (not shown) that depend from the cross-members of the frame (FIG. 5).
The bellcrank mechanisms 35 and 36 are engaged by cam or striker members 65 and 66 substantially at the same time the lifting mechanisms 54 and 55 engage the right and left lint-removal doors 25 and 26. The striker members, as shown in FIGS. 5 and 8, are straight rails that have upwardly slanted front and rear ends. The striker members are mounted to the underside of the leveling frame LF parallel to the direction of travel of the cleaner unit CU and at locations that are aligned with the associated bell crank 37 of the bellcrank mechanism. Such striker members are mounted to downwardly cam the bellcranks to simultaneously open the access doors 19 and 20 and to hold the access doors open while the screens are below the removal hoods HD1 and HD2, and to cause such doors to simultaneously close under their own spring mountings after the lint has been removed from the associated canister screen.
The hoods HD1 and HD2 are of identical construction, but are mounted in a reversed relationship so that the connector portions 70 and 71 at their upper ends are located nearer the center of the leveling frame (FIGS. 5 and 6). Such mounting arrangement is convenient, as it minimizes the overall length of the leveling frame while yet permiting the frame to be rigidly attached at its ends to the ceiling by the aforementioned supports. The hoods are elongated in the direction of travel of the cleaning unit. A leather flap 73 is mounted in a notch formed at the leading or upstream end of each hood 70, and a similar leather flap 74 is mounted in a notch formed in the downstream edge of the hood 70. The elongate configuration of the mouth of the hood 70 and 71 enables a partial vacuum to be applied for a longer time to the opened lint collection chambers formed within the interior of the screens 22 within the canisters 17 and 18. A substantial amount of the lint accumulated within this respective screen is removed during such transit time which has been found to be only a matter of a couple of seconds.
Given the exemplary dimensions of the hood as just set forth, when the cleaner unit is driven on the trackway TW at approximately 85 feet per minute, which is a typical speed, the relatively small discharge openings to the respective screens 22 are exposed to partial vacuum within the hood for a period of only about 1 second. Due to the vigorous upward gust of air that is created with the conical screens at the lint collection station, substantially all of the accumulated masses of lint within the screens is discharged into the hoods.
FIG. 7 schematically illustrates the central collector CCU and common duct DUC for applying suction to the hoods, HD1 and HD2. It will be seen that a valve 77A is connected between the common duct and the hoods at the lint collection station LCS. The valve 77A may be a bladder valve that is operated by separate pneumatic control valves (not shown). The pneumatic valves are controlled by a double-acting electric solenoid valve (also not shown). A limit switch (not shown) is mounted to the trackway TW at a position upstream from and adjacent the lint collection station LCS to be engaged by the tractor and cleaner unit. The limit switch actuates the aforementioned solenoid valve which controls the valve 77A. Valve 77A is normally closed and is opened upon actuation of the limit switch. As may be noted from FIG. 7, other valves 77B and 77C are connected in the connector ducts that lead to the pairs of lint removal hoods situated at the other lint collection stations within the textile room.
From the foregoing, it will be appreciated that the travelling cleaner apparatus of the present invention is adapted to rapidly evacuate the lint from within both conical screens 22 while the cleaner unit CU is traveling at its normal speed through the lint collection station LCS. At the lint collecting station, the blower therein continues to operate to circulate air through the associated suction trunks 12 and 13 into the associated screens 22 and then outwardly through the blower tubes 14 and 15. This air flow serves to support the accumulated masses of lint within the conical screens 22 (FIG. 8) and urge the masses of lint upwardly toward the narrow discharge end of the screens. When brought under the hoods HD1 and HD2, the accumulated lint is sucked quickly from the upper end of the screen. As shown by the arrows in FIG. 8, air flows through the opening formed between the lower access door 19, 20 and the cleaner housing 16 and then upwardly into the lower end of the screen. A vigorous air circulation pattern is induced immediately when the opened discharge ends of the screens come under the hoods, which air flow causes the accumulated lint to be abruptly ejected directly through the discharge openings formed in the screen collars 49 into the lint collection hood HD1, HD2.
Preferably, a thin mat of accumulated lint, e.g. 1/16 in. thick, is left within the associated canister 17, 18 against the inner surfaces of the screens 22. Such thin mats of lint enhance the filtration effectiveness of the screens to strip further contaminants from the room air than would be obtained by the perforate screen surfaces alone. The conical screen configuration and discharge circulation pattern is such that such relatively thin layer of lint is normally retained in each screen after the cleaning unit CU traverses the lint collection station LCS and the access doors and lint removal doors are shut.
The travelling cleaner unit CU and leveling frame LF may be operated as just described together with a straight trackway--as opposed to an endless trackway in the form of a loop-- without making structural changes to the automatic lint removal arrangement. When a straight trackway is used, the drive motor of tractor TR is reversed at the ends of the trackway to thereby cause the cleaner unit to move back and forth over the underlying row of textile machines. When moving in the direction opposite that shown in the drawings, the latch bars 57 of the lifting mechanisms 54 and 55 will simply swing out of the way of the cover latches 30. The cover latches 30 will, when moved in such opposite direction, plow through the resilient flaps 73 and 74 (FIGS. 5 and 8) mounted in the notches in the ends of the lint removal hoods HD1 and HD2. Also when being driven in such opposite direction, the bellcrank mechanisms 35 and 36 for the access doors will be actuated in the opposite direction by the cam rails 65 and 66. Thus, the pushrods 38 will be momentarily raised by means of the cam rails; the access doors will accordingly remain closed. It is noted that the bellcranks 37 are biased by torsion springs received on pins 42 to return the bellcranks to the upright positions illustrated in FIGS. 2 and 3. Thus, it will be understood that the present mechanically operated lint removal arrangement is readily adaptable to any trackway configuration.
Although the best mode contemplated for carrying out the present invention has been shown and described, it will be apparent that modifications and variations may be made without departing from what is regarded to be the subject matter of the invention.
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An improved cleaning apparatus for textile machines, of the type that includes overhead trackways and cleaner units propelled along the trackways, is provided with an arrangement for automatically removing accumulated lint from the cleaner units while cleaner units are moving along the trackways. During cleaning of the textile machines, lint is stripped from lint-laden intake air by conical screens respectively associated with the depending suction tubes of the cleaner unit. Hinged doors are arranged above and below each conical lint-stripping screen, and all four of these doors are opened at a lint collection station so that the accumulated lint may be rapidly withdrawn from the smaller ends of the screens directly into suction hoods. Mechanical door-actuating mechanisms are provided so that the cleaner unit is automatically doffed when moving in one direction through the lint removal station and so that the cleaner unit can, dependent on the desired trackway configuration, be driven in the opposite direction through the lint removal station without necessarily opening the doors.
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CLAIM OF PRIORITY
This application claims priority under 35 USC §119(a) to European Patent application number 04004604.7, filed on Feb. 28, 2004, the entire contents of which are hereby incorporated by reference.
TECHNICAL FIELD
This disclosure relates to a laser processing machine.
BACKGROUND
Sensors have been used in prior art laser processing machines to continuously follow the welding seam during laser welding. The sensor can monitor the exact position of the joint, and, in conjunction with a regulation and control unit, maintain tolerances during the welding process. It is thereby ensured that the laser welding head is always located directly above the joint. Welding seam tracing sensors and/or process control sensors are important mainly when used in connection with industrial robots, for example, for controlling the seam geometry of the weld. Process control is also important in addition to welding seam tracing. Thus, during laser processing, the degree of coupling of the laser beam, the production of splashes, and the welding depth can be monitored.
An additional way to supplement a laser welding process is by supplying a solid or gaseous additional material, for example, a process gas or a wire, during the welding.
The sensor and/or the means for supplying the additional material are generally disposed at a corresponding separation distance from the laser welding beam. The sensor is directed either at an angle toward the processing point (i.e., the sensor “faces” the processing location at an angle) or is located in a perpendicular orientation to a location in front of or behind the processing location (i.e., the sensor does not “face” processing itself, but a location that is leading or trailing relative to the processing location). However, because the laser beam typically is directed toward the workpiece from directly above the workpiece, the sensor or other supplementary laser processing element cannot also be located directly above the workpiece, because it would interfere with the laser beam or the laser beam optics. Thus, because of the orientation of the sensor (or other supplemental elements) with respect to the laser beam, in conventional arrangements, an exact rapid response by the sensor or by the additional material in three-dimensional laser processing is difficult or requires demanding technical solutions. For example, additional axes to move the sensor or the additional material can be required. The supplied data is either distorted or is not derived from the process itself. A further disadvantage is the increased size of the head, and the so-called interference contour.
SUMMARY
The invention is based, at least in part, on arranging a supplementary laser processing element directly above the surface of the processed workpiece while directing two laser beams to the processed workpiece at slight angles to the overhead direction, which permits a rapid response from the supplemental element without orientation problems in three-dimensional laser processing and also minimizes the interference contour during laser processing.
In one general aspect, a laser processing machine includes a beam splitter for splitting an incoming laser beam into a first laser beam having a first intensity and a second laser beam having a second intensity, a first focusing mirror for focusing the first laser beam onto a first laser processing site on a workpiece at an angle from a direction directly above the workpiece, a second focusing mirror for focusing the second laser beam onto a second laser processing site on the workpiece at an angle from a direction directly above the workpiece, and a supplementary laser processing element for supplementing laser processing of the workpiece, wherein the supplementary laser processing element is disposed directly above the first or second laser processing site.
Implementations can include one or more of the following features. For example, the first and second laser processing sites can be different or identical laser processing sites (i.e., they are the same site). The supplementary laser processing element can be an optical sensor adapted and arranged for monitoring laser processing of the workpiece. The supplementary laser processing element can also be an optical element adapted and arranged for directing light to a remote optical sensor that is adapted for monitoring laser processing of the workpiece. The optical element can be a mirror. The optical element can be an end of an optical fiber. In certain embodiments, the supplementary laser processing element can be a mounting element for supporting and supplying additional material to the first or second laser processing site, or to both. The supplementary laser processing element can also be a gas supply nozzle for supplying a process gas to the first or second laser processing site, or to both.
In various embodiments, the first intensity can be the same or different from the second intensity. For example, the first intensity can be more than about twice as great as the second intensity. In some embodiments, the beam splitter can be a knife-edge mirror.
The laser processing machine can further include an actuating drive adapted to pivot the supplementary laser processing element in different directions above the workpiece. The laser processing machine can further include an actuating drive adapted to displace the supplementary laser processing element above the workpiece.
The first laser processing site can be a focus of the first laser beam, the second laser processing site can be a focus of the second laser beam, and the first and second laser processing sites can be located at the same position. The supplementary laser processing element can be disposed directly above the first and second laser processing sites. In certain embodiments, the first laser beam and the second laser beam can define a cone directly above the workpiece in which the supplementary laser processing element is located.
In another general aspect, the invention features a method of processing a workpiece by providing a supplementary laser processing element directly above the workpiece and providing an input laser beam. The input laser beam is split into a first laser beam having a first intensity and a second laser beam having a second intensity. The first laser beam is focused onto a first laser processing site on a workpiece at an angle from a direction directly above the workpiece, and the second laser beam is focused onto second laser processing site on the workpiece at an angle from a direction directly above the workpiece.
Implementations can include one or more of the following features. For example, the method can further include sensing light reflected from the first and/or second laser processing site with the supplementary laser processing element and adjusting an optical property of the first or second laser beam in response to the sensed light. The first intensity can be the same or different from the second intensity. The method can further include providing a material to the first or second laser processing site from the supplementary laser processing element.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.
The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features and advantages will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic perspective view of a laser processing machine having a double focusing unit.
FIG. 2 is a sectional view of the laser processing machine along the line II-II of FIG. 1 .
FIG. 3 is a sectional view of the laser processing machine along the line III-III of FIG. 1 .
FIG. 4 is a schematic perspective view of a laser processing machine having a double focusing unit.
FIG. 5 is a schematic perspective view of a laser processing machine having a double focusing unit.
Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
A simple arrangement of a laser processing element that permits rapid follow-up without orientation problems and also minimizes the interference contour during three-dimensional laser processing can be achieved by splitting the laser beam into two beam portions that are focused onto the workpiece and arranging the laser processing element between the two beam portions.
As shown in FIG. 1 , a double focusing unit 1 of a laser processing machine includes an angle apparatus 2 , a beam splitter 3 and two focusing mirrors 4 and 5 . A laser beam 6 that enters the double focusing unit 1 is initially deflected and split by the beam splitter 3 into two laser beam portions 7 and 8 . The beam splitter 3 can be, for example, a knife-edge mirror that can be passed into a portion of the beam to split the beam. The two laser beam portions 7 and 8 are subsequently reflected by focusing mirrors 4 and 5 and directed to a common focus 9 on a workpiece surface 10 of a workpiece 11 or 11 ′. A light-gathering optical sensor 12 is provided to track a welding seam 13 as the double focusing unit 1 of the laser processing head moves across the workpiece surface 10 .
The two focusing mirrors 4 and 5 can be adjusted and/or pivoted in three dimensions independently of each other using piezo actuating drives. Instead of one single focus 9 , two foci that are disposed closely next to or behind each other can be generated by the focusing mirrors 4 and 5 . The foci may be adjusted relative to each other.
The beam splitter 3 can be fixed in the center of the impinging laser beam 6 . The beam splitter 3 (e.g., a knife-edge mirror) may also be disposed to be movable and be moved out of the center of the laser beam 6 , thereby permitting correction of the position of the foci or obtaining an asymmetric distribution of the power in the laser beam portions 7 and 8 , such that the two laser beam portions 7 and 8 can have different intensities. For example, one laser beam portion 7 can have a minority of the overall power (e.g., about 25, 30, 35, 40, or 45%) of the laser beam 6 and serve for pre-heating the workpieces 11 and 11 ′. The other laser beam portion 8 can have a majority of the overall power (e.g., about 55, 60, 65, 70, or 75%) of the laser beam 6 and be used for welding the workpieces 11 and 11 ′.
The beam splitter 3 can be a prism disposed in the usual position of a single focusing mirror of a conventional focusing unit that does not include a beam splitter. This arrangement generates a space directly above focus 9 of the laser beam portions 7 and 8 on the workpieces 11 and 11 ′ with good accessibility through which the laser processing of the workpieces 11 and 11 ′ can be centrally monitored by a sensor 12 and/or through which an additional material may be centrally supplied to the laser processing site. This arrangement facilitates precise follow-up in three-dimensional processing with the sensor or other supplementary elements. For precise follow-up, the light-gathering optical sensor 12 may be immovably connected to the movable laser processing head, or the sensor 12 can be connected to the laser processing head, such that the sensor can be pivoted and displaced in the space below the beam splitting region, for example, directly above the welding joint.
A light-gathering optical element, for example, a mirror or the end of a light guide or optical fiber, can be disposed at this position instead of the sensor 12 , and the optical element can guide light to a remotely located sensor. This arrangement is favorable if a sensor is used that is too large to be located in the position above the focus 9 of the laser beam portions 7 and 8 .
As shown in FIGS. 2 and 3 , the laser beam 6 is deflected by a deflecting mirror 14 housed in the angle apparatus 2 toward the beam splitter 3 . The beam splitter 3 splits the laser beam 6 into laser beam portions 7 and 8 that are directed towards focusing mirrors 4 and 5 , respectively. The laser beam portion 8 is focused onto the workpieces 11 and 11 ′ (e.g., sheet metal) using the focusing mirror 5 .
The sensor 12 can monitor, for example, the degree of coupling between the laser beam portions 7 and 8 , the formation of splashes from the workpieces 11 and 11 ′, and/or the welding depth. Changes in the region of the workpiece surface 10 can be detected by the sensor 12 during laser welding. The sensor 12 is mechanically connected to the angle apparatus 2 in a manner that allows positioning of the double focusing unit 1 and additional adjustment of the sensor 12 with respect to the double focusing unit 1 . The sensor 12 is electrically connected to a regulation and control unit 15 , although, for clarity, the cables and connections between the sensor and the control unit 15 , which are integrated in the laser processing machine, are not shown. The sensor 12 in combination with the control unit 15 can be used to control optical properties of the laser beam portions 7 and 8 (e.g., the total and relative intensities of the laser beam portions 7 and 8 ). For example, the control unit 15 can control the position of a knife-edge mirror beam splitter 3 in response to feedback from the sensor to vary the relative intensity of the laser beam portions 7 and 8 .
Actuating drives for the two focusing mirrors 4 and 5 and for the beam splitter 3 can be provided in the focusing unit 1 and can be connected to the regulation and control unit 15 , such that their positions and/or orientations can be controlled as a function of data detected by the sensor 12 .
The beam splitter 3 and beam portions 7 and 8 define a space 30 —a “triangle” as shown in FIG. 3 —below the beam splitter 3 and starting from or above the welding joint on the workpiece 11 . The sensor 12 is arranged within this “triangle.” Beam portions 7 and 8 impinge onto the welding joint at an angle <90° from the side rather than directly from above the workpiece 11 , and enclose together an angle α that opens from the joint. Thus, a space 30 is provided directly above the welding joint, and the sensor 12 is located in the space 30 . The sensor 12 is disposed to be pivotable and displaceable (as shown by the double arrows 32 and 34 in FIGS. 2 and 3 ), such that the sensor 12 can be disposed between the two beam portions 7 and 8 within the angle α directly above the welding joint.
In other implementations, the space 30 between the two laser beam portions 7 and 8 can be used to position other materials or parts directly above the workpiece, either in place of, or in conjunction with, sensor 12 . For example, as shown in FIG. 4 , a mounting element 102 is provided in the region of the focusing unit 101 (which substantially corresponds to the focusing unit 1 of FIG. 1 ) and can be provided to support and supply an additional material (e.g., a wire or rod 103 , for example, a welding rod or wire) to the welding seam 13 of the two workpieces 11 and 11 ′ from directly above the workpieces 11 and 11 ′ and between the two laser beam portions 7 and 8 . The mounting element 102 can be, for example, a pliers, a collet, a tube, or a plurality of tubes or rings for supporting the additional material 103 , and the additional material 103 can be fed through the mounting element to the welding seam 13 .
As shown in FIG. 5 , a process gas supply 202 (e.g., a nozzle) can be disposed between the laser beam portions 7 and 8 directly above the welding seam 13 in the region of a focusing unit 201 (which substantially corresponds to the focusing unit 1 of FIG. 1 ). The process gas 203 can be supplied to the laser processing region from directly above the laser processing region. The process gases 203 (e.g., protective gases and/or working gases) can be supplied to the welding location in or on the laser processing head.
OTHER EMBODIMENTS
It is to be understood that while particular implementations have been described, the foregoing description is intended to illustrate and not limit the scope of the invention that can be claimed. For example, it is clear that an implementation may include the sensor 12 , the supply of additional material 103 and the supply of process gases 203 .
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A laser processing machine includes a beam splitter for splitting an incoming laser beam into a first laser beam having a first intensity and a second laser beam having a second intensity, a first focusing mirror for focusing the first laser beam onto a first laser processing site on a workpiece at an angle from a direction directly above the workpiece, a second focusing mirror for focusing the second laser beam onto second laser processing site on the workpiece at an angle from a direction directly above the workpiece, and a supplementary laser processing element for supplementing laser processing of the workpiece, wherein the supplementary laser processing element is disposed directly above the first or second laser processing site.
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FIELD OF THE INVENTION
The present invention relates to hot roll fusers for electrostatic copying machines, and more particularly, to a cleaning system for cleaning a backup roll in such a hot roll fuser.
BACKGROUND OF THE INVENTION
In the field of electrostatic copying employing fusable toners, various devices have been proposed to perform the fusing function, which devices rely upon radiant heat transfer, conductive heat transfer and even convective heat transfer. The present invention relates to apparatus relying upon conductive heat transfer and thus employs a hot roll fuser. The invention, however, is applicable to any appropriate roll fuser, heated or not. In hot roll fusers, desirably a backup roll is provided arranged so as to form a nip between the hot roll and backup roll. Preferably, the backup roll is relatively cooler than the hot roll.
With such an arrangement there is a tendency for toner to accumulate on the backup roll either from minor contact with the hot roll, from loose toner carried by air within the machine or from contact with a previously fixed copy which is passed through the roll pair for fixing an image on a reverse side. This toner must be cleaned from the backup roll for, although the toner may initially exist in a liquid state, toner accumulated on the backup roll can become sufficiently hard to emboss the carrier and may even lead to jamming of the fuser by preventing the carrier from passing through the nip.
The necessity for cleaning the backup roll is demonstrated by considering that, typically, the pressure between the hot roller and the backup roll is on the order of 130 to 140 lbs. per square inch and the hot roll temperature is in the range of 350°-370° (F.). Subjected to these conditions, toner on the backup roll can become hard enough, after being subjected to these conditions for a period of time, to actually emboss the carrier or paper passing through the roll pair. This is, of course, undesirable. Furthermore, the toner build-up on the backup roll, under the conditions of pressure and temperature normally encountered, can build up sufficiently to cause wrinkling of the carrier or paper and even jamming which necessarily results in terminating copier operation so that the jam can be removed.
Even before toner buildup on the backup roll becomes hard enough to cause embossing, sufficient heat is transferred to the backup roll to cause any toner located thereon to become tacky. Under these circumstances, the paper travelling through the paper path may tend to adhere to the backup roll which, of course, is also undesirable.
Prior art hot roll fusers have employed coated backup rolls coated to facilitate release. However, for a number of reasons, it would be desirable to employ a backup roll consisting of an uncoated conductor. One reason is cost; an uncoated roll is less expensive than a coated roll. Another reason is that electrostatic charging during image transfer to the paper tends to leave a residual charge on the paper. Desirably, this charge should be removed since it only inhibits proper paper flow. Clearly, a conductive backup roll will tend to "ground" the paper and drain off any residual charge thereon, whereas a coated backup roll will not perform this function, or will not perform it to the same extent.
A cleaning device for a coated backup roll comprises a scraper blade with a sharp leading edge composed of a plurality of individually flexible fingers for scraping toner from the backup roll is described in U.S. Pat. No. 3,794,417. Another cleaning arrangement employing a scraper blade for a backup roll in a hot roll fuser is shown in published patent application B579,116. The backup roll disclosed in both the aforementioned references comprises an aluminum cylinder with a thin surface coating such as polytetrafluoroethylene, aluminum oxide, chromium oxide or aluminum oxide imbedded within polytetrafluoroethylene.
Other arrangements for cleaning cylindrical surfaces in an electrostatic copier include that shown in U.S. Pat. No. 3,970,038 wherein a plurality of flexible fingers are supported for wiping contact, as opposed to scraping contact, with the fuser roll, or that shown in U.S. Pat. No. 3,940,282 wherein a pair of scraping blades are in contact with an image supporting surface.
It is an object of the present invention to provide a cleaning arrangement for an uncoated backup roller in a hot roll fuser. It is another object of the present invention to provide a cleaning arrangement which comprises a pair of scraper blades each having serrated or interrupted scraping edges in contact with the backup roll. It is a further object of the present invention to provide a cleaning arrangement of the foregoing type in which the serrations or interruptions of each scraper blade are offset with respect to the other such that the entire surface of the backup roll is scraped by either the first or the second scraper blade, or both. It is another object of the present invention to provide a cleaning arrangement for an uncoated backup roll which includes a flexible scraper blade, made flexible by the presence of serrations or interruptions in the blade surface which, at the same time, insures that all of the backup roll surface area is scraped by providing a second flexible scraper blade with serrations or interruptions in the surface of the scraper blade offset with respect to the first scraper blade.
SUMMARY OF THE INVENTION
These and other objects of the invention are met by providing in a roll fuser including a main roller, which may be heated and an uncoated backup roll forming a nip through which a carrier with unfused toner may pass, an improvement for cleaning the backup roll including a first scraper blade supported in contacting relation with the backup roll surface, a second scraper blade supported in contacting relation with the backup roll surface, each of the first and second blades having an interrupted surface contacting the backup roll thereby leaving areas of the backup roll surface unscraped by the first or second blade, with the first and second blades positioned so that their interruptions are offset with respect to each other to insure that a surface area of the backup roll unscraped by one of the blades is scraped by the other of the blades.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be further described when taken in conjunction with the attached drawings in which like reference characters identify identical apparatus, and in which:
FIG. 1 is a schematic cross-section illustrating the relation between heated roller, backup roll and the pair of scraping blades;
FIGS. 2A-2C show, respectively, the backup roll and scraping blade assembly, a side view and a cross-section;
FIG. 3A shows a developed plan view of the blades illustrating the relationship between their serrations; and
FIG. 3B is an end view of a typical blade in the vicinity of the scraping edge.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 is a schematic illustration of one embodiment of the invention. As shown there, a hot roll fuser for an electrostatic copier machine includes a rotatable hot roller 10 which may comprise an aluminum core, with an internal heater, for example, a radiant energy heater, and a resilient coating thereon. Associated with the hot roll 10 is a backup roll 15. Backup roll 15 may comprise a steel, nickel plated or chrome plated steel roller which is mounted for rotation about its longitudinal axis in the direction of the arrow 11. The backup roll 15 is also mounted for movement relative to the hot roll 10 in the direction of the arrow 12. In its idle position, the backup roll 15 is moved away from the hot roll 10 and when copying is to commence, the backup roll 15 is moved in the direction of the arrow 12 into contact with the hot roll 10 forming a nip between the rolls. One or the other of the hot roll 10 or backup roll 15 is driven, and normally it is the backup roll 15 which is driven and the engagement between the backup roll 15 and the hot roll 10 causes rotation of the hot roll 10 as well as imparting a force to a paper sheet engaged in the nip to move the paper in the direction of the arrow 13. The combination of the pressure between the rolls 10 and 15 as well as the heat from the hot roll 10 causes fusing of toner on the paper to thereby fix the toner. As mentioned above, it is the primary object of the invention to maintain the backup roll 15 clean from dirt, dust and particularly toner.
To effect these ends, a scraper assembly is provided including a scraper body 16 which is fixed relative to the backup roll 15 and thereby moves with the backup roll when the backup roll is moved toward or away from the hot roller. The scraper body 16 supports a primary scraper blade 17 having a scraping edge in contact with the surface of the backup roll 15 and making an angle α with a tangent to the backup roll surface at the point of contact. The scraper body 16 also supports a secondary scraper blade 18 having a scraping edge in contact with the surface of the backup roll 15 and making an angle β with a tangent to the backup roll surface at the point of engagement. The scraper body pivots about a pivot 19 under the force of a spring bias exerted by a bias spring 20 to load the primary and secondary blades 17 and 18 into proper scraping relationship with the surface of the backup roll 15. The bias or loading between blade and backup roll is adjusted by varying the tension of spring 20 as will be explained below.
Although the backup roll is cylindrical to a first approximation, desirably it is slightly tapered with the ends slightly greater in diameter than the center. To ensure good scraping action, therefore, the blades should not be so stiff that they cannot follow the backup roll contour. To decrease the stiffness of the blades, the scraping edge is interrupted or serrated. To ensure that the entire surface of the backup roll is scraped, the interruptions or serrations of the two blades are offset with respect to each other. Desirably, the serrations are wide enough and deep enough to allow toner beads to pass without becoming trapped.
FIGS. 2A, 2B and 2C illustrate, respectively, an assembly view, an end view and a typical cross-section of the scraper assembly and backup roller. As shown in FIG. 2A, for example, the backup roller 15 rotates about, and is driven by a shaft 28. Also supported on the shaft 28 and fixed against longitudinal movement or rotation are a pair of scraper assembly arms 27, one at each end of the backup roller 15. The scraper body 16 assembly is supported on and pivoted about a pivot shaft 19 supported between the arms 27. As shown more clearly in FIG. 2C, the scraper body 16 has a primary scraper blade 17 and a secondary scraper blade 18 attached thereto. More particularly, the scraper body 16 may comprise an elongated body slightly longer than the backup roll 15 and of generally L-shaped cross-section with a hole running longitudinally therethrough for pivot shaft 19. Pairs of groups of tapped holes 22a in one surface and 23a in another surface of the body 16 are provided for attaching the scraper blades 17 and 18 to the scraper body 16. Each of the blades are provided with a series of holes so that a plurality of screws 22 and 23 can secure the blades to the body. Associated with scraper blade 17 is a cover 22 which serves both to secure the blade to the body as well as to protect the same. Similarly, a cover 24 is associated with the blade 18 for securing purposes.
For the purpose of loading the blades against the surface of the backup roll 15, each of the scraper assembly arms 27 includes a tapped hole 29 at least partially therethrough. The scraper body 16 includes generally planar extensions 30 which overlie the tapped holes 29 in the scraper assembly arms 27 when the scraper body 16 is in its assembled position. A spring 20 secured between the extensions 30 and the head of a screw 21 provides a bias for loading the blades against the backup roll surface as the screw 21, which is threaded into the hole 29, is tightened. Loading force may be adjusted merely by rotating the screw 21.
While the backup roll 15 is generally cylindrical in shape, it preferably includes a slight taper so that the diameter of the backup roll 15 adjacent the center of the roll, is slightly less than the diameter of the roll adjacent its ends. To increase the compliance of the blades, and to insure that they conform to the surface of the backup roll 15 at least the scraping edge and preferably a substantial extent of the width of the blade includes a plurality of interruptions or serrations. This increased compliance of the blade is desirable even if the backup roll 15 is substantially cylindrical without the taper.
FIGS. 3A and 3B are, respectively, a developed plan view of a typical blade such as the primary blade 17 and its relation to the secondary blade 18, and an end view of a typical blade in the vicinity of the scraping edge. More particularly, as shown in FIG. 3A, the blade 17 comprises a generally rectangular blade having a plurality of holes 22b to allow the screws 22 to pass therethrough for the purpose of securing the blade to the scraper body 16. The scraping edge portion of the blade is interrupted or serrated such that the blade itself comprises a plurality of blade sections 17a, separated by serrations or interruptions 17b. In a typical embodiment, for example, each blade may be 8.75 inches long with each of the serrations 17b being 0.072 inches wide or wider. For the embodiment shown in FIG. 3A, each blade comprises ten sections 17a.
While the serrations are effective to increase the compliance of the blade and insure that it lies in effective scraping relationship with respect to the entire surface of the backup roll 15, the interruptions or serrations 17b allow toner to build up in stripes at the locations of the serrations or interruptions. In order to remove the stripes or to prevent their production, the secondary blade 18 has its serrations or interruptions 18a offset with respect to the serrations or interruptions 17a of the primary blade 17. Thus, FIG. 3A also shows a broken top view of the secondary blade 18 showing the relationship between the serrations 18b and 17b, when both blades are mounted on the blade assembly body 16. Those skilled in the art will understand that the number of sections and hence the number of serrations in any blade can be varied although, of course, as the number of serrations or interruptions is reduced, so is the compliance of the blade. At the same time, there is no necessity that the serrations 18b are located at the midpoint of the serrations 17b, so long as the serrations or interruptions are sufficiently offset so as to preclude the buildup of a toner stripe on the surface of the backup roll 15 being scraped.
FIG. 3B is a cross-section of the edge area of the scraper blade showing that the blade, which may be 0.006 inches in thickness, has a bevel adjacent the scraping edge, preferably, the bevel is 45°, although this particular amount of bevel is not critical. In addition, the extreme edge of the scraping edge of the blade has a tip radius on the order of 0.001 inches. A suitable material for both blades is spring steel.
In operation, with the scraper assembly as shown in FIGS. 2A-2C mounted to the shaft 28, the primary blade 17 makes an angle to the tangent to the backup roll at its point of contact of about 21°, which angle is changed as the blade is loaded by rotation of the screw 21. In the embodiment we have produced, with a load of 0.256 pounds per inch, the 21° angle is reduced to 19°. Secondary blade 18 makes an angle which is about 20°, either loaded or unloaded. In view of the fact that the scraper assembly and the blades are mounted to the shaft supporting the backup roll 15, movement of the backup roll into and out of contact with the hot roll 10 does not change the relationship of the scraper body or blades to the backup roll. At the same time, removal of the pivot shaft 19 and the loading screws 21 allows the scraper blade assembly to be removed from the backup roller arms 27 and thereby removed from the apparatus.
From the foregoing, those skilled in the art will appreciate that, when loaded, each of the primary and secondary scraper blades lifts contaminants off the surface of the backup roller 15 except for the area in which serrations or interruptions exist in the blade edge. The mounting and arrangement of serrations in the pair of blades insures that the serrations or interruptions do not "line up" and thus the entire surface of the backup roll 15 is cleaned.
As mentioned above, preferably the scraper blades comprise spring steel, the scraper body 16 can be either steel or die-cast aluminum, the covers 22 and 24 are preferably aluminum and while the backup roll 15 has been disclosed as comprising steel or plated steel, it can also be an aluminum core covered with a Teflon® based polymer or other low surface energy material.
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A hot roll fuser includes a heated roller and a substantially non-deformable backup roll forming a nip through which a carrier with unfused toner may pass, the toner becoming fused by virtue of the heating action from the hot roll. A cleaning arrangement for cleaning the backup roll comprises a support and a pair of scraping blades, each supported in contacting relationship with the backup roll. To insure good scraping action, each of the blades has a serrated or interrupted scraping edge, and the serrations or interruptions of the first and second blades are offset so that the entire surface area of the backup roll is scraped either by the first or second blades, or both.
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BACKGROUND OF THE INVENTION
Field of Invention
This invention is related to facial weights of varying sizes and shapes designed for total facial muscle toning and development.
BACKGROUND OF THE INVENTION
For centuries efforts have been made to enhance and beautify our facial appearance. There have been developed thousands of creams, gels, toners, and masks with claims of reducing wrinkles and increasing skin tone. Exercise gadgets as well have been designed with the promise of improving ones' appearance. There is cosmetic surgery to remove excessive sagging skin and give the face a tighter more youthful look. This has been favored by the public perhaps because of its immediate observable change. Unfortunately this procedure is costly and leaves the individual with permanent scars. Gadgets and specifically designed facial instruments have been patented for the purpose of facial muscle strengthening, toning, and development. These, however, have not gained popularity for one reason or another. Mainly for the lack of quick results, hassle of assembling the gadgets, public awareness of their availability, or cost factors.
U.S. Pat. No. 4,823,778 to Ewing describes a method of exercising facial muscles by first applying a stiffener to the surface of the skin and attaching weights to the stiffener. The weights are metal discs, the size of a penny arranged in a row. They are encased in thin cardboard plates which are taped together. The individual is to contract facial muscles a predetermined number of times against resistance of this cardboard encased metal discs.
U.S. Pat. No. 6,406,405 to Chu describes a facial muscle exercise device that one places in the mouth with part of the device extending out of the mouth and weighted by steel discs. The gravitational force of the weights put pressure on the part that is held inside the mouth causing one to contract the cheek muscles against this resistance. This contraction will tone specific muscles of the face.
In U.S. Pat. No. 4,189,141, Rooney devised an exercise mask which is convexed and with holes cut out for the eyes, nose, and mouth. It has sewn-in pockets on the underside where lead weights are arranged at specific points. The mask is held in place by head and chin straps. The individual straps on the mask and contracts facial muscles against the resistance of the weights inside the pockets. A plastic liner in between the mask and the face is required to maintain the stretch cloth material clean.
U.S. Pat. No. 4,280,696 to Ramon describes an exercise apparatus consisting of a pair of flat spring arms which are pivotally connected to each other. The individual places this device in between their upper and lower teeth and attempts to squeeze the arms of the device together by pressing the upper and lower teeth together. Squeezing the arms of the device in between the teeth will cause the jaw muscles to contract therefore toning them.
U.S. Pat. No. 4,195,833 to Svendsen describes a method of toning facial muscles by use of a weighted band around the head. The elastic band has fabric encased metal weights that are sewn onto it. This elastic band is placed inside a tubular structure such as a sock. The ends are sewn together to form a circular band. The elastic band is placed over the head with the metal weights over the facial muscles to be worked. The person then contracts facial muscles against resistance of metal disc sewn to the elastic band.
Some of these past developments focus on a particular part of the face (e.g. U.S. Pat. No. 4,195,833 to Svendsen; U.S. Pat. No. 4,280,696 to Roman; and U.S. Pat. No. 6,406,405 to Chu), others may apply to the entire face but lack the diversity of shapes and weights required for full facial development (e.g. U.S. Pat. No. 4,823,778 to Ewing; U.S. Pat. No. 4,189,141 to Rooney).
It is a well known fact that if you want to tone or build muscle you need to work out those muscles you intend to build. To build your upper extremities would require the use of different types of weights. You may use 5 lb barbells to strengthen your wrists or forearms but bench press 60 lbs using free weights for your biceps. The diversity in type and mass of weights to be resisted against is quite different, and this is only for the upper extremities! The face is not all that different when it comes to muscle building. Even though facial muscles are close together, the weight difference required to build muscles around the eyes as opposed to those over the cheeks is significantly different. The shape of the weights used around the eyes should also be of a different conformation than that used, lets say, over the forehead or on the chin. I have designed six flexible weights in different shapes that range from 8 oz (227 gm) to 2.2 lbs (1 kg) that can be used for total facial muscle development, or facial building if you wish. The variable shapes allow weights to be used in specific areas of the face, for example, smaller shaped weights are used around the eyes while the larger ones over the cheeks. The variable fixed sizes (8 oz vs. 2.2 lbs) are advantageous in that you do not need to be adjusting the weight repeatedly with each exercise. Just take the smaller 8 oz weight to use over the eyes and switch to the 2.2 lb elongated weight to work the muscles of the forehead or the cheeks. The special design for use over the eyes, around the eyes, and over the nose bridge is another advantage of this invention. These facial weights are contoured, by addition of pleats, so that there is maximum contact between it and the intended muscle to be developed without the need for adhesives or Velcro.
The weights require no assembly. They are made of an exterior water resistant vinyl fabric, which make them easy to clean, and are weighted with steel beads. The steel beads are an excellent choice for use in weights because of its higher density, requiring less bulky weights and because of its ability to maintain a stable weight despite humidity as compared, for example, to sand. An instructional booklet with illustrations for weight positioning and an exercise routine accompanies the weights.
BACKGROUND OF THE INVENTION
Object and Advantages
Accordingly, besides the objects and advantages of the facial weights described in the above patent, several objects and advantages of the present invention are:
(a) to provide a guided method for proper conditioning, toning, and development of the whole facial muscles in their entirety (b) to facilitate facial workouts by improving ease of use of facial weights (c) to provide exercise weights in variable sizes and shapes that will contour to facial features for maximum contact with facial muscles. (d) to provide facial weights that are easy to maintain clean (e) to provide facial weights that require no assembly (f) to provide a means by which an individual is able to workout at his own pace in the privacy of his home. (g) to bring public awareness that facial muscles can be toned and developed just as can any muscle in our bodies via advertisement of facial weights. (h) to encourage the public to start an exercise routine that includes facial toning and development.
The above are accomplished by means of using individual weighted material filled vinyl covered facial weights designed in varying sizes and shapes and applied over specific facial muscle groups to provide resistance against facial muscle contraction. Twenty facial exercises have been designed for the facial weights.
SUMMARY OF THE INVENTION
The present invention consists of weighted material filled, vinyl covered facial weights of varying sizes and shapes designed to be used directly over the facial muscles to provide resistance against the contracting muscle groups. The varying sizes, shapes, ease of use, and no need for adhesives or assembly offer an advantage in design over previously patented facial weights and apparatus. Weights vary from 8 oz (227 gm) to 2.2 lbs (1 kg). They are designed for a complete facial workout.
Accompanying the facial weights is a booklet with illustrations of 20 exercises designed for total facial muscle toning and development.
BRIEF DESCRIPTION
FIG. 1 is an exploded view of the elongated 1 kg (2.2 lbs) weight. This weight measures 24 cm at its greatest length, 9 cm at the widest part of each wing, and 5 cm at the narrow mid-section. It has six pleats.
FIG. 2 is an exploded view of the elongated 681 gm (1.5 lbs.) This weight measures 23 cm at its greatest length, 8 cm at the widest part of each wing, and 5 cm at the narrow mid-section. It resembles FIG. 1 except that it has four pleats and its dimensions are smaller.
FIG. 3 is an exploded view of the irregular shaped 766 gm (1.8 lbs.) weight. This weight measures 14 cm at its greatest length, 10 cm at its widest part on the base, and 5.5 cm at its widest part on the apex. It has two pleats
FIG. 4 is an exploded view of the irregular shaped 454 gm (1.0 lb.) weight. This weight measures 12 cm at its greatest length, 8.5 cm at its widest part on the base, and 5.25 cm at its widest part on the apex. It resembles FIG. 3 except that it has one pleat and is slightly smaller.
FIG. 5 is an exploded view of the Oculus 284 gm (10 oz) weight. The oculus measures 12.0 cm at its greatest length and 9.0 cm at its widest width. It has a 5 mm circular stitch at its center and has two pleats.
FIG. 6 is an exploded view of the Oculus 227 gm (8 oz) weight. This weight measure 12.0 cm at its greatest length and 9.0 cm at its widest width. It has a 10 mm circular stitch at its center and has one pleat.
FIGS. 7–12 are what the actual finished products look like.
DRAWINGS
Reference Numerals
2 a–f pleats
4 center straight stitch
6 a–b the wing part of the weight
8 the neck part of the weight
10 straight stitch at ¼ inch from periphery
12 2.5 cm opening
14 a–b pleats
16 apex of weight
18 base of weight
20 curve
22 a–b pleats
24 center stitch
DETAILED DESCRIPTION
FIGS. 1 and 7 :
FIG. 1 depicts two pieces of water-resistant material of identical size and shape. I used vinyl material for the covering. Each piece has six pleats ( 2 a–f ). First, stitch each pleat along the broken lines as shown in figure one. You will have formed six pleats on each piece of material. Next, place the two pieces of material with outsides surfaces facing each other and match the pleats of one piece to the pleats of the opposite piece of material so that all pleats will line up with each other. Stitch the two pieces together ¼ inch from the periphery as shown by the broken lines ( 10 ) leaving a 2.5 cm area without stitching ( 12 ). Turn the weight inside out through this opening. Use this opening to fill with a weighted material. I used 1 kg (2.2 lbs) of 4.5 mm steel beads. When you fill the weight with 500 gm (1.1 lbs) of weighted material, stitched the weight with a simple straight stitch ( 4 ) at the center as shown in FIG. 1 . After this stitch, proceed to fill the other 500 gm. This is a very important step because it will be directly related to good symmetrical development of facial muscles. Once you have filled the weight stitch the 2.5 cm opening closed using an outside straight seam.
FIG. 7 is what the finished product actually looks like.
FIGS. 2 and 8 :
FIG. 2 depicts two pieces of water resistant material of identical size and shape. For this weight I also chose vinyl. Each piece has four pleats ( 2 a–d ) as shown in FIG. 2 . First stitch each pleat along the broken lines at shown in FIG. 2 . Place the two pieces of material together with outside surfaces facing each other and with pleats of one piece matching the pleats of the opposite piece. Stitch along the edge ¼ inch from periphery along the broken lines ( 10 ) as shown in FIG. 2 leaving a 2.5 cm area ( 12 ) free of stitching. Turn the weight inside out through this 2.5 cm opening. Fill weight with weighted material to 340.5 gm (0.75 lbs), I again used 4.5 mm steel beads. Stitch the center of the weight with a longitudinal outside simple straight stitch ( 4 ). Continue to fill the weight with another 340.5 gm (0.75 lbs), of weighted material then stitch the 2.5 cm opening with an outside straight stitch. The two center pleats allow for flexibility.
FIG. 8 is a view of the finished product.
FIGS. 3 and 9 :
FIG. 3 depicts two pieces of water resistant material of identical size and shape. For this weight I used a simulated leather, softer in texture than the vinyl because this weight will be used for working muscles close to the eyes. Each piece of material has two pleats. First, stitch each pleat ( 14 a–b ) along the broken lines as shown in FIG. 3 . Next, with outside surface of pieces facing each other stitch ¼ inch along the periphery ( 10 ) as shown in FIG. 3 leaving a 2.5 cm area ( 12 ) open. Turn the weight inside out through this opening. Fill weight with 766 gm (1.8 lbs) of weighted material. Stitch the 2.5 cm opening with an outside straight stitch.
FIG. 9 is a view of the finished product.
FIGS. 4 and 10 :
FIG. 4 shows two pieces of water resistant material of identical size and shape. I used a soft simulated leather. Each piece has one pleat ( 14 a ). First, stitch each pleat along the broken lines as shown in FIG. 4 . Next, place the two pieces of material together with outside surfaces of material facing each other and pleats matching. Stitch around the periphery along the broken lines ( 10 ) as shown in FIG. 4 leaving a 2.5 cm opening ( 12 ). Turn the weight inside out through this opening. Fill the weight with 454 gm (1 lb) of a weighted material, such as steel beads. After filling the weight, stitch opening with an outside straight stitch.
FIG. 10 is a view of what the finished weight looks like.
FIGS. 5 and 11 :
FIG. 5 depicts two pieces of water resistant material of identical size and shape. For this weight I used a simulated leather because this weight is designed to be used directly over the eye. Each piece of material has two pleats ( 22 a–b ). First, stitch each pleat along broken lines as depicted on FIG. 5 . Next, place the two pieces of material with outside surface facing each other and stitch around the periphery along the broken lines ( 10 ) as shown in FIG. 5 leaving a 2.5 cm opening ( 12 ). Turn the weight inside out through this opening. Double stitch a 5 mm circle at center of weight ( 24 ). This is a crucial step because this stitch will keep the pressure off your eyeball. Fill weight with 284 gm (10 oz) of weighted material. Close opening using an outside straight stitch.
FIG. 11 is a view of the finished product.
FIGS. 6 and 12 :
FIG. 6 depicts two pieces of water resistant material of identical size and shape. I used a simulated leather because this weight is designed to be used directly over the eye. Each piece of material has one pleat ( 22 a ). First stitch each pleat along the broken lines as depicted on FIG. 6 . Next place the two pieces of material with outside surface facing each other and stitch around the periphery along the broken lines ( 10 ) as shown in FIG. 6 , leaving a 2.5 cm opening. Turn the weight inside out through this opening. Double stitch a 10 mm circle ( 24 ) at center of weight. Fill weight with 227 gm (8 oz) of weighted material. Close opening using an outside straight stitch.
FIG. 12 is a view of what the finished weight looks like.
These weights are designed to be used while in the supine position and are designed to be used while performing twenty facial exercises. Those exercises are listed below.
Exercise 1, designed for the 284 gm oculus weight, consists of placing weight over eye, closing eye tightly, and then releasing.
Exercise 2, designed for the 227 gm oculus weight, consists of placing weight over eye, raising eyebrow, and then relaxing it.
Exercise 3, designed for the 454 gm irregular shaped weight, consists of placing weight over temple, closing eye tightly, and then relaxing.
Exercise 4, designed for the 454 gm irregular shaped weight, consists of placing weight below lower eyelid, closing eye tightly, and then relaxing it.
Exercise 5, designed for the 454 gm irregular shaped weight, consists of placing weight as in exercise 4, except raise corner of mouth up toward weight.
Exercise 6, designed for the 766 gm irregular shaped weight, consists of placing weight over cheek and raising corner of mouth toward weight.
Exercise 7, designed for the 766 gm irregular shaped weight, consists of placing weight as in exercise 6 except tighten lips, pucker, and stretch lips away from weight.
Exercise 8, designed for the 766 gm irregular shaped weight, consists of placing weight over cheek but closer to nose and stretching upper lip over top teeth.
Exercise 9, designed for the 766 gm elongated shaped weight, consists of placing weight over higher part of forehead near hairline and lowering eyebrows.
Exercise 10, designed for the 766 gm elongated shaped weight, consists of placing weight over lower part of forehead near brows and raising brows.
Exercise 11, designed for the 766 gm elongated shaped weight, consists of placing weight over bridge of nose with center pleats toward brows and wings over lower half of eyes while tightening eyes, and then relaxing.
Exercise 12, designed for the 766 gm elongated shaped weight, consists of placing weight over bridge of nose with center pleats toward lips and wings over checks, and raise brows.
Exercise 13, designed for the 766 gm elongated shaped weight, consists of placing weight over bridge as for exercise 12 but wrinkle nose and then relax.
Exercise 14, designed for the 1 kg elongated shaped weight, consists of placing weight as in exercise 12, with lips together smile.
Exercise 15, designed for the 1 kg elongated shaped weight, consists of placing weight over bridge of nose as for exercise 12 but move the wings closer to the corner of the mouth, pucker lips, and then relax.
Exercise 16, designed for the 1 kg elongated shaped weight, consists of placing weight as in exercise 15 but stretch upper lip over upper teeth as in exercise 8.
Exercise 17, designed for the 1 kg elongated shaped weight, consists of placing weight between nose and upper lip with center pleats toward nose and wings over cheekbones, and with lips together smile.
Exercise 18, designed for the 1 kg elongated shaped weight, consists of placing weight as in exercise 17 except with center pleats toward chin and wings over cheeks, pucker lips and then relax.
Exercise 19, designed for the 1 kg elongated shaped weight, consists of placing weight as in exercise 18 except that neck is directly over both lips and then pucker lips.
Exercise 20, designed for the 1 kg elongated shaped weight, consists of placing weight as in exercise 19 but over lower lip, and then open and close mouth.
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The invention consists of steel-bead weighted facial exercise weights designed in varying shapes, sizes, and weights. The weights are designed so that they are placed over the face providing resistance against the intended group of facial muscles to be developed. The method is designed for total facial muscle toning and development necessitating the use of varying sized, shapes, and weights that maximize the development of intended muscle group to be developed.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. provisional application No. 61/060,288 filed on Jun. 10, 2008.
BACKGROUND OF THE INVENTION
[0002] This invention concerns automatically resetting torque limiting clutches and more particularly automatically resetting torque limiters which can disconnect on overload.
[0003] Resetting torque limiting clutches have been in existence for many years, typically of a friction clutch or ball detent type. The friction type will release or slip at a preset overload torque value, and will reengage when the overload is removed. The disadvantage of this arrangement is that repeated heating of the torque limiter friction linings (as heat is generated the slipping) causes the clutch capacity to fade, as the higher lining temperatures reduces the coefficient of friction, until the torque limiter slips continuously and destroys itself.
[0004] Another long known torque limiter type is the ball-detent reset torque limiter, which uses spring forces to push balls into drill point cavities with the geometry thereof establishing forces and angles to produce a release at a preset torque level. The torque limiter will reengage when the torque demand falls somewhere below the release torque. The disadvantage of this device is the sudden changes in the acceleration of the connected components, which produces shock loads on the components when running disengaged, or when reengaging, which produces high stresses and deformations which greatly reduce the torque limiter service life.
[0005] It is an object of the present invention to provide an automatically resetting torque limiting clutch in which a connected drive member can run with the torque limiter in a released condition without overheating or imposing shock loads during normal operation or when an overload causes relative rotation between driving and driven members.
SUMMARY OF THE INVENTION
[0006] The above recited object and others which will be understood by those skilled in the art upon a reading of the following specification and claims are achieved by an automatic resetting torque limiting clutch acting between two rotary members which transmits torque through one or more cam followers carried by one rotary member urged into contact with a cam surface carried on the other rotary member. The cam followers transmit forces to the cam surface which has a smoothly continuous undulating shape which provides a displacement curve for the cam followers to trace so that there are no abrupt acceleration changes imparted to the cam followers as they are displaced by the cam undulations. The cam followers are prevented from overrunning the cam undulation peaks or lobes by spring arrangements producing an engagement pressure and increasing forces resisting displacement of the cm followers by the cam surface contour preventing the cam followers from passing over the cam lobes until a predetermined torque level is applied by the driving member whereupon the cam followers are able to overcome the forces and be displaced sufficiently to overrun the cam lobes and thereby interrupt the transmission of torque through the torque limiter.
[0007] The development of forces necessary to produce the displacement of the cam followers sufficient to release the torque limiter can be set to a selected characteristic providing the release and also the reengagement performance characteristics required. Harmonic motion characteristics, cyclodial motion characteristics and eighth-power polynomial motion characteristics can be used alone or in combinations. Acceleration and velocity curves are matched so that “jerk” is not infinite at any point in the cycle.
[0008] The cam undulation peaks or cam lobes are located radially out from the axis of rotation of the members in order to transmit torque by the engagement of the cam followers and the cam surface but can be arranged to undulate either radially or axially to generate the displacement resisting forces exerted on the cam followers in contact therewith. The undulation can also be formed on internal or external surfaces.
[0009] The cam followers may be mounted in various ways, including on rocker arm assemblies carried by a driving or driven member so as to engage and follow the cam surface and generates forces transmitting the driving torque to the driven rotary cam member. The arrangement can be reversed so that the cam member is the driver and the cam followers are on the driven member.
[0010] Other arrangements include radial slides having cam follower rollers on the ends thereof or rollers rotatably mounted on radially extending pins carried on an axially movable ring urged to engage the rollers with an axially varying cam surface.
[0011] The typical driving load for the reset torque limiter would be about one third to one half the torque release settings for the limiter. The normal “drive torque to release torque ratio” can be varied or adjusted by changes to the cam displacement curve.
[0012] A cam-follower automatic resetting torque limiting clutch according to the invention can be manufactured in various designs depending on application requirements.
DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a pictorial view of a first embodiment of a torque limiter according to the present invention with an outer rotary member shown in phantom lines to reveal interior details.
[0014] FIG. 2 is an enlarged fragmentary side view of a portion of the torque limiter shown in FIG. 1 .
[0015] FIG. 3A is a pictorial view of a rotary cam member included in the torque limiter of FIG. 1 .
[0016] FIG. 3B is a pictorial view of a different embodiment of the rotary cam member shown in FIG. 3A .
[0017] FIG. 3C is a pictorial view of another embodiment of the rotary cam member shown in FIG. 3A .
[0018] FIG. 4A is a pictorial view of a cam follower assembly in engagement with a fragmentary portion of a rotary cam member.
[0019] FIG. 4B is another pictorial view of the cam follower assembly in engagement with a fragmentary portion of a rotary cam member.
[0020] FIGS. 5A and 5B are pictorial views of the cam follower assembly and rotary cam member from different angles.
[0021] FIG. 6 is a pictorial view of another embodiment of the torque limiter incorporating a rotary cam member having an internal cam surface.
[0022] FIG. 7A is an end view of another embodiment of a rotary cam member having an axially varying cam profile.
[0023] FIG. 7B is a pictorial view of the axially varying cam member shown in FIG. 7A .
[0024] FIG. 7C is a fragmentary pictorial view of the components of a torque limiter incorporating a rotary cam member as shown in FIGS. 7A and 7B .
[0025] FIG. 7D is an end view of components of the torque limiter shown in FIG. 7C .
[0026] FIGS. 7E-1 and 7 E- 2 are two different sectional views through a torque limiter incorporating the components shown in FIGS. 7A-7D .
[0027] FIG. 8 is a pictorial view of an embodiment of torque limiter according to the invention incorporating an external rotary cam member and rocker arm followers with a particular rocker arm spring mounting arrangement.
[0028] FIG. 9A is an exploded pictorial view of components of a rocker arm cam follower incorporating an internal spring arrangement.
[0029] FIG. 9B is a pictorial view of the rocker arm assembly shown in FIG. 9A .
[0030] FIG. 9C is an end view of the rocker arm assembly shown in FIGS. 9A and 9B .
[0031] FIGS. 10A and 10B are fragmentary views in different positions of a torque limiter using the rocker arm assembly shown in FIGS. 9A-9C .
[0032] FIG. 11 is an end view of an embodiment of torque limiter according to the invention incorporating the internal rocker arm springs shown in FIGS. 9A-9C and 10 A and 10 B.
[0033] FIG. 12 is an enlarged sectional view of a rocker arm assembly incorporating a built in lubricating oil pump.
[0034] FIG. 13 is a sectional view through a rocker arm incorporating a built in centrifugal oil pump.
[0035] FIG. 14A , 14 B are partially sectional, partially diagrammatic views of a direct drive torque limiter according to the invention.
[0036] FIG. 15A and 15B are partially sectional, partially diagrammatic views of an indirect drive torque limiter according to the invention.
[0037] FIGS. 16A and 16B are diagrams of the force relationship between an external cam and follower cam roller in normal operation and release conditions.
[0038] FIG. 17 is a pictorial view of a preferred embodiment of an axially cammed torque limiter according to the invention.
[0039] FIG. 17A is a fragmentary pictorial sectional view of a variation of the torque limiter shown in FIG. 17 .
[0040] FIG. 18 is an enlarged view of a portion of FIG. 17A showing details thereof.
DETAILED DESCRIPTION
[0041] In the following detailed description, certain specific terminology will be employed for the sake of clarity and a particular embodiment described in accordance with the requirements of 35 USC 112, but it is to be understood that the same is not intended to be limiting and should not be so construed inasmuch as the invention is capable of taking many forms and variations within the scope of the appended claims.
[0042] A radially acting external cam torque limiter 10 is shown in FIG. 1 .
[0043] The automatically resetting torque limiter 10 includes two rotary members 12 , 14 . One member 12 is formed with a cam surface 16 , which extends circumferentially about the axis of rotation of the member 12 . The cam surface 16 in this embodiment undulates to form one or more peak undulations or cam lobes 16 A, the distance from the axis of rotation to points on the cam surface varying about the outer perimeter of the member 12 .
[0044] The other rotary member 14 mounts one or more cam follower assemblies 18 including rolling engagement elements comprising rollers 20 spring urged into engagement with the cam surface 16 with a radially inwardly directed force which increases as the rollers 20 move up a cam lobe 16 A. As long as the torque level transmitted between the members 12 , 14 is below a predetermined release torque, the spring force prevents the rollers 20 from completely ascending the peaks undulation or cam lobes 16 A since the spring force resisting movement of the rollers increases as the rollers 20 move up the cam lobe 16 A until the applied torque can no longer generate sufficient force to further displace the roller 20 .
[0045] A rotary driving connection is therefore maintained acting between the cam surface 16 and the rollers 20 , and is there is no relative rotation therebetween and the driving relationship between the cam surface 16 and followers 18 is maintained (except for a very minor relative motions due to drive torque variations). This is because the radially directed spring force will prevent movement of the rollers 20 all the way up the cam lobe 16 A, preventing relative rotation until the cam follower rollers 20 can rotate past the lobes 16 A on the cam surface 16 which occurs when the applied torque becomes sufficiently high to overcome the spring force.
[0046] The reaction force between the cam follower rollers 20 and the cam surface 16 produces a tangential component capable of generating a torque if the members do not rotate relative to each other. This relative rotation is prevented as long as the torque level generates a radial or axial component not sufficiently high to be able to move the cam follower elements 20 completely past the peak undulations or cam lobes 16 A. That is resisting spring the torque must be high enough to develop a force component able to overcome the urging force and force the cam follower to move a sufficient distance in a direction away from the cam surface to clear the cam lobes 16 A against the resistance of the urging spring force acting on the cam follower rollers in opposition to the torque generated component.
[0047] Once that torque level is exceeded, the cam follower rollers 20 will overcome the spring force and completely ascend and move past the respective peak undulations 16 A on cam surface 16 , and relative rotation between the members 12 , 14 continue as long as the applied torque remains at or above that level. If the torque level declines below that predetermined level, drive is automatically re-established between the members 12 , 14 as the follower rollers 20 can no longer completely ascend the cam surface peak undulations or lobes 16 A due to the resistant of the spring forces. The displacement of the cam followers 18 produced by the curve of the cam surface 16 produces smooth, continuous accelerations of the rollers 20 when ascending the undulations 16 A, which avoids shocks when the torque limiter 10 is running released or when resetting.
[0048] The moving parts may be submerged in an oil bath, the oil held outward by centrifugal force, and heat from churning the oil when the torque limiter 10 in a released state is thereby dissipated to air.
[0049] The cam follower assemblies 18 and cam surfaces 16 may be variously configured and mounted.
[0050] The cam surface shape can be varied to accommodate any number of cam follower assemblies as required to produce the required release torque level, with one lobe for each cam follower. The cam surface shape can also be varied to produce high torque attack, i.e., resistance to radial or axial movement of the cam followers 18 can be made to increase rapidly when ascending the lobes 16 A and a lower rate of torque decline when descending the cam lobes 16 A.
[0051] The cam surface 16 can be on the exterior perimeter of the rotary member 12 with the cam follower rollers 20 moving radially outwardly against inwardly directed spring forces to release as shown in FIG. 1 , or a cam surface 17 can be formed on an internal surface, with the cam follower rollers 20 spring urged to move radially outwardly as seen in FIG. 6 to engage the internal surface.
[0052] The cam surface can also be formed on an axial face of a cam member 12 A with the cam follower rollers 20 cammed to move axially as in the embodiments of FIGS. 7 A through 7 E- 2 described further below.
[0053] In the embodiment of FIGS. 1-5 , one rotary member 12 comprises a rotor having a peripherally extending external cam surface 16 as described above, and the cam followers 18 each include a roller 20 mounted on one end of a pair of rocker arms 22 pivotally mounted on the other rotary member 14 with pivot pin assemblies 29 .
[0054] The other rotary member 14 is formed in an annular shape which encloses the rotary member 12 . The other end of each of the pivoted rocker arms 22 mounts a cross pin 24 which acts to compress a pair of springs 26 disposed in spring seat cavities 27 formed in the member 14 . The rocker the arms 22 pivot up as the cam follower rollers 20 are moved radially outwardly in ascending the cam surface lobes 16 A but are unable to completely pass over the cam lobes 16 A until the transmitted torque exceeds a predetermined level.
[0055] FIG. 8 shows an alternate mounting for the rocker arm springs 26 A in which the springs 26 A extend generally tangentially to the axis of rotation of the member 14 , and are compressed by pivoting of the rocker arms 22 A pushing half round end pieces 28 together, with a stop feature 30 preventing the far end piece 28 from moving away so that compression of the springs 26 A occurs upon outward movement of the rollers 20 . Other spring configurations can also provide the resisting urging forces on the cam follower rollers 20 A, which establishes the transmitted torque.
[0056] Another cam follower configuration is shown in FIGS. 9A-9C and 10 A, 10 B. This configuration minimizes the space required. The springs 26 B force balls 32 along an axis parallel to the axis of pivoting of the rocker arm 22 B. The balls 32 are seated in conical stepped recesses 25 (specifically designed detents), which increasingly compress the springs 26 B as the balls 32 are moved up the recess stepped surfaces to be cammed out as the rocker arms 22 B are pivoted.
[0057] The rocker arms 22 B are pivoted by engagement of the cam follower rollers 20 B with the cam lobes 16 A formed on the member 12 . The rocker arms 22 B are pivotally mounted on the outer rotary member 14 B by pivot pin 29 B- 1 held with caps 29 B.
[0058] As seen in FIGS. 3A , 3 B and 3 C, various alternate mountings of the drive member 12 are shown. In FIG. 3A , an integral shaft can be keyed or splined to an input or output member. In FIG. 3B an integral tube 12 B can be keyed or splined to an input or output shaft. In FIG. 3C , threaded holes are formed in an integral shaft to allow attachment of a flange to connect a sheave, gear, etc.
[0059] In the embodiment of FIG. 6 , the annular outer rotary member 19 has a circumferentially undulating cam surface 17 on the inside of a cavity, and inner rotary member 15 carries cam followers comprised of sliders 21 having rollers 20 A rotatably mounted on the ends thereof, the sliders 21 movable radially in slots formed in the rotary member 15 and urged radially outwardly by springs 23 into engagement with the cam surface 17 .
[0060] In the embodiment of FIGS. 7 A through 7 E- 2 , the cam surface on a rotary member 38 has cam lobes 40 projecting in an axial direction ( FIGS. 7A , 7 B), although located spaced radially out from the axis of rotation in order to generate a torque. Tapered cam follower rollers 42 (FIGS. 7 C- 7 E- 1 ) are mounted on a spring ring 44 carried on another rotary member 48 . The tapered rollers 42 are mounted for rotation about radial axes defined by axle pins 46 , and are urged axially into engagement therewith by a set of springs 52 acting in an axial direction on the spring ring 44 . Guide rollers 50 are mounted on pins 53 projecting radially from the spring ring 44 .
[0061] The guide rollers 50 move in slots 54 ( FIG. 7E-2 ) in the other rotary member 48 so as to cause the spring ring 44 to rotate with rotary member 48 while freely allowing relative axial movement thereof necessary to axially displace the spring ring 44 by engagement of the rollers 42 with lobes 40 .
[0062] The driving and driven rotary members are held to be concentric with each other by frictionless bearings (usually ball bearings or tapered roller bearings if thrust forces are applied.) Bearings can be oil or grease lubricated. During the driving mode the entire bearing assembly rotates as a unit with no relative rotation between races so as to not require lubrication. For oil lubrication, the bearing mounting may provide dams which hold oil in the bearings against centrifugal forces.
[0063] As seen in FIGS. 12 and 13 , oil for the main bearings, in the center of the torque limiter 10 , is pumped from the oil annulus at the outer portion of the torque limiter assembly by small centrifugal pumps 58 mounted within bearings 59 on each end of the pins 60 for the rollers 20 A. The pumps 58 are built into the rocker arms 22 and are driven by the rotation of the rocker arm cam rollers 20 A which occurs only upon relative rotation. The cam follower roller 20 A rotates, driven by (or driving) the engagement with the cam surface 16 when the torque limiter 10 is overrunning in an overload condition. At this time the main bearings begin to function and may require lubrication. Each cam follower roller 20 A drives its attached pin 60 which in turn drives the pump rotors 62 . Oil is conveyed to the bearings 66 , 67 and other parts by internal drillings 64 .
[0064] If rotational speeds are high and the torque limiter is disengaged, the temperature of the oil will rise above ambient and may exceed the heat rejection rate of the torque limiter. Internal wireless sensors or external fixed sensors (not shown) may provide the high temperature signal.
[0065] For inline mounting, the torque limiter 10 may be mounted on the input or output shaft 70 A, 70 B of the drive as seen in FIGS. 14A-14C . A flexible coupling 72 is required to provide for shaft misalignment.
[0066] FIGS. 14A-14C also show a “drop out” mount, in which the torque limiter 10 can be slipped out after removal of bolts 73 as indicated. This eliminates the need to completely disassemble the drive line to remove or replace the torque limiter 10 .
[0067] For indirect drives, sheaves 74 , sprockets 76 or gears etc., can be mounted on the input or output members of the torque limiter as required. ( FIGS. 15A , 15 B)
[0068] FIGS. 16A and 16B diagram the forces generated in a driving condition transmitting low torque ( 16 A) and high torque ( 16 B). As torque is applied to the cam member the follower element begins to roll up the undulation increasingly compressing the spring through the rocker arm. The force of the spring (F S ) keeping the cam follower in constant contact with the cam surface (through the rocker arm) causes a reaction force (F N ) normal to the cam surface. A component of (F N ) acting perpendicular to a radial line to the point of contact is shown as (F T ). The magnitude of (F T ) multiplied by the radial distance to the point of contact is the torque transmitted by the follower. The magnitude of (F T ) increases as the follower rolls further up the cam undulation due to the increased spring compression combined with the increased pressure angle between (F N ) and the radial line to the point of contact. As the magnitude of (F T ) increases and the radial distance between (F T ) and the axis of rotation increases, the transmitted torque increases until it equals the input torque. When an over torque situation occurs and the cam follower rolls up and over the cam lobe 16 A, the torque transmitted drops until the follower encounters the next lobe 16 A on the cam in a continuous cycle.
[0069] Referring to FIG. 17 , a preferred form of the axially varying cam surface torque limiter 78 is shown.
[0070] An input flange 80 and input shaft 81 and output member 82 and output shaft 83 are drivingly connected by interengagement of a cam ring 84 formed with axial undulations 86 located radially outward from the axis of rotation of the assembly. The input flange 80 and cam follower carrier ring 88 have a splined connection 90 therebetween so that the output member 82 and carrier ring 88 can have relative axial movement while maintaining a rotary connection therebetween.
[0071] The carrier ring 88 mounts a plurality of cam follower rollers 92 mounted on radial axle pins 94 .
[0072] The rollers 92 are urged into axially undulating cam surface 86 by a series of compression springs 96 contained in pockets 98 in the carrier ring and an output member flange 100 .
[0073] A thrust bearing 102 absorbs the axial thrust generated by the springs 96 and follower rollers 92 .
[0074] FIG. 17A shows a variation 78 A of the axial torque limiter 78 which includes a series of axially extending pistons 104 mounted in individual pockets 118 in the cam follower member 106 . A cam follower tapered roller 108 pivoted on pins is disposed in a slot in the end of each of the pistons 104 and is urged to engage undulating surfaces 112 formed on a cam ring 108 fixed to the cam member 110 . Each piston is urged in an axial direction by a compression spring 116 also installed in each pocket 118 in the cam follower 106 and adjustably compressed with threaded plugs 120 received in the ends of pockets 118 . FIG. 18 shows that each roller 108 is of preferably of a tapered generally barrel shape although having partially spherically curved sides and cam surface 112 is correspondingly shaped. The rollers 108 are each mounted on a pin 119 installed after insertion of the roller 108 in the slot in the end of the respective piston 104 . This configuration minimize the axial length of the pistons and the torque limiter. A piston 104 for each undulation cam lobe balances the axial forces around the axis of the torque limiter 78 A.
[0075] The torque limiters are adjustable and provide variable release torque settings. This is accomplished by varying the number of cam followers or by adjusting the spring forces applied to the rocker arms or other cam follower element supports.
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A resettable torque limiter for installation between two rotary members, which can smoothly disengage upon application of a predetermined torque acting between the members and smoothly reset upon decline of applied torque below the predetermined level. An undulating cam surface formed on one member is engaged by one or more cam followers on the other member which smoothly ride over undulation peaks comprising cam lobes when the torque limit is exceeded and the driving connection between the rotary members is interrupted until the applied torque declines below the preset limit.
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RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 11/294,973, filed Dec. 6, 2005, now U.S. Pat. No. 8,070,745, which is a continuation of PCT Application Serial No. PCT/US2004/020117, filed Jun. 23, 2004, which claims priority to U.S. Provisional Application Ser. No. 60/483,015, filed Jun. 25, 2003.
FIELD OF THE INVENTION
This invention relates generally to medication infusion devices which include a chamber for storing fluid medication and means for extracting medication from the chamber for delivery to a patient's body site.
BACKGROUND OF THE INVENTION
Various types of implantable and/or external medication infusion devices are described in the literature. For example only, see U.S. Pat. Nos. 4,772,263 and 6,283,943 and the references cited therein which relate primarily to implantable devices. Many such devices employ a medication chamber together with a propellant reservoir which functions to isolate the chamber from changes in ambient pressure attributable, for example, to changes in altitude. More particularly, a typical propellant reservoir contains a biphasic propellant balanced between gas and liquid phases to maintain a constant pressure regardless of changes in reservoir volume. The pressure in the medication chamber is typically referenced (either positive or negative) to the constant reservoir pressure. Positive referenced devices have the advantage that the propellant can be selected to provide a constant driving pressure under defined operating conditions (e.g., constant flow applications) acting in a direction to force medication out of the chamber. Alternatively, negative referenced devices have inherent safety advantages; e.g., when refilling the chamber with a hypodermic needle, medication can be drawn into the chamber without the application of manual pressure to the needle. This assures that the needle will not discharge medication unless it has been properly placed in a device fill port and reduces the possibility of chamber overpressurization. Also, during normal operation, since chamber pressure is lower than ambient pressure, the pressure differential acts in a direction to draw fluid from the outlet catheter toward the chamber thus tending to reduce the risk of medication leakage into the patient's body.
Although the use of a propellant reservoir has the advantage of isolating the medication chamber from changes in ambient pressure, it nevertheless adds to device size, complexity, and cost. Accordingly, it has been recognized that, in some situations, it may be preferable to reference the medication chamber directly to ambient pressure. For example, U.S. Pat. No. 4,772,263 describes an infusion pump which includes a spring for producing a positive force on the drug chamber to force the solution therefrom.
SUMMARY OF THE INVENTION
The present invention is directed to a method and apparatus for infusing medication into a patient's body using a medication chamber referenced to ambient pressure (so as to avoid the need for, and attendant complexity of, a propellant reservoir) while achieving the safety and reliability of negative referenced propellant reservoir designs. Embodiments of the invention can be configured for use either exterior to a patient's body or implanted within a patient's body
An apparatus in accordance with the invention includes a medication chamber enclosed by a peripheral (or boundary) member which includes a movable portion configured to transfer exterior ambient pressure into the chamber. Means are provided in accordance with the invention for exerting a negative bias force acting on the movable portion in a direction opposed to the force produced by the ambient pressure. Thus, the resultant pressure in the chamber will always be negative with respect to ambient pressure, reducing the risk that the chamber can be overpressurized and produce an unintended medication discharge.
The peripheral member defining the chamber can be variously formed in accordance with the invention. For example, the peripheral member (or wall) can be comprised of one or more rigid and/or flexible wall portions which cooperate to fully enclose the chamber. At least one wall portion is movable and has an exterior surface exposed to ambient pressure.
In one preferred embodiment, the peripheral member is defined by a rigid wall portion and a flexible wall portion, e.g., a resilient membrane, secured around its edge to the rigid wall portion to enclose the chamber therebetween. The exterior surface of the flexible wall portion is exposed to ambient pressure and a negative bias force is applied to the flexible wall portion acting in opposition to the ambient pressure. The negative bias force can be provided by various types of force generators, e.g., a magnet, the inherent resiliency of a properly configured resilient membrane, or by a spring member (e.g., leaf, coil, bellows, elastomeric material, etc). In any event, the bias force acts to create a pressure in the chamber which is negative with reference to ambient.
In accordance with the invention, medication is extracted from the negatively biased chamber by a selectively actuatable outlet pump.
In one alternative preferred embodiment, the chamber peripheral wall member can be comprised of first and second rigid wall portions connected by a flexible wall portion, e.g., a flexible shroud or bellows, which permits the rigid wall portions to move toward and away from one another to vary the chamber volume therebetween.
In a still further preferred embodiment, the chamber peripheral wall can be formed by the interior wall surface of a hollow cylinder and by a piston mounted for reciprocal linear movement in the cylindrical volume.
Regardless of the particular implementation of the chamber peripheral wall, embodiments of the invention are characterized by a movable wall portion which is exposed to ambient pressure and a bias force acting in opposition to the ambient pressure to produce a resultant chamber pressure which is negative with respect to the ambient pressure. The chamber peripheral wall, including the moveable wall portion, preferably has a geometry which optimizes volumetric efficiency, i.e., maximizes the useable volume and minimizes dead space volume or ullage. The bias force can be produced by a variety of force members including, for example, discrete springs of various types, elastomeric material, magnets, etc.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a schematic plan view of a preferred medication infusion device in accordance with the invention;
FIG. 2 is a schematic sectional view through the device of FIG. 1 showing the movable portion (e.g., resilient membrane) of the chamber peripheral (or boundary) wall in a fully extended (i.e., chamber full) position;
FIG. 3 is a schematic representation of the movable chamber wall portion depicting the application of ambient and bias forces to the wall portion in accordance with the invention;
FIGS. 4A and 4B schematically depict an alternative embodiment of the invention using a spring to provide the bias and respectively showing the movable wall portion in its compressed and extended positions;
FIG. 5 is a schematic illustration of a further alternative embodiment of the invention using a bellows or exterior spring to provide the bias force;
FIG. 6 is a schematic illustration of a still further alternative embodiment using magnetic repulsion to provide the bias force; and
FIG. 7 is a schematic illustration of a still further embodiment using a hollow cylinder and a movable piston to define the chamber.
DETAILED DESCRIPTION
Attention is now directed to FIGS. 1 and 2 which illustrate a preferred embodiment of a medication device 20 in accordance with the present invention for controllably delivering medication to a patients body site. Although the particular device 20 illustrated in FIGS. 1 and 2 is intended for implanting in a patient's body, it should be understood that the invention also finds utility in applications where the device is carried externally.
As depicted in FIGS. 1 and 2 , the device 20 is comprised of a housing 24 including a base plate 26 and a cover 28 supported on the base plate 26 . The base plate 26 and cover 28 define one or more compartments therebetween, e.g., compartments 30 , 34 , 38 for housing various components such as battery 32 , an electronics module 36 , and an active medication pump 40 .
FIG. 2 depicts a flexible and resilient membrane 44 secured along its edge 46 to the underside of the base plate 26 . As will be explained in greater detail hereinafter, the membrane 44 is configured to naturally expand to the fully extended position shown in FIG. 2 to maximize the space, i.e., volume, of the closed medication chamber 50 formed between the membrane 44 and base plate surface 47 . When the content of chamber 50 is evacuated, the ambient pressure acting against the membrane 44 will collapse it against base plate surface 47 .
An inlet valve 54 is supported by the cover 28 and base plate 26 and affords communication to the interior of chamber 50 . The inlet valve 54 can be conventionally constructed comprising a self healing septum 56 through which a hypodermic needle can be inserted to discharge medication into the chamber 50 . As will be discussed hereinafter, inasmuch as the medication chamber 50 , in accordance with the present invention, is maintained at a negative pressure relative to ambient pressure, the hypodermic needle, when properly inserted through septum 56 , is able to discharge medication into the chamber 50 without the application of manual pressure to the hypodermic needle.
The active pump 40 has an inlet 60 which communicates with the chamber 50 for extracting medication therefrom. The pump 40 is coupled to a catheter outlet connector 62 through which medication is pumped for distribution to a body site.
In accordance with the present invention, the membrane 44 comprises a movable portion of a peripheral member or wall which defines and encloses the medication chamber 50 . The exterior surface 68 of the membrane 44 is configured to be exposed to ambient pressure, i.e., that is the internal body pressure when the implantable device 20 is in situ. Typically, this ambient pressure will be very close to atmospheric pressure, which of course is dependent upon altitude, temperature, etc. The ambient pressure acts in a direction tending to compress the membrane 44 against the base plate 26 . More particularly, when the chamber 50 is filled with medication, the membrane 44 will expand to its natural fully extended position shown in FIG. 2 . However, when the medication is evacuated by action of pump 40 , then the ambient pressure acts to collapse the membrane 44 toward the base plate surface 47 .
In accordance with the present invention, a spring bias force is applied to the chamber movable wall portion, i.e., membrane 44 in FIG. 2 , which acts in a direction to oppose the ambient pressure force so as to create a residual pressure in the chamber which is negative with reference to ambient.
More particularly, with reference to FIG. 3 , note that the ambient pressure P A acting on the exterior surface 68 of movable wall portion 44 produces a force F A tending to move the wall portion 44 toward the base plate 26 , i.e., to collapse the chamber 50 . In accordance with the present invention, a bias force F B is created which acts in opposition to the force F A . As shown, the chamber pressure P C will be negative with respect to the ambient pressure P A attributable to the negative bias force F B .
The force F B can be provided in a variety of different ways. For example, the membrane 44 of FIG. 2 can comprise a part formed of metal or plastic material (e.g., nitinol, titanium, stainless steel, super alloys, composite material) configured so that in its natural or quiescent state it resiliently expands to the extended position represented in FIGS. 2 and 3 . Thus, as the ambient pressure bears against, the movable wall portion of membrane 44 tending to move it toward its compressed position, it will develop a restoration force F B acting to oppose the compression. As an alternative to configuring wall portion 44 to inherently exhibit the desired resilient characteristic, a separate force generator, e.g., a spring, a magnet, a frictional member, etc. can be incorporated into the device structure.
Attention is now directed to FIG. 4A which depicts an alternative embodiment 100 . The embodiment 100 includes a base plate 102 and cover 104 which can be considered identical to the corresponding components 26 and 28 discussed in connection with FIG. 2 . The plate 102 defines a substantially rigid portion of a peripheral wall extending around and enclosing a medication chamber 106 . The chamber peripheral wall, in accordance with the present invention, also includes a movable portion which in embodiment 100 comprises a flexible boot or shroud 108 . The boot 108 carries a rigid wall portion 110 which is spaced from and oriented substantially parallel to plate 102 . Thus, the chamber 106 in embodiment 100 is defined by the inner surfaces of wall portions 102 and 110 and flexible wall portion or boot 108 .
In the embodiment 100 , a force generator, or member, comprises a coil spring 120 mounted between the inner surfaces of wall portions 102 and 110 . The spring member 120 is shown as a coil spring which is configured so that in its natural or quiescent state, e.g., in a vacuum, it is extended to the position shown in FIG. 4B . Ambient pressure acting on the outer surface of movable portion 110 acts in the direction to compress spring member 120 with the spring member thus providing a restoration or bias force acting in opposition to the force of the ambient pressure. Thus, the pressure within the chamber 106 will be maintained below the ambient pressure as a consequence of the force produced by spring 120 as was discussed in connection with FIG. 3 . Typically, this spring force is selected to produce a chamber pressure which is negative with respect to ambient pressure by a differential within the range 0.1 to 5.0 psig.
FIG. 5 depicts a further alternative embodiment 200 in which the inner surfaces of a base plate 202 , a movable rigid portion 204 , and a flexible shroud or bellows 206 define and enclose a medication chamber 208 . A coil spring 210 is depicted as being formed around the exterior of the shroud 206 . The shroud 206 and coil spring 210 be formed separately or alternatively can be formed as an integral bellows member.
The embodiment of FIG. 5 operates identically to the embodiment of FIGS. 4A and 4B in that the spring 210 produces a bias force opposing the force of the ambient pressure bearing on wall portion 204 . As medication is drawn from the chamber 208 by action of the active pump, the ambient pressure will displace wall portion 204 toward support plate 202 acting against the bias force provided by spring 210 .
FIG. 6 illustrates an embodiment 300 which is similar in construction to the embodiment 200 in FIG. 5 . However, in lieu of using a spring member to provide the negative bias force, the embodiment 300 uses magnetic repulsion to develop the negative bias force. More particularly, note in FIG. 6 that adjacent magnets 302 and 304 are similarly poled. Also note that adjacent magnets 306 and 308 are similarly poled. Thus, as the force produced by ambient pressure on the exterior surface of wall portion 310 acts to displace wall portion 310 toward base plate 312 , the repulsion force produced by the magnets will increase in opposition to the ambient force. Of course, as has been discussed in connection with the earlier embodiments, this negative bias force will produce a chamber pressure which is negative with respect to the ambient pressure.
FIG. 7 depicts a still further embodiment 400 . In the embodiment of FIG. 7 , a hollow cylinder 402 is provided defining an interior wall surface 404 . A piston 408 is mounted for reciprocal linear motion within the cylindrical volume defined by the interior wall surface 404 . The piston 408 interior surface 409 , together with wall surface 404 , defines a medication chamber 410 . An inlet valve 412 opens to the medication chamber and an outlet 414 couples the chamber 410 to an actuatable pump 416 . A force generator, e.g., spring member 418 , is shown mounted in the chamber 410 bearing against piston interior surface 409 . The piston outer surface 420 is exposed to ambient pressure.
FIG. 7 depicts spring 418 in its expanded state with the chamber 410 filled with medication supplied via inlet valve 412 . As medication is extracted from the chamber 410 by action of the pump 416 , ambient pressure acting on the piston outer surface 420 will act to move the piston 408 along the interior wall surface 404 to compress spring 418 and diminish the volume of chamber 410 . This action will be opposed by the restoration force of spring member 418 thus producing a pressure in chamber 410 which is negative with respect to the ambient pressure applied to the piston surface 420 .
From the foregoing, it should now be appreciated that multiple exemplary embodiments have been described herein characterized by a chamber peripheral wall portion which is exposed to ambient pressure together with means for producing a bias force acting in opposition to the ambient pressure to produce a pressure within the chamber which is negative with respect to the ambient pressure. Although only a limited number of embodiments have been specifically described, it should be recognized by those skilled in the art that the invention can be implemented by a variety of alternative, essentially equivalent, structures conforming to the spirit of the invention and within the intended scope of the appended claims.
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A method and apparatus for infusing medication into a patient's body using a medication chamber referenced to ambient pressure. The apparatus includes a medication chamber enclosed by a peripheral wall which includes a movable portion configured to transfer exterior ambient pressure into the chamber. Means are provided for exerting a negative bias force acting on the movable portion in a direction opposed to the ambient pressure force. Thus, the resultant pressure in the chamber will be negative with respect to ambient pressure, reducing the risk that the chamber can be overpressurized and produce an unintended medication discharge.
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1. CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of the filing date of U.S. provisional patent application No. 60/414,528, filed Jul. 12, 2002, and entitled “Radiolucent Frame Element For External Long Bone Fixators,” the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 2. Field of the Invention
[0003] The present invention relates generally to an external fixation apparatus for use in osteosynthesis and osteoplasty, particularly involving diaphyseal bone. More specifically, the present invention relates to a radiolucent component for an external fixation apparatus.
[0004] 3. Background of the Invention
[0005] External fixation of bone is a well-known means of treating bone trauma and correcting deformities. Various fixation devices, or fixators, are used to support and align bone fragments in a relatively fixed relationship during regeneration or deformity correction. Such devices include the Sheffield fixator, manufactured by Orthofix, Srl, of Italy, the Ilizarov Fixator described in U.S. Pat. Nos. 4,615,338 and 4,978,347, and the fixator described in U.S. Pat. No. 4,450,834 to Fischer, each of which may utilize annular or arcuate frame segments interconnected by adjustable rods, and established around a bone by means of transfixing and non-transfixing wires and pins.
[0006] Typically, an annular, or, alternatively, an arcuate frame segment is established around either metaphyseal or diaphyseal bone by multiple transfixing wires to provide variable elastic support to the bone during loading. A second such frame is established around diaphyseal bone by either another set of transfixing wires or by non-transfixing pins. The frames are typically connected to each other threaded rods that may be adjusted so as to urge the frames either toward or away from each other into a desired relationship.
[0007] External fixation devices may be used to stabilize a bone fracture to permit bone regeneration. For this purpose, wires or screws are affixed to various bone fragments, and are further mounted to annular or arcuate frames and adjusted so as to place the bone segments in desired alignment.
[0008] Another use for external fixation devices is for distraction of diaphyseal bone for such purposes as increasing its length. It is known that bone has piezo-electric properties; that is, stresses to bone cause small electrical charges that promote bone growth. Accordingly, diaphyseal bone may be circumferentially scored and annular frames established around the bone on each side of the score by screws or wires or both. Rods connecting the frame elements are adjusted so as to provide tensile stress along the long axis of the bone. Piezo-electric stimulation of bone growth at the score site causes lengthening of the bone over a period of time.
[0009] During both installation and use of the fixator, the placement of pins and wires and the progress of bone regeneration are typically revealed by x-radiographs. Known fixator devices, however, do not include radiolucent (x-ray transparent) components. The non-radiolucent components of known fixator devices, such as the annular or arcuate frame segments, pins, wires, and connecting rods, hinder a proper view of the bone, and require that the bone be viewed from multiple and inconvenient angles. Thus, assessing pin and wire placement, as well as bone alignment and regeneration, is unnecessarily complicated by obstructing fixator components.
SUMMARY OF THE INVENTION
[0010] It is an object of the present invention to provide an annular or arcuate fixator frame comprised of radiolucent body materials.
[0011] It is another object of the present invention to provide an annular or arcuate fixator frame comprised of radiolucent, autoclavable polycarbonate.
[0012] It is a further object of the present invention to provide an annular or arcuate fixator frame embedding stiffening rings comprised of radiolucent beryllium.
[0013] It is yet another object of the present invention to provide an annular or arcuate fixator frame that is both light weight and rigid.
[0014] Another object of the present invention is to provide an annular fixator or arcuate frame that is chemically inert with respect to the human body and commonly-encountered household substances, e.g., mild acids, alcohols and bases, such as common cleansers, hygienic and medical products, and food substances.
[0015] It is a further object of the present invention to provide an annular or arcuate fixator frame sufficiently versatile that it may be interchanged with non-radiolucent annular frames of common external fixation devices, such as those various fixators disclosed in, for example, U.S. Pat. Nos. 4,615,338, 4,450,834, 4,006,740, 4,365,624, 4,978,347 and 5,067,954.
[0016] An additional object of the present invention is to provide an annular or arcuate fixator frame to which a variety of wire- and pin-securing devices may be attached.
[0017] These and other objects and advantages will become apparent from a consideration of the accompanying drawings and ensuing description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] [0018]FIG. 1 is a plan view of an annular frame of the invention having multiple apertures.
[0019] [0019]FIG. 2 is a detailed cross-sectional elevation of an annular frame of the invention, shown in FIG. 1, having embedded stiffening rings.
[0020] [0020]FIG. 3 is a cross-sectional plan view of an annular frame of the invention depicting the relative position of each stiffening ring.
[0021] [0021]FIG. 4 is a perspective view generally depicting a typical installed fixator device having radiolucent annular frame components.
[0022] [0022]FIG. 5 is a plan view of an arcuate frame of the invention having multiple apertures.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] An apparatus for external bone fixation commonly includes an annular, or ring-shaped, frame 1 upon which known fixator components such as connector rods 6 , pin clamps (not shown), wires 7 , wire-tensioning carriages 8 and other such hardware may be mounted. This annular frame 1 will now be described in greater detail with reference to FIGS. 1 - 4 . Those skilled in the art will appreciate that the frame 1 may be arcuate, or arc-shaped, rather than annular, as shown in FIG. 5.
[0024] As may be seen in FIG. 1, the fixator frame 1 of one embodiment is annular, or ring-shaped, and has a generally constant thickness “t”. Preferably, the body of the frame 1 is comprised of radiolucent, autoclavable polycarbonate. Of course, those skilled in the art will recognize that the body of the frame 1 may be comprised of other types of radiolucent material, such as carbon fiber. A plurality of apertures 2 through the frame are preferably provided for rapid mounting of connector rods 6 , wires 7 and wire-tensioning carriages 8 , as in FIG. 4.
[0025] A cross-sectional view of the frame 1 , as in FIG. 2, discloses a smaller stiffening ring 3 and a larger stiffening ring 4 embedded in the frame 1 annulus for the purpose of providing rigidity and durability to the frame 1 . Preferably, stiffening rings 3 & 4 are comprised of radiolucent metal, such as beryllium. The diameters of the smaller ring 3 are greater than the inner diameter of the frame 1 annulus, and the diameters of the larger ring 4 are less than the outer diameter of the frame 1 annulus. Each aperture 2 , as more clearly seen in FIG. 1, is situated within the area 5 defined by the smaller ring 3 and larger ring 4 .
[0026] An orthogonal cross-sectional view of the frame 1 , as in FIG. 3, further discloses the relative disposition of each stiffening ring 3 & 4 within the annular frame 1 , as well as the relative situation of each aperture 2 with respect to the stiffening rings 3 & 4 and annular frame 1 . Each stiffening ring 3 & 4 preferably forms an unbroken circle. However, those of skill in the art will appreciate that stiffening rings 3 & 4 may be arcuate.
[0027] The dimensions of the annular frame 1 may be varied so as to accommodate the physiology of the long bones to be treated, as well as the soft tissue surrounding those bones.
Use of the Preferred Embodiment
[0028] Initially, an annular frame size is selected according to the anatomical portion upon which it will be installed, and should provide approximately 0.5-0.75 in. clearance between frame and limb. By way of illustration, as in FIG. 4, installation of the fixator upon the tibia 9 by transfixing wire 7 is described. More particularly, use of the fixator to lengthen the tibia 9 is generally described.
[0029] In most instances, two annular frames will be connected by at least three adjustable rods 6 disposed through apertures of each frame 1 such that a system of rigid alignment of one frame 1 with respect the other along a central axis (tibia 9 ) is achieved.
[0030] In the case of bone extension, the tibia 9 is circumferentially scored 10 to advantageously utilize the piezoelectric properties of bone. The tibia 9 is centered within the annular frame system such that one annular frame 1 is located on each side of the score 10 . In the each of the regions encircled by a frame 1 , two to four wires 7 transfix the bone in a manner that avoids tendons or neurovascular elements. Each wire 7 is tensioned and each wire end is secured to a wire carriage 8 attached to the frame.
[0031] Upon installation of the fixator, distraction force is introduced by adjusting the connector rods 6 to increase the distance between the annular frames 1 . This pressure causes electrical charges to be generated at the score 10 site, thus focusing bone growth in that region. Over time, as the annular frames are continuously urged away from each other, the bone lengthens.
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An annular or arcuate frame element made of entirely of substantially radiolucent body material is provided for an external fixation device for bones. In particular, an annular or arcuate frame of substantially radiolucent body material embeds two beryllium rings. Such frames may be interchanged with the non-radiolucent annular or arcuate frames of various external fixators.
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TECHNICAL FIELD
Aspects of this document relate to the field of irrigation tools, and more particularly, to tools for installing irrigation emitter barbs.
BACKGROUND
Many conventional irrigation systems use plastic tubing to distribute water to various locations. In such use, hollow irrigation emitter barbs are mounted as desired. Small diameter flexible tubing can be mounted on the barbs to place the water where desired.
Irrigation emitter barbs or emitters are generally symmetrical and are provided with sharp piercing points at either end to penetrate the wall of the tubing. Further, enlarged heads are provided to impede the withdrawal of the barb from the tubing. While irrigation emitter barbs can be installed by hand, the sharp piercing points pose a risk of injury to workers.
SUMMARY
Embodiments of irrigation tools like those disclosed in this document may include a punch handle and a cradle handle where each of the punch handle and cradle handle has a cylindrical shape. The punch handle may be slidably and telescopically received within the cradle handle. The cradle handle may have a cylinder receiving cavity at one end into which the punch handle extends and a crescent jaw having a seat adapted to support irrigation tubing at the other end. The crescent jaw may be mounted on the cradle handle opposite the punch handle. The punch handle may have a cylindrical cavity positioned proximate to the cradle handle where the cylindrical cavity has a closed threaded punch end and an open end adjacent to the cradle handle. A punch pin may extend into the cylindrical cavity and may thereby partially occlude the open end. The punch pin may have a first position extending into the crescent jaw when the punch handle is fully slidably received within the cradle handle. The punch pin may have a second position which does not extend into the crescent jaw when the punch handle is not received fully within the cradle handle. The punch pin may be biased to the second position whereby irrigation tubing held within the crescent jaw is punctured when the punch pin is moved from the second position to the first position.
At least one barb holder may be mounted on the punch handle and the at least one barb holder may include a lower cavity, a middle cavity, and an upper cavity concentrically oriented and cylindrically shaped with the upper cavity being of smaller diameter than the middle cavity thereby forming an upper shoulder therebetween. The middle cavity may be a smaller diameter than the lower cavity thereby forming a lower shoulder therebetween. A plurality of resilient flaps may extend inwardly from the periphery of the lower cavity. The upper shoulder within the hollow cylinder may be suitable for acting against an annular disk shoulder on a barb emitter to force a piercing point on the barb emitter to penetrate a periphery of an irrigation tubing when forced thereupon. The plurality of flaps may releasably hold the barb emitter within the barb holder. A barb remover including a lower crescent gap and an upper crescent gap positioned at the distal ends of the crescent jaw may be included where the crescent gaps may be in parallel alignment. The crescent gaps may be adapted to engage shoulder disks of emitter barbs to pry the emitter barbs from irrigation tubing.
The foregoing and other aspects, features, and advantages will be apparent to those artisans of ordinary skill in the art from the DESCRIPTION and DRAWINGS, and from the CLAIMS.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments may be more readily described by reference to the accompanying drawings in which:
FIG. 1 is a front, side and top perspective view of one embodiment;
FIG. 2 is a rear, side and top perspective view of the embodiment of FIG. 1 ;
FIG. 3 is a rear, side and top perspective view of the embodiment of FIG. 1 in a closed position;
FIG. 4 is a side view of separated items of FIG. 3 ;
FIG. 5 is a front view of FIG. 1 ;
FIG. 6 is a back view of FIG. 1 with irrigation emitter barb installed therein;
FIG. 7 is a rear view of FIG. 1 ;
FIG. 8 is a top view of FIG. 1 ;
FIG. 9 is a side view of irrigation emitter barb;
FIG. 10 is a top view of FIG. 1 with irrigation emitter barbs installed therein; and
FIG. 11 is a side cross sectional view of FIG. 1 .
DESCRIPTION
Referring more particularly to the drawings by characters of reference, FIGS. 1-11 disclose one embodiment of an irrigation tool 10 . Irrigation tool 10 comprises a punch handle 12 and a cradle handle 14 , both the punch handle 12 and the cradle handle 14 having concentric cylindrical shape. Punch handle 12 and cradle handle 14 are arranged in parallel relation and connected intermediate their ends at roll pin 16 . In the illustrated embodiment, cradle handle 14 has a cylinder receiving cavity 13 at end of handle through which punch handle 12 extends into.
Cradle handle 14 includes circular finger holds 52 and 56 extending perpendicular thereto and laterally therefrom. In addition, punch handle 12 includes a circular palm push 58 mounted opposite cradle handle 14 .
Mounted on cradle handle 14 opposite punch handle 12 is a crescent jaw 22 adapted to receive and support a conduit or pipe 68 to be punched. Crescent 22 is formed of a generally channel-shaped configuration thereby defining a semi-circular seat 72 for supporting conduit or pipe 68 to be punched. As best seen in FIG. 3 , a user drives a punch pin 42 into conduit or pipe 68 by applying downward pressure on punch handle 12 with the user's palm pushing downward on push handle 58 while using finger holds 52 and/or 56 of cradle handle 14 to maintain a hold on tool 10 .
As shown in FIGS. 4 and 11 , punch pin 42 is mounted at the end of punch handle 12 opposite palm push 58 . That end includes a hollow first cylindrical cavity 44 having a closed threaded punch end 46 at the upper end of cylinder 44 . At the open, lower end of cylinder 44 , punch pin 42 extends inwardly therefrom to partially occlude the lower, open end of cylinder 44 .
Cylinder receiving cavity 13 in cradle handle 14 telescopically receives punch handle 12 . Cylinder receiving cavity 13 includes a hollow cylinder 49 at the lower end of cylinder receiving cavity 13 to sizably engage the exterior section of first cylindrical cavity 44 . Punch handle 12 in combination with a slit 48 in punch handle 12 and roll pin 45 mounted on cradle handle 14 prevents complete separation of punch handle 12 and cradle handle 14 .
Punch handle 12 has a punch holder body 36 extending downward therefrom. A spring 51 is wrapped concentrically around punch holder body 36 which rests against shoulder 34 of punch holder 12 and against shoulder 56 of cradle handle 14 . Spring 51 resiliently urges punch handle 12 away from cradle handle 14 , thereby keeping second hollow cylinder 44 at a maximum extension from cylinder 49 in cradle handle 14 . Punch pin 42 having a sharp tip 59 extends downwardly from punch holder 36 to extend through a second cylinder 49 in cradle handle 14 to a point beyond first hollow cylinder 56 but within crescent 22 when spring 51 is at its full permitted compression. In the maximum extension configuration, sharp tip 59 of punch pin 42 is completely contained within hollow cylinder 49 .
To use, conduit or pipe 68 is placed into crescent 22 and punch pin 42 is placed into hollow cylinder 44 . Punch pin 42 is positioned on top of conduit or pipe 68 . A user employs finger holds 52 or 56 of crescent handle 14 and palm push 58 of punch handle 12 to squeeze handles 12 and 14 together thereby pushing punch pin 42 downwardly. Punch pin 42 of second hollow cylinder 44 first engages the periphery of irrigation tubing 68 . As handles 12 and 14 are squeezed together it forces cylinder 44 to retract downwardly with spring 51 compressing. Sharp point 58 of punch pin 42 then extends beyond second hollow cylinder 49 and engages the periphery of irrigation tubing 68 and with additional force, punches a hole therethrough.
After a hole is punched, punch pin 42 is withdrawn. As punch 42 moves away, crescent 22 secures the periphery of irrigation tubing 68 and prevents movement of said tubing. Spring 51 forces punch pin 42 of second hollow cylinder 44 upward whereby punch pin 42 is forced from said periphery of irrigation tubing 68 . In various embodiments, the forced release of punch pin 42 from irrigation tubing 68 may prevent said sharp point 58 from hanging up on said tubing.
Mounted on punch handle 12 is a barb holder 30 . Barb holder 30 is positioned on the top end of punch handle 12 centered on palm push 58 oriented opposite to cradle handle 14 .
As best seen in FIG. 11 , in particular embodiments, barb holder 30 can be threaded into punch handle 12 which comprises a lower cavity 32 , a middle cavity 33 and an upper cavity 34 concentrically oriented with respect to one another. All cavities 32 , 33 , and 34 are cylindrically shaped with upper cavity 34 being of larger diameter and threaded than middle cavity 33 which, in turn is of larger diameter than lower cavity 32 thus forming shoulders 35 and 37 therebetween. Extending inwardly in upper cavity 34 is a threaded barb holder 30 with flaps 35 . In the illustrated embodiment of FIG. 8 , five flaps 35 are symmetrically orientated about the periphery of inner ring 31 . Each flap 35 is preferably, a resilient rubber or plastic material. Outer ring 30 has male threads for installation into upper cavity 34 . Those skilled in the art will recognize that the five flaps used herein are exemplary in nature and that other flaps and flap types may be utilized in other embodiments.
An emitter barb 38 shown in embodiment FIG. 9 generally comprises a hollow cylinder 40 having two enlarged heads 39 having a larger diameter than cylinder 40 at either end thereof. Each enlarged head 39 includes a sharp piercing point 4 which allows barbs 38 to pierce the periphery of irrigation tubing 68 . Once enlarged head 39 extends completely into irrigation tubing 68 its larger diameter impedes its withdrawal from irrigation tubing 68 .
Further, emitter barb 38 includes an annular shoulder disk 43 . Shoulder disk 43 in cooperation with enlarged heads 39 hold the wall of irrigation tubing 68 therebetween when emitter barb 38 is properly inserted therein. As is well known in the art, emitter barb 38 may vary in configuration and both emitter barb 38 and irrigation tubing 68 are manufactured of plastics.
Cooperatively upper cavity 34 is sized and threaded to reasonably engage threaded barb holder 30 . Emitter barb 38 can be pushed thru flaps 35 of barb holder into lower cavity 32 of punch handle 12 which is large enough to accommodate shoulder disk 43 . To use, enlarged head 39 of emitter barb 38 is inserted into and engaged by upper cavity 34 and barb holder 30 while shoulder disk 43 engages shoulder 35 of barb holder 30 . When fully inserted, the second shoulder disk 43 of barb emitter 38 is engaged by flaps 35 which act to reasonably retain barb emitter 38 therewithin. In various embodiments, this aspect may allow insertion and retention of emitter barb 38 within barb holder 30 before insertion into irrigation tubing.
Irrigation tubing 68 is laid on the ground or held while a user grasps tool 10 to push barb 38 which is placed into barb holder 30 into punched hole in irrigation tubing 68 , and with additional force, is inserted therethrough. Shoulder 35 in cooperation with barb holder 30 forces piercing point 41 through the periphery of irrigation tubing 68 while lower shoulder disk 43 prevents insertion beyond the appropriate point. The periphery of the irrigation tubing 68 is thereby captured between enlarged head 39 and lower shoulder disk 43 .
After insertion, barb holder 30 of tool 10 is withdrawn. As barb holder 30 moves away, flaps 35 release shoulder disks 43 as upper enlarged head 39 releases from upper cavity 34 and barb emitter 38 is left properly inserted within irrigation tubing 68 . As seen, the resiliency of flaps 35 holding shoulders 43 therein may be less than the force required to withdraw lower enlarged head from irrigation tubing 68 in particular embodiments.
As best seen in FIGS. 1-11 , in various embodiments, barb remover includes a lower crescent gap 24 and an upper crescent gap 27 positioned at the distal ends of main body crescent 22 . Crescents 24 and 27 are positioned on the front of crescent 22 and in parallel alignment with one another centered on tool 10 .
To use, main body 40 of emitter barb 38 is inserted into either crescent gap 24 and 27 with shoulder disk 43 of barb 38 placed on the outside thereof. While rotating tool 10 in a backwardly motion, barb emitter 38 is pried out of irrigation tubing 68 . This aspect of particular embodiments may allow removal of emitter barb 38 from said tubing 68 .
In places where the description above refers to particular embodiments of irrigation tools, it should be readily apparent that a number of modifications may be made without departing from the spirit thereof and that these embodiments may be applied to other irrigation tool embodiments.
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A tool for installing irrigation barb emitters into irrigation tubing including a cradle handle and a punch handle, the cradle handle and the punch handle being arranged in a parallel relation and connected intermediate their ends at a center point. A cradle which receives irrigation tubing is included. A punch pin allows a user to punch holes in irrigation tubing as desired with a spring loaded body which removes the punch pin when it has been driven into irrigation tubing. A barb holder allows a user to install emitter barbs into irrigation tubing as desired. A barb remover allows removal of barbs from irrigation tubing as desired.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 14/253,546, entitled “METHOD AND APPARATUS FOR ECONOMIZING POWER CONSUMPTION IN WIRELESS PRODUCTS” (Attorney Docket No. 110729-8037.US01) filed Apr. 15, 2014, which is entitled to the benefit of and claims priority to U.S. Provisional Patent Application No. 61/928,960, entitled “METHOD AND APPARATUS FOR ECONOMIZING POWER CONSUMPTION IN WIRELESS PRODUCTS” (Attorney Docket No. 110729-8037.US00) filed Jan. 17, 2014, the contents of each which are incorporated herein by reference in their entirety for all purposes.
FIELD
[0002] Various of the disclosed embodiments concern power and/or operational efficiency in wireless devices.
BACKGROUND
[0003] As the demand for wireless connectivity increases additional regulations and constraints are being imposed upon wireless devices across a wider geographic and market spectrum. Many of these wireless devices provide only one or a few possible configurations. Accordingly, these devices cannot operate efficiently in all the existing operation environments, let alone adapt when the regulations are changed or user preferences modified. Thus, there exists a need for efficient, easily configured, and possibly automated systems to adjust wireless device configurations to particular environments and regulations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] One or more embodiments of the present disclosure are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements.
[0005] FIG. 1 is a table depicting transmission power regulation information for various jurisdictions as may apply in certain of the disclosed embodiments.
[0006] FIG. 2 is a table depicting transmission power regulation information for various jurisdictions as may apply in certain of the disclosed embodiments.
[0007] FIG. 3 is a system-level block diagram of an example system configured for one or more stimuli as may be implemented in some embodiments.
[0008] FIG. 4 is a system-level block diagram of various components as may be implemented in some embodiments.
[0009] FIG. 5 is a plot of current, voltage, and power consumption relations in 802.11b/g/n modes as may be associated with some embodiments.
[0010] FIG. 6 is a plot of current, voltage, and power consumption relations in 802.11a/n/ac modes may be associated with some embodiments.
[0011] FIG. 7 is a flow diagram depicting various transmitter/receiver power consumption control operations as may be implemented in some embodiments.
[0012] FIG. 8 is a flow diagram depicting various power consumption control operations using profiles as may be implemented in some embodiments.
[0013] FIG. 9 is a flow diagram depicting various power consumption control operations as may be implemented in some embodiments.
[0014] FIG. 10 is a table depicting various current and power levels for various channels as may be associated with some embodiments.
[0015] FIG. 11 is a table depicting various current and power levels for various channels as may be associated in some embodiments.
[0016] FIG. 12 is a plot of the DC power consumption for various channels in 802.11g mode as may be associated with some embodiments.
[0017] FIG. 13 is a plot of the DC power consumption for various channels in 802.11n mode as may be associated with some embodiments.
[0018] FIG. 14 is a bar plot depicting various power consumption levels for various channels as may be associated with some embodiments.
[0019] FIG. 15 is a plot of the DC power consumption for various channels as may be associated with some embodiments.
[0020] FIG. 16 shows a diagrammatic representation of a machine in the example form of a computer system within which a set of instructions for causing the machine to perform one or more of the methodologies discussed herein may be executed.
[0021] Those skilled in the art will appreciate that the logic and process steps illustrated in the various flow diagrams discussed below may be altered in a variety of ways. For example, the order of the logic may be rearranged, substeps may be performed in parallel, illustrated logic may be omitted, other logic may be included, etc. One will recognize that certain steps may be consolidated into a single step and that actions represented by a single step may be alternatively represented as a collection of substeps. The figures are designed to make the disclosed concepts more comprehensible to a human reader. Those skilled in the art will appreciate that actual data structures used to store this information may differ from the figures and/or tables shown, in that they, for example, may be organized in a different manner; may contain more or less information than shown; may be compressed, scrambled and/or encrypted; etc. One will recognize that various of the operations performed at a device may be performed at any point in its operation (e.g., at boot, following initialization, during steady-state operations, etc.).
DETAILED DESCRIPTION
[0022] Various embodiments of the present disclosure include systems and methods for improving efficiency of wireless systems. For example, a wireless WLAN device may adjust the bias point of one or more amplifiers based upon channel preferences and relevant regional regulatory requirements. Regulations in the United States may differ greatly than regulations in e.g., Saudi Arabia. Accordingly, in some embodiments, the wireless system may retrieve and/or consult profiles specifying suitable operating conditions for its current geographic and/or operational circumstances.
[0023] Various example embodiments will now be described. The following description provides certain specific details for a thorough understanding and enabling description of these examples. One skilled in the relevant technology will understand, however, that the invention may be practiced without many of these details. Likewise, one skilled in the relevant technology will also understand that the invention may include many other obvious features not described in detail herein. Additionally, some well-known structures or functions may not be shown or described in detail below, to avoid unnecessarily obscuring the relevant descriptions of the various examples.
[0024] The terminology used below is to be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific examples of the invention. Indeed, certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this Detailed Description section.
System Topology Overview for Delivering/Running Applications
[0025] Various of the disclosed embodiments concern systems and methods to improve power consumption in, e.g., a WLAN device based upon the operating channel and/or the regional settings of the device. The WLAN protocol may require a linear RF power amplifier to amplify complex modulation signals (such as 64/256 QAM). In order to have linear operation the power amplifier may need to operate in, e.g., the Class-A/AB mode. Operating in this mode may consume considerable DC Power (e.g., due to the bias point being at the middle of the AC load line).
[0026] Due to various regulatory requirements (e.g., the FCC, CE, etc.) some systems may not be allowed to transmit the same transmit powers on all channels. For example, in North America (FCC), the transmit power of Channels 1 and 11 in the 2.4 GHz band may be limited by FCC regulations to 3-9 dB. In contrast, the middle channels 2-10 may be allowed to operate in a different range, e.g., a higher range. Various of the disclosed embodiments contemplate reducing power in Channels 1 & 11 to reduce amplifier DC power dissipation.
[0027] As another example, in response to FCC limits some embodiments can transmit low power in channels 36-64 (EIRP=23 dBm) and high power in channels 149-165 (EIRP=36 dBm) in the 5 GHz range. Absent the power amplifier biasing adjustments of the disclosed embodiments, the system may dissipate a similar amount of DC power for both channel ranges 36-64 & 149-165. In contrast, various of the disclosed embodiments may reduce DC power dissipation based upon the selected channel. As the regulations may be region-based, various embodiments may include a plurality of profiles addressing the constraints imposed by each region, as discussed in greater detail herein. These profiles may be included with the device when manufactured, or installed manually or over a network at a subsequent time.
[0028] FIG. 1 is a table 100 depicting transmission power regulation information for various jurisdictions as may apply in certain of the disclosed embodiments. For example, in the United States the Federal Communications Commission (FCC) dictates that the 2.4-2.4835GHz frequency range have a maximum power of 1 watt, while the 5.470-5.725 GHz frequency range have a maximum power of only 250 milliwatts. While Canada and Taiwan impose similar restrictions on the 2.4-2.4835 GHz and 5.470-5.725 GHz frequency ranges, China instead requires a 100 mW or 500 mw upper bound for the 2.4-2.4835 GHz frequency range depending upon the gain level. FIG. 2 is a table 200 depicting transmission power regulation information for various jurisdictions as may apply in certain of the disclosed embodiments. As indicated, Japan and Korea also impose different restrictions for the 2.4-2.4835 GHz and 5.470-5.725 GHz frequency ranges than in the United States. Additionally, these jurisdictions base the maximum power on an incremental cap determined by the frequency of the receiving device, (e.g. 10 mW per additional 1 MHz in Korea until 20 MHz and then 5 mW per additional 1 MHz until reaching 40 MHz). At present, China does not use the 5.15 GHz-5.35 GHz bands. Accordingly, in some embodiments discussed below, the profiles will be adjusted or updated to reflect the availability of these bands once they are approved.
[0029] While these jurisdictional requirements alone impose considerable complications to efficient transmitter operation, operators within each jurisdiction may impose additional requirements. For example, operators may desire to limit transmitter functionality in certain locations of a facility during particular times of day or within the presence/absence of certain devices. Abiding by operator preferences and regional regulation requirements while simultaneously addressing transmitter efficiency can be a daunting task. Various embodiments contemplate methods and system-level organizational approaches which can facilitate efficient, effective, and relatively easy configuration by an operator or an automated system to meet these operational goals.
[0030] FIG. 3 is a system-level block diagram of an example system 300 configured for one or more stimuli as may be implemented in some embodiments. The example system 300 , may be, e.g., a wireless access point, router, relay, mobile device, etc. A processor 310 may receive a plurality of stimuli 305 a - f. The stimuli 305 a - f and/or action to be taken based thereon may be specified in a profile as described in greater detail herein. The processor 310 may be in communication with a WLAN transceiver 315 via bus 345 . The transceiver 315 may generate communications signals which are amplified by power amplifier 325 and transmitted via transmit/receive switch 330 across antenna 335 . Incoming signals may be received by the antenna 335 and conveyed to low noise amplifier 340 via switch 330 . Low noise amplifier 340 may amplify the signal and convey it to transceiver 315 , where the signal is passed across the bus 345 to processor 310 for processing.
[0031] The stimuli provided to the processor 310 may include regional-based power control 305 a, regulatory-based power control 305 b, temperature measurements 305 c, auto-channel based power control 305 d, user-defined power control 305 e, frequency-based power control 305 f, etc. These stimuli may be used, in conjunction with a profile, to determine the appropriate operating conditions for the system 300 , e.g., the operation of power amplifier 325 , transceiver 315 , etc. For example, the 802.11 power management operations (such as a sleep time or mode) and current levels of the power amplifiers in the system may be adjusted based on a comparison of one or more stimuli values with a profile's criteria (e.g., processor 310 may use acc adjustable/variable power supply 320 to adjust the current levels of power amplifier 325 ). As another example, if the profile specifies a first bias for a first channel and a second bias for a second channel, the system may adopt the second bias after consulting the profile following a transition stimulus from the first channel to the second channel. The profile may be used to weight various of the stimuli values and to select a course of action based thereon. For example, the system may consider the scaled values in isolation, or as a weighted average.
[0032] FIG. 4 is a system-level block diagram of various components as may be implemented in some embodiments. The system 400 may be the same as system 300 in some embodiments (e.g., various modules such as the “region select” module 415 may be run as software on processor 310 ). Accordingly, the wireless device 405 may be a WLAN system, e.g. a router, wireless access point, USB peripheral, or the like. The device 405 may be in communication with a configuration server 455 via a network 410 , e.g., a cloud-based system and/or the Internet. In some embodiments, the system 400 is a standalone system and operates without a network connection (and may instead, e.g., receive user input directly regarding profile data and regional information).
[0033] The wireless device 405 may include a region selection module 415 and a frequency adjustment module 430 . In some embodiments, the region selection module 415 and the frequency adjustment module 430 may receive configuration data from the server 455 . For example, the server may indicate the location of the system 400 to the region select module 415 . The frequency adjustment module 430 and the region selection module 415 may convey the information to a calibration selector 440 . The calibration selector 440 may select one or more profiles from a plurality of profiles 450 a - c. High and low voltage configurations 415 (and in some embodiments many more than these binary states) may be provided to DC-DC current component 425 . The calibration selector 440 may adjust one or more operational amplifiers 435 a - b directly or via DC-DC current component 425 . Adjustment of a bias point associated with one or more amplifiers 435 a - b may reduce DC power dissipation while still permitting suitable operation within a desired frequency range.
[0034] The profiles 450 a - c may specify the bias points for amplifiers 435 a - b based on one or more desired frequency ranges of operation, user preferences, and/or regional specifications. For example, the profiles 450 a - c may specify a particular device configuration based upon the desired operating channel and/or regional setting (and the corresponding regulation requirements) given one or more stimuli. Note that the profiles may specify different power levels for different channels. The profiles 450 a - c may be installed in the device 405 at the time of manufacture in some embodiments, or may be downloaded from configuration server 455 . In some embodiments, the device 405 may determine its geographic location based upon an Internet Protocol (IP) address dynamically assigned to the device 405 (e.g., by consulting a gateway server) or based upon configuration and/or installation information provided by a user.
[0035] FIG. 5 is a plot 500 of current, voltage, and power consumption relations in 802.11b/g/n modes as may be associated with some embodiments. Particularly, current and voltage may vary as depicted by a first relation 505 and a second relation 510 . As depicted, a system adopting a configuration effecting the first relation 505 may consume an additional watt (power=current×voltage) of power as compared to the second configuration 510 . Thus, various embodiments provide profile configurations that facilitate operation in the second relation 510 rather than the first relation 505 whenever possible.
[0036] FIG. 6 is a plot 600 of current, voltage, and power consumption relations in 802.11a/n/ac modes may be associated with some embodiments. Particularly, current and voltage may adjust as depicted by a first relation 605 and a second relation 610 . As depicted, a system adopting a configuration effecting the first relation 605 may consume an additional 0.72 watts (power=current×voltage) of power as compared to the second configuration 610 . Thus, various embodiments provide profile configurations that facilitate operation in the second relation 610 rather than the first relation 605 whenever possible.
[0037] FIG. 7 is a flow diagram depicting various transmitter/receiver power consumption control operations as may be implemented in some embodiments. At block 705 the system may monitor various factors, e.g. the Received Signal Strength Indication (RSSI) from all stations, system or ambient temperature, etc. (e.g., consider the factors 305 a - f ). The monitoring may occur periodically or aperiodically and may or may not be part of standard processes of 802.11 beacon/frame transmission and receipt. At block 710 , the system may also verify that the transmission power used is appropriate for the current mix of stations. Though separated for clarity, one will recognize that this determination may be included in the factors monitored at block 705 . The current mix of stations may correspond to the “stimuli” in this example.
[0038] At block 715 , the system may determine whether the current power allocation is acceptable based upon the factors and/or station assessment. Acceptability may be determined based upon a plurality of criterion, e.g., power levels preferred by a user, preferred communication ranges and quality of service, the conditions of one or more service level agreements, a channel to bias correspondence, regional location, etc. Even if the power is acceptable, e.g., if it satisfies a required or preferred number of the criterion, at block 720 the system may still determine if the temperature and/or power consumption may be reduced. For example, if a satisfactory number of the criterion from block 715 may still be satisfied at a lower power level, the system may consider transitioning to block 725 . Otherwise, if the power is acceptable and the adjustments of block 720 are not to be performed, the system may return to monitoring at blocks 705 and 710 .
[0039] If the power level is unacceptable to meet the criterion of block 715 , or if an adjustment is determined to be appropriate at block 720 , the system may transition to block 725 and determine if it is acceptable to change the power level at this time. For example, even though the system's current operation may exceed or fall short of a desired criterion, the current moment may not be suitable for making an adjustment. The system may be meeting a temporary service criterion (e.g., operating at a higher power during a busy part of the workday) that takes precedence to more efficient operation. The conditions, criteria, and factors to monitor in each of blocks 705 - 725 may be specified in whole or in part by a profile in some embodiments.
[0040] If it is acceptable to make a power adjustment at this time at block 725 , then at block 730 the system may run power optimization algorithms for the stations. At block 735 , the system may select a transmission and/or reception power level suitable for all or some (e.g., a majority) of the stations. At block 740 , the system may adjust the appropriate settings, e.g., the parameters of variable power supply 320 or amplifier 325 . Such adjustments may be in accordance with local regulatory requirement as confirmed, e.g., by one or more profiles.
[0041] FIG. 8 is a flow diagram depicting various power consumption control operations 800 using profiles as may be implemented in some embodiments. At block 805 the system, e.g., device 300 may determine its regional status. This status may be hard coded in the device, inferred from an IP address, provided by a user, etc. At block 810 , the system may determine an operating channel status. For example, a user may have specified the desired channels of operation, or the system may have inferred the channels based upon local regulations (e.g., as specified in a previously retrieved profile), available frequencies, desired operation, etc.
[0042] At block 815 , the device may retrieve one or more profiles based upon the regional status and/or the operating channel status. As discussed, these profiles may be, e.g., preinstalled on the device, may be downloaded by request from a server, or may be periodically updated automatically. Each profile may specify one or more operating configurations, e.g., bias points for one or more linear operational amplifiers, and may do so in correlation with one or more stimuli values or ranges. At block 820 the system may select one or more profiles based upon the regional status, operating channel status, an operational configuration of the device (e.g., user-specified desire to operate in a low-power configuration), and/or one or more device-specific characteristics. For example, the profiles may be used for a family of devices and this particular device may need to tailor the application of the profile to its particular capabilities and circumstances.
[0043] At block 825 , the device may adjust various configuration settings based upon the profile. For example, the system may adjust a bias point on one or more amplifiers to reduce energy loss. In some regions, the device may only be permitted to operate in a lower frequency than its entire potential range. Rather than operating the amplifiers so that they may operate in both ranges, the adjustment may reduce operation to only the allowed range, and power dissipation may be reduced in consequence. In some embodiments, users may also specify power profiles to reduce power during certain times of day or when the device is located in a particular location of a building or other environment.
[0044] At block 830 , the device may monitor internal and/or external conditions to determine if reassessment is necessary. For example, the system may consult an internal timetable specified by a user and adjust the behavior based thereon. As another example, regulatory changes by local governments may be pushed from the server to the device, e.g., via the profile, and the device may reconsider the profiles to determine if a more appropriate configuration, e.g., such as the amplifier bias points, should be adopted.
[0045] FIG. 9 is a flow diagram depicting various power consumption control operations as may be implemented in some embodiments. At block 905 , the system may be powered on, either manually by a user or automatically via, e.g., an internal or external timer. At block 910 , the system may present an automatic channel selection code used for a wireless interface. The selection code may run upon a host processor or upon a wireless module of a wireless access point and may identify each channel the access point should operate on for each wireless interface. For example for dual band APs, there may be one or two instances of the selection code running to pick the channel for each band. The selection code may permit the user to specify a desired channel selection. In some embodiments, the selection may be specified automatically by a profile.
[0046] At block 915 , the system may read optimization criteria, e.g., from a profile, or as specified by the manufacturer and/or user. At block 920 , the system may collect the WLAN and non-WLAN information on all the candidate channels. This information may include, e.g., the number and type of stations to be associated with each channel, the interference on the channel, power levels, WLAN activity (a number of APs, how busy they are, etc.), a spectral mask of WLAN signals, TX power level on different channels, non-WLAN activity (baby monitor, microwave, etc.) etc. The power may vary due to regulatory and/or hardware limitations.
[0047] At block 925 , the system may run one or more optimization algorithms, e.g., a weighted sum of each grade for each optimization criteria, weighted square summation of each optimization criteria, etc. The system may calculate a grade, or metric, for each channel, and then based upon the grades the preferred channel(s) may be selected. The grade may be calculated for overlapping and/or non-overlapping channels in some embodiments. For each WLAN OBSS a negative grade may be added based upon the magnitude of the overlapping part of the spectrum mask of the OBSS. A spectral mask measurement may include the effect of a nominal BSS on a neighboring BSS′ adjacent channels in the frequency domain using a spectral mask as defined in the 802.11 specification. The WLAN activity, e.g., the number of APs on different channels, may be calculated using a deep scan. The percentage of activity on each channel may also be measured. If the overlapping part of the mask is smaller than a threshold, no negative grade may be added. A negative grade may be added in proportion to the amount of noise present on a channel. If the noise is above a certain threshold, the channel may not be used in some embodiments. A positive grade may be added based upon the maximum transmit power in each channel. Once a cumulative grade has been created for each channel, a total or partial ordering of the channels may be created.
[0048] As mentioned, the metric for each channel based upon the above parameters may be a weighted sum. The weight for each parameter may depend upon the hardware and software characteristics of the access point or of the STAs to be serviced. For example some wireless designs may be more prone to noise from non-WLAN interference while others may be more prone to a strong overlapping signal that may saturate the radio, etc.
[0049] The type of traffic serviced may also affect the weights used in the grading system. Delay sensitive traffic (VoIP, video, gaming) may suffer more from intermittent noise or interference while non-real-time traffic (file transfer, email, etc.) is less affected.
[0050] At block 930 , the system may select a channel for each WLAN module, e.g., using the partial or total ordering determined above. At block 935 , the system may adjust WLAN parameters based upon collected statistics from an Active Channel Selection (ACS) or driver. Parameters such as transmit power and receive sensitivity may be adjusted based on the amount of interference and type of service. The selected transmit power may be used to adjust power amplifier parameters to achieve the best power consumption or best transmit signal quality. The best power consumption and the best transmit signal quality may be based upon the requirement and the channel status. The adjustment may be performed via a software command changing one or more of wireless hardware settings, toggling an I/O line, adjusting a voltage or bias current, etc. At block 940 , the system may wait for the channel selection period, either as automatically specified or as determined by the user. At block 945 , the system may update the WLAN and/or non-WLAN information (interference such as baby monitors, microwave ovens, and other noise sources determined, e.g., using spectral analysis) on all or a subset of the candidate channels. At block 950 , the system may determine if the statistics are acceptable. At block 955 , the system may determine if a channel switch condition is satisfied, and if so, proceed to run a new round of optimizations at block 925 . Otherwise, the system may return to block 940 .
[0051] FIG. 10 is a table 1000 depicting various current and power levels for various channels as may be associated with some embodiments. FIG. 11 is a table 1100 depicting various current and power levels for various channels as may be associated with some embodiments. FIG. 12 is a plot 1200 of the DC power consumption for various channels in 802.11g mode as may be associated with some embodiments. FIG. 13 is a plot 1300 of the DC power consumption for various channels in 802.11n mode as may be associated with some embodiments. FIG. 14 is a bar plot 1400 depicting various power consumption levels for various channels as may be associated with some embodiments. FIG. 15 is a plot 1500 of the DC power consumption for various channels as may be associated with some embodiments.
[0052] Computer System
[0053] FIG. 16 is a block diagram of a computer system as may be used to implement certain features of some of the embodiments. Though generally presented herein as an access point or router, the computer system may be a server computer, a client computer, a personal computer (PC), a user device, a tablet PC, a laptop computer, a personal digital assistant (PDA), a wireless access point, a cellular telephone, an iPhone, an iPad, a Blackberry, a processor, a telephone, a web appliance, a network router, switch or bridge, a console, a hand-held console, a (hand-held) gaming device, a music player, any portable, mobile, hand-held device, wearable device, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine.
[0054] The computing system 1600 may include one or more central processing units (“processors”) 1605 , memory 1610 , input/output devices 1625 (e.g., keyboard and pointing devices, touch devices, display devices), storage devices 1620 (e.g., disk drives), and network adapters 1630 (e.g., network interfaces) that are connected to an interconnect 1615 . The interconnect 1615 is illustrated as an abstraction that represents any one or more separate physical buses, point to point connections, or both connected by appropriate bridges, adapters, or controllers. The interconnect 1615 , therefore, may include, for example, a system bus, a Peripheral Component Interconnect (PCI) bus or PCI-Express bus, a HyperTransport or industry standard architecture (ISA) bus, a small computer system interface (SCSI) bus, a universal serial bus (USB), IIC (I2C) bus, or an Institute of Electrical and Electronics Engineers (IEEE) standard 1394 bus, also called “Firewire”.
[0055] The memory 1610 and storage devices 1620 are computer-readable storage media that may store instructions that implement at least portions of the various embodiments. In addition, the data structures and message structures may be stored or transmitted via a data transmission medium, e.g., a signal on a communications link. Various communications links may be used, e.g., the Internet, a local area network, a wide area network, or a point-to-point dial-up connection. Thus, computer readable media can include computer-readable storage media (e.g., “non-transitory” media) and computer-readable transmission media.
[0056] The instructions stored in memory 1610 can be implemented as software and/or firmware to program the processor(s) 1605 to carry out actions described above. In some embodiments, such software or firmware may be initially provided to the processing system 1600 by downloading it from a remote system through the computing system 1600 (e.g., via network adapter 1630 ).
[0057] The various embodiments introduced herein can be implemented by, for example, programmable circuitry (e.g., one or more microprocessors) programmed with software and/or firmware, or entirely in special-purpose hardwired (non-programmable) circuitry, or in a combination of such forms. Special-purpose hardwired circuitry may be in the form of, for example, one or more ASICs, PLDs, FPGAs, etc.
Remarks
[0058] The above description and drawings are illustrative and are not to be construed as limiting. Numerous specific details are described to provide a thorough understanding of the disclosure. However, in certain instances, well-known details are not described in order to avoid obscuring the description. Further, various modifications may be made without deviating from the scope of the embodiments.
[0059] Reference in this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others. Similarly, various requirements are described which may be requirements for some embodiments but not for other embodiments.
[0060] The terms used in this specification generally have their ordinary meanings in the art, within the context of the disclosure, and in the specific context where each term is used. Certain terms that are used to describe the disclosure are discussed above, or elsewhere in the specification, to provide additional guidance to the practitioner regarding the description of the disclosure. For convenience, certain terms may be highlighted, for example using italics and/or quotation marks. The use of highlighting has no influence on the scope and meaning of a term; the scope and meaning of a term is the same, in the same context, whether or not it is highlighted. It will be appreciated that the same thing can be said in more than one way. One will recognize that “memory” is one form of a “storage” and that the terms may on occasion be used interchangeably.
[0061] Consequently, alternative language and synonyms may be used for any one or more of the terms discussed herein, nor is any special significance to be placed upon whether or not a term is elaborated or discussed herein. Synonyms for certain terms are provided. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification including examples of any term discussed herein is illustrative only, and is not intended to further limit the scope and meaning of the disclosure or of any exemplified term. Likewise, the disclosure is not limited to various embodiments given in this specification.
[0062] Without intent to further limit the scope of the disclosure, examples of instruments, apparatus, methods and their related results according to the embodiments of the present disclosure are given above. Note that titles or subtitles may be used in the examples for convenience of a reader, which in no way should limit the scope of the disclosure. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. In the case of conflict, the present document, including definitions will control.
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Various of the disclosed embodiments concern efficiency improvements in wireless products. For example, some embodiments specify profiles for regional and custom-specified operational constraints. The profiles may be retrieved from across a network or stored locally upon the device. The profiles may specify various configuration adjustments that optimize the system's performance. For example, when possible, some embodiments may allow the system to operate at a lower power level and to thereby save energy. Various factors and conditions may be assessed in some embodiments prior to adjusting the existing power configuration.
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The present application is a 37 C.F.R. §1.53(b) continuation of U.S. patent application Ser. No. 12/985,389 filed on Jan. 6, 2011, which is a 37 C.F.R. §1.53(b) continuation of U.S. patent application Ser. No. 12/639,872 filed on Dec. 16, 2009, now U.S. Pat. No. 7,930,910 B2, which is a 37 C.F.R. §1.53(b) continuation of U.S. patent application Ser. No. 12/267,457 filed Nov. 7, 2008, currently pending, which is a 37 C.F.R. §1.53(b) continuation of U.S. patent application Ser. No. 10/461,451 filed Jun. 16, 2003, now U.S. Pat. No. 7,533,548 B2, which claims priority to Korean Patent Application No. 85521/2002, filed Dec. 27, 2002, the entire contents of which are hereby incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a drum type washing machine, and more particularly, to a drum type washing machine which can maximize a capacity of a drum without changing an entire size of a washing machine.
2. Description of the Related Art
FIG. 1 is a side sectional view showing a drum type washing machine in accordance with the conventional art, FIG. 2 is a front sectional view showing the drum type washing machine in accordance with the conventional art.
The conventional drum type washing machine comprises: a cabinet 102 for forming an appearance; a tub 104 arranged in the cabinet 102 for storing washing water; a drum 106 rotatably arranged in the tub 104 for washing and dehydrating laundry; and a driving motor 110 positioned at a rear side of the tub 104 and connected to the drum 106 by a driving shaft 108 thus for rotating the drum 106 .
An inlet 112 for inputting or outputting the laundry is formed at the front side of the cabinet 102 , and a door 114 for opening and closing the inlet 112 is formed at the front side of the inlet 112 .
The tub 104 of a cylindrical shape is provided with an opening 116 at the front side thereof thus to be connected to the inlet 112 of the cabinet 102 , and a balance weight 118 for maintaining a balance of the tub 104 and reducing vibration are respectively formed at both sides of the tub 104 .
Herein, a diameter of the tub 104 is installed to be less than a width of the cabinet 102 by approximately 30-40 mm with consideration of a maximum vibration amount thereof so as to prevent from being contacted to the cabinet 102 at the time of the dehydration.
The drum 106 is a cylindrical shape of which one side is opened so that the laundry can be inputted, and has a diameter installed to be less than that of the tub 104 by approximately 15-20 mm in order to prevent interference with the tub 104 since the drum is rotated in the tub 104 .
A plurality of supporting springs 120 are installed between the upper portion of the tub 104 and the upper inner wall of the cabinet 102 , and a plurality of dampers 122 are installed between the lower portion of the tub 104 and the lower inner wall of the cabinet 102 , thereby supporting the tub 104 with buffering.
A gasket 124 is formed between the inlet 112 of the cabinet 102 and the opening 116 of the tub 104 so as to prevent washing water stored in the tub 104 from being leaked to a space between the tub 104 and the cabinet 102 . Also, a supporting plate 126 for mounting the driving motor 110 is installed at the rear side of the tub 104 .
The driving motor 110 is fixed to a rear surface of the supporting plate 126 , and the driving shaft 108 of the driving motor 110 is fixed to a lower surface of the drum 106 , thereby generating a driving force by which the drum 106 is rotated.
In the conventional drum type washing machine, the diameter of the tub 104 is installed to be less than the width of the cabinet 102 with consideration of the maximum vibration amount so as to prevent from being contacted to the cabinet 102 , and the diameter of drum 106 is also installed to be less than that of the tub 104 in order to prevent interference with the tub 104 since the drum is rotated in the tub 104 . According to this, so as to increase the diameter of the drum 106 which determines a washing capacity, a size of the cabinet 102 has to be increased.
Also, since the gasket 124 for preventing washing water from being leaked is installed between the inlet 112 of the cabinet 102 and the opening 116 of the tub 104 , a length of the drum 106 is decreased as the installed length of the gasket 124 . According to this, it was difficult to increase the capacity of the drum 106 .
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a drum type washing machine which can increase a washing capacity without changing an entire size thereof, in which a cabinet and a tub is formed integrally and thus a diameter of a drum can be increased without increasing a size of the cabinet.
Another object of the present invention is to provide a drum type washing machine which can increase a washing capacity by increasing a length of a drum without increasing a length of a cabinet, in which the cabinet and a tub are formed integrally and thus a location of a gasket is changed.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a drum type washing machine comprising: a cabinet for forming an appearance; a tub fixed to an inner side of the cabinet and for storing washing water; a drum rotatably arranged in the tub for washing and dehydrating laundry; and a driving motor positioned at the rear side of the drum for generating a driving force by which the drum is rotated.
The tub is a cylindrical shape, and a front surface thereof is fixed to a front inner wall of the cabinet.
Both sides of the tub are fixed to both sides inner wall of the cabinet.
A supporting plate for mounting the driving motor is located at the rear side of the tub, and a gasket hermetically connects the supporting plate and the rear side of the tub, in which the gasket is formed as a bellows and has one side fixed to the rear side of the tub and another side fixed to an outer circumference surface of the supporting plate.
A supporting unit for supporting an assembly composed of the drum, the driving motor, and the supporting plate with buffering is installed between the supporting plate and the cabinet.
The supporting unit comprises: a plurality of upper supporting rods connected to an upper side of the supporting plate towards an orthogonal direction and having a predetermined length; buffering springs connected between the upper supporting rods and an upper inner wall of the cabinet for buffering; a plurality of lower supporting rods connected to a lower side of the supporting plate towards an orthogonal direction and having a predetermined length; and dampers connected between the lower supporting rods and a lower inner wall of the cabinet for absorbing vibration.
The drum is provided with a liquid balancer at a circumference of an inlet thereof for maintaining a balance when the drum is rotated.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
In the drawings:
FIG. 1 is a side sectional view showing a drum type washing machine in accordance with the conventional art;
FIG. 2 is a front sectional view showing the drum type washing machine in accordance with the conventional art;
FIG. 3 is a side sectional view showing a drum type washing machine according to one embodiment of the present invention;
FIG. 4 is a front sectional view showing the drum type washing machine according to one embodiment of the present invention;
FIG. 5 is a lateral view showing a state that a casing of the drum type washing machine according to one embodiment of the present invention is cut;
FIG. 6 is a front sectional view of a drum type washing machine according to a second embodiment of the present invention;
FIG. 7 is a front sectional view showing a drum type washing machine according to a third embodiment of the present invention;
FIG. 8 is a longitudinal sectional view of the drum type washing machine according to the third embodiment of the present invention; and
FIG. 9 is a rear sectional view showing the drum type washing machine according to the third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
FIG. 3 is a side sectional view showing a drum type washing machine according to one embodiment of the present invention, and FIG. 4 is a front sectional view showing the drum type washing machine according to one embodiment of the present invention.
The drum type washing machine according to one embodiment of the present invention comprises: a cabinet 2 for forming an appearance of a washing machine; a tub 4 formed integrally with the cabinet 2 and for storing washing water; a drum 6 rotatably arranged in the tub 4 for washing and dehydrating laundry; and a driving motor 8 positioned at the rear side of the drum 6 for generating a driving force by which the drum 6 is rotated.
The cabinet 2 is rectangular parallelepiped, and an inlet 20 for inputting and outputting laundry is formed at the front side of the cabinet 2 and a door 10 for opening and closing the inlet 20 is formed at the inlet 20 .
The tub 4 is formed as a cylinder shape having a predetermined diameter in the cabinet 2 , and the front side of the tub 4 is fixed to the front inner wall of the cabinet 2 or integrally formed at the front inner wall of the cabinet 2 . Both sides of the tub 4 are contacted to both sides inner wall of the cabinet 2 or integrally formed with both sides inner wall of the cabinet 2 thus to be prolonged.
Herein, since both sides of the tub 4 are contacted to both sides inner wall of the cabinet 2 , a diameter of the tub 4 can be increased.
Also, the supporting plate 12 is positioned at the rear side of the tub 4 and the gasket 14 is installed between the supporting plate 12 and the rear side of the tub 4 , thereby preventing washing water filled in the tub 4 from being leaked.
The gasket 14 is formed as a bellows of a cylinder shape and has one side fixed to the rear side of the tub 4 and another side fixed to an outer circumference surface of the supporting plate 12 .
The supporting plate 12 is formed as a disc shape, the driving motor 8 is fixed to the rear surface thereof, and a rotation shaft 16 for transmitting a rotation force of the driving motor 8 to the drum 6 is rotatably supported by the supporting plate 12 . Also, a supporting unit for supporting the drum 6 with buffering is installed between the supporting plate 12 and the inner wall of the cabinet 2 .
The supporting unit comprises: a plurality of upper supporting rods 22 connected to an upper side of the supporting plate 12 and having a predetermined length; buffering springs 24 connected between the upper supporting rods 22 and an upper inner wall of the cabinet 2 for buffering; a plurality of lower supporting rods 26 connected to a lower side of the supporting plate 12 and having a predetermined length; and dampers 28 connected between the lower supporting rods 26 and a lower inner wall of the cabinet 2 for absorbing vibration.
Herein, the buffering springs 24 and the dampers 28 are installed at a center of gravity of an assembly composed of the drum 6 , the supporting plate 12 , and the driving motor 8 . That is, the upper and lower supporting rods 22 and 26 are prolonged from the supporting plate 12 to the center of gravity of the assembly, the buffering springs 24 are connected between an end portion of the upper supporting rod 22 and the upper inner wall of the cabinet 2 , and the dampers 28 are connected between an end portion of the lower supporting rod 26 and the lower inner wall of the cabinet 2 , thereby supporting the drum 6 at the center of gravity.
A diameter of the drum 6 is installed in a range that the drum 6 is not contacted to the tub 4 even when the drum 6 generates maximum vibration in order to prevent interference with the tub 4 at the time of being rotated in the tub 4 .
Operations of the drum type washing machine according to the present invention are as follows.
If the laundry is inputted into the drum 6 and a power switch is turned on, washing water is introduced into the tub 6 . At this time, the front side of the tub 6 is fixed to the cabinet 2 and the gasket 14 is connected between the rear side of the tub 6 and the supporting plate 12 , thereby preventing the washing water introduced into the tub 6 from being leaked outwardly.
If the introduction of the washing water is completed, the driving motor 8 mounted at the rear side of the supporting plate 12 is driven, and the drum 6 connected with the driving motor 8 by the rotation shaft 16 is rotated, thereby performing washing and dehydration operations. At this time, the assembly composed of the drum 6 , the driving motor, and the supporting plate 12 is supported by the buffering springs 24 and the dampers 28 mounted between the supporting plate 12 and the inner wall of the cabinet 20 .
FIG. 6 is a front sectional view of a drum type washing machine according to a second embodiment of the present invention.
The drum type washing machine according to the second embodiment of the present invention has the same construction and operation as that of the first to embodiment except a shape of the tub.
That is, the tub 40 according to the second embodiment has a straight line portion 42 with a predetermined length at both sides thereof. The straight line portion 42 is fixed to the inner wall of both sides of the cabinet 2 , or integrally formed at the wall surface of both sides of the cabinet 2 .
Like this, since the tub 40 according to the second embodiment has both sides fixed to the cabinet 2 as a straight line form, the diameter of the tub 40 can be increased. Accordingly, the diameter of the drum 6 arranged in the tub 40 can be more increased.
FIG. 7 is a front sectional view showing a drum type washing machine according to a third embodiment of the present invention, FIG. 8 is a longitudinal sectional view of the drum type washing machine according to the third embodiment of the present invention, and FIG. 9 is a rear sectional view showing the drum type washing machine according to the third embodiment of the present invention.
The drum type washing machine according to the third embodiment of the present invention comprises: a cabinet 2 for forming an appearance of a washing machine; a tub 50 formed integrally with the cabinet 2 and for storing washing water; a drum 6 rotatably arranged in the tub 50 for washing and dehydrating laundry; and a supporting unit positioned at the rear side of the tub 50 and arranged between the supporting plate 12 to which the driving motor 8 is fixed and the cabinet 2 for supporting the drum 6 with buffering.
The tub 50 is composed of a first partition wall 52 fixed to the upper front inner wall and both sides inner wall of the cabinet 2 ; and a second partition wall 54 integrally fixed to the lower front inner wall and both sides inner wall of the cabinet 2 .
The first partition wall 52 of a flat plate shape is formed at the upper side of the cabinet 2 in a state that the front side and both sides are integrally formed at the inner wall of the cabinet 2 or fixed thereto. Also, the second partition wall 54 of a semi-circle shape is formed at the lower side of the cabinet 2 in a state that the front side and both sides are integrally formed at the inner wall of the cabinet 2 or fixed thereto.
The supporting unit comprises: a plurality of upper supporting rods 56 connected to the upper side of the supporting plate 12 and having a predetermined length; buffering springs 58 connected between the upper supporting rods 56 and the upper inner wall of the cabinet 2 for buffering; a plurality of lower supporting rods 60 connected to the lower side of the supporting plate 12 and having a predetermined length; and dampers 62 connected between the lower supporting rods 60 and the lower inner wall of the cabinet 2 for absorbing vibration.
Herein, the upper supporting rods 56 are bent to be connected to the upper side of the supporting plate 12 and positioned at the upper side of the first partition wall 52 , and the buffering springs 58 are connected to the end portion of the upper supporting rods 56 . Also, the lower supporting rods 60 are bent to be connected to the lower side of the supporting plate 12 and positioned at the lower side of the second partition wall 54 , and the dampers 62 are connected to the end portion of the lower supporting rods 56 .
In the drum type washing machine according to the present invention, a size of the drum can be maximized by fixing the tub in the cabinet, thereby increasing washing capacity of the drum without increasing a size of the cabinet.
Also, since the front surface of the tub is integrally formed at the inner wall of the cabinet and the gasket is installed between the rear surface of the tub and the supporting plate, a length of the drum can be increased and thus the washing capacity of the drum can be increased.
As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalence of such metes and bounds are therefore intended to be embraced by the appended claims.
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A drum type washing machine is provided. The drum type washing machine may include a cabinet, a tub fixed to an inner side of the cabinet, a drum rotatably arranged in the tub, and a driving motor positioned at a rear side of the drum for generating a driving force that rotates the drum. The washing machine may also include a supporting plate to rotatably support a rotational shaft extending between the motor and the drum, and a plurality of supporters connected between the supporting plate and the cabinet. Such an arrangement may increase washing capacity by increasing a diameter of the drum without increasing an external size of the cabinet.
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INTRODUCTION
The present invention relates to a marine riser tower, of the type used in the transport of hydrocarbon fluids (gas and/or oil) from offshore wells. The riser tower typically includes a number of conduits for the transport of fluids and different conduits within the riser tower are used to carry the hot production fluids and the injection fluids which are usually colder.
The tower may form part of a so-called hybrid riser, having an upper and/or lower portions (“jumpers”) made of flexible conduit U.S. Pat. No. 6,082,391 proposes a particular Hybrid Riser Tower consisting of an empty central core, supporting a bundle of riser pipes, some used for oil production some used for water and gas injection. This type of tower has been developed and deployed for example in the Girassol field off Angola. Insulating material in the form of syntactic foam blocks surrounds the core and the pipes and separates the hot and cold fluid conduits. Further background is to be published in a paper Hybrid Riser Tower: from Functional Specification to Cost per Unit Length by J-F Saint-Marcoux and M Rochereau, DOT XIII Rio de Janeiro, 18 Oct. 2001.
Deepwater and Ultra-deepwater field developments usually require stringent thermal insulation criteria which are a cost driver and consequently a design driver. The cost of insulating material in the known design is very large and therefore the diameter of the core pipe is set to the minimum. Where this central core, which has a small inertia, is connected to the top submerged buoyancy tank of the tower, high stresses develop. An expensive taper joint is necessary.
Furthermore the heat transfer from the production lines is increased by their position being closer to the surrounding very cold water.
GB-A-2346188 (2H) presents an alternative to the hybrid riser tower bundle, in particular a “concentric offset riser”. The riser in this case includes a single production flowline located within an outer pipe Other lines such as gas lift, chemical injection, test, and hydraulic control lines are located in the annulus between the core and outer pipe. The main flow path of the system is provided by the central pipe, and the annular space may be filled with water or thermal insulation material. Water injection lines, which are generally equal in diameter to the flowline, are not accommodated and presumably require their own riser structure.
U.S. Pat. No. 4,332,509 (Reynard et al; Coflexip) proposes a rigid riser tower made from sections of a large-diameter rigid pipe, wherein flexible flowlines are subsequently deployed, and can be removed and replaced in case of failure. The cost of flexible flowlines must make this proposal very costly compared with the rigid metal pipes used in the Girassol riser.
The aim of the present invention is to provide a riser tower having a reliable thermal efficiency and/or greater thermal efficiency for a given overall cost. Particular embodiments of the invention aim for example to achieve heat transfer rates of less than 1 W/m 2 K.
The invention in a first aspect provides a marine riser tower comprising a plurality of rigid metallic conduits bundled together with a metallic tubular core, the conduits including at least one production line for hydrocarbons and at least one water injection line, and wherein at least one said production line is located within the core, while the water injection line is located outside the core.
Gas lift lines may not be provided in all implementations, or may be provided separately from the unitary riser tower. Where they are provided, however, insulation for the gas lift lines may also be important. The gas lift lines are also smaller, and so may be more easily accommodated within a core structure.
Accordingly, the invention in a second aspect provides a marine riser tower comprising a plurality of rigid metallic conduits bundled together with a metallic tubular core, the conduits including at least one production line for hydrocarbons, at least one water injection line, and at least one gas lift line, and wherein at least one of said gas lift and production lines is located within the core, while the water injection line is located outside the core.
In one embodiment, at least one production line is located inside of the metallic core, whereas the water injection line(s) are located to the outside of the core.
The use of the space within the core increases the efficiency of the use of the space in the design overall, and adds to the separation between warm and cold fluids. The expense of the insulation is thereby reduced. In addition, the core of the riser can now be sized larger to reduce stresses at the top of the tower and eliminate or at least simplify the taper joint at the buoy.
The conduits in a preferred embodiment comprise at least two production lines, at least two gas lift lines and at least one water injection line.
A plurality of conduits from among the production and gas lift lines may be located within the core.
All other things being equal, the production lines together with the gas lift line and other service and heating lines that are associated with the production lines would all be located within the core, whereas other service lines and umbilicals (bundles of pipes and cables for power, control and communication) would be located to the outside of the core.
On the other hand, other design considerations are such that the core should not become too large. The typical bundle includes at least two production lines (to allow pigging while the other remains on line), and accommodating these with insulation in the core may not be practical.
Accordingly, in another embodiment, only the gas lift lines are located within the core and the production lines are located outside the core.
Each production line(s) may be provided with its own insulation. This insulation may be provided substantially by foam encasing the bundle as a whole, by a coating or pipe-in-pipe insulation applied to the production line itself, or by a combination of both.
The bundle of conduits may still be encased along at least part of its length within buoyant foam material, as in the known design.
As in the known design, the buoyant foam material extends the full height of the tower, and forms the primary means of insulation for at least some of the lines.
In an alternative embodiment, buoyant material encasing the bundle of conduits may be provided only at certain spaced sections along the length of the tower, not forming the primary means of insulating the production line(s). This again reduces the cost associated with the buoyant material, by separating the functions of buoyancy and insulation. The varying profile of the tower also contributes to reduced vortex-induced vibration in the presence of currents within the seawater.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described, by way of example only, by reference to the accompanying drawings, in which:
FIG. 1 illustrates schematically a deepwater installation including a floating production and storage vessel and rigid pipeline riser bundles in a deepwater oil field;
FIG. 2 is a more detailed side elevation of an installation of the type shown in FIG. 1 including a riser tower according to a first embodiment of the present invention;
FIG. 3 is a cross-sectional view of the riser tower in the installation of FIG. 2 ;
FIG. 4 is a cross-sectional view of the riser tower in a second embodiment of the invention;
FIG. 5 is a cross-sectional view of the riser tower in a third embodiment of the invention; and
FIG. 6 illustrates a modification of the first or third embodiment, in which the foam blocks extend only over parts of the tower's length.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Referring to FIG. 1 , the person skilled in the art will recognise a cut-away view of a seabed installation comprising a number of well heads, manifolds and other pipeline equipment 100 to 108 . These are located in an oil field on the seabed 110 .
Vertical riser towers constructed according to the present invention are provided at 112 and 114 , for conveying production fluids to the surface, and for conveying lifting gas, injection water and treatment chemicals such as methanol from the surface to the seabed. The foot of each riser, 112 , 114 , is connected to a number of well heads/injection sites 100 to 108 by horizontal pipelines 116 etc.
Further pipelines 118 , 120 may link to other well sites at a remote part of the seabed. At the sea surface 122 , the top of each riser tower is supported by a buoy 124 , 126 . These towers are pre-fabricated at shore facilities, towed to their operating location and then installed to the seabed with anchors at the bottom and buoyancy at the top.
A floating production and storage vessel (FPSO) 128 is moored by means not shown, or otherwise held in place at the surface. FPSO 128 provides production facilities, storage and accommodation for the wells 100 to 108 . FPSO 128 is connected to the risers by flexible flow lines 132 etc., for the transfer of fluids between the FPSO and the seabed, via risers 112 and 114 .
As mentioned above, individual pipelines may be required not only for hydrocarbons produced from the seabed wells, but also for various auxiliary fluids, which assist in the production and/or maintenance of the seabed installation. For the sake of convenience, a number of pipelines carrying either the same or a number of different types of fluid are grouped in “bundles”, and the risers 112 , and 114 in this embodiment comprise bundles of conduits for production fluids, lifting gas, injection water, and treatment chemicals, methanol.
As is well known, efficient thermal insulation is required around the horizontal and vertical flowlines, to prevent the hot production fluids cooling, thickening and even solidifying before they are recovered to the surface.
Now referring to FIG. 2 of the drawings, there is shown in more detail a specific example of a hybrid riser tower installation as broadly illustrated in FIG. 1 .
The seabed installation includes a well head 201 , a production system 205 and an injection system 202 . The injection system includes an injection line 203 , and a riser injection spool 204 . The well head 201 includes riser connection means 206 with a riser tower 207 , connected thereto. The riser tower may extend for example 1200 m from the seabed almost to the sea surface. An FPSO 208 located at the surface is connected via a flexible jumper 209 and a dynamic jumper bundle 210 to the riser tower 207 , at or near the end of the riser tower remote from the seabed. In addition the FPSO 208 is connected via a dynamic (production and injection) umbilical 211 to the riser tower 207 at a point towards the mid-height of the tower. Static injection and production umbilicals 212 connects the riser tower 207 to the injection system 202 and production system 205 at the seabed.
The FPSO 208 is connected by a buoyancy-aided export line 213 to a dynamic buoy 214 , the export line 213 being connected to the FPSO by a flex joint 215 .
FIGS. 3 to 5 show in cross-section respective embodiments of the a riser tower such as 112 or 114 . Within these examples, the central metallic core pipe is designated C. Within the core are production flowlines P and gas lift lines G. Outside the core are water injection lines W and umbilicals U. Major interstices are filled with shaped blocks F of syntactic foam or the like. The designations C, P, W, G, F and U are used throughout the description and drawings with the same meaning. The designation I will also be used for insulating coatings.
In FIG. 3 of the drawings there is shown a construction of riser having a hollow core pipe C. Located within the core pipe are two production lines P and two gas lift lines G and located outside the core pipe are four water injection lines W and three umbilicals U. The production lines P have their own insulating coating I. The spaces between the line both internally and externally of the core pipe P are filled with blocks F of syntactic foam that are shaped to meet the specific design requirements for the system It should be noted that in this example the foam blocks externally located about the core pipe C have been split diametrically to fit around the core between the water injection lines, which do not themselves require substantial insulation from the environment There are no insulated lines within the foam outside the core, and no circumferential gaps between the foam blocks, such as would be required to insulate production and gas lift lines located outside the core.
Production flowlines P in this example also carry their own insulation, being coated with a polypropylene layer, of a type known per se, which also adds to their insulation properties. Relatively thick PP layers can be formed, for example of 50–120 mm thickness. Higher-insulated foam and other coatings can be used, as explained below.
FIG. 4 shows a second example in cross-section. In this arrangement as with the previously described arrangement located within the core pipe C are two production lines P and two gas lift lines G and located outside the core pipe are four water injection lines W and three umbilicals U. In this example foam blocks F as with the previous example are provided as insulation externally of the core pipe C. However in this example the insulation between the lines internally of the core pipe C is provided by a body of grease or paraffin (wax like) material which completely fills the space in the core pipe C. The use of the grease or wax like material in this fashion helps to prevent natural convection being established about the hot production lines. The increase the thermal efficiency of the riser design markedly and is described in more detail in our co-pending patent application PCT/EP01/09575 (Agents' Ref 63639WO), not published at the present priority date.
Both of the above examples accommodate all of the temperature-critical lines within the core, and all of the water lines outside it. This has the highest thermal efficiency, but will not always be possible in view of the number and size of the production lines, and other design considerations.
FIG. 5 of the drawings shows a third example in which only the gas lift lines G are located in the core pipe C, and the production lines P are located externally of the core pipe C with the water injection lines W and umbilicals U. The figure shows the use of foam insulation F internally of the core pipe C but it will be appreciated that the use of grease or wax like material insulation is another options. In this example, since the production lines P are closer to the environment and to the water lines, they are provided with enhanced insulation I such as PUR or other foam. Pipe-in-pipe insulation (essentially a double-walled construction) is also possible here.
In other examples, the foam blocks F may also be shaped so as to surround the production lines. The co-pending patent application PCT/EP01/09575, mentioned above., also discloses the use of grease to prevent convention currents in the gaps between foam blocks F, should that be necessary
Of course the specific combinations and types of conduit are presented by way of example only, and the actual provisions will be determined by the operational requirements of each installation. The skilled reader will readily appreciate how the design of the installation at top and bottom of the riser tower can be adapted from the prior art, including U.S. Pat. No. 6,082,391, mentioned above, and these are not discussed in further detail herein
As explained above, the present disclosure proposes to use the empty space within the core C to locate temperature sensitive lines such as the hot production flowlines P or gas lift lines G. The central core pipe C can be either open at its bottom end or closed. Closure could be achieved with bulkhead plates at top and bottom.
The generic advantages of accommodating some lines in the central core are: The core diameter is increased which allows a direct connection to the buoy without taper joint; The central core does not require to be designed for collapse The hot area of the tower is reduced which minuses heat losses to surrounding seawater; Active heating, that can be provided either with hot water piping or electrical cables, benefits from the insulation within the tubular core member; Monitoring of the central core temperature and pressure can be provided.
The arrangement shown in FIG. 3 may have the metallic core C open to the bottom. Advantages specific to a central core open at bottom are:
The central core section can receive different types of insulation material, and/or also convection-reducing material such as, but not limited to, high viscosity oil, gels, grease, paraffins or granular materials, all with or without a filler such as open cell foam or glass beads (the use of grease and paraffin materials is proposed in our co-pending applications GB0018999.3 and PCT/EP01/09575, not published at the present priority date);
The example shown in FIG. 4 shows a “dry” embodiment that would also include a top and bottom bulkhead. Advantages of a central core C, with top and bottom bulkheads, and which is designed for collapse are:
The central section may be filled with ambient pressure high insulation material I such as PUR foam or microporous aerogels; Reduced pressure can be applied inside of the core either for buoyancy and/or insulation enhancement of the above material;
The central section may alternatively receive pipes which are directly coated with highly insulated material such as, PUR foam or microporous material (this is subject of our co-pending applications GB0100413.4 and 0103020.4 and 0124801.2 (63752GB, GB2 and GB3).
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The invention relates to a marine riser tower having a plurality of rigid metallic conduits bundled together with a metallic tubular core. The conduits may include production lines for hydrocarbons, water injection lines, and/or gas lift lines. A production line or gas lift line is located within the core, while the water injection line is located outside the core.
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[0001] This application is a non-provisional patent application of and claims the benefit of U.S. provisional patent application No. 61/315,904, which was filed on Mar. 19, 2010, and U.S. provisional patent application No. 61/318,129, which was filed on Mar. 26, 2010, the entire contents of each of which is herein incorporated by reference.
TECHNICAL FIELD
[0002] The invention generally relates to the field of document cameras and the field of document scanning apparatuses, and methods for achieving scanning high resolution still images of documents at high speed.
BACKGROUND
[0003] In the field of document scanners, it is desirable to be able to scan a document with the highest resolution possible and as fast as possible. Furthermore, when there are multiple pages of documents, it is highly desirable to scan the multiple pages automatically with an automatic paper feeder without manual intervention during the process.
[0004] Currently, commercial multifunctional scanner-copier-printer-fax machines typically employ a linear scan head as the primary imaging device before one or multiple copies of the scanned image is printed out as a photo copy, or faxed to a receiving fax machine. In this type of multifunctional machine, document is either placed on a platen scan surface while the scan head moves from one edge of the surface to the other to process scanning of the paper one line at a time until the entire surface is scanned, or when an automatic document feeder is present, a document is rolled pass a stationary scan head which is positioned on the paper path to finish scanning one line at a time with the movement of the paper until the entire surface of the document is scanned.
[0005] The main drawback of such a prior art scanning mechanism is that it consumes significant time to finish scanning in a linear fashion. For monochrome color scanning, with scanning resolution of approximately 200 dpi, the current scanning mechanism can take multiple seconds, depending on the paper size and whether the device is consumer grade or professional grade.
[0006] For higher resolution scanning such as 300 dpi or 600 dpi scanning, the time to finish a full page scanning can be in tens of seconds. For 32-bit or higher color depth full color scanning, the time to finish a single page scanning can take more than 30 seconds, and depending on whether it is a consumer grade scanner, the time required can go beyond 1 minute for a single page.
[0007] Also currently available are some document camera products that are designed and used primarily for the purpose of projecting 3D objects on a larger screen for classroom instructions and product or procedure demonstrations. Traditionally, these document cameras are limited by fairly narrow field of view and shallow depth of field due to the primary application requirement of being able to zoom in on objects with greatly magnified views. The images produced by such document camera devices are often only able to show a portion of a full page document clearly, and requires the document to be held fairly flat in order to capture an image that is not blurred.
[0008] Such document cameras are not very suitable for capturing images for documents, and are more suitable for 3D, even though they are called document cameras. Additionally, the traditional application of document cameras normally requires projecting real time video onto large screens. The desire for smoothness of the video projection demands limited per frame image resolution so that the cost of video compression and time of video signal transmission is kept low. Such considerations limit the video image quality for document cameras to less than 100 dpi, which is not high enough for scanning documents with printed small font sized letters and other symbols, requiring at least 200 dpi resolution to be reproduced clearly.
[0009] As digital cameras began to be integrated into cell phones, laptop PCs, and other personal computers, optical components and digital sensing component, which have become more and more capable in terms of high resolution, color reproduction, and being highly compact, are becoming more and more common place. The cost for such high quality digital imaging components is also reduced significantly which makes it possible to integrate digital camera devices into more and more electronic products. Revising the imaging components in facing-down document cameras, with resolutions as high as 8, 12, 20, or even 30 mega pixels, for the purpose of document imaging or “scanning” at 300 dpi, 600 dpi, or higher, is not only technically feasible, but also increasingly more cost effective.
[0010] Scanners or copier technologies are typically used with an automatic document feeder. Such prior art devices typically have a base frame with a platen glass on top, with originals positioned facing down and above a scanning mechanism. A motor typically drives a scan head beneath the original to capture light reflected off individual linear areas of the original. This is the flatbed scanning module of modern day scanners and copiers. It is common place now for scanners and copiers to have an accompanying automatic document feeder module on top of the flatbed scanning base module. When users feed Multiple pages of paper through the document feeder, an elaborate assembly of mechanical and electrical parts are employed to load paper one sheet at a time, and steadily transport each sheet of paper through a scanning mechanism, which emits a beam of light and captures the reflected light through the beam opening, as the paper rolls through, from the feeder, all the way to the output receiving tray. An example of such prior art can be seen in FIGS. 1 and 2 , showing a HP® ScanJet 5590 Digital Flatbed Scanner. Such prior art digital imaging devices encounters certain limitations. In one aspect, such prior art devices are limited in speed of scanning.
[0011] Commercially available scanners often publish scan time per line between 0.5 ms to several milliseconds depending on the dpi setting. The time delay to finish scanning a full page document is likely caused by not only the mechanical movement of scan head from line to line, but also the processing time required to compose single line images together into a full page image. This per line scan time coupled with the limitation in paper transport speed through often highly complex and elaborate gear and roller assemblies, in order to ensure paper moves through evenly and steadily while in the meantime avoiding any potential paper clogging inside the assemblies, limits the overall speed greatly. As a result, the vast majority of commercially available scanners are limited to scan no more than 30 pages of monochrome colored paper per minute at 300 dpi resolution. For scanning 32-bit or 48-bit colored paper, the speed drops down significantly, sometimes down to single digit number of pages per minute. When the dpi resolution increases, the scan speed also drops down significantly, sometimes even to the level of less than one page a minute for 600 dpi resolution in consumer grade scanners. High speed professional grade scanners do exist at much higher price than a regular consumer can afford. However, even the professional grade scanners suffer significant speed loss when dpi resolution increases and when scanning with color. In another aspect, such prior art digital imaging devices must employ highly elaborate and complex mechanisms to ensure that paper originals can be loaded properly into the scanning mechanism housing, pulled through the scanning mechanism evenly and steadily so that the captured image is of high quality, and to ensure that paper originals are unloaded properly into a receiving tray when scanning is finished.
[0012] Such complex mechanical assemblies are most often not space efficient in either surface dimensions or vertical dimension. Furthermore, the higher the scanning speed requirement, the more complex the mechanism is required to be, and the bulkier such devices tend to become. Also, such prior art imaging devices are not suitable for capturing images of 3D objects not in the form of a sheet of paper, due to the flat glass top and the paper loading mechanism.
[0013] When there is the need of scanning multiple paged documents, automatic paper feeding methods or systems are no longer suitable for working with these new document camera-scanner devices. An example of a prior art paper loading apparatus is described in U.S. Pat. No. 5,213,426. If one is to follow the general process of paper loading, transporting, scanning, and then unloading, an automatic paper feeder mechanism has to include a highly sophisticated mechanism to stop a sheet of paper completely while ensuring that it is exposed in full view of the camera-scanner looking down, before a complete image can be captured, and before the paper is removed in an unloading action sequence. Following such traditional design, the resulting mechanical assembly required to work with a document camera-scanner, could be even more complex, elaborate, and bulkier than the automatic paper feeder units included in the prior art devices.
SUMMARY OF THE INVENTION
[0014] The disclosed apparatus combines a highly compact high resolution document camera in place of a commonly used linear scan head, with a scanner-copier-printer mechanism, which is most likely but not limited to a laser or inkjet printer. Optionally, the apparatus can be further integrated with a facsimile transmission and receiving device to send and receive faxes, hence becoming a scanner-copier-printer-fax apparatus in one.
[0015] The facing-down document camera is capable of capturing digital images of minimum resolution of 2 mega pixels, and reach higher resolutions beyond 20 or 30 mega pixels. The document camera is supported on an adjustable stand that is mounted on the side of a printer encasing with a flat surface on top. The adjustable stand can be further folded and rotated along one side of the printer for portability and space efficiency when not used. The printer unit can be a ready-made printer “engine” re-purposed and enclosed in a custom casing shell to ensure that facing-down document camera, the adjustable camera stand, a control and display panel unit, and the casing shell for the internal printer “engine” all fit into an integrated device.
[0016] The facing-down camera can take a snapshot digital image of a document lying on the top surface above the printer unit, which is equivalent to finishing scanning of a full page document, and subsequently transmit the digital image to an internal storage device or a host computer, with a single click action often in less than 100 ms or significantly faster in time. This speed improvement is an improvement over the linear scanning mechanism employed in prior art multifunction scanner-copier-printer-fax devices. This addresses the scanning aspect of the multifunction apparatus.
[0017] Once the digital image is captured by the facing-down document camera device, in parallel to the transmission of the image to a permanent storage or a host PC, the captured image is stored in real time access memory and serves as the input image for the printer's driver software and produces a printed copy of the document image. This is the copier function of the multifunction apparatus. The captured digital image can also be forwarded to an optionally integrated facsimile transmission unit which can be connected via a telephone line to send fax out to other regular fax machines. The same facsimile unit can receive incoming fax communications and forward to the printer for printing out. Hence fax functionality is integrated into the apparatus in this fashion.
[0018] An optional Automatic Document Handler device can be further integrated into the apparatus to enable automatic batch processing of multiple pages of document placed into the apparatus as a stack of paper. An embodiment of the document imaging apparatus includes a housing that has a paper storage tray for statically retaining a plurality of sheets of paper. A digital image sensing device for capturing a bitmap image is attached to the housing via an adjustable digital image sensing device stand. A document removal apparatus is operable through a suction picker and a plurality of rollers. The suction picker applies a suction force to a top surface of a single sheet of paper on top of the plurality of sheets of paper, raises and removes the single sheet of paper from the stack of paper and transfers the single sheet of paper toward the plurality of rollers. A fan unit within the suction picker creates a vacuum. Alternatively, a pump can be used to create the vacuum.
[0019] A variation of the document imaging apparatus is one that includes a paper position sensing unit. A central processing unit is also included to determine a position of the single sheet of paper and to capture an image via the digital image sensing device. To capture an entire image of a page in one pass and to eliminate the need to scan a document line-by-line as has been done in the past, the digital image sensing device includes an infinite length focal lens. To accommodate various sizes and positions of paper, the digital image sensing device is adjustable in three dimensions. Also, if necessary, the digital image sensing device can capture video in real time.
[0020] A second embodiment of the document imaging apparatus is one that includes a motorized document removal assembly that has at least one roller wheel picker and a plurality of rollers. The roller wheel picker can be raised and lowered and has a picker wheel that is made of a material that is sticky enough (i.e., a coefficient of friction of 1 or more) so that a roller of the roller wheel picker can apply a frictional force to a top sheet of the paper and thereby remove the top sheet of paper from the stack. The material of the picker wheel can be, for example, any type of rubber such as silicone or acrylic. The roller wheel picker is capable of transferring the top sheet of paper toward a plurality of rollers that are positioned to cause the top sheet of paper to exit the document imaging apparatus. The components of the present embodiment are housed in a housing that contains a paper storage tray and that supports an adjustable digital image sensing device stand, which supports the digital image sensing device. Through the adjustable digital image sensing device stand, the digital image sensing device is adjustable in three dimensions.
[0021] This embodiment of the document imaging apparatus also includes a central processing unit that can work along with a paper position sensing unit and thereby determine a position of the top sheet of paper and to capture an image via the digital image sensing device. Any of the embodiments disclosed herein can include a digital image sensing device that comprises an infinite length focal lens and that can be configured to capture or create a real-time video stream.
[0022] Another embodiment is a document imaging apparatus that can scan an entire document with a single scan. In other words, line-by-line scanning, as is done in existing systems, is not required. This embodiment includes a housing that supports an adjustable swing arm unit and a document camera scanner unit that is housed within the swing arm unit.
[0023] Other features of the disclosed embodiments can be added to this embodiment (similarly, features of any embodiment disclosed herein can be mixed and matched with any other embodiment). For example, the present embodiment can be used with a digital image sensing device having an infinite length focal lens and that can be configured to capture a real-time video stream. Also, this embodiment can include any of the above described document removal assemblies, position sensing units and central processing units. This embodiment also includes lighting accessories that enable the document image sensing device to attain a clearer image of the document being imaged. Use of the lighting accessories is not limited to this embodiment. The lighting accessories can be used in any of the embodiments disclosed herein.
[0024] Yet another embodiment, the present invention includes a display panel, which is significantly bigger than commonly used display panels used in most multifunction scanner-copier-printer-fax devices. The display can be pulled out or retracted into a slot on the top part of the apparatus. A larger screen allows users preview image or a realtime video effectively on the display. The electronic components of the apparatus can include Micro Controller Units (MCU) or other types of full function system centered around a Central Processing Unit (CPU), on which an Operating System (OS) can run. In a preferred embodiment, the apparatus can include a full functioned OS such a condensed Linux kernel, Google Android, or other small footprint OS. Such OS embedding within the apparatus can allow for connectivity between the apparatus and another host computer, or with other computers on an IP network, through networking functionalities supported by the OS. Electronic mail software and other software programs which can transmit data over TCP/IP networks can execute within such an environment. Digital images captured by the document camera unit can be stored and managed locally, and can be also transmitted via email, uploaded to web sites, or any other utility that can transport image files over IP networks. There are numerous online electronic faxing service establishments over IP networks. Once the apparatus is connected to an IP network, users can link directly with any online electronic faxing service of their choice to send and receive faxes digitally. Such functionality can be considered as the apparatus being a virtual fax machine.
[0025] By combining a facing-down high resolution document camera with a printer device and an optional facsimile machine unit, linear scanning mechanisms in commercially available multifunction machines, which are limited by the linear scanning speed, are virtually replaced. A new type of high speed, high resolution scanner-copier-printer-fax, all in one machine is enabled.
DESCRIPTION OF THE ACCOMPANYING FIGURES
[0026] FIG. 1 is an illustrative example of a document camera device;
[0027] FIG. 2 is perspective view of the document camera device with optional functional components;
[0028] FIG. 3 a is a perspective view of another embodiment of the multi-function apparatus;
[0029] FIG. 3 b is a closer view of the components of the embodiment shown in FIG. 3 a ;
[0030] FIG. 4 a shows details of a motorized suction picker housing in an raised position;
[0031] FIG. 4 b shows details of the motorized suction picker housing in a lowered position;
[0032] FIG. 5 shows details of the motorized roller paper picker housing;
[0033] FIG. 6 is an embodiment of the document camera device's electronic control system;
[0034] FIG. 7 is another embodiment of the document camera device's electronic control system;
[0035] FIG. 8 illustrates methods for operating the apparatus in a logic flow diagram;
[0036] FIG. 9 illustrates another embodiment of the document camera device;
[0037] FIG. 10 is cross-sectional view of the embodiment illustrated in FIG. 10 ;
[0038] FIG. 11 is an illustration of the internal configuration of the apparatus's imaging electronic and optical components;
[0039] FIG. 12 is another embodiment of the electronic control components of the document camera device; and
[0040] FIG. 13 illustrates an operation procedure and internal system processing logic flow.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0041] FIG. 1 is a perspective view of a disclosed apparatus 100 , which combines a facing-down document camera 107 (alternatively referred to herein as a “document camera-scanner unit” or “DCSU”) with a printer that has a printer top cover 103 on which documents are scanned. The DCSU 107 has a field of view of the entire top surface area of the printer top cover 103 . DCSU 107 is enclosed in a swing arm unit (SAU) 101 , which is connected to and can rotate on the top of a Document Camera Stand 102 . When the swing arm unit 101 is rotated down in a folded position, the document camera stand 102 structure can be rotated at its base clockwise to be in a fully folded configuration toward the printer so that the apparatus as a whole is space efficient, making it easier for storage when not in use, and more portable.
[0042] The document camera stand 102 is motorized to move up or down in a telescoping motion to move the document camera-scanner unit 107 closer to or further from a paper document or 3-dimensional object 109 that is placed on the printer top cover 103 . Such mechanical telescoping motion is equivalent to zooming in or zooming out in optical engineering teinis. At the document camera-scanner unit 107 's maximum imaging resolution, moving the document camera-scanner-unit 107 physically closer to the object 109 , ensures that object images can be captured at the highest dots per inch (dpi) or pixel per inch (ppi) measure. The DCSU 107 has a minimum resolution of 2 mega pixels, and can reach 30 mega pixels. The image capture is executed with a single click input from a User Interface implemented on a Retractable display screen and central control Unit (hereinafter alternatively referred to as “DSC-CCU”) 104 . The time it takes to complete the capture is significantly below 100 milliseconds.
[0043] Once a digital image of the object 109 is captured, it will be displayed as a preview picture as a live video stream or a still image shown as an object picture 110 displayed on a sufficiently sized display screen and central control 104 . The display screen and central control 104 can initiate a transfer of the captured object picture 110 electronically through a printer driver to an integrated printer unit (alternatively referred to hereinafter as “IPU”) 108 . There can be numerous implementations of printer units such as laser, inkjet, or other types of printers. Upon receiving electronic data of the object picture 110 , and control instruction from the display screen and central object picture 104 , integrated printer unit 108 prints one or more copies of the object picture 110 , which realizes the copier function of the apparatus.
[0044] The display screen and central control unit 104 can be pulled out or retracted into a slot on the top part of the apparatus 100 . A larger screen allows users to preview an image or a real-time video on the display. The electronic components of the apparatus 100 can include Micro Controller Units or other types of full function systems centered around a central processing unit, on which an operating system can run. In some embodiments, the apparatus includes a full functioned operating system such a condensed Linux kernel, Google Android, or other small footprint operating system. Such operating systems embedded within the apparatus can allow for connectivity between the apparatus and another host computer, or with other computers on an IP network, through networking functionalities supported by the operating system.
[0045] Also shown in FIG. 1 is a Printer Paper Loading Tray (PPLT) 106 , where blank paper for the integrated printer unit 108 can be placed before being loaded into the integrated printer unit 108 for printing. Paper exit tray 105 is at the bottom part of the apparatus 100 where printed documents are deposited.
[0046] FIG. 2 is a perspective view of an embodiment 100 that integrates optional functional components into the apparatus 100 . A motorized paper unloading assembly 203 is located on the apparatus and is responsible for picking up a top sheet of paper and removing it to the outside of the enclosure structure of the apparatus. A static paper tray unit 207 is located in the middle and main section of the apparatus 100 , and should be operated with an open top. A top cover is optional which allows for placing 3D or 2D objects on the cover to be photographed. The top cover is provided to serve as a surface on which to place objects. In this way, an object will not have to rest directly on the stack of paper or static paper tray unit 207 , thereby avoiding damage to each. The document camera-scanner unit 107 captures a digital image of the top sheet of paper on the paper stack placed inside the static paper tray unit 207 in a single snapshot motion. This image capture motion is completed in the same way for capturing an image for a single sheet of paper on the top cover of a printer base unit enclosure as illustrated in FIG. 1 .
[0047] Immediately following completion of capturing the image of the top sheet of paper, the motorized paper unloading assembly 203 is responsible for moving in on top of the paper stack, lifting up and removing the top sheet of paper away from the static paper tray unit 207 and transporting the top sheet of paper to the outside of the apparatus' overall enclosure, by employing a suction picker mechanism combined with rollers with high friction coefficient. Such motion of the motorized paper unloading assembly 203 temporarily obstructs the field of view of the DSCU 107 , and the motorized paper unloading assembly 203 quickly retreats back to its position outside of the field of view of the DSCU 107 . As soon as the motorized paper unloading assembly 203 completes the removal of the top sheet of paper from the static paper tray unit 207 , it signals the DSC-CCU 104 to initiate another snapshot image capturing of the next sheet of paper now on the top of the paper stack. Such picture capturing and removal of the top sheet of paper repeats until all sheets of paper on the stack are digitally photographed and emptied from the static paper tray unit 207 . The above mentioned devices and methods fulfill the function of combining an automatic document handler with the apparatus 100 .
[0048] The roller and gear assembly MPUA for removing one sheet of paper at a time can be achieved in the embodiment illustrated by 301 in FIG. 3 a . FIG. 3 a is a perspective view of another embodiment of the multi-function apparatus. A motorized paper unloading assembly (MPUA) 301 is located on the right end of the apparatus, which is responsible for picking up the top sheet of paper and removing it out to the Receiving Tray Unit (RTU) 306 . An outer shell unit (OSU) 303 functions as the apparatus's housing and supporting all parts that comprise the whole apparatus. Electronic printed-circuit board units are located inside the OSU 303 and under a display panel of a central control unit (CCU) 307 . The electronic units control the entire sequence of motions to move the DSCU, trigger paper picking actions as soon as an image is captured, removes the top sheet paper to a receiving tray unit 306 , and repeats the image capturing for the next sheet of paper until the entire stack of paper is digitally photographed and removed from the SPTU 302 . A Swing Arm Unit (SAU) 305 houses the camera lens, image sensor, and the digital imaging unit inside. When fully extended, the SAU 305 can be moved along side the OSU 303 to a predetermined position either closer to or farther from the MPUA 301 to center its location when paper size is adjusted. The DSCU 304 also adjusts its height to predetermined positions according to different paper sizes through a telescoping motion. The ability of adjust the position of the DSCU 304 both vertically and laterally, makes it possible for the system to capture digital images or “scan” documents of variable sizes. Lighting accessories 310 can be built into the side wall of the SPTU 302 to ensure good lighting conditions to achieve the optimal quality in color and clarity reproduction in captured digital images.
[0049] FIG. 3 b is a closer view of the embodiment shown in FIG. 3 a with a partial section view of the outer shell unit 303 , within the same preferred embodiment as shown in FIG. 3 . The MPUA 301 is comprised of at least one Suction Fan 401 whose turning creates a vacuum and suction force in the suction picker unit (SPU) 402 , a suction picker mover (SPM) 403 , a set of paper remover rollers (PRR) 404 , and a finished paper chute (FPC) 405 . The field of view for the facing-down camera unit housed inside the swing arm unit 305 is illustrated by 407 . Initially, when a stack of paper is placed into the static paper tray unit 302 , the camera unit has an unobstructed field of view covering the entire surface area of the top sheet of the paper stack, while all the parts of the MPUA being outside of the field of view 407 . As soon as a digital photograph of the top sheet of paper is captured, the DSCU 304 sends a signal to the central control unit 307 , which will in turn signals the motorized paper unloading assembly 301 to initiate the paper removal motions. Once initiated, the suction picker mover 403 moves the suction picker unit 402 on top of the paper stack, then lowers the suction picker unit 402 close to the paper, with the Suction Fan(s) 401 running which creates the air suction force against the top sheet of paper on the stack (alternatively, a pump can be used to create the vacuum). The suction picker mover 403 then immediately moves the suction picker unit 402 upward to lift up the top sheet of paper, followed by a swift lateral movement toward the paper removal rollers 404 . At this point, the suction picker remover 403 is moved back to its original standby position, and has then removed itself from obstructing the Field of View 407 . Once paper is engaged with paper removal rollers 404 , it is quickly guided and pulled through the belts enclosing the paper removal rollers 404 , traveling through the finished paper chute 405 , and being transported into the receiving tray unit 406 .
[0050] FIGS. 4 a and 4 b show further detail of the MPUA 301 in a section view. FIG. 4 a shows the path a sheet of paper follows from the point it is picked up, to being captured by paper removal rollers 406 , guided through the finished paper chute 405 , and eventually reaching the receiving tray unit at the bottom of the apparatus. In FIG. 4 b , 507 is the paper stack to be “scanned” by the apparatus; Suction Nozzle (SN) 501 makes direct contact with the top sheet of paper on the paper stack 507 , and lifts up the first sheet by the suction force created by the suction fan 401 . Once a number of sheets on the top of the stack are removed, the paper stack can be moved higher through a controlled or spring loaded mechanism. Such a design ensures that only the top sheet of paper is lifted with virtually no possibility of lifting and removing more than one sheet of paper at a time from the Paper Stack 507 . In FIG. 4 b , suction nozzle 501 and suction nozzle roller (SNR) 502 are in a “DOWN” position to make direct contact and to exert suction force on the top sheet of paper. In FIG. 4 a , the SN 501 and the suction nozzle roller 502 are lifted in a vertical motion first, by the motorized mover system (MMS) 504 , and followed by a lateral motion also actuated by MMS 504 , which moves the lifted top sheet of paper to be secured in between the suction nozzle roller 502 and a paper alignment roller 503 . The rotation motion of suction nozzle roller 502 and PAR 503 , guides the paper sheet toward the paper removal rollers 404 , which are enclosed in a pair of Motorized Paper Mover Belts (MPMB) 506 . Once the paper sheet reaches and engages the motorized paper mover belts 506 , it will be further guided through to pass through a smooth and curved are in the FPC 405 . The paper sheet eventually reaches the RTU 306 . The above mentioned process of unloading the top sheet of paper is only limited in speed by the lowering motion, which is similar to a cat claw down swing motion, and the up-lifting motion of the SN 501 , SNR 502 , created by the MMS 504 . As long as this paper sheet capturing and removal motion is executed expeditiously, there is virtually no other complex paper controlling mechanism necessary in the subsequent actions to transport the paper sheet to its final destination in the RTU 306 . Hence, the end result of this embodiment is that the apparatus can remove a stack of paper at very high speed. Additionally, the elimination of complex and prolonged paper sheet transportation within the apparatus makes it possible for the embodiment to avoid frequent paper jams or other possible errors. The employment of suction force ensures that the second or other sheets of paper further down the paper stack 507 are not removed together with the top sheet undesirably.
[0051] In the embodiment shown in FIG. 5 , the Suction Nuzzle 501 and the suction nozzle remover 502 are replaced by a motorized roller assembly, which follows a similar down swing motion as the suction nozzle remover 502 , but employs only a roller to pick up the top sheet of paper. The surface material of the roller reaching down to contact the paper, is made of specialized rubber material, which has significantly high friction coefficient (i.e., a coefficient of friction of about 1 or more) in order to move the top sheet of paper with friction without pulling the second sheet of paper or the sheets further below. In this embodiment, element 602 is the paper picker roller, element 603 is the paper alignment roller, element 604 is the motorized mover system, element 606 is the paper remover roller and belt unit (PRRBU), element 607 is the paper stack, and element 605 is the finished paper chute (FPC). The other parts in the MPUA 301 remain similar to the embodiment using the suction nozzle. The material of the picker wheel can be, for example, any type of rubber such as silicone or acrylic.
[0052] FIG. 6 is one embodiment of the electronic control system that can execute the necessary logic processing in software and electronic circuits. These components can be implemented on one or more Printed Circuit Boards, which can be housed inside the CCU 307 and the swing arm unit 305 . Central Processing Unit (CPU) 703 processes a series of computational functions, including: a) the format encoding and transcoding of a captured bitmap image; b) image file compression such as compression in JPEG or Motion JPEG formats; c) implementation and execution of USB high speed data communication protocol; d) receiving resulting signals of Paper Position Sensor (PPS) 711 and Stack Empty Sensor (SES) 712 , and processing subsequent actions in response to these sensor signals; e) performing User Interface functionalities by receiving user inputs from a keyboard unit 710 while computing and producing data for the graphics display unit 704 ; and f) general logic processing and computations.
[0053] The Memory Unit (MU) 701 is responsible for: a) storing or caching intermediate results of various computations by the CPU 703 ; b) saving image compression result data; c) storing and relaying the stream of data communication between the CPU 703 and the USB Ports (USB) 702 . Image Sensor (IS) 709 is responsible for converting optical images into digital information in forms of image bitmaps as still images or PCMs for real time video stream. Keyboard Unit (KBU) 710 captures user inputs and user feedback to system displays through buttons and the accompanying electronic circuitry. Paper Position Sensor (PPS) 711 signals the CPU the current position of a sheet of paper in the process of being removed from the PTU 302 and whether it is completely removed. The mechanism used to sense the position of a sheet of paper is a light beam, infrared for example, that is sent out toward a receiver at or near the static paper tray unit. When paper is in the path of the light beam, no light will pass through from the light emitter to the light beam and the system can be programmed to capture an image. However, when paper completely passes through from the emitter to the beam, the system will know that a new sheet of paper needs to be placed on the static paper tray or the sheet of paper needs to be adjusted. Stack Empty Sensor (SES) 712 signals the CPU 703 whether the paper stack placed in PTU 302 is emptied. USB Ports (USB) 702 a) transfer encoded still image or video stream data to a host computer; b) relay control signals and status data from the apparatus to a host computer; c) relay control signals and status data from a host computer to the apparatus. Graphics Display Unit (GDU) 704 receives information from the CPU 703 such as system status, system function selection menu, and confirms user selection inputs. Paper Picker Controller (PPC) 705 is the electronic controller for moving and stopping, the speed of the motions of motorized mover system 504 . Paper Picker Motor (PPM) 706 receives control signals from PPC 705 and is the actual motor which actuates motion of the motorized mover system 504 . The paper removal controller 708 is the electronic controller for signaling the starting, stopping, and speed of the Paper Remover Motor (PRM) 707 , which in turn actuates and stops the motion of motorized paper mover lids 506 in FIGS. 4 a and 4 b , also illustrated as paper removal roller and belt unit 606 in FIG. 5 .
[0054] FIG. 7 is an alternative embodiment of the electronics control and image processing system for the apparatus, based on a Micro Controller Unit (MCU) 804 chip. In this embodiment, the CPU 703 is replaced by a MCU 804 in junction with an Image Processing Co-Processor (IPCP) 802 . The MCU 804 processes a number of control functions, including: a) implementation and execution of the USB high speed data communication protocol in communicating with the USB Ports (USB) 803 ; b) receiving result signals of Paper Position Sensor (PPS) 811 and Stack Empty Sensor (SES) 812 , and processing subsequent actions in response to these sensor signals; c) performing User Interface functionalities by receiving user inputs from the Keyboard Unit (KU) 810 while computing and producing data for the Graphics Display Unit (GDU) 805 ; and d) general logic processing and computations. IPCP 802 processes functions including: a) format encoding and transcoding of a captured bitmap image; b) image file compression such as compression in JPEG or Motion JPEG formats; c) implementation and execution of the USB high speed data communication protocol; d) signaling MCU 804 for image processing status; and e) executing instructions received from MCU 804 . All other components in FIG. 7 correspond to identical parts in FIG. 6 and have identical functions. The only exception is USB 803 not only communicates with MCU 804 but also communicates with IPCP 802 in this embodiment.
[0055] To operate the disclosed embodiments, a the user presses a button or clicks on a control icon implemented in software running on an accompanying PC, sending a signal to the Central Control Unit (CCU) 307 thereby initiating the whole process of automatic capturing of images for the paper stack. The DSCU 304 is sent a signal to capture a still image of the top sheet of paper on the stack. The captured image is sent to a personal computing device via high speed data communications link for storage or processing. As soon as the DSCU 304 finishes the image capturing action, the motorized paper unloading assembly 301 receives a signal to move in a sliding and swinging motion from a position that was outside of the field of view of the DSCU 304 to position itself above the top sheet of paper. Through a suction force created by a minimum of one suction fan mounted outside of a suction picker housing 402 , the motorized paper unloading assembly lifts up the top sheet of paper, and moves it laterally out through a set of Paper Remover Rollers 404 , eventually reach the receiving paper tray 406 . In an alternative embodiment, a roller assembly can be employed in place of the Suction Picker mechanism in the MPUA 301 . The gears and rollers as part of the MPUA are actuated to cause the rollers to rotate and cause the top sheet of paper to be moved to the outside of the static paper tray unit 302 . Once the top sheet of paper is removed from the paper stack, an optical sensor unit senses the completion of the removal action, and sends a signal to the CCU 307 to initiate the sliding motion of the MPUA 301 to move back to its hidden location to clear the field of view for the DSCU 304 . The sequence of action repeats until the image of last sheet of paper on the stack is captured and removed from the SPTU 302 .
[0056] Unlike a prior art image capturing device, when a document camera-scanner is deployed as the primary image capturing device from a facing-down suspended position, the batch scanning of multiple pages of documents can be accomplished by simply removing the top sheet of paper from the stack of originals placed inside the paper tray within the MPUA 301 . After a still image is captured for that top sheet, the image capturing and paper removal actions and automatically repeated until the whole stack of paper is processed and removed from the paper tray. In this novel approach for batch scanning multiple sheets of paper, there is no need for automatic or motorized paper loading gear assembly, and there is no need to consider paper jam prevention in subsequent transportation of paper while being pulled through a scanning mechanism, and there is no need to limit the speed of paper movement inside any complex and elaborate motorized gear and roller assembly. The removal of one sheet of paper at a time from a stack of paper is a significantly simpler and more straight forward process in comparison to the traditional paper feeding methods used in prior art devices.
[0057] When the digital document camera-scanner resolution increases to 5 mega pixel, 8 mega pixel, 10 mega pixel, or even 30 mega pixel levels, captured document images can reach clarity of 300 dpi to beyond 600 dpi level. This overcomes the problem of significant scan time delay experienced in prior art scanner devices. As an illustrative example, the traditional scan time delay for scanning a 48-bit color image of an 8.5″×11″ document at 600 dpi can take between 30 to 60 seconds or more in certain commercially available scanner product today. The time required to scan the same document with 48-bit color, at approximately 600 dpi resolution with a 10 mega pixel DSCU 304 described in this invention is less than 100 ms. Such time saving is highly significant, and makes scan time a non-factor regardless of dpi resolution or color depth of the captured images. The preferred embodiment of the presentation also adjusts to variable sized paper. the MPUA 301 employs a suction picker housing unit or a roller based unloading unit, which spans across the entire width of the static paper tray unit (SPTU) 302 , while the DSCU 304 adjusts its position vertically and horizontally to center and zoom in onto variable sized paper objects, which result in the capability of digitally photographing and properly removing any sized paper using this mechanism.
[0058] FIG. 8 illustrates the methods for operating the apparatus in a logic flow diagram. At 901 , a user places a stack of paper with a minimum of one sheet of paper in the SPTU 302 . The user then inputs the paper size information into the system at Step 903 , and inputs a “start” instruction through the keyboard unit 710 or 810 . At step 904 , the apparatus adjusts the vertical position of DSCU 304 to zoom in on the paper surface as much as possible to achieve the highest possible resolution. If the paper size is a standard size known to the apparatus, the DSCU 304 will move to predetermined corresponding positions vertically to achieve optimal resolution. The DSCU 304 also moves horizontally so that the camera lens is always placed straight on top of the center of the paper surface according to the user selected paper size. At Step 905 , the DSCU 304 takes a digital picture of the top sheet of paper and creates a bitmap image data file. At Step 906 , the captured bitmap image data is encoded and compressed by the IPCP 802 or is temporarily stored in the Memory Unit 701 and later encoded and compressed by the CPU 703 . At Step 907 , the electronic control and imaging system transmits captured and compressed images to a host computer (PC) via a high speed data link like the USB 702 or 803 . At Step 908 , once the transmission of the image data file to the host computer is complete, the CPU receives the status signal, and initiates the next stage of action control within the CCU 307 . At the next Step 909 , the CPU 703 or MCU 804 instructs the PPC 705 or 806 to initiate the motion sequence in picking up and removing the top sheet of paper from the paper stack 507 or 607 . At Step 910 , the MPUA 301 executes the picking and removal action.
[0059] At Step 913 , the CPU 703 receives a signal from the paper position sensor 711 regarding the paper removal status; or in the alternative embodiment, the MCU 804 receives a status signal from paper position sensor 811 . If the paper is not successfully removed, Step 912 and 911 are initiated to check for error conditions and process handling of the error condition or paper jam. At the end of Step 911 , Step 910 maybe repeated for the apparatus to resume operation. If the paper is successfully removed, the CPU 703 or the MCU 804 checks for stack empty sensor 712 or 812 stack emptied status, if the stack is not emptied, the process loops back to Step 905 for the image capturing for the next sheet of paper on the top of the stack, and followed by subsequent removal of that sheet of paper. If the stack is emptied at this point, the entire process ends.
[0060] FIG. 9 illustrates another possible embodiment using a more conventional configuration for placing the paper stack into the apparatus. In this embodiment, a paper tray unit cover 1002 can be swung open from a position overlying the static paper tray to rest in a slanted downward angle and serve as a paper loading tray. Paper Size Adjustment Lever (PSAL) 1001 adjusts a width of the paper loading tray 1002 to fit any sized paper within, and signals a central control unit (CCU) of the paper size. The central control unit signals the paper moving belt assembly (PMBA) 1004 to move inward to the center region so that paper will be secured underneath PMBA 1004 and on top of a vacuum table 1003 . A sheet of paper is removed from the bottom of the paper loading tray unit 1002 , transported to the vacuum table 1003 , and then stopped so that DSCU 301 can take a snapshot image of the top side of the paper surface, before the paper is moved away to the right side of the vacuum table through a finished paper chute into a receiving paper tray. Suction holes 1005 in the vacuum table help secure a sheet of paper firmly against the vacuum table. Paper removal roller assembly 1006 transports finished paper sheets through the finished paper chute.
[0061] FIG. 10 is a cross sectional view of the embodiment illustrated in FIG. 9 . It shows the detailed view of paper loading roller assembly 1101 , paper moving belt 1102 , paper removal roller assembly 1103 , finished paper chute 1104 , and receiving paper tray 1106 for depositing scanned in paper sheets.
[0062] FIG. 11 illustrates the internal configuration of the DSCU 301 ′s imaging electronic and optical components. Below printed circuit board (PCB) 1201 is optical lens 1203 . Above it is the imaging sensor chip 1204 . Images are captured when light 1205 is reflected through the lens 1203 onto the imaging sensor surface 1204 .
[0063] With further reference to FIG. 2 , an optional facsimile device is integrated into the embodiment 100 . Connectors 209 , 210 and 211 , respectively, connect the integrated Ethernet, USB and facsimile modules of the apparatus to a regular telephone line for sending and receiving faxes.
[0064] Electronic mail software and other software programs that can transmit data over TCP/IP networks can execute within such an environment. Digital images captured by the document camera unit can be stored and managed locally, and can be also transmitted via email, uploaded to web sites, or any other utility that can transport image files over IP networks. There are numerous online electronic faxing service establishments over IP networks. Once the apparatus is connected to an IP network, users can link directly with any online electronic faxing service of their choice to send and receive faxes digitally. Such functionality can be considered as the apparatus being a virtual fax machine.
[0065] When one or more images are captured into the RAM of DSC-CCU 104 , the image(s) are transferred to the fax module, which can then be transmitted via the connection 211 through a telephone line. For incoming fax transmission, the fax module receives fax images and then transfers to the DSC-CCU 104 , which will instruct the integrated printer module to print out copies so that the user can obtain paper fax copies. Alternatively, the received fax can be stored in the internal storage of the apparatus or be transferred to the host computer for viewing or management. In this embodiment, the pull out DSC-CCU 104 also includes electronic components, which supports TCP/IP network connectivity. This allows for the apparatus to transmit or receive images directly over the internet as an independent and fully functioning computer, which can allow images to be sent and received via email application software embedded in the apparatus or send or receive images via electronic or often referred to as virtual fax services offered on various web sites.
[0066] FIG. 12 is the diagram of the entire electronic control components in a preferred embodiment. The central control unit is the Micro Controller Unit (MCU) 454 , which receives data from supporting components of the apparatus, computes, and sends out control instructions or transfer data to the supporting components of the apparatus. For image capturing and processing, instructions are sent from the MCU 454 to DCSU 107 so that image is captured by the Image Sensor 451 , and subsequently processed by Image Processing Co-Processor (IPCP) 452 , which encodes and compresses images. The Images can be transmitted through the USB Ports 453 to a Host PC 455 , or stored temporarily within the RAM Unit 465 , or be stored within the Internal Storage Unit (ISU) 463 , or transmitted via the Network Unit 462 to other computers or devices connected via TCP/IP network on the internet.
[0067] For copier and printer functions, the MCU 454 will instruct and transfer data for captured images to the Printer Controller Module (PCM) 458 and through certain Printer Driver software which will enable the Printer 459 to produce physical printed copies of these images. For faxing functions, the MCU 454 will instruct and transfer data for captured images to the Fax Machine Controller Module (FMCM) 461 which will enable the Fax Machine 460 to send the images out to a receiving fax machine connected via a telephone line. For receiving faxes, the Fax Machine 410 will receive an incoming image, which it will transfer to the MCU 454 for processing via the FMCM 461 . The MCU 454 will subsequently instruct and transfer data to the Printer 459 via PCM 458 to print out a paper copy of the incoming fax.
[0068] FIG. 13 illustrates an operation procedure and internal system processing logic flow in a flow chart. At a first Step 551 , a user places one sheet of document on the top cover or a stack of paper into the SPTU 207 for the apparatus to scan, copy, or fax. At Step 553 , a user inputs paper size information into the apparatus through either a keypad unit or through a touch sensitive display unit. At Step 552 , a user presses a control button to start the processing sequence, along with further intention information such as whether to copy, scan, or fax. At Step 554 , the apparatus adjusts the DCSU 107 by moving it up or down to a predetermined vertical position on the document camera stand 102 according to the user imputed paper size; it also moves the DCSU 107 with the document camera stand 102 laterally along a guiding rail structure to position the camera's lens in the center of the paper document.
[0069] At Step 555 , the DCSU 107 is instructed to capture a digital snapshot image of the top sheet of paper on the paper stack. At Step 556 , the Image Processing Co-Processor encodes and compresses the captured digital image. At Step 557 , the encoded and compressed digital image is stored in RAM memory awaiting further action.
[0070] At Step 558 , the system performs logic switching based on the user's earlier input. If the user's earlier input was to send a fax, the apparatus performs fax sending at Step 559 . If the user's earlier input was to make copies of the original document(s), the apparatus performs printing function of one or more pages of the captured image of the original(s) at Step 560 . If the user's earlier input was to scan to local storage, the apparatus performs a storage processing of the captured image(s) into a Local Storage Unit at Step 561 . If the user's earlier input was to scan to a Host PC, the apparatus performs the necessary processing to transfer the captured digital image(s) to a Host PC via USB Ports or via IP network connections at Step 562 . Further, on the Host PC, a software program may execute faxing of the captured image via electronic fax services (also can be referred to as virtual faxing) at Step 563 .
[0071] At Step 565 , the apparatus checks the status data of a paper position sensor to detect whether the top sheet paper is successfully removed from the paper stack and completely transported out. If the status is not successful, the apparatus performs Error Handling processing, such as removing paper jams, at Step 564 . If the status is successful, then the apparatus proceeds to the next step.
[0072] At Step 566 , the apparatus further checks the paper position sensor to determine whether the paper stack is emptied completely. If not, the apparatus loops its processing sequence back to Step 555 to repeat the process until the SPTU 207 is completely emptied. At Step 567 , if the SPTU 207 is completely emptied and all images processed successfully, the entire process ends.
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Disclosed is a document imaging apparatus that includes a housing, which contains a paper storage tray, a digital image sensing device for capturing an image, an adjustable digital image sensing device stand supported by the housing and supporting the digital image sensing device, and a motorized document removal assembly comprising at least one roller wheel picker and a plurality of rollers, wherein the at least one roller wheel picker can be raised and lowered and is configured to apply a frictional force to a top surface of a single sheet of paper and to transfer the single sheet of paper toward the rollers. Optionally, a fax, copier, and printer and be integrated into the document imaging apparatus.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims priority to co-pending U.S. patent application Ser. No. 11/276,193 filed on Feb. 17, 2006.
TECHNICAL FIELD
[0002] The invention relates generally to the field of ceramic composite materials and, specifically, to a composite ceramic material having a tailored failure mode and including a lightweight foamed glass or foamed silaceous slag portion and a cemetitious, concrete, gypsum or other ceramic portion, and method of using the same.
BACKGROUND
[0003] Foamed glass is an established lightweight ceramic material. Typically, foamed glass is made in one of two ways. The first way involves preparing a stable foam from water and foaming agent, preparing a wet mixture or slurry of solid components (where cement is the main substance), quick mixing the foam and the slurry, filling molds with prepared the mixed foam/slurry, and firing the same. The second way to make foamed glass involves making use of the property of some materials to evolve a gas when heated. A foamed glass material may be prepared by mixing crushed vitreous particles and a foaming agent (such as CaCO 3 or CaSO 4 ), placing the mixture in a mold, heating the mold (such as by passing the mold through a furnace) to a foaming temperature, and cooling the mold to produce foamed glass bodies.
[0004] Slag is a nonmetallic byproduct of metallurgical operations. Slags typically consist of calcium, magnesium, and aluminum silicates in various combinations. Iron and steel slags are byproducts of iron and steel production. For example, an iron blast furnace is typically charged with iron ore, fluxing agents (such as limestone or dolomite) and coke (as fuel and reducing agent). Iron ore is typically a mixture of iron oxides, silica, and alumina. When sufficiently heated, molten slag and iron are produced. Upon separation of the iron, the slag is left over. The slag occurs as a molten liquid melt and is a complex solution of silicates and oxides that solidifies upon cooling.
[0005] The physical properties of the slag, such as its density, porosity, mean particle size, particle size distribution, and the like are affected by both its chemical composition and the rate at which it was cooled. The types of slag produced may thus conveniently be classified according to the cooling method used to produce them—air cooled, expanded, and granulated. Each type of slag has different properties and, thus, different applications.
[0006] While useful as insulation and as abrasive materials, foamed glass bodies (made with or without foamed slag), are typically unsuitable for use as lightweight filler and/or in composite materials due to factors including cost and the propensity for foamed glass to hydrate and expand.
[0007] Thus, there remains a need for an easily produced foamed glass material that is more resistant to expansion from hydration and/or more easily aged, and for composite materials incorporating the same. The present invention addresses this need.
SUMMARY
[0008] The technology discussed below relates to manufactured composite materials, such as roadbed and airport runway safety areas (RSA's) incorporating lightweight foamed glass and cementitious or other ceramic materials to define structural composite materials having controlled failure mode properties, and the method for making the same. One object of the present invention is to provide an improved foamed glass-containing structural composite RSA material. Related objects and advantages of the present invention will be apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic view of a first embodiment of a process for making foamed glass composites.
[0010] FIG. 2A is a schematic view of a second embodiment of a process for making foamed glass bodies and composites and its uses.
[0011] FIG. 2B is a schematic view of a third embodiment of a process for making foamed glass bodies and composites and its uses.
[0012] FIG. 3A is a schematic view of a process for mixing a batch of precursors for a foamed glass article according to a fourth embodiment of the present novel technology.
[0013] FIG. 3B is a schematic view of a process for firing a foamed glass article mixed according to FIG. 3A .
[0014] FIG. 3C is a perspective view of as milled glass powder according to the process of FIG. 3B .
[0015] FIG. 3D is a perspective view of rows of milled glass powder mixture ready for firing.
[0016] FIG. 3E is a perspective view of FIG. 3D after firing into a substantially continuous foamed glass sheet.
[0017] FIG. 4 is a process diagram of the process illustrated in FIGS. 3A and 3B .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] For the purposes of promoting an understanding of the principles of the claimed technology and presenting its currently understood best mode of operation, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, with such alterations and further modifications in the illustrated device and such further applications of the principles of the claimed technology as illustrated therein being contemplated as would normally occur to one skilled in the art to which the claimed technology relates.
[0019] Vitreous materials, such as soda-lime-silica glasses and metallurgical byproduct slags, are typically foamed through a gasification processes to yield a typically predominately vitreous, typically silaceous resultant cellular product. Typically, a foaming precursor is predominately vitreous or non-crystalline prior to the foaming process, since a glassy precursor slag material typically has a viscosity at temperature that is convenient to the foaming process. More typically, the vitreous starting material will have a traditional soda-lime-silica glass composition, but other compositions, such as aluminosilicate glasses, borosilicate glasses, vitreous peralkaline slag or other vitreous slag compositions may be foamed as well. For example, a peraluminous slag with significant alkali and alkaline earth oxides may also be utilized. After the vitreous precursor is foamed, the foamed glass is physically combined with cement to form a composite material suitable for building or structural applications or the like.
[0020] In the case of slagaceous precursor materials, the slag is typically predominately vitreous in character, and more typically has a maximum 40% by volume crystalline material. The slag is typically initially crushed and sized to approximately 10 microns median particle size, more typically at least 90 percent of all particles are less than 75 microns.
[0021] If the crushed and/or powdered slag is dry, water is added to the powdered slag to about 0.1 to about 0.5% (by mass). Alternately, if no water is added, limestone or other solid foaming agent may be added (typically about 4 percent or less by mass, more typically about 2 percent or less by mass). The mixture is then formed into pellets (between 0.05 and 1 cubic centimeter), preheated (to no more than within 25° C. of the dilatometric softening point) and then passed through a high temperature zone, such as one generated by a rotary kiln or a flame (contained in a ceramic or refractory metal tube). The residence time in the zone is short, typically about 0.5 to about 10 seconds, and the temperature is high (adiabatic flame temperature in excess of 1300° C.). In the case of a flame, the thermal energy provided to the material by the direct flame enables a change of state reaction in the foaming agent and the resulting gas will force the now viscous matter to foam. The foamed pellets or foamed media are air quenched below the dilatometric softening point of the material, and then allowed to dry by slow cooling.
[0022] The foamed media typically have a relative volume expansion in excess of three fold, and more typically the volume expansion is as high as 10 fold or greater. This process results in individual, low-density (specific gravity less than 0.3) foamed media with a median pore size in the range of 0.1 to 2 mm.
[0023] Composite materials may be prepared by mixing the foamed slag with Portland cement; at least two types of composite materials may be made according to this technique. A first composite material may be prepared by mixing a thin mixture of cement with foamed media, wherein the foamed media comprises at least 85 volume percent of the total cement/other aggregate. The foamed media are typically incorporated into the cement (and aggregates, if needed) after the water has been added. The resulting mixture acts as a very viscous material and is pressure or gravity formed into a slab (or other coherent shape) or direct cast into a prefabricated form. The shape or form is then allowed to set. The resulting composite material sets up to be a rigid, relatively lightweight (specific gravity <0.75) material with surface properties typical of Portland cements. Chemicals and finishing systems compatible with Portland cement can be used in conjunction with this material.
[0024] A second composite material is formed as a mixture of cement with typically less than 50 volume percent foamed slag media. The media is typically dry mixed with cement prior to water additions. The mixture is then prepared as common cement. Additional aggregates may be incorporated as per common practice. This second composite material has a very high strength; the composite compressive strength is typically at least 25% higher per unit mass than is that of the identical cement prepared without the foamed slag addition. It can be used in any application compatible with Portland cement.
[0025] A third composite material is formed as aqueous slurry mixture comprised of gypsum with typically less than 50 percent by volume foamed glass or slag. The media are typically added to the gypsum after the material is slurried. Additional binders, fillers and setting agents may be added per common practice. The resulting material has a very low density and high acoustic absorption. There are no chemical compatibility limitations on the extent of foamed glass additions. Any limitations typically arise from strength considerations and other physical properties.
[0026] In another example, the vitreous precursors 210 to the foaming process are waste glasses. Waste glasses typically have a soda-lime-silica composition, and are generally first crushed or ground 220 , and then typically sized 230 , to produce a particulate frit 235 suitable for pelletizing 250 or otherwise forming into regular shapes for foaming.
[0027] As with slagaceous precursors as described above, if the particulate waste glass 210 is dry, water may be added to the in small amounts to promote handling and to better adhere the foaming agent uniformly to the particles for more even distribution. Alternately, if no water is added, limestone or other solid foaming agent 240 may still be added, typically in small amounts (such as less than 2 percent by mass) and mixed to form a substantially heterogeneous foamable vitreous mixture. The mixture 245 is then typically formed 250 into pellets (between 0.05 and 1 cubic centimeter), loaves, or other regular green bodies 260 convenient for foaming and is next preheated 265 , typically to no more than within 25° C. of the dilatometric softening point. Preheating 265 readies the green bodies 260 for rapid heating 270 into the foaming temperature region.
[0028] The preheated green bodies 260 are then passed through a high temperature zone 275 , such as one generated by a rotary kiln or a flame (contained in a ceramic or refractory metal tube). The residence time in the zone is short, typically about 0.5 to about 10 seconds, but may be longer for larger green bodies 260 . The temperature is substantially high (adiabatic flame temperature at least about 1200° C. and typically around 1300° C. or higher). The rapid influx of thermal energy provided to the material enables a change of state reaction in the foaming agent 240 and the resulting gas will force the now viscous matter to foam.
[0029] The foamed bodies 275 are then rapidly quenched 280 to below the dilatometric softening point of the material, and then allowed to cool to room temperature at a second, typically slower, cooling rate. The cooling rate is typically rapid enough such that the foamed glass 275 does not anneal or only partially anneals, resulting in a harder foamed glass body 285 with built-in stresses that enhance its crushing strength and toughness, and also give rise to a crushing failure mode in compression and torsion. The cooling rate typically varies due to belt speed. The high end is typically about 15-25° C. per minute, while the low end is typically about 10-20° C. per minute for the temperature range from the foaming temperature to just below the dilatometric softening point; more typically, cooling from the foaming temperature to below the dilatometric softening pint temperature occurs at a rate of about 20 degrees Celsius per minute. The cooling rate typically diminishes as the body 285 approaches the softening point.
[0030] After foaming, the bodies 275 leave the kiln and are quenched 280 , typically via exposure to air or forced water jacket cooling, and the cooling rate is increased to about 25-40° C. per minute during the rapid quench, more typically at least about 30 degrees Celsius per minute. After the rapid quench, the cooling rate is decreased to about 3-10° C. per minute. All cooling rate values are for the center of the foamed glass bodies 285 .
[0031] For foamed media produced on a belt process, the pellets or green bodies 260 are typically configured such that the resultant foamed glass bodies 275 , 285 have irregular oblong or ovoid shapes. More typically, the green bodies 260 are preformed or pressed pellets sized such that the resultant foamed bodies 275 , 285 have major axis dimensions of between about 10 mm and 80 mm. Accordingly, these bodies 285 are typically sized and shaped to be engineered drop-in replacements for mined gravel aggregate and have superior water management, compressive strength, failure mode, erosion, stackability, chemical stability and toughness properties. Alternately, the foamed bodies 285 may be made to other convenient size and shape specifications, such as in larger orthorhombic parallelepiped or ‘brick’ shapes, still larger ‘cinder block’ dimensions, relatively thin plates, and the like.
[0032] One advantage of this process is that the furnace residence time of vitreous bodies 275 during the foaming process is reduced a factor of 4-9 over most conventional glass foaming techniques. Moreover, the foamed glass bodies 285 can be produced with mean cell sizes of less than about 0.2 mm in diameter, and with typically individual cells sizes ranging down to about 0.1 mm in diameter or less. Bodies 285 having such small cell sizes are typically of the closed cell type, which gives rise to crushing strengths of well over the typical 100 psi (for comparably dense open cell material) to well over 200 psi. Further, bodies 285 having substantially open cells sized in the less than 0.1-0.2 mm range exhibit enhanced capillary action and accordingly rapidly absorb and efficiently retain water.
[0033] The natural break-up of the material under rapid cool down, due to thermally induced stresses, results in a more angular, jagged foamed glass body 285 as opposed to a foamed glass piece shaped by crushing a large body. The physical measure is that the so-produced foamed glass bodies 285 have a range of aspect ratios (largest to smallest diameter) about 50% higher than the 1 to 1.25 ratio average for smaller bodies formed via a crushing process. This gives rise to the 35 degree stacking angle and ensures the material breaks up before slip failure.
[0034] In one example, oblong, irregularly shaped foamed bodies 285 produced as described above and having major axial dimensions of about 80 mm are used as fill material 290 behind rock retaining walls. As these fill material bodies are relatively light weight, relatively strong in compression, have a characteristic stacking angle of about 35 degrees and are characterized by an open pore structure, a substantially smaller volume of foamed glass aggregate fill is required as compared to traditional mined gravel. For a 6 foot retaining rock wall, the required foundation thickness is reduced from 54 inches to 24 inches, the required rock is reduced by 7.5 cubic feet per linear foot of wall, and the required concrete is reduced by 2.5 cubic feet per linear foot of wall. The amount of graded fill is reduced from 40 cubic feet per linear foot of wall to 24 cubic feet per linear foot of wall. This reduction is made possible by the high stacking angler (about 35 degrees) of the foamed glass aggregate material 290 , the physical manifestation of which is its tendency to fail by a crushing mechanism (shattering of the individual cells) instead of the individual aggregate pieces sliding over themselves. Additionally, the open pore structure of the foamed glass aggregate 285 gives rise to superior drainage and water management properties, reducing or eliminating the need for a separate inlaid drain pipe. In other words, by replacing mined gravel with engineered foamed glass aggregate 290 characterized by a high stacking angle, the amount of fill may be nearly halved and, consequently, the foundation depth and wall thickness may likewise be substantially reduced.
[0035] Likewise, the foamed glass aggregate fill may replace traditional mined fill gravel 295 in road beds. Less volume of the foamed glass aggregate fill is required, as it has superior strength, porosity and failure mode characteristics, giving rise to shallower road beds, reduced construction time and expenses, less excavated dirt to be trucked away, reduced energy usage in road construction, simplified road drainage, and the like. Moreover, the roads themselves may be constructed of concrete including foamed glass aggregate made as described above, which likewise has enhanced strength and decreased weight characteristics.
[0036] In another embodiment, the foamed glass bodies produced as described above may be incorporated into acoustic ceiling tiles 300 . The foamed glass material is chemically stable and inert, non-toxic, lightweight, and its porosity gives rise to sound-dampening. The tiles may be made entirely of shaped foamed glass (in the form of relatively thin panels), or may incorporate foamed glass particles or bodies in a structural matrix, such as a polymer based, fibrous, cementitious, or like matrix material. Of course, the foamed glass bodies 285 may also be used as aggregate 305 in traditional concrete.
[0037] In another embodiment, foamed glass bodies 285 are produced, in some typical embodiments as described above, for incorporation into RSA's 350 . Typically, the foamed glass bodies are produced having a closed cell or closed porosity structure to prevent water infiltration and hydration. The foamed glass material is chemically stable and inert. The RSA's 350 are typically formed from a foamed glass composite material 360 including foamed glass bodies 295 in a ceramic matrix 370 . Typically, the composite material includes at least about 50 volume percent foamed glass, more typically at least about 60 volume percent foamed glass, still more typically at least about 70 volume percent foamed glass, yet more typically at least about 80 volume percent foamed glass, and in some embodiments at least about 90 volume percent foamed glass. The foamed glass bodies may be in the form of aggregate 305 , shaped foamed glass blocks, or a combination of sizes and shapes incorporated into a structural matrix 370 , such as a polymer based, fibrous, cementitious, or like matrix material. In some embodiments, the foamed glass bodies 285 may also be used as aggregate 305 in traditional concrete. For RSA's, a higher relative volume of the foamed glass aggregate 305 and/or bodies 285 fill is required, as the composite RSA 360 typically has lower crush strength to provide the desired predetermined failure mode characteristics, i.e., the RSA 360 will crush under the weight of an oncoming aircraft to bleed off its kinetic energy and slow its progress across the RSA 360 until it stops. Moreover, the RSAs 360 are typically constructed of foamed glass bodies 285 and/or aggregate 305 (more typically closed cell foamed glass aggregate 305 and/or bodies 285 ) in a thin ceramic or structural matrix 370 , wherein the surface 375 of the RSA 360 is matrix material 370 . The matrix 370 may be concrete, asphalt, or the like. The RSA 360 typically has a solid surface 375 , and more typically has a textured or contoured surface 375 to further bleed kinetic energy from an oncoming aircraft.
[0038] The foamed glass bodies 285 for the RSA composite 360 may generally be prepared as described above, albeit the bodies 285 are typically foamed at a higher temperature, typically between about 1600 degrees Celsius and about 1900 degrees Celsius, to yield a closed pore structure. In other embodiments, the foamed glass may be prepared by the techniques described in U.S. Pat. Nos. 5,821,184 and 5,983,671, or the like.
[0039] FIGS. 3A-4 illustrate another method of producing lightweight foamed glass matrix 110 defining a plurality of voluminous, closed off and/or interconnecting pores 115 . The pores 115 typically have diameters ranging from about 0.2 mm to about 2.0 mm. The pore walls 117 can be formed to exhibit a crazed or microcracked microstructure 119 . As illustrated schematically in FIGS. 3A-4 , a ground, milled and/or powdered glass precursor 120 , such as recycled waste bottle and/or window glass, is mixed with a foaming agent 122 (typically a finely ground non-sulfur based gas evolving material, such as calcium carbonate) to define an admixture 127 . The foaming agent 122 is typically present in amounts between about 1 weight percent and about 3 weight percent and sized in the average range of about 80 to minus 325 mesh (i.e. any particles smaller than this will pass through—typically, the apertures in 80 mesh are between about 150 and about 200 micrometers across and the apertures in −352 mesh are between about 40 and about 60 micrometers across). More typically, the foaming agent has a particle size between about 5 and about 150 microns. Typically, a pH modifier such as dicalcium phosphate 124 is added to the admixture 27 , wherein the pH modifier 124 becomes effective when the foamed glass product 110 is used in an aqueous environment. The pH modifier 124 is typically present in amounts between about 0.5 and 5 weight percent, more typically between about 1 and about 2 weight percent. Additional plant growth nutrient material may be added to the starting mixture to vary or enhance the plant growth characteristic of the final product 110 .
[0040] Foamed glass, like most ceramics, is naturally hydrophobic. As hydrophobic surfaces are not conducive to wetting and impede capillary action, treatment is typically done to make the pore walls 117 hydrophyllic. In one embodiment, the pore walls 117 are coated to form a plurality of microcracks 119 therein. The microcracks 119 supply increased surface area to support wicking. Alternately, or in addition, an agent may be added to further amend the surface properties to make the foamed glass more hydrophilic. Such an agent may be a large divalent cation contributor, such as ZnO, BaO, SrO or the like. The hydrophilic agent is typically added in small amounts, typically less than 1.5 weight percent and more typically in amounts of about 0.1 weight percent.
[0041] The combination is mixed 126 , and the resulting dry mixture 127 may then be placed into a mold 128 , pressed into a green body and fired without the use of a mold, or, more typically, arrayed into rows 131 of powder mixture 127 for firing and foaming. Typically, whether placed 129 into the mold 128 or not, the mixture 127 is typically arrayed in the form of several rows 131 , such as in mounds or piles of mixture typically having a natural angle of repose of about 15 to 50 degrees, although even greater angles to the horizontal can be achieved by compressing the dry mixture 127 . This arraying of the rows 131 allows increased control, equilibration and optimization of the heating of the powder 127 during firing, reducing hot and cold spots in the furnace as the powder 127 is heated. This combing of the powder 127 into typically rows 131 of triangular cross-sections allows heat to be reflected and redirected to keep heating of the rows generally constant.
[0042] The mold 128 , if used, is typically a refractory material, such as a steel or ceramic, and is more typically made in the shape of a frustum so as to facilitate easy release of the final foamed glass substrate 110 . Typically, the inside surfaces of the mold 128 are coated with a soft refractory release agent to further facilitate separation of the foam glass substrate 110 from the mold 128 . In a continuous process, the powder 127 is typically supported by a fiberglass mesh fleece or the like to prevent fines from spilling as the powder 127 is moved via conveyor through a tunnel kiln; the fleece is burned away as the powder 127 sinters.
[0043] The so-loaded mold 128 is heated 130 in a furnace by either a batch or continuous foaming process. More typically, the mixture 127 is then heated 130 in order to first dry 132 , the sinter 134 , fuse 136 , soften 138 , and foam 140 the mixture 127 and thereby produce a foamed glass substrate 110 having a desired density, pore size and hardness. As the powdered mixture 127 is heated to above the softening point of glass (approximately 1050 degrees Fahrenheit) the mixture 127 begins to soften 138 , sinter 134 , and shrink. The division of the powdered mixture 127 into rows or mounds allows the glass to absorb heat more rapidly and to therefore foam faster by reducing the ability of the foaming glass to insulate itself. At approximately 1025 degrees Fahrenheit, the calcium carbonate, if calcium carbonate has been used as the foaming agent 122 , begins to react with some of the silicon dioxide in the glass 120 to produce calcium silicate and evolved carbon dioxide. Carbon dioxide is also evolved by decomposition of any remaining calcium carbonate once the mixture reaches about 1540 degrees Fahrenheit, above which calcium carbonate breaks down into calcium oxide and carbon dioxide gas. Once the temperature of the mixture 127 reaches about 1450 degrees Fahrenheit, the glass mixture 127 will have softened sufficiently for the released carbon dioxide to expand and escape through the softened, viscous glass; this escape of carbon dioxide through the softened glass mass is primarily responsible for the formation of cells and pores therein. The mixture 127 in the mold 128 is held for a period of time at a peak foaming temperature of, for example, between about 1275 and about 1900 degrees Fahrenheit, more typically between about 1550 and about 1800 degrees Fahrenheit, still more typically between about 1650 and about 1850 degrees Fahrenheit, or even higher, depending on the properties that are desired. By adjusting the firing temperatures and times, the density and hardness as well as other properties of the resultant substrate 110 may be closely controlled.
[0044] As the mixture 127 reaches foaming temperatures, each mass of foaming 140 glass, originating from one of the discrete rows or mounds, expands until it comes into contact and fuses with its neighbors. The fused mass of foaming glass then expands to conform to the shape of the walls of the mold 128 , filling all of the corners. The shapes and sizes of the initial mounds of mixture are determined with the anticipation that the foaming 140 mixture 127 exactly fills the mold 128 . After the glass is foamed 140 to the desired density and pore structure, the temperature of the furnace is rapidly reduced to halt foaming 140 of the glass. When the exterior of the foamed glass in the mold has rigidified sufficiently, the resultant body 110 of foamed glass is removed from the mold 128 and is typically then air quenched to thermally shock the glass to produce a crazed microstructure 119 . Once cooled, any skin or crust is typically cut off of the foamed glass substrate 110 , which may then be cut or otherwise formed into a variety of desired shapes. Pore size can be carefully controlled within the range of about 5 mm to about 0.5 mm, more typically within the range of between about 2.0 mm and 0.2 mm. Substrate density can be controlled from about 0.4 g/cc to about 0.26 g/cc. Typically, the bulk density of the crushed foam may be as low as 50% of the polyhedral density.
[0045] The substrate 110 may be either provided as a machined polyhedral shape 110 or, more typically, as a continuous sheet that may be impacted and/or crushed to yield aggregate or pebbles 150 (typically sized to be less than 1 inch in diameter). The crushed substrate material 150 may be used to retain water and increase air volume in given soil combinations. The polyhedrally shaped substrate bodies 110 are typically sized and shaped as aggregate for use in an RSA composite material. The foamed glass material 110 itself is typically resistant to aqueous corrosion and has minimal impact on solution pH. In order to provide better pH control, the foamed glass material 110 is typically doped (in batch stage, prior to foaming) with specific dicalcium phosphate or a like pH stabilizing material 124 which dissolves in water to help stabilize the pH. The foamed glass substrate 110 can typically hold between about 1.5 and about 5 times its own weight in water in the plurality of interconnected pores 117 .
[0046] Crushed foam bodies 150 may be rapidly made by an alternate method. Using soda-lime glass frit or powder as the glass component 122 , the processing is similar to that described above but without the annealing step. The alternate method employs the same foaming temperature ranges as related above. The batch material 127 consists of up to 8 percent by mass limestone, magnesite, or other applicable foaming agent 122 , usually less than 2 percent by mass dicalcium phosphate 124 , with the balance being a borosilicate, silicate, borate or phosphate glass frit 122 . The batch 127 is then placed in a typically shallow mold 128 , more typically having a configuration of less than 2″ batch for every square yard of mold surface. The mold 128 is typically then heated to approximately 250° C. above the dilatometric softening point for soda-lime glass (or the equivalent viscosity for other glass compositions) and allowed to foam. The mold 128 is held at the foaming temperature for less than 30 minutes and then pan quenched, i.e. substantially no annealing is allowed to occur
[0047] This method typically yields a material 110 of density less than 0.25 g/cc, and more typically as low as about 0.03 g/cc. This material 110 is then crushed into pebbles 150 , with a corresponding lower bulk density as per the above-described method. Material made by this alternate method has similar chemical properties as described above but has substantially lower strength.
[0048] Still another alternate method of preparing foamed glass substrate material 110 is as follows. A batch 127 is prepared as discussed above and pressed into small (typically less than 5 mm diameter) pellets. The pellets are rapidly heated, such as by passage through a flame source, passage through a rotary furnace, or the like. Typically, the pellets are heated to about 1500 degrees Fahrenheit, such as to cause the pellet to expand as a foam particulate without the need for a mold. This material yields the weakest, but least dense foam particles. The typical density may be as low as 0.02 g/cc or as high as 0.2 g/cc, or higher.
[0049] The foamed glass substrate 110 typically has a porosity in the range of between about sixty-five and about eighty-five percent. Air holding capacity is typically between about forty and about fifty-five percent.
[0050] The pore size is typically between about 0.2 mm and about 2.0 mm in diameter, with a relatively tight pore size distribution. The finished substrate 110 is typically processed through a series of conveyors and crushing equipment to yield a desired size spread of pellets 150 .
[0051] The precursor glass material is typically recycled or post-consumer waste glass, such as plate, window and/or bottle glass. The glass is ground or milled to a fine mesh profile of minus 107 microns. A typical sieve analysis of the precursor glass is given as Table 1, and a compositional analysis of the glass is given as Table 2.
[0000]
TABLE 1
Sieve Analysis
Class up to
Pass
Remaindser
Incidence
(μm)
(%)
(%)
(%)
0.7
1.3
98.7
1.3
0.9
1.6
98.4
0.3
1
1.8
98.2
0.2
1.4
2.8
97.2
1.0
1.7
3.7
96.3
0.9
2
4.6
95.4
0.9
2.6
6.4
93.6
1.8
3.2
7.9
92.1
1.5
4
9.9
90.1
2.0
5
12.0
88
2.1
6
14.0
86
2.0
8
17.5
82.5
3.5
10
20.5
79.5
3.0
12
23.3
76.7
2.8
15
27.3
72.7
4.0
18
31.1
68.9
3.8
23
37.2
62.8
6.1
30
45.1
54.9
7.9
36
51.2
48.8
6.1
45
59.2
40.8
8.0
56
67.6
32.4
8.4
63
72.3
27.7
4.7
70
76.6
23.4
4.3
90
86.5
13.5
9.9
110
92.7
7.3
6.2
135
97.1
2.9
4.4
165
99.3
0.7
2.2
210
100.0
0
0.7
[0000]
TABLE 2
Glass oxide
Wt. %
SiO 2
71.5
Na 2 O
12.6
K 2 O
0.81
Al 2 O 3
2.13
CaO
10.1
MgO
2.3
TiO 2
0.07
Fe 2 O 3
0.34
BaO
0.01
SO 3
0.05
ZnO
0.01
[0052] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character. It is understood that the embodiments have been shown and described in the foregoing specification in satisfaction of the best mode and enablement requirements. It is understood that one of ordinary skill in the art could readily make a nigh-infinite number of insubstantial changes and modifications to the above-described embodiments and that it would be impractical to attempt to describe all such embodiment variations in the present specification. Accordingly, it is understood that all changes and modifications that come within the spirit of the invention are desired to be protected.
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A method of slowing an aircraft overrunning a runway, including paving an area immediately beyond the end of a runway with foamed glass bodies to define a bed, covering the bed with a layer of cementitious material to define a composite bed, and crushing at least a portion of the composite bed with an oncoming aircraft, wherein crushing the at least a portion of the composite bed removes kinetic energy from the oncoming aircraft to slow the oncoming aircraft. The composite bed is generally resistant to fire.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to and is a continuation-in-part of U.S. Provisional Patent Application No. 61/206,864 filed on Feb. 5, 2009, entitled EYE DOMINANCE APPARATUS AND METHOD (J. E. McDonald, II, Randolph Blake, Eunice Yang).
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This work was supported by NIH grants EY13358 and 5T32 EY007135.
BACKGROUND OF THE INVENTION
I. Field of the Invention
Surgical treatment for cataract(s) represents the most common form of ocular surgery, with almost 3 million procedures performed during 2007 within the United States alone, according to the 2007 Market Scope survey. As people continue to live longer, treatment for cataracts will surely increase in incidence, at least until preventive strategies are discovered. At the same time, major advances in the design and fabrication of intraocular lenses (IOLs) provide the ophthalmologist with an expanding number of options for the patient's presbyopia.
Despite the increased reliance on multifocal and accommodating IOLs, the vast majority of lenses implanted following cataract surgery continue to be monofocal IOLs, and it is estimated that whether accommodative or non-accommodative this trend will remain true for decades to come (Linstrom, 2008). As ophthalmologists have continued to strive to relieve the cataract patient of post operative dependence on spectacle correction, the strategy of mixing and matching intraocular lenses, the timing between surgery as well as which eye to fix first centers around the selection of “ocular dominance.”
New corneal solutions to refractive and presbyopic issues (Presbylasik and Acufocus) as patients preferred or dominant eye. In all of these situations ophthalmologist tends to select the dominant eye for distance and the non dominant eye for near, in part because of the belief that seeing at a distance is more important in patients' everyday lives. Putting aside the validity of this belief in the primacy of distance vision, we are more immediately concerned with the bases for deciding which eye is an individual's dominant eye in the first place.
In the clinic, an individual's dominant eye is conventionally defined using some kind of test that relies on pointing or sighting under conditions where the individual is forced to view an object with one eye (e.g., the Miles A-B-C Method: Miles, 1929). While such tests provide fairly consistent measures of dominance (as evidenced by test/retest reliability), it is arguable whether sighting dominance taps into those sensory/neural processes that are essential for maximizing coordinated binocular vision under conditions where the two eyes are receiving retinal images that differ in spatial frequency content, as they inevitably will when dealing with IOLs. It has long been known (Washburn et al, 1934) that sighting dominance tests can be affected by factors such as handedness that are extraneous for purposes of estimating sensory balance between the two eyes.
II Description of the Known Art
Several recent studies have advocated measures of interocular suppression as valid measures of eye dominance. These recent studies follow the tradition of using relative predominance during binocular rivalry as a means for indexing eye dominance, a tradition that dates back decades (see review by Porac & Coren, 1976). In one study, Valle-Inclan et al. (2008) asked individuals to view two sequences of letters rapidly presented one after the other separately to the two eyes (the authors dubbed this the dichoptic RSVP task, where RSVP stands for rapid serial visual presentation). Following each sequence, people reported whether or not a pre-specified “target” letter was seen on that trial. Some participants only saw a target letter when it was contained within the RSVP stream presented to a given eye, implying that the other eye's view was suppressed under the conditions of dichoptic stimulation; for other people, however, detection performance was equally good regardless of the eye receiving the RSVP stream containing the target, implying that both eyes' views were available to awareness for processing. This technique showed good test/retest reliability, but one has concern whether the RSVP task taps into aspects of interocular suppression plausibly engaged under more sustained viewing conditions. It is known, for example, that streams of transient stimulation can disrupt conventional binocular rivalry (Lee and Blake, 1999), which may explain why a substantial number of participants in the RSVP task described seeing two superimposed letters at the same time. The RSVP task does, however, have the advantage of using an objective performance measure—target detection—as an index of eye dominance.
In another recent study focusing on interocular suppression as an index of eye dominance, Ooi and He (2001) had participants view a briefly presented dichoptic display consisting of an array of six differently colored gratings presented separately to the two eyes; the orientation and color of gratings falling on corresponding retinal areas of the two eyes were dissimilar, creating the stimulus conditions for binocular rivalry. Rather than presenting the rival display for an extended viewing period, Ooi and He presented the array of rival gratings for just 0.33 sec, and following each presentation the participant indicated by pressing one of two keys which they saw, more “red” or more “green”. Over trials the relative intensities of the gratings presented to the two eyes were adjusted to find the so-called balance point where both responses were equally likely. In their sample of several dozen people, balance point values varied from strongly right-eye dominant to strongly left-eye dominant, with some showing essentially perfect balance between the eyes. Interestingly, their measure of eye dominance was unrelated to eye dominance measured using a conventional sighting test, the Ring test (Borish, 1970).
Ooi and He's task is useful in that it permits parametric variation of stimulus strength (intensity, in their study) and stimulus characteristics such as complexity (spatial frequency in their study). However, with their task there is no objectively correct answer on any trial, meaning that each subject must figure out for himself/herself how to judge the strength of a color sensation that will vary over trials unpredictably. This kind of judgment could be confusing to explain and difficult to make for clinical patients, particularly older individuals unfamiliar with vision testing. Moreover, Ooi and He's task uses a very brief exposure duration near the lower limit for producing reliable interocular suppression (Wolfe, 1984; Leonards & Sireteanu, 1993; Blake et al, 2001). Finally, it is likely that their stimulus presentation regime effectively measures biases in initial dominance during rivalry, but it may not tap into neural events responsible for sensory eye dominance operating under more sustained viewing conditions under which the consequences of bilateral IOLs emerge.
In a similar fashion, Handa and colleagues (2004a) quantitatively assessed ocular dominance by manipulating the contrast values of the rival images until they were equally predominant. They were further able to apply this technique to monovision wearers (2004b) and to cataract patients pre- and post-operatively, with the aid of retinometers (2006). Monovision success coincided with smaller differences in contrast thresholds between the monocular images and ocular dominance measures were consistent pre- and post-surgery. In terms of disadvantages in technique, a similar argument can be made here, as with Ooi and He's paradigm. In addition, the size of the stimulus displays were large enough to induce relatively moderate amounts of ‘piecemeal’ rivalry, which increases response uncertainty during binocular rivalry monitoring. Measuring several contrast values for each eye also lengthens testing duration.
A variety of tests have been created to assess ocular dominance (review by Evans, 2007), and more than 25 different types of ocular dominance have also been proposed (Walls, 1951). It is no wonder, therefore, that controversy still exists over which test and type of ocular dominance are most applicable to clinical practice (Evans, 2007; Mapp, Ono & Barbeito, 2003). The types of ocular dominance and corresponding tests have been categorized into three domains: sighting dominance, sensory dominance based on persistence during binocular rivalry, and sensory dominance based on functions inherent to spatial vision, including acuity (Coren & Kaplan, 1973; Suttle et al., 2008). Assessment of dominance within and across these domains has usually lacked agreement (Suttle et al., 2008; Ooi & He, 2001; Walls, 1951; Coren & Kaplan, 1973; Seijas et al., 2007; review by Evans, 2007; Mapp, Ono, & Barbeito, 2003; Pointer, 2007). Similarly in our study, we found little consistency in dominant eye or dominance strength across the hole-in-the-card test, acuity measures, and our interocular suppression task. Overall, this suggests that, for an individual, there is no eye which is clearly superior across all visual functions, and the dominant eye may depend on the test used and function assessed (Suttle et al., 2008; Seijas et al., 2007; Mapp, Ono, & Barbeito, 2003).
One objective here is to produce a technique best suited for determining ocular dominance as a means of successfully implementing monovision with refractive surgery. Monovision correction entails the monocular “fogging” of one eye, usually the non-dominant eye, which is corrected for near vision (Evans, 2007). It is presumed that it is less demanding to suppress a blurred image in the non-dominant than the dominant eye (corrected for distance vision), thus minimizing discomfort for the subject. Indeed, there is evidence to suggest the interocular suppression occurs in monovision (Kirschen, Hung & Nakano, 1999; Simpson, 1991; Schor, Landsman & Erickson, 1987) and ocular dominance may influence one's ability to suppress anisometropic blur in monovision (Evans for review, 2007). In addition, one of the major complaints by monovision patients is the inability to suppress blurred images at night which may also account for the appearance of ghosting or haloes around lights, especially during driving (Evans, 2007). Thus, it is our intuition as well as those of many clinical practitioners that measuring interocular suppression is the most relevant approach in determining ocular dominance in that it best simulates the patients' situation after monovision correction.
Several sensory tests have been created to measure interocular suppression by presenting dissimilar stimuli dichoptically (Ogle, 1962, Collins & Goode, 1994; Ooi & He, 2001; Handa et al., 2004a,b & 2006; Valle-Inclan et al., 2008). For the reasons previously mentioned, these forms of binocular rivalry may be challenging for patients to perform and may not be reliable for a clinical setting (but see Handa et al., 2006). In contrast, our approach is more akin to the technique by Humphriss (1982) whereby individuals interocularly suppressed the lens-induced blurred image without awareness and without ever perceiving rivalry. Interestingly, within the few studies that found agreement among tests of ocular dominance, several found a correlation between sighting eye and dominant eye during rivalry or blur suppression (Spry et al., 2002; Ooi & He, 2001; Handa et al., 2004a; Schor, Landsman & Erickson, 1987; Porac & Coren, 1978). We found a similar consistency but only among individuals with significant interocular differences in suppression. Collins and Goode (1994) found that individuals with matched ocular dominance for sighting and rivalry were better at suppressing blurred information. This may imply that there is a level of suppression involved when individuals' are forced to choose one monocular view over another in a sighting test. This also highlights individual differences in the ability to suppress blur and other scene information and may be predictive of one's suppression abilities after monovision correction.
Promising evidence exists which suggests that patient's success or satisfaction with monovision correction is related to his or her ability to suppress interocular information (Evans for review, 2007). Handa and colleagues (2004b) reported that individuals with weaker sensory dominance, as determined by binocular rivalry, were more likely to be satisfied with intraocular lens monovision. Schor and colleagues (1987) reported that successful long-term monovision individuals were interocularly balanced for blur suppression. But a significant correlation between monovision success and interocular suppression has not always been found (Collins and Bruce, 1994).
Eye Dominance was one visual function to be tested in apparatus disclosed by Task, Henry L.; and Genco Louis V; Jun. 3, 1987, U.S. Statutory Invention Registration Number H293. Illustrated and described therein is a portable boxlike structure having a first and second illuminated visual displays disposed for viewing by respective left and right eyes of a subject. Among the functions to be tested is eye dominance for which the display pair includes two sets of oppositely oriented diagonal lines. There is no disclosure of separate controls for the two displays for left and right eyes.
One objective here is to produce a technique best suited for determining ocular dominance as a means of successfully implementing monovision with refractive surgery. Monovision correction entails the monocular “fogging” of one eye, usually the non-dominant eye, which is corrected for near vision (Evans, 2007). It is presumed that it is less demanding to suppress a blurred image in the non-dominant than the dominant eye (corrected for distance vision), thus minimizing discomfort for the subject. Indeed, there is evidence to suggest the interocular suppression occurs in monovision (Kirschen, Hung & Nakano, 1999; Simpson, 1991; Schor, Landsman & Erickson, 1987) and ocular dominance may influence one's ability to suppress anisometropic blur in monovision (Evans for review, 2007). In addition, one of the major complaints by monovision patients is the inability to suppress blurred images at night which may also account for the appearance of ghosting or haloes around lights, especially during driving (Evans, 2007). Thus, it is our intuition as well as those of many clinical practitioners that measuring interocular suppression is the most relevant approach in determining ocular dominance in that it best simulates the patients' situation after monovision correction.
SUMMARY OF THE INVENTION
Informed by these earlier studies and instructed by their limitations, we have devised a test and evaluation of eye dominance that isolates the sensory component of eye dominance, without any involvement in pointing or aiming or looking through small apertures with one eye. We devised a test that measured the relative “strength” of a given eye when the two eyes were placed in conflict by receiving dissimilar target and mask images whose relative strength was varied; at the same time, our test employs a forced-choice judgment that minimizes the subjective nature of the response measure. We reasoned that when someone has a strongly dominant eye, the non-dominant eye would require relatively more image contrast to overcome the influence of the contrast received by the dominant eye. Fundamentally the basis of our test is as follows: on each 10-sec trial, one eye starts with a strong image that gets progressively weaker while, at the same time, the other eye gets an image that gets progressively stronger. The initially strong image will always be seen at the beginning and eventually vision will flip to the other eye's view once that image has achieved sufficient strength to overcome the dominance of the initially strong stimulus (which itself is getting progressively weaker). The time at which a subject recognized the strengthening image is recorded.
It is an object of the invention that the apparatus to conduct the test is assembled from available components, typically a PC, a monitor, liquid crystal shutter glasses, a response pad or normal computer keyboard, and software platforms for programming the procedure, recording results and analyzing their significance.
It is another object of the invention that this measure of eye dominance gives reliable results which are shown to vary significantly among people within a sample of normal adults.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of test station apparatus and subject position according to the invention.
FIG. 2 is a side view of a test station similar to that of FIG. 1 .
FIG. 3 is a time chart of target and mask image presentation to left and right eyes in typical procedures.
FIG. 4 is another time chart supplemental to that of FIG. 3 .
FIG. 5 is a graphic illustration of stimuli presented to eyes of the subject in a typical procedure.
FIG. 6 is a histogram of eye dominance index for a group of subjects in one test procedure.
FIG. 7 is a chart of left and right eye response times for a group of subjects in a test procedure.
DETAILED DESCRIPTION
As shown in FIGS. 1 and 2 , test stations 11 provided for access by a test subject 9 seated in chair 10 include a video monitor 13 connected to a personal computer 15 (PC) used as a control unit. Also connected to PC 15 is a response pad 17 , serving as a subject response acceptor. Receiving a control signal from PC 15 is a viewer 14 in the form of shutter glasses to be worn by subject 9 . Interconnections between computer, glasses, and response pad may be wireless, or wired as shown. Response pad 17 may have additional controls or may be replaced or augmented by a conventional computer keyboard. The FIG. 2 embodiment is provided with an optional chin support 21 .
In a preferred embodiment of the invention stimuli are presented in the center of a display on video monitor 13 (800×600 resolution; 100 Hz) against a uniform background at mean luminance and viewed at a distance of about 80-90 cm (optionally with a chin rest.) The masking display includes gray scale Mondrian patterns used as a mask image that subtended 4.3°×4.3° and are preferably normalized to 60 percent contrast (root mean square). The target stimulus normally is an image of an arrow pointing either left or right (.preferably about 67°×1.33°; 20 percent contrast, root mean square). See FIG. 5 .
In an alternative embodiment, the target stimulus is a gray scale photograph of a female face (1.67°×1.17°; 15 percent contrast, root mean square) angled toward the left or the right. The location of the target stimulus may be jittered around the center coordinates of the masking display across trials to avoid fixation on one location. Black and white circles (0.33° diameter) frame the boundaries of the masking display in this embodiment. Other embodiments may involve a mask or a blank display which does not reduce in contrast while the target is increasing in contrast.
Liquid crystal shutter glasses (for example Crystal Eyes; HTTP://reald-corporate.com) are used to present the masking display and target stimulus dioptically. The presentation of the mask and the target may alternate with refreshes of the monitor. The opening and closing of the glass lenses allow the left and right eyes to view temporally alternate frames on the screen without flicker. Thus, each eye may view one of the target or mask stimuli during a given trial. The eye viewing the dynamic Mondrian mask or the target stimulus is randomized across trials. In another alternative embodiment, this masking display is replaced with a different display, preferably at mean luminance. All such procedures may be programmed in Matlab version 7.6, 2008a (http://www.mathworks.com/) and Psychtoolbox version 3 (http://psychtoolbox.org or in other available protocols compatible with PC 15 .
Other methods and apparatus could be employed to present the two dissimilar images to left and right eyes within the scope of the invention. For example orthogonally polarized images could be presented to a subject wearing appropriately polarized goggles or glasses using projection or a half-silvered mirror to merge the images.
Paradigm of Method of Eye Dominance Evaluation:
Although the parameters of the test procedure are flexible, one specific program provides that at the beginning of a trial, one eye views a full contrast Mondrian mask pattern and the other eye views the target at 0% contrast (no stimulus). During a trial, the target linearly increases in contrast at a rate of 1% every 100 ms. At the same time the Mondrian pattern of the masking display linearly decreases in contrast, preferably at the same rate as the target contrast increases. Subjects are instructed to immediately indicate the direction in which the target stimulus was pointing (left vs. right) by pressing a corresponding one of two response keys. Error feedback was not given. If subjects did not detect the target stimulus while the Mondrian mask pattern was visible, the target remained on the screen at full contrast until a response was made. Trials terminated once responses were made, and reaction time (RI) and accuracy were recorded. subjects performed 10 practice trials before moving on to an extended series of record trials (either 100 trials or 50 trials, depending on time available). Record trials took on average six to seven minutes to complete.
Referring to FIG. 5 , the left and middle columns represent the stimuli presented to each eye. During a trial, the contrast of the arrow increases and, at the same time, the contrast of the dynamic Mondrian patterns decreases. The right column represents subjects' perception during the trial. Subjects initially perceived the Mondrian display and eventually the target stimulus (in this case, the arrow) breaks suppression. Subjects respond as soon as they discriminate the direction of the target stimuli.
To quantify the results of testing a subject, an eye dominance index may be derived by calculating the ratio of mean RTs when the arrow was presented to the left eye (leRT) relative to the mean right eye RTs (reRT). The stronger sensory eye would facilitate the breakage of suppression by the target stimulus and lead to shorter reaction times in the discrimination task. On the other hand, when the sensory dominant eye is presented with dynamic noise, it more strongly suppresses the target stimulus viewed by the other eye, which produces longer RTs for identification of the direction in which the test stimulus was pointing. Hence, this particular dominance index value greater than one indicates right eye sensory dominance and dominance index value less than one indicates left eye sensory dominance. Alternative dominance indices could include a beRT for when target and mask were presented to both eyes equally. Such index value could be a numeral plus an indicator of R or L for the dominant eye.
FIG. 3 illustrates (top line) the time sequence for monitor target or mask display with the second and third lines indicating the two alternative viewer shutter openings of target or mask to left or right eye. The alternative controls produce leRT and reRT. In FIG. 4 the top line is the same as FIG. 3 , but lines 2 an 3 show two different sequences usable to obtain beRT, i.e. response time in the same apparatus for subject viewing with both eyes for comparison with leRT or reRT.
In addition to the variations and modifications to the apparatus and method described herein, numerous other variations will be apparent to those skilled in the art, and the scope of the invention extends to all such variations and modifications.
CONCLUSION
We have devised and implemented a novel technique for quantifying the magnitude of interocular suppression as a means of measuring a given individual's sensory dominant eye. It offers advantages over other ocular dominance tasks for several reasons. First, the task is objectively straightforward and easy for participants to understand and perform, as evidenced by near perfect accuracy evidenced in a sample subject set. With other suppression techniques, particularly those that employ binocular rivalry, states of perceptual uncertainty associated with transition states and mixed dominance create response uncertainty; this uncertainty can be particularly problematic in that mixed dominance varies with stimulus features such as size and spatial frequency. With masking, mixed dominance rarely occurs, and the subject is not being asked to track rivalry but, instead, simply to indicate when the target emerging into dominance is sufficiently visible to report the direction in which it is pointing. Second, our task can be completed in less than 10 min, unlike other tasks that require extended test trials to assess interocular suppression. Third, the dominance measures derived here are reliable across time and with different stimulus targets. Finally, this technique provides a variable distribution of scores and is sensitive enough to measure significant interocular differences within individuals. Other studies have either failed to assess individual differences or have failed to find interocular differences.
The present apparatus and method can reliably measure interocular suppression in cataract patients pre- and post-operatively, in order to better determine the relationship between suppression and monovision success as well satisfying other needs for reliable, reproducible measurement of interocular suppression.
APPENDIX I
Experimental Results
Participants 88 observers (44 females) were recruited from the Vanderbilt University Psychology Department or through the Vanderbilt University subject pool. 23 and 21 observers also participated in Experiment 2 and 3, respectively, in addition to Experiment 1. Another 23 observers returned 1 day to 13 months later (median=8 months) to repeat the Experiment 1 in order to acquire test-retest reliability. Participants ranged in age from 18-61, with a mean age of 27 (SD=8). Approximately 10% were left handed. All participants provided written informed consent and, with the exception of 2 participants (authors), were naïve to the purpose of the study.
Acuity Measure
Far and near acuity values were measured using standardized tests provided by the Bausch and Lomb Orthorator (Rochester, N.Y.). Both eyes were presented with a diamond square, which was delineated into quadrants representing the top, bottom, left and right of the diamond. A checkerboard pattern was presented to one or both eyes and observers were instructed to indicate the quadrant in which the pattern was located (4-alternative-forced-choice); for monocular testing, the untested eye viewed only the outline of the transparent quadrants. The size of the stimulus display was smaller for each subsequent trial, for a total of 9 stimulus displays. Scores were based on the number of consecutive trials correctly answered; they were collected dioptically and dichoptically, with and without participants' corrective lenses, and for far and near acuity, for a total 12 scores per observer.
Sighting Dominance Measure
The preferred sighting eye was determined using the hole-in-the card test. A red cross (3 cm×3 cm) was presented approximately 5m in front of the observer. The observer held a card (13 cm×20 cm) with both hands, at arms length and moved the card until the cross was seen through hole in the center of the card (1.5 cm in diameter), with both eyes open. Then the observer was instructed to close one eye and report whether the cross remained in his/her line of view. The eye that allowed the observer to maintain the view of the cross while the other eye was closed was documented as the preferred sighting eye.
Sensory Eye Dominance Measure
Stimuli were presented in the center of a video monitor (800×600 resolution; 100 Hz) against a uniform background at mean luminance and viewed at a distance of 86 cm with a chin rest ( FIG. 5 ). The CFS display (10 Hz) consisted of grayscale Mondrian patterns that subtended 4.3°×4.3° and were normalized to 60 percent contrast (root mean square). In Experiments 1 and 3, the target stimulus was an image of an arrow pointing either left or right (0.67°×1.33°; 20 percent contrast, root mean square). In Experiment 2, the target stimulus was a grayscale photograph of a female face (1.67°×1.17°; 15 percent contrast, root mean square) angled toward the left or the right. The location of the target stimulus was jittered around the center coordinates of the CFS display across trials to avoid fixation on one location. Black and white circles (0.33° diameter) framed the boundaries of the CFS display at all times.
Liquid crystal shutter glasses (CrystalEyes; http://reald-corporate.com) were used to present the CFS display and target stimulus dioptically. The presentation of the CFS and the target stimuli alternated with every refresh of the monitor. The asynchrony between the opening and closing of the glass lenses allowed the left and right eyes to view temporally alternate frames on the screen without any sensation of flicker. Thus, each eye exclusively viewed one of the two stimuli during a given trial. The eyes viewing the dynamic Mondrian and target stimulus were counterbalanced and randomized across trials. In the case of Experiment 3, the CFS display was replaced with a blank display at mean luminance. The experiment was programmed in Matlab version 7.6, 2008a (http://www.mathworks.com/) and Psychtoolbox version 3 (http://psychtoolbox.org).
Paradigm of Experiment 1 & 2:
At the beginning of a trial, one eye viewed a full contrast Mondrian pattern and the other eye viewed the target stimulus at 0% contrast (no stimulus). During a trial, the target linearly increased in contrast at a rate of 1% every 100 ms. At the same time the Mondrian pattern comprising the CFS display linearly decreased in contrast at the same rate as the target contrast. Observers were instructed to immediately indicate the direction in which the target stimulus was pointing (left vs right) by pressing one of two response keys. Error feedback was not given. If observers did not detect the target stimulus while the Mondrian pattern was visible, the target remained on the screen at full contrast until a response was made. Trials terminated once responses were made, and reaction time (RI) and accuracy were recorded. Observers performed 10 practice trials before moving on to an extended series of experimental trials (either 100 trials or 50 trials, depending on experiment). Experiments 1 and 2 took on average, 6-7 minutes to complete.
Paradigm of Experiment 3:
The design and task of Experiment 3 were identical to that of Experiment 1 with the exception that the CFS display was replaced with a blank screen fixed at mean luminance throughout the trial. The experiment took 2 minutes on average to complete. FIG. 5 : Experiment 1 paradigm. The left and middle columns represent the stimuli presented to each eye. During a trial, the contrast of the arrow increased and, at the same time, the contrast of the dynamic Mondrian patterns decreased. The right column represents observers' perception during the trial. Observers initially perceived the Mondrian display and eventually the target stimulus (in this case, the arrow) broke suppression. Observers responded as soon as they could discriminate the direction of the target stimulus.
The principal results of the experiments are shown in FIGS. 6 , 7 , and 8 and are described below. Participants in Experiment 1 averaged at 98 percent correct accuracy. An eye dominance index was derived by calculating the ratio of mean RTs when the arrow was presented to the left eye (leRT) to the mean right eye RTs (reRT). The stronger sensory eye would facilitate the breakage of suppression by the target stimulus and lead to shorter reaction times in the discrimination task. In the same way, when the sensory dominant eye is presented with dynamic noise, it more strongly suppresses the target stimulus viewed by the other eye, which produces longer RTs for identification of the direction in which the test stimulus was pointing. Hence, dominance index values greater than one indicate right eye sensory dominance and dominance index values less than one indicate left eye sensory dominance.
FIG. 6 illustrates the group distribution of these eye dominance index values. The mean ratio between leRT and reRT was 1.02, and the relatively small standard deviation associated with these index values, 0.18, implies that sensory dominance was evenly distributed and relatively modest among our participants. Still, a few individuals produced results indicative of extreme eye dominance, particularly for the left eye (see inset to FIG. 6 ). Two were at least 3 standard deviations below the mean and their data were excluded in subsequent group analyses. Values greater than 1 indicate right eye dominance and values below 1 indicate left eye dominance. The insert in the upper left corner plots separate histograms for leRT (red) and reRT (blue).
The mean RT observed in Experiment 1 was 6.85 s (SD=1.29 s). Across observers, there was a small but statistically significant difference in condition (t(85)=2.21, p=0.03), such that participants were on average faster on trials where the arrow was presented to the right eye (reRT: M=6.74 s, SD=1.27 s) than when it was presented to the left (leRT: M=6.96 s, SD=I.32 s). Indeed, the number of participants categorized as sensory right eye dominant (62%) was significantly greater than the number of participants categorized as left eye dominant (38%) based on the dominance index (chi square=4.65, p=0.03). A similar proportion of individuals (59%) used their right eye as their preferred sighting eye, as measured with the hole-in-the-card test. However, differences in sighting dominance were not significant (chi square=3.05, p>0.05) and neither was the proportion of individuals with consistent sensory and sighting dominant eye significantly different from those who were inconsistent (chi square=0.429, p>0.05). Apparently our measure of sensory eye dominance does not tap into the same processes as those involved in sighting dominance.
We further examined whether individual differences in left eye and right eye suppression were associated with differences in acuity. However after correcting for multiple correlations, there was no significant relationship between any of the acuity scores and leRT, reRT or the dominance index.
Intra-individual interocular differences were also observed. 32 of 86 participants, i.e., 37% of those tested, showed significant differences between their leRT and reRT, based on sample t-tests. Significant differences were also consistently found on the basis of non-overlapping 95% confidence intervals ( FIG. 3 ; Suttle et al., 2008). This suggests that our technique is sensitive enough to detect interocular differences within a large portion of our sample.
FIG. 7 : shows mean RTs for left eye (filled circles) and right eye (empty circles) conditions for each participant. Participants' data are ordered by their dominance index. Error bars indicate 95% confidence intervals.
To determine the reliability of RT values across time, we conducted two separate control experiments. First, 12 observers performed 100 trials in which half of the time, the arrow was presented to one eye and the Mondrian patterns to the other. This is twice the number of trials originally administered. We compared the mean leRT and reRT for the first and last 25 trials of each condition. Although there was a main effect of block, which is the mean RT for the first 50 versus last 50 trials (F(1,11)=7.45; MSE=0.269; p=0.02), its interaction with condition was not significant (F(1,11)=0.096; MSE=0.068; p>0.05). Similarly, the dominance index was not
Second, we examined test-retest reliability in 23 observers. There was a significant main effect of time (F(I,22)=4.73; MSE=0.832; p=0.04) but the interaction between time and mean RT for each condition was not significant (F(1,22)=0.224; MSE=0.191; p>0.05). Furthermore, leRT, reRT, and dominance index was significantly correlated between and test and retest (r=0.69, p<0.001; r=0.63, p<0.001; r=0.61; p=0.002, respectively). The large majority of observers maintained the same eye dominance on retest, as indicated (these individuals correspond to data points in the upper left and lower right quadrants of FIG. 8 , right). Only six individuals reversed their eye dominance index, and 5 of those 6 had very small index values to begin (implying no significant eye dominance on this test). Among those observers with significant eye dominance, test-retest index values consistently implicated the same eye as the dominant eye.
We also examined whether our results could be obtained using other, more naturalistic stimuli. In Experiment 2, the arrow was replaced with an image of a woman's face angled towards the left or right. Participants were significantly slower at responding to the angle of the face than the direction of the arrow (F(1,22)=10.57; MSE=0.296; p=0.004). However, there was no interaction between the type of stimulus and condition (F(1,22)=1.3; MSE=.I; p>0.05), which indicates the pattern of RTs were similar across experiments. Furthermore, a significant correlation existed between the dominance index values measured under the arrow and face conditions(r=0.74, p<0.001). Hence, sensory eye dominance can be reliably measured with different stimuli using this interocular suppression technique.
One may wonder whether we would obtain the same results without interocular suppression, that is, presenting the arrow monocularly without a competing stimulus. This would be analogous to the measurement of contrast sensitivity. In Experiment 3, the arrow (increasing in contrast) was viewed by one eye while a blank display was viewed by the other. Participants performed the same task as in Experiment 1. We found no significant correlation between the dominance index obtained when participants performed the task with and without the CFS display.
APPENDIX II
References
Blake, R., Yang, Y. & Westendorf, D. (1991) Discriminating binocular fusion from false fusion. Investigative Opthalmology & Visual Science, 32, 2821-2825
Borish, I. M. (1970) Clinical refraction, 3 rd Edition. Professional Press Books: Fairchild Publications, New York.
Collins, M. J. & Bruce, M. S. (1994). Factors influencing performance with monovision. J. Br. Contact Lens Assoc. 17, 83-89.
Collins, M. J., & Goode, A. (1994). Interocular blur suppression and monovision. Acta Ophthalmologica, 72(3), 376-380.
Coren, S., & Kaplan, C. P. (1973). Patterns of ocular dominance. American Journal of Optometry & Physiological Optics, 50, 283-292.
Evans, B. J. W. (2007). Monovision: a review. Ophthalmic & physiological optics, 27, 417-439.
Handa, T., Mukuno, K., Uozato, H., Niida, T., Shoji, N., & Shimizu, K. (2004a). Effects of dominant and nondominant eyes in binocular rivalry. Optometry and vision science, 81(5), 377-382.
Handa, I., Mukuno, K., Uozato, H., Niida, T., Shoji, N., Minei, R., Nitta, M., & Shimizu, K. (2004b). Ocular dominance and patient satisfaction after monovision induced by intraocular lens implantation. Journal of Cataract Refractive Surgery, 30, 769-774.
Handa, T., Uozato, H., Higa, R., Nitta, M., Kawamorita, T., Ishikawa, H., Shoji, N., & Shimizu, K. (2006). Quantitative measurement of ocular dominance using binocular rivalry induced by retinometers. Journal of Cataract Refractive Surgery, 32, 831-836
Harmon, D. (2008) Refractive IOLs—economic demographics. In Mastering Refractive IOLs: The Art and Science , D. F. Chang (Ed), Slack Incorp. Thorofare N.J., pp 5-6.
Humphriss, D. (1982). Binocular refraction. In Optometry (eds K. Edwards and R. Lewellyn), Butterworths, London, 130-149.
Kirschen, D. G., Hung CC., & Nakano, T. R. (1999). Comparison of suppression, stereo acuity, and interocular differences in visual acuity in monovision and acuvue bifocal contact lenses. Optometry and vision science, 76, 832-837.
Lee, S. H. & Blake, R. (1999) Rival ideas about binocular rivalry. Vision Research, 39, 1447-1454.
Lindstrom, R. L. (2008) Refractive survery and IOLs—future trends. In Mastering Refractive IOLs: The Art and Science , D. F. Chang (Ed), Slack Incorp. Thorofare N.J., pp. 13-14.
Miles, W. (1929) Ocular dominance demonstrated by unconscious sighting, Journal of Experimental Psychology, 12, 113-126.
Ogle, K. N. (1962). Ocular dominance and binocular retinal rivalry. In Chapter 18 : The eye (ed. H. Dayson), Academic Press, New York, 409-417.
Ooi, T. L. & He, Z. J. (2001) Sensory eye dominance. Optometry, 72, 168-177.
Mapp, A. P., Ono, H., & Barbeito, R. (2003). What does the dominant eye dominate? A brief and somewhat contentious review. Perception & Psychophysics, 65(2), 310-317.
Pointer, J. S. (2007). The absence of later congruency between sighting dominance and the eye with better visual acuity. Ophthalmic & physiological optics, 27, 106-110.
Porac, C., & Coren, S. (1978). Sighting dominance and binocular rivalry. American Journal of Optometry & Physiological Optics, 55, 208-213.
Schor, C., Landsman L., & Erickson, P. (1987). Ocular dominance and the interocular suppression of blur in monovision. American Journal of Optometry & Physiological Optics, 64(10), 723-730.
Seijas, 0., Gomez de Liano, P., Gomez de Liano, R., Roberts, C. J., Piedrahita, E., & Diaz, E. (2007). Ocular dominance diagnosis and its influence in monovsion. American Journal of Ophthalmology, 144(2), 209-216.
Simpson, T. (1991). The suppression effect of simulated anisometropia. Ophthalmic & physiological optics, 11, 350-358.
Spry, P. G., Furber, J. E. & Harrad, R. A. (2002). The effect of ocular dominance on visual field testing. Optometry and vision science, 79, 93-97.
Suttle, C., Alexander, J., Liu, M., Ng, S., Poon, J., & Iran, 1. (2008). Sensory ocular dominance based on resolution acuity, contrast sensitivity and alignment sensitivity. Clinical and Experimental Optometry.
Valle-Inclán, F., Blanco, M. J., Soto, D. & Leirós, L. (2008) A new method to assess eye dominance. PsicolOgica, 29, 55-64.
Walls, G. L. (1951). A theory of ocular dominance. Arch Ophthalmol. 45, 387-412.
Washburn, M. F., Faison, C. & Scott, R. (1934) A comparison between the Miles A-B-C method and retinal rivalry as tests of ocular dominance. American Journal of Psychology, 46, 633-636.
Wolfe, J. (1983) Influence of spatial frequency, luminance, and duration on binocular rivalry and abnormal fusion of briefly presented dichoptic stimuli. Perception, 12, 447-456.
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There is disclosed apparatus and method for a test of eye dominance of human subjects for which on each 10-sec trial, one eye starts with a strong image that gets progressively weaker or does not get progressively stronger, while, at the same time, the other eye gets a weak image that gets progressively stronger. The initially strong image will always be seen at the beginning and eventually vision will flip to the other eye's view once that image has achieved sufficient strength to overcome the dominance of the initially strong stimulus (which itself is getting progressively weaker). The subject indicates recognition of the strengthening image and the time is recorded. Results show that the test provides a reliable measure of eye dominance which is seen to vary considerably among people within a sample of normal adults.
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BACKGROUND OF THE INVENTION
In carrying out production of an oil well, wherein a pumpjack apparatus reciprocates a downhole pump device, the production zone often contains paraffinic hydrocarbons. The hydrocarbon zone usually is at an elevated temperature; and therefore, the paraffinic fraction of the liquid hydrocarbons are dissolved within the production fluid. As the production fluid is pumped uphole toward the surface of the ground, the temperature of the surrounding strata diminishes, especially when an aquifier near the surface of the earth is encountered. This produces a temperature gradient in the flowing production fluid. The reduction in temperature crystallizes the waxy or paraffinic material, and the paraffin commences to accumulate within a marginal length of the production tubing until the production rate diminishes to an unsatisfactory flow rate. In order to eliminate the deposition of the crystallized paraffin, various treatment fluids are sometimes introduced into the casing annulus. Still others have gone to great expense to install scraper devices on the sucker rod so that the deposited paraffin is mechanically scraped from the interior side wall of the production tubing. Still others have pumped treatment fluid downhole through the production string, through a bypass valve, into the casing annulus, thereby dissolving the paraffin deposits.
Installation of a bypass valve downhole in a borehole is limited by the design and construction of the biasing forces which cause the valve to remain in a closed configuration until a predetermined hydrostatic head is encountered to move the valve to the open position. Inasmuch as limited space is available, this expedient has heretofore been limited to very low pressure ranges which usually are unsuitable for hydrostatic heads encountered in most hydrocarbon producing wells.
Accordingly, it is desirable to be able to install a valve means downhill in a borehole wherein the valve means has associated therewith a novel valve construction which remains closed under an extremely high hydrostatic pressure, and which is able to be opened when still a greater pressure is artificially applied to the tubing string.
THE PRIOR ART
Tomlin, U.S. Pat. No. 3,376,936,
Waldron, U.S. Pat. No. 3,361,205,
Grounds, U.S. Pat. No. 3,102,590,
Henderson, U.S. Pat. No. 3,085,629,
Weaver, U.S. Pat. No. 3,014,531,
Dana, U.S. Pat. No. 2,300,348,
and to the art cited therein.
SUMMARY OF THE INVENTION
Method and apparatus for removing paraffin from a tubing string by series connecting a sub therewithin at a position which underlies the area subjected to the accumulated paraffin. A lateral flow passageway extends from the interior of the sub into the casing annulus. A valve means controls the flow of fluid through the lateral flow passageway of the sub. The valve means is closed at relatively low pressures and is moved to the open position under relatively high pressure. A ball check valve is biased into seated position by a caged set of bellville washers so that a tremendous opening force is required to unseat the ball; and at the same time, the bellville washers are housed within a cylinder so that they are isolated from the deleterious effects of debris which may flow through the lateral flow passageway.
In a second embodiment of the invention, the required opening force is greatly increased by the provision of a servo mechanism which includes a piston assembly. The servo mechanism augments the biasing action of the bellville washers.
A primary object of the present invention is the provision of apparatus for circulating treatment fluid downhole through a tubing string and into the casing annulus along a flow path which bypasses a downhole pump means.
Another object of the invention is the provision of improvements in production apparatus which enables paraffin to be removed from the production tubing string of an oil well.
A further object of this invention is the provision of oil well treatment apparatus having a valve means associated therewith which is normally closed, and which is moved to the open position only upon the provision of an extremely high hydrostatic head.
A still further object of this invention is the provision of improvements in a valve means for use in conjunction with a production tubing of an oil well having a pumpjack associated therewith by which the tubing string can be treated to remove paraffin deposits therefrom.
Another and still further object is the provision of apparatus for removing paraffin from the production string of an oil well by the application of treatment fluid to the string under a tremendous hydrostatic head, such that the treatment fluid dissolves the paraffin and bypasses the downhole pump while flowing into the casing annulus.
These and various other objects and advantages of the invention will become readily apparent to those skilled in the art upon reading the following detailed description and claims and by referring to the accompanying drawings.
The above objects are attained in accordance with the present invention by the provision of an apparatus which is fabricated in a manner substantially as described in the above abstract and summary.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a tool sub made in accordance with the present invention;
FIG. 2 is another perspective view of the tool sub disclosed in FIG. 1, with some parts being removed therefrom and some of the remaining parts being shown in crosssection;
FIG. 3 is a fragmentary, enlarged, longitudinal cross-sectional view of the apparatus disclosed in the foregoing figures;
FIG. 4 is a cross-sectional view taken along line 4--4 of FIG. 3;
FIG. 5 is an enlarged, exploded, part cross-sectional, detailed view of part of the apparatus disclosed in FIG. 3;
FIG. 6 is a cross-sectional view taken along line 6--6 of FIG. 5;
FIGS. 7, 8, and 9, respectively, are cross-sectional views taken along lines 7--7, 8--8, and 9--9, respectively, of FIG. 3;
FIG. 10 is an enlarged, longitudinal cross-sectional view which sets forth a second embodiment of the present invention, and which is similar in some respects to the apparatus disclosed in FIG. 3;
FIG. 11 is an enlarged, exploded, part diagrammatical, part cross-sectional, detailed view of some of the parts of the apparatus disclosed in FIG. 10;
FIGS. 12, 13, and 14, respectively, are cross-sectional views taken along lines 12--12, 13--13, and 14--14, respectively, of FIG. 10; and,
FIG. 15 is a part schematical, part diagrammatical representation of an operative embodiment of the present invention, and which discloses a method for carrying out one aspect of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Throughout the various figures of the drawings, wherever it is logical to do so, like or similar numerals are employed to denote like or similar elements of the invention.
In FIGS. 1 and 2, there is disclosed a preferred form of the present invention. The invention is comprised of a tool sub 16, also called a sub-assembly, having threaded opposed marginal end portions 18 and 20 by which the sub can be series connected within the production tubing string associated with a hydrocarbon producing borehole. The sub has a central, enlarged portion 22 which is eccentrically disposed respective to the axial center line of the tubing string. Lateral ports, 23 and 24, are positioned within the cam-like, enlarged portion of the sub, while a pair of vertical parallel passageways, 25 and 26, are arranged normal to the lateral ports, and more or less parallel to the longitudinal central axis of the sub.
The enlargement 22 includes an upper sloped portion 27 and a lower sloped portion 28 formed thereon which facilitates running the tool into and out of a borehole. The sub is provided with an axial passageway 29 which is defined by the circumferentially extending interior wall 30. A passageway 32 communicates the axial bore 29 with a vertical passageway 33 which terminates at 26. The upper marginal end of the sub is of sufficient length to constitute a fishing neck.
The passageway 26 includes a working chamber 34 which extends downwardly toa threaded adjustment screw 36. The screw is threadedly received within a marginal threaded length of the passageway 26. The upper extremity of the working chamber is defined by a tungsten carbide seat 38 against which a tungsten carbide ball 40 is seated. Piston 42 is reciprocatingly received in low friction relationship within a marginal length of the working chamber and is slidably received in a telescoping manner within a cylindrical, upwardly opening cage 44. The slidable interface formed between the piston and the cage is of a sufficiently close tolerance fit to constitute a seal means. The interior 46 of the cylindrical cage housesa biasing means in the form of a plurality of stacked bellville washers 50.The base 45 of the cage is in the form of a closure member. An o-ring seal 48 prevents fluid flow about the cage.
As seen disclosed in FIGS. 2 and 4, a plurality of parallel passageways maybe positioned within the enlargement so that dual passageways, 33 and 33', may be employed for a purpose which will be better appreciated later on inthis disclosure.
As best seen illustrated in FIG. 5, the valve means of the first embodimentof the invention preferably includes the before mentioned special tungsten carbide seat 38. The seat is provided with a circumferentially extending side wall 39 which determines the force exerted on the special tungsten carbide ball 40 when a pressure is exerted within the axial passageway 29.The before mentioned piston 42 is provided with a concavity formed at 41 for positive seating of the ball thereagainst. The piston is vertically counterbored at 43 for telescopingly receiving a centrally disposed, upwardly extending alignment pin 47. The pin is positioned normally and centrally respective to the before mentioned base of the cage.
Where the relative diameter of the washer and the cage are of a value to maintain proper alignment of the respective washers, the pin 47 and bore 43 may be eliminated if desired.
Numeral 42' indicates the lower annular end portion of the piston; numeral 47' indicates the upper free or terminal end portion of the central alignment pin; while numeral 49 indicates the upper circumferentially extending terminal edge portion of the cylindrical cage. Hence, it can be seen that the base of the cylindrical cage engages the upper face 36' of the adjustment screw in abutting relationship thereto.
FIGS. 5 and 6 illustrate the configuration of the bellville washers, and itwill be appreciated that pin 47 is received throughout the central apertureformed within the washers so that the deformed bell-like washers are maintained in stacked relationship respective to one another and to the cage. The washers are stacked in opposed pairs to provide a spring action of tremendous biasing force.
In the embodiment disclosed in FIGS. 10-14 of the present disclosure, thereis seen a servo valve mechanism disposed within each of the working chambers of the sub. As best seen illustrated in FIG. 11, in conjunction with FIGS. 10 and 12-14, a piston assembly 142 is sealingly received in a reciprocating manner within a cylinder assembly 55. Upper surface 56 of the piston is provided with a concavity 58 for receiving a ball 40 in positive seated relationship thereon. A reduced diameter portion of the piston forms an opposed face 60 to form an annular area which is approximately 20 percent less than the measured cross-sectional area of the passageway 39 of the seat 38. Seal means 62 are expansion seal rings which sealingly engage the peripheral side wall 34 of the working chamber.The seal means can take on several different forms, but preferably are close tolerance metallic rings fitted within the illustrated piston grooves. Reduced diameter portion 64 of the piston terminates at the annular base 66 thereof. Small counterbore 67 formed in the lower end of the piston communicates with passageway 68, which extends through the entire piston assembly, thereby equalizing any pressures thereacross. Circumferentially extending interior side wall 70 defines a working chamber 72, within which an isolated biasing means in the form of a plurality of stacked bellville washers 50 are captured. The upper or opened end 74 of the cylinder is spaced from the annular area 60 sufficiently to provide ample working room for movement between the ball and seat. The lower end 78 of the cylinder is seated in seated relationship against the base of the adjustment screw 36, while o-ring 79 is positioned to prevent fluid flow across the cylinder.
As best seen in FIG. 10, the before mentioned port 56 communicates the variable chamber 80 with the axial passageway 29 so that any pressure effected within the tubing string is also effected within the variable chamber as well as side 39 of the seat. Outlet chamber 82 communicates with the casing annulus by means of the port 24. The adjustment screw includes an internally formed, wrench-engaging surface 84, so that manual adjustment of the biasing force can be effected.
Looking now to the diagrammatical illustration of FIG. 15, a cased borehole88 is seen to extend below the surface 90 of the ground. The casing annulusis connected to the usual above-ground piping 91, while production tubing 92 is connected to an outflow piping 92'. Sucker rod 93 is provided with the usual packing gland 94 and is reciprocated by a conventional pumpjack 95. A downhole pump 96 is suitably seated at 97 while formation fluid flows into the casing through the perforations 98.
A paraffin deposit 99 is seen to have previously accumulated above the toolsub 22 of the present invention. Piping 100 and 101 is connected to piping 92' by means of valve 102.
In operation, the sub of the present invention is positioned above the downhole pump and below the paraffin deposit. Over a prolonged period of time, the paraffin accumulates within the production tubing and must be removed to enhance the production rate. Accordingly, a source of treatmentfluid 103 is connected to piping 100, while piping 101 is isolated from piping 92' by means of the valve 102. The treatment fluid is forced down the production tubing 92 by applying sufficient pressure at 100. When adequate pressure is applied to the axial passageway 29, the ball is unseated and the treatment fluid flows through port 32, passageway 33, andthrough port 24 into the casing annulus. The treatment fluid dissolves the paraffin deposits and translocates the deposits into the casing annulus. The well is thereafter returned to its normal production configuration until production data again indicates that another treatment of the well is desirable.
In the second embodiment of the invention disclosed in FIGS. 10-14, the servo piston 142 augments the action of the bellville washers in proportion to the ratio of the cross-sectional area of port 39 respective to the annular area 60 of the piston. This expedient enables the sub 22 tobe placed downhole adjacent to the pump 96 so that the downhole production formation can be subjected to treatment during the paraffin removal operation.
The downhole pump apparatus is of conventional design and includes the usual standing valve and traveling valve associated therewith which normally precludes downhole flow of fluid. Accordingly, when sufficient fluid pressure in the form of treatment fluid is applied to the interior of production tubing, flow cannot occur through the downhole pump assembly; and therefore, flow must accordingly occur through the valve assembly located in the tool sub of the present invention. As stated above, sufficient hydrostatic pressure must be effected to overcome the biasing force of the valve in order to actuate the valve to the open position. This expedient enables a precise adjustment to be made to the biasing means prior to downhole installation of the tool sub. Accordingly,should an analysis of the specific borehole indicate that the tool sub should be placed at 1800 feet below ground level, for example, and furtherthat the working well has 100 psi wellhead pressure, it then becomes apparent that the biasing means should be set to be actuated at some pressure in excess of 1200 psi, for example. This setting gives a margin of safety so that the balls are not cyclically lifted from their respective seats each stroke of the pump.
In one embodiment of the invention, a 5/16 inch diameter seat was employed while using a stack comprised of 24 pairs of bellville washers. This requires a total of 48 washers in each cage. The actual opening force presented by the washers can be set up to 2400 pounds force. The number ofwashers, the relationship of one washer to another, and the size of the washer, along with the configuration of the ball and the seat, can be varied as may be desired to accomodate various different downhole conditions.
By utilizing 48 (24 × 2) stacked bellville washers, the actual travelof the ball to full open position is less than 0.106 inches. The bellville washers may be fully collapsed with no resulting damage, which enhances the operative design of the present invention. The strength of the biasingforce is determined by the thickness, diameter, and curvature of the washers.
The enclosure 44 and the cylinder 55 each encapsulate the bellville washersand prevent foreign debris from contaminating the biasing means. The enclosure 46 or 72 can be filled with a corrosion-preventing oil solution to further avoid contamination of the washers and any consequent disruption of operation or changes in setting over a prolonged period of time. The enclosure isolates the washers from the deleterious downhole conditions.
Dual passageways are provided within the valve assembly to provide adequatelateral flow. The tool sub is to small for a single passageway to produce the volume required to treat the tubing string. When hot water is used as a treatment fluid, it is desirable to translocate the water through the paraffin zone and through the valve as fast as possible to avoid any unduedrop in temperature as the hot treatment fluid travels downhole. Furthermore, the quicker the well can be treated, it follows that less rigtime will be involved, as well as the loss of production. Moreover, should one valve assembly clog, the second valve assembly can be utilized at reduced efficiency until the time arrives when the pump must be pulled forservicing, whereupon the tool sub of the instant invention can then be replaced with a more operative assembly.
The carbide ball and seat are necessary to prevent washout therebetween. Pressures up to 5000 psi are exerted across the seat. Therefore, abrasive foreign material erodes away other metallic substances.
One source of the bellville washers is Associated Spring Corporation, Dallas, Tex., part no. B0500-0255.
The tool of the present invention enables the paraffin deposits to be treated with hot water. The hot water cleans the tubing and rod string down to the bare metal and avoids the prior art necessity of utilizing hotoil for the treatment. The use of hot water is far less expensive, more convenient, and far less hazardous for handling and heating.
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Method and apparatus for removing paraffin deposits from the production tubing of an oil well. A sub is series connected into the production string at a location below the area where deposition of paraffin occurs, and treatment fluid, such as hot water, is pumped downhole towards the inlet end of the string. A spring loaded valve means is located in a lateral flow passageway of the sub and opens when a pre-set tubing pressure is exceeded, thereby enabling the treatment fluid to be forced down the upper production tubing, past the paraffinic deposition, into the sub, through the lateral flow passageway, and into the casing annulus, thereby dissolving the crystalline paraffin so that the production tubing is no longer obstructed with paraffinic deposits.
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RELATED APPLICATION
The present application is related to Applicants commonly assigned U.S. patent application Ser. No. 11/430,934 filed concurrently herewith and entitled Clothes Dryer Door Assembly.
FIELD OF THE INVENTION
The present invention relates to clothes dryers, and more particularly relates to a clothes dryer door assembly with a viewing window that is adapted to be reversibly mounted to a clothes dryer cabinet.
BACKGROUND OF THE INVENTION
A domestic clothes dryer typically has a cabinet including a front panel with an access opening through which clothes are loaded and unloaded into a rotating drum. The door is mounted through one or more hinges to the cabinet front panel on one side of the access opening.
Typically, these doors are manufactured to open by pivoting out to the right or the left. While it is possible to order the door to pivot out in the direction required for the user, should the need arise by the user changing living space or laundry space in the home, it may be necessary to reverse the door and change the side to which the door pivots open. For example, the location of the washing machine relative to the dryer is fixed by pre-existing plumbing and/or dryer vent holes and this may require changing the pivot direction the door opens to facilitate transfer of clothing from the washing machine to the clothes dryer. Thus, it would be desirable to have a window dryer door that could be reversed so that it could readily be hung or mounted from either side of the access opening depending on the requirements of the particular installation. Further, it may be desirable for a manufacturer to be able to easily reverse the mounting side of the door.
For a door having a viewing window, many of these doors are port hole type doors and the clothes dryer typically has a front panel with a circular opening and a circular door jam. The dryer drum bulkhead is mounted in the dryer adjacent the panel and has a circular opening that is cropped horizontally along the bottom of the opening permitting the dryer bulkhead to provide a trap duct for receiving a filter through which air exits the dryer drum. This type of dryer construction results in the window door typically comprising an outer circular window of plastic and an inner glass window that is non-circular and is cropped to conform to the opening in the bulkhead of the dryer. Reversing the hinge for this type of dryer door involves the disassembly of the door, reversing of the hinge and then re-assembly of the complete door.
Clearly, there is a need for an improved window type dryer door that may be converted to open from an opposite side of the dryer that does not involve the complete disassembly of the door.
BRIEF DESCRIPTION OF THE INVENTION
The present invention relates to a clothes dryer door assembly with a viewing window that is adapted to be reversibly mounted to a clothes dryer cabinet. The door assembly comprises an inner door assembly supporting an inner window and an outer door assembly supporting an outer window. The inner door assembly removably carries a hinge and the outer door assembly is removably secured with the inner door assembly. In order to reverse the door, the outer door assembly is removed from the inner door assembly. The hinge is removed from the inner door assembly and re-positioned 180 degrees on the inner door assembly. The outer door assembly is then rotated 180 degrees and reattached to the inner door assembly. The reversing of the inner door assembly relative to the outer door assembly of the present invention does not require disassembly of either the inner and outer door assemblies.
In accordance with a method of the present invention, the door assembly may be reversibly mounted to a clothes dryer cabinet by the steps of:
removing the door assembly at the hinge from the clothes dryer cabinet,
removing the outer door assembly from the inner door assembly,
removing the hinge from the inner door assembly and re-securing the hinge on the inner door assembly rotated 180 degrees from an initial position,
re-attaching the outer door assembly to the inner door assembly; and,
re-attaching the door assembly at the hinge to the clothes dryer cabinet.
In an embodiment of the door assembly where the outer door assembly comprises a handle mounted to one side of the door, the method of the invention further comprises, prior to the step of re-attaching the outer door assembly, the step of rotating the outer door assembly relative to the inner door assembly to rotate the handle to another side of the door. The rotation of the outer door assembly to the inner door assembly may be a 180 degrees rotation.
In an embodiment of the door assembly where the inner door assembly further removably carries a retainer disposed 180 degrees from the hinge, the method further comprises, prior to re-attaching the outer door assembly to the inner door assembly, the step of removing the retainer from the inner door assembly and re-securing the retainer on the inner door assembly rotated 180 degrees from an initial position.
In one embodiment of the invention there is provided a door assembly adapted to be mounted in alternate positions on the front panel of a clothes dryer cabinet so that the door assembly can be configured to be opened from either left or right side. The door assembly comprises an inner door assembly. The Inner door assembly comprises an inner door frame support for supporting an inner window, a mask frame secured to the inner door support frame for masking the inner door frame, and a hinge structure removably secured in one of two first positions to the inner door frame support. The door assembly comprises an outer door assembly removably secured in one of two second positions to the inner door assembly. The outer door assembly comprises an outer window secured to an outer peripheral cover. The cover covers the hinge structure, the mask frame and the inner door frame support when the outer door assembly is secured to the inner door assembly.
In one embodiment of the invention there is provided a door assembly adapted to be mounted in alternate positions on the front panel of a clothes dryer cabinet so that the door assembly can be configured to be opened from either left or right side. The door assembly comprises an inner door assembly and an outer door assembly removably secured in one of alternate positions to the inner door assembly. The inner door assembly comprises an inner door frame support having a first peripheral flange having two horizontally disposed hinge seat portions. The inner door frame support has a recessed window seat portion surrounding a first central opening defined by the inner door frame support. The inner door assembly comprises an inner window seated in the window seat portion across the first central opening, a mask frame secured to the inner door frame support for masking the inner door support and for securing the inner window in the recessed window seat portion. A hinge structure is removably secured in one of the horizontally disposed hinge seat portions and comprises a hinge element extending from the inner door assembly. The outer door assembly comprises an outer window attached to an outer cover. The cover comprises a second central opening and a second peripheral flange adapted to cover the hinge structure, the mask frame and the first peripheral flange of the inner door frame support. The second window extends across the second central opening of the cover.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the nature and objects of the present invention reference may be had by way of example to the accompanying diagrammatic drawings.
FIG. 1 is a perspective view of an exemplary clothes dryer that may benefit from the present invention;
FIG. 2 is a side sectional view of an exemplary clothes dryer that may benefit from the present invention;
FIG. 3 is an exploded view of the clothes dryer door assembly of the present invention;
FIG. 4 is a front view of the door assembly of FIG. 3 ;
FIG. 5 is a sectional view of the door assembly taken through lines V-V of FIG. 4 ;
FIG. 6 is a sectional view of the door assembly taken through lines VI-VI of FIG. 4 ;
FIG. 7 is a rear perspective view of the mask frame of the door assembly;
FIG. 8 is an enlarged view showing the connection made by the barb-like connectors of the present invention; and,
FIG. 9 is an inside perspective view of the inner door frame support, inner window, the hinge and retainer.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 and 2 show perspective and side sectional views of an exemplary clothes dryer 10 that may benefit from the present invention. The clothes dryer includes a cabinet or a main housing 12 having a front panel 14 , a rear panel 16 , a pair of side panels 18 and 20 spaced apart from each other by the front and rear panels, and a top cover 24 . Within the housing 12 is a drum or container 26 mounted for rotation around a substantially horizontal axis. A motor 44 rotates the drum 26 about the horizontal axis through, for example, a pulley 40 and a belt 42 . The drum 26 is generally cylindrical in shape, has an imperforate outer cylindrical wall 28 , and is closed at its front by a bulkhead wall or bearing 30 defining an opening 32 into the drum 26 . Clothing articles and other fabrics are loaded into the drum 26 through the opening 32 . A plurality of tumbling ribs (not shown) are provided within the drum 26 to lift the articles and then allow them to tumble back to the bottom of the drum as the drum rotates. The drum 26 includes a rear wall 34 rotatably supported within the main housing 12 by a suitable fixed bearing 35 . The rear wall 34 includes a plurality of holes (not shown) that receive hot air that has been heated by a heater such as electrical heating elements 38 in the heater housing 22 . The housing 22 receives ambient air via an inlet 36 . Although the exemplary clothes dryer 10 shown in FIG. 1 is an electric dryer, it could just as well be a gas dryer having a gas burner. The heated air is drawn from the drum 26 by a blower fan 48 which is also driven by the motor 44 . The air passes through a screen filter 46 which traps any lint particles. As the air passes through the screen filter 46 , it enters a trap duct 50 and is passed out of the clothes dryer through an exhaust duct 52 . After the clothing articles have been dried, they are removed from the drum 26 via the opening 32 . The dryer has a control panel 54 with touch and or dial controls 56 whereby a user can control the operation of the dryer.
Clothes are inserted into, and removed from, the drum 26 through opening 32 . Opening 32 is shown closed by a window or port-hole like door 60 . Door 60 has a handle 62 for pivotally opening the door about hinge 64 .
In accordance with the present invention, the assembly of the door 60 is now described with respect to FIGS. 3 through 9 . The door assembly 60 includes four peripheral flanges 74 , 142 , 134 and 93 . The first peripheral flange is peripheral flange 74 . The second peripheral flange is peripheral flange 142 . The third peripheral flange is peripheral ring-like flange 134 . The fourth peripheral flange includes two arcuate peripheral flanges 93 . In FIG. 3 , the door assembly 60 is shown to comprise an inner door assembly 66 and an outer door assembly 68 . The inner door assembly 66 comprises an inner door frame support 70 . The inner door frame support is made from a steel or stainless steel material. The inner door frame support 70 is shown in perspective view in FIG. 9 with the inner window 82 . Backed onto the inner door frame support 70 is a gasket 72 which forms a seal with a clothes dryer cabinet 12 when the door 60 is closed. The inner door frame support 70 comprises first peripheral flange 74 that has two horizontally disposed or alternate hinge seat portions 76 . The peripheral flange 74 comprises a circular flange that has a first collar 78 depending rearwardly therefrom. The collar 78 defines a recessed window seat portion 80 in the form of a lip portion. The recessed seat portion 80 surrounds a first central opening 81 in the inner door frame support 70 .
The inner door assembly 66 further comprises an inner window 82 . The inner window 82 comprises a flat glass piece which is circular in shape and has a truncated or cropped lower edge portion 86 . In alternative embodiments, the glass may be a molded glass. The peripheral edge of the glass is surrounded by a gasket 88 . The window 82 is adapted to be seated within the recessed seat portion 80 of the inner door frame support 70 so as to extend across the first central opening 81 .
The inner door assembly 66 further comprises a mask frame 90 that is secured with the inner door frame support 70 to secure the window 82 in place in the window seat portion 80 . The mask frame 90 is illustrated as a separate part in FIG. 7 and has a collar 92 that depends rearwardly from the two arcuate peripheral flanges 93 . The arcuate flanges 93 are adapted to overlay the peripheral flange 74 of the inner door frame support 70 and the mask collar 92 is adapted to overlay the collar 78 of the inner door frame support 70 . The purpose of the mask frame 90 is two fold. Its first purpose is to mask from view the structure of the inner door frame support 70 . The mask frame 90 has a lower portion 94 that also masks from view the lower portion 96 of the inner door frame support 70 . It should be understood that the lower portion 94 of the inner door support frame 70 below collar 78 overlays the lint filter trap 50 between the front panel 14 and the bulk head wall 30 of the dryer when door 60 is closed (see FIG. 2 ). The second purpose of the mask frame 90 is to hold the window 62 in place in the recessed seat portion 80 .
The mask frame 90 defines a second central opening 98 . The mask frame 90 has two cut out slots 100 between the flanges 93 . These cut out slots 100 are positioned adjacent to the horizontally disposed hinged seat portions 76 when the inner door assembly 66 is assembled. From FIG. 7 , it can be seen that the collar 92 of mask frame 90 extends rearwardly from the peripheral flanges 93 . The collar 92 comprises an inner surface 106 and an outer surface 108 . The outer surface 108 is positioned to face towards the first collar 78 of the inner door frame support 70 . The mask frame 90 further comprises rearwardly extending rib spacers 104 that are attached to the outer surface 108 of the collar 92 . These spacers 104 have a tip 110 with a cut out section 102 . The tip 110 together with the cut out section 102 of the ribs 104 act to secure the inner window 82 within the recessed seat portion 80 of the inner door frame support 70 when the mask frame 90 is secured to the inner door frame support 70 . In FIG. 6 , it can also be seen that the spacer or ribs 104 have a tip portion 110 with its cut out slot 102 that surrounds and engages the gasket 88 of the inner window 82 .
Referring to FIG. 7 , the peripheral flanges 93 of the mask frame 90 each comprise a plurality of barb like connectors 112 . As better seen in FIG. 8 , the barb like connector 112 has a hook portion 114 that passes through an opening 117 in the first peripheral flange 74 of the inner door frame support 70 . As the barb connector 112 passes through opening 117 , the hook portion 114 is compressed and then springs open to lock the peripheral flanges 93 relative to the peripheral flange 74 . In this way the barb connectors 112 in co-operation with the openings 117 act to assemble the mask frame 90 relative to the inner door frame support 70 with the window 82 sandwiched between the mask frame 90 and the inner door support frame 70 . As shown in FIG. 7 , the rear face of the flanges 93 have spacers 255 with pass through apertures 250 . Spacers 255 together with barb connectors 112 maintain the relative positioning of the mask frame 90 and the inner door frame support 70 . Hence the connectors 112 and the openings 117 co-operate to assemble the inner door assembly 66 without the use of any fasteners.
Referring to FIG. 6 the distance the recesses of the collars 78 and 92 rearwardly extend is greater at the lower portion 202 of the door than at the upper portion 200 of the door. This results in the recessed window seat portion 80 sloping downwardly and rearwardly to present a lower seat portion 206 thereof that is more recessed than the upper seat portion 208 . As a result the inner window 82 seated in the recessed seat portion 80 slopes downwardly and rearwardly towards the interior of the dryer cabinet. The lower seat portion 80 extends over the lint trap 46 (as best seen in FIG. 2 ). This results in a door effectively covering the opening for the filter 46 in the trap duct 50 while at the same time optimizing volume within the dryer drum.
Referring to FIGS. 3 , 5 , and 9 , the inner door assembly 66 further comprises hinge 64 and retainer 116 . The hinge structure 64 is secured to the inner door frame support 70 by fasteners 218 that pass through openings in the hinge structure 64 and into corresponding openings in the seat portions 76 of the inner door support frame 70 . The hinge structure 64 is secured in one of the horizontally disposed hinged seat portions 76 of the inner door frame support 70 . The hinge structure 64 has a first hinge element 118 ( FIG. 3 ) that extends from the inner door assembly 66 for securement with the front panel 14 and/or bulk head 30 of the dryer adjacent the opening 32 . As shown in FIGS. 5 and 9 , the hinge structure 64 has a second hinge element 120 that is adapted to engage the inner window 82 at the gasket 88 to secure the window 82 in the recessed seat portion 80 . The hinge element 120 of the hinge structure 64 extends rearwardly between the collar 78 of the inner door frame support 70 and collar 92 of the mask frame 90 .
In a similar manner the retainer 116 is removably mounted by fasteners 122 in the other one of the horizontally disposed hinged seat portions 76 of the inner door support frame. The retainer 116 comprises a cover 124 and a retainer portion 126 . The retainer portion 126 is adapted to engage the gasket 88 of the inner window 82 to positively hold the window 82 in the recessed seat portion 80 . In the detailed description the hinge 64 , retainer 116 and mask frame 90 act to hold the window 82 in place on the inner door frame support 70 . It should be understood that either the mask frame 90 or the hinge 64 and retainer 116 may be used mutually exclusive of each other to secure the window 82 in place on the inner door frame.
Referring to FIG. 3 , the door assembly 60 further includes an outer door assembly 68 . The outer door assembly 68 comprises an outer window 130 . The outer window 130 comprises a concave circular shaped central portion surrounded by peripheral ring like flange 134 . The flange 134 extends substantially around the circular concave center portion except for the cut out section 136 . Cut out section 136 is located adjacent the hinge element structure 64 . The outer window 130 comprises a plastic and preferably comprises a transparent polycarbonate material. The outer door assembly 68 further comprises a cover 140 that has peripheral flange 142 comprising a ring flange with a central opening 144 . The cover 140 has a depending rim 146 that depends from its peripheral flange 142 . The peripheral flange 142 is further provided with an outer handle portion shown as 62 . The outer door assembly 68 further comprises a structural handle portion 148 that is mounted by two fasteners 156 passing through apertures 150 in the outer window 130 , apertures 152 in the handle portion 148 and into receiving studs (not shown) in the reverse face of the outer handle portion 62 . The fasteners 156 effectively secure the outer window 130 to the cover 140 and thereby complete the assembly of the outer door assembly 68 . The outer window 130 provides further structural support for the door assembly 60 .
The peripheral ring like flange 134 of the outer window 130 is nested in the ring like peripheral flange 142 and the rim 146 of the cover 140 . The flange 134 is substantially coextensive with the peripheral flange 142 of the cover 140 except for the cut out portion 136 that is provided to allow the cover flange 142 to overlay the hinge structure 64 .
To complete the assembly of the door 60 the inner door 66 is secured to the outer door 68 by a plurality of fasteners 160 that pass through aligned apertures 250 in the peripheral flange 74 of the inner door frame support 70 , the peripheral flanges 93 of the mask frame 90 , the peripheral flange 134 of the outer window 130 and into receiving studs (not shown) found on the rear surface of the peripheral flange 142 of the cover member 140 .
Additionally latches or spacers 170 (see FIGS. 3 and 5 ) are provided to mount and orientate the hinge element 164 and the retainer portion 126 and cover 124 in the respective horizontally disposed seat portion 76 .
Referring to FIG. 4 , the front cover 140 covers the appearance of the door such that the central opening 144 of the front cover and the central opening 98 of the mask frame 90 are covered by the concave shaped circular central portion of the outer window 130 . Disposed horizontally opposite to the handle 62 on the rim 146 of the cover 140 are two slotted openings 162 . Openings 162 permit for the first hinge element 118 to extend from the door assembly 60 for connection with the clothes dryer cabinet.
The construction of the clothes dryer door assembly 60 allows for a the mask frame 90 to be secured to the inner door frame support 70 so as to hold the inner window 82 in place without having to utilize additional fasteners other than the hinge 64 and the retainer 126 to hold the window 82 in place. Further, the door structure of the present invention is adapted for reversibility or for rotation of the outer door assembly 68 relative to the inner door assembly 66 .
The door assembly 60 is adapted to be mounted in alternate positions on the front panel 14 of the clothes dryer cabinet 12 so that the door assembly 60 can be configured to open either from the left or ride side. As shown in FIG. 1 the door assembly 60 opens from the left side of the dryer 10 . If one were to reverse the opening of the door this can be done by removing the door assembly 60 at the hinge structure 64 from the clothes dryer cabinet 12 . Next, the fasteners 160 are removed so that the outer door assembly 68 is removed from the inner door assembly 66 . Thereafter the hinge structure 66 and the retainer 116 are removed by removing fasteners 218 and 122 . The hinge 64 and the retainer 116 are then rotated 180 degrees from their initial position into the other or alternate horizontally disposed seat portion 76 . Then the hinge structure 64 and the spacer 126 are reattached by fasteners 218 and 122 . The outer door assembly 68 is then rotated 180 degrees relative to the inner door assembly 66 . The fasteners 160 are reinserted to secure the outer door assembly 68 to the inner door assembly 66 . This is facilitated by the apertures 250 , through which the fasteners 160 pass, being aligned symmetrical to each other about the horizontal axis extending through the door assembly 60 . This symmetrical or mirroring arrangement facilitates placement of the outer door assembly 68 relative to the inner door assembly 66 at 180 degrees disposed from its previous position. The hinge structure 64 is then reattached to the dryer housing 12 to complete the reversing of the door relative to the dryer 10 . Rotation of the outer door assembly 68 relative to the inner door assembly 66 permits for the dryer to be changed between left and right opening doors without completely disassembling each of the inner door assembly 66 and the outer door assembly 68 while at the same time maintaining the lower portions 94 and 96 of the inner drum support 70 and the mask frame 90 in the same orientation adjacent the lint trap duct 50 .
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modifications within the spirit and scope of the present invention disclosed herein.
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A clothes dryer door assembly with a viewing window is adapted to be reversibly mounted to a clothes dryer cabinet and has an inner door assembly supporting an inner window and an outer door assembly supporting an outer window. The inner door assembly removably carries a hinge and the outer door assembly is removably secured with the inner door assembly. In order to reverse the door, the outer door assembly is removed from the inner door assembly and rotated 180 degrees. The hinge is removed from the inner door assembly and re-positioned 180 degrees on the inner door assembly. The outer door assembly is then reattached to the inner door assembly. This reversing of the door assembly of the present invention does not require complete disassembly of either of the inner or outer door assemblies.
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This application is a continuation of Ser. No. 08/322,879 filed Oct. 13, 1994 now abandoned, which is a continuation-in-part of Ser. No. 07/436,285 filed Nov. 14, 1989 now abandoned.
BACKGROUND OF THE INVENTION
Polyurethane foams, engineering thermoplastics coatings and elastomers are commonly admixed with flame retardants to achieve the desired degree of flame retardancy for the final material desired. Pumpable fluid (or liquid) flame retardant compositions are a preferred class since such pumpable formulations are needed in environments where automation and machine mixing of the various components are used. Examples of the chemical classes for such fluid or liquid flame retardants include brominated aryl flame retardants, such as polybromodiphenyl oxide, and various viscous organophosphorus flame retardants such as the oligomeric phosphate esters, such as the chlorinated oligomeric phosphate esters (e.g. FYROL 99 brand) and the reaction product of 2-chloro-1-propanol phosphate (3:1) with ethylene oxide and phosphorus pentoxide (FYROL PCF brand), and the aromatic oligomeric phosphate esters such as those containing an arylene bridging group derived from a diol such as bisphenol A, hydroquinone or resorcinol.
High viscosity in such fluid or liquid flame retardant compositions can be disadvantageous since it makes the pumping and movement of such compositions more difficult thereby complicating manufacturing operations. It can also hinder the flow of thermoplastic polymers containing such a viscous flame retardant. For example, it is known that polybrominated diphenyl oxide flame retardants are very viscous. U.S. Pat. No. 4,746,682 to J. Green indicates that either alkyl diphenyl phosphates or alkylated triaryl phosphates can be used to achieve blends having acceptably low viscosity as compared to the polybrominated aryl flame retardant itself. Copending U.S. Ser. No. 215,406, filed Mar. 14, 1994, describes the use of triphenyl phosphate as a viscosity reduction additive for viscous flame retardants. However, the relatively low volatility of the triaryl phosphates makes them unsuitable for certain applications where high processing temperatures may cause juicing.
SUMMARY OF THE INVENTION
It has now been found that an alkylene-bridged diphosphate compound is an effective viscosity modifying, namely, reducing agent in the aforementioned types of liquid, but viscous, flame retardant compositions. This type of material is less volatile than a triaryl phosphate compound. It also has a higher phosphorus content resulting in an increased flame retardancy efficacy as compared to a triaryl phosphate compound.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The terminology “alkylene-bridged diphosphate compound” is to be understood to encompass monomeric and low oligomeric species of the formula
Where R is aryl, such as unsubstituted phenyl, n is a number ranging from 0 to about 5, and R 1 is alkylene of from 1 to 8 carbon atoms.
The level of use of the diphosphate viscosity modification additive of the present invention with a particular flame retardant will depend upon its initial compatibility or miscibility with the flame retardant component whose viscosity is initially high and in need of reduction. The level of diphosphate to use is also dependent upon the ultimate viscosity that is desired for the composition containing it. Generally, the amount of diphosphate that needs to be added will range from about 5% to about 80%, by weight of the fluid or liquid flame retardant whose viscosity is to be reduced, preferably from about 5% to about 50%, more preferably from about 5% to about 30%.
The liquid flame retardants to which the instant invention can be added include polybrominated diphenyl oxide and aromatic oligomeric phosphates (e.g., resorcinol bis(diphenyl phosphate), bisphenol A bis(diphenyl phosphate), poly(resorcinol phenylphosphate), and high molecular weight chloroalkyl phosphates.
The aromatic bisphosphates to which the above-described alkylene-bridged diphosphate species can be added are of the same formula given above with the exception that R 1 is derived from an arylene diol, such as resorcinol, bisphenol A, or hydroquinone, and n is generally from 0 to about 15. The diphosphate viscosity reducing additive of the instant invention can also be used in similar amount with flame retardant compositions which contain oligomeric phosphate esters as the sole or predominant component. Generally speaking, it has been found that up to about 50%, by weight of the alkylene-bridged diphosphate compound, based on the weight of the entire composition, can be used in such systems in preferred embodiments.
The instant invention allows for the obtaining of low enough viscosities to achieve pumpable flame retardant compositions which are required to satisfactorily process flexible and rigid polyurethane foams, for example. Easier machine mixing and miscibility are achieved by bringing the viscosities of the components closer and preferably lower. Coating and elastomers also require low viscosities for better flowability and processing.
The present invention is illustrated by the Examples which follow.
EXAMPLES
A series of compositions were tested in regard to their viscosity at 23° C.±0.5° C. in a Brookfield viscometer. The Table given below shows the results which were obtained. (The viscosity of the additives responsible for viscosity reduction were as follows: neopentyl glycol bis(diphenylphosphate)-549; ethylene glycol bis(diphenylphosphate)-319; and propylene glycol bis(diphenylphosphate)-367.5.
TABLE
Composition - Amount (wt %)
Viscosity (cps)
Bisphenol A bis(diphenyl phosphate)
100%
20,900
Bisphenol A bis(diphenylphosphate)
90%
Neopentyl glycol bis(diphenylphosphate)
10%
12,000
Bisphenol A bis(diphenylphosphate)
80%
Neopentyl glycol bis(diphenylphosphate)
20%
8,292
Bisphenol A bis(diphenylphosphate)
50%
Neopentyl glycol bis(diphenylphosphate)
50%
2,616
Bisphenol A bis(diphenylphosphate)
90%
Ethylene glycol bis(diphenylphosphate)
10%
11,700
Bisphenol A bis(diphenylphosphate)
80%
Ethylene glycol bis(diphenylphosphate)
20%
6,548
Bisphenol A bis(diphenylphosphate)
50%
Ethylene glycol bis(diphenylphosphate)
50%
1,752
Bisphenol A bis(diphenylphosphate)
80%
Propylene glycol bis(diphenylphosphate)
20%
7,380
Bisphenol A bis(diphenylphosphate)
50%
Propylene glycol bis(diphenylphosphate)
50%
2,052
Resorcinol bis(diphenyl phosphate)
100%
691
Resorcinol A bis(diphenylphosphate)
90%
Neopentyl glycol bis(diphenylphosphate)
10%
670.5
Resorcinol A bis(diphenylphosphate)
90%
Ethylene glycol bis(diphenylphosphate)
10%
636
Resorcinol A bis(diphenylphosphate)
90%
Propylene glycol bis(diphenylphosphate)
10%
666
Pentabromo Diphenyloxide
70%
Neopentyl glycol bis(diphenylphosphate)
30%
8,670
Pentabromo Diphenyloxide
50%
Neopentyl glycol bis(diphenylphosphate)
50%
2,090
Pentabromo Diphenyloxide
70%
Ethylene glycol bis(diphenylphosphate)
30%
5,090
Pentabromo Diphenyloxide
50%
Ethylene glycol bis(diphenylphosphate)
50%
1,225
Pentabromo Diphenyloxide
70%
Propylene glycol bis(diphenylphosphate)
30%
5,590
Pentabromo Diphenyloxide
50%
Propylene glycol bis(diphenylphosphate)
50%
1,395
The foregoing data is presented for purposes of illustrating certain embodiments of the present invention and, for that reason, should not be construed in a limiting sense. The scope of protection sought is set forth in the claims which follow.
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Alkylene-bridged diphosphate compounds can be used to modify, namely, reduce, the viscosity of fluid flame retardants (polybrominated aryl oxides, oligomeric phosphate esters, etc.) which are useful in flame retarding polyurethane and thermoplastic compositions.
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BACKGROUND
1. Field of the Invention
This invention relates to a foldable and extensible structure and, more particularly, to a foldable and curvilinearly extensible structure and method, the structure fabricated from a plurality of base modules, each base module being configurated from six rigid members flexibly interconnected end-to-end by swivels in a closed configuration generally approximating a double isosceles triangle in appearance when folded flat and having intersecting rigid members pivotally secured with the location of one pivot at the midpoint of the base of the isosceles triangle as defined by the respective rigid members and the other two pivots offset from the swivels adjacent the base by a distance equal to one-half the base to thereby impart a desired external contour to the curvilinear configuration and to provide the desired folding and unfolding characteristics.
2. The Prior Art
Extensible structures are well-known in the art and one particularly familiar form of an extensible arm structure is the common "scissors" extension arm. The scissors extension arm involves at least a first pair of pivotally joined rigid members. The structure may also include additional pairs of rigid members adjoined to the ends of the first pair in an end-to-end relationship. Lateral movement of the free ends of the rigid members imparts a corresponding movement to the pivotally interconnected pairs of rigid members resulting in a linear contraction and/or extension of the scissors extension arm. While this well-known apparatus is found in numerous applications, it is generally considered to be a two-dimensional configuration and therefore lacks the necessary structural stability for various applications. Additionally, the nature of the construction limits the extension of the scissors extension arm to a generally straight line.
The foregoing limitations of a two-dimensional structure have been overcome by the apparatus disclosed in my previous patent, U.S. Pat. No. 4,155,975, issued Sept. 26, 1978. In this patent, the basic element of the foldable and extensible structure is a foldable and extensible base module. The base module is fabricated from six equal-length, rigid members swivelly interconnected end-to-end in a closed figure with intersecting rigid members being pivotally connected adjacent the midpoint of the rigid members. A plurality of the base modules are selectively interconnected at adjacent swivels and may include additional rigid struts to thereby provide an enlarged, foldable and extensible truss-like structure. However, in each of the configurations set forth in this patent, extension is limited to a straight line or plane and is, therefore, incapable of being extended in a curvilinear configuration.
Zeigler (U.S. Pat. No. 3,968,808) discloses a collapsible, self-supporting structure made up of a network of rod elements pivotally joined at their ends and forming scissor-like pairs in which rod element crossing points are pivotally joined.
Zeigler (U.S. Pat. No. 4,026,313) discloses a collapsible, self-supporting structure in which basic assemblies of crossed rod elements are employed to achieve the desired shape. Further, the crossing points of crossed rod element in the structure may include limited sliding connections to affect the transfer of collapsing force to other crossing points which are pivotally joined.
Lotto, et al (U.S. Pat. No. 4,017,932) discloses a temporary, modular, self-erecting bridge which is expandable to form a truss-like structure.
While the foregoing list of references have come to the attention of the inventor, no representation is made that all of these references may be "prior art" within the meaning of that term under the provisions of 35 USC 102 or 35 USC 103, although these references are disclosed herein so as to fully comply with the duty of candor and good faith as required in 37 CFR 1.56.
In view of the foregoing, it would be an advancement in the art to provide a foldable and extensible structure which is extensible in a generally curvilinear orientation, the curvature of the curvilinear configuration being a function of the length of the rigid members with a corresponding placement of the pivotal points on the structure, and the degree of extension of the structure. It would also be an advancement in the art to provide a novel foldable and curvilinearly extensible structure wherein the rigid members are configurated with a predetermined arcuate curve therein to thereby provide a predetermined toroidal profile to the structure.
BRIEF SUMMARY AND OBJECTS OF THE INVENTION
The present invention relates to a foldable and curvilinearly extensible structure fabricated from a plurality of basal modular elements with each basal modular element or base module being configurated from six rigid members flexibly joined end-to-end by swivels into a closed structure having a generally double, isosceles triangular profile when folded flat. The intersecting rigid members are pivotally interconnected.
The rigid members that form the base of the isosceles triangle are pivotally joined at their midpoint while the pivots for the other two sets of rigid members are each offset from the intervening swivels by a distance that equals one-half the length of the base or, correspondingly, are offset from the swivel by the same distance as the basal pivot.
It is, therefore, a primary object of this invention to provide improvements in foldable and curvilinearly extensible structures.
Another object of this invention is to provide improvements in the method of providing foldable and curvilinearly extensible structures.
Another object of this invention is to provide a foldable and curvilinearly extensible structure wherein a plurality of basal modular elements are selectively interconnected end-to-end for the purpose of providing a curvilinearly extensible structural element.
Another object of this invention is to provide a truss-like structure wherein a plurality of basal modular elements are selectively interconnected to provide a structure which is foldable and curvilinearly extensible into a truss structure having a generally cylindrical profile.
Another object of this invention is to combine rigid members having predetermined lengths to provide a foldable structure having a predetermined isosceles triangular profile and being curvilinearly extensible.
These and other objects and features of the present invention will become more fully apparent from the following description and appended claims taken in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of a basal modular element for a first preferred embodiment of this invention shown in the generally open or extended configuration;
FIG. 2 is a perspective view of a plurality of the basal modular elements of FIG. 1 shown interconnected to provide a first preferred embodiment of the foldable and curvilinearly extensible structure of this invention;
FIG. 3 is a perspective view of another preferred embodiment of the basal modular element of this invention shown in the partially opened configuration;
FIG. 4 is a perspective view of a plurality of basal modular elements of FIG. 1 interconnected to form another preferred embodiment of the foldable and curvilinearly extensible structure of this invention;
FIG. 5 is a perspective view of another preferred embodiment of the basal modular element of this invention showing each of the rigid members having a predetermined curved configuration;
FIG. 6 is a perspective view of a plurality of modular elements of FIG. 5 interconnected end-to-end to provide another preferred embodiment of the foldable and curvilinearly extensible structure of this invention.
FIG. 7 is a perspective view of a pair of modular elements joined side by side;
FIG. 8 is a perspective view of a plurality of pairs of modular elements of FIG. 7 interconnected in another preferred embodiment of the foldable and curvilinearly extensible truss structure of this invention to create a vault-like structure having a generally cylindrical profile;
FIG. 9 is a schematic, side elevation of the truss structure of FIG. 8 to more clearly illustrate the cylindrical curvature of the curvilinearly extensible structure; and
FIG. 10 is a diagramatic representation of the pivot points for the isosceles triangular configuration of the basal modular elements of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention is best understood by reference to the drawing wherein like parts are designated by like numerals throughout.
Referring now to FIG. 1, a first preferred embodiment of the base module of this invention is shown generally at 10 and includes a plurality of rigid members 11-16 flexibly interconnected end-to-end by flexible swivels 17a-17f, respectively. Representative swivel arrangements are shown in my patent, U.S. Pat. No. 4,115,975 issued Sept. 26, 1978. Swivels 17a-17f provide the necessary twisting and hinge-type movement between the interconnected rigid members 11-16 when base module 10 is flexed between the flat and the extended configurations.
The respective lengths of adjoining pairs of rigid members 11-16 are selectively predetermined to thereby provide an essentially isosceles triangular profile when base module 10 is folded into a flat configuration. For example, rigid members 11 and 14 are provided with a length that is longer than the equal lengths of rigid members 12, 13, 15 and 16. This configuration presents a profile corresponding to an isosceles triangle with a wide base as represented by rigid members 11 and 14 so that the sides of the triangle represented by rigid members 12 and 15 on one side and rigid members 13 and 16 on the other side are essentially equal in length.
Rigid members 11 and 14 are pivotally interconnected by a pivot 18a while rigid members 12 and 15 are pivotally interconnected by a pivot 18b and rigid members 13 and 16 are pivotally interconnected by a pivot 18c. It will be noted that pivot 18a is located at the midpoint of each of rigid members 11 and 14. However, pivots 18b and 18c are offset a predetermined distance from the interceding swivels of the respective rigid members. The relationship between the lengths of the rigid members that form the isosceles triangle and the relationship between the location of the respective pivots can best be understood by reference to the schematic illustration of FIG. 10.
With particular reference now to FIG. 10, an isosceles triangle ABC is shown generally at 100 and has a base AC with equal sides represented by leg AB and leg BC. A pivot 102 is located at the midpoint of base AC so that the distance from pivot 102 to corner A is represented by distance x and likewise the distance from pivot 102 to corner C is also represented by the distance x. Importantly, pivot 103 is located distance x from corner A and pivot 104 is also located distance x from corner c. Any significant alteration of the relationship of the respective pivots from the foregoing relationship will interfere with the foldable and also the curvilinear extension characteristics of the structure of this invention.
While triangle ABC of FIG. 10 is shown with base AC shorter than coequal legs AB and BC, the foregoing relationship must be followed when base AC is longer than legs AB and BC. The only difference will be in the direction in which the structure will curve when unfolded.
Referring again to FIG. 1, the base of the isosceles triangle of base module 10 is represented by rigid members 11 and 14. Accordingly, it is to be clearly understood that pivot 18b is located equidistantly from swivels 17a and 17d as is pivot 18a from swivels 17a and 17d. Likewise, pivot 18c is also located equidistantly from swivels 17c and 17f along with pivot 18a from the same swivels.
Since the base represented by rigid members 11 and 14 is longer than the remaining rigid members, the foregoing relationship places pivots 18b and 18c closer to swivels 17b and 17e. The resulting placement of pivots 18b and 18c means that the assembled truss member, as will be discussed more fully hereinafter with respect to FIG. 2, will tend to place swivels 17b and 17e on an inside portion of the resultant curvilinear profile.
Attention should also be directed to the inside/outside relationship between the pivotally joined rigid members 11-16. In particular, the relationship alternates for each rigid member in the serial sequence. For example, rigid member 11 is pivotally connected to the outside of rigid member 14 whereas rigid member 12 is pivotally connected to the inside of rigid member 15. Correspondingly, rigid member 13 is pivotally connected to the outside of rigid member 16. The terms "inside" and "outside" have been arbitrarily chosen herein to designate the appropriate position relative to the internal structure of base module 10.
Referring now also to FIG. 2, a plurality of base modules 10 (shown herein as base modules 10a-10e) are selectively interconnected in an end-to-end relationship to provide this one preferred embodiment of the foldable and curvilinearly extensible truss element 20 of this invention. In particular, swivels 17b, 17d, and 17f are flexibly interconnected with corresponding swivels of base module 10b in interties 22a-22c, respectively, thereby flexibly interconnecting base module 10a with base module 10b. Corresponding flexible interties are also made between each of base modules 10b-10e thereby providing the foldable and curvilinearly extensible truss-like structure 20. However, it should be pointed out that the foregoing inside/outside relationship between adjacent rigid members is alternated between successive base modules 10a-10e. This successive alternation corrects the tendency for the assembled truss element 20 to form a generally twisting characteristic in the structure. In particular, each of rigid members 11-16 are interconnected end-to-end and are foldable into a generally flat, double, isosceles triangular configuration. The double triangular configuration is composed of two isosceles triangles (when folded flat and viewed in plan view) with the first triangle including rigid members 11, 12 and 13 and the second triangle including rigid members 14, 15 and 16. However, since all of rigid members 11-16 are interconnected end-to-end, the overlying pairs of swivels (swivels 17a and 17d; swivels 17b and 17e; and swivels 17c and 17f) tend to be offset from each other by approximately the thickness of the respective rigid members. Therefore, in the absence of an alternating base module internal structure, the total structure of truss element 20 would tend to twist by an amount approximating the thickness of the rigid members of each base module to the next base module.
The degree of curvature of truss element 20 is a function of the relative lengths of the respective rigid members and the degree of extension of truss element 20. Accordingly, any person practicing the teachings of this invention will be able to use simple, well-known mathematical relationships to selectively predetermine the distance to be covered by truss element 20, the degree of desired curvature, and the degree of extension for the various base modules 10a-10e therein. These mathematical concepts are well-known in the art and are, therefore, not included herein for each of presentation and simplicity. The foregoing calculation will necessarily include a determination of the length of rigid members 11 and 14 for the purpose of providing the desired overall profile characteristics to truss structure 20. For example, increasing the length of rigid members 11 and 14 shifts the location of pivots 18b and 18c in the remaining rigid members and provides a corresponding change in the curvature of truss element 20. Correspondingly, foreshortened rigid members 11 and 14 relative to the remaining rigid members provides a corresponding alteration in the overall appearance of truss element 20.
With reference now to FIG. 3, another preferred embodiment of the base module of this invention is shown as base module 30. Base module 30 differs from base module 10 (FIG. 1) primarily in the length of its base as defined by rigid members 32 and 35, as will be set forth more fully hereinafter.
Base module 30 is fabricated from a plurality of rigid members 31-36 serially interconnected end-to-end by swivels 37a-37f, respectively. Rigid members 32 and 35 are pivotally interconnected at their respective midpoints by pivot 38b. Pivot 38a pivotally interconnects rigid members 31 and 34 while pivot 38c pivotally interconnects rigid members 33 and 36. It should be particularly noted that pivot 38a is equidistantly located from swivels 37a and 37d along with pivot 38b. Correspondingly, pivot 38c is located equidistantly with pivot 38b from swivels 37b and 37e. This relationship is best seen by reference again to the foregoing discussion regarding the schematic illustration of FIG. 10.
The length of rigid members 32 and 35 in relation to the remaining rigid members, rigid members 31, 33, 34 and 36, in conjunction with the predetermined placement of pivots 38a and 38c imparts the desired curvilinear extension characteristics to a truss structure fabricated from a plurality of base modules 30 serially interconnected in an end-to-end relationship as will be set forth more fully hereinafter with respect to the discussion relating to FIG. 4.
Referring now more particularly to FIG. 4, a truss element 40 is shown and is fabricated from a plurality of base modules similar to base module 30 (FIG. 3) and shown herein as base modules 30a-30h. In particular, swivels 37b, 37d, and 37f are interconnected with corresponding swivels of adjacent base module 30b to form interties 42a-42c, respectively. Corresponding interties are made between adjacent swivels of base modules 30b-30h to provide the curvilinearly extensible structure of truss element 40. However, as set forth hereinbefore with respect to FIGS. 1 and 2, each of base modules 30a-30h are sequentially alternated with respect to the "inside" and "outside" relationship between the intersecting rigid members.
The basal portion of truss structure 40, as represented by rigid members 32 and 35 (see also FIG. 3), forms a curvilinear surface which generally represents a segment of a cylindrical surface whereas the apex of the triangular configuration as represented by swivels 37c and 37f (see also FIG. 3) generally represents an arc which is substantially parallel to the cylindrical planar surface represented by rigid members 32 and 35. Accordingly, in comparison with truss element 20 (FIG. 2), truss element 40 is configurated with an arch-like inner surface corresponding to the cylindrical surface as represented by rigid members 32 and 35. On the other hand, the truss element 20 (FIG. 2) provides an outer cylindrical surface as represented by rigid members 11 and 14 as the outer surface to truss element 20.
The circular arch superintended by truss element 40 will, therefore, be a function of the length of rigid members 31, 33, 34 and 36 in relation to rigid members 32 and 35 which determines the location of pivots 38a and 38c in combination with the degree of extension of base modules 30a-30h that make up truss element 40.
Referring now more particularly to FIG. 5, another preferred embodiment of the novel base module of this invention is shown generally at 50 and includes a plurality of rigid members 51-56 serially interconnected in an end-to-end relationship by swivels 57a-57f, respectively. While base module 50 is substantially similar to the construction of base module 10 (FIG. 1) is should be particularly noted that each of rigid members 51-56 are formed with a predetermined curvature therein. The curvature of each of rigid members 51-56 is selectively oriented so that when base module 50 is folded into the generally flat or triangular configuration, the arcuate curvatures of corresponding pairs of rigid members 51 and 54; 52 and 55; and 53 and 56, are substantially parallel. In each instance, the curvature is outwardly from the center of the generally triangular configuration of flat folded base module 50.
Rigid members 51 and 54 form the "base" to the isosceles triangle represented by base module 50 when folded into a generally flat configuration and are pivotally joined at their respective midpoints. Rigid members 51 and 54 are also longer than the remaining equal length rigid members, rigid members 52, 53, 55, and 56. Thus, rigid members 52 and 55 are pivotally joined at a distance from swivels 57a and 57d equal to the distance that pivot 58a is located from swivels 57a and 57d. Correspondingly, rigid members 53 and 56 are pivotally joined at pivot 58c located at a distance from swivels 57c and 57f equal to the distance that pivot 58a is from swivels 57c and 57f. The respective lengths of rigid members 51 and 54 with respect to the lengths of rigid members 52, 53, 55, and 56 with the corresponding placement of pivots 58b and 58c, imparts the desired curvilinear characteristic to truss element 60 (FIG. 6) similar to that found in base module 10 in its relationship to truss element 20 (FIG. 2) as set forth hereinbefore.
With particular reference to FIG. 6, truss element 60 is shown as fabricated from a plurality of base modules 50a-50e similar to base module 50 (FIG. 5). Base module 50a is flexibly interconnected in an end-to-end relationship to base module 50b by flexibly interconnecting swivels 57b, 57d and 57f to corresponding swivels on base module 50b in interties 62a-62c. Corresponding interconnection is made between the successive base modules 50d-50e, respectively. Accordingly, truss element 60 is foldable and curvilinearly extensible in a generally curvilinear profile substantially identical to the extension of truss element 20 (FIG. 2). Additionally, the degree of curvature of truss element 60 in the extension thereof will be a function of the respective length relationships between rigid members 51 and 54 with respect to rigid members 52, 53, 55, and 56. The resultant length of rigid members 51 and 54 will selectively predetermine the location of pivots 58b and 58c. These features combined with the number and degree of extension of base modules 50a-50e will selectively determine the arch superintended by truss element 60.
Importantly, however, it should be noted that the arcuate profile of each of rigid members 51-56 also imparts an overall toroidal contour to the internal portion of truss element 60 when truss element 60 is extended into a predetermined degree of extension. The interrelationship between the extension of truss element 60 to obtain the toroidal profile will, therefore, also be a function of the curvature of each of rigid members 51-56. The formation of a generally toroidal surface by truss element 60 would provide a useful structure for supporting an internally placed toroidal surface (not shown) for any suitable purpose. Additionally, the internal relationship between adjacent base modules 50a-50e will be selectively alternated to preclude the previously discussed "twisting" of truss element 60.
Referring now to FIG. 7, another basal element of the truss structure of this invention is shown wherein a pair of base modules 70a and 70b are joined in a side-to-side relationship through flexible interties 92a and 92b. In particular, base module 70a is fabricated from a plurality of rigid members 71-76 flexibly interconnected in an end-to-end relationship by swivels 77a-77f, respectively. Rigid members 71 and 74 are pivotally interconnected at their respective midpoints by pivot 78a. Rigid member 72 is pivotally interconnected to rigid member 75 by pivot 78b while rigid member 73 is pivotally interconnected to rigid member 76 by swivel 78c. Swivels 78b and 78c are located so that the respective distance from the adjacent swivel between it and swivel 78a is the same to thereby impart the desired curvilinear characteristics to the truss structure as will be set forth more fully hereinafter and as also set forth hereinbefore with respect to each of the structures of this invention. Base module 70b is fabricated from a plurality of rigid members 81-86 flexibly interconnected in an end-to-end relationship by swivels 87a-87f, respectively. Correspondingly, rigid members 81 and 84 are pivotally interconnected by pivot 88a adjacent their midpoint. Pivot 88b pivotally joins rigid members 82 and 85 while rigid members 83 and 86 are pivotally joined by pivot 88c. The placement of pivot 88b relative to rigid members 82 and 85 is such that the distance from pivot 88b to swivels 87a and 87d is equal to the distance from pivot 88a to these same swivels. Pivot 88c is likewise located on rigid members 83 and 86 equidistantly with pivot 88a from swivels 87c and 87f.
Intertie 92a flexibly interconnects swivel 77c of base module 70a with swivel 87a of base module 70b. Correspondingly, intertie 92b flexibly interconnects swivel 77f of base module 70a with swivel 87d of base module 70b. The particular orientation of base module 70a to base module 70b is such that rigid members 71 and 74 of base module 70a in cooperation with rigid members 81 and 84 of base module 70b define a generally planar configuration across the corresponding surface of base modules 70a and 70b. Additional base modules (not shown), comparable to base modules 70a and 70b, can be joined also in a side-to-side relationship therewith to further extend laterally the basal structure 70. For example, additional interties may be made with swivel 77a and 77d of base module 70a in addition to swivels 87c and 87f of base module 70b.
Referring now more particularly to FIG. 8, another preferred truss structure embodiment of this invention is shown generally at 80 and is fabricated from a plurality of basal elements such as basal element 70 (FIG. 7) (fabricated from base modules 70a and 70b) flexibly joined in an end-to-end relationship with additional basal elements. For example, base modules 70a and 70b are joined in a side-to-side relationship (see also FIG. 7) and are, in turn, flexibly joined end-to-end with corresponding base modules 70c and 70d, respectively. Additionally, base modules 70c and 70d are flexibly joined end-to-end with base modules 70e and 70f, respectively, while base modules 70g and 70h, respectively, are flexibly joined therewith. Accordingly, the planar configuration defined by rigid members 71 and 74 in conjunction with rigid members 81 and 84 (FIG. 7) becomes a substantially widened cylindrical surface when truss structure 80 is curvilinearly extended. The curvature of the resulting cylindrical surface is a function of the various features set forth hereinbefore.
Truss structure 80 is shown as being fabricated from base modules 70a and 70b (FIG. 7) which are similar in construction to base module 10 (FIG. 1) so that truss structure 80 is then generally similar in its basic construction to truss element 20 (FIG. 2).
Therefore, it will be seen that the configuration of truss structure 80 is substantially identical to truss element 20 (FIG. 2) with the exception that truss structure 80 consists of two side-by-side truss elements similar to truss element 20 (FIG. 2) joined in a side-to-side relationship. However, a similar configuration for truss structure 80 may also be prepared using the combination of features relative to the structure of base module 30 (FIG. 3) as the basal element for a plurality of truss elements similar to truss element 40 (FIG. 4). Correspondingly, truss structure 80 may also be prepared from a combination of base modules 50 (FIG. 5) connected into a plurality of joined truss elements similar to truss element 60 (FIG. 6). In any of these configurations, the length of the base of the triangular (isosceles) profile relative to the two legs predetermines the placement of the respective pivots in those legs and, thereof, the curvature characteristics of the particular truss element or truss structure.
With reference now to FIG. 9, trus structure 80 is indicated schematically as extending in a semicircular arch to provide thereby a semicylindrical vault. This figure is included herein primarily for the purpose of showing the arch-forming characteristics of truss structure 80 of FIG. 8 when viewed in a side elevation. The broken lines schematically illustrate the continuum formed when the overall truss structure is extended with additional basal elements similar to basal element 70 (FIG. 7).
The invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive and the scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
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A foldable and curvilinearly extensible structure fabricated from a plurality of foldable and extensible base modules. Each base module is fabricated from six rigid members swivelly connected end-to-end in a closed figure with intersecting rigid members being pivotally connected. The length of the first and fourth rigid members is selectively predetermined to provide the overall triangular configuration of the structure with a generally isosceles triangular configuration. Importantly, the placement of pivots in the second and fifth rigid members and the third and sixth rigid members is predetermined by the length to the midpoint of the first and fourth rigid members. A plurality of base modules are selectively interconnected at adjacent swivels to thereby provide the enlarged, foldable and curvilinearly extensible truss-like structure. A plurality of base modules may be selectively interconnected side-by-side and also in an end-to-end configuration to form an elongated, three-dimensional structure which folds into a relatively flat profile while, simultaneously, being extensible at a relatively high ratio and in a generally curvilinear contour. The respective rigid members can also be configurated as curved rigid members to thereby provide a generally toroidal contour to the curvilinearly extensible structure.
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This is a divisional application Ser. No. 07/964,056, filed on Oct. 21, 1992.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a process for the production of substituted vinylbenzenes of general formula: ##STR2## wherein R is a lower alkyl group having 1 to 4 C atoms R 1 is a hydrogen or an acetyl group and R 2 is a hydrogen, a lower alkyl group having 1 to 4 C atoms or a benzyl group.
2. Background Art
Substituted vinylbenzenes are valuable intermediate products for the production of antioxidants, such as, of Trolox C® (U.S. Pat. No. 5,080,886).
It is known from Chem. Berichte, Vol. 92, (1959), pages 2958 to 2961 that 1-vinyl-2,4,5-trimethyl-3,6-dihydroxybenzene can be produced over four stages starting from trimethylhydroquinone or trimethylphenol. In such process, especially the last stage, the decarboxylation of 3,6-dihydroxy-2,4,5-trimethyl cinnamic acid proves to be extremely difficult. Thus, the desired vinylbenzene was able to be obtained in a yield of only 4 percent relative to the cinnamic acid derivative used.
BROAD DESCRIPTION OF THE INVENTION
The main object is to provide a process that does not have the above specified drawbacks and with which it is possible to produce the substituted vinylbenzenes on an industrial scale. Other objectives and advantages of the invention are set out herein or are obvious herefrom to one skilled in the art.
The objectives and advantages of the invention are achieved by the process and compounds of the invention.
The invention involves a process for the production of the substituted vinylbenzenes of the general formula: ##STR3## wherein R is a lower alkyl group having 1 to 4 C atoms, R 1 is hydrogen or an acetyl group and R 2 is hydrogen, a lower alkyl group having 1 to 4 C atoms or a benzyl group. A trialkylhydroquinone of the general formula: ##STR4## wherein R has the mentioned meaning, is reacted with an aldehyde of the general formula: ##STR5## wherein R 2 has the mentioned meaning, in the presence of an acid with exclusion of water to an acetal of the general formula: ##STR6## wherein R and R 2 have the mentioned meanings. This acetal is optionally reacted with acetyl chloride to the acetylated acetal of the general formula: ##STR7## wherein R and R 2 have the mentioned meanings. Finally, the acetal of the general formula IV or V is pyrolized to a vinylbenzene of the general formula: ##STR8## wherein R, R 1 and R 2 have the mentioned meanings.
Preferably the trimethyl derivative with R being CH 3 is used as the trialkylhydroquinone of the general formula II and the acetylaldehyde with R 2 being hydrogen is used as the aldehyde of the general formula III. Preferably the reaction to the acetal of general formula IV is performed at a temperature between -30° to 30° C. in the presence of an inert solvent. Preferably hydrochloric acid is used as the acid for the reaction to the acetal of the general formula IV. Preferably the acetylation to the acetal of the general formula V takes place with acetyl chloride in the presence of a tertiary amine at a temperature between 0° and 100° C. Preferably the pyrolysis of the acetal of the general formula IV or V takes place at a temperature of over 300° C. under reduced pressure. Preferably the pyrolysis of the acetal of the general formula IV or V takes place at a temperature between 400° and 500° C. and a reduced pressure between 0.5 and 100 mbar.
The invention also involves acetals of the general formula: ##STR9## wherein R is a lower alkyl group having 1 to 4 C atoms, R 1 is hydrogen or an acetyl group and R 2 is hydrogen, a lower alkyl group having 1 to 4 C atoms or a benzyl group. Preferably the acetal of the general formula VIII is 2,4,5,7,8-pentamethyl--4H[1,3]dioxin-ol of the formula: ##STR10##
The invention further involves substituted vinylbenzenes of the general formula: ##STR11## wherein R is a lower alkyl group having 1 to 4 C atoms, R l is a hydrogen or an acetyl group and R 2 is hydrogen, a lower alkyl group having 1 to 4 C atoms or a benzyl group. Preferably the substituted vinylbenzene of the general formula I is acetic acid-4-hydroxy-2,5-6-trimethyl-3-vinylphenyl ester of the formula:
DETAILED DESCRIPTION OF THE INVENTION
According to the invention process, in the first stage, a trialkylhydroquinone of the general formula: ##STR13## wherein R has the above-mentioned meaning, is reacted with an aldehyde of the general formula: ##STR14## wherein R 2 has the above-mentioned meaning, in the presence of an acid and with exclusion of water to the acetal of the general formula: ##STR15## wherein R and R 2 have the above-mentioned meanings. Preferably trimethylhydroquinone is reacted with acetaldehyde to the corresponding acetal of the general formula IV with R being CH 3 and R 2 being hydrogen. Suitably the reaction takes place at a temperature between -30° to 30° C. preferably at a temperature under 20° C. in the presence of an inert solvent. Suitably the aldehyde is used in excess. Suitable anhydrous acids are, e.g., hydrochloric acid, hydrobromic acid, sulfuric acid and methanesulfonic acid. Preferably hydrochloric acid is used.
The acetals of the general formula IV resulting in good yields can be isolated from the reaction mixture in ways known in the art.
The acetals of the general formula IV so far have not been described in the prior art and therefore are also part of the invention. The preferred acetal of the general formula IV is the compound with R being CH 3 and R 2 being hydrogen.
If desired the acetals of the general formula IV can be acetylated to acetylated acetals of the general formula: ##STR16## wherein R and R 2 have the above-mentioned meanings. These acetals so far have also not been described in the prior art and, therefore, are also part of the invention. The preferred acetylated acetal of the general formula V is the compound with R being CH 3 and R 2 being hydrogen.
The acetylation takes place suitably with acetyl chloride in the presence of a tertiary amine, such as, triethyl amine, in a suitable inert solvent. Usually the reaction takes place practically quantitatively at a temperature between 0° and 100° C.
The acetylated acetal can be isolated from the reaction mixture in the usual way and fed to the further reaction (pyrolysis).
In the next stage, the acetals of the general formula IV or V are pyrolyized to the substituted vinylbenzenes of the general formula: ##STR17## wherein R, R 1 and R 2 have the above-mentioned meanings. The pyrolysis takes place suitably at a temperature of over 300° C., (up to the highest effective pyrolysis temperature), preferably between 400° and 500° C., at a reduced pressure of between 0.5 and 100 mbar.
Corresponding to the preferred acetals of the general formula IV or V with R being CH 3 and R 2 being hydrogen, the methylated derivatives with R being CH 3 , R 1 being hydrogen or acetyl and R 2 being hydrogen resulted as the preferred vinylbenzenes of the general formula I.
The acetylated vinylbenzenes of the general formula I with R 1 being acetyl so far have not been described in the prior art and, therefore, are also part of the invention.
The corresponding vinylbenzenes can be obtained in this way in a good yield of about 70 percent relative to the trialkylhydroquinone used.
EXAMPLE 1
(a) Process for the production of 2,4,5,7,8-pentamethyl-4H-benzene [1,3]dioxin-6-ol
Trimethylhydroquinone (60.8 g, 0.4 mol) was suspended in CH 2 Cl 2 (11). A solution of acetaldehyde (135 ml, 105.6 g, 1,3 mol) in CH 2 Cl 2 (280 ml) was added to this suspension so that the temperature did not exceed 20° C. Then the suspension was saturated with gaseous HCl until the reaction was complete (tracked with TLC, toluene/acetone, 4:1). The suspension gradually dissolved during the HCl-addition. The yellow solution was concentrated by evaporation under vacuum. 83 g (93.7 percent) of yellow solid with a melting point of 101° to 103° C. was obtained. Other data for the product was:
1 H-NMR: (C 6 D 6 , 300 MHz) δ in ppm 5.21 (q, 1 H, J=7 Hz);
4.87 (q, 1 H, J=6 Hz);
3.78 (s, 1 H);
2.21 (s, 3 H);
1.94 (s, 3 H);
1.69 (s, 3 H);
1.52 (d, 3 H, J=5 Hz);
1.28 (d, 3 H, J=6 Hz);
Isomer: 5.01 (q, 1 H, J=6 Hz );
4.83 (q, 1 H, J=5 Hz);
3.82 (s, 3 H);
1.93 (s, 3 H);
1.78 (s, 3 H); 1.50 (d, 3 H, J=5 Hz); 1.42 (d, 3 H, J-6 Hz).
(b) Process for the production of 1,4-dihydroxy-2,3,5-trimethyl-6-vinylbenzene
(2 g, 9.0 mmol) of 2,4,5,7,8-pentamethyl-4H-benzene[1,3]dioxin-6-ol was pyrolized under vacuum (20 mbar) in a quartz tube at 460° C. A light brown solid (1 g, 62 percent) with a melting point of 143° to 145° C. was obtained. Other data for the production was:
1 H-NMR: (CDCl 3 , 300 MHz) δ in ppm 6.67 (dd, 1 H, J=12,5 Hz, 19 Hz );
5.68 (d, 1 H, J=12.5 Hz);
5.50 (d, 1 H, J=19 Hz);
5.33 (s, 1 H);
4.25 (s, 1 H);
2.20 (s, 6 H);
2.13 (s, 3 H).
EXAMPLE 2
(a) Process for the production of acetic acid 2.4,5,7,8-penta-methyl -4H-benzene[1,3]dioxin-6-yl ester
2,4,5,7,8-Pentamethyl-4H-benzene[1,3]dioxin-6-ol (117.4 g, 0.528 mol) and triethylamine (63.14 g, 0.624 mol) were dissolved in CH 2 Cl 2 (800 ml) at 0° C. Acetyl chloride (49.0 g, 0.624 mol) was instilled in this solution during 1 hour. This mixture was stirred for 30 minutes and then mixed with water (400 ml). The organic phase was dried with MgSO 4 and concentrated by evaporation under vacuum. A light yellow solid (130.1 g, 93 percent) with a melting point of 91.8° to 92.2° C. was obtained. Other data for the product was:
1 H-NMR: (CDCl 3 , 300 MHz) δ in ppm. 5.34 (q, 1 H, J=7.5 Hz);
4.98 (q, 1 H, J=7.5 Hz);
2.35 (s, 3 H);
2.13 (s, 3 H);
2.04 (s, 3 H);
1.95 (s, 3 H);
1.54 (d, 3 H, J=7.5 Hz);
1.52 (d, 3 H, J=7.5 Hz);
Isomer: 5.20 (q, 1 H, J=7.5 Hz);
4.96 (q, 1 H, J=7.5 Hz);
2.35 (s, 3 H);
2.13 (s, 3 H);
2.04 (s, 3 H);
1.99 (d, 3 H);
1.54 (d, 3 H, J=7.5 Hz);
1.47 (d, 3 H, J=7.5 Hz).
(b) Process For The Production of Acetic Acid-4-Hydroxy-2,5,6-trimethyl-3-vinylphenyl ester
Acetic acid-2,4,5,7,8-pentamethyl-4H-benzene[1,3]dioxin-6-yl ester (20 g, 75.6 mmol) was pyrolized in a quartz tube at 450° C. under vacuum (10 mbar). After recrystallization from hexane (65 ml), a white solid (14.80 g, 77 percent) with a melting point of 73.5° to 74.8° C. was obtained. Other data for the product was:
1 H-NMR: (CDCl 3 , 400 MHz) δ in ppm 6.63 (dd, 1 H, J=11.5 & 18.2 Hz );
5.69 (dd, 1 H, J=1.8 & 11.5 Hz );
5.58 (s, 1 H);
5.51 (dd, 1 H, J=1.8 & 18.2 Hz );
2.32 (s, 3 H);
2.17 (s, 3 H);
2.05 (s, 3 H);
2.01 (s, 3 H).
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A process for the production of substituted vinylbenzenes of the general formula: ##STR1## wherein R is a lower alkyl group having 1 to 4 C atoms, R 1 is hydrogen or an acetyl group and R 2 is hydrogen, a lower alkyl group having 1 to 4 C atoms or a benzyl group. A trialkylhydroquinone is cyclized with an aldehyde to an acetal and the latter is pyrolized to the end product. The substituted vinylbenzenes are valuable intermediate products in the synthesis of antioxidants.
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This application is a continuation of application Ser. No. 08/607,322, filed Feb. 26, 1996, now abandoned.
FIELD OF THE INVENTION
The present invention relates generally to elastic bands for use in the construction of garments, and more particularly, to a method and apparatus for conveniently and cost effectively forming a composite elastic band and drawcord.
BACKGROUND OF THE INVENTION
Many types of clothing, such as athletic shorts and sweatpants, use an elastic waistband in combination with a drawstring so that the garment can be worn by persons of different size. In most garments of this type, the elastic waistband and drawstring are incorporated into the garment in separate steps. First, the waistband is stretched and sewn to the garment. The second step involves forming a channel for the drawstring and then inserting the drawstring into the channel. The drawstring is inserted into the channel by inserting a flexible wire with a hook into the channel and pulling the drawstring through the channel. This technique is labor intensive and significantly increases production costs.
Attempts to overcome the advantages of the aforementioned process are described in U.S. Pat. No. 4,477,928 and U.S. Pat. No. Re 33,586. The patents disclose the fabrication of a woven, knitted or braided elastic band with a pull cord embedded in the band as part of the knitting, weaving or braiding process. One disadvantage of the process is that it requires the knitting or weaving machine used to manufacture the bands to be specially set up before production of the composite waistband. Setting up the knitting and weaving machines can be a time consuming process during which the machine is out of production. Once the knitting or weaving machine is properly set up to produce the composite waistband, the manufacturer will ordinarily produce a relatively large inventory of composite waistbands before switching production back to conventional elastic bands. Another disadvantage of this technique is that it requires the replacement of one or more elastomeric strands in the fabric and with the drawcord. This alters the elastic properties of the fabric band which may be undesirable.
A further attempt to produce composite elastic band/drawcords is disclosed in U.S. Pat. Nos. 5,040,244 and 5,186,779. The patents disclose the adhesion of a drawcord to one surface of a previously formed elastic band. The chosen adhesive retains the drawcord in place along with the length of the band until fabrication of the composite band into a garment, but releases the drawcord from the band thereafter to serve as a freely slidable drawcord. One disadvantage of this product is the tendency of the releasable adhesive to allow the drawcord and elastic band to become separated prematurely. Further, the manufacturer of this type of composite waistband requires the use of special manufacturing equipment to heat and cure the adhesive.
In order to overcome the above disadvantages and deficiencies, applicant has earlier invented a composite elastic band/drawcord product including an elongated band of elastic material and a drawcord disposed adjacent a surface of the elastic band and secured thereto by a stitching yarn defining a longitudinally extending channel through which the drawcord extends. This invention is further described in applicant's U.S. Pat. No. 5,375,266 to Crisco.
One method and apparatus for forming composite drawcord/elastic waistbands according to applicant's U.S. Pat. No. 5,375,266 is disclosed in U.S. Pat. No. 5,400,729 to Bryant. The method involves feeding an elastic band through a sewing machine, feeding a drawcord through the sewing machine, and connecting the drawcord to a stretched segment of the elastic band with the sewing machine by forming a plurality of longitudinally spaced stitches extending over the drawcord. Typically, this method requires that the waistband be formed on a first knitting machine with the drawcord being secured to the waistband at a second sewing machine. This process requires additional capital expense for sewing equipment. Further, care must be taken in the sewing operation to avoid penetration of the drawcord itself with the sewing thread so that the drawcord remains free to move relative to the elastic band.
A further method and apparatus for forming composite drawcord/elastic waistbands according to applicant's U.S. Pat. No. 5,375,266 is disclosed in U.S. Pat. No. 5,452,591 to King. In that patent, a process is disclosed wherein an elastic band is fabricated with an integrated drawcord utilizing a crochet-type warp knitting machine. The process includes initially knitting a finished elastic band and then rerouting the finished band back through the knitting machine to a second knitting location at which fabric piercing needles are utilized to knit additional warp and filling yarns while a drawcord is simultaneously fed between the piercing needles to form a covering web over the drawcord defining a tunnel area between the covering web and the finished band in which the drawcord is captured. One significant drawback of this process and apparatus is that the number of composite waistbands which may be formed on a given machine is limited. Because the knitting bed must include locations both for forming the elastic band and for securing the drawcord to the elastic band, the number of elastic bands which may be formed on the needle bed is reduced by half or more. Further, because the apparatus as disclosed requires that the band be looped back around behind the needle bed, monitoring of the travel of the band is compromised. Because the elastic band follows a path which at one portion has a component parallel to the needle bed, there may be a tendency for the elastic band and/or the drawcord to become mispositioned along the needle bed.
Thus, there exists a need for a method and apparatus for forming composite drawcord/elastic waistbands of the type having a drawcord secured to an elastic band by a covering web which extends over the drawcord which is convenient and cost effective to implement. Further, there exists a need for such a method and apparatus which increases the production rate of such composite drawcord/elastic waistbands. Moreover, there exists a need for a method and apparatus for forming such waistbands which may be practiced on conventionally available machinery with convenient and cost effective modifications. There exists a need for a method and apparatus as described above wherein machinery so modified may be conveniently and cost effectively converted to operate in conventional fashion.
SUMMARY OF THE INVENTION
The present invention is directed to a knitting machine for forming a composite band including an elongate knitted band and a drawcord secured to a front face of the knitted band by a covering yarn overlying the drawcord and stitched to the elongate band. The knitting machine includes a frame. A first knitting station is provided supported by the frame for forming the elongate knitted band. A second knitting station is provided supported by the frame and downstream of the first knitting station for receiving the knitted band after it exits the first knitting station. The second knitting station is operative to stitch the covering yarn to the knitted band from opposite sides of and across the drawcord to form a channel area defined between the covering yarn and the front face of the knitted band, the drawcord disposed in the channel area.
Preferably, the first knitting station includes a first reciprocating elongate needle bed along a first plane, a first warp yarn guide bar, and at least one first filling yarn guide bar. Preferably, the second knitting station includes, a second reciprocating elongate needle bed along a second plane, a second warp yarn guide bar, and at least one second filling yarn guide bar. The first and second planes are spaced apart from each other. Preferably, the respective needle beds are interconnected such that their respective reciprocating movements are synchronized with one another. The elongate needle may be interconnected by a timing belt. Preferably, the respective warp yarn guide bars interconnected such that their respective reciprocating movements are synchronized with one another. The respective warp yarn guide bars may be interconnected by a timing belt. Preferably, the first warp yarn guide bar is reciprocated side to side by a first roller arm engaging a rotating cam at a first location and the second warp yarn guide bar is reciprocated side to side by a second roller arm engaging the rotating cam at a second location.
The knitting machine may further include a take-up mechanism mounted on the frame and downstream of the second knitting station, the take-up mechanism operative to draw the composite band downwardly from the second knitting station.
Where the second knitting station includes a second elongate needle bed and a second filling yarn guide bar, a vertical support having an upper end and a lower end may be provided. The second filling yarn guide bar is mounted on the lower end and positioned proximate the second elongate needle bed, and the upper end is mounted on a head forming a part of the knitting machine for up and down movement. The upper end of the vertical support may be mounted on the knitting machine for side to side reciprocal movement. Preferably, means are provided for adjusting the distance between the second filling yarn guide bar and the second elongate needle bed. The adjusting means may include an elongate slot formed through the lower end of the vertical support and a bolt extending through the slot and to the second filling yarn guide bar. A second vertical support may be spaced from and disposed parallel to the first vertical support, the second filling yarn guide bar extending between the vertical supports.
The present invention is further directed to a method for forming a composite band including an elongate knitted band and a drawcord secured to a front face of the knitted band by a covering yarn overlying the drawcord and stitched to the elongate band. The elongate knitted band is formed at a first knitting station of a knitting machine by progressively knitting a first set of yarns on a set of knitting needles carried along an upper needle bed. The elongate knitted band is directed downstream to a second knitting station forming a part of the knitting machine. At the second knitting station, the covering yarn is stitched to the elongate knitted band from opposite sides of and across the drawcord to form a channel area defined between the covering yarn and the front face of the knitted band, the drawcord disposed in the channel area. Further, the composite band formed at the second knitting station may be drawn away from the second knitting station by means of a take-up mechanism forming a part of the knitting machine.
The preceding and further objects of the present invention will be appreciated by those of ordinary skill in the art from a reading of the figures and the detailed description of the preferred embodiment which follow, such description being merely illustrative of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front, perspective view of a knitting machine according to the present invention;
FIG. 2 is a schematic, vertical cross sectional view of the knitting machine showing an upper knitting station, a lower knitting station and a take-up mechanism;
FIG. 3 is a fragmentary, side elevational view of the knitting machine showing a drive shaft, main shafts, and linkages for controlling movements of upper and lower rear needle beds and upper and lower warp yarn guide bars;
FIG. 4 is a fragmentary, front, schematic view of the knitting machine showing mechanisms for controlling up and down and side to side movements of a lower front filling yarn guide bar of the knitting machine;
FIG. 5 is a fragmentary, perspective view showing a means for adjusting the position of the lower filling yarn guide bar;
FIG. 6 is a fragmentary, schematic, cross sectional front view of the knitting machine showing mechanisms for controlling side to side movements of the upper and lower warp yarn guide bars; and
FIG. 7 is a perspective view of a section of a composite drawcord/elastic waistband as produced by the knitting machine.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The terms "left", "right", "front", and "rear", and words of like nature are used herein only for the purposes of explaining and describing the preferred embodiments of the invention.
With reference to FIG. 1, a knitting machine according to the present invention is shown therein and generally denoted by the numeral 10. Knitting machine 10 serves to produce composite drawcord/elastic waistbands 50 as shown in FIG. 7. Each composite drawcord/elastic waistband web 50 includes an elastic band 52 having a drawcord 30 slidably secured thereto by a covering yarn web 32. Knitting machine 10 may be a purpose built apparatus or, alternatively, a conventional flat bed, warp knitting machine modified as described below. Preferably, the knitting machine is a crochet-type knitting machine. Suitable crochet-type warp knitting machines which may be modified to form the knitting machine 10 include crochet machine model no. CX-400 manufactured by Fillattice SPA of Milano, Italy. It will be appreciated by those of ordinary skill in the art that other types of knitting machinery and methods may be used to practice the method of the present invention.
As best seen in FIG. 2, composite drawcord/elastic bands 50 are produced on knitting machine 10 as follows. Elastic bands 52 are formed from elastic yarns 40, filler yarns 42, and warp yarns 44 by means of upper knitting station 100. Elastic bands 52 continue downwardly to lower knitting station 200 at which point cords 30 are secured thereto by means of filler yarns 32. The composite drawcord/elastic bands 50 formed thereby are drawn downwardly from lower knitting station 200 by driven take off mechanism 20. The composite band 50 may thereafter be packaged as desired. It is important that each of the many motions of various components of the upper and lower knitting stations 100, 200 be synchronized to allow smooth and accurate formation of the composite band. To this end, knitting machine 10 includes several mechanisms and components for insuring the synchronization of certain elements and components of the knitting stations. The following discussion describes the formation of a single composite band 50, however, it will be appreciated that several such bands may be formed simultaneously and in parallel, the actual number depending on the size of the knitting machine and the sizes of the knitted bands.
Knitting machine 10 includes conventional frame 12 to which are appended cam drum 14 and long throw box 16 in conventional fashion. With reference to FIGS. 1 and 2, knitting machine 10 includes upper knitting station 100 which is conventional in nature. More particularly, upper knitting station 100 includes rear needle bed 110, front needle bed 120, warp yarn guide bar 150 (hereinafter "warp bar 150"), guide plate 130, and elastic yarn guide bar 140. Rear needle bed 110 has needle bed slots 112 and needles 114 secured therein. Rear needle bed 110 reciprocates forwardly and rearwardly as indicated by direction arrow 110A, toward and away from front needle bed 120 which has slots (not shown) aligned with slots 112. Warp bar 150 is disposed forwardly of front needle bed 120 and carries a series of warp yarn guide eyelets 152 projecting rearwardly toward the front needle bed. Warp guide eyelets 152 correspond in number and spaced arrangement to needles 114 in needle bed slots 112. A selected number of warp yarns 44 are fed in side by side parallel spaced relation from a yarn creel 17 for feeding each individual warp yarn 44 to a respective needle 114.
Rear filling yarn guide bar 160 (hereinafter "rear filler bar 160") extends widthwise across frame 12 above front needle bed 120 on the rear side thereof and carries filling yarn guide sleeve elements 162. Front filling yarn guide bar 170 (hereinafter "front filler bar 170") extends widthwise across frame 12 above front needle bed 120 on the front side thereof. Front filler bar 170 carries filling yarn guide sleeve elements 172. A pair of filling yarns 42 are fed from the creel to and through respective guide sleeves 162, 172 for delivery to needles 114 simultaneously with warp yarns 44.
An elastic yarn guide bar or "rubber bar" 140 is disposed directly above and somewhat forwardly of front needle bed 120 and carries a series of elastic yarn guide eyelets 142 extending downwardly toward needle bed 120. Guide eyelets 142 correspond in number and spaced arrangement to needles 114 and warp yarn guide eyelets 152. A series of elastic yarns 40 are fed to the rear side of the knitting machine and in parallel side by side relation over a series of tensioning guide rollers 18 downwardly to eyelets 142 from which each elastic yarn 40 is fed to a respective knitting needle 114 simultaneously with warp yarns 44.
Each of the aforementioned guide bars 140, 150, 160, and 170 are supported on frame 12 of knitting machine 10 by a conventional mechanical arrangement including a patterning mechanism. The patterning mechanism controls the respective reciprocatory movements of the guide bars in timed synchronism relative to the forward-rearward reciprocations of rear needle bed 110. In this manner, the respective yarns 40, 42, and 44 are manipulated with respect to reciprocating needles 114 to effect, in conjunction with the reciprocating motion of the needles 114, a knitting action on the yarns to fabricate them progressively into an elongate knitted band 52 of a conventional crochet-type knitted fabric structure of an extended indefinite length. The mechanical arrangements for effecting the aforementioned movements will be described below to the extent that they facilitate the explanation or operation of the modifications to the conventional crochet-type knitting machine.
Upper rear needle bed 110 reciprocates frontwardly and rearwardly as described above. With reference to FIG. 3, this movement of upper rear needle bed 110 is accomplished by upper main shaft 320, upper first linkage 322, and needle bed connection 324. Each of these elements are conventional and their operation and configuration will be appreciated by those of ordinary skill in the art.
Warp bar 150 reciprocates laterally from side to side relative to frame 12 of the knitting machine 10, as indicated in FIG. 6, and also pivots upwardly and downwardly, as indicated in FIG. 2. The combined motions of warp bar 150 effect a wrapping of yarns 44 about respective needles 114. The mechanisms for controlling upper warp bar 150 are conventional and their overall operation will be understood by those of ordinary skill in the art upon a reading of the following description.
With reference to FIG. 3, the up-down reciprocation of upper warp bar 150 is accomplished by the rotation of upper main shaft 320 which is connected to upper warp bar 150 by upper second linkage 326 and warp bar connection 328, each of which are conventional. Main drive shaft 302 drives lower main shaft 340 by means of transmission belt 304. Lower main shaft 340 in turn drives upper main shaft 320 by means of timing belt 310 as discussed in more detail below. Alternatively, shaft 320 may be driven by a transmission belt between shaft 320 and shaft 302, in which case shaft 340 would be driven by timing belt 310. Further, chains or gears may be provided in place of one or both of the belts.
The side to side reciprocation of upper warp bar 150 is accomplished by the rotation of cam 80 of cam drum 14. As cam 80 is rotated, upper roller arm 190 is pivoted upwardly and downwardly. The pivoting of roller arm 190 rotates abutment 192 against which warp bar head 194 is spring biased, causing warp bar 150 to be laterally displaced as roller arm 190 moves up and down. Warp bar 150 is free to slide side to side through hole 12A formed in frame 12.
Elastic yarn guide bar 140 is driven up and down by head mounts 70, as best seen in FIG. 1. Head mounts 70 are selectively driven up and down by a conventional shaft (not shown) forming a part of the knitting machine 10. Elastic yarn guide bar 140 is also moved sidewardly relative to the knitting machine by a cam in the cam box and a suitable linkage (not shown). The mechanisms and operations for reciprocating the elastic yarn guide bar 140 are conventional and will be understood by those of ordinary skill in the art.
Upper front filler bar 170 and upper rear filler bar 160 are each reciprocated up and down by head mounts 70. The filler bars are each reciprocated side to side relative to frame 12 by long throw box 16. Tic mechanisms and operations for controlling these movements of the upper front and rear filler bars are conventional and will be understood by those of ordinary skill in the art.
Generally, warp bar 150 reciprocates laterally and vertically to wrap warp yarns 44 about the respective needles 114. Filler bars 160, 170 simultaneously reciprocate side to side to cause the respective filling yarn guide elements 162, 172 to traverse back and forth laterally through a range of motion essentially corresponding to the number of needles 114 being utilized to knit the band of a given width to lay filling yarns 42 laterally across all of needles 114 during each reciprocatory cycle of rear needle bed 110. Elastic yarn guide bar 140 simultaneously reciprocates side to side to feed elastic yarns 42 to respective needles 114. As this knitting operation progresses, the resultant knitted band 52 is drawn downwardly from the forward side of front needle bed 120 between front needle bed 120 and guide plate 130 mounted at a forward spacing therefrom, by a driven take off assembly 20. Take off assembly 20 is preferably a conventional mechanism including two or more driven rollers. Take off assembly 20 is preferably lowered from its conventional position in frame 12 to allow space for lower knitting station 200 as described below.
Once knitted band 52 has been formed by upper knitting station 100 as described above, it continues downwardly as a continuous web to lower knitting station 200. Lower knitting station 200 includes rear needle bed 210 which reciprocates forwardly and rearwardly as indicated by direction arrow 210A. Rear needle bed 210 includes needle slots 212 formed therein. For each web 52, a pair of laterally spaced needles 214 are mounted in respective needle slots 212. Needles 214 are positioned such that as they pierce elastic band 52 they are disposed on opposite sides of drawcord guide element 242 which presents cord 30 to the front surface of web 52. Drawcord guide element 242 is preferably sidewardly adjustable and remains stationary in operation. Lower knitting station 200 includes front needle bed 220 and guide plate 230 corresponding to front needle bed 120 and guide plate 130 of upper knitting station 100. Lower warp yarn guide bar 250 (hereinafter "lower warp bar 250") includes a pair of warp guide eyelets 252 for each pair of needles 214, eyelets 252 corresponding in location and arrangement with needles 214. Lower front filling yarn guide bar 270 (hereinafter "lower filler bar 270") includes a filling yarn guide element 272 for each cord 30, the filling yarn guide element extending downwardly and rearwardly adjacent front needle bed 220.
A pair of warp yarns 34 are fed from the creel and through the pair of warp yarn guide eyelets 252 to respective piercing needles 214. One or more filling yarns 32 are fed from the creel through guide element 272 to the piercing needles 214. At the same time, drawcord 30 is fed through guide sleeve 242 downwardly between front needle bed 220 and guide plate 230 centrally along the forward face of knitted band 52 between piercing needles 214. Drawcord 30 is preferably tensioned and guided by a series of rollers 19. Rollers 19 also serve to hold the drawcord away from the components of upper knitting station 100.
The respective reciprocatory motions of lower rear needle bed 210, lower warp bar 250, and lower front filler bar 270 manipulate the piercing needles 214, warp yarn guide eyelets 252, and filling yarn guide elements 272 relative to one another in the same fashion as described with regard to upper knitting station 100. The several reciprocatory motions cause filling yarn(s) 32 to traverse laterally back and forth across drawcord 30 as the band penetrating and withdrawing reciprocations of piercing needles 214 knit and anchor warp yarns 34 and filling yarns 32 in the fabric of knitted band 52 along opposite sides of drawcord 30. In this maimer, warp yarns 252 and filling yarns 32 form a channel area between the forwardly facing surface of knitted band 52 and the web-like successive crossovers of filling yarn 32 in which drawcord 30 is captured.
It will be appreciated that, whereas conventional crochet-type flat bed knitting machines are typically provided with the components of upper knitting station 100, such knitting machines are not known to include components corresponding to lower knitting station 200 as well. Thus, while conventional knitting machines include the mechanisms required to control the reciprocatory movements of the components of upper knitting station 100, special provision must be made to move the several components of lower knitting station 200. In particular, means must be provided to reciprocate lower rear needle bed 210 frontwardly and rearwardly, lower warp bar 252 upwardly and downwardly and side to side, and lower front filler bar 270 upwardly and downwardly and side to side. Preferably, the movement of needle bed 210, warp bar 250, and front filler bar 270 are synchronized with the movements of the corresponding components of upper knitting station 100. Such synchronization is desirable to provide smooth, continuous, and accurate formation of the composite drawcord/elastic bands 50. Further, this ensures that the needle bed and guide bars of the lower knitting station are appropriately synchronized with respect to one another as well. However, while the use of a common drive as discussed below is the preferred approach, it will be understood that separate drive mechanisms may be used to drive each of the upper and lower knitting stations.
With reference to FIG. 3, the frontward and rearward reciprocation of lower rear needle bed 210 and the upward and downward reciprocation of lower warp bar 250 are accomplished by means of drive assembly 300. Conventional main drive shaft 302 drives lower main shaft 340. Rotation of lower main shaft 340 is translated to reciprocal movement of lower rear needle bed 210 by means of lower first linkage 342 and needle bed connection 344. Rotation of lower main shaft 340 is further translated into upward and downward reciprocation of lower warp bar 250 by lower second linkage 346 and lower warp bar connection 348. Lower main shaft 340, linkages 342, 346, and connections 344, 348 correspond to elements 320, 322, 326, 324, and 328, respectively, of upper knitting station 100. Again, these mechanisms of upper knitting station 100 are conventional and their operation will be understood by those of ordinary skill in the art. The reciprocations of lower rear needle bed 210 and lower warp bar 250 are synchronized with the movements of the corresponding structures of upper knitting station 100 by means of timing belt 310 which extends between the pulley of lower main shaft 340 and the pulley of upper main shaft 320. Preferably, a tension adjustment mechanism 312 including pulley 314 and set means 316 is provided to maintain an appropriate tension in timing belt 31 0. Set means 316 may be, for example, a screw-type mechanism including a threaded shaft mounted in an interiorly threaded collar, a ratchet-type mechanism, or any other suitable means.
With reference to FIG. 6, lower roller arm 290 is provided to effect the side to side reciprocation of lower warp bar 250. Roller arm 290 preferably rides on the same cam 80 as upper roller arm 190. The up and down pivoting of roller arm 290 as it follows the profile of cam 80 causes the rotation of abutting surface 292 against which warp bar head 294 is spring biased, and the resulting lateral displacement of lower warp bar 250. Preferably, the roller of lower roller arm 290 is positioned directly vertically below the roller of upper roller arm 190. In this manner, the side to side reciprocations of the upper and lower warp bars are synchronized.
With reference to FIG. 4, lower front filler bar 270 must be reciprocated upwardly and downwardly as well as side to side to form the desired covering web 32 of composite band 50. Lower front filler bar 270 is moved up and down by means of conventional head mounts 70 which are raised and lowered with respect to frame 12, and thus needle bed 210, on shafts 70A. More particularly, filler bar 270 is mounted between vertical supports 274. Vertical supports 274 include holes 274B through which cross rod 286 extends. Vertical supports 274 are also provided with holes 274C through which short rods 288 extend. Each of rods 286, 288 are rigidly secured in the respective holes 274B and 274C. It will be appreciated that as head mounts 70 are moved up and down by the main drive shaft in conventional manner, filling yarn guide elements 272 mounted on filler bar 270 which is in turn mounted on vertical supports 274, which are in turn mounted on rods 286, 288, are raised and lowered as well. The provision of two horizontal rods 286, 288 prevents torsion or rotation of vertical supports 274 frontwardly or rearwardly with respect to the knitting machine. Preferably, cross brace 275 is also provided.
Side to side movement of lower filler bar 270 is accomplished by means of cam box 14. Rods 286 and 288 are slidably mounted in bores 70B of heads 70. As cam 280 rotates, the vertical displacement of roller arm 282 which follows the profile of the cam is translated by means of linkage 284 into side to side movement of rods 286, 288. Accordingly, filler bar 270 fixedly mounted on rods 286, 288 is likewise moved side to side. Typically, bores suitable for serving the purpose of bores 70B are provided on conventional crochet-type knitting machines. Further, supplemental brackets or the like may be provided to secure rods 286, 288 to head mounts 70 for vertical displacement therewith and lateral movement with respect thereto.
The combination of the up and down and side to side movements of lower filler bar 270 allows the filling yarn guide elements 272 to lay the filling yarn in the needles as desired without scraping the needles with the filling yarn guide elements. With reference to FIG. 5, knitting machine 10 is preferably provided with means for adjusting the proximity of guide elements 272 to needle bed 210 as well as the angle of guide elements 272 with respect to vertical. Each vertical support 274 includes a longitudinal, vertical slot 274A formed therethrough. A bolt 276 extends through each slot 274A and screws into a threaded bore 275 formed in the adjacent end of filler bar 270. The height of filler bar 270 may be selected by loosening bolt 276 and sliding filler bar 270 upwardly or downwardly along slots 274A. Further, the angle of guide elements 272 may be adjusted by loosening bolt 276 and rotating filler bar 270 about the axis of the bolt. When the desired settings have been made, bolt 276 may be retightened, thereby locking filler bar 270 in place. Other means for selectively fixing the relative positions of the filler bar and the vertical supports may be used as well. For example, a threaded stud may be fixedly secured to the end of the filler bar and extending through the slot with a bolt on the end thereof serving to lock the bar and support in place.
After drawcord 30 has been secured to knitted band 52 by filling yarn 32, composite band 50 is drawn downwardly by take-up mechanism 20. Take-up mechanism 20 is preferably of the same design and driven in the same manner as in conventional knitting machines making such provision. If knitting machine 10 is formed by modifying a conventional knitting machine, it may be necessary to lower the take-up mechanism to allow room for lower knitting station 200.
Knitting machine 10 provides several advantages over known methods and apparatus for forming composite drawcord/elastic bands. For example, as compared with the method and apparatus described in U.S. Pat. No. 5,452,591 to King, twice as many composite bands 50 may be produced on a machine of a given width. This is because, rather than using, a single needle bed half of which is dedicated to forming the knitted band and half of which is dedicated to securing the drawcord to the band, knitting machine 10 provides a second knitting station so that the entire needle bed of the first knitting station may be used to form knitted bands. As a result, for a given amount of floor space, production may be doubled.
Notably, conventional knitting machines may be modified to practice the method of the present invention. Further, such modifications need not be permanent, rather a modified machine may be used for its original purpose by simply removing or disabling the added components, and if the take-up mechanism has been lowered, returning it to its original position.
The preceding and further objects of the present invention will be appreciated by those of ordinary skill in the art from a reading of the figures and the detailed description of the preferred embodiment which follow, such description being merely illustrative of the present invention.
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A knitting machine and method for forming a composite band including an elongate knitted band and a drawcord secured to a front face of the knitted band by a covering yarn overlying the drawcord and stitched to the elongate band. The knitting machine includes a frame. A first knitting station is provided supported by the frame for forming the elongate knitted band. A second knitting station is provided supported by the frame and downstream of the first knitting station for receiving the knitted band after it exits the first knitting station. The second knitting station is operative to stitch the covering yarn to the knitted band from opposite sides of and across the drawcord to form a channel area defined between the covering yarn and the front face of the knitted band, the drawcord disposed in the channel area.
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This application is a 371 of PCT/US99/22268 filed Sep. 25, 1999, which claims benefit of U.S. provisional application Ser. No. 60/101,876 filed Sep. 25, 1998.
TECHNICAL FIELD OF INVENTION
The present invention relates to the treatment of sickle cell disease with N-L-alpha-aspartyl-L-phenylalanine 1-methyl ester.
BACKGROUND OF THE INVENTION
Under low oxygen tension, sickle cell deoxyhemoglobin (HbS) forms multi-stranded fibers (Rodgers, et al. 1987. Proc Natl Acad Sci USA 84:6157-6161; Eaton, W. A. and Hofrichter, J. 1990. Adv Protein Chem 40:63-279) that force a red blood cell (RBC) into a crescent (sickle) shape (Carache, S. and Davies, S. 1991. Acad Med 66:748-74). In 1949, Pauling et al. demonstrated that HbS was electrophoretically distinct from normal human adult hemoglobin (HbA) and coined the name molecular disease to describe the pathological effects of HbS (Pauling, et al. 1949. Science 110:543-548). Seven years later, Ingram (Ingram, V. M. 1956. Nature 178:792-794) reported that HbS differed from HbA by the substitution of valine for glutamic acid in position 6 of the β chain. This hydrophobic for polar substitution occurs on the surface of the three-dimensional structure of HbS on the first (A) α-helix (Padlan, E. A. and Love, W. E. 1985. J Biol Chem 260:8280-8291). It creates a sticky site which is covered by a complementary (acceptor) crevice between the E and F helices in the β chain of an antiparallel Hb molecule in the fibril. Key contact residues in the acceptor site are phenylalanine 85 and leucine 88 from the F helix. Each β chain thus contains a donor and acceptor site which together interact with two other offset Hb molecules, the key condensation events in producing double stranded helical stacks of indefinite length. As the strands of hemoglobin molecules stack together they, continue to elongate and stretch the normally round, flexible RBC into an inflexible sickle or spiculated shape.
Physiologically, the sickled RBCs impair blood flow, enhance hypoxia and accentuate the production of more sickling (Embury, S. H. 1986. Ann Rev Med 37:361-376). The HbS gene is present in about 8-9% of African Americans (Schneider, et al. 1976. Blood 48:629). If homozygous for the gene, a patient shows the severe symptoms of “sickle cell disease” such as anemia, hemolysis, severe muscle pain, thrombotic complications, and even sudden exertional death. A heterozygous individual has “sickle cell trait” with milder symptoms and more infrequent crises. The gene is believed to have been preserved in successive generations because RBCs containing HbS appear to promote survival in endemic malarial regions of Africa, Asia and European countries on the Mediterranean Sea (Allison, A. C. 1956. Scientific American 195:87-94; Friedman, M. J. and Trager, W. 1981. Scientific American 244:154-164).
Research for therapeutic agents known to delay the onset of sickle cell gelation without introducing unacceptable side effects has been ongoing for many years. (Murayama, M. 1966. Science 153:145-149; Dean, J. and Schechter, A. N. 1978. New Engl J Med 299:804-811; Dean, J. and Schechter, A. N. 1978. New Engl J Med 299:863-870; Dean, J. and Schechter, A. N. 1978. New Engl J Med 299:752-763). No significant approach has been advanced for the treatment of sickling phenomena (Ranney, H. M. 1972. Blood 39:433-439; Aluoch, J. R. 1984. Trop Geogr Med 36:SI-26; Serjeant, G. R. 1997. Br J Haematol 97:253-255; Olivieri, N. F. and Vichinsky, E. P. 1998. J Pediatr Hematol Oncol 20:26-31), although there are many stimulating research approaches and hydroxyurea has some effect. (Dickerson, R. E. and Geis, I. Hemoglobin: Structure, Function, Evolution, and Pathology. Benjamin/Cummings Publishing Co., Menlo Park, 1st Park, ed., 1983). Clinical management of a sickle-cell crisis is usually described as supportive, using fluids for hydration (Scott-Conner, R. E. and Brunson, C. D. 1994. Am J Surg 168:268-274), oxygen for alleviation of hypoxic sickling and analgesics for pain relief (Pollack, et al. 1991. J Emerg Med 9:445-452). Though often effective, even exchange transfusion remains controversial as preventive therapy (Selekman, J. 1993. Pediatr Nurs 19:600-605).
U.S. Pat. No. 5,654,334 discloses APM as a pain reliever which is especially effective in relieving pain associated with osteoarthritis and multiple sclerosis. Further, International Application WO 97/00692 discloses APM as an antipyretic. In a clinical trial, APM was demonstrated to alleviate the pain and inflammation of osteo- and mixed osteo- and rheumatoid arthritis by an unknown mechanism (Edmundson, A. B. and Manion, C. V. 1998. Clin Pharm Therap 63:580-593). Additionally, International Application WO 98/13062 discloses the efficacy of APM in the treatment of a disease affected by the presence of TNFα, particularly arthritis and rheumatoid arthritis. U.S. Pat. No. 5,629,285 discloses sickle cell anemia as one of numerous diseases in which the overproduction or unregulated production of TNFα has been implicated
It has now been found that APM displays binding behavior with HbS resulting in a modified HbS molecule useful for treatment of the sickle cell family of diseases.
SUMMARY OF THE INVENTION
The present invention relates to the use of the compound
where R is CH 3 or an alkyl which allows transport of the compound across the red blood cell membrane to prepare a pharmaceutical composition useful for effecting a reduction in sickle cells in a mammal. The preferred compound used to prepare the pharmaceutical composition is N-L-alpha-aspartyl-L-phenylalanine 1-methyl ester (R=CH 3 ). In one embodiment, these compounds are used to prepare a pharmaceutical composition useful for treating sickle cell disorders.
In another aspect the present invention relates to a pharmaceutical preparation in dosage unit form adapted for administration to obtain an antisickling effect in red blood cells, comprising, per dosage unit, an antisickling effective non-toxic amount of a compound comprising
where R is CH 3 or an alkyl which allows transport of the compound across the red blood cell membrane and a pharmaceutical carrier. Preferably, the compound comprises N-L-alpha-aspartyl-L-phenylalanine 1-methyl ester (R=CH 3 ).
In another aspect, the present invention relates to a pharmaceutic dosage form for use as an antisickling agent comprising the compound
where R is CH 3 or an alkyl which allows transport of the compound across the red blood cell membrane, wherein the dosage form comprises preferably from about 1.5 milligrams to about 6 milligrams per kilogram body weight of the compound. More preferably, the dosage form comprises about 6 milligrams per kilogram body weight of the compound, preferably to be administered twice a day. The preferred dosage form comprises N-L-alpha-aspartyl-L-phenylalanine 1-methyl ester (R=CH 3 ).
In another aspect, the present invention relates to a pharmaceutical dosage form comprising an active antisickling ingredient, wherein the active antisickling ingredient comprises the compound
where R is CH 3 or an alkyl which allows transport of the compound across the red blood cell membrane. The effective amount of the compound in the active ingredient is preferably from about 1.5 milligrams to about 6 per kilogram body weight. More preferably, the effective amount of the compound in the active ingredient is about 6 milligrams per kilogram body weight, preferably to be administered twice a day. The preferred active ingredient comprises N-L-alpha-aspartyl-L-phenylalanine 1-methyl ester (R=CH 3 ).
In another aspect, the present invention relates to the use of the compound
where R is CH 3 or an alkyl which allows transport of the compound across the red blood cell membrane to produce an antisickling effect in red blood cells in vitro. The preferred effective amount of the compound is from about 1 milligrams to about 2 milligrams per milliliter. Preferably, the compound is N-L-alpha-aspartyl-L-phenylalanine 1-methyl ester (R=CH 3 ).
In yet another aspect, the present invention relates to a formulation for treatment of red blood cells suspected to contain sickle cells, the formulation comprising the compound
where R is CH 3 or an alkyl which allows transport of the compound across the red blood cell membrane and calcium. Preferably, the formulation comprises N-L-alpha-aspartyl-L-phenylalanine 1-methyl ester (R=CH 3 ).
In yet another aspect, the present invention relates to a method for reducing the number of sickle cells relative to the number of normal red blood cells in a patient blood sample from the time of collection of the blood sample from the patient to a second time of laboratory analysis, comprising the steps of: (a) collecting a blood sample from a patient having a sickle cell disorder, wherein red blood cells in the blood sample have a predisposition to sickle; and (b) adding to the blood sample at the time of collection an effective amount of a composition comprising the compound
where R is CH 3 or an alkyl which allows transport of the compound across the red blood cell membrane, wherein the effective amount causes a reduction in the number of sickle cells relative to the number of normal red blood cells in a patient blood sample at the time of laboratory analysis. Preferably, the compound in the composition is N-L-alpha-aspartyl-L-phenylalanine 1-methyl ester (R=CH 3 ).
In yet another aspect, the present invention relates to a method of treatment of sickle cell disease in a patient by administration of an effective amount of a composition comprising the compound
where R is CH 3 or an alkyl which allows transport of the compound across the red blood cell membrane, wherein the treatment results in a reduction of the number of sickle cells relative to the number of normal cells in the patient's blood. A preferred effective amount of the compound is from about 1 milligrams to about 6 milligrams kilograms body weight. A more preferred effective amount of the compound is about 6 milligrams of per kilograms body weight. Preferably, the compound in the composition is N-L-alpha-aspartyl-L-phenylalanine 1-methyl ester (R=CH 3 ). The treatment is preferably administered daily. Preferably, the treatment is administered orally.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph depicting the proportion of sickle cells in the population of RBCs (erythrocytes) plotted against time in the absence of APM (Control) and in the presence of APM added in quantities of 1 and 2 mg. The blood samples and slides were prepared according to the methods given in Example 1. Results were measured as the average number of sickle cells per 100 cells counted over time after slide preparation, with the data from the 12 patients combined into treatment groups: control, 1 milligram APM, and 2 milligram APM. Standard error, bars of the mean values are shown for N=12 tested patients.
FIG. 2 is a graph depicting the duration of APM effect on sickling of RBCs. Blood samples and slides were prepared according to the methods given in Example 1, and results were measured as the average numbers of sickle cells per 100 cells counted at 0, 1, 2, 3, 4, 5, 24, and 27 hours after slide preparation. The data from the 12 patients is combined into treatment groups (control, solid square; 1 milligram APM, upward pointing triangle; 2 milligram APM, downward pointing triangle).
FIG. 3 is a graph depicting the proportion of sickle cells in the RBC population plotted against time in the absence of APM (Control) and in the presence of APM added in quantities of 1 and 2 milligrams with (Lav.) and without (Green) the addition of EDTA. The blood samples and slides were prepared according to the procedures given in Example 1. The results were measured as the average number of sickle cells per 100 cells counted at 0, 30 and 120 minutes after slide preparation, with the data from the 12 patients combined into treatment groups. In each grouping at 0, 30, and 120 minutes, the bars appear from left to right in the same order as the listings in the legend presented from top to bottom.
FIG. 4 is a graph illustrating the in vivo response of a patient with a known HbS syndrome to treatment with 60 milligrams APM. Heparinized blood specimens were obtained before (solid square) and 1 hour after (solid triangle) APM ingestion: The blood samples and slides were prepared according to the procedures given in Example 1. Results were measured as the average number of sickle cells per 100 cells counted over time after slide preparation.
FIG. 5 is a graph depicting the in vivo response of patient with a known HbS syndrome to treatment with 160 milligrams APM. Heparinized blood samples were obtained before (solid triangle) and 1 hour after (solid diamond) APM ingestion. Blood samples and slides were made according to the procedures given in Example 1. Results were measured as the number of sickle cells per 100 cells counted over time after slide preparation.
FIG. 6 is a graph depicting the dose comparisons over time for HgBss patients treated with 1.5 (low dosage; triangle pointing downward), 3 (medium dosage; triangle pointing upward), or 6 (high dosage; closed square) milligrams APM per kilogram body weight. Results are reported as the number of sickle cells per 100 cells counted taken at 0, 30, 60, 120, 240, and 1,440 minutes after blinded administration of APM.
FIG. 7 is a graph depicting the dose comparisons over time for combination of HgBss and sbthal patients treated with 1.5 (low dosage; broken line with triangle pointing downward), 3 (medium dosage; broken line with triangle pointing upward), or 6 (high dosage; solid line with closed square) milligrams APM per kilogram body weight. Results are reported as the number of sickle cells per 100 cells counted taken at 0, 30, 60, 120, 240, and 1,440 minutes after blinded administration of APM.
FIG. 8 is a graph depicting the dose comparisons over time for Hgbsc patients treated with 1.5 (low dosage; triangle pointing downward), 3 (medium dosage; triangle pointing upward), or 6 (high dosage; closed square) milligrams APM per kilogram body weight. Results are reported as the number of sickle cells per 100 cells counted taken at 0, 30, 60, 120, 240, and 1,440 minutes after blinded administration of APM.
FIG. 9 is a graph depicting the viscosity measurements for each of the ten patient samples taken at baseline and 120 minutes post-APM administration. The first grouping is the concurrent measurement of the viscosity of water at the time and conditions under which the patient's blood sample was tested; the second grouping is the concurrent measurement of the viscosity of saline at the time and conditions under which the patient's blood sample was tested; the third grouping is the viscosity measurement for each patient taken at baseline (Time 0); and the fourth grouping is the viscosity measurement for each patient taken at 120 minutes post-treatment. In each grouping, the bars appear from left to right in the same order as the listings in the legend presented from top to bottom. The patients identified as TM, BB, and CH whose data is given in the respective 5th, 6th and 7th bar from the left in each treatment group had Hgbsc, or SC disease. The patient identified as TC whose data is given in the 4th bar from the left in each treatment group had sbthal disease. The other patients had sickle cell disease, or SS disease.
FIG. 10 is a graph depicting the viscosity measurements for each of the ten patient samples taken at 480 minutes post-in vivo APM treatment after the in vitro addition of 0, 1 milligram, or 2 milligrams of APM per milliliter. The first grouping was viscosity readings for patient samples measured at 480 minutes post-treatment to which no in vitro addition of APM was made; the second grouping was viscosity readings for patient samples measured at 480 minutes post-treatment to which 1 milligram per milliliter APM was added in vitro; and the third grouping was viscosity readings for patient samples measured at 480 minutes post-treatment to which 2 milligram per milliliter APM was added in vitro. In each grouping, the bars appear from left to right in the same order as the listings in the legend presented from top to bottom. The patients identified as TM, BB, and CH whose data is given in the respective 5th, 6th and 7th bar from the left in each treatment group had Hgbsc, or SC disease. The patient identified as TC whose data is given in the 4th bar from the left in each treatment group had sbthal disease. The other patients had sickle cell disease, or SS disease.
FIG. 11 is a graph depicting the correlation of sickle cell count to viscosity, demonstrating a linearly proportional correlation, i.e., as the number of sickle cells per total number of cells counted increases, viscosity also increases.
DETAILED DESCRIPTION
It has now been found that N-L-alpha-aspartyl-L-phenylalanine 1-methyl ester (APM) interacts with the HbS molecule to the extent that the stacking of the HbS molecules within the RBC is significantly altered, leading to a reduction in the capacity of RBCs containing HbS to sickle with hypoxemia. Upon administration of an effective amount of APM, patients having genetic diseases of the sickle cell family experience a reduction in the number of sickle cells relative to the number of normal cells within one hour of administration, demonstrating APM's medicinal qualities beneficial in the treatment of sickle cell diseases.
A preferred effective amount of APM which can effect a reduction in sickle cells after one dose is from about 1 milligrams to about 6 milligrams per kilogram body weight. A more preferred range is from about 3 milligrams to about 6 milligrams per kilogram body weight. Most preferred is about 6 milligrams per kilogram body weight. The dosage can be repeated over time for continued relief, preferably at 6 milligrams every 12 hours.
APM can be administered orally, parenterally, intraperitoneally, or sublingually. It can be administered via ingestion of a food substance containing APM in a volume sufficient to achieve therapeutic levels. Alternatively, it can be enclosed in capsules, compressed into tablets, microencapsulated, entrapped in liposomes, in solution or suspension, alone or in combination with a substrate immobilizing material such as starch or poorly absorbable salts. Pharmaceutically compatible binding agents and/or adjuvant materials can be used as part of a composition. Tablets or capsules can contain any of the following ingredients, or compounds of similar nature: a binder such as microcrystalline cellulose, gum tragacanth or gelatin; an excipient such as starch or lactose; an integrating agent such as alginic acid; corn starch; a lubricant such as magnesium stearate; a glidant such as colloidal silicon dioxide; and additional sweetening and flavoring agents. When a capsule form is used the liquid carrier such as a fatty oil may be used. Capsules and tablets can be coated with sugar, shellac and other enteric agents as is known. APM can also be in a controlled-release formulation.
With the exception of patients suffering from phenylketonuria, APM is considered as a GRAS (generally regarded as safe) substance. APM is commercially available, e.g., as ASPARTAME™ (G. D. Searle & Company, Chicago, Ill.). Its preparation is also disclosed in U.S. Pat. No. 3,492,131. While APM is preferred, it is believed that a derivative of APM which can cross the RBC membrane and interact with the HbS molecule to the extent that the stacking of the HbS molecules is significantly altered can also be administered as an effective treatment for sickle cell disease. Exemplary derivatives include but are not limited to the ethyl, propyl and butyl esters, and the derivatives should maintain the sweetening property of the dipeptide. Such derivatives, which can be determined using the monitoring methods provided in the examples below, are considered to fall within the scope of this invention. It is to be understood that “APM” used herein refers to N-L-alpha-aspartyl-L-phenylalanine 1-methyl ester or its derivative as defined above.
The effectiveness of APM treatment for sickle cell diseases can be monitored by several methods. Routine laboratory screening methods known in the art for testing for sickle cell disorders can be used. For example, normal RBCs are more soluble than sickled RBCs, and the observation of an increased solubility of RBCs in blood samples taken from a patient suffering from a sickle cell disease is indicative of effective APM treatment. Use of a metabisulfite slide test on heparinized blood samples as presented in Example 1 can also be used, wherein a decrease in the number of sickle cells relative to normal cells indicates effective APM treatment. This metabisulfite screening method does not distinguish sickle cell trait (heterozygous for HbS) from sickle cell disease (homozygous for HbS), because all RBCs containing HbS will sickle. As presented in Example 4, a monitoring method based on the fact that the viscosity of blood from patients with sickle cell diseases decreases when treated with APM can also be used. This monitoring procedure can be used to distinguish sickle cell disease from sickle cell trait, although hemoglobin electrophoresis is more commonly used.
Sickling of RBCs in a patient sample changes both the physical and chemical characteristics of the sample over time. There are advantages to reducing the degradation caused by sickling for certain applications, particularly crisis. Because of its antisickling properties, APM can be used as a stabilizing agent to reduce sickling of RBCs in whole blood and RBC specimens from the time of collection of the whole blood specimens from the patient until the time the specimen is either analyzed by the laboratory or utilized in in vitro experimentation. An effective amount of APM can be added to a transport container either before or immediately after the blood sample is added to the transport container.
EXAMPLE 1
Reduction of Sickle Cells in in vitro Blood Samples
In an in vitro study, APM was shown to be transported across the RBC membrane and to effect a decrease in the sickling of cells in blood samples taken from patients suffering from sickle cell disorders.
Blood was drawn from twelve patients of pediatric age who were being treated by phlebotomy and exchange transfusion for their sickling disorders. Blood samples from each patient were drawn directly into heparin tubes, stored in a refrigerator at approximately 10° C., and routinely tested within 36 hours of collection. Some samples were rechecked or reanalyzed within a week of collection, and the effects on sickle hemoglobin was still present with counted values similar to those obtained within 36 hours.
Normal blood devoid of HbS was used as a control. For each heparinized patient blood sample and the normal blood control, three experimental samples were prepared containing 0.25 milliliters of normal saline and 0.25 milliliters of blood and then treated as follows: (1) one was left untreated; one was treated with 1 milligram APM; and (3) one was treated with 2 milligrams APM. All experimental samples were stored in a refrigerator at approximately 10° C. for one hour prior to testing to allow time for the APM to be absorbed by the RBCs.
Using metabisulfite to reduce HbS to the deoxy form (Daland, G. A. and Castle, W. B. 1948. J Lab Clin Med 33:1082-1088; Nelson, D. A. In Todd-Sanford-Davidsohn Clinical Diagnosis by Laboratory Methods, J. B. Henry, ed. (W. B. Saunders Co., Philadelphia, 1979, vol. 1, p. 1020), a sickling test was run on each experimental sample. The sickling inducing agent was prepared fresh daily as follows: 10 milligrams metabisulfite in 1 milliliter isotonic saline. Multiple test slides were prepared for each experimental sample by adding 3 drops of the metabisulfite inducing agent and 1 drop of the experimental sample onto the surface of a glass slide, placing a coverslip over the sample, and sealing the coverslip with a petroleum jelly bead to prevent oxygen from entering the sample. Photomicrographs were taken with a phase contrast microscope at 400 magnification at 0, 30, and 120 minutes after slide preparation, and the results were obtained from the photomicrographs as the number of sickle cells per 100 cells counted.
To account for natural or non-induced sickling of the experimental samples, a baseline sickling count was obtained for each heparinized patient blood sample and the normal blood control. Slides were prepared by adding 3 drops of saline and 1 drop of the experimental sample onto the surface of a glass slide, placing a coverslip over the sample, and sealing the coverslip with a petroleum jelly bead to prevent oxygen from entering the sample. Photomicrographs were taken with a phase contrast microscope at 400 magnification at 0, 30, and 120 minutes after slide preparation, and the results were obtained from the photomicrographs as the number of sickle cells per 100 cells counted. This number of sickle cells per 100 cells counted was considered the baseline sickling count and was subtracted from the cell counts obtained with the metabisulfite induced samples.
As shown in Table 1 and FIG. 1, after exposure to metabisulfite in the presence of APM, heparinized blood samples from all twelve patients contained fewer sickle cells than the controls. The effects of APM in reducing the number of sickle cells was immediate and increased with increasing APM concentration. Analysis of variance was statistically significant at p<0.00004. In the photomicrographs, relatively small numbers of sickle cells were observed in the APM-treated slides. Moreover, in contrast to the uniform appearance of normal biconcave RBCs or sickle cells, the APM-treated cells developed uneven hemoglobin patches with sharply defined borders, indicating the presence of irregular, small bundles of sickled fibers which were prevented by APM from becoming sufficiently large enough to deform the cells into the sickle shape.
A timeline for APM effect was made by repeating the experiment given above with cell counts obtained at 0, 1, 2, 3, 4, 5, 24, and 27 hours post-metabisulfite induction. The results are presented in FIG. 2 as combined APM timelines for each treatment method. The antisickling effect of APM in vitro lasted for at least 27 hours. During this period, the rate of sickling in the APM treated
TABLE I
Sickle Cell Counts from Twelve Pediatric Patients with Known HbS Syndrome
Number of Cells Sickled per Hundred Counted
Time
Patient
(MIN)
1
2
3
4
5
6
7
8
9
10
11
12
Mean
Control
0
8.5
8.5
10.0
20.0
15.5
4.0
21.5
20.5
12.5
22.5
13.0
18.5
30
13.5
10.5
12.5
22.5
18.0
9.5
27.5
21.0
13.5
23.5
12.0
22.0
120
16.5
15.5
22.5
20.0
21.5
33.5
27.5
15.5
29.5
18.0
25.5
Avg
12.8
9.5
12.7
21.7
17.8
11.7
27.5
23.0
13.8
25.2
14.3
22.0
17.7
APM 1 mg
0
2.5
2.0
2.5
9.5
9.5
1.5
2.0
−1.0
1.5
1.0
0.5
0.0
30
1.5
3.5
3.0
10.5
9.0
4.5
3.5
−0.5
2.5
2.0
−1.0
6.0
120
2.5
3.0
12.0
11.0
3.5
4.0
0.5
1.5
3.5
1.0
21.0
Avg
2.2
2.8
2.8
10.7
9.8
3.2
3.2
−0.3
1.8
2.2
0.2
9.0
4.0
APM 2 mg
0
2.5
1.0
2.0
6.5
8.5
0.5
1.0
−5.5
0.5
0.0
0.0
2.0
30
2.0
1.5
2.0
5.0
8.5
2.0
0.5
−6.5
0.5
1.0
−0.5
6.0
120
2.5
5.0
2.0
9.5
2.0
1.0
−6.5
−0.5
0.5
−0.5
19.0
Avg
2.3
1.3
3.0
4.5
8.8
1.2
0.8
−6.2
0.0
0.5
−0.3
9.0
2.1
Heparinized specimens of whole blood were treated with metabisulfite to induce sickling before and after exposure to APM. Number of sickle cells observed in the specimens before metabisulfite additions were subtracted from the totals, resulting in some values with negative numbers.
cells was significantly less than that in the controls. Thus, while sickling was not prevented by APM over time, its progression was limited over time.
The effect of calcium (Ca 2+ ) on the effectiveness of APM was examined by repeating the experiment above with the addition of EDTA, a Ca 2+ chelating agent, to normal blood control and the patient experimental samples prior to testing. FIG. 3 illustrates the comparative heparin versus EDTA treatment of the blood. The addition of EDTA completely eliminated the antisickling effect of APM, a result indicating that APM does not pass the RBC membrane in the absence of Ca 2+ . These results also demonstrate that the use of EDTA as an anticoagulant in screening tests will negatively bias conclusions of the effectiveness of APM which require Ca 2+ for transport across the RBC membrane. Moreover, the addition of a calcium salt to APM formulations useful for antisickling treatment as well as in vitro applications is desirable.
EXAMPLE 2
Reduction of Sickle Cells in vivo
The antisickling effect of APM was observed in heparinized blood samples taken from a female patient with sickle cell anemia.
During Week 1 of the study, blood samples were taken from the patient before and one hour after an orally administered dose of 60 milligrams APM. During Week 2, blood samples were taken from the patient before and one hour after an orally administered dose of 160 milligrams APM. The blood samples and slides were prepared according to the methods given in Example 1, and cell counts were taken at 0, 30, and 120 minutes post-induction.
The results of the study are given in FIGS. 4 and 5 for the 60 milligram and 160 milligram treatments, respectively. A decrease in the number of sickling RBCs relative to the control was observed after administration of the lower dosage, thereby confirming an antisickling response upon APM ingestion. At the higher 160 milligram dosage, the antisickling effect was proportionately larger than the effect observed with the 60 milligram dosage, indicating a significant dose response effect.
EXAMPLE 3
APM Dose-Response Study of Patients with Sickle Cell Disorders
A blinded study was conducted with 23 patients diagnosed with sickle cell disorders. Blood samples were obtained from the 23 patients having sickle cell disease (homozygous HgBss), sickle cell trait (heterozygous Hgbsc), or homozygous HbS with a β-thalassemia chain (“sbthal”) before and after a blinded administration of APM at 1.5 (low dosage), 3 (medium dosage), or 6 (high dosage) milligrams per kilogram body weight. The patients' characteristics are presented in Table II.
Blood was drawn before and 120 minutes after treatment with 0, 1.5, 3, or 6 milligrams APM per kilogram body weight in a blinded fashion from the ten patients into heparin tubes, stored in a refrigerator at approximately 10° C. and routinely tested within 36 hours of collection.
Normal blood devoid of abnormal hemoglobin was used as a control. For each heparinized patient blood sample and the normal blood control, experimental samples were prepared containing 0.25 milliliters of normal saline and 0.25 milliliters of blood. Following the metabisulfite induction as given in Example 1, the number of sickle cells relative to the number of normal cells was obtained at 0, 30, 60, 120, 240, 480, and 1440 minutes post-induction.
The results of the study are presented as the number of sickle cells per 100 total cells counted over time. Dose comparisons for the combined HgBss patients, combined HgBss and sbthal patients, and combined Hgbsc patients are presented in FIG. 6, FIG. 7, and FIG. 8, respectively. A decrease in the number of sickling RBCs relative to the control was observed after administration of the lower dosage, thereby confirming an antisickling response upon APM ingestion (data not shown). At the higher dosage, the antisickling effect was proportionately larger than the effect observed with the medium dosage, and the antisickling effect of medium dosage was greater than the effect of the low dosage, indicating a significant dose-response effect. No dose-response effect was observed with Hgbsc.
TABLE II
Patient Characteristics for Dose-Response Study
ELECTROPHORESIS
ID
Age
Sex
Disease b
Hgb
Hct
Dose c
ss
f
a
c
TD a
13
m
ss
7.6
25.4
H
100
AH a
11
f
ss
6.1
23.3
M
JC a
13
m
sbthal
7.5
25.1
L
77.1
18
TC a
9
f
sbthal
7.9
25.6
H
64.5
32
JU a
4
m
ss
7.9
22.6
M
84.8
10.9
LJ a
4
m
ss
7.9
22.6
L
TM a
19
f
sc
10.3
30.2
L
BB a
39
f
sc
11.5
39
H
CH a
52
f
sc
8
26
M
LW a
3
f
ss
7.4
24
M
DM
19
m
ss
9.8
29.4
H
83.2
13.1
CM
21
m
ss
9.9
29.3
M
58.4
29.4
CA
14
m
ss
7.5
21.1
L
92.8
1.9
QR
6
m
ss
7.1
20.2
M
90.1
5.1
OF
2
f
ss
9.6
29
L
75
20.5
DA
4
f
ss
7.12
21.3
H
67
12.7
18.4
DW
4
m
ss
8.1
24.9
M
63.4
11.2
21.7
JR
16
f
sbthal
11.7
36.4
H
66.1
6.6
20.5
AS
29
f
ss
7.2
21.5
L
KP
9
f
sc
10.9
33.7
L
LT
7
m
sc
11.4
35.1
H
28.7
37.9
33.9
SP
f
sc
11.1
33.1
H
CS
m
ss
7.5
22.1
L
Mean
14.2
8.83
27.00
73.16
15.45
22.50
a Patient blood sample used in viscosity study discussed in Example 4.
b ss = homozygous HbS; sc = heterozygous HbS and HbC; sbthal = HbS with β-thalassemia chain.
c H = high dose, 6 mg/kg body weight; M = medium dose, 3 mg/kg body weight; L = low dose, 1.5 mg/kg body weight.
EXAMPLE 4
Viscosity Screening Method for APM Efficacy
The efficacy of APM treatment can be monitored by measuring the viscosity of patient blood samples before and after treatment. Normal blood viscosity increases with increasing hemoglobin concentration. While patients with sickle cell disease are anemic, the viscosity of their blood appears in the normal range; however, the viscosity is increased by an increase in the number of sickle cells relative to the number of normal cells.
Blood samples were obtained from ten patients having homozygous HbSS disease or heterozygous HbSC disease before and after a blinded administration of APM at 1.5 (low dosage), 3 (medium dosage), or 6 (high dosage) milligrams per kilogram body weight. The patients' characteristics are given in the first ten entries in Table II.
Viscosity determinations using the RBC pipette method of Wright and Jenkins (Wright, D. J. and Jenkins, Jr., D. E. 1970. Blood 36:516-522) were made on each blinded whole blood sample before and 120 minutes after blinded administration of APM. Each measurement was made in triplicate. Control viscosity measurements using saline and water for each patient and normal whole blood sample were also made to validate the viscosity measurements.
To measure viscosity, 1.01 cc of the test fluid, i.e., either water, saline or blood, was drawn into an RBC pipette using a 50 cc syringe attached via rubber tubing to the top of the RBC pipette. Using a constant pressure of 20 mm by maintaining the pressure with visual feedback and hand pressure, the amount of time it took for the test fluid to drip out of the RBC pipette was measured with a stopwatch. Each measurement was made in triplicate.
The results of the viscosity study obtained by comparing viscosity measurements obtained at baseline and 120 minutes post-treatment are summarized in FIG. 9 and Table III. Of the five patients identified as HgBss (homozygous for HbS), blood viscosity decreased after treatment over time. For the two patients diagnosed as sbthal (homozygous HbS with β-thalassemia chain), blood viscosity also decreased after treatment over time, resembling the results obtained with HgBss. In contrast, blood samples taken from three patients diagnosed as Hgbsc (heterozygous HbS and HbC) showed increased viscosity after treatment over time. According to this data, this method of monitoring can be used to delineate “sickle cell disease” from certain “sickle cell trait” disorders, e.g., Hgbsc. The viscosity data was also compared against Pirofsky's change in viscosity vs. hematocrit standard, and the results were that the viscosity decreased in blood samples from patients with sickle cell disease (HgBss) and increased in blood samples from patients with sickle cell trait (Hgbsc).
TABLE III
Viscosity results
No. of Patients
Viscosity change
HgBss
sbthal
Hgbsc
7
decreasing
5
2
3
increasing
3
For comparative purposes, the number of sickle cells relative to the number of normal cells was obtained for each blinded sample before and 30, 60, 120, 240, and 1,440 minutes after blinded administration of APM using the metabisulfite test given in Example 1, with the exception that the ratio of metabisulfite to whole blood was 6:1, rather than 3:1.
Samples with high viscosity readings at 480 minute or 1,440 minute posttreatment, chosen to represent patients with a validated response to APM who were returning to normal, were divided and treated with an additional 0, 1, or 2 milligrams/milliliter APM in vitro, in an effort to measure whether a second inducible sickling response was possible and if a second response to the in vitro APM addition could be observed. The viscosity of each sample at 480 minutes post-treatment was measured. As presented in FIG. 10, the viscosity of the blood samples from the patients classified as HgBss decreased over time when compared to the control. In contrast, blood samples from the Hgbsc patients showed an increase in viscosity over time compared to the control.
Baseline and 120 minute post-treatment viscosity measurements were compared with the number of sickle cells relative to the number of normal cells for correlation. A correlation was also made between the sickle cell count and viscosity, as shown in FIG. 11 . The results demonstrated that as the number of sickle cells relative to the number of normal cells increased, the blood viscosity also increased in an essentially linearly proportional correlation.
APM given orally reduced the number of sickle cells in Hbss blood and also reduced the viscosity of HbSS blood. The addition of APM in vitro also reduced the number of sickle cells in HbSS blood and the viscosity of HbSS blood. The HbSC blood was not affected by APM in vivo or in vitro.
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It has now been found that N-L-alpha-aspartyl-L-phenylalanine 1-methyl ester (APM) exhibits antisickling properties. In vitro testing verified that APM significantly lowered the frequency of sickling of red blood cells from each of twelve pediatric aged patients being treated for sickle-cell anemia by exchange transfusion. Sickling was also inhibited in an “index” patient after oral administering of APM. These in vitro and in vivo results identify APM as a therapeutic agent for the family of sickle cell molecular diseases.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of a provisional application Ser. No. 60/656,817 filed on Feb. 25, 2005.
FIELD OF THE INVENTION
[0002] The invention relates to an automotive driveline application and in particular to a flow-formed differential housing for supporting a differential mechanism for transmitting torque from a transmission of a vehicle to axle shafts of the vehicle and a method of forming the flow-formed differential housing.
BACKGROUND OF THE INVENTION
[0003] A differential housing supports a differential mechanism having gears that transmit torque from a transmission of a vehicle to axle shafts of the vehicle. Generally, bevels gears of the differential mechanism are housed in the differential housing. Alternatively, planetary gears can also be housed in the differential housing. The typical differential mechanism of the vehicle transmission is designed to transmit torque from a transmission output to the opposing axle shafts allowing right and left wheels to rotate at different speeds, particularly important when negotiating a turn. While performing generally the same function, differential mechanism have different dimensional requirements for rear wheel and front wheel drive vehicles. Specifically, differentials intended for use on the front wheel drive vehicles require a beveled and even annular shape in order to compensate for both the smaller packaging area available and to account for the steering characteristics of the front wheels of the vehicle.
[0004] Rear wheel drive vehicles are typically larger and require more torque production than the front wheel drive vehicles and include sport utility, pick-ups, and even heavy duty vehicles. Therefore, the rear wheel drive differential is typically dimensioned larger with heavier gauge steel than is a front wheel drive differential. Iron castings presently used to form a housing of a differential requires a large number of machining operations to produce finished parts having the dimensions necessary to provide adequate tolerances to support the gears disposed within the housing.
[0005] Given the high torque requirements that is typical of the rear wheel drive vehicle, it is believed that the differential housing should include a more dimensionally stable and durable configuration than what is required of a front wheel drive differential housing. Furthermore, many of the manufacturing drawbacks of cast differential housings have resulted in excessive cost of a typical vehicle transmission.
[0006] The art is replete with various designs of the differential housings and methods of forming the differential mechanisms, which are disclosed in the U.S. Pat. No. 6,045,479 to Victoria et al; U.S. Pat. No. 6,061,907 to Victoria et al; U.S. Pat. No. 6,176,152 to Victoria et al.; and U.S. Pat. No. 6,379,277 to Victoria et al. Each of the aforementioned United States Patents discloses a method of forming a differential housing using a cold flow-forming process. While the differential housing formed by the process disclosed in these prior art references are believed to be effective for use in a front wheel drive transmission, it is believed that the differential housings will not be as effective for use in a rear wheel drive vehicle. However, the dimensional improvements produced by the cold flow-forming process that enable sheet steel to be used to form the differential housing can also be used to form a differential housing for a rear wheel drive differential. Therefore, the cold flow-forming process disclosed in these prior art patents are included by reference herein.
[0007] The differential housings, as disclosed in the aforementioned prior art references, are formed from a single casting that is machined subsequent to casting. In particular, a housing portion is formed in a series of steps starting with a cup-shaped workpiece. The cup-shaped workpiece is fitted over a chuck and flow-formed into a housing preform. Operations such drilling and surface finishing are performed on the housing preform subsequent to the flow-forming process. Gears are placed in the differential housing and the housing is permanently sealed. After being sealed, the entire assembly cannot be serviced and must be replaced if one of the internal components fails.
[0008] There is a constant need in the area of differential housings, formed by the cold flow-forming process and by forging and the like, for an improved design of the differential housing that is easily disassembled and is easily serviceable in a short period of time, particularly when one or more of the gears need to be replaced without having to replace the entire differential housing.
SUMMARY OF INVENTION
[0009] A differential housing of the present invention is designed for supporting a differential mechanism having a pin, a pair of axle shafts, i.e. the shafts, and a set of gears, such as pinion gears and beveled gears, disposed on the axle shafts and the pin and presenting driving engagement therebetween for transmitting torque from a transmission of a vehicle to the shafts. The shafts and the gears are disposed in the differential housing. A housing portion of the differential housing is defined by an annular wall circumscribing an axis. The annular wall is exposed to an open end for receiving one of the shafts. The annular wall is further exposed to an open front being opposite from the open end. A lid or a secondary gear assembly of the differential housing is attached to the open front thereby forming an enclosure within the housing portion for engaging the shafts and the gears therein. A locking device defined by a snap-ring extends peripherally about the housing portion at the open front. The snap-ring is elastically deformed between a stressed position and an unstressed position for releasibly connecting the lid to the housing portion for forming the enclosure within the housing portion to support the differential mechanism and for selectively removing the shafts and the gears of the differential mechanism from the enclosure when the snap-ring is in the stressed position as the lid is removed from the engagement with the housing portion.
[0010] An inventive method of forming the aforementioned differential housing includes the step of cold-working a first housing preform by one of a group consisting of spin-forming or flow-forming the inner surface of the preform into conformance with a contour of a first mandrel to form a differential housing. The method also includes the step of installing a differential mechanism subassembly including the aforementioned plurality of gears and a pin in the differential housing. The method also includes the step of releasibly connecting the housing portion of the differential housing with one of a lid and a secondary gear assembly.
[0011] One of the advantages of the present invention is that the releasable connection between the lid or the secondary gear assembly and the housing portion of the differential housing allows the differential housing to be easily serviced. For example, one or more of the gears can be replaced without having to replace the entire differential housing, which is required of prior art differential housings formed by cold working.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
[0013] FIG. 1A is a cross-sectional view of a first exemplary embodiment of a differential housing of the present invention;
[0014] FIG. 1B is a partially exploded view of the first exemplary embodiment of the differential housing;
[0015] FIG. 1C is a fragmental view of a housing portion and a lid of the differential housing with the lid connected to the housing portion by a snap-ring having a beveled peripheral edge;
[0016] FIG. 1D is a fragmental view of the housing portion and the lid connected by a snap-ring having a V-shaped or tapered peripheral edge;
[0017] FIG. 2 is a perspective view of a second exemplary embodiment of the differential housing;
[0018] FIG. 3 is a cross-sectional view taken along section lines 3 - 3 in FIG. 2 ;
[0019] FIG. 4 is right-hand view of the second exemplary embodiment of the differential housing;
[0020] FIG. 5 is a cross-sectional view taken along section lines 5 - 5 in FIG. 4 ;
[0021] FIG. 6 is a perspective view of the a gear assembly received in differential housing according to a third exemplary embodiment of the present invention;
[0022] FIG. 7 is a perspective view of the differential housing according to the third exemplary embodiment of the present invention; and
[0023] FIG. 8 is a cut-away view showing the gear assembly and differential housing of the third exemplary embodiment of the present invention engaged with respect to one another.
DETAILED DESCRIPTION OF THE INVENTION
[0024] A differential housing assembly 10 of the present invention is designed for supporting a differential mechanism or differential mechanism subassembly (to be discussed in details further below) for transmitting torque from a transmission of a vehicle (not shown) to axle shafts (not shown) of the differential mechanism of the vehicle. Plurality of different embodiments of the invention are shown in the Figures of the application. Similar features are shown in the various embodiments of the invention. Similar features have been numbered with a common two-digit reference numeral and have been differentiated by a third digit placed before the two common digits. Similar features are structured similarly, operate similarly, and/or have the same function unless otherwise indicated by the drawings or this specification. Furthermore, particular features of one embodiment can replace corresponding features in another embodiment unless otherwise indicated by the drawings or this specification.
[0025] Referring now to FIG. 1 , in a first exemplary embodiment of the invention, the differential housing assembly 10 includes a differential housing or housing portion 12 and a lid 14 . The differential housing 12 is formed according the cold forming process set forth in the U.S. Pat. No. 6,061,907 to Victoria et al., which is hereby incorporated by reference in its entirety. The housing portion 12 is defined by an annular wall circumscribing an axis A with the annular wall exposed to an open end, generally indicated at 13 , for receiving one of the shafts and an open front, generally indicated at 15 , opposite from the open end 13 . The lid 14 is releasibly engaged with the differential housing 12 .
[0026] The differential mechanism of the differential housing assembly 10 also includes gears 16 , 18 , 20 , 22 and a pin 24 presenting driving or meshing engagement therebetween. After the differential housing 12 has been formed according to the cold forming process set forth in the United States Patent No. 6 , 061 , 907 to Victoria et al., a longitudinal aperture 26 is formed and finished. The longitudinal aperture 26 receives a shaft (not shown. The shaft defines splines (not shown) which matingly engage splines 28 defined by the gear 16 . Also, a transverse aperture 30 is formed and finished. The transverse aperture 30 passes through the differential housing 12 . The pin 24 is received in the transverse aperture 30 . The lid 14 is releasibly associated with the differential housing 12 after the gears 16 , 18 , 20 , 22 have been assembled and inserted into the differential housing 12 . The lid 14 defines a second longitudinal aperture 32 which receives a second shaft (not shown). The second shaft defines splines (not shown) which matingly engage splines defined by the gear 18 .
[0027] The lid 14 and the differential housing 12 are releasibly engaged with respect to one another with a locking device such as, for example a snap-ring 36 extending into a groove 38 defined in the differential housing 12 . The snap-ring 36 extends peripherally about the inner surface of the differential housing 12 at the open front 15 . The snap-ring 36 is elastically deformed between a stressed position and an unstressed position to remove the lid 14 from the differential housing 12 and to connect the lid 14 to the differential housing 12 , respectively. When the snap-ring 36 is disengaged from the groove 38 , the lid 14 is removed from the differential housing 12 to allow a technician (not shown) to remove the differential mechanism from the enclosure to replace one or all of the gears 16 , 18 , 20 , 22 . When the differential mechanism is serviced, the technician re-connects the lid 14 with the differential housing 12 as the snap-ring 36 is moved the stressed position to the unstressed position as the snap-ring 36 is radially retracted, disposed over the lid 14 and then allowed to radially expand from the stressed position to the unstressed position with the snap-ring 36 engaging the groove 38 to form the enclosure within the differential housing 12 . The releasable connection between the lid 14 and the differential housing 12 allows the differential housing 12 of the differential assembly 10 to be easily serviced in a short period of time. For example, one or more of the gears 16 , 18 , 20 , 22 can be replaced without having to replace the entire differential housing assembly 10 .
[0028] As best illustrated in FIGS. 1C and 1D the snap-ring 36 and the respective peripheral groove 38 . In one embodiment, as illustrated in FIG. 1C , the snap-ring 36 extends to a peripheral edge having a beveled configuration. The peripheral groove 38 presents a configuration to complement the beveled configuration of the snap-ring 36 . FIG. 1D illustrates an alternative embodiment of a snap-ring 336 having a tapered or a V-shaped peripheral edge to complement with a V-shaped groove 338 defined in the differential housing 12 . Those skilled in the mechanical art will appreciate that other configurations of the snap-ring 34 and the peripheral groove may be utilized in practicing the invention.
[0029] Referring now to FIGS. 2-5 , in a second exemplary embodiment of the invention, a differential housing assembly 110 includes a differential housing 112 and a secondary gear assembly 40 . The secondary gear assembly 40 includes a support housing 41 and a plurality of secondary gears 43 rotatably supported 45 by the support housing 41 . The support housing 41 extends to a peripheral edge 47 that abuts the differential housing 112 . The differential housing assembly 110 also includes gears 116 , 118 , 120 , 122 and a pin 124 . After the differential housing 112 has been formed according to the cold forming process set forth in the U.S. Pat. No. 6,061,907 to Victoria et al., a longitudinal aperture 126 is formed and finished. The longitudinal aperture 126 receives a shaft. The shaft (not shown) defines splines which matingly engage splines 128 defined by the gear 118 . Also, a transverse aperture 130 is formed and finished. The transverse aperture 130 passes through the differential housing 112 . The pin 124 is received in the transverse aperture 130 .
[0030] The differential housing 112 and the secondary gear assembly 40 defining mating castle-teeth. For example, the differential housing 112 forms first connectors such as castle teeth 42 , 44 , 46 , 48 , 50 , 52 and the secondary gear assembly 40 forms second connectors such as castle teeth 54 , 56 . The castle teeth 42 , 44 , 46 , 48 , 50 , 52 , 54 , 56 engage one another to prevent relative rotation between the differential housing 112 and the secondary gear assembly 40 . As shown in FIG. 5 , the castle teeth, such as castle-tooth 42 , of the differential housing 112 extend radially inward greater than the castle teeth, such as castle-tooth 56 , of the secondary gear assembly 40 .
[0031] The differential housing 112 and the secondary gear assembly 40 are releasibly engaged with one other with a snap-ring 136 terminated into fingers 137 adaptable to be engaged by the technician in a manner known to those skilled in the art to manipulate the snap-ring 136 between the stressed and unstressed positions. The secondary gear assembly 40 includes a peripheral notch 139 defined in the peripheral edge 47 of the support housing 41 to form a clearance for the snap-ring 136 as will be discussed further below. The thickness of the peripheral edge 47 and the size of the peripheral notch 139 , as shown in FIG. 3 , may vary and are not intended to limit the present invention. The snap-ring 136 is releasibly associated with the differential housing 112 after the gears 116 , 118 , 120 , 122 have been assembled and inserted into the housing 12 . The mandrel used in the cold forming process used to form the differential housing 112 can include an annular projection so that the differential housing 112 is formed with an annular groove 138 . When the snap-ring 136 is disengaged from the groove 138 and disposed in the peripheral notch 139 , the secondary gear assembly 40 is removed from the differential housing 112 to allow the technician to remove the differential mechanism from the enclosure to replace one or all of the gears 116 , 118 , 120 , 122 . When the differential mechanism is serviced, the technician re-connects the secondary gear assembly 40 with the differential housing 112 as the snap-ring 136 is moved the stressed position, i.e. out from the peripheral notch 139 to the unstressed position as the snap-ring 136 is radially retracted to the groove 138 with the snap-ring 136 engaging the groove 138 to form the enclosure within the differential housing 112 after the secondary gear assembly 40 is placed over the gears 116 , 118 , 120 , 122 . The releasable connection, i.e. the snap-ring 136 , between the secondary gear assembly 40 and the differential housing 112 allows the differential housing assembly 110 to be easily serviced. For example, one or more of the gears 116 , 118 , 120 , 122 are replaceable without having to replace the entire differential housing assembly 110 .
[0032] Referring now to FIGS. 6-8 , in a third exemplary embodiment of the invention, a differential housing assembly 210 includes a differential housing 212 and a secondary gear assembly 240 . The secondary gear assembly 240 includes a support housing 241 and a plurality of secondary gears 243 rotatably supported 245 by the support housing 241 . The differential housing assembly 210 also includes gears 216 , 218 , 220 , 222 and a pin 224 . After the differential housing 212 has been formed according to the cold forming process set forth in U.S. Pat. No. 6,061,907 to Victoria et al., a longitudinal aperture 226 is formed and finished. The longitudinal aperture 226 receives a shaft (not shown). The shaft defines splines (not shown) which matingly engage splines (not shown) defined by the gear 218 . Also, a transverse aperture (not shown) is formed and finished. The transverse aperture passes through the differential housing 212 . The pin 224 is received in the transverse aperture.
[0033] The differential housing 212 defines a plurality of notches, such as notch 58 , and the secondary gear assembly 240 defines a plurality of teeth, such as tooth 60 . The teeth and notches engage one another and cooperate to prevent relative rotation between the differential housing 212 and the secondary gear assembly 240 .
[0034] The differential housing 212 and the secondary gear assembly 240 are releasibly engaged with one other with a snap-ring 236 . The functional characteristics of the snap-ring 236 are identical to the functional characteristics of the snap-ring 36 and 136 . The secondary gear assembly 240 is releasibly associated with the differential housing 212 after the gears 216 , 218 , 220 , 222 have been assembled. The mandrel used in the cold forming process used to form the differential housing 212 can include an annular projection so that the differential housing 212 is formed with an annular groove 238 . After the secondary gear assembly 240 is placed over the gears 216 , 218 , 220 , 222 , the snap-ring 236 is radially retracted, disposed over the secondary gear assembly 240 and then allowed to radially expand into the groove 238 . The releasable connection between the secondary gear assembly 240 and the differential housing 212 allows the differential housing assembly 210 to be easily serviced. For example, one or more of the gears 216 , 218 , 220 , 222 are replaceable without having to replace the entire differential housing assembly 210 . Those skilled in the art will appreciate that the locking device, i.e. the snap-ring 36 of the present invention is not intended to be limited to differential housing assembly formed by the cold forming process and may be utilized by other forger or iron casted differential housing assemblies.
[0035] While the invention has been described with reference to an exemplary 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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The present invention includes a differential housing and a method for forming the differential housing. The method includes the step of cold-working a first housing preform by one of a group consisting of spin-forming or flow-forming the inner surface of the preform into conformance with a contour of a first mandrel to form the differential housing. The method also includes the step of installing a differential mechanism subassembly including a plurality of gears and a pin in the differential housing. The method also includes the step of releasibly connecting a housing portion of the differential housing with one of a lid and a second gear assembly.
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This application is a divisional of Ser. No. 07/937,589, filed Aug. 31, 1992, now U.S. Pat. No. 5,244,175, which is a continuation of Ser. No. 07/709,716, filed Jun. 3, 1991, now U.S. Pat. No. 5,143,335, which is a continuation of application Ser. No. 07/460,860, filed Jan. 31, 1990, now U.S. Pat. No. 5,020,755. U.S. Pat. No. 5,020,755 is the U.S. National application which was filed based upon PCT Application No. US89/2402, filed Jun. 1, 1989, for which priority was claimed based upon Ser. No. 07/201,480, filed Jun. 1, 1988, now U.S. Pat. No. 4,856,744.
FIELD OF THE INVENTION
The present invention pertains to handle support fixtures and, more particularly, to an article support assembly adapted for integral formation wish or demountable attachment to handles of strollers, carts, bicycles and the like.
BACKGROUND OF THE INVENTION
The art is replete with portable article carrying units. These units have been designed and constructed for support of a myriad of items and for a plurality of applications. The items include beverages, books, newspapers and small personal items. Their applications include securement to bicycle handle bars, grocery baskets, crutches and similar devices adapted for facilitating ambulatory motion with the conveyance of associated articles. It is not uncommon for such assemblies to have designs adapted specifically for the primary article support application. For example, shopping basket support assemblies have included configured plate assemblies adapted for interengaging the orthogonal frame basket members in a fashion facilitating stability of the configured plate. Such a plate has been constructed for supporting beverage containers as shown in U.S. Pat. No. 2,633,278. It may be seen in this 1953 patent that the overall configuration affording said stability and ease in assembly is unique to this particular application.
Numerous other attachment devices have been the subject of innovation in the art. For example, U.S. Pat. No. 1,134,577 illustrates a bicycle handle bar connection assembly affording support for a basket. Although this is a somewhat antiquated design (1915), it illustrates the importance of freedom of the user's hands relative to handle bars and the like. More recent developments include handle assemblies for more conventional ambulatory assistance structures. Wheelchairs, for example, are designed to assist the physically impaired and therefore convenience assemblies mounted to the wheelchair facilitate both the wheelchair operator and/or those persons assisting the wheelchair operator. Such assemblies include beverage container supports and clipboard mountings to allow the wheelchair occupant immediate access to the article supported thereby. Indeed, it is the ability to afford the occupant, or controller of the particular vehicle for which the handle bar is associated, ease in access that comprises the most important utilitarian function of the mounting. The method and apparatus of attachment have thus been the subject of individual design and engineering considerations. Many of these designs and considerations have been deemed novel throughout the previous decades for a plurality of vehicle and/or frame structures generally associated with ambulatory motion.
Structures associated with ambulatory motion include not only wheelchairs but also bicycles, crutches, shopping carts, and infant strollers. These articles generally require attention by the operator or, in the case of wheelchairs and crutches, by the patient. In these instances, the hands of the patient are generally fully occupied in controlling the wheelchair or the crutch. Even so, access to objects such as drinking containers or related support articles is necessary for the convenience and comfort of the user. Relative to handle bars for bicycles, strollers, shopping carts and the like, it is often necessary for the user to manually steer the particular wheeled structure. It is clearly an encumbrance for the user to also deal with loose articles such as purses, sweaters, drinks, or infant care articles while handling a stroller or cart. Many innovations in the art have thus addressed these various utilitarian needs by the provision of mechanical assemblies adapted for mounting to handle bar areas for particular structures era applications. U.S. Pat. No. 4,071,175 teaches a beverage container holder for a handle bar which permits its attachment in a convenient location and orientation. The same holds true for U.S. Pat. Nos. 4,312,465 and 4,570,835 which teach related beverage container holder supports facilitating user operation. These references manifest the advantages and need for such innovation.
A distinct area of need in handle bar support structures adapted for facilitating the convenience of the user is not only a beverage container support but means for easily supporting the loose articles described above. In the case of shopping carts and baby strollers, it is common for the operator to carry loose sweaters, purses, shopping bags and/or infant care bags. Without proper securement of these articles relative to the shopping cart or stroller, both inconvenience and danger can result due to lack of attention by the operator in the event that the articles become loose, dislodged and/or generally unsecured. It would be a distinct advance over the art to provide a support assembly specifically adapted for handle bar regions for strollers, carts and the like facilitating the support of the aforesaid articles in a safe, convenient and economical fashion. The method and apparatus of the present invention provide such an assembly in an integrally formed article support adapted for securement to, or integration with, handle bars and the like.
SUMMARY OF THE INVENTION
The present invention relates to handle bar support accessories for the securement of collateral articles. More particularly, one aspect of the present invention comprises a handle bar support assembly integrally formed with a plurality of hook shaped elements adapted for the securement and support of articles therefrom relative to the handle bar upon which the assembly is attached.
In another aspect, the invention includes a support assembly for use with a handle on a stroller or the like comprising an integrally formed body portion and handle engaging means integral with and extending generally upwardly from the body portion. The handle has means adapted to engage a generally horizontal portion of a stroller handle. Hook means integral with and extending generally downwardly from the body portion are available for selective hooking engagement with articles to be supported by the assembly; said hooking means possesses a secondary fastening means for complementary use with ancillary fixtures attachable to the support assembly. The handle engaging means may be integrally connected to said handle or include threaded fastener means for connection to the handle In the latter case, the handle engaging means comprises gripping means frictionally engagable with the handle.
In yet another aspect, the invention includes a support assembly for use with a handle on a stroller or the like comprising an integrally formed body portion and handle engaging means integral with and extending generally upwardly from the body portion with means adapted to engage a generally horizontal portion of a stroller handle or the like. Hook means integral with and extending generally downwardly from the body portion provide selective hooking engagement with an article to be supported by the assembly. The hook means comprise at least a pair of hooks in one embodiment and a clamp hook in another. Likewise, the hook means are positioned directly between the handle engaging means in one embodiment and in a laterally offset position from the handle engaging means in another. The hooks may face in opposite directions or the same direction. Moreover, a beverage container holding means may extend generally laterally from the body portion. The beverage container holding means may comprise a generally upright wall means for at least partially surrounding a beverage container and the wall means can define compartments for a plurality of beverage containers.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and for further: objects and advantages thereof, reference may now be had to the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a fragmentary perspective view of one embodiment of the article support apparatus of the present invention;
FIG. 2 is a fragmentary perspective view of an alternative embodiment of the article support apparatus of FIG. 1;
FIG. 3 is a fragmentary perspective view of another alternative embodiment of the article support apparatus of FIG. 1;
FIG. 4 is a fragmentary perspective view of yet another alternative embodiment of the article support apparatus of FIG. 1;
FIG. 5 is a perspective view of yet another article support assembly secured to a baby stroller to illustrate an aspect of the present invention;
FIG. 6 is an enlarged perspective view of an alternative embodiment of the article support assembly of FIG. 5;
FIGS. 7 through FIGS. 12 are side elevational views of Alternative constructional embodiments of the article support assembly of FIG. 6;
FIG. 13 is an enlarged perspective view of another embodiment of the article support assembly of FIG. 6;
FIG. 14 is a perspective view of an attachable article support assembly illustrating yet another embodiment of the present invention;
FIG. 15 is an enlarged cross-sectional view of the article support assembly of FIG. 14 taken along line 15--15;
FIG. 16 is an enlarged cross-sectional view of the article support assembly of FIG. 14 taken along line 16--16;
FIG. 17 is an enlarged perspective view of an alternative embodiment of the attachable article support assembly of FIG. 14;
FIG. 18 is a fragmentary side elevational view of an alternative embodiment of the article support assembly of FIG. 17;
FIG. 19 is a fragmentary side elevational view of an alternative embodiment of the article support assembly of FIG. 18;
FIG. 20 is an exploded view of yet another alternative embodiment of the attachable article support assembly of FIG. 14;
FIG. 21 is a cross-sectional view of the article support assembly of FIG. 20 taken along line 21--21;
FIG. 22 is a perspective view of an alternative embodiment of the article support assembly of FIG. 20 mounted to the handle bars of a conventional bicycle;
FIG. 23 is an enlarged side elevational view of the support hook assembly of FIG. 22;
FIG. 24 is a side elevational view of an alternative embodiment of the article support assembly of FIG. 23;
FIG. 25 is a perspective view of an alternative embodiment of a beverage container holder constructed in accordance with the principles of the present invention;
FIG. 26 is an enlarged fragmentary cross-sectional view of a portion of the beverage container holder of FIG. 25 taken along line 26--26;
FIG. 27 is a perspective view of yet another article support assembly wherein a cylindrical receptacle is affixed to the article support assembly;
FIG. 28 is a side elevational view of the article support assembly with attached cylindrical receptacle illustrated in FIG. 27;
FIG. 29 is a back elevational view of the article support assembly with attached cylindrical receptacle illustrated in FIG. 27;
FIG. 30 is a bottom elevational view of the article support assembly with attached cylindrical receptacle illustrated in FIG. 27; and
FIG. 31 is an exploded side elevational view of the article support assembly of FIG. 27 detached from the cylindrical receptacle.
DETAILED DESCRIPTION
Referring first to FIG. 1, there is shown a perspective view of a support hook assembly 10 screw mounted to handle 12. Handle 12 may be of the type utilized for strollers, buggies, bicycles, carts, and other conventional ambulatory assistance devices. The support assembly 10 comprises a body portion 14 having an upper handle engagement region 16 adapted for attachment with an integrally formed handle body 18 by means of a threaded screw. An intermediate body portion 20 is constructed of a substantially planar configuration region 20 which descends into a lower hook region 22 comprising a first hook section 24 and a second hook section 26. Each of the hook sections 24 and 26 are formed in a curvilinear configuration adapted for facilitating the attachment of a handle of a purse, a sweater or the like. As shown herein, the article support assembly 10 is adapted for facilitating such ease of attachment. This integral configuration of the article support assembly 10 and handle 12 is but one embodiment of the present invention.
Referring now to FIG. 2 there is shown an integral construction of an alternative embodiment of article support assembly 10 incorporating a beverage container holder. The body portion 28 of the article support assembly 10 comprises a compartment 30 adapted for receiving and securing first and second beverage containers. The compartment 30 is constructed of substantially planar sidewalls 31 and 32 with an intermediate wall 33 disposed therebetween and frontal wall 34 therein defining a first beverage container holding section 35 and a second beverage container holding section 36. Beneath beverage container holding sections 35 and 36 are disposed hook sections 24 and 26 of the type shown in FIG. 1. In this particular embodiment, handle 12 may be utilized with a stroller for facilitating both the attachment of purses and loose articles as well as containing beverages during the use of the stroller for which handle 12 is attached.
Referring now to FIG. 3, there is shown yet another embodiment of an integral hook assembly for handle 12. Article support assembly 10 as shown herein comprises first and second hook sections 40 and 41 integrally formed with top handle bar portion 18. In this configuration, handle 12 facilitates the attachment of articles by the utilization of two integrally molded hook sections formed in a curvilinear configuration.
Referring now to FIG. 4, there is shown yet another alternative embodiment of article support assembly 10 of the present invention as it is secured to a cross bar 42 of a stroller handle assembly 44. Cross bar 42 is pivotally mounted in the center at a point 45 permitting its pivotal actuation for the collapse of the stroller 44 in a conventional fashion. Arrows 46 illustrate the manner in which the cross bar 42 is permitted to flex about pivot point 45. Again, a pair of hooks 48 and 49 are integrally formed with cross bar member 42 for facilitating the attachment of loose articles thereto as described and illustrated above.
Referring now to FIG. 5, there is shown article support assembly 10 utilizing yet another alternative structural configuration which includes a hook assembly 50. Article support assembly 10 is fabricated from plastic or the like in a configuration which facilitates attachment to handle 12 of a conventional stroller or the like. A stroller 52 is shown in a perspective view for illustrating the functional use thereof. The handle 12 seen to comprise a portion of the overall stroller frame 54 which supports a stroller seat 56 by a set of wheels 58. A child positioned within stroller seat 56 may in this way be dealt with while articles such as purse 60 or the like may be hung from the hook assembly 50. A pair of generally C-shaped hook elements 61 and 62 are provided for supporting the handle 63 of purse 60. It may be seen that not only purse 60 but also other flaccid articles (not shown) such as a sweater or towels can be carried by article support assembly 10. In this way the portion of handle 12 adjacent and on either side of the article support assembly 10 is available for conventional securement by the hands of the user for control of stroller 52.
Referring now to FIG. 6, them is shown an enlarged perspective view of the support member of hook assembly 50. In this view, it may be seen that generally C-shaped hook members 61 and 62 are constructed with a generally flat flange region 65 on the upper portion thereof. A tubular body portion 66 is constructed with a central hollow region 68 formed therethrough A lower lip 70 depends down from the cylindrical body portion 66 for permitting elasticity and depending engagement after attachment to the handle 12. It may be seen that the plastic flexing action permits attachment to a plurality of handles. A recess area 72 is also provided to enable a label to be affixed wherein for identification purposes. This assembly facilitates an easy-on and easy-off, nonpermanent, installation for strollers and the like. In this manner the particular article support assembly 10 can be secured to any number of handles 12 including various strollers, carts and buggies.
Referring now to FIGS. 7 through 12, a plurality of cross sectional configurations are illustrated for the attachable article support assembly 10. Each article support assembly 10 is provided with its own identification number for purposes of further illustration. For example, FIG. 7 comprises an attachable assembly 75 having a generally rectangular handle engagement portion 76. The handle engagement portion 76 includes a serrated area 78 facilitating the flexibility of the lower member 79 around handle bars and the like. Without such a design sufficient flexibility may not be possible without breakage. The actual hook region 80 is constructed for easy attachment of any of the plurality of garments or handles. The hook region 80 is seen to be oriented directly beneath the handle section 76 as compared to the generally "FIG. 8" configuration shown in FIG. 8. In FIG. 8, a hook assembly 82 is constructed in a generally "FIG. 8" shape. A handle engagement portion 84 is constructed with serrations 85 facilitating the expansion of the body portion 86 around a handle or the like. A depending body portion 88 is constructed in a generally U-shaped configuration for holding straps and loose articles as defined above.
Referring now to FIG. 9, there is shown an adjustable clasp 90 having a snap-down vertical clasp configuration formed by depending section 92. Expansion sections 93 and 94 are likewise constructed therein for purposes of allowing flexibility and the lower hook section 95 is constructed with the lower base member 96 aligned in generally parallel spaced relationship with upper clasp member 97. This is yet another cross sectional configuration comprising an alternative embodiment of the article support assembly 10 of the present invention.
Referring now to FIG. 10, there is shown yet a further symmetrical clasp and article support assembly 10 in a reversible design. The symmetrical clasp 100 shown herein includes an upper cylindrical attachment section 101 and a lower cylindrical hook section 102. The hook section 102 has an outwardly flared flange 104 to permit receipt of articles therein. The reversible hook configuration provides aesthetic symmetry as well as depending structural rigidity for purposes of functional and decorative applications. Likewise, FIG. 11 illustrates a vertical clasp assembly 106 having a lower generally rectangular or U-shaped section 108 for providing a hook region therebeneath. Again, the hook region 108 is disposed in alignment with the upper clasp section 106 which may be constructed for adjustable mounting through the serrated portion 110 and fastening section 112. In this manner a number of handle bar configuration sizes and shapes may be secured therewith. FIG. 12 is yet a third version of the symmetrical vertical clasp and hook configuration provided with the hook portion immediately disposed beneath the clasp portion In this section the rectangular friction clasp 115 includes an upper handle engagement section 116 and lower hook section 118 of generally rectangular design. The overall configuration resembles that of the letter G and provides the general benefits as set forth above.
Referring now to FIG. 13, there is shown a perspective view of yet another alternative embodiment of the present invention. A hook assembly 120 is shown with a cylindrical handle engaging body portion 122 of the aforedescribed expansion shape. A lower snap flange 124 is constructed for permitting outwardly flaring receipt of a handle section (not shown) through the axial region 125 thereof. Three hooks are herewith provided in an opposed or back-to-back configuration. A first hook 126 depends from the upper cylindrical body portion 122 through a transition region 127. A second hook 128 is disposed in generally parallel spaced relationship to hook 126 and is likewise disposed in a position depending from the upper cylindrical body portion 122 through the transition region 129. Finally, a third hook 130 is disposed in a reverse orientation relative to hooks 126 and 128 while depending from upper cylindrical body section 122 through elongate planer transition region 131. It may be seen that this three hook design in assembly 120 provides a friction clasp assembly facilitating attachment to not only strollers but also grocery and shopping carts and the like. Securement to shopping carts is facilitated by the expansion clasp defined above and the availability of the three hooks 126, 128 and 130 affords ease in application and multiplicity in the number of articles that can be supported therefrom.
Referring now to FIG. 14, there is shown an alternative embodiment to the present invention whereby the article support assembly 10 is provided in a permanently attachable configuration by attachment hook 140. The attachment hook 140 is shown to be constructed with an upper generally rectangular body section 142 and two depending hooks 143 and 144 of generally rectangular design. The design and functionality of these hooks is described in some detail above. What is not described above is the means by which this particular configuration is secured to conventional handles 12 of strollers and the like. The hook assembly 140 is constructed with a mounting brace 146 which clamps around the handle the body portion 148 of the handle 12. A pair of threaded fasteners in the forms of screws 150 are utilized to permanently secure the clasp 146 thereto. A threaded mounting nut 152 is likewise provided for permitting mounting, demounting and interchange of the actual hook member 142. This construction is seen in more detail in FIGS. 15 and 16 where cross sections thereof are illustrated. The clasp 146 is shown to be constructed of two sections 155 and 156 that are threadibly connected to one another around the handle 12. The hook 144 shown depending from the upper hook attachment section 142 which is maintained thereon by rotatable fastener 152. Likewise FIG. 16 illustrates the manner of penetration of the handle 12 by threaded member 150 which utilizes a nut 159 on the lower end thereof to secure the lower clamping section 156 to the upper clamping section 155 of the clamping member 146. In this manner, hook 142 can be securably retained on handle.
Referring now to FIG. 17 there is shown yet another embodiment of the present invention for facilitating carrying beverage containers. As shown in FIG. 2 beverage container compartments are disclosed above but not in a permanently attachable configuration. Permanently attachable hook assembly 160 is thus shown with an attachment head 162 extending through an attachment section 164 adapted for engaging in the handle bar region as described above. A pair of hooks 165 and 168 is shown depending beneath a beverage container compartment 168 a adapted for supporting the beverage container 170 shown in phantom herein. A generally rectangular configuration is afforded whereby first and second outer walls 171 and 172 provide a generally parallel spaced relationship which is orthogonal to an inner wall 173. A bottom (not shown) is afforded for supporting the beverage container 170 therein. It may be seen that in this configuration the permanently attachable hook assembly 160 can be attached to the clamping mechanism 146 shown in FIG. 14 above. It is the utilization of the clamping mechanism 146 comprising the upper/lower clamping members 155 and 156, respectively, which affords the ability for the permanent mounting and demounting of these units. Consistent therewith a variation in the configuration of the lower hook elements is also illustrated. In FIG. 18 it may be seen that the lower hook elements 165 and 166 in FIG. 17 are provided in a variation of shape, illustrated as clamp hook 180. Clamp hook 180 has an upper flange 181 facilitating the grasp of the user for the purpose of inserting a garment or the like to be securely held therewithin. The utilization of an open hook such as 165 is not as conducive to securement of flaccid articles such as sweaters and towels due to the fact that without the clamping mechanism clearly shown in the hook 180, such articles can become easily dislodged. One of the applications for the present invention is the utilization of such a unit 160 on a bicycle or the like whereby the need may often occur for secured support of flaccid articles in conjunction with the holding of a cold drink. FIG. 19 shows yet another embodiment whereby a hook region 183 is shown in a generally rectangular configuration with an upper detent mating section 184 provided. The beverage container section 168 disposed thereabove thus facilitates the overall construction thereof.
Referring now to FIG. 20, there is shown yet another embodiment of the permanent hook attachment mechanism of FIG. 14. As shown in FIG. 14, the securement clasp 146 comprises upper and lower clamping elements. In the present embodiment the attachment bracket 190 is constructed with a clamping assembly 192 comprising upper and lower, generally U-shaped, clamping members 193 and 194 secured by a pair of conventional threaded fasteners 195 extending therethrough Nuts 196 are shown therebeneath for purposes of secured engagement. The actual clamping member 190 is constructed of a generally rectangular body section 198 having a pair of depending hook sections 199 and 200. The hook sections 199 and 200 are constructed in a slant configuration adapted for securely retained articles positioned therebehind. The body section 198 is demountably secured to the bracket 192 by a pair of take 201 and 202 which are insertable into apertures 203 and 204 formed in the lower bracket section 194. In this manner expansion of the body portion 198 will allow sufficient flexibility to permit the member to be secured to the bracket 192. This assembly is further illustrated in FIG. 21 where the generally rectangular body 198 is illustrated in mating engagement over upper clamping member 193 and lower clamping member 194. The tab 201 is shown inserted into aperture 204 formed in lower bracket 194. It is by the flexibility of this member that sufficient securement force is provided for the securement of articles behind the slanted hooks 199 and 200 described above.
Referring now to FIG. 22 there is shown yet a further embodiment of the present invention wherein a beverage container holder 210 is shown with a pair of beverage container sections 211 and 212. This particular assembly is for securement to the handle bars 214 of a conventions bicycle 216 (shown fragmentarily). It may be seen that the attachment of the beverage container holder 210 may be afforded by means of the method and apparatus described above. Likewise FIG. 23 shows one embodiment of such an attachment mechanism whereby the unit 210 supports the beverage container 220 (shown in phantom) in a beverage container section 222 having the lower portion thereof 224 formed in spaced relationship. A series of recesses 226 are provided in the upper rectangular section 210 for purposes of permitting flexibility and expansion for clasping the handle bar 214. Such an expansion is further illustrated in FIG. 24 whereby a series of recesses 228 are shown in a generally cylindrical handle bar engagement section 230 also adapted to a beverage container section 232. In beverage container section 232 a beverage container 234 is shown in phantom. Also shown in phantom is the expanded portion of the cylindrical body region 230 of section 236 whereby the outward flexing thereof to facilitate engagement of the handle bar section 214 is provide. A locking member 238 is likewise included for purposes of securing the engagement around a handle bar, or the like.
Referring now to FIG. 25 there is shown a perspective view of an alternative embodiment of the beverage container holder of FIG. 24. A tapered beverage container holder 250 is illustrated secured to a cylindrical handlebar 252 of a bicycle, stroller, cart or the like. An attachment region 254 of generally planar construction is provided in an upstanding configuration adjacent the beverage container section. A plurality of recesses 256 have been constructed in attachment region 254 to facilitate its engagement and "wrap aroura" securement to handlebar 252. In this view a back section 257 of attachment region 254 permits securement of the said attachment region by a locking member 258. A cut out 259 facilitates the molding of attachment region 254 adjacent the tapered walls 260 of the beverage container body portion. It may be seen that the tapered construction of walls 260 facilitate a sufficient draft angle to maximize the simplicity of molding.
Still referring to FIG. 25 the lower body portion thereof is constructed with a hook member 262 adapted for the securement of loose articles as described above. Hook member 262 is formed beneath an aperture 264 formed in the bottom of the beverage container holder. In this configuration injection molding of plastics and the like is greatly facilitated with ribs 266 provided therein for purposes of rigidity and structural reinforcement. It may be seen that the size of the aperture 264 is larger than the lateral width of the top plan of the hook 262 whereby the type of mold may be simplified. The aperture 264 provides not only improved molding techniques but also a drainage aperture for the containment area within tapered walls 260. In this embodiment it may be seen that baby bottles, cold drinks and the like can be conveniently stored during use of the present invention.
Referring now to FIG. 26, there is shown an enlarged side elevational cross-sectional view of the locking mechanism 258 taken along lines 26--26 thereof. In this view it may be seen that the back section 257 of attachment section 254 has been brought into flush engagement with the tapered walls 260 and a locking button 268 extends outwardly therefrom. Locking button 268 has an outwardly flared end which facilitates interlocking engagement with an aperture 270 formed within the back section 257. This "snap" locking is inexpensive to fabricate yet provides sufficient structural attachment integrity to permit efficient utilization of tapered beverage container assembly 250. It should be noted that other attachment devices are contemplated in accordance with the principles of the present invention.
The present invention thus teaches a plurality of article support devices in the plurality of configurations. In FIGS. 1 through 4 the article support assemblies 10 are integrally formed with the handle section 12 provide not only a region for supporting loose or flaccid articles and/or strape but also containers directly to strollers, carts and the like. In FIGS. 5 through 13 a flexibly mounting hook assemblage is shown in a myriad of configurations. Each hook is adapted for a particular application and the manner of attachment is described in detail. In FIGS. 16 through 20, both hook and beverage container, permanent attachment configurations are illustrated. These attachment configurations include the utilization of a demountable body portion to a permanent clamping section which affords great versatility as well as utility in the support of both beverage containers and loose articles relative to bicycles, strollers, carts and the like.
Referring to FIG. 27, there is illustrated a perspective view of yet another embodiment of article support assembly 506 wherein a means for affixing a tapered, cylindrical receptacle 507 exists within the invention. Tapered, cylindrical receptacle 507 is secured to article support assembly 506 in attachment region 504. The attachment region 504 consists of two generally parallel vertically oriented planar appendages 511, 512. Integral with the tip of the interior surface of each appendage exist grooves 510 and 513 which lie face to face forming a thread guiding means for article support assembly 506. Channel 514 operates as a guide for the locking means used to affix article support assembly 506 and the cylindrical receptacle 507.
The article support assembly 506 consists of two parts, the upper, tubular body portion 500, constructed with a central hollow region 509 formed therethrough, and a lower planar body surface 508. A lower lip 501 is flared outward from the tubular body portion 500 to facilitate entry of a plurality of handles into the central hollow region 509. The flexing action of the tubular body portion 500 and lower lip 501 provide the frictional gripping means whereby the article support assembly 506 attaches to a multitude of handles, bars, shafts and the like. Three hooks reside upon the lower planar surface 508 of the support assembly, one large hook 503 on the exterior surface and two smaller hooks, 502 and 505 on the interior surface. More specifically, hook 502 lies above hook 505 and both smaller hooks are aligned in opposing relationship with hook 503. Hook 502, 503 and 505 each possess a generally similar design. Hook 505 displays the general hook configuration consisting of a superior curved section 515, an inferior curved section 516, as well as an outwardly flared flange 517 angled from the superior curved edge to facilitate receipt of articles therein.
Referring next to FIG. 28, a side elevational view of article support assembly 506 with the attached tapered, cylindrical receptacle 507 may be seen. This view shows the extent of the outward flaring of opposing hooks 502 and 503. Also disclosed are the reinforcing brackets 520, 521 below the large hook 503 and the upper, opposing small hook 502, respectively. FIG. 29 further illustrates the reinforcing bracket 520 of hook 503. The bracket is integrally formed with both the lower planar surface 508 of the hook assembly 506 and the inferior curved section of the hook.
Referring next to FIG. 30, there is shown a bottom elevational view of the article support assembly and attached receptacle. A solid bottom surface 530 underlays the tapered cylindrical receptacle 507 thereby permitting the storage of various loose articles within the receptacle 507. This view clearly illustrates attachment region 504. Complementary grooves 510 and 513 on the tips of the vertical planar appendages 511, 512 create a guiding thread for the edges of the lower surface of the hook assembly. A means for locking the article support assembly 506 to the cylindrical receptacle 507 results from the slidably engagable hook-like fasteners 531 and 532; fastener 531 is integrally placed upon the apex of lower hook 505, and fastener 532 is integrally located upon the outer surface of the cylindrical receptacle 507, between the vertical planar appendages 511 and 512.
Referring next to FIG. 31, an exploded view of the article support assembly 506 and cylindrical receptacle 507 may now be seen. This view more clearly illustrates the locking system utilized by the invention. When connecting article support assembly 506 and the tapered cylindrical receptacle 507, fastener 531 of the article support assembly 506 slides over and subsequently engages fastener 532 located on the surface of the cylindrical receptacle 507. Ridge 540 of the article support assembly 506 impacts with the upper edge 541 of the vertical planar appendage 512 and prevents the article support assembly from sliding through the guide-thread once fasteners 531 and 532 connect.
In such a manner, the embodiment of the invention illustrated in FIGS. 27 through 31 teaches a article support assembly which employs an integrally formed gripping means whereby the assembly unit may be affixed to a multitude of bars, handles, shafts or the like. The support unit possesses hooks that provide a means for suspending various flaccid articles and/or straps. The support unit may be used alone or a receptacle may be attached as a means for storing various loose articles.
Having described the invention in connection with certain specific embodiments thereof, it is to be understood that further modifications may now suggest themselves to those skilled in the art and it is intended to cover such modifications as fall within the scope of the appended claims.
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A support assembly for utilization with generally horizontal handles, bars, shafts and the like for securement of articles thereto. The support assembly includes both a unit which is integrally formed with a handle and a discrete assembly for attachment to handles. The assembly is preferably of integrally molded plastic that comprises at least first and second hook portions adapted for supporting articles such as packages, clothes and purses from strollers, carts and the like. The assembly may also include a receptacle region adapted for the retention of a canned drink, baby bottle, loose articles or the like. The assembly provides a myriad of hook configurations and demountable attachment sections for the securement of loose articles such as purses, sweaters, towels or other infant items. In this manner, strollers, bicycles and the like may be rendered safer and more convenient for the user who must handle loose articles.
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BACKGROUND
[0001] All references cited in this specification, and their references, are incorporated by reference herein where appropriate for teachings of additional or alternative details, features, and/or technical background.
[0002] Disclosed is a smart jewelry system as distinguished from common jewelry systems some of which are even capable of expressing a user's emotional state albeit through manual manipulation of certain parts of the system. Among them is “Jewelry System and Method for Expressing Emotional State” described by Anita Scott in her US Patent Publication No: 2011/0209501 A1 as follows:
[0003] The jewelry system 100 shown in FIG. 1 includes a body member 110 having a front 120 and a back face 130 (shown facing the reader) oppositely disposed to the front face 120 , where various emotional states are shown. For illustrative purposes, back face 130 is shown here indicating in detail the various emotional states. When in use, back surface 130 rests on user's body (not shown) while front surface 120 rests away from the user's person; thus, front surface 120 is viewable by the general public. As such, front surface 120 can include attractive and decorative designs such as floral design. Noting however that body member 110 can also be worn such that front surface 120 rests on the user's body, while back surface 130 is away from the user's person, thus viewable by the public. The position of a bead 150 as explained further below expresses the user's current emotional state to the general public. The jewelry system further includes one or more detachable charms (not shown) reflecting one's love or grief for someone.
[0004] As Anita Scott describes in detail, the grief stages are listed in the order of occurrence below each other on surface 130 . Here, the first grief stage is shock 132 . The next grief stage is denial 134 (below shock 132 ). Denial 134 is followed by guilt 136 . Guilt 136 is followed by anger 138 , bargaining 140 , depression 142 , hope 144 , and finally survivor 146 . The emotional states shown are not exhaustive, according to Anita. Other emotional states can be displayed. Back surface 130 also comprises a means for selecting any one of the plurality of emotional states. Specifically, said means is bead of acknowledgment system 160 . Bead of acknowledgment system 160 comprises pin 154 and smart bead 150 . A smart bead has a silicone lining through an aperture (not shown). The silicone allows the smart bead to clutch onto pin 154 . In this manner, smart bead 150 is maneuverable along pin 154 and remains in place when positioned by the user. User can move smart bead 150 upwards and downwards along pin 154 according to the user's current emotional state. Pin 150 is itself incorporated at its proximal end 158 and its distal end 152 into a contiguous groove or channel 156 . In operation, the user wishing to utilize the system described begins by grasping jewelry system 100 in the palm of one hand. Here, if user is unfamiliar with the various grief stages, the user can slide smart bead 150 along pin 160 to study each of the various stages. In this manner, the system can assist users to become aware of the various grief stages and at what stage they might possibly be.
[0005] Prior art as shown in the References below, provides examples of many other types of wearable devices for the purposes for not only expressing one's emotions but also for monitoring activities at a body surface, and for that matter, changing the artistic appearance of jewelry worn on a body surface electronically. In contribution to these endeavors, a smart jewelry system disclosed herein and described further below in Detailed Description section provides a culmination of various wearable aspects into a single device capable of performing a plethora of expressive functions into a single electronic unit.
REFERENCES
[0006] U.S. Pat. No. 6,801,140 B2 discloses a system and method for wearable electronic devices and smart clothing that includes integrating an electronic circuit into one or more fastening devices on an article of clothing. One or more electronic devices integrated with or attached to the clothing are controlled or monitored based on a position of the fastening device where the position relates to how much the fastening device is fastened.
[0007] US Publication 20150087925 describes a contact sensor and system for incorporation within clothing and other wearable items to monitor activity at a body surface. The sensor includes a contact membrane having a body surface contacting area and one or more base layers of knitted fabric. The base layer(s) is thicker over an area congruent with the body surface contacting area of the contact membrane. As a result, the contact membrane is urged into the forming of a raised outer surface for projection against a body surface.
[0008] US Publication 20140366123 shows systems and techniques are disclosed for detecting whether a wearable computing device is worn by a user or not. The detection can be made based on whether the device is secured to a user or based on a sensor. A device worn by a user may be operated in a private mode such that the user wearing the device is provided information that is useful while wearing the device. For example, the user may receive message notifications, news updates, telephone call information, or the like. A wearable computing device maybe operated in a public mode while not being worn by a user. While in the public mode, the device may provide non user specific information such as a current time, media items, or the like.
[0009] US Publication 2013/0311132 yet another wearable computing device, comprising a wig that is adapted to cover at least a part of a head of a user, at least one sensor for providing input data, a processing unit that is coupled to the at least one sensor for processing said input data, and a communication interface that is coupled to the processing unit for communicating with a second computing device. The at least one sensor, the processing unit and the communication interface are arranged in the wig and at least partly covered by the wig in order to be visually hidden during use.
[0010] U.S. Pat. No. 5,798,907 describes a wearable computing device including at least one computing-device component module and flexible circuitry operably connected to the module. The module includes a top module portion, a bottom module portion, and at least one protrusion for holding the top module portion in substantially fixed relationship with the bottom module portion. The protrusion passes into and/or through the flexible circuitry. A plurality of such modules is also contemplated.
[0011] US Publication 20110209501 A1 shows a jewelry system and teaches a method for expressing a user's emotional state. The jewelry system includes a body member having various emotional states that are visible on its face. The jewelry system also includes a smart bead for selecting any one of the emotional states. The selected emotional state expresses the user's current emotional state to the general public. The jewelry system further includes one or more detachable charms namely an affected loved one charm and a cause of grief charm
[0012] US Publication US 2013/0093590 A1 discloses a jewelry item to which a location tracking module can be attached. The location tracking module could use a GPS circuit or a GPS circuit. A geo fence is defined around the jewelry item. If the jewelry is taken out of the geo fence, a message or an alarm may be sent to specified phone numbers and email IDs.
[0013] U.S. Pat. No. 6,308,891 B1 discloses a jewelry piece including a jewelry substrate having a recess formed therein, and an identification device, having detectable identification data formed thereon, disposed in the recess.
[0014] US Patent 2013/0088329 A1 shows a smart bracelet system having a first smart bracelet and second smart bracelet. The first smart bracelet comprises a first bracelet body having a first inner volume; a first attacher; a first pocket; a first powerer; a first chip; and a first illuminator. The second smart bracelet comprising; a second bracelet body having a second inner volume; a second attacher; a second pocket; a second powerer; a second chip; and a second illuminator. The first smart bracelet and the second smart bracelet are in communication with one another. The communication uses electromagnetic waves useful to enable communication between the bracelet during periods of darkness; thus tracking means are presented.
[0015] US Publication 2003/0046228 A1 shows a user-wearable electronic wireless transaction apparatus. The user-wearable electronic wireless transaction apparatus comprises a housing which houses a wireless communication device, one or more electronic circuits, a power source, a display device and a biometric data reading device. While enabled as a timepiece or performing other functions suitable to a user-wearable apparatus, the apparatus can establish wireless communication with a counterpart communication apparatus in order to conduct a transaction. The biometric data reading device can read the user's applicable biometric data and then transmit a user identity validation and the wireless communication device can transmit user authorization for the transaction.
[0016] US Publication 2014/0116085 A1 discloses a wearable communication device including a necklace having an integrated first power source, and a telecommunications device having a transceiver configured to allow wireless communication, wherein the telecommunications device is configured to couple and decouple with the necklace, and wherein the telecommunications device is configured to receive power from the first power source when coupled with the necklace.
SUMMARY
[0017] Aspects disclosed herein include
[0018] a Wireless Charging Smart-Gem Jewelry System and Associated Cloud Server comprising an electronic gemstone having a front side and an opposing backside, the backside carved to receive electronic components with capability to flash signals of pre-defined forms through the front side while the backside is sealed; a plurality of electronic devices paired with at least one or more of the electronic gemstones; an application software program loaded onto the plurality of electronic devices with instructions to recognize and ping the at least one or more of the electronic gemstones; a cloud server having a traffic control program for directing ping traffic emanating from the plurality of electronic devices; a wireless portable charger capable of wirelessly charging the electronic gemstone by mating with the electronic devices; and wherein the at least two or more of the electronic gemstones and the paired plurality of electronic devices directed by a cloud server form a social network system where groups of people can communicate to each other their feelings through flashing emoticons as well as through electro-stimulation achieved by bi-phasic neural stimulus waveforms that are generated through electronics embedded in said Smart-Gem.
[0019] a Wireless Charging Smart-Gem Jewelry System and Associated Cloud Server comprising an electronic gemstone; a mobile device capable of communicating with the electronic gemstone; a charger capable of charging the electronic gemstone; and a cloud server that manages communications between at least two or more the gemstones.
BRIEF DESCRIPTION OF DRAWINGS
[0020] FIG. 1 shows a jewelry system displaying a plurality of emotional states of a user according to prior art.
[0021] FIG. 2 shows a Smart-Gem Jewelry system connecting social network of people through a cloud based ping-blink traffic management service according to the present disclosure.
[0022] FIG. 3 - a shows the presently disclosed Smart-Gem hooked to a bracelet as jewelry.
[0023] FIG. 3 - b shows the electronic subassembly of the presently disclosed Smart-Gem.
[0024] FIGS. 4 - a through 4 - c show the presently disclosed Smart-Gem hooked or formed on a ring, necklace and expandable men's bracelet, respectively, in un-pinged or dimmed mode.
[0025] FIGS. 4 - d through 4 - f show the presently disclosed Smart-Gem hooked or formed on a ring, necklace and expandable men's bracelet, respectively, in pinged or lit-up mode.
[0026] FIGS. 5 - a through 5 - c show the presently disclosed Smart-Gem hooked or formed on a ring, necklace and expandable men's bracelet, respectively, owned by members of a particular group having the same logo in a pinged or connected mode.
[0027] FIGS. 5 - d through 5 - f show the presently disclosed Smart-Gem hooked or formed on a ring, necklace and expandable men's bracelet, respectively, owned by members of a different group having the same logo in a pinged or connected mode.
[0028] FIG. 6 shows the presently disclosed wireless charger utilizing audio port for wirelessly charging the presently disclosed Smart-Gem when coupled with a smart-phone.
[0029] FIG. 7 shows the presently disclosed wireless charger utilizing power and communication port of a mobile device for wirelessly charging the presently disclosed Smart-Gem when placed on the disclosed wireless charger.
[0030] FIG. 8 shows the presently disclosed jewelry storage box fitted with electronics to charge wirelessly the presently disclosed Smart-Gem when simply dropped inside the box for storage.
[0031] FIG. 9 shows the presently disclosed jewelry storage box having solar cells on its lid and fitted with electronics to charge wirelessly the presently disclosed Smart-Gem when simply dropped inside the box for storage.
DETAILED DESCRIPTION
[0032] In embodiments there is illustrated
[0033] a smart jewelry system comprising an electronic/smart gemstone configured to pair with a mobile device to connect with loved ones or fans through an application specific traffic management cloud system capable of pinging specifically designated devices. The smart gemstone is personalized with customized logo and symbol carvings such that the gemstone is capable of emotionally connecting with a social network of two or more related people such as family, friends, and fans of a team having a common theme carvings on the semi-transparent smart gemstone worn by the same group of people that comprise the users of the cloud system server. When a user of the application software pings the other user or users wearing or carrying the disclosed semi-transparent or translucent smart-gem equipped with electronic Light-Emitting-Diodes (LEDs) special light effect blinks a pattern on the gem of the worn with a wireless communication command from the proximately receiving mobile communication devices such as tablets or cell phones. In addition to light patterns, the electronics embedded in the smart gemstone can inject electro-neural signals into the two point contact electrodes protruding from the backside of the gemstone and making contact with the body of the wearer when pinged by a faraway pinging party. For illustrative purposes, consider soccer team Barcelona scores a goal. With a ping generated by the bodily sensations generated of a soccer club member watching the game to club of jewelry wearer's network, the bodies of those members of the same club actively wearing the disclosed Smart-Gem jewelry would be triggered with the electro-neurological signal patterns in such a way so as to feel the same sensational impulses in addition to observing special light effects on their jewelry. Still another aspect of the disclosed smart electronic jewelry system is the direct wireless charging capability through audio-port of the mobile device having an audio channel. Still another aspect is charging through any available wireless power transfer device or charging through the charge port of the device, such as for example, when the smart jewelry is kept in a safe box.
[0034] More specifically, FIG. 2 shows a plurality of components of the disclosed system 200 comprising electronically smart jewelry objects 210 ′, 210 ″, 210 ′″ . . . 210 n , worn or carried by at least two or more people 220 ′, 220 ″, 220 ′″ . . . 220 n at their respective locations 225 ′, 225 ″, 225 ′″ . . . 225 n , and an associated cloud computing 230 with server 235 . Persons 220 ′, 220 ″, 220 ′″ . . . 220 n may have social relationships such as family, friend or fans of a club, each preferably having a mobile electronic device (smart-phone, tablet, etc.) 240 ′, 240 ″, 240 ′″ . . . 240 n capable of communicating with cloud server 235 .
[0035] An aspect of the disclosed system is an application software program that is shared by each of the mobile electronic devices 240 ′, 240 ″, 240 ′″ . . . 240 n in order to be able to ping only each other through cloud server 235 in cloud 230 . In other words, individuals with an accepted social relationship can install the common application software in their mobile devices and give each other permissions to allow pinging when desired. As an example, a user person 220 ′ at location 225 ′ with a mobile device 240 ′ can create a ping through his or her user profile in the application specific traffic management cloud server 235 directed to selected profiles of say, persons 220 ″, 220 ′″ at locations 225 ″, 225 ′″ in his/her social network using the configured Smart-Gem activated jewelry 210 ″, 210 ′″ each having a logo/symbol that is a part of a family of logos/symbols carved on the device as explained in more detail later below. The application software of the receiving end user mobile devices 210 ″, 210 ′″ checks server 235 to see if there is any ping request directed to their particular Smart-Gem jewelry device or module. The connection to the specific server, such as 235 is allowed through cellular mobile access base stations 250 ′, 250 ″, 250 ′″ . . . 250 n that relay the ping requests to this particular server 235 . If the application program receives such a request, the software commands a translucent Smart-Gem (explained further below) in the smart jewelry activate the blinking pattern unique to a particular mood/message and lighting up the common theme symbol, say a star 310 shown in FIG. 2 , carved on the smart gemstone accordingly. This local wireless connection to jewelry items can utilize any wireless communication standards such as Bluetooth or WiFi.
[0036] Still another aspect of the Smart-Gem Jewelry system 200 wirelessly connects a particular social network of people 220 ′, 220 ″, 220 ′″ . . . 220 n through a particularly carved Smart-Gem 300 signaling a particular graphical and illuminated message (a star like appearance 310 for illustrative purposes here, as shown in both FIGS. 2 and 3 - a , 3 - b ) that is activated by the cloud based ping-blink traffic management software 235 ′ (shown in FIG. 2 ) loaded onto the cloud server 235 . Smart-gem 300 itself, displaying the blinking signal message can be attached to any jewelry accessory item such as schematically shown necklaces 210 ′, 210 ″, ring 210 ′″, bracelet 210 n in FIG. 2 . Smart-Gem 300 comprises appurtenances 320 such as hooks that enable attachability to a carrier 330 such as a necklace, wristband and the like. It will be understood by those skilled in the art that the Smart-Gem 300 can be installed on any suitable object that can be worn or carried by the user.
[0037] The presently disclosed Smart-Gem 300 is better seen enlarged in FIG. 3 - b . Smart-Gem 300 comprises a precious or semiprecious translucent gemstone such as a garnet (not shown) cut in any desired shape, including a circular or rectangular shape 305 as shown for illustrative purposes in FIG. 3 - b . Gemstone has a front side 305 ′ (not shown) and an opposing backside 305 carved out to receive an electronic subassembly 315 comprising a circuit board including an array of Light-Emitting-Diodes (LEDs) 317 which can be patterned into a desired graphical form, such as star 310 and bi-phasic neuro-stimulus electronics with two point contact electrodes 380 and 385 shown in FIG. 3 - b touching the wearer. LEDs 317 can flash with the desired pattern and the electrodes are driven with the desired neurological electro-stimulus signals when commanded through any one of mobile devices 220 ′, 220 ″, 220 ′″ . . . 220 n shown in FIG. 2 and paired with a wireless module 340 inside the electronic subassembly 315 . The semi-transparent precious or semiprecious gemstone 300 , including at least one or more appurtenances 320 is attached to jewelry and sealed. It will be evident to those skilled in the art that the translucent character of the gemstone 300 is such that it has the appearance of a desired jewelry while at the same time hiding the subassembly electronics 315 . That is to say, while the backside 305 is sealed (such as with silicone rubber RTV™, not shown, but showing the two point contact electrodes 380 and 385 ) front side 305 ′ (not shown) has the opacity to hide the electronic components from view, at the same time it has the transparency to display the programmed icons as an ornament of the Smart-Gem 300 .
[0038] Subassembly electronics 315 shown in FIG. 3 - b further comprises a controller 340 , wireless charging coils 325 , solar charging cells 360 and a battery charger 370 all embedded in the stone and sealed to be a water proof smart gemstone 300 except for the two wire electrodes 380 and 385 emerging from the sealant RTV, for example, ready to be in intimate contact with the wearer as shown schematically in FIG. 3 - b . When LEDs 317 are activated, light rays illuminate and expose the shared theme symbol 310 , a star in this example, carved on to the visible side of the stone. It will be obvious to those skilled in the art that shared symbol 310 can be the initials of a beloved person, symbol of a constellation for a group of star gazers, a logo of a sports club or a company, shape of a common theme object (heart, flowers etc.) depending upon the common interests of each group of people. Ping-blink traffic management software 235 ′ in cloud server 235 than directs a ping from a mobile device of a particular group as distinguished by their special symbol to the appropriate group having the same special group symbol by pinging their mobile devices 220 ′, 220 ″, 220 ′″ . . . 220 n shown in FIG. 2 .
[0039] For illustrative purposes, FIGS. 4 - a, b, c show a ring 405 , a pendant 415 on a necklace, and a men's expandable bracelet 425 , respectively, engraved with a logo 310 , which is a star for illustrative purposes here, but in an unpinged normal dimmed state, and hence barely visible in contrast with the brilliancy of the jewel that is being worn. FIGS. 4 - d, e, f , on the other hand, show the instant in which the logos 310 are lit up (in bold) the instant pinged from one of the users.
[0040] FIGS. 5 - a, b, c and FIGS. 5 - d, e, f , on the other hand, show the similar accessories, namely, a ring 505 , a pendant 515 on a necklace, and a men's expandable bracelet 525 , respectively, in pinged (that is, lit-up) state; however, FIGS. 5 - a, b, c show pinging/messaging among members of one group different from the pinging/messaging taking place among the members of a different group of FIGS. 5 - d, e, f , each group having a different secondary logos 510 (concentric circles) and 510 ′ (a circle inside a polygon) superimposed on the master logo 310 (star) for all, to distinguish between the two groups within the larger group encompassing the two groups, in this illustrative case. It will be understood for those skilled in the art that there can be an infinite n number of such groups having n number of superimposed secondary logos/icons which are distinctly recognizable as secondary groups within a larger universe of all accordingly by the traffic management software 235 ′ of cloud server 235 of FIG. 2 .
[0041] In operation, a ping from a member of a group, say a sports club member is immediately directed to other members of the same group. In a further aspect of the presently disclosed Smart-Gem Jewelry System & Associated Cloud Server, traffic management program 235 ′ is capable of pinging an emotional message, for example, across different groups by lighting up an appropriate symbol, such as happiness for a newly born baby, or sympathy for the loss of a loved one, and so on as those skilled in the art can contemplate other expressive graphics for various occasions. This feature is accomplished by superimposing still another special symbol (emoticon) for the occasion over the existing master symbol 310 commonly shared by all members of all the groups as it will be evident that the array of LEDs 317 on the electronic subassembly 315 is capable of generating any combination of graphics with various intensities and configurations. Emoticons reside in cloud server 235 and can be activated by a separate application program (not shown) provided in the mobile devices of all members of the groups having access to the cloud server 235 .
[0042] Another aspect of the presently disclosed battery operated Smart-Gem 300 is the wireless charging though component 370 that is incorporated into the electronic subassembly 315 shown in FIG. 3 . Wireless charging is accomplished through wireless coupling of component 370 with the associated mobile device carried by the user of Smart-Gem 300 , say user 220 ′ in position 225 ′ in FIG. 2 . The presently disclosed wireless charging of Smart-Gem 300 utilizes two different modes; namely, charging through universal audio port of the mobile device of the user, or thorough power and communication port of the mobile device of the user.
[0043] FIG. 6 discloses a first portable charging device through universal audio jack port 245 ′ of mobile device 240 ′ of user 220 ′ of FIG. 2 . A wireless charging device 600 comprises a multi-layer circuit board 610 having planar transmission coil windings 620 (dashed lines) and 630 (solid lines), and a headphone emulation load R 605 . When activated through a charging application program in mobile device 240 ′, audio jack port 245 ′ provides differential full swing audio-band AC signal to the left and right ( 640 , 645 ) connectors on port and creates a magnetic field to be coupled to the receiver coil 350 and electronics 315 embedded in the Smart-Gem 300 of FIG. 3 - b when placed on charging device 600 . The full-strength artificial audio signal that is fed into the headphone audio drivers of the phone, tablet or any other type of mobile electronic device with headphone jack port, say a full-swing 10 KHz sine tone swinging in positive signal polarity at the right channel of the stereo and opposite polarity negative signal at the left channel of the stereo creates large current into an headphone emulation load formed by the series combination of R 605 and the multi-layer charging coil 620 and 630 of FIG. 6 . In this manner, largest amount of current possible is drawn from the driver combining the drive strengths from both the left and right stereo channels by emulating a real headphone load but in reality serving another purpose; namely transferring the power to the smart-gem. Thus, with the presently disclosed left-channel and right-channel opposite polarity drive scheme, since the applied signal is arranged to be a differential opposite signals, ground port of the audio jack is not even needed. Both channels use the same ground reference on the phone board (not shown). It will be obvious to those in the art that the two-layer printed circuit board (PCB) 610 can include many more layers of windings and ferrite material coating to increase the power transfer efficiency to the power receiving Smart-Gem 300 . Efficient external coils with many more windings rather than the embedded planer PCB coils may also be employed to maximize the charging efficiency and speed.
[0044] FIG. 7 discloses a second portable charging device 700 that connects directly to the power and communication port 255 ′ of mobile device 240 ′ through a matching male connector 750 . The charging electronic circuits 760 generate the drive waveforms by additional power circuitry that taps into battery 765 of the device directly and generates the necessary AC drive current into the multi-layer planar PCB coil 770 to wirelessly charge the disclosed Smart-Gem 300 .
[0045] A jewelry storage box 800 shown in FIG. 8 provides further convenience in keeping the presently disclosed Wireless Charging Smart-Gem 300 charged automatically when it is placed or dropped from an opening having a lid 890 into the box for storage as shown in FIG. 9 . The electronically configured jewelry storage box 800 shown schematically in FIG. 8 comprises a multi-layered printed circuit board (PCB) 810 secured on four pedestals 805 installed at four corners of the rectangular box. It will be evident to those skilled in the art that the box can be made of any desired material such as wood, metal, glass with lining, etc., and the shape of the box can be circular, octagonal or any other shape, and the raised floor secured onto pedestals 805 can be accomplished in many other different ways which will not be discussed here further in order not to unnecessarily obscure the present disclosure of the box. Furthermore, the electronic circuits are printed and components mounted on the bottom side 810 ′ of the Printed Circuit Board, as depicted under a shaded surface 810 . It will be noted that top surface 810 does not include any electronic components to allow smooth surface where the wirelessly chargeable Smart-Gem 300 jewelry can be placed or simply dropped onto ( FIG. 9 ). If desired, the wireless power transmit coil winding traces 820 and 830 shown to be two layers can be printed on the top surface 800 since they are very thin so as to not incur any rough surface, although they are shown here towards the bottom surface 810 for illustrative purposes. The charging electronics 840 , universal micro-USB (not shown) or any other universal female power connector 850 , turn-ON and LED switches 860 , 870 , respectively, are placed on the back surface 810 of the PCB 800 where socket openings 880 are provided for a universal wall charger (not shown) to have access to a wall outlet 887 . The electronically configured jewelry box 800 as presently disclosed in FIG. 8 can be disconnected readily by pulling the electrical cord 885 from the wall outlet 887 , or disconnecting cord 885 from the socket openings 880 on the side of the jewelry box. It will be known to those skilled in the art that if desired, an additional pushbutton switch can be used to activate or deactivate the box charger.
[0046] A further aspect of the jewelry box 900 is shown in FIG. 9 wherein lid 890 of the box is fitted with a solar panel 895 and associated energy lines 897 that connect the solar panel 895 to the electronic subassembly 810 of jewelry box 800 of FIG. 8 . The user can always unplug box 900 fitted now with a solar panel lid from the wall 887 and carry the jewel box anywhere to expose its solar panel 895 to sunlight so that the battery (not shown) in box 800 / 900 can recharge for wirelessly recharging a Smart-Gem 300 with its associated jewelry, such as men's expandable bracelet 425 is dropped into the box shown in FIG. 9 anytime and anywhere.
[0047] Though these numerous details of the disclosed device have been set forth here, such as electronic components installed or embedded into a gemstone and associated wireless chargers including energy captured from solar cells of the presently disclosed Wireless Charging Smart-Gem Jewelry System & Associated Cloud Server, it is to be understood that these details of the present disclosure have been described by way of illustration and not limitation. It will be obvious to those skilled in the art that there are other specific details which are inherent in the Smart-Gem, such as, for example, the device can be made to operate on a private mode where only confidential information may be displayed by the clicking of a special icon or can be put on a public mode by clicking the same or another icon for, say, displaying the time of the day, weather or other public information that is readily available elsewhere. The device can also be programmed to go to public mode after a set time when not in use. Furthermore, a code can also be entered remotely to move from one mode to another for security purposes.
[0048] While the disclosed invention has been particularly shown and described with reference to a particular embodiment(s) or aspect(s), it will be appreciated that variations of the above-disclosed embodiments(s) and other features and function, or alternatives thereof, may be desirably combined into many other different systems or applications Also that various presently unforeseen and unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
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Wireless Charging Smart-Gem Jewelry System and Associated Cloud Server comprising a wearable electronic gemstone capable of sensing the emotional state and bodily vital signs of the user and being wirelessly charged and a mobile device capable of communicating with the electronic gemstone such that a cloud server manages communications between members of a social network wearing the electronically smart gemstone. The disclosed Jewelry System provides a custom gemstone with symbol-carved light effects, wireless charging of the stone electronics through universal audio jack of any mobile device, and electrical stimulation of the user along with visual triggers as a specific mode of social interaction.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This Application is a continuation-in-part of my copending Application, Ser. No. 862,020, filed Dec. 19, 1977, now U.S. Pat. No. 4,157,438, which is a continuation-in-part of my copending Application, Ser. No. 757,239, filed Jan. 6, 1977, now U.S. Pat. No. 4,069,391, which is a division of Application Ser. No. 622,525, filed Oct. 15, 1975, now U.S. Pat. No. 4,020,259.
BACKGROUND OF THE INVENTION
This invention relates in general to the process for the product of allyl halide amine compounds and poly(allyl halide amine) copolymer and their reaction products by using an oxidized silicon compound as the catalyst to polymerize the allyl halide with amine compounds.
Various silicon acids, silica, silicates containing silicon acids and silicates that will react with the halides in the allyl halides to produce silicon acids may be used as the catalyst. Various silicon acids such as silicoformic acid, polysilicoformic acid, hydrated silica and natural silicates containing free silicic acid radicals may be used as the catalyst. Various alkali silicates that will react with the halide in allyl halide such as alkali metal silicates, and alkaline earth metal silicates including sodium silicate, potassium silicate, lithium silicate, calcium silicate, cadminum silicate, barium silicate, zinc silicate, barium silicate, magnesium silicate, aluminum silicate, etc. may be used as the catalyst.
Silica may be heated in a dilute aqueous alkali metal hydroxide such as sodium hydroxide and potassium hydroxide, in the ratio of about 1 to 1 mols, until the water evaporates thereby producing a mono alkali metal silicate which may be used as the catalyst in this invention. Hydrated silica is the preferred catalyst and is preferred to be in a fine granular form. The silicoformic acid may be produced by the methods outlined in U.S. Pat. No. 3,674,430. Hydrated silica may be produced by any of the commonly known methods.
Some of the natural occuring silicates that may be used in this invention are clay, kaolin, silica, talc, asbestos, natrolite, garnet, mica, feldspar, beryl etc. and mixture thereof.
The natural occuring silicates may be treated with a dilute mineral acid to produce more active silicic acid radicals present in the silicates.
Allyl halides may be produced by the addition of a halide to propylene. Methallyl halides may be produced by the addition of a halide to isobutylene. Other compounds with the combination ##STR1## which is knows as the allylic syste, may be used in this invention. Allyl chloride is the preferred allyl halide.
Various mono-olefinic allyl type mono-halide with the essential grouping of atoms which may be represented as ##STR2## wherein R is a hydrogen or a C 1 to C 4 alkyl group wherein X represents a halogin atom. Furthermore, these compounds contain only one olefinic group of which one of the unsaturated carbon atoms contains at least one hydrogen atom per molecule.
Representive examples of mono-olefinic allyl type mono-halides are such compounds as allyl chloride, allyl bromide, crotyl chloride, crotyl iodide, beta-methylallyl chloride, betamethylallyl bromide, methyl vinyl carbinyl fluoride, alphadimethyl-allyl chloride, beta-cyclohexylallyl chloride, cinnamyl chloride, beta-ethyl-crotyl chloride, beta-phenylally bromide, alpha-dicyclohexylally chloride, beta-propylallyl iodide, betaphenyl-allyl chloride, beta-cyclohexylallyl fluoride, 2-chloromethyl butene-1, 2-chloromethyl pentene-1, 2-chloromethyl hexene-1 and mixtures thereof.
Various organic amine compounds may be used in this instant invention such as alkylenepolyamines, alkylenimines, arylenediamines, alkyleneamines, aryleneamines, condensation products of an epihalonydrin and a poly(alkylene polyamine), ammonia, condensation products of epichlorohydrin and ammonia, hydrazine, alkanolamines, aminoethyl alkanolamine and mixtures thereof.
The alkylenepolyamines which may be used in this invention are well known compounds corresponding to the formula H 2 N(CCH 2 ) y NH) x -H in which x is one or more any y is an integer having a value of 4 to 10. Typical amines of this class are the alkylenediamines such as ethylenediamine, 1,6-diamino-3-methyl-n-hexane, 1,3-propylenediamine 1,4-diamino-n-butane; 1,6-diamine-n-hexane, 1,10-diamino-n-decane and polyalkylenepolyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine and the corresponding polypropylenepolyamines and polybutylenepolyamines. Arylenediamines such as p-phenylenediamine may be used. Arylenedipolyamines may be used. Polyamide polymers with free amine radicals may be used in this instant process.
Various aliphatic and aromatic mono-amines such as methylamine, propylamine, isopropylamine, butylamine, amylamine, hexylamine, aniline, toluidine amine, xylidine amine, naphthylamine, benzylamine, vinyl amines and mixtures thereof may be used in this process, or they may be mixed with the polyamines and used in this process.
Various organic compounds containing an amine radical may be used in this process such as aminocaproic acid, aminobenzoic acid, vinyl amines, fatty acid amides, hydroxy amines, and mixtures thereof.
The polyamines may first be reacted with dicarboxyl acids, dicarboxyl anhydrides, epoxy compound and carbon disulfide to produce polyamine compounds with unreacted amine groups that may be used in this invention.
The organic polyamine compounds may be reacted chemically with silica, hydrated silica, and silicoformic acid to produce an organic polyamine silicate compound then may be reacted chemically with the allyl halide compound to produce a poly(mono-olefinic allyl type mono-halide amine silicate) copolymer.
Various polyamide resins containing 2 or more active amine radicals per molecule may be used in this invention. The polyamide resins may be produced by any of the commonly known methods.
Polyfunctional polyamines will also act as a cross-linking agent with poly(allyl halide) polymers and in the production of poly (allyl halide amine) polymers. Bifunctional amines and polyfunctional amines may be mixed then reacted with the allyl halides to produce thermosetting resins. Various bifunctional amines may be used such as methylamine, ethylamine, ethanolamine, propylamine, N,N'-dimethylenediamine, piperazine, aniline, etc. Various polyfunctional polyamines may be used such as ethylenediamine, N-methylenediamine, polyalkylenepolyamines, polypropylenepolyamines, p-phenylenediamine; p,p'-bisaniline; 1,3-diamino-2-propanol, 1 mol of ammonia reacted with 3 mols of epichlorohydrin, etc. The reaction is enhanced by the presence of an alkali catalyst.
The allyl halide amine compound and polymer may be further reacted chemically with cross linking agents such as aldehydes, ketones, organic dicarboxyl acids, organic dicarboxyl anhydrides, aliphatic dihalide compounds, aliphatic trichlorides, sulfur, dihydroxy phenols, cyanides, lignin, epoxy compounds and resins, epihalohydrins, halohydrins, isocyanates, furan compound, thiocyanates, polyester resins with 2 or more carboxyl acid radicals per molecule, acrylate polymers, polysulfides, sodium polysulfides, silicon acids, silicon tetrachloride, carbon disulfide and mixtures thereof to produce resins that can be used as adhesives, coating agents, impregnants, molding resins and powders, thermosetting resins, thermoplastic resins, etc.
SUMMARY OF THE INVENTION
I have discovered that an amine and a mono-olefinic allyl type mono-halide compound will polymerize in the presence of a fine granular silica, silicon acid, alkali metal silicate, alkaline earth metal silicate and natural occuring silicates containing silicic acid radicals to produce a poly(amine allyl chloride) polymer.
The chemical reactions of this invention may take place under any suitable physical conditions. while many of the reactions will take place acceptably at ambient temperature and pressure, in some cases, better results may be obtained at somewhat elevated temperature and pressure. Preferably the reaction takes place at a temperature between 0° and 100° in a closed system. The reaction time to produce poly(amine allyl halide) polymers in quite varied. At ambient temperature about 70% to 90% of the reactants are polymerized is about 1 to 12 hours. The poly(amine allyl chloride) copolymer will form emulsions in water and most are water soluble.
The mono-olefinic allyl type mono-halide compound will react chemically with an amine to produce a mono-olifinic allyl type mono-halide amine compound. This compound will react chemically with aldehydes, ketone, organic dicarboxyl acids, organic dicarboxyl anhydrides, organic dihalide compounds, epoxy compounds and resins, epihahydrin, halohydrins isocyanates, furan compounds, thiocyanates, polysulfides, carbon disulfides, sodium sulfides, silicon acids, silicon tetrachloride, polyester resins with 2 or more active carboxyl acid radicals per molecule, aliphatic trihalides, organic cyanides, phenoplasts, aminoplasts, and mixtures thereof.
Various polyfunctional halohydrins may be used as a cross-linking agent such as alpha-dichlorohydrin, dibromhydrin, di-iodohydrin, epichlorohydrin, epibromhydrin, and mixtures thereof. They may be reacted chemically with the mono-olefinic allyl type allyl mono-halide amine compound and poly(mono-olefinic allyl type mono-halide amine) copolymer. When an acid catalyst is used, a thermosetting copolymer is produced, and when an alkali catalyst is used, a thermosetting copolymer is produced. In certain cases where a large amount of the allyl halide is used, it may be thermoplastic.
Various alkali catalysts and reactants may be used in this invention such as sodium hydroxide, potassium hydroxide, sodium carbonate sodium oxide, potassium oxide, calcium hydroxide, sodium polysulfide, potassium silicate and mixtures thereof.
Various acid catalysts may be used in this invention such as hydrochloric acid, sulfuric acid, sodium hydrogen sulfate, potassium hydrogen sulfate, acetic acid, phospheric acid, benzoic acid, acetic acid and mixtures thereof.
The preferred method to produce mono-olefinic allyl type mono-halide reaction products is to mix an organic amine compound or polymer containing active amine radicals with a mono-olefinic allyl type mono-halide compound, in the ratio of 0.5 to 2 mols of the allyl halide to 1 mol of the amine while agitating at a temperature between ambient temperature and the boiling temperature of the mixture, and at ambient pressure for 10 to 60 minutes, thereby producing a mono-olefinic allyl type mono-halide amine reaction product.
The mono-olefinic allyl type mono-halide amine may be reacted chemically with a cross-linking agent to produce a copolymer. The copolymer, when produced with an acid catalyst, is a thermosetting copolymer, and when an alkali catalyst is used, a thermosetting polymer is produced, as a general rule. The preferred crosslinking agent is an epihalohydrin, epichlorohydrin.
The mono-olefinic allyl type mono-halide amine reaction product may be further polymerized by mixing it with an oxidized silicon catalyst then by agitating for 10 to 60 minutes, thereby producing a poly(mono-olefinic allyl type mono-halide amine) copolymer.
The preferred method to produce poly(mono-olefinic allyl type mono-halide amine) copolymers is to mix 1 mol of an amine, 0.5 to 6 mols of a mono-olefinic allyl type mono-halide with an oxidated silicon compound in the ratio of about 0.25 to 1 part by weight of the oxidated silicon compound per 1 part by weight of the allyl halide and amine compounds. The mixture is then agitated for 10 to 60 minutes thereby producing poly(mono-olefinic allyl type mono-halide amine) copolymer. The copolymers in general are water soluble and may be filtered from the oxidated silicon catalyst.
An alternate method to produce poly(mono-olefinic allyl type mono-halide amine) copolymers is to mix 2 to 3 parts by weight of allyl halide with 1 part by weight of a fine granular oxidated silicon compound then to agitate for 10 to 60 minutes thereby producing a poly(mono-olefinic allyl type mono-halide) polymer. An amine is then mixed with the polymer in the ratio of 1 mol of the amine per 0.5 to 6 mols of the allyl halide while agitating for 10 to 60 minutes at ambient pressure and from ambient temperature to a temperature just below the boiling temperature of the mixture thereby producing poly(mono-olefinic allyl type mono-halide amine) co-polymer.
The poly(mono-olefinic allyl type mono-halide amine) copolymer may be reacted chemically with cross-linking agents to produce thermoplastic and thermosetting resins. When an acid catalyst is used with the cross-linking agent, usually a thermosetting resinous product is produced. When an alkali catalyst is used with the cross-linking agent, usually a thermosetting resin is produced. Epichlorohydrin is the preferred cross-linking agent.
The preferred method to produce a poly(allyl halide amine silicate) copolymer is to mix an alkali catalyst such as alkali metal sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, and sodium silicate in about the amount of 1 mol per 2 to 6 mols of the allyl halide. The alkali catalyst is added in the first step of the preferred and alternate method of producing poly(mono-olefinic allyl type monohalide amine) copolymer, as outlined in this invention, thereby producing a poly(mono-olefinic allyl type mono-halide amine silicate) copolymer.
The poly(allyl halide amine silicate) polymer may be reacted chemically with a cross-linking agent to produce thermoplastic and thermosetting resins. The preferred cross-linking agent is an epichlorohydrin.
The mixture of poly(mono-olefinic allyl type monohalide amine) and oxidated silicon compounds may be reacted with a cross-linking agent such as epihalohydrin, halohydrins, epoxy compound or an epoxy resin with free epoxy groups, in the ratio of 1 mol of the cross-linkage agent per mol of the oxidated silicon compound, by slowly adding the cross-linking agent while agitating at ambient temperature to about 70° C., thereby producing thermoplastic and thermosetting poly(allyl amine silicate) resins. When an acid catalyst is used, a thermosetting resin is usually produced, and when an alkali catalyst is used a thermosetting resin is usually produced. The resin is cured by heating to 80° to 120° C. for a few minutes, 10 to 60 minutes.
The polyamine compounds may be reacted chemically with the oxidized silicon compounds then reacted chemically with the mono-olefinic allyl mono-halide compounds to produce poly(allyl halide amine silicate) copolymer. The polyamine compounds may be reacted chemically with oxidated silicon compounds such as silica, hydrated silica and silicoformic acid by mixing the polyamine compound with the oxidated silicon in the ratio of 2 mols of the amine to 1 to 4 mols of the oxidated silicon; then mixing in an alkali catalyst, selected from the group consisting of sodium carbonate, sodium hydroxide, and potassium hydroxide in the amount of 1% to 10% by weight, percentage based on the weight of the oxidated silicate; then heating the mixture to just below the boiling temperature of the mixture while agitating at ambient pressure for 20 to 90 minutes, thereby producing an amine silicate. The method is further outlined in U.S. Patent Application No. 842,557 filed Oct. 11, 1977 by David H. Blount.
The various allyl halide-amine-halohydrin water soluble reaction product and allyl halide-amine-silicate-halohydrin water soluble reaction products can be utilized as an adhesive, impregnant and water resistant coating agent in the production of paper products, by applying the water soluble reaction product to the callulose or paper then heating to 80° to 120° C. until the water evaporates, thereby producing a thermosetting resin on the paper product. The various allyl halide-amine-halohydrin liquid resinous products and halide-amine-halohydrin silicate liquid resinous products may be poured into molds of useful objects such as gears, knobs, art objects, washers, toys, etc. then heated to 80° to 120° C., thereby producing a hard, tough, resinous product.
The primary object of the present invention is to produce allyl halide amine compounds and reaction products. Another object is to produce poly(allyl halide-amine) resinous products. Another objects is to produce poly(allyl halide amine polyfunctional halohydrin) resinous products. Still another object is to produce poly(allyl halide amine polyfunctional halohydrin silicate) resinous producte. A further object is to produce water soluble thermosetting resinous products.
DESCRIPTION OF PREFERRED EMBODIMENTS
The following examples describe in detail certain preferred embodiments of the process of my invention. These preferred processes, of course, may be varied as described above with similar results. Parts and percentages are by weight unless otherwide indicated.
EXAMPLE 1
About 1 part by weight of methylamine, 2 parts by weight of allyl chloride and 1 part by weight of fine granular hydrated silica are mixed at ambient temperature and pressure. The chemical reaction is complete in 1 to 12 hours thereby producing poly (methylamine allyl chloride) copolymer.
(a) 10 parts by weight of water are added to the mixture of poly(methylamine allyl chloride) copolymer and hydrated silica, then filtered to remove the hydrated silica; then 1.5 parts by weight of epichlorohydrin is gradually added while agitating and keeping the temperature below 70° C. for 10 to 60 minutes thereby producing a liquid poly(methylamine allyl chloride epichlorohydrin) resinous product. It is then heated to 80° to 100° C. for 10 to 60 minutes thereby producing a solid resinous product.
EXAMPLE 2
About 2 parts by weight of ethylenediamine and 2 parts by weight of allyl chloride are mixed then agitated for 10 to 30 minutes thereby producing allyl chloride ethylenediamine reaction product, (a mono-olefinic allyl type mono-halide polyamine reaction product). The allyl chloride ethylenediamine reaction product is soluble in water.
EXAMPLE 3
2 parts by weight of methyl allyl chloride, 2 parts by weight of 1,6-hexamethylenediamine are mixed in 6 parts by weight of water, containing hydrochloric acid which gives a pH of 4 to 5. Epichlorohydrin is slowly added to the mixture while agitating and keeping the temperature between ambient temperature and 70° C. until 3 parts by weight are added, thereby producing a water soluble polymer. The polymer is then heated to 80° to 120° C. for 10 to 30 minutes, thereby producing a thermosetting light yellow poly (mono-olefinic allyl type mono-halide amine polyfunctional halohydrin) reaction product.
EXAMPLE 4
2 parts by weight of methyl allyl chloride, 2 parts by weight of 1,6-hexamethylenediamine and 2 parts by weight of water are mixed then heated to just below the boiling temperature of methyl allyl chloride thereby producing a mono-olefinic allyl type mono-halide amine reaction product.
(a) 2 parts by weight of epichlorohydrin are slowly added to the above reaction product while agitating and keeping the temperature below 70° C. thereby producing a water soluble reaction product. The water soluble reaction product is then heated to 80° to 120° C. until the water evaporates, 10 to 60 minutes, thereby producing a thermosetting light yellow poly(mono-olefinic allyl type mono-halide amine polyfunctional halohydrin) reaction product.
EXAMPLE 5
2 parts by weight of 1,6-hexamethylenediamine are mixed in 6 parts by weight of water containing 2 parts by weight of sodium hydroxide flakes. 3 parts by weight of allyl chloride are added to the mixture while agitating for 10 to 60 minutes and keeping the temperature below the boiling temperature of allyl chloride thereby producing allyl chloride 1,6-hexamethylenediamine reaction product.
(a) Slowly add 3 parts by weight of epichlorohydrin to the above mixture while agitating and keeping the temperature below 70° C. thereby producing a water soluble allyl chloride 1,6-hexamethylenediamine epichlorohydrin reaction product.
(b) The above reaction product is then heated to 80° to 120° C. while agitating for a few minutes until foaming begins; the mixture expands 8 to 10 times its original volume thereby producing a poly(mono-olefinic allyl type monochloride amine polyfunctional halohydrin) cellular solid reaction product.
EXAMPLE 6
1 part by weight of aminobenzoic acid, 2 parts by weight of ethylenediamine and 3 parts by weight of allyl chloride are mixed then agitated for 10 to 60 minutes thereby producing a mono-olefinic halide amine reaction product.
(a) About 3 parts by weight of epichlorohydrin are slowly added to the above reaction product while agitating and keeping the reaction temperature below 70° C. for 10 to 60 minutes thereby producing a poly(mono-olefinic allyl type mono-halide amine polyfunctional halohydrin) reaction product.
(b) The above reaction product is heated to 80° to 120° C. while agitating thereby producing a thermoplastic solid reaction product.
EXAMPLE 7
1 part by weight of fine granular hydrated silica and 3 parts by weight of allyl chloride are mixed. The mixture sets for 1 to 12 hours thereby producing poly(allyl chloride) polymer. 1 part by weight of diethylenetriamine is mixed with the above poly(allyl chloride) polymer and agitated for 10 to 60 minutes thereby producing a poly(mono-olefinic allyl type mono-halide amine) reaction product.
(a) The said reaction product is filtered to remove the hydrated silica, then 2 parts by weight of epichlorohydrin are slowly added to 4 parts by weight of the above reaction product while agitating and keeping the temperature below 70° C., thereby producing a liquid poly(allyl chloride diethylenetriamine epichlorohydrin) reaction product. The liquid reaction product is then heated to 80° to 120° C. while agitating for a few minutes until the mixture begins to expand. It expands 3 to 5 times its original volume thereby producing a thermosetting poly(allyl chloride diethylenetriamine epichlorohydrin) cellular solid reaction product.
(b) 10 parts by weight of water are added to the above mixture of poly(mono-olefinic allyl type mono-halide amine) reaction product and hydrated silica then filtered to remove the hydrated silica; 0.5 parts by weight of potassium hydroxide pellets are mixed in with the aqueous reaction product, then 2 parts by weight of epichlorohydrin are slowly added while agitating and keeping the temperature below 70° C. for 10 to 60 minutes, thereby producing an aqueous solution of poly(allyl chloride diethylenetriamine epichlorohydrin) reaction product. The reaction product is then heated to 80° to 120° C. while agitating for 10 to 60 minutes until the water evaporates thereby producing a thermosetting solid resinous product.
(a) About 2.5 parts by weight of epichlorohydrin are slowly added to 5 parts by weight of the above poly(mono-olefinic allyl type mono-halide amine) reaction product and hydrated silica mixture while agitating and keeping the temperature below 70° C. for 10 to 60 minutes at ambient pressure. The mixture is then heated to 80° to 120° C. while agitating for a few minutes until the mixture begins to expand. The mixture expands 6 to 10 times its original volume thereby producing a solid cellular resinous product, poly(mono-olefinic allyl type halide mono-halide amine silicate).
EXAMPLE 8
2 parts by weight of methyl allyl chloride, 2 parts by weight dipropylenetriamine, 3 parts by weight of a fine granular silica and 1 part by weight of epichlorohydrin are mixed then agitated to keep the temperature below the boiling temperature of the reactants. Then 2 parts by weight of epichlorohydrin are slowly mixed while agitating and keeping the temperature below 70° C. for 10 to 60 minutes. The mixture is then heated to 80° to 120° C. while agitating until the mixture begins to expand, thereby producing a solid cellular, poly(mono-olefinic allyl mono-halide amine polyfunctional halohydrin silicate) reaction product.
EXAMPLE 9
A poly(mono-olefinic allyl halide amine polyfunctional halohydrin silicate) reaction product is produced by the following steps:
(a) mixing 1 part hydrated silica containing 5% sodium hydrogen sulfate with 2 parts by weight of allyl chloride: let it set for 1 to 12 hours thereby producing poly (allyl chloride) polymer;
(b) mixing in 1 part by weight of ethylenediamine and agitating for 10 to 60 minutes at ambient temperature and pressure;
(c) adding 10 parts by weight of water containing 0.5 part by weight of sodium carbonate;
(d) adding slowly 3 parts by weight of epichlorohydrin while agitating at ambient to 70° C. for 10 to 60 minutes, thereby producing a water soluble thermosetting resinous product;
(e) heating the water soluble resinous product to 80° to 120° C. for 10 to 60 minutes, thereby producing a tan, rubbery solid reaction product.
EXAMPLE 10
2 parts by weight of allyl chloride, 2 parts by weight of fine granular clay and 2 parts by weight of an amine-terminated polymerized oil resin are mixed; then 3 parts by weight of epichlorohydrin are slowly added while agitating and keeping the temperature below 70° C. for 10 to 60 minutes. The mixture is then heated to 80° to 120° C. while agitating until the mixture begins to expand. It expands 6 to 10 times its original volume thereby producing a clear colored, cellular solid poly(mono-olefinic allyl type monohalide amine polyfunctional halohydrin silicate) reaction product.
EXAMPLE 11
1 part by weight of fine granular hydrated silica containing 10% sodium carbonate and 2 parts by weight of diethylenetriamine are mixed then heated to just below the boiling temperature of diethylenetriamine while agitating for 20 to 60 minutes, thereby producing diethylenetriamine silicate. 2 parts by weight of methyl allyl chloride and 1 part by weight of allyl bromide are mixed with the diethylenetriamine silicate then agitated for 10 to 30 minutes, thereby producing a mono-olefinic allyl type mono-chloride amine silicate reaction product. About 3 parts by weight of epichlorohydrin are slowly added to the reaction product while agitating and keeping the temperature below 70° C. for 10 to 60 minutes. The mixture is then heated to 80° to 120° C. for 10 to 60 minutes thereby producing a solid poly(mono-olefinic allyl type mono-chloride amine polyfunctional halohydrin silicate) reaction product.
EXAMPLE 12
About 2 parts by weight of fine granular silica, 2 parts by weight of ethylenediamine and 1 part by weight of sodium hydroxide flakes are mixed then heated to just below the boiling temperature of ethylenediamine for 20 to 60 minutes at ambient pressure, thereby producing an aminosilicate compound. 3 parts by weight of allyl chloride are added to the aminosilicate compound while agitating for 10 to 60 minutes; then 3 parts by weight of epichlorohydrin are slowly added while agitating and keeping the temperature below 70° C. for 10 to 60 minutes. The mixture is then heated to 80° to 120° C. for 10 to 60 minutes thereby producing a cream colored, cellular sodid poly(mono-olefinic allyl type mono-halide aminosilicate polyfunctional halohydrin) resinous product.
EXAMPLE 13
0.5 part by weight of fine granular sodium silicate, 0.5 part by weight of silicoformic acid. 3 parts by weight of allyl chloride and 6 parts by weight of water and 1 part by weight of propylamine and 1 part by weight of triethylenetetramine are added while agitating. Then 2 parts by weight of alpha-dichlorohydrin and 1 part by weight of allyl chloride are slowly added to the mixture while agitating and keeping the temperature below 70° C. for 10 to 60 minutes. The mixture is then heated to 80° to 120° C. for 10 to 60 minutes thereby producing a solid poly(mono-olefinic allyl mono-halide amine polyfunctional halohydrin silicate) resinous product.
EXAMPLE 14
About 6 mols of allyl halide, 3 mols of fine granular hydrated silica, 1 mol of diethylenetriamine and 200% by weight of water, containing sulfuric acid in an amount to give a pH of 5, percentage based on the weight of above reactants, are mixed then agitated for 10 to 60 minutes; then 1 mol of epichlorohydrin is slowly added while agitating and keeping the temperature below 70° C. for 10 to 60 minutes. The water soluble thermosetting reaction product is then heated to 80° to 120° C. for 10 to 60 minutes thereby producing a solid poly(mono-olefinic allyl type mono-halide amine polyfunctional halogen) resinous product.
EXAMPLE 15
One mol of diethylenetriamine, 0.5 mol of allyl chloride and 20% by weight of water, containing hydrochloric acid giving a pH of 5, are mixed; then 1 mol of epichlorohydrin is slowly added while agitating at a temperature between ambient and 70° C. for 10 to 60 minutes, thereby producing a water soluble thermosetting poly(allyl halide diethylenetriamine epichlorohydrin) reaction product. The reaction product is then heated to 80° to 120° C. for 10 to 60 minutes thereby producing a solid reaction product.
EXAMPLE 16
One mol of allyl chloride, one mol of tetraethylenepentamine and 300% by weight of water, percentage based on the weight of the reactant, are mixed; then dichlorohydrin (Cl CH 2 .CH(OH).CH 2 Cl) in the amount of 1 mol is slowly added while agitating and keeping the temperature between ambient and 70° C. for 10 to 60 minutes, thereby producing a water soluble resinous product. A concentrated aqueous solution, containing about 1 mol of sodium hydroxide, is slowly added while agitating and keeping the temperature below 70° C. for 60 minutes. This water soluble resinous product may be used in the production of wet strength paper by adding the resinous product to the paper pulp in water in the amount of about 3%, based on weight of the pulp. The paper sheets are then cured by heating at 80° to 120° C. for 10 to 60 minutes.
EXAMPLE 17
One mol of sodium silicate pentahydrate, one mol of methyl allyl chloride, one mol of tetraethylenepentamine and 300% by weight of water, percentage based on weight of the reactants, are mixed; 1.5 mols of dihalohydrin are slowly added while agitating and keeping the temperature below 70° C. for 10 to 60 minutes thereby producing a water soluble resinous product and sodium silicate. This aqueous solution may be diluted with water and used as an adhesive and to improve wet strangth. The paper is cured by heating the paper to 80° to 120° C. for 10 to 60 minutes.
EXAMPLE 18
3 mols of allyl chloride and 1 mol of 1,6-hexamethylenediamine, 1 mol of fine granular magnesium silicate and 300% by weight of water, percentage based on weight of reactants, are mixed then agitated for 10 to 60 minutes then filtered to remove the magnesium silicate. One mol of sodium hydroxide flakes is added slowly and mixed thoroughly; then about 1.2 mols of epichlorohydrin are slowly added while agitating and keeping the temperature below 70° C. for 10 to 60 minutes, thereby producing a liquid thermosetting resinous product. The liquid resinous product is then poured into a mold for gears, toy wheels, art objects, etc. and then heated to 80° to 120° C. thereby producing hard, tough, solid objects made of a poly(mono-olefinic allyl mono-halide amine polyfunctional halohydrin) resinous product.
EXAMPLE 19
About 1 mol of fine granular silica, 1 mol of sodium hydroxide flakes and 200% by weight of water, percentage based on weight of the silica and sodium hydroxide, are mixed; then 2 mols of methyl allyl chloride are added while agitating for 10 to 60 minutes and keeping the temperature below the boiling temperature of methyl allyl chloride; 2 mols of 1,6-hexamethylene diamine are thoroughly mixed into the mixture; then 2.5 mols epichlorohydrin are slowly added to the mixture while agitating and keeping the temperature below 70° C. for 10 to 60 minutes, thereby producing a liquid thermosetting resinous product. The resinous products may be poured into molds of knobs, toys, gears, halides, etc., then heated to 80° to 120° C. for 10 to 60 minutes, thereby producing hard, tough, useful objects made from a poly (mono-olefinic allyl mono-halide amine polyfunctional halogenated silicate) resinous product.
Although specific materials and conditions were set forth in the above Examples, these were merely illustrative of preferred embodiments of my invention. Various other compositions, such as the typical materials listed above may be used, where suitable. The reactive mixture are products of my invention may have other agents added thereto to enhance or otherwise modify the reaction and products.
Other modifications of my invention will occur to those skilled in the art upon reading my disclosure. These are intended to be included within the scope of my invention, as defined in the appended Claims.
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Poly(amine allyl halides) copolymer may be produced by mixing an amine compound and a mono-olefinic allyl type monohalide compound in the presence of an oxidized silicon catalyst.
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BACKGROUND OF THE INVENTION
PRIORITY CLAIM
[0001] Priority under 35 U.S.C. §119 is hereby claimed to German Patent Application Serial No. 103 52 820.2 filed Nov. 12, 2003.
[0002] 1. Field of the Invention
[0003] The invention relates to a flange assembly of an optical system. The invention relates, furthermore, to a method for connecting two flanges. The invention likewise relates to an objective, in particular a projection objective in semiconductor lithography.
[0004] 2. Description of the Related Art
[0005] When connecting two components with different coefficients of thermal expansion, the temperature-induced changes in diameter of the components result in stresses which can lead in precision systems to impermissible deformations, irreversible changes in frictional connections or destruction of components.
[0006] Particularly in the case of projection exposure machines with projection objectives for producing semiconductors, even minimal changes can lead to maladjustment of the projection objective when stresses occur in the above named way on the basis of different thermal expansions between the mounts of the lenses and the housing of the projection objective as support structure.
[0007] Consequently, as emerges from U.S. Pat. No. 6,166,868, in the case of such designs use is made of elastically resilient elements, often leaf spring elements, which are intended to balance out the different thermal expansions, these being arranged between the two components with the different coefficients of expansion, although as a result the connection frequently cannot be implemented with the desired rigidity. In order to produce the individual leaf spring elements, a connecting element with cut-outs must be provided by sawing up the connecting element in the edge region, or the spring elements must be individually fastened. Equally disadvantageous in this case is the high outlay on processing in order to achieve adequate planarity of a cut-up connecting element (disturbance of the internal stress conditions upon sawing up a turned part, and yielding of the leaf springs owing to processing forces) and the outlay on adjustment for individual elements. Furthermore, there is no gas tightness. Reference may be made to U.S. Pat. No. 6,229,657 B1, U.S. Pat. No. 6,097,553 A, U.S. Pat. No. 5,781,355 A and U.S. Pat. No. 2002/176094 A1 for the prior art.
SUMMARY OF THE INVENTION
[0008] Consequently, it is an object of the invention to provide a flange assembly for balancing out different thermal expansions between two components, which flange assembly avoids the disadvantages, mentioned in the beginning, of the prior art, and connects the components to one another very rigidly.
[0009] The object is achieved according to the invention by means of the features of claim 1 . Claim 24 achieves the object for a type of use in an objective.
[0010] Two components, in particular an optical assembly such as, for example, a lens mount, and a support structure, for example an objective housing, are intended according to the invention to be connected to one another in such a way that their different coefficients of linear thermal expansion or their thermal expansions as far as possible do not effect lens displacement or lens deformation. The connection between the flanges is performed according to the invention via a compensation element which is radially soft and connects the two flanges rigidly in their spatial position, the compensation element advantageously having a thin-walled, in particular closed cross section.
[0011] The thin-walled nature of the compensation element, in particular in the shape of a cylinder, ensures that the two flanges can expand independently of one another and that, in the process, the planarity, roundness and co-axiality of the flanges is retained. By contrast with the prior art, the de-coupling effect is not based on a bending softness of spring elements which have only a very restricted rigidity in the degrees of freedom which are not consciously released. Owing to the inventive configuration, the rigidity of the flange assembly can be substantially greater in all directions than would be the case for devices according to the prior art. Furthermore, the flanges can be processed in an uninterrupted cut, which leads to clean and more precise surfaces. The internal stress conditions in the flange assembly according to the invention are likewise not disturbed, since there is no need for sawing up as required in the prior art when use is made of leaf springs.
[0012] Owing to the inventive configuration of the flange assembly, a CTE jump (location at which the coefficient of thermal expansion of one material comes into contact with the coefficient of thermal expansion of the other material) can be moved to a stable joint in relation to at least one flange inside the compensation element or coupling element. This means that the CTE jump is moved to the site where the compensation element is stably connected to the flange, for example by adhesion or welding. The joint can be designed in this case to be so stable that the connection is not impaired in the event of differences in expansion. The stresses resulting in the region of the CTE jump can be kept small, particularly through the thin-walled nature of the compensation element. In addition, in accordance with the conditions of rigidity for the compensation element and flange, the stresses predominantly effect a harmless deformation of the compensation element, while the flange experiences only very slight deformations.
[0013] Further important advantages of the flange assembly are that, for example, the stress conditions resulting from the joining do not affect the geometry or their accuracy, and that the internal stresses and their variations over time (relaxation) play a subordinate role, rather, in the accuracy of the flange assembly by comparison with the individual leaf springs in the prior art. A small radial space requirement and a simple design of the flange assembly are likewise further advantages. It is advantageously possible by means of the flange assembly according to the invention to prevent an introduction of a three leaf clover to a lens which is supported in the lens mount.
[0014] In a particularly advantageous refinement of the invention, it is provided that the compensation element is monolithic with at least one flange, the result being that the compensation element has the coefficient of thermal expansion of the flange with which it is monolithically embodied. The advantage of the monolithic refinement is the simple production of the flange assembly, since one flange and the compensation element can be designed jointly in a concentric fashion, for example, it being possible for the compensation element to be produced approximately true to size.
[0015] Exemplary embodiments of the invention are explained below in more detail with the aid of the drawings, in which:
BRIEF DESCRIPTON OF THE DRAWINGS
[0016] FIG. 1 shows a sketch of a flange assembly according to the invention, in a (partially) perspective view;
[0017] FIGS. 2 a to 2 i show sketches of various types of joint of the flange assembly shown in FIG. 1 ;
[0018] FIG. 3 shows an alternative embodiment of the inventive flange assembly according to FIG. 1 with two connecting elements;
[0019] FIG. 4 shows an objective for semiconductor lithography with an embodiment according to FIG. 3 .
DETAILED DESCRIPTION
[0020] FIG. 1 shows a device or flange assembly 1 which has two flanges 2 and 2 ′ which are preferably embodied as annular flanges. The flanges 2 and 2 ′ serve the purpose of connecting two components such as, for example, a lens with a lens mount as optical assembly, and a support structure, for example an objective housing, as illustrated in principle in FIG. 3 . The two flanges 2 , 2 ′ each have mutually differing coefficients α 1 and α 2 of linear thermal expansion, the flanges 2 and 2 ′ being able in each case to have one coefficient of thermal expansion which can correspond approximately to that of the respectively adjacent component. The flanges 2 and 2 ′ are provided with bore holes 3 and 3 ′, the components, in particular the lens mount and the support structure, being able to be connected to the flanges 2 and 2 ′ via screwed connections. The flanges 2 and 2 ′ are connected to one another via a compensation element or connecting element 4 . The compensation element 4 preferably has a thin-walled, closed cross section in the shape of a cylinder or a tube, the cross section preferably being circular, oval or else polyhedral, with a wall thickness of approximately 0.01 mm to 3 mm, in particular 0.1 mm to 1 mm.
[0021] It is particularly advantageous that the compensation element 4 is unipartheid or monolithic with the flange 2 ′, the unipartheid nature meaning that the compensation element 4 has the same coefficient α 2 of linear thermal expansion as the flange 2 ′, which is a one piece with it.
[0022] If the compensation element 4 is not monolithic with the flange 2 ′, the coefficient of linear thermal expansion of the compensation element 4 can have a value which lies between the values of the coefficients α 1 and α 2 of linear thermal expansion of the two flanges 2 and 2 ′, in order as a result to produce only minimal differences in expansion of paired flanges 2 and 2 ′ with the compensation element 4 in the event of temperature changes. The result of this is only minimal loading of the respective joint with the flange 2 or 2 ′, respectively.
[0023] FIGS. 2 a to 2 i illustrate various possible types of joint of the compensation element 4 with the flanges 2 and 2 ′.
[0024] FIGS. 2 a to 2 c show the two flanges 2 and 2 ′, the first flange 2 being produced, for example, from INVAR or ceramic, and the second flange 2 ′ from, for example, steel. In each case, the compensation element 4 is here monolithic with a flange. A connecting site 5 between the compensation element 4 and the flange 2 can be produced by soldering, welding, pressing in, shrinking on or adhesion. The part of the compensation element 4 which is to be connected to the flange 2 can have a somewhat greater wall thickness.
[0025] FIG. 2 d shows a further possibility of connecting the compensation element 4 to the flange 2 , specifically via a screwed connection 6 . Here, the compensation element 4 has an external thread, and the flange 2 an internal thread. The flange 2 can therefore be connected to the compensation element 4 or to the further flange 2 ′ by being screwed on. Furthermore, an even more secure connection can be ensured by additional bonding or welding of the screwed connection 6 .
[0026] The connection of the compensation element 4 to the flange 2 is implemented in FIG. 2 e by a cone 7 . This connection can be secured by an adhesive, if appropriate. The conical part 7 , which is illustrated specifically in the enlarged detail corresponding to X, can likewise be provided with a groove 8 at the connecting surface to the flange 2 . It is thereby possible for an adhesive to soften when introduced, and to ensure optimal security. Roundness tolerances and diameter tolerances of the compensation element 4 can be balanced out by the cone 7 . The connection can also be performed without an integral connection such as bonding. As already mentioned above, it would be possible to perform adhesion or welding for the sake of security.
[0027] A similar connecting possibility to that in FIG. 2 e is illustrated in FIG. 2 f. Here, the thin-walled, preferably cylindrical compensation element 4 is introduced into the flange 2 by pressing (frictional joining method) (elastic to plastic tapering of the compensation element 4 ). It can be smeared with adhesive and secured, if appropriate. Welding is also possible for the sake of securing and sealing.
[0028] The connection of the compensation element 4 to the flange 2 is performed in FIG. 2 g by welding. As in FIGS. 2 a to 2 c , here the part of the compensation element 4 which is to be connected to the flange 2 is embodied with a larger wall thickness so that the thin-walled part of the compensation element 4 is not damaged by the welding. The integral joining method of welding is advantageous because there is no need to use adhesives, and therefore outgasings are prevented.
[0029] It is also conceivable to produce both flanges 2 and 2 ′ as monolithic parts with in each case a segment of the compensation element 4 , as illustrated in FIG. 2 h, the result being that the joint is situated approximately in the middle of the overall compensation element 4 . The influence of the joint would thereby be smaller. This means that the connecting site is not so rigidly designed, and so it can yield to both sides. The result of this is a very small loading of the joint.
[0030] The smallest stresses inside the flange assembly 1 can be produced by the compensation element 4 made from a third material with a coefficient α 3 of linear thermal expansion which should lie between the first and the second flange 2 and 2 ′ ( FIG. 2 i ). The advantage here resides in the fact that the transition from α 1 to α 2 is distributed over two sites. Producing the compensation element 4 from a third material with a very small coefficient α 3 <2 ppm/K of linear thermal expansion, for example INVAR, is advantageous for minimizing the axial change in length, irrespective of the coefficient of expansion of the two flanges 2 and 2 ′, for example aluminium, INVAR or steel.
[0031] FIG. 3 shows an alternative embodiment of the flange assembly 1 illustrated in FIGS. 1 and 2 . The connection of the two flanges 2 and 2 ′ is performed here by two coaxial, thin-walled compensation elements 4 and 4 ′. The flange 2 , which is intended to be connected to the compensation elements 4 and 4 ′, can be conically embodied, as illustrated in this exemplary embodiment. This connection of the flange 2 to the compensation elements 4 and 4 ′ can be undertaken with the aid of various connecting methods, as already described in the preceding exemplary embodiments. As already mentioned, the flanges 2 and 2 ′ have bore holes 3 and 3 ′ for holding screws 9 , in order to connect the flange assembly 1 to the components 10 and 11 , the component 10 constituting the support structure, for example the objective housing, of an objective 12 for semiconductor lithography and the component 11 constituting the lens mount with a lens 11 a.
[0032] FIG. 4 shows an objective 12 with the embodiment according to FIG. 3 in principle. The objective 12 images a mask M on a substrate W, which is provided with a photoresist layer. When the flange assembly 1 is embodied with two compensation elements 4 and 4 ′, the bore hole 3 can have a larger opening, in order to be able to pass the screw 9 through together with the screw head. As a result, the screw 9 can be inserted into the bore hole 3 ′, in order thus to connect the flange 2 to the component 10 , i.e. the objective housing 10 .
[0033] The compensation element 4 can also alternatively be provided with cut-outs, there being no preference for any specific shape of the cut-outs.
[0034] A stable and very precise connection can be rendered possible by pressing together axially or shrinking in or on. In the case of shrinking on, the compensation element 4 can be connected to the flange 2 without force. The flange 2 can likewise be provided here with a cone, as in the case of pressing together.
[0035] The coaxial nature of the elements relative to one another is retained in the case of both methods.
[0036] Although the flanges 2 and 2 ′ are designed as annular flanges in the exemplary embodiments, they can, of course, also be produced in another shape, for example a triangular or polygonal flange.
[0037] The planarity and coaxial and parallel nature of the two flanges 2 and 2 ′ can be retained in the event of changes in temperature owing to the configuration of the flange assembly 1 .
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A flange assembly ( 1 ) of an optical system has a first flange ( 2 ), a compensation element ( 4 ) and a second flange ( 2 ′). The flanges ( 2, 2 ′) and the compensation element ( 4 ) are substantially axially symmetric both flanges ( 2, 2 ′) being suitable for being connected to other components ( 10, 11 ) of the optical system in a non-destructive, non-positive axially separable fashion. The two flanges ( 2, 2 ′) consist of different materials with different coefficients of linear thermal expansion. The compensation element ( 4 ) is radially soft, but connects the two flanges ( 2, 2 ′) rigidly in their relative spatial position.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates generally to optical receivers and more particularly to an optical receiver having signal level transient compensation.
[0003] 2. Description of the Background Art
[0004] Optical transmission systems include a transmitter for transmitting a modulated optical signal into a link and a receiver for receiving the signal from the link. The link may span a short distance or thousands of kilometers. Existing optical receivers have an optical to electrical (OE) converter, typically using a photodiode, for converting the incoming optical signal to an electrical signal. The electrical signal drives a clock data recovery (CDR) system that recovers the clock and then uses the clock for sampling the electrical signal. The modulated data is recovered by comparing the sampled signal to a fixed decision threshold level. A sampled signal level that is above the threshold level yields a bit sense of one and a level below the threshold level yields a bit sense of zero.
[0005] When the decision threshold level is fixed, any variation or transient in average power of the incoming signal can lead to bit errors. Some workers have attempted to resolve this problem by leveling the variations and transients with optical devices in the link. This has been done with variable gain erbium-doped fiber amplifiers (EDFA)s and variable optical attenuators (VOA)s. However, these optical devices can be expensive for new systems and the installation cost for retrofitting into existing systems can be prohibitive.
[0006] There is a need for an inexpensive way to minimize bit errors when variations and transients occur in optical signal power.
SUMMARY OF THE INVENTION
[0007] Briefly, the present invention is an optical receiver having an electrical method for improving tolerance for the variations and transients on an incoming modulated optical signal. The receiver includes an optical to electrical (OE) converter, a transient threshold compensator, a threshold combiner and a clock data recover (CDR) system. The OE converter receives the incoming optical signal and provides a modulated electrical signal having a high speed response for tracking the modulation on the optical signal and an averaged electrical signal having a moderate speed response for tracking changes in the average level of the optical is signal. The transient threshold compensator processes the averaged electrical signal for providing a transient feedforward adjustment. The threshold combiner combines the transient feedforward adjustment with a low speed BER-based feedback adjustment for providing a decision threshold signal. The CDR system uses the decision threshold signal for recovering a clock, providing the BER-based feedback adjustment, and estimating the data carried by the modulation.
[0008] The optical receiver of the present invention has the benefit of using low cost electrical circuitry contained within the receiver for improving bit error rate (BER) performance for an optical signal when the optical signal level has transients and/or variations.
[0009] This and other benefits of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiments which are illustrated in the various figures.
IN THE DRAWINGS
[0010] FIG. 1 is a block diagram of an optical receiver of the present invention;
[0011] FIG. 2A is a time chart showing a decision threshold signal for the receiver of FIG. 1 for an incoming optical signal having a positive transient;
[0012] FIG. 2B is a time chart showing a decision threshold signal for the receiver of FIG. 1 for an incoming optical signal having a negative transient; and
[0013] FIG. 3 is flow chart of a method of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] FIG. 1 is a block diagram of a receiver of the present invention referred to with a reference number 10 . The receiver 10 includes an optical to electrical (OE) converter 12 , a clock and data recovery (CDR) system 14 and a transient threshold compensator 16 . The CDR system 14 includes a clock recovery circuit 22 , a data estimator 24 , and an error detection/correction circuit 26 . It should be noted that a “circuit” typically includes both hardware and software. The receiver 10 may also include other components such as optical and electrical demultiplexers, amplifiers and filters.
[0015] The OE converter 12 couples to an optical link 32 for receiving an incoming amplitude or intensity modulated optical signal 34 and converting the signal 34 to a modulated electrical signal 36 . The modulated electrical signal 36 may be baseband where the modulation is the signal 36 , or the modulation may be carried on an intermediate frequency carrier signal. In either case, the pattern and rate of the modulation on the electrical signal 36 is representative of the pattern and rate of the modulation on the optical signal 36 .
[0016] The OE converter 12 also converts the optical signal 34 into an electrical signal 37 having a level proportional to the average of the optical signal 34 and passes the averaged signal 37 to the transient threshold compensator 16 . The averaged electrical signal 37 has a response time fast enough to follow transients in the optical signal 34 but not fast enough to track the modulation. The frequency response of the averaged electrical signal 37 may be about one-tenth to about one one-thousandth the frequency response of the signal 36 . The transient threshold compensator 16 uses the averaged electrical signal 37 for providing a dynamic transient feedforward adjustment 40 .
[0017] One or more photodetectors may be used by the OE converter 12 for providing both the modulated electrical signal 36 and the averaged electrical signal 37 . The signal for the average of the level of the optical signal 34 can be the average current in a photodiode. Alternatively, the transient threshold compensator 16 filters the electrical signal 36 for providing the averaged electrical signal 37 .
[0018] The OE converter 12 passes the electrical signal 36 to the clock recovery circuit 22 and the data estimator 24 in the CDR system 14 . The clock recovery circuit 22 uses the level of a decision threshold signal 42 for synchronizing a clock to the modulation on the electrical signal 36 and passes the clock to the data estimator 26 .
[0019] The data estimator 24 uses the clock for sampling the electrical signal 36 and compares the samples to the level of the decision threshold signal 42 for providing estimated data having a sense or level of 1 (one) when the sampled signal is greater than the decision threshold signal 42 and a sense or level of 0 (zero) when the sampled signal is less than the decision threshold signal 42 . The senses of 1 and 0 are used for data words having single bit data estimation. It should be noted that multiple bits may be used for the estimated data. For example, for two bit data a word of “11” might indicate a high level one, a word of “10” might indicate a lower level one, a word of “01” a high level zero and a word “00” might indicate a lower level zero. The same idea can be extended to words having many bits.
[0020] The data estimator 24 passes the ones and zeroes as estimated data to the error detection/correction circuit 26 . The error detection/correction circuit 26 uses the estimated data for detecting and correcting errors in the estimated data and then issues corrected estimated data as an output data signal 43 .
[0021] The CDR system 14 optionally includes a BER estimator 44 and a BER-based threshold controller 46 . The BER estimator 44 estimates a bit error rate based on error detection information from the error detection/correction circuit 26 . The BER-based threshold controller 46 uses the estimated bit error rate for providing a BER feedback threshold adjustment 52 to a threshold combiner 54 . The threshold combiner 54 combines the BER feedback threshold adjustment 52 with transient feedforward adjustment 40 received from the transient threshold compensator 16 for providing the decision threshold signal 42 . It should be noted that the response time of the transient feedforward adjustment 40 may be about ten to a thousand or more times faster than the response time of the BER feedback threshold adjustment 52 .
[0022] The electrical signals 36 and 37 , transient feedforward adjustment 40 , the decision threshold signal 42 and the BER feedback transient adjustment 52 are multi-level signals (more than two levels) when the incoming optical signal 34 is a multi-level signal.
[0023] FIGS. 2A and 2B are exemplary eye diagram time charts 60 A and 60 B showing positive and negative amplitude transients, respectively, for the modulated optical signal 34 and the responsive modulated electrical signal 36 . The drawing is scaled so that the signals 34 and 36 are shown with the same levels. In order to make the drawing easier to understand, the level 1 transients are shown in a compressed time scale as compared to the eye pattern modulation, that is, the transients are shown to occur with a faster rise and fall time (compared to the modulation) than is typical.
[0024] The eye chart 60 A shows a level 1 and a level 0 . The level 1 has a first signal level 62 followed by a positive transient 63 having a higher signal level and settling at a second signal level 64 . The second level 64 may be greater, lesser, or the same as the first level 62 . A fixed decision threshold level 72 is shown at the mid level between the level 0 and the level 1 for the first signal level 62 . It can be seen by inspection that the fixed decision threshold level 72 is not at the mid level for the transient signal level 63 or the second signal level 64 . The transient threshold compensator 16 applies a scale factor to the averaged electrical signal 37 for providing a dynamic transient feedforward adjustment 40 that results in the decision threshold signal 42 shown as a level 74 .
[0025] The eye chart 60 B also shows the level 1 and the level 0 . The level 1 has the first signal level 62 followed by a negative transient 66 having a lower signal level and settling at a third signal level 67 . The third level 67 may be greater, lesser, or the same as the first level 62 . The fixed decision threshold level 72 is shown at the mid level between the level 0 and the level 1 for the first signal level 62 . It can be seen by inspection that the fixed decision threshold level 72 is not at the mid level for the transient signal levels 66 or the third signal level 67 . The transient threshold compensator 16 applies a scale factor to the averaged electrical signal 37 for providing a dynamic transient feedforward adjustment 40 that results in the decision threshold signal 42 shown as a level 76 .
[0026] For the exemplary cases 60 A and 60 B, the optimum decision threshold level is shown as the mid level between the level 1 and the level 0 . However, the scale factor that is applied by the transient threshold compensator 16 may be selected so that the levels 74 and 76 are higher or lower than the mid level.
[0027] Without the transient feedforward adjustment 40 of the present invention, the BER feedback threshold adjustment 52 would eventually drive the decision threshold signal 42 ( FIG. 1 ) to an optimum level for minimizing errors. However, the BER feedback transient adjustment 52 necessarily requires errors to be detected over some period of time before the BER feedback threshold adjustment 52 can adjust the level of the decision threshold signal 42 . The transient feedforward adjustment 40 of the present invention can act more quickly than the BER feedback threshold adjustment 52 in order to reduce the number of bit errors that occur before the BER feedback threshold adjustment 52 has time to adjust.
[0028] For a multi-level incoming optical signal 34 (two or more on-condition states and one zero state), the level 1 in the eye diagrams and the corresponding levels 62 - 76 are multi-level (corresponding in level to the two or more on-condition states). For example, for the optical signal 34 having three state modulation (two on-conditions states and one zero state), the level 1 and each of the corresponding levels 62 - 76 have two levels (corresponding to the two on-condition states); for five state modulation (four on-conditions states and one zero state), the level 1 and each of the corresponding levels 62 - 76 have four levels (corresponding to the four on-condition states); and so on.
[0029] FIG. 3 is a flow chart of a method of the present invention for minimizing bit errors in the presence of transients and variations in a modulated optical signal. In a step 102 an amplitude or intensity modulated optical signal is received from an optical link. In steps 104 and 106 the optical signal is converted into a modulated electrical signal and an averaged electrical signal. The modulation on the electrical signal tracks the modulation on the optical signal. The level of the averaged electrical signal tracks the average level of an on-condition of the modulated optical signal. In a step 108 data is estimated for the modulated electrical signal by comparison to a level of a decision threshold signal.
[0030] At least some of the errors on the estimated data are detected and corrected in a step 112 . In a step 114 the corrected estimated data is issued as an output data signal. A bit error rate is estimated in a step 122 . In a step 124 the bit error rate is used for generating a BER feedback threshold adjustment.
[0031] A transient feedforward adjustment is generated in a step 132 from the averaged electrical signal. In a step 134 the decision threshold signal is determined from the transient feedforward adjustment and the BER feedback threshold adjustment. The decision threshold signal is used in the step 108 for estimating data.
[0032] Although the present invention has been described in terms of the presently preferred embodiments, it is to be understood that such disclosure is not to be interpreted as limiting. Various alterations and modifications will no doubt become apparent to those skilled in the art after having read the above disclosure. Accordingly, it is intended that the appended claims be interpreted as covering all alterations and modifications as fall within the true spirit and scope of the invention.
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An optical receiver having compensation for signal level transients. The receiver includes an OE converter, a transient threshold compensator, a threshold combiner and a CDR system. The OE converter receives the incoming optical signal and provides a modulated electrical signal having a high speed response for tracking the modulation on the optical signal and an averaged electrical signal having a moderate speed response for tracking changes in the average level of the optical signal. The transient threshold compensator processes the averaged electrical signal for providing a transient feedforward adjustment. The threshold combiner combines the transient feedforward adjustment with a lower speed BER feedback threshold adjustment for providing a decision threshold signal. The CDR system uses the decision threshold signal for recovering a clock, providing the BER feedback threshold adjustment, and estimating the data carried by the modulation.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit under 35 U.S.C. §119(e) of Provisional Patent Application Ser. No. 61/454,079 entitled “METHOD FOR THE REMOVAL OF HEAT STABLE AMINE SALTS FROM AN AMINE ABSORBENT” filed Mar. 18, 2011, the disclosure of which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The proposed invention relates to a system and a method for the removal of heat stable amine salts from an amine absorbent used in a carbon dioxide (CO 2 ) capture process.
BACKGROUND
[0003] In the combustion of a fuel, such as coal, oil, natural gas, peat, waste, etc., in a combustion plant, such as those associated with boiler systems for providing steam to a power plant, a hot process gas (or flue gas) is generated. Such a flue gas will often contain, among other things, carbon dioxide (CO 2 ). The negative environmental effects of releasing carbon dioxide to the atmosphere have been widely recognized, and have resulted in the development of processes adapted for removing carbon dioxide from the hot process gas generated in the combustion of the above mentioned fuels.
[0004] In processes used for industrial separation of CO 2 , liquid solutions comprising amine compounds are commonly used as an absorbent. Examples of amine compounds commonly used in absorption of CO 2 from gas streams include monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine (MDEA), diisopropylamine (DIPA) and aminoethoxyethanol (diglycolamine) (DGA). The most commonly used amines compounds in industrial plants are the alkanolamines MEA, DEA, and MDEA.
[0005] CO 2 in the gas stream is captured in the liquid absorbent solution in an absorption process. A CO 2 absorber is employed to establish suitable conditions (temperature, pressure, turbulence, etc.) for chemical absorption of CO 2 into the amine absorbent from a mixed gas stream.
[0006] The amine absorbent containing absorbed CO 2 is subsequently regenerated, whereby absorbed CO 2 is separated from the absorbent, and the regenerated absorbent is then reused in the CO 2 absorption process. Thus, a circulating absorbent stream is formed. Regeneration is generally achieved by heating the amine absorbent in a stripper reboiler to a temperature at which CO 2 is released from the absorbent.
[0007] In the regenerator reboiler the absorbent is subjected to high temperature (generally about 115° C. or higher), whereas in the absorber the absorbent is exposed to a higher O 2 environment. As a result of the exposure to high temperature and/or the presence of O 2 , the amine solvent(s) of the absorbent may undergo degradation, whereby undesired degradation products are formed in the liquid phase. These degradation products, known as heat stable salts or heat stable amine salts (HSS), may accumulate in the circulating absorbent stream. The HSS reduce the CO 2 removal potency of the absorbent and may therefore preferably be removed from the absorbent stream. A common method of HSS removal is to take a slipstream from the circulating absorbent, separate the bulk absorbent from the HSS in a reclaimer and recycle the separated amine back to the circulating absorbent loop as reclaimed absorbent. A relaimer can consist of a distillation, ion exchange, or electrodialysis unit.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide an improved system and process for removal of heat stable salts (HSS) from an amine absorbent stream used in a carbon dioxide (CO 2 ) capture process.
[0009] In amine based CO 2 capture systems, a separation step, e.g. electrodialysis (ED), is often employed for separating amine absorbent from the undesired HSS in order to recycle the absorbent in the capture process. It has been found, however, that CO 2 in the amine absorbent can be detrimental to the separation process, such as electrodialysis.
[0010] Amine based CO 2 capture systems are sometimes operated in a way such that a relatively high CO 2 loading is observed in the lean solvent leaving the stripper. It has been found that when a slip stream of the lean solvent is sent to the reclamation unit, either electrodialysis or ion exchange, the relatively high lean loading fed to the reclamation unit results in significant quantities of amine lost through the reclamation waste stream. Reduced amine losses can significantly reduce amine make-up of the system and provide an economic advantage.
[0011] As a solution to this problem, there is provided a method and a system, wherein the amine absorbent containing the heat stable salts to be removed is first subjected to stripping and/or flashing, e.g. in a stripper or flash drum respectively, to remove residual CO 2 , before being forwarded to the amine reclaimer for separation of amine absorbent from the HSS. The stripping/flashing step is simple and reliable, involves low additional investment and operational costs, and is easy to integrate into existing systems. Stripping is performed in a stripper, wherein the incoming amine absorbent is heated, e.g. by steam or electricity, to a temperature at which more volatile components, such as CO 2 in this case, are at least partly evaporated and leave the stripper via a gas/vapor exit. Stripping may be performed at atmospheric pressure or at increased or reduced pressure as necessary. Less volatile components, such as the bulk amine absorbent in this case, remain in liquid form and leave the stripper via a liquid exit. Flashing is generally performed in a flash drum, wherein the incoming amine absorbent undergoes a reduction in pressure, e.g. by passing through a throttling valve or other throttling device. More volatile components, such as CO 2 , are at least partly evaporated and leave the flash drum via a gas/vapor exit. Less volatile components, such as the bulk amine absorbent in this case, remain in liquid form and leave the flash drum via a liquid exit. The stripping/flashing step should result in a reduction of the amount of CO 2 in the amine absorbent.
[0012] According to aspects illustrated herein, there is provided a method for the removal of heat stable amine salts from an amine absorbent used in a carbon dioxide (CO 2 ) capture process, comprising:
[0013] withdrawing amine absorbent containing heat stable amine salts from the CO 2 capture process;
[0014] subjecting the withdrawn amine absorbent containing heat stable amine salts to a residual CO 2 removal step;
[0015] subjecting the amine absorbent from the residual CO 2 removal step to a separation step to separate heat stable amine salts from the amine absorbent; and
[0016] returning the amine absorbent having a reduced concentration of heat stable amine salts to the CO 2 capture process.
[0017] According to embodiments, the residual CO 2 removal step comprises stripping and/or flashing the withdrawn amine absorbent to remove residual CO 2 .
[0018] According to embodiments, the residual CO 2 removal step comprises stripping the withdrawn amine absorbent to remove residual CO 2 .
[0019] According to embodiments, the residual CO 2 removal step comprises flashing the withdrawn amine absorbent to remove residual CO 2 .
[0020] According to embodiments, the residual CO 2 removal step comprises stripping and then flashing the withdrawn amine absorbent to remove residual CO 2 .
[0021] According to embodiments, the flashing is performed under near vacuum conditions. By performing flashing at near vacuum conditions the absorbent may be kept at relatively low temperature. In addition to saving energy required for heating the absorbent, this also reduces the exposure of the absorbent to higher temperatures which could cause further degradation of the absorbent. The flashing may for example be performed at a pressure in the range of 0-2 bar gauge.
[0022] The method for the removal of heat stable amine salts from an amine absorbent is useful in a carbon dioxide (CO 2 ) capture process comprising regeneration of the amine absorbent at elevated temperatures. When performed in such a process, the method for the removal of heat stable amine salts can be operated with little additional energy requirement, by withdrawing the slipstream of amine absorbent from a point in the process where the amine absorbent has a low CO 2 loading.
[0023] Thus, according to embodiments, the CO 2 capture process comprises: scrubbing a gas stream comprising CO 2 with an amine absorbent such that a CO 2 rich amine absorbent is formed;
[0024] regenerating the CO 2 rich amine absorbent by heating it to separate CO 2 from the amine absorbent, such that a CO 2 lean amine absorbent is formed; and
[0025] recycling regenerated CO 2 lean amine absorbent to the scrubbing step.
[0026] It has been found that for the purposes of the present method for the removal of heat stable amine salts, the slipstream of amine absorbent containing HSS may advantageously be withdrawn from the lean amine absorbent from the regenerator. More particularly, the slipstream of amine absorbent may be withdrawn from the regenerator or from the liquid conduit between the regenerator and a lean absorbent/rich absorbent heat exchanger. The lean amine absorbent from the regenerator generally has a temperature of 100° C. or higher. This allows the thermal energy provided to the lean amine absorbent in the regenerator to be utilized in the stripping and/or flashing step. If necessary, the slipstream of lean amine absorbent containing HSS may also be withdrawn from the lean absorbent/rich absorbent heat exchanger or from the liquid conduit between the lean absorbent/rich absorbent heat exchanger and the CO 2 absorber performing the scrubbing step. When this is the case, the temperature of the slipstream of lean amine absorbent containing HSS may have a temperature of less than 100° C.
[0027] According to embodiments, the withdrawn amine absorbent containing heat stable amine salts is regenerated CO 2 lean amine absorbent.
[0028] According to embodiments, the regenerated CO 2 lean amine absorbent has a temperature of at least 100° C., such as at least 120° C.
[0029] According to embodiments, the separation step comprises subjecting the amine absorbent from the residual CO 2 removal step to electrodialysis and/or ion exchange.
[0030] According to embodiments, the separation step comprises subjecting the amine absorbent from the residual CO 2 removal step to electrodialysis.
[0031] According to embodiments, the separation step comprises subjecting the amine absorbent from the residual CO 2 removal step to ion exchange.
[0032] According to embodiments, the method further comprises cooling the amine absorbent from the residual CO 2 removal step before subjecting it to the separation step.
[0033] According to embodiments, the method further comprises subjecting the amine absorbent from the residual CO 2 removal step to indirect heat exchange with the amine absorbent coming from the separation step.
[0034] According to other aspects illustrated herein, there is provided a carbon dioxide (CO 2 ) capture system using an amine absorbent for absorption of CO 2 from a gas stream, having a subsystem for the removal of heat stable amine salts from an amine absorbent, said subsystem comprising:
[0035] a residual CO 2 removal unit in liquid connection with, and configured to receive, an amine absorbent stream containing heat stable amine salts from the CO 2 capture system, and operative for separating residual CO 2 from said amine absorbent stream; and
[0036] an amine reclaimer in liquid connection with, and configured to receive, an amine absorbent stream containing heat stable amine salts and having a reduced concentration of CO 2 from the residual CO 2 removal unit, and operative for separating heat stable amine salts from said amine absorbent stream.
[0037] According to embodiments, the residual CO 2 removal unit comprises a stripper and/or a flash drum.
[0038] According to embodiments, the residual CO 2 removal unit comprises a stripper.
[0039] According to embodiments, the residual CO 2 removal unit comprises a flash drum.
[0040] According to embodiments, the residual CO 2 removal unit comprises a stripper and a flash drum arranged in series.
[0041] The stripper or flash drum provides for inexpensive, efficient and reliable removal of residual CO 2 from amine absorbent containing HSS before the absorbent is fed to the amine reclaimer for separation of heat stable amine salts.
[0042] The use of a stripper or flash drum for removal of residual CO 2 from an amine absorbent containing HSS is useful in a carbon dioxide (CO 2 ) capture system which regenerates the amine absorbent at elevated temperatures. When used in such a system, the stripper or flash drum can be operated with little additional energy requirement, by withdrawing the slipstream of amine absorbent from a point in the process where the amine absorbent has a low CO 2 loading.
[0043] According to embodiments, the carbon dioxide (CO 2 ) capture system comprises: a CO 2 absorber operative for scrubbing a gas stream comprising CO 2 with an amine absorbent such that a CO 2 rich amine absorbent is formed;
[0044] a regenerator operative for regenerating CO 2 rich amine absorbent by heating it to separate CO 2 from the amine absorbent, such that a CO 2 lean amine absorbent is formed.
[0045] It has been found that for the purposes of the present method for the removal of heat stable amine salts, the slipstream of amine absorbent containing HSS may advantageously be withdrawn from the lean amine absorbent from the regenerator. More particularly, the slipstream of amine absorbent may be withdrawn from the regenerator or from the liquid conduit between the regenerator and a lean absorbent/rich absorbent heat exchanger. The lean amine absorbent from the regenerator generally has a temperature of 100° C. or higher, such as 120° C. or higher. This allows the thermal energy provided to the lean amine absorbent in the regenerator to be utilized in the stripping and/or flashing step. If necessary, the slipstream of lean amine absorbent containing HSS may also be withdrawn from the lean absorbent/rich absorbent heat exchanger or from the liquid conduit between the lean absorbent/rich absorbent heat exchanger and the CO 2 absorber performing the scrubbing step.
[0046] According to embodiments, the residual CO 2 removal unit is in liquid connection with, and configured to receive, an amine absorbent stream from the regenerator, and operative for separating residual CO 2 from the CO 2 lean amine absorbent.
[0047] According to embodiments, the amine reclaimer comprises an electrodialysis unit or an ion exchange unit.
[0048] According to embodiments, the amine reclaimer comprises an electrodialysis unit.
[0049] According to embodiments, the amine reclaimer comprises an ion exchange unit.
[0050] According to embodiments, the subsystem for removal of heat stable amine salts further comprises an amine absorbent cooler arranged between the residual CO 2 removal unit and the reclaimer and operative for cooling the amine absorbent from the residual CO 2 removal unit before it enters the reclaimer.
[0051] According to embodiments, the subsystem for removal of heat stable amine salts further comprises an indirect heat exchanger operative for subjecting the amine absorbent from the residual CO 2 removal unit to indirect heat exchange with the amine absorbent coming from the reclaimer.
[0052] The above described and other features are exemplified by the following figures and detailed description. Further objects and features of the present invention will be apparent from the description and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] Referring now to the figures, which are exemplary embodiments, and wherein the like elements are numbered alike:
[0054] FIG. 1 is a diagram generally depicting an amine based gas purification system comprising an amine absorbent reclaimer circuit.
[0055] FIG. 2 is a diagram generally depicting an embodiment of an amine based gas purification system comprising an amine absorbent reclaimer circuit.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0056] The term “amine absorbent” or simply “absorbent”, as used herein, refers to a liquid composition comprising at least one amine compound useful in absorption of CO 2 from gas streams. Such compositions and suitable amine compounds are well known to a person skilled in the art. Examples of amine compounds commonly used in absorption of CO 2 from gas streams include, but are not limited to, monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine (MDEA), diisopropylamine (DIPA) and aminoethoxyethanol (diglycolamine) (DGA). The most commonly used amine compounds in industrial plants are the alkanolamines MEA, DEA, and MDEA. The absorbent may comprise a single amine compound or a mixture of two or more amine compounds. In addition, the absorbent may comprise up to about 90% by volume of water, for example from about 50 to about 90% by volume of water. The absorbent may also comprise varying amounts of absorbed CO 2 . Absorbent containing none or only a low concentration of absorbed CO 2 , e.g. following regeneration, is referred to as “CO 2 lean” or simply “lean” absorbent, whereas absorbent containing higher concentrations of absorbed CO 2 , e.g. following absorption, is referred to as “CO 2 rich” or simply “rich” absorbent.
[0057] FIG. 1 is a schematic representation of an amine based carbon dioxide (CO 2 ) capture system ( 100 ). The system comprises an absorption unit ( 101 ) arranged to allow contact between a gas stream to be purified and one or more wash liquids. The absorption unit represented in FIG. 1 comprises a CO 2 absorption section ( 102 ) and a water wash section ( 103 ). Flue gas, from which CO 2 is to be removed, is fed to the absorption unit ( 101 ) via line ( 104 ). In the CO 2 absorption section ( 102 ), the flue gas is contacted with a first wash liquid comprising an amine compound, e.g. by bubbling the flue gas through said first wash liquid or by spraying the first wash liquid into the flue gas. The first wash liquid is fed to the absorption unit ( 101 ) via line ( 105 ). In the CO 2 absorption section ( 102 ) CO 2 from the flue gas is absorbed in the first wash liquid. Flue gas depleted of CO 2 in the CO 2 absorption section then enters the water wash section ( 103 ) of the absorption unit. The water wash section ( 103 ) is arranged to allow contact between the flue gas depleted of CO 2 from the CO 2 absorption section ( 102 ) and a second wash liquid, which is generally water. The second wash liquid is fed to the absorption unit via line ( 106 ). In the water wash section, contaminants remaining in the flue gas when it leaves the CO 2 absorption section are absorbed in the second wash liquid. Flue gas depleted of CO 2 and contaminants leaves the absorption unit via line ( 107 ). The used first and second wash liquid containing absorbed CO 2 and contaminants leave the absorption unit via line ( 108 ). The used first and second wash liquid may be recycled via a regenerator unit ( 109 ), wherein contaminants and CO 2 are separated from the wash water. The separated CO 2 leaves the system via line ( 110 ).
[0058] The used first and second wash liquid to be regenerated enters the regenerator ( 109 ) via line ( 111 ). In the regenerator, the used wash liquids are heated, generally using steam, in a reboiler ( 112 ). The heating causes desorption of absorbed CO 2 from the wash liquids. The desorbed CO 2 then exits the regenerator via line ( 113 ) together with some water vapor also formed during heating. Regenerated wash liquid, containing a reduced concentration of CO 2 , leaves the regenerator ( 109 ) via line ( 114 ). The regenerated wash liquid is also referred to herein as “CO 2 lean amine absorbent” or simply “lean amine absorbent”. The lean amine absorbent may also contain heat stable salts (HSS) formed as degradation products in the regenerator as a result of the exposure to high temperature and/or the presence of O 2 (absorbed by the absorbent in the absorption unit). The lean amine absorbent leaving the regenerator may be directed to a lean absorbent/rich absorbent heat exchanger ( 123 ) where it is used for pre-heating rich amine absorbent from line ( 108 ) directed towards the regenerator ( 109 ).
[0059] The amine based carbon dioxide (CO 2 ) capture system ( 100 ) may further comprise an amine absorbent reclaimer circuit ( 115 ) operative for at least partial removal of HSS from the circulating amine absorbent, so as to prevent accumulation of HSS and the problems associated therewith. The amine absorbent reclaimer circuit ( 115 ) is generally configured to withdraw a slipstream of the main amine absorbent flow. The amine absorbent reclaimer circuit ( 115 ) may preferably be configured to withdraw the slipstream of lean amine absorbent from a point in the process where the amine absorbent has a low CO 2 loading, i.e. lean amine absorbent. More particularly, the slipstream of amine absorbent may be withdrawn from the regenerator ( 109 ) or from the liquid conduit ( 114 ) between the regenerator ( 109 ) and a lean absorbent/rich absorbent heat exchanger ( 123 ). The lean amine absorbent from the regenerator generally has a temperature of 100° C. or higher, such as 120° C. or higher. This allows the thermal energy provided to the lean amine absorbent in the regenerator to be utilized in the stripping and/or flashing step. If necessary, the slipstream of lean amine absorbent containing HSS may also be withdrawn from the lean absorbent/rich absorbent heat exchanger ( 123 ) or from the liquid conduit ( 105 ) between the lean absorbent/rich absorbent heat exchanger ( 123 ) and the CO 2 absorber ( 101 ) performing the scrubbing step. The slipstream may generally comprise in the range of 0.001-50% by volume of the main amine absorbent flow, such as in the range of 0.01-10% by volume of the main amine absorbent flow.
[0060] FIG. 2 represents an amine based carbon dioxide (CO 2 ) capture system according to the invention, comprising an amine absorbent reclaimer circuit ( 115 ). The amine absorbent reclaimer circuit ( 115 ) is connected to the regenerator side of an amine based carbon dioxide (CO 2 ) capture system, e.g. as described above with reference to FIG. 1 .
[0061] The amine absorbent reclaimer circuit ( 115 ) comprises an amine reclaimer ( 116 ) for separating heat stable salts from the amine absorbent. In this embodiment, the amine reclaimer ( 116 ) is an electrodialysis (ED) unit.
[0062] The ED unit is used to transport salt ions, e.g. HSS, from the amine absorbent through ion-exchange membranes to another solution under the influence of an applied electric potential difference. This is done in a configuration called an electrodialysis cell. The cell consists of a feed (diluate) compartment and a concentrate (e.g. brine) compartment formed by an anion exchange membrane and a cation exchange membrane placed between two electrodes. Multiple electrodialysis cells may be arranged into a configuration called an electrodialysis stack, with alternating anion and cation exchange membranes forming the multiple electrodialysis cells. The ED process results in a reduction of HSS in the amine absorbent as HSS ions are concentrated in the concentrate solution.
[0063] In an alternative embodiment, the amine reclaimer ( 116 ) is an ion exchange unit comprising an ion exchange resin suitable for the removal of HSS ions from the amine absorbent.
[0064] The amine absorbent reclaimer circuit ( 115 ) further comprises a residual CO 2 removal unit ( 117 ) arranged upstream of the amine reclaimer ( 116 ) with reference to the lean amine absorbent stream. In the embodiment of FIG. 2 the residual CO 2 removal unit ( 117 ) is a flash drum. Flash (or partial) evaporation is the partial vaporization that occurs when a saturated liquid stream undergoes a reduction in pressure by passing through a throttling valve or other throttling device. If the throttling valve or device is located at the entry into a pressure vessel so that the flash evaporation occurs within the vessel, then the vessel is often referred to as a flash drum.
[0065] The flash drum ( 117 ) comprises a pressure vessel having a feed inlet, a gas outlet and a liquid outlet. The feed inlet is equipped with a throttling device configured to decrease the pressure of the feed stream before it enters the pressure vessel. The exact configuration of flash drums suitable for use in the system described herein will be readily recognized by a person skilled in the art.
[0066] The lean amine absorbent enters the flash drum ( 117 ) via a feed line ( 118 ). The temperature and pressure of the lean amine absorbent is determined by the temperature and pressure of the lean amine absorbent in, or leaving, the regeneration unit ( 109 ). The pressure of the lean amine absorbent may optionally be decreased by means of a throttling valve or device arranged in the feed inlet of the flash drum. In the flash drum ( 117 ), the pressure is then reduced, such that more volatile components, e.g. residual CO 2 , at least partially evaporate, while less volatile components, e.g. amine absorbent and water, remain in liquid phase. The pressure inside of the flash drum may preferably be low, such as in the range of 0-2 bar gauge. Evaporated components, e.g. residual CO 2 , leave the flash drum ( 117 ) through a gas outlet via line ( 119 ), while liquid components, e.g. amine absorbent and water, leave the flash drum ( 117 ) through a liquid outlet via line ( 120 ).
[0067] In an alternative embodiment, the residual CO 2 removal unit ( 117 ) is a stripper. The stripper may, for example, comprise a generally cylindrical steel vessel configured to operate within a pre-determined pressure range. The stripper is preferably equipped with one or more suitable mass transfer devices, such as valve trays, sieve trays, structured packing, random packing or other suitable packing materials, or a combination thereof. A heating system/device may be provided in the stripper for heating the amine absorbent. The stripper is preferably configured to provide sufficient heat to the amine absorbent so that low boiling point components, for example CO 2 , are transferred to a gas phase, while high boiling point components, for example water and amine, are collected in a liquid phase at the bottom of the stripper. The amine absorbent may be heated up appropriately via, for example, a reboiler. The reboiler may be heated using, for example, electrically generated heat or steam. The stripper is configured to discharge the gas phase, containing CO 2 , via a gas exit, and the liquid phase, containing water and amine, via a liquid exit.
[0068] In yet another alternative embodiment, the residual CO 2 removal unit ( 117 ) comprises a stripper and a flash drum arranged in series, such that a first portion of residual CO 2 may be removed in the stripper, and a second portion of residual CO 2 may be removed in the flash drum. The stripper and flash drum may be as described above. The lean amine absorbent first enters the stripper, where it is heated to a temperature sufficient to transfer low boiling point components, for example CO 2 , to a gas phase, while high boiling point components, for example water and amine, are collected in a liquid phase at the bottom of the stripper. The liquid phase is then forwarded to the flash drum, where the pressure is reduced so that more volatile components, e.g. residual CO 2 , at least partially evaporate, while less volatile components, e.g. amine absorbent and water, remain in liquid phase. The liquid components, e.g. amine absorbent and water, leave the flash drum through a liquid outlet and is forwarded to the reclaimer.
[0069] Referring now to FIG. 2 , the lean amine absorbent, from which residual CO 2 has been at least partially removed, is forwarded via line ( 120 ) to the amine reclaimer ( 116 ), wherein heat stable salts are at least partially separated from the amine absorbent to produce a lean amine absorbent depleted in HSS.
[0070] Optionally, the amine absorbent reclaimer circuit ( 115 ) further comprises a cooler ( 121 ) arranged between the residual CO 2 removal unit ( 117 ) and amine reclaimer, and configured to adjust the temperature of the lean amine absorbent from the residual CO 2 removal unit before it enters the amine reclaimer ( 116 ).
[0071] Furthermore, an amine absorbent reclaimer circuit ( 115 ) comprising a cooler ( 121 ), may optionally further comprise an indirect heat exchanger (not shown) arranged between the residual CO 2 removal unit ( 117 ) and the cooler ( 121 ) and configured to cool the lean amine absorbent from the residual CO 2 removal unit ( 117 ) using the lean amine absorbent depleted in HSS leaving the amine reclaimer ( 116 ). The indirect heat exchanger may for example be a conventional plate or shell and tube type heat exchanger.
[0072] The lean amine absorbent depleted in HSS leaves the amine reclaimer ( 116 ) and is forwarded via return line ( 122 ) back to the CO 2 capture system ( 100 ). The lean amine absorbent depleted in HSS may, for example be reintroduced into the regenerator ( 109 ), absorber ( 101 ), or into a suitable liquid conduit connecting the regenerator ( 109 ) and absorber ( 101 ). The position for reintroduction of the lean amine absorbent from the amine reclaimer circuit may be selected depending on the specific temperature and pressure of the absorbent. One suitable position for reintroduction, as shown in FIG. 2 , would be into line ( 114 ), either upstream or downstream of a lean absorbent/rich absorbent heat exchanger ( 123 ). The separated heat stable salts leave the amine reclaimer via line ( 124 ).
Example
Amine Loss into the Waste Brine Stream of the Electrodialysis Unit
[0073] Amine losses from a lean amine absorbent into the waste brine of a 3-loop ElectroSep electrodialysis unit (ElectroSep Inc., USA) was evaluated with various CO 2 loadings in the lean amine absorbent. 1.2 and 1.4 wt % amine was observed in the waste brine stream when the lean amine absorbent had CO 2 loadings of 2.2 and 2.9 wt % CO2, respectively. Only 0.3 wt % amine was observed in the waste brine stream with 0.01 wt % CO 2 in the lean amine absorbent. This represents a 75-80% reduction in amine losses compared to the higher lean loadings. This example shows that a significant reduction of amine losses can be achieved by reduction of the CO 2 loading of the lean amine absorbent, e.g. by stipping or flashing, prior to feeding it to a reclaimer unit, such as a electrodialysis unit.
[0074] While the invention has been described with reference to a number of preferred 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 embodiments 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. 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.
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The proposed invention relates to a method and a system for the removal of heat stable amine salts from an amine absorbent used in a carbon dioxide (CO 2 ) capture process, the method comprising: withdrawing amine absorbent containing heat stable amine salts from the CO 2 capture process; subjecting the withdrawn amine absorbent containing heat stable amine salts to a residual CO 2 removal step; subjecting the amine absorbent from the residual CO 2 removal step to a separation step to separate heat stable amine salts from the amine absorbent; and returning the amine absorbent having a reduced concentration of heat stable amine salts to the CO 2 capture process.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. Utility patent application Ser. No. 09/448,311, filed Nov. 23, 1999, and issued Apr. 16, 2002, as U.S. Pat. No. 6,370,801.
TECHNICAL FIELD
The present invention relates generally to equipment using one tool member to collect and a second tool member cooperatively positioned to assist in collecting, and more particularly, to hydraulic powered tools mountable on a boom of a vehicle or stationary platform.
BACKGROUND OF THE INVENTION
Assemblies such as large grapples or buckets with a bucket extension or a lid have been employed in the past for collection and sorting of large and small objects or quantities of material. Many of these collection assemblies have two members such as a bucket and a bucket extension which are selectively operable to work together. The collection assembly is generally attached to a boom arm of a platform such as a vehicle. The two members of the collector assembly are positioned to cooperatively engage each other to assist in the collection operation. One member assists the other member by providing a complimentary function such as in the case of the bucket lid or extension providing the bucket with enlarged capacity extension in one position, or grasping therebetween materials scooped up by the bucket. In the case of a grapple, the two members grasp items therebetween.
Generally, means are provided to separately supply rotational torque to one or both members in order to move one member relative to the other member. The operational limitation of a particular collection assembly is directly dependent upon the maximum amount of torque that can be supplied to the members. If the torque is not sufficient, the object size or the quantity of the material collected is limited.
It will therefore be appreciated that there has long been a significant need for an improved collection assembly. It should include a torque-transmitting member which is able to reliably supply sufficient torque to perform rough work such as tearing down a building and more delicate work such as sorting bricks from wood for recycling. The present invention fulfills these needs and further provides other related advantages.
SUMMARY OF THE INVENTION
The present invention resides in a fluid-powered tool assembly usable with a stationary or movable support platform having an arm. The tool assembly includes an arm connection member pivotably connectable to the arm for rotation about a first axis. It also includes a first tool member, and a second tool member positioned to cooperate with the first tool member. The assembly includes a body having a longitudinal axis and one of the first and second members attached thereto for movement with the body. A shaft is rotatably disposed within the body in general alignment with the body axis for rotation about a second axis spaced apart from the first axis. The shaft has the other of the first and second tool members attached thereto for movement with the shaft. A linear-to-rotary torque transmission member is mounted for longitudinal movement within the body in response to selective application of pressurized fluid thereto. The torque-transmitting member engages the body and the shaft to translate longitudinal movement of the torque-transmitting member into rotational movement of the shaft relative to the body. The first and second tool members are rotatable relative to each other about the second axis by operation of the torque-transmitting member. The pivotal connection of the arm connection member to the arm allows rotation of the tool assembly as a unit about the first axis.
In some embodiments, the tool assembly includes a support housing sized to receive and support the body therein. In one embodiment the body has first and second end portions, and the first body end portion is attached to the support housing and the second body end portion is engaged by the support housing to restrict transverse movement of the second body end portion. The one of the first or second tool members attached to the body is indirectly attached to the body through the support housing in one embodiment.
In another embodiment, the tool assembly includes a lateral tilt assembly having an actuator operable to laterally tilt the first and second tool members relative to the arm. The arm connection member is attached to the lateral assembly. This embodiment may also include a rotation assembly to selectively rotate the tool assembly about a transverse axis. A disclosed embodiment uses a turntable bearing.
In certain embodiments, the shaft has first and second opposite shaft end portions with the other of the first and second tool members attached to both the first and second shaft end portions for movement with the shaft.
One embodiment of the invention further includes a vehicle frame to which the arm of the support platform is attached. The tool assembly is preferably attached to the arm.
Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a left side elevational view of a backhoe vehicle shown with a tool assembly embodying the present invention having a bucket and a bucket extension for a collection operation.
FIGS. 2 a - 2 d are enlarged, left side elevational views of the boom arm and the tool assembly of FIG. 1 removed from the vehicle, with the bucket shown in various rotational positions relative to the boom arm and the bucket extension shown in various rotational positions relative to the bucket.
FIG. 3 is an enlarged, front elevational, sectional view of the fluid-powered rotary actuator of FIG. 1 used to rotate the bucket extension relative to the bucket shown without attachment members for the boom arm.
FIG. 4 is an enlarged, front elevational, sectional view of the tool assembly of FIG. 1 shown removed from the boom arm using an alternative manner of attaching the bucket to the actuator body.
FIG. 5 is a front elevational view of the tool assembly of FIG. 4 .
FIG. 6 is a left side elevational view of the tool assembly of FIG. 5 .
FIG. 7 is a front elevational, sectional view of a first alternative embodiment of the tool assembly of FIG. 1 .
FIG. 8 is a left side elevational view of the tool assembly of FIG. 7 .
FIG. 9 is a front elevational, sectional view of a second alternative embodiment of the tool assembly of FIG. 1 .
FIG. 10 a is a left side fragmentary, elevational view of the boom arm modified for use with a third alternative embodiment of the tool assembly of FIG. 1 showing only the rotary actuator thereof.
FIG. 10 b is a right side fragmentary, elevational view of the third alternative embodiment of the tool assembly mounted to the boom arm coaxial with the bucket.
FIG. 10 c is an enlarged, fragmentary, front view of the third alternative embodiment of the tool assembly shown in FIG. 10 b.
FIG. 11 a is a left side elevational view of the boom arm and a fourth alternative embodiment of the tool assembly of FIG. 1 also providing lateral tilting and rotation of the tool assembly relative to the plane swept out by the boom arm.
FIG. 11 b is a left side elevational view of the fourth alternative embodiment of the tool assembly of FIG. 11 a with the bucket rotated 90°.
FIG. 11 c is a left side elevational view of the fourth alternative embodiment of the tool assembly of FIG. 11 a with the bucket rotated 180°.
FIG. 11 d is a front elevational view of the fourth alternative embodiment of the tool assembly of FIG. 11 a with the bucket laterally tilted.
FIG. 11 e is a front elevational view of the fourth alternative embodiment of the tool assembly of FIG. 11 a in the rotational position of FIG. 11 b.
FIG. 11 f is a front elevational view of the fourth alternative embodiment of the tool assembly of FIG. 11 a in the rotational position of FIG. 11 b and with the bucket laterally tilted.
FIGS. 12 a and 12 b are left side elevational views of the boom arm and an alternative tool assembly embodying the present invention having first and second grapple members, with the first grapple member shown in various rotational positions relative to the boom arm and the second grapple member shown in various rotational positions relative to the first grapple member.
FIG. 13 is an enlarged, front elevational, sectional view of the alternative tool assembly of FIGS. 12 a and 12 b shown removed from the boom arm.
FIG. 14 is a left side elevational view of the alternative tool assembly of FIGS. 12 a and 12 b shown removed from the boom area.
FIG. 15 a is a front elevational view of the first grapple member of the alternative tool assembly of FIGS. 12 a and 12 b.
FIG. 15 b is a left side elevational view of the first grapple member of FIG. 15 a.
FIG. 15 c is a front elevational view of the second grapple member of the alternative tool assembly of FIGS. 12 a and 12 b.
FIG. 15 d is a left side elevational view of the second grapple member of FIG. 15 c.
FIG. 16 a is a left side elevational view of the boom arm and a first alternative embodiment of the alternative tool assembly of FIGS. 12 a and 12 b providing lateral tilting and rotation of the alternative tool assembly relative to the plane swept out by the boom arm.
FIG. 16 b is a front elevational view of the first alternative embodiment of the alternative tool assembly of FIG. 16 a with the tool assembly rotated 90°.
FIG. 16 c is a front elevational view of the first alternative embodiment of the alternative tool assembly of FIG. 16 a in the rotational position of FIG. 16 b and with the alternative tool assembly laterally tilted.
FIG. 17 is a left side elevational view of the boom arm and a second alternative embodiment of the alternative tool assembly of FIGS. 12 a and 12 b also providing lateral tilting and rotation to the alternative tool assembly relative to the plane swept out by the boom arm.
DETAILED DESCRIPTION OF THE INVENTION
As shown in the drawings for purposes of illustration, the present invention is embodied in a fluid-powered tool assembly, indicated generally by reference numeral 10 . As shown in FIG. 1, the tool assembly 10 is usable with a support platform shown as a vehicle 12 . The support platform may also be a stationary platform. The vehicle 12 has a first boom arm 14 which is pivotally connected by one end to a base member 16 . A pair of hydraulic cylinders 18 (only one being shown in FIG. 1) is provided for raising and lowering the first arm 14 in a generally vertical arm rotation plane with respect to the base member 16 . A second boom arm 20 is pivotally connected by one end to an end of the first arm 14 remote from base member 16 . A hydraulic cylinder 22 is provided for rotation of the second arm 20 relative to the first arm 14 in the same vertical arm rotation plane as the first arm operates.
The base member 16 is pivotally attached to the vehicle 12 for pivotal movement about a vertical axis so as to permit movement of the first and second arms 14 and 20 in unison to the left or right, with the first and second arms always being maintained in the arm rotation plane. It is noted that while the arm rotation plane is forwardly extending as shown in FIG. 1, as the base member 16 is pivoted the arm rotation plane turns about the vertical pivot axis of the base member and thus loses its forward-to rearward orientation, with the plane actually extending laterally should the base member be sufficiently rotated. When the tool assembly 10 is used by an excavator with a cab unit mounted by a turntable bearing to a tracked carriage, the cab and hence the arm rotation plane of the first and second arms 14 and 20 can rotate 360° relative to the carriage.
A rotation link 24 is pivotally connected through an interconnecting link 26 to an end portion 28 of the second arm 20 remote from the point of attachment of the second arm to the first arm 14 . A hydraulic cylinder 30 is provided for selective movement of the rotation link 24 relative to the second arm 20 .
As is conventional, a free end portion 31 of the second arm 20 and a free end portion 32 of the rotation link 24 each has a transverse aperture therethrough for connection of the second arm and the rotation link to a tool using selectively removable attachment pins 33 a and 33 b , respectively. The attachment pins 33 a and 33 b are insertable in the apertures to pivotally connect a conventional tool to the second arm and the rotation link. When using a conventional tool, this permits the tool to be rotated about the attachment pin 33 of the second arm 20 upon movement of the rotation link 24 relative to the second arm as a result of extension or retraction of the hydraulic cylinder 30 to rotate the tool in the arm rotation plane defined by the first and second arms 14 and 20 . A quick coupler or other mounting means may be used to connect the tool to the second arm 20 and the rotation link 24 . In an alternative embodiment not shown, the links 24 and 26 are not used and the hydraulic cylinder 30 is directly attached to the tool to be rotated.
As illustrated in FIG. 1, the tool assembly 10 comprises a first tool which in the case of the illustrated embodiment is a bucket 34 . The bucket 34 has a forward working edge 35 extending laterally, generally transverse to the arm rotation plane. The bucket 34 further includes a first clevis 36 and a second clevis 38 . The first clevis 36 is located toward the bucket working edge 35 and is attached to the free end portion 31 of the second arm 20 with the attachment pin 33 a . The second clevis 38 is located rearwardly away from the first clevis 36 and is attached to the free end portion 32 of the rotation link 24 with the attachment pin 33 b . The first and second devises 36 and 38 are in general parallel alignment with the arm rotation plane of the bucket 34 . It should be understood the present invention may be practiced using other tools as work implements, and is not limited to buckets or other collection tools and devices.
The tool assembly 10 also includes a second tool which in the case of the embodiment illustrated in FIG. 1 is a lid or bucket extension 39 . As part of the tool assembly 10 , both the bucket 34 and the bucket extension 39 are connected to a rotary actuator 40 for pivotal movement relative to each other. This allows for the bucket extension 39 to rotate relative to the bucket 34 about an axis of rotation 41 of the rotary actuator 40 (see FIG. 3 ). The rotary actuator 40 provides rotational torque which causes the bucket extension 39 to rotate about the axis 41 of the rotary actuator 40 relative to the bucket 34 .
FIGS. 2 a - 2 d illustrate four positions of the bucket 34 relative to the second arm 20 . In operation, the movement of the rotation link 24 relative to the second arm 20 causes the bucket 34 to be selectively rotated through the arm rotation plane about the attachment pin 33 a of the second arm 20 as the rotation link is moved relative to the second arm 20 by the hydraulic cylinder 30 . FIGS. 2 a and 2 c show the bucket 34 rotated in a fully counterclockwise position relative to the second arm 20 with the hydraulic cylinder 30 in a fully retracted state. FIG. 2 b shows the bucket 34 in a midway position relative to the second arm 20 with the hydraulic cylinder in a semi-extended state. FIG. 2 d shows the bucket 34 rotated in a fully clockwise position relative to the second arm 20 with the hydraulic cylinder 30 in a fully extended state.
FIGS. 2 a - 2 d also illustrate possible positions of the bucket extension 39 relative to the bucket 34 resulting from operation of the rotary actuator 40 causing the bucket extension to rotate about the axis 41 of the rotary actuator. The position of the bucket extension 39 relative to the bucket 34 produced by operation of the rotary actuator 40 is independent of the position of the bucket 34 relative to the second arm 20 produced by operation of the hydraulic cylinder 30 , although in certain positions of the bucket the presence of the second arm blocks full movement of the bucket extension through its full range of movement. FIG. 2 a shows the bucket extension 39 in a fully counterclockwise closed position relative to the bucket 34 . FIG. 2 c shows the bucket extension 39 in a fully clockwise open position relative to the bucket 34 . FIGS. 2 b and 2 d show the bucket extension 39 in a midway position relative to the bucket 34 with the bucket 34 and bucket extension grasping therebetween an object such as a large rock (FIG. 2 b ) or a culvert pipe (FIG. 2 d ). The bucket extension may also be selectively and delicately used to grasp chosen articles in cleanup or sorting processes.
The construction of the rotary actuator 40 is best shown in FIG. 3 . The rotary actuator 40 has an elongated housing or body 42 with a cylindrical sidewall 44 and first and second ends 46 and 48 , respectively. An elongated rotary drive or output shaft 50 is coaxially positioned within the body 42 and supported for rotation relative to the body 42 . The shaft 50 extends the full length of the body 42 , and has a flange portion 52 at the first body end 46 . The shaft 50 has an annular shaft nut 58 threadably attached thereto at the second body end 48 . The shaft nut 58 has a threaded interior portion threadably attached to a correspondingly threaded perimeter portion 60 of the shaft 50 and the shaft nut rotates with the shaft. The shaft nut 58 is generally locked in place against rotation relative to the shaft 50 .
Seals 62 are disposed between the shaft nut 58 and the shaft 50 , and between the shaft nut and the body sidewall 44 to provide a fluid-tight seal therebetween. Seals 64 are disposed between the shaft flange portion 52 and the body sidewall 44 to provide a fluid-tight seal therebetween. Radial bearings 66 and thrust bearings 68 are disposed between the shaft flange portion 52 and the body sidewall 44 , and between the shaft nut 58 and the body sidewall 44 to support the shaft 50 against radial and longitudinal thrust loads and to secure the shaft 50 in the body 42 .
The exterior end surfaces of the shaft flange portion 52 and the shaft nut 58 are flat and each have a plurality of apertures 70 and 72 , respectively, which threadably receive attachment bolts 74 (shown in FIGS. 2 a - 2 d ) to attach the bucket extension 39 to the shaft 50 for movement therewith relative to the body 42 . The first body end 46 also has a flange portion 76 with apertures 78 which receive attachment bolts 80 (shown in FIGS. 2 a - 2 d ) for attaching the body 42 of the rotary actuator 40 to the bucket 34 .
As shown in FIG. 3, an annular piston sleeve 82 is coaxially and reciprocally mounted within the body 42 coaxially about the shaft 50 . The piston sleeve 82 has outer splines, grooves or threads 84 over a portion of its length which mesh with inner splines, grooves or threads 86 of a splined intermediate interior ring gear portion 87 of the body sidewall 44 . The piston sleeve 82 is also provided with inner splines, grooves or threads 88 which mesh with outer splines, grooves or threads 90 provided on a portion of the shaft 50 toward the first body end 46 . It should be understood that while helical splines are shown in the drawings and described herein, the principle of the invention is equally applicable to any form of linear-to-rotary motion conversion means, such as balls or rollers. At least one pair of meshing splines, grooves or threads are helical to convert axial motion of the piston sleeve 82 to rotary motion of the shaft 50 . Alternatively, all the splines, grooves or threads can be helical and/or can be threaded in the same direction (e.g., left-handed or right-handed) or different directions, depending on the desired direction and amount of shaft rotation per unit of axial motion the piston sleeve 82 . It should be understood that while splines are shown in the drawings and described herein, the principle of the invention is equally applicable to any form of linear-to-rotary motion conversion arrangement, such as balls or rollers, and that the splines can include any type of groove or channel suitable for such motion conversion.
In the illustrated embodiment of the invention, the piston sleeve 82 has an annular piston head member 92 which has a threaded exterior portion 94 threadably attached to a second annular piston head member 96 by a correspondingly threaded interior portion 98 of the second annular piston head member 96 . The two piston head members 92 and 96 are thus joined to form a common piston head 99 . Seals 100 are disposed between the piston head member 92 and a smooth exterior wall shaft of the shaft 50 to provide a fluid-tight seal therebetween. Seals 102 are disposed between the piston head member 96 and the interior wall surface of the body-sidewall 44 to provide a fluid tight seal therebetween. A seal 104 is disposed between the piston head member 92 and piston head member 96 to provide a fluid tight seal therebetween.
As will be readily understood, reciprocation of the common piston head 99 within the body 42 occurs when hydraulic oil, air or any other suitable fluid under pressure selectively enters through one or the other of a first port P 1 which is in fluid communication with a fluid-tight compartment within the body to a side of the piston head toward the first body end 46 or through a second port P 2 which is in fluid communication with a fluid-tight compartment within the body to a side of the piston head toward the second body end 48 . As the piston head 99 and the piston sleeve 82 , of which the common piston head is a part, linearly reciprocates in an axial direction within the body 42 , the outer splines, grooves or threads 84 of the piston sleeve engage or mesh with the inner splines, grooves or threads 86 of the body sidewall 44 to cause rotation of the piston sleeve, where both the outer splines 84 and the inner splines 86 are helical. The linear and rotational movement of the piston sleeve 82 is transmitted through the inner splines, grooves or threads 88 of the piston sleeve to the outer splines, grooves or threads 90 of the shaft 50 to cause the shaft to rotate. The smooth wall surface of the shaft 50 and the smooth wall surface of the body sidewall 44 have sufficient axial length to accommodate the full end-to-end reciprocating stroke travel of the piston sleeve 82 within the body 42 . Longitudinal movement of the shaft 50 is restricted, thus most movement of the piston sleeve 82 is converted into rotational movement of the shaft 50 . Depending on the slope and direction of turn of the various splines, grooves or threads, there may be provided a multiplication of the rotary output of the shaft 50 and a high level of torque may also be provided.
The application of fluid pressure to the first port P 1 produces axial movement of the piston sleeve 82 toward the second body end 48 . The application of fluid pressure to the second body port P 2 produces axial movement of the piston sleeve 82 toward the body first end 46 . The rotary actuator 40 provides relative rotational movement between the body 42 and shaft 50 through the conversion of linear movement of the piston sleeve 82 into rotational movement of the shaft, in a manner well known in the art. The shaft 50 is selectively rotated by the application of fluid pressure, and the rotation is transmitted to the bucket extension 39 or other tool attached thereto through the flange portion 52 of the shaft 50 to selectively rotate the bucket extension about the axis 41 of the rotary actuator 40 relative to the bucket 34 . It is noted that operation of the rotary actuator 40 to move the bucket extension 39 relative to the bucket 34 is not only independent of the rotation of the bucket 34 relative to the second arm 20 by operation of the hydraulic cylinder 30 , but is also about the axis 41 which is different and spaced apart from the axis of rotation of the bucket about the attachment pin 33 a.
FIGS. 4-6 show the tool assembly 10 having an alternative manner of attaching the bucket 34 to the body 42 of the rotary actuator 40 . In particular, the opposing side walls 34 a and 34 b of the bucket 34 each have an aperture 34 c therein which receives a corresponding one of the first and second body ends 46 and 48 of the body 42 therein. The first and second body ends 46 and 48 are welded to the corresponding side walls 34 a and 34 b of the bucket 34 by welds W. Thus, the attachment apertures 78 in the flange portion 76 of the first body end are not necessary.
FIGS. 7 and 8 depict a first alternative embodiment of the tool assembly 10 in which the rotary actuator 40 is removably positioned within a support housing or tube 105 . In this embodiment, the flange portion 76 of the first body end 46 uses the attachment bolts 80 to attach the actuator body 42 to a flange portion 106 of the support tube 105 . The second body end 48 of the rotary actuator 40 is snugly received in the support tube 105 in engagement with a cylindrical wall 108 thereof, but is not attached thereto. This limits transverse movement of the second body end 48 during operation of the tool assembly 10 . The support tube 105 also allows the actuator 40 to be slidably received coaxially within the support tube and protected from damage by the cylindrical wall 108 of the support tube. The support tube 105 further adds structural rigidity to the assembly 10 . The rotary actuator 40 is slidably removable from the support tube 105 for servicing of the actuator. In this embodiment, the bucket side walls 34 a and 34 b are welded to the support tube 105 by welds W, rather than to the first and second body ends 46 and 48 .
FIG. 9 depicts a second alternative embodiment of the tool assembly 10 in which the rotary actuator 40 does not extend the entire length of the support tube 105 . Like the embodiment of FIGS. 7 and 8, in the embodiment of FIG. 9, the actuator body 42 is attached to the support tube 105 only at the first body end 46 of the actuator and is slidably received in the support tube with the second body end 48 snugly received by the cylindrical wall 108 . In an alternative design, to improve alignment, rather than bolting the bucket extension 39 to the shaft 50 , the shaft may be terminated with straight splines which project axially outward and drivingly engage corresponding straight splines of a recess in the bucket extension coaxially aligned with the shaft of the rotary actuator 40 . Because the rotary actuator 40 used in FIG. 9 is shorter than the bucket 34 is wide, the bucket extension 39 is not attached directly to the shaft nut 58 as in the previously described embodiments. Instead, a pivot pin 109 is used to rotatably mount the bucket extension 39 to an end plate 110 closing the end of the tube support 105 at the end opposite the end to which the flange portion 76 of the first body end 46 is attached. The pivot pin 109 provides an axis of rotation aligned with the axis 41 of the rotary actuator 40 .
A third alternative embodiment of the tool assembly 10 is shown in FIGS. 10 a - 10 c using a bucket lid 39 ′ instead of a bucket extension. In this embodiment the rotary actuator 40 is mounted to the second arm 20 in coaxial arrangement with the bucket 34 and the bucket lid 39 ′ for both rotation of the bucket relative to the second arm and rotation of the bucket lid relative to the bucket about the axis 41 of the rotary actuator. It is noted that with this arrangement the bucket lid 39 ′ is located laterally inward of the sidewalls 34 a and 34 b of the bucket 34 .
In this third alternative embodiment, the body 42 of the rotary actuator 40 has a pair of attachment flanges 43 by which the actuator body is securely attached to a pair of attachment flanges 21 projecting from the free end portion 31 of the second arm 20 . The attachment flanges 43 of the actuator body 42 and the attachment flanges 21 of the second arm 20 each have two transverse apertures therethrough. The one set of apertures of the attachment flanges 21 and 43 are aligned to accept a first pin 111 a and the other set of apertures of the attachment flanges 21 and 43 are aligned to accept a second pin 111 b to securely attach the rotary actuator 40 to the second arm 20 for movement therewith and to prevent rotation of the actuator body 42 relative to the second arm. To provide pivotal movement of the bucket 34 relative to the second arm 20 by operation of the hydraulic cylinder 30 using the links 24 and 26 , in the manner describe above, the attachment pin 33 a is rotatably received in an aperture 50 a extending longitudinally fully through the shaft 50 of the rotary actuator 40 . As before, the first clevis 36 of the bucket 34 receives the attachment pin 33 a for rotation of the bucket thereabout in response to operation of the hydraulic cylinder 30 . To facilitate independent rotation of the bucket 34 on the attachment pin 33 a from rotation of the shaft 50 of the rotary actuator 40 , the attachment pin 33 a is rotatably supported in the shaft aperture 50 a by bearings 50 b . To rotate the bucket lid 39 ′ relative to the second arm 20 attached to the actuator body 42 , and hence also the bucket 34 , the bucket lid is attached to the shaft flange portion 52 and shaft nut 58 of the shaft 50 , as described above, and rotates with the shaft in response to the linear reciprocation of the piston sleeve 82 . In this embodiment, the relative rotational movement of the bucket lid 39 ′ and the bucket 34 depends upon the operation of both the hydraulic actuator 30 and the rotary actuator 40 .
FIGS 11 a - 11 f show a fourth alternative embodiment of the tool assembly 10 which allows the bucket 34 , bucket extension 39 and rotary actuator 40 to be tilted and rotated relative to the arm rotation plane defined by the first and second arms 14 and 20 . The rotary actuator based tiltable feature is fully disclosed in U.S. Pat. No. 5,487,230, Tool Actuator With Adjustable Attachment Mount, which is incorporated herein in its entirety. The first and second celvises 36 and 38 are used to removably attach the rotary actuator 40 and bucket 34 to a turntable bearing assembly 113 . The turntable bearing assembly 113 is also attached to a rotary actuator assembly 112 having a rotary actuator constructed generally as described above for rotary actuator 40 and arranged transverse to the rotary actuator 40 . The rotary actuator assembly 112 has a pair of clevis 112 b which are attached to the free end portion 31 of the second arm 20 and to the free end portion 32 of the rotation link 24 .
The bucket 34 , bucket extension 39 and rotary actuator 40 can be selectively rotated or tilted about an axis of rotation 112 a of the rotary actuator assembly 112 and selectively rotated about an axis of rotation 113 a of the turntable bearing assembly 113 . The turntable bearing assembly 113 includes a turntable bearing with a first member 113 b thereof to which the tool assembly 10 is attached using the first and second devises 36 and 38 for rotation therewith. The first turntable member 113 b has a ring gear with internal teeth. A second turntable member 113 c rotatably supports the first turntable member 113 b therebelow and supports a hydraulic motor and brake unit 113 d with a bull gear drivingly engaging the ring gear to selectively rotate the first turntable member 113 b relative to the second turntable member 113 c when the hydraulic motor 113 d is powered. This provides 360° of continuous rotation.
The axis of rotation 112 a of the rotary actuator assembly 112 is transverse to the axis of rotation 41 of the rotary actuator 40 , and the axis of rotation 113 a of the turntable bearing assembly 113 is transverse to the axis of rotation 41 of the rotary actuator 40 . Further, the axis of rotation 112 a of the rotary actuator assembly 112 is transverse to the axis of rotation 113 a of the turntable bearing assembly 113 , to provide an orthogonal arrangement of axes of rotation 41 , 112 a and 113 a , and provide a degree of movement of the bucket 34 and bucket extension that significantly increases the efficiency and effectiveness of operation. The bucket 34 , bucket extension 39 and rotary actuator 40 are shown in the side view of FIG. 11 b rotated as a unit by 90° about the turntable bearing axis of rotation 113 a from the position shown in the side view of FIG. 11 a by operation of the turntable bearing assembly 113 . In the side view of FIG. 11 c the rotation is 180° from the position in FIG. 11 a . In the front view of FIG. 11 d , the bucket 34 , bucket extension 39 and rotary actuator 40 are shown in the same rotational position as shown in FIG. 11 a , but tilted laterally relative to the arm rotation plane by rotation about the rotational axis 112 a of the rotary actuator assembly 112 by operation of the rotary actuator assembly 112 .
In the front views of FIGS. 11 e and 11 f , the bucket 34 , bucket extension 39 and rotary actuator 40 are shown in the same rotational position as shown in FIG. 11 b , but in FIG. 11 f they are tilted laterally relative to the arm rotation plane by rotation about the rotational axis 112 a of the rotary actuator assembly 112 by operation of the rotary actuator assembly 112 .
FIGS. 12 a and 12 b show an alternative tool assembly 10 ′ which comprises a brush rake or grapple having a first grapple member 120 and an opposing second grapple member 122 . The first grapple member 120 is attached to the actuator body 42 by the attachment bolts 80 and the second grapple member 122 is attached to the shaft flange portion 52 by the attachment bolts 74 , much as described above for the embodiment of FIGS. 1-3. FIG. 12 a shows the tool assembly 10 ′ in a fully open position and FIG. 12 b shows the tool assembly in a closed position grasping a pipe. As viewed in FIGS. 12 a and 12 b , the rotary actuator 40 rotates the second grapple member 122 in a counterclockwise direction relative to the first grapple member 120 when moving from an open position (FIG. 12 a ) to a closed position (FIG. 12 b ).
FIGS. 13 and 14 illustrate the tool assembly 10 ′ of FIGS. 12 a and 12 b as having a similar construction to the tool assembly 10 of FIG. 7 with the rotary actuator 40 slidably received into the support tube 105 and with the several fingers comprising the first grapple member 120 fixedly attached to the support tube. Two of the fingers comprising the second grapple member 122 are attached to the shaft flange portion 52 and shaft nut 58 of the rotary actuator 40 by the attachment bolts 74 for rotation with the shaft 50 .
FIGS. 15 a and 15 b illustrate the first grappling member 120 as having four grappling prongs or fingers 128 and cross members 130 extending through transverse apertures 132 in the grappling fingers and fixedly attached thereto. FIGS. 15 c and 15 d illustrate the second grappling member 122 as having grappling prongs or fingers 134 and cross members 136 extending through transverse apertures 138 in the grappling fingers and fixedly attached thereto. Two of the fingers 134 each have at one end a flange 140 and are spaced about to receive the rotary actuator 40 therebetween. The flanges 140 are attached to the flange portion 52 and the shaft nut 58 of the shaft 50 by the attachment bolts 74 .
FIGS. 16 a - 16 c show a first alternative of the tool assembly 10 ′ of FIGS. 12 a and 12 b which allow the first and second grapple members 120 and 122 , and the rotary actuator 40 to be tilted and rotated relative to the arm rotation plane defined by the first and second arms 14 and 20 , much as in the embodiments of the tool assembly 10 shown in FIGS. 11 a - 11 f . As described above, the rotary actuator assembly 112 has a rotary actuator constructed generally as described above for rotary actuator 40 and is arranged transverse to the rotary actuator 40 . The first and second grapple members 120 and 122 and the rotary actuator 40 can be selectively rotated or tilted about the axis of rotation 112 a of the rotary assembly 112 and selectively rotated about the axis of rotation 113 a of the turntable bearing assembly 113 , as described above for the fourth alternative embodiment of the tool assembly 10 of FIGS. 11 a - 11 f . As described above, the rotary actuator 40 , the rotary actuator assembly 112 and the turntable bearing assembly 113 have an orthogonal arrangement of axes of rotation 41 , 112 a , and 113 a to provide a high degree of movement for the first and second grapple members 120 and 122 as a unit.
FIG. 17 shows a second alternative of the tool assembly 10 ′ of FIGS. 12 a and 12 b of a similar construction as shown in FIGS. 16 a - 16 c but with the first grapple member 120 and the rotary actuator 40 fixedly attached to the first turntable member 113 b whereas FIGS. 16 a - 16 c depict attachment using the devises 36 and 38 .
It will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.
All of the above U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, are incorporated herein by reference, in their entirety.
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A tool assembly using a fluid-powered actuator and including first and second tool members. The first tool member is pivotably connectable to a boom arm of a vehicle or stationary support platform for rotation about a first axis. The first tool member is also attached to a body of the actuator and the second tool members is attached to a shaft of the actuator so that operation of the actuator rotates the second tool member relative to the first tool member about a second axis spaced apart from the first axis and independent of rotation of the first tool member about the first axis. The second tool member is positioned to cooperatively engage the first tool member to assist in collection operations. The actuator has a generally cylindrical body with an output shaft rotatably disposed therein for rotation about the second axis. A linear-to-rotary transmission device disposed within the actuator body produces selective rotational movement of the shaft relative to the body and hence the second tool member relative to the first tool member. As the actuator goes through a range of motion the tool assembly moves between fully open and fully closed positions. In one embodiment, the actuator body is disposed in and attached to a protective support tube having the first tool member attached thereto. Other embodiments have further rotation and tilting assemblies to provide three orthogonal axes of rotation. Another attaches the tool members so that the first and second axes are coaxial.
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BACKGROUND OF THE INVENTION
The field of the present invention is hot water supply systems employing solar energy.
With the increasing scarcity of fossil fuels and the particular supply problems experienced over the past years by the United States, a plurality of other forms of energy have gained wide attention. One of the most important areas of new interest is solar energy. Solar energy has been particularly of interest for use in heating buildings and potable water. Often, such solar energy systems incorporate mechanisms for heating water which may then be stored and used as both the source of heat and a source of hot water. Such systems generally include a solar panel or panels having an array of tubes for heating water contained within the tubes. Storage tanks are also employed to save the heat energy thus obtained. Boilers are often commonly employed to augment the solar energy source during times of darkness and inclement conditions.
Certain difficulties have been experienced with solar systems which have inhibited the adoption of such systems. A first problem is initial cost. It remains difficult to justify the initial expense of many solar systems because the lifetime expense of conventional fossil fuel systems remains less. Consequently, a major effort in the solar energy industry has been to improve the efficiency of the solar energy systems to make them more competitive with more conventional heating and water heating systems.
Another difficulty which has been experienced with solar energy systems is in harsh environments where the potential for the water with the solar panel to freeze is substantial. Because the solar panels are designed to pick up as much heat as possible during daytime hours, they are highly susceptible to giving off substantial heat during cold and dark periods. Thus, the relatively exposed tubes filled with water are likely to freeze. One solution has been to drain the panels. However, draining the system is not generally preferred.
Another problem that has been encountered in solar energy systems is that that the designs of the panels for maximum efficiency are at times in conflict with the durability required of such panels which must be exposed much if not all of the time to the environment. One particularly efficient panel design incorporates thin films of plastic material best suited for durability, light transmissivity and heat opacity. This system incorporates two thin films as will be more fully described in the preferred embodiment herein. However, difficulties have been experienced in mounting these films to achieve the proper strength and durability and to meet sealing requirements.
Finally, the advent of new and varied solar energy systems have come into conflict with the building codes in the United States. Building codes have been developed to promote maximum safety and maximum durability of structures. Consequently, the solar energy industry has had to pay particular attention to the myriad codes which exist and conform to these codes which have generally been formulated without much attention to solar energy needs and designs.
SUMMARY OF THE INVENTION
The present invention is directed to a solar energy system for producing heated water. The system is designed to provide maximum efficiency of operation and includes design components directed to solving the problems encountered in the environment in which such systems must function in a manner consistent with the present building codes.
In accomplishing the foregoing, the present invention contemplates as one aspect thereof the advantageous placement of certain components of the solar energy system to accomplish a maximum efficiency. To this end, certain components of the system are placed in a location which may be in a housing or frame over which the solar panels are positioned. The boiler exhaust, the boiler itself and storage tanks and the like may be included in such a frame.
The advantage of such a system is to provide heat to the solar panel from beneath. Such heat would be generated during the colder hours when the continuously used systems are often augmented by such a boiler. A result of the employment of such a system is that the water within the solar panel is heated from the underside by the components and the exhaused gases. The heating of the water in the solar panels adds to the efficiency of the system in that exhausted heat from the boiler is transferred into the water of the system. This arrangement cuts down initial cost by eliminating the need for heavy insulation on the underside of the panel. Finally, the exhaust heat helps maintain the solar panel above freezing when the water within the panel might otherwise freeze and break the pipes or tubes.
The exhausting of heater or boiler gases into a closed frame, albeit efficient, has drawn some concern vis-a-vis building code requirements because of the low level of oxygen contained in the exhaust gases. However, the frame on which the solar panel rests includes the appropriate venting to achieve the required safety dictated by common sense and the building codes. A vent is contemplated at the uppermost part of the enclosure defined by the supporting frame to insure against the entrapment of gases. Other vents may be employed as needed to insure proper air movement for ultimate exhausting of the heater gases.
In a more detailed feature of the present invention, the solar energy system is further protected from the environment by the employment of an appropriate mounting means for the overlying transparent covering on the panels. A system employment interlocking elements with the use of adhesives has been developed to insure proper solar panel strength and maximum solar efficiency.
Accordingly, it is an object of the present invention to provide an improved solar water heating system and components therefor. Other and further objects and advantages will appear hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of an assembly of the present invention with portions broken away for clarity.
FIG. 2 is a side view taken along line 2--2 of FIG. 1.
FIG. 3 is a top view detail taken along line 3--3 of FIG. 1.
FIG. 4 is a plan view of a solar panel.
FIG. 5 is a cross-sectional end view taken along line 5--5 of FIG. 4.
FIG. 6 is a detailed cross-section also taken along line 5--5 of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning in detail to the drawings, a hot water supply system is illustrated as including solar panels 10, a boiler 12 having an exhaust 14 and storage tanks 16. In this preferred embodiment, the boiler 12, the boiler exhaust 14 and the storage tanks are located within a structure or frame, generally designated 18. The frame 18 is constructed in accordance with generally accepted building practice, including studs, braces and rails of commonly-available lumber. The structure or frame may be a portion of another structure, such as an attic or the like.
A back wall is constructed of studs 20 spaced across the back wall. Plywood panels 22 are then affixed to the studs 20 to enclose the back portion of the frame. At the top of the back wall, two rails 24 and 26 are fixed to either side of the upstanding studs 20. As can be seen, vent passageways 28 are defined between the studs 20 and between the rails 24 and 26. A cap 30 provides an uppermost piece to the back wall and present excessive water and other material from passing into the vent passageways 28. At the bottom of the back wall, the panels 22 may be cut as can best be seen in FIG. 2 to provide a lower vent passageway 30. An outside stud 32 is placed at each end of the back panel to form a surface upon which sheeting may be added to enclose the compartment defined with the frame 18. Base boards 34 are employed to tie together the various portions of the frame 18. These base boards 34 extend from the back wall to the front wall and along either. The front wall is also conventionally constructed with studs 36 capped by a beam 38. Paneling 40 may be employed to finish the closure of the frame 18. The front wall is substantially lower than the back wall because of the inclination of the solar panels. This inclination may vary depending on the latitude of the construction and other factors.
Spanning between the top of the front wall and the top of the back wall are rafters 42 spaced to accommodate the solar panel construction. Paneling 44 may be employed to close off the portions surrounding the solar panel elements. A fascia board covers the end of the rafters 42. A vent 48 may be provided along the front intersection between the plane of the solar panels and the front wall as can best be seen in FIG. 2.
The sides of the frame 18 are also conventionally constructed and include studs 50 and braces 52.
The solar panels 10 are constructed as best illustrated in FIGS. 4 and 5 and are positioned on the frame 18 by positioning on the rafters 42 which are sized to accommodate the panels. In FIG. 5, an end panel is illustrated on rafter 42 to show a convenient means for sealing the panel to the surrounding structure.
Each panel 10 includes a dish-shaped housing 54 having tubes 56 arranged in an array within the housing 54. The tubes extend longitudinally and mutually parallel through substantially the full length of the housing 54 and are coupled at the ends of manifolds 58. The inlet and outlet pipes 60 extend through the bottom of the housing 54. Between the tubes 56 there are heat transfer elements 62 which are generally painted black and more readily convert light energy to heat. This heat is then transferred to the tubes 56 and to the water therein.
To protect the inside of the solar panel and to produce a greenhouse effect to retain heat within the panel, glazing has been generally employed. One such system which has been used and found to be more transparent and more efficient than glass is glazing by two transparent sheets 64 and 66 of plastic. The external glazing is a 0.004 inch sheet of Tedlar, a composition and trademark of DuPont. The inner glazing is a transparent sheet 0.001 to 0.0015 inches in thickness of polytetrafluorethylene. The Tedlar provides a tough and clear outer coating and the PTFE is clear and opaque to heat. These two sheets are drawn taut over the solar panel and retained by a frame according to the present invention.
The frame for the glazing includes a channel 68 positioned about the periphery of the solar panel and above the tubes 56. The channel includes first and second leg members 70 and 72 with a web 74 extending between the leg members 70 and 72 and beyond for fastening to the solar panel and sealing between panels or between a panel and the adjacent surface structure. For sealing, U-shaped channels 76 are employed as can be seen in FIG. 5. The legs of the channel 68 extend from the web inwardly for receipt of an insert 78 which has a first side 80 that is adjacent the upper or first leg member 70 and the second side 82 that is adjacent to the lower or second leg member 72. This arrangement can best be seen in FIG. 6.
Adhesive is placed on the sides 80 and 82 of the sides 80 and 82 of the insert 78 and the glazing sheets 64 and 66 are fixed to the adhesive. The insert is then forced into the channel to a position as shown in FIG. 6. First and second means are located in the respective surfaces for interlocking the insert into the channel. In the present embodiment, these means include ridges on the first and second sides 80 and 82 of the insert 78 and grooves on the insides of the leg members 70 and 72. The physical positioning of the insert 78 into the channel 68 locks the sheets 64 and 66 in place. The adhesive is subject to creep and would not be able to retain tension on the sheets if the sheets were not locked into place. However, the adhesive provides a seal to prevent dirt and moisture from getting into the area between the glazing sheets. Furthermore, the adhesive helps in the assembly of the structure.
With the full assembly in place, the exhaust from the boiler, the boiler lost heat and the lost heat from the storage tanks is absorbed by the back side of the solar panels. In turn, this energy heats the water in the tubes.
To obtain the appropriate vent openings in the compartment for satisfying code requirements and boiler manufacturer specifications, testing of the atmosphere within the compartment is undertaken when the wind is not blowing and the boiler is on. The vent passageway 28 is then restricted by means of plywood or other material being positioned over portions of the vent until the appropriate restriction is achieved. The appropriate restriction retains as much exhaust as possible for heating purposes without reducing the amount of oxygen within the compartment within a dangerous level.
The present system may be employed in an overall system as disclosed in Pipers U.S. patent application Ser. No. 289,403, filed Aug. 3, 1981. The disclosure of this application is incorporated herein by reference.
Thus, an improved hotwater supply system employing solar energy is disclosed. While embodiments and applications of this invention have been shown and described, it would be apparent to those skilled in the art that many more modifications are possible without department from the inventive concepts herein described. The invention, therefore, is not to be restricted except in the spirit of the appended claims.
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A solar energy system employing solar panels used to heat water. The system includes a boiler with the vent for the boiler being located beneath the solar panels to distribute exhaust heat thereto. A structure is defined to allow venting of the enclosed area behind the panels. The panels are constructed with multiple sheets of plastic as glazing which are retained by means of interlocking elements and adhesive.
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FIELD OF THE INVENTION
The present invention relates to turf mowers and, more particularly, relates to a traction enhancement system for turf mowers.
BACKGROUND OF THE INVENTION
As is well known in the art, turf mowers are often used for maintenance in varying topographical environments, such as field mowing, lawn mowing, golf course maintenance, and the like. These turf mowers are typically riding-type and include at least one mowing deck suspended for the vehicle frame. The mowing deck is movable between a raised non-cutting position, often used during vehicle travel from one cutting area to another to avoid hitting obstacles such as curbs and stones, and a lowered cutting position. Conventional mowing decks often employ decks wheels and/or rollers which serve to support the mowing deck on the ground in this lowered cutting position. Consequently, the weight of the mowing deck is carried by these deck wheels and/or rollers. This arrangement ensures that a constant and consistent cut height is maintain during the cutting operation.
Many riding turf mowers are equipped with mechanisms for positioning the mowing deck to a desired cutting height. Most of these mechanisms consist of linkages interconnecting the mowing deck and a lever, which is directly controlled by a hydraulic or electric actuation system. The actuation system is often controlled by the operator's hand or foot.
Operators of these turf mowers must often traverse slippery and/or inclined terrain during the cutting operation, when the mowing deck is in the lowered cutting position. Depending upon the slope of the grade or the condition of the turf, many known turf mowers exhibit loss of traction in the drive wheel in such situations, which complicate or even prevent cutting of some difficult areas.
Accordingly, there exists a need in the relevant art to provide a turf mower having improved traction performance. Furthermore, there exists a need in the relevant art to provide a traction enhancing system for a turf mower to improve operation thereof. Still further, there exists a need in the relevant art to provide a turf mower that is capable of overcoming the disadvantages of the prior art.
SUMMARY OF THE INVENTION
According to the principles of the present invention, a traction enhancement system is provided having an advantageous construction and method of use. The traction enhancement system is ideally for use with a turf mower having a vehicle frame, a first drive wheel operably mounted to the vehicle frame, and a cutting unit positionable in a first position, where the cutting unit is support by ground engaging rollers, and a second position, where the cutting unit is support by the vehicle frame. A traction system is then operably coupled between the cutting unit and the vehicle frame such that the traction system can modulate the cutting unit between the first position and the second position for improved traction of the first drive wheel.
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 perspective view of a first turf mower employing a traction enhancement system according to the principles of the present invention;
FIG. 2 is a schematic view of the traction enhancement system according to the principles of the present invention;
FIG. 3 . is a schematic view of an operator control panel; and
FIG. 4 is a perspective view of a second turf mower employing the traction enhancement system according to the principles of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
With reference now to the figures, FIG. 1 is a general illustration of a mower 10 incorporating a traction enhancement system 12 of the present invention. Although the invention is described with respect to the preferred embodiment, those skilled in the art will recognize that other versions of the mower 10 are possible and that the invention is not limited to any specific embodiment.
In the embodiment shown in FIG. 1 , mower 10 generally includes three wheels 20 , 22 , and 24 operably mounted to a vehicle frame 14 . Two front drive wheels 20 and 22 are powered by a drive motor 26 . Rear wheel 24 is positioned behind and between front drive wheels 20 and 22 and is pivotable to steer mower 10 . In the present embodiment, a plurality of mowing decks or cutting units 28 , 30 , and 32 are provided. It should be understood that the present invention is not limited to reel-type or rotary-type mowing decks. The present invention could be used with any one of a number of available cutting units while still remaining within the spirit and scope of the invention.
Still referring to FIG. 1 , cutting units 28 , 30 , and 32 generally are positioned ahead of each wheel 20 , 22 , and 24 , respectively. Of course other positions are possible. Cutting units 20 , 22 , and 24 are mounted on lift arms 34 , 36 , and 38 , which are in turn operably coupled to a lifting actuation system 40 ( FIG. 2 ). Lifting actuation system 40 may be either hydraulically or electrically operated. The operator selectively raises and lowers lift arms 34 , 36 , and 38 depending on which cutting unit the operator wishes to use or to service. Each cutting unit 20 , 22 , and 24 is preferably individually actuatable to provide varying cut heights.
Cutting units 20 , 22 , and 24 each include a plurality of ground rollers 42 , which are adapted to engage a ground surface. As seen in FIG. 4 , ground rollers 42 may be wheels mounted upon cutting unit or mowing deck 20 ′. In operation, when cutting units 20 , 22 , and 24 are positioned in the lowered cutting position, the plurality of ground rollers 42 engage the ground surface and support a substantial portion of the weight of cutting units 20 , 22 , and 24 .
As best seen in FIG. 2 , traction enhancement system 12 is illustrated schematically to provide a general overview of its structure. However, it should be appreciated that traction enhancement system 12 may be varied to provide additional features or utilize different control and/or data acquisition techniques. With particular reference to FIG. 2 , traction enhancement system 12 includes the aforementioned lifting actuation system 40 , which is operably coupled to cutting units 28 , 30 , and 32 via control lines 44 , 46 , and 48 and lifting arms 34 , 36 , and 38 , respectively. Lifting actuation system 40 is either hydraulically or electrically operated to produce a lifting force sufficient to raise each cutting unit 28 , 30 , and 32 from a lowered cutting position (shown in FIG. 1 ) to a raised transport (non-cutting) position. Preferably, lifting actuation system 40 is capable of positioning each cutting unit 28 , 30 , and 32 individually at any position between the lowered cutting position and the raised transport position to provide varying cutting heights.
Still referring to FIG. 2 , traction enhancement system 12 further includes a pair of wheel sensors 50 and 52 operably coupled to drive wheels 20 and 22 . The pair of wheel sensors 50 and 52 are operable to detect a spin rate of each drive wheel 20 and 22 and output a signal to a modulation controller 54 via lines 56 and 58 , respectively. Modulation controller 54 in turn compares the signals of wheel sensors 50 and 52 to sense drive wheel slippage.
When drive wheel slippage is detected, modulation controller 54 outputs a modulating signal to lifting actuation system 40 via a line 60 . The modulating signal preferably commands lifting actuation system 40 to raise at least one cutting unit 28 , 30 , and 32 . Specifically, this raising of at least one cutting unit 28 , 30 , and 32 is preferably sufficient to transfer the weight of cutting unit 28 , 30 , and/or 32 to vehicle frame 14 , but without raising cutting unit 28 , 30 , or 32 so much as to change the cutting height. In other words, the modulating signal preferably commands lifting actuation system 40 to transfer the weight of cutting unit 28 , 30 , and/or 32 to vehicle frame 14 so as to increase the overall weight of turf mower 10 . Increasing the overall weight of turf mower 10 consequently increases the downward force and, thus, the traction force of drive wheels 20 and 22 .
Most preferably, modulation controller 54 commands a periodic raising and lowering (or dithering) of cutting unit 28 , 30 , and/or 32 to further increase the downward force exerted on drive wheels 20 and 22 due to the acceleration of the mass of cutting unit 28 , 30 , and/or 32 . That is, as one recalls, force equals mass times acceleration. Therefore, by accelerating the mass of cutting unit 28 , 30 , and/or 32 , the resultant force is greater than if the cutting unit 28 , 30 , and/or 32 is merely supported above the ground surface. Ideally, modulation controller 54 would modulate cutting unit 28 , 30 , and/or 32 at a predetermined frequency to provide maximized downward force. This may be accomplished via a hydraulic proportional valve or electrical switching system. This modulation or dithering preferably continues for a predetermined amount of time or until slippage is no longer detected.
It has been found that this predetermined modulation frequency ideally varies with the mass of the cutting units. Therefore, cutting units having a larger mass may only require a lower modulation frequency, while cutting units having a lower mass may require a higher modulation frequency.
Referring now to FIGS. 2 and 3 , modulation controller 54 and lifting actuation system 40 are each configurable via an operator control panel 62 . Operator control panel 62 preferably includes a cutting unit lift lever 64 and a traction assist switch 66 . Cutting unit lift lever 64 is preferably operable to raise and lower cutting units 28 , 30 , and 32 either collectively or individually. Traction assist switch 66 is preferably a three-position switch positionable between an ‘auto’ position, an ‘on’ position, and an ‘off’ position. In the ‘auto’ position, modulation controller 54 will continuously monitor wheel sensors 50 and 52 and upon detection of slippage will output a modulating command signal to improve traction of drive wheels 20 and 22 . In the ‘on’ position, modulation controller 54 will immediately output a modulating command signal irrespective of wheel sensors 50 and 52 . In this way, an operator can bypass wheel sensors 50 and 52 to achieve on-demand traction assist. Finally, in the ‘off’ position, traction enhancement system 12 is deactivated.
It should be appreciated that traction assist switch 66 may be a two-position switch positionable in any two of the three setting described above. Additionally, traction assist switch 66 may be such that it returns to a desired position either after actuation or upon ignition of turf mower 10 .
As best seen in FIG. 4 , traction enhancement system 12 , indicate at 12 ′, may be used with a wide variety of turf mowers, such as zero-turning radius riding mowers 10 ′. Additionally, it should be understood that the principles of the present invention are equally applicable to other applications, such as the modulation of snow plow blades on vehicles.
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 traction enhancement system and method of using the same for use with a turf mower having a vehicle frame, a first drive wheel operably mounted to the vehicle frame, and a cutting unit positionable in a first position, where the cutting unit is support by ground engaging rollers, and a second position, where the cutting unit is support by the vehicle frame. A traction system is then operably coupled between the cutting unit and the vehicle frame such that the traction system can modulate the cutting unit between the first position and the second position for improved traction of the first drive wheel.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to and the benefit of Korean Patent Application No. 10-2007-0131657 filed in the Korean Intellectual Property Office on Dec. 14, 2007, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The present invention relates to an automatic transmission. More particularly, the present invention relates to a planetary gear set used in an automatic transmission.
(b) Description of the Related Art
A typical automatic transmission employs a planetary gear set. The planetary gear set includes a sun gear, pinion gears, a ring gear, and a carrier that carries the pinion gears.
While a vehicle is driven, the automatic transmission frequently changes gears, and power interaction between the sun, pinion, and ring gears also frequently changes. When the sun, pinion, and ring gears or an arrangement thereof is not precisely designed, vibration or noise may be increased during shifting of the gears.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
SUMMARY OF THE INVENTION
Embodiments of the present invention provide a planetary gear set having advantages of reduced vibration and/or noise.
An exemplary embodiment of the present invention provides a planetary gear set of a transmission of a vehicle that includes: a sun gear; a first planetary gear that is externally meshed with the sun gear; a second planetary gear that is externally meshed with the sun gear and is away from the first planetary gear by a first angular spacing around the sun gear; a third planetary gear that is externally meshed with the sun gear and is away from the second planetary gear by a second angular spacing larger than the first angular spacing around the sun gear; and a carrier that interconnects the first, second, and the third planetary gears.
The first angular spacing may be smaller than 120°, and the second angular spacing may be greater than 120°.
The exemplary planetary gear may further include: a fourth planetary gear that is externally meshed with the first planetary gear; a fifth planetary gear that is externally meshed with the second planetary gear; and a sixth planetary gear that is externally meshed with the third planetary gear, wherein the fourth, fifth, and sixth planetary gears are also interconnected by the carrier.
The second angular spacing may be 120.05°.
An exemplary embodiment of the present invention provides a planetary gear set of a transmission of a vehicle that includes: a sun gear; a plurality of planetary gears externally meshed with the sun gear; and a carrier that interconnects the plurality of planetary gears such that the plurality of planetary gears revolve around a exterior circumference of the sun gear, wherein an arrangement of the plurality of planetary gears is arranged rotationally non-symmetrical.
A plurality of angular differences between adjacent planetary gears may form a plurality of values.
The plurality of planetary gears may include three planetary gears of first, second, and third planetary gears.
An angular difference of at least one pair of adjacent planetary gears may be greater than 120°.
The angular difference of the at least one pair of adjacent planetary gears may be 120.05°.
An angular difference of at least one pair of adjacent planetary gears may be less than 120°.
The angular difference of the at least one pair of adjacent planetary gears may be 119.95°.
A first angular difference between a first pair of adjacent planetary gears may be greater than 120°, and a second angular difference between a second pair of adjacent planetary gears may be less than 120°.
The first angular difference between the first pair of adjacent planetary gears may be 120.05°.
The second angular difference between the second pair of adjacent planetary gears may be 119.95°.
A third angular difference between a third pair of adjacent planetary gears may be 120°.
The first angular difference may be 120.05° and the second angular difference may be 119.95°.
The exemplary planetary gear set may further include a plurality of outer planetary gears that are externally meshed with the plurality of planetary gears respectively.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a planetary gear set according to an exemplary embodiment of the present invention.
FIG. 2 is a chart showing reduction of noise obtained by a planetary gear set according to an exemplary embodiment of the present invention.
In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing.
REPRESENTATIVE REFERENCE NUMERALS
100 : sun gear
105 a , 105 b , 105 c : planetary gear
110 a , 110 b , 110 c : planetary gear
115 : carrier
DETAILED DESCRIPTION OF THE EMBODIMENTS
Hereinafter reference will now be made in detail to various embodiments of the present invention, examples of which are illustrated in the accompanying drawings and described below. While the invention will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention to those exemplary embodiments. On the contrary, the invention is intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.
Referring to FIG. 1 , a planetary gear set includes a sun gear 100 and inner planetary gears of a first planetary gear 105 a , a second planetary gear 105 b , and a third planetary gear 105 c . The first, second, and third planetary gears 105 a , 105 b , and 105 c are externally meshed with the sun gear 100 , respectively.
In addition the exemplary planetary gear set includes outer planetary gears of a fourth planetary gear 110 a , a fifth planetary gear 110 b , and a sixth planetary gear 110 c that are externally meshed with the first, second, and third planetary gears, respectively. The first to sixth planetary gears 105 a , 105 b , 105 c , 110 a , 110 b , and 110 c are assembled to a carrier 115 so that they may revolve around the sun gear 100 with a fixed spatial configuration.
Conventionally, planetary gears are symmetrically disposed. That is, planetary gears are disposed with a uniform angular difference between adjacent planetary gears.
However, according to an exemplary embodiment, an arrangement of the first to third planetary gears 105 a , 105 b , and 105 c is rotationally non-symmetrical. In more detail, a plurality of angular differences between adjacent planetary gears form a plurality of different values.
For example, the second planetary gear 105 b is angularly away from the first planetary gear 105 a by 120° around the sun gear 100 . However, the third planetary gear 105 c is angularly away from the second planetary gear 105 b by 120.05° around the sun gear 100 . Thus, the third planetary gear 105 c is angularly away from the first planetary gear 105 a by 119.95°. That is, according to an exemplary embodiment of the present invention, three different values of 120°, 120.05°, and 119.95° are formed between adjacent planetary gears.
When an entire angle of 360° is divided into three uniform angles, three radial reference lines 120 a , 120 b , and 120 c shown in FIG. 1 may be formed with a uniform angular difference of 120° around a rotation center 150 of the sun gear 100 .
A rotation center of the first planetary gear 105 a lies on a first reference line 120 a , and a rotation center of the second planetary gear 105 b lies on a second reference line 120 b.
However, a rotation center of the third planetary gear 105 c does not lie on a third reference line 120 c but lies on a fourth reference line 120 d that is offset from the third reference line 120 c by 0.05°.
Considering that teeth of the sun gear 100 and the planetary gears 105 a , 105 b , and 105 c have finite size and the numbers of the teeth thereof are also finite, the sun gear 100 may not always maintain tight contact with all the three planetary gears 105 a , 105 b , and 105 c during the operation of the planetary gear set when the planetary gears 105 a , 105 b , and 105 c are arranged with exactly the same angular spacing.
Therefore, by disposing one or more planetary gears slightly offset from a geometrically symmetrical position, the sun gear 100 may better maintain the contact with the planetary gears in the average. That is, if the contact with one planetary gear becomes looser, the contact with another planetary gear may become tighter so as to compensate the loosened contact. In this way, the average contacting strength of all the planetary gears 105 a , 105 b , and 105 c with the sun gear 100 may be better maintained, and thus, vibration, noise, and backlash of an automatic transmission may be reduced.
FIG. 2 illustrates noise reduction obtained by a planetary gear set according to an exemplary embodiment of the present invention. As shown therein, the horizontal axis denotes rotation speed and the vertical axis denotes noise level. Broken line represents noise level of a conventional planetary gear set, and the solid line represents noise level of a planetary gear set according to an exemplary embodiment of the present invention. Thus, as shown in FIG. 2 , noise is decreased throughout an overall range by altering the planetary gear position on the carrier, by more than 5 dBA for a low speed range of 1,000-2,000 rpm.
In the above description, a double pinion planetary gear set is taken as an example for an embodiment of the present invention. However, it is obvious that the present invention is not limited thereto, since the spirit of the present invention may easily be applied to a single pinion planetary gear set by a person of ordinary skill in the art.
Furthermore, in the above description, a simple planetary gear set is taken as an example for an embodiment of the present invention. However, it is obvious that the present invention is not limited thereto, since the spirit of the present invention may easily be applied to a compound pinion planetary gear set by a person of ordinary skill in the art.
Furthermore, in the above description, a planetary gear set having three inner/outer planetary gears is taken as an example for an embodiment of the present invention. However, it is obvious that the present invention is not limited thereto, since the spirit of the present invention may easily be applied to a planetary gear set having four or more planetary gears by a person of ordinary skill in the art.
Furthermore, in the above description, angular differences have a deviation of 0.05°. However, it is obvious that the present invention is not limited thereto. A specific value of the deviation may be altered by a person or ordinary skill taking into account of the number of pinion gears, the number of teeth for the sun gear and the pinion gears, etc. While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
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A planetary gear set includes: a sun gear, a plurality of planetary gears externally meshed with the sun gear, and a carrier that interconnects the plurality of planetary gears such that the plurality of planetary gears revolve around a exterior circumference of the sun gear, and an arrangement of the plurality of planetary gears is rotationally non-symmetrical.
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BACKGROUND
The present invention is related to digital-to-analog converters (DACs).
Current steering DAC is based on an array of matched current cells elements that are steered to the DAC output depending on the digital input code. The DAC can be implemented either in a binary or unary structures. In a binary implementation, a current switched to the output is directly proportional to the binary weight of the corresponding bit in the input word. The binary weighted DAC suffer from large mismatch errors due to a number of current source switches during code change. In contrary, for the unary implementation, every current source provides the same current, and is switched independently. The digital input code is first decoded to thermometer code. This thermometer code is then used to control the switches. The fully unary implementations can obtain good linearity performance but add complexity and spend more power consumption.
The segmented implementation combines the previous two structures by introducing thermometer decoding for a few of the most significant bits (MSB's) and using binary weight structure on the few least significant bits (LSB's) bits. Segmentation DAC provides a trade-off between complexity, speed, power and performance.
Due to the process variation during IC fabrication, the attributes of transistors such as oxide thickness, width and length vary. For analog circuit, this variance can be represented as mismatch. Transistor mismatch in the current sources of DAC introduces different amount of current into the load. This mismatch error is the main source of converter nonlinearity.
In order to minimize the mismatch between different devices, the same device dimension should be used. Use multiple of the same dimension device can achieve a better matching for current sources. However, for high resolution, low power featured segmented current steering DAC, the device is decreased such that the device size is limited by the technology design rule. It is very difficult to get good differential non-linearity (DNL) for high resolution and low power current steering DAC.
SUMMARY
A current steering converter fabricated using a predetermined integrated circuit technology includes a unary portion having one or more current sources and a binary portion including a plurality of switches controlled by a decoder, the switches coupled to a converter output; and a plurality of devices commonly connected at a first end and coupled to each respective switch at a second end, wherein each device size comprises (W/L)*M, where W and L is the width and length of the device and M is an integer representing multiple number of the device.
Advantages of the converter may include one or more of the following. The present converter provides an accurate splitting of the current source for current steering DAC. The process of doubling the device size and then splitting into two halves reduces the mismatch of the device and improves the DAC linearity. A trimming method is presented to further adjust the current that can achieve small DNL for high-resolution high accuracy current steering DAC.
A more complete appreciation of the present invention and its improvements can be obtained by reference to the accompanying drawings, which are briefly summarized below, to the following detailed description of illustrative embodiments of the invention, and to the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a basic architecture of 4-bit segmented current steering DAC.
FIG. 2 shows an exemplary 5-bit binary portion of high resolution current steering DAC.
FIG. 3 shows an exemplary 5-bit binary portion of low power current steering DAC.
FIG. 4 shows an exemplary diagram of voltage divider.
FIG. 5 shows an exemplary of current divider.
FIG. 6 shows an exemplary circuit diagram of current source splitting by 2 and 4.
FIG. 7 shows an exemplary circuit diagram of adjustable current source splitting.
FIG. 8A-8B shows an exemplary diagram of resistive load to trim current sources.
DETAILED DESCRIPTION
The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes.
The terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.
Furthermore, it is to be noticed that the term “comprising”, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. Thus, the scope of the expression “a device comprising means A and B” should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.
Similarly, it is to be noticed that the term “coupled” discloses both direct and indirect coupling and should not be interpreted as being restricted to direct connections only. Thus, the scope of the expression “a device A coupled to a device B” should not be limited to devices or systems wherein an output of device A is directly connected to an input of device B. It means that there exists a path between an output of A and an input of B which may be a path including other devices or means.
FIG. 1 shows a basic 4-bit segmented current steering DAC. The DAC is segmented into 2-bit binary and 2-bit unary current sources that steer current to either the positive or negative terminals based on the input bits. A 2-to-3 decoder is needed to convert the two uppermost input bits into thermometer code. The two terminals are connected to resistor load to convert current into voltage.
FIG. 2 shows a 13-bit DAC using 8 unary and 5 binary segmented architecture. The illustration only shows the binary part and the unary portion is not shown. Each NMOS device size is described as (W/L)*M, where W and L is the width and length of each device and M is a multiple number. The multiple number M for Bit 0 , Bit 1 , Bit 2 , Bit 3 and Bit 4 are 1, 2, 4, 8 and 16 respectively. The mismatch between the current sources created error in terms of current amount and the errors represent the nonlinearity of the DAC. The main mismatch sources between two MOS devices are threshold voltage mismatch A vt and conductance parameter mismatch A β . A vt and A β are given for one specific technology and both A vt and A β are inversely proportional to the square root of the device area.
σ Vt = A Vt WL σ ( Δ β ) β = A β WL
where σ is the standard deviation of Gaussian distribution
For 5-bit binary implementation, the total number of M is 31 which represents 31 current sources. The maximum differential non-linearity (DNL) happens at the mid-scale when input code 01111 switches to 10000, where 15 current sources from Bit 0 to Bit 3 turn off and 16 current sources of Bit 4 turn on. For N-bit binary current steering DAC, assuming currents sources errors are not correlated, the maximum DNL can be described as the following equation:
σ DNL , m a x = 2 N - 1 σ ( I ) I ≅ 2 N / 2 σ ( I ) I σ ( I ) I = unit current standard deviation
unit current standard deviation
N is Total Number of Binary Bits
To minimize the mismatch of the current sources, the circuit embodiment on FIG. 2 uses only one same dimension W/L for the 31 current sources, the difference between these 31 current source is the multiple number M. For the physical implementation or mask layout, using the exactly same dimension enable a very symmetrical floorplan which helps to minimize the mismatch of the physical layout implementation in addition to inherent device mismatch.
However, for the applications require high resolution and very low power features, the current amount is reduced in such a way that the dimension of the device reaches the minimum size of the technology accordingly to MOSFET IV characteristic equation:
I D = 1 2 u n C ox W L ( V GS - V TH ) 2
I D is the current going through the device
u n C ox is the product of the electron mobility and the oxide layer capacitance
(V GS -V TH ) is the difference between gate to source voltage and threshold voltage
FIG. 3 illustrates the 5-bit binary current source of the low power current steering DAC. W min is the minimum width allowed in the technology design rule. In this case, Bit 4 current source 310 . 2 uses the same dimension of the reference current source 310 . 1 . Bit 3 uses half of the multiple number to cut the current by half. Bit 2 and Bit 1 cut the device width by half and by a quarter respectively to further decrease the current. For Bit 0 , it has reaches the minimum width so two minimum size are stack up in series which effectively reduce the W/L ratio by half.
Note that the mismatches of devices 310 . 4 , 310 . 5 , 310 . 6 and 310 . 7 are worse than 310.3 since different device widths are used. Once the physical dimension is different the threshold voltage will be different especially for advanced deep submicron technology which has very thin oxide thickness. Compared with FIG. 2 the maximum DNL of this 5-bit binary current sources in FIG. 3 is much worse due to the different physical dimension and decreased device size. For the applications that require monotonic DAC characteristic with very low power feature, the structure of FIG. 3 is very difficult to meet half LSB DNL specification.
Instead of reducing the device size, the same device size can be used if the current can be split equally. FIG. 4 shows a diagram of voltage divider, Vo voltage is half of V IN when the value of R 1 equals R 2 . The same concept can be applied to split the current into two half currents. According to an embodiment illustrated in FIG. 5 , a reference circuit I B can be split into I 1 and I 2 . The resistances R 1 and R 2 looking into 510 and 520 have to be the same to make I 1 current has the same amount of I 2 .
FIG. 6 illustrates a circuit diagram of current splitting scheme used on last 2 bits Bit 1 610 and Bit 0 620 . As the diagram describes, Bit 2 , Bit 1 and Bit 0 should have the 4I, 2I and 1I amount of current respectively by their binary representation. The device dimension of Bit 2 current source is (2*W/L). For Bit 1 , it uses the same device size (2*W/L) and split the current into two halves. There are two switches 610 . 2 and 610 . 3 connecting to Bit 1 current source 610 . 1 but only switch 610 . 2 is controlled by input data D[ 1 ]. Only the current out of switch 610 . 2 is directed to output nodes OUTP/OUTN. The output of another switch 610 . 3 is connected to Load 2 640 which is not coupled with DAC outputs OUTP/OUTN. Note that only the current flowing to Load1 630 is associated with DAC's differential outputs OUTP/OUTN. The current flowing into Load2 640 doesn't contribute to differential voltage OUTP/OUTN. Similarly for LSB Bit 0 , there are four switches 620 . 2 , 620 . 3 , 620 . 4 and 620 . 5 connecting to current source device 620 . 1 but only the output of switch 620 . 2 is connected to DAC's output node OUTP/OUTN. The outputs of other three switches are connected to Load 3 650 which is not coupled with DAC's outputs OUTP/OUTN. The currents that go to OUTP/OUTN are illustrated in solid line while the currents that don't connect to DAC outputs are illustrated in dash lines on FIG. 6 .
With this current splitting implementation, Bit 1 610 and Bit 0 620 use the exact same current source device dimension as Bit 2 to minimize the mismatch between these current sources. Using the exact same device dimension (W/L)*M with the same width, length and multiple number ensures these devices can be placed right next to each other during layout and they are surrounded in the same physical environment and pattern. Using the exact size dimension will minimize the difference between these current sources and a good matching characteristic can be achieved during IC fabrication.
Instead of reducing the device size and introducing mismatch, current splitting method use the same device size and diverts the needed current amount to DAC's loading elements. The unneeded current is diverted to another load which is not coupled to DAC's outputs. The overhead of the current splitting structure is some extra current since the extra amount of current is produced but not used. However, the current amount of last few less significant bits are very small and is considered negligible compared with the total DAC's full scale current.
As explained in FIG. 5 earlier, the electrical characteristic looking into load elements has to be the same to equally separate the current. The equivalent resistances looking into Load 1 630 and Load 2 640 need to be the same in order to split the current equally into 2 load elements. Similarly, the equivalent resistances looking into Load 2 640 and Load 3 650 need to be the same so that only one quarter of the current from current source 620 . 1 is sent to DAC's outputs OUTP/OUTN.
Note that there is also mismatch between two load elements. This mismatch of the load elements exists regardless of using current splitting implementation or not. The mismatch of load elements is considered as one of the mismatch sources of DAC and should be minimized in such a way that the overall DAC linearity is limited by the current source mismatch. There are multiple sources of mismatch like threshold voltage mismatch A vt and conductance parameter mismatch A β for active MOS devices NFET or PFET which are used in the current sources. However, for passive resistor load element which most DAC's use, the source of mismatch is purely the dimension difference between these elements. Also the number of load elements is only two whereas the number of unit current sources can be 2 N for N-bit current steering DAC. Thus the mismatch contribution of load elements to the overall DAC's mismatch is much smaller compared with the contribution of the current sources. Besides, since the load elements only occupy a very small percentage of the total DAC layout area, the size of the load element can be sized up with the same width/length ratio to reduce the mismatch while maintaining the same resistor value.
Even a good design practice of using the same dimension, same rotation, same surrounding environment has been made to minimize the mismatch of current sources, there still exists a random mismatch between devices due to lithography variation, process variations and physical gradients from IC manufacturing. This random mismatch will change the equivalent resistance of the load elements from one silicon part to another silicon part. To achieve higher accuracy of current source, further trimming can be applied on the load elements to adjust the current amount. This load trimming method is illustrated on FIG. 7 . DAC's load element Load 1 720 is a fixed value load while Load 2 720 and Load 3 730 are load elements that their equivalent resistance can be adjusted. Users adjust Load 2 720 and Load 3 730 equivalent resistance respectively to match DAC's Load 1 710 . By adjusting the equivalent resistance of the load, the desired current amount can be accurately obtained to minimize the DAC nonlinearity after IC is fabricated. The trimming reduces the mismatch either the mismatch is the systematic mismatch due to design or the statistical random mismatch due to process variation.
FIG. 8A and FIG. 8B illustrates possible trimming structures of the load element for current steering DAC. FIG. 8A is used for NFET current sources and FIG. 8B is used for PFET current sources. The load element consists of a fixed value resistor 810 and a gate controlled PFET device 820 . The PFET device 820 is biased and operated at its linear region with the resistance value described below. The total equivalent resistance R T is the sum of the two resistance values.
R T = R 1 + R ds = R 1 + 1 u n C ox W L ( V C - V TH ) R ds = 1 u n C ox W L ( V C - V TH )
is the equivalent resistance of the NFET in linear region
By changing the control voltage V c , the resistance of the load element can be adjusted to be the exact desired value such that the current amount from the current splitting switch is the right value to the DAC output nodes OUTP/OUTN. The trimming on current splitting load element produces the accurate current and minimize the nonlinearity of high-resolution low power current steering DAC.
Although the operations of the method herein are shown and described in a particular order, the order of the operations of the method may be altered so that certain operations may be performed in an inverse order or so that certain operations may be performed, at least in part, concurrently with other operations. In another embodiment, instructions or sub-operations of distinct operations may be implemented in an intermittent and/or alternating manner.
In addition, although specific embodiments of the invention that have been described or depicted include several components described or depicted herein, other embodiments of the invention may include fewer or more components to implement less or more feature.
Furthermore, although specific embodiments of the invention have been described and depicted, the invention is not to be limited to the specific forms or arrangements of parts so described and depicted. The scope of the invention is to be defined by the claims appended hereto and their equivalents.
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A current steering converter fabricated using a predetermined integrated circuit technology includes a unary portion having one or more current sources and a binary portion including a plurality of switches controlled by a decoder, the switches coupled to a converter output; and a plurality of devices commonly connected at a first end and coupled to each respective switch at a second end, wherein each device size comprises (W/L)*M, where W/L is a width and length of the device and M is an integer representing multiple number.
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This application is a divisional of copending application, Ser. No. 08/541,111, filed on Oct. 11, 1995.
TECHNICAL FIELD
The present invention relates to an electrical energy cable.
DESCRIPTION OF THE PRIOR ART
Electric power cables of the type having plastic insulated conductors, and a single wire which is twisted with the plastic insulated conductors and is enveloped by a lengthwise running insulating tape, where all are enclosed in a common sheath can be obtained in the market. For example, such a cable may be of the kind where a copper wire covered by a paper tape is a so-called ground wire which is included with the insulated conductors. During the manufacture of such a cable, ground wire and conductors are drawn from respective storage supplies and are then guided to a twisting installation. Aside from the fact that this manufacturing technique requires a separate manufacturing step for covering the ground wire with the paper tape, there is the danger of damaging the paper cover when the paper-insulated wire is reeled and unreeled, so that the paper cover can rip or be torn off when the elements to be twisted are inserted into a twisting head. A cable produced in this manner no longer fulfills the conditions placed on such a cable with an added ground wire.
SUMMARY OF THE INVENTION
Objects of the invention include ensuring the required quality of a cable having plastic insulated conductors and a ground wire enveloped by an insulating tape, the conductors and tape enveloped ground wire being enclosed in a common outer sheath, but at the same time to ensure that the manufacturing process takes place without problems, in addition to increasing the manufacturing speed. A device for performing the manufacture of such a cable must have a simple construction and guarantee high operating safety at elevated discharge speeds.
This task is fulfilled by providing conductors and a wire in a storage path and guiding the conductors and wire to a twisting point after passing through the storage path. The conductors and wire are twisted in alternating directions and/or rpm, and an insulating tape for enveloping the wire is guided in a lengthwise stretched condition along the storage path and is formed into a sheath around the wire at or before the twisting point.
The foregoing and other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of exemplary embodiments thereof, as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a stranding device for manufacturing the electrical energy cable of the present invention rotated by 90° for better viewing;
FIG. 2 is an enlarged perspective view of a storage path of the device of FIG. 1;
FIG. 3 is a plan view of a disk or holding element of the device of FIG. 1;
FIG. 4 is a plan view of the holding element of FIG. 3 having a U-shaped guide hole (guide slot);
FIG. 5 is a cross-sectional view of a guide cone positioned at the end of a storage path in the stranding device of FIG. 1; and
FIG. 6 is a cross-sectional view of a twisting disc and guide tube of the stranding device of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
As illustrated in FIG. 1, the storage path 3 is located between the stationary guide disk 1 and the twisting disk 2 that rotates in alternating directions, in which the stranding elements 4 are twisted in one direction while the twisting disk 2 rotates, and from which they are discharged after the change in the direction of rotation. Holding elements 5 with guide holes 6 are spaced along the storage path 3 to guide the stranding elements 4, which are drawn from stationary storage supplies not shown in the drawing, only one of which is illustrated for reasons of clarity. In the illustrated configuration example, the holding elements 5 are disks with a central guide hole 6 for example, with a core inlet and other guide holes distributed around the periphery for twisting the stranding elements.
The holding elements 5 are located on tensile strength support elements 7, which in turn are held in place by separate spacer rings 18. The support elements 7 are made of highly flexible plastic coated steel cables for example, and the plastic tubes 8 serve to space and secure the holding elements 5 on these support elements. As can easily be seen in FIG. 1, these tubes 8 have different lengths, so that the spaces between individual holding elements 5 can be of different lengths. It was proven advantageous to increase the distance between each two holding elements 5 with respect to the center of the storage path 3, starting from the stationary guide disk 1, as well as from the rotating twisting disk 2. For example, an advantageous configuration of the invention starts with a first space of about 10 mm from the holder 9, then increases the distance in steps of 5 mm up to 55 mm at the storage center, and then decreases the distance in the direction of the rotating twisting disk in steps of 5 mm down to the original 10 mm.
According to the invention, both ends of the support elements 7 can swivel and/or rotate. This is accomplished with holders 9, into which the support elements 7 are inserted and clamped tight. The last tube 10 is made of a coiled steel wire covered with an external plastic layer, as protection against buckling; this tube 10 is flexible in itself and can easily follow the movements of the support elements 7. The danger of buckling in this area or damage from external influences, perhaps during clamping due to an installation error, are avoided. As illustrated, the holder 9 itself can swivel vertically and horizontally from the depicted position by means of universal joint 11, and can rotate by means of axial bearings 12 and radial bearings 13, so that torsional stresses occurring from the rotation of the two support elements 7 during the twisting process are equalized, and need not be absorbed by the support elements 7 themselves.
The driven, rotating twisting disk 2 is located in the housing 14; after the stranding elements 4 have passed through in the direction of the arrow, they are joined into the twisted strand at the adjacent, not illustrated twisting point.
The perforated stationary disk 1 is located at the other end of the storage path 3. The holder 16 is able to move back and forth in order to adapt the support elements 7 in regard to their prestress to the momentary operating condition of the storage path 3 during the twisting process. A pneumatic system 17 with so-called linear compressed air cylinders is used to that effect, which makes it possible to separately prestress each individual support element. Another advantage of this clamping system is the linear guidance with a relatively small mass, which is integrated into the compressed air cylinders, in this way reducing the inertia of the parts to be moved even further.
FIG. 2 illustrates the storage path of the twisting installation according to the invention in an enlarged measure with respect to FIG. 1. The individual elements have the already selected reference numbers of FIG. 1.
The still bare ground wire 19, made for example of copper or aluminum, passes through the storage path in the same manner as the insulated conductors 4, as well as the tape 20, made for example of paper. The tape 20 is guided in a stretched condition, for which purpose guide slots 21 are provided in the holding elements, and are preferably located in the center to prevent the tape from rotating during passage through the storage path. In this way the tape is kept free of torsion, the active tensile forces are without effect because of the negligible friction during the passage through the holding elements.
As can be seen in the drawing, in this case the ground wire 19 is guided lengthwise along tape 20, this guidance facilitates wrapping the tape 20 around the wire 19 at the end of the storage path. To that effect, the last holding elements 5 in the passage direction could have holes with diameters that decrease towards the twisting head 16, to ensure the tube-like envelopment of the ground wire 19 by the tape 20.
Referring to FIG. 3, the holding element (or disc) 5 is shown in greater detail. The holding element 5 includes through going apertures (boreholes) 31 for receiving support elements (carrying elements) 7 (FIG. 2). Additionally, guide holes 32 are formed in the holding element 5 for receiving the stranding elements (conductors) 4 (FIG. 2). An additional guide hole or through going aperture 33 is provided for receiving an additional stranding element 19 (FIG. 2), e.g., a ground conductor 19 as described hereinabove with respect to FIG. 2. The paper tape or insulating tape 20 (FIG. 2) is received through a slit (lengthwise aperture or guide hole) 34 formed in the holding element 7.
As described above, the last holding elements 5 in the storage path may be provided with guide holes (guide slots) 34 with decreasing diameter approaching the twisting head. Additionally, as shown in FIG. 4, the holding elements 5 may be provided with U-shaped guide holes (guide slots) 40 approaching the twisting head to ensure the tube-like envelopment of the ground wire 19 (FIG. 2) by the tape 20 (FIG. 2.). In one embodiment of the invention, the bending radius of the U-shaped guide slots 40 decreases for guide slots in guide disks positioned towards the discharge end of the storage path adjacent to the twisting head.
In another embodiment of the invention, as shown in FIG. 5, a guide cone 42 having an internal diameter 43 that decreases toward the end of the storage path may be provided to ensure the tube-like envelopment of the ground wire 19 by the tape 20. The guide cone 42 is positioned adjacent to the twisting head at the end of the storage path.
Referring now to FIG. 6, the twisting disk 2 is provided with throughgoing apertures 45 for guiding the stranding elements (conductors) 4 and the additional stranding element 19 (FIG. 2), e.g., the ground wire enveloped by the tape 20. The twisting disk is driven to rotate in alternating directions and at alternating speeds. A guide tube 48 may be positioned between the twisting disk 2 and a twisting point 50, with the tape enveloped wire passing through the guide tube 48 to the twisting point 50. The twisted cable 52 exits the twisting point 50.
Although the invention has been described and illustrated with respect to exemplary embodiments thereof, the foregoing and various other additions and omissions may be made therein and thereto without departing from the spirit and scope of the present invention.
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An electrical power cable includes plastic-insulated conductors and a single wire, which is enveloped by a lengthwise incoming insulating tape and is twisted together with the conductors, all of which are surrounded by a common sheath. The conductors and the single wire are twisted together with alternating stroke directions (SZ), and the tape is loosely placed around the single wire in the form of a strand with opposing edges of the tape having alternating directions of rotation along the length of the strand.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/759,687, filed on Jan. 17, 2006 and entitled “Distributed Loss Compensation For Low-Latency On-Chip Interconnects,” which is hereby incorporated by reference herein in its entirety.
TECHNOLOGICAL FIELD
[0002] The disclosed subject matter relates to systems and methods for on-chip signaling.
BACKGROUND
[0003] On-chip interconnects, such as wires, are used to connect different parts of an integrated circuit together. The delay of a wire is approximately equal to R wire *C wire *L 2 (where R wire is the resistance of the wire per unit length, C wire is the capacitance per unit length, and L is the length of the wire). From this equation it can be seen that, as the length of a wire decreases, the delay of the wire also decreases. Therefore, the latency of a wire decreases along with feature size scaling. The delays associated with gates also decrease with feature size scaling. However, because the gate delays are shrinking faster than the interconnect delays, the relative delay of interconnects to gates is increasing with feature size scaling. The delay per unit length of interconnects relative to gate delays approximately doubles every technology generation.
[0004] One way to reduce the delay of a wire is to break it into multiple smaller segments using buffers or repeaters. This makes the delay of the wire grow linearly with the number of segments. Wider wires can also be used to improve overall delay, because they require a fewer numbers of repeaters. However, wider wires also require more energy per bit to drive because of their larger capacitance, and they take up a greater amount of space on an integrated circuit.
[0005] For example, optimally repeated copper wires of typically minimum width and spacing deliver a relatively constant delay per unit length, increasing from 55 ps/mm for 0.18 μm technology to approximately 80 ps/mm in 35 nm technology. However, when measured proportionally to gate delay, this delay per mm increases dramatically from 1 FO4 (fanout of 4) gate delay in a 0.18 μm technology to 7 FO4 gate delays in a 35 nm technology. This shows that, although wires may have a relatively constant delay per unit length, when compared to decreasing gate delays, the relative delay of interconnect is actually increasing.
SUMMARY
[0006] Systems and methods for on-chip signaling are disclosed.
[0007] In some embodiments, an integrated circuit having on-chip signaling between a first component and a second component includes, a differential interconnect capable of coupling the first component to the second component, a driver capable of being coupled to the first component that sends data on the differential interconnect, a receiver capable of being coupled to the second component that receives the data, and a plurality of negative impedance converters capable of being coupled to the differential interconnect that provide loss compensation.
[0008] In some embodiments, a method for on-chip signaling on an integrated circuit includes, transmitting a data signal from a first component on the integrated circuit to a second component on the integrated circuit over a differential interconnect, and providing a differential admittance to the data signal.
[0009] In some embodiments, systems for an integrated circuit having on-chip signaling between a first component and a second component include, a means for coupling the first component to the second component, a means for sending data on the means for coupling located at the first component, a means for receiving the data at the second component, and a plurality of means for providing loss compensation coupled to the means for coupling.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1A is a schematic diagram of the system architecture of an on-chip signaling system in accordance with some embodiments of the disclosed subject matter.
[0011] FIG. 1B is a schematic diagram of an interconnect design in accordance with some embodiments of the disclosed subject matter.
[0012] FIG. 2 is a schematic diagram of a driver in accordance with some embodiments of the disclosed subject matter.
[0013] FIG. 3 is a schematic diagram of a receiver in accordance with some embodiments of the disclosed subject matter.
[0014] FIG. 4A is a schematic diagram of a phase lock loop in accordance with some embodiments of the disclosed subject matter.
[0015] FIG. 4B is a schematic diagram of the voltage controller oscillator of a phase lock loop in accordance with some embodiments of the disclosed subject matter.
[0016] FIG. 4C is a schematic diagram of a loop filter in accordance with some embodiments of the disclosed subject matter.
[0017] FIG. 5A is a schematic diagram of a negative impedance converter in accordance with some embodiments of the disclosed subject matter.
[0018] FIG. 5B shows a small signal model representing the impedance looking in at the terminals of the circuit of FIG. 5A , in accordance with some embodiments of the disclosed subject matter.
[0019] FIG. 6A is a graph showing the attenuation constant for different negative impedance converter designs, and for an interconnect without a negative impedance converter in accordance with some embodiments of the disclosed subject matter.
[0020] FIG. 6B is a graph showing the magnitude of the admittance for a negative impedance converters as a function of frequency in accordance with some embodiments of the disclosed subject matter.
[0021] FIG. 6C is a graph showing the imaginary part of the admittance for a negative impedance converter as a function of frequency in accordance with some embodiments of the disclosed subject matter.
[0022] FIG. 7 shows an eye diagram of alternating 0 's and 1 's transmitted through an interconnect during a calibration sequence in accordance with some embodiments of the disclosed subject matter.
DETAILED DESCRIPTION
[0023] Systems and methods for on-chip signaling are provided. In some embodiments, negative impedance converters (NICs) can be used to compensate for transmission line losses in on-chip interconnects. The NICs can include a source degeneration network to compensate for attenuation of a signal on the interconnect. The interconnect can be a pair of differentially operated wires. By operating the interconnect in a double data rate manner using multiplexing, the amount of energy expended per bit transmitted can be reduced.
[0024] FIGS. 1A and 1B show a schematic diagram of a system architecture of an on-chip signaling system in accordance with some embodiments of the disclosed subject matter. FIG. 1 shows an interconnect 1010 used in a transmission line manner. The interconnect 1010 has a driver 1020 at one end, and a receiver 1030 at the other end. Distributed along the interconnect 1010 are one or more negative impedance converters 1040 (NICs) (although only one is shown for clarity) used to compensate for signal attenuation.
[0025] Driver 1020 and receiver 1030 can communicate at the same frequency (mesochronously), although arbitrary skews can be accommodated with an automated calibration at start-up. Phase lock loop (PLL) 1070 can be used to provide a clock signal for double data rate (DDR) data transmission. Data skew circuit 1050 and data de-skew circuit 1090 can control data skew for interconnect 1010 . Pre-driver 1060 receives data from data skew circuit 1050 and multiplexes it into a single stream for transmission by driver 1020 . Finally, clock skew calibration circuit 1080 can be used to calibrate receiver 1030 .
[0026] FIGS. 1A and 1B show interconnect 1010 with two wires for differential operation. The advantages of differential operation include controlled inductance, high common-mode noise rejection, and reduced shielding requirements. Interconnect 1010 can be made on various levels of a process, for example, a fifth metal level of a six-level-metal process. As shown in FIG. 1B , one design for an interconnect 1010 in accordance with some embodiments of the disclosed subject matter is a co-planar waveguide topology, with a line-width 1100 of 8 μm and a spacing between lines 1110 of 8 μm.
[0027] The operating point for NICs 1040 can be set by the common-mode voltage at the driver 1020 . In order to do, the driver 1020 can be programmed to inject different levels of bias current. Each level of bias current can set a different common mode voltage, and therefore a different level of compensation. For a 14 mm interconnect, seven NICs evenly spaced along the interconnect can be used to compensate for signal attenuation.
[0028] FIG. 2 is a schematic diagram showing more details of portion of driver 1020 and pre-driver and power-control 1060 in accordance with some embodiments of the disclosed subject matter. The pre-driver 1060 can have input multiplexing 2020 . Input multiplexing allows double data rate (DDR) operation to be employed. The driver 1020/pre-driver 1060 combination multiplexes two bitstreams Data 1 2150 and Data 2 2160 .
[0029] The pre-driver stage 1060 can use ratioed logic to reduce the circuit complexity when compared to static complementary metal oxide semiconductor (CMOS) circuits, resulting in a lower area overhead. Transistors M 3 -M 7 ( 2030 , 2040 , 2050 , 2060 , 2070 ) form a pseudo n-type metal oxide semiconductor gate, with transistor M 3 2030 acting as the pull-up load.
[0030] Driver 1020 can consist of two p-type field effect transistors (pFETs) M 1 2120 and M 2 2130 , along with a termination resistor R T 2110 to reduce the effect of reflections as well as crosstalk noise. When transistors 2120 and 2130 are pFETs, n-type field effect transistors (nFETs) can be used for the cross-coupled transistor pair in the NICs. Transistor M 3 2030 can be sized relative to the pull-down transistors M 4 2040 , M 5 2050 , M 6 2060 , and M 7 2070 to keep M 1 2120 and M 2 2130 in saturation. Although using pFETs in driver 1020 requires larger driver transistors than if nFETs were used, this can be compensated for by using smaller nFETs rather than pFETs in the NIC devices for a given gain.
[0031] The value of R T 2110 can be chosen to achieve a compromise between reflection and far-end voltage swing. Larger values of R T can increase the near-end voltage-swing, but can also increase reflection of signals at higher-frequencies. Because of resistive losses in the interconnect, the common-mode voltage on the wire and the associated bias currents of the NICs decrease toward the far-end of interconnect 1010 . These NIC can be sized larger to provide uniform g m (gain).
[0032] In accordance with some embodiments of the disclosed subject matter, there can be multiple copies of driver 1020 with varying sizes to dynamically control the drive current ( 2 I D ) from 3.0 mA to 6.0 mA in steps of 0.35 mA, although other step sizes can be used. Larger driver currents (e.g., 6.0 mA) boost signaling levels as well as increase the g m of the devices in the NICs, improving interconnect bandwidth. Smaller driver currents (e.g., 3.0 mA) reduce power consumption.
[0033] FIG. 3 is a schematic diagram of a receiver 3000 in accordance with some embodiments of the disclosed subject matter. Receiver 3000 has inputs D 3030 and D 3040 . The receiver can also have an output latch 3050 for storing received data. The receivers can be StrongARM gate-isolated sense-amplifier latches. These latches can be differential-edge-triggered latches. The circuit for the latch can be a differential sense amp followed by a pair of cross-coupled NAND gates. These latches can provide a clock slew time of 75 ps, and an aperture time of 15 ps.
[0034] A digitally trimmed capacitive load 3060 can be used for input offset cancellation, which can be on the order of a few tens of millivolts. Increasing the size of the transistors to lower this offset voltage can degrade the overall performance of the receiver and increase the loading at the far end of interconnect 1010 . Positioning trimming capacitors at the output of the latch can offer improved offset control for smaller capacitance (and switch) sizing over adding these capacitors at the drains of the differential input pair. A silicided 320 ohm polysilicon resistor can be used for line termination at the receiver. This may be slightly larger than the high-frequency impedance of the interconnect, and enough to boost far-end voltage swing while not creating an impedance discontinuity large enough to produce significant reflection at the far end.
[0035] Standard PLLs known in the art can be used with some embodiments of the disclosed subject matter. An overview of an improved PLL 4000 for providing on chip-clock multiplication, in accordance with some embodiments of the disclosed subject matter, is shown in FIG. 4A . A voltage controlled oscillator 4010 and a loop filter 4200 of PLL 4000 are described below in connection with FIGS. 4B and 4 c . FIG. 4B is a schematic diagram of voltage controlled oscillator 4010 of PLL 4000 shown in FIG. 4A in accordance with some embodiments of the disclosed subject matter. The current source drains (V tail ) can be connected together 4025 to reduce the variation in the tail current, further reducing power-supply-induced jitter. When the tail nodes are tied together, the VCO becomes two single-ended rings, to rectify this, a cross-coupled transistor pair 4020 can be used prior to the last stage 4030 .
[0036] FIG. 4C is a more detailed schematic diagram of a part of the PLL's 4000 feedback loop. FIG. 4C shows in more detail loop filter R z 4040 in accordance with some embodiments of the disclosed subject matter. Loop filter R z 4040 can be implemented with field effect transistors (FETs) M 1 4050 , M 2 4060 , M 3 4100 , and M 4 4130 . M 1 4050 can be biased in the triode region. For transistor M 1 4050 , R on −1 =μC ox (W/L)(V GS −V TH ), which is equal to the transconductance of M 2 4060 if both transistors have the same geometry. This resistor along with capacitor C 1 4070 , sets the zero of the PLL transfer function. The value of V GS −V TH , and hence the transconductance of loop filter Rs 4040 , is set by transistors M 2 4060 and M 3 4100 along with bias voltage V BP 4080 .
[0037] When operating in the triode region, the resistance of M 1 is proportional to 1/√{square root over (I D )} (through V BP 4120 ), where I D is the buffer bias current. A second capacitor C 2 4090 can be added to reduce the variation in V ctrl 4110 . Setting C 2 to one-tenth the value of C 1 can be used to balance input-jitter rejection and stability of the feedback loop.
[0038] FIG. 5A is a schematic diagram of a negative impedance converter (NIC) 5000 in accordance with some embodiments of the disclosed subject matter. NIC 5000 can have two cross-coupled transistors 5010 and 5020 . The NIC can also have a source degeneration network, one example embodiment is the resistor-capacitor network shown in FIG. 5A . The resistor-capacitor network comprises resistors 5030 and 5040 with capacitor 5050 connected between them.
[0039] FIG. 5B shows a small signal model representing the impedance looking in at the terminals of the circuit of FIG. 5A . Transistors 5010 and 5020 are characterized by an input capacitance C gs and transconductance g m . Based on this model, when resistance and capacitance are equal to zero in the source degeneration network, the NIC delivers a negative differential impedance 5060 of −2/g m .
[0040] Turning back to FIG. 5A , at low frequencies, resistors 5030 and 5040 degenerate differential admittance Y dd 5060 of the NIC. As frequencies increase, capacitance 5050 acts to shunt this degeneration and increase Y dd , providing the admittance of a negative capacitance. In this way, the cross-coupled transistor pair transforms the parallel RC combination (impedance Z) into a negative impedance (−Z). Ignoring gate-to-drain overlap capacitance, the differential admittance of the NIC, Y dd 5060 , is given by:
Y dd = - g m / ( 2 R ) g m + 1 / R [ 1 + s 2 RC 1 + s ( C gs + 2 C ) g m + 1 / R ]
[0041] For R>>1/gm, and C>>C gs , this expression approximates to:
Y dd = - 1 2 R [ 1 + s 2 RC 1 + s 2 C / g m ]
with a pole at zero and at g m /2C and (1/(2RC) ), respectively.
[0042] To give an example of a design for a NIC using these equations, assume the desired gain g m =4 mS, R=1 k (which is much greater than 1/gm) and the capacitance C=600 fF. The zero of the differential admittance is at 1/(2RC), which, for the assumed values, is approximately 132 MHz. This gives a negative admittance that increases with increasing frequency (negative capacitance) until the pole is reached at approximately g m /2C or 660 MHz. This design delivers loss compensation matching for the interconnect that increases with increasing frequency.
[0043] An appropriate selection of the values for R and C maintains stability of the interconnect. Instability is the result of overcompensation of the transmission-line losses leading to excessive overshoot, oscillations, or latch-up of the transmission line. Unconditional stability requires that both of the following conditions be satisfied for the S-parameters of the compensated transmission line:
k = 1 + S 22 S 11 - S 12 S 21 2 - S 11 2 - S 22 2 2 S 12 S 21 > 1
S 12 S 21 < 1 - S 11 2 , S 12 S 21 < 1 - S 22 2
[0044] For the doubly terminated transmission lines considered here, S 11 =S 22 and S 12 =S 21 , resulting in the simplification of the above equations to:
k = 1 + S 11 2 - S 21 2 2 - 2 S 11 2 2 S 21 2 > 1
and
S 21 2 < 1 - S 11 2
[0045] S 11 is given by (Z L −Z 0 )/(Z L +Z 0 ). For a matched termination at either ends of the interconnect, S 11 is approximately equal to zero, and the above expression for S 21 simplifies to:
| S 21 2 |=|e −2yl |=e −2αl <1
which is true when α>0. Therefore, unconditional stability of the compensated interconnect requires a choice of g m , R, and C for the NICs such that the attenuation constant is greater than zero for all frequencies.
[0046] FIG. 6A is a graph showing the attenuation constant of an interconnect versus frequency. The graph shows two groups of plots 6010 and 6020 for various values of R, and for two different values of C, 50 fF and 600 fF, respectively. For comparison the attenuation constant 6030 (represented by the dashed line) of an uncompensated interconnect is also shown. Increasing the value of C enhances the compensation at higher frequencies (e.g., 20 MHz to 3 GHz) but also increases the risk of the on-chip signaling system becoming unstable (α<0). Higher values of R for C=600 fF may make the interconnect unstable. An unstable interconnect may overcompensate for signal attenuation, changing the value of the sent signal.
[0047] FIG. 6B is a graph showing two sets of curves 6040 and 6050 for the magnitude of the admittance Y dd for C=50 fF and C=600 fF respectively. Y dd has a zero a 1/RC and a pole at approximately g m /C. There also a right-half-plane zero associated with the device's f T which is equal to g m /C gs at frequencies>10 GHz. The device's f T represents the frequency above which a device has a current gain of less than one, making it unsuitable for providing amplification.
[0048] FIG. 6C shows two set of curves 6060 and 6070 for the imaginary part of Y dd for C=50 fF and C=600 fF respectively, which is negative for low frequencies (implying a negative capacitance). FIG. 6C shows frequencies for which a NIC 1040 can provide loss compensation. Increasing C to enhance the compensation leads to a lower crossover (negative to positive) frequency for the imaginary part making this compensation less effective at high frequencies.
[0049] The operation of one embodiment of the on-chip signaling system is now described with respect to FIG. 1A . The signaling system can be a clocked system that operates with two cycles of latency, including data skewing and de-skewing. The serialized data enters the data skew circuit 1050 . The first bit (Data 1 ) of the input can be latched by a skewing latch (not shown) at a rising clock edge of the system clock, followed by a second bit (Data 2 ) which is latched, in a second latch, on at the next falling clock edge of the system clock. Both bits Data 1 and Data 2 of the input are available at the output of the skewing latches after two clock cycles.
[0050] After the data has been latched, it is multiplexed into a single bit stream by predriver 1060 . Depending on whether Data 1 and Data 2 are 1 's or 0 's, this causes M 4 2040 ( FIG. 2 ) or M 6 2060 ( FIG. 2 ) and the corresponding branch of the pull-down network, either M 4 2040 and M 5 2050 , or M 6 2060 and M 7 2070 , to be turned on for a half a cycle of the system clock. The clock signal is provided by PLL 1070 .
[0051] At any instant, one of transistors M 1 2120 or M 2 2130 of driver 1020 is sourcing current through M 3 2030 , resulting in a steady-state, common-mode current, I D , upon which a bipolar differential signal current (ΔI) is superimposed. The total current of 2I D drawn from the power supply during normal operation is obtained when either M 6 2060 ( FIG. 2 ) and M 7 2070 ( FIG. 2 ) (Data 2 ) or M 4 2040 ( FIG. 2 ) and M 5 2050 ( FIG. 2 ) (Data 1 ) of either pre-driver is switched on. M 1 2120 ( FIG. 2 ) and M 2 2130 ( FIG. 2 ) cannot be both turned on at any given instant, except in the offset calibration mode, which is discussed below. The ratio ΔI=I D is given by R T /(R T +2Z l ), where Z l is the impedance looking into each half of the interconnect.
[0052] As the differential signal current travels down interconnect 1010 , it is naturally attenuated by the transmission. However, each NIC 1040 acts like a gain element, and compensates for attenuation of the differential signal. As described above (and shown in FIGS. 6B and 6C ), by proper design, this compensation can increase with increasing frequency to compensate for the increased attenuation a higher-frequency signal experiences.
[0053] When the signal arrives at the receiver, it is de-skewed by deskew circuit 1090 and then provided to inputs 3030 ( FIG. 3 ) and 3040 ( FIG. 3 ) of the receiver, it is then latched into latch 3050 ( FIG. 3 ). The data is then ready to be used by the receiving component.
[0054] To adjust clock timing between the driver and receiver, receiver offsets (not shown) within the receiver are calibrated by the clock skew calibration controller 1080 before the interconnect is used. During the receiver calibration mode, the transmitter is configured to source the common-mode current I D on both lines of the interconnect. This is done by setting the data inputs to each of the two driver transistors M 1 2120 ( FIG. 2 ) and M 2 2130 ( FIG. 2 ) such that they are never both off at the same time. Following this, a calibration sequence is performed to tune the position of the receiver clock edge to optimally sample the data.
[0055] During the calibration sequence, the transmitter is configured to send a bitstream consisting of alternating 0 's and 1 's. These alternating 0 's and 1 's are illustrated in an overlapping fashion in the eye diagram of FIG. 7 . The data rate of the bitstream defines a window of time 7010 in which the data signal can be sampled by the receiver. The clock skew calibration controller adjusts the receiver to ensure that the signal is sampled properly within this window. Clock delay elements in the receiver, which can be formed from inverter stages with digitally trimmed capacitive loading, can provide any suitable delay for controlling the sampling of the received signal. The calibration controller can vary this clock delay to position the clock edge at the optimal location for receiving of signals on the interconnect.
[0056] Although the invention has been described and illustrated in the foregoing illustrative embodiments, it is understood that the present disclosure has been made only by way of example, and that numerous changes in the details of implementation of the invention can be made without departing from the spirit and scope of the invention, which is limited only by the claims that follow. Features of the disclosed embodiments can be combined and rearranged in various ways.
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Systems and methods for on-chip signaling are disclosed. In some embodiments, an integrated circuit having on-chip signaling between a first component and a second component includes, a differential interconnect capable of coupling the first component to the second component, a driver capable of being coupled to the first component that sends data on the differential interconnect, a receiver capable of being coupled to the second component that receives the data, and a plurality of negative impedance converters capable of being coupled to the differential interconnect that provide loss compensation.
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This invention relates to a mowing machine for mowing crop, comprising a cutter bar having a cutting unit which is rotatable about an upwardly extending rotary axis.
SUMMARY OF THE INVENTION
According to the present invention an engaging member is releasably provided on the upper face of the cutting member. The engaging member can be fitted to the cutting unit to assist the displacement of the crop over and across the cutting units and the cutter bar to the rear, particularly when mowing crop which tends to pass less easily over the cutting units and the cutter bar. The mowing machine can be used without the engaging members when mowing crop which passes easily over the cutting units and the cutter bar to the rear during the operation of the mowing machine.
An advantageous embodiment of the mowing machine in accordance with the invention is obtained when the engaging member is fastened to a supporting member or body, which is releasably mounted on the cutting unit.
In a further embodiment of the mowing machine in accordance with the invention the engaging member has a V-shaped section, the ends of the limbs being rigidly secured to the body. The resulting shape of the engaging member has an advantageous effect on the displacement of the cut crop over and across the cutting units and the cutter bar.
In another aspect of the present invention, the cutting unit is movably arranged on a carrying shaft journalled in the cutter bar and extending upwards therefrom. The cutting unit is slightly movable with respect to the rotary shaft when encountering obstacles. In this way damage to the cutting unit and other components of the mowing machine is avoided.
A further advantageous embodiment is obtained when the cutting unit is resiliently mounted on the top end of the carrying shaft.
A simple construction is obtained when the cutting unit comprises a carrying arm having an angled opening which fits, with clearance, around an angled top end of the carrying shaft of the cutting unit, the carrying arm being tiltable about the top end of the carrying shaft.
A mowing machine embodying the present invention can be advantageously constructed by fastening the cutting unit to a carrying shaft journalled in a drive housing of the cutter bar, which cutter bar is assembled from intermediate pieces and drive housings interconnected by a tie rod.
An advantageous support for the cutter bar of the mowing machine is obtained by providing the drive housing with a supporting skid which is rigidly secured to the rear of the drive housing, with respect to the normal direction of operative travel of the mowing machine, the front of the supporting skid being coupled with the drive housing by a nose provided on the drive housing and engaging a recess of the supporting skid. In this way the supporting skid can be readily fastened to the driving housing. The connection at the rear of the housing is unlikely to be damaged during operation. The supporting skid can furthermore be readily removed for replacement, if necessary, by a different supporting skid.
In a further embodiment of the mowing machine in accordance with the invention the cutter bar is fastened at its inner end to a gear box, to which a support frame is connected, by means of which the mowing machine can be coupled with the lifting device of a tractor or similar vehicle. The support frame can turn with respect to the cutter bar about a pivotal axis which is substantially normal to the length of the cutter bar and the support frame is connected with the gear box by means of a forked member which can turn over and across the gear box for turning at least part of the supporting frame over and across the gear box to a position above the cutter bar. The mowing machine can thus be reduced in its overall dimensions, which is particularly advantageous when shipping the mowing machine.
For a better understanding of the present invention and to show how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a mowing machine;
FIG. 2 is an enlarged plan view of part of the mowing machine of FIG. 1;
FIG. 3 corresponds to FIG. 2 but shows a different embodiment;
FIG. 4 is an enlarged view of part of the mowing machine taken on the line IV--IV in FIG. 1;
FIG. 5 is an enlarged view of part of the mowing machine taken on the line V--V in FIG. 1;
FIG. 6 is an enlarged plan view showing three cutting members of the mowing machine;
FIG. 7 is an enlarged sectional view taken on the line VII--VII in FIG. 6;
FIG. 8 is a sectional view taken on the line VIII--VIII in FIG. 6;
FIG. 9 is a view taken on the line IX--IX in FIG. 8;
FIG. 10 is an enlarged sectional view of the detail indicated in FIG. 8 by the arrow X;
FIG. 11 is an enlarged sectional view of the detail indicated in FIG. 8 by the arrow XI;
FIG. 12 is a sectional view taken on the line XII--XII in FIG. 6; and
FIG. 13 is a partly sectioned view of the mowing machine packed, in a collapsed condition, in a crate for transit.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The mowing machine shown in the drawings comprises a support frame 1 carrying a cutter bar 2. The cutter bar 2 is provided with a plurality of cutting units 3 arranged in a row. The cutter bar is assembled from intermediate pieces 4 and drive housings 5, which are held together by a tie rod 6.
The support frame 1 comprises a mounting trestle 10 provided with coupling pins 11 and coupling lugs 12 for hitching the frame 1 to the three-point lifting device of a tractor or similar vehicle. The trestle 10 is connected by an upwardly extending pivotal shaft 13 to a vertical frame beam 15. The vertical frame beam 15 is connected to a carrying arm 16 by a pivotal shaft 17 which extends substantially in the normal direction of operative travel of the mowing machine, as indicated by an arrow 112. The trestle 10 is also connected to the carrying arm 16 by a shear mechanism 14. At the end of the carrying arm 16 away from the pivotal shaft 17 there is a fork arm 18. On the opposite side of the carrying arm 16 from the fork arm 18, a bracket 19 is fastened to the arm 16. A strip 20 is fastened to the end of the carrying arm 16 and extends between the bracket 19 and the fork arm 18. A fork arm 21 is secured by bolts 22 to the bracket 19. The fork arms 18 and 21 are situated on opposite sides of a bearing housing 23, which is connected with a gear box 24. The cutter bar 2 is fastened to the lower end of the gear box 24.
The fork arms 18 and 21 can turn about the center line 28 of a drive shaft 25 which is journalled in the bearing housing 23. The bearing housing 23 contains meshing bevel gear wheels 26 which drive two meshing spur gear wheels 27 in the gear box 24. The drive shaft 25 carries a pulley 31 which is connected by three belts 38 to a pulley 32. The pulley 32 is mounted on a shaft 33 which is journalled in a supporting lug 34 fastened to the carrying arm 16. The pulley 31 and the belts 38 are surrounded by a protective casing 35.
A tension spring 36 acts between the top of the frame beam 15 and the carrying arm 16. A stop 37 fixed to the carrying arm 16 limits the movement of the carrying arm 16 about the pivotal shaft 17 with respect to the beam 15.
An angled support 41 is secured to the top of the bearing housing 23 and the gear box 24 and comprises a top plate 42 and a side plate 43. A support 44 is fastened to the top plate 42 and is provided with a carrier 45 for a fabric screen 49. The carrier 45 extends parallel to and above the cutter bar 2. The carrier 45 is provided with supports 46 to which rails 47 and 48 are fastened, over which the fabric screen 49 is arranged. The end of the carrier 45 away from the supporting frame 1 is provided with a protective bar 50 having a fastening rod 51 which is releasably fastened in the hollow end of the carrier 45. The top plate 42 and the support 44 are provided with a substantially horizontal pin 55, about which a coupling segment 56 is rotatable. A lifting cylinder 57 acts between the coupling segment 56 and the top of the frame beam 15.
The mowing machine shown in FIG. 2 comprises four cutting units 3. The cutter bar 2 comprises four identical intermediate pieces 4 and four identical drive housings 5. The intermediate pieces 4 and the drive housings 5 are held together by the tie rod 6 and are fastened to the lower end of the gear box 24. The tie rod 6 is solid (i.e. continuous) and has a circular section with a diameter 61 (FIG. 5) of thirty millimeters. FIG. 3 shows an embodiment having five cutting units 3. An integral continuous drive shaft 62 extends through the intermediate pieces 4 and the drive housing 5. The drive shaft 62 has an angular cross-section which, in the illustrated embodiment, is square. The drive shaft 62 is journalled at one end in the underside of the gear box 24, where it is in mesh, via a small spur gear with the lower gear wheel 27 as shown in FIG. 5.
Each drive housing 5 carries a cutting unit 3. The cutting units 3 are rotatable about upwardly extending rotary axes 63, which are vertical in the horizontal working position of the mowing machine. The rotary axes 63 of all of the cutting units lie in the same plane which contains the centerline of the drive shaft 62. The construction of the drive housings 5 is shown in detail in FIGS. 7 to 10 for the drive housing located at the outermost end of the cutter bar 2. These figures and FIGS. 6 and 12 also show in detail the construction of the cutting units.
Each cutting unit 3 comprises a carrying arm 66, which extends for equal distances to both sides of the rotary axis 63. The carrying arm 66 has an angular (shown square) opening 67 which receives, with some clearance, a correspondingly shaped top end 68 of a carrying shaft 69 journalled in the drive housing 5. On top of the carrying arm 66 there is a disc 71, which is circular, as viewed on plan, with its centerline coincident with the rotary axis 63. Blade carriers 72 are provided on the undersides of the ends of the carrying arm 66. The blade carriers 72 and the disc 71 are fastened to the carrier 66 by flat-headed bolts 73 and machine bolts 74, the centerlines of which lie in a vertical plane containing the rotary axis 63. The machine bolts 74 are nearer the rotary axis 63 than the flat-headed bolts 73. The blade carriers 72 have projections 75 (FIG. 9) on their lower faces, about which cutting blades 76 are rotatable. The projections 75 define recesses 77 which receive lugs 78 on the bolts 73, so that the bolts 73, when inserted, cannot turn. Each blade carrier 72 has a stop 79. The bolts 73 are secured in place by nuts 80. The disc 71 has a raised ridge 81 which extends around the bolt 73 and its nut 80 to the periphery of the disc 71. The machine bolt 74 is on the opposite side of the ridge 81 from thenut 80. Each cutting unit 3 is provided with two cutting blades 76, which are diametrically opposite each other with respect to the axis 63. At the periphery of the disc 71 and midway between the two cutting blades 76 on each cutting unit 3, the disc 71 has upwardly bulging parts 82, which, in the illustrated embodiment, are offset about the axis 63 through 90° with respect to the blades 76.
The shaft 69 has at its lower end a bevel gear wheel 85 which co-operates with a bevel gear wheel 86 rotationally fixed to the drive shaft 62. The bevel gear wheel 86 is part of a sleeve 87 journalled in bearings 88 and 89 in the wall 70 of the drive housing 5. The space between the sleeve 87 and the inner side of the wall 70 is sealed from the outside by closing elements 90 provided on the outer side of the bearings 88 and 89. The bearing 89 bears in the axial direction on a ring 91, which lies in a groove 92 in the wall 70. One or more spacer rings 93 can be provided, if necessary between the bearing 89 and the ring 91 to ensure correct location of the bearing 89 in the housing and satisfactory meshing of the teeth of the bevel gear wheels 85 and 86. Near the bearing 88 a further ring 91 lies in a groove 92 in the wall 70 to locate the sleeve 87 in the housing 70. The bores in the wall 70 adjoining the adjacent intermediate pieces 4 or a closing plate 94 are provided with alignment rings 95. Near the gear wheel 86 the sleeve 87 has a hole 96 which corresponds to the section of the shaft 62 and in which the shaft 62 fits. The remaining length of the sleeve 87 may surround the shaft 62 with ample clearance and its sectional shape need not correspond to the section of the shaft 62.
The carrying shaft 69 is journalled in bearings 100 supported in a cover 97 of the drive housing 5, which cover lies over an upper opening 98 in the wall 70 and is rigidly secured by bolts 99 to the wall 70. The bearings 100 in the cover 97 are covered at the top by a closing ring 101. The closing ring 101 is provided with one or more spacer rings 102, on which a closing hood 103 is arranged. The closing hood is rotatable by an opening (not shown) with the carrying shaft 69 about the top end 68 of the carrying shaft. The carrying arm 66 lies on the closing hood 103. The carrying shaft 69 has a screwthreaded end 104 which receives a nut 105. Between the nut 105 and the top of the carrying arm 66 there is a cup spring 106 which urges the carrying arm 66, the hood 103 and the rings 101 and 102 firmly against the parts of the upper bearing 100 which rotate with the shaft 69. The nut 105 and the cup spring are situated below the central part of the disc 71 covering the whole length of the carrying arm 66.
The carrying shaft 69 has a channel 107 opening at one end near the shaft 63 in the interior of the drive housing 5. The other end of the channel 107 opens at the top end of the carrying shaft to below the cup spring 106 at a position away from the axis 63.
Below each carrying shaft 69, beneath the cutter bar, there is a supporting skid 110. The skids 110 are situated mainly below the drive housings 5 and are secured to them. The rear edge of each skid 110 has a width 130, which is substantially equal to the width of the drive housing 5. The width of the skid widens to the front to become equal to the width 131 near the front of the cutter bar 2. At the rear of the cutter bar 2, viewed with respect to the direction 112, the supporting skids are provided with upwardly directed parts 113, which are fastened by bolts 114 to the housing 5. The supporting skids are provided with segment-shaped protective members 115 disposed in front of the cutter bar with respect to the direction 112. The outer periphery 116 of each member 115 is centered on the rotary axis 63 of the cutting member concerned. The outer periphery 116 of each protective member 115 is situated approximately directly below the circumferential edge of the disc 71 and extends radially beyond the bolt 73 which connects the blade to the carrier arm 66. At the top, the protective member 115 has a plate 117 which is parallel to the plane in which the cutting blades 76 move. The rear edge 118 of the plate 117 adjoins the drive housing 5 and extends at the side of the drive housing 5 to positions near the front of each intermediate piece 4. Between the top plate 117 and a bottom plate 119 of the skid 110, there are two spaced support plates 120 which extend, as viewed on plan, parallel to the lengthwise direction of the cutter bar 2 (FIG. 6). A gap 121 is left between the supporting plates 120, in which fits a nose 122 on the front of the drive housing 5. The height of the nose 122 is such that its lower edge 123 contacts the top of the bottom plate 119 of the supporting skid 110, and its top edge 124 contacts the underside of the top plate 117.
The underside of the supporting skid 110 is provided with a sliding shoe 125, the rear end of which is fastened by the bolts 114 to the rear of the housing 5. The front edge of the sliding shoe 125 has an upwardly deflected lug 126 which fits into a hole 127 in the bottom plate 119 of the protective member 115. The sliding shoe 125 is narrower than the supporting skid 110 and has a width 128, which is slightly smaller than the width of the drive housing 5. At the front, the supporting skid 110 has a width 131 equal to about twice the width 129 of the housing 5.
The cutting unit 3 farthest from the support frame 1 is provided with an upwardly extending body 135 in the form of a drum. The body 135 has a continuous bottom plate 138, which has the same shape at the top of the disc 71. The disc 71 has a central, upwardly extending, conical part 136 having an annular depression 137. The bottom plate 138 of the body 136 fits over the central part 136 and is centered and lightly secured thereon by an annular depression 139 which engages the depression 137. At its periphery, the bottom plate 138 is provided with protruding lugs 140. An upwardly tapering conical jacket 141 is supported on the bottom plate 138 and has a top plate 142 extending at right angles to the rotary axis 63. The jacket 141 tapers at an angle 143 of about 10° to the rotary axis 63. The lower edge of the jacket 141 has two protruding lugs 144 which have the same size as and match the top faces of the lugs 140. The lugs 140 and 144 have openings which are in register with holes in the disc 71 and through which the machine bolts 74 pass to secure the supporting member 135 with the disc 71 to the carrying arm 66. The conical jacket 141 is provided with two engaging members 145 having an angled, V-shaped section comprising two limbs, the outer ends of the limbs being welded or otherwise approximately fastened to the jacket 141. The two engaging members 145 are diametrically opposite each other with respect to the rotary axis 63. The height 146 of the body 135 is not critical; in the illustrated embodiment it is approximately equal to the distance between the underside of the skid 110 and the top side of the carrying shaft 69, i.e. about fifteen centimeters.
The cutting units 3 other than the outermost cutting unit of the row may be provided with bodies 150 provided with engaging members 153. One such body is shown in FIG. 6, on the penultimate cutting unit 3 of the row and in FIG. 12 in a sectional view. The body 150 mainly comprises a conical plate having an annular depression 151 which engages the depression 137 of the disc 71. The body 150 has substantially the same shape as the conical, central parts 136 of the discs 71 and has lugs 152 by means of which the body 150 is secured with the disc 71, to the carrying arm 66 by the bolts 74. The body 150 is substantially identical to the bottom plate 138 of the body 135. The body 150 is provided with diametrically oppositely disposed engaging members 153 which, like the engaging members 145 of the body 135, have angled, V-shaped sections, the ends of the limbs being fastened to the upper surface of the body 150.
The drive housing 5 at the outermost end of the cutter bar 2 is provided with a swath guide 155. The swath guide 155 is fastened by means of a plate 156 to the rear of the housing 5 using the bolts 114 which also secure the supporting skid 110 to the housing 5. The swath guide 155 comprises a cranked supporting plate 160, which is fastened to the closing plate 94. The plate 160 has a fastening element 162, to which is fastened a guide plate 161 provided with a guide bar 163. The guide bar 163 is inclined inwardly of the direction 112 at an angle 158. The end 164 of the guide bar 163 lies in a vertical plane 159 extending in the direction 112 and going at least substantially through the side of the penultimate cutting unit facing the support frame 1. The end 164 lies at a distance 157 of about 115 centimeters behind the cutting bar 2. The guide bar 163 slopes slightly upwardly away from the guide plate 161.
Near the junction of the cutter bar 2 with the gear box 24 there is a supporting inner skid 165 which is disposed below the gear-box 24 and the adjacent intermediate piece 4. This inner skid is fastened by bolts 166 to a lug 167 secured to the rear of the gearbox 24. In front of the gearbox 24, the skid 165 has a lug 168, which is rigidly secured by a bolt 169 to the gearbox 24. The inner skid 165 has a curved part 170 which extends approximately up to the height of the drive shaft 25. The top end of the curved part 170 is connected by means of a strip 171 to the gearbox 24. Like the supporting skid 110, the inner skid 165 is provided with a sliding shoe 172, the rear edge of which is fastened by bolts 188 to the rear of the skid. The front of the sliding shoe 172 there is a lug 173 corresponding with the lugs 126 and engaging a hole (not shown) in the inner skid 165 corresponding with the holes 127.
A screening plate 174 is provided along one side of the inner skid 165. The screening plate 174 has a lower edge adjoining the curved part 170 of the inner skid 165. The top edge 175 of the plate 174 extends between the top end of the part 170 and the gearbox 24, where the top edge 175 adjoins the gearbox slightly above the centerline 28 of the shaft 25. The top edge 175 has a horizontal part 176 with a lug 177, which is fastened, with the strip 171, to the gearbox 24 by a bolt 178. The screening plate 174 is substantially at right angles to the lengthwise direction of the cutter bar 2.
For operation, the mowing machine is coupled by the pins 11 and the lugs 12 of the fastening trestle 10 to the lifting device of a tractor or similar vehicle. The shaft 33 is connected by an auxiliary shaft with the power take-off shaft of the tractor.
During operation the mowing machine is moved in the direction 112, the cutter bar 2 extending transversely of this direction. The cutting units 3 cut crop in a strip lying at the side of the tractor to which the mowing machine is hitched, as viewed in the direction 112. The cutting units are rotated in the directions indicated by the arrows 179 and 180 in FIG. 2. The cutting units are driven from the shaft 33 via the pulleys 32 and 31, the gear wheels 26 and 27 and the drive shaft 62. The drive shaft 62 extends from the gearbox 24 through the intermediate pieces 4 and the drive housings 5. The drive shaft 62 is connected to drive the gear wheels 86 in the drive housings 5 by means of the polygonal section of the drive shaft and the corresponding polygonal openings 96 in the sleeves 87. From the gear wheels 86, via the gear wheels 85, the rotary shafts 69, on which the cutting units are fastened by means of the carriers 66, are rotated. The cutting units are driven so that the innermost cutting unit, i.e. the one nearest the support frame 1, rotates about its rotary axis 63 in a direction 179, in which at the front, the cutting member moves away from the support frame 1. Where there is an even number of cutting units, for example four cutting units as shown in FIG. 2, the other cutting units are driven so that adjacent cutting units rotate in opposite senses to each other. The cutting units thus form pairs rotating in opposite senses in the directions of the arrows 179 and 180. The regions of closest approach of the cutting units of each pair will move to the rear with respect to the direction 112. When the cutter bar has an odd number of cutting units, for example five as shown in FIG. 3, the direction of rotation of the cutting units is selected so that the two cutting members nearest the support frame 1 rotate in the same direction 179 as each other about their rotary axes. In order to prevent the cutting blades of these two cutting units from contacting in an undesirable manner, they are spaced apart by an intermediate piece 183, disposed between the two driving housings 5 of the cutting units concerned, which is longer than the other intermediate pieces 4. The other adjacent pairs of cutting units rotate in opposite senses during operation of the mowing machine. By causing the first and the second cutting units of the row to rotate in the same direction when there is an odd number of cutting units, the second cutting unit and the remaining cutting unit can co-operate in pairs moving in opposite senses so that the outermost cutting unit rotates in the desired manner in the direction of the arrow 180. This direction of rotation 180 is desired in order to enable crop to be deposited in a swath on the cutter bar by the rotation of the outermost cutting unit. The edge of the swath, as viewed in the direction 112, is some distance from the end of the cutter bar so that a strip of ground is left free of crop at the side of the swath. The direction of rotation 179 of the innermost cutting unit is desired to ensure that, near the inner end of the cutter bar, the crop can move over and across it without accumulating in front of the gearbox 24 and the inner skid 165.
The screening plate 174 is provided on the inner skid 165 in order to prevent cut crop from moving towards the carrying frame 1 over the top of the inner skid 165 when cutting high crop. As shown in the Figures, the screening plate 174 is preferably disposed on the side of the inner skid 165 facing the row of cutting units. The length of the mowing machine can be selected simply by assembling the cutter bar from the required number of intermediate pieces 4 and driven housings 5. By using a larger or smaller number of identical drive housings carrying the cutting units and a larger or smaller number of intermediate pieces, the length of the cutter bar and the number of cutting units can readily be altered with uniform components. If the number of cutting units is increased, the pulleys may need to have more grooves, as shown in FIG. 3, in order to transfer the driving force from the shaft 33 to the shaft 25. The section of the drive shaft 62 is such that shaft 62 is sufficiently strong to drive more or fewer cutting units. By arranging the outermost cutting member of the row so that it protrudes beyond its drive housing 5, constituting the end of the cutter bar, it is ensured that uncut crop on the strip of soil adjacent the strip being mowed by the mowing machine will not touch the cutter bar, or be otherwise affected by it. The cutter bar is then as short and as inexpensive as possible. During rotation of the cutting units, the blades 76 cut the crop, and the crop then passes over the top of the cutting units to the rear during travel of the mowing machine in the direction 112. This movement is assisted by the rotation of the cutting units, since in particular the rearwardly moving parts of the cutting units push the mown crop to the rear. When the long crop is being mown, it passes over and across the cutting units to the rear substantially throughout the length of the cutter bar. The swath guide 155 at the end of the cutter bar guides the crop slightly inwardly i.e. towards the junction between the cutter bar and the support frame 1. Thus at the side of the formed swath is left a strip of ground free of mown crop. The position of the end of the swath guide is such that the strip of ground has the desired width. In particular the body 135 arranged on the outermost cutting unit, with its engaging members 145 will assist in keeping the strip of ground free of mown crop. This body 135 will displace the crop cut by the outermost cutting unit in the direction of the arrow 180 to pass it to the rear of the cutter bar 2. The engaging members 145 contribute in passing the crop from the cutting unit 135 in the direction of the arrow 180 to the rear of the cutting bar. The engaging members are particularly useful when cutting heavy humid crop, since otherwise the smooth periphery of the drum jacket 141 would be likely to slide along the crop. The height 146 of the body 135 may be larger or smaller than illustrated, for example to suit the kind of crop to be mown by the mowing machine. The depressed rims 139 of the bottom plates 138 ensure satisfactory location of the body 135 on the top of the discs 71.
When the more or less smooth top of the discs 71 of the cutting units cannot grip the crop adequately to assist the movement of the crop over and across the cutter bar, for example when cutting heavy, wet crop, the engaging members 153 can be provided on the top of the cutting units. For this purpose, as is shown in FIGS. 6 and 12, bodies 150 provided with engaging members 153 are fitted to the discs. Depending on the crop to be mown, these bodies 150 can be fitted to or removed from the cutting units. Fitting and removing of the members 150 can be carried out simply by means of the connection via the bolts 74 on the carrier 66 and the discs 71. Satisfactory centering of the bodies 150 on the discs 71 is ensured by the depressions 151, which fit in the depressions 137 of the discs 71.
The carrying arm 66 with the parts mounted on it is slightly movable with respect to the carrying shaft 69 so that the carrier 66 can tilt relatively to the top end 68 of the carrying shaft 69. The carrying arm 66 is prevented from turning about the rotary shaft 69 by means of the cooperating shapes of the opening 67 and the top end 68 of the carrying shaft 69. The tilting movement of the carrying arm 66 with respect to the carrying shaft 69 occurs when the cutting unit comes into contact with large obstacles such as stones. The cutting unit, formed by the carrying arm 66 and the parts fastened to it, can then slightly deflect by tilting. The energy required to undergo this tilting deflection neutralizes wholly or partly the energy produced by impact of the cutting unit on the obstacle so that damage to the cutting unit is avoided. It is an advantage that the cutting unit can deflect resiliently. For this purpose the cup spring 106 is provided between the carrying arm 66 and the nut 105. This cup spring 106 has a maximum deflection of four millimeters. In the assembled state the cup spring is compressed by about one and a half milimeters. The cup spring tends to hold the carrying arm and hence the cutting unit 3 in the desired position relative to the carrying shaft 69. At maximum compression the cup spring 196 exerts a counter-pressure of about 1500 kilograms. The shape and rigidity of the disc 71 itself is such that it can distort upon impact with large obstacles without damage to the carrying arm 66 with the blades and/or other parts of the machine. Any damaged disc 71 can easily be replaced by a new one on the carrying arm. By fastening the bodies 150 and 135 to the disc 71 its rigidity is increased. When the bodies 150 and 135 are provided on the disc 71 it is particularly important for the cutting units to be resiliently tiltable on the carrying shaft 69 in order to avoid damage in the event of contact between the cutting units and an obstacle. In the event of serious damage, the cutting blades 76 might fly loose of the cutting unit, but they are then captured by the screening fabric 49. The screening fabric 49 will also capture stones or other loose material ejected by the rotation of the cutting units so that this material cannot fly out and damage objects at some distance. The blades 76 themselves are capable of deflection and turn underneath the disc 71. Such turning is limited by the stops 79 in order to prevent the blades 76 from coming into contact with parts of the cutter bar.
At the front of the cutter bar 2, the undersides of the cutting units are protected by the sectorshaped parts 115 of the supporting skids 110. Movement of these sector-shaped parts of the skids in a direction normal to the direction 112 is avoided since the nose 122 fits into the gap 122 between the supporting strips 120 and between the top plate 117 and the bottom plate 119. The supporting skids 110 can be fitted easily by slipping the skids 110 onto the nose 122 and fastening the ends 113 to the wall 70 by the bolts 114. The bolts 114 are at the rear of the cutter bar so that damage to them during travel of the machine in normal operation is practically excluded. In this way the connection of the supporting skids 110 with the cutter bar 2 is satisfactorily protected. The nose 122 and the bolts 114 enable the supporting skids to be readily mounted and permit equally simple removal for repair or replacement.
The sliding shoes 125 prevent undesirably rapid wear of the supporting skids 110. The sliding shoes 125 can be readily replaced when they have become excessively thin. The sliding shoes 125 can easily be fitted on or removed from the underside of the supporting skids by means of the lug 126 fitting in the hole 127 and the bolts 114 which secure the rear of the shoe to the rear of the center bar. Again, it is advantageous that the bolts 114 are positioned where they are unlikely to be damaged, while replacement of the sliding shoe 125 can be readily carried out.
The movement ofthe blades 76 about the projections 75 provided on the blade carrier 72 avoids wear of the bolt 73. The bolt 73 is prevented from turning by engagement of the lugs 78 in the recesses 77 between the projections 75 so that release of the bolts 73 is avoided and screwing of the nut 80 onto the bolt 73 is also facilitated. Since the stop 79 and the blade carrier 72 are formed integrally, the stop 79 is correctly positioned relative to the blade 76 to prevent the blade 76 from turning too far in its movement underneath the disc 71. The blade 76 is thus prevented from striking parts of the cutter bar 2. By making the height of the projections 75 slightly larger than the thickness of the blades 76, free rotation of the blades is ensured. Jamming of the blades between the blade carriers and the head of the bolt 73 is thus avoided, while mounting of the blades is facilitated.
The axial forces exerted by the gear wheel 86 on the bearings 89 when the cutting units are driven, can be satisfactorily transferred through the spacer rings 93 to the ring 91. Since it is possible to utilize as desired thicker or thinner spacer rings 93, correct location of the gear wheel 80 with respect to the gear wheel 85 is facilitated. When the cutting unit and the carrying shaft 69 with the gear wheel 85 fastened on it are driven in a sense opposite that of the gear wheel 85 of FIG. 8, the sleeve 87 is fitted so that the gear wheel 85 will be nearer the bearings 88. The spacer rings 93 are then provided at the bearings 88 in order to transfer the axial forces exerted by the gear wheel 86 to the respective supporting ring 91. The inclination of the channel 107 in the shaft 69 results in a sufficiently light centrifugal force on any parts of this channel to ensure that the channel 107 is unlikely to become clogged, so keeping the space in the wall 70 in communication with the open air. Consequently the lubricants and air in the interior of the housing 5 can readily expand and contract. The alignment rings 95 bridging adjoining edges of the intermediate pieces 4 and the drive housings 5 or of the closing piece 94 and the outermost housing 5 improve the rigidity of the cutter bar 2. The parts 4 and 5 which mainly constitute the cutter bar 2 are pressed towards one another by the tension in the tie rod 6. This stress can be adjusted by means of the nut 182 at the end of the tie rod, the end of the tie rod 6 in the gearbox 24 being axially fixed.
In order to protect vital parts of the machine against obstacles, the protective bar so is mounted on the outer side of the screening fabric 149. The bar 50 protects persons standing too near to the end of the cutter bar against contact with the cutting units
For the purposes of shipping the machine, the carrying frame 1 is designed so that it can be turned through about 180° with respect to the cutter bar 2 about the centerline of the shaft 25. To this end, forked arms 18 and 21 are spaced apart by a distance exceeding the width of the gearbox 24 and the housing 23. The forked arms 18 and 21 have furthermore such a length that the housing 23 is a distance 187 from the strip 20 and the arm 16 can be turned over the top of the gearbox 24. The carrying arm 16 with the frame beam 15 fastened to it can be moved into the position shown in FIG. 13. To effect this turn of the carrying arm 16 with respect to the cutter bar 2, the fastening trestle 10 is disengaged from the bar 2. Moreover, the shear mechanism is removed from the trestle 10. In order to put the mowing machine in the crate 186, the protective bar 50 is removed from the screening fabric carrier 45. The fabric screen 49 is removed from the rails 48 and 47 and the rails 47 and 48 are removed from the carrier 45. The carrier 45 is removed from the gear wheel box by releasing the top plate 42 and the side plate 43. The cylinder 57 with the segment 56 is detached from the pin 55. Otherwise all parts can remain on the mowing machine, and the remaining parts fastened to the carrying frame 1 can remain in place. The transmission gear formed by the pulleys 31 and 32 and the protecting casing 35 can also remain fastened to the carrying frame 1. Also the spring 36 can remain fastened to the carrying beam 16 and the frame beam 15.
When the cutter bar 2 and the cutting members 3 fastened thereto are put in the crate 186, the carrying beam 16 being tilted over, the rails 47 and 48 can be disposed along an upright side of the crate. The fabric screen 49 can be put along a short side of the crate. The trestle 10 can be put at one end of the tilted-over carrying beam 16 with the frame beam 15 as shown in FIG. 13. The inner skid 165 can be disconnected from the gear box 24 and be arranged in the crate 186. Thus the crate 186 need not have a length much greater than the length 189 corresponding to the length of the cutter bar 2 and the gear boxes 23 and 24 fastened to it. The width of the crate need not be much larger than than the diameter 194 of the cutting members. The height 191 of the crate 186 is about twice the height of the gear box 24. In this way the mowing machine can be packed in a relatively small space, which facilitates shipping.
Although various features of the mowing machine that have been described, and illustrated in the drawings will be set forth in the following claims as inventive features, the invention is not necessarily limited to these features and may encompass all inventive features disclosed both individually and in various combinations.
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A mowing machine has a cutter bar which is a plurality of drive housings and intermediate members between the drive housing held firmly together in compressing by a tie rod in tension. Each drive housing has a cutting unit which includes a rotatable disc and blades. At least some discs (for example the outermost two) have on their upper sides engaging members for engaging cut crop to convey the crop to the rear. The engaging members of outermost cutting unit are provided on a body which extends upwardly to where it is spaced above the cutting unit while the adjacent cutting unit has its engaging members closer to the disc. The machine is constructed so that it can be folded and partially dismantled for packing in a container of limited dimensions without it being unduly difficult to assemble for the purpose of providing an operable machine.
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RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 12/802,486, filed on Jun. 7, 2010 now abandoned, which application is a continuation-in-part of application Ser. No. 12/653,126, filed Dec. 8, 2009 now U.S. Pat. No. 8,291,628. Applicant claims priority under 35 U.S.C. §120 therefrom. Applicant also claims priority under 35 U.S.C. §119 from United Kingdom application number 1002334.9, filed Feb. 11, 2010, United Kingdom application number 1019865.3, filed Nov. 24, 2010 and European application number EP10194003 filed on Dec. 7, 2010.
FIELD OF THE INVENTION
The present invention relates to a method displaying a selected image in an illuminated display, using components sold fully assembled, partly assembled or ready to assemble in alternate configurations, all with easily exchangeable images.
BACKGROUND OF THE INVENTION
An example of the utilization of this invention is the museum shop market and this application will use production for this market as an example. It should be noted that the utilization of this invention is not intended to be limited to production for museum shops. It can be produced for a wide variety of institutions and businesses for many purposes using production methods, appropriate to those markets.
Museum gift shops often have items for purchase related to their purpose. With the advent of wide format high resolution digital printers and the availability of images on digital media, low volume, high quality reproductions of images are feasible, custom produced for each museum shop to reflect the museum's unique collection.
Visitors to museums are varied. Some arrive by car and would therefore be able to purchase a bulky item; place it in a car, and take it home. Others arrive by public transportation such as a subway or bus, and therefore their carrying capability is limited. Still others may visit a museum while on a distant trip; but they must return by air thereby limiting the bulk and fragility of their purchase at a museum shop. Purchasing compactly packaged components consisting of a customer selected electric/frame kit and a customer selected printed image sheet packaged separately but sold in combination with easy to follow instructions for home assembly requiring no tools or special skills solves this problem. For those who would balk at purchasing anything that would require even the minimum of assembly involvement, purchase of an assembled unit delivered at point of purchase or for shipment to their home, assembled and shipped by the museum, or by the company in accordance with a museum order, could also be accommodated by the museum shop.
A second factor favoring a compactly packaged kit is the fact that storage space for inventory is at a premium at a typical museum shop. This is addressed by compactly packaged kits that can be flexibly combined to fulfill a customer order.
A third factor favoring a frame kit is that same frame components can be assembled in alternate configurations depending on which model of the unit the customer prefers. In addition, the original configuration selection can easily be exchanged subsequently for another configuration at the option of the customer.
The prior art reveals many types of illuminated display units. Some are for the display of two dimensional art reproductions. A sampling of such patents follows. For example, the lamp shade of Lewis, U.S. Pat. No. 2,660,317, has a fenestration on its surface and a recessed plate for accepting an art object in sheet form to be illuminated indirectly by reflected light from the lamp. Buzick's picture display panel for lamp shades (U.S. Pat. No. 2,177,204) is primarily for display of black and white pictures printed on translucent paper by transmitted light. Morgen's light box lampshade (U.S. Pat. No. 6,821,002) provided uniform illumination on its surface for viewing photographic slides placed on its surface. The U.S. Pat. No. of Swanson (7,347,593) relates to a Giclee printed lamp shade that is capable of displaying a high resolution art reproduction made from a digital image file using a process for adhering an image printed on canvas to the surface of an existing lamp shade, where the printing in Swanson occurs before the canvas is adhesively secured to the base lamp shade.
Many other patents in the prior art deal with the bulkiness of lampshades. They relate to knockdown, collapsible, or foldable lamp shades which can be shipped or stored compactly and then assembled and used on a lamp. Four such U.S. patents and one US patent application are identified here as a sampling of the field. They are U.S. Pat. No. 3,742,210 of Chapman, U.S. Pat. No. 3,787,676 of Korach, U.S. Pat. No. 4,075,684 of Witz, U.S. Pat. No. 4,354,222 of Gall, and U.S. patent application US 2006/0239012 of Bin. None of these relate directly to the display of images.
Indeed, while the prior art teaches several approaches to the design of illuminated display units for displayirig images or storing lampshade frames more compactly, none describe an efficient method to display a selected image in the home or elsewhere on an illuminated display unit that is comprised of compactly packaged interchangeable components.
OBJECTS OF THE INVENTION
An example of this invention is to create an efficient business model that serves the needs of museum gift shops and their customers so that exhibits visitors have seen in the museum may be enjoyed in the home after being appreciated in the museum. Many other markets besides museum gift shops can be served. Along the way, a viable manufacturing business is also created.
Another object is to provide illuminated image display units consisting of a set of interchangeable components capable of constructing illuminated image display units for a plurality of presentation modes, such as free standing, pedestal mounted, ceiling suspended and the like.
Other objects which become apparent from the following description of the present invention.
SUMMARY OF THE INVENTION
Museums and particularly museum gift shops have been identified as one potential market for the utilization of this invention and display by a purchaser in a home is anticipated throughout this narrative. But this should be interpreted only as an example and should not be regarded as limiting the scope of the usefulness of the invention. Many institutions and/or businesses could be a potential market and the display unit could be located anywhere for any purpose.
The vehicle for the system and method is an illuminated display unit (IDU) for displaying two dimensional high quality reproductions of images. One aspect of the concept for the IDU of this invention that differs from that of an ordinary lamp and lampshade is that it facilitates the display of special images, which is an integral part of the lighting unit. In addition, low manufacturing cost, compact packaging in kit form, and ease of customer assembly without tools and without special skills are the hallmarks of the IDU. Although the manufactured frame parts are standardized in a range of circumferences to minimize cost, the technique for creating the image sheets, which are illuminated, permits a wide range of image heights to be accommodated by each standardized circumference frame. The IDU component parts can be assembled as a table-top, pedestal or suspended unit, or in other configurations to display images. The same frame elements can be used to illuminate and display a variety of image reproductions just by changing one image for another. Since the electrical parts are provided as a completely pre-wired electrical cord set and a unique slot is provided to insert the wire of the cord set into the frame, no electrical experience is required for customer assembly of the IDU.
Basically, in the preferred embodiment, the lamp socket is a standard AC powered lamp socket, which is secured to the hub of the support frame part with a hand-tightened nut. The image sheet is first formed into a cylinder, then one end of the cylinder is inserted into a slot and secured in a support frame member. The other end is then inserted and secured in a slot in second plain frame member. The frame members then form the cylinder into a conforming closed shape. For example, for table-top use the support frame is at the bottom and the plain frame is at the top of the image sheet. For suspended use this is reversed. For table-top use with a pedestal, a tube and a second support frame to serve as a base (or alternately a modified base) is added. In an alternate embodiment, the light source may be a light emitting diode (LED) light source or other light source, such as a compact florescent light source, and may be powered by a DC power source, such as, for example, a battery.
The production technique to be utilized for the museum shop market, of printing the image sheet by high resolution wide-format ink jet printers is well known, but while the material of the image sheet may be a flexible translucent sheet of various materials, such as styrene or laminated fabric, for example, in a preferred embodiment in this use the material of the image sheet is fine art grade paper, coated for optimal acceptance of inkjet printing, custom manufactured for the IDU application to insure heat resistance, archival type ink acceptance, a translucent appearance, and rigidity once formed into a closed shape which may be straight sided, such as a triangle, a continuous curve, such as a circle, or a combination of straight and curved sections, such as an expanded circle, such shape determined by the frame members to which it is secured at both ends. While any printer capable of printing a high quality image upon a flexible media may be used, a preferred embodiment for this market is a roll-fed wide format ink jet printer, such as printers made by companies as Epson, Canon, Hewlett Packard, Xerox and others which print on rolls having widths from 24 inches to 72 inches. For example, the 10-color 24 inch wide Epson 7900 is one such printer that can be used to print high quality image sheets yielding cylindrical shapes 23 11/16 inch in circumference, with 5/16 inch overlap.
The IDU of this invention will be described as having an elliptical crossectional cylindrical shape as the display surface of the image sheet. For instance, a 24 inch wide image sheet formed into an ellipse by the appropriate size frames would have a major oval diameter of approximately 9.2 inches and a minor diameter of about 5.7 inches. Using this type of printing method the circumference of the IDU display is fixed by the width of the sheet being printed, but the height of the image sheet can be easily varied since this is determined by how the rolled sheet is programmed to be printed and cut apart after printing for use in the IDU. In this way, actual image sheet heights can practically be infinitely varied.
The business model for this invention presupposes that a “company” is formed to produce image sheets and frame/electrical kits for IDU's that would interface with, for example, a variety of museum shops around the country or around the world. The company has a computer system which will communicate between the company and its customers.
The computer system has data processing systems by which the company and respective gift shops communicate via internet or a browser controlling communications over a network via a server, including images plus text required, formatted for printing by the company and includes a database for storing images for printing image sheets when ordered. All communications can be handled via internet for receiving and processing orders. Products can be shipped by common carrier. For example, when a museum gift shop gears up for support of a special museum exhibit, images related to the exhibit can be produced. For the initial order for a new image the company must first create an Image Art Unit (IAU) file with the exact edited digital representation of the image and any text required to be printed on an image sheet, plus cutting instructions. This is what will drive the wide format printer. The formatting for the IAU using the source digital image file can either be done by the company (with instructions from the museum), or it can be performed by museum personnel using the company's website and editing software. The museum also provides text for a description of the image information about the museum and this is printed separately by the company and included with the packaged image that is a component of the IDU, as are instructions for customer assembly.
The company uses pricing software which prices each image sheet corresponding to each desired IAU. Part of the pricing algorithm is based on the height and width of the particular resulting image sheet reflecting the actual substrate material and printing cost. Another pricing aspect may be the ink cost for a particular image sheet reflecting the actual digital color and color density information on each pixel of the image reproduction. Other aspects of pricing may include printer set-up charges and/or amortized formatting charges related to volume ordered. Once the pricing is set for the images, this is relayed to the museum gift shop. Based on demand estimates an initial order is placed by the museum for both the various image sheets as well as for IDU frame/electrical kits selected by the museum. The company will then schedule production and fulfill the initial order for image sheets and IDU frame/electric kits for the museum shop. Subsequent orders for IDU frame/electric kits, and/or image sheets will be fulfilled as required.
At the museum gift shop, customer order fulfillment can be accomplished in a number of ways. Customers may purchase pre-packaged image sheets and IDU frame/electric component kits ready for assembly, pay for them and leave. Or a customer may request an assembled IDU. This can be handled by on-demand assembly at the museum shop or from stock pre-assembled by the museum, or the museums shop can assemble the unit and ship it to the address given by the customer. Assembly for stock can be performed at the museum shop during slack periods. In addition the museum can place an order with the company for a specific unit to be assembled by the company and shipped directly to the customer.
In an alternate embodiment, a packaged unit could be partly assembled and include an assembled support frame with 3 or 4 or more legs, a lamp socket support hub and an electric cord set, a plain frame and an image sheet packaged ready to assemble as an illuminated display unit (IDU) of this invention. The packaging is less compact and less flexible than the previous kits embodiments but only the assembly of the image sheet to the frames by the customer is required.
In another alternate embodiment, the unit could be packaged by the company fully assembled and supplied to the museum with no assembly required by the customer.
When the IDU is sold as a component kit the support frame is assembled by inserting one end of each leg into a mating feature incorporated into one of the frame loops and the other end into a similar mating feature on a hub which serves as the lamp socket support disc in the center. The legs are “V-shaped”. The V-shaped legs may be symmetrical or, in a further embodiment may be asymmetrical. The “V” shape of the legs is preferably asymmetric to place the vertex closer to the, outside of the frame rim than to the lamp support hub at the center, which provides more clearance from the surface of the light bulb and better stability for the support of the tabletop model. Marks are provided on the rims of the frames to correctly align the flexible image sheet with the frames.
The configurations for the various IDU models are as follows:
*For the tabletop model—
Bottom: Assembled support frame slot faces up, legs face down
Top: Plain frame slot faces down
*For the hanging model—
Bottom: Plain frame slot faces up
Top: Assembled support frame slot faces down, legs face down
*For the pedestal model—
Bottom: Assembled support frame slot faces up, legs face up
Top: Plain frame slot faces down
Base: Support frame slot faces down, legs face up
Note that these alternate configurations from one kit are only possible if the support frame is not made in one piece but in separate pieces for customer assembly as described herein.
Although the mating features are illustrated in one embodiment as a male and a female dovetail joint, other molded simple sliding and/or snap fit joining features, as are commonly known for joining pieces of an item can be used instead.
In one design, the tapered dovetail slots on the legs have the open end in the same direction at the end of each leg. The matching tapered dovetail lugs on the support frame and lamp socket support hub face alternately in opposite directions around their circumferences. Assembly is achieved by sliding the leg slots onto the hub and frame lugs. The legs may be installed either way up (by turning the legs over and moving each leg around the circumference of the support frame to the next set of rim lugs), depending on which leg position, up or down, is required for the model being assembled. There may be two sets of lugs on the lamp socket support disc at two different radii and/or there may be projections incorporated into the rim to compensate for different radii, so that a range of support rims can be accommodated by the same leg length.
In an alternate embodiment, the opposite distal ends of legs connecting the rim frame to the central lamp socket support hub have attachment extensions which mate with slots or holes associated with the support frame at one end and with the central lamp socket support hub at the other end. The extensions are inserted into and through slots or holes in the support frame and in the lamp socket support hub. As these extensions are pushed in toward the step region, molded cantilevered tongues are compressed until they again snap out locking extensions in the slots or holes. The cantilevered tip of each tongue is flexible, so that it compresses as the tongue is inserted into the leg attachment slot/hole and decompresses outward when through the slot/hole, thereby locking the legs in place in the respective slot/holes in the support frame at one end and in the lamp support hub at the other end.
With either design the legs may be detached from the rim and hub and reassembled in a different configuration if a different model IDU is desired.
In the preferred alternate embodiment, an illuminated display unit (i.e. IDU) is comprised of two component kits (1) a multi-part frame kit and electric cord set for assembly without the use of tools, and (2) an image sheet imprinted on fine art paper media such as the Toscana™ product provided by Hahnemuhle which is specially coated on one side for high quality inkjet printing.
The image sheet is unrolled and formed into a cylindrical shape then captured in a conforming shape within a circumferentially extending slot in the top and bottom frame members and locked in place using multiple resilient clips (rim inserts) which impinge on the top and bottom edges of the image sheet. Depending on how the frame parts are assembled the IDU can be configured as a tabletop, pedestal or as a pendant model. The clips can easily be taken out to permit the image sheet to be removed and exchanged at will since the image sheet is not bonded permanently to the frame. Changing the IDU configuration from table top, pedestal, or pendant to another configuration is also made easy simply by removing the image sheet, re-configuring the frame by disassembling and reassembling the component parts, then re-inserting and re-securing the image sheet.
The four steps that may be used to assemble either a tabletop or a pendant model of this preferred alternate embodiment are presented here as they also summarize the various parts of the IDU:
Table Top Model
1. Image Sheet Preparation—Remove the image sheet from box A.
Let it unroll and it will form a cylindrical shape. Put it down on a table with the ends of the roll facing up.
Remove the cover from the two sided adhesive tape that is located at one end of the image sheet.
Position that end of the image sheet above the other end so the full length of its edge is aligned between the two lines printed on the other end.
Press the two ends together and the image sheet is now formed into a continuous cylinder. Turn the cylinder over and place it horizontally on a table, then press down along the overlap to ensure a strong bond the full length of the overlap.
Note: You may want to practice this before removing the cover from the tape. Try positioning the edge of the sheet between the lines, starting at one end.
2. Frame Preparation—Remove the three legs, the triangular hub, and the two frames from
box B. Leave the other items in the box.
Place the hub (either side up) on a table and push the ends of the long arms of the three legs (marked O) into the slots in the hub (marked O).
Place the frame with slots for the legs on a table with the side of the frame that does not have a perimeter slot facing up and push the short ends of the three legs (marked X) into the three slots in the frame (marked X).
Note: If you want to disconnect a leg after it is installed just tilt it and it will come out of the slot.
3. Install Electric Parts—Remove the electric assembly from box B. Only the frame inserts now remain in the box.
Pull the nut along the electric cord a short distance away from the bulb socket.
Slide the electric cord wire through the slot in the triangular hub so that the bulb socket is facing in the opposite direction to the legs.
Push the threaded nipple on the bulb socket through the center hole in the hub.
Slide the nut along the electrical cord up to the nipple on the bulb socket. Tighten the nut by hand until the bulb socket is secure in the hub.
4. Final Assembly—Remove eight frame inserts from box B. There is an extra frame insert in the box in case one is mislaid.
Position the image sheet cylinder vertically on a table so the picture faces up.
Position the vertical mark on the outside face of the plain frame so it aligns with the overlapping vertical edge of the image sheet cylinder.
Push the frame downward on to the image sheet cylinder so the cylinder engages the slot in the frame. Use the lugs on the inside of the frame to help guide the image sheet cylinder into position. The frame must be pushed all the way down so that the cylinder edge goes to the bottom of the slot all the way around.
Reach inside the cylinder and push four of the frame inserts into the four horizontal slots in the frame until they are all the way in and grip the edge of the image sheet securely. You can do this most easily by first inserting one end, then use two thumbs to both compress the insert and push the other end into the slot.
Turn the image sheet cylinder and rim upside down so the plain frame is now on the bottom.
With the legs facing in an upward position the frame which has three legs attached above the image sheet cylinder so that the vertical mark on the outside face of the frame aligns with the overlapping vertical edge of the image sheet cylinder.
Push the frame downward on to the image sheet cylinder and repeat the above installation steps for the cylinder.
Turn the unit right side up, screw in a 75 watt incandescent bulb, plug in the electric cord and the MuseumLight™ is operational.
Note: To release the MuseumLight™ image sheet cylinder from the frame, for instance to exchange one image sheet for another or to realign the existing image if necessary, just insert a screwdriver (or similar) in the space at either end of the insert between the insert and the rim and pry the insert out of the rim slot. When the insert are removed the image sheet cylinder will be released from the rim.
Pendant Model
1. Image Sheet Preparation—Remove the image sheet from box A.
Let it unroll and it will form a cylindrical shape. Put it on a table with the ends of the roll facing up.
Remove the cover from the two sided adhesive tape that is located at one end of the image sheet.
Position that end of the image sheet above the other end so the full length of its edge is aligned between the two lines printed on the other end.
Press the two ends together and the image sheet is now formed into a continuous cylinder. Turn the cylinder over and place it horizontally on a table, then press down along the overlap to ensure a strong bond the full length of the overlap.
Note: You may want to practice this before removing the cover from the tape. Try positioning the edge of the sheet between the lines, starting at one end.
2. Frame Preparation—Remove the three legs, the triangular hub, and the two frames from box B. Leave the other items in the box.
Place the hub (either side up) on a table and push the ends of the long arms of the three legs (marked O) into the slots in the hub (marked O).
Place the frame with slots for the legs on a table with the side of the frame that has a perimeter slot facing up and push the short ends of the three legs (marked X) into the three slots in the frame (marked X).
Note: If you want to disconnect a leg after it is installed just tilt it and it will come out of the slot.
3. Install Electric Parts—Remove the electric assembly from box B. Only the rim inserts and canopy kit now remain in the box.
Pull the nut along the electric cord a short distance away from the bulb socket. Slide the electric cord wire through the slot in the triangular hub so that the bulb socket is facing in the same direction as the legs.
Push the threaded nipple on the bulb socket through the center hole in the hub.
Slide the nut alone the electrical cord up to the nipple on the bulb socket. Tighten the nut by hand until the bulb socket is secure in the hub.
4. Final Assembly—Remove eight frame inserts from the frame and electric parts box B. There is an extra frame insert in the box in case one is mislaid. Only the canopy kit now remains in the box.
Position the image sheet cylinder vertically on a table so the picture faces down.
Position the vertical mark on the outside face of the plain frame so it aligns with the overlapping vertical edge of the image sheet cylinder.
Push the frame downward on to the image sheet cylinder so the cylinder engages the slot in the frame. Use the lugs on the inside of the frame to help guide the media cylinder into position. The frame must be pushed all the way down so that the cylinder edge goes to the bottom of the slot all the way around.
Reach inside the cylinder and push four of the frame inserts into the four horizontal slots in the frame until they are all the way in and grip the edge of the image sheet securely. You can do this most easily by first inserting one end, then use two thumbs to both compress the insert and push the other end into the slot.
Turn the image sheet cylinder and rim upside down so the plain frame is now on the bottom.
With the legs facing in a downward position the frame which has the legs attached above the image sheet cylinder so that the vertical mark on the outside face of the rim aligns with the overlapping vertical edge of the image sheet cylinder.
Push the frame downward on to the image sheet cylinder and repeat the above installation steps for they cylinder.
Connect to power supply in ceiling. Use the canopy parts that are in box B, if required. Note that this step must be done by a qualified electrician.
Screw in a 75 watt incandescent bulb, and your MuseumLight™ is operational.
Note: To release the MuseumLight™ image sheet cylinder from the frame, for instance to exchange one art media sheet for another or to realign the existing image if necessary, just insert a screwdriver (or similar) in the space at either end of the insert between the insert and the frame and pry the insert out of the frame slot. When the inserts are removed the image sheet cylinder will be released from the frame.
Besides the differences in the IDU from the previous embodiments, some changes have been made to streamline a new IDU set-up. Instead of providing software to a museum for formatting a new IDU, the formatting software is now an integral part of the company website so that the museum can do this itself and review the result immediately.
In general, the present invention is an illuminated display unit including:
A) A support frame having at least one surface along the inside of the frame;
B) An image sheet placed directly against at least one surface of the frame with an edge thereof abutting against at least one surface; and
C) A fastener fastening the image sheet against at least one surface to retain the image sheet secure in the frame, whereby the image sheet is held securely for display without the use of adhesives or any attachment device potentially damaging the image sheet and
D) Whereby the image sheet is releasable by releasing the fastener from the frame and allowing withdrawal of the fastener from the frame, thereby releasing the image sheet free of any damage.
Optionally, the frame can have slots formed in the loop member which engage with the fastener, so that the image sheet is held flat directly against the at least one surface of the frame with an edge thereof abutting against at least one surface. The fastener within the slot pressing the image sheet against at least one surface to retain the image sheet securely in the frame without the use of adhesives or any attachment device damaging the image sheet. The image sheet is releasable by releasing the resilient fastener from the loop frame member and allowing withdrawal of the fastener from the slot, thereby releasing the image sheet free of any damage.
In a preferred embodiment, the insert contained within the slot has a center leg pressing the image sheet against the surface to retain the image sheet secure in the frame. This preferred insert has separate resilient end legs on opposite sides of the center leg with a tooth on outer edges thereof to engage end edges of the slot, to retain the insert within the slot, with the center leg engaging with the image sheet, holding the image sheet in place on the support frame, so that the image sheet is held securely. The image sheet is releasable by pressing the end legs of the insert inwardly toward the center leg, to disengage the insert from the frame member and allow withdrawal of the insert from the slot, thereby releasing the image sheet free of any damage.
Optionally, the support frame is an extended member which is provided with multiple, spaced leg members.
Furthermore, the support frame includes a hub for supporting a lighting fixture.
The support frame has an annular shape rim for securing an image sheet which extends from the support frame, with the lighting fixture located within said annular shaped image sheet so that the image is viewable from outside of the annular shaped image sheet.
Before assuming its closed annular shape, the image sheet is a flat, flexible and transparent or translucent member with an image reproduced on a surface thereof.
The support frame and the hub can have integrally formed separate spaced leg attachments, for attaching legs.
These leg attachments may include slots in the hub along outer edges thereof and in the frame for releasable engaging the supporting legs from each attachment slot.
The hub has a central opening for receiving a light socket fixture, and a slot extending out from the central opening to allow for the wire of an assembled cord set to be inserted into the hub. The lighting element of the lighting fixture is enclosed within the confines of the closed shape image sheet, whereby the image is viewed from outside of the display unit.
In one embodiment the supporting legs are V-shaped and face downwardly to form a support for the display unit on a table top surface with the image sheet and lighting fixture extending upwardly.
In an alternate embodiment, the supporting legs and hub form a support for the display unit suspended from a wall bracket or ceiling forming a pendant with the supporting legs, image sheet and lighting fixture extending downwardly, so that the supporting legs are not extending above the support frame.
While it is theoretically possible to support and retain the image sheet with a single frame with fasteners, preferably the display unit has a second frame at the opposite end of the image sheet forming top and bottom frames holding the image sheet therebetween.
The image sheet will then have an annular shape determined by the frames to which it is attached.
The present invention also entails a method of assembling a transparent or translucent art sheet for display of an image formed on a surface thereof, including the steps of:
A) Rolling a rectangular shaped image sheet into a cylindrical configuration, with end edges overlapping and secured with an adhesive strip or otherwise secured;
B) Inserting an open end of the rolled image sheet into an annular supporting frame, with the supporting frame preferably having an L-shaped or U-shaped crossection with bottom and side adjacent surfaces along the inside of the L-shaped or U-shaped crossection of the frame and optionally having a slot formed in the rim member with the image sheet being held directly against the adjacent surface of the frame with an edge thereof abutting against the side adjacent surface;
C) Inserting fasteners into the frame, such as a frame insert within a slot, each frame insert having a center leg pressing the image sheet against the frame surface, to retain the image sheet secure in the frame, with each respective frame insert having separate and resilient spaced end legs, off opposite sides of the center leg, with a tooth on outer edges thereof, to engage end edges of each respective slot to retain the insert within the slot, with the center leg engaging the image sheet holding said image sheet in place on the frame;
D) Mounting a light source on the support frame and extending into a space formed within said image sheet for lighting the image sheet from within, for displaying the image on the image sheet;
E) The image sheet being held securely for display without the use of any attachment device damaging the image sheet; and
F) Releasing the image sheet, by releasing the fastener, such as by pressing the end legs of each respective fastener inwardly toward the center leg, to disengage the fastener from the frame member and allow withdrawal of the fastener from the slot thereby releasing the image sheet free of any damage.
The method further includes providing the support frame with a central hub for mounting of said the electrical light source.
Supporting legs are provided for connecting the hub to the support frame. The supporting legs are shaped to act as legs to support the IDU on a table top surface with the image sheet extending upwardly from said support frame and the hub and supporting legs inside the image sheet, with the light source extending above the hub within the image sheet.
Alternatively, the supporting legs are provided for connecting the hub to the support frame with the supporting legs used to suspend the IDU as a pendant from a ceiling fixture or wall bracket, with the image sheet extending down from said support frame, and the hub and supporting legs inside the image sheet, with the light source extending down below the support frame within the image sheet.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention can best be understood in connection with the accompanying drawings. It is noted that the invention is not limited to the precise embodiments shown in drawings, in which:
FIG. 1 is a perspective view of an assembled IDU in use on a table top.
FIG. 1A is a perspective view of an assembled IDU with a pedestal using a second support frame at the base in use on a table top.
FIG. 1B is a perspective view of an assembled IDU with a base using a modified base in use on a table top.
FIG. 2 is a perspective view of an assembled IDU suspended by a pulley cord.
FIGS. 3A and 3B are top plan views of the two part frame set showing the plain frame as well as the support frame if molded in one piece, incorporating, in this case, 4 legs.
FIG. 4 is a crossection detail of the image sheet support surface of each frame member showing the edge of the image sheet abutting a layer of two sided attachment tape.
FIG. 5 is a plan view of the pre-wired electrical assembly that is part of the IDU kit. (In the case illustrated this is for a table top unit and incorporates a dimmer. Alternative electrical kits will be available, including an electric assembly with a pulley cord for pendant units.)
FIG. 5A is a plan view of an alternative electrical assembly for a table top unit with a pedestal that will use a second support frame as a base.
FIG. 5B is a plan view of an alternative electrical assembly for a table top unit with a pedestal using a modified base.
FIG. 6 is a side view crossection of an assembled table top IDU taken along the major diameter of an oval shape.
FIG. 6A is a side view crossection of an assembled table top IDU of an alternate embodiment using a frame with a slot to engage the image sheet edge.
FIG. 6B is a side crossection detail of a modified edge shown in FIG. 6A .
FIG. 6C is a side view crossection of an assembled table top IDU with a pedestal using a second support frame member as a base.
FIG. 6D is a side view crossection of an assembled table top IDU with a pedestal using a modified base.
FIG. 7 is a perspective schematic view showing a continuous portion of image sheet material merging from a printer with a variety of images printed on image sheet sections (prior to cutting apart for each IDU).
FIG. 8 is a flow chart describing the assembly of an IDU formed with a one piece support frame and a plain frame.
FIG. 9 is a flow chart of the initial order set-up supporting a new museum exhibit.
FIG. 9A is a block diagram reflecting the hardware and network entities involved in implementing the flow chart of FIG. 9 .
FIG. 10 is a flow chart depicting the various customer fulfillment options at a museum gift shop.
FIG. 11 is a schematic top view of four different designs of IDU shapes each in which will have the same circumference for use with the same width image sheet.
FIG. 12 is a perspective view of the separate parts of a frame kit of one type of alternate embodiment, in this case with four legs and a hub with two sets of four attachment lugs to accommodate frames with two different radii, such as, for example, an ellipse as compared to a circular rim frame. In this case, either of the rim frames may be used for the support frame since both incorporate attachment lugs.
FIG. 13 is a perspective view of an assembled support frame using parts from the frame kit of FIG. 12 .
FIG. 14 is a perspective view of a single leg from the frame kit using parts from the frame kit of FIG. 12 .
FIG. 15 is a top plan view of the socket support hub of this alternate embodiment, using parts from the frame kit of FIG. 12 .
FIG. 16 is a crossectional view of the support hub of FIG. 15 , when viewed along crossectional line “ 16 - 16 ” of FIG. 15 using parts from the frame kit of FIG. 12 .
FIG. 17 is a side view in partial crossectional showing the attachment of a leg with a frame on one end and the socket support hub at the opposite end using parts from the frame kit of FIG. 12 .
FIG. 18 is a perspective view of the parts of FIG. 17 from another viewpoint using parts from the frame kit of FIG. 12 .
FIG. 19 is a perspective close-up detail view of a leg-end, showing the tapered dovetail attachment slot.
FIG. 20 is a flow chart of the assembly of an illuminated display unit (IDU), including alternate embodiments with a multi-part support rim/frame with a plurality of attachable legs.
FIG. 21 is a side elevation of a hanging illuminated display unit (IDU) with legs pointing down and positioned between support and plain frame.
FIG. 22 is a side elevation of a pedestal supported illuminated display unit (IDU) with legs pointing upward and positioned between support and plain frame.
FIG. 23 is a perspective view of the separate parts of a further alternative frame kit with three legs.
FIG. 23A is a perspective view of the separate parts of another further alternative frame kit with an equivalent set of three legs with an alternate end coupling.
FIG. 23B is a perspective close-up detail view of the end coupling of one of the equivalent fame legs of FIG. 23A , as viewed within dashed circle line “ 23 B” of FIG. 23A .
FIG. 24 is a perspective view of an assembled support frame using parts from the frame kit of FIG. 23 or 23 A.
FIG. 25 depicts a leg using the system or attachment of FIG. 23 and configured in an asymmetrical V.
FIG. 25A depicts a leg using the alternate system of attachment of FIG. 23A .
FIG. 26 is a top plan view of a socket support hub of the embodiment in FIG. 23 or 23 A.
FIG. 27 is a top plan view of the leg attachment slot on two alternative frame shapes for this embodiment.
FIG. 28 is a perspective view of one of the support frame with projections with slots for the attachment of legs and triangular socket support hub of a further embodiment of an IDU of this invention.
FIG. 29 is a perspective view of one of three identical legs of the further alternate embodiment.
FIG. 30 is a perspective view of the basic design of a frame insert of this embodiment.
FIG. 30A is a perspective view of an alternate design of a frame rim insert of this embodiment.
FIG. 31 is a perspective view of the plain frame rim of this embodiment with slots for inserts but without projections for leg attachment.
FIG. 32 is a perspective detail showing a frame insert FIG. 30 inserted into one of four horizontal slots in a frame member.
FIGS. 33A-33E show the steps of assembling an image sheet into a cylinder shape prior to attachment to a frame for either a table top or pendant IDU, wherein:
FIG. 33A is a perspective view of a box containing a rolled up image sheet.
FIG. 33B is a perspective view of an image sheet unrolled with the release strip being pulled off one side of the two-sided tape attached to the edge of the image sheet.
FIG. 33C is a perspective view of the step of attaching the free ends of the image sheet after removing the release strip.
FIG. 33 CC is a perspective enlarged detail of FIG. 33C to illustrate the accurate adhesion of the image sheet cylinder along the overlap.
FIG. 33D is a perspective view of an image sheet cylinder lying horizontally after assembly.
FIG. 33 DD is an edge elevation detail of the overlapped seam of FIG. 33D showing directions of pressure required to permanently adhere the seam.
FIG. 33E is a perspective view of a vertically oriented completed image sheet cylinder.
FIGS. 34A-34D illustrate the steps of assembling the support frame of a table top IDU, wherein:
FIG. 34A is a perspective view of a box containing the frame members of an IDU.
FIG. 34B is a perspective view illustrating the step of inserting the three legs into the triangular socket support hub. The legs marked O are inserted into the socket support hub slots marked O.
FIG. 34C is a perspective view showing the step of attaching legs and hub to the support frame. The leg ends marked X are inserted into the rim slots marked X.
FIG. 34 CC is a crossectional detail of the edge of the support frame showing the orientation of perimeter slot if assembled for the tabletop model IDU.
FIG. 34D is a perspective view of an assembled support frame.
FIG. 34E is a crossectional detail of the edge of the support frame showing the orientation of the perimeter slot if assembled for a pendant model IDU.
FIG. 35A-35F illustrate the steps of attaching the electrical components to the assembled support frame for a table top IDU and for a pendant IDU, wherein:
FIG. 35A is a side elevation of lamp socket with threaded nipple and a retaining nut on electrical wire.
FIG. 35B is a perspective detail showing insertion of electrical wire through a side slot into center hole of triangular socket support hub.
FIG. 35C is a perspective detail showing setting the nipple on the socket into hole in socket support hub.
FIG. 35D is a perspective detail showing nut dangling wire under socket support hub.
FIG. 35E is a side elevation detail showing nut engaging socket nipple to attach socket to socket support hub.
FIG. 35F is a side elevation in partial crossection showing support frame with socket attached and orientation of frame slot and socket for a tabletop IDU.
FIG. 35G shows side elevation details of socket and rim slot as used in a pendant IDU with orientation opposite to that of FIG. 35F .
FIGS. 36A-36I illustrate the assembly steps to complete the assembly of a table top IDU by attaching the image sheet cylinder to the assembled frame members, wherein:
FIG. 36A is a perspective view of orientating the plain frame atop the image sheet cylinder.
FIG. 36B is a perspective view of the completion of action of 35 A.
FIG. 36C is a perspective view illustrating insertion of four frame inserts to retain the image sheet in the slot in the plain frame.
FIG. 36 CC is a perspective detail of a rim insert inserted in a horizontal frame slot.
FIG. 36D is a perspective view illustrating inverting an image sheet with the plain frame attached.
FIG. 36E is a perspective view showing support frame oriented atop open end of the formed image sheet.
FIG. 36F is a perspective view showing the completion of the action of 36 E.
FIG. 36G is a perspective view illustrating insertion of four frame inserts to retain the image sheet in the support frame.
FIG. 36 GG is a perspective detail of one rim insert inserted through one horizontal rim slot.
FIG. 36H is a perspective view illustrating inversion of assembled tabletop IDU so that legs can rest on a horizontal surface.
FIG. 36I is a perspective view showing addition of a lamp to the complete IDU.
FIG. 37A-37H illustrate the final assembly of a pendant IDU of this further alternate embodiment, wherein:
FIG. 37A is a perspective view of orienting the plain frame atop the image sheet cylinder.
FIG. 37B is a perspective view of the completion of action of 37 A.
FIG. 37C is a perspective view illustrating insertion of four frame inserts to retain the image sheet in the slot in the plain frame.
FIG. 37 CC is a perspective detail of a frame insert inserted through one horizontal frame slot.
FIG. 37D is a perspective view illustrating inversion of image sheet with plain frame attached.
FIG. 37E is a perspective view showing support frame oriented atop open end of the formed image sheet.
FIG. 37F is a perspective view showing the completion of the action of 37 E.
FIG. 37G is a perspective view illustrating insertion of four frame inserts to retain image sheet in the support frame.
FIG. 37 GG is a perspective detail of one frame insert inserted though one horizontal rim slot.
FIG. 37H is a perspective view illustrating adding a lamp to the complete pendant IDU.
FIG. 38 is a flow chart of the order set-up for a new or previously ordered museum image for use with this further alternate embodiment.
FIG. 39 is a block diagram reflecting the hardware and network entities in implementing the flow chart of FIG. 38 .
FIG. 40 is a flow chart depicting the customer fulfillment options at a museum gift shop for this further alternate embodiment.
DETAILED DESCRIPTION OF THE INVENTION
The present invention has broad applications to many fields for a variety of IDU's. For illustrative purposes only, a preferred mode for carrying out the invention is described herein.
FIG. 1 shows a table top 9 on which illuminated display unit (IDU) 1 with image sheet 3 displaying image 2 rests. Image sheet 3 is contained and shaped between a support frame 4 at the bottom edge incorporating support legs facing down and a plain frame 5 at top edge. A small overlap 6 of the free ends is at the rear of the display unit. Electrical control (switch or switch/dimmer) 8 is shown on electrical line 7 .
FIG. 1A is a similar image of the same IDU 1 but with a pedestal tube and second support frame added at the base, wherein the support legs extend upward within the region surrounded by image sheet 3 of the illuminated display unit (IDU) 1 .
FIG. 1B is a similar image of the same IDU 1 but with a pedestal tube and with a modified base, also wherein the support legs extend upward within the region surrounded by image sheet 3 of the illuminated display unit (IDU) 1 .
FIG. 2 is a similar image of the same IDU 1 configured for hanging from pulley cord 10 with support legs at the top.
FIGS. 3A and 3B show the two frame parts. In this illustration the plain frame 5 is an oval shape. The support frame 4 is also oval but incorporates four legs (drawn flat) 14 leading at the center to a hub, such as a lamp socket support hub 12 with a central hole for the socket nipple 17 and a side slot for electric wire insertion 18 .
Each of the image sheet support edges of the frames in this illustration have a preferably L-shaped crossection (see FIG. 4 ) which supports a top or bottom edge of image sheet 3 . These supports also have a layer of tape attached with a release liner 15 . The release liner can be removed prior to assembly to expose an adhesive layer for permanent attachment of the image sheet to the frame. This is optional for the table top unit where gravity holds the image sheet tot eh support frame 4 and to the plain frame 5 . For the hanging configuration where gravity tends to pull the three sections apart, the adhesive layer 15 must be exposed and used.
FIG. 5 shows a pre-wired electrical cord set for the table top model 20 consisting of lamp socket 21 with pre-attached short threaded nipple 22 , nut 23 , control 8 , extension cord 7 , and wall plug 25 . Line cord 7 fits through slot 18 on socket support hub 12 which then permits short threaded nipple 22 to fit through the center hole 17 for attachment of the lamp socket even though the entire electrical set is pre-wired.
FIG. 5A shows a pre-wired electrical set for the pedestal model 20 consisting of lamp socket 21 with pre-attached short threaded nipple 22 , tube with internal threads to fit nipples at both ends 21 , with pre-attached short threaded nipple at the end opposite the lamp socket 22 , nut 23 , control 1 , extension cord 7 , and wall plug 25 . Line cord 7 fits through slot 18 on socket support hub 12 which then permits short threaded nipple 22 to fit through the center hole 17 for attachment even though the entire electrical set is pre-wired.
FIG. 5B shows the same electrical set as 5 A but with a modified base unit 36 on line cord 7 .
FIG. 6 shows how the various parts fit together for the table top model; bulb 7 (or optional CFL) is not part of the electrical kit because of fragility concerns. Note that legs 14 on support frame 4 angle down to create integral legs. The preferred fabrication of both frame parts is injection molding using a glass filled polycarbonate resin. In this illustration the support frame 4 would be formed as a single piece.
FIG. 6A shows an alternate embodiment of an illuminated table top model display unit (IDU) using another design of a support edge with an outer support lip added on plain frame 35 and support frame 34 . The detail of FIG. 6B shows how such an edge engages art sheet 3 at top edge. Note that double-sided tape with release liner 36 A may be attached to art sheet 3 or to the frame edge is in either design. Frame edge material thickness T is nominally EDM 3/32″ with other dimensions relatively scaled.
FIG. 6C shows a pedestal model illuminated display unit (IDU) which provides a pedestal between the image display unit and table top. This shows how the pedestal tube internally threaded at both ends 24 screws on to the short threaded nipple 22 an the lamp socket 21 and at the other end on to a second short nipple 22 which is inserted into center hub 12 on a second support frame 34 , and held in place by nut 23 . Legs 14 are shown extending upward within the region surrounded by image sheet 3 and on the bottom frame which would be possible if also made, with the legs thus oriented or if the support frame parts are provided separately for customer assembly as described on a later page herein concerning FIGS. 12-27 .
FIG. 6D shows the modified base 36 illustrated in FIG. 1A , which assembles in same manner as the parts in FIGS. 6C but must be provided pre-threaded on the electric wire as part of the electric kit because it does not have the unique slot provided for wire insertion that is on the support frame 34 . Legs 14 are shown optionally extending upward within the region surrounded by image sheet. Electric cord 7 preferably exits out through a hole in base 36 .
FIG. 7 shows a printer, such as a wide format printer 30 , spewing out a long sheet of image sheet material which will be sliced at dashed lines 31 to form individual strips (all of the same circumference length as the width of the image sheet material but cut in various lengths “W”) which will become image sheets 3 displaying images “AW” after cutting into separate units. Note the heights of the different image sheets (“W”) varies with the particular AW being printed since they are determined by the programmed instructions to the printer and are therefore infinitely variable. However, any printer capable of printing an image upon a flexible translucent or transparent such as a sheet of plastic, laminated textile or art paper may be used, wherein one or more images and lettering may be printed on the flexible sheet.
The IDU assembly flow chart of FIG. 8 is largely self-explanatory. Note that the orientation of the art to the support frame is different depending on whether a table top, pedestal or hanging version of IDU 1 is being assembled; this can be easily seen in FIGS. 1 and 2 . Although permanent or temporary assembly is an option for a table top unit, the hanging version must be bonded together with the tape around the edge of the frame sections. Temporary assembly of the table top unit permits using the same frame kit serially for a variety of art sheet displays.
The process for the initial and subsequent order set-up with a museum gift shop was described in words in the summary section. FIG. 9 shows this process in flow chart form. This shows the optional methods of performing the formatting of the museum Image to create and Image Unit file of formatted digitized images that actually drives the printer to print out image sheets. The accurate pricing of each image sheet can only be performed after this step.
The flow chart of FIG. 9A clearly illustrates the computer hardware and network entities involved in actually implementing the order process. The box labeled “Company” in FIG. 9A includes a computer system including a central processing unit (CPU) or microprocessor facilitating communications enabled by a server through the internet between the company and three different museum gift shops is shown. Museums A and B are involved in initial order set-up, but Museum A lets the company edit their exhibit image file while Museum B edits their, own exhibit image file to an IAU file using software provided by the company. In both cases, IAU pricing is provided by the company. Museum C sends a drop shop order to the company for a customer named “Smith”. Both IDU kits as well as fully assembled IDU's with attached image sheets can be shipped out. The company keeps up with the museum interacting with its computer and microprocessor throughout the internet. Field representatives or company sales persons (as represented by “laptops” SP-A and SP-B) can also be used to send in orders resulting from museum gift shop visits or other communications. FIG. 9A also indicates how the company with its computer CPU or microprocessor creates the image sheets on printer 30 and produces kits from an internal production line (as shown). Electric/frame kits and image sheets, or fully assembled IDU's, are shipped by a common carrier to the museum shops or to specific “drop ship” museum customers.
The different customer order fulfillment options discussed above in the summary are detailed in the flow chart of FIG. 10 .
Although the main objective of this invention is to create an efficient method of displaying images that may be purchased at a museum shop, many other uses for an IDU unrelated to museums art exist. One is a direct internet to customer marketing method whereby the images (which may, for instance, consist of family or travel snapshots) is provided by the customer for creating an image sheet. Another possibility is advertising use of IDU's such as displays promoting a certain brand of beer at a tavern. Another is images depicting local tourist attractions for sale in souvenir shops. The oval format described may not be optimal for all applications. It is possible to use the identical manufacturing steps to create IDU's of any annular crossection by using frames that have alternate peripheral shapes.
While intended use is to illuminate the translucent image sheet, under ambient light the image sheet still displays the image thereon.
FIG. 11 schematically shows four examples of alternative top outline views of an IDU. They are drawn at the same scale to show the relative feature size for a constant circumference. The circle and extended circle shapes would be easily produced, while the sharp corners of the square and hexagonal shapes would be somewhat rounded in practice to prevent creasing of the image sheet and is applicable to any shaped polygon, such as hexagonal or pentagonal, etc.
The parts comprising a frame kit of an illuminated display unit (IDU) of an alternate embodiment are shown in FIG. 12 . Two plain frames 104 with image sheet alignment marks on the outside 138 , and leg attachments lugs 137 in the inside, a plurality of legs, such as, for example, four legs 114 , with a coupling at each end, such as, for example, four legs 114 , with a coupling at each end, such as, for example, a tapered dovetail coupling slot feature 136 at each end, and a lamp socket support hub 112 are included. For this example cooperative couplings, such as, for example, protruding lugs 137 , are located on the inside of each plain frame 104 and on the outer surfaces of socket support hub 112 , and the lugs 137 fit into the couplings in this example tapered slots at the leg ends 136 . It is further noted that other configurations for the hub may be pro tided, so long as it is capable of holding the light source within the confines of the formed images sheet held in place by the support frame and the plain frame, wherein further the hub is connected to the support frame by a plurality of legs or spokes.
FIG. 13 shows such an assembled support frame with the legs 114 down. Note that the inner lugs 137 on hub 112 are used; a different shape or circumferential size of frame may require the use of the outer lugs 137 on hub 112 .
FIG. 14 provides a clear view of a single, preferably V-shaped leg 114 with preferably slotted leg ends 136 . In this case the V is asymmetrical.
FIGS. 15 and 16 show details of lamp socket support hub 112 including lugs 137 and electrical wire access slot 140 . That is one of the parts illustrated in FIG. 12 .
FIGS. 17-19 show details of an attachment system for the parts illustrated in FIG. 12 for the couplings associated with legs 114 . For example, FIG. 17 is a side view showing the fit of couplings such as lugs 137 within cooperative couplings, such as tapered slots, in ends 136 . FIG. 18 is a perspective view showing a similar attachment. FIG. 19 shows an enlarged leg end 136 . The tapered dovetail slot (note width “w 1 ” greater than width “w 2 ”) is shown clearly. Tapered dovetail lugs 137 are sized so that they will engage the inner walls of the slot in 136 at the mid slot position to lock the two members together.
The flow chart of IDU assembly of FIG. 20 contrasts the assembly of the previous embodiment with the one-piece molded support frame shown in FIGS. 1-11 with that of the unassembled frame kit of the alternate embodiment of FIGS. 12-26 . The entire difference in procedure involves the removal of the kit parts from the box and the assembly of the support frame by connecting each leg to the rim of a plain frame and to the lamp socket support while being aware of the desired configuration. From there on, the procedure is substantially identical to that of the previous embodiment, including the production of FIG. 7 as well as the assembly and organizational computerized flow charts of FIGS. 9 , 9 A and 10 and the schematic view of possible shapes shown in FIG. 11 .
FIGS. 21 and 22 illustrate illuminated display unit (IDU) configurations that are not possible with the original one-piece molded support frame. A tabletop configuration using the support frame kit of this embodiment would be configured as in the original embodiment (support frame faces up with legs down); in fact FIG. 2 from the original embodiment is a good representation of it.
In FIG. 21 , hanging illuminated display unit (IDU) 140 is configured such that support frame 141 is assembled with the support groove for image sheet 3 on member 104 facing down, as are legs 114 . Plain frame 141 is simply a member 104 with the groove for image sheet 3 facing upward. Note that legs 114 now reside between support frame 141 and plain frame 142 . This orientation is not possible with the original one-piece support frame which included the legs pointing in the opposite direction. Legs, socket support hub and lamp are shown in dashed lines as obscured by image sheet 3 .
FIG. 22 illustrates a pedestal lamp 150 where support frame 151 is assembled from a member 104 facing upward and legs 114 also pointing upward. Plain frame 152 is a member 104 facing downward. Again here it can be observed that legs are positioned between plain and support frames (see dashed lines). Base 153 is assembled from a member 104 facing down and legs 114 facing up with a socket support hub in the center. Alternatively, a modified base 136 can be used (as shown in FIG. 6D ).
In yet, another embodiment shown in FIGS. 23 and 27 , there are preferably three legs 1114 provided, and the attachment system of the legs 1114 to the hub 1104 and to the rim frame 1104 is changed to a tongue and slot system.
FIG. 23 shows the parts comprising of a frame kit of an illuminated display unit, (IDU) of this alternate embodiment. This embodiment includes one frame 1105 which does not have any provision for attachment of legs 1114 and another frame 1104 with such attachment provisions. The kit constitutes the two frames with sheet align marks on the outside 1138 and leg attachment slots 1139 on the inside, three legs 1114 with a coupling tongue at each end and a lamp socket support hub 1112 with slots for leg attachment of leg 1114 .
FIG. 23A shows the parts comprising of a frame kit of an illuminated display unit (IDU) of a further alternative embodiment with equivalent component coupling parts. This embodiment includes one frame 1105 ′ which does not have any provision for attachment of legs 1114 ′ and another frame 1104 ″ with such attachment provisions. The kit constitutes the two frames with sheet align marks on the outside 1138 ′ and leg attachments slots 1139 ′ on the inside three legs 1114 ′ with a coupling tongue at each end and a lamp socket support disc 1112 ′ with slots for leg attachment of leg 1114 ′.
FIG. 23B shows the end coupling of one of the equivalent frame legs 1114 ′ of FIG. 23A , as viewed within dashed circle line “ 23 B” of FIG. 23A .
FIGS. 24 and 24A shows the assembled support frame 1104 with legs 1114 and lamp socket support hub 1112 attached.
FIGS. 25 and 25A shows one of the legs 1114 of FIG. 23 and FIG. 23A respectively. The leg is an asymmetrical “V-shape” to enable the support of the unit to be spread farther apart and the system for attachment for the leg 1114 to the lamp support hub 1112 and to the frame 1104 . The attachment details are shown clearly in this figure. Each leg 1114 has two attachment extensions 1140 at an angle to the angled leg portions 1142 and 1143 of each leg 1114 . Extensions 1140 are angled vertically for insertion into and through slots or holes, such as for example, rectangular holes/slots 1139 in support frame 1104 and lamp support hub 1112 . As the extensions 1140 are pushed in toward the step region, molded cantilevered tongues 1141 are compressed until they again snap out locking extensions in slots or holes, such as for example, rectangular slots/holes 1139 . The “V” shape of legs 1114 is preferably asymmetric to place the vertex closer to the rim (X 1 ) than to the lamp support hub 1112 at the center (X 2 ) affording better stability. Tongue 1140 has a cantilevered tip which is spring loaded, so that it compresses as tongue 1140 is inserted into leg attachment slot/hole 1139 and decompresses outward when through the slot/hole 1139 , thereby locking leg 1114 in place in respective slots/holes 1139 in frame 1104 at one end and in lamp support hub 1112 at the other end.
FIG. 26 shows details of the lamp socket support hub 1112 including leg attachment slots/holes 1139 for legs of FIG. 23 or FIG. 23A and electrical wire access slot 1118 .
FIG. 27 shows examples of the leg attachment slots 1139 configured for a circular rim frame 1104 and an elliptical rim frame 1104 . The slot on the circular rim frame 1104 is positioned a distance inside the rim frame 1104 to illustrate provisions to accommodate a leg of one size to fit frames with a different radial difference from the hub lamp support hub 1112 to the rim/frame 1104 .
In a further alternate embodiment, the frame of the illuminate display unit (IDU is comprised of multiple component parts, and the image sheet may be printed on a coated art paper designed for inkjet printing. The image sheet is retained in a non-permanent method using frame inserts in the support and plain frame members.
FIG. 28 shows an assembled support frame of this embodiment 2000 having integrally molded attachments 2001 , 2002 , and 2003 with slots (marked X) at each respective slot attachment to accept one end (marked X) at one end of each respective leg member for insertion of three identical leg members 2010 . The distal end (marked O) of each of the legs is inserted into a rectangular slot (marked O) of each respective slot of the central hub 2020 in the triangular socket support hub 2020 which completes the assembly. Note that the three leg attachments ( 2001 , 2002 , and 2003 ) are asymmetric but the locations of their attachment points around an oval rim 2000 conspire to place triangular hub 2020 in the center. Hub 2020 will accept attachment of a lamp socket with a threaded nipple at hole 2023 and permit entry of electrical cord through slot 2024 . Integral molded horizontal rim slots 2004 are used for the frame inserts retaining the image sheet. The rim slots 2004 are located within lugs projecting above the inner rim of the support frame 2000 , which, together with the lugs 2064 , also projecting above the inner rim of the support frame 2000 and located at both ends of the major axis of the frame 2000 , facilitate the insertion of the image sheet 2052 into the circumferential rim slots within support frame 2000 and plain frame 2040 .
FIG. 29 shows one of three legs 2010 with frame engaging end 2011 (marked X) and hub engaging end 2012 (marked O).
FIG. 30 shows one of the frame inserts 2030 that are inserted through horizontal slots 2004 in both the support frame 2000 and the plain frame 2040 to retain the image sheet by impingement with central member end 2032 . FIG. 31 shows an outer perspective view of the plain frame rim 2040 of this embodiment with slots 2004 for inserts 2030 but without projection attachments 2001 , 2002 , and 2003 for leg attachment that are shown in FIG. 28 . As shown in FIG. 32 , wing members 2031 compress on insertion then snap back, thereby locking into slots 2004 to hold the insert in position pressing the image sheet 2052 against the outer rim slot surface of the outer circumferential rim slot 2063 of outer circumferential frame portion 2061 of frame 2000 . Inserts 2030 may be made of an elastomeric resin with high durometer. Materials such as polyurethane and silicone exhibit the desirable features discussed. Note the serrated end 2032 which (enhances grip on the surface of image sheet 2052 . Perspective view detail FIG. 32 also shows the resilient frame insert 2030 inserted in a horizontal slot 2004 edge of rim 2000 . A crossectional detail view of the outer circumferential frame portion 2061 with rim slot 2063 in a region away from a slot 2004 is shown at FIGS. 34 CC and 34 E. The image sheet 2052 edge is pressed between end 2032 of a resilient insert 2030 and the long outer wall of recess slot 2063 as shown in FIGS. 32 , 34 CC and 34 E. The location of the region in which the image sheet 2052 is located in FIGS. 30A and 32 is indicated by arrows identified as reference numeral 2052 ′, but because these views in FIGS. 30A and 32 are not cross sections, the actual image sheet 2052 is not illustrated.
FIG. 30A shows an alternate design for the frame insert 2030 inserted into a horizontal frame slot 2004 .
The assembly details for the image sheet for either a table top or a pendant type IDU, taking an image sheet 2052 from package box A 2050 through forming it into a cylinder for frame attachment using adhesive strip 2053 to attach the free edges, is shown is the sequence of drawings of FIGS. 33A-33E . The comments in the brief descriptions of the drawings are sufficient to follow the steps.
The assembly details of the support frame for a table top IDU from package box B 2060 through completion are shown in the steps of FIGS. 34A-34D . Note that detail 34 CC shows the crossection 2062 of rim 2000 with the rim slot 2063 facing down. The same assembly steps but with an inverted rim 2000 as shown in detail of FIG. 34E would be used for assembly of a support frame for a pendant IDU.
The attachment of the bulb socket, which is part of the electrical subassembly, to the hub of the support frame for a table top IDU is illustrated in FIGS. 35A (showing bulb socket 21 , with threaded nipple attached 22 and nut 23 threaded onto the electric cable) through the completed attachment of FIG. 35F . FIG. 35B shows the slot in the hub which enables the electric cord of a fully assembled cord set to be inserted in the hub 2020 . The details are explained in the brief description of this figure sequence. The detail of FIG. 35G shows the different orientation of the bulb socket 21 as well as the rim slot 2063 for the assembly sequence for a pendant IDU.
The attachment of the image sheet to the frame for a table top IDU is detailed in the sequence of FIGS. 36A-36I . In reviewing these figures, note that image sheet 2052 orientation as depicted by the human form. FIGS. 36D and 36H show the details for the next assembly sequence. Details of each illustration can be gleaned from the components in the brief descriptions of the drawings. This sequence ends in the completed table top IDU.
A similar sequence of FIGS. 37A-37H details of the same parts assembled for a pendant IDU.
In this further alternate embodiment, the order set-up flow chart of FIG. 9 for previous embodiments is modified at FIG. 38 to reflect changes incorporating an enhanced company web site. One change is that the museum (or the institution or business or individual customer) can format their art directly on the company website as this now has the required software to make this possible. These changes streamline the communications and save time.
While the block diagram of FIG. 39 is similar to that of FIG. 9A of earlier embodiments, FIG. 39 shows the actual communicating pairs through the Internet for IAU pricing and image file setup. The customer fulfillment flow chart of FIG. 10 for previous embodiment has been simplified at FIG. 40 for this further alternate embodiment to eliminate the drop ship request option to the company.
While the foregoing illustrations depict a light source including a lamp with an AC socket and electrical cord connected to an AC power source, it is known that other light sources could be utilized, such as light emitting diode lamps, or DC powered lamps with DC power sources, such as batteries or other low voltage power sources.
In the foregoing description, certain terms and visual depictions are used to illustrate the preferred embodiment. However, no unnecessary limitations are to be construed by the terms used or illustrations depicted, beyond what is shown in the prior image, since the terms and illustrations are exemplary only a, and are not meant to limit the scope of the present invention.
It is further known that other modifications may be made to the present invention, without departing the scope of the invention, as noted in the appended Claims.
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A system for displaying an illuminated image which includes (1) a frame kit with interchangeable components and an assembled electric cord set and (2) a flexible sheet imprinted with an image which combine to make a unit for display of the image as on a table lamp or hanging lamp. The printed sheet is art paper or other media formed into a closed shape defined by the shape of the frame rims to which it is attached at both ends. One of the frame rims includes provision for the attachment of legs which connect the rim to a central hub, which provides support for a lamp holder. A slot is provided in the central hub so the complete electric cord set with the lamp holder attached can be inserted without disassembly. A website is set up whereby institutions or businesses can upload selected images with instructions for formatting for printing on the flexible sheet.
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PRIORITY
[0001] This application claims priority to an application entitled “Transmitting/Receiving Apparatus and Method for Packet Retransmission in a Mobile Communication System” filed in the Korean Industrial Property Office on Oct. 31, 2001 and assigned Serial No. 2001-67694, the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to a W-CDMA (Wide-band Code Division Multiple Access) mobile communication system, and in particular, to a transmitting/receiving apparatus and method for reducing a transmission error rate and thus increasing decoding performance at retransmission.
[0004] 2. Description of the Related Art
[0005] Adverse influences on high-speed, high-quality data service are attributed to a channel environment in a mobile communication system. The radio channel environment varies frequently because of signal power changes caused by white noise and fading, shadowing, the Doppler effect that occurs due to the movement and frequent velocity change of a terminal, and interference from other users and multi-path signals. Therefore, aside from conventional technologies in the second or third generation mobile communication system, an advanced technique is required to support wireless high-speed data packet service. In this context, the 3GPP (3 rd Generation Partnership Project) and the 3GPP2 commonly addressed the techniques of AMCS (Adaptive Modulation & Coding Scheme) and HARQ (Hybrid Automatic Repeat Request).
[0006] The AMCS adjusts a modulation order and a code rate according to changes in downlink channel condition. The downlink channel quality is usually obtained by measuring the SNR (Signal-to-Noise Ratio) of a received signal at a UE (User Equipment). The UE transmits the channel quality information to a BS (Base Station) on an uplink. Then the BS estimates the downlink channel condition based on the channel quality information and determines an appropriate modulation scheme and code rate according to the estimated downlink channel condition.
[0007] QPSK (Quadrature Phase Shift Keying), 8PSK (8-ary PSK), and 16QAM (16-ary Quadrature Amplitude Modulation) and code rates of ½ and ¼ are considered in the current high-speed wireless data packet communication system. In AMCS, a BS applies a high-order modulation (e.g., 16QAM and 64QAM) and a high code rate of ¾ to a UE having good channel quality such as its adjacent UEs, and a low-order modulation (e.g., 8PSK and QPSK) and a low code rate of ½ to a UE having bad channel quality such as a UE at a cell boundary. The AMCS reduces interference signals remarkably and improves system performance, as compared to the conventional method relying on high-speed power control.
[0008] HARQ is a retransmission control technique to correct errors in initially transmitted data packets. Schemes for implementing HARQ include chase combining (CC), full incremental redundancy (FIR), and partial incremental redundancy (PIR).
[0009] With CC, the entire initial transmission packet including systematic bits and parity bits is retransmitted. A receiver combines the retransmission packet with the initial transmission packet stored in a reception buffer. The resulting increase of the transmission reliability of coded bits input to a decoder brings the performance gain of the overall mobile communication system. An approximate 3-dB performance gain is effected on average since combining of the same two packets is equivalent to repeated coding of the packet.
[0010] In FIR, a packet having only parity bits, different from an initial transmission packet, is retransmitted to thereby increase a decoding gain. A decoder decodes data using the new parity bits as well as initially transmitted systematic and parity bits. As a result, decoding performance is improved. It is well known in coding theory that a higher performance gain is yielded at a low code rate than by repeated coding. Therefore, FIR is superior to CC in terms of performance gain.
[0011] As compared to FIR, PIR is a retransmission scheme in which a packet having systematic bits and new parity bits is retransmitted. A receiver combines the retransmitted systematic bits with initially transmitted systematic bits for decoding, achieving similar effects to those of CC. PIR is also similar to FIR in that the new parity bits are used for decoding. Since PIR is implemented at a relatively high code rate than FIR, PIR is in the middle of FIR and CC in performance.
[0012] A combined use of the independent techniques of increasing adaptability to varying channel condition, AMCS and HARQ can improve system performance significantly.
[0013] [0013]FIG. 1 is a block diagram of a transmitter in a typical high-speed wireless data packet communication system. Referring to FIG. 1, the transmitter includes a channel encoder 110 , a rate matching controller 120 , an interleaver 130 , a modulator 140 , and a controller 150 .
[0014] Upon input of information bits in transport blocks of size N, the channel encoder 110 encodes the information bits at a code rate R (=n/k, n and k are prime), for example, ½ or ¾. With the code rate R, the channel encoder 110 outputs n coded bits for the input of k information bits. The channel encoder 110 can support a plurality of code rates using a mother code rate of ⅙ or ⅕ through symbol puncturing or symbol repetition. The controller 150 controls the code rate.
[0015] The future mobile communication system adopts turbo coding considered a more robust channel coding technique for high-speed reliable transmission of multimedia data. It is known that turbo coding has the nearest Shannon Limit performance in BER (Bit Error Rate) at a low SNR. Turbo coding is also adopted in the 1×EV-DV (Evolution in Data and Voice) standards which are under discussion in the 3GPP and 3GPP2.
[0016] The output of the channel encoder 110 being a turbo encoder includes systematic bits and parity bits. The systematic bits are information bits to be transmitted and the parity bits are error correction bits added to the information bits for a receiver to correct errors generated during transmission of the information bits at decoding.
[0017] The rate matching controller 120 generally matches the data rate of the coded bits generally by transport channel-multiplexing, or by repetition and puncturing if the number of the coded bits is different from that of bits transmitted in the air. To minimize data loss caused by burst errors, the interleaver 130 interleaves the rate-matched bits. Interleaving distributes damaged bits in a fading environment. Therefore, the interleaving allows adjacent bits to be randomly influenced by fading and thus prevents burst errors, increasing channel encoding performance. The modulator 140 maps the interleaved bits to symbols in a modulation scheme determined by the controller 150 .
[0018] The controller 150 selects the code rate and the modulation scheme according to the radio downlink channel condition. To selectively use QPSK, 8PSK, 16QAM, and 64QAM according to the radio environment, the controller 150 supports AMCS. Though not shown, a UE spreads the modulated data with a plurality of Walsh codes to identify transport channels and with a PN (Pseudorandom Noise) code to identify a BS.
[0019] As stated before, the modulator 140 supports various modulation schemes including QPSK, 8PSK, 16QAM and 64QAM with respect to the interleaved bits. As a modulation order increases, the number of bits in one modulation symbol increases. Particularly in a higher-order modulation scheme greater than 8PSK, one modulation symbol includes three or more bits. In this case, bits mapped to one modulation symbol have different transmission reliabilities according to their positions.
[0020] With regard to transmission reliability, two bits of a modulation symbol representing a macro region defined by left/right and up/down have a relatively high reliability in an I (In Phase)-Q (Quadrature Phase) signal constellation. The other bits representing a micro region within the macro region have a relatively low reliability.
[0021] [0021]FIG. 2 illustrates an exemplary signal constellation in 16QAM. Referring to FIG. 2, one 16QAM modulation symbol contains 4 bits [i 1 , q 1 , i 2 , q 2 ] in a reliability pattern [H, H, L, L] (H denotes high reliability and L denotes low reliability). That is, the two upper bits [i 1 , q 1 ] have a relatively high reliability and the two lower bits [i 2 , q 2 ], a relatively low reliability. One 64QAM modulation symbol contains 6 bits [i 1 , q 1 , i 2 , q 2 , i 3 , q 3 ] in a reliability pattern [H, H, M, M, L, L] (M denotes medium reliability). Similarly, an 8PSK modulation symbol contains 3 bits. One of them has a lower reliability than the other two bits. Thus, a reliability pattern is [H, H, L].
[0022] Considering the above reliability patterns, it is preferable to map coded bits output from the channel encoder 110 to regions having different reliabilities according to their significance levels. As stated before, the coded bits are divided into systematic bits and parity bits having different priority levels. In other words, if errors are generated at different rates in a transport channel according to the reliabilities, a receiver can recover original bits more accurately by decoding when the parity bits have errors than when the systematic bits have errors because the systematic bits are actual information and the parity bits are error correction bits.
[0023] In this context, SMP (Symbol Mapping method based on Priority) has been proposed in which systematic bits are mapped to a high reliability region and parity bits are mapped to a low reliability region, so that the error rate of the relatively significant systematic bits can be decreased.
[0024] Aside from the different reliabilities of coded bits, each modulation symbol is transmitted with a different error rate on a radio channel in a modulation scheme having a modulation order equal to higher than 16QAM. For example, in the signal constellation for 16QAM, 4 coded bits form one modulation symbol and are mapped to one of 16 signal points. The 16 signal points are classified into three regions according to their error rates. As a modulation symbol is farther along a real or imaginary number axis, it has a lower error rate, which means that the receiver identifies the modulation symbol more easily.
[0025] [0025]FIG. 3 illustrates graphs showing the error probabilities of the regions in a simulation under an AWGN (Additive White Gaussian Noise) environment. As shown in FIG. 2, the 16 modulation symbols are classified into region 1 having a high error probability, region 2 having a medium error probability, and region 3 having a low error probability. For example, modulation symbols 6 , 7 , 10 and 11 in region 1 have a relatively high error probability.
[0026] In packet data retransmission by HARQ, therefore, retransmission with the same reliability and/or error probability as that of initial transmission does not increase retransmission efficiency. Retransmission of specific bits with a consistently low reliability and/or high error probability deteriorates decoding performance since a channel decoder being a turbo decoder has good decoding performance when the LLRs (Log Likelihood Ratios) of input bits are homogeneous. Therefore, there is a need for exploring a novel retransmission technique that improves transmission performance at retransmission.
[0027] Techniques for improving transmission performance at retransmission include SRRC (Shifted Retransmission for Reliability Compensation) and BIR (Bit Inverted Retransmission). In the SSRC, the coded bits of a modulation symbol are shifted by a predetermined number of bits, for example, two bits and thus mapped to different reliability parts at a retransmission from those at their initial transmission. In the BIR, the coded bits are inverted and thus mapped to different error probability parts at a retransmission from those at the initial transmission. Those techniques commonly comprise the LLRs of bits input to a turbo decoder and thus improve decoding performance.
[0028] To describe the SRRC in more detail, an M-ary modulation symbol includes log 2 M bits having different reliabilities. For example, four coded bits form one modulation symbol with the two upper bits mapped to a high reliability and the two lower bits mapped to a low reliability in 16QAM, as illustrated in FIG. 2. Two-bit cyclic shifting of the coded bits of each modulation symbol at a retransmission effects averaging the transmission reliabilities of the coded bits, thereby improving decoding performance.
[0029] With regard to the BIR, 16 modulation symbols each having 4 coded bits are classified into region 1 having a relatively high error probability, region 3 having a relatively low error probability, and region 2 having a medium probability in 16QAM, as illustrated in FIG. 2. Inversion of the coded bits of each modulation symbol prior to symbol mapping at a retransmission also effects averaging the error probabilities of the coded bits and thus improves system performance at decoding.
[0030] Despite the advantage of improved system performance, however, a simple combined use of the above techniques is not effective in their application to systems. Therefore, the techniques need to be combined effectively so that optimum transmission efficiency can be achieved in a CDMA mobile communication system.
SUMMARY OF THE INVENTION
[0031] It is, therefore, an object of the present invention to provide in a wireless communication system a transmitting/receiving apparatus and method in which packet retransmission is carried out with system performance increased.
[0032] It is another object of the present invention to provide in a wireless communication system a transmitting/receiving apparatus and method that increase the reliabilities of bits at a packet retransmission.
[0033] It is also another object of the present invention to provide in a wireless communication system a transmitting/receiving apparatus and method for enabling a receiver to receive bits with a higher reception probability.
[0034] It is a further object of the present invention to provide a wireless communication system supporting HARQ a transmitting/receiving apparatus and method for more efficient packet retransmission.
[0035] It is still another object of the present invention to provide an apparatus and method for efficiently combining an initial transmission technique with a retransmission technique.
[0036] It is yet another object of the present invention to provide an apparatus and method for simultaneously supporting the BIR with the SRRC.
[0037] To achieve the above and other objects, according to one aspect of the present invention, upon request for a retransmission from a receiver, a transmitter generates first coded bits by inverting initially transmitted coded bits, generates second coded bits by separating the initially transmitted coded bits into a first bit group having a relatively high priority and a second bit group having a relatively low priority and exchanging the first bit group with the second bit group, and generates third coded bits by inverting the exchanged coded bits. The transmitter selects one of the first coded bits, the second coded bits (according to the sequence number of a retransmission request received from the receiver), and the third coded bits, and maps the selected coded bits to modulation symbols. The transmitter then transmits the modulation symbols to the receiver.
[0038] According to another aspect of the present invention, upon request for a retransmission from a receiver, a transmitter generates first coded bits by inverting initially transmitted coded bits, generates second coded bits by cyclically shifting the initially transmitted coded bits by a predetermined number of bits, and generates third coded bits by inverting the shifted coded bits. The transmitter selects one of the first coded bits, the second coded bits (according to the sequence number of a retransmission request received from the receiver), and the third coded bits, and maps the selected coded bits to modulation symbols. The transmitter then transmits the modulation symbols to the receiver.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:
[0040] [0040]FIG. 1 is a block diagram of a transmitter in a typical CDMA mobile communication system;
[0041] [0041]FIG. 2 illustrates an example of a signal constellation in 16QAM in the CDMA mobile communication system;
[0042] [0042]FIG. 3 illustrates the error probabilities of regions in the signal constellation of 16QAM;
[0043] [0043]FIG. 4 is a block diagram of a transmitter in a CDMA mobile communication system according to an embodiment of the present invention;
[0044] [0044]FIG. 5 is a detailed block diagram of a channel encoder illustrated in FIG. 4 ;
[0045] [0045]FIG. 6 is a flowchart illustrating the operation of the transmitter in the CDMA mobile communication system according to an embodiment of the present invention;
[0046] [0046]FIG. 7 is a block diagram of a receiver for receiving signals from the transmitter illustrated in FIG. 4 in the CDMA mobile communication system according to the embodiment of the present invention;
[0047] [0047]FIG. 8 is a flowchart illustrating the operation of the receiver in the CDMA mobile communication system according to an embodiment of the present invention;
[0048] [0048]FIG. 9 illustrates bit inversion in the transmitter according to an embodiment of the present invention;
[0049] [0049]FIG. 10 is a block diagram of a transmitter in a CDMA mobile communication system according to a second embodiment of the present invention;
[0050] [0050]FIG. 11 is a flowchart illustrating the operation of the transmitter in the CDMA mobile communication system according to the second embodiment of the present invention;
[0051] [0051]FIG. 12 is a block diagram of a receiver for receiving signals from the transmitter illustrated in FIG. 10 in the CDMA mobile communication system according to the second embodiment of the present invention;
[0052] [0052]FIG. 13 is a flowchart illustrating the operation of the receiver in the CDMA mobile communication system according to the second embodiment of the present invention; and
[0053] [0053]FIG. 14 illustrates a comparison between frame error rates at retransmissions according to an embodiment of the present invention and at a retransmission according to a conventional method under an AWGN environment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0054] Preferred embodiments of the present invention will be described herein below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.
[0055] HARQ, to which the present invention, is applied is a link controlling technique for correcting packet errors by retransmission. As is applied from its name, retransmission is one more transmission of initially transmitted but failed packet data. Therefore, new data is not transmitted at a retransmission.
[0056] As described before, HARQ techniques are divided into HARQ type II and HARQ type III depending on whether systematic bits are retransmitted or not. The major HARQ type II is FIR, and HARQ type III includes CC and PIR which are discriminated according to whether the same parity bits are retransmitted.
[0057] The present invention as described below is applied to all of the above HARQ techniques. In the CC, a retransmission packet has the same bits as an initial transmission packet, and in the FIR and PIR a retransmission packet and an initial transmission packet have different bits. Since the present invention pertains to a method of increasing the transmission efficiency of a retransmission packet, it is obviously applicable to the case where an initial transmission packet is different from its retransmission packet. Yet, the following description is made in the context of the CC by way of example.
[0058] The present invention can be implemented in two embodiments. In a first embodiment, SMP (Symbol Mapping method based on Priority) is combined with the BIR, and in a second embodiment, the SRRC is combined with the BIR.
[0059] First Embodiment: SMP+BIR
[0060] [0060]FIG. 4 is a block diagram of a transmitter in a CDMA mobile communication system according to an embodiment of the present invention. Referring to FIG. 4, the transmitter includes a CRC (Cyclic Redundancy Check) adder 210 , a channel encoder 220 , a rate matching controller 230 , a distributor 240 , an interleaver unit 250 , an exchange 260 , a parallel-to-serial converter (PSC) 270 , a bit inverter 280 , a modulator 290 , and a transmission controller 200 .
[0061] The transmitter exchanges systematic bits with parity bits at a retransmission when necessary. Therefore, the exchange 260 is optional.
[0062] Referring to FIG. 4, the CRC adder 210 adds CRC bits to input information bits for an error check on a packet data basis. The channel encoder 220 encodes the packet data with the CRC bits at a predetermined code rate by predetermined coding.
[0063] The packet data is coded to systematic bits and parity bits being error control bits for the systematic bits. Turbo coding or convolutional coding can be used.
[0064] The code rate determines the ratio of the parity bits to the systematic bits. With a code rate of ½, for example, the channel encoder 220 outputs one systematic bit and one parity bit for the input of one information bit. With a code rate of ¾, the channel encoder 220 outputs three systematic bits and one parity bit for the input of three information bits. In the embodiment of the present invention, other code rates can also be applied aside from ½ and ¾.
[0065] The rate matching controller 230 matches the data rate of the coded bits by repetition and/or puncturing. The distributor 240 separates the rate-matched bits into systematic bits and parity bits and feeds the systematic bits to a first interleaver 252 and the parity bits to a second interleaver 254 . With a symmetrical code rate such as ½, the first and second interleavers 252 and 254 receive the same number of bits. On the other hand, with an asymmetrical code rate such as ¾, systematic bits are first fed to the first interleaver 252 and the remaining systematic bits and the parity bits are then fed to the second interleaver 254 .
[0066] The first interleaver 252 interleaves the systematic bits and the second interleaver 254 interleaves the parity bits in a predetermined interleaving method. While the first and second interleavers 252 and 254 are discriminated in hardware in FIG. 4, they can also be discriminated logically. This means that the interleaver unit 250 uses a single memory having a memory area for storing systematic bits and a memory area for storing parity bits. The thus-constituted interleaver unit 250 operates to map the systematic bits and the parity bits to different reliability parts. In other words, the SMP is achieved with the use of the distributor 240 and the interleaver unit 250 .
[0067] The interleaver outputs are stored in a buffer (not shown) for use at retransmission. Upon request of a receiver for a retransmission, the whole or part of the buffered bits are output under the control of the transmission controller 200 .
[0068] The coded bits, of which the sequences have been permuted by the first and second interleavers 252 and 254 , are exchanged in the exchange 260 under the control of the transmission controller 200 . At an initial transmission, the transmission controller 200 disables the exchange 260 so that the first interleaver output and the second interleaver output bypass the exchange 260 . At a retransmission, the transmission controller 200 determines whether to enable the exchange 260 according to the number of retransmission occurrences. For example, bit exchange occurs at each third or fourth retransmission, and no bit exchange occurs at each first or second retransmission.
[0069] The coded bits that have passed through the exchange 260 are converted to a serial bit stream in the PSC 270 . The bit inverter 280 inverts the bits of the serial bit stream under the control of the transmission controller 200 . The transmission controller 200 enables or disables the bit inverter 280 according to the sequence number of a retransmission. For example, the bit inverter 280 inverts the coded bits only at each odd-numbered retransmission. The bit inverter 280 is an inverter that inverts input bits 0 or 1.
[0070] When bit inversion is not needed, the input coded bits bypass the bit inverter 280 . This bit inverter 280 functions to map coded bits to a modulation symbol with a different error probability at a retransmission from that at an initial transmission, to thereby implement the BIR.
[0071] The modulator 290 modulates input coded bits in a predetermined modulation scheme. In 16QAM, the modulator 290 maps every four input coded bits to a modulation symbol having a bit reliability pattern [H, H, L, L]. H denotes a high reliability part and L denotes a low reliability part.
[0072] The transmission controller 200 provides overall control to the components of the transmitter in accordance with upper layer signaling. The transmission controller 200 determines the code rate of the channel encoder 220 and the modulation scheme of the modulator 290 according to the current radio channel condition.
[0073] The transmission controller 200 also controls the exchange 260 and the bit inverter 280 by a retransmission request from an upper layer in response for a retransmission request from a receiver. The retransmission request information from the upper layer indicates whether the receiver has requested a packet retransmission and how many times retransmission has been carried out so far.
[0074] Aside from the sequence number of a retransmission, the bit inverter 280 is enabled or disabled according to an SFN (System Frame Number). In this case, the transmitter can determine whether to perform bit inversion or not using the SFN only without the need for additional information such as the sequence number of a retransmission. This is because modulation without inversion at an initial transmission and inversion prior to modulation at a retransmission is equivalent to inversion prior to modulation at an initial transmission and modulation without inversion at a retransmission. That is, it does not matter whether bit inversion is performed at an initial transmission or at a retransmission in the present invention.
[0075] [0075]FIG. 5 is a detailed block diagram of the channel encoder 220 illustrated in FIG. 4. It is assumed that the channel encoder 220 uses a mother code rate of ⅙ adopted in the 3GPP (3 rd Generation Partnership Project) standards.
[0076] Referring to FIG. 5, the channel encoder 220 simply outputs one data frame of size N as a systematic bit frame X (=x 1 , x 2 , . . . , x N ). Here, N is determined according to the code rate. A first constituent encoder 224 outputs two different parity bit frames Y 1 (=y 11 , y 12 , . . . , y 1N ) and Y 2 (=y 21 , y 22 , . . . , y 2N ) for the input of the data frame.
[0077] An internal interleaver 222 interleaves the data frame and outputs an interleaved systematic bit frame X′ (=x′ 1 , x′ 2 , . . . , x′ N ). A second constituent encoder 226 encodes the interleaved systematic bit frame X′ to two different parity bit frames Z 1 (=z 11 , z 12 , . . . , z 1N ) and Z 2 (=z 21 , z 22 , . . . , z 2N ).
[0078] A puncturer 228 generates intended systematic bits S and parity bits P by puncturing the systematic bit frame X, the interleaved systematic bit frame X′, and the parity bit frames Y 1 , Y 2 , Z 1 and Z 2 in a puncturing pattern received from the controller 270 .
[0079] The puncturing pattern is determined according to the code rate of the channel encoder 220 and an H-ARQ method used. For example, when the code rate is ½, puncturing patterns available in H-ARQ type III (CC and PIR) are as follows.
P 1 = [ 1 1 1 0 0 0 0 0 0 0 0 1 ] ( 1 ) P 2 = [ 1 1 1 0 0 0 0 0 0 1 0 0 ] ( 2 )
[0080] where 1 indicates a transmission bit and 0 indicates a punctured bit. Input bits are punctured from the left column to the right column.
[0081] One of the above puncturing patterns is used at an initial transmission and retransmissions in the CC, while they are alternately used at each transmission in the PIR.
[0082] In HARQ type II (FIR), systematic bits are punctured at retransmission. In this case, a puncturing pattern is “010010”, for example.
[0083] In the CC, if the puncturing pattern P 1 (i.e., “110000” and “100001”) is used, the puncturer 228 outputs bits X, Y 1 , X and Z 2 with the other bits punctured at each transmission. If the puncturing pattern P 2 (i.e., “110000” and “100010”) is used, the puncturer 228 outputs bits X, Y 1 , X and Z 1 with the other bits punctured at each transmission.
[0084] In the PIR, the puncturer 228 outputs bits X, Y 1 , X and Z 2 at an initial transmission and bits X, Y 1 , X and Z 1 at a retransmission.
[0085] Though not shown, a channel encoder using a mother code rate of ⅓ adopted in the 3GPP2 is realized using one constituent encoder and a puncturer.
[0086] [0086]FIG. 6 is a flowchart illustrating the operation of the transmitter according to the embodiment of the present invention. Referring to FIG. 6, the CRC adder 210 adds CRC bits to input data on a packet basis in step 300 and the channel encoder 220 encodes the packet data with the CRC bits at a code rate preset between the transmitter and the receiver in step 305 .
[0087] Specifically, the input packet data is simply output as a systematic bit frame X in the channel encoder 220 . The first constituent channel encoder 224 encodes the systematic bit frame X at a predetermined code rate and outputs different parity bit frames Y 1 and Y 2 .
[0088] The internal interleaver 222 interleaves the packet data and outputs another systematic bit frame X′. The second constituent channel encoder 226 encodes the systematic bit frame X′ and outputs two different parity bit frames Z 1 and Z 2 .
[0089] The puncturer 228 punctures the systematic bit frames X and X′ and the parity bit frames Y 1 , Y 2 , Z 1 and Z 2 according to a desired code rate in a predetermined puncturing pattern.
[0090] As described before, the same puncturing pattern is used at an initial transmission and retransmissions in the CC. The puncturing pattern is stored in the puncturer 228 or received from the transmission controller 200 . In FIG. 5, the puncturing pattern is illustrated to be externally received.
[0091] In step 310 , the rate matching controller 230 matches the rate of the coded bits by repetition and puncturing. The rate matching controller 230 operates for transport channel multiplexing, or when the number of encoder output bits is different from the number of bits in a transmission frame.
[0092] In step 315 , the distributor 240 separates the rate-matched bits into systematic bits and parity bits. If the number of the systematic bits are equal to that of the parity bits, the systematic bits and the parity bits are fed to the first and second interleavers 252 and 254 , respectively. On the other hand, if they are different, the first interleaver 252 first receives systematic bits. The first and second interleavers 252 and 254 interleave the input coded bits in step 320 .
[0093] The transmission controller 200 determines in step 325 whether a retransmission request command received from the upper layer indicates the initial transmission of a new packet or a retransmission of a previous packet. In the case of the initial transmission of the new packet, the procedure goes to step 340 .
[0094] In the case of a retransmission of the same packet, the transmission controller 200 calculates MOD (the sequence number of the retransmission, log 2 M) in step 330 . MOD denotes a modulo operation and M indicates the modulation order used in the modulator 290 . If the solution is less than 2, the procedure jumps to step 340 . On the other hand, if the solution is equal to or greater than 2, the transmission controller 200 enables the exchange 260 . The exchange 260 then exchanges in step 335 the outputs of the first and second interleavers 252 and 254 . As a result, the systematic bits are fed to the second interleaver 254 , and the parity bits to the first interleaver 252 .
[0095] In step 340 , the PSC 270 converts the coded bits received in two paths to a serial bit stream. The transmission controller 200 in step 345 calculates MOD (the sequence number of the retransmission, 2) to determine whether to invert the bits of the serial bit stream. If the solution is 0, this indicates an even-numbered retransmission and if the solution is not 0, this indicates an odd-numbered retransmission. In the former, the transmission controller 200 disables the bit inverter 280 , and in the latter, it enables the bit inverter 280 . When enabled, the bit inverter 280 inverts in step 350 the bits of the serial bit stream. On the contrary, when the bit inverter is disabled, the serial bit stream is directly fed to the modulator 290 without bit inversion.
[0096] The modulator 290 maps the input bits to symbols in step 355 . In 16QAM, every four coded bits are mapped to a modulation symbol having a reliability pattern [H, H, L, L]. The modulation symbols are spread with a predetermined spreading code and transmitted to the receiver in step 360 .
[0097] [0097]FIG. 7 is a block diagram of a receiver being the counterpart of the transmitter illustrated in FIG. 4 according to an embodiment of the present invention. Referring to FIG. 7, the receiver includes a demodulator 410 , a bit inverter 420 , a serial-to-parallel converter (SPC) 430 , an exchange 440 , a deinterleaver unit 450 , a combiner 460 , a buffer 470 , a channel decoder 480 , a CRC checker 490 , and a reception controller 400 .
[0098] In operation, the demodulator 410 demodulates data received from the transmitter in a demodulation method corresponding to the modulation scheme used in the modulator 290 . The bit inverter 420 inverts the bits of the demodulated symbols under the control of the reception controller 400 . The reception controller 400 enables the bit inverter 420 only at each odd-numbered retransmission.
[0099] The bit inverter 420 is a multiplier that selectively multiplies −1 by input bits because demodulated bits output from the demodulator 410 have soft values −1 and 1. That is, the multiplier converts 1 to −1 and −1 to 1 by sign inversion. Specifically, the multiplier multiplies −1 by input bits at each odd-numbered retransmission of the same packet under the control of the reception controller 400 . Thus, the multiplier performs the same function as the inverter illustrated in FIG. 4. If the demodulator 410 outputs coded bits expressed in hard values 0 and 1, the multiplier must be replaced with an inverter.
[0100] The SPC 430 converts the coded bits received from the bit inverter 420 to two parallel bit streams under the control of the reception controller 400 . If the solution of MOD (the sequence number of a retransmission, log 2 M) is less than 2, the reception controller 400 disables the exchange 440 . Then the two parallel coded bit streams are directly fed to the deinterleaver. If the solution of MOD (the sequence number of a retransmission, log 2 M) is equal to or greater than 2, the reception controller 400 enables the exchange 400 and the exchange 440 exchanges the two parallel coded bit streams with each other.
[0101] One of the parallel coded bit streams is fed to a first deinterleaver 452 and the other coded bit stream, to a second deinterleaver 454 . The first and second deinterleavers 452 and 454 deinterleave the input coded bits in a deinterleaving rule corresponding to the interleaving rule used in the first and second interleavers 252 and 254 of the transmitter.
[0102] The combiner 460 combines the current received coded bits of a packet with the coded bits of the same packet accumulated in the buffer 470 . If there are no coded bits of the same packet in the buffer 470 , that is, in the case of initial transmission, the combiner 460 simply outputs the current received coded bits and simultaneously stores them in the buffer 470 .
[0103] The channel decoder 480 recovers the coded bits received from the combiner 460 by decoding them in a predetermined decoding method, turbo decoding here corresponding to the coding method in the channel encoder 220 of the transmitter.
[0104] The CRC checker 490 extracts CRC bits from the decoded information bits on a packet basis and determines whether the packet has errors using the extracted CRC bits. An upper layer processes the packet if the packet has no errors and an ACK (Acknowledgement) signal for the packet is transmitted to the transmitter. On the contrary, if the packet has errors, an NACK (Non-Acknowledgement) signal for the packet is transmitted to the transmitter, requesting a retransmission of the packet.
[0105] If the ACK signal is transmitted to the transmitter, the buffer 470 is initialized with the coded bits of the corresponding packet deleted. If the NACK signal is transmitted to the transmitter, the coded bits of the packet remain in the buffer 470 . The reception controller 400 counts transmissions of the NACK signal to determine the sequence number of the next retransmission and control the bit inverter 420 and the exchange 440 correspondingly.
[0106] [0106]FIG. 8 is a flowchart illustrating the operation of the receiver according to an embodiment of the present invention. Referring to FIG. 8, upon receipt of data on a radio transport channel in step 500 , the demodulator 410 recovers coded bits by demodulating the received data on a modulation symbol basis according to a modulation scheme preset between the receiver and the transmitter in step 505 . In step 510 , the reception controller 400 determines whether the coded bits are an initial transmission packet or a retransmission packet.
[0107] In the case of retransmission, the reception controller 400 calculates MOD (the sequence number of the retransmission, 2) in step 515 . If the solution is not 0, that is, if the retransmission is an odd-numbered one, the reception controller 400 enables the bit inverter 420 . The bit inverter 420 then inverts the coded bits in step 520 . On the other hand, in the case of initial transmission, the reception controller 400 disables the bit inverter 420 and the coded bits bypass the bit inverter 420 .
[0108] Bit inversion will be described in more detail with reference to FIG. 9. FIG. 9 illustrates a 12-bit frame with a modulation order of 16. Here, one modulation symbol has 4 bits. Referring to FIG. 9, the first, second and third modulation symbols are [0000], [1100], and [0111], respectively. When an NACK signal is received and thus a retransmission is requested, the original bits are inverted. Thus, [0000], [1100] and [0111] are converted [1111], [0011] and [1000], respectively.
[0109] In connection with the signal constellation of FIG. 2, the initial transmission modulation symbol [0000] in region 1 is retransmitted as [1111] in region 3 . From the graphs of FIG. 3, it is noted that the error probability of region 1 is much higher than that of region 3 . Transmission of a specific symbol consistently in a region with a high error probability adversely influences system performance. However, retransmission of a symbol in a different transmission region leads to averaging the error probabilities of bits and thus increases decoding performance according to the present invention.
[0110] Returning again to FIG. 8, coded bits that have passed through or bypassed the bit inverter 420 are separated into two parallel bit streams in the SPC 430 in step 525 . The reception controller 400 calculates MOD (the sequence number of the retransmission, log 2 M) in step 530 . If the solution is less than 2, the reception controller 400 disables the exchange 440 and the parallel coded bit streams are directly fed to the deinterleaver 450 . On the other hand, if the solution is equal to or greater than 2, the reception controller 400 enables the exchange 440 and the exchange 535 exchanges the two parallel coded bit streams with each other in step 440 . The first and second deinterleavers 452 and 454 deinterleave the coded bit streams in two paths in step 540 .
[0111] The combiner 460 in step 545 combines the deinterleaved coded bits with coded bits of the same packet accumulated in the buffer 470 . In step 550 , the channel decoder 480 decodes the combined bits in a decoding method preset between the transmitter and the receiver and outputs the original information bits.
[0112] In step 555 , the CRC checker 490 determines whether the packet has errors by a CRC check on the decoded information bits on a packet basis. If the packet has no errors, the buffer 470 is initialized and an ACK signal is transmitted to the transmitter in step 560 . Then the packet is provided to the upper layer.
[0113] On the contrary, if the packet has errors, the coded bits stored in the buffer 470 are preserved and an NACK signal requesting a retransmission of the packet is transmitted to the transmitter in step 565 .
[0114] Packet retransmission with 16QAM used as a modulation scheme according to the embodiment of the present invention can be generalized as follows:
[0115] (1) coded bits are initially transmitted;
[0116] (2) the coded bits are inverted for modulation at a first retransmission;
[0117] (3) systematic bits are exchanged with parity bits prior to modulation at a second retransmission;
[0118] (4) the systematic bits are exchanged with the parity bits and then the coded bits are inverted prior to modulation at a third retransmission;
[0119] (5) the coded bits are modulated without modification in the same manner as at the initial transmission at a fourth retransmission; and
[0120] (6) steps (1) to (5) are repeated upon request for the next retransmissions.
[0121] Second Embodiment: SRRC+BIR
[0122] [0122]FIG. 10 is a block diagram of a transmitter in a CDMA mobile communication system according to another embodiment of the present invention. Referring to FIG. 10, the transmitter includes a CRC adder 610 , a channel encoder 620 , a rate matching controller 630 , an interleaver 640 , a bit rearranger 650 , a bit inverter 660 , a modulator 670 , and a transmission controller 600 . The transmitter shifts retransmission bits by a predetermined number of bits and inverts the shifted bits according to the sequence number of a retransmission.
[0123] Referring to FIG. 10, the CRC adder 610 adds CRC bits to input information bits for an error check on a packet data basis. The channel encoder 620 encodes the packet data with the CRC bits at a predetermined code rate by predetermined coding.
[0124] The packet data is coded to systematic bits and parity bits being error control bits for the systematic bits. Turbo coding or convolutional coding can be used. The detailed structure of the channel encoder 620 is illustrated in FIG. 5.
[0125] The code rate determines the ratio of the parity bits to the systematic bits. With a code rate of ½, for example, the channel encoder 620 outputs one systematic bit and one parity bit for the input of one information bit. With a code rate of ¾, the channel encoder 620 outputs three systematic bits and one parity bit for the input of three information bits. In the embodiment of the present invention, other code rates can also be applied aside from ½ and ¾.
[0126] The rate matching controller 630 matches the data rate of the coded bits by repetition or puncturing. The interleaver 640 interleaves the rate-matched bits and the interleaver output is stored in a buffer (not shown) for use at retransmission. Upon request of a receiver for a retransmission, the whole or part of the buffered bits are output under the control of the transmission controller 600 .
[0127] The coded bits, of which the sequence has been permuted by the interleaver 640 , are shifted in the bit rearranger 650 under the control of the transmission controller 600 . The bit rearranger 650 includes a shifter for cyclically shifting input coded bits by a predetermined number of bits. The transmission controller 600 determines whether to rearrange coded bits at the bit rearranger 650 according to the sequence number of a retransmission and the bit rearranger 650 rearranges the coded bits when the transmission controller 600 commands bit rearrangement. The bit rearranger 650 implements the SRRC.
[0128] For example, the transmission controller 600 disables the bit rearranger 650 at each first or second retransmission, and enables the bit rearranger 650 at each third or fourth retransmission. In the former case, the coded bits bypass the bit rearranger 650 , and in the latter case, the bit rearranger 650 cyclically shifts the coded bits by a predetermined number of, for example, two bits.
[0129] As described before, pairs of coded bits are mapped to different reliability parts in 16QAM or 64QAM. Hence the bit rearranger 650 cyclically shifts the coded bits of each modulation symbol by two bits so that the coded bits can be mapped to different reliability parts at a retransmission from those at an initial transmission.
[0130] If coded bits for initial transmission are [a, b, c, d] in 16QAM, the two upper bits [a, b] are mapped to a high reliability part and the two lower bits [c, d], to a low reliability part. At a retransmission, the coded bits [a, b, c, d] are converted to [c, d, a, b] by two-bit cyclic shifting. The two upper bits [c, d] are mapped to have a high reliability, and the two lower bits [a, b], to have a low reliability.
[0131] The bit inverter 660 inverts the coded bits that have passed through or bypassed the bit rearranger 650 under the control of the transmission controller 600 . The transmission controller 600 enables or disables the bit inverter 660 according to the sequence number of a retransmission. For example, the bit inverter 660 inverts the coded bits only at each odd-numbered retransmission. The bit inverter 280 is an inverter that inverts input bits 0 or 1.
[0132] When bit inversion is not needed, the input coded bits bypass the bit inverter 660 . This bit inverter 660 functions to map coded bits to a modulation symbol with a different error probability at a retransmission from that at an initial transmission.
[0133] The modulator 670 modulates input coded bits in a predetermined modulation scheme. In 16QAM, the modulator 670 maps every four input coded bits to a modulation symbol having a bit reliability pattern [H, H, L, L].
[0134] The transmission controller 600 provides overall control to the components of the transmitter according to the second embodiment of the present invention. The transmission controller 600 determines the code rate of the channel encoder 620 and the modulation scheme of the modulator 670 according to the current radio channel condition. The transmission controller 600 also processes a retransmission request from an upper layer that has received a retransmission request from a receiver and controls the bit rearranger 650 and the bit inverter 660 correspondingly.
[0135] The retransmission request information from the upper layer indicates whether the receiver has requested a packet retransmission and how many times retransmission has been carried out so far. At a retransmission of the same packet, the bit rearranger 650 is enabled only if MOD (the sequence number of the retransmission, log 2 M) is equal to or greater than 2, and the bit inverter 660 is enabled only if MOD (the sequence number of the retransmission, 2) is 1.
[0136] [0136]FIG. 11 is a flowchart illustrating the operation of the transmitter according to the second embodiment of the present invention. Referring to FIG. 11, the CRC adder 610 adds CRC bits to input data on a packet basis in step 700 and the channel encoder 620 encodes the packet data with the CRC bits in step 705 . In step 710 , the rate matching controller 630 matches the rate of the coded bits by repetition or puncturing. The interleaver 640 interleaves the rate-matched bits in step 715 .
[0137] In step 720 , the transmission controller 600 determines whether a retransmission request command received from the upper layer indicates the initial transmission of a new packet or a retransmission of a previous packet. In the case of the initial transmission of the new packet, the procedure goes to step 745 .
[0138] In the case of a retransmission of the same packet, the transmission controller 600 calculates MOD (the sequence number of the retransmission, log 2 M) in step 725 . If the solution is equal to or greater than 2, the procedure jumps to step 735 . On the other hand, if the solution is less than 2, the transmission controller 600 enables the bit rearranger 650 . The bit rearranger 650 then rearranges the interleaver output by two bit-cyclic shifting in step 730 .
[0139] In step 735 , the transmission controller 600 calculates MOD (the sequence number of the retransmission, 2) to determine whether to enable the bit inverter 660 . If the solution is 0, this indicates an even-numbered retransmission and if the solution is not 0, this indicates an odd-numbered retransmission. In the former, the transmission controller 600 disables the bit inverter 660 and in the latter, it enables the bit inverter 660 . When enabled, the bit inverter 660 inverts the coded bits in step 740 . On the contrary, when the bit inverter 660 is disabled, the coded bits are directly fed to the modulator 670 without bit inversion.
[0140] The modulator 670 maps the input bits to symbols in step 745 . In 16QAM, every four coded bits are mapped to a modulation symbol having a reliability pattern [H, H, L, L]. The modulation symbols are spread with a predetermined spreading code and transmitted to the receiver in step 750 .
[0141] [0141]FIG. 12 is a block diagram of a receiver being the counterpart of the transmitter illustrated in FIG. 10 according to the second embodiment of the present invention. Referring to FIG. 12, the receiver includes a demodulator 810 , a bit inverter 820 , a bit rearranger 830 , a deinterleaver unit 840 , a combiner 650 , a buffer 860 , a channel decoder 870 , a CRC checker 880 , and a reception controller 800 .
[0142] In operation, the demodulator 810 demodulates data received from the transmitter in a demodulation method corresponding to the modulation scheme used in the modulator 670 . The bit inverter 820 inverts the bits of the demodulated symbols under the control of the reception controller 800 . The reception controller 800 enables the bit inverter 820 only at each odd-numbered retransmission.
[0143] The bit inverter 820 is a multiplier that multiplies −1 by input bits selectively. Specifically, the multiplier multiplies −1 by input bits at each odd-numbered retransmission of the same packet under the control of the reception controller 800 . Thus, the multiplier performs the same function as the inverter illustrated in FIG. 10. If the demodulator 810 outputs coded bits expressed in hard values 0 and 1, the multiplier is replaced with an inverter.
[0144] The bit rearranger 830 rearranges the coded bits received from the bit inverter 820 under the control of the reception controller 800 . If the solution of MOD (the sequence number of a retransmission, log 2 M) is less than 2, the reception controller 800 disables the bit rearranger 830 . Then the coded bit streams are directly fed to the deinterleaver 840 . If the solution of MOD (the sequence number of a retransmission, log 2 M) is equal to or greater than 2, the reception controller 800 enables the bit rearranger 830 and the bit rearranger 830 rearranges the coded bits by reverse cyclic shifting in correspondence to the bit rearrangement in the transmitter.
[0145] The deinterleaver 840 deinterleaves the input coded bits in a deinterleaving rule corresponding to the interleaving rule used in the interleaver 640 of the transmitter. The combiner 850 combines the current received coded bits of a packet with the coded bits of the same packet accumulated in the buffer 860 . If there are no coded bits of the same packet in the buffer 860 , that is, in the case of initial transmission, the combiner 850 simply outputs the current received coded bits and simultaneously stores them in the buffer 860 .
[0146] The channel decoder 870 recovers the coded bits received from the combiner 850 by decoding them in a predetermined decoding method corresponding to the coding method in the channel encoder 620 of the transmitter. By decoding, systematic bits are decoded for the input of the systematic bits and parity bits.
[0147] The CRC checker 880 extracts CRC bits from the decoded information bits on a packet basis and determines whether the packet has errors using the extracted CRC bits. If the packet has no errors, an ACK signal for the packet is transmitted to the transmitter. On the contrary, if the packet has errors, an NACK (Non-Acknowledgement) signal for the packet is transmitted to the transmitter, requesting a retransmission of the packet.
[0148] If the ACK signal is transmitted to the transmitter, the buffer 860 is initialized with the coded bits of the corresponding packet deleted. If the NACK signal is transmitted to the transmitter, the coded bits of the packet remain in the buffer 870 . The reception controller 800 counts transmissions of the NACK signal to determine the sequence number of the next retransmission and control the bit inverter 820 and the bit rearranger 830 correspondingly.
[0149] [0149]FIG. 13 is a flowchart illustrating the operation of the receiver according to the second embodiment of the present invention. Referring to FIG. 13, upon receipt of data on a radio transport channel in step 900 , the demodulator 810 recovers coded bits by demodulating the received data on a modulation symbol basis according to a modulation scheme preset between the receiver and the transmitter in step 905 . In step 910 , the reception controller 800 determines whether the coded bits are an initial transmission packet or a retransmission packet. In the case of initial transmission, the reception controller 800 disables the bit inverter 820 and the coded bits bypass the bit inverter 820 .
[0150] In the case of retransmission, the reception controller 800 calculates MOD (the sequence number of the retransmission, 2) in step 915 . If the solution is not 0, that is, if the retransmission is an odd-numbered one, the reception controller 800 enables the bit inverter 820 . The bit inverter 820 then inverts the coded bits in step 920 .
[0151] In step 925 , the reception controller 800 calculates MOD (the sequence number of the retransmission, log 2 M). If the solution is less than 2, the reception controller 800 disables the bit rearranger 830 and the coded bits are directly fed to the deinterleaver 840 . On the other hand, if the solution is equal to or greater than 2, the reception controller 800 enables the bit rearranger 830 and the bit rearranger 830 rearranges the coded bits by reverse cyclic shifting in correspondence to the bit rearrangement in the bit rearranger 650 of the transmitter in step 930 .
[0152] The deinterleaver 840 deinterleaves the input coded bits in a deinterleaving method corresponding to the interleaving in the interleaver 640 in step 935 , and the combiner 850 combines the deinterleaved coded bits with coded bits of the same packet accumulated in the buffer 860 in step 940 . In step 945 , the channel decoder 870 decodes the combined bits in a decoding method preset between the transmitter and the receiver and outputs the original information bits.
[0153] In step 950 , the CRC checker 880 determines whether the packet has errors by a CRC check on the decoded information bits on a packet basis. If the packet has no errors, the buffer 860 is initialized and an ACK signal is transmitted to the transmitter in step 955 . Then the packet is provided to the upper layer. On the contrary, if the packet has errors, the coded bits stored in the buffer 860 are preserved and an NACK signal requesting a retransmission of the packet is transmitted to the transmitter in step 960 .
[0154] Packet retransmission with 16QAM used as a modulation scheme according to the second embodiment of the present invention can be generalized as follows:
[0155] (1) coded bits are initially transmitted;
[0156] (2) the coded bits are inverted for modulation at a first retransmission;
[0157] (3) the coded bits are shifted by two bits prior to modulation at a second retransmission;
[0158] (4) the coded bits are shifted by two bits and then inverted prior to modulation at a third retransmission;
[0159] (5) the coded bits are modulated without modification in the same manner as at the initial transmission at a fourth retransmission; and
[0160] (6) steps (1) to (5) are repeated upon request for the next retransmissions.
[0161] [0161]FIG. 14 illustrates graphs comparing throughputs of retransmissions according to the present invention and a conventional method in terms of frame error rates under an AWGN environment. Referring to FIG. 14, PRIOR ART denotes a retransmission according to the conventional method, BIR+SMP denotes a retransmission according to the first embodiment of the present invention, and BIR+SRRC denotes a retransmission according to the second embodiment of the present invention. As noted from FIG. 14, BIR+SRRC brings a 0.5 to 1 dB error rate decrease and BIR+SMP brings an up to 2.5 dB error rate decrease, as compared to the conventional method.
[0162] In accordance with the present invention as described above, a combined use of BIR and SMP or BIR and SRRC effects a remarkable performance improvement without modifying the conventional packet retransmission method. Therefore, the reliabilities and error probabilities of transmitted bits are averaged at retransmission, decoding performance is improved, and transmission efficiency is increased.
[0163] The present invention is applicable to all transmitters irrespective of wireless or wired communication, and it can be expected that the overall system performance will be significantly improved without an increase in system complexity. That is, a decrease in BER from the existing systems leads to an increase in transmission throughput. By application of the present invention, retransmission techniques are effectively combined, not to speak of an effective combination of an initial transmission technique and a retransmission technique, creating a synergy of benefits.
[0164] While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
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A transmitting/receiving apparatus and method for packet retransmission in a mobile communication system. Upon request for a retransmission from a receiver, a transmitter generates first coded bits by inverting initially transmitted coded bits, generates second coded bits by separating the initially transmitted coded bits into a first bit group having a relatively high priority and a second bit group having a relatively low priority and exchanging the first bit group with the second bit group, and generates third coded bits by inverting the exchanged coded bits. The transmitter selects one of the first coded bits, the second coded bits according to the sequence number of a retransmission request received from the receiver, and the third coded bits and maps the selected coded bits to modulation symbols. The transmitter then transmits the modulation symbols to the receiver.
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TECHNICAL FIELD
The invention relates to a displacement device for slidable and turnable separation elements and to a functional entity with foldable separation elements that are equipped with such a displacement device.
BACKGROUND AND SUMMARY
Turnable and slidable separation elements are often used for partitioning and closing functional entities. For opening the functional entity, the slidable separation elements are turned, folded and preferably driven into a door compartment. Parked within the door compartment, the separation elements are no longer an obstacle, wherefore the functional entity can freely be accessed. After termination of the work in the functional entity, it can again be closed by pulling the separation elements out of the door compartment and by unfolding and moving the separation elements along the front side of the functional entity. Functional entities can be for example wardrobes or cupboards designed for storing material. Further, functional entities can be working areas or building units, such as a kitchen, that shall be closed after use, in order to prevent further access to the functional entity or in order to present an aesthetical front, instead of the working area.
[1], U.S. Pat. No. 8,336,972B2, discloses a furniture unit with a displacement device, with which a door, which is pivotally held by a mounting bracket, can be moved from a closed position into a door compartment. The mounting bracket is held vertically aligned when moving in and out of the door compartment by a scissor assembly that comprises two scissor beams that are connected by a joint. In addition, the upper and the lower side of the mounting bracket are connected to carriages that are guided along auxiliary rails that extend inside the door compartment.
[2], U.S. Pat. No. 8,303,056B2, discloses a wardrobe with a sliding foldaway door, which is foldable and can then be moved into a door compartment. The foldable door comprises a first door wing, which on one side is connected to a mounting bracket, which can be driven into the door compartment and which is pivotally connected on the other side to a second door wing. The second door wing is guided by two guiding devices, the first guiding device pivotally connected above the upper edge of the second door wing and the second guiding device pivotally connected below the lower edge of the second door wing. Further, the guide devices are movable along guide tracks, which extend along the front side of the wardrobe and further into the door compartment. An intermediate panel is arranged between the two door wings, which intermediate panel is connected with hinges to the first and the second door wing.
The arrangement of guide tracks along the lower side and the upper side of the wardrobe as well as the arrangement of guide carriages at the lower side and the upper side of the second door wing requires significant space and a specific embodiment of the wardrobe. Hence, this device cannot be used universally and is limited to the use in wardrobes that are equipped with the mentioned device elements at the lower side and the upper side.
Hence, the present invention is based on the object of providing an improved displacement device, with which slidable and turnable separation elements can advantageously be held and operated.
Further, an improved functional entity with foldable separation elements shall be created, which is equipped with the inventive displacement device.
The separation elements of the inventive displacement device shall be movable with only one hand with minimal force. Thereby, it shall be ensured, that the process of folding the separation elements can be performed smoothly. Noise and mechanical stresses shall be avoided when operating the displacement device.
With the inventive displacement device any functional entity, such as wardrobes, cupboards and working areas or building units, particularly kitchen, shall preferably be closable with one or a plurality of separation elements, particularly a plurality of foldable separation elements.
The inventive displacement device shall not appear distracting and shall require little space. In the state, in which the separation elements are opened, no elements of the displacement device shall be visible. Bezels and covers with which device parts need to be covered shall not be required.
Furthermore, the separation elements shall firmly be held, so that adjustments can be avoided or reduced to a minimum. However, in the event that an adjustment is required, then little effort shall be required.
These problems are solved with a displacement device and with a functional entity provided with such a displacement device, which comprise the features of claims 1 and 11 , respectively. Preferred embodiments of the invention, particularly a hinge in a preferred embodiment, are defined in further claims.
The displacement device comprises a guide carriage that is slidable along a running rail and that is pivotally connectable to a first separation element.
According to the invention, the guide carriage comprises a carriage body with a carriage head and a carriage foot, which carriage head and carriage foot are connected with one another by a connecting beam. The carriage head holds at least one support wheel and at least two guide wheels and wherein the carriage foot is connected torque proof with a first end piece of a hinge lever, whose second end piece is pivotally held by a hinge shaft that is connectable to a sidewall of the first separation element.
The hinge lever is connected to the carriage foot and designed in such a way, that the hinge lever holds the guide hinge on the first side or the second side of the rail plate.
With the inventive displacement device a separation element, e.g. a sliding door made from wood or glass, can firmly be held and moved along a running rail and can simultaneously be turned. In preferred embodiments, the separation element can be turned by 180°, so that, if aligned in parallel to the running rail, the front side or the backside of the separation element is facing the user. Hence, the front side of the separation element can be moved into the one or the other direction along the running rail, whereby the separation element can execute a required rotation.
The displacement device requires little space and does not engage into the space above the functional entity. The functional entity, e.g. a wardrobe or cupboard, can therefore precisely be fitted into a space provided therefore, without requiring additional space for the displacement device. The displacement device can be inserted in a conventional functional entity that can be installed in a room without restrictions or limitations.
In preferred embodiments the at least one support wheel and the guide wheels are arranged on the one side and the guide hinge and the separation element on the other side of the rail plate. In spite of the fact that the displacement device is not arranged outside of the functional entity, the displacement device can be arranged in such a way, that it also does not appear distracting inside the functional entity. Hence, bezels and covers are not required.
The inventive displacement device can advantageously be installed in any functional entity. In the event that the displacement device holds one separation element only, then the separation element is preferably guided at its lower side as well. For this purpose, guide carriages are used that comprise two guide wheels each, in order to keep the separation element in vertical alignment. The functional entity can comprise one or a plurality of separation elements that can be moved individually by means of the inventive displacement device. After opening the separation elements can for example be aligned side-by-side and can be stapled in a parking area requiring little space.
Use of the inventive displacement device in a functional entity, which comprises at least a first and a second separation element that are pivotally connected with one another and which can be stored within a door compartment, when the functional entity is opened, is particularly advantageous. The displacement device is mounted laterally at the front side of the leading first separation element and thus can guide the first separation element along a first rail section of the running rail, that runs along the front side the functional entity, and along a second rail section of the running rail, which runs inside the door compartment. During the movement along the running rail, the hinge lever can turn within the guide hinge by 180°, so that the separation element always follows the displacement device that pulls the separation element or is pushed by the separation element.
In further preferred embodiments, the displacement device is provided with a drive unit, e.g. a drive unit which drives a wheel of the guide carriage or a toothed wheel that engages in a tooth belt that runs in parallel to the running rail and preferably is held within the running rail. The drive devices of this kind are known for example from [3], U.S. Pat. No. 7,578,096B2. With a motorised displacement device, both separation elements can be pulled into or pushed out of the door compartment. Subsequently, the motorised displacement device allows folding and again unfolding the two separation elements. Preferably, the two separation elements are connected with one another via an articulated joint, which holds the two separation elements in symmetrical alignment. I.e., the two separation elements are always inclined by identical angles. Hence, the separation elements can be equipped with a single drive device, which can drive the two separation elements, which are connected with one another, out of the door compartment, can unfold, fold and can drive back the separation elements back into the door compartment.
Particularly, if heavy separation elements are used, then motorised carriages are preferably mounted on the distal sides of the separation elements. A motorised guide carriage connected to the first separation element can be used for unfolding and folding of the separation elements, while a motorised auxiliary carriage, which is connected to the second separation element, can drive the separation elements into and out of the door compartment. Furthermore, the inventive displacement device can also be used advantageously, when the separation elements are not driven into a door compartment, but are merely stapled in a terminal position or an intermediate position along the running rail.
Functional entities equipped with the inventive displacement device can manually be operated, since the inventive guiding mechanism requires only a little force. The articulated joint, which connects the two separation elements with one another, is preferably provided with a holding grip, which can manually be operated. By pulling the holding grip, the two separation elements can be pulled out of the door compartment, whereafter the first separation element can further be guided along the first rail section of the running rail by pushing the holding grip back against the functional entity.
In preferred embodiments the guide hinge comprises a hinge cup, which is recessed at the front sided edge of the first separation element and which preferably exhibits a cup recess, through which the hinge lever can be turned towards the outside. This embodiment ensures that the hinge lever can be turned by 180° against the hinge cup and thus can also the held first separation element can be turned by 180° against the running rail.
The use of a concealed hinge with a hinge cup recessed in the separation element allows arranging the hinge shaft within the separation element, wherefore a space-saving solution results. However, the use of a concealed hinge is not required, if the hinge shaft can be held within the separation element by other means. For example, a recess can be provided in the separation element, in which a bearing is inserted, with which the hinge shaft is held. Further, the hinge shaft can also be held on the outside of the separation element, so that a concealed hinge is not required.
The hinge lever preferably comprises a holding sleeve that is held slidable by the hinge shaft. In a preferred embodiment the hinge lever and the hinge cup comprise elements that abut one another without play after the hinge lever has been turned completely into the hinge cup. This feature can be realised for example by providing the hinge cup with a corresponding form. E.g., a recess is embossed into the hinge cup which serves for receiving and holding the hinge lever in the terminal position without play. Alternatively, a cup insert is provided that can be inserted into the hinge cup and that comprises a cup insert recess, into which the hinge lever can be turned and in which the hinge lever is held in the terminal position without play. In this preferred embodiment of the guide hinge a play is provided between the hinge lever and the hinge cup before unfolding the separation elements, which play avoids friction resistances, which otherwise can occur due to minimal differences in the alignment of the separation elements. However, after the separation elements have been folded, they are held precisely without play, so that the separation elements are aligned flush with the other elements of the functional entity, e.g. with the top of the wardrobe.
In a further preferred embodiment the hinge lever is connected with the carriage body in such a way that the hinge lever is vertically adjustable and/or turnable. By the vertical movement of the hinge lever, the separation elements can be lifted and aligned flush with the upper edge of the wardrobe. By turning the hinge lever, the guide hinge can be shifted towards the guide carriage, until the separation elements abut the walls of the wardrobe.
For this purpose, the carriage body, i.e. the carriage foot is preferably provided with a bolt chamber. The hinge lever is provided with a lever block, which comprises a threaded bore, into which the bolt shaft of a mounting bolt can be screwed. The bolt shaft is seated within the bolt chamber aligned vertically, i.e. perpendicularly to the running direction of the guide carriage.
The mounting bolt preferably comprises a bolt head that is seated in a bearing seat provided in the bolt chamber and a cylindrical bolt foot that is inserted into a base opening provided in the bolt chamber. The bolt foot that is extending out of the lower side of the bolt chamber is preferably provided with a coupling element, e.g. a hexagonal opening into which a tool can be inserted, in order to turn the mounting bolt and to shift the hinge lever to a desired height level.
The lever block, which is pivotally held within the bolt chamber, can preferably be fixed in a desired angular position by means of at least one adjustment screw, preferably two adjustment screws that are coaxially aligned. The at least one adjustment screw is arranged eccentric to the axis of rotation of the mounting bolt, so that a lever is obtained, with which the hinge lever can be turned and fixed. In the selected position, the lever block is then firmly held by the adjustment screw or from opposite sides by the two adjustment screws.
The displacement device is guided in the running rail preferably in such a way that no elements of the displacement device and the running mechanism are visible after the functional entity, e.g. the wardrobe or the kitchen, has been opened. According to the invention the at least one support wheel and the at least one guide wheel are engaged on the backside of the running rail, which is designed asymmetrically and which comprises a rail plate that is facing the outside of the functional entity. The running rail comprises a rail foot and a rail head that are adjoining the backside of the rail plate and that serve for guiding the support wheels and the guide wheels. The carriage body is connected in such a way to the hinge lever that the hinge cup and therefore the installed first separation element is held in front of the front side of the rail plate. Hence, when opening or folding the separation elements as well as after laterally moving the separation elements, e.g. into the door compartment, only the front side of the rail plate is visible, behind which the guide carriage with the support wheel and the guide wheels is hidden. Hence, the running rail serves also as a bezel, wherefore a separate bezel and related mounting means are not required.
All in all, a simple, compact, space-saving and cost-efficient set up of the device is achieved. Further, with the use of the inventive displacement device and the running rail a stable setup of the device is obtained, which ensures that also heavier separation elements, particularly foldable separation elements that are connected with one another, can precisely be held and guided. Hence, a guiding device arranged at the lower side of the separation elements is not required. Alternatively, a simplified displacement device or a locking device can be provided at the lower side of the separation elements, which hold and secure the separation elements for example in the terminal position only.
Below, the invention is described in detail with reference to the drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1A-C show an inventive displacement device 1 with a guide carriage 2 guided in a running rail 4 , which guide carriage 2 is connected via a hinge lever 32 with a guide hinge 3 that is peripherally recessed in the sidewall of a separation element 5 A, which is shown in three different positions;
FIG. 2A shows the displacement device 1 of FIG. 1A with the asymmetrical running rail 4 , which comprises a rail plate 41 with a rail head 43 and a rail foot 42 , in which the support wheel 26 and the guide wheels 29 are guided on one side 412 of the rail plate 41 , with the opposite side 411 of the rail plate 41 facing the separation element 5 A;
FIG. 2B shows the displacement device 1 of FIG. 2A in an embodiment, in which the separation element 5 A as well as the support wheel 26 and the guide wheels 29 are arranged on the same side 411 of the rail plate 41 ;
FIG. 3A shows the displacement device 1 of FIG. 1A without separation element in spatial view;
FIG. 3B shows the displacement device 1 of FIG. 3A from a different angle;
FIG. 4 shows the displacement device 1 of FIG. 1A with the guide carriage 2 and the guide hinge 3 in an explosion view;
FIG. 5 shows the guide carriage 2 of FIG. 4 with a carriage body 20 , which comprises a carriage foot 22 with a bolt chamber 220 , out of which two coaxially aligned adjustment screws 91 , 92 and a mounting bolt 8 have been removed, which serve for adjusting and fixing the hinge lever 32 ;
FIG. 5A shows the hinge lever 32 held by the mounting bolt 8 and the adjustment screws 91 , 92 perpendicularly aligned;
FIG. 5B shows the hinge lever 32 held by the mounting bolt 8 and the adjustment screws 91 , 92 inclined;
FIG. 5C shows the hinge lever 32 held by the mounting bolt 8 and the adjustment screws 91 , 92 , inclined;
FIG. 6A shows the guide hinge 3 of FIG. 4 with a hinge cup 31 , in which a cup insert 36 is held, into which the hinge lever 32 that is held by the hinge shaft 35 can be turned;
FIG. 6B shows the cup insert 36 of FIG. 6A , which comprises a cup insert recess 360 that narrows towards the inside and that exhibits inclined sidewalls 361 ;
FIG. 6C shows the hinge lever 32 , which is released from the cup insert 36 and which is vertically movable along the hinge shaft 35 of FIG. 6A ;
FIG. 6D shows the hinge lever 32 while turning towards the cup insert recess 360 ;
FIG. 6E shows the hinge lever 32 held without play inside the cup insert 36 ;
FIG. 7 shows a functional entity, i.e. a wardrobe or a cupboard 5 , with two separation elements 5 A, 5 B, which are foldable towards one another and of which the first separation element 5 A, as shown in FIG. 1A , is held on the front side by a displacement device 1 that is guided along a running rail 4 and of which the second separation element 5 B is held on the backside in vertical alignment by a mounting bracket 61 and a scissor assembly 62 ;
FIG. 8 shows the wardrobe or cupboard 5 of FIG. 7 from above with the running rail 4 , which extends along the front side of the wardrobe 5 and further into a door compartment 55 , into which the two connected separation elements 5 A, 5 B can be inserted;
FIG. 9 shows a part of the wardrobe 5 of FIG. 8 without separation elements 5 A, 5 B and sidewalls with a view to the exposed door compartment 55 , into which the running rail 4 extends and in which a lower and an upper auxiliary rail 40 are arranged, along which the mounting bracket 61 , which is guided by auxiliary carriages 63 and held by a scissor assembly 62 (not shown) is movable, which mounting bracket 61 can be connected with bracket hinges 30 ′ to the second separation element 5 B;
FIG. 10A shows partially the two separation elements 5 A, 5 B, which are connected with one another by connecting hinges 30 that are connected by an articulated shaft 73 , which further holds an intermediate bracket 71 ;
FIG. 10B shows the two connecting hinges 30 of FIG. 10A and the articulated shaft 73 , which holds a clamp 72 , that engages in the intermediate bracket 71 ; and
FIG. 10C shows the two connecting hinges 30 of FIG. 10A and the articulated shaft 73 , which engages in a bearing sleeve 720 that can be inserted into a wedge shaped clamp 72 that can be fixed on the intermediate bracket 71 by means of a locking element 74 .
DETAILED DESCRIPTION
FIG. 1A , FIG. 1B and FIG. 1C show an inventive displacement device 1 , which comprises a guide carriage 2 guided in a running rail 4 and a guide hinge 3 that is connected to a first separation element 5 A.
The guide carriage 2 comprises a carriage body 20 with a carriage head 23 and a carriage foot 22 , which are connected with one another by a connecting beam 21 . The carriage head 23 is provided with a horizontal alignment wheel axle 260 serving for holding a support wheel 26 and with two vertically aligned wheel axles 290 serving for holding guide wheels 29 A, 29 B (see FIG. 3A ).
The asymmetrically designed running rail 4 comprises a rail plate 41 that is vertically aligned and that connects a rail head 43 and a rail foot 42 with one another. At the upper side of the rail foot 42 a running surface 420 is horizontally extending, on which the support wheel 26 is running. The two guide wheels 29 A and 29 B, which hold the guide carriage 2 in alignment in parallel to the running rail 4 , are guided within the rail head 43 , which exhibits a U-profile that is opened downwards.
The guide carriage 2 and the guide hinge 3 , which is recessed in a sidewall of the separation element 5 A, are connected with one another via a hinge lever 32 , which is held below the running rail 4 . Hence, the space above the separation element 5 A and above the running rail 4 is kept free, wherefore the displacement device 1 and the running rail 4 can be installed in any functional entity without requiring additional space.
The separation element 5 A can be moved along the running rail 4 and be turned as desired by up to 180°. FIG. 1A shows the separation element 5 A is aligned parallel to the running rail 4 . FIG. 1B shows the separation element 5 A opened, i.e. perpendicularly aligned to the running rail 4 . FIG. 1C shows the separation element 5 A again aligned in parallel to the running rail 4 , however turned by 180° compared to the alignment shown in FIG. 1A .
FIG. 1A shows the guide hinge 3 with a hinge cup 31 that is recessed peripherally in a sidewall of the separation element 5 A and that exhibits a cup recess 312 which is open towards the front face of the separation element 5 A, into which cup recess 312 the hinge lever 32 can be turned, as shown in FIG. 1C .
FIG. 1B shows that after opening and moving the separation element 5 A, only the front side 411 of the rail plate 41 of the running rail 4 is visible, which therefore serves as a bezel. Hence, a separate bezel and related mounting devices are not required. The support wheel 26 and the two guide wheels 29 as well as the functional parts of the rail head 43 and of the rail foot 42 are covered aesthetically advantageous by the rail plate 41 and lie within the functional entity. Hence, after the separation element 5 A has been moved for example into a door compartment, only the rail plate 41 is visible, which is not distracting and which can be provided with a design if required by the user.
FIGS. 2 a , 3 a , 3 b , 4 and 5 show the displacement device 1 of FIG. 1A in different views. FIG. 2A shows the displacement device 1 from the side with the carriage foot 22 comprising a bolt chamber 220 , in which a mounting bolt 8 is seated. In bores 311 in the hinge cup 31 , a hinge shaft 35 is seated. The hinge lever 32 is held on one side in the bolt chamber 220 by a mounting bolt 8 and is pivotally held on the other side in the hinge cup 31 by the hinge shaft 35 . The distance “a” or “a*”, respectively, between the longitudinal axes x 8 , x 35 of the mounting bolt 8 and the hinge shaft 35 can be adjusted by turning the hinge lever 32 , which is described below with reference to FIGS. 5 a and 5 b . After the adjustment, the hinge lever 32 can be fixed in a desired position by means of adjustment screws 91 , 92 , which are screwed into threaded bores 2291 , 2292 provided in the bolt chamber 220 (see FIG. 4 ).
The rail head 43 of the running rail 4 comprises a guide channel opened downwards for receiving the guide wheels 29 A. If additional stabilisation of the guide carriage 2 is desired, then the rail foot 42 is may be provided with a guide channel, which can receive two additional guide wheels. E.g., a U-profile that is opened downwards may be provided that exhibits on the upper side the running surface for guiding the support wheel 26 . Hence, the inventive displacement device 1 can interact with different designs of running rails 4 , whereby FIG. 2A shows a particularly compact running rail 4 .
FIG. 2B shows the displacement device 1 of FIG. 2A in an embodiment, in which the separation element 5 A as well as the support wheel 26 and the guide wheels 29 are arranged on the same side 411 of the rail plate 41 .
FIG. 3A and FIG. 3B show the displacement device 1 of FIG. 1A and FIG. 1B without separation element. The bolt chamber 220 with mounting bolt 8 inserted therein is shown from two sides.
FIG. 4 shows the displacement device 1 of FIG. 1A with the guide carriage 2 and the guide hinge 3 in an explosion view. The mounting bolt 8 , which comprises a bolt head 81 , a bolt shaft 82 with a threading and a cylindrical bolt foot 83 , has been removed out of the bolt chamber 220 .
FIG. 5A shows the bolt chamber 220 with a bearing seat 2281 on the upper side, which exhibits a front sided seat recess 22810 , with a front-sided chamber opening 2201 and on the lower side a chamber base 2202 with a base opening 2283 . The mounting bolt 8 can be inserted through the chamber opening 2201 and to the seat recess 22810 into bolt chamber 220 in such a way that the bolt foot 83 can enter the base opening 2283 and the bolt head 81 can be seated into the bearing seat 2281 . The bolt shaft 82 which holds the hinge lever 32 is freely exposed in the bolt chamber 220 and can be turned by means of a tool, which can be coupled to the bolt foot 83 that is extending out of the bolt chamber 220 . With the engagement of the mounting bolt 8 in the bolt chamber 220 , a release protection is implemented. I.e., the separation element 5 A that is connected to the guide hinge 3 cannot get released self-acting from the guide carriage 2 . Hence, the separation element 5 A can provisorily be engaged in the guide carriage 2 and can then be adjusted conveniently.
FIG. 4 further shows the detached hinge lever 32 , which comprises a holding sleeve 322 and a lever block 323 , which are connected with one another via an L-shaped lever plate 321 . The holding sleeve 322 has a cylindrical opening 3221 , in which the hinge shaft 35 can be inserted. The lever block 323 comprises a threaded bore 3231 , into which the bolt shaft 82 of the mounting bolt 8 can be screwed. When turning the mounting bolt 8 the lever block 323 held inside the bolt chamber 220 and therefore the separation element 5 A held by the hinge lever 32 is shifted upwards or downwards. Hence, the height of the separation element 5 A can be adjusted. It is further shown that the sidewalls of the bolt chamber 220 , which are opposing one another, are provided with coaxially aligned threaded bores 2291 , 2292 , into which threaded bolts, i.e. the adjustment screw 91 , 92 , can be turned. The adjustment screws 91 , 92 are provided with a coupling element 911 each, such as a hexagonal opening, which can be coupled with a tool.
FIG. 4 further shows that the cup insert 36 can be inserted into the hinge cup 31 , whose function is described below with reference to FIGS. 6A-6E .
FIG. 5 shows the bolt chamber 220 with the adjustment screw 91 , 92 from a different angle. The mounting bolt 8 , which is connected to the lever block 323 of the hinge lever 32 , can be inserted from the front side into the bolt chamber 220 . The chamber opening 2201 that is provided on the front side is designed in such a way, that the front side of the hinge lever 32 that is held by the mounting bolt 8 can be turned to the left and to the right.
FIG. 5A shows the detached hinge lever 32 , which is held by the mounting bolt 8 and the adjustment screws 91 , 92 , in straight alignment. FIG. 5B shows the hinge lever 32 , which is held by the mounting bolt 8 and the adjustment screws 91 , 92 , inclined. The longitudinal axis x 8 of the mounting bolt 8 and the longitudinal axis x 9 of the adjustment screws 91 , 92 are located a lever distance “h” apart from one another. By turning the adjustment screws 91 , 92 the hinge lever 32 can be turned with the result that the distance “a” between a line, which runs in parallel to the running rail 4 and which intersects the longitudinal axis x 8 of the mounting bolt 8 , and the holding sleeve 322 changes. With a clockwise turn of the hinge lever 32 a smaller distance “a*” results with a turn counter-clockwise of the hinge lever 32 a larger distance “a*” results. In total an adjustment range “r” is reached, which allows suitable adjustment of the distance between the separation element 5 A and the running rail 4 . By fastening the two adjustment screws 91 , 92 the lever block 321 can then be fixed in a selected position.
FIG. 6A shows the guide hinge 3 of FIG. 4 with the hinge cup 31 , in which the cup insert 36 is inserted. The hinge cup 36 , which is preferably made from plastic, comprises a cup insert recess 360 that narrows towards the inside and that exhibits inclined sidewalls 361 , as shown in FIG. 6B . Hence, the hinge lever 32 , which is adapted to the cup insert recess 360 can be turned into the hinge cup 31 , i.e. into the cup insert recess 360 provided in the cup insert 36 , until it is held in the terminal position by the sidewalls 361 without play. The sidewalls 361 , which are inclined towards the inside, serve as inside slope, which grasp and center the hinge lever 32 , while it is turned into the terminal position. Hence, turning the separation element 5 A held by the hinge lever 32 into the terminal position is executed smoothly without obstacles.
FIG. 6A and FIG. 6C show the hinge lever 32 released from the cup insert 36 and held by the hinge shaft 35 only. Hence, the hinge lever 32 can be moved along the hinge shaft 35 upwards and downwards. When turning the separation element 5 A, e.g. during the folding process of the two pivotally connected separation elements 5 A, 5 B shown in FIG. 8 , the hinge lever 32 is released from the cup insert 36 and therefore exhibits mechanical play and is movable, in order to compensate misalignments, which can occur under load or after a longer period of operation. Hence, the inventive displacement device 1 provides optimal running properties.
FIG. 6D shows the hinge lever 32 while turning into the cup insert recess 360 provided in the cup insert 36 . FIG. 6E shows the hinge lever 32 held in the terminal position without play by the cup insert 36 .
The inventive displacement device 1 can advantageously be installed in different functional entities, particularly conventional and standardised functional entities. The inventive displacement device can be installed for example in building units, such as kitchens, or wardrobes, which can be closed by foldable separation elements that, after opening, can be folded and be shifted into a door compartment.
FIG. 7 and FIG. 8 show a wardrobe or a cupboard 5 with sidewalls 5 C, 5 D, with a cover plate 5 E and with a first and a second separation element 5 A, 5 B, which are connected to one another by joints 70 and which are foldable and can be moved into a door compartment 55 . The leading first separation element 5 A is holding on the front side an inventive displacement device 1 and is movable along a running rail 4 , as shown in FIG. 1A . The two separation elements 5 A, 5 B are provided with connecting hinges 30 at the sides facing one another. The connecting hinges 30 comprise a connecting hinge lever 320 each, which are pivotally connected pairwise by an articulated shaft 73 , as shown in FIG. 10A and FIG. 10B . Two connecting hinges 30 each and the articulated shaft 73 , which connects the connecting hinge levers 320 , form a joint 70 .
The second separation element 5 B is connected on the other side with bracket hinges 30 ′ to a mounting bracket 61 , which is held in vertical alignment by a scissor assembly 62 and which, in this preferred embodiment, is movable within the door compartment 55 by means of auxiliary carriages 63 .
FIG. 8 shows the wardrobe or cupboard 5 of FIG. 7 from above with the running rail 4 , which extends with a first rail section 45 along the front of the wardrobe 5 and further with a second rail section 455 into the door compartment 55 , into which the foldable separation elements 5 A, 5 B can be entered. The door compartment 55 , which is laterally delimited by a wardrobe wall 5 D and an outer wall 5 F, is dimensioned in such a way that the two separation elements 5 A, 5 B can be received. Hence, the running rail 4 , which consists of one or more rail elements, extends practically without intersection or transition from a first terminal position to a second terminal position of the displacement device 1 . The inventive guide hinge 3 thereby allows, turning the first separation element 5 A relative to the guide carriage 2 by 180°, so that the guide carriage 2 can run ahead when closing or opening the separation elements 5 A, 5 B.
In a preferred embodiment the guide carriage 2 can be provided with a drive unit A 1 as mentioned above. For this purpose the two separation elements 5 A, 5 B are connected with one another by an articulated joint 70 , which holds the two separation elements in symmetrical alignment. In a further embodiment, the two distal sides of the separation elements 5 A, 5 B are connected to motorised carriages. A motorised carriage 2 connected to the first separation element 5 A can be used for folding and unfolding the separation elements 5 A, 5 B, while a motorised auxiliary carriage 63 connected to the second separation element 5 B can drive the separation elements 5 A, 5 B into and out of the door compartment 55 . In further arrangements the guide carriage 2 and the auxiliary carriage can be driven towards one another at first and then together along the running rail 4 , e.g. into a park room or staple room. For controlling the drive unit A 1 or the drive units A 1 and A 2 a control unit C is provided.
FIG. 9 shows a part of the wardrobe 5 of FIG. 8 , without separation elements 5 A, 5 B and without sidewalls with a view to the auf the exposed door compartment 55 , into which the running rail 4 extends and in which a lower (not shown) and an upper auxiliary rail 40 are mounted, along which the mounting bracket 61 can be driven by means of auxiliary carriages 63 . The mounting bracket 61 is held in vertical alignment preferably by a scissor assembly 62 . Further device is known, with which the mounting bracket can be held in vertical alignment.
FIG. 10A shows partly the two separation elements 5 A, 5 B, which are connected with one another by connecting hinges 30 and articulated shafts 73 . FIG. 10A and FIG. 10B show that the connecting hinge levers 320 of the connecting hinges 30 are provided with hinge sleeves, which are coaxially aligned and are traversed by an articulated shaft 73 . The articulated shafts 73 hold clamps 72 that engage in an intermediate bracket 71 , which covers the free space between the two separation elements 5 A and 5 B.
FIG. 10C shows the two connecting hinges 30 and the articulated shaft 73 of FIG. 10A . Further, a wedge shaped clamp 72 is shown, which engages in a form locking manner into the intermediate bracket 71 and is slidably held therein and which can be locked by a bridge-shaped locking element 74 . The wedge shaped clamp 72 exhibits an axial bore 721 , into which a bearing sleeve 720 can be inserted, which serves for receiving the articulated shaft 73 . The wedge shaped clamp 72 further comprises a threaded bore 722 , which serves for receiving a locking screw 741 , with which the wedge shaped clamp 72 can be pulled against the locking element 74 , which is supported by the intermediate bracket 71 . Thereby the wedge shaped clamp 72 is also connected by force to the intermediate bracket 71 and can no longer be shifted axially.
Hence, the intermediate bracket 71 is connected in a form locking manner to the articulated shaft 73 and therefore with the connecting hinges 30 . Hence, for moving the separation elements 5 A, 5 B the intermediate bracket 71 can be grasped, which is preferably provided with a holding element 700 , as shown in FIG. 8 . Even under the impact of considerable forces, the intermediate bracket 71 is firmly held by the connecting hinges 30 .
Hence, in the event that no electrical drive unit is provided, the two separation elements 5 A, 5 B can be pulled out of the door compartment 55 , can be unfolded, and can be folded and pushed back into the door compartment 55 by means of the holding element 700 .
REFERENCED DOCUMENTS
[1] U.S. Pat. No. 8,522,398B2
[2] U.S. Pat. No. 8,303,056B2
[3] U.S. Pat. No. 7,578,096B2
LIST OF REFERENCES
1 displacement device
2 guide carriage
20 carriage body
21 connecting beam
22 carriage foot
220 bolt chamber
2201 chamber opening (front sided)
2202 chamber base
2281 bearing seat
22810 seat recess in the bearing seat (front sided)
2283 base opening
2291 , 2292 threaded bores
23 carriage head
26 support wheel
260 wheel axle for the support wheel 26
29 , 29 A upper guide wheels
29 U lower guide wheels
290 wheel axles for the guide wheels 29
3 guide hinge
30 connecting hinge
31 hinge cup
311 hinge bore
312 cup recess
32 hinge lever
320 connecting hinge lever
321 lever plate
322 holding sleeve
3221 sleeve bore
323 lever block
3231 block bore
35 hinge shaft
36 cup insert
360 cup insert recess
361 inclined sidewalls of the cup insert recess 360
4 , 4 ′ running rail
40 auxiliary rail
400 adapter plate
41 rail plate
411 front side of the rail plate 41
412 backside of the rail plate 41
42 rail foot
420 running surface
43 rail head
45 first rail section
455 second rail section within the door compartment
5 functional entity, wardrobe, building unit
5 A first separation element
5 B second separation element
5 c , 5 d wardrobe walls
5 E head plate
5 F compartment wall
55 door compartment
61 mounting bracket
62 scissor assembly
63 auxiliary carriages
70 articulated joint
700 holding element
71 intermediate bracket
72 clamp
720 bearing sleeve
721 , 722 bores in the wedge shaped clamp 72
73 articulated shaft
74 locking element
741 locking screw
8 mounting bolt
81 bolt head
82 bolt shaft
83 bolt foot
831 coupling element
91 , 92 adjustment screw
911 coupling element
A 1 , A 2 drive units for the guide carriage and the auxiliary carriage
C control unit for controlling the drive units A 1 , A 2
30 ′ bracket hinge
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The displacement device includes a guide carriage that is slidable along a running rail and that is pivotally connectable to a first separation element. The guide carriage includes a carriage body with a carriage head and a carriage foot, which carriage head and carriage foot are connected with one another by a connecting beam, wherein the carriage head holds at least one support wheel and at least two guide wheels and wherein the carriage foot is connected torque proof with a first end piece of a hinge lever, whose second end piece is pivotally held by a hinge shaft that is connectable to a sidewall of the first separation element.
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BACKGROUND OF THE INVENTION
This invention concerns a round baler with at least one traction means to move crop for baling or to or in a baling chamber and with rolls over which the traction means runs and more specifically concerns a tracking control for such traction means.
Round balers are used to take up crop to be baled and to wrap it on itself. Such round balers are frequently used in agriculture to collect straw or hay that is deposited in windrows on the ground. The outer shape of the bale depends upon the uniformity of supply of the crop to be baled. If the supply of the crop to be baled is not uniform, the traction means is loaded on one side, which sets the bale into rotation, so that in addition to the component of movement in the direction of operation of the traction means, a component perpendicular thereto is developed that permits the traction means to run at a slant. This slant running can lead to tearing of the traction means or, if several traction means are running in parallel on the roll, they may cross over one another.
It is known from U.S. Pat. No. 4,224,867, that the shape of a round bale can be monitored by sensors that detect the tension of the traction means configured as belts and provide the corresponding information to an operator as the distortion of the round bale by means of an optical or acoustic indicator. By modifying the loading, for example, the direction of driving, the operator can supply more crop to the side of the baler that is deficient in crop. However, following the signals of such sensors is not entirely satisfactory since it requires the constant attention of the operator.
In addition, it is known practice when using a multiplicity of belts alongside each other to provide guide vanes between the belts, which at the least prevent crossover between adjacent belts. However, the use of guide vanes is also not entirely satisfactory since it may lead to damage to the edges of the belts.
SUMMARY OF THE INVENTION
According to the present invention there is provided a tracking mechanism for the traction means of a round baler for causing the traction means to constantly track in a straight line motion without the use of guide vanes or without the supply to the baling chamber being adjusted constantly to the shape of the bale.
An object of the invention is to provide a tracking system for the traction means of a baler which operates to adjust the end position of one or more of the support rolls for maintaining an even tension in the conveying means so that it tracks straight.
A further object of the invention is to provide a tracking system for the traction means which permits the usage of a single traction means which spans the entire width of the baling chamber.
Yet another object of the invention is to provide a tracking system for round baler traction means, in the form of multiple belts, which eliminates the need for using guide vanes between the belts.
Still another object of the invention is to provide a tracking system which maintains straight tracking automatically.
These and other objects of the invention will become apparent from a reading of the ensuing description together with the appended drawing.
BRIEF DESCRIPTION OF THE DRAWING
The sole figure is a schematic right front perspective view of a round baler equipped with a traction means embodying a tracking control or regulating arrangement constructed in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
According to the drawing a round baler 10 includes a main frame 12, supported by ground wheels 14 and having a drawbar 16 for coupling to a prime mover 16, not shown, such as an agricultural tractor.
The round baler 10 is used to take up and compact crop, which is usually deposited on the ground in windrows for drying. It can, however, be configured as any type of round baler that can compact silage, wool or other agricultural or industrial materials.
In its interior, the frame 12 contains a baling chamber 18 whose circumference is largely surrounded by a traction means 20 and whose end faces are enclosed by side walls 22.
The traction means 20, here shown as a belt, runs over a multiplicity of support rolls 24 that guide it in a path so as to form a loop in which the crop to be baled is rolled up between two oppositely moving spans of the traction means 20. Such a configuration of a round baler is adequately known and does not require any further description.
In contrast to known round balers, the traction means 20 of this embodiment covers the entire width of the baling chamber 18 and thus does not permit any small pieces of crop to escape from the baling chamber 18. The traction means 20 is preferably formed from a flexible rubberized belt having internal reinforcement and having an embossed surface.
The rolls 24 are arranged such that their axles 26 extend parallel to each other. The opposite ends of some of the rolls 24 are rotatably supported directly by the side walls 22 while others of the rolls 24 have their opposite ends supported in carriers (not shown) which are pivotally mounted to the side walls in a manner also adequately known. Each carrier can pivot against the force of a spring, so that it can vary the size of the loop defined by the rolls 24 supported by the carrier and therewith the size of the baling chamber 18 in response to the increasing diameter of the bale during the baling process.
The rolls 24 mounted in the side walls 22 as well as those mounted on the carrier, cannot be moved in their position from their attachments.
Some of the rolls 24, such as those marked with an arrow, are provided with a mounting as shown in the lower part of the drawing. For this purpose the axles 26 extend axially beyond the body 28 of the rolls 24.
The axle 26 of each adjustable roll 24 is mounted on an angle lever 30 having a first and a second leg 32 and 34, respectively, that extend at right angles to each other, the angle lever 30 acting to amplify the force of an adjustment actuator that is coupled thereto as described below.
To one side of the first leg 32 a bearing pin 36 extends that is supported, free to rotate, in a respective one of the side walls 22 or in one of the aforementioned carriers. In addition, a bore is provided in the first leg 32 that is used for a connection to an actuator to be described below.
In its free end region, the second leg 34 is also provided with an opening forming a part of a ball joint socket in which is received a ball element 38 in which the free end of a respective one of the axles 26 is fixedly received. As can be seen, the angle lever 30 is pivotable about the bearing pin 36 and thereby displaces the axle 26 radially and with it the roll 24. The ball joint, defined by the socket and ball element 38, makes it possible for the axle 26 to take on an inclined position with respect to the legs 32, 34 without inducing any stresses.
In order to effect an adjustment of the angle lever 30, a tracking control or regulating arrangement 40 is provided, whose input is connected to several sensors 42 and whose output side is connected to one or more actuators 44.
The control or regulating arrangement 40 preferably contains a programmable small computer, in which boundary values, time delay values or other parameters are stored for use in the adjustment of a respective one of the rolls 24. Whether the result intended by the adjustment of the roll 24 is monitored or not, a control or regulating arrangement is needed. The control or regulating arrangement 40 is supplied with energy by an electric circuit and may be in constant operation or switched on and off by an operator. For the input and output of signals the control or regulating arrangement 40 is permanently connected by electrical lines with the sensor 42 and each actuator 44.
In this embodiment there are several sensors 42 that may be arranged at almost any desired location and may operate according to various principles; the one thing the various configurations have in common is their ability to recognize a condition in the traction means 20 that could be capable of causing a motion in the belt perpendicular to the normal running direction. This condition can be detected by means of a sensor that reacts to the tension in the traction means 20, i.e., if it experiences more or less tension in a particular region. For this purpose a sensor 42 with a contact plate may be employed that interrupts or opens a flow of current as soon as it is moved by the traction means 20 if it should deviate towards one side. In another case, the sensor 42 may contain a sensor actuator that emits a beam of light or sound that are either blocked by or bypass the traction means 20 and whose reception is monitored by a receiver. In the preferred embodiment, two sensors 42 are provided that are configured as linear potentiometers located at opposite side edges of the traction means 20. One of the sensor 42 monitors the running of the traction means 20 in the span between the baling chamber 18 and the drawbar 16, while the other sensor 42 monitors the running of the span between the baling chamber 18 and the rear end of the round baler 10. Here the movement of the span of the traction means 20 is monitored in the part that is not loaded directly by the bale, since generally this part moves to the side, while the part of the span loaded by the bale is forced too strongly against the rolls 24.
Each actuator 44 is preferably configured as a device that can be adjusted linearly either electrically, hydraulically or pneumatically. For one or both ends of the roll 24 that is desired be adjusted, an actuator 44 is required. In order to simplify the control of the controller regulating arrangement 40, an electric motor or an electromagnetic valve may be used. As disclosed herein, the actuator 44 consists of a reversible electric motor 46, a reduction gear set located within a housing 48 and coupled to a drive hub 50 that is in turn coupled for effecting extension or retraction of a rod 51 relative to the hub 50. In the preferred embodiment, the gear housing 48 is pivotally connected to the frame 12 or side walls 22 by means of a pivot pin 52 which permits pivotal movement of the actuator 44 during the pivoting of the angle lever 30. The actuator rod 51 has a fork 54 at its free end coupled, as by a pin 55, received in a bore in the first leg 32 of the lever 30 and is able to pivot the lever 30 about the bearing pin 36. Accordingly, a linear motion of the rod 51 of the actuator 44, in a first direction, results in the pivoting of the angle lever 30 about the bearing pin 36 and in the arcuate adjustment of the attached axle 26 of the associated roll 24 in a second direction generally opposite to said first direction.
In a simple configuration, an actuator 44 is provided on only one end of the roll 24, which can move the roll above and below a neutral position. According to another variation, an actuator 44 is provided on each end of the roll 24 for adjusting either end in one direction from a neutral position.
If an actuator 44 is provided which acts in only one direction, such as a one-way, extensible and retractable hydraulic or pneumatic motor, for example, then an external force such as a supplementary mechanical or gas spring may be provided to yieldably maintain the traction means in its neutral or collapsed position, in case the inherent tension in the traction means 20 is not adequate. Furthermore, the energy storage device provided will act to return the traction means to its corresponding neutral position after the release or deactivation of all actuators.
According to the foregoing, the operation is as follows.
In order to compact a bale from crop, the round baler 10 is driven by an agricultural tractor such that some of the rolls 24 are set in motion and cause the traction means 20 to be driven longitudinally. Following this, the round baler 10 is towed across a field and thereby takes up crop from the ground and conducts it to the baling chamber 18 where it is grasped by the traction means 20 and rolled upon itself. While the outside diameter of the bale steadily increases within the baling chamber 18, the tension in the traction means 20 increases. As long as the crop is supplied uniformly across the width of the baling chamber 18, the tension in the traction means 20 is substantially constant across the entire width of the baling chamber 18. As long as the rotational axes of the rolls 24 are oriented parallel to each other in their normal or neutral position, the traction means 20 also runs in a straight line motion.
If the supply of crop in the baling chamber 18 is not uniform, the traction means 20 is put under greater tension on its one side than on the other side. In its attempt to evade this higher tension, the traction means 20 tends to move across its normal running direction. The increased tension of the traction means 20 or its sideways movement is detected by the sensor 42 and transmitted to the control or regulating arrangement 40. According to a particular circuit or a particular algorithm, an output signal is generated there and transmitted to at least one of the actuators 44. Depending on the magnitude and the direction of the output signal transmitted, the motor 46 drives the hub 50 in one direction or the other, which in turn extends or retracts the rod 51 fork 54 thereby rotating the angle lever 30 to correspond. As a result of the pivoting of the angle lever 30, the attached end of the roll 24 is moved radially and takes on a position in which its rotational axis is no longer parallel to that of the other rolls 24. For example, the lever-attached end of the roll 24 may be moved radially away from the traction means 20 on the side on which the traction means 20 is subject to the highest tension. The same result can be obtained if the lever-atttached end of the roll is moved toward the side of the traction means 20 with the lower tension. In any case, the roll 24 is moved in such a way that the tension is equalized across the entire width of the traction means 20 so that no crosswise movement occurs. After the detection of a crosswise movement, a crosswise movement to the opposite side could be brought about by a corresponding adjustment of the roll 24 before a tension is built up in the traction means 20 that is not uniform.
If several rolls 24 are adjustable from their normal position, the control or the regulation can be performed in such a way that initially only one roll 24 is adjusted, and only after evaluation of the desired result, one or more additional rolls 24 are adjusted. Such operation makes it unnecessary to adjust any one location of the traction means an excessive amount in order to balance out the tension across the traction means, i.e., by making small adjustments of the traction means at various locations making a large adjustment at a single location is avoided.
Thus, it will be appreciated that the tracking control system of the present invention permits the usage of a single traction means, configured as a belt, which spans the entire width of the bale chamber and prevents smaller crop components, such as leaves and blossoms, from falling out of the baling chamber onto the ground. Further, even if the traction means is configured as a chain, its durability is improved since side forces no longer occur which could deform the joints and chain links.
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The bale-forming belt for wrapping crop upon itself to form a cylindrical bale within a baling chamber of a round baler is automatically maintained in a straight tracking condition, despite an uneven supply of crop entering across the width of the baler, by a tracking control that is responsive to uneven tension across or the mistracking of the belt for effecting radial adjustment of one end of one or more of the rolls supporting the belt.
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Priority is claimed to provisional patent application Ser. No. 60/104,239, filed Oct. 14, 1998.
FIELD OF THE INVENTION
The invention is directed toward feed and feed additives for ruminant and monogastric animals, including humans, which increase the amount of butyric acid and non-digestible oligosaccharides in the intestine.
DESCRIPTION OF THE PRIOR ART
n-Butyric acid (n-butanoic acid) is known as a source of energy for the intestinal mucosa of animals. In general, increasing the concentration of butyric acid within the lumen of the intestine results in increased mucosal growth and an increase in the aspect ratio of the mucosal villi and the depth of the cripts. This, in turn, increases the surface area of the mucosa and hence the ability of the mucosa to absorb nutrients from within the contents of the intestine.
Tributyrin, also known as glyceryl tributyrate or tributyl glycerol, has the following formula:
Tributyrin can be prepared synthetically by the esterfication of glycerol in the presence of excess butyric acid. Tributyrin is readily available in bulk quantities from several national and international suppliers, such as Aldrich, Milwaukee, Wis. Acid and/or enzymatic hydrolysis of tributyrin yields three molar equivalents of butyric acid.
Lactitol, the common name for the oligosaccharide 4-β-D-galactosyl-D-sorbitol, has the following formula:
Lactitol is prepared synthetically by the hydration of lactose. Lactitol is readily available in bulk quantities from numerous national and international suppliers, such as Purac, Arlington Heights, Ill. In one application it is used as a non-caloric sweetener in foods such as ice cream. Host 62-galactosidases found in the small intestines of mammals degrade lactitol to only an extremely limited extent. As a consequence, lactitol is not absorbed to any appreciable extent by the mammalian gut. However, lactitol is utilized as an energy source by the microflora residing within the intestinal lumen of mammals. Other oligosaccharides containing a galactosyl unit which is β-linked to another sugar moiety (such as lactulose) behave similarly.
Several prior art references describe the addition of lactitol to animal feeds. For instance, EPA 0 218 324 A1 describes a growth-stimulating animal feed containing lactitol. This reference specifically states, at page 3, lines 12-14, that “the addition of lactitol to the feed of a monogastric domestic animal improves the growth of the animal.” See also EPA 0 464 362 A1 for a similar discussion by the same inventors.
Piva et al. (1996) “Lactitol Enhances Short-Chain Fatty Acid and Gas Production by Swine Cecal Microflora to a Greater Extent When Fermenting Low Rather Than High Fiber Diets,” J. Nutr. 126:280-289, report the addition of lactitol to swine feed in an effort to enhance cecal fermentation. The results presented in this paper indicate that lactitol is more beneficial as a feed additive when used in combination with a low-fiber diet as compared to a high-fiber diet.
European Patent Application 0 661 004 A1 describes an animal feed composition containing lactitol and amino acids. The specification states that any sugar alcohol, including lactitol, can be used in the composition, so long as the sugar alcohol does not undergo aminocarbonylation with the amino group of amino acids. The composition is puported to improve the “nutritional condition” of an animal.
See also W. C. Sauer (1997) “The Mode and Action of Oligosaccharides in the Digestive Tract of Early-Weaned Pigs,” Alberta Agricultural Research Institute, Project No. 93-0305. This reference describes a line of research investigating the mode of action of oligosaccharides in the digestion of early-weaned pigs. The pigs' diet was supplemented with various oligosaccharides, including lactitol. This reference states that “supplementation with . . . lactitol had little effect on the apparent ileal digestibilities of amino acids and monosaccharides.” Sauer, therefore, concludes that “the supplementation of diets for weanling pigs . . . with oligosaccharides or lactitol at these levels does not affect nutrient digestibilities and bacterial populations in the small intestine.”
Of particular note regarding these prior art references is that the beneficial nature of lactitol as a feed additive for monogastric or ruminant animals, and swine in particular, has not been unambiguously established, nor has its activity been established in combination with butyrate or derivatives thereof, including tributyrin.
DEFINITIONS
The following terms are expressly defined herein:
Non-digestible oligosaccharide (NDO): A subset of pre-biotic compounds which are non-digestible by a host animal and which are comprised of two or more sugar moieties. Expressly, but not exclusively, included within the term NDO are galacto-oligosaccharides of all types, including lactitol, lactulose, lactosucrose, fructo-oligosaccharides, palatinose-oligosaccharides, glycosyl sucrose, malto-oligosaccharides, isomalto-oligosaccharides, cyclodextrins, gentio-oligosaccharides, soy-oligosaccharides, and xylo-oligosaccharides.
Pre-biotic: A non-digestible food ingredient that beneficially affects a host animal by preferentially stimulating the growth and/or activity of one or a limited number of bacteria in the colon, and thus improves health, growth, vigor, etc. of the host animal. Pre-biotics are neither wholly hydrolyzed nor completely absorbed in the upper part of the gastro-intestinal tract.
SUMMARY OF THE INVENTION
The invention is directed to a synergistic animal feed composition comprising, in combination, tributyrin and a pre-biotic compound, preferably a non-digestible oligosaccharide (NDO). The pre-biotic compound is essentially non-digestible by the host animal but is fermentable by intestinal microflora present in the colon of the host animal. In the most preferred embodiment, the NDO is lactitol. Other preferred pre-biotic compounds include fructo-oligosaccharides and galacto-oligosaccharides other than lactitol and/or other pre-biotics.
The combination of tributyrin and a pre-biotic such as lactitol is synergistic in that the two ingredients are believed to generate butyric acid in the intestine of an animal host, while simultaneously encouraging the growth of beneficial bacteria in the lower intestine, thereby synergistically increasing the rate of weight gain and/or feed utilization of the animals. While not being bound to any particular mechanism, it is believed that tributyrin is degraded, presumably by acid hydrolysis and/or lipase activity, in the stomach and upper small intestine to yield butyric acid. The released butyric acid is then utilized as an energy source by the mucosal cells lining the intestine, resulting in improved mucosal trophism.
Pre-biotic compounds, such as NDO's, pass through the stomach and small intestine essentially unchanged and ultimately enter the large intestine, where such compounds are preferentially fermented by select microflora which inhabit the gut of animals.
The pre-biotic compounds are preferentially utilized by the lactic acid group of bacteria, including lactobacilli and bifidobacteria, which are capable of flourishing in the animal gut under the proper conditions. These beneficial bacteria produce mainly lactic acid as a fermentation end product which lowers the pH of the lower gut. This lower pH is inhospitable to many undesirable microorganims (including human and animal pathogens) which cannot survive in the lowered pH conditions. Consequently, the invention encourages a more favorable microbial balance in the GI tract. The benefical bacteria thrive due to the presence of a ready energy source such as a NDO, produce lactic acid which lowers the pH of the gut (which is also antimicrobial), and thereby competitively exclude colonization by other, potentially detrimental organisms.
These beneficial bacteria may also produce antimicrobial compounds, including bacteriocins, hydrogen peroxide, etc., which also inhibit the growth of undesirable and/or pathogenic organisms.
Another advantage of the invention is that by encouraging the vigorous growth of beneficial bacteria, this may prevent conversion of pre-oncogenic compounds into oncogenic compounds by enzymatic hydrolysis.
Some of the beneficial organisms found in the animal gut also produce butyric acid as an end product of fermentation. As noted above, the butyric acid is then utilized by the colonocytes which line the lower intestine.
Another advantage of the composition is the intrinsic sweetness of many NDO's (lactitol in particular) coupled with the taste of tributyrin, which is far less pungent than butyric acid itself. The composition is, therefore, very desirable to most animals. In particular, swine are very particular about bitter or “off” tasting feed. Swine are, however, very fond of anything sweet. Consequently, the subject composition is willingly ingested by swine. Additionally, if NDO's are used as the pre-biotic, because of their indigestibility, they add little, if any, caloric content to the diet. This may be advantageous in certain circumstances, such as in low-calorie foods for human consumption.
The subject composition is particularly useful when used as a feed additive for humans, swine, cattle, poultry, dogs, cats, sheep, goats, and horses.
DETAILED DESCRIPTION OF THE INVENTION
As noted above, the invention is a feed or feed additive composition comprising tributyrin and a pre-biotic, preferably a NDO. The preferred oligosaccharide is lactitol. When ingested, the composition functions to increase the rate of weight gain in animals by: (1) generating butyric acid by the hydrolysis of tributyrin which is then utilized as an energy source by the intestinal mucosa; and (2) encouraging the growth of beneficial microflora (notably lactobacilli and bifidobacteria) within the lower intestine. This results in a synergistically increased weight gain in animals fed the subject composition as compared to control animals fed either tributyrin or a pre-biotic.
The feed is produced by admixing tributyrin and the pre-biotic to a base feed ration suitable for the animal being fed. Mixing can be done by hand or by using any number of suitable mixing devices, such as an auger-type mixer. For large quantities of feed, large drum mixers or extruders can be used to thoroughly admix the tributyrin and the pre-biotic with the other feed ingredients. If the base feed is not already particulate in nature, the tributyrin and pre-biotic may be added at the same time the base feed is pulverized and/or granulated. Any number of conventional granulating methods can be used to comminute and intimately associate the base ration with the tributyrin and the pre-biotic. These methods include extrusion granulation, fluidized granulation, rolling granulation, or agitation granulation. (See, for instance, Kobayashi et al., U.S. Pat. No. 4,996,067, incorporated herein by reference for its teaching of conventional granulation methods.) Conventional binders, fillers, and excipients, so long as physiologically acceptable, may be added to facilitate granulation. The method of granulation is not critical to the present invention. Once granulated, the composition may be extruded into pellets, if desired.
Suitable base rations and pre-mixes for livestock, poultry, fish, etc. are exceedingly well known in the art and need not be elaborated upon in great detail.
A typical base ration for poultry is as follows:
Typical Base Diet Formulation for Poultry
Base Diet
kg/100 kg
Corn
48.75
Soybean Meal
41.23
CaCO 3
1.40
Corn Oil
6.89
Methionine
0.23
Salt
0.50
Premix
1.00
Premix:
g/100 kg
Vitamin A (10,000 IU/g)
4,500
Vitamin D 3 (8900 IU/g)
666.7
Vitamin E
900.0
Riboflavin (100 g/lb)
243.3
Vitamin B 12 (300 mg/lb)
120.0
ZnSO 4 (36%)
666.7
MnO
633.3
Niacin (50%)
733.3
Pantothenic acid (25%)
933.3
Choline (60%)
9,567
Bring to 100 kg with ground corn.
The base poultry diet can also be supplemented with inorganic phosphorous (e.g., monocalcium phosphate) and grit to aid mechanical breakdown of food particles within the gizzard. As used herein, the term “poultry” includes, without limitation, chickens of all types (bantam weights, game hens, egg-producers, broilers, etc.), turkeys, ducks, geese, pheasant and ratites (e.g., ostrich, emu, rhea). Other regularly encountered species falling within the term “poultry” include grouse, woodcock, pigeons, and other avian species either desired as livestock or sporting birds. In short, as used herein, the term “poultry” is synonymous with “avian.”
An exemplary base ration for swine is given in the Example below.
For both the pre-biotic and tributyrin, it is preferred that they each comprise from about 0.03% to about 3% by weight, and more preferably from about 0.3% to about 1.0% by weight of the total diet. That is, it is most preferred that from about 0.3 to about 10 grams per kg total feed is the pre-biotic and that from about 0.3 to about 10 grams per kg total feed is tributyrin.
Silage has been regularly used to feed ruminant livestock and is now starting to find increased use in the feeding of monogastric livestock. “Silage” as used herein is defined to mean vegetable matter, often fodder, which has been converted into a feed for livestock through various processes of anaerobic acid fermentation within a silo. A wide variety of vegetable matter, such as corn, beans, peas, alfalfa, and the like, can be converted within silos into silage. As used herein, the term “silo” encompasses any and all types of structures used to produce silage (e.g., vertical silos, trench silos, silage bags, “harvestores,” and the like). The invention encompasses admixing tributyrin and a NDO with silage to ultimately arrive at a feed or feed additive for monogastric or ruminant livestock.
In general, however, silage by itself does not constitute a nutritionally complete base feed ration for most monogastric species. Many amino acids and vitamins (most notably, Vitamins B and E) found within raw vegetable matter are degraded during the ensilation process. Ruminant animals can survive when fed only silage owing to rumen microorganisms which synthesize the needed nutrients de novo. Monogastric species, however, are unable to biosynthesize the nutrients destroyed during ensilation and, therefore, suffer from defects owing to malnutrition when fed unsupplemented silage. Therefore, to serve as a nutritionally complete base ration for monogastrics, silage must be supplemented with essential vitamins and other nutrient additives.
However, if the pre-biotic, especially a NDO, is to be admixed with a base ration containing a significant amount of silage, or if the lactitol is to be added directly to silage or materials to be ensiled, or if the ultimate feed product is to be fed to ruminants, the lactitol must be microencapsulated to protect it from fermentation by the organisms contained in the silage and the rumen of the host. Several methods of microencapsulation to protect biologically active compounds are known in the art. See, for example, U.S. Pat. No. 5,589,187 to Wentworth and Wentworth. See also Piva et al. (1997), “Effect of microencapsulation on absorption processes in the pig,” Livestock Production Science, p. 1521. Both of these documents are incorporated herein by reference.
A preferred method of encapsulation is to encase the pre-biotic and the tributyrin in lipid vesicles (e.g., liposomes, multi-lamellar vesicles, etc.) comprised of long-chain fatty acids. Suitable lipid compositions for use in encapsulation include mixtures of stearic, palmitic, myristic, linoleic (including conjugated linoleic), and oleic acids. The pre-biotic and the tributyrin are admixed with a liquified portion of the long-chain fatty acids in a suitable ratio to adequately disperse the active ingredients. The mixture can then be spray-dried and/or spray-chilled to yield capsules of the long-chain fatty acid which contain pre-biotic and tributyrin.
It is preferred that the tributyrin and pre-biotic be encapsulated together and then added to the materials to be ensiled at the time they are placed into the silo. Alternatively, the encapsulated tributyrin and pre-biotic may be admixed with the silage when it is removed from the silo.
Once the composition is complete, it is fed to animals, either monogastric or ruminant, ad libitum or in any suitable or desired metered fashion, as is well known in feed lot management and animal husbandry.
EXAMPLE
The following Example is included solely to aid in a more complete understanding of the invention. The following Example does not limit the invention described or claimed herein in any fashion.
Example of a Feeding Trial:
Animals: Swine from about 6 to 15 kg of live weight (l.w.)
Genotype: (Large White×Landrace)×Duroc
Number of animals: 64
Experimental treatments:
1 - control diet (given below)
2 - control diet+1% tributyrin
3 - control diet+0.3% non-digestible oligosaccharide (lactitol)
4 - control diet+1% tributyrin+0.3% non-digestible oligosaccharide (lactitol)
Number of animals/treatment: 16
Number of replicates(box)/treatment: 4
Feed consumption and animal weight gain were measured on a regular basis to evaluate feed efficiency and growth rate. The hypothesis was that animals fed diet number 4, that is, the control diet plus 1% tributyrin and 0.3% non-digestible oligosaccharide, will display an increased average growth rate and greater feed efficiency. The animals fed diet number 4 will also have an improved intestinal morphology as compared to the control animals.
Tributyrin
DIET (as fed)
Tributyrin
Lactitol
1% +
kg/100 kg
Control
1%
0.3%
Lactitol 0.3%
Corn
37.33
37.33
37.33
37.33
Wheat
13.00
13.00
13.00
13.00
Barley Flakes
20.00
20.00
20.00
20.00
Soy Bean Meal
16.50
16.50
16.50
16.50
Meat Meal
2.00
2.00
2.00
2.00
Fish Meal
3.00
3.00
3.00
3.00
Fat
2.00
2.00
2.00
2.00
Whey Powder
3.00
3.00
3.00
3.00
L-lysine HCl
0.29
0.29
0.29
0.29
DL-methionine
0.08
0.08
0.08
0.08
L-tryptophan
0.05
0.05
0.05
0.05
L-treonine
0.03
0.03
0.03
0.03
CaCO 3
0.70
0.70
0.70
0.70
CaHPO 4 2H 2 O
1.40
1.40
1.40
1.40
NaCl
0.22
0.22
0.22
0.22
Premix
0.40
0.40
0.40
0.40
Tributyrin
1.00
1.00
Lactitol
0.30
0.30
DM = Dry Matter
89.04
89.04
89.04
89.04
CP = Crude Protein
19.04
19.04
19.04
19.04
EE = Ether Extract
4.2
4.2
4.2
4.2
CF = Crude Fiber
2.64
2.64
2.64
2.64
Ash
5.9
5.9
5.9
5.9
Starch
45.55
45.55
45.55
45.55
Lysine
1.2
1.2
1.2
1.2
Methionine + Cystine
0.72
0.72
0.72
0.72
Threonine
0.72
0.72
0.72
0.72
Tryptophan
0.24
0.24
0.24
0.24
Calcium
1.07
1.07
1.07
1.07
Phosphorous (total)
0.75
0.75
0.75
0.75
Sodium
0.18
0.18
0.18
0.18
Digestible Energy
3549
3549
3549
3549
Expressed kcal per
kg
Net Energy Expressed
2468
2468
2468
2468
kcal per kg
This Example monitored the effect of diet on 64 weaned piglets {(Large White×Landrace)×Duroc} for 42 days. The experiment was initiated when the piglets were 28 days old (ca. 5.9±1.22 kg). At 21 days after their birth, the piglets were transported from the piggery to the production barn. Before the trial was initiated, the piglets were kept in flat-deck cages for 7 days to monitor their health status. During this adaptation time, the animals were fed a commercially-available, medicated diet (containing clorotetracycline (1,000 mg per Kg diet) and spiramycin (400 mg per Kg diet)) as a prophylactic to minimize the negative consequences of stress due to travel from the piggery to the production barn. The piglets always had free access to water and feed.
At 28 days after birth, the piglets were allotted homogeneously into the following 4 experimental groups according to their initial weight and gender (females and castrated males) and provided with a pelletized feed: 1) control diet (CTR); 2) control diet with 1% tributyrin (TRB); 3) control diet with 0 3% lactitol (LCT); 4) control diet with 1% tributyrin and 0.3% lactitol (TRB+LCT) (see Tables 1 and 2). On days 0, 14, and 42 after the feeding trial was initiated the animals were weighed, and animal health, feed consumption, and feed conversion index were determined. After 42 days, the heaviest 2 castrated males and 2 females from each dietary treatment were sacrificed to measure the empty and full weights of their stomach, cecum, and colon, as well as the weights of their liver and kidneys.
Tributyrin=C 15 H 26 O 6 , MW 302.37, Chemical Abstract number 60-01-5, butanoic acid 1,2,3-propanetriyl ester, density 1.032, color white, odorless, manufactured by Fluka.
Lactitol monohydrate=C 12 H 24 O 11 , MW 344.32, Chemical Abstract number 8 1025-04-9, 4-O-B-D-galactopyranosyl-D-glucitol, melting point 120° C., color white, odorless, crystals, manufactured by Xyrofin Oy-Kotka.
Results:
Animals health status. No untoward clinical conditions were observed during the 7-day adaptation period. As such, no medical interventions or treatments were performed. During the 42 days of the feeding trial, it was observed that most animals in each treatment group intermittently experienced some form of mild diarrhea, presumably as a consequence of the relatively short 7-day adaptation period the animals had to adjust to the production barn and to solid feeding. Necropsy of the 5 piglets that died during the feeding trial indicated the occurrence of pneumonia and/or enteritis. The veterinarian attributed death to the stress the animals were exposed to during weaning and transport, as well as the stress experienced during grouping and weighing. A 7-day adaptation period was implemented to assess the possible efficacy of the dietary treatments for stressed animals. This situation is very common in the field and it is often associated with increased weight loss and mortality. The comparative morbidity and mortality among animals in the different dietary treatment groups are listed in Table 3. It should be noted that weight loss was calculated as the difference between the final and initial weight for either days 0 through 14 of the trial or for days 0 through 42 of the trial.
Animal performance. As listed in Table 3, fewer piglets fed tributyrin and lactitol died than piglets fed a diet containing either of these additives used alone. Likewise, fewer piglets fed a diet containing either tributyrin or lactitol died than piglets in the control diet that were not fed either of these additives. A similar trend was observed when weight loss was measured. In general, fewer animals lost weight when fed tributyrin and lactitol, followed by animals fed lactitol alone, followed by animals fed tributyrin alone, followed by animals fed the control diet. Moreover, within the first 14 days of the trial, animals fed tributyrin and lactitol displayed a higher live weight (+15%, P<0.05), higher daily weight gain (±85%, P<0.05), and higher feed efficiency (5.18 vs 1.62 Kg feed per Kg weight gain) than animals fed the control diet. Similar results were obtained over the entire 42 day trial: animals fed tributyrin and lactitol displayed a final weight (+5.7%), daily weight gain (+10%), and feed efficiency (±9%) appreciably higher than animals fed the control diet (Table 4a).
Animals receiving the control diet were particularly affected by the stress conditions employed in this study. Records from the same production barn for a 5-year period for otherwise similar feeding trials using piglets of the same genotype revealed that piglets displayed an average daily weight gain of 400 and 500 grams per day for days 0-14 and 0-42, respectively, and a feed conversion ratio of 1.3 and 1.6 for days 0-14 and 0-42, respectively (data not shown). In the present study, only animals receiving both tributyrin and lactitol approached these performance levels. It should also be noted that in contrast to previous reports by other investigators, animals fed tributyrin in general did not perform as well as animals fed the control diet over the 42-day feeding trial (Table 4a). Lastly, the organ weights were within the expected/normal ranges, and no alterations were observed among the internal organs of the heaviest male or female animals sacrificed for each treatment group (Table 4b). However, comparisons of the average live weights and attendant standard deviations of the 16 animals in the control group after 42 days revealed that the live weights of these animals were less homogeneous than animals in the other treatment groups (Table 4a). These data intimate that animals within the control group reacted less well to stress. Due to the higher standard deviations in live weights displayed by animals in the control group, sacrificing the heaviest animals from the control group may explain, in part, why such animals displayed higher live weights than animals in the other treatment groups. In contrast, when the live weights of all animals in each treatment group were considered after 42 days, the live weights of animals fed tributyrin and lactitol or animals fed lactitol alone were higher than the live weights of the control animals.
The piglets used in this study were exposed to stress associated with: i) transport from the piggery to the production barn; ii) weaning; iii) adaptation to solid feeding; and iv) grouping and weighing. For these stressed piglets, the combined feeding of tributyrin (1%) and lactitol (0.3%) was more beneficial than feeding either tributyrin (1%) or lactitol (0.3%) alone or feeding the control diet for reducing mortality and weight loss and for improving weight gain and feed efficiency. These results show the utility of the present invention as an animal feed composition.
TABLE 1
Diet composition (%).
CTR
TRB
LCT
TRB + LCT
Corn
37.33
Wheat
13.00
Barley
20.00
Soybean meal 48%
16.50
Meat meal
2.00
Fish meal
3.00
Tallow
2.00
Dried whey
3.00
L-lysine HCl
0.29
DL-methionine
0.08
L-tryptophan
0.05
L-treonine
0.03
Calcium carbonate
0.70
Dicalcium phosphate
1.40
Sodium chloride
0.22
Premix
0.40
Tributyrin
—
1.00
—
1.00
Lactitol
—
—
0.30
0.30
TABLE 2
Proximate analysis of diets (g/Kg of dry matter).
TRB +
CTR
TRB
LCT
LCT
Dry Matter
g/kg diet
892.0
890.8
893.7
890.6
Crude protein
g/kg DM
199.3
204.2
201.6
200.4
Ether extract
g/kg DM
53.6
63.4
54.7
62.0
Crude fiber
g/kg DM
38.8
38.5
42.1
39.1
Ash
g/kg DM
62.3
60.8
62.9
60.6
Starch
g/kg DM
487.4
469.8
474.3
474.1
Digestible energy 1
MJ/kg
16.09
16.11
16.08
16.10
Net energy 2
MJ/kg
12.00
12.02
12.00
12.02
1 According to Whittemore (1980)
2 According to Noblet et al. (1994)
TABLE 3
Incidence of mortality and weight loss during
the experimental period.
CTR
TRB
LCT
TRB + LCT
Number of piglets
Beginning of the study
16
16
16
16
0-14 d
Mortality
1
1
0
0
Weight loss
5
4
2
1
0-42 d
Mortality
3
1
1
0
Weight loss
1
3
0
0
Mortality incidence %
18.75
6.25
6.25
0
TABLE 4a
Piglet growth performance and feed efficiency.
TRB +
CTR
TRB
LCT
LCT
Number of piglets
16
16
16
16
Initial live weight
kg
5.9
5.9
6.0
5.9
14 d
Live weight
kg
7.3
7.1
7.9
8.4
Weight gain
kg
1.32
1.12
1.87
2.44
Average Daily Gain
g/d
94
80
133
174
Feed intake
g
250
240
265
279
Feed Conversion Ratio
5.18
3.95
2.08
1.62
42 d
Live Weight
kg
13.9 ±
11.1 ±
14.5 ±
14.7 ±
5.5
4.9
3.5
3.9
Weight gain
kg
7.89
5.10
8.48
8.70
Average Daily Gain
g/d
188
121
202
207
Feed intake
g
365
299
370
362
Feed Conversion Ratio
1.94
2.53
1.87
1.77
Total weight of weaned
180.7
166.5
217.5
235.2
piglets (kg)
Deviation from CTR
—
−7.86%
+20.36%
+30.16%
TABLE 4b
Piglet growth performance and feed efficiency after slaughter.
CTR
TRB
LCT
TRB + LCT
Number of piglets
4
4
4
4
Live weight
kg
19.15
16.75
17.08
18.43
Metabolic Weight
9.12
8.24
8.37
8.89
(MW = live weight 0.75 kg)
Liver
% MW
7.07
5.57
6.45
6.66
Right kidney
% MW
0.52
0.46
0.54
0.46
Left kidney
% MW
0.51
0.48
0.53
0.47
Full stomach
% MW
13.58
8.55
15.58
13.39
Empty stomach
% MW
2.70
2.66
2.82
2.73
Full cecum
% MW
1.61
1.37
1.35
1.66
Empty Cecum
% MW
0.55
0.53
0.52
0.58
Full colon
% MW
6.86
5.97
6.42
7.92
Empty colon
% MW
3.98
2.96
3.06
3.82
It is understood that the invention is not confined to the particular reagents or their concentrations, formulations, or sources described above, but embraces all equivalent forms thereof as come within the scope of the attached claims.
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Disclosed is a feed additive which increases the availability of butyric acid and a pre-biotic to the intestinal mucosa and to beneficial microflora in the gut, respectively. The feed composition contains tributyrin and lactitol, a non-digestible oligosaccharide.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to the field of electrical connectors and more specifically to the area of interconnecting a plurality of printed wiring boards.
2. Description of the Prior Art
Various engineering applications require the interconnection of printed wiring or printed circuit boards. In some instances, it is necessary that the boards be oriented perpendicular with respect to each other.
In U.S. Pat. No. 3,693,135, a printed circuit board is shown mounted in a socket and retained therein by a holding frame. The printed circuit board has a plurality of circuit elements printed thereon and a plurality of contact "tails". The contact tails connect to the printed circuit elements and extend to the bottom of the board in parallel arrangement so as to make contact with corresponding terminals within the socket element. Flexible wiring between sockets would provide interconnection between printed wiring boards held in the sockets.
In a Nov. 24, 1983, article from Machine Design, Vol. 55, No. 27, entitled, "Solving Problems with Elastomeric Connectors" by Ben Carlisle, layered elastomeric connectors are described. Elastomeric connectors are comprised of stacked alternate sheets of conducting and nonconductive elastomeric material and are usually placed between the terminals formed on the surface of one printed circuit board and those on the surface of another. The elastomeric connector is described as providing interconnection of the oppositely disposed terminals. That article also describes a perpendicular connection between a mother board and a daughter board. In that configuration the surface terminals of one board and the surface terminals of the other board are interconnected at a perpendicular joint by the elastomeric connector being compressed into the joint.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide interconnection between two perpendicularly disposed conductor surfaces without the use of sockets or wiring harnesses.
It is another object of the Present invention to provide an elastomeric connector between two perpendicularly disposed conducting surface circuit boards to obtain interconnection therebetween.
It is a further object of the present invention to provide a uniquely formed printed circuit board that contains electrically isolated end terminals integrally formed on its defined connector edge.
It is still a further object of the present invention to provide a composite structure for a liquid crystal display in which perpendicularly disposed printed wiring boards are interconnected with the surface terminals on the liquid crystal display element.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a portion of a printed wiring board containing the present invention.
FIG. 2 is an exploded view of a printed wiring board containing the present invention and other components which make up an interconnected assembly.
FIG. 3 is a cross-sectional view of a liquid crystal display panel assembly utilizing the present invention.
FIG. 4 is a plan view of a large substrate board used in a method of manufacturing the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In those instances where it is necessary to install a printed wiring board perpendicular to another and provide interconnection therebetween, the present invention is ideally suited. It provides integrated electrical contacts that extend from the edge of the printed wiring board so that they may be interconnected with exposed conductors on the surface of a second board.
FIG. 1 illustrates a portion of a printed wiring board 20 having a first layer of electrically conducting material disposed in a predetermined pattern and having portions 22a, . . . 22e extending towards and adjacent to the connector edge 21.
The substrate 20 is a conventional insulator material that may be ceramic or of other composite resin based materials suitable for supporting the desired wiring pattern and any electrical components that may be mounted thereon. The substrate 20 has a known thickness "t" and a defined linear connector edge 21.
A second layer 24 of conducting material is deposited over the edge 21 of the substrate 20 so as to provide an electrically conductive surface over the thickness t of the edge 21 that connects with the first layer on the surface of the substrate 20. Arcuate shaped cuts 30a . . . 30d are shown in FIG. 1 along the edge 21 to separate the layer 24 into individual connector pads 24a . . . 24e.
In FIG. 2, a larger portion of the printed wiring board substrate 20 is shown which contains a printed wiring pattern 22a . . . 22j and an electronic component 50. The connector edge 21 is shown opposing an elastomer connector material 60. The elastomer connector material 60 is a conventional product which is available commercially from PCK Elastomerics, Inc. of Hatboro, Pa. or Technic of Cranford, N.J. The elastomeric connector material is normally configured as a stack of alternate sheets of conductive and nonconductive elastomeric material that is disposed to carry electrical currents across the stack. In this case, element 62 represents a conductive layer and element 64 represents a nonconductive layer. Generally the conductive layers number approximately 240 per inch. Other densities ranging from 100 to 600 conductive layers per inch are also available. Therefore, several conductive layers provide interconnection between conductors on each printed circuit board.
Element 70 represents a substrate lying in a plane that is substantially perpendicular to the orientation of substrate 20 and contains a plurality of exposed electrical conductors such as 72a . . . 7j indicated on its surface. The substrate 70 may be another printed circuit board or it may be the peripheral portion of a substrate such as that which leads to a liquid crystal display. In any event, the assembled elements 20, 60 and 70 of FIG. 2 provide that the connector edge 21 abuts the upper surface of the elastomer connector 60 and the lower surface of the elastomer connector 60 contacts the exposed conductors 72a+ on substrate 70.
In FIG. 3 the composite elements shown in FIG. 2 are illustrated as part of a liquid crystal display assembly 100. The first substrates 120 and 120' are shown as each having a defined connector edge with edge connector elements 124 (124') compressed against an elastomer connector 160 (160'). Therefore, contact is made with the exposed electrical conductors 172 (172') on the perpendicularly oriented surface on substrate 110. In this case, the substrate 110 comprises a liquid crystal display cell. A light reflector 104 lies behind the liquid crystal display cell on substrate 110. The reflector 104 contains oppositely extending support arms 106, 106', 108 and 108' which are used to interconnect the various elements which make the compressive connection between the edge connector elements 124 (124') on board 120 (120') to the electrical conductors 172 (172') on the perpendicularly oriented substrate 110.
FIG. 4 represents a mother board that is used in the process of manufacturing printed wiring boards containing the connectors of the present invention on a designated connector edge as illustrated above.
The mother board 200 is normally a copper plated substrate. A plurality of slots 202a, 202b, . . . 202f are cut into the board 200 to expose the thickness of the substrate. In each case the slots are configured to provide a defined linear connector edge of a smaller printed circuit board. The smaller printed circuit boards are designated in broken line configurations 220a . . . 220f along one edge of each slot. The key to the process of forming the desired boards is to create a conductor surface on the (slot) edge of each board. In this case, the slots provide an unplated exposed edge of the board over its entire thickness. By using an electroless plating process, a layer of copper 224 is deposited on the exposed edge of the slot 202 so as to cover the entire thickness of the substrate. The printed wiring board is subsequently processed in a conventional manner to create a predetermined solder coated, conductive trace pattern in layer 222 and having portions thereof extend to areas adjacent to the edge of the slot 202 and to be electrically connected with the entire solder coated layer 224. Individual boards 220a, 220b . . . 220f are cut from the mother board 200 by a punch process. As part of that punch process, small portions 230 of the printed circuit board substrate 200 are trimmed from the slot edge between each portion of the conductive trace pattern 222 extending to the connector edge. The result is a printed wiring board having a plurality of linearly disposed connector elements deposited across the edge thickness of the board. Each of the integrated connector elements have surfaces that are normal to the surface of the board and extend from the edge in a direction that is parallel to the surface of the board.
It will be apparent that many modifications and variations may be implemented without departing from the scope of the novel concept of this invention. Therefore, it is intended by the appended claims to cover all such modifications and variations which fall within the true spirit and scope of the invention.
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A method of fabricating a printed wiring substrate board to have integral contacts over the thickness of a defined connector edge in order to allow for perpendicular mating to exposed conductors on the surface of a second substrate.
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This application is a continuation-in-part of Ser. No. 08/354,992 filed Dec. 13, 1994, which is pending. This application is also related to co-owned application Ser. No. 08/284,793 filed Aug. 2, 1994, now the U.S. Pat. No. 5,569,243, the complete disclosure of which is hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to endoscopic surgical instruments. More particularly, the invention relates to a ceramic insulator for a bipolar push rod assembly for an endoscopic surgical instrument having bipolar endoscopic cautery capability.
2. State of the Art
Endoscopic surgery is widely practiced throughout the world today and its acceptance is growing rapidly. In general, endoscopic/laparoscopic surgery involves one or more incisions made by trocars where trocar tubes are left in place so that endoscopic surgical tools may be inserted through the tubes. A camera, magnifying lens, or other optical instrument is often inserted through one trocar tube, while a cutter, dissector, or other surgical instrument is inserted through the same or another trocar tube for purposes of manipulating and/or cutting the internal organ. Sometimes it is desirable to have several trocar tubes in place at once in order to receive several surgical instruments. In this manner, organ or tissue may be grasped with one surgical instrument, and simultaneously may be cut with another surgical instrument; all under view of the surgeon via the optical instrument in place in the trocar tube.
Various types of endoscopic surgical instruments are known in the art. These instruments generally comprise a slender tube containing a push rod which is axially movable within the tube by means of a handle or trigger-like actuating means. An end effector is provided at the distal end of the tube and is coupled to the push rod by means of a clevis so that axial movement of the push rod is translated to rotational or pivotal movement of the end effector. End effectors may take the form of scissors, grippers, cutting jaws, forceps, and the like.
Modern endoscopic procedures often involve the use of electrocautery, as the control of bleeding by coagulation during surgery is critical both in terms of limiting loss of blood and in permitting a clear viewing of the surgical site. As used herein, cautery, electrocautery, and coagulation are used interchangeably. Several types of electrocautery devices for use in endoscopic surgery are described in the prior art. Monopolar electrosurgical instruments employ the instrument as an electrode, with a large electrode plate beneath and in contact with the patient serving as the second electrode. High frequency voltage spikes are passed through the instrument to the electrode (i.e., end effector) of the endoscopic instrument to cause an arcing between the instrument and the proximate tissue of the patient. The current thereby generated continues through the patient to the large electrode plate beneath the patient. Monopolar cautery has the disadvantage that the current flows completely through the patient. Because control of the current path through the body is not possible, damage can occur to tissue both near and at some distance from the surgical site. In addition, it is has been observed that monopolar cautery can result in excessive tissue damage due to the arcing between the end effector and the tissue.
In order to overcome the problems associated with monopolar cautery instruments, bipolar instruments have been introduced. In bipolar electrosurgical instruments, two electrodes which are closely spaced together are utilized to contact the tissue. Typically, one end effector acts as the first electrode, and the other end effector acts as the second electrode, with the end effectors being electrically isolated from each other and each having a separate current path back through to the handle of the instrument. Thus, in a bipolar instrument, the current flow is from one end effector electrode, through the tissue to be cauterized, to the other end effector electrode.
Various endoscopic instruments with cautery capability are known in the art. U.S. Pat. No. 4,418,692 to Guay, for example, discloses a device for use in laparoscopic tubal cauterization for blocking the Fallopian tubes of a patient. The device comprises a substantially tubular body member having a spring-biased piston slidably mounted therein. A pair of electrodes (either monopolar or bipolar) are disposed to grasp living tissue when the piston is in a first position biased by the spring and to release the tissue when a button is pressed which moves the piston into a second position. The device includes a circuit breaker which interrupts current flowing to the electrodes when the piston is in the second position. When the electrodes grasp the tissue, however, current is supplied to the entire surface of the electrode, that is, both the grasping surface and the outer non-grasping surface.
Another electrosurgical instrument for use in combination with an endoscope is disclosed in U.S. Pat. No. 5,007,908 to Rydell for "Electrosurgical Instrument Having Needle Cutting Electrode and Spot-Coag Electrode". Rydell's device includes an elongated flexible tubular member with a plurality of lumens. The distal end of the tubular member is provided with a bullet shaped ceramic tip covered with a conductive layer and having an opening coupled to a first one of the lumens. The conductive layer is coupled to a conductor which extends through a second one of the lumens to an electrical source. A second conductor, also coupled to the electrical source is slidable through the first lumen by a plunger. The two electrodes form a bipolar pair. In a second embodiment, the conductive layer on the ceramic tip is split by an insulating gap and both halves of the tip form a bipolar pair of electrodes. As with the Guay device, above, substantially the entire distal surface of Rydell's device serves as an electrode when energized.
Several hemostatic bipolar electrosurgical scissors have also been described. U.S. Pat. No. 3,651,811 to Hildebrandt describes a bipolar electrosurgical scissors having opposing cutting blades forming active electrodes. The described scissors enables a surgeon to sequentially coagulate the blood vessels contained in the tissue and then to mechanically sever the tissue with the scissor blades. In particular, with the described bipolar electrosurgical scissors, the surgeon must first grasp the tissue with the scissor blades, energize the electrodes to cause hemostasis, de-energize the electrodes, and then close the scissor blades to sever the tissue mechanically. The scissors are then repositioned for another cut accomplished in the same manner. With the bipolar electrosurgical scissors of Hildebrandt, the surgeon cannot maintain the electrodes in a continuously energized state because the power supply would be shorted out and/or the blades damaged if the blades are permitted to contact each other while energized.
The disadvantages of the bipolar scissors of Hildebrandt are overcome by the disclosure in U.S. Pat. Nos. 5,324,289 and 5,330,471 to Eggers. In its preferred embodiment, the bipolar electrosurgical scissors of Eggers comprise a pair of metal scissor blades which are provided with an electrically insulating material interposed between the shearing surfaces of the blades so that when the scissor blades are closed, the metal of one blade never touches the metal of the other blade; i.e., the insulating material provides the cutting edge and the shearing surface. With the arrangement provided by Eggers, a cautery current will pass from the top back edge of the bottom metal blade through the tissue which is to be cut and to the bottom back edge of the top metal blade directly in advance of the cutting action. As the scissors are gradually closed, the hemostasis preferentially occurs at a location just in advance of the cutting point which itself moves distally along the insulated cutting edges of the blades in order to sever the hemostatically heated tissue. With this arrangement, the scissors may be maintained in a continuously energized state while performing the cutting. The Eggers patent describes various alternative embodiments of the bipolar scissors, including the use of metal blades with only one blade being insulated on its shearing surface, and the use of insulating blades with back surfaces coated with metal.
In all of the bipolar instruments, and particularly in double acting instruments such as scissors, safe and effective delivery of the cautery current to the end effectors is always a difficult engineering problem. In particular, it is difficult to deliver a bipolar current source within the limited space in which endoscopic surgery is performed. It is necessary to assure that the conductors delivering the current are well insulated from each other, that they are easily connected to the end effectors, and that they are easily connected to a standard source of bipolar cautery current. Both Rydell et al. (U.S. Pat. No. 5,258,006) and Eggers (U.S. Pat. No. 5,330,471) have proposed bipolar push rod arrangements. Eggers has proposed a bifurcated cylindrical push rod in which two halves of the push rod are conductive and which are both covered with an insulating material. Rydell et al. has proposed a pair of conductive leads which extend through a double lumen silastic or polyurethane push rod. Neither of the bipolar push rod arrangements is easy to implement, and neither has been commercially successful. Moreover, the arrangement taught by Rydell et al. cannot be used with pivoting double acting end effectors as is required in the art of interest.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a bipolar push rod assembly for a bipolar endoscopic instrument.
It is another object of the invention to provide a bipolar push rod assembly which is easy to manufacture.
It is also an object of the invention to provide a bipolar push rod assembly which is well insulated to prevent a short circuit.
It is another object of the invention to provide a bipolar push rod assembly which is easily coupled to double acting end effectors.
It is still another object of the invention to provide a bipolar push rod assembly which is easily coupled to a standard source of cautery current.
In accord with the objects of the invention, a bipolar push rod assembly is disclosed in conjunction with an endoscopic bipolar cautery scissors instrument which is substantially as is described in copending application U.S. Ser. No. 08/284,793. The push rod assembly, according to the invention, has two conductive push rods which are stabilized relative to each other at their proximal and distal ends and which are otherwise substantially covered by a double lumen flexible sheath. The proximal ends of the push rods are stabilized by an overmolded plastic collar, and the distal ends of the push rods are stabilized by a ceramic insulator.
In accord with one aspect of the invention, the proximal ends of the push rods are swaged so that they exit a plastic collar spaced apart from each other approximately the same distance as the pins of a conventional cautery connector plug. The plastic collar is provided with a snap retainer for coupling it to a plastic plug retainer having a pair of spaced apart passages. A pair of female plug adapters are press fit onto the proximal ends of the push rods and are maintained in place by the plug retainer with each adaptor residing in a respective one of the passages. The distal ends of the push rods are swaged approximately 90° in opposite directions.
In accord with another aspect of the invention, the ceramic insulator may either be a one-piece unit into which the distal ends of the push rods are inserted, or a two-piece member which fits around the distal ends of the push rods. In either case, the ceramic insulator provides longitudinal channels for the push rods with substantially right angle bends at the distal ends of the channels. In addition, intersecting the substantially right angle bends are distal slots which can accommodate links which couple the push rods to the end effectors.
The push rod assembly according to the invention extends through the hollow tube of the bipolar instrument with the swaged distal ends of the push rods being coupled to the end effectors by links and the plastic collar being coupled to the movable lever of the handle. According to a preferred embodiment of the invention, a double lumen sealing gasket is located between the plastic collar and the ceramic insulator. Preferably, the double lumen sheath is bifurcated and the sealing gasket is located between a proximal double lumen sheath and a distal double lumen sheath. The sealing gasket fills the space between the push rod assembly and the interior of the hollow tube to prevent fluids from escaping the surgical site through the hollow tube.
Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a broken side elevation view in partial section of an endoscopic bipolar scissors instrument incorporating the push rod assembly according to the invention;
FIG. 1a is an enlarged broken exploded top view in partial section of the distal end of the instrument of FIG. 1;
FIG. 1b is a cross sectional view taken along line 1B--1B of FIG. 1a;
FIG. 2 is an exploded broken partially transparent side elevation view of the push rod assembly according to the invention;
FIG. 3 is an exploded broken partially transparent top view of the push rod assembly according to the invention;
FIG. 4 is an enlarged broken partially transparent side elevation view of the proximal end of the push rod assembly;
FIG. 5 is an enlarged broken partially transparent top view of the proximal end of the push rod assembly;
FIG. 6 is a broken side elevation view of a double lumen sheath according to the invention;
FIG. 7 is a cross section taken along line 7--7 of FIG. 6;
FIG. 8 is a plan view of a double lumen gasket according to the invention;
FIG. 9 is a cross section taken along line 9--9 of FIG. 8;
FIG. 10 is a sectional view taken along line 10--10 of FIG. 8;
FIG. 11 is a side elevation view of a one-piece ceramic insulator according to the invention;
FIG. 12 is a proximal end view of the insulator of FIG. 11;
FIG. 13 is a distal end view of the insulator of FIG. 11;
FIG. 14 is a top view of the insulator of FIG. 11;
FIG. 15 is an exploded top view of a two-piece ceramic insulator according to the invention;
FIG. 16 is an exploded distal end view of the insulator of FIG. 15; and
FIG. 17 is a side elevation view of one piece of the two-piece insulator of FIG. 15.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to FIG. 1, a bipolar endoscopic instrument 10 includes a proximal handle 12 with a manual lever actuator 14 pivotally coupled to the handle by a pivot pin 15. A hollow stainless steel tube 16 is rotatably coupled to the handle 12 and is preferably rotatable about its longitudinal axis relative to the handle 12 through the use of a ferrule 18 such as described in detail in previously incorporated copending application Ser. No. 08/284,793. A push rod assembly 20 extends through the hollow tube 16 and is coupled at its proximal end 22 to the manual lever actuator 14 as described in more detail in copending application Ser. No. 08/284,793. The distal end of the tube 16 has an integral clevis 24 within which a pair of end effectors (in this case scissor blades) 26, 28 are mounted on an axle screw 30. The distal end 23 of the push rod assembly 20 is coupled to the scissor blades 26, 28 so that reciprocal movement of the push rod assembly 20 relative to the tube 16 opens and closes the scissor blades 26, 28. It will be appreciated that the reciprocal movement of the push rod assembly 20 relative to the tube 16 is effected by movement of the manual lever actuator 14 relative to the handle 12. According to a preferred aspect of the instrument 10, as illustrated in FIGS. 1a and 1b, the axle screw 30 is secured in the clevis 24 by a nut 31 which has a flat side 31a and a D-shaped flange 31b. The clevis 24 is provided with a round hole 24a for receiving the screw 30 and a D-shaped hole 24b for receiving the nut 31. The nut 31 facilitates the tightening of the screw 30. When the nut 31 is inserted in the hole 24b, the flat side 31a of the nut 31 engages the flat side of the D-shaped hole 24b so that the nut is keyed to the hole and is prevented from rotating. The flange 31b prevents the nut from passing through the hole 24b. The screw 30 can then be tightened a desired amount without holding the nut 31 while tightening.
Turning now to FIGS. 2 and 3, the push rod assembly 20, according to the invention, includes a pair of stainless steel rods 32, 34 having proximal ends 32a, 34a, and distal ends 32b, 34b. The proximal ends 32a, 34a of the push rods have divergent bends (not shown) which cause the rods to terminate in parallel proximal pins 32c, 34c. The proximal ends of the rods, with the exception of the pins 32c, 34c, are provided with an over-molded proximal collar 36. The proximal collar 36 has an increased diameter proximal portion 37 which accommodates the proximal bent portions of the rods, and a radial groove 40 which is located distally of the increased diameter portion and which is used for coupling the lever actuator 14.
According to one aspect of the invention, the proximal end 22 of the push rod assembly 20 is provided with a snap-together female cautery connector 42, described in detail below with reference to FIGS. 4 and 5. According to another aspect of the invention, a double lumen insulating sheath 44, described in more detail below with reference to FIGS. 6 and 7, covers substantially the entire length of the rods 32, 34 between the proximal collar 36 and the distal ends 32b, 34b. According to a further aspect of the invention, a double lumen sealing gasket 46, described in more detail below with reference to FIGS. 8-10, is provided on the rods 32, 34, between the proximal collar 36 and the distal insulator 38. According to still another aspect of the invention, the distal ends 32b, 34b of the push rods are swaged approximately 90° in opposite directions as shown in FIG. 3, and are captured in a distal ceramic insulator 38 which is described in detail below with reference to FIGS. 11-17.
Referring now to FIGS. 2 through 5, the female cautery connector 42 includes a plug retainer 48 and a pair of female plug adapters 50, 52. The plug retainer 48 has a substantially cylindrical distal portion 48a and a substantially rectilinear proximal portion 48b. The distal portion 48a has a pair of interior proximally ramped protrusions 48c, 48d and the proximal portion 48b has two substantially parallel passages 48e, 48f. Each plug adaptor 50, 52 is a substantially cylindrical conductive metal member having a smaller diameter distal portion 50a, 52a and a larger diameter proximal portion 50b, 52b. The distal portions 50a, 52a are dimensioned to fit snugly over the respective proximal pin ends 32c, 34c of the rods 32, 34, and the proximal portions 50b, 52b are dimensioned to fit snugly in respective passages 48e, 48f of the plug retainer 48. The increased diameter proximal portion 37 of the collar 36 is substantially frustroconical (i.e., ramped) and has a pair of distally ramped outer protrusions 37a, 37b. The cautery connector 42 is assembled by fitting the distal portions 50a, 52a of the female plug adapters 50, 52 onto the respective proximal ends 32a, 34a of the rods 32, 34, and then snap-fitting the plug retainer 48 onto the proximal portion 37 of the collar 36. As seen best in FIGS. 4 and 5, the distal portion 48a of the plug retainer 48 fits over the proximal portion 37 of the collar 36 with the ramped protrusions 48c, 48d engaging the protrusions 37a and 37b of the proximal portion 37 of the collar 36. The proximal portions 50b, 52b of the plug adapters 50, 52 are captured in the passages 48e, 48f of the plug retainer 48. When assembled, the cautery connector 42 receives a standard male cautery plug (not shown).
Turning now to FIGS. 6 and 7, the double lumen insulating sheath 44, according to the invention, has a first lumen 44a and a second lumen 44b, which are defined by a dividing wall 44c, and an outer wall 44d. The first lumen 44a and second lumen 44b are substantially identical in size and shape, and are large enough in cross-sectional size to accommodate respective rods 32, 34. According to a presently preferred embodiment, the sheath 44 has an oblate cross section as seen best in FIG. 7 and the lumens 44a, 44b have a substantially D-shaped cross section. The sheath is preferably made of Himont Profax 6523 polypropylene and has an outer wall thickness of approximately 0.020 inches. When used with the instrument 10 shown in FIG. 1, the external diameter of the sheath is less than 0.169 inches and the interior diameter of the tube 16 is 0.170 inches. When so dimensioned, the lumens 44a, 44b are each approximately 0.050 inches by approximately 0.112 inches in cross section.
While not essential to the electrical or mechanical performance of the push rod assembly, it is preferable to provide a sealing gasket to seal the annular space between the push rod assembly and the tube of the endoscopic instrument as mentioned above. Turning now to FIGS. 8-10, a sealing gasket 46, according to the invention, is preferably formed of injection molded Santoprene 281-64 thermoplastic rubber having a Durometer of 64. The gasket 46 is preferably tapered proximally and distally to define a waist portion 46a which has a diameter larger than the inner diameter of the tube 16 of the instrument 10 (FIG. 1). For example, when used with a tube having an inner diameter of 0.170 inches, the diameter of the waist portion 46a is preferably approximately 0.177 inches. The gasket 46 is provided with two lumens 46b, 46c which are flared proximally and distally to define respective inner waists 46d, 46e having diameters which are preferably smaller than the outer diameters of the rods 32, 32 (FIGS. 1-5). For example, the instrument 10 described above has rods 32, 34 which each have a diameter of approximately 0.040 inches. When used with rods so dimensioned, the waists 46d, 46e each have a diameter of approximately 0.033 inches. As so dimensioned, the overall width of the gasket 46 is approximately 0.090 inches. As mentioned above, the gasket may be placed between the sleeve 44 and the proximal collar 36 or between the sleeve 44 and the distal insulator 38. As mentioned above, the presently preferred method of making the gasket 46 is by injection molding and FIGS. 8 and 10 show the approximate gate location where a portion 46f of the molded material protrudes from the gate of the mold. In accord with the exemplary dimensions given above, a gate protrusion of approximately 0.020 inches is permissible. As mentioned above, the sealing gasket 46 may be placed almost anywhere between the proximal collar 36 and the distal ends 32b, 34b of the push rods. According to a presently preferred embodiment, however, as shown in FIGS. 2 and 4, the sheath 44 is bifurcated into a proximal portion 44a and a distal portion 44b, and the sealing gasket 46 is located between these portions 44a, 44b.
Referring now to FIGS. 11 through 14, the presently preferred embodiment of the distal insulator 38 comprises a single piece ceramic member. The insulator 38 is substantially circular in cross section except for upper and lower projections 147, 149. These projections engage the space between arms of the clevis 24 (FIG. 1) and prevent the insulator 38 from rotating in the clevis during reciprocation 24 and from passing beyond the proximal end of the clevis as described in copending application Ser. No. 08/354,992. Consequently, the projections each have a pair of substantially parallel edges 147a, 147b, 149a, 149b and a rounded proximal edge 147c, 149c. The insulator 38 has a pair of push rod receiving channels 150, 152 for fixedly receiving the push rods 32, 34 (FIGS. 1-5) respectively. The channels have portions 150a, 152a which are radially open to the surface of the insulator 38 from the proximal end thereof to a point approximately half way under the projections 147, 149. The channels 150, 152 terminate under the projections 147, 149 with a right angle bend 150b, 152b. A radial opening 150c, 152c extends proximally along each side of the insulator from the right angle bend 150b, 152b to a point contiguous with the radially open part 150a, 152a of the channels 150, 152. The radial openings 150c, 152c are each substantially orthogonal to the radially open parts 150a, 152a. The distal end of the insulator 38 has a pair of ramped slot openings 154, 156 which terminate at their proximal ends with curved grooves 158, 160. The slot openings and grooves are provided to accommodate the ends of links as described in copending application Ser. No. 08/354,992 for coupling the distal ends 32b, 34b (FIG. 3) of the push rods 32, 34 to scissor blades (FIG. 1). The insulator 38 is easily attached to the distal ends of the push rods by pressing the push rods into the radially open parts 150a, 152a of the channels 150, 152 so that the bent ends 32b, 34b of the push rods enter the radial openings 150c, 152c. The push rods and/or the insulator 38 are pushed towards each other so that the bent ends of the push rods fixedly abut the right angle bends 150b, 152b in the channels 150, 152, at which location the links are coupled to the push rods. As a result of the fixed connection between the push rods and distal insulator 38, reciprocation of the push rods produces a reciprocation of the insulator.
Referring now to FIGS. 15 through 17, an alternate embodiment of a distal insulator 238 is constructed of two substantially identical ceramic pieces 238a, 238b. Each piece is substantially semi-circular in cross section except for distal radial projections 247, 249. When the pieces are assembled as suggested in FIGS. 15 and 16, these projections form the same kind of projection as the projections 147, 149 described above. In addition, each of the pieces 238a, 238b has a push rod receiving channel 250 for receiving a respective one of the push rods 32, 34 (FIGS. 1-5). The channel 250 terminates adjacent to the projection 249 with a right angle bend 251. The distal end of each piece 238a, 238b has a slot opening 254 which is substantially diametrically opposite to the right angle bend 251, and a radial opening 256 adjacent to the slot opening 251 interrupts the projection 247. The slot openings and radial openings are provided to accommodate the ends of links as described in copending application Ser. No. 08/354,992 for coupling the distal ends 32b, 34b (FIG. 3) of the push rods 32, 34 to scissor blades (FIG. 1). The insulator 238 is easily attached to the distal ends of the push rods by pressing each push rod into the channel 250 of a respective piece 238a, 238b so that the bent ends 32b, 34b of the push rods abut the right angle bend 251. The two pieces are pressed together as suggested in FIGS. 15 and 16 and the distal end of each push rod enter the radial opening 256 of a respective piece.
There have been described and illustrated herein several embodiments of a push rod assembly and a bipolar endoscopic surgical instrument incorporating them. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. Thus, while particular conductive and non-conductive materials have been disclosed, it will be appreciated that other materials could be utilized. Also, while specific dimensions have been disclosed, it will be recognized that different dimensions could be used with similar results obtained. In addition, while the push rod assembly has been shown in conjunction with a bipolar scissors instrument, it will be appreciated that the push rod assembly can be used with any double-acting bipolar surgical instrument. Further, while the sealing gasket has been shown as interrupting the double-lumen tubing, it will be appreciated that the gasket could be located proximally or distally of the tubing as desired. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as so claimed.
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A bipolar push rod assembly is disclosed in conjunction with an endoscopic bipolar cautery scissors instrument. The push rod assembly has two conductive push rods which are substantially covered and insulated from each other by a double lumen flexible sheath. The proximal ends of the push rods are stabilized by an overmolded plastic collar and the distal ends of the push rods are stabilized by a ceramic insulator. The plastic collar is provided with a snap retainer for coupling it to a plastic plug retainer having a pair of spaced apart passages. A pair of female plug adapters are press fit onto the proximal ends of the push rods and are maintained in place by the plug retainer with each adaptor residing in a respective one of the passages. The distal ends of the push rods are swaged approximately 90° in opposite directions. A ceramic insulator is disclosed as a one-piece unit into which the distal ends of the push rods are inserted. Another ceramic insulator is disclosed as a two-piece member which fits around the distal ends of the push rods. A double lumen sealing gasket which interrupts the double lumen sheath is also disclosed.
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BACKGROUND
The present application claims priority under 35 U.S.C. 119 and 35 U.S.C. 365 to Korean Patent Application No. 10-2006-0128326 (filed on Dec. 15, 2006), which is hereby incorporated by reference in its entirety.
An image sensor may be a semiconductor device that may convert optical images into electric signals. An image sensor may be classified into horizontal and vertical image sensors.
A horizontal image sensor may be operated in such a manner that transistors may be formed on a semiconductor substrate corresponding to the number of pixels through a CMOS technology. The transistors may be switched such that an output signal may be detected.
Further, in the horizontal image sensor, a color filter may be formed on a pixel array, and the color filter may transmit a specific wavelength of light to the transistors. However, since the color filter may require three pixels to detect red, green and blue colors, the required area of a pixel needed to realize one color may become broader.
In contrast, a vertical image sensor may include photodiodes having various colors, which may be vertically formed on a plurality of epitaxial layers. Accordingly, various colors may be realized using a single pixel.
Gates may be formed in an upper layer of the vertical image sensor, and a diffusion area may be formed between the gates. A photoresist pattern may be used to perform two functions, including defining the diffusion area and selectively isolating ions implanted into the diffusion area.
The photoresist pattern should preferably have a small thickness, less than or equal to a reference value, to precisely define the diffusion area. However, the photoresist pattern should preferably have a large thickness to selectively isolate ions implanted into the diffusion area.
Therefore, a gate may be first formed using a first photoresist pattern, and a second photoresist pattern may be formed on the gate, thereby selectively opening the diffusion area.
However, since the dual photoresist patterns may contain a large amount of ions, they may be easily cured in the subsequent process. Since it may be difficult to remove the dual photoresist patterns through the cleaning process, the electrical characteristic and operation reliability of a device may be degraded.
SUMMARY
Embodiments relate to an image sensor and a method of manufacturing an image sensor.
According to embodiments, a method for manufacturing an image sensor may include forming a photodiode structure including a plurality of photodiodes formed into a vertical structure, forming an upper epitaxial layer having trenches on the photodiode structure, forming an oxide layer on the upper epitaxial layer and forming dummy ion implantation mask patterns for forming a floating diffusion area by patterning the oxide layer, forming an ion implantation mask pattern formed on the upper epitaxial layer including the dummy ion implantation mask patterns and exposing the upper epitaxial layer at a portion in which the floating diffusion area may be formed, and forming the floating diffusion area by performing an ion implantation process.
DRAWINGS
FIG. 1 is a side sectional drawing illustrating a configuration after a photodiode structure is formed on a semiconductor substrate, according to embodiments.
FIG. 2 is a side sectional drawing illustrating a configuration after an upper epitaxial layer is formed, according to embodiments.
FIG. 3 is a side sectional drawing illustrating a configuration after an oxide layer is patterned, according to embodiments.
FIG. 4 is a side sectional drawing illustrating a configuration after the oxide layer is etched, according to embodiments.
FIG. 5 is a side sectional drawing illustrating a configuration after an ion implantation mask pattern is formed, according to embodiments.
FIG. 6 is a side sectional drawing illustrating a configuration after a floating diffusion area is formed, according to embodiments.
FIG. 7 is a side sectional drawing illustrating a configuration after dummy ion implantation mask patterns and the ion implantation mask pattern are removed, according to embodiments.
FIG. 8 is a side sectional drawing illustrating a configuration after a gate and a third photodiode are formed, according to embodiments.
DESCRIPTION
FIG. 1 is a side sectional view showing a configuration after a photodiode structure 130 is formed on semiconductor substrate 200 , according to embodiments.
Referring to FIG. 1 , photodiode structure 130 may be formed on semiconductor substrate 200 . Photodiode structure 130 may include a plurality of photodiodes vertically arranged.
The image sensor according to embodiments may include three photodiodes, i.e., first photodiode 110 , second photodiode 120 , and third photodiode 170 (See FIG. 8 ).
First, second, and third photodiodes 110 , 120 and 170 may not be horizontally formed in one epitaxial layer, but may be vertically arranged in different epitaxial layers, i.e., lower epitaxial layer 105 , middle epitaxial layer 115 , and upper epitaxial layer 140 (See FIG. 8 ).
In embodiments, the image sensor may have the structure of a vertical image sensor.
Lower epitaxial layer 105 may be formed on semiconductor substrate 200 , and a photoresist pattern (not shown) may be formed on lower epitaxial layer 105 and may define an area of first photodiode 110 .
When performing an ion implantation process, ions may be implanted through an opening area of the photoresist pattern, and first photodiode 110 may be formed in a portion of lower epitaxial layer 105 .
In embodiments, first photodiode 110 may be a red photodiode.
After forming first photodiode 110 , the photoresist pattern may be removed, and middle epitaxial layer 115 may be formed on lower epitaxial layer 105 .
A photoresist pattern (not shown) may then be formed on middle epitaxial layer 115 , and may define an area of second photodiode 120 .
When performing an ion implantation process, ions may be implanted through an opening area of the photoresist pattern, and second photodiode 120 may be formed in a portion of middle epitaxial layer 115 . The photoresist pattern for forming second photodiode 120 may be removed.
In embodiments, second photodiode 120 may be a green photodiode.
Subsequently, as vertically projected from a top side, a photoresist pattern (not shown) may be formed such that a portion of middle epitaxial layer 115 corresponding to the area of first photodiode 110 may be exposed, and an ion implantation process may be performed.
Thus, ions may be implanted through an opening of the photoresist pattern, and lower plug 125 , which may be electrically connected to first photodiode 110 beneath lower plug 125 , may be formed in middle epitaxial layer 115 . After that, the photoresist pattern used to form lower plug 125 may be removed.
In embodiments, photodiode structure 130 may thus be completed.
FIG. 2 is a side sectional view showing a configuration after upper epitaxial layer 140 is formed, according to embodiments.
Referring to FIG. 2 , upper epitaxial layer 140 may be grown on middle epitaxial layer 115 , and a photoresist pattern (not shown) may be formed to have an opening at a portion in which isolation layers may be formed.
Trenches 145 may then be formed in upper epitaxial layer 140 at the portion in which the isolation layers may be formed, for example by performing an etching process using the photoresist pattern as an etching mask.
FIG. 3 is a side sectional view showing a configuration after oxide layer 150 is patterned, according to embodiments.
Referring to FIG. 3 , oxide layer 150 may be formed on a surface, for example the entire surface, of upper epitaxial layer 140 while filling trenches 145 .
Photoresist patterns 155 may then be formed on oxide layer 150 .
Photoresist patterns 155 may be formed through a development and exposure process of a photoresist. In embodiments, photoresist patterns 155 may be formed at positions corresponding to trenches 145 and floating diffusion area 153 (See FIG. 8 ).
FIG. 4 is a side sectional view showing a configuration after oxide layer 150 is etched, according to embodiments.
Referring to FIG. 4 , oxide layer 150 may be patterned using photoresist patterns 155 as an etching mask.
Patterned oxide layer 150 may have a shape protruding upward from trenches 145 and floating diffusion area 153 ( FIG. 8 ). Particularly, pattern portions formed at both sides of floating diffusion area 153 may serve as dummy ion implantation mask patterns 157 .
Photoresist pattern 155 may be removed.
FIG. 5 is a side sectional view showing a configuration after ion implantation mask pattern 159 is formed, according to embodiments.
Referring to FIG. 5 , ion implantation mask pattern 159 may be formed in an area of upper epitaxial layer 140 except for area 158 between dummy ion implantation mask patterns 157 .
In embodiments, ion implantation mask pattern 159 may be formed to cover oxide layer 150 on the trench area, a portion of upper epitaxial layer 140 , and a portion of dummy ion implantation mask patterns 157 .
Area 158 between dummy ion implantation mask patterns 157 may be a portion in which floating diffusion area 153 ( FIG. 8 ) may be formed, and the position of dummy ion implantation mask patterns 157 may be positions at which gates may be formed. For reference, dummy ion implantation mask patterns 157 may be removed in a subsequent process.
Dummy ion implantation mask pattern 157 may be an area for defining floating diffusion area 153 ( FIG. 8 ), and ion implantation mask pattern 159 may be an area for blocking ions implanted to form floating diffusion area 153 ( FIG. 8 ).
Thus, dummy ion implantation mask pattern 157 may be formed to have a sufficiently low height for the purpose of satisfying a precise interval of floating diffusion area 153 , e.g., an interval of about 0.25 μm, according to embodiments.
For example, the dummy ion implantation mask pattern 157 may be formed to have a height of about 0.95 μm or less.
Ion implantation mask pattern 159 may be formed as sufficiently high as blocking may be performed in the ion implantation of floating diffusion area 153 ( FIG. 8 ).
For example, ion implantation mask pattern 159 may be formed to have a height of about 1.25 μm or more.
FIG. 6 is a side sectional view showing a configuration after floating diffusion area 153 is formed, according to embodiments.
Referring to FIG. 6 , ions may be implanted into upper epitaxial layer 140 using ion implantation mask pattern 159 and dummy ion implantation mask patterns 157 as an ion implantation mask. As ions are implanted into upper epitaxial layer 140 , floating diffusion area 153 may be formed.
In embodiments, ion implantation energy for forming floating diffusion area 153 may be about 120 to 140 keV.
FIG. 7 is a side sectional view showing a configuration after dummy ion implantation mask patterns 157 and ion implantation mask pattern 159 are removed, according to embodiments.
Referring to FIG. 7 , after forming floating diffusion area 153 , dummy ion implantation mask patterns 157 and ion implantation mask pattern 159 may be removed from upper epitaxial layer 140 through a chemical mechanical polishing (CMP) process.
Isolation layers 160 may thus be finally formed in upper epitaxial layer 140 .
FIG. 8 is a side sectional view showing a configuration after gate 177 and third photodiode 170 are formed, according to embodiments.
Referring to FIG. 8 , after forming isolation layers 160 , third photodiode 170 may be formed in upper epitaxial layer 140 . In embodiments, third photodiode 170 may be a blue photodiode.
According to embodiments, third photodiode 170 may be formed through photoresist and ion implantation processes.
Subsequently, as vertically projected from a top side, a photoresist pattern (not shown) may be formed such that an area of upper epitaxial layer 140 corresponding to lower plug 125 and a portion of upper epitaxial layer 140 corresponding to the area of second photodiode 120 may be exposed, and an ion implantation process may be performed.
Ions may be implanted using the photoresist pattern as an ion implantation mask, and upper plugs 175 electrically connected to lower plug 125 and second photodiode 120 may be formed in upper epitaxial layer 140 . After that, the photoresist pattern for forming the upper plugs 175 may be removed.
Transistor structures, including gates 177 , may be formed in upper epitaxial layer 140 at both sides of floating diffusion area 153 , thereby completing an image sensor.
It may be apparent to those skilled in the art that various modifications and variations may be made to embodiments. Thus, it is intended that embodiments cover modifications and variations thereof within the scope of the appended claims. It is also understood that when a layer is referred to as being “on” or “over” another layer or substrate, it may be directly on the other layer or substrate, or intervening layers may also be present.
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Embodiments relate to an image sensor and a method for manufacturing an image sensor that may prevent a photoresist pattern from remaining on gates by forming a floating diffusion area faster than the gates. According to embodiments, since the gates may not be influenced by an ion implantation process, current characteristics and operation reliability may be enhanced. According to embodiments, the method may include forming dummy ion implantation mask patterns for forming a floating diffusion area over an epitaxial layer and forming an ion implantation mask pattern over the epitaxial layer and at least a portion of the dummy ion implantation mask patterns, so as to form the floating diffusion area by performing an ion implantation process.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a reverse osmosis (RO) water filtration device and, more particularly, to an RO water filtration device with water storage function.
[0003] 2. Description of the Related Art
[0004] Conventional reverse osmosis (RO) water filtration devices with small capacity of treated water under 300 G in the current market need to be equipped with an extra storage tank to meet the demand of flow rate when the faucet is opened. Also because the RO water filtration devices are usually mounted inside kitchen cabinets, the additional storage tank is space-taking and inconvenient to use and the water in the storage tank is easily contaminated by bacteria.
SUMMARY OF THE INVENTION
[0005] An objective of the present invention is to provide a RO water filtration device and a method for operating the RO water filtration device.
[0006] To achieve the foregoing objective, the RO water filtration device includes a body, a first cartridge, an RO cartridge, a storage tank and a second cartridge.
[0007] The body has a water inlet, a filtered water outlet and a waste water outlet formed in a periphery of the body. The filtered water outlet is connected with and communicates with a faucet.
[0008] The first cartridge is mounted inside the body and is connected with and communicates with the water inlet through a channel formed inside the body.
[0009] The RO cartridge is mounted inside the body and has an inlet, an outlet and an RO waste water outlet.
[0010] The inlet is connected with and communicates with the first cartridge through a channel formed inside the body. A pump is mounted to the channel between the RO cartridge and the first cartridge.
[0011] The RO waste water outlet is connected and communicates with the waste water outlet through a channel formed inside the body.
[0012] The storage tank is mounted inside the body, is connected with and communicates with the outlet of the RO cartridge through a channel formed inside the body, and has a liner mounted on an inner wall of the storage tank. The liner is made of a resilient material.
[0013] The second cartridge is mounted inside the body, and is connected with and communicates with the filtered water outlet and the storage tank respectively through two channels formed inside the body. A high-pressure switch is mounted to the channel between the second cartridge and the storage tank to control operation of the pump.
[0014] When the faucet is closed, the pump is operated to fill the storage tank with filtered water until a water pressure of filtered water inside the storage tank sensed by the high-pressure switch reaches a water pressure threshold, and when the faucet is open and a water pressure between the storage tank and the second cartridge sensed by the high-pressure switch drops below the water pressure threshold, the filtered water inside the storage tank pushed out by the liner of the storage tank and filtered water outputted from the RO cartridge flows to the faucet.
[0015] To achieve the foregoing objective, the method for operating an RO water filtration device includes steps of:
closing the faucet; operating the pump at an output water pressure; stopping the pump from operating when a water pressure between the RO cartridge and the faucet reaches a water pressure threshold, wherein the water pressure threshold is lower than the output water pressure, and the storage tank is filled with filtered water at the water pressure threshold and the liner of the storage tank is squeezed by the filtered water inside the storage tank; opening the faucet for a water pressure between the RO cartridge and the faucet to drop; and starting the pump when the water pressure between the RO cartridge and the faucet is below the water pressure threshold, wherein the filtered water in the storage tank pushed out of the storage tank by the liner and the filtered water outputted from the RO cartridge flow to the faucet.
[0021] When compared to conventional techniques, the present invention has the following advantages that because the storage tank and all the cartridges are all mounted inside the body, the issues arising from insufficient space and aesthetic concern can be tackled, production cost can be reduced, and bacteria contamination in the storage tank can be resolved.
[0022] Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a functional block diagram of an RO water filtration device with water storage function in accordance with the present invention;
[0024] FIG. 2 is a schematic top view of the RO water filtration device in FIG. 1 ; and
[0025] FIG. 3 is a cross-sectional view of a storage tank of the RO water filtration device in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0026] With reference to FIGS. 1 and 2 , an RO water filtration device in accordance with the present invention includes a body 100 , a RO filter cartridge 140 , a first cartridge 150 , a second cartridge 160 and a storage tank 170 .
[0027] The body 100 has a water inlet 110 , a filtered water outlet 120 and a waste water outlet 130 . The water inlet 110 and the waste water outlet 130 are mounted in a first lateral portion of the RO water filtration device 100 , and the filtered water outlet 120 is mounted in a second lateral portion opposite to the first lateral portion.
[0028] The first cartridge 150 is mounted inside the body 100 and has a first inlet 151 and a first outlet 152 . The first inlet 151 communicates with the water inlet 110 through a first channel 210 formed inside the body 100 and connected between and communicating with the first inlet 151 and the water inlet. A low-pressure switch 380 is mounted to the first channel 210 . The first outlet 152 communicates with the RO cartridge 140 through a second channel 220 formed inside the body 100 and connected between and communicating with the first cartridge 150 and the RO cartridge 140 . A solenoid valve 320 , a water TDS (total dissolved solids) transducer 330 and a pump 340 are mounted to the second channel 210 , and the pump 340 is electrical connected with the low-pressure switch 380 . The solenoid valve 320 is to control water flows direction and flow speed. The water TDS transducer 330 is to detect any minerals, salts, metals, cations or anions dissolved in water.
[0029] The low-pressure switch 380 has a controller 381 , and the low-pressure switch 380 detects a water pressure into the first channel 210 . When the water pressure is low or no pressure at all, the controller 381 sends a signal to the pump 340 to stop the pump 340 from working.
[0030] The RO cartridge 140 is mounted inside the body 100 and has an inlet 141 , an outlet 142 and a RO waste water outlet 143 . The inlet 141 communicates with the first cartridge 150 through the second channel 220 . The outlet 142 communicates with the storage tank 170 through a third channel 230 . A check valve 310 is mounted into the outlet 142 . The RO waste water outlet 143 communicates with the waste water outlet 130 through a fifth channel 250 formed inside the body 100 and connected between and communicating with the RO waste water outlet 143 and the waste water outlet 130 , and water containing impurities flows out of the waste water outlet 130 through the RO waste water outlet 143 and the fifth channel 250 sequentially.
[0031] The storage tank 170 is mounted inside the body 100 and has a storage tank inlet 172 and a storage tank outlet 173 . The storage tank inlet 172 communicates with the RO cartridge 140 through a third channel 230 formed in the body 100 and connected between the storage tank 170 and the RO cartridge 140 . The storage tank outlet 173 is connected with and communicates with a fourth channel 240 formed in the body 100 and connected between the storage tank 170 and a second cartridge 160 . With reference to FIG. 3 , a liner 171 is mounted on an inner wall of the storage tank 170 and is made of a resilient material.
[0032] The second cartridge 160 is mounted inside the body 100 and has a second inlet 161 and a second outlet 162 . The second inlet 161 is connected with and communicates with the fourth channel 240 . The second outlet 162 is connected with and communicates with the filtered water outlet 120 through the fourth channel 240 .
[0033] A flowmeter 370 , a high-pressure switch 350 , and a filtered water TDS transducer 360 are mounted to the fourth channel 240 . The filtered water TDS transducer 360 is to detect any minerals, salts, metals, cations or anions dissolved in water. A controller 351 is mounted into the high-pressure switch 350 , and the high-pressure switch 350 is electrical connected with the pump 340 . The high-pressure switch 350 senses the water pressure in the storage tank 170 and is switched to be open or closed by the water pressure in the storage tank 170 , and respectively sends a start signal and a stop signal to the controller 351 when the water pressure in the storage tank 170 is below 40 psi and when the water pressure in the storage tank 170 reaches 40 psi.
[0034] The filtered water outlet 120 communicates with the second outlet 162 of the second cartridge 160 through a sixth channel 260 formed inside the body 100 and connected between and communicating with the filtered water outlet 120 and the second outlet 160 , and is connected with and communicates with a faucet 400 .
[0035] Operation of the RO water filtration device 100 is described as follows. Water to be filtered enters the water inlet 110 of the RO water filtration device 100 , and flows in the first cartridge 150 through the first channel 210 . Water filtered by the first cartridge 150 flows out of the first cartridge 150 through the first outlet 152 , then flows through the second channel 220 , the solenoid valve 320 , the TDS transducer 330 and the pump 340 . After the pressure of water in the pump 340 is boosted to be stable, water in the pump 340 flows out and then enters the RO filter cartridge 140 through the inlet 141 of the RO filter cartridge 140 . Impurities in water pass through the osmosis membrane and are removed and filtered water flows out of the outlet 142 . Meanwhile, water containing impurities flows to the waste water outlet 130 of the RO water filtration device 100 through the RO waste water outlet 143 and the fifth channel 250 . Filtered water flow from the outlet 142 flows through the third channel 230 and then enters the storage tank 170 through the storage tank inlet 172 . A portion of filtered water is stored in the storage tank 170 , the remaining portion of filtered water flows out of the storage tank 170 through the storage tank outlet 173 , and then enters the second cartridge 160 through the fourth channel 240 . Filtered water enters the second cartridge 160 through the second inlet 161 and reacts with the second cartridge 160 , and water flowing out of the second outlet 162 further flows to the faucet 400 .
[0036] In normal use, water pressure between the pump 340 and the RO cartridge 140 is 70 psi. After the faucet 400 is closed, water is detained inside the RO water filtration device 100 , and the pump 340 is started operating to pump out the water in the pump 340 . Filtered water flowing out of the RO cartridge 140 flows in the storage tank 170 to fill the storage tank 170 and squeeze the liner 171 . After the storage tank 170 is fully filled, the water pressure acted on the liner 171 of the storage tank 170 is 40 psi and filtered water further enters the fourth channel 240 . When the water pressure of the fourth channel 240 detected by the high-pressure switch 350 reaches 40 psi, the controller 351 receives the stop signal from the high-pressure switch 350 and sends a signal to the pump 340 to stop the pump 340 from working.
[0037] When the faucet 400 is opened, filtered water flows out of the faucet 400 , water pressure between the RO cartridge 140 and the faucet 400 drops. Once the water pressure of the fourth channel 240 sensed by the high-pressure switch 350 drops below 40 psi, the controller 351 sends another signal to the pump 340 for the pump 340 to start working. Further, as the pressure acted on the liner 171 of the storage tank 170 is 40 psi, which is higher than the pressure in the fourth channel 240 , the liner 171 releases its elastic force to push the filtered water out of the storage tank 170 . Both filtered water from the storage tank 170 and filtered water outputted from the outlet 142 flows to the faucet 400 to increase water flow out of the faucet 400 .
[0038] As the storage tank 170 and all the cartridges 140 , 150 , 160 are all mounted inside the body 100 , the issues arising from insufficient space and aesthetic concern can be tackled, production cost can be reduced, and bacteria contamination in the storage tank can be resolved.
[0039] Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only. Changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
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A reverse osmosis (RO) water filtration device includes a body, a RO cartridge, a first cartridge, a second cartridge and a storage tank all mounted inside the body. Water to be filtered sequentially goes through a water inlet of the RO water filtration device, the first cartridge, the RO cartridge, the storage tank, the second cartridge, and a faucet to get the water filtered. The storage tank provides additional water supply when the pressure between the faucet and RO cartridge is below the water pressure inside the storage tank to increase water volume upon opening a faucet.
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BACKGROUND
[0001] The electrophoretic display is a non-emissive device based on the electrophoresis phenomenon influencing charged pigment particles suspended in a solvent. This general type of display was first proposed in 1969. An electrophoretic display typically comprises a pair of opposed, spaced-apart plate-like electrodes, with spacers predetermining a certain distance between the electrodes. One of the electrodes is typically transparent. A dispersion composed of a colored solvent and suspended charged pigment particles is enclosed between the two plates.
[0002] When a voltage difference is imposed between the two electrodes, the pigment particles migrate to one side by attraction to the plate of polarity opposite that of the pigment particles. Thus the color showing at the transparent plate may be determined by selectively charging the plates to be either the color of the solvent or the color of the pigment particles. Reversal of plate polarity will cause the particles to migrate back to the opposite plate, thereby reversing the color. Intermediate color density (or shades of grey) due to intermediate pigment density at the transparent plate may be obtained by controlling the plate charge through a range of voltages.
[0003] There are several types of electrophoretic displays available in the art, for example, the partition-type electrophoretic display (see M. A Hopper and V. Novotny, IEEE Trans. Electr. Dev., Vol ED 26, No. 8, pp 1148-1152 (1979)) and the microencapsulated electrophoretic display (as described in U.S. Pat. Nos. 5,961,804 and 5,930,026). In a partition-type electrophorectic display, there are partitions between the two electrodes for dividing the space into smaller cells in order to prevent undesired movements of the particles such as sedimentation. The microencapsulated electrophoretic display has a substantially two dimensional arrangement of microcapsules each having therein an electrophoretic composition of a dielectric fluid and a dispersion of charged pigment particles that visually contrast with the dielectric solvent.
[0004] Furthermore, an improved electrophoretic display (EPD) technology was recently disclosed in the co-pending applications, U.S. Ser. No. 09/518,488, filed on Mar. 3, 2000, U.S. Ser. No. 09/759,212, filed on Jan. 11, 2001, U.S. Ser. No. 09/606,654, filed on Jun. 28, 2000 and U.S. Ser. No. 09/784,972, filed on Feb. 25, 2001, all of which are incorporated herein by reference. The improved electrophoretic display comprises cells formed from microcups of well-defined shape, size, and aspect ratio and filled with charged pigment particles dispersed in a dielectric solvent.
SUMMARY OF THE INVENTION
[0005] Multifunctional UV curable compositions have been employed to fabricate the microcup array for the improved electrophoretic display. However, the microcup structure formed tends to be quite brittle. The internal stress in the cups due to the high degree of crosslinking and shrinkage often results in undesirable cracking and delamination of the microcups from the conductor substrate during demolding. The microcup array prepared from the multifunctional UV curable compositions also showed a poor flexure resistance.
[0006] It has now been found that resistance toward flexure or stress may be significantly reduced if a rubber component is incorporated into the microcup composition. Two other key properties: demoldability during microembossing and adhesion between the sealing layer and the microcups have also been considerably improved with the composition containing this additional rubber component.
[0007] Suitable rubber materials for this purpose include SBR (styrene-butadiene rubber), PBR (polybutadiene rubber), NBR (acrylonitrile-butadiene rubber), SBS (styrene-butadiene-styrene block copolymer), SIS (styrene-isoprene-styrene block copolymer), and their derivatives. Particularly useful are functionalized rubbers such as polybutadiene dimethacrylate (CN301 and CN302 from Sartomer, Ricacryl 3100 from Ricon Resins Inc.), graft (meth)acrylated hydrocarbon polymer (Ricacryl 3500 and Ricacryl 3801 from Ricon Resins, Inc.), and methacrylate terminated butadiene-acrylonitrile copolymers (Hycar VTBNX 1300×33, 1300×43 from B F Goodrich).
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] [0008]FIGS. 1A and 1B show the basic processing steps for preparing the microcups involving imagewise photolithographic exposure through a photomask of conductor film coated with a thermoset precursor (“top exposure”).
[0009] [0009]FIGS. 2A and 2B show alternative processing steps for preparing the microcups involving imagewise photolithographic exposure of the base conductor film coated with a thermoset precursor, in which the base conductor pattern on a transparent substrate serves a substitute for a photomask and is opaque to the radiation (“bottom exposure”).
[0010] [0010]FIGS. 3A and 3B show alternative processing steps for preparing the microcups involving imagewise photolithographic exposure combining the top and bottom exposure principles, whereby the walls are cured in one lateral direction by top photomask exposure and in the perpendicular lateral direction by bottom exposure through the opaque base conductor film (“combined exposure”).
DETAILED DESCRIPTION OF THE INVENTION
[0011] Unless defined otherwise in this specification, all technical terms are used herein according to their conventional definitions as they are commonly used and understood by those of ordinary skill in the art. The terms “microcup”, “cell”, “well-defined”, “aspect ratio” and “imagewise exposure” in the context of the present application are as defined in the copending applications identified above, as are the dimensions of the microcups.
[0012] The microcups may be prepared by microembossing or by photolithography.
[0013] I. Preparation of Microcups by Microembossing
[0014] Preparation of the Male Mold
[0015] The male mold may be prepared by any appropriate method, such as a diamond turn process or a photoresist process followed by either etching or electroplating. A master template for the male mold may be manufactured by any appropriate method, such as electroplating. With electroplating, a glass base is sputtered with a thin layer (typically 3000 Å) of a seed metal such as chrome inconel. It is then coated with a layer of photoresist and exposed to UV. A mask is placed between the UV and the layer of photoresist. The exposed areas of the photoresist become hardened. The unexposed areas are then removed by washing them with an appropriate solvent. The remaining hardened photoresist is dried and sputtered again with a thin layer of seed metal. A master is then ready for electroforming. A typical material used for electroforming is nickel cobalt. Alternatively, the master can be made of nickel by electroforming or electroless nickel deposition as described in “Continuous manufacturing of thin cover sheet optical media”, SPIE Proc. Vol. 1663, pp.324 (1992). The floor of the mold is typically between about 50 to 400 microns. The master can also be made using other microengineering techniques including e-beam writing, dry etching, chemical etching, laser writing or laser interference as described in “Replication techniques for micro-optics”, SPIE Proc. Vol.3099, pp76-82 (1997). Alternatively, the mold can be made by photomachining, using plastics, ceramics or metals.
[0016] The male mold thus prepared typically has protrusions between about 1 to 500 microns, preferably between about 2 to 100 microns, and most preferably about 4 to 50 microns. The male mold may be in the form of a belt, a roller, or a sheet. For continuous manufacturing, the belt type of mold is preferred.
[0017] Micro-cup Formation
[0018] Micro-cups may be formed either in a batchwise process or in a continuous roll-to-roll process as disclosed in the co-pending application, U.S. Ser. No. 09/784,972, filed on Feb. 25, 2001. The latter offers a continuous, low cost, high throughput manufacturing technology for production of compartments for use in electrophoretic or liquid crystal displays. Prior to applying a UV curable resin composition, the mold may be prepared with a mold release to aid in the demolding process, if desired. The UV curable resin may be degassed prior to dispensing and may optionally contain a solvent. The solvent, if present, readily evaporates. The UV curable resin is dispensed by any appropriate means, such as coating, dipping, pouring and the like, over the male mold. The dispenser may be moving or stationary. A conductor film is overlaid on the UV curable resin. Examples of suitable conductor films include transparent conductor ITO on plastic substrates such as polyethylene terephthalate, polyethylene naphthate, polyaramid, polyimide, polycycloolefin, polysulfone, epoxy and their composites. Pressure may be applied, if necessary, to ensure proper bonding between the resin and the plastic and to control the thickness of the floor of the micro-cups. The pressure may be applied using a laminating roller, vacuum molding, press device or any other like means. If the male mold is metallic and opaque, the plastic substrate is typically transparent to the actinic radiation used to cure the resin. Conversely, the male mold can be transparent and the plastic substrate can be opaque to the actinic radiation. To obtain good transfer of the molded features onto the transfer sheet, the conductor film needs to have good adhesion to the UV curable resin, which should have a good release property from the mold surface.
[0019] II. Preparation of Microcup Array by Photolithography
[0020] The photolithographic processes for preparation of the microcup array are described in FIGS. 1, 2 and 3 .
[0021] II(a) Top Exposure
[0022] As shown in FIGS. 1A and 1B, the microcup array 10 may be prepared by exposure of a radiation curable material 11 a coated by known methods onto a conductor electrode film 12 to UV light (or alternatively other forms of radiation, electron beams and the like) through a mask 16 to form walls 11 b corresponding to the image projected through the mask 16 . The base conductor film 12 is preferably mounted on a supportive substrate base web 13 , which may comprise a plastic material.
[0023] In the photomask 16 in FIG. 1A, the dark squares 14 represent the opaque area and the space between the dark squares represents the opening (transparent) area 15 of the mask 16 . The UV radiates through the opening area 15 onto the radiation curable material 11 a . The exposure is preferably directly onto the radiation curable material 11 a , i.e., the UV does not pass through the substrate 13 or base conductor 12 (top exposure). For this reason, neither the substrate 13 nor the conductor 12 needs to be transparent to the UV or other radiation wavelengths employed.
[0024] As shown in FIG. 1B, The exposed areas 11 b become hardened and the unexposed areas 11 c (protected by the opaque area 14 of the mask 16 are then removed by an appropriate solvent or developer to form the microcups 17 . The solvent or developer is selected from those commonly used for dissolving or reducing the viscosity of radiation curable materials such as methylethylketone, toluene, acetone, isopropanol or the like.
[0025] II(b) Bottom Exposure or Combined Exposure
[0026] Two alternative methods for the preparation of the microcup array of the invention by imagewise exposure are illustrated in FIGS. 2A and 2B and 3 A and 3 B. These methods employ UV exposure through the substrate web, using the conductor pattern as a mask.
[0027] Turning first to FIG. 2A, the conductor film 22 used is pre-patterned to comprise cell base electrode portions 24 corresponding to the floor portions of the microcups 27 . The base portions 24 are opaque to the UV wavelength (or other radiation) employed. The spaces 25 between conductor base portions 22 are substantially transparent or transmissive to the UV light. In this case, the conductor pattern serves as a photomask. The radiation curable material 21 a is coated upon the substrate 23 and conductor 22 as described in FIG. 2A. The material 21 a is exposed by UV light projected “upwards” (through substrate 23 ) and cured where not shielded by the conductor 22 , i.e., in those areas corresponding to the space 25 . As shown in FIG. 2B, the uncured material 21 c is removed from the unexposed areas as described above, leaving the cured material 21 b to form the walls of the microcups 27 .
[0028] [0028]FIG. 3A illustrates a combination method which uses both the top and bottom exposure principals to produce the microcup array 30 of the invention. The base conductor film 32 is also opaque and line-patterned. The radiation curable material 31 a , which is coated on the base conductor 32 and substrate 33 , is exposed from the bottom through the conductor line pattern 32 which serves as the first photomask. A second exposure is performed from the “top” side through the second photomask 36 having a line pattern perpendicular to the conductor lines 32 . The spaces 35 between the lines 34 are substantially transparent or transmissive to the UV light. In this process, the wall material 31 b is cured from the bottom up in one lateral orientation, and cured from the top down in the perpendicular direction, joining to form an integral microcup 37 .
[0029] As shown in FIG. 3B, the unexposed area is then removed by a solvent or developer as described above to reveal the microcups 37 .
[0030] The radiation curable material used in the processes described above is a thermoplastic or thermoset precursor, such as multifunctional acrylate or methacrylate, vinylether, epoxide and their oligomers, polymers and the like. Multifunctional acrylates and their oligomers are the most preferred. A combination of multifunctional epoxide and multifunctional acrylate is also very useful to achieve desirable physico-mechanical properties.
[0031] It has now been found that addition of a rubber component significantly improves the quality of the microcups, such as resistance toward flexure or stress, demoldability during the microembossing step, and adhesion between the sealing layer and the microcups.
[0032] Suitable rubber materials have a Tg (glass transition temperature) lower than 0° C. Unsaturated rubber materials are preferred and rubber materials having uncapped or side chain unsaturated groups such as vinyl, acrylate, methacrylate, allyl groups are particularly preferred. More specifically, suitable rubber materials include SBR (styrene-butadiene rubber), PBR (polybutadiene rubber), NBR (acrylonitrile-butadiene rubber), SBS (styrene-butadiene-styrene block copolymer), SIS (styrene-isoprene-styrene block copolymer), and their derivatives. Particularly useful are functionalized rubbers such as polybutadiene dimethacrylate (CN301 and CN302 from Sartomer, Ricacryl 3100 from Ricon Resins Inc.), graft (meth)acrylated hydrocarbon polymer (Ricacryl 3500 and Ricacryl 3801 from Ricon Resins, Inc.), and methacrylate terminated butadiene-acrylonitrile copolymers (Hycar VTBNX 1300×33, 1300×43 from B F Goodrich).
[0033] The percentage of rubber component in the UV curable formulation can be in the range from 1 wt-% to 30 wt-%, preferably from 5 wt-% to 20 wt-%, even more preferably from 8-15 wt-%. The rubber components can be soluble or dispersible in the formulation. Ideally, the rubber component is soluble in the formulation before UV curing and phase separates into microdomains after UV curing.
EXAMPLES
Example 1
Microcup Composition Without Rubber
[0034] 35 parts by weight of Ebercryl® 600 (UCB), 40 parts of SR-399 (Sartomer®), 10 parts of Ebecryl 4827 (UCB), 7parts of Ebecryl 1360 (UCB), 8 parts of HDDA (UCB), and 0.05 parts of Irgacure® 369 (Ciba Specialty Chemicals), 0.01 parts of isopropyl thioxanthone (Aldrich) were mixed homogeneously and used to prepare the microcup arrary by either the microembossing or photolithographic process.
Example 2-7
Rubber-containing Microcup Compositions
[0035] The same procedure as Example 1 was repeated except that 6, 7, 8, 10, 11 or 14 phr (parts per hundred resin) of Hycar® VTBNX 1300×33 were added to the compositions of Examples 2-7, respectively.
[0036] Comparison of Flexure Resistance
[0037] The microcup compositions of Examples 1-7 were coated onto 2 mil PET film with a targeted dry thickness of about 30 μm, covered by untreated PET, and then cured for 20 seconds under UV light at an intensity of ˜5 mW/cm 2 . The coated samples were then 90 degree hand bended to determine the flexure resistance, after the untreated PET was removed. It was found that the flexure resistance of formulations containing more than 8 phr of Hycar VTBNX 1300×33 (Examples 4, 5, 6, 7) was improved significantly (Table 1).
[0038] Comparison of Release Properties Between the Cured Microcup and the Ni—Co Microembossing Male Mold
[0039] The microcup compositions of the Example 1-7 were coated onto 2 mil PET film with a targeted thickness of about 50 μm, microembossed with a Ni—Co male mold of 60×60×35 μm with partition lines of 10 μm width, UV cured for 20 seconds, and removed from the mold with a 2″ peeling bar at a speed of about 4-5 ft/min. The formulations containing more than 6 phr of rubber (Examples 2-7) showed significantly improved demoldability (Table 1). Little defect or contamination on the mold was observed for formulations containing 10-15 phr of rubber (Examples 5, 6, 7) after at least 100 molding-demolding cycles
[0040] Comparison of Adhesion Between the Microcup and the Sealing Layers
[0041] The microcup compositions of Example 1-7 were coated onto 2 mil PET film with a targeted dry thickness of about 30 μm, covered by untreated PET, and then cured for 20 seconds under UV light at an intensity of ˜5 mW/cm 2 . The untreated PET cover sheet was removed. A 15 wt % solution of the sealing material (Kraton® FG-1901X from Shell) in 20/80 (v/v) toluene/hexane was then coated onto the cured microcup layer and dried in 60° C. oven for 10 minutes. The thickness of the dried sealing layer was controlled to be about 5 μm. A 3M 3710 Scotch® tape was laminated at room temperature onto the sealing layer by a Eagle® 35 laminator from GBC at the heavy gauge setting. The T-peel adhesion force was then measured by Instron® at 500 mm/min. The adhesion forces listed in Table 1 were the average of at least 5 measurements. It was found that adhesion between the sealing layer and the cured microcup layer was significantly improved by incorporating rubber into the microcup.
TABLE 1 T Peel Adhesion Between the Cured Microcup Material and the Sealing Layer Hycar Adhesion VTBNX (peel) to Example 1300 × 33 sealing layer Flexure Release Number (phr) (gm/12.5 mm) Resistance from the mold 1 0 431 +/− 33 poor, bending fair, some line defects broke 2 6 513 +/− 12 fair, bending Good, no line broke defect after 50 cycles 3 7 — fair-good, good bending line broke 4 8 — Good, bending good- mark excellent 5 10 543 +/− 20 Excellent, no Excellent, no bending mark defect after 100 cycles 6 11 — excellent excellent 7 14 536 +/− 12 excellent excellent
Example 8
Microcup Composition Without Rubber
[0042] 36 parts by weight of Ebercryl® 830 (UCB), 9 parts of SR- 399 (Sartomer®), 1.2 parts of Ebecryl 1360 (UCB), 3 parts of HDDA (UCB), 1.25 parts of Irgacure® 500 (Ciba Specialty Chemicals), and 25 parts of MEK (Aldrich) were mixed homogeneously and used to prepare the microcup array by microembossing as described previously, except that the UV curing time was 1 minute. This example showed some defect on the microcup or contamination on a Ni—Co male mold of 60×60×50 μm with 10 μm partition lines after about 10 molding-demolding cycles.
Example 9
Microcup Composition With Rubber
[0043] The same procedure as in Example 8 was repeated except that 5.47 parts of poly(butadiene-co-acrylonitrile) diacrylate (Monomer-Polymer & Dajac Labs, Inc.) was added to the composition. No observable defect on the microcup array or contamination on the Ni—Co male mold was found after about 10 molding-demolding cycles.
Example 10
Pigment Dispersion
[0044] 6.42 Grams of Ti Pure R706 was dispersed with a homogenizer into a solution containing 1.94 grams of Fluorolink® D from Ausimont, 0.22 grams of Fluorolink® 7004 also from Ausimont, 0.37 grams of a fluorinated copper phthalocyanine dye from 3M, and 52.54 grams of perfluoro solvent HT-200 (Ausimont).
Example 11
Pigment Dispersion
[0045] The same as in Example 10, except the Ti Pure R706 and Fluorolink were replaced by polymer coated TiO 2 particles PC-9003 from Elimentis (Hihstown, N.J.) and Krytox® (Du Pont) respectively.
Example 12
Microcup Sealing and Electrophoretic Cell
[0046] The electrophoretic fluid prepared in Examples 10 was diluted with a volatile perfluoro cosolvent (FC-33 from 3M) and coated onto a microcup array containing 11 phr of Hycar® VTBNX 1300×33 (Example 6) on a ITO/PET conductor film. The volatile cosolvent was allowed to evaporate to expose a partially filled microcup array. A 7.5% solution of polyisoprene in heptane was then overcoated onto the partially filled cups by a Universal Blade Applicator with an opening of 6 mil. The overcoated microcups were then dried at room temperature. A seamless sealing layer of about 5-6 microns thickness with acceptable adhesion was formed on the microcup array. No observable entrapped air bubbles in the sealed microcups were found under microscope. The sealed microcup array was then post treated by UV radiation or thermal baking to further improve the barrier properties. A second ITO/PET conductor precoated with an adhesive layer was laminated onto the sealed microcups. The electrophoretic cell showed satisfactory switching performance with good flexure resistance. No observable weight loss was found after being aged in a 66° C. oven for 5 days.
Example 13
Microcup Sealing and Electrophoretic Cell
[0047] The electrophoretic fluid prepared in Example 11 was diluted with a volatile perfluoro cosolvent (FC-33 from 3M) and coated onto a microcup array containing 12 phr of Hycar® VTBNX 1300×33 on a ITO/PET conductor film. The volatile cosolvent was allowed to evaporate to expose a partially filled microcup array. A 7.5% solution of polyisoprene in heptane was then overcoated onto the partially filled cups by a Universal Blade Applicator with an opening of 6 mil. The overcoated microcups were then dried at room temperature. A seamless sealing layer of about 5-6 microns thickness with acceptable adhesion was form on the microcup array. No observable entrapped air bubbles in the sealed microcups were found under microscope. The sealed microcup array was then post treated by UV radiation or thermal baking to further improve the barrier properties. A second ITO/PET conductor precoated with an adhesive layer was laminated onto the sealed microcups. The electrophoretic cell showed satisfactory switching performance with good flexure resistance. No observable weight loss was found after aged in a 66° C. oven for 5 days.
[0048] While the present invention has been described with reference to the specific embodiments thereof, it should be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation, materials, compositions, processes, process step or steps, to the objective, spirit and scope of the present invention. All such modifications are intended to be within the scope of the claims appended hereto. For example, it should be noted that the method of the invention for making microcups may also be used for manufacturing microcup arrays for liquid crystal displays. Similarly, the microcup selective filling, sealing and ITO laminating methods of the invention may also be employed in the manufacture of liquid crystal displays.
[0049] It is therefore wished that this invention to be defined by the scope of the appended claims as broadly as the prior art will permit, and in view of the specification.
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This invention relates to a novel composition suitable for use in the manufacture of electrophoretic display cells. The mechanical properties of the cells are significantly improved with this composition in which a rubber material is incorporated.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to virus scanning in a networked environment.
2. Related Art
Computer networking and the Internet in particular offer end users unprecedented access to information of all types on a global basis. Access to information can be as simple as connecting some type of computing device using a standard phone line to a network. With the proliferation of wireless communication, users can now access computer networks from practically anywhere.
Connectivity of this magnitude has magnified the impact of computer viruses. Viruses such as “Melissa” and “I love you” had a devastating impact on computer systems worldwide. Costs for dealing with viruses are often measured in millions and tens of millions of dollars. Recently it was shown that hand-held computing devices are also susceptible to viruses.
Virus protection software can be very effective in dealing with viruses, and virus protection software is widely available for general computing devices such as personal computers. There are, however, problems unique to specialized computing devices, such as filers (devices dedicated to storage and retrieval of data). Off-the-shelf virus protection software will not run on a specialized computing device unless it is modified to do so, and it can be very expensive to rewrite software to work on another platform.
A first known method is to scan for viruses at the data source. When the data is being provided by a specialized computing device the specialized computing device must be scanned. Device-specific virus protection software must be written in order to scan the files on the device.
While this first known method is effective in scanning files for viruses, it suffers from several drawbacks. First, a company with a specialized computing device would have to dedicate considerable resources to creating virus protection software and maintaining up-to-date data files that protect against new viruses as they emerge.
Additionally, although a manufacturer of a specialized computing device could enlist the assistance of a company that creates mainstream virus protection software to write the custom application and become a licensee this would create other problems, such as reliance on the chosen vendor of the anti-virus software, compatibility issues when hardware upgrades are effected, and a large financial expense.
A second known method for protecting against computer viruses is to have the end user run anti-virus software on their client device. Anti-virus software packages are offered by such companies as McAfee and Symantec. These programs are loaded during the boot stage of a computer and work as a background job monitoring memory and files as they are opened and saved.
While this second known method is effective at intercepting and protecting the client device from infection, it suffers from several drawbacks. It places the burden of detection at the last possible link in the chain. If for any reason the virus is not detected prior to reaching the end user it is now at the computing device where it will do the most damage (corrupting files and spreading to other computer users and systems).
It is much better to sanitize a file at the source from where it may be delivered to millions of end users rather than deliver the file and hope that the end user is pre-pared to deal with the file in the event the file is infected. End users often have older versions of anti-virus software and/or have not updated the data files that ensure the software is able to protect against newly discovered viruses, thus making detection at the point of mass distribution even more critical.
Also, hand-held computing devices are susceptible to viruses, but they are poorly equipped to handle them. Generally, hand-held computing devices have very limited memory resources compared to desktop systems. Dedicating a portion of these resources to virus protection severely limits the ability of the hand-held device to perform effectively. Reliable virus scanning at the information source is the most efficient and effective method.
Protecting against viruses is a constant battle. New viruses are created everyday requiring virus protection software manufacturers to come up with new data files (solution algorithms used by anti-virus applications). By providing protection at the source of the file, viruses can be eliminated more efficiently and effectively.
Security of data in general is important. Equally important is the trust of the end user. This comes from the reputation that precedes a company, and companies that engage in web commerce often live and die by their reputation. Just like an end user trusts that the credit card number they have just disclosed for a web-based sales transaction is secure they want files they receive to be just as secure.
Accordingly, it would be desirable to provide a technique for scanning specialized computing devices for viruses and other malicious or unwanted content that may need to be changed, deleted, or otherwise modified.
SUMMARY OF THE INVENTION
The invention provides a method and system for scanning specialized computing devices (such as filers) for viruses. In a preferred embodiment, a filer is connected to one or more supplementary computing devices that scan requested files to ensure they are virus free prior to delivery to end users. When an end user requests a file from the filer the following steps occur: First, the filer determines whether the file requested must be scanned before delivery to the end user. Second, the filer opens a channel to one of the external computing devices and sends the filename. Third, the external computing device opens the file and scans it. Fourth, the external computing device notifies the filer the status of the file scan operation. Fifth, the filer sends the file to the end user provided the status indicates it may do so.
This system is very efficient and effective as a file needs only to be scanned one time for a virus unless the file has been modified or new data files that protect against new viruses have been added. Scan reports for files that have been scanned may be stored in one or more of the external computing devices, in one or more filers, and some portion of a scan report may be delivered to end users.
In alternative embodiments of the invention one or more of the external computing devices may be running other supplementary applications, such as file compression and encryption, independently or in some combination.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a block diagram of a system for decentralized appliance virus scanning.
FIG. 2 shows a process flow diagram for a system for decentralized virus scanning
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the following description, a preferred embodiment of the invention is described with regard to preferred process steps and data structures. Those skilled in the art would recognize after perusal of this application that embodiments of the invention can be implemented using one or more general purpose processors or special purpose processors or other circuits adapted to particular process steps and data structures described herein, and that implementation of the process steps and data structures described herein would not require undue experimentation or further invention.
Lexicography
The following terms refer or relate to aspects of the invention as described below. The descriptions of general meanings of these terms are not intended to be limiting, only illustrative.
Virus—in general, a manmade program or piece of code that is loaded onto a computer without the computer user's knowledge and runs against their wishes. Most viruses can also replicate themselves, and the more dangerous types of viruses are capable of transmitting themselves across networks and bypassing security systems. client and server—in general, these terms refer to a relationship between two devices, particularly to their relationship as client and server, not necessarily to any particular physical devices. For example, but without limitation, a particular client device in a first relationship with a first server device, can serve as a server device in a second relationship with a second client device. In a preferred embodiment, there are generally a relatively small number of server devices servicing a relatively larger number of client devices. client device and server device—in general, these terms refer to devices taking on the role of a client device or a server device in a client-server relationship (such as an HTTP web client and web server). There is no particular requirement that any client devices or server devices must be individual physical devices. They can each be a single device, a set of cooperating devices, a portion of a device, or some combination thereof. For example, but without limitation, the client device and the server device in a client-server relation can actually be the same physical device, with a first set of software elements serving to perform client functions and a second set of software elements serving to perform server functions. web client and web server (or web site)—as used herein the terms “web client” and “web server” (or “web site”) refer to any combination of devices or software taking on the role of a web client or a web server in a client-server environment in the internet, the world wide web, or an equivalent or extension thereof. There is no particular requirement that web clients must be individual devices. They can each be a single device, a set of cooperating devices, a portion of a device, or some combination thereof (such as for example a device providing web server services that acts as an agent of the user).
As noted above, these descriptions of general meanings of these terms are not intended to be limiting, only illustrative. Other and further applications of the invention, including extensions of these terms and concepts, would be clear to those of ordinary skill in the art after perusing this application. These other and further applications are part of the scope and spirit of the invention, and would be clear to those of ordinary skill in the art, without further invention or undue experimentation.
System Elements
FIG. 1 shows a block diagram of a system for decentralized appliance virus scanning.
A system 100 includes a client device 110 associated with a user 111 , a communications network 120 , a filer 130 , and a processing cluster 140 .
The client device 110 includes a processor, a main memory, and software for executing instructions (not shown, but understood by one skilled in the art). Although the client device 110 and filer 130 are shown as separate devices there is no requirement that they be physically separate.
In a preferred embodiment, the communication network 120 includes the Internet. In alternative embodiments, the communication network 120 may include alternative forms of communication, such as an intranet, extranet, virtual private network, direct communication links, or some other combination or conjunction thereof.
A communications link 115 operates to couple the client device 110 to the communications network 120 .
The filer 130 includes a processor, a main memory, software for executing instructions (not shown, but understood by one skilled in the art), and a mass storage 131 . Although the client device 110 and filer 130 are shown as separate devices there is no requirement that they be separate devices. The filer 130 is connected to the communications network 120 .
The mass storage 131 includes at least one file 133 that is capable of being requested by a client device 110 .
The processing cluster 140 includes one or more cluster device 141 each including a processor, a main memory, software for executing instructions, and a mass storage (not shown but understood by one skilled in the art). Although the filer 130 and the processing cluster 140 are shown as separate devices there is no requirement that they be separate devices.
In a preferred embodiment the processing cluster 140 is a plurality of personal computers in an interconnected cluster capable of intercommunication and direct communication with the filer 130 .
The cluster link 135 operates to connect the processing cluster 140 to the filer 130 . The cluster link 135 may include non-uniform memory access (NUMA), or communication via an intranet, extranet, virtual private network, direct communication links, or some other combination or conjunction thereof.
Method of Operation
FIG. 2 shows a process flow diagram for a system for decentralized appliance virus scanning.
A method 200 includes a set of flow points and a set of steps. The system 100 performs the method 200 . Although the method 200 is described serially, the steps of the method 200 can be performed by separate elements in conjunction or in parallel, whether asynchronously, in a pipelined manner, or otherwise. There is no particular requirement that the method 200 be performed in the same order in which this description lists the steps, except where so indicated.
At a flow point 200 , the system 100 is ready to begin performing the method 200 .
At a step 201 , a user 111 utilizes the client device 110 to initiate a request for a file 133 . The request is transmitted to the filer 130 via the communications network 120 . In a preferred embodiment the filer 130 is performing file retrieval and storage at the direction of a web server (not shown but understood by one skilled in the art).
At a step 203 , the filer 130 receives the request for the file 133 and sends the file ID and path of the file 133 to the processing cluster 140 where it is received by one of the cluster device 141 .
At a step 205 , the cluster device 141 uses the file ID and path to open the file 133 in the mass storage 131 of the filer 130 .
At a step 207 , the cluster device 141 scans the file 133 for viruses. In a preferred embodiment, files are tasked to the processing cluster 140 in a round robin fashion. In alternative embodiments files may be processed individually by a cluster device 141 , by multiple cluster device 141 simultaneously, or some combination thereof. Load balancing may be used to ensure maximum efficiency of processing within the processing cluster 140 .
There are several vendors offering virus protection software for personal computers, thus the operator of the filer 130 may choose whatever product they would like to use. They may even use combinations of vendors' products in the processing cluster 140 . In an alternative embodiment of the invention, continual scanning of every file 133 on the filer 130 may take place.
The processing cluster 140 is highly scalable. The price of personal computers is low compared to dedicated devices, such as filers, therefore this configuration is very desirable. Additionally, a cluster configuration offers redundant systems availability in case a cluster device 141 fails—failover and takeover is also possible within the processing cluster.
At a step 209 , the cluster device 141 transmits a scan report to the filer 130 . The scan report primarily reports whether the file is safe to send. Further information may be saved for statistical purposes (for example, how many files have been identified as infected, was the virus software able to sanitize the file or was the file deleted) to a database. The database may be consulted to determine whether the file 133 needs to be scanned before delivery upon receipt of a subsequent request. If the file 133 has not changed since it was last scanned and no additional virus data files have been added to the processing cluster, the file 133 probably does not need to be scanned. This means the file 133 can be delivered more quickly.
Other intermediary applications may also run separately, in conjunction with other applications, or in some combination thereof within the processing cluster 140 . Compression and encryption utilities are some examples of these applications. These types of applications, including virus scanning, can be very CPU intensive, thus outsourcing can yield better performance by allowing a dedicated device like a filer to do what it does best and farm out other tasks to the processing cluster 140 .
At a step 211 , the filer 130 transmits or does not transmit the file 133 to the client 110 based on its availability as reported following the scan by the processing cluster 140 . Some portion of the scan report may also be transmitted to the user.
At this step, a request for a file 133 has been received, the request has been processed, and if possible a file 133 has been delivered. The process may be repeated at step 201 for subsequent requests.
Generality of the Invention
The invention has wide applicability and generality to other aspects of processing requests for files.
The invention is applicable to one or more of, or some combination of, circumstances such as those involving:
file compression; file encryption; and general outsourcing of CPU intensive tasks from dedicated appliances to general purpose computers.
ALTERNATIVE EMBODIMENTS
Although preferred embodiments are disclosed herein, many variations are possible which remain within the concept, scope, and spirit of the invention, and these variations would become clear to those skilled in the art after perusal of this application.
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The invention provides a method and system for scanning specialized computing devices for viruses. In a preferred embodiment, a filer is connected to one or more supplementary computing devices that scan requested files to ensure they are virus free prior to delivery to end users. When an end user requests a file the following steps occur: First, the filer determines whether the file requested must be scanned before delivery to the end user. Second, the filer opens a channel to one of the external computing devices and sends the filename. Third, the external computing device opens the file and scans it. Fourth, the external computing device notifies the filer the results of the file scan operation. Fifth, the filer sends the file to the end user provided the status indicates it may do so.
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FIELD OF THE INVENTION
The field of this invention is the treatment of dyed bleachable cotton garments with abrading and/or bleaching agents to produce a "frosted" appearance.
BACKGROUND OF INVENTION
In the United States, and, in fact, throughout the world, there is a large demand for cotton denim garments which have a distinctly faded, partially worn appearance. These garments are referred to as "frosted", "iced", "whitewashed", or "acid-washed". Although cotton denim accounts for the bulk of the "frosted" fabrics, other cotton materials, such as different types of twills and cotton corduroys are also subject to frosting.
It has been known for many years to use abrasive materials, such as pumice, to "stone-wash" dyed cotton twills to create a preworn appearance. More recently, this "worn" or "distressed" look has become particularly fashionable in apparel made from denim or similar cotton fabric, which has usually been dyed a bluish to black color. Earlier processing consisted primarily of dry tumbling the cotton garments with a quantity of pumice stones in commercial washing machines so that part of the dye was mechanically removed from the fabric. However, a non-abrasive bleaching process for "bluejeans" has been proposed (U.S. Pat. No. 4,218,220). Currently, the "bluejean" industry's preference is for methods which include mechanical abrasion in combination with chemical bleaching.
In one industry practice, natural pumice stones, which are porous, are soaked in an aqueous solution of an oxidizing-type bleaching agent. Both sodium hypochlorite and potassium permanganate have been used. There is a preference for potassium permanganate since the hypochlorite tends to damage the fabric. Any staining from residual manganese dioxide can be removed with a neutralizing agent, such as sodium bisulfite. Permanganate is also advantageous in that it avoids the production of irritating fumes which can result from a chlorine-liberating bleaching agent.
In the use of natural pumice stones pre-soaked in an aqueous solution of a bleaching agent, several practical disadvantages have been encountered. Even though the stones are drained of excess solution, they can continue to release the bleaching solution by seepage during storage. Further, the initial contacting of the stones with the moist denim garments can result in overbleaching. As the treatment continues the degree of bleaching decreases. Such irregular bleaching can result in a streaked, unattractive appearance. Moreover, the bleach solution is substantially exhausted with each use of the stones, and they must be resoaked frequently.
Several improvements have been proposed. In one procedure which is being used commercially to some extent, the natural pumice stones are pre-impregnated under pressure/vacuum conditions, the details of which are not known. This preparation treatment may provide for greater degree of impregnation, and more use of the stones without recharging. However, these stones do continue to exude solution on standing, and the initial use of the stones can result in spotty bleaching which is generally undesirable.
Another alternative which has also received some degree of commercial use is to employ a loose mixture of a bleaching agent with an inert but somewhat abrasive filler, such as, for example, potassium permanganate powder and fine quartz sand or other siliceous material. The frosting effect obtained from such a free-flowing mixture is rather "flat" and is considered to be less attractive.
Potassium permanganate and other bleaching agents have been encapsulated or adsorbed on support materials or embedded in formed bodies for other purposes. See, for example, U.S. Pat. Nos. 3,535,262, 4,279,764, 4,460,490, 4,665,782, 4,657,784, and 4,711,748. German Patent No. 2,311,964 describes the preparation of a product for decontaminating radioactive waste containing manganese dioxide (MnO 2 ) in Plaster of Paris (gypsum). A slurry is formed from manganese sulfate (MnSO 4 ) and potassium permanganate (KMnO 4 ) and gypsum which is cast into blocks. The MnSO 4 and KMnO 4 react in the slurry to form the MnO 2 , which is dispersed throughout the gypsum mass and removes radionuclides by adsorption.
SUMMARY OF INVENTION
This invention provides a greatly improved method of frosting dyed bleachable cotton garments. Instead of natural pumice stones, especially prepared artificial stones are employed. In accordance with the present invention, the artificial stones are composed of cemented aggregates of mineral particles which provide abradable surfaces. A bleaching agent is dispersed throughout the stones, being embedded in the cemented aggregate. Thus, this bleaching agent, which is preferably an alkali metal permanganate, occurs in the form of fine to microscopic particles rather than being present as an aqueous solution as in prior practice.
When the garments are tumbled in moist condition in contact with the artificial stones, exterior surfaces of the stones abrade, gradually releasing the bleaching agent. Light to moderate to high contrast bleaching can be produced without overbleaching and without fiber damage, and the stones can be reused repeatedly until they completely disintegrate.
The artificial stones can be shipped and stored after manufacture without concern about the leaking of bleach solution. They will retain their capacity to provide a gradual bleaching action. Initial overbleaching or subsequent underbleaching is avoided. Last, but not least, this product takes much of the drudgery out of the garment frosting operation and eliminates most of the hazards normally associated with the handling of bleaching agents in their concentrated forms.
DETAILED DESCRIPTION
The artificial stones of this invention are especially suitable for use with potassium permanganate (KMnO 4 ) and sodium permanganate (NaMnO 4 ) as the bleaching agents. However, they can be advantageously used with other bleaching agents, including potassium or other alkali metal manganates, such as K 2 MnO 4 . Chlorinebased bleaching agents can also be used, including sodium hypochlorite or other alkali metal hypochlorites. Other active chlorinereleasing bleaching agents which can be used include organic halogen bleaches, for example, chlorocyanurates. Of this class, sodium dichloroisocyanurate dihydrate is preferred. The bleaching agent is added to the cement formulation in either solid or liquid form, i.e., as an aqueous solution. KMnO 4 and sodium dichloroisocyanurate are preferably added as particulate solids, whereas in the case of sodium permanganate and sodium hypochlorite, addition as a solution is preferred. With liquid addition, the use of a hydrable self-curing cement is preferred, as will subsequently be described. Even though the bleaching agent is added as an aqueous solution, the water-binding action of the cement can leave most of the bleaching agent as highly dispersed solid particles.
Even though some bleaching agents other than potassium or sodium permanganate, i.e., sodium hypochlorite and sodium dichlorocyanurate dihydrate, function as active ingredients in the artificial frosting stones, their performance is at a much lower level than those of permanganate-containing formulations. The preferred choices for high-intensity frosting are combinations of sodium or potassium permanganate in either gypsum or magnesia cements. Where low bleaching intensities are desired (such as in chemically enhanced stone washing), combinations of Na or K permanganate with Portland cement--preferably white cement--can be used.
The artificial stones of this invention are prepared with abradable surfaces. More specifically, they comprise cemented aggregates of mineral particles with a bleaching agent embedded therein, which is preferably in particulate form. The bleaching agent may be mixed dry or as an aqueous solution with the aggregate material, and may be self-curing in cemented form, or there may be included a binder in addition to the aggregate material. An appropriate amount of water is added to the mix. The stones can be formed from low moisture mixes, which may be a paste or thick slurry, which can be formed into the stones by forming processes, such as extrusion, molding, agglomeration, etc.
A preferred major component of the stones' matrix material is a self-curing inorganic cement. Gypsum (plaster of paris) is particularly desirable. Hydratable gypsum may be used in a similar form as for preparing gypsum wallboard. When mixed with a small amount of water the gypsum will hydrate and set to an integrated solid body. By premixing the hydratable gypsum powder with the particulate bleaching agent, adding a small amount of water to form a thick paste, the artificial stones can be formed with the agent particles dispersed therethrough essentially in encapsulated or embedded form. Even though the porosity or the artificial stones is limited, the bleaching agent can e progressively released by surface abrasion.
Depending on the method of aggregation chosen, various commercial forms of gypsum may be used. Unformulated gypsum, in the hemihydrate form, is a rapid setting material, allowing only a very limited time for forming into pellets. Specifically when using extrusion as the aggregation method, the hydration of gypsum is accelerated by the addition of permanganate. The setting rate can be controlled by addition of one or more decelerants, to allow time to mix and form the material into pellets prior to setting. Commercially available slow-set gypsums are usually retarded by addition of an organic component, e.g., citric acid or hydrolyzed protein, which are attacked by the oxidizing agent. The retardants used for this process should be inorganics such as H 3 PO 4 , NaH 2 PO 4 , Ca(H 2 , PO 4 ) 2 , Na 2 B 4 O 7 , etc. Elevated temperature and pressure are also accelerants of gypsum setting, so a very dry mixture, which will generate heat and pressure when being worked, should be avoided.
Other self-curing cements include the family of magnesia cements, viz., magnesium oxychloride and magnesium oxysulfate. These cements are also referred to as "Sorel" cements. Further usable cements also include Portland cement (white Portland cement is especially desirable because of its low iron content), Pozzolan cement, calcium aluminate cement, and related cements.
An advantage of forming the stones from a self-curing or hydratable cement is that the cement component provides sufficient abrasive action so that the fabric is subjected simultaneously to both bleaching and abrasion. When a binder is used which is not itself abrasive, mineral filler can be used in combination with the binder. The stones may be composed of an abrasive mineral filler united by an inorganic binder, and the particulate or liquid bleaching agent may be distributed therethrough in the same manner as described for the self-curing cement type of stones. A preferred inorganic binder is sodium silicate (water glass) or potassium silicate. Alternatively, sodium or other alkali metal or water-soluble aluminate binders can be used. The abrasive mineral fillers may be selected from a wide variety of materials including clays, diatomaceous earth, ground pumice, precipitated silica, fine quartz sand, finely-divided perlite, natural or synthetic zeolites, etc.
Representative formulations of the artificial stones are set out below.
______________________________________Ingredients Wt. % Range Preferred Wt. %______________________________________General Formulas for Artificial StonesFormed From Self-Curing CementsCement 70-99.5 85-90Bleaching agent 0.5-30 10-15______________________________________Formulas for Artificial Stones Producedfrom Mineral Fillers and Inorganic BindersBleaching agent 5-25 10-15Mineral binder 3-20 5-10Mineral filler 55-92 75-85Water______________________________________
For effective use as frosting agents, the bleach-containing solidified cements are formed into suitable lump or pellet form, comprising the artificial stones. The stone size and form can influence the bleaching pattern obtainable in the frosting step. Given comparable tumbling times, the regularity and uniformity of the bleach effect increases with decreasing stone size. Conversely, the larger the stone, the more spotty and irregular the bleached areas become. Preparation of stones of various sizes can be achieved in a number of ways. For example, the bleach-containing cement paste can be poured into molds of a variety of shapes and sizes. For example, large slabs of 0.5 to 1.5 inches thickness can be formed, and then cut into rectangular or square pieces of 1" to 1.5" side length, or any other desirable dimension. Alternately, the slabs can be mechanically crushed to give irregular shaped lumps, with desirable size ranges to be separated out by a classifier. As another procedure, the cement paste can be poured directly into individual molds of the desired shape and size. For agglomeration by molding, the water content of the paste should be slightly higher (to make it pourable) than for the aggregation methods described below. Stones suitable for frosting or garments can also be made by extrusion, disk pelletization, briquetting, tabletting, or other methods familiar to those skilled in the art.
For example, 60 to 95 parts of a slow setting gypsum material (preferred 80 to 90 parts) are mixed with 5 to 15 parts of KMnO 4 and 0 to 25 parts of a thickener (preferred 0 to 10 parts), and water sufficient to form a stiff dough. This dough can then be formed into pellets by any method familiar to those skilled in the art; for example, by extrusion, or by rolling between textured rolls, or by pelletization, etc. Once formed, the pellets are self-drying and self-hardening due to the rehydration and setting of the gypsum. The amount of KMnO 4 used is an added control of bleaching intensity, along with tumbling time, and weight ratio of garments to pellets selected during the "frosting" step of this process.
This invention is further illustrated by the following examples.
EXAMPLE I
A measured quantity of crystalline or powdered potassium permanganate is dry mixed with a predetermined amount of filler. After a homogeneous blend is obtained, a predetermined quantity of binder plus the proper amount of water is worked in the mixture so that an extrudable mass is obtained. This, in most cases, represents a still powdery but slightly cohesive material. The mass is then extruded to form 1/4" to 1/2" diameter rounds of about 3/4" to 11/2" in length. The sizes and shapes of the product are selected for convenience and maximum production rate. Diameters of 1/16" or even less or of 1" or more are possible. Instead of rounds, other geometrical shapes such as triangular, rectangular, or stars can be used. After extrusion, the product is cured at either ambient or elevated temperature (60°-110° C.). Curing at higher temperatures produces products of higher hardness and with slower release characterization.
The extruded product, containing about 10% KMnO 4 (or about 12% K 2 MnO 4 ) is tumbled with damp denim garments for a period of 5 to 25 minutes. The weight ratio between the quantity of frosting agent and dry garment weight may range from 3 to 0.1, depending on the degree of bleaching desired. In the course of the tumbling operation the extruded pellets are abraded, being finally reduced to a powder. In this manner, the garments make a large number of contacts with the permanganate-containing extrudates of various sizes, whereby each contact produces localized bleaching action.
After completion of the frosting step, the garments are treated with a reducing agent--commonly sodium metabisulfite--to remove the brown stains of manganese dioxide.
EXAMPLE II
89 lb gypsum was mixed with 1 lb Ca(H 2 PO 4 ) 2 (to retard hydration) and 10 lb KMnO 4 crystals, forming a uniform dry blend. Water was added to this blend in a high shear mixer to form a wet dough, which was then extruded through a die plate having 1/2" square holes. The soft pellets formed were fed onto a moving belt to set.
About 20 lb of water was used in forming this dough. As the gypsum hydrates, it uses about 15 lb of the water present (CaSO 4 .1/2 H 2 O+1.5 H 2 O→CaSO 4 .2 H 2 O). The heat of hydration causing vaporization of part of the remaining water. Some free water apparently remained in a highly dispersed form. A hard, dry plaster pellet containing KMnO 4 crystals was obtained.
EXAMPLE III
89 lb gypsum was mixed with 1 lb Na 2 B 4 O 7 retardant and 10 lb KMnO 4 crystals to a uniform dry blend, which was then mixed with water to form a wet dough. The dough was extruded through 1/2" square holes, forming soft pellets on a moving belt. These pellets were sprayed with a 10% K 2 SO 4 solution to accelerate the gypsum set. The reaction of the gypsum hemihydrate to dihydrate absorbed most of the water from the system, and the heat of hydration drives off most of the rest. Hard, dry pellets were formed.
EXAMPLE IV
80 lb of slow setting gypsum was mixed with 10 lb of a clay extrusion aid and 10 lb of KMnO 4 crystals in a dry blending operation. A dough was formed from this blend by addition of about 20 lb of H 2 O. The presence of clay thickened the dough so that firm, tough pellets were formed on extrusion through a die plate having 1/2" diameter round holes. These pellets were self-dried and hardened as in Examples II and III.
EXAMPLE V
260 g of slow setting gypsum was intimately mixed with 72 ml of a commercial 40% solution of sodium permanganate and 30 ml of water. The resulting deep purple paste was transferred into plastic molds of about 3.5 ml volume each. The mass began to stiffen after about 20 minutes and was set after 45 minutes, at which point the gypsum castings were removed from their molds. The black cherry colored pieces contained 10.3% sodium permanganate in a highly dispersed form.
A frosting test with this product (50 g frosting agent with 60 g blue denim tumbled for 30 minutes) showed high intensity, high contrast bleaching.
EXAMPLES VI to XI
Additional stone formulations and test results are summarized in Table A.
TABLE A__________________________________________________________________________Quantity Quantity & KindExample& Kind of of Bleaching Water Thickening Set Results ofNo. Cement Used Agent Used Used Time Time Hardness Frosting Test__________________________________________________________________________VI Magnesia cement 25 g KMnO.sub.4 -- 1 hr 2.5 hr hard low intensity50 g MgO + 120 ml (solid) bleachingsaturated MgCl.sub.2solutionVII Magnesia cement 45 mL = 63 g 58 mL 1 hr 2.5 hr hard high intensity50 g MgO + 66 g 40% NaMnO.sub.4 bleachingMgCl.sub.2.6 H.sub.2 OVIII 260 g Portland 28.9 g KMnO.sub.4 84 mL 1.5 hr 6 hr very hard very low intensityCement (white) (as solid) bleachingIX 260 g Portland 52 mL = 72.8 g 50 mL 10 min 1.5 hr very hard moderate intensityCement (white) 40% NaMnO.sub.4 bleachingX 260 g Portland 107.7 g NaOCl none 25 min 1 hr very hard low intensityCement (white) solution bleaching (17% active chlorine)XI 260 g Portland 28.9 g sodium 125 mL 40 min 1.5 hr rough, low intensityCement (white) dicyanurate crumbly bleaching dihydrate surface__________________________________________________________________________
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A method is provided for selectively bleaching dyed, bleachable cotton garments. The garments are tumbled in damp condition with reuseable pre-formed solid pellets of limited porosity having abradable surfaces. The pellets comprise substantially water-insoluble cemented aggregates of mineral particles with a finely-divided particulate bleaching aent imbedded therein. The bleaching agent, which preferably is substantially uniformly distributed in the pellets, bleaches the garments by surfaces of the pellets wearing away during the garment tumbling to release the bleaching agent as the pellets contact the garments.
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FIELD OF THE INVENTION
The subject invention relates generally to digital data processors and, more particularly, to a digital data processor capable of explicitly evaluating conditions existing therein.
BACKGROUND ART
In general, digital data processors generate as a result of executing most instructions one or more "condition codes" which reflect the state of selected "conditions" existing within the hardware comprising the processor as of the time the instruction is completed. For example, as a result of executing an arithmetic or logic instruction on one or more "data operands", the processor may evaluate such condition codes as Zero (Z) if the "result operand" was zero, Negative (N) if the result operand was negative, Overflow (O) if an overflow occured in the Arithmetic and Logic Unit (ALU) as a result of the particular operation, or Carry-out (C) if the ALU provided a carry-out signal as a result of the operation. Often, as a result of executing an instruction requiring the simple movement of a data operand to or from memory or between working registers, the processor will evaluate many of the same condition codes. Typically, the evaluated condition codes are automatically stored in a "condition code register" (CCR) or the like, whether or not they are actually needed. Usually, the contents of the CCR are used by conditional control transfer instructions, such as "branches" or "jumps", executed later in the program. Alternatively, the contents can be moved from the CCR into a working register or to memory using one of the data movement instructions. Thereafter, the individual code bits can be isolated and used as required. However, since the condition codes are often in an very primitive form, synthesis of a more useful logical predicate, such as Greater Than (GT) or Less Than or Equal (LE), usually requires the execution of one or more additional instructions.
Since the processor automatically evaluates the several conditions after the execution of substantially every instruction, the condition codes must be utilized by the very next instruction or not at all. Usually, this is an acceptable limitation, since the condition codes resulting from most operations are used, if at all, to control the following conditional branch instruction. On the other hand, in "pipelined" processors, this limitation becomes less acceptable as the number of stages in the pipeline increases. If the condition codes resulting from a particular operation must be used by more than just the next instruction, that next instruction must transfer the condition codes out of the CCR into a working register or into memory. Otherwise, the original operation must be repeated each time the condition codes are needed. In either event, one or more additional instructions must be executed to make the critical condition codes available when needed.
In some data processors having more than one type of execution unit (EU), the format and meaning of the condition codes for each unit are usually unique. While it is not uncommon to group all condition codes into a single CCR, that practice results in complex scheduling if the EU's have different execution times. It also limits the architectural freedom to change the "mix" of EU's. Additionally, each different type of EU usually requires a corresponding set of conditional branch instructions. This proliferation of instructions makes instruction decoding more difficult, and requires additional hardware to receive the codes, interpret each set of condition codes and control the execution of each branch instruction.
In some other data processors having multiple EU's, the evaluation of condition codes is not implicit, but rather occurs only in response to an explicit request. In some of these processors, a set of "compare and branch" instructions was defined, with the branch being conditioned upon the evaluation of a particular logical predicate. In other processors, a set of "set on condition" instructions are defined, with a result operand being set to the logical truth value of a specified logical predicate. Again, the resulting proliferation of instructions requires additional decode and control logic.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a data processor which simultaneously evaluates a plurality of conditions only in response to an explicit instruction to do so.
Another object of the present invention is to provide a processor in which conditions are evaluated in terms of a set of logical predicates.
Yet another object of the present invention is to provide a processor which provides the truth value of each of a set of logical predicates, evaluated using conditions existing within the processor, as respective bits of a result operand.
These and other objects are achieved in a data processor comprising an execution unit for executing each of a plurality of instructions, and for providing a result operand in response to executing at least one of the plurality of instructions; and a control unit for controlling the execution by the execution unit of each of the plurality of instructions. In accordance with the present invention, the processor includes condition evaluation logic for evaluation a set of conditions in the execution unit only in response to the execution of a selected one of the plurality of instructions, and the execution unit provides the evaluated set of conditions as the result operand.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates in block diagram form, a data processor in which the present invention may be advantageously employed.
FIG. 2 illustrates a preferred implementation within the execution units of FIG. 1 of the EVALUATE instruction of the present invention.
DESCRIPTION OF THE INVENTION
Shown in FIG. 1 is a data processor 10 comprising an control unit (CU) 12, a pair of execution units (EUs) 14a-14b, a set of registers 16 and a memory 18, which communicate via an address bus 20, a control bus 22 and a data bus 24. In general, programs, both supervisor and user, are stored in the memory 18 in the form of sequences of instructions. The CU 12 sequentially fetches the instructions from the memory 18 and dispatches each to an appropriate one of the EUs 14a-14b for execution. Depending upon the instruction, the selected EU 14a-14b performs a particular arithmetic or logic operation upon one or more input operands provided by selected "source" registers 16, and may return a result operand for storage in a selected "destination" register 16. Such result operands may be left in the respective register and used in subsequent operations, or moved to the memory 18 for longer term storage, as desired.
In addition to being significant, in and of themselves, certain characteristics of the result operands may be determined from the condition of the particular EU 14a-14b as of the time the operation was completed. For example, it is often convenient to know that the result operand was equal to zero (Z). Similarly, the sign (S) of the result operand is usually of interest. In some situations, it is quite useful to know if a carry-out (C) occured as a result of a particular arithmetic operation. Using such "condition codes", decisions can be made as to program flow, error conditions, and the like. However, by using these simple condition codes to evaluate more useful logical predicates, the decision process may be simplified.
In accordance with the present invention, condition evaluation is not "implicit", that is, neither of the EUs 14a-14b evaluates any condition(s) as a result of performing a normal arithmetic or logic operation. Instead, condition evaluation is "explicit", that is, an EU 14a-14b will evaluate conditions only in response to executing a "condition evaluation" (EVALUATE) instruction specific to that EU. In the preferred form, the evaluation consists of determining the truth value of a set of logical predicates. These values are then "packed" into respective bits of a result operand and returned to a specified destination register 16. Decisions can be made on the truth value of each logical predicate using simple "branch on bit value" instructions. Alternatively, one or more of the bits can be extracted and isolated for further processing or assignment.
In general, the EVALUATE instruction may take any of a number of forms. For example, if multiple EUs 14a-14b are present, a generic form may be as follows:
COMPARE:Sx,Sy,Dz;EU
where:
Sx,Sy=pointers to the input operands to be evaluated, usually in registers;
Dz=a pointer to the destination of the result operand, usually a register; and
EU=a pointer to the particular one of the EUs 14a-14b selected to perform the evaluation.
If only a single EU is available, the form could be reduced to:
COMPARE:Sx,Sy,Dz
where:
Sx,Sy=pointers to the input operands to be evaluated, usually registers;
Dz=a pointer to the destination of the result operand, usually a register.
A primitive EVALUATE instruction may take the following form:
EVALUATE:Sx,Dz
where:
Sx=a pointer to the input operand to be evaluated, usually a register;
Dz=a pointer to the destination of the result operand, usually a register.
Of course, the primitive EVALUATE can be performed using the generic form if one of the input operands is made to be zero (0).
In general, each EU 14a-14b operates on operands of only a single type, for example, integer or floating point. However, the generic form is equally suitable for an EU 14a-14b capable of operating upon mixed operand types.
In the preferred form, an integer-type EVALUATE instruction evaluates a number of different logical predicates and returns the truth value of each as a respective bit of the result operand as follows:
______________________________________ ##STR1##where:EQ: true (1) if and only if Sx == SyNE: true (1) if and only if Sx != SyGT: true (1) if and only if Sx > SyLE: true (1) if and only if Sx <= SyLT: true (1) if and only if Sx > SyGE: true (1) if and only if Sx >=SyHI: true (1) if and only if Sx U> SyLS: true (a) if and only if Sx U<= SyLO: true (1) if and only if Sx U< SyHS: true (1) if and only if Sx U>= SyU implies unsigned comparison.______________________________________
Shown in FIG. 2 is a preferred embodiment of an integer EU 14a capable of executing either form of the EVALUATE instruction. In general, the first and second input operands, OP1 and OP2, respectively, are simultaneously input to both an Arithmetic Unit (AU) 26 and a Logic Unit 28. In the AU 26, both input operands are zero extended as required to the same width, say 32-bits. The extended operand OP2 is then subtracted from the extended OP1 to determine the sign (S) of the difference and if a carry-out (C) occurs. Simultaneously, in the LU 28, the input operands are bit-by-bit logical EXCLUSIVE ORed. The 32-bit output of the LU 28 is input into an OR gate 30, which will assert a Zero (Z) signal if the two operands are logically identical. Evaluation (EVAL) logic 32, implemented in either discrete logic or in a PLA, logically combine the C, S and Z signals as follows:
EQ==Z
NE==Z*
GT==S* & Z*
LE==S+Z
LT==S
GE==S*
HI==C* & Z*
LS==C+Z
LO==C
HS==C*
where:
*=>logical inverse
&=>logical AND
+=>logical OR
In the preferred form, a floating-point-type EVALUATE instruction evaluates a number of different logical predicates and returns the truth value of each as a respective bit of the result operand as specified below. All arithmetic is performed in accordance with the IEEE P754 standard. ##STR2## where: NC: true (1) if and only if Sx and Sy are not comparable
CP: true (1) if and only if Sx and Sy are comparable
EQ: true (1) if and only if Sx==Sy
NE: true (1) if and only if Sx !=Sy
GT: true (1) if and only if Sx>Sy
LE: true (1) if and only if Sx<=Sy
LT: true (1) if and only if Sx<Sy
GE: true (1) if and only if Sx>=Sy
HI: true (1) if and only if Sy>=0, and ((Sx>Sy) OR (Sx<0))
LS: true (1) if and only if Sy>=0, and ((Sx<=Sy) AND (Sx>=0))
LO: true (1) if and only if Sy>=0, and ((Sx<Sy) AND (Sx>0))
HS: true (1) if and only if Sy>=0, and ((Sx>=Sy) OR (Sx<=0))
Although the conditions which are of interest are related to one or more input operands, the EVALUATE instruction is not limited to such conditions. For example, in some EUs 14a-14b, other conditions which are unrelated to operands, such as parity, may be of interest. If desired, these operand-independent conditions may be evaluated at the same time the operand-dependent conditions are evaluated and provided in those bits, if any, of the result operand not dedicated to the operand-dependent conditions.
Although the present invention has been disclosed in a preferred form, various changes and modifications may be made without departing from the spirit and scope of the present invention.
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In a data processor, the conditions associated with an operand are evaluated only in response to the execution of a special instruction. The results of this evaluation is provided as a result operand and stored in a general purpose destination register. The evaluated conditions are each provided in discrete form, that is, unencoded, rather than in encoded form.
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BACKGROUND OF THE INVENTION
The present invention relates to a power driven swivel connection for turning hanging loads about an upright axis, having a rotor joined by axial and radial bearings with a stator, at least one hydraulic duct running from the stator into the rotor by way of a rotary connection and a driving unit for acting on and turning the rotor in relation to the stator. The driving unit is made up of a collar on the stator or rotor with radial or axial cylinders therein having hydraulic cam drivers extending past a radial or (as the case may be) an axial face of the collar for driving against cams of a cam box on the stator (if the collar is joined with the rotor) or otherwise on the rotor. For timed distribution of hydraulic liquid to the cylinders so that the drivers are only pushed against such cam parts that the resultant is in the desired direction of swivel, a ported distribution spool is liquid-tightly seated within the collar for forcing liquid into the cylinders and letting it off in turn. The hydraulic ducts running from the stator to the rotor are, for example, for connection with the actuator of a clam-shell bucket. The pressure-tight rotary connections are needed for stopping tangling of hoses on swivelling the load. As noted, the driving unit may be a radial or an axial piston motor, while the cam box may be the rotor or the stator.
A swivel connection with a radial piston motor has been put forward in the prior art (see German Pat. No. 2,338,736) having two rotary joints running through the interface of a radial plain bearing, the interface being between a neck of the stator and the rotor. The rotor is furthermore supported by way of an axial rolling element bearing on a shoulder of the collar or cylinder drum of the motor. At the lower end of the hydraulic motor there are furthermore, in the space between the collar and the cam box, two washers acting as plain bearings in the case of a hanging load, and as thrust bearings when the bucket is pressed against the earth etc. When put into general use, this bearing system has, however, not given the desired effects, and specially on supporting or digging heavy loads, more specially when the bucket was acted upon by axial and radial blows, parts of the stator near the radial plain bearing were frequently broken and damaged. A further point is that the bearing gap with the rotary connections therein is open at one end on the outer side of the motor where full sealing is not possible so that there are losses of hydraulic liquid, this being responsible for the building up of dirt coatings on the housing and nearby parts and structures. Because the rotor connections or ports are generally high up on the motor housing, the hoses joined up at this position and running to the bucket are more likely to be damaged than if they were placed lower down. A further shortcoming is the generally great overall height and the great weight, caused thereby, of the swivel connection.
In the case of a further swivel connection designed on the same lines and whose cam box is constitutes the stator and whose collar is constitutes the rotor, the timing or distribution spool being locked on the stator (see German Offenlegungsschrift specification No. 2,838,428), the hydraulic ducts for operation of the bucket are by way of axial holes through the distribution spool from the stator to the rotor. The rotary connections are, in this case, at the lower part of a cylindrical interface between the distribution spool and the rotor. Because of the stiff connection between the distribution spool and the stator, there are, it is true, no sealing troubles at the connections of the hydraulic ducts between the distribution spool and the stator, but, however, for cutting down the forces acting on the distribution spool as a reaction to the effect of outside forces on the motor, it is necessary for complex bearings to be used to be generally free of play. Because, more specially, when working with heavy loads and blows, material is likely to be deformed, such deformation not being stopped by the bearings, the distribution spool and the parts, touching it, have a higher wear rate, this more specially being true on use with heavy loads.
GENERAL OVERVIEW OF THE INVENTION
One purpose of the present invention is that of improving the design of the known swivel connection discribed above, so that it may be used for heavy loads without any danger of being broken and with only a low degree of wear at the bearings and at the interfaces of the distribution spool, even for heavy loads, the connection nevertheless having a generally low overall height and, accordingly, a low weight.
For effecting this and further purposes, one suggestion of the present invention is a design in which the part of the hydraulic duct, running through the collar or cylinder drum, is joined by way of the rotary connection with the one end of a duct running through the distribution spool, the other end of the duct being joined at a connection point or junction with the part, running through the cam box, of the hydraulic duct, the connection point being sealed off for stopping hydraulic liquid making its way into the inside of the box, the sealing parts letting radial play take place between the distribution spool distributor and the rotor which is greater than the bearing play of the radial bearing. It is furthermore possible for the design to be such that the part, running through the collar or cylinder drum, of the hydraulic duct is joined up by way of the rotary connection with one end of such a duct running through the distribution spool, the other end of such duct being joined up at a connection point with the part, running through the cam box, of the hydraulic duct, there being two radial bearings which are placed on opposite sides of the cams and the cylinders. Further useful developments and forms of the invention will be seen from the dependent claims.
One important idea on which the present invention is based is that more specially the floating distribution spool which allows axial and radial play and furthermore bending of the rotor to take place in relation to the stator without itself being acted upon by forces, is more specially to be desired for work with heavy loads and heavy blows. In order, furthermore, to make certain of a low overall height, the hydraulic ducts for the connection with the bucket have to be designed running through the distribution spool from the stator to the rotor. Correspondingly, the rotary connections for of the hydraulic ducts may be placed inside the cam box so that there is now generally no danger of leakage to the outside. An important point is that, at the connection points at which the hydraulic ducts make their way from the distribution spool into the cam box, at least radial play has to be possible to a degree greater than the bearing play of the radial bearing, such play being sealed or bridged over by seals at this point. There may be axial play of the distribution spool at the collar and/or at the junctions with a cam box relative to the rotor.
As part of a preferred embodiment of the invention, the distribution spool has a central axial hole having a pipe with a smaller diameter running through it from end to end in the lengthwise direction. The pipe-like or ring cross-section duct between the inner face of the central hole and the outer face of the pipe, constitutes part of the hydraulic supply channel namely the rotary connections between the distribution spool and the collar. The pipe itself is joined up with the stator duct at its one end by way of a further rotary connection. At its other end there is a further junction, having gaskets, so as to give axial and radial play and producing a pipe connection to a duct in the rotor.
It is often desired to have more than two hydraulic ducts running through the stator into the rotor, as for example if in addition to operating the cam-shell bucket or grapple, further hydraulic functions are needed, for example when using a hydraulically powered saw on the bucket for sawing through a tree where it is gripped by the bucket. For such a gripper saw generally at least two further hydraulic ducts will be needed. While it is true that such further hydraulic ducts may be placed running through the distribution spool, the increase in diameter and weight, necessary for this, would be undesired. For this reason, one suggestion of the invention is for the further hydraulic ducts to be joined up outside the distribution spool by a direct rotary joint between the stator and the rotor. In this case, the radial plain bearings are best placed outside the interface with the rotary joints going through it, on opposite sides of the cams and the cylinders so that, at the interface, a small radial gap may be present to generally put to an end any danger of parts at this position being broken.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an vertical section through a first embodiment of a power driven swivel with two rotary connections.
FIG. 2 is a view of a somewhat changed embodiment of the invention with four rotary connections.
FIGS. 3 to 6 are views of four further possible embodiments of the design of the connection point between the distribution spool and the rotor, illustrated in vertical sections of the key parts of the system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The power driven swivel connections to be seen in the figures and constituting a hydraulic motor have, as their main parts, a stator 1, and a rotor 4 which may be turned relative to the stator about an upright axis. The a pot-like rotor 4 forms the cam box 41 of the hydraulic motor, while the stator 1 has, as part of it, a collar 11 or cylinder drum (placed within the cam box) of the hydraulic motor. The distribution or timing spool 7 is liquid-tightly placed in the middle hole 12 of the stator and is locked to the rotor 4 for turning therewith. Spool 7 has an axial hole 70 with a separate pipe 9 within it.
The cam box 41 may be generally said to be made up of three lathe-turned parts 42, 43 and 44, that is to say a top gray iron part 42 with an upwardly and outwardly turned hose guard skirt 45, a middle part 43 having within it the cams 46, acted upon by balls 13, of high quality steel, and a bottom part 44, having the threaded ports 47 and 48 for the hydraulic actuator of the bucket. The lower part 44 will generally be of different design on its outer side, dependent on the sort of bucket with which it is to be used so that its connection may be made with the connecting parts of the bucket. Rotor 4 is turningly supported on stator 1 by way of two radial plain bearings 14 and 15 and two axial or thrust rolling element bearings 16, 17, placed as far from each other as possible axially on the two sides of, that is to say under and over, the cams 46 and the cylinders 18.
Spaced round the neck 19 of the stator there are four threaded ports 20, 20' for hydraulic lines or hoses, hydraulic ducts 21, 22, 23, 24, running from such ports to the distribution spool 7 and, in the other case, the pipe 9 and then opening into hydraulic ducts 71, 91, 72 and 73. Duct 21 leads by way of rotary connection 31 into pipe-like (or ring cross-section) duct 71 and then past a junction 50 (which is sealed by seal 49 to stop losses of liquid into the inside of the cam box 41) to a duct 51 placed within the rotor 4 and extending to a threaded outlet port 47. For the rotor position shown in FIG. 1, port 20' may be an inlet port. Liquid then passes through duct 23, duct 72 into slot 74. On the exhaust side, liquid passes from slot 75 to duct 73, duct 24, and then to a drain duct. A further stator duct 22, after running through a rotary joint 32, is joined up with the duct 91 in pipe 9, such duct 91 opening at its other end by way of a further connection point 53 into rotor duct 54, the same, for its part, being joined with threaded hose outlet port 48.
The two further stator ducts 23 and 24 communicate with a number of slot-like ducts 74 and 75 which are formed by axial grooves (which are equally circumferentially spaced from each other) in the distribution spool 7 and the inner face of the hole 12 in stator 1 in which the distribution spool is liquid-tightly seated. The inlet and drain pipes, for hydraulic liquid placed outside the swivel connection, may be joined up with their threaded ports 20' on the neck of the stator.
Depending on the desired direction of rotation of the rotor, one of ports 20 and one of ports 20' is connected to the drain duct, while the other two are connected to the input duct of a hydraulic pump.
Within the collar 11 or cylinder drum, there are a number of circumferentially equally spaced radial pressure cylinders 18, each having within it a piston 25, whose outer end face comes up against a ball 13, extending outward radially from openings of the cylinders to a greater or lesser degree. The inner, back ends of pistons 25 are acted upon by hydraulic liquid, coming in by way of a hole 26 into the cylinder 18. Balls 13 have their parts which are furthest to the outside resting against cams 46, the cams being undulating so that they are at changing distances from the axis of the rotor. The cams are located on the inner face of the cam box 41. The radial positions of the pistons 25 are dependent all the time on the form of the cams 26.
If a ball 13 is pushed by way of its piston 25, acted upon by the hydraulic liquid with a given radial force against the inner face of the cam box 41, that is to say against the cam, there will be a greater or lesser resultant force or torque in the one or the other direction of turning, acting on the rotor, the resultant being dependent on the size and direction of the slope of the cam 46 at the given position of the ball 13. For getting turning motion of the rotor started, torques in the same direction have to be transmitted to the rotor 4 by way of the balls 13, acting on the cams. For this reason, only such cylinders 18 are to be put under pressure as have balls 13 running on a length of the cams 46 sloping outwards against the direction of turning. The balls 13 are forced outwards by the high pressure coming in through the input duct so that cam box 41 is turned, the balls then moving outwards against cam 46 till the balls get to the outer dead center positions. All those cylinders 18 whose balls 13 are running on lengths of cams 46 which, in the direction or turning have an inward slope, on the other hand have to be joined up with the drain duct which is at a low pressure so that these balls may be moved inwards without much force being needed by the cams running over them, this forcing the hydraulic liquid out of the cylinders 18 in question into the drain duct. When the balls get to their separate dead center positions or maxima and minima of the cams, the connections between the cylinders 18 with the input and drain ducts are cut off and, in each case, changed over on further motion of the cam box. This timed change-over in the connections so as to be in-phase with respect to the cams 46, with the input and drain ducts is caused by distribution spool 7 which is keyed to cam box 41 by way of a pin 56. Timing or distribution is by way of slot ducts 74 and 75 which, on turning of the distribution spool in relation to collar 11, are put in line with the different holes 26.
Distribution spool 7 has, at the rotary connection 31, an upwardly pointing cylinder part 76 seated in a cylindrical hole 33 in stator 1, in which it may be turned and moved axially to a certain degree. The rotary connection 31 is sealed by a gasket ring 77 placed in a peripheral groove of distribution spool 7 against liquid flow past this point in an outward or inward direction.
Near connection point 50 there are, at the end of the distribution spool 7 nearest the rotor 4, further gaskets or seals 49 and 49' which let radial and/or axial play, greater than the bearing play between the stator and the rotor take place, for stopping any overgreat forces, caused by blows against the outside of the structure on operation in a crane or excavator, from taking effect on the distribution spool. This is explained in greater detail below.
At the same time steps, however, have to be taken at connection point 50 to see that the pipe-like duct (duct of ring cross-section) 71 is sealed off to the necessary degree for stopping liquid from making its way into the inside of the cam box 41 and stopping any liquid flow in the opposite direction. In the figures, five possible different forms of such a connection point 50 will be seen, of which an account will now be given.
In the case of the embodiments to be seen in FIGS. 1 to 5, the distribution spool 7 has its end face 78 resting axially against an elastic gasket ring 49, placed in a ring-like cutout in the bottom part 44 of the rotor. The means retaining distributor 7 in this position differ for each of the embodiments.
In the embodiments to be seen in FIGS. 1 and 2, there is the compression spring 80, compressed axially, in a ring space between the stator and a skirt of the lower end of distribution spool 7, spring 80 forcing distribution spool 7 at connection point 50 springingly against axial gasket 49 and the rotor 4 at end face 78. On opposite axial forces coming into being, spring 80 is compressed so that there will be axial play of the distribution spool 7 not only in relation to stator 1, but furthermore with respect to rotor 4.
In the working example to be seen in FIG. 3, it will be seen that the spring in the gap between stator 1 and distributor 7 has been replaced by a shim 41'. Shim 41' limit axial play of distribution spool 7 in relation to the rotor 4 to an amount which may be taken up by elastic squeezing in a sideways direction of gasket ring 49, this stopping any undesired lifting of distribution spool 7 clear of gasket ring 9 which would make loss of liquid possible.
In the embodiment of FIGS. 4 and 5 there is a locking connection, acting in an axial direction, between distribution spool 7 and rotor 4, for stopping any axial gap coming into being at the ring gasket 49. In the embodiment of FIG. 4 the shoulder 82 which extends into the groove 60 in the radially outer face of a headpiece in the middle of the lower part of rotor 4 is rigidly connected to the distribution spool 7. In the case of the embodiment of FIG. 5, shoulder 84 takes the form of separate ring piece 84, fastened by screw 83 to the distribution spool, or in the form of a nut.
The radial ring gap 85 between the rotor 4 and distribution spool 7 gives, in all these working examples of the invention, the desired radial play between the said spool and the rotor.
In the embodiment of FIG. 6, in place of the axially acting gasket 49 there is a radially acting one 49' bridging over the ring gap 85' between the skirt 86 at the lower end of distribution spool 7 and the inner face 61 of the headpiece on the lower part of rotor 4, this making radial and axial play possible.
The top end 92 of pipe 9, running through the hole 70 within the distribution spool 7, is seated in an axial hole 34 of stator 1, while its lower end 93 is taken up in an axial hole 62 of the rotor 4 with a certain amount of play (indicated by a thickening of line 62 in the drawing) so that a change in position of the rotor 4 in relation to the stator 1 in an axial and/or radial direction is not responsible for any great forces acting on pipe 9, which is simply moved out of the way. At the two ends, pipe 9 is sealed by elastic gasket rings 94, 95 seated in ring grooves on the outside of pipe 9. Dependent on the amount of friction at the top and lower ends of pipe 9 where it is seated in holes 34 and 62, pipe 9 will be turned in relation to the rotor 4 and/or the stator 1 when the rotor is power-turned, so that the two pipe connections may form a rotary connection (32) or a junction (53), that is to say a simple joint without turning of the two parts in relation to each other.
In the embodiment of FIG. 2, in addition to the hydraulic ducts 21, 71, 51; 22, 91, 54, running through from the stator 1 by way of distribution spool 7 and pipe 9 to the rotor, there are two further hydraulic ducts 35, 65; 36, 66 running from the stator into the rotor, their rotary connections 63 and 64 being in the neck part 19 of the stator 1 at a simple interface between stator 1 and rotor 4. Here as well there is a top and a lower radial plain bearing 14, 15 so that at the interface itself with the rotary connections running therethrough, there is no friction. In an upward direction the bearing gap is gasketed with the help of a special-purpose seal or gasket 67, taking effect between rotor 4 and stator 1, for stopping liquid from making its way through out of the part of the interface with the rotary joints 63, 64.
The embodiments of the invention to be seen in the figure are all in the form of powered swivel connections whose collars are made part of the stator and whose cam boxes are made part of the rotor. However, as a general teaching of the present invention, the parts might be placed the other way round, that is to say so that the collar would be joined to the rotor and the cam box would be joined with the stator while there would nevertheless be a floating distribution spool with radial and, if desired, axial play. In such a system, not shown herein, the input and drain ducts would have to be designed running from ports on the cam box to connection points and then to the distribution spool and from the same to the collar. At the connection points between the cam box and the distribution spool it will be necessary to have one gasket in each case for bridging over the play, that is to say the radial and possibly axial play (in addition thereto) as desired.
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A hydraulic motor either of the radial or axial piston type is used for swivelling a hanging load about an upright axis. The motor has a distributor for controlling the flow of hydraulic fluid to the input and drain ducts of the motor. The motor further has hydraulic ducts extending from the stator to the rotor for transmitting fluid required for operation of the actuator of a gripping device or bucket. The distributor floats, so that radial and axial play as well as deformation of the rotor relative to the stator may be taken up without stress. At least some of the hydraulic ducts pass through the distributor, connections being made by suitable rotary transmissions and connecting points within the motor.
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The present invention relates to ore processing like for example to the enrichment of ore, based on measuring of the ore content. More specifically, the invention relates to a method and an apparatus for on-line measuring of the ore content as well as to processing of the ore based on the measured ore content.
BACKGROUND OF THE INVENTION
The ore content of ore mined from an ore mine is usually defined by taking samples of the ore in the mine and by analyzing them in a laboratory. The analyzing of the samples usually takes a couple of days. Based on the received results, the mined ore is generally separated to waste rock and ore to be taken to further processing.
After that the ore to be taken to further processing will be crushed into grains of a desired size, that in some cases are further agglomerated to pellets of a desired size, for example in an agglomeration drum, whereby for example sulfuric acid is added to the ore in connection with the pellet production in order to intensify the further processing. After that, the agglomerated ore is taken to the further processing or storage.
One method for further processing of ore, known in the art, is heap leaching, whereby the crushed and agglomerated ore is stacked into a heap of a desired art and form, liquid dissolvent being sprayed evenly onto said heap, consisting for example of acid and microbes in a biological dissolution procedure. In the biological dissolution procedure, at first sulfur acid is sprayed onto the heap, corroding the ore pellets in a suitable way, after which the microbes to be sprayed onto the heap access the metals to be corroded out of the ore. These microbes dissolve the metal contained in the ore, said metal flowing along with the microbes in the solvent on the bottom of the heap. From the bottom of the heap the concentrated solvent is collected for further treatment of the metal. In general, the metal is removed from the concentrated solvent in a desired way, whereby the reclaimed solvent with its microbes can be reused as a solvent in the heap leaching process.
In the heap leaching process also air can be blown to the heap, if necessary, to intensify the action of the microbes and to accelerate the leaching process. In addition, also nutrients can be brought for the microbes. If necessary, the heap can also be covered for example for maintaining a suitable temperature in the heap for the leaching process.
Alternatively, the heap leaching process can also be implemented by using only acid as a solvent.
The ore content of the ore mined from an ore mine, however, varies very much, because the ore content of the mined ore is determined from a large amount of ore only with a couple of laboratory samples. Due to this big variation of ore content, it is difficult to manage the efficiency of the further processing of the ore, because in general the norms for the further processing are defined specifically according to the average ore content. For example in the above mentioned heap leaching process, this means that the same quantity of solvent is sprayed for each portion of the heap. Therefore in many portions of the heap, too much liquid dissolvent will be sprayed, whereas in some portions there is not enough liquid dissolvent with respect to the ore content.
GENERAL DESCRIPTION OF THE INVENTION
The aim of the present invention is to continuously monitor the ore content of the stored ore and to determine the location of the ore in question in the storage. Based on this information, the enrichment process can be controlled, for example by determining the correct amounts of solvent to be sprayed to each portion of the heap according to the ore content of each portion of the heap.
Alternatively, with the solution according to the invention, the ore can be sorted/guided to different destinations depending on its ore content. Thus, ore having desired ore contents can be guided to different destinations, whereby the ore to be guided to different destinations is homogenous within a predetermined range of the ore content. In that way the most profitable and efficient enrichment process can be chosen for each different range of the ore content.
With the solutions in accordance with the invention, different types of enrichment processes can be optimized depending on the ore content and the location of the ore, or alternatively, the right types of enrichment processes can be chosen for each different homogenized ore content, thus intensifying the enrichment process and the metal amount received from the ore.
More specifically, the method according to the present invention is characterized by what is stated in the characterizing part of Claim 1 , and the apparatus according to the present invention is characterized by what is stated in the characterizing part of Claim 10 .
DETAILED DESCRIPTION OF THE INVENTION
The invention will be described in more detail by way of example in the following, with reference to the enclosed drawing, wherein
FIG. 1 is a schematic drawing of the heap leaching process.
In the heap leaching process shown in FIG. 1 , ore is stacked onto a base 2 for example by means of a conveyor system (not shown) to form a heap. When building up the heap, the conveyor system travels along the front edge of the heap in the transversal direction feeding ore to form a heap of a desired height and width. Correspondingly, the heap is unloaded after the desired leaching time from the rear end of the heap, for example by means of a conveyor system (not shown) connected to a bucket loader, the desired leaching time being for example three years. The form of the heap as a top view can be preferably round or elliptical (f.ex. form of C), whereby the area required by the heap can be optimized and the heap loaded and unloaded according to this form.
The desired liquid dissolvent is sprayed from a tank 3 via pipe line 4 . The solvent can be acid or microbes mixed to the liquid, or a mixture of those. In the solutions known in the art, the solvent is sprayed evenly to the heap with continuous feed during the whole leaching time.
After the liquid dissolvent has flown through the heap and dissolved the desired metal into itself, the enriched liquid is collected from the draining base 2 via receiving points connected to the receiving pipeline 5 . The enriched liquid dissolvent is lead through the receiving pipeline 5 to the separation process 6 , from where the recovered solvent is moved back to the tanks 3 for reutilization.
Also air can be blown to the heap through a pipeline 7 , in order to intensify the leaching by the microbes. Correspondingly, through the pipeline 7 or alternatively also through the pipeline 4 , also nutrients can be dispensed to the microbes, when necessary.
In a solution according to one embodiment of the invention, the conveyor system building up the heap 1 is equipped with a gauge of ore content of the ore to be fed, monitoring on-line the ore content of the ore to be fed. This kind of a gauge can be for example a sensor arrangement based on x-ray or laser technology. In this way the information on the ore content of the ore fed to the ore heap can be collected. In addition, the location of the conveyor system is monitored, for example by means of a solution based on a satellite positioning system, triangulation, base station positioning, coordinate positioning or another corresponding system, based on which the positioning information on the location of the ore in the heap can be defined in the plane coordinate system. Based on these two pieces of information, the ore content of the heap at each point of the heap can be defined. The location of the fed ore in vertical direction can also be determined, when necessary, by measuring the height of the heap to be built up, but it is not essential information in the heap leaching process, because the liquid dissolvent flows through the heap in the vertical direction of the heap.
Based on the information on the ore content in different points of the heap 1 , a correct amount of liquid dissolvent can be supplied to each point of the heap with the necessary means through the pipeline 4 .
Also the measurement of the ore content dissolved from the heap 1 can be included in the system, and based on that the spraying of the liquid dissolvent to the heap can be controlled as a function of the change of the ore content. The enriched liquid dissolvent diluted from the heap 1 is collected to the base 2 , from where it is collected through the discharge openings and the receiving pipeline 5 to the separation process 6 , where the metal diluted to the liquid dissolvent is separated from the liquid dissolvent. Because each of the discharge openings corresponds to a certain portion of the heap, by arranging in connection with each of the discharge openings the measuring of the metal content of the liquid dissolvent dissolved from the heap, the ore content dissolved from each portion of the heap can be detected. Based on that information, the quantity of the liquid dissolvent to be sprayed can be regulated to correspond to the remaining ore content in each portion of the heap.
In a solution according to another embodiment of the invention, the ore content of the ore received from the ore crushing and agglomeration process is monitored on-line, and the ore is separated to different destinations according to the desired ore contents. Thereby for example in the heap leaching, several different heaps can be formed depending on the ore content, and the spraying of the liquid dissolvent can be controlled to the whole heap according to the ore content data received from the classification of the ore. Thus, the pre-distribution of the ore acts as a kind of an ore homogenizer. By this kind of a solution also for example the heap leaching process can be intensified.
The solution in accordance with the invention is not limited to the measurement and enrichment of the ore content of metallic ores, but it can be applied to any ore type, for which the further treatment of the ore in question can be intensified by means of the on-line measurement information and positioning information or alternatively homogenizing.
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Method and apparatus for determining the ore content and for further treatment of the ore, the ore content of the crushed ore being monitored in the method on-line and the information on the ore content being utilized in the further treatment of the ore.
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CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a continuation-in-part of design patent application Ser. No. 29/183,333, filed Jun. 9, 2003, entitled, “Wireless Number Pad”, and design patent application Ser. No. 29/183,332, filed Jun. 9, 2003, entitled, “Wireless Keyboard.” This application is related to co-pending application Ser. No. 60/484,629, filed even date herewith, entitled “Wireless Input Devices for Computer System”, the disclosure of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
The present invention relates to wireless computer input devices, and in particular to keyboards using Bluetooth™ wireless technology.
Microsoft has recently released a combination wireless keyboard and mouse using Bluetooth™ technology, which communicates with a wireless hub. The hub connects to the computer via a cable to the USB port of the computer.
Logitech, the assignee of the present application, makes a cordless keyboard and mouse using 27 mHz radio transmissions to a wireless hub connected to a USB receiver, connected to the computer.
A number of keyboards incorporate a small LCD display, such as U.S. Pat. No. 5,181,029. A keyboard with a flat panel display is shown in U.S. Pat. No. 6,396,483.
A number of patents disclose providing indicators on a keyboard for notification of an e-mail message, such as U.S. Pat. Nos. 6,085,232 and 6,088,516.
U.S. Pat. No. 6,114,977 discloses a calculator integrated with a keyboard with a send key for sending the data on the calculator to an application on the computer.
Separately from keyboard, numerous remote control devices exist which have a display and keys. For example, U.S. Pat. No. 5,412,377 illustrates a hand-held remote with an LCD display.
BRIEF SUMMARY OF THE INVENTION
The present invention uniquely separates the number pad from a keyboard providing a separate, wireless device. This separate wireless device with the number pad includes a display and has multiple modes of operation.
In a first mode of operation, the device acts as a classic number pad. In a second mode of operation, the device acts as a calculator. The calculated result can be automatically uploaded to the clipboard of application software on a computer through a wireless hub. In a third mode, the device provides a navigating function, allowing navigation through options in application software either on a PC display or on a small display on the device, which has been described as a MediaPad™ device.
In one embodiment, the MediaPad™ device includes a media button for launching a media application for playing music or displaying video or pictures. This media button is duplicated on the keyboard.
For a further understanding of the nature and advantages of the invention, reference should be made to the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram illustrating the components of a system according to the present invention.
FIG. 2 is a perspective view of the keyboard of FIG. 1 .
FIG. 3 is a perspective view of the MediaPad™ device of FIG. 1 .
FIG. 4 shows a portion of the MediaPad™ device of FIG. 3 , illustrating the LCD display.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a wireless keyboard 10 , wireless mouse 12 and wireless MediaPad™ device 14 . All three of these communicate with a wireless hub 16 , which is connected via a USB cable 18 to the USB port of a computer 20 . The computer can be loaded with software from a compact disk 22 , and includes a display 24 .
Keyboard 10 , mouse 12 and MediaPad™ device 14 all communicate using Bluetooth™ technology with hub 16 . Hub 16 also acts as a battery charger for charging the batteries of mouse 12 , which is preferably an optical mouse.
FIG. 2 illustrates keyboard 10 in more detail. The keyboard includes a standard alpha-numeric key array 26 , and function keys 28 . In addition, it includes a media button 30 for launching a media application which can play music, videos, and display pictures. Media button 30 is visually linked to a four-way button 32 for selecting among media options, such as stop, forward, reverse and play/pause. Buttons 30 and 32 are visually linked by a plate 34 . The keyboard also includes a volume up button 36 , volume down button 38 and mute button 40 .
MediaPad™ device 14 is illustrated in more detail in FIG. 3 . The MediaPad™ device includes a liquid crystal display (LCD) 42 . A number pad 44 is included, and a number pad button 46 selects the number pad function for the number pad buttons. A navigate button 48 selects the alternate functions for these number pads. In one embodiment, button 1 is “open”, button 3 is “closed”, button 7 is “back”, button 9 is “forward”, button 5 is a Windows Start launching button, and buttons 4 , 8 , 6 , and 2 are directional arrows for left, up, right, and down, respectively.
Also included is a clear button 50 , an enter button 52 , a subtraction button 54 , an addition button 56 , and backslash (/) and asterisk (*) buttons as indicated. A calculate button 58 activates a calculator application.
The MediaPad™ device also includes buttons which duplicate buttons on the keyboard. These are the volume up button 36 , mute button 40 , and volume down button 38 , as well as media button 30 , four-way button 32 and plate 34 .
In one embodiment, the MediaPad™ device also includes a scrolling wheel 60 which allows scrolling up or down in any application. In addition, a rocker switch 62 or a wheel could be used to allow zooming in and out of any type of document.
The number pad and calculator can be used with the computer display, or with the small display on the MediaPad™ device itself. The LCD can also display a variety of other information, which is either a subset of what is on the computer display or separate from what is on the computer display. For example:
(1) Music related information, such as the artist's name, song title or track number.
(2) Video-related information, such as the track name and length of video.
(3) Digital pictures related information, such as the name of the picture, and preview of the next image while running a slide show on the monitor.
(4) E-mail notification, a notification one has received a new e-mail in the mailbox.
(5) Instant messaging—the buddy list, instant messages, text messages relayed from a cell phone, etc.
(6) News notifications, such as news headlines, sports scores, and stock prices. The MediaPad™ device can then be used to get more detailed information from the PC monitor. The navigation button allows selection of what should be displayed on the LCD.
By putting the number pad on the MediaPad™ device of the present invention, the keyboard can be made smaller, and more flexibility is provided for the arrangement of the keyboard, mouse and MediaPad™ device on a desktop. For example, the mouse can be placed closer to the keyboard, with the MediaPad™ device being placed on the outside where a mouse would normally be. This allows the user to easily reach the mouse from the keyboard. The low profile and zero degree slope surface of the keyboard and MediaPad™ device shifts the wrist of the user to a more neutral posture. Alternately, the MediaPad™ device can be placed on the left for left-handed users.
FIG. 4 illustrates the display of the MediaPad™ device in more detail, showing the example of a song being played, with the top line showing the artist (the group U2), the track number, and the title of the track. The second line shows the status (playing) and the current elapsed time.
Hub 16 of FIG. 1 allows other devices to be connected as well via the Bluetooth™ technology. For example, a connection to a printer can be established, so that print jobs can be initiated from the keyboard, mouse or MediaPad™ device by instructions to application software on the computer, which will then send the print job over the USB cable 18 to the hub 16 , which includes a transmitter for sending, using Bluetooth™, the print job to a Bluetooth™-equipped printer.
A mobile phone or PDA can also be in communication with Bluetooth™ hub 16 . Both can synchronize with the software on the computer through the Bluetooth™ hub. Data, photos, etc. can be shared between the mobile phone, PDA, PC and MediaPad™ device. The shared photos or other data could be sent by e-mail or other applications. SMS or text messages received by a cell phone can also be shared via the Bluetooth™ hub when the cell phone is within Bluetooth™ distance of the hub. For example, an SMS text message can be sent from the cell phone, through hub 16 to MediaPad™ device 14 for display on the MediaPad™ device's display. A dialog box can be created on the computer display, and the user, once notified, can go to a keyboard 10 to reply to the text message. This allows a user to use the desktop keyboard, instead of the phone, to do a text message reply.
In another embodiment, a Bluetooth™ headset is used to communicate with hub 16 . This can be used for listening to music, or for using a headset and microphone after launching instant message or chat, with the communication over the Bluetooth™ link to hub 16 , and from there over the IM application running on the computer 20 .
The present invention with its MediaPad™ device thus allows the personal computer to be used as a real media center, controllable from anywhere within Bluetooth™ range. The MediaPad™ device can be used either with the computer display in a desk usage mode, or using its own LCD display in a mobile usage mode. Information can be exchanged in both directions between the computer and the MediaPad™ device. The LCD display allows the user to have visibility and understanding of the computer application status. The two displays can be used together, with the user using control information on the MediaPad™ device display, for example, but actually viewing a video or photo on the computer display.
As will be understood by those of skill in the art, the present invention could be embodied in other specific forms without departing from the essence of the invention. For example, the display could be LEDs instead of an LCD, a wireless technology other than Bluetooth™ could be used, and the hub could be integrated into a laptop or other computer. Accordingly, the foregoing description is intended to be illustrative, but not limiting, of the scope of the invention which is set forth in the following claims.
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The present invention uniquely separates the number pad from a keyboard providing a separate, wireless device. This separate wireless device with the number pad includes a display and has multiple modes of operation.
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FIELD OF INVENTION
The present invention relates to dispensers and dispensing systems for bags.
BACKGROUND
Consumers and shoppers purchasing items, such as produce or other grocery items, often use bags to collect and carry those items. In many stores, the bags are stored in and dispensed from dispensers.
SUMMARY OF THE INVENTION
The present invention provides a novel and useful dispenser for bags. In one embodiment, the invention is a dispenser that includes one or more braking surfaces for contacting a portion of a wound roll of bags; two support arms configured to receive a wound roll of bags therebetween; at least one tab on each support arm configured to engage a core of the wound roll of bags and to provide an inward force against the wound roll of bags; and a separator positioned relative to the braking surface to separate an individual bag from the wound roll of bags. In addition, the two support arms are positioned relative to the one or more braking surfaces so as to allow the wound roll of bags to contact at least one of the braking surfaces when the core of the wound roll of bags is engaged by the tabs. The two support arms also are configured to swivel so that the wound roll of bags remains in contact with at least one of the braking surfaces as the wound roll of bags is depleted.
In another embodiment, the present invention is a dispensing system for dispensing individual bags from a wound roll of bags. In one embodiment, the dispensing system includes a wound roll of bags having a core and comprising a plurality of bags that are continuously and detachably connected. The dispensing system also includes a dispenser that includes a braking surface for contacting a portion of a wound roll of bags; two support arms configured to receive a wound roll of bags therebetween; at least one tab on each support arm configured to engage a core of the wound roll of bags and to provide an inward force against the wound roll of bags; and a separator positioned relative to the braking surface to separate an individual bag from the wound roll of bags. In addition, the two support arms are positioned relative to the braking surface so as to allow the wound roll of bags to contact the braking surfaces when the core of the wound roll of bags is engaged by the tabs. The two support arms also are configured to swivel so that the wound roll of bags remains in contact with at least one of the braking surfaces as the wound roll of bags is depleted. In the dispensing system, the tabs engage the core of the wound roll of bags, and a portion of the wound roll of bags contacts a portion of the braking surface.
The present invention may be better understood by reference to the description and figures that follow. It is to be understood that the invention is not limited in its application to the specific details as set forth in the following description and figures. The invention is capable of other embodiments and of being practiced or carried out in various ways.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects, and advantages of the present invention are better understood when the following Detailed Description is read with reference to the accompanying drawings, wherein:
FIG. 1 is a perspective view of a dispenser in accordance with an embodiment of the present invention;
FIG. 2 is a top view of the dispenser embodiment illustrated in FIG. 1 ;
FIG. 3 is a side view of the dispenser illustrated in FIG. 1 ;
FIG. 4 is a perspective view of the support arms, tabs, and spring coils of the dispenser embodiment illustrated in FIG. 1 ;
FIG. 5 is a schematic top view of the components illustrated in FIG. 4 ;
FIG. 6 is a perspective view of the dispenser embodiment illustrated in FIG. 1 , wherein the dispenser is loaded with a roll of bags;
FIG. 7 is a front view of a bag that may be used in connection with the dispenser embodiment of FIG. 1 ;
FIG. 8A is a side view of the dispenser in FIG. 1 having a roll of bags loaded thereon;
FIG. 8B is a side view of the dispenser in FIG. 8A after the roll of bags has been partially depleted;
FIG. 8C is a side view of the dispenser in FIG. 8C after the roll of bags has been further depleted;
FIG. 9 is a side view of the dispenser of FIG. 1 with a loaded roll of bags illustrating various positions of the dispenser components as the roll of bags becomes depleted;
FIG. 10 is a perspective view of an alternative embodiment of support arms, tabs, and spring coils that can be used with various embodiments of dispensers of the present invention;
FIG. 11 is a perspective view of an alternative embodiment of support arms, tabs, and spring coils that can be used with various embodiments of dispensers of the present invention;
FIG. 12 is a perspective view of an alternative embodiment of support arms, tabs, and spring coils that can be used with various embodiments of dispensers of the present invention;
FIG. 13A is a perspective view of an alternative embodiment of a dispenser of the present invention;
FIG. 13B is a perspective view of an alternative embodiment of a dispenser of the present invention;
FIG. 14 is a perspective view of an alternative embodiment of a dispenser of the present invention having a roll thereon show in shadow;
FIG. 15 is a perspective view of an alternative embodiment of a dispenser of the present invention;
FIG. 16 is a perspective view of an alternative embodiment of a dispenser of the present invention; and
FIG. 17 is a perspective view of an alternative embodiment of a dispenser of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
The use of reference characters with the same two ending digits as other reference characters to indicate structure in the present specification and drawings, without a specific discussion of such structure, is intended to represent the same or analogous structure in different embodiments. For example, and as further seen herein, the structures indicated by reference characters 108 , 508 , 608 , 708 , and 808 all indicate the separator of a bag dispenser in various embodiments of the present invention.
Embodiments of the present invention include bag dispensers and dispensing systems for a wound roll of continuously and detachably separable bags, and FIGS. 1-3 depict an illustrative embodiment of a dispenser of the present invention in which dispenser 100 has plate 102 with braking surface 103 , frame 106 , support arms 110 , tabs 114 , and separator 108 . As depicted in FIG. 1 , plate 102 is shown as a single plate that may be formed in a three-sided cradle position. In alternative embodiments, more than one plate 102 may be present, with each plate 102 optionally adhered or joined to another plate 102 or spaced apart from each other. In further embodiments, plate 102 can be planar or of various shapes and geometric configurations. In alternative embodiments, dispenser 100 can have an open construction made of wire or frame without plate 102 .
Plate 102 has braking surface 103 , which is positioned to have at least partial contact with a roll of bags when loaded in dispenser 100 . In some embodiments having more than one plate 102 , each plate 102 may have braking surface 103 . In other embodiments having more than one plate 102 , less than each plate 102 will have braking surface 103 . In alternative embodiments, frame 106 may have braking surface 103 in addition to or in lieu of braking surface 103 on plate 102 . As shown in FIGS. 8A-8C , the portions of braking surface 103 that may contact a roll of bags 120 may vary as the roll of bags 120 is depleted.
In the embodiment shown in FIGS. 1-2 , plate 102 has mounting holes 104 , which can vary in number, size, and location in accordance with the present invention. Mounting holes 104 permit dispenser 100 to be attached to a post, wall, stand, counter, shelf, or other suitable supporting beam or surface by use of conventional fasteners such as nails, screws, bolts, or the like. In alternative embodiments, mounting holes 104 are optional and dispenser 100 can be attached to a surface or structure using alternative attachment means that are readily known in the art, such as adhesion. In other embodiments, dispenser 100 can rest freely on a surface, such as a counter top or shelf, without the use of mounting holes 104 , fasteners, or any attachment means.
As shown in FIGS. 1 and 2 , plate 102 is mounted onto frame 106 , which extends under the braking surface as shown with dashed lines in FIG. 2 . As illustrated in FIGS. 1-2 , separator 108 is attached to plate 102 , which can be by any conventional means, such as welding or bonding. In alternative embodiments, separator frame 108 may be attached to frame 106 . In other embodiments, frame 106 may be a wire frame and may extend beyond plate 102 to form separator 108 , in which embodiment frame 106 and separator 108 are integral. In yet other embodiments, separator 108 may be integral with or attached to plate 102 , and frame 106 may optionally be excluded from dispenser 100 .
Separator 108 can have various shapes and formations. As shown in FIG. 1 , separator 108 is a tongue pointed upwards. In other embodiments, separator 108 can be a tongue pointed downwards. In alternative embodiments, separator 108 can be any structure that is configured to separate a bag from a wound roll of bags. Examples of separators that can be used in the present invention are disclosed in U.S. Published Patent Application No. 2010/0316309 (U.S. patent application Ser. No. 12/813,695, filed on Jun. 11, 2010) and which is incorporated herein in its entirety by reference thereto. By way of example, separator 108 can be a double tongue or a plate with a slot. In some embodiments, separator 108 may be angled in a direction toward frame 106 .
In addition, the position of separator 108 can be varied so long as it is positioned to engage and separate a bag being dispensed from the dispenser. In some embodiments, separator 108 may be located in close proximity to a loaded roll of bags. In some embodiments, separator 108 may be located about 0.5 to 1.0 inch from a roll of bags. In addition, the top of separator 108 may be in the same plane as the most immediate portion of the braking surface, as shown in FIG. 3 with regard to plate 102 and separator 108 .
As shown in FIGS. 1-2 and in isolation in FIGS. 4-5 , wire 109 forms support arms 110 , spring coils 112 (depicted as each having three coils in the particular embodiment shown in FIGS. 1-2 and 4-5 ), and tabs 114 . Although support arms 110 , spring coils 112 , and tabs 114 are shown in FIG. 1 as integrally formed from wire 109 , some or all of these components may be constructed of other material and adhered or connected together by conventional means in alternative embodiments. In some embodiments, one support arm 100 , one spring coil 112 , and one tab 114 may be integrally formed.
As illustrated in FIG. 1 , tabs 114 include inner engagement tab 116 and outer grasping tab 118 . However, it will be appreciated that tabs 114 can have alternative shapes and configurations that engage the core of a wound roll of bags. As shown in FIG. 1 , tabs 114 may not extend through the entire core of a wound roll of bags, and some embodiments of dispenser 100 require at least two support arms 110 and two tabs 114 .
In addition, as illustrated in FIG. 1 , tabs 114 may be biased inwardly towards each other. The inward bias of tabs 114 may result from an inward bias of support arms 110 . In particular, support arms 110 may be biased inward due to the bending of support arms 110 and/or bias provided by the closest spring coil 112 to each support arm 110 . In some embodiments, the distance between tabs 114 at their default resting position is less than the width of a roll of bags used with dispenser 100 .
Holder 119 (depicted as a crimp or bend in plate 102 ) engages wire 109 and attaches wire 109 to plate 102 in a manner that permits support arms 110 to swivel as described subsequently herein with respect to FIGS. 8A-C and 9 . Although holder 119 is depicted as a crimp or bend in plate 102 , it will be apparent to one of ordinary skill in the art that different attachments can be used that permit the support arms 110 to swivel as described herein, and such mechanisms are within the scope of the present invention. In other embodiments, support arms 110 may not be directly or indirectly connected to each other and each support arm 110 may be independently attached to frame 106 or plate 102 .
In certain embodiments of the present invention, support arms 110 and spring coils 112 may be constructed of wire, such as stainless steel wire. In some embodiments, it is beneficial if the wire has an adequate combination of flexibility and force for the dispenser to function as described subsequently herein. Wire having a composition and hardness suitable for the manufacture of springs, such as music wire per ASTM Specification A228, which is available from suppliers such as United Wire Company, Inc. of New Haven, Conn., has been found to provide the adequate properties in some embodiments of the present invention.
In addition, the placement and number of spring coils 112 in dispenser 100 is a factor in providing the requisite inward force of the tabs 114 . Although each set of spring coils is shown in FIG. 1 as having three coils, the number of coils will vary based upon the location and wire used in a particular dispenser and the desired bias force.
The dimensions of the components of the dispenser can vary based upon the parameters of rolls of bags to be used with the dispenser, but the dimensions should ensure that adequate force is applied to the roll of bags by the tabs as described herein. In certain embodiments, the default resting distance between the tabs is less than the width of the roll of bags for use with the dispenser. Although any dimensions that offer the functionality of the dispenser are within the scope of the present invention, approximate dimensional ranges for illustrative embodiments of the invention include the following with reference to the dimension characters of FIG. 5 :
S: 0.125″ to 0.1875″
T: 0.75″ to 1.25″
U: 0.75″ to 1.25″
V: 3″ to 5″
W: 3″ to 5″
X: 0.25″ to 0.75″
Y: 1″ to 2″
Z: 0.5″ to 2″
In one particular example, the dispenser may have the following dimensions: S=0.156″; T=1.03″; U=0.96″; V=4″; W=4.25″; X=0.5″; Y=1.38″; and Z=0.54″. Other embodiments may have proportions that are approximately relative to these dimensions.
As indicated, the dispenser of the present invention is for use with a roll of bags. FIG. 6 depicts the embodiment of FIG. 1 in which a roll of bags 120 having a core 122 has been loaded onto the dispenser. Core 122 can be the inner most bag itself but is more desirably one or more tube-like inserts within the bag that are constructed of a durable material, such as plastic, and that spans some or all of the width of the roll of bags 120 . In some embodiments, as illustrated in FIG. 6 , core 122 may be completely hollow.
Although it will be readily apparent to a person having ordinary skill in the art that numerous types of bags may be used with dispenser embodiments of the present invention, some rolls of bags used with the present invention may have a plurality of continuously and detachably separable bags. An example of a roll of bags that can be used in the present invention is disclosed in U.S. Published Patent Application No. 2010/0316309 (U.S. patent application Ser. No. 12/813,695).
As an example of a roll of bags that may be used with dispensers of the present invention, FIG. 7 illustrates in more detail roll of bags 120 shown in FIG. 6 . As shown in FIG. 7 , roll of bags 120 with core 122 has been partially unwound to show bag 124 and bag 125 . As depicted, bag 124 has a bottom end 126 that is formed by a heat seal, a mouth end 128 , two opposing faces 130 , and two opposing lateral sides 132 . As shown, bottom end 126 and mouth end 128 are on opposing longitudinal ends. In the depicted embodiment, bag 124 is shown with gussets 133 on each side 132 . Bag 125 , which is identical to bag 124 but without all features shown in the illustration, is continuously and detachably connected to bag 124 by perforation line 134 . Perforation line 134 generally comprises alternating cuts, in which the tubing forming the bag is severed, and the uncut portions between the cuts in the perforation line are called ties.
FIG. 7 also depicts center slit 136 in perforation line 134 , although it will be understood by one of ordinary skill in the art that center slit 136 alternatively can be located on either longitudinal side of perforation line 134 , such as closer to mouth end 128 or bottom end 126 . In another embodiment, the center slit 136 can alternatively be located closer to one of opposing lateral sides 132 . In similar manner, additional bags are continuous and detachably connected in series similar to the arrangement and attachment of bag 124 to bag 126 and are wound into a roll of bags 120 . It is apparent that other types of bags are contemplated for use in the present invention, including, for example, folded or unfolded, gusseted or nongusseted, sealed or star-sealed bags, and combinations thereof. Other bags for use with the dispenser of the present invention are readily apparent to those of ordinary skill in the art.
In order to load roll of bags 120 onto dispenser 100 , with reference to FIGS. 1 and 6 for illustration, tabs 114 , which are biased inwards toward each other, may be pulled outwardly apart from each other to separate them with sufficient distance such that a roll of bags can be placed between them. For convenience, the user may grasp outer grasping tabs 118 , when present, to assist with separating tabs 114 to load the roll of bags. After placing roll of bags 120 between tabs 114 such that engagement tabs 116 are aligned with core 122 , tabs 114 are released and permitted to move back inwardly toward each other such that engagement tabs 116 engage core 122 of the roll of bags 120 (as shown in FIGS. 6 and 8A -C). It is beneficial in some dispenser embodiments of the present invention if support arms 110 swivel at a point such that roll of bags 120 maintains a constant or approximately constant distance from separator 108 .
When a roll of bags 120 is loaded on the dispenser of the present invention, the roll of bags may be automatically centered with respect to separator 108 , i.e., the roll of bags may be aligned in the left to right direction such that an optional center slit (not shown) on the bags in the roll is aligned with the dispenser's separator 108 . This feature avoids the necessity of a user having to manually center the bags on the dispenser and eliminates centering errors. In addition, the support arms 110 and tabs 116 maintain the roll of bags 120 in a centered position, which prevents the roll of bags from undesirably wobbling or sliding as observed in other types of dispensers. Tabs 114 engagement with the core of the roll of bags also prevents the roll from undesirably “jumping” out of the dispenser when a hag is pulled by a user for dispensing, which has been found to occur in some other commercial dispensers (especially when the user pulls on the bag being dispensed with a large degree of force and the roll of bags is nearing depletion and has less mass). In addition, as a result of tabs 114 positioning roll of bags 120 , roll of bags 120 may be automatically centered and positioned in the front to back direction within dispenser 100 due to the cradle shape of the plate 102 and the positioning by tabs 114 .
With reference to FIG. 6 , because a roll of bags is loaded between tabs 114 , which may be biased inward, dispenser 100 may advantageously allow for the use of rolls of bags having different widths. For example, in some embodiments of the present invention, a dispenser can hold a roll having a width from three inches to five inches. In other embodiments of the present invention, both smaller or larger rolls width rolls of bags can be used. In addition, unlike other commercial dispensers, there is no need for the core of the roll of bags to be greater than the width of the roll of bags for use with the dispenser of the present invention, which results in material, cost, and waste savings.
With reference to FIGS. 1, 6, and 7 , a person desiring to dispense a bag from dispenser 100 , such as a shopper or consumer, may pull the outermost bag (bag 124 ) on roll of bags 120 toward separator 108 . When a user pulls bag 124 from roll of bags 120 toward separator 108 , center slit 136 may be engaged by separator 108 . As a result, separator 108 may provide a force to begin tearing perforation line 134 in each outward direction from center slit 136 . As a result of perforation line 134 tearing, bag 124 may be separated and dispensed from roll of bags 120 . In other embodiments, the bags may lack a center slit 136 and the separator 108 could directly engage perforation line 134 .
In operation, the dispenser of the present invention may beneficially prevent or significantly diminish any overspin (or freewheeling) of the roll of bags by applying various braking forces to the roll of bags. First, a gravitational force provides a braking function. For instance, FIGS. 8A-8C depict a side view of the embodiment of dispenser 100 shown in FIG. 1 at various stages of the dispensing process as roll of bags 120 have been gradually depleted. Similarly, FIG. 9 depicts this depletion of the roll of bags with shadow images. As illustrated, because support arms 110 are capable of rotating or swiveling in a direction such that a portion of roll of bags 120 remains in contact with braking surface 103 as roll of bags 120 is depleted. As a result, a downward gravitational force exists that is proportional with the mass of the roll of bags, and this force serves a braking function on the roll of bags 120 against braking surface 103 . A frictional braking force also exists due to the contact of the roll of bags 120 against braking surface 103 .
In addition, because support arms 110 and, correspondingly, tabs 114 may be biased inwardly towards each other, there may also be an inward force exerted on each side of roll of bags 120 by tabs 114 . In certain embodiments, this force may result from the resting (or default) position between tabs 114 being a lesser distance than the width of a loaded roll of bags 120 . This force that is applied by tabs 114 may provide a braking mechanism that prevents or reduces overspin (or freewheeling) of roll of bags 120 during dispensing. In addition, as indicated above, this configuration may also permit a dispenser of the present invention to accommodate rolls of bags of various widths due to the possibility of tabs 114 being separable to varying degrees.
Dispensers of the present invention may provide a sufficient braking force to reduce or eliminate the roll of bags overspinning or freewheeling even as a roll of bags is depleted. This operation is advantageous over previous dispensers in which a roll of bags is more likely to overspin as the number of bags is diminished due to the decreased gravitational and frictional forces. As a result, partially-diminished rolls of bags prone to overspinning have been conventionally discarded prematurely when used with previous dispensers, thereby increasing costs and waste.
In particular, with dispensers of the present invention, such as shown in FIGS. 8A-8C , a larger roll of bags 120 shown in FIG. 8A contacts greater surface area of braking surface 103 than the smaller (more depleted) roll of bags in FIG. 8C . In addition, the mass of the larger roll of bags 120 in FIG. 8A is greater than the mass of the more depleted roll of bags 120 in FIG. 8C . As a result, the gravitational force and friction on the roll of bags in FIG. 8A is greater than that force on the more depleted roll of bags 120 in FIG. 8C . Furthermore, as compared with the more depleted roll of bags 120 in FIG. 8C , there is also a greater mechanical advantage for dispensing the larger roll of bags 120 shown in FIG. 8A , such that the pull force felt by a user to dispense a bag is not excessive for a large roll of bags.
However, as support arms 110 swivel toward braking surface 103 as roll of bags 120 is depleted, the inward force from tabs 114 is not diminished but instead remains constant. As a result, an adequate amount of force is applied to the roll of bags 120 to prevent overspin even as the bags are used. This function is advantageous over previous dispensers that have insufficient braking force as the number of bags is being diminished. In addition, although the mechanical advantage is decreased as the bags are depleted, the gravitational and frictional braking forces have diminished. As a result, the user may experience a nearly constant pull force to dispense a bag as the bags are depleted.
As discussed above, the bias force applied by tabs 114 to a roll of bags 120 in the present dispenser is a significant factor in the operation of the dispenser of the present invention. The force necessary to separate tabs in dispensers of the present invention relates to the amount of force applied to a roll of bags after being loaded. In some embodiments of the present invention, the inward force of tabs when engaged with the core of a loaded roll of bags is from about 0.5 pounds of pressure to about 2.0 pounds of pressure, which corresponds with a deflection of about 0.5 to about 2.0 inches of deflection of tabs in certain embodiments.
In addition, embodiments of the dispenser having a spring coil, and particularly a spring coil associated with each support arm such as spring coils 112 in FIG. 1 , provide for a range of motion such that tabs can be separated to accommodate a wide variety of widths of bag rolls. By contrast, support arms that do not have spring coils, such as the embodiments shown in FIGS. 13A-B and 14 , may have a limited range of motion, thereby restricting the range of bag roll widths that can be loaded. For example, the inward pressure of tabs at a point with the arms deflected to be approximately parallel in a dispenser embodiment having two spring coils (with three coils per spring coil) was measured at 2.0 pounds of pressure, whereas the same measurement for tabs on a u-shaped wire without spring coils was measured at 10.5 pounds of pressure. Accordingly, dispenser embodiments having spring coils may permit the use of a larger range of bag widths than similar dispenser embodiments without spring coils.
Tests confirm that dispensers of the present invention in which tabs provide an inward bias on a roll of bags beneficially decrease or eliminate the likelihood of the roll of bags overspinning or freewheeling. In particular, the force necessary to pull a bag forward on a roll of bags having a width of 3.75 inches was measured on multiple dispensers at two stages: (i) when the roll had a 7-inch diameter and weighed 4.39 pounds and (ii) after being partially depleted such that the roll diameter was reduced to 1.5 inches and the weight was reduced to 0.09 pounds. Three alternative dispensers were tested: (i) a commercial dispenser available in the market that is similar to the dispenser shown in FIG. 7 of U.S. Pat. No. 6,279,806, (ii) a dispenser of the present invention having the embodiment shown in FIG. 1 , and (iii) a cradle dispenser in which the roll of bags freely rests without any inward bias, as depicted in FIG. 2 of U.S. Pat. No. 7,270,256. Each bag was tested using a slow, medium, and fast pull, and the following results indicate the average pull force required to pull a bag forward using each dispenser:
Roll
Commercial
Invention
Cradle
Diameter
Dispenser
Embodiment
Dispenser
7″
2.45 LBS
3.05 LBS
2.2 LBS
1.5″
1.1 LBS
2.1 LBS
0.05 LBS
A greater requisite force to pull a bag forward indicates that a greater braking force exists on the roll of bags. With a greater braking force, the roll of bags is less likely to overspin or freewheel. Accordingly, as evidenced by the test results shown above, the invention embodiment tested provides an improved braking force on the roll of bags, thereby improving the dispensing process by diminishing overspinning as a roll of bags is depleted. In addition, the tested embodiment of the invention was the only dispenser tested in which the force required to pull a bag forward from the smaller roll was consistently greater than the weight of the smaller roll.
In addition, it was observed during the testing that the smaller roll of bags was likely to jump out of the cradle dispenser when a relatively quick motion was used to dispense a bag. In addition, the cradle dispenser lacked adequate resistance or braking force to consistently engage bags on the smaller roll on the separator. It was also observed that bags in the commercial dispenser were also likely to jump out of the dispenser if the bags were pulled quickly in an upward motion, which is a practical scenario for use in commercial settings. By contrast, these disadvantages were not observed with dispensers of the present invention.
The tendency for a depleted roll of bags to overspin and jump out of the other dispensers may be due in part to the increasing spin speed of the roll of bags as the bags become depleted. In particular, when a user pulls at a rate of 22 inches per second, a 7-inch diameter roll of bags will rotate at approximately 1 revolution per second. By contrast, when a 1.4-inch diameter roll of bags is pulled at the same rate, it will rotate at approximately 5 revolutions per second, which is nearly five times faster than the larger roll. This increased spin speed likely contributes to depleted rolls of bags overspinning or jumping from dispensers. However, with the configuration of the dispensers of the present invention, these unfavorable characteristics may be overcome.
FIGS. 10-12 depict illustrative alternative embodiments of components that can be used with dispensers of the present invention. The various examples of components shown in FIGS. 4 and 10-12 are all designed in a manner so that when used with a particular dispenser embodiment, a sufficient force is applied to a roll of bags to reduce or eliminate overspinning during dispensing. These examples are illustrative in nature and do not exclude other embodiments from within the scope of the present invention.
For instance, FIG. 10 shows two support arms 210 , spring coil 212 , and tabs 214 formed from wire 209 . Tabs 214 are biased inwardly towards each other and have an inner engagement tab 216 and an outer grasping tab 218 . In this embodiment, spring coil 212 is a single set of multiple coils. Although the components in this embodiment and other illustrative embodiments are shown as integrally formed from wire 209 , some or all of these components may not be integral in other embodiments.
FIG. 11 shows support arms 310 , spring coil 312 , and tabs 314 formed from wire 309 . As depicted, tabs 314 are biased inwardly towards each other and have an inner engagement tab 316 and an outer grasping tab 318 . In this embodiment, inner engagement tabs 316 , which are shown as loops of wire for grasping by the user, are not integral to the support arms 310 but are attached by any conventional means, such as welding or bonding. In addition, spring coil 312 is shown as a single coil set (which has multiple coils therein) and is not integrally formed from the same wire forming support arms 310 . Instead, in this depicted embodiment, spring coil holder 313 is attached to wire 309 at each end of spring coil 312 (although only one spring coil holder 313 can be seen from the view in FIG. 11 ). This attachment can be by any conventional means, such as welding or bonding. Spring coil 312 may be coiled around wire 309 and freely held in position by spring coil holders 313 .
In the embodiment in FIG. 11 , the force of spring coil 312 may maintain or aid in maintaining support arms 310 in a default resting position so that tabs 314 are biased inward. When tabs 314 are separated to load a roll of bags, spring coil 312 may be compressed and exert a force so that tabs 314 exert an inward force on a loaded roll of bags of a magnitude to provide the aforementioned braking force on a roll of bags. In this illustrated embodiment, the distance between tabs 314 may be less than the width of a roll of bags for use in dispenser 300 . In addition, the number of coils in spring coil 312 can vary in alternative embodiments and as suitable for particular applications. In other embodiments, wire 309 may be comprised of two separate wires that are joined (such as with a hinge or other conventional means) at a location within the portion where spring coil 312 is located. In such embodiments, the force exerted by spring coil 312 may be increased due to such a hinged construction.
FIG. 12 depicts an alternative embodiment of the support arms 410 of the present invention. In this embodiment, wire 409 forms support arms 410 and tabs 414 . As illustrated, support arms 410 are shaped such that they serve as S-shaped springs, which may increase the deflection, range of motion, and potential inward bias of support arms 410 . In addition, tabs 414 are biased inwardly towards each other and have an inner engagement tab 416 and an outer grasping tab 418 .
To further illustrate the scope of the present invention, another dispenser embodiment is shown in FIG. 13A . In this embodiment, dispenser 500 is constructed of frame 506 . Plate 502 and plate 502 ′ are mounted on frame 506 , and plate 502 has braking surface 503 . In addition, the upper portion of frame 506 has braking surface 503 . As shown, plate 502 ′ is mounted on the outside of frame 506 . In alternative embodiments, plate 502 ′ can be mounted on the inner side of frame 506 in order to contact a loaded roll of bags such that the upper surface may serve as a braking surface. In other embodiments, both plate 502 and plate 502 ′ can be omitted and the roll of bags can rest upon and contact frame 506 directly so that frame 506 itself serves as the braking surface.
As depicted in FIG. 13A , frame 506 and plate 502 form a cradle structure that corresponds with the cradle structure formed by plate 102 in dispenser 100 shown in FIG. 1 . Plates 502 and 502 ′ also include mounting holes 504 . Dispenser 500 also includes separator 508 that is integral with frame 506 and extends in a downward direction. A single wire, which is attached to frame 506 by holders 519 , forms support arms 510 , and each support arm 510 has tab 514 on its distal end. Tabs 514 are biased inwardly towards each other and have inner engagement tab 516 and outer grasping tab 518 .
As in previously described embodiments, support arms 510 are capable of swiveling in a direction to continually engage a roll of bags with braking surface 503 as the roll of bags is depleted. However, in contrast to the previously-described embodiments, dispenser 500 does not have any spring coils on support arms 510 . Instead, as depicted in this embodiment, tabs 514 are biased inwardly solely by the bending or angling of support arms 510 . Also, in this embodiment, as bags are being unwound from the roll for dispensing, the bags may pass through the open portion of frame 506 at the distal end of dispenser 500 as shown by the arrow. In this manner, frame 506 can also function as a guide channel for the bags being dispensed. To engage separator 508 , the bag being dispensed may be pulled in a slightly upward direction.
For further illustration, FIG. 13B , depicts an identical dispenser to FIG. 13A except that separator 508 ′ of FIG. 13B is depicted as a double tongue. In this embodiment, a bag is dispensed in the same manner as described with FIG. 13A , except the bags are also pulled between upper wire 508 A and lower wire 508 B that form separator 508 ′. The bag being dispensed may be pulled slightly upward to engage the perforation of the bag against upper wire 508 A forming separator 508 ′, such that a perforation tears and separates the bag being dispensed from the subsequent bag in the roll. In this manner, separator 508 ′ also serves the function of guiding the bag during dispensing.
It will be evident to one of ordinary skill in the art that components illustrated in the various illustrative embodiments herein can be interchanged into other embodiments of the invention, just as separator 508 and 508 ′ in FIGS. 13A and 13B can be altered and remain within the scope of the present invention. In addition, it will be apparent to a person of ordinary skill in the art that alternative embodiments of depicted components, such as alternative separators, are known and can be used within the scope of the dispensers of the present invention.
FIG. 14 provides another illustrative embodiment of a dispenser of the present invention that has a roll of bags 620 with core 622 loaded thereon. In this embodiment, dispenser 600 is constructed of a frame 606 , which has plates 602 mounted thereon. Frame 606 and plates 602 form a cradle position. As shown, plates 602 may optionally have a plurality of mounting holes 604 . In addition, plates 602 have braking surfaces 603 , which may contact roll of bags 620 . In alternative embodiments, plates 602 may be integral with each other and with plate 608 ′, and in such embodiments frame 606 can optionally be excluded.
Support arms 610 are attached to plate 602 by holders 619 and may be capable of swiveling in an up and down direction. Although support arms are depicted as formed from a single piece of wire, in other embodiments support arms 610 may be nonintegral to each other and each support arm 610 may be independently attached to plate 602 . Tabs 614 are adjoined to the distal end of each support arm 610 . In this embodiment, tabs 614 do not include an outer grasping tab to assist in separating tabs 614 . In this depicted embodiment, separator 608 is a slot formed within plate 608 ′. In this embodiment, a user pulls the outermost bag on a loaded roll of bags through separator 608 , which then aids in tearing the perforation on the series of bags to dispense a bag.
FIG. 15 shows dispenser 700 constructed of frame 706 with plates 702 mounted thereon. As shown, plates 702 include braking surfaces 703 and mounting holes 704 . Dispenser 700 also includes support arms 710 , spring coils 712 (depicted as each having two coils), and tabs 714 . Tabs 714 are biased inwardly towards each other and have inner engagement tab 716 and outer grasping tab 718 . As illustrated, wire 709 is also attached to dispenser 700 by holder 719 , and wire 709 forms two support arms 710 , two spring coils 712 , and tabs 714 . However, it will be appreciated, as with other illustrative embodiments disclosed herein, that these components can be nonintegral.
Unlike the three-sided cradle structure depicted in FIGS. 1 and 3 , plates 702 in FIG. 15 form a two-sided cradle structure in which braking surfaces 703 contact a roll of bags when loaded on the dispenser. As illustrated with respect to the dispenser embodiment in FIGS. 8A-8C , it is appreciated that each of braking surfaces 703 may not contact the roll at all points of dispensing and less contact with braking surfaces 703 may be present as a roll of bags is depleted. Dispenser 700 also has separator 708 . For illustration of an alternative embodiment, FIG. 16 shows dispenser 700 wherein plate 702 ′ is extended as compared with plate 702 in FIG. 15 . In yet other embodiments, the extended portion of plate 702 ′ in FIG. 16 could consist of a separate plate that is mounted separately upon frame 706 .
FIG. 17 depicts dispenser 800 having plate 802 mounted on frame 806 . In addition, plate 802 has a braking surface 803 and mounting holes 804 . In contrast to the two-sided and three-sided cradle structures discussed in previous embodiments of the present invention, dispenser 800 only has a single braking surface 803 and plate 802 is planar. Dispenser 800 also includes separator 808 . As with other embodiments disclosed herein, it will be appreciated that separator 808 , which is shown as integral with frame 806 , can be nonintegral and alternatively attached or mounted to frame 806 , plate 802 , or both.
Dispenser 800 includes wire 809 that forms support arms 810 , spring coils 812 , and tabs 814 , which may be separately formed and attached to one another in alternative embodiments. Holders 819 attaches wire 809 to plate 802 in a manner that permits support arms 810 to swivel in a vertical direction. In addition, tabs 814 may be biased inwardly towards each other and have inner engagement tab 816 and outer grasping tab 818 . Dispenser 800 also includes separator 808 , which is shown as a tongue. As compared with dispenser 100 in FIG. 1 , in which spring coils 112 have three coils, spring coils 812 each have one coil.
Although the present invention includes different shapes of the plates carrying the braking surface, the three-sided cradle structure offers more contact with a roll of bags and thereby provides a greater force to avoid overspin. In addition, these structures may advantageously provide for centering the roll of bags in the front and back direction of the dispenser and maintain and securing that position and any unwanted movement of the roll of bags.
The foregoing description of illustrative embodiments of the invention has been presented only for the purpose of illustration and description and is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Numerous modifications and adaptations thereof will be apparent to those of ordinary skill in the art without departing from the scope of the present invention.
It will be understood that each of the elements described above, or two or more together, may also find utility in applications differing from the types described. While the invention has been illustrated and described in the general context of bag dispensers, it is not intended to be limited to the details shown, since various modifications and substitutions can be made without departing in any way from the spirit and scope of the present invention. As such, further modifications and equivalents of the invention herein disclosed may occur to persons skilled in the art using no more than routine experimentation, and all such modifications and equivalents are believed to be within the spirit and scope of the invention as described herein.
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A dispenser for bags is disclosed. The dispenser is capable of storing a roll of bags and dispensing individual bags therefrom. In addition, a dispensing system for use in dispensing individual bags from a wound roll of continuously and detachably connected bags is disclosed.
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[0001] This application claims priority from co-pending U.S. Provisional Patent Application No. 60/308,738 (Docket 0396-008) for Flexible Mapping of Circuits into Packets.
FIELD OF THE INVENTION
[0002] This invention relates to communications systems and methods, in particular, to packet communication systems and methods.
BACKGROUND OF THE INVENTION
[0003] Circuit emulation (CEM) systems, such as ATM CES, map native circuit frames received from a circuit into packets or cells. Sometimes this mapping is designed to minimize delay, as with ATM CES. Minimization of delay is accomplished by creating small packets, which minimizes the “capture delay”. Capture delay is the time that it takes to acquire enough incoming circuit frames to create a packet. The drawback to minimizing capture delay is that the ratio of overhead (non-data control information) to data can be high, which leads to inefficient use of bandwidth. Other mappings are designed to increase efficiency and minimize overhead by increasing the number of transported frames, while holding constant the amount of overhead data. Reducing the percentage of overhead in this fashion has the disadvantage of increasing the capture delay.
[0004] Capture delay is one component in the round trip delay (RTD) for a packet to travel from one unit across the network to a second unit and then for a packet to return back from the second unit across the network to the first unit. The prior art has included means for measuring round trip delay, but these means have required the use of special test packets that were sent periodically. The use of periodic test packets adds to the overhead because these packets do not carry a CEM payload. The use of periodic test packets adds another tradeoff between having recent representative data on RTD and sending a large number of test packets without CEM payloads. The term payload is being use here and in the claims that follow to designate “real data” in contrast with packet headers, various types of overhead for sending control data, and dummy data that is called “filler” or “stuff”. Delivering real data (“payloads”) is the purpose for having a system, and everything else just facilitates that process.
[0005] Thus, prior art solutions have forced a fixed choice on the number of payload frames per CEM packet and thus a fixed choice between inefficient use of bandwidth or increasing the capture delay. A further shortcoming is that the prior art has not provided a method of collecting RTD while continuing to carry CEM payloads.
[0006] It is therefore an object of the invention to define a flexible mapping of circuits into packets. This method will allow flexibility in these dimensions:
[0007] The amount of data from a given circuit can be varied manually or automatically based on the measured end-to-end delay or round trip delay (RTD). The amount of data mapped to each packet is inversely proportional to the measured round trip delay.
[0008] If two or more circuits are destined for the same emulation endpoint, their data may be manually or automatically mapped into the same packet.
[0009] It is furthermore the object of this invention to provide a simple means of measuring RTD based on timestamps carried in a CEM packet that also conveys CEM payloads.
SUMMARY
[0010] This disclosure provides a method for dynamically adjusting the number of data frames placed in a data unit or packet based on one or more recent measurements of round trip delay from the source device to a target device and back. Also disclosed is a method for measuring round trip delay by capturing certain relevant time values and transmitting these values within the packets carrying data frames so that new measurements of round trip delay can be made without the use of control packets that do not carry data frames.
[0011] Data structures for use with the disclosed methods are provided for a variety of protocols.
BRIEF DESCRIPTIONS OF THE DRAWINGS
[0012] [0012]FIG. 1 shows the layout of the CEM Protocol Data Unit (PDU) in accordance with one version of the present invention.
[0013] [0013]FIG. 2 shows the placement of multiple CEM PDUs in the same packet in accordance with another version of the present invention.
[0014] [0014]FIG. 3 shows a standard TCP/IP UDP packet to carry the CEM data in accordance with another version of the present invention.
[0015] [0015]FIG. 4 shows the format of a CEM/IP packet carried over Ethernet without a VLAN tag in accordance with another version of the present invention.
[0016] [0016]FIG. 5 shows the format of an IP packet carried over Ethernet with an explicit VLAN tag in accordance with another version of the present invention.
[0017] [0017]FIG. 6 shows a CEM PDU mapped to Multiprotocol Label Switching (MPLS) in accordance with another version of the present invention.
[0018] [0018]FIG. 7 shows a CEM/MPLS packet mapped to Ethernet, with no VLAN tag in accordance with another version of the present invention.
[0019] [0019]FIG. 8 shows a CEM/MPLS packet mapped to an Ethernet frame with an explicit VLAN tag in accordance with another version of the present invention.
[0020] [0020]FIG. 9 shows the state machine for managing the TxTimeDelay timer and the time fields in the PDU in accordance with one version of the present invention.
[0021] [0021]FIG. 10 shows the state machine to control the number of payload frames in a CEM PDU based on the RTD in accordance with one version of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
CEM Format
[0022] The layout of the CEM Protocol Data Unit (PDU) is shown in FIG. 1
[0023] The CEM header is 12 bytes in length, and it is used by the CEM application to multiplex and demultiplex circuits, detect packet loss, maintain packet order, and compute packet network transit delay. A variable number of bytes of Time Division Multiplexing (TDM) data may be carried. Table 1 describes the fields of the CEM Header.
TABLE 1 CEM Header Fields Field Description Values Size CVER Circuit Emulation Version 4 bits CTYPE Circuit Type (T1, E1, T3, E3, OC3, OC12) 0 = T1, 1 = E1, 2 = T3, 4 bits 3 = E3, 4 = OC3, 5 = OC12 COPT Bit mask of options 0xAA55 4 bits TxTime TxTime is valid 1 = valid, 0 = invalid 1 bit EchoTxTime EchoTxTime is valid 1 = valid, 0 = invalid 1 bit TxTimeDelay TxTimeDelay is valid 1 = valid, 0 = invalid 1 bit More More CEM frames after this one 1 = more, 0 = this is the last 1 bit CFRAMES Number of Native Circuit Frames contained in 1 to 15, 0 = 16 frames 4 bits the packet CEM LABEL Circuit Emulation Label 16 bits CEM SEQUENCE# Sequence Number for packet loss detection 0 to 65535 16 bits and reordering TxTimeDelay Clock ticks between receipt of Transmit # of 125 μs ticks 16 Bits Timestamp and transmission of this packet. This is used to account for holding delay. TxTime Transmit Timestamp In units of 125 μs ticks 16 Bits EchoTxTime The last captured TxTime from the Far Side In units of 125 μs ticks 16 Bits
[0024] Multiple CEM PDUs can be placed in the same packet, as shown in FIG. 2. For the PDUs shown in FIG. 2, the “More” bit in the COPT field would be set to “1” for CEM PDUs # 1 and # 2 and to “0” for PDU # 3 .
CEM Mappings
[0025] CEM Over IP Format
[0026] The mapping of CEM to IP uses a standard TCP/IP UDP packet to carry the CEM data. The layout of this packet is shown in FIG. 3.
[0027] [0027]FIG. 4 shows the format of a CEM/IP packet carried over Ethernet with no VLAN tag.
[0028] [0028]FIG. 5 shows the format of an IP packet carried over Ethernet with an explicit VLAN tag.
[0029] CEM Over MPLS
[0030] A Multiprotocol Label Switching (MPLS) label is 2 bytes in length. FIG. 6 shows a CEM PDU mapped to MPLS.
[0031] [0031]FIG. 7 shows a CEM/MPLS packet mapped to Ethernet, with no VLAN tag. Those of skill in the art understand the use of the VLAN tag for use in an architecture for Virtual Bridged LANS, such as found in IEEE Standard 802.1Q-1998 IEEE Standards for Local and Metropolitan Area Networks: Virtual Bridged Local Area Networks approved Dec. 8, 1998 by the IEEE-SA Standards Board.
[0032] [0032]FIG. 8 shows a CEM/MPLS packet mapped to an Ethernet frame with an explicit VLAN tag.
[0033] CEM Over Other Protocols
[0034] It will be apparent to someone skilled in the art that the CEM PDU shown in FIG. 1 may be mapped to other protocols. For example, the mapping shown in FIG. 3 may be combined with standard mappings of IP to ATM or Frame Relay to provide the transport of CEM over those protocols.
Measurement of RTD
[0035] The current invention measures RTD through the use of timestamps embedded in the CEM Packet.
[0036] General Processing Flow
[0037] A process to measure roundtrip delay from Unit A to Unit B and back to Unit A comprises:
[0038] Step 104—Unit A generates a circuit emulation packet (CEM PDU) and places the value of local time into the TxTime field (transmit time) into a field within the CEM PDU.
[0039] Step 108—Unit A transmits the packet to Unit B through a packet network.
[0040] Step 112—Unit B receives the transmitted packet and records the TxTime field from the received packet and Unit B starts a timer to measure TxTimeDelay.
[0041] Step 116—Unit B generates a CEM PDU and fills the TxTime field with local time, places the TxTimeDelay timer value in the TxTimeDelay field and copies the stored TxTime into EchoTx Time to send back the time received in the packet from Unit A. The TxTimeDelay contains the holding delay that occurred between the receipt of the packet at Unit B and the preparation of the packet for transmission to Unit A.
[0042] Step 120—Unit B transmits the packet to Unit A through the packet network.
[0043] Step 124—Unit A receives the transmitted packet and records the TxTime field from the received packet and Unit A starts a timer to measure TxTimeDelay.
[0044] Step 128—Unit A marks the local time then subtracts from local time the EchoTxTime and the TxTimeDelay obtained from the packet received from Unit B. This provides a Round Trip Delay. The one-way delay can be approximated as one half of the RTD time.
[0045] The actions at Unit A and Unit B are symmetric. As the process continues, the next packet back to Unit B will have enough information for Unit B to calculate a Round Trip Delay. Note that there is not any requirement that the local time clock in Unit A be synchronized to the local time clock in Unit B.
[0046] State Machine Diagram
[0047] [0047]FIG. 9 shows an implementation of a state machine for managing the TxTimeDelay timer and the time fields in the PDU.
[0048] State Machine Table
[0049] Table 2 describes the state machine depicted in FIG. 9.
TABLE 2 RTD State Machine State Event Idle Timing Received 1. Record TxTime in EchoTxTime 1. Ignore TxTime CEM PDU 2. Set TxTimeDelay = 0 3. →Timing Time to Send 1. Set EchoTxTime and 1. Record EchoTxTime and CEM PDU TxTimeDelay invalid in packet TxTimeDelay in packet and set valid 2. →Idle
[0050] RTD Measurement Example
TABLE 3 Table 3 shows an example of RTP measurement. Table 3: RTD Example Unit A Unit B Unit A Time Local Local Curr New Recv'd TxTime Recv. Index Time Event Time State Event State TxTime Delay Event Time RTD 0 22 342 Idle Receive #6 Timing 20 0 1 23 343 Timing Timing 20 1 Receive #330 23 23 − 16 − 3 = 4 2 24 Send #7 344 Timing Timing 20 2 3 25 345 Timing Send #331 Idle 20 3 4 26 346 Idle Receive #7 Timing 24 0 5 27 347 Timing Timing 24 1 Receive #331 27 27 − 20 − 3 = 4 6 28 Send #8 348 Timing Timing 24 2 7 29 349 Timing Send #332 Idle 24 3 8 30 350 Idle Idle 24 — 9 31 351 Idle Idle 24 — Receive #332 31 31 − 24 − 3 = 4 10 32 Send #9 352 Idle Idle 24 — 11 33 353 Idle Send #333 Idle 24 — 12 34 354 Idle Receive #8 Timing 28 0 13 35 355 Timing Receive #9 Timing 28 1 Receive #333 35 No calculation 14 36 Send #10 356 Timing Timing 28 2 15 37 357 Timing Send #334 Idle 28 3 16 38 358 Idle Receive #10 Timing 36 0 17 39 359 Timing Timing 36 1 Receive #334 39 39 − 28 − 3 = 8 18 40 Send #11 360 Timing Timing 36 2 19 41 361 Timing Send #335 Idle 36 3 20 42 362 Idle Receive #11 Timing 40 0 21 43 363 Timing Timing 40 1 Receive #335 43 43 − 36 − 3 = 4
[0051] The following time indices are of interest.
[0052] Time indices 0 , 4 , 16 and 20 show normal reception of a packet at Unit “B”. The TxTime field is recorded, the TxTimeDelay timer is started and the state machine moves to the “Timing” state.
[0053] Time indices 3 , 7 , 15 and 19 show normal transmission of a packet from Unit “B”. The previously received value of the TxTime field is placed in the EchoTxTime field of the outgoing packet, the TxTimeDelay timer is stopped and the state machine transitions to the “Idle” state.
[0054] Time index 11 shows Unit “B” sending a packet without a valid time measurement. The TxTimeDelay and EchoTxTime bits in the COPT field are set to 0 to reflect that this packet may not be used at Unit “A” to calculate RTD at time index 13 .
[0055] Time index 13 shows packet # 9 arriving at Unit B. Since Unit “B” is already in the “Timing” state, the packet is ignored as far as the RTD state variables are concerned.
[0056] Time indices 1 , 5 , 9 , 17 and 21 show a normal calculation of RTD at Unit “A”. The calculated value of RTD is 4 for each of these except for time index 8 . Time index 8 properly shows a value of 8, reflecting the delayed arrival of packet # 8 at Unit “B” at time index 12 . Note the taking half of the RTD as an estimate of one way delay is only an approximation since the delays in this case were not symmetric.
Automatic Control of Flexible Mapping
[0057] Control of Mapping Multiple Circuits
[0058] When multiple circuits are destined for the same far end point, they will have the same IP destination address or MPLS Label. All such circuits can be mapped into the same packet using multiple CEM PDUs, with the COPT More flag set appropriately. Thus as illustrated in FIG. 2, a single transmission packet to be transmitted from device A to device B can contain a set of CEM PDUs that are all destined for Device B.
[0059] Control of Frames Per PDU (FPP)
[0060] As mentioned above, there is a trade-off in sending many partially loaded CEM PDU packets and thereby making inefficient use of the network, or waiting until the CEM PDU can be loaded with many payloads before sending. While the latter mode would send fewer packets, it would increase the average RTD because payloads would have to wait for a CEM PDU to become “full” and depart.
[0061] The present invention dynamically changes the balance between efficiency and responsiveness by altering the number of payload frames in a CEM PDU based on the RTD for recent transmissions. One-way delay may also be used, but it is not usually available directly.
[0062] [0062]FIG. 10 shows the state machine. In a preferred embodiment of the present invention, there are three states, each with its own FPP value (Frames per Packet). This invention can be extended to any system that dynamically changes from one FPP value to another based on current conditions. Thus, the number of states can be any number two or larger. Two states would probably be too coarse. It is currently felt that the optimal number of states would be from 3 to 5 states to avoid having an unduly complex system. This disclosure will explain the concept through the use of a three state example.
[0063] The three states are:
[0064] Low-This is the steady state when the current RTD is low as defined by the threshold L.
[0065] Medium-This is the steady state when the current RTD is medium as defined by the thresholds L and M.
[0066] High-This is the steady state when the current RTD is high as defined by the threshold M.
[0067] Note that there are no timers in this state machine. Since the number of frames per CEM PDU is contained within the PDU, the FPP could change on every single PDU without impairing the operation of the system. Hysteresis (or control deadbands), holdoff timers and/or smoothing of the RTD samples could be introduced to prevent minor changes in RTD from triggering changes in state and FPP.
[0068] Table 4 shows the state transitions for each range of RTD.
TABLE 4 State Machine for Control of FPP State RTD Status Low Medium High RTD < L No change 1. Set FPP = C L 1. Set FPP = C L 2. →Low 2. →Low L <= RTD < M 1. Set FPP =C M No change 1. Set FPP = C M 2. →Medium 2. →Medium RTD >= M 1. Set FPP = C H 1. Set FPP = C H No change 2. →High 2. →High
[0069] Typical values for the values are:
[0070] L=10 ms
[0071] M=50 ms
[0072] C L =20
[0073] C M =10
[0074] C H =1
[0075] For the convenience of the reader, applicant has added a number of topic headings to make the internal organization of this specification apparent and to facilitate location of certain discussions. These topic headings are merely convenient aids and not limitations on the text found within that particular topic.
[0076] Those skilled in the art will recognize that the methods and apparatus of the present invention has many applications and that the present invention is not limited to the specific examples given to promote understanding of the present invention. Moreover, the scope of the present invention covers the range of variations, modifications, and substitutes for the system components described herein, as would be known to those of skill in the art.
[0077] In order to promote clarity in the description, common terminology for components is used. The use of a specific term for a component suitable for carrying out some purpose within the disclosed invention should be construed as including all technical equivalents which operate to achieve the same purpose, whether or not the internal operation of the named component and the alternative component use the same principles. The use of such specificity to provide clarity should not be misconstrued as limiting the scope of the disclosure to the named component unless the limitation is made explicit in the description or the claims that follow.
Acronyms CEM Circuit Emulation CES Circuit Emulation Service FPP Frames Per PDU MPLS Multiprotocol Label Switching - described in IETF RFC3031. PDU Protocol Data Unit RTD Round Trip Delay TCP/IP Transmission Control Protocol/Internet Protocol-a network control protocol for host-to-host transmissions over a packet switching communication network. UDP User Datagram Protocol - described in RFC 768. VLAN Virtual Local Area Network
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A system for optimally mapping circuits into packets based on round trip delay (RTD), and a system for measuring RTD for use in packet communications systems such as circuit emulation (CEM) systems is disclosed. The measured RTD value can be used in a system that adjusts packet size to reduce capture delay to partially offset an increase in RTD. As the use of smaller packets increases the overhead burden on the packet communication system, the packet size can be increased to reduce the overhead burden when the size of the current RTD becomes appropriately short. The disclosure also teaches the placement of data from two or more circuits destined for the same emulation endpoint into the same transmission packet in order to improve system performance. The abstract is a tool for finding relevant disclosures and not a limitation on the scope of the claims.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a process for mixing a liquid sample to be analyzed, in which the liquid sample is placed in a sample container, particularly a cell, and is mixed by a periodic air movement.
The invention also relates to an apparatus for mixing a liquid sample to be analyzed in a sample container, particularly a cell, in which an air movement can be produced above the sample surface.
2. Description of the Related Art
In known processes and apparatuses of this type (European Patent Application No. 0 098 949 and West German Offenlegungsschrift No. 15 98 514), the sample container is sealed and the air column between the seal and the sample surface is subjected to periodic vibrations or oscillations, so that the liquid sample in the sample container is periodically oscillated and consequently mixed either by deforming an elastic container wall or by moving the sample backwards and forwards between the two legs of the U-shaped sample container, whereof one leg is sealed in the aforementioned manner and whereof the other leg is open.
Thus in the known process, it is necessary to seal the sample container in order to be able to periodically oscillate an air column above the sample surface. This is not only relatively complicated, but also leads to sealing problems. In addition, special sample containers are required, which are either U-shaped or have an elastically deformable wall.
The problem of the present invention is to provide a simple process and a simple apparatus for mixing a liquid sample to be analyzed in a standard container, with the aid of which a contact-free mixing takes place without sealing problems occurring.
SUMMARY OF THE INVENTION
According to the invention, this problem is solved in the case of a process of the aforementioned type in that air jets are alternately directed onto different regions of the sample surrace to thereby displace the particular sample surface regions and produce turbulence in the liquid sample, the air jets preferably having a higher temperature than the sample liquid.
Thus, in the process according to the invention, the movement and consequently the thorough mixing of the sample liquid takes place solely through air jets being alternately directed onto different surface regions of the samples and through a wavy movement being imparted to the sample liquid, so that turbulence is produced leading to a rapid and complete mixing of the sample. There is no need for the performance of this mixing process to seal the sample container, which is in one embodiment a standard container with a single liquid column, and/or no need to bring large parts of the device with which the air jets are directed onto the sample surface into contact with the sample container or sample, so that an effective and rapid mixing of the liquid sample is achieved in a simple manner.
It is necessary in many cases to keep the liquid sample at a constant temperature both during the mixing process and during the analysis, and due to the fact that the air jets have a higher temperature than the sample liquid, it is ensured that the air of the air jets coming into contact with the sample liquid does not cool the liquid sample as a result of an evaporation action.
Evaporation of the sample liquid when carrying out the mixing process is additionally reduced in one embodiment in that the air used for the air jets has an atmospheric humidity of approximately 100%, so that said saturated air does not absorb any moisture from the sample liquid.
It has been found that a particularly good mixing action is obtained if the air jets are directed onto the sample surface in the form of laminar flows, because there is then a particularly good transfer of momentum from the air jets to the sample liquid.
The problem of the invention is also solved with an apparatus of the aforementioned type by at least two air ducts or passages positioned with their outlets above the sample container and which are connected to pumping means alternately applying air pulses thereto.
As described hereinbefore, in connection with the process according to the invention, such an apparatus makes it possible to mix a liquid sample to be analyzed in a very simple manner without it being necessary to seal the sample container opening and without there having to be a contact between parts of the apparatus and the sample container and/or the liquid sample.
It has been found that a particularly effective, rapid mixing of a liquid sample is achieved if the pumping means operates at a frequency of 9 to 14 Hz.
In order to warm the air for the air jets to a temperature above the sample liquid temperature, the air to be supplied to the air passages, in one embodiment, passes through a temperature control or tempering chamber which can be heated in a regulated manner.
In order to moisten the air to be supplied to the air openings, it is in one embodiment passed through a humidifier, which can e.g. comprise a water dish or tray on the bottom of the tempering chamber over which dish or tray the air is passed.
As it has been found that the mixing process takes place in a very favorable manner if the air jets consist of laminar flows, the length and inside diameter of the air openings are selected in one embodiment in such a way that laminar air flows pass out of the same.
In order to keep low the external air proportion from the ambient air coming into contact with the sample surface, the sample container is in one embodiment covered with a cover having air openings for the passage of the air jets, e.g. in the form of a foil fixed to the sample container or a resilient covering mounted on the apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in greater detail hereinafter relative to the drawings.
FIG. 1 is a partly broken-away, diagrammatic, partial view of an apparatus for mixing a liquid sample, located in a sample container.
FIG. 2 is in section a basic diagram of the pump used in FIG. 1.
FIG. 3 is a simplified sectional view of the tempering chamber with the air passages above a sample container containing a liquid sample.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The apparatus shown contains a temperature control or tempering chamber 3 and a pump 12 driven by a drive 20, which pump is connected via connecting hoses 10, 11, to the tempering chamber 3.
As can be seen in FIG. 2, pump 12 has two pump chambers 18, 19, which are in each case closed with a diaphragm 16, 17. An actuating part 15 is fixed by means of screws to diaphragms 16, 17, and is provided with a slot, in which extends a cam 14. This cam is located on a shaft 13, driven by the drive 20 and is rotated in the direction of the arrow shown in FIG. 2.
The connecting hoses 10, 11 are in each case connected to one of the chambers 18, 19 and extend in tempering chamber 3 into sectional chambers 6, 7 at a limited distance above the bottom thereof. Through said bottoms the air passages 4, 5 extend downwards out of the tempering chamber 3, whilst the upper ends of the air passages 4, 5 terminate well above the connections for the connecting hoses 10, 11 in sectional chambers 6, 7.
Tempering chamber 3 is surrounded by an electrical heating jacket 26 and in its wall is located a temperature sensor 27, with the aid of which and by means of a diagrammatically represented thermostat 8, the heating of the tempering chamber is chosen in such a way that in the sectional chambers 6, 7 the desired temperature is maintained.
The air passages 4, 5 are removed at the bottom from tempering chamber 3 in such a way that, on positioning a sample container 1 below the outlet of air passages 4, 5, they are located in the vicinity of the internal opening diameter of container 1, but at a maximum distance from one another, whereas the sample container 1 is covered by a covering 22 held resiliently on the tempering chamber 3, which covering has openings 23 for the air jets.
In operation, drive 20 drives shaft 13 and consequently rotates cam 14, so that periodically air is compressed in chambers 18, 19 of FIG. 2 and is consequently displaced therefrom. Thereby, such air is forced via connecting hoses 10, 11 into sectional chambers 6, 7. There is in one embodiment water on the bottom of the sectional chambers, so that the air supplied thereto flows over said water and is humidified, whilst the air in the sectional chambers 6, 7 is also heated to a temperature above the temperature of the sample to be mixed.
As a result of the increased pressure in the sectional chambers 6, 7, during the supply of air pulses from chambers 18, 19, air is correspondingly forced downwards through air passages 4, 5, i.e. air jets pass alternately out of said passages 4, 5 and their frequency and duration are dependent on the construction and operation of pump 12. It is pointed out that when air is being forced out from one of the air passages, air is being sucked back via the other air passage into the associated sectional chamber and via the connecting hose into the associated pump chamber closed by a diaphragm.
The dimensions of air passages 4, 5 are preferably selected in such a way that laminar flows pass out of the same. According to an embodiment, air passages with a length of 40 mm and an internal diameter of 0.8 mm are used for a discharge velocity of the air jets of 1 to 2 m/sec and a volume of 5 to 10 cm 3 /sec. The resulting laminar flow led to an effective thorough mixing when the outlet ends of the air passages 4,5 were 21 to 30 mm above the sample surface.
When the apparatus is in operation, a sample container 1, e.g. a cell containing the liquid sample 2 to be mixed is placed under air passages 4, 5, as indicated in FIGS. 1 and 3. When an air jet indicated by an arrow in FIG. 1 passes out of air passage 4, then the surface of the sample liquid 2 is deformed in the indicated manner, whereas, when an air jet passes out of the other air passage, indicated for this purpose as 5' in FIG. 1 and represented in laterally displaced form, said air jet brings about a deformation of the liquid sample surface 2' in the laterally displaced sample container 1', which is identical to the sample container 1, cf. FIG. 1. Thus, there is alternately a deformation of the liquid sample surface in conjunction with the turbulence indicated by the curved arrows in accordance with FIG. 1, which leads to a rapid, effective, thorough mixing of the liquid sample. Due to the increased temperature and the high atmospheric humidity of the air jets, neither a temperature change nor a liquid loss in the liquid sample need be feared.
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A process for mixing a liquid sample to be analyzed with periodic air movements includes the steps of placing the sample in a sample container and alternately directing air jets onto different regions of the surface of the sample, wherein the air jets displace the surface regions and produce turbulence in the sample. An apparatus is provided for practicing the process.
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REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of application Ser. No. 400,096 filed Aug. 29, 1989, now abandoned..
TECHNICAL FIELD
This invention relates to processes for reducing the amount of free formaldehyde released from formaldehyde based resins in the manufacture of wood and textile products.
TERMS
The term "composition board" refers to products made by reducing wood to small particles and re-forming the particles into panels by an adhesive action achieved by the addition of adhesive binders to the particles. Examples of these products are particle board, fiberboard and chip board.
The term "durable press finished fabrics" refers to textile web products made in part or entirely from cellulosic based fibers in which durable press resins are incorporated into the manufacture of the product to impart crease and wrinkle resistance properties. Examples of these products are durable press sheeting, shrink resistant knits and wrinkle resistant shirting.
BACKGROUND OF THE INVENTION
The use of formaldehyde based resins has been fundamental in the manufacture of many wood and textile products for many years. In the wood products industry urea-formaldehyde (UF) resin has been in prevalent use as an adhesive in particle board manufacture with phenolic resins and isocyanate used to a lesser extent. Low cost and ease of use of UF resins have been the driving forces for their acceptance. Resins used in the textile industry are a different type than those used in wood products and have generally been used as chemical finishing agents to impart durable press or shrink resistant properties to cellulosic based fabrics such as shirting and knit materials. In the resin finishing of cellulosic fiber fabrics, nitrogen containing methylol compounds have been preferred because of their ease of application and low cost. The resin most extensively used in recent years for durable press finishes has been dimethyloldihydroxyethyleneurea (DMDHEU) or a modified version thereof.
Associated with products that contain UF and DMDHEU resins is the release of formaldehyde. Such is measured by large chamber test method FTM-2 for wood products and by AATCC Test Method 112-1984 for textile products.
Formaldehyde was first prepared by A. M. Butlerov in 1859 as a by-product of the synthesis of methylene glycol. It was known to have a pungent odor and to be extremely irritating to the mucous membranes of the eyes, nose, and throat. Because it was a severe irritant even in small amounts, research and development over the years was devoted to developing resins, particularly in the textile industry in order to minimize this form of toxicity. Within the last few years formaldehyde has come under scrutiny as a potential carcinogen. This has served to increase pressure by governmental agencies to reduce or eliminate formaldehyde evolution from wood and textile products.
The chemical industry has responded to the concern over formaldehyde by modifying some of the present formaldehyde based resin systems and by developing formaldehyde resins. Unfortunately, the non-formaldehyde resin systems have been costly to produce. Modified formaldehyde based resins have proven more successful in reducing the level of released formaldehyde from wood and textile products. For example, UF resins used in particle board manufacture have been modified by changing the mole ratio of formaldehyde to urea in the resin system. High fuming resins with mole ratios of 1.5 to have been modified to low fuming resins of 1.1 to 1 mole ratios. This has resulted in a significant reduction in released formaldehyde from particle board. In the durable press finishing of fabrics the pendant N-methylol group (N--CH 2 -OH) in DMDHEU has been restructured by "capping" with a polyol to form N--CH 2 --OR where R is traditionally a methoxy of a diethylene glycol ether group. This chemical restructuring stabilizes the resin molecule to hydrolysis thereby reducing the liberation of free formaldehyde from fabrics treated with such modified resins.
In addition to the foregoing there are methods described in the literature other than resin modification that have had some success at reducing the levels of released formaldehyde. Most of these methods have involved additional production processes such as after-washing or post spraying. These are generally considered costly, although effective, alternatives. A method more acceptable to manufacturing has been the use of additive chemicals called formaldehyde scavengers that can suppress or reduce the liberation of free formaldehyde from wood or textile products containing formaldehyde based resins.
Development of formaldehyde scavengers has been more prevalent in textiles than in wood products and dates back some twenty years. Generally, in textiles a formaldehyde scavenger is added to a resin mixture. The mixture is applied to cellulosic based materials in manufacturing processes to produce a product characterized by a reduced level of residual formaldehyde over that of non-treated products. Articles that discuss formaldehyde scavenger development in textile durable press finish of fabrics include R. S. Perry et al, Textile Chemist and Colorist, Vol. 12, No. 12, Dec. 1980, p. 311, Northern Piedmont Section, AATCC, Textile Chemist and Colorist, Vol. 13, No. 1, Jan. 1981, p. 17; C. Tomasino and M. B. Taylor II, Textile Chemist and Colorist, Vol. 16, No. 12, Dec. 1984, p. 259; and Perry, R. S., U.S. Pat. No. 4,127,382. Some of the compounds discussed in these articles have indeed been found to be effective as formaldehyde scavengers per se. For example, urea and other urea compounds such as ethylene urea and carbohydrazide significantly reduce formaldehyde release from fabrics but suffer themselves from odor formation, fabric discoloration, chlorine retention and buffering of the cure. Nitrogen containing aromatic hetercyclics such as pyrrole, indole and triazoles are also effective scavengers but tend to yellow fabrics at the application levels needed to reduce formaldehyde release to current standards. Non-aromatic alcohols have proven to be effective as formaldehyde scavengers without imparting detrimental physical properties to the fabric. Sorbitol, methoxy glucoside and diethylene glycol are scavengers presently being used to reduce formaldehyde levels.
Although alcohols when used as an additive scavenger can reduce formaldehyde levels of, for example, DMDHEU, their effectiveness depends on the form of the resin. For example, it is not unreasonable for DEG or sorbitol at 3 to 4% on bath weight to reduce the level of a DMDHEU resin which is 800 ppm odor formaldehyde on control fabric to 300 ppm on test fabric for a 63% formaldehyde reduction. Fabric finished with a modified DMDHEU resin may only have 100 ppm odor formaldehyde on the control fabric. The addition of polyols in the durable press finishing formulation as a scavenger may not reduce the formaldehyde level in the test fabric to any significant extent, at least not at reasonable usage levels. In this case polyols can be ineffective as additive formaldehyde scavengers.
It thus is seen that at present there is not a commercially viable formaldehyde scavenger available to reduce odor formaldehyde of a DMDHEU or modified DMDHEU resin as measured by AATCC test method 112-1984 to 25 ppm or less. Chemicals that have been reported to be able to reduce formaldehyde levels on fabrics to very low levels are carbohydrazide and dimethyl-1, 3-acetonedicarboxylate. However, the former adversely affects fabric properties and the latter is water insoluble and costly.
In wood products, particularly particle board, urea has been the scavenger that has received the greatest attention. Other chemical systems such as resorcinol, peroxides, and ammonia treatment have proven marginal in results and expensive. The usage of urea does not pose problems with particle board as it does in textile fabrics, however it must be carefully used or it will adversely affect physical properties of the particle board itself.
In general, urea is not added to the resin mix but is sprayed in a 40% solution as a separate application on the wood particles after resin application. The application level is approximately 0.3% based on the total board weight. This is generally the upper limit of usage on low fuming resins before board properties are affected. At present, the effectiveness of urea as a formaldehyde scavenger in particle board, as well as in other composition board products, is rather variable depending on manufacturing conditions and resin type. Only the low cost of urea accounts for its continued usage. As long as the wood products industry uses UF resins, and as long as formaldehyde reduction remains a governmental priority, there will be a need to develop a more effective scavenger. It is to the provision of such therefore, that the present invention is primarily directed.
SUMMARY OF THE INVENTION
It has now been discovered that acetoacetamide and to a less extent its derivatives dimethylacetoacetamide, monomethylacetoacetamide, diethylacetoacetamide and monoethylacetoacetamide serve as formaldehyde scavenger in reducing the levels of free formaldehyde released from certain cellulosic based products. Specifically, acetoacetamide has been found to be an excellent scavenger in the manufacture of composition boards wherein wood particles are treated with a urea formaldehyde adhesive resin. It has also been discovered that the acetoacetamide also increases the internal bond strength of the board which in turn reduces the needed amount of resin. Acetoacetamide has also been found to be an excellent formaldehyde scavenger in the production of durable press finished fabrics that are finished with a nitrogen containing methylol resin.
DETAILED DESCRIPTION
Acetoacetamide has been discovered to possess many % 25 advantages as a formaldehyde scavenger when used in the process of manufacturing composition board. Unlike urea it can be added directly to the UF resin mix or a component of a UF resin mix thereby eliminating the need for a separate application spray. Acetoacetamide does not interfere with the curing process of the resin; nor does it affect moisture absorbency of the finished product as does urea. Although today it is more costly than urea, it may be used at application levels far less than urea and still be effective in achieving very substantial reduction in formaldehyde release from composition board products. As it has been discovered also to increase bond strength of particle board its use enables a lesser amount of the resin to be required without degradation in bond strength. This can effect a cost savings that can generally offset the cost of the scavenger for which it is in effect substituted.
Acetoacetamide also has been discovered to demonstrate a superiority as a formaldehyde scavenger over other known scavengers when used in the process of manufacturing durable press finished fabrics. It is believed to be truly the only known commercially viable formaldehyde scavenger that can reduce the formaldehyde level of durable press finished fabrics to 25 ppm or lower as measured by AATCC test method 112-1984 without affecting fabric properties and at economic usage levels.
EXAMPLE I
10,000 pounds of particle board at 25 lbs./cu. ft. was produced by spray treating wood particles with the following identified urea formaldehyde resin mix in the amount of 10% solution weight based on wood weight:
______________________________________ Percent SolidsComponent on Weight of Bath______________________________________UF Resin (low fuming) 52.00Wax paraffin base 3.20Catalyst NH.sub.4 SO.sub.2 4.20Acetoacetamide .11______________________________________
The treated wood particles were transferred to a continuous particle board press and the sawdust material cured at 375° F. to form board. Control samples and test samples were evaluated as follows for formaldehyde release using the small chamber desiccator method:
______________________________________Component Odor Formaldehyde (μg/ml) % Reduction______________________________________Control Board 1.69 --Test Board 1.29 24______________________________________
EXAMPLE 2
75,000 pounds of particle board was produced using three different urea-formaldehyde resin formulation mixes. The board weight was three pounds per square foot on 3/4 inch board. Sawdust was treated with the resin mixes by spraying the chemicals on the sawdust in a continuous vortex blender. Key variables such as board weight, face and core moisture, blender retention time and press cycle were held constant.
More specifically, three tests were run producing 25,000 pounds of board each. The first trial was the control, the second trial incorporated acetoacetamide, and the third trial used the same amount of acetoacetamide but with a reduction in the resin and catalyst. The formaldehyde level was measured by the small chamber desiccator method which measures parts per million off-gassing of formaldehyde from the board in a four-hour period. Internal board bond strength was measured by the Instron pull test which measure the face in pounds required to pull a 4 by 4 piece of board apart.
______________________________________ % Solids (on weightChemicals of board)______________________________________Trial 1 - Controlurea-formaldehyde 6.5catalyst (NH.sub.4 SO.sub.4) 0.5wax emulsion 0.5Trial 2 (standard percent resin)urea-formaldehyde 6.5catalyst (NH.sub.4 SO.sub.4) 0.5wax emulsion 0.5acetoacetamide 0.06Trial 3 (resin % reduced by 18%)urea-formaldehyde 5.33catalyst (NH.sub.4 SO.sub.4) 0.41wax emulsion 0.50acetoacetamide 0.06______________________________________
The results of the trials were as follows:
______________________________________ Trial No. 1 2 3______________________________________Formaldehyde (PPM) 808 666 622percent reduction -- 17.6 20.5Internal bond strength (lbs) 81 96 92percent increase -- 18.5 13.6______________________________________
This shows that not only does the addition of acetoacetamide act to reduce the formaldehyde level in particle board but that it also serves to enhance internal bond strength. This in turn permits the use of less of the resin without a corresponding loss in internal bond strength.
In these trials the resin, acidic catalyst and the acetoacetamide were applied to t he wood as a sprayed mixture. However, these three chemicals may be applied separately and in any order provided such is done before pressing.
EXAMPLE 3
A 50/50 polyester cotton fabric was treated with a DMDHEU resin mix at 90% solution add-on, dried and cured at 330° F. for two minutes. The durable press finishing mix contained the following:
______________________________________Component Percent Solids OWB______________________________________DMDHEU 8Catalyst 1.6Acetoacetamide 2.5______________________________________
The cured samples were tested for odor formaldehyde by AATCC test method 112-1984 with the following results:
______________________________________Acetoacetamide Odor %% OWB Formaldehyde PPM Reduction______________________________________0 439 --2.5 None 100______________________________________
EXAMPLE 4
A 50/50 polyester cotton fabric was used with two types of modified precatalyzed DMDHEU resins. The fabrics were treated at 80% solution add-on by fabric weight, predried and cured at 330° F. for one minute. The samples were analyzed for odor formaldehyde using the AATCC test method 112-1984. The durable press finishing mixes contained the following:
______________________________________Component Percent Solids OWB______________________________________Modified Precatalyzed 7.5DMDHEU Resin*Acetoacetamide .3-2.5______________________________________ PPM % PPM %% (LO Reduc- (MO Reduc-Acetoacetamide DMDHEU) tion DMDHEU) tion______________________________________0 (control) 77 -- 149 -- .30 40 48 66 56 .45 28 64 31 79 .60 22 71 14 91 .75 18 77 None 1001.50 None 100 None 1002.25 None 100 None 100______________________________________ *LO DMDHEU = Low Odor Resin MO DMDHEU = Medium Odor Resin
This data shows a reduction in released formaldehyde from samples treated with durable press finishing compositions containing acetoacetamide as a formaldehyde scavenger. A reduction of approximately 50% occurs at the lowest level of scavenger usage 0.30%)
Although acetoacetamide is preferred, its derivatives also act as a formaldehyde scavenger but at added cost. For example, it has been experimentally found to take 2% OWB of dimethylaccetoacetamide to achieve the same reduction as 0.3% of acetoacetamide. The dimethyl derivative is initially 40% more expensive than acetoacetamide today.
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Acetoacetamide is used as an effective formaldehyde scavenger in the manufacture of composition board using a urea formaldehyde adhesive resin and in the manufacture of durable press finished fabrics using a nitrogen containing methylol resin.
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BACKGROUND OF THE INVENTION
A common method of perforating oil and gas wells for the production of petroleum and hydrocarbon gases is to use perforating guns wherein the explosive trains (i.e. the detonator, detonating cord and shaped charges) are exposed to wellbore fluids. It is possible in hot deep wells to encounter temperatures in excess of 500° F. and pressures over 20,000 psi. Thus, considerable stress can be placed on the explosive train, particularly the detonating cord since it is encased in a pressure transmitting jacket which subjects the explosive in the cord to the simultaneous influence of temperature and pressure. Explosives decompose at some finite rate under the influence of heat. They tend to decompose even faster when both high pressure and high temperature are present. Because of the nature of its function in high temperature wellbores, it is necessary to manufacture detonating cords from thermally stable explosive compounds. Two such explosives which are commonly used for this purpose are known as PYX and ONT. Both of these thermally stable detonating compounds possess excellent thermal stability, up to 500° F. for 100 hours, and are relatively easy and inexpensive to manufacture.
Unfortunately, however, detonating cords made from these explosives can be difficult to initiate or start in the explosive process. Three factors which can contribute to the difficulty in initiating these compounds are:
(1) the inherent thermal stability of many high temperature explosives makes them insensitive, not only to heat, but usually to other initiation stimuli such as shock or impact;
(2) downhole pressure acting on the detonating cord increases its density which tends to decrease the explosive sensitivity of the cord; and
(3) the explosive particle size that is best for detonating cord manufacture is usually not conducive to initiation.
Thus detonating cords which contain thermally stable explosives under the influence of downhole wellbore pressure can be extremely difficult to initiate. Conventional detonators simply might not generate sufficient shock strength to initiate these detonating cords.
A detonator package for use in this type of environment is described in U.S. Pat. No. 4,759,291 which is assigned to the common Assignee of the present application. This patent and its disclosure are incorporated herein by reference. Even utilizing a detonator package such as that described in the foregoing patent one may encounter difficulty in initiating high temperature cords. However, it may be possible to improve the functioning of a detonator device such as that shown in the aforementioned U.S. patent by using special detonation transfer techniques and apparatus. Such techniques and apparatus are the subject of the present application.
BRIEF DESCRIPTION OF THE INVENTION
Briefly, the present invention contemplates the use of methods and apparatus for the detonation or initiation of detonating cord under high temperature and pressure wellbore conditions. Utilizing the concepts of the present invention, the aforementioned difficulties encountered with apparatus of the type described in the previously mentioned U.S. patent may be overcome. According to the present invention, the use of a thermally stable secondary explosive initiating compound in conjunction with the detonating cord and the geometry of particular devices for this purpose can improve the initiation of detonating cord. Several thermally stable secondary explosive initiating compounds are suggested for this purpose. Similarly, a shock wave focusing lens which focuses the initiator energy onto a concentrated area or section of the detonating cord or initiating compound can be utilized. Finally, the technique of using triple wave interaction can be used to improve the initiation of the detonating cord.
The above and other features and advantages of the present invention can be better understood by reference to the detailed description to follow when taken in conjunction with the accompanying drawings. The accompanying drawings are intended to be illustrative of the present invention without being limitative on the aspects of its incorporation. These drawings are provided in an attempt to explain the workings of the invention to those skilled in the art.
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 is a longitudinal sectional view illustrating an apparatus for a through bulkhead explosive initiator in which concepts of the present invention may be utilized;
FIG. 1A is an enlarged detail shown in sectional view showing a bulkhead and secondary explosive in the initiator apparatus according to the present invention;
FIG. 2 is a further detail of a portion of the initiator of FIG. 1 utilizing one of the improvement concepts of the present invention;
FIG. 3 is a further cross-sectional detail view of a portion of the apparatus of FIG. 1 showing further concepts according to the present invention;
FIG. 4A is another sectional view in more detail showing yet another embodiment of concepts according to the present invention taken along the line 4A--4A of FIG. 4C;
FIG. 4B is a schematic diagram illustrating a triple wave interaction according to concepts of the invention; and
FIG. 4C illustrates the geometrical arrangement of secondary explosive initiators according to concepts of the present invention utilized in the apparatus of FIG. 4A.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring initially to FIGS. 1 and 1A, a detonator device such as illustrated in U.S. Pat. No. 4,759,291 is shown in sectional view and detailed sectional view. It will be understood that the concepts according to the present invention may be applied to the apparatus of FIGS. 1 and 1A with the modifications as shown and discussed with respect to the added views herein.
In FIG. 1 an explosive initiator comprising a pressure resistant housing 4 is hermetically sealed at the upper end with an electrical feedthrough connector 1. A set of retaining pins 2 retains the feedthrough connector 1 while the elastomeric O-rings 3 prevent fluid leakage into the interior of housing 4. An explosive device 5 is attached to the electrical feedthrough 1. This device 5 may be a conventional hot-wire detonator commonly called a blasting cap, an exploding bridgewire detonator, or an exploding foil detonator.
A cooperative portion of the initiator comprises a crimp sleeve 6 that contains a pressed pellet of secondary explosive 10 in its upper end. This pressed pellet of secondary explosive is sometimes referred to as a booster load. The concepts of the present invention extend to improvements in the geometry as well as to other aspects of the initiator of FIG. 1.
The lower end of crimp sleeve 6 is designed to slide over the detonating cord 9. It is retained thereto by crimping onto the detonating cord with suitable hand crimps in a manner well known in the art. The crimp sleeve 6 and the attached detonating cord 9 slip inside the housing 4 and abut the shoulder 11. The bulkhead 12 is shown in more detail in FIG. 1A. This is an integral part of the crimp sleeve 6. The bulkhead 12 prevents the detonating cord 9 from extruding forward due to the piston effect from wellbore fluid pressure acting on the cross-sectional area of the detonating cord and forcing it internally in the housing 4. For typical cross-sectional areas of detonating cord such a force can be as much as 700 pounds in a 20,000 psi wellbore.
A retainer 7 is threaded into the end of the housing 4 so that it retains the crimp sleeve 6 against the shoulder 11. A metal to metal seal is formed at the interface 13 between the crimp sleeve 6 and the retainer 7. This prevents the detonating cord 9 extruding through any gaps into the interior of the initiator housing 4. The pressurized detonating cord also expands radially very slightly and closes the clearance gap 14 between the retainer 7 and the cord 9. This expansion allows an elastomeric boot 8 to form a high pressure seal at the lower end of the initiator. Extrusion of the boot 8 into the initiator is not possible since the clearance gap 14 has now been closed due to the aforementioned radial expansion of the pressurized detonating cord.
Detonation transfer across the barrier 12 of FIG. 1 takes place only if the shock pressure generated by the explosive 10 is of sufficient magnitude to initiate the insensitive high explosive in the detonating cord. Often it is not. A special technique which can be applied to assure detonation transfer is to utilize, between the barrier 12 and detonating cord 9, a small quantity of a high temperature secondary explosive which is more sensitive to initiation than ONT or PYX. Such explosives are frequently referred to as thermally stable secondary explosive initiating compounds. These include such explosives as:
Table I
(1) ABH--azobis(2,2',4,4',6,6'hexanitrobiphenyl
(2) DODECA--2,2',2",2'",4,4',4",4'",6,6', 6",6'"dodecanitro--m,m' quatraphenyl
(3) NONA--2,2',2",4,4',4",6,6',6" nonanitroterphenyl
(4) TNTPB--1,3,5--trinitro 4,6--tripicrylbenzene
(5) DPO--2,5--dipicryl 1,3,4--oxadiazole
The sensitivity of these explosives is derived both from chemical formulation and explosive particle size. Typically, the particle size which is best for explosive initiation is rather fine (even fluffy) which does not lend itself to detonating cord manufacture. Also, certain initiating compounds can be rather difficult and expensive to make. However, it is possible to place a small quantity of one of these initiating compounds as shown in FIG. 2 at a location 20 between the barrier 21 and the detonating cord 22. The incident shock wave from the source or donor explosive 23 (corresponding to the pellet 10 of FIG. 1), heretofore unable to initiate the insensitive high explosive detonating cord directly, is now able to initiate the more sensitive initiating compound 20 chosen from the table of thermally stable secondary explosives given above. The detonation pressure created by the initiating compound 20 is then sufficient to cause initiation of the detonating cord 22.
Referring now to FIG. 3 (similar to FIG. 2), the same portion of the detonating apparatus is shown in cross section. The crimp sleeve 6 (see FIG. 1) has a concave barrier 30 corresponding to barrier 12 of FIG. 1. The concave barrier 30 focuses the shock wave from the source or donor explosive 33. Differences in shock impedance between the barrier 30 and the explosive 31 create a focusing effect. The explosive 31 may be a thermally stable secondary explosive from the list above. The transmitted shock wave from the donor explosive 33 converges at a point within the thermally stable initiating compound 31 due to the focusing effect of the concave surface. At this convergence point the pressure is sufficiently high to cause the shock initiation of the explosive 31 which then propagates to the detonating cord 32. Thus, the donor explosive 33 shock wave is focused by the concave lens 30 onto the thermally stable secondary initiator 31 which in turn detonates to trigger detonating cord 32.
Finally, referring to FIGS. 4A, 4B and 4C, a geometrical explosive convergence principle which may be termed "triple wave interaction" is illustrated schematically. A crimp sleeve corresponding to the crimp sleeve 6 in FIG. 1 is arranged such that the single cylinder of pressed explosive 10 of FIG. 1 is now replaced by three smaller cylinders 40 of pressed explosives. When these three explosive pellets are simultaneously initiated at the upper end, they each propagate expanding shock waves which collide and reinforce along the axis of the crimp sleeve as illustrated in FIG. 4B. Along this axis, the shock wave pressure is multiplied sufficiently high to initiate either the insensitive detonating cord 43 directly or an initiating compound 41, a stable secondary explosive placed between the barrier 42 and the detonating cord 43. In FIG. 4B, the shaded area represents the region of highest pressure generated by the interaction of shock waves from the three explosive pellets 40.
The foregoing descriptions may make other alternative arrangements according to the concepts of the present invention apparent to those skilled in the art. It is therefore the aim in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.
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In a high pressure, high temperature detonator for deep well use, an improved device is disclosed. It includes an elongate housing with axial bore and an electrical conductor at one end. A first explosive initiator is electrically ignited. In turn, a sleeve having a transverse bulkhead aligns one or more secondary explosive transfer pellets. The transfer pellets cooperate in ignition of the detonating cord. The secondary explosive pellets and sleeve are configured into described shapes to focus the shock wave for cord ignition.
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PRIORITY
[0001] This application claims priority to U.S. provisional application Ser. No. 61/845,980.
GOVERNMENT SUPPORT
[0002] Research leading to this invention was in part funded by the National Cancer Institute, National Institutes of Health, Bethesda, Md., USA.
FIELD OF THE INVENTION
[0003] This invention relates to formulations and compositions of Vitamin D analogs for the prevention and treatment of cancers and other diseases to minimize the toxic side-effects of the Vitamin D hormone while improving therapeutic index. The formulation methods feature supercritical, critical and near-critical fluids with and without polar cosolvents. This invention also discloses compositions of the analogs of the non-toxic and inert Vitamin D3 and the non-toxic and mostly inert Vitamin D3 pre-hormone.
BACKGROUND OF THE INVENTION
[0004] Vitamin D is the general name for a collection of natural sterol-like substances including vitamin D2 and D3. As shown in FIG. 1 , Vitamin D3 is synthesized in the skin from 7-dehydrocholesterol, a cholesterol breakdown product, via photochemical reactions using ultraviolet (UV) radiation from sunlight. The inert vitamin D3 is first converted to a largely inert intermediate by the liver to 25-HydroxyVitamin D3 (25-OH-D3) and then converted by the kidney to the bioactive hormone 1-25-DihydoxyVitamin D 3 (1,25(OH) 2 D 3 ) ( FIG. 1 ). The bioactive vitamin D hormone, 1,25(OH) 2 D 3 , mediates its action by binding to vitamin D receptor (VDR) that is principally located in the nuclei of the target cell.
[0005] Vitamin D is a natural molecule that is biosynthesized by the interaction of sunlight with 7-dehydrochoelsterol in the epidermis. 1,25-dihydroxyvitamin D 3 (1,25(OH) 2 D 3 named calcitriol), the dihydroxylated metabolite of vitamin D3 is an essential nutrient for skeletal health. Calcitriol has profound effects on the growth and maturation of normal and malignant cells. Several epidemiological studies have demonstrated that people who live in higher latitudes are at higher risk of developing and dying of many cancers, including prostate cancer. It has also been demonstrated that there is an inverse relationship between latitude, sun-exposure and cutaneous synthesis of vitamin D (20). In 1989, Garland et al. carried out an eight-year prospective study among 26,520 healthy adults to demonstrate that if the initial level of serum of calcifediol [25-hydroxyvitamin D 3 (25-OH-D 3 )], the mono-hydroxylated pre-hormonal form of calcitriol is at least 20 ng/ml, there is a 50% reduced risk of developing colon cancer. Since this observation other investigators have confirmed latitudinal impact and vitamin D intake on reducing risk of various cancers, including breast, prostate, renal and ovary. Vitamin D deficiency has also been correlated with autoimmune disease such as Multiple Sclerosis, hypertension, osteoporosis, bone diseases, rickets, psoriasis and infectious diseases.
[0006] Prostate cancer (PCA) is the most prevalent cancer among men; and the second leading cause of cancer death among men in the US. More than 500,000 PCA cases are diagnosed each year, 1 in 6 American males will develop PCA and 30,000 die each year in the US. Current clinical interventions for PCA include surgical removal of prostate and radiation therapy, with adverse side effects such as impotence, incontinence and alopecia. The mainstay of hormone-sensitive prostate cancer (HSPCA) chemotherapy is androgen-deprivation. After 9 to 30 months, HSPCA usually becomes insensitive to hormonal therapy and rapidly leads to HRPCA for which there are few interventions except for Sanofi-Aventis' Taxotere® (docetaxel) that has problems of toxicity and other adverse side-effects. New drugs have been recently approved for castration-resistant, docetaxel-refractory prostate cancers that extend life by 4.8 months.
[0007] Numerous studies have registered strong promise of calcitriol as a therapeutic agent for prostate and other cancers. However, its clinical use has been limited by risk of toxicity related to hypercalcemia, hypercalciuria, and significant loss of body weight. Attempts to address the toxicity-issue have taken two paths. In the first, combinations of calcitriol with standard chemotherapeutic agents are being investigated to harness synergy between these compounds. For example, clinical and animal studies have been carried out demonstrate that toxic effects of calcitriol can be mitigated by a combination with dexamethasone or paclitaxel.
[0008] Several attempts have been made to develop less/non-toxic analogs of calcitriol with potent antiproliferative activities as potential therapeutic agents. A Phase II clinical trial evaluated Seocalcitol (EB-1089), a side-chain analog of the active vitamin D hormone, in patients with inoperable pancreatic cancer. No objective responses (anti-tumor) activity was observed; the most frequent toxicity was dose-dependent hypercalcemia with most patients tolerating a dose of 10-15 μg/day in chronic administration.
[0009] The nuclear vitamin D receptor (VDR) plays a central role in the cell signaling process leading to anti-proliferation, and in some cases apoptosis of cancer cells. In this respect calcitriol is very similar to other steroidal and non-steroidal hormones such as estrogen, androgens, retinoids, glucocorticoids etc. Furthermore, VDR has high structural homology with nuclear receptors of other hormones. It is well established that cellular regulation by calcitriol and its analogs are initiated by highly specific binding to VDR, which is translated into pro-differentiation and concomitant antiproliferation of cells. Most human prostate cancer cells contain VDR; and numerous studies have shown that several prostate cancer cells respond to calcitriol. These findings strongly support the use of vitamin D-based agents for first line therapy and/or second line therapy when androgen deprivation fails.
[0010] However, cancer-therapy with calcitriol is limited by its rapid catabolic degradation by CYP-hydroxylases, which reduces its potency. As a result high doses of calcitriol are required clinically to harness its beneficial property; but such pharmacological doses cause toxicity. A way of circumventing this problem will be to covalently attach calcitriol into the ligand-binding pocket of VDR as shown in FIG. 2 , so that (i) calcitriol is prevented from interacting with catabolic enzymes; and (ii) VDR-mediated transcriptional process could be set in motion since the ligand is inside the ligand-binding pocket of VDR leading to conformational changes required for the transcriptional process.
[0011] During the past decade hundreds of vitamin D analogs have been synthesized with the goal of obtaining a better antitumor/toxicity ratio and tumor-specific effect. Although a few of these analogs have successfully completed preclinical studies for several cancers; and at least one analog has recently failed Phase II clinical trials for pancreatic carcinomas, the majority of these compounds have been proved to be of limited therapeutic value due to toxicity. As a result new strategies for developing such analogs are required.
[0012] Aspects of the present invention employ materials known as supercritical, critical or near-critical fluids. A material becomes a critical fluid at conditions which equal its critical temperature and critical pressure. A material becomes a supercritical fluid at conditions which equal or exceed both its critical temperature and critical pressure. The parameters of critical temperature and critical pressure are intrinsic thermodynamic properties of all sufficiently stable pure compounds and mixtures. Carbon dioxide, for example, becomes a supercritical fluid at conditions which equal or exceed its critical temperature of 31.1° C. and its critical pressure of 72.8 atm (1,070 psig). In the supercritical fluid region, normally gaseous substances such as carbon dioxide become dense phase fluids which have been observed to exhibit greatly enhanced solvating power. At a pressure of 3,000 psig (204 atm) and a temperature of 40° C., carbon dioxide has a density of approximately 0.8 g/cc and behaves much like a nonpolar organic solvent, having a dipole moment of zero Debyes.
[0013] A supercritical fluid displays a wide spectrum of solvation power as its density is strongly dependent upon temperature and pressure. Temperature changes of tens of degrees or pressure changes by tens of atmospheres can change a compound solubility in a supercritical fluid by an order of magnitude or more. This feature allows for the fine-tuning of solvation power and the fractionation of mixed solutes. The selectivity of nonpolar supercritical fluid solvents can also be enhanced by addition of compounds known as modifiers (also referred to as entrainers or cosolvents). These modifiers are typically somewhat polar organic solvents such as acetone, ethanol, methanol, methylene chloride or ethyl acetate. Varying the proportion of modifier allows wide latitude in the variation of solvent power.
[0014] In addition to their unique solubilization characteristics, supercritical fluids possess other physicochemical properties which add to their attractiveness as solvents. They can exhibit liquid-like density yet still retain gas-like properties of high diffusivity and low viscosity. The latter increases mass transfer rates, significantly reducing processing times. Additionally, the ultra-low surface tension of supercritical fluids allows facile penetration into microporous materials, increasing extraction efficiency and overall yields.
[0015] A material at conditions that border its supercritical state will have properties that are similar to those of the substance in the supercritical state. These so-called “near-critical” fluids are also useful for the practice of this invention. For the purposes of this invention, a near-critical fluid is defined as a fluid which is (a) at a temperature between its critical temperature (T c ) and 75% of its critical temperature and at a pressure at least 75% of its critical pressure, or (b) at a pressure between its critical pressure (P c ) and 75% of its critical pressure and at a temperature at least 75% of its critical temperature. In this definition, pressure and temperature are defined on absolute scales, e.g., Kelvin and psia. To simplify the terminology, materials which are utilized under conditions which are supercritical, near-critical, or exactly at their critical point with or without polar co-solvents such as ethanol will jointly be referred to as “SuperFluids™” or referred to as “SFS.” SuperFluids™ were used for the nanoencapsulation of the Vitamin D analog in the protective lipid layer of phospholipid nanosomes.
SUMMARY OF THE INVENTION
[0016] Embodiments of the present invention are directed to the composition, formulation and use of Vitamin D analogs, that bind tightly into the Vitamin D receptor, and can be used therapeutically at lower doses than their Vitamin D counterparts, and are such less toxic than their Vitamin D counterparts.
[0017] AMPI-109 is a bromoacetate derivative (1α,25-dihydroxyvitamin D 3 -3-bromoacetate [1,25(OH) 2 D 3 -3-BE]) the active Vitamin D3 hormone ( FIG. 3 ).
[0018] AMPI-105 is a bromoacetate derivative (25-hydroxyvitamin D 3 -3-bromoacetate[25-OH-D 3 -3-BE]) of the non-toxic pre-hormonal form of Vitamin D 3 ( FIG. 4 ).
[0019] AMPI-106 is the epoxide derivative (25-hydroxyvitamin D 3 -3-epoxide [25-OH-D 3 -3-EPO]) of the non-toxic pre-hormonal form of Vitamin D 3 ( FIG. 5 ).
[0020] AMPI-107 is the epoxide derivative (D 3 -3-epoxide [D 3 -3-EPO]) of the non-toxic and inert Vitamin D 3 ( FIG. 6 ).
[0021] Embodiments of the present invention are directed to formulations of these Vitamin D analogs to prolong circulation time while reducing systemic toxicity and enhancing therapeutic index.
[0022] In order to prolong circulation time while reducing systemic toxicity and enhancing therapeutic index, the less toxic Vitamin D analogs are nanoencapsulated within the lipid bilayer of phospholipid nanosomes. Nanoencapsulation also enhances serum stability. Phospholipid nanosomes will also protect the ester bond from hydrolysis increasing the half-life of Vitamin D analogs.
[0023] Nanoencapsulation allows Vitamin D analogs to kinetically engage VDR to increase the half-life of calcitriol, thereby potentially increasing its potency with less toxicity.
[0024] Using SCCNC fluids, AMPI-109 was encapsulated into phospholipid nanosomes (APH-0701), which were ˜100 to 200 nm in size, had high encapsulation efficiencies around 75%, with passive in vitro release rates of ˜3 days.
[0025] APH-0701 was found to be stable in human serum and mouse liver homogenates.
[0026] Both AMPI-109 and APH-0701 were effective in reducing tumor-size in mouse xenograft models of DU-145 (androgen-insensitive) tumors. Compared to a nanosomal vehicle control, AMPI-109 and APH-0701 reduced tumor size approximately 37% and 49%.
[0027] Gross body-weights of AMPI-109 and APH-0701-treated animals were not significantly different from control animals, indicating lack of gross toxicity.
[0028] Collectively these results demonstrated that AMPI-109 and APH-0701 have a strong translational potential as a therapeutic agent in androgen-insensitive prostate cancer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 depicts Biosynthesis of inert Vitamin D 3 in skin, conversion into the largely inert pre-hormone in the liver and the highly bioactive hormone in the kidney.
[0030] FIG. 2 depicts Cross-linking of 1,25(OH) 2 D 3 -3-BE (AMPI-109) into the VDR-ligand binding pocket via Cys 288 .
[0031] FIG. 3 depicts the bromoacetate derivative (1α,25-dihydroxyvitamin D 3 -3-bromoacetate [1,25(OH) 2 D 3 -3-BE]) of the active Vitamin D 3 hormone (AMPI-109).
[0032] FIG. 4 depicts the bromoacetate derivative (25-hydroxyvitamin D 3 -3-bromoacetate[25-OH-D 3 -3-BE]) of the non-toxic pre-hormonal form of Vitamin D 3 (AMPI-105).
[0033] FIG. 5 depicts the epoxide derivative (25-hydroxyvitamin D 3 -3-epoxide [25-OH-D 3 -3-EPO]) of the non-toxic pre-hormonal form of Vitamin D 3 (AMPI-106).
[0034] FIG. 6 depicts the epoxide derivative (Vitamin D 3 -3-epoxide [D 3 -3-EPO]) of the non-toxic and inert Vitamin D 3 (AMPI-107).
[0035] FIG. 7 depicts AMPI-109 Standard Curve.
[0036] FIG. 8 depicts SFS-CFN Apparatus.
[0037] FIG. 9 depicts Particle Size Analysis of APH-0701-27-02 Nanosomes.
[0038] FIG. 10 depicts Photomicrograph of APH-0701-27-02.
[0039] FIG. 11 depicts SEC Separation of APH-0701-27-02.
[0040] FIG. 12 depicts Release of AMPI-109 from APH-0701-27-02.
[0041] FIG. 13 depicts LNCaP cells: Antiproliferation assay with AMPI-109 and APH-0701.
[0042] FIG. 14 depicts antiproliferative and cytotoxic activity of AMPI-109 (Vitamin D 3 -3-epoxide [D 3 -3-EPO]) vs Calcitriol (1,25(OH) 2 D 3 ) in normal kidney cells by 3 H-thymidine incorporation assay.
[0043] FIG. 15 depicts antiproliferative and cytotoxic activity of AMPI-109 (Vitamin D 3 -3-epoxide [D 3 -3-EPO]) vs Calcitriol (1,25(OH) 2 D 3 ) in kidney cancer cells by 3 H-thymidine incorporation assay.
[0044] FIG. 16 depicts DU-145 cells treated with various doses of Calcitriol or AMPI-109 or ethanol (vehicle) for 20 hours followed by 3 H-thymidine incorporation assay.
[0045] FIG. 17 depicts Effect of AMPI-109, Calcitriol or EB-1089 on the growth of DU-145 cells.
[0046] FIG. 18 depicts Effect of 1,25(OH) 2 D 3 -3-BE and 1,23(OH) 2 D 3 (Hormone) (q.o.d.×10, i.p.) on tumor volume in athymic DU-145 mice.
[0047] FIG. 19 depicts Effect of 1,25(OH) 2 D 3 -3-BE and 1,23(OH) 2 D 3 (Hormone) (q.o.d.×10, i.p.) on Body Weight in athymic DU-145 mice.
[0048] FIG. 20 depicts Effect of 1,25(OH) 2 D 3 -3-BE (q.o.d.×10, p.o.) on tumor volumes against tumor model DU-145 in athymic mice.
[0049] FIG. 21 depicts Effect of 1,25(OH) 2 D 3 -3-BE (q.o.d.×10, p.o.) on body weights in tumor model DU-145 in athymic mice.
[0050] FIG. 22 depicts Tumor Size of Androgen-Insensitive Tumor (DU-145) Bearing Athymic Mice Treated with 1,25(OH) 2 D 3 -3-BE, Liposomal 1,25(OH) 2 D 3 -3-BE and Vehicle Control.
[0051] FIG. 23 depicts Body Weight of Androgen-Insensitive Tumor (DU-145) Bearing Athymic Mice Treated with 1,25(OH) 2 D 3 -3-BE, Liposomal 1,25(OH) 2 D 3 -3-BE and Vehicle Control.
[0052] FIG. 24 depicts 3 H-Thymidine Incorporation Assays of Keratinocytes, MCF-7, PZ-HPV-7, LNCaP and PC-3 Cells.
[0053] FIG. 25 depicts Cell Counting Assay of LAPC-4, LNCaP, MCF-7 and MC3T3 Cells Treated with 25-0H-D 3 -BE or 1,25(OH) 2 D 3 .
[0054] FIG. 26 depicts Effect of 25-OH-D 3 -3-BE (every 3 days, starting on day 11 and ending on day 31, p.o.) on tumor volumes against tumor model DU-145 in athymic mice.
[0055] FIG. 27 depicts Effect of 25-OH-D 3 -3-BE (every 3 days, starting on day 11 and ending on day 31, p.o.) on body weights of tumor model DU-145 in athymic mice.
[0056] FIG. 28 depicts Effect of 24 h Treatment on WPMY-1 Cells (Mean and SEM) by AMPI-107 and Calcitrol.
[0057] FIG. 29 depicts Antiproliferative evaluation of AMPI-107 vs. Calcitrol in DU-145 Prostate Cancer Cells.
[0058] FIG. 30 depicts Antiproliferative evaluation of AMPI-107 vs. Calcitrol in LNCaP Prostate Cancer Cells.
[0059] FIG. 31 depicts Antiproliferative evaluation of AMPI-107 vs. Calcitrol in PC-3 Prostate Cancer Cells.
[0060] FIG. 32 depicts Effect of AMPI-109 (Vitamin D 3 -3-epoxide [D 3 -3-EPO]) vs Calcitriol (1,25(OH) 2 D 3 ) (q.o.d.×10, i.p.) on tumor volumes against tumor model DU-145 in athymic mice.
[0061] FIG. 33 depicts Effect of AMPI-109 (Vitamin D 3 -3-epoxide [D 3 -3-EPO]) vs Calcitriol (1,25(OH) 2 D 3 ) AMPI-017 (q.o.d.×10, i.p.) on body weights of tumor model DU-145 in athymic mice.
[0062] FIG. 34 depicts Effect of AMPI-109 (Vitamin D 3 -3-epoxide [D 3 -3-EPO]) vs Calcitriol (1,25(OH) 2 D 3 ) (q.o.d.×10, p.o.) on tumor volumes against tumor model DU-145 in athymic mice.
[0063] FIG. 35 depicts Effect of AMPI-109 (Vitamin D 3 -3-epoxide [D 3 -3-EPO]) vs Calcitriol (1,25(OH) 2 D 3 ) AMPI-017 (q.o.d.×10, p.o.) on body weights of tumor model DU-145 in athymic mice.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
AMPI-109 (1α,25-dihydroxyvitamin D 3 -3-bromoacetate[1,25(OH) 2 D 3 -3-BE])
[0064] The Vitamin D analog 1α,25-dihydroxyvitamin D 3 -3-bromoacetate[1,25(OH) 2 D 3 -3-BE]), AMPI-109, is a derivative of calcitriol covalently links calcitriol inside the ligand-binding pocket of VDR via a cysteine residue as shown in FIG. 2 . We also observed that such a process constitutively activated VDR. Thus, AMPI-109 became a significantly stronger anti-proliferative agent than calcitriol on a mole-per-mole basis in LNCaP, PC-3 and DU-145 prostate cancer cells (6.5 more times for DU-145 in hormone refractory prostate cancer (HRPCA) animal models). AMPI-109 is a significantly stronger antiproliferative agent than EB-1089, a side-chain analog of calcitriol that underwent clinical trials, in DU-145 cancers. In addition, AMPI-109 induced apoptosis in these cells. Furthermore, in in vivo studies, AMPI-109 produced strong anti prostate tumor effect without inducing significant toxicity in athymic mice. Therefore, AMPI-109 demonstrates a strong translational potential as a therapeutic agent for prostate cancer.
[0065] There may be concerns that AMPI-109 may: (i) behave like protein/DNA alkylating compounds with significant side effects at pharmacological doses; (ii) generate adverse immune responses; and (iii) be prematurely hydrolyzed since it contains an ester bond. Unlike protein/DNA alkylating compounds such as estramustine and lomustine that are non target-specific and produce significant side effects particularly at pharmacological doses, AMPI-109 will interact with specific targets and cross-link to the substrate/ligand-binding sites of enzymes and receptors and thus, will have less side effects. Adverse immune response of the alkylating agents, such as AMPI-109, is difficult to predict. Calcitriol and its analogs are touted as potential drug-candidates for immune-deficiency diseases, such as Type I diabetes. Therefore, AMPI-109 is expected, if anything to show a positive immune response. Since AMPI-109 contains an ester bond, hydrolysis would produce calcitriol and bromoacetic acid; such a phenomenon might limit bioavailability of the intact molecule. This phenomenon is minimized by nanoencapsulation of the Vitamin D analog in the protective lipid membrane of the nanoparticles. In a cellular proliferation study, the antiproliferative property of AMPI-109 is due solely to its un-hydrolyzed and intact form.
[0066] The covalent attachment of calcitriol into the ligand-binding pocket of VDR prevents the catabolism of calcitriol because it will be sitting deep inside the binding pocket, and will be inaccessible to catabolizing CYP enzymes.
[0067] DU-145 is a highly aggressive androgen-insensitive human prostate cancer cell line that does not respond well to calcitriol due to increased expression of CYP 24-OHase and rapid catabolism. AMPI-109 shows a strong and dose-dependent antiproliferative effect in DU-145 cells, while calcitriol shows no effect. By decreasing catabolism of calcitriol by first protecting its analog in the lipid layer and then cross-linking it to the ligand-binding pocket of VDR (via AMPI-109), the potency of the hormone is significantly increased. AMPI-109 also modulate messages for human osteocalcin and CYP 24-OHase (genes that are involved in the VDR-mediated mechanism) in keratinocytes similar to clacitriol. The message for 24-OHase is up regulated by calcitriol and AMPI-109 in LNCaP cells, and this message is obliterated by ZK 159222, a clacitriol antagonist. These results strongly indicate that cellular effects of AMPI-109 follow a mechanism similar to that of calcitriol.
Synthesis of AMPI-109
[0068] 1,25(OH) 2 D 3 -3-BE (AMPI-109) shown in FIG. 3 was synthesized. The structure of AMPI-109 was confirmed by proton and 13 C NMR; the molecular weight was established by mass spectral analysis to be 536.25; and the purity determined to be >98.3% at 265 nm by reversed phase HPLC.
Analysis of AMPI-109
[0069] AMPI-109 and the formulated product were analyzed by HPLC. The HPLC method utilized a Phenomenex Luna C18(2), 100 A, 5 micron, 150×4.6 mm HPLC column (P/No.: OOF-4252-EO; S/No. 425310-16), a mobile phase consisting of 95% acetonitrile:5% water, a flow rate of 1.0 mL/min, a column temperature of 30° C., an injection volume of 20 μL and a run time of 10 minutes with monitoring at 265 nm. AMPI-109's standard curve is shown in FIG. 7 . A system suitability requirement of Plates >4,000 was established for the method. The limit of detection (LOD) was determined to be 0.013 ppm and limit of quantification (LOQ) to be 0.04 ppm. Injection replication was determined to have a root square difference (RSD) of 0.21%.
Formulation of AMPI 109
[0070] We utilized the SuperFluids™ critical fluid nanosome (CFN) process for the formation of small, uniform liposomes (nanosomes) for encapsulating AMPI-109. Liposomal preparations are identified as AMPI-109 (L) and APH-0701.
[0071] Twenty-seven encapsulation runs were performed in the SFS-CFN apparatus shown schematically as FIG. 8 . In a typical SFS-CFN experiment, the solids chamber was charged with dimyristoyl-phosphatidylcholine (DMPC) or phosphatidylcholine (PC) and cholesterol and placed inline within the apparatus. The molar ratio of lipid:cholesterol:drug was designed to be 20:1:1. The system was then pressurized between 2,000 and 3,000 psig with a SFS (Freon 23 or propane) and heated to the desired temperature (40 to 60° C.). The lipids were dissolved into the SFS through circulation of the SFS within the upper high pressure circulation loop in the apparatus for ˜60 min, before adding AMPI-109 dissolved in ethanol (EtOH) via an injection port into the high pressure circulation loop. After a specific residence time, the resulting mixture was decompressed via a backpressure regulator (valve) though a dip tube with a nozzle into a decompression chamber (vessel B), which contained a buffer such as a 10% sucrose solution. After decompression through the nozzle, the SuperFluids™ were evaporated off leaving an aqueous solution of nanosomes entrapping the hydrophobic AMPI-109 within the lipid bilayers, forming APH-0701.
[0072] Three samples were typically taken: depressurization at constant pressure, depressurization from operating pressure to 400 psig, and depressurization from 400 psig to atmospheric pressure. Most of the AMPI-109 was contained in the second fraction. This fraction was the sterile filtered through a 0.2 μm polycarbonate or a nitroplus cellulosic filter using compressed N2. The filtrates were checked for AMPI-109 content as well as for particle size. In a typical example, after filtration, the sterile samples were dispensed with a sterile, disposable pipette in 5 mL aliquots into sterile 20 mL vials and frozen at −80° C. The samples were then freeze-dried overnight and weighed. Lyophilized samples were then reconstituted in 5 mL DI-H 2 O, sonicated for 20 seconds three times, and analyzed for particle size and AMPI-109 content.
AMPI-105 and AMPI-106 (25-OH-D 3 Analogs)
[0073] AMPI-105 and AMPI-106 are analogs of 25-HydroxyVitamin D 3 (25-OH-D 3 ). AMPI-105 is a bromoacetate derivative (25-hydroxyvitamin D 3 -3-bromoacetate[25-OH-D 3 -3-BE]) of the non-toxic pre-hormonal form of Vitamin D 3 ( FIG. 4 ). AMPI-106 is the epoxide derivative (25-hydroxyvitamin D 3 -3-epoxide [25-OH-D 3 -3-EPO]) of the non-toxic pre-hormonal form of Vitamin D 3 ( FIG. 5 ).
[0074] AMPI-105 and AMPI-106 are a class of novel, non-toxic VDR affinity-binding analogs of 25-OH-D 3 . By covalently attaching (alkylating) 25-OH-D 3 , a non-toxic and biologically inert pre-hormonal form of 1,25(OH) 2 D 3 , to the hormone-binding pocket of VDR, 25-OH-D 3 was to converted into a transcriptionally active form. This makes 25-OH-D 3 biologically active. Furthermore, it translates the non-toxic nature of 25-OH-D 3 into its VDR-alkylating analog. Thereby, the 25-OH-D 3 analogs now have the anti-cancer property of a ‘1,25(OH) 2 D 3 -like molecule’ without systemic toxicity.
[0075] As shown in the examples, the two (2) VDR-alkylating analogs of 25-OH-D 3 (AMPI-105 and AMPI-106) possess strong anti-tumor activity in a mouse prostate tumor xenograft model.
AMPI-107 (Vitamin D 3 Analog)
[0076] AMPI-107 is an epoxide analog of Vitamin D 3 ( FIG. 6 ). Vitamin D 3 is normally considered to be biologically inert.
[0077] As shown in the examples, the very strong anti-growth activity of AMPI-107, a vitamin D 3 derivative, even at 10-times higher dose level is highly unexpected and significant.
EXAMPLES
Example 1
APH-0701 Nanosomes Characterization
[0078] Experiment APH-0701-27 was conducted with SFS propane at 3,000 psig and 60° C. Three depressurization fractions were collected in 10% sucrose. The first was obtained by displacement under constant pressure, the second by depressurization from 3,000 psig to ˜400 psig and the third by depressurization from ˜400 psi to 0 psig. These were APH-0701-27-01, APH-0701-27-02 and APH-0701-27-03 respectively. The results of the analysis of APH-0701-27 are summarized in Table 1.
Table 1: AMPI-109 Content and Size of APH-0701-27
[0079]
[0000]
TABLE 1
AMPI-109 Content and Size of APH-0701-27
APH-0701-27
Amount of AMPI-
Recovered
Fractions
109 (mg)
Size (nm)
(%)
APH-0701-27-01
0.013
4740
1.5
APH-0701-27-02
0.745
197
88.5
APH-0701-27-03
0.084
—
10.0
Total
0.842
—
100.0
[0080] The particle size of APH-0701-27-02, which contained 88.5% of AMPI-109, was determined to be 197 nm using a Coulter 4MD particle size analyzer ( FIG. 9 ). This particle size was confirmed by photomicrography at a magnification of 1,000× ( FIG. 10 ).
Example 2
Size Exclusion Chromatography
[0081] In order to determine the extent of encapsulation of AMPI-109, a size exclusion separation of VDD-27-02 was conducted on Sephadex LH-20. In this size exclusion separation, phospholipid nanosomes should elute with the void volume with smaller molecules retained onto the column and eluted after solvent wash. The results, shown in FIG. 11 , indicate that the majority (˜90%) of AMPI-109 elutes with the phospholipid nanosomes in the first three fractions with particle sizes of 151 nm, 150 nm and 200 nm, around those originally measured.
Example 3
In Vitro Release of AMPI-109 from Nanosomes
[0082] Release studies of VDD-27-02 into 10% Tween 80 solution in FIG. 12 indicate that AMPI-109 is releasing from nanosomes slowly over time until almost all has either diffused out or the nanosomes have broken apart. Maximum release is observed after 3 days, after which time, AMPI-109 is either precipitating or degrading.
Example 4
Antiproliferative and Cytotoxic Activity of APH-0701 and AMPI-109 in Prostate Cancer Cells by 3 H-Thymidine Incorporation Assay
[0083] The activities of AMPI-109 in nanosomes (APH-0701) vs. naked AMPI-109 were measured in androgen-sensitive LNCaP prostate cancer cells. Anti-proliferative activity was compared with nanosomal preparation of AMPI-109 (APH-0701) versus naked AMPI-109. Antiproliferative activities in these cells were measured by 3 H-thymidine incorporation assay.
3 H-Thymidine-Incorporation Assay:
[0084] In a typical assay cells were grown to 50-60% confluence in 24-well plates in respective media containing 5% FBS, and serum starved for 20 hours, followed by treatment with various agents (in 0.1% ethanolic solution) or ethanol (vehicle) in serum-containing medium for 16 hours. After the treatment media was removed from the wells and replaced with media containing 3 H-thymidine (Sigma, 0.1 μCi) per well, and the cells were incubated for 3 hours at 37° C. After this period media was removed by aspiration and the cells were washed thoroughly (3×0.5 ml) with PBS. Ice-cold 5% perchloric acid solution (0.5 ml) was added to each well and the cells were incubated on ice for 20 minutes. After this incubation, perchloric acid was removed by aspiration, replaced with 0.5 ml of fresh perchloric acid solution and the cells were incubated at 70° C. for 20 minutes. Solution from each well was mixed with scintillation fluid and counted in a liquid scintillation counter. There were eight (8) wells per sample; statistics was carried out by Student's t test.
[0085] AMPI-109, both in naked and nanosomal forms has strong antiproliferative effect in LNCaP prostate cancer cells ( FIG. 13 ). Both AMPI-109 and APH-0701 [aka AMPI-109 (L)] almost completely inhibited the growth of LNCaP cells.
[0086] At 10 −7 M dose level of APH-0701 has significantly stronger effect than an equivalent amount of AMPI-109. Encapsulation of AMPI-109 prevents catabolic degradation of naked AMPI-109; and as a result APH-0701 has a stronger biological/cellular effect, as we have observed with LNCaP prostate cancer cells.
Example 5
Antiproliferative and Cytotoxic Activity of AMPI-109 Vs 1,25(OH) 2 D 3 (Calcitriol) in Normal Kidney and Kidney Cancer Cells by 3 H-Thymidine Incorporation Assay
[0087] The antiproliferative activities of AMPI-109 and Calcitriol (1,25(OH) 2 D 3 ) are shown in FIG. 14 for normal kidney cells and in FIG. 15 for RCC 54 kidney cancer cells.
[0088] At 10 −6 M, neither Calcitriol nor AMPI-109 had any statistically different impact on normal kidney cells than the control ( FIG. 14 ).
[0089] Surprisingly, at doses ranging from 7.5×10 −7 to 10 −6 M, Calcitriol did not have any statistically different impact on RCC 54 kidney cancer cells over control whereas AMPI-109 had a >95% impact on the reduction of proliferation of RCC 54 kidney cancer cells ( FIG. 15 ).
[0090] The APH-0701 nanosomal formulation of AMPI-109 will have a similar impact to that shown in Example 4 of reducing its toxicity to normal kidney cells and increasing its efficacy on kidney cancer cells.
Example 6
Effect of 1,25(OH) 2 D 3 -3-BE (AMPI-109) Vs 1,25(OH) 2 D 3 (Calcitriol) and EB-1089 on the Growth of Androgen-Insensitive Human Prostate Cancer DU-145 Cells
[0091] DU-145 is a highly aggressive androgen-insensitive human prostate cancer cell line that does not respond well to calcitriol due to increased expression of CYP 24-OHase and subsequent rapid catabolism. We hypothesized that covalent attachment of calcitriol (via AMPI-109) into the ligand-binding pocket of VDR might make it inaccessible to catabolic enzymes; and hence restore its activity. To prove this point we treated DU-145 cells (grown to approximately 60% confluence) in DMEM media containing 5% FBS with 2.5×10 −7 M, 5.0×10 −7 M, 7.5×10 −7 M and 10.0×10 −7 M (10 −6 M) of AMPI-109, calcitriol or ethanol for 20 hours followed by antiproliferation analysis by 3 H-thymidine-incorporation assay.
[0092] The data in FIG. 16 demonstrates that AMPI-109 showed a dose-dependent antiproliferative effect in DU-145 cells with maximum effect at 10 −6 M dose, while calcitriol showed no effect. In a separate experiment (data shown in FIG. 17 ), we treated DU-145 cells with 10 −6 M of calcitriol, AMPI-109 or EB-1089 (a non-calcemic analog of calcitriol). AMPI-109 showed a strong anti-proliferative effect at 0 −6 M, but both calcitriol and EB-1089 failed to produce any discernible anti-proliferative effect.
Example 7
Serum-Stability Study of AMPI-109 and APH-0701
[0093] One ml of pooled human serum was incubated at 37° C. for 60 minutes with 10 μg of AMPI-109 or an equivalent amount of APH-0701 followed by multiple (5 times) extraction with 0.5 ml of ethyl acetate. The organic layer was dried in a stream of nitrogen and the residue was analyzed by HPLC (5% H 2 O— 95% methanol 1.5 ml/min, 265 nm detection, Agilent C18 column). Organic extracts of both AMPI-109 and APH-0701 produced a peak at 6.68 min which corresponds to the peak of a standard sample of AMPI-109.
[0094] These results demonstrate that APH-0701 is stable in human serum.
Example 8
Stability Study of AMPI-109 and APH-0701 in Liver Homogenate
[0095] Pieces of liver, obtained from normal mice were minced and homogenized in phosphated saline with a polytron. One mL of the homogenate was incubated at 37° C. for 60 minutes with 10 μg of AMPI-109 or an equivalent amount of APH-0701 followed by multiple (5 times) extraction with 0.5 mL of ethyl acetate. The organic layer was dried in a stream of nitrogen and the residue was analyzed by HPLC (as above). Organic extracts of both AMPI-109 and APH-0701 produced a peak at 6.1-6.3 min which corresponds to the peak of a standard sample of AMPI-109.
[0096] These results demonstrate that APH-0701 is stable in a mouse liver homogenate.
Example 9
Maximum Tolerated Dose (MTD) of AMPI-109 and APH-0701 in SCID Mice
[0097] DU-145 prostate cancer cells (ATCC, Manasas, Va.) were grown in culture, and then approximately 5 million cells/animal was injected under the skin in the flank area of SCID mice (Charles River). Tumors grew in 2-3 weeks, and when they reached a size of approximately 1 cm 3 , they were injected with 0.1, 0.5 and 1 μg/kg dose of AMPI-109 (in 5% dimethylacetate in sesame oil) intraperitoneally. Dosing levels were limited by concentrations and volumes. Each group had six mice. Dosing was carried out every third day and weight of each mouse was recorded. All mice in the 1 μg/Kg dose died after three dosing.
[0098] Based on dosing, the relative MTD of AMPI-109 is estimated to be ≦3 μg/Kg.
[0099] Twenty (20) male nu/nu mice, 6 weeks old (Charles River Laboratories, Wilmington, Mass.) were grouped in five (5) animals each and injected (i.p.) with either vehicle (blank liposome) or 0.75 μg/kg, 1.0 μg/kg and 1.25 μg/kg of APH-0701, the liposomal preparation of AMPI-109 on every third day. Mice were observed for sign of toxicity including lack of appetite, weight loss, lethargy etc. After seven (7) injections three (3) mice (out of a total of 5) receiving 1.25 μg/kg of APH-0701 died, and the experiment was stopped.
[0100] Based on dosing, the relative MTD of APH-0701 is estimated to be >9 μg/Kg.
[0101] Thus the maximum tolerated dose of APH-0701, the nanoformulated Vitamin D analog, is at least 300% higher than that of the naked Vitamin D analog, AMPI-109.
Example 10
In Vivo Efficacy of AMPI-109 and Calcitriol in Mouse Xenograft Models of Androgen-Insensitive DU-145 Human Prostate Cancer Cells (I.P.-Administration)
[0102] Male, athymic mice (average weight 20 gm) were fed normal rat chow and water ad libitum. They were inoculated with DU 145 cells, grown in culture in their flanks under light anesthesia. When the tumor size grew to approximately 100 mm 3 the animals were randomized into groups of ten (10) tumor-bearing animals, and they were given AMPI-109 (0.1 μg/kg), calcitriol (0.5 and 1 μg/kg), and vehicle (5% DMA in sesame oil) by intraperitoneal injection (i.p.) on every third day (when body weights were determined); and one group was left untreated. Treatment started on day 11 and stopped on day 30; and they were left untreated for two (2) additional days when they were sacrificed.
[0103] AMPI-109 (0.1 μg/kg) showed a strong anti-tumor effect (solid purple triangle in FIG. 18 ). Effect of AMPI-109 (0.1 μg/kg) was similar to calcitriol (0.5 μg/kg). AMPI-109 was approximately 5 times stronger in potency than calcitriol in reducing tumor-size. However, molecular weights of calcitriol and AMPI-109 are 416.65 and 537.8 respectively. Therefore, on a molar basis AMPI-109 is approximately 6.5 times more potent than calcitriol. Thus, covalently attaching calcitriol to VDR might increase its potency (by decreasing catabolism).
[0104] As shown in FIG. 19 AMPI-109 (0.1 μg/kg) showed some reduction in body weight which was significantly less than with calcitriol (0.5 μg/kg and 1.0 μg/kg). Another interesting observation was that after the withdrawal of AMPI-109 (day 30) weights of animals started increasing (similar to calcitriol). This is an important finding because AMPI-109 is an alkylating compound, and there may be concerns of sustained systemic toxicity.
Example 11
In Vivo Studies of AMPI-109 and Calcitriol in Nude Mice Inoculated with DU-145 Human Prostate Cancer Cells (P.O.-Administration)
[0105] In the p.o. administration oral gavage mode AMPI-109 (0.5 μg/kg) showed a strong anti-tumor effect ( FIG. 20 ). This effect was similar to calcitriol (0.5 μg/kg). However, calcitriol (0.5 μg/kg and 1.0 μg/kg) caused significant loss in body weight denoting toxicity, while AMPI-109 did not cause any significant change in body weight of the animals ( FIG. 19 ).
[0106] It is noteworthy that AMPI-109 was five (5) times less potent in the p.o.-mode than in the i.p.-mode. This is to be expected because in the i.p. mode the compound goes directly in the blood stream, while in the p.o. mode a significant portion of AMPI-109 is expected to undergo hydrolysis/metabolism before reaching the blood stream. Therefore higher amounts would be required to show any biological effect. Therapeutic agents containing hydrolysable bonds are fairly common; for example aspirin and acetaminophen contain hydrolysable ester and amine bonds.
[0107] In summary, the results described above showed strong anti-tumor activity and significant bioavailability of AMPI-109.
Example 12
In Vivo Studies of AMPI-109 and APH-0701 in Nude Mice Inoculated with DU-145 Human Prostate Cancer Cells (P.O.-Administration)
[0108] Male, athymic mice (average weight 20 gm) were fed normal rat chow and water ad libitum. They were inoculated with DU-145 cells (5×10 6 cells, dispersed in 100 μl PBS) in the flank. When the tumor size grew to approximately 100 mm 3 the animals were randomized into groups of eight (8), and they were given AMPI-109 (0.5 μg/Kg in 5% DMA in sesame oil, 5% DMA in sesame oil (vehicle control), or APH-0701 (0.5 μg/Kg, in 5% DMA in sesame oil) by intraperitoneal injection (i.p.) on an average every third day (body weights were determined at each dosing). Treatment started on day 7 after tumor-implantation and was stopped on day 42, when they were sacrificed.
[0109] Results of our in vivo efficacy and safety study are shown in FIGS. 22 and 23 . At the end of the experiment, average size of vehicle-control, AMPI-109-treated and APH-0701-treated tumors were approximately 750, 475 and 385 mm 3 respectively, demonstrating a strong reduction of tumor size by AMPI-109 (37% of control) and APH-0701 (49% of control), with a 33% improvement of liposomal versus naked drug ( FIG. 22 ). On the other hand, gross body-weights of AMPI-109- and APH-0701-treated animals were not significantly different from control animals, indicating lack of toxicity ( FIG. 23 ). Therefore, collectively these results demonstrated that AMPI-109 and APH-0701 have a strong translational potential as a therapeutic agent in androgen-insensitive prostate cancer.
Example 13
Antiproliferation Studies of Normal and Cancerous Cell Lines Treated with AMPI-105 or Bioactive Vitamin D 3 Hormone
[0110] Antiproliferation studies of keratinocytes (normal skin), MCF-7 (breast cancer), PZ-HPV-7 (immortalized normal prostate), LNcap (androgen-sensitive prostate cancer) and PC-3 (androgen-insensitive prostate cancer) cells, treated with 10 −6 M of 25-OH-D 3 -3-BE (AMPI-105) or 1,25(OH) 2 D 3 (bioactive Vitamin D 3 hormone) were performed with a 3 H-thymidine incorporation assay
[0111] Growth-inhibitory effect of 1,25(OH) 2 D 3 and its analogs is known to vary among cell-lines and even among lines from the same tissue. But, in general, strongest effect is observed at a 10 −6 M concentration of the hormone or its analogs. Although this concentration is considered to be physiologically irrelevant, it produces optimal effect. Therefore, this dose was used for screening of various cell lines.
[0112] PZ-HPV-7 cells were grown in MCDB media containing pituitary extract, epidermal growth factor (EGF) and 1% penicillin/streptomycin. Keratinocytes were also grown in the same media with additional PG1 and insulin. PC-3, LNCaP, DU-145 cells were grown in RPMI media containing 10% fetal bovine serum (FBS) and antibiotics. MCF-7 cells were grown in DMEM media containing 10% FBS and antibiotics. LAPC-4 cells were maintained in IMEM media containing antibiotics, 1% L-glutamine and 10 nM of R1881, a synthetic progestin. MC3T3 mouse bone cells were grown in α-MEM media containing 10% FBS and antibiotics. In general, cells were grown in 35 mm dishes to 70-80% confluence and then plated into 24-well plates in respective media. After the cells grew to approximately 70% confluence, they were serum-starved for 20 hours (MCF-7, PC-3, LNCaP and DU-145 cells) followed by incubation with steroid samples. Keratinocytes and PZ-HPV-7 cells, after reaching 70% confluence, were kept in MCDB media without additives for 20 hours before treatment with steroids. In general, reagents were dissolved in ethanol (EtOH), and dilution with the media was adjusted in such a way that the concentration of EtOH was 0.1% v/v.
[0113] Assays were carried out with six (6) replicates and student's t-test was employed for statistical analysis. Results are expressed relative to EtOH (100%) in FIG. 24 .
[0114] As shown in FIG. 24-E , 10 −6 M of 25-OH-D 3 -3-BE and 1,25(OH) 2 D 3 inhibited the growth of all the cells with varying efficiency. However, the effect of 25-OH-D 3 -3-BE was strongest in LNCaP and PC-3 prostate cancer cells.
[0115] For example, growth of LNCaP cells were inhibited by approximately 60% and 98% with 1,25(OH) 2 D 3 and 25-OH-D 3 -3-BE, respectively ( FIG. 24-D ), while growth of PC-3 cells was reduced by 70% and 90% by 1,25(OH) 2 D 3 and 25-OH-D 3 -3-BE, respectively ( FIG. 24-E ). In contrast, growth of normal immortalized prostate cells (PZ-HPV-7 cells) were inhibited by approximately 50% and 65% by 10 −6 M of 25-OH-D 3 -3-BE and 10 −6 M of 1,25(OH) 2 D 3 , respectively ( FIG. 24-C ).
[0116] While growth inhibition by 25-OH-D 3 -3-BE was stronger than an equivalent amount of 1,25 (OH) 2 D 3 in keratinocytes ( FIG. 24-A ), the effect of 25-OH-D 3 -3-BE was weaker than 1,25(OH) 2 D 3 in MCF-7 breast cancer cells ( FIG. 24-B ). Furthermore, 10 −6 M of 25-OH-D 3 showed marginal antiproliferative effect in PC-3 cells ( FIG. 24-F ). We also observed that 10 −6 M of 25-OH-D 3 -3-BE was cytotoxic only to LNCaP and PC-3 cells, causing the cells to lift, float and die, as seen under a phase contrast microscope.
[0117] In a cell counting assay, LNCaP and LAPC-4 cells had sharply reduced number of cells with 10 −6 M of 25-OH-D 3 -3-BE after 24 hours incubation ( FIG. 25 ) while MCF-7 and MC3T3 cells (incubated for 48 hr) were affected to a much lesser extent than for LNCaP and LAPC-4 cells, although the effect on MC3T3 cells was significantly stronger than in MCF-7 cells. It should be noted that in this assay cells were not serum-starved prior to addition of the reagents, and 10 −7 M of 1,25(OH) 2 D 3 had little effect on all the cells. 10 −7 M of 1,25(OH) 2 D 3 was shown to produce a significant effect in LNCaP cells after a longer period (3-6 days) of incubation.
Example 13
Efficacy Study of 25-OH-D 3 -3-BE in Athymic Nude Mice
[0118] Male, athymic nude mice (average weight 20 gm) were fed normal rat chow and water ad libitum. They were inoculated with DU 145 cells, grown in culture, in the flank under light anesthesia. After the tumor size grew to approximately 100 mm 3 , the animals were randomized into three (3) groups of ten (10) tumor-bearing animals and they were given 25-OH-D 3 -3-BE (0.25 and 0.5 mg/kg, dissolved in 5% DMA in sesame oil) or left untreated. Administration of the compound was done by oral gavage on every third day (when weights were determined). Treatment started on day 11 and stopped on day 31; and they were left untreated for several additional days (as shown in FIG. 26 ) when they were sacrificed and blood was collected.
[0119] 25-OH-D 3 -3-BE showed a dose-dependent anti-tumor effect at 0.25 and 0.5 mμg/kg doses ( FIG. 26 ). For example, at the end of treatment average size of the untreated tumor was approximately 900 mm 3 , while average tumor volumes were 650 mm 3 and 500 mm 3 with 0.25 and 0.5 μg/kg of 25-OH-D 3 -3-BE respectively. Toxicity was measured by following gross weight of the animals during and after the treatment. As shown in FIG. 27 there was no significant difference between the 25-OH-D 3 -3-BE-treated and untreated animals. It is to be noted that these results are preliminary in nature and we plan to carry out more extensive dose-response studies both by oral gavage administration mode as well as determination of serum-calcium levels in the proposed studies.
Example 15
Viability Testing of Vitamin AMPI-107 and Calcitrol in Normal Prostate Cells by MTT Reduction
[0120] Vitamin D epoxide (AMPI-109) was received at a concentration of 10 −2 M (diluting 1000-fold to give 10 −5 M, and a later 10× dilution produced 10 −6 M. The hormone [1,25(OH) 2 D 3 ] or Calcitrol positive control sample was received at a concentration of 10 −3 M. A 1000-fold dilution gave 10 −6 M.
[0121] Normal prostate WPMY cells were cultured to confluency in 10% fetal calf serum supplemented Dulbecco's modified Eagle's medium plus 1% antibiotic/antimycotic in 96 well dishes and at confluency, cells were exposed to 1 μM Calcitrol, 1 and 10 μM AMPI-107 in complete medium for 24 hours.
[0122] Cells were then incubated with yellow tetrazolium MTT (3-(4,5-dimethyl thiazolyl-2)-2,5-diphenyltetrazolium bromide) for 3 h and was then extracted in acid isopropanol (0.1 N HCl in anhydrous isopropanol). MTT is reduced in metabolically active cells, in part by the action of dehydrogenase enzymes, to generate reducing equivalents such as NADH and NADPH. The resulting intracellular purple formazan can be solubilized and quantified by spectrophotometry. After 5 minutes at room temperature, absorbances in plates were measured using a plate analyzer set for in dual wavelength comparisons at wavelength of 540 nm with a reference wavelength of 620 nm.
[0123] Compared to control cells, FIG. 28 , AMPI-107 at 1 and 10 μM did not significantly depress cell metabolism. By comparison, 1 μM Calcitrol did slightly, but significantly reduce cell metabolism (**p<0.01, one way ANOVA with Bonferroni post-testing).
Example 16
Antiproliferative Evaluation of AMPI-107 Versus Calcitrol in Prostate Cancer Cells
[0124] Prostate cancer cells (DU-145, PC-3 and LNCaP) were grown in DMEM medium with 10% FBS, antibiotics, etc. When the confluence reached approximately 50% they were dosed with ethanolic solutions (0.1% in media) with various doses of either AMPI-107 or the hormone [1,25(OH) 2 D 3 ] aka Calcitrol or ethanol (control) on days 1,3 and 5, and cells were counted on a hemocytometer on the 7 th day. Results are designated as percentage of ethanol control.
[0125] As shown in FIG. 29 , Calcitrol (10 −6 M) and AMPI-107 (10 −5 M) had approximately similar growth inhibitory activity in DU-145 cells.
[0126] As shown in FIG. 30 , Calcitrol (10 −6 M) and AMPI-107 (10 −5 M) strongly inhibited the growth of LNCaP cells, but AMPI-107 had a significantly stronger effect at this dose.
[0127] As shown in FIG. 31 , Calcitrol (10 −6 M) and AMPI-107 (10 −5 M) strongly inhibited the growth of PC-3 cells, but AMPI-107 had a significantly stronger effect at this dose.
[0128] Cell-counting assay (dosing on 1 st , 3 rd , and 5 th days, harvesting and counting on 7 th day) demonstrated that AMPI-107 is either equally effective (DU-145 and PC-3 cells) or more (LNCaP cells) than Calcitrol. However, concentration of AMPI-107 was 10-times higher than Calcitrol.
Example 17
In Vivo Studies of AMPI-107 in Nude Mice Inoculated with DU-145 Human Prostate Cancer Cells (P.O. and I.P. Administration)
[0129] Male, athymic mice (average weight 20 gm) were fed normal rat chow and water ad libitum. They were inoculated with DU 145 human androgen-insensitive prostate cancer cells (10 6 ), grown in culture in the flank under light anesthesia. When the tumor size grew to approximately 100 mm 3 the animals were randomized into groups of ten (10) tumor-bearing animals, and they were given vitamin D 3 -3-epoxide, AMPI 107 (1 mg/kg), 1,25(OH) 2 D 3 hormone (0.5 and 1.0 μg/kg), and vehicle (5% DMA in sesame oil) by intraperitoneal injection (i.p.) or by oral gavage (p.o.) on every third day (when body weights were determined); and one group was left untreated. Treatment started on day 11 and stopped on day 30; and they were left untreated for two (2) additional days when they were sacrificed. The i.p. results are respectively shown in FIGS. 32 and 33 for the effect of AMPI-107 and the 1,25(OH) 2 D 3 hormone on tumor growth and body weight. The p.o. results are respectively shown in FIGS. 34 and 35 for the effect of AMPI-107 and the 1,25(OH) 2 D 3 hormone on tumor growth and body weight. Note AMPI-107 is referred to as MPI-107 in these figures.
[0130] In terms of efficacy vitamin D 3 -3-epoxide, MPI 107 (1 mg/kg) was similar to hormone (0.5 μg/kg) in both i.p. and p.o. administration modes ( FIGS. 32 and 34 ). But 1,25(OH) 2 D 3 , hormone (0.5 and 1.0 μg/kg) was clearly toxic as evidenced by considerable loss of body weight in both cases, while vitamin D 3 -3-epoxide, MPI 107 was completely non-toxic ( FIGS. 33 and 35 ).
[0131] Surprisingly, the results of this study demonstrated that vitamin D 3 -3-epoxide strongly reduced tumor size in this model both in i.p. and p.o. administration modes without any significant toxicities.
[0132] The APH-0701 nanosomal formulation of AMPI-105 will have a similar impact to that shown in Example 4 of reducing its toxicity and increasing its efficacy.
Example 18
Polymeric Nanoencapsulation of Vitamin D 3 Analogs
[0133] Polymeric Spheres were formed which contained the Vitamin D 3 analogs in the following manner. A feed rate of 0.25 mg/ml Vitamin D 3 analog in an ethanolic buffer solution and a supercritical, critical or near critical solution of solution of poly(D, L-lactic acid), poly(glycolic acid) in propane was injected into a decompression fluid of de-ionized water and produced a batch of spheres having a mean particle diameter of 200 to 400 nanometers. The polymer solution was maintained prior to injection at a pressure of 21 MPa and 30 degrees centigrade.
[0134] This suspension of spheres in a phosphate buffer was then lyophilized. Dried spheres were stored at five degrees centigrade until used or compressed into tablets. Prior to use, dried spheres were re-constituted and formulated into a phosphate buffer solution.
Example 19
Oil Capsule Formulation of Vitamin D 3 Analogs
[0135] The Vitamin D 3 analogs are formulated in different doses ranging from 500 IU to 5,000 IU in gel capsules containing the following.
500 IU to 5,000 IU of Vitamin D 3 analogs 30 mg of mixed tocopherol 90% as an antioxidant [10.7%] 30 mg of Lecithin as an emulsifier to improve solubility and bioavailability [10.7%] 15 mg of Medium Chain Triglyceride (MCT) as a co-emulsifier [5.4%] 175 mg of Olive Oil as an excipient with some nutritional value [62.5%]; Nitrogen head
Example 20
Water Capsule Formulation of Vitamin D 3 Analogs
[0141] The Vitamin D 3 analogs are formulated in different doses ranging from 500 IU to 5,000 IU in gel capsules containing the following: Medium Chain Triglyceride (MCT) as a co-emulsifier, Lecithin Soy, Hydroxyl Propyl Methyl Cellulose (HPMC) and Purified Water.
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This invention is for formulations of analogs of the non-toxic and inert Vitamin D3, its non-toxic and mostly inert pre-hormone and its toxic and biologically active hormone, and for using these formulations for preventing and treating certain cancers such as breast, prostate, ovarian, kidney, renal and other cancers, Vitamin D deficiency, autoimmune disease such as Multiple Sclerosis, hypertension, osteoporosis, bone diseases, rickets, psoriasis and infectious diseases. This invention also discloses compositions of the analogs of the non-toxic and inert Vitamin D3 and the non-toxic and mostly inert Vitamin D3 pre-hormone.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an apparatus and process for the production of a non-woven structure formed from thermoplastic resin fine fibers and yarns.
2. Discussion of Prior Arts
Non-woven fabrics or theromplastic resins (which will hereinafter be referred to as "webs" have hitherto been produced by the melt blowing methods, in which a thermoplastic resin is extruded from small holes to form fibers, blown against a collection screen by a hot gas and thus collected, and have widely been used in various fields. Such a web, in particular, composed of fine fibers has been used for special uses because of its eminently suitable characteristics, but has the disadvantage that the mechanical properties of the web such as tensile strength, bending stiffness, etc. are low because the fibers have extremely small diameters and are not stretched; or if the fibers are stretched, the degree of stretching is not sufficient and accordingly, the uses of the web must be limited.
In order to overcome this disadvantage, there have been proposed methods for increasing the strength of a web by increasing its integrity, for example, by binding or fixing warps or wefts to one side or both sides of the web or into the web with adhesives or through thermal fusion. These methods, however, are all complicated; further due to the adhesives used the methods limit application of the web.
An object of the present invention is to provide a web wherein the above described problems are eliminated.
SUMMARY OF THE INVENTION
In accordance with this invention a non-woven fabric of superior strength is attained by feeding or charging a yarn, e.g. a monofilament into a non-woven fabric or web during production thereof and forming the web and yarn into a unitary body.
That is to say, the present invention comprises (1) a process for the production of a non-woven structure, which comprises blowing a high speed hot gas against a melted thermoplastic resin to form a fiber stream comprising fine thermoplastic resin fibers of 0.5 to 50 microns in fiber diameter and collecting the fiber stream while feeding at least one continuous yarn having a size of 1 to 600 denier to the fiber stream by a high speed gas, and (2) an apparatus for the production of a non-woven structure, which comprises, a means for extruding a thermoplastic resin to form fine fibers and blowing the fibers to form a fiber stream comprising fine thermoplastic resin fibers, means for collecting the fiber stream, said means being spaced apart from the thermoplastic resin blowing means and a means for feeding a yarn, into the fiber stream by a high speed gas, said feeding means being arranged between the thermoplastic resin blowing means and fiber stream collecting means.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of the apparatus according to the present invention;
FIG. 2 is a side view, partially in cross section, of the yarn charging means in the apparatus of the present invention;
FIG. 2A is the same as FIG. 2 but with the regulator 17 moved to the left;
FIG. 3 is a partially enlarged view of FIG. 2;
FIG. 4 is a perspective view of the apparatus according to the present invention, and
FIG. 5, FIG. 6 and FIG. 7 are respectively plan views of the thermoplastic resin blowing means and yarn charging means designed to show the method of charging yarns according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The web of the present invention is composed of extremely fine fibers of a thermoplastic resin having a fiber diameter of 0.5 to 50 microns, obtained by the melt blowing method. Useful examples of the thermoplastic resin are polyolefins such as polyethylene and polypropylene, polyamides, polyesters, polyvinyl chloride, polycarbonates, polyurethanes and the like. Modified polyolefins obtained by grafting unsaturated carboxylic acids to polyolefins lacking in adhesiveness can be used so as to increase the adhesvieness to yarns.
As the yarn of the present invention, any vegetable, mineral and synthetic resin materials can be used having a size of about 1 to about 600 denier. Yarns of synthetic resins, in particular, thermoplastic resins are preferred, which may be most preferably stretched; any spun yarns or filament yards can be used. The same kinds of thermoplastic resins may be used for the yarn as those used as a starting material for the web; the particular thermoplastic resins used for the web and yarn may be the same or different.
The present invention provides a process for the production of a non-woven structure, wherein during production of a web by the melt blowing method, at least one yarn which may be continuous is fed by a high speed gas into a high speed fiber stream comprising extremely fine fibers of a thermoplastic resin extruded from a die and blown by a hot gas against a collecting screen and then fibers and yarns are collected on the collecting screen.
DETAILED DESCRIPTION OF THE DRAWINGS
Referring to FIG. 1, a thermoplastic resin is melted and extruded by means of an extruder 1 to a die means 2 (not shown specifically) and then injected therefrom with a hot gas, preferably heated air, supplied from a gas pipe 6 to form a high speed fiber stream 8. At the same time, a yarn 7 is drawn from a yarn feeding means 3 by a pressure gas supplied from a pipe 5 and fed into the fiber stream 8. A non-woven structure (12) formed in this way is collected on a flexible collecting screen 9 which is driven by one of the rolls 10, and then taken up by a product roll 13.
As shown in FIG. 1 collection of the non-woven structure 12 on the screen 9 is aided by the suction box 11 which applies gentle suction to the screen thereby drawing the non-woven structure 12 onto it.
The space relation of the die 2 and yarn feeding means 3 depends on the conditions of the web-producing process and the intended use of the non-woven structure product, but is preferably such that, as shown in FIG. 1, the distance A is 5 to 300 mm and the distance between the yarn feeding means 3 and fiber stream 8 (Distance B FIG. 1) is 10 to 1000 mm. Furthermore, the charging angle of the yarn 7 in the fiber stream 8 (θ (theta) FIG. 1) is generally, 30 degrees to 140 degrees, preferably 50 degrees to 110 degrees (θ equals 90 degrees in FIG. 1). The charging speed of the yarn 7 in the fiber stream 8 depends on the speed of the fiber stream, but ordinarily is 30 to 400 m/sec, which can be controlled by changing the pressure of the pressurized gas, preferably compressed air, supplied to the yarn charging means 3.
In the present invention, at least one continuous yarn is fed to a fiber stream, but if the system is so constituted that charging of the yarn into the fiber stream 8 is carried out at only one position, the yarn may be one-sided in the fiber stream, resulting in an uneven non-woven structure. Therefore, it is desirable to provide a plurality of yarn charging means or to install yarn charging means which may reciprocate or may rotate through a small angle, thereby charging the yarn evenly in the fiber stream and raising the strength of the resulting non-woven structure evenly. The detail of the yarn charging means will be illustrated hereinafter.
In accordance with the present invention, it is important to add the yarn 7 into the fiber stream 8 without disturbing the fiber stream 8, and this can effectively be accomplished by using a small quantity of air when using the yarn charging means 3 having the structure described below.
As shown in FIG. 2, the yarn charging means of the present invention is provided inside with a yarn path 18 and two air paths 15 and 16 separated by a spacer 14, to which a pipe 5 for feeding a pressurized gas is connected. In FIG. 3, the air paths 15 and 16 are separated (by spacer 14) by an interval of 0.3 to 1 mm, preferably 0.4 to 0.6 mm and the angles θ 1 (θ (theta) and θ 2 (θ (theta) to the yarn path 18 are adjusted so as to satisfy the relation of θ 1 >θ 2 . In this case, θ 1 is generally 30 to 70 degrees, preferably 40 to 50 degrees and θ 2 is generally 20 to 40 degrees, preferably 25 to 35 degrees. These air paths 15 and 16 are turned in the downstream courses so as to have spaces a and b in parallel to the yarn path 18. The space a is generally 0.5 mm to 3 mm, preferably 0.7 to 1.5 mm and the space b is generally 1 to 5 mm, preferably 1.5 to 2.5 mm, the space being larger than the space a.
In the interior of the yarn charging means 3, moreover, there is provided a nozzle regulator 17 to regulate the flowing direction and speed of air to the yarn 7 at the outlet of the air paths 15 and 16, the nozzle regulator being optionally moved back and forth by a screw 19.
As explained above, the nozzle regulator 17 can be moved back and forth, and thereby the charge speed of yarn 7 can be regulated. The yarn charging means having inside two varying air paths for feeding air, provides an air stream in the yarn charging means which is faster than that provided in other charging means having one air path, and as a result the yarn can be drawn strongly by a relatively small quantity of air. If the regulator 17 is withdrawn all the way to the right so that it does not affect air paths 15 and 16, the yarn cannot be drawn out. But as it is moved to the left, the yarn can be pulled out, and charged into the fiber stream. When the position of the sharp end of regulator 17 is as shown in FIG. 2A, the yarn may be drawn most strongly.
The yarn charging means 3 of the present invention has the above described structure as one embodiment and can have further modifications as shown in FIGS. 4 to 7.
In FIG. 4 and FIG. 5, the yarn charging means 3 is subjected to reciprocating motion perpendicular to the longitudinal direction of the fiber stream 8. Thus, in FIG. 4 the yarn charging means 3 is reciprocated along the arms 20 by means of the chain 21. In FIG. 5 the yarn charging means 3 is reciprocated along the arms 20 by means not shown. In FIG. 6 a number of yarn charging means 3 are provided; and in FIG. 7, each yarn charging means 3 is rotatable through a small angle to right and left perpendicular to the direction of the fiber stream. In these embodiments, a yarn or yarns can be charged uniformly into a fiber stream and, accordingly, the properties of the resulting non-woven fabric structure obtained in this way can be made uniform.
The non-woven structure of the present invention can be produced in an easy and effective manner, in particular, by the use of the apparatus of the invention. The proportion of web and yarn in such a non-woven structure, depending upon the use thereof, is in such a range that the strength of the web is increased to a required level for the object of the present invention, that is, ordinarily 1 to 5 parts by weight of yarn to 100 parts by weight of web, since if the proportion of yarn is too much, the characteristics of the web as a non-woven fabric are diminished.
The non-woven structure obtained by the process of the present invention has not only a greater strength but also a better hand than prior art webs and, in addition, it can be applied to various uses, for example, filters, synthetic leather, building materials, electric materials, medical materials, etc.
The following examples are offered by way of illustration.
EXAMPLE 1
As shown in FIG. 4, a polypropylene heated and melted at 310° C. was extruded from the die 2 and blown by heated air at 320° C. to form a fiber stream comprising extremely fine fibers of polypropylene. While subjecting the yarn charging means 3 to reciprocating motion, a stretched nylon-6 yarn (monofilament) with a size of 6 to 8 denier was drawn by heated air at 80° C., charged into the fiber stream at a speed of 60 m/sec and collected on a collecting plate 9 to obtain a non-woven structure 12 with a thickness of 1.5 mm. For this example the distances and angles in FIG. 1 and FIG. 3 had the following values;
A=50 mm, B=350 mm, θ=80 degrees, Space 15=0.5 mm, Space 16=0.5 mm, a=0.7 mm, b=1.5 mm, θ 1 =40 degrees, θ 2 =25 degrees.
The non-woven structure obtained by this method consisted of 98% by weight of a web of polypropylene with a fiber diameter of 7 microns and 2% by weight of a nylon-6 yarn as described above, and had a basis weight of 180 g/m 2 . The properties as described in the following, were superior to those of a similar web, produced without the addition of the nylon-6 yarn. In particular when used as a synthetic leather of filter, the performance was improved.
______________________________________ Non-woven Structure Web______________________________________Tensile Strength (ASTM D 1628) MD (Kg/25 mm) 6.2 4.7 CD (Kg/25 mm) 5.8 4.5Tear Strength (ASTM D 2261) MD (Kg) 0.50 0.29______________________________________
EXAMPLE 2
A mixture of 4 parts by weight of modified polypropylene obtained by grafting endo-bis-bicyclo (2,2,1)-5-heptene-2,3-dicarboxylic anhydride to polypropylene and 6 parts by weight of polypropylene was heated and melted at 310° C., extruded from the die 2 and blown with heated air at 320° C. to form a fiber stream. While the yarn charging means 3 was subjected to a shaking motion as shown in FIG. 7, a stretched polypropylene yarn (monofilament) with a size of 8 denier was drawn by heated air at 90° C., charged in the fiber stream at a speed of 70 m/sec and collected on the collecting plate 9 to obtain a non-woven structure having a thickness of 1.7 mm. For this example the distances and angles in FIG. 1 and FIG. 3 had the following values:
A=70 mm, B=250 mm θ=70 degrees, Space 15=0.5 mm, Space 16=0.5 mm, a=0.7 mm, b=1.5 mm, θ 1 =40 degrees, θ 2 =25 degrees.
The non-woven structure obtained by this method consisted of 98% by weight of the polypropylene mixture with a fiber diameter of 8 microns and 4% by weight of the above-described polypropylene yarn and had a basis weight of 200 g/m 2 . Properties as described in the following, were superior to those of a similar web produced without the addition of the polypropylene yarn. In particular, the web showed superior performances when used as synthetic leather, filters, separators for lead batteries and alkaline batteries.
______________________________________ Nonwoven Structure Web______________________________________Tensile Strength (ASTM D 1682) MD (Kg/25mm) 6.7 5.0 CD (Kg/25mm) 6.3 4.7Tear Strength (ASTM D 2261) MD (kg) 0.60 0.31______________________________________
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A process and apparatus are provided for the production of a non-woven fabric by melt-blowing wherein one or more yarns, e.g. monofilaments, are added or charged into the fabric stream between the extruder and collector by means of a supporting and drawing pressure gas stream. In one embodiment means are provided to regulate flow of the gas stream in another embodiment means are provided to reciprocate or to rotate through a small arc the one or more charging means.
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This application is a continuation of Ser. No. 09/135,210, filed Aug. 17,1998.
FIELD OF THE INVENTION
The present invention is directed to a method and apparatus for processing semiconductor wafers.
BACKGROUND OF THE INVENTION
A phenomenon which can reduce the yield of useful die from wafers during a semiconductor wafer processing step is the occurrence of arcing, also known as microarcing. Generally, during wafer processing, arcing can occur across the semiconductor wafer and in particular can be concentrated at material defects such as a crack, or at prominent feature of the wafer, which has been processed into the wafer, such as for example pillars. When such arcing occurs, part or all of the wafer can be irreparably damaged.
SUMMARY OF THE INVENTION
The present invention is directed to minimizing or eliminating arcing across a semiconductor wafer during a semiconductor wafer processing.
The invention describes a methodology and apparatus used to eliminate and/or substantially decrease the arcing or dielectric breakdown which may occur on a semiconductor wafer or substrate. The invention includes using a chuck and preferably an electrostatic chuck to control the electrostatic clamp voltage applied to the wafer to within a suitable range of values, such that arcing or dielectric breakdown is substantially reduced or eliminated. Such controlling can occur dynamically as process values change during the process steps. Further, by way of example only, such invention is of particular value with wafers containing film having a high dielectric constant or wafers containing films of ferroelectric material. However, such invention is useful for etching all types of standard and conventional films where arcing can also be a problem.
In particular, the apparatus and method are particularly useful for reducing or eliminating arcing or dielectric breakdown during etching in a plasma reactor.
Further, the invention includes a reactor for processing a semiconductor wafer which includes a reactor chamber and a chuck, and preferably an electrostatic chuck, which can accept a wafer for processing. The reactor includes a power supply associated with the reactor chamber, which the power supply is capable of generating a first voltage at the surface of the wafer adjacent to the plasma during the processing of the wafer. The invention further includes a control mechanism that can control a second voltage that the electrostatic chuck applies to the wafer in order to hold the wafer to the chuck during wafer processing. The control mechanism is capable of adjusting the second voltage so that the difference between the first voltage and the second voltage or, in other words, the potential across the wafer, is kept below a threshold in order to minimize arcing across the wafer. Such adjustments can be made dynamically, if desired throughout the wafer fabrication process.
Accordingly, one aspect of the invention includes apparatus that controls the voltage applied to the surface of a wafer in contact with an electrostatic chuck in order to minimize the difference between the applied clamping voltage and the voltage built up on the other side of the wafer which is in contact with, for example, a plasma generated in an etch reactor.
A method of the invention includes the steps of placing a semiconductor wafer into a reactor and onto an electrostatic chuck, and generating a plasma in the reactor. The method further includes controlling the voltage across the wafer in order to minimize arcing.
In an aspect of the invention, the controlling step includes controlling the difference between the voltage at the first surface of the wafer in contact with the plasma, and the voltage at a second surface of the wafer in contact with the chuck.
In another aspect of the present invention, the plasma is generated by at least one of a high frequency power supply and a low frequency power supply.
In a further aspect of the present invention, both the high frequency power supply and a low frequency power supply are applied to the chuck.
In a further aspect of the present invention, the method includes applying a semiconductor processing step to one of high dielectric constant film on a substrate and a ferroelectric film on a substrate.
Accordingly, it can be seen that the present invention is effective in reducing or eliminating arcing across a wafer and in particular a wafer which has a high dielectric constant film and/or ferroelectric film. Such invention is advantageous in that it increases the yield of die.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a schematical representation of an embodiment of a reactor of the invention which can be used to carry out a method of the invention.
FIG. 2 depicts an enlargement of the wafer positioned on an embodiment of the electrostatic chuck of the invention of FIG. 1 .
FIG. 3 depicts a chart showing the controller step function of an embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The method of the present invention can be performed in an etch reactor, such as the etch reactor of the invention depicted in FIG. 1, using the chuck configuration, such as the electrostatic chuck configuration shown in FIG. 2 . As is known in the art, electrostatic chucks apply an electrostatic force in order to clamp a wafer onto said chucks. It is to be understood that other reactors including, but not limited to other etch reactors, and other chuck configurations can be used and be within the scope and spirit of the invention. By way of example only, mechanical clamping chucks which have been modified to apply a potential to a wafer are within the spirit and scope of the invention.
The etch reactor of FIG. 1 is identified by the number 20 and is configurated as a tri-electrode reactor. The etching apparatus 20 includes a housing 22 and an etching chamber 24 . A wafer 26 is positioned on a bottom electrode 28 . The chamber 24 further includes a side peripheral electrode 30 and an upper electrode 32 . In a preferred embodiment, the side peripheral electrode 30 can be grounded or allowed to establish a floating potential as a result of the plasma developed in the chamber 24 . The upper electrode 32 is generally grounded. In typical operation, both the side peripheral electrode 30 and the upper electrode 32 are grounded as shown in FIG. 1 .
Preferably two A.C. power supplies, first power supply 34 and second power supply 36 , are connected to the bottom electrode 28 through a appropriate circuitry 38 which includes matching networks and a combiner. Further a controller 40 controls the sequencing of the first and second AC power supplies 34 , 36 . Typically, the first power supply 34 operated in the kilohertz range and is optimally provided at about 450 KHz, and typically in the range of less than 500 KHz. The second power supply 36 operates in the megahertz range, and typically operates at about 13.56 MHz, although other frequencies above about 1 MHz and also multiples of 13.56 MHz can be used with the present invention. The power supply 34 is preferably powered at 200 watts and the second power supply 36 is preferably powered at 500 watts for this example. The low frequency KHz power supply can cycle up to about 500 watts if desired, and the high frequency MHz power supply can cycle up to about 1150 watts if desired during an etch process. Ion energy increases towards the kilohertz range while ion density increases towards the megahertz range. Additionally, reactor 20 includes gas inlet head 42 and a gas outlet port 44 .
The chuck 48 which is incorporated in the bottom electrode 28 is an electrostatic chuck. Electrostatic chucks are well known in the industry. This electrostatic chuck includes an electrostatic clamp electrode 50 , to which is preferably applied a DC voltage from voltage source 52 . Controller 40 , in this preferred embodiment, can dynamically (over time accordingly to changing process conditions such as changing power input to the electrodes) control the voltage applied to the electrostat clamp electrical 50 by the source 52 . Such control depends on, for example, the ramping and cycling of one or more of the other power supplier.
In this particular embodiment, the wafer 26 includes a film 54 which is comprised of one of a high dielectric constant material or a ferroelectric material. It is to be understood, however, that the invention can work successfully on any film and in any situation where arcing can be a problem.
It is to be understood that the above inventive structure can be modified such that one or more of the power supplies can be applied to electrodes 30 and/or 32 in addition to being applied to electrode 28 if desired. Further, it is to be understood that the invention can include only a single power supply applied to the lower electrode 28 . It is also to be understood that the electrode can be those used to establish both a capacitively coupled reactor and an inductively coupled reactor.
When a substrate is being etched in a plasma, the potential of the front surface 56 (FIG. 2) of the wafer assumes a time averaged negative potential with respect to the plasma potential. The time averaged negative potential or DC potential (commonly referred to as the “DC Bias”, V dc ) is generally dependent on the plasma conditions and the low and high frequency power applied to the wafer. In this particular situation, due to the presence of the high dielectric constant and/or ferroelectric material layer on the substrate, the back surface 58 of the wafer 26 is insulated from the front surface 56 of the wafer. The DC potential of the back surface 58 of the wafer is determined primarily by the clamping voltage from the chuck 48 . For example, in the case of using an electrostatic clamp, the DC potential of the back side 58 of the wafer is greatly influenced by the claiming voltage (V ESC ). By way of example only, in a representative etch process, V dc can be for example −1000 volts, and V ESC can be for example −700 volts. The difference would then be (−1000 volts)−(−700 volts), or −300 volts. The less negative the difference is the less likely that arcing will occur. In other words, the lower the absolute value of V dc −V ESC is the less likely that arcing will occur. It is to be understood that arcing can occur at a potential of −200 volts or smaller negative potential values, but that it generally occurs at a potential of −300 volts and certainly at greater negative potential values.
For a system with a pure mechanical clamp, the potential of the back surface of the wafer is not generally well controlled and assumes a value somewhere between zero and the potential of the front surface of the wafer. Thus, due to the presence of the high dielectric constant and/or ferroelectric layer between the front and the back surface of the wafer, a potential difference between the two surfaces can exist. The potential difference between the front and the back surfaces of the wafer (across the high dielectric constant and/or ferroelectric layer) can be high (several hundred volts), especially when high dielectric constant materials such as strontium bismuth tantalate (Y−1) are being used.
Another high dielectric constant film material that can benefit from the invention include lead zirconium titanate (PZT).
The DC potential difference between the front and the back surface of the wafer can lead to very high electric fields, especially across thinner dielectric layers or material defects. The value of this electric field can far exceed the breakdown strength of the dielectric leading to an electrical breakdown.
It has been found that Y 1 films can have material defects caused during the Y 1 film formation, which defects consists of “cracks” in the dielectric layer, where the dielectric layer is very thin. Electrical breakdown of the dielectric can occur in the “crack” area leading to an arc on the front side of the wafer.
When the ESC potential, V ESC , is set to a value which is close to the potential of the front surface of the wafer, the potential difference and hence the electric field in the dielectric layer and/or ferroelectric layer are substantially reduced. This prevents and/or substantially decreases the number and physical size of the arc spots on the wafer being etched.
Accordingly, the electrostatic clamp voltage is adjusted to eliminate and/or substantially reduce arcing or dielectric breakdown which may occur when a substrate containing a layer of, by way of example only, a high dielectric constant and/or ferroelectric material, is being etched in a plasma.
The invention thus makes use of the electrostatic clamp for a novel application of eliminating and/or substantially reducing arcing or dielectric breakdown which may occur when a substrate containing a layer of high dielectric constant and/or ferroelectric material is being etched in a plasma. Although electrostatic clamps are widely used in practice for clamping substrates without the need for any front side contact, the electrostatic clamp potential has never been used as a “knob” to control the occurrence of arcing and/or dielectric breakdown.
FIG. 3 demonstrates a dramatic step function jump from essentially little or no arcing or microarcing below about 900 watts from the MHz power supply 36 to damaging arcing at above about 900 watts. Accordingly, arcing increases with the increase in the MHz power and with an increase in V de −V ESC . Further, increasing the KHz power can also provide an onset of arcing. Accordingly, the invention includes programming the control 40 to ensure that the V ESC is appropriately set in order to dynamically keep the difference V de −V ESC during an etch operation in a desirable range, and below a arcing threshold value, no matter what the operating condition for power supply 34 and 36 are. Thus, as the power supplies are ramped and cycled, the control 40 can keep V ESC and the difference V de −V ESC below an appropriate threshold to minimize or prevent arcing.
Industrial Applicability
Accordingly, the present invention is useful in successfully etching emerging films such as high dielectric constant and ferroelectric films. It can be seen that the present invention allows for improved throughput by minimizing or eliminating arcing which can destroy some or all of the wafer.
Other features, aspects and objects of the invention can be obtained from a review of the figures and the claims.
It is to be understood that other embodiments of the invention can be developed and fall within the spirit and scope of the invention and claims.
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A method and apparatus for minimizing or eliminating arcing or dielectric breakdown across a wafer during a semiconductor wafer processing step includes controlling the voltage across the wafer so that arcing and/or dielectric breakdown does not occur. Using an electrostatic clamp of the invention and by controlling the specific clamp voltage to within a suitable range of values, the voltage across a wafer is kept below a threshold and thus, arcing and/or dielectric breakdown is reduced or eliminated.
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RELATED APPLICATIONS
This application is a continuation under 35 U.S.C. §120 of U.S. patent application Ser. No. 12/179,769, filed 25 Jul. 2008, which claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 60/952,053, filed 26 Jul. 2007.
TECHNICAL FIELD
This disclosure generally relates to proximity sensors.
BACKGROUND
Capacitive position sensors have recently become increasingly common and accepted in human interfaces and for machine control. For example, in the fields of portable media players it is now quite common to find capacitive touch controls operable through glass or plastic panels. Some mobile telephones are also starting to implement these kinds of interfaces.
Many capacitive touch controls incorporated into consumer electronic devices for appliances provide audio or visual feedback to a user indicating whether a finger or other pointing object is present or approaches such touch controls. A capacitive sensing microprocessor may typically be comprised in touch-controlled devices which are arranged to provide an “on” output signal when a finger is adjacent to a sensor and an “off” output signal when a finger is not adjacent to a sensor. The signals are sent to a device controller to implement a required function dependent on whether a user's finger is in proximity with or touching an associated touch control.
Some touch-controlled devices remain “on” or “active” despite the user having moved away from the device or a particular function no longer being required. This results in the device consuming a large amount of power which is not efficient.
OVERVIEW
Particular embodiments provide a sensor for determining the presence of an object comprising: a sensing element; a capacitance measurement circuit operable to measure the capacitance of the sensing element; and a control circuit operable to determine whether an object is in proximity with the sensor based on a measurement of the capacitance of the sensing element, the control circuit further being operable to provide an output signal to control a function of an apparatus when it is determined that an object has not been in proximity with the sensor for a predetermined time duration.
The control circuit may be configured so that the predetermined time duration is selectable from a number of different predefined time durations.
The control circuit may include a time input terminal and the predetermined time duration may selectable from the number of different predefined time durations according to a voltage applied to the time input terminal.
The control circuit may include a delay multiplier terminal and be configured so that a selected one of the number of different predefined time durations is multiplied by a multiplication factor according to a voltage applied to the delay multiplier terminal so as to provide the predetermined time duration.
The control circuit may be configured so that the predetermined time duration is programmable by a user to provide a user-selected time duration.
The sensor may comprise a resistor-capacitor (RC) network coupled to the control circuit and the predetermined time duration may depend on a time constant of the RC network.
The control circuit may include a delay multiplier terminal and be configured so that the user-selected time duration is multiplied by a multiplication factor according to a voltage applied to the delay multiplier terminal to provide the predetermined time duration.
The control circuit may be configured such that the provision of the output signal to control a function of an apparatus after the predetermined time duration may be overridden so the output signal is not provided when it is determined that an object has not been in proximity with the sensor for a predetermined time duration. For example, the control circuit may be operable to receive an override pulse and on receipt of the override pulse to retrigger the predetermined time duration to so as to extend the time before the output signal to control a function of an apparatus is provided.
The control circuit may be configured such that the provision of the output signal to control a function of an apparatus after the predetermined time duration may be overridden so the output signal is provided before it is determined that an object has not been in proximity with the sensor for a predetermined time duration. For example, the control circuit may be operable to receive an override pulse and on receipt of the override pulse to provide the output signal to control a function of an apparatus.
The sensor may be configured to perform a recalibration when the sensor is powered up, when an object is determined to be in proximity with the sensor for more than a timer setting, and/or when an override is released.
The control circuit may be configured such that the output signal is toggled between a high state and a low state when an object is determined to be in proximity with the sensor.
The function of an apparatus controlled by the output signal may be a switch-off function.
The capacitance measurement circuit may employ bursts of charge-transfer cycles to acquire measurements.
The capacitance measurement circuit may be configured to operate in one of more than one acquisition modes depending on the output signal, for example a low-power mode or a fast mode.
The capacitance measurement circuit and the control circuit may be comprised in a general purpose microcontroller under firmware control.
The capacitance measurement circuit and the control circuit may be comprised within a six-pin integrated circuit chip package, such as an SOT23-6.
Particular embodiments provide an apparatus including a sensor as described above.
Particular embodiments provide a method for controlling a function of an apparatus comprising: determining whether an object is in proximity with a sensor based on a measurement of the capacitance of a sensing element and providing an output signal to control the function of the apparatus when it is determined that an object has not been in proximity with the sensor for a predetermined time duration.
The function of the apparatus controlled by the output signal may be a switch-off function.
Particular embodiments provide a sensor for determining the presence of an object comprising: a sensing element, a capacitance measurement circuit operable to measure the capacitance of the sensing element, and a control circuit operable to determine whether an object is in proximity with the sensor based on a measurement of the capacitance of the sensing element, the control circuit also being operable to provide an output signal to control a function of an apparatus based on an object not being in proximity with the sensor and the output signal being produced after a predetermined time duration.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference is now made by way of example to the accompanying drawings in which:
FIG. 1 schematically shows sense electrode connections for an example chip for implementing an auto-off function in particular embodiments;
FIG. 2 schematically represent an application of drift compensation in the chip of FIG. 1 ;
FIG. 3 schematically shows a basic circuit configuration for providing a 15 minute auto switch-off function in an active high output implementation of particular embodiments;
FIG. 4 schematically shows a series of fast mode bursts on the SNSK pin of the chip shown in FIG. 1 where in an on condition;
FIG. 5 schematically shows a series of low-power mode bursts and a switch to fast mode power bursts on the SNSK pin of the chip shown in FIG. 1 when switching from an off condition to an on condition;
FIG. 6 schematically shows use of an output configuration resistor Rop to configure the chip of FIG. 1 to have an active high or an active low output;
FIG. 7 schematically shows an example circuit configuration for the chip shown in FIG. 1 with the output connected to a digital transistor;
FIG. 8 schematically shows an example circuit configuration for the chip shown in FIG. 1 configured to provide a predefined auto-off delay;
FIG. 9 schematically shows an example circuit configuration for the chip shown in FIG. 1 configured to provide a programmable auto-off delay;
FIG. 10 schematically shows an example pulse applied to the chip shown in FIG. 1 to override an auto-off delay;
FIG. 11 schematically shows another example pulse applied to the chip shown in FIG. 1 to override an auto-off delay;
FIG. 12 schematically shows example voltage levels for the chip shown in FIG. 1 in overriding of an auto-off delay;
FIGS. 13 and 14 schematically show typical values of RC divisor K as a function of supply voltage VDD for the chip shown in FIG. 1 with active high output and active low output respectively;
FIG. 15 schematically shows typical curves of auto-off delay as a function of timing resistor value for different capacitor values and different supply voltages for an active high output configuration;
FIG. 16 schematically shows typical curves of auto-off delay as a function of timing resistor value for different capacitor values and different supply voltages for an active low output configuration;
FIG. 17 schematically shows an example application of the chip shown in FIG. 1 in an active low output configuration driving a PNP transistor with an auto-off time of 3.33 hours;
FIG. 18 schematically shows another example application of the chip shown in FIG. 1 in an active high output configuration driving a high impedance with an auto-off time of 135 seconds;
FIG. 19 schematically shows an implementation of the chip shown in FIG. 1 in an SOT23-6 package; and
FIG. 20 schematically shows a pin diagram for an implementation of the chip shown in FIG. 1 in an SOT23-6 package.
DESCRIPTION OF EXAMPLE EMBODIMENTS
Particular embodiments may be implemented in an integrated circuit chip providing a proximity sensor function. The integrated circuit chip may thus be incorporated into a device or apparatus to provide and control a proximity sensor functionality for the device or apparatus in particular embodiments. For the purposes of explanation, a specific integrated circuit chip providing the functionality of an example embodiment will be described further below. The chip will in places be referred to by product name QT102. However, it will be appreciated that the QT102 chip is merely a specific example application of an example embodiment. Particular embodiments need not be implemented in a chip in this way, and furthermore, particular embodiments may be provided in conjunction with all, some or none of the additional features of the QT102 chip described further below.
Before turning specifically to the QT102 chip embodiment, a summary is provided.
It is known that a touch sensitive sensor may comprise a sensor element, such as an etched copper electrode mounted on a PCB substrate, and a control circuit for measuring a capacitance of the sensor element to a system reference potential. The sensor element may be referred to as a sense electrode. The capacitance of the sense electrode is affected by the presence of nearby objects, such as a pointing finger. Thus the measured capacitance of the sense electrode, and in particular changes in the measured capacitance, may be used to identify the presence of an object adjacent the sense electrode. The control circuit may be configured to provide an output signal, e.g. by setting an output logic level as high or low, indicating whether or not an object is deemed to be adjacent the sense electrode. A controller of a device in which the touch sensitive sensor is implemented may receive the output signal and act accordingly.
There are various known technologies for measuring capacitance of a sense electrode in a capacitive touch sensor. Particular embodiments may be implemented in conjunction with any of these technologies or measurement circuits. For example, the fundamental principles underlying the capacitive sensors described in U.S. Pat. No. 5,730,165, U.S. Pat. No. 6,466,036, and U.S. Pat. No. 6,452,514 could be used.
In particular embodiments, the control circuit of the sensor can determine whether an object or a user's finger is no longer in proximity with the sensor and based on a predetermined time duration, the control circuit can produce an output signal automatically to prevent the capacitance measurement circuit from continually measuring changes in capacitance due to, for example, the perceived presence of an object in proximity with the sensor.
Therefore, the control circuit is able to deactivate, turn-off, or power down the capacitance measurement circuit where an apparatus has inadvertently been left on or with the erroneous perception that a user is still present. This may, for example, be referred to as an “auto-off” feature. The signal for preventing the capacitance measurement circuit from continually measuring changes in capacitance may be referred to as an auto-off signal. The capacitance measurement circuit and the auto-off control circuit may be comprised in a general-purpose microcontroller under firmware control, for example, such as the QT102 chip described further below.
As described in Section 3.5 of the below numbered sections, and in conjunction with the drawings, the control circuit of the sensor may be implemented by different methods—for example, the auto-off signal output may be produced automatically after different predetermined time durations to effect powering down the capacitance measurement circuit due to no presence of the user; the control circuit may be programmed by a user so that it may power down an apparatus based on a user-selected time duration; the control circuit output signals may be overridden, for example, to extend time durations before an apparatus is turned-off or to immediately turn-off an apparatus when a user is no longer present.
The sensor of particular embodiments may be useful in various applications, for example in kitchen appliances, light switches, headsets, and other electronic consumer devices. For example, a coffee machine incorporating a sensor of particular embodiments may be programmed to power-down after a time period of, say, 30 minutes, where the coffee machine has been left on inadvertently. This will beneficially conserve energy use and minimize the possibility of damage or accidents caused by the coffee machine or glass container(s) overheating.
Aspects of the QT102 chip referred to above will now be described in the following numbered sections.
The numbered sections may be considered to relate generally to features of the QT102 chip as follows: Section 1—Overview (including 1.1 Introduction, 1.2 Electrode Drive, 1.3 Sensitivity, 1.3.1 Introduction, 1.3.2 Increasing Sensitivity, 1.3.3 Decreasing Sensitivity, 1.4 Recalibration Timeout, 1.5 Forced Sensor Recalibration, 1.6 Drift Compensation, 1.7 Response Time, 1.8 Spread Spectrum). Section 2—Wiring and Parts (including 2.1 Application Note, 2.2 Cs Sample Capacitor, 2.3 Rs Resistor, 2.4 Power Supply, PCB Layout, 2.5 Wiring). Section 3—Operation (including 3.1 Acquisition Modes, 3.1.1 Introduction, 3.1.2 OUT Pin “On” (Fast Mode), 3.1.3 OUT Pin “Off” (Low Power Mode), 3.2 Signal Processing, 3.2.1 Detect Integrator, 3.2.2 Detect Threshold, 3.3 Output Polarity Selection, 3.4 Output Drive, 3.5 Auto Off Delay, 3.5.1 Introduction, 3.5.2 Auto Off—Predefined Delay, 3.5.3 Auto Off—User-programmed Delay, 3.5.4 Auto Off—Overriding the Auto Off Delay, 3.5.5 Configuring the User-programmed Auto-off Delay, 3.6 Examples of Typical Applications). Section 4—Specifications (including 4.1 Absolute Maximum Specifications, 4.2 Recommended Operating Conditions, 4.3 AC Specifications, 4.4 Signal Processing, 4.5 DC Specifications, 4.6 Mechanical Dimensions, 4.7 Moisture Sensitivity Level (MSL)).
1 Overview
1.1 Introduction
The QT102 is a single key device featuring a touch on/touch off (toggle) output with a programmable auto switch-off capability.
The QT102 is a digital burst mode charge-transfer (QT) sensor designed specifically for touch controls; it includes hardware and signal processing functions to provide stable sensing under a wide variety of changing conditions. In examples, low cost, non-critical components are employed for configuring operation.
The QT102 employs bursts of charge-transfer cycles to acquire its signal. Burst mode permits power consumption in the microampere range, dramatically reduces radio frequency (RE) emissions, lowers susceptibility to electromagnetic interference (EMI), and yet permits good response time. Internally the signals are digitally processed to reject impulse noise, using a “consensus” filter which in this example requires four consecutive confirmations of a detection before the output is activated.
The QT switches and charge measurement hardware functions are all internal to the QT102.
1.2 Electrode Drive
FIG. 1 schematically shows the sense electrode connections (SNS, SNSK) for the QT102.
For improved noise immunity, it may be helpful if the electrode is only connected to the SNSK pin.
In examples the sample capacitor Cs may be much larger than the load capacitance (Cx). E.g. typical values for Cx are 5 to 20 pF while Cs is usually 1 or 2 to 50 nF. (Note: Cx is not a physical discrete component on the PCB, it is the capacitance of the touch electrode and wiring. It is shown in FIG. 1 to aid understanding of the equivalent circuit.)
Increasing amounts of Cx destroy gain, therefore it is important to limit the amount of load capacitance on both SNS terminals. This can be done, for example, by minimizing trace lengths and widths and keeping these traces away from power or ground traces or copper pours.
The traces and any components associated with SNS and SNSK will become touch sensitive and so may need to be considered to help in limiting the touch-sensitive area to the desired location.
A series resistor, Rs, may be placed in line with SNSK to the electrode to suppress electrostatic discharge (ESD) and Electromagnetic Compatibility (EMC) effects.
1.3 Sensitivity
1.3.1 Introduction
The sensitivity of the QT102 is a function of such things as:
the value of Cs
electrode size and capacitance
electrode shape and orientation
the composition and aspect of the object to be sensed
the thickness and composition of any overlaying panel material
the degree of ground coupling of both sensor and object
1.3.2 Increasing Sensitivity
In some cases it may be desirable to increase sensitivity; for example, when using the sensor with very thick panels having a low dielectric constant. Sensitivity can often be increased by using a larger electrode or reducing panel thickness. Increasing electrode size can have diminishing returns, as high values of Cx will reduce sensor gain.
The value of Cs also has an effect on sensitivity, and this can be increased in value with the trade-off of slower response time and more power. Increasing the electrode's surface area will not substantially increase touch sensitivity if its diameter is already significantly larger in surface area than the object being detected. Panel material can also be changed to one having a higher dielectric constant, which will better help to propagate the field.
Ground planes around and under the electrode and its SNSK trace may lead to high Cx loading and destroy gain. Thus in some cases the possible signal-to-noise ratio benefits of ground areas may be more than negated by the decreased gain from the circuit, and so ground areas around electrodes may be discouraged in some circumstances. Metal areas near the electrode may reduce the field strength and increase Cx loading and so it may be helpful if these are avoided if possible. It may be helpful to keep ground away from the electrodes and traces.
1.4 Recalibration Timeout
If an object or material obstructs the sense electrode the signal may rise enough to create a detection, preventing further operation. To help reduce the risk of this, the sensor includes a timer which monitors detections. If a detection exceeds the timer setting (known as the Max On-duration) the sensor performs a full recalibration. This does not toggle the output state but ensures that the QT102 will detect a new touch correctly. The timer is set to activate this feature after ˜30 seconds. This will vary slightly with Cs.
1.5 Forced Sensor Recalibration
The QT102 has no recalibration pin; a forced recalibration is accomplished when the device is powered up, after the recalibration timeout or when the auto-off override is released.
However, supply drain is low so it is a simple matter to treat the entire IC as a controllable load; driving the QT102's VDD pin directly from another logic gate or a microcontroller port will serve as both power and “forced recal(ibration)”. The source resistance of most CMOS gates and microcontrollers are low enough to provide direct power without problems.
1.6 Drift Compensation
Signal drift can occur because of changes in Cx and Cs over time. It may be helpful if drift is compensated for, otherwise false detections, nondetections, and sensitivity shifts may follow.
Drift compensation is schematically shown in FIG. 2 . Drift compensation is performed by making a reference level track the raw signal at a slow rate, but only while there is no detection in effect. It may be helpful if the rate of adjustment is performed relatively slowly, otherwise there may be a risk that legitimate detections may be ignored. The QT102 drift compensates using a slew-rate limited change to the reference level; the threshold and hysteresis values are slaved to this reference.
Once an object is sensed, the drift compensation mechanism ceases since the signal is legitimately high, and therefore should not cause the reference level to change (as indicated in FIG. 2 during the period between the vertical dotted lines).
The QT102's drift compensation is “asymmetric”; the reference level drift-compensates in one direction faster than it does in the other. Specifically, it compensates faster for decreasing signals than for increasing signals. It may be helpful if increasing signals are not compensated for quickly, since an approaching finger could be compensated for partially or entirely before approaching the sense electrode.
However, an obstruction over the sense pad, for which the sensor has already made full allowance, could suddenly be removed leaving the sensor with an artificially elevated reference level and thus become insensitive to touch. In this latter case, the sensor will compensate for the object's removal more quickly, for example in only a few seconds.
With relatively large values of Cs and small values of Cx, drift compensation will appear to operate more slowly than with the converse. Note that the positive and negative drift compensation rates are different.
1.7 Response Time
The QT102's response time is dependent on burst length, which in turn is dependent on Cs and Cx. With increasing Cs, response time slows, while increasing levels of Cx reduce response time.
1.8 Spread Spectrum
The QT102 modulates its internal oscillator by ±7.5 percent during the measurement burst. This spreads the generated noise over a wider band reducing emission levels. This also reduces susceptibility since there is no longer a single fundamental burst frequency.
2 Wiring and Parts
FIG. 3 schematically shows a basic circuit configuration for an implementation of particular embodiments.
2.1 Application Note
Although not necessarily relevant to particular embodiments, for completeness, reference may be made to Application Note AN-KDO2 (“Secrets of a Successful QTouch™ Design”), included herein in its entirety by reference, and downloadable from the Quantum Research Group website, for information on example construction and design methods. Go to http://www.qprox.com, click the Support tab and then Application Notes.
2.2 Cs Sample Capacitor
Cs is the charge sensing sample capacitor. The required Cs value depends on the thickness of the panel and its dielectric constant. Thicker panels require larger values of Cs. Typical values are 1 or 2 nF to 50 nF depending on the sensitivity required; larger values of Cs may demand higher stability and better dielectric to ensure reliable sensing.
The Cs capacitor may be a stable type, such as X7R ceramic or PPS film. For more consistent sensing from unit to unit, 5 percent tolerance capacitors are recommended. X7R ceramic types can be obtained in 5 percent tolerance for little or no extra cost. In applications where high sensitivity (long burst length) is required, the use of PPS capacitors is recommended.
Series resistor Rs is in line with the electrode connection and may be used to limit electrostatic discharge (ESD) currents and to suppress radio frequency interference (RF1). It may be approximately 4.7 kΩ to 33 kΩ, for example.
Although this resistor may be omitted, the device may become susceptible to external noise or RF1. For more details of how to select these resistors see the Application Note AN-KDO2 referred to above in Section 2.1.
2.4 Power Supply, PCB Layout
The power supply (between VDD and VSS/system ground) can range between 2.0V and 5.5V for the QT102 implementation. If the power supply is shared with another electronic system, it may be helpful if care is taken to ensure that the supply is free of digital spikes, sags, and surges which can adversely affect the device. The QT102 will track slow changes in VDD, but it may be more affected by rapid voltage fluctuations. Thus it may be helpful if a separate voltage regulator is used just for the QT102 to isolate it from power supply shifts caused by other components.
If desired, the supply can be regulated using a Low Dropout (LDO) regulator. See Application Note AN-KDO2 (see Section 2.1) for further information on power supply considerations.
Suggested regulator manufacturers include:
Toko (XC6215 series)
Seiko (S817 series)
BCDSemi (AP2121 series)
Parts placement: The chip may be placed to minimize the SNSK trace length to reduce low frequency pickup, and to reduce Cx which degrades gain. It may be helpful if the Cs and Rs resistors (see FIG. 3 ) are placed close to the body of the chip so that the trace between Rs and the SNSK pin is relatively short, thereby reducing the antenna-like ability of this trace to pick up high frequency signals and feed them directly into the chip. A ground plane can be used under the chip and the associated discretes, but it may be helpful if the trace from the Rs resistor and the electrode do not run near ground, to reduce loading.
For improved Electromagnetic compatibility (EMC) performance the circuit may be made entirely with surface mount technology (SMT) components.
Electrode trace routing: It may be helpful to keep the electrode trace (and the electrode itself) away from other signal, power, and ground traces including over or next to ground planes. Adjacent switching signals can induce noise onto the sensing signal; any adjacent trace or ground plane next to, or under, the electrode trace will cause an increase in Cx load and desensitize the device.
Note: a 100 nF (0.1 μF) ceramic bypass capacitor (not shown in FIG. 3 ) might be used between VDD and VSS in cases where it is considered appropriate to help avoid latch-up if there are substantial VDD transients; for example, during an ESD (electrostatic discharge) event. It may furthermore be helpful if the bypass capacitor is placed close to the device's power pins.
TABLE 2.1
QT102 Pin Descriptions (referring to
the pin numbering shown in FIG. 3)
PIN
NAME
TYPE
DESCRIPTION
1
OUT
O
To switched circuit and output polarity
selection resistor (Rop)
2
VSS
P
Ground power pin
3
SNSK
IO
To Cs capacitor and to sense electrode
4
SNS
IO
To Cs capacitor and multiplier configura-
tion resistor (Rm). Rm connected to either
VSS or VDD. Refer to Section 3.5 for details.
5
VDD
P
Positive power pin
6
TIME
I
Timeout configuration pin, connected to
either VSS, VDD, OUT or an RC network.
Refer to Section 3.5 for details.
Type: P—Ground or power; IO—Input and output; OD—Open drain output; O—Output only, push-pull; I—Input only
Regarding FIG. 3 , the following sections provide guidance for some example component values: Section 2.2 for Cs capacitor (Cs); Section 2.3 for Sample resistor (Rs); Section 2.4 for Voltage levels; Section 3.5.2 for Rm; and Section 3.3 for Rop.
3 Operation
3.1 Acquisition Modes
3.1.1 Introduction
The polarity for the OUT pin of the QT102 can be configured to be “active high” or “active low” (see Section 3.3). If configured active high, then “on” is high and “off” is low. If configured active low, then “on” is low and “off” is high.
The QT102 has more than one acquisition mode with the mode depending on the state of the OUT pin (on or off) and whether a touch is detected. In the following text “on” is when the output is in its active state (which could be high or low depending on how the polarity for the OUT pin is configured).
3.1.2 OUT Pin “On” (Fast Mode)
The QT102 runs in a “Fast mode” when the OUT pin is on. In this mode the device runs at maximum speed at the expense of increased current consumption. The delay between bursts in Fast mode is approximately 2.6 ms. FIG. 4 schematically shows bursts on the SNSK pin during fast mode acquisition.
3.1.3 OUT Pin “Off” (Low Power Mode)
The QT102 runs in Low Power (LP) mode if the OUT pin is off. In this mode it sleeps for approximately 85 ms at the end of each burst, saving power but slowing response. On detecting a possible key touch, it temporarily switches to Fast mode until either the key touch is confirmed or found to be spurious (via the detect integration process). If the touch is confirmed the QT102 will switch to Fast mode. If a touch is denied the device will revert to normal LP mode operation automatically. FIG. 5 schematically shows bursts on the SNSK pin during a touch detection event. Also schematically represented is the output signal on the OUT pin. A key touch occurs around halfway along the figure. Prior to the key touch, the OUT pin is off (schematically shown here as a low logic level) and the QT102 is running in Low Power mode with sleep periods between bursts. The capacitance measured during the first burst after the key touch is higher and this triggers Fast mode acquisition. Following four burst in which the higher capacitance is seen (see Section 3.2.1), the OUT pin switches to on (schematically shown here as a high logic level) and Fast mode acquisition continues.
3.2 Signal Processing
3.2.1 Detect Integrator
It is desirable to suppress detections generated by electrical noise or from quick brushes with an object. To accomplish this, the QT102 incorporates a “detect integration” (DI) counter that increments with each detection until a limit is reached, after which the output is activated. If no detection is sensed prior to the final count, the counter is reset immediately to zero. In the QT102, the required count is four. The DI can also be viewed as a “consensus” filter, that requires four successive detections to create an output.
3.2.2 Detect Threshold
The device detects a touch when the signal has crossed a threshold level, in this example the threshold level is fixed at 10 counts.
3.3 Output Polarity Selection
The output (OUT pin) of the QT102 can be configured to have an active high or active low output by means of the output configuration resistor Rop. The resistor is connected between the output an output configuration voltage Vop, which may be either VSS or VDD as schematically shown in FIG. 6 . For the QT102, if Vop is VSS, the output polarity is configured active high. If Vop is VDD, the output polarity is configured active low
It is noted that some devices, such as Digital Transistors, have an internal biasing network that will naturally pull the OUT pin to its inactive state. If these are being used then the resistor Rop is not required, as schematically shown in FIG. 7 .
3.4 Output Drive
The OUT pin in the QT102 embodiment can sink or source up to 2 mA. When a relatively large value of Cs (e.g. >20 nF) is used, it may be helpful if the OUT pin current is limited to <1 mA to reduce the risk of gain-shifting side effects. These may happen when the load current creates voltage drops on the die and bonding wires; in some cases these small shifts can materially influence the signal level to cause detection instability.
3.5 Auto Off Delay
3.5.1 Introduction
In addition to toggling the output on/off with key touch, the QT102 can automatically switch the output off after a specific time. This feature can be used to save power in situations where the switched device could be left on inadvertently.
The QT102 has:
three predefined delay times (Section 3.5.2)
the ability to set a user-programmed delay (Section 3.5.3)
the ability to override the auto off delay (Section 3.5.4)
The QT102 chip is programmed such that the TIME and SNS pins may be used to configure the auto-off delay t o and may be connected in one of the ways described in Sections 3.5.2, 3.5.3 and 3.5.4 to provide different functionality.
3.5.2 Auto Off—Predefined Delay
To configure a predefined delay t o the TIME pin may be wired to a voltage V t , as schematically indicated in FIG. 8 . Voltage V t may be VSS, VDD or OUT. These provides nominal values of t o =15 minutes, 60 minutes or infinity (remains on until toggled off) as indicated in Table 3.2 for an active high output configuration and in Table 3.3 for an active low output configuration.
Furthermore, also as shown in FIG. 8 , a resistor Rm (e.g. a 1 MΩ resistor) may be connected between the SNS pin and the logic level Vm to provide three auto off functions: namely delay multiplication, delay override and delay retriggering. On power-up the logic level at Vm is assessed and a delay multiplication factor is set to ×1 or ×24 accordingly (see Table 3.4). At the end of each acquisition cycle the logic level of Vm is monitored to see if an Auto off delay override is required (see Section 3.5.4).
Setting the delay multiplier to ×24 will decrease the key sensitivity. Thus in some cases it may be appropriate to compensate for this by increasing the value of Cs.
TABLE 3.2
Predefined Auto-off Delay (Active High Output)
Vt
Auto-off delay (t o )
VSS
Infinity (remain on until toggled to off)
VDD
15 minutes
OUT
60 minutes
TABLE 3.3
Predefined Auto-off Delay (Active Low Output)
Vt
Auto-off delay (t o )
VSS
15 minutes
VDD
Infinity (remain on until toggled to off)
OUT
60 minutes
TABLE 3.4 Auto-off Delay Multiplier Vm Auto-off delay multiplier VSS t o * 1 VDD t o * 24
3.5.3 Auto Off—User-Programmed Delay
If a user-programmed delay is desired, a resistor Rt and capacitor Ct can be used to set an auto-off delay (see Table 3.5 and FIG. 9 ). The delay time is dependent on the RC time constant (Rt*Ct) the output polarity (i.e. whether active high or active low), and the supply voltage. Section 3.5.5 gives more details of how to configure the QT102 to have auto-off delay times ranging from 1 minute to up to 24 hours.
TABLE 3.5
Programmable Auto Off Delay
Output type
Auto Off Delay (seconds)
Active high
(Rt * Ct * 15)/42
Active low
(Rt * Ct * 15)/14.3
Notes: The RC divisor values K(42 and 14.3) may be obtained from FIGS. 13 and 14 . In this example the values are for a supply voltage VDD=3.5 volts. For the parameterization shown in Table 3.5, Rt is in kΩ and Ct is in nF.
3.5.4 Auto Off—Overriding the Auto Off Delay
In normal operation the QT102 output is turned off automatically after the auto-off delay. However, in some applications it may be useful to extend the auto-off delay (“sustain” function), or to switch the output off immediately (“cancel” function). This can be achieved by pulsing the voltage on the delay multiplier resistor Rm as schematically shown in FIG. 10 (positive-going pulse from VSS to VDD for delay multiplier ×1 configuration) and FIG. 11 (negative-going pulse from VDD to VDD for delay multiplier ×24 configuration). The pulse duration tp may determine whether a retrigger of the auto-off delay or a switch of the output to off is desired. To help ensure the pulse is detected it may be present for a time greater than the burst length as shown in Table 3.6.
TABLE 3.6
Time Delay Pulse
Pulse Duration
Action
tp > burst time +
Retrigger (reload auto-off delay
10 ms (typical
counter)
value 25 ms)
tp > burst time +
Switch output to off state and
50 ms (typical
inhibit further touch detection until
value 65 ms)
Vm returns to original state
While Vm is held in the override state (i.e. the duration of the pulse) the QT102 inhibits bursts and waits for Vm to return to its original state (at the end of the pulse). When Vm returns to its original state the QT102 performs a sensor recalibration before continuing in its current output state.
FIG. 12 schematically shows override pulses being applied to a QT102 with delay multiplier set to ×1 (i.e. Vm normally at VSS with positive going pulses). The QT102 OUT signal is shown at the top of FIG. 12 . Vm is shown in the middle. Acquisition bursts on SNSK are shown at the bottom. Each short pulse P on Vm causes a sensor recalibration C and a restart of the auto-off timer. During the long pulse applied to Vm (i.e. where tp>t off ), the output is switched off at O. When the pulse finishes, the output remains switched off and a sensor recalibration C is performed.
3.5.5 Configuring the User-Programmed Auto-Off Delay
As described in Section 3.5.3 the QT102 can be configured to give auto-off delays ranging from minutes to hours by means of a simple CR network and the delay multiplier input.
With the delay multiplier set at ×1 the auto-off delay is calculated as follows:
Delay value=integer value of ( Rt*Ct/K )*15 seconds.
(i.e. Rt*Ct =Delay value (in seconds)* K/ 15
Note: Rt is in kΩ, Ct is in nF.
In some applications improved operation may be achieved if the value of Rt*Ct is between 4 and 240. Values outside this range may be interpreted as the hard wired options TIME linked to OUT and TIME linked to “off” respectively, causing the QT102 to use the relevant predefined auto-off delays (see Tables 3.2 and 3.3).
FIGS. 13 and 14 show typical values of K versus supply voltage for a QT102 with active high or active low output.
Example Using the Formula to Calculate Rt and Ct
Requirements/operating parameters:
Active high output (Vop connected to VSS)
Auto-off delay 45 minutes
VDD=3.5v
Proceed as follows:
1. Calculate Auto-off delay in seconds 45*60=2700
2. Obtain K from FIG. 13 (active high): K=42 for VDD=3.5 v
3. Calculate Rt*Ct=2700*42/15=7560
4. Select a value for Ct (or conversely Rt). E.g. Ct=47 nF
5. Calculate Rt (or conversely Ct)=7560/47=160 kΩ
As an alternative to calculation, Rt and Ct values may be selected from pre-calculated curves such as shown in FIGS. 15 and 16 . FIGS. 15 and 16 show charts of typical curves of auto-off delay against resistor and capacitor values for active high ( FIG. 15 ) and active low ( FIG. 16 ) outputs at various values of VDD and for delay multiplier=×1.
Example Using Plot Shown in FIG. 15 or 16 to Calculate Rt and Ct
Requirements/operating parameters:
Active low output (Vop connected to V55)
Auto-off delay 10 hours
VDD=4V
Proceed as follows:
1. Calculate Auto-off delay in seconds 10×60×60=36000. This value is outside of the range of the charts so use the ×24 multiplier (connect Rm to VDD). Note: this will decrease the key sensitivity, so in some circumstances it may be helpful to increase the value of Cs. 2. Find 36000/24=1500 on the 4V chart in FIG. 16 3. Read across to see appropriate Rt/Ct combinations. This example shows the following Rt/Ct combinations to be appropriate: 100 nF/10 kΩ, 47 nF/27 kSΩ, 22 nF/60 kΩ and 10 nF/130 kΩ.
Of course the Auto-off delay times given here are nominal and will vary slightly from chip to chip and with capacitor and resistor tolerance.
3.6 Examples of Typical Applications
FIG. 17 shows a first example application of a QT102 chip in particular embodiments. Here the QT102 is in an active low configuration and is shown driving a PNP transistor with an auto off time of 500 s×24 (3.33 hours)
The auto off time for the circuit configuration shown in FIG. 16 may be obtained from the VDD=3V chart in FIG. 16 . Setting the delay multiplier to ×24 will decrease the key sensitivity, so it may be helpful in some cases to increase the value of Cs.
FIG. 17 shows a second example application of a QT102 chip in particular embodiments. Here the QT102 is in an active high configuration and is shown driving high impedance with an auto off time of 135 s×1 (2.25 minutes).
The auto off time for the circuit configuration shown in FIG. 18 may be obtained from the VDD=5V chart in FIG. 15 .
4. Example Specifications for an Example QT102 Chip
An example chip incorporating particular embodiments may have the following specifications.
4.1 Suggested Maximum Operating Specifications
Operating temperature: −40° C. to +85° C.
Storage temperature: −55° C. to +125° C.
VDD: 0 to +6.5V
Maximum continuous pin current, any control or drive pin: ±20 mA
Short circuit duration to VSS, any pin: infinite
Short circuit duration to VDD, any pin: infinite
Voltage forced onto any pin: −0.6 to (VDD+0.6) Volts
4.2 Recommended Typical Operating Conditions
VDD: +2.0 to 5.5V
Short-term supply ripple+noise: ±5 mV
Long-term supply stability: ±100 mV
Cs value: 1 or 2 nF to 50 nF
Cx value: 5 to 20 pF
4.3 AC Specifications
VDD=3.0V, Cs=10 nF, Cx=5 pF, Ta=recommended range, unless otherwise noted
Parameter Description Min Typ Max Units Notes T RC Recalibration time 250 ms Cs and Cx dependent T PC Charge duration 2 μs ±7.5% spread spectrum variation T PT Transfer duration 2 μs ±7.5% spread spectrum variation T Time between end of 2.6 ms burst and start of the next (Fast mode) T GZ Time between end of 85 ms Increases with reducing burst and start of the VDD next (LP mode) T BL Burst length 20 ms VDD, Cs and Cx dependent. See Section 2.2 for capacitor selection. T R Response time 100 ms
4.4 Signal Processing
Description Min Typ Max Units Notes Threshold differential 10 counts Hysteresis 2 counts Consensus filter length 4 samples Recalibration timer 40 secs Will vary with VDD
4.5 DC Specifications
VDD=3.0V, Cs=10 nF, Cx=5 pF, Ta=recommended range, unless otherwise noted
Parameter Description Min Typ Max Units Notes V pp Supply voltage 2 5/5.5 V I DD Supply current 5 60 μA Depending on supply and run mode IddI Supply current, LP 23 μA 2 V Mode 37 3 V 90 5 V V DDS Supply turn-on 100 V/s Required for slope proper start-up V IL Low input logic 0.8 V level V HL High input logic 2.2 V level V OL Low output 0.6 V OUT, 4τA sink voltage V OH High output VDD-0.7 V OUT, 1 mA source voltage I IL Input leakage ±1 μA current Cx Load capacitance 0 100 pF range A R Acquisition 9 14 bits resolution
4.6 Mechanical Dimensions
In one example embodiment a chip implementing the above-described QT102 chip functionality may be provided in an SOT23-6 package type. Referring to FIG. 19 , the chip may thus have the following dimensions.
Package type: SOT23-6
Millimeters
Inches
Symbol
Min
Max
Notes
Min
Max
Notes
M
2.8
3.10
0.110
0.122
W
2.6
3.0
0.102
0.118
Aa
1.5
1.75
0.059
0.069
H
0.9
1.3
0.035
0.051
h
0.0
0.15
0
0.006
D
—
—
0.95 BSC
—
—
0.038 BSC
L
0.35
0.5
0.014
0.02
E
0.35
0.55
0.014
0.022
e
0.09
0.2
0.004
0.008
Φ
0°
10°
0°
10°
A QT102 chip provided in an SOT23-6 package type may have a pin arrangement as schematically indicated in FIG. 20 .
4.7 Moisture Sensitivity Level (MSL)
A chip implementing the above-described QT102 chip functionality may be rated as follows:
Peak Body
MSL Rating
Temperature
Specifications
MSL1
260° C.
1PC/JEDEC J-STD-020C
Thus, in particular embodiments, the QT102 charge-transfer (QT) touch sensor is a self-contained digital IC capable of detecting near-proximity or touch. It may project a touch or proximity field through any dielectric like glass, plastic, stone, ceramic, and even most kinds of wood. It can also turn small metal-bearing objects into intrinsic sensors, making them responsive to proximity or touch. This capability, coupled with its ability to self calibrate, can lead to entirely new product concepts. It may be implemented in human interfaces, like control panels, appliances, toys, lighting controls, or anywhere a mechanical switch or button may be found.
The QT102 example embodiment may be seen as a single key chip combining a touch-on/touch-off toggle mode with timeout and timing override functions, oriented towards power control of small appliances and battery-operated products, for example. With a small low-cost SOT-23 package, this device can suit almost any product needing a power switch or other toggle-mode controlled function.
An environmentally friendly (“green”) feature of the QT102 is the timeout function, which can turn off power after a specified time delay ranging from minutes to hours. Furthermore, external “sustain” and “cancel” functions permit designs where the timeout needs to be extended further or terminated early. A user's interaction with a product might trigger a “sustain” input, prolonging the time to shutoff. A safety sensor, such as a tip-over switch on a space heater, can feed the “cancel” function to terminate early.
The QT102 embodiment(s) features automatic self-calibration, drift compensation, and spread-spectrum burst modulation. The device can in some cases bring inexpensive, easy-to-implement capacitive touch sensing to all kinds of appliances and equipment, from toys to coffee makers. The small, low cost SOT-23 package lets this unique combination of features reside in almost any product.
The QT102 chip embodying particular embodiments may be summarized as having the following operational features/application parameters:
Number of keys: One touch on/touch off (toggle mode), plus hardware programmable auto switch-off/switch-off delay and external cancel
Technology: Spread-spectrum charge-transfer (direct mode)
Example key outline sizes: 6 mm×6 mm or larger (generally panel thickness dependent); widely different sizes and shapes possible
Example electrode design: Solid or ring electrode shapes
PCB Layers required: One
Example electrode materials: Etched copper, silver, carbon, Indium Tin Oxide (ITO), Orgacon®
Example electrode substrates: PCB, FPCB, plastic films, glass
Example panel materials: Plastic, glass, composites, painted surfaces (including relatively low particle density metallic paints)
Example panel thickness: Up to 50 mm glass, 20 mm plastic (generally electrode size dependent)
Key sensitivity: Settable via external capacitor
Interface: Digital output, active high or active low (hardware configurable)
Moisture tolerance: Good
Power: 2V˜5.5V; drawing, for example, 23 μA at 2V
Example package: SOT23-6 (3×3 mm) RoHS compliant
Signal processing: Self-calibration, auto drift compensation, noise filtering
Example Applications: Power switch replacement in countertop appliances, irons, battery powered toys, heaters, lighting controls, automotive interior lighting, commercial and industrial equipment such as soldering stations and cooking equipment
In particular embodiments, the above-described sensors may be used in apparatus or devices with one touch key. In particular embodiments the sensing element of the sensor may include more than one key, for example two, three, or more keys.
Herein, “or” is inclusive and not exclusive, unless expressly indicated otherwise or indicated otherwise by context. Therefore, herein, “A or B” means “A, B, or both,” unless expressly indicated otherwise or indicated otherwise by context. Moreover, “and” is both joint and several, unless expressly indicated otherwise or indicated otherwise by context. Therefore, herein, “A and B” means “A and B, jointly or severally,” unless expressly indicated otherwise or indicated otherwise by context.
This disclosure encompasses all changes, substitutions, variations, alterations, and modifications to the example embodiments herein that a person having ordinary skill in the art would comprehend. Similarly, where appropriate, the appended claims encompass all changes, substitutions, variations, alterations, and modifications to the example embodiments herein that a person having ordinary skill in the art would comprehend. Moreover, reference in the appended claims to an apparatus or system or a component of an apparatus or system being adapted to, arranged to, capable of, configured to, enabled to, operable to, or operative to perform a particular function encompasses that apparatus, system, component, whether or not it or that particular function is activated, turned on, or unlocked, as long as that apparatus, system, or component is so adapted, arranged, capable, configured, enabled, operable, or operative.
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In one embodiment, a method includes monitoring detection by a sensing element of a key touch on a touch screen; determining an amount of time that has elapsed since the sensing element last detected a change of capacitance indicative of a key touch on the touch screen; and, if the amount of time that has elapsed exceeds a predetermined time duration, then initiating a particular function of an apparatus.
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RELATED APPLICATIONS
[0001] This application is a Continuation of U.S. patent application Ser. No. 13/937,883 filed on Jul. 9, 2013 and entitled “Power Compounder”, which is a Continuation of U.S. patent application Ser. No. 12/653,718 filed on Dec. 16, 2009 and entitled “Power Compounder”, now abandoned, which is a Continuation-in-Part application of U.S. patent application Ser. No. 11/656,309, now U.S. Pat. No. 7,637,108, filed on Jan. 19, 2007 and entitled “Power Compounder”, which claimed priority from U.S. Provisional Patent Application No. 60/760,633, entitled “Power Compounder” filed on Jan. 19, 2006. The instant application claims priority from and incorporates herein by reference in their entireties, and for all useful purposes, all four of the applications enumerated above (Ser. Nos. 13/937,883, 12/653,718, 11/656,309, and 60/760,633).
BACKGROUND
[0002] The conversion of fuels into electricity has long been the focus of engineers. The supply of the fuel to a generation site, as well as the reliability and cost of the supply, is factored into the engineering decision process.
[0003] The thrust of waste heat recovery technology is to make use of thermal energy normally discarded from a primary power conversion process. In many prior art devices, the discarded thermal energy (i.e., waste heat) is harnessed to drive additional thermo-fluid processes that can yield additional energy (i.e., electricity).
[0004] Referring to prior art FIG. 1 , the prior art waste heat recovery system directs a supply of waste heat measured at temperatures between 300° F. to 800° F. from a heat source to an evaporator (see numeral 1 ). The waste heat is transferred to a working fluid in the evaporator. The working fluid is evaporated; changes from a liquid to a vapor, in the evaporator and is expanded through a turbine (see numeral 2 ). The expansion of the working fluid through the turbine drives the turbine. The turbine, in turn, drives an electric generator coupled to the turbine. The generator produces electrical power. The working fluid flows to a condenser and changes phase from vapor to a liquid (see numeral 3 ). The liquid working fluid is then pumped back to the evaporator and begins the cycle again (see numeral 4 ). The above described system employs a closed-loop Organic Rankine Cycle to produce electricity from a thermal energy source, such as waste heat. This example illustrates that the prior art waste heat recovery systems were utilized to produce electricity.
[0005] Using the above concept of a reverse refrigeration cycle, either a Rankine Cycle or Organic Rankine Cycle (ORC), the waste heat of an engine can be converted to produce a more efficient engine; not electricity. However, the above example relies on turbines to operate the generator. Turbines operate at a greater rotational speed than conventional engines and require extensive, complex machinery in order to try and capture the thermal energy for reuse as mechanical energy.
[0006] What is needed in the art is a Rankine Cycle or an Organic Rankine Cycle system to convert waste heat from an engine into useful power for the engine that is simple, reliable and cost effective.
SUMMARY
[0007] The following presents a simplified summary of the present disclosure in order to provide a basic understanding of some aspects of the present disclosure. This summary is not an extensive overview of the present disclosure. It is not intended to identify key or critical elements of the present disclosure or to delineate the scope of the present disclosure. Its sole purpose is to present some concepts of the present disclosure in a simplified form as a prelude to the more detailed description that is presented herein.
[0008] A power compounder is disclosed. The power compounder comprises a working fluid configured to receive thermal energy from waste heat of a prime mover, a working fluid collector, an evaporator configured to transfer waste heat to a working fluid producing a phase change to vapor (or gas) in the working fluid, a double screw expander configured to receive the working fluid for creating rotational mechanical energy, and a condenser configured to produce another phase change in the working fluid to liquid. The double screw expander transfers the rotational mechanical energy via a shaft to the prime mover.
[0009] The disclosure is also directed toward a power compounder system. The power compounder system comprises a prime mover producing waste heat and a power compounder coupled to the prime mover. The power compounder comprises a working fluid configured to receive thermal energy from the waste heat from the prime mover; a working fluid collector configured to hold the working fluid as a liquid working fluid; an evaporator fluidly coupled to the working fluid collector, such that the evaporator is configured to transfer the waste heat to the working fluid to change the working fluid from a liquid working fluid to a vapor working fluid; a double screw expander fluidly coupled to the evaporator, such that the expander is configured to receive the vapor working fluid to create rotational mechanical energy from expansion of the vapor working fluid through the double screw expander, the double screw expander transfers the rotational mechanical energy via a shaft to the prime mover; and a condenser fluidly coupled to the double screw expander, such that the condenser is configured to receive the vapor working fluid and change the vapor working fluid to the liquid working fluid, the condenser is fluidly coupled to the working fluid collector.
[0010] The disclosure is also directed toward a method of using a power compounder system. The method comprises directing waste heat produced in a prime mover to a power compounder; transferring thermal energy from the waste heat to a liquid working fluid; transforming the liquid working fluid to a vapor working fluid in an evaporator; directing the vapor working fluid through a double screw expander fluidly coupled to the evaporator; creating rotational mechanical energy in the double screw expander when the vapor working fluid flows through the double screw expander; transferring the rotational mechanical energy via a shaft of the double screw expander to the prime mover; and directing the vapor working fluid to a condenser for transforming to the liquid working fluid, the condenser is fluidly coupled to the expander.
[0011] A power compounder system is provided and includes a prime mover producing waste heat and a power compounder coupled to the prime mover. The power compounder includes a working fluid configured to receive thermal energy from the waste heat from the prime' mover, a working fluid collector configured to hold the working fluid as a liquid working fluid, an evaporator fluidly coupled to the working fluid collector, the evaporator configured to transfer the waste heat to the working fluid to change the working fluid from the liquid working fluid to a vapor working fluid, a feed pump configured to cause the working fluid to flow between the working fluid collector and the evaporator and a double screw expander fluidly coupled to the evaporator, wherein the expander is configured to receive the vapor working fluid to create rotational mechanical energy from expansion of the vapor working fluid through the double screw expander, such that the double screw expander transfers the rotational mechanical energy via a shaft to the prime mover. The double screw expander is further coupled to the prime mover via at least one of a mechanical clutch, an electrical clutch and a Sprag clutch. The power compounder further includes a condenser fluidly coupled to the double screw expander, wherein the condenser is configured to receive the vapor working fluid and change the vapor working fluid to the liquid working fluid, wherein the condenser is fluidly coupled to the working fluid collector.
[0012] A method of using a power compounder system is provided and includes directing waste heat produced in a prime mover to a power compounder, transferring thermal energy from the waste heat to a liquid working fluid, transforming the liquid working fluid to a vapor working fluid in an evaporator, directing the vapor working fluid through a double screw expander fluidly coupled to the evaporator, wherein the double screw expander is further coupled to the prime mover via at least one of a mechanical clutch, an electrical clutch and a Sprag clutch, creating rotational mechanical energy in the double screw expander when the vapor working fluid flows through the double screw expander, transferring the rotational mechanical energy via a shaft of the double screw expander to the prime mover and directing the vapor working fluid to a condenser for transforming to the liquid working fluid, wherein the condenser is fluidly coupled to the expander.
BRIEF DESCRIPTION OF THE FIGURES
[0013] Referring now to the figures, wherein like elements are numbered alike:
[0014] FIG. 1 is a diagram of a prior art waste heat recovery system;
[0015] FIG. 2 is a schematic of an exemplary power compounder system;
[0016] FIG. 3 is a side view of an exemplary power compounder system;
[0017] FIG. 4 is another side view of the exemplary power compounder system of FIG. 3 ;
[0018] FIG. 5 is a side view of another exemplary power compounder system;
[0019] FIG. 6 is a bottom view of a double screw expander;
[0020] FIG. 7 is a front view of a double screw expander;
[0021] FIG. 8 is a front view of a profile of the rotors of a double screw expander;
[0022] FIG. 9 is a front view of another profile of the rotors of a double screw expander;
[0023] FIG. 10 is a side isometric view illustrating a clutch device being employed between the expander and a prime mover; and
[0024] FIG. 11 is a side isometric view of illustrating a clutch device being employed between a pump and the expander.
DETAILED DESCRIPTION
[0025] Persons of ordinary skill in the art will realize that the following disclosure is illustrative only and not in any way limiting. Other embodiments of the disclosure will readily suggest themselves to such skilled persons having the benefit of this disclosure.
[0026] The present disclosure is a power compounder system that converts waste heat thermal energy from a source (or prime mover or engine) into rotational mechanical energy. Power compounding is the process of directly attaching an expander (or a compressor configured to act as an expander) to a shaft of a prime mover. For example, in a typical combustion engine, the thermal energy is normally discarded via jacket water heat through a radiator, engine exhaust out a stack, oil cooler, or any other conventional means. In the present disclosure, the normally discarded waste heat is recovered from the engine and harnessed. The waste heat is harnessed using either a Rankine Cycle or an Organic Rankine Cycle (ORC) power compounder having an expander (i.e., double or twin screw). The waste heat is harnessed by conversion to rotational mechanical energy which is redirected back to the engine, increasing the engine's net power output by as much as about 10% additional horsepower. This additional horsepower is achieved without using additional fuel or producing additional emissions.
[0027] FIG. 2 is a schematic of an embodiment of the present disclosure. FIGS. 3, 4, and 5 illustrate exemplary embodiments of the power compounder 10 system coupled to a prime mover (e.g., an engine) 12 . The power compounder 10 has an expander 14 that is coupled to the prime mover 12 via a shaft 16 . In one embodiment illustrated in FIGS. 3 and 4 , elements (i.e., the evaporator 18 , the condenser 20 , and the like) of the power compounder 10 are contained within a system cabinet 22 .
[0028] Although a combustion engine is illustrated in FIGS. 3, 4, and 5 as the prime mover 12 , any machine that utilizes mechanical energy can be utilized, including but not limited to, pumps, external combustion engines, internal combustion engines, turbines, compressors, and the like.
[0029] Referring again to FIG. 2 , as the prime mover 12 is operated, waste heat (illustrated as arrow 24 ) is discarded from the prime mover 12 . The waste heat 24 can be transferred via any known means compatible to the prime mover, including but not limited to, engine lube oil, coolant, exhaust, water jacket, and the like. Waste heat is a term that generally covers various sources of thermal energy in a transfer medium at temperatures as low as about 140° F. (such as a fluid, a hot gas, hot oil, hot water, steam, and the like). In another embodiment disclosed on page 45 of Provisional U.S. Patent Application No. 60/760,633, previously cited as priority for the instant application and incorporated herein by reference in its entirety, the waste heat supply has a minimum temperature of 180° F. The waste heat can be supplied from a wide variety of sources including but not limited to: internal combustion engines, gas turbines, gas flares in landfills, industrial manufacturing processes that continuously produce thermal energy, incinerators, boilers, water heaters, geothermal wells, methane, bio-gas sources, and the like.
[0030] In the preferred embodiment, waste heat 24 is directed from the prime mover 12 to the power compounder 10 via an outlet 26 . The thermal energy 28 is transferred to a working fluid (illustrated as arrow 30 ) in the evaporator 18 . The waste heat 24 medium is returned to the prime mover 12 via inlet 27 . The working fluid 30 can be any known working fluid, including but not limited to, water, refrigerants, light hydrocarbons, and the like. The working fluid must be compatible with the power compounder system. Examples of refrigerants include but are not limited to, R-124, R-134a, R-245fa, and the like. The working fluid 30 is transformed in an evaporator 18 located in the system cabinet 22 . The evaporator 18 transfers the thermal energy 28 from the waste heat 24 from the prime mover 12 to the working fluid 30 .
[0031] The evaporator 18 exchanges the thermal energy 28 from the waste heat 24 to the working fluid 30 . The evaporator 18 can be any variety of heat exchangers and fashioned to operate with the waste heat, including, but not limited to, plate, tube and shell, tube and fin, and the like. For example, if the waste heat is in the form of an internal combustion engine exhaust, the heat exchanger can comprise a gas heat exchanger. Intermediate heat exchangers (not shown) can be employed to separate the waste heat medium from the evaporator.
[0032] The working fluid 30 is heated in the evaporator 18 and changes phase from a liquid phase to a vapor (or gas) phase. The working fluid 30 having gained the thermal energy 28 and having reached a higher energy state (i.e., vapor or gas phase), flows from the evaporator 18 through piping 32 to the expander 14 , and expands through the expander 14 transferring the higher thermal energy into mechanical energy. The working fluid 30 is compressed (i.e., under pressure) having potential energy as it enters the expander 14 through the inlet 46 . After proceeding through the expander 14 , the working fluid exits through the outlet 48 having transferred the potential energy to the shaft 16 creating kinetic energy.
[0033] In a preferred embodiment, the shaft 16 of the expander 14 can be coupled directly to a drive shaft of the prime mover 12 through a generator (see FIG. 5 ) or coupled with belts 34 and/or gears or pulleys 36 , 38 to the crankshaft 40 (or drive shaft or any other appropriate location) of the prime mover 12 (see FIGS. 3 and 4 ). The shaft 16 of the expander 14 can also be connected via a pulley and idler arrangement (or directly in the case of the engine's power take-off (PTO) shaft) (not shown) to the output shaft of the prime mover 12 itself.
[0034] The preferred expander 14 is a double (or twin) screw expander 32 . FIG. 6 illustrates a bottom view of an interior of a double screw expander 32 . The double screw expander 32 uses the working fluid 30 to create mechanical rotation. The working fluid 30 expands through the double screw expander 32 causing the two rotors (or screws) 34 , 36 to turn (or rotate), thus creating mechanical energy. The mechanical energy is transferred into shaft power. Referring now to FIG. 7 , a front view of a double screw expander 32 is illustrated. The working fluid 30 flows into the double screw expander 32 via inlet 46 and exits via outlet 48 . As the working fluid 30 expands through the double screw expander 32 , mechanical energy is created. The mechanical energy is then transferred into shaft power.
[0035] A double screw expander 32 has two meshing helical rotors 34 , 36 that are contained within a casing 42 , which surrounds the rotors 34 , 36 with a very small clearance. The spaces between the rotors 34 , 36 and the casing 42 create working chambers 44 . The working fluid 30 enters the double screw expander 32 through inlet 46 and expands through the working chambers 44 in the direction of rotation until it is expelled through outlet 48 . Power is transferred between the working fluid 30 and the shaft 16 from torque created by the forces on the rotor 34 , 36 surfaces due to the pressure of the working fluid 30 , which changes with the volume of the working fluid 30 .
[0036] In order to achieve a high flow rate and efficiency, the profile of the rotor 34 , 36 is important. A conventional profile is illustrated in FIG. 8 , in which a symmetric profile of the rotors 34 , 36 is provided. The preferred embodiment for the double screw expander 32 profile is illustrated in FIG. 9 . A rack generated “N” profile utilized as a rotor profile increases the rotational speed of the double screw expander 32 .
[0037] Referring again to FIGS. 2 and 3 , upon exiting the expander 14 through the outlet 48 to piping 50 , the working fluid 30 is now a low pressure gas (or vapor) that flows to a condenser 20 , where the working fluid 30 undergoes a phase change again from vapor (or gas) to liquid. In a preferred embodiment, the condenser 20 comprises at least one of shells, tubes, and fins. The use of a refrigerant, cooling water, or cooling air can enhance the cooling capabilities of the condenser 20 .
[0038] In still yet another embodiment, referring to FIG. 10 and FIG. 11 , the shaft 62 of the expander 32 (such as a double screw expander) is coupled to the shaft 64 of another device, such as the prime mover 12 or a pump 12 B (see FIG. 11 ) via a clutch device 60 , such as a mechanical clutch, an electrical clutch and/or a Sprag clutch (non-reversible and/or reversible), wherein the clutch device 60 can be used to disengage the shaft 62 of the expander 32 from the shaft 64 of the prime mover 12 to lower the revolutions per minute (RPM) of the expander 32 . Simply put, a clutch is a device that can be engaged or disengaged to transmit/remove rotational forces of a rotating shaft and is particularly useful in mechanisms that include two or more rotating shafts where it is desirable to selectively transmit the motion of one shaft to another shaft. As is known, there are many different types of clutches. One type of clutch, for example, is the “Sprag” clutch which is a one-way overrunning (or freewheel) clutch that can be used to disengage a driveshaft from a driven shaft as desired. A Sprag clutch typically includes a cylindrical inner race surrounded by a cylindrical outer race with an annular space therebetween and is particularly useful when two or more motors can be used to drive the same mechanism or when the disengagement of one motor is desired. The use of a Sprag clutch is advantageous in different situations where it is desirable to lower the revolutions per minute (RPM) of the shaft of the expander 32 . For example, when the prime mover 12 (or pump 12 B) is sitting idle or when the prime mover 12 is not generating enough heat, it may desirable to lower the RPM's of the shaft 62 of the expander 32 to prevent the expander 32 from being damaged (i.e. burning out). This may be accomplished by engaging the clutch device 60 to allow the shaft 62 of the expander 32 to slow its rotation. When the prime mover 12 is generating a sufficient amount of waste heat, the clutch device 60 may be disengaged to allow the rotation of the shaft 62 of the expander 32 to increase.
[0039] It should be appreciated that the clutch device 60 may be controlled via any device and/or method suitable to the desired end purpose, such as an electrical switch, a mechanical switch and/or an electromechanical switch. It is contemplated that a sensing device and a controller device may be included in the power compounder system 10 , wherein the sensing device and a controller device are communicated with each other and the power compounder system 10 to monitor various desired parameters of the power compounder system 10 , such as the expander 32 and/or prime mover 12 (and/or pump 12 B). The sensing device may monitor various parameters of the power compounder system 10 as desired, such as the waste heat from the prime mover 12 and/or the rotation speed of the shaft 62 of the expander 32 and/or the shaft 64 of the prime mover 12 and communicate these parameters to the controller device. The controller device may then control the clutch device 60 to engage and/or disengage the shaft 62 of the expander 32 from the rest of the system (i.e. prime mover 12 ) responsive to the parameters received from the sensing device. It is also contemplated that the controller may send instructions to the sensing device to configure which parameters the sensing device will sense. It is further contemplated that the sensing device and/or the controller may be communicated with a computing device (a local device and/or a remote device) to allow a third party to monitor the power compounder system 10 and/or control the clutch device 60 as desired. It is further contemplated that all communications may be accomplished via wired and/or wireless communications.
[0040] It should be appreciated that as used herein, working fluids include any type of working fluid suitable to the desired end purpose, such as water, steam and/or organics (including, but not limited to refrigerants and/or hydrocarbons).
[0041] The liquid working fluid 30 then flows by gravity to a receiver tank 52 configured to contain the liquid working fluid 30 (i.e., preferably a tank that is about 30 gallons to about 100 gallons). A feed pump 54 controls the flow rate of the working fluid 30 to the evaporator 18 . A cooling medium, such as liquid or air, can be utilized to further condense the gaseous working fluid into a liquid working fluid. As illustrated in FIG. 2 , a cooling tower 56 (or cooling fan, and the like) can be utilized to supply the cooling medium.
[0042] The admission of wet vapor to the expander 14 can be used to improve the performance of the power compounder 10 by simplifying and reducing the cost of expander 14 lubrication by dissolving or otherwise dispersing about 5% oil by mass in the working fluid 30 .
[0043] The above system is a closed loop Rankine Cycle, employing water as the working fluid, or an Organic Rankine Cycle, using refrigerants or light hydrocarbons as the working fluid, or some combination thereof, in order to produce rotational mechanical power from thermal energy sources. This use of a power compounder results in an increase of net power to the host prime mover of about 5% to about 15% net power, with about 10% net power preferred.
[0044] The present disclosure includes a simple and reliable cost efficient power compounder system, either a Rankine Cycle or an Organic Rankine Cycle, using a double screw expander to produce rotational power. This rotational mechanical energy can be used to increase power output by as much as about 10% net increase to many prime movers, such as engines, pumps and mechanical power outputs for hundred of applications. Since the rotational speed of the expander of the power compounder is operated at similar rotational speeds as the prime mover, there is no need for any high speed reduction gear reducer or electronics. The rotational mechanical energy of the expander can be synchronized to the rotation of the prime mover.
[0045] While the disclosure has been described with reference to an exemplary 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 disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings without departing from the essential scope thereof. Therefore, it is intended that the disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this disclosure.
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An apparatus and method is disclosed wherein mechanical power is returned to a prime mover producing waste heat. The apparatus includes a working fluid configured to receive thermal energy from the waste heat, a collector to hold the working fluid, an evaporator fluidly coupled to the working fluid collector for transferring the waste heat to the working fluid to change the working fluid to vaporized working fluid, a feed pump to cause the working fluid to flow between the working fluid collector and the evaporator, an expander fluidly coupled to the evaporator to receive the heated working fluid to create rotational mechanical power, and a condenser to cool the expanded working fluid. The expander is mechanically associated with the prime mover directly or via a clutch.
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REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 09/474,391, filed Dec. 29, 1999, the content of which are expressly incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The technical field of the invention is the treatment of urinary incontinence. It is known in the act of surgery that one can treat patients with stress urinary incontinence by constructing a sling to support the bladder. The slings are usually designed to prevent leakage by providing circumferential pressure at the level of the bladder neck. The construction of such slings typically involves rotating various muscles and their attendant fascias (Mohenfellnev (1986) Sling Procedures in Surgery , In Stanton SI, Tanaglo E (eds) Surgery ofFemale Incontinence, 2nd edn, Berlin; Springer-Vevlag).
[0003] Many natural and synthetic materials have been used to construct these slings, such as the Martex sling (Morgan, et al. (1985) Amer. J. Obst. Gynec. 151:224-226); the fascia lata sling (Beck, et al. (1988) Obst. Gynec. 72:699-703); the vaginal wall sling (Juma, et al. (1992) Urology, 39:424- 428); the Aldridge sling (Mclndoe et al. (1987) Aust. N. Z. J. Obst. Gynaecol. 27: 238-239); and the Porcine corium sling (Josif (1987) Arch. Gynecol. 240:131-136). Slings have also been produced from allogenic grafts, particularly if the patient has poor quality fascia.
[0004] There are however, a number of problems associated with using these procedures and materials. Problems associated with using natural material as slings include, shrinkage, necrosis, and gradual thinning of the fascia which ultimately affects the efficiency and long term durability of the sling (Blaivas (1991) J. Urol. 145:1214-1218). Another major disadvantage with using natural material is that extensive surgery is required, which can cause morbidity, typically as a result of nerve damage or wound infection (McGuire, et al. (1978) J. Urol. 119:82-84; Beck, et al. (1974) Am. J. Obstet. Gynecol. 129:613-621.) In addition, natural slings obtained from human donors carry with them the added risk of causing an immune reaction in the recipient.
[0005] As an alternative, synthetic materials have been used in patients who had poor quality, or insufficient fascial tissue for reconstructive purposes. However, reports of graft rejection, sinus formation, urethral obstruction and urethral erosion have limited the widespread use of these materials (See e.g, Nichols (1973) Obstet. Gynecol. 41:88-93; Morgan, et al. (1985) Am. J. Obstet. 151:224-226; and Chin et al. (1995) Br. J. Obstet. Gyneacol., 102:143-147.)
[0006] Accordingly, there exists a need to produce artificial fascial slings to treat urinary incontinence without the need of extensive surgery. There is also a need to produce artificial fascial slings which do not result in the disadvantages associated with synthetic materials used as fascial slings to date.
SUMMARY OF THE INVENTION
[0007] The present invention provides methods for producing artificial fascial slings and their subsequent use in treating subjects with urinary incontinence. The invention is based, in part, on the discovery that mesenchymal cells that secrete elastin and collagen, two extracellular proteins responsible for elasticity and strength, respectively, can be used to engineer artificial fascia in vitro.
[0008] Accordingly, in one aspect, the invention features a method for producing an artificial fascial sling comprising:
[0009] creating a polylayer of collagen-secreting cells derived from a cultured cell population on a biocompatible substrate; and
[0010] creating a polylayer of elastin-secreting cells derived from a second cultured cell population on the polylayer of the collagen-secreting cells, such that the cells of the two different populations form a chimeric interface.
[0011] The invention can further include the step of creating a fibroblast polylayer derived from a cultured fibroblast cell population on the polylayer of elastin-secreting cells, such that the fibroblast polylayer forms a chimeric interface with the polylayer of elastin-secreting cells.
[0012] The substrate is preferably a strip having a length of about 10 cm to about 30 cm, and a width of about 0.5 cm to about 4.0 cm. The strip can further include attachment sites that provide attachment to a support surface.
[0013] The method further comprising selecting a biocompatable substrate from the group consisting of cellulose ether, cellulose, cellulosic ester, fluorinated polyethylene, phenolic, poly-4-methylpentene, polyacrylonitrile, polyamide, polyamideimide, polyacrylate, polybenzoxazole, polycarbonate, polycyanoarylether, polyester, polyestercarbonate, polyether, polyetheretherketone, polyetherimide, polyetherketone, polyethersulfone, polyethylene, polyfluoroolefin, polymide, polyolefin, polyoxadiazole, polyphenylene oxide, polyphenylene, sulfide, polypropylene, polystyrene, polysulfide, polysulfone, polytetrafluoroethylene, polythioether, polytriazole, polyurethane, polyvinylidene fluoride, regenerated cellulose, urea-formaldehyde, or copolymers or physical blends thereof. In one preferred embodiment, the biocompatable substrate is polyglycolic acid.
[0014] In one embodiment, the collagen-secreting cells are selected from the group consisting of fibroblasts, chondroblasts, osteoblasts, and odontoblasts. In another embodiment, the elastin-secreting cells are selected from the group consisting of smooth muscle cells, chondrocytes, and fibroblasts.
[0015] In another aspect, the invention features a method for producing an artificial fascial sling comprising:
[0016] creating a polylayer of a collagen-secreting cells derived from a cultured cell population on a first surface of a biocompatible substrate; and
[0017] creating a polylayer of elastin-secreting cells derived from a second cultured cell population on a second surface of the biocompatible substrate, wherein the second surface is opposite the first surface.
[0018] The invention can further include the step of creating a fibroblast polylayer derived from a cultured fibroblast cell population, such that the fibroblast polylayer forms a chimeric interface with the at least one polylayer selected from the group consisting of a collagen polylayer or an elastin polylayer.
[0019] In yet another aspect, the invention features a method for treating a subject with urinary incontinence with an artificial fascial sling comprising:
[0020] positioning the artificial fascial sling around a urinary structure, the artificial sling comprising a polylayer of collagen-secreting cells derived from a cultured cell population deposited on a biocompatible substrate, and a polylayer of elastin-secreting cells derived from a second cultured cell population deposited on the polylayer of collagen-secreting cell population, such that the cells of the two different populations form a chimeric interface;
[0021] moving the urinary structure to a position that ameliorates urinary incontinence; and
[0022] securing the artificial fascial sling in a position that supports the urinary structure, to thereby treat a subject with urinary incontinence.
[0023] Optionally, a fibroblast polylayer, derived from a cultured fibroblast cell population, can be deposited on the polylayer of elastin-secreting cells, such that the fibroblast polylayer forms a chimeric interface with the polylayer of elastin-secreting cells. In one embodiment, the method further comprising altering the tension of the artificial fascial sling to change the position of the urinary structure. In another embodiment, the step of positioning the artificial fascial sling around a urinary structure further comprises positioning the artificial fascial sling around a bladder. In another embodiment, the step of positioning an artificial fascial sling around a urinary structure comprises positioning the artificial fascial sling around a urethra. In yet another embodiment, the step positioning an artificial fascial sling around a urinary structure comprises positioning the artificial fascial sling around a ureter.
[0024] In one embodiment, the step of securing the artificial fascial sling to a support structure comprises securing the artificial fascial sling with a securing agent. The securing agent can be selected from the group consisting of felt matrix, mesh patch and/or sutures.
[0025] In another embodiment, the step of securing the artificial fascial sling to a support structure comprises securing the artificial sling to a support structure selected from the group consisting of the pubis bone, pelvic bone and inferior pubic arch.
DETAILED DESCRIPTION
[0026] So that the invention may more readily be understood, certain terms are first defined:
[0027] The term “polylayer” as used herein refers to an arrangement comprising multiple layers of a homogenous cultured cell population superimposed over each other. The process of producing a “polylayer” involves depositing one layer of a cell population on surface, e.g., a biocompatible substrate. The deposited cells are cultured in growth medium until they develop and proliferate to produce a monolayer comprising cells with a desired phenotype and morphology. Once the first monolayer has attained a desired cell density, a second layer of the same cell population is depositing on the first monolayer. The second layer of deposited cells are cultured in growth medium which supplies nutrients to both the second cell layer and the first monolayer, until the cells in the second layer develop and proliferate to a desired cell density to produce a bilayer having cells with a desired phenotype and morphology. A third layer of same cell population can be deposited on the bilayer, and the cells are cultured in growth medium which supplies nutrients to the bilayer and the cells of the third layer, until the cells of the third layer develop and proliferate to a desired density to produce a trilayer with a desired phenotype and morphology. The process can be repeated until a polylayer comprising many layers of a homogenous cell population is produced. The characteristics of the polylayer are such that they closely resemble the morphology and functional characteristics of the equivalent parenchyma tissue of an in-vivo organ. For example, a polylayer comprising a smooth muscle cell population may have functional characteristics of the smooth muscle tissue of a bladder, i.e., the detrusor.
[0028] The term “chimeric interface” as used herein refers to the boundary formed between two different cell populations. Chimeric interface is also intended to include the boundary formed between a cell population and a non-cell population, for example, a fibroblast cell population and isolated collagen.
[0029] The term “interstitial biomaterial” as used herein refers to the formation of cellular material at the chimeric interface where two different cell populations are in mutual contact with each other. The term “interstitial biomaterial” in its broadest concept is intended to include the formation of any new cellular material formed when two or more different cell populations are in contact with each other. The new cellular material resembles the equivalent cellular material produced in normal in-vivo cellular development of the organ.
[0030] The term “biocompatible substrate” as used herein refers to a material that is suitable for implantation into a subject onto which a cell population can be deposited. A biocompatible substrate does not cause toxic or injurious effects once implanted in the subject.
[0031] The term “collagen-secreting cells” is intended to refer to cells that produce collagen such as, mesenchymal cells, for example, fibroblasts, chondroblasts, osteoblasts, and odontoblasts. Collagen that has been extracted from a mammalian source, such as collagen extracted from skin and tendons, can also be deposited on the biocompatible substrate.
[0032] The term “elastin-secreting cells” is intended to refer to cells that produce elastin such as, mesenchymal cells, for example, smooth muscle cells, chondrocytes, and fibroblasts. Elastin that has been extracted from mammalian source, such as elastin extracted from skin, can also be deposited on the biocompatible substrate.
[0033] The term “subject” as used herein is intended to include living organisms in which an immune response is elicited. Preferred subjects are mammals. Examples of subjects include, but are not limited to, humans, monkeys, dogs, cats, mice, rats, cows, horses, pigs, goats and sheep.
[0034] The term “urinary structure” as used herein refers to a structure responsible for urinary incontinence that requires repositioning using an artificial sling. Repositioning the urinary structure results in amelioration of urinary incontinence. Examples of urinary structure include, but are not limited to the bladder, urethra and ureter.
[0035] Various aspects of the invention are described in more detail in the following subsections:
[0036] I. Biocompatible Substrates
[0037] A biocompatible substrate refers to materials which do not have toxic or injurious effects on biological functions. Examples of biocompatible substrates include, but are not limited to, polyglycolic acid and polyglactin, developed as absorbable synthetic suture material. Polyglycolic acid and polyglactin fibers may be used as supplied by the manufacturer. Other biodegradable materials include cellulose ether, cellulose, cellulosic ester, fluorinated polyethylene, phenolic, poly-4-methylpentene, polyacrylonitrile, polyamide, polyamideimide, polyacrylate, polybenzoxazole, polycarbonate, polycyanoarylether, polyester, polyestercarbonate, polyether, polyetheretherketone, polyetherimide, polyetherketone, polyethersulfone, polyethylene, polyfluoroolefin, poly1mide, polyolefin, polyoxadiazole, polyphenylene oxide, polyphenylene, sulfide, polypropylene, polystyrene, polysulfide, polysulfone, polytetrafluoroethylene, polythioether, polytriazole, polyurethane, polyvinylidene fluoride, regenerated cellulose, urea-formaldehyde, or copolymers or physical blends of these materials. The material may be impregnated with suitable antimicrobial agents and may be colored by a color additive to improve visibility and to aid in surgical procedures.
[0038] II. Culturing Cells
[0039] One aspect of the invention pertains to production of artificial slings comprising one or more cell populations. The artificial slings can be allogenic artificial slings, where the cultured cell populations are derived from the subject's own tissue. The artificial slings can also be xenogenic, where the cultured cell populations are derived form a mammalian species that is different from the subject. For example the cells can be derived from organs of mammals such as monkeys, dogs, cats, mice, rats, cows, horses, pigs, goats and sheep.
[0040] Cells can be isolated from a number of sources, for example, from biopsies, or autopsies. The isolated cells are preferably autologous cells, obtained by biopsy from the subject. For example, a biopsy of smooth muscle from the area treated with local anaesthetic with a small amount of lidocaine injected subcutaneously. The cells from the biopsied tissue can be expanded in culture. The biopsy can be obtained using a biopsy needle, a rapid action needle which makes the procedure quick and simple. The small biopsy core can then be expanded and cultured, as described by Atala, et al., (1992) J. Urol. 148, 658-62; Atala, et al. (1993) J. Urol. 150: 608-12, incorporated herein by reference. Cells from relatives or other donors of the same species can also be used with appropriate immunosuppression, for example, endothelial cells from dissected veins, or fibroblast cells from foreskins (see examples 1 and 2, respectively).
[0041] Dissociation of the cells to the single cell stage is not essential for the initial primary culture because single cell suspension may be reached after a period of in vitro culture. Tissue dissociation may be performed by mechanical and enzymatic disruption of the extracellular matrix and the intercellular junctions that hold the cells together. Preferred cell types include, but are not limited to, mesenchymal cells, especially smooth muscle cells, skeletal muscle cells, myocytes (muscle stem cells), fibroblasts, chondrocytes, osteoblasts, chondroblasts, ondoblasts, adipocytes, fibromyoblasts, and ectodermal cells, including ductile and skin cells, hepatocytes, and other parenchymal cells. In a preferred embodiment, fibroblast cells are isolated.
[0042] Cells can be cultured in vitro to increase the number of cells available for coating the biocompatible substrate. The use of allogenic cells, and more preferably autologous cells, is preferred to prevent tissue rejection. However, if an immunological response does occur in the subject after implantation of the artificial organ, the subject may be treated with immunosuppressive agents such as, cyclosporin or FK506, to reduce the likelihood of rejection. In certain embodiments, chimeric cells, or cells from a transgenic animal, can be coated onto the biocompatable substrate.
[0043] Cells may be transfected with genetic material prior to coating. Useful genetic material may be, for example, genetic sequences which are capable of reducing or eliminating an immune response in the host. For example, the expression of cell surface antigens such as class I and class II histocompatibility antigens may be suppressed. This may allow the transplanted cells to have reduced chance of rejection by the host. In addition, transfection can also be used for gene modification.
[0044] Cell cultures may be prepared with or without a cell fractionation step. Cell fractionation may be performed using techniques, such as flourescent activated cell sorting, which are known in the art. Cell fractionation may be performed based on cell size, DNA content, cell surface antigens, and for viability.
[0045] The isolated cells can be normal or can manipulated genetically to provide additional functions. Methods for genetically engineering cells with retroviral vectors, polyethylene glycol, or other methods known to those skilled in the art can be used. These include using expression vectors which transport and express nucleic acid molecules in the cells. (See Goeddel; Gene Expression Technology: Methods in Enzymology 185, Academic Press, San Diego, Calif. (1990), incorporated herein by reference). Vector DNA can be introduced into cells via conventional transformation or transfection techniques. Suitable methods for transforming or transfecting host cells can be found in Sambrook et al. ( Molecular Cloning: A Laboratory Manual, 2nd Edition, Cold Spring Harbor Laboratory press (1989), incorporated herein by reference), and other laboratory textbooks.
[0046] III. Production of Artificial Slings
[0047] In one aspect, the invention features methods of producing artificial slings using one or more cultured cell populations on a biocompatible substrate. Cells can be expanded as described in Section II, and used to create polylayers on a biocompatible substrate. The cultured cell populations can be used to produce heterogenous polylayers on one or more surface(s) of a biocompatible substrate. Examples of suitable biocompatible substrates are described in Section 1.
[0048] In one embodiment, one surface of the biocompatible substrate is used to produce the artificial sling. This can be performed by depositing a suspension of a collagen-secreting cell population (e.g., mesenchymal cells such as, fibroblasts, chondroblasts, osteoblasts and ondoblasts.) one side of the biocompatible substrate. The collagen-secreting cells are incubated until the cells develop and proliferate to produce at least a monolayer of cells. A second suspension of collagen-secreting cells can then be deposited on the first layer, and the cells are incubated until they develop and proliferate to produce a bilayer. The process is repeated to produce a polylayer of collagen-secreting cells.
[0049] In another embodiment, collagen can be added to the biocompatible substrate. For example, collagen can be derived from any number of mammalian sources, typically bovine, porcine, or ovine skin and tendons. The collagen can be acid-extracted from the collagen source using a weak acid, such as acetic, citric, or formic acid. Once extracted into solution, the collagen can be salt-precipitated using NaCl and recovered, using standard techniques such as centrifugation or filtration. Details of acid extracted collagen are described, for example, in U.S. Pat. No. 5,106,949, issued to Kemp et al. incorporated herein by reference.
[0050] In another embodiment, additional collagen can be added between the heterogenous polylayers to promote growth and development between the cells of heterogeneous polylayers. In yet another embodiment, factors such as nutrients, growth factors, cytokines, extracellular matrix components, inducers of differentiation or dedifferentiation, products of secretion, immunomodulation, and/or biologically active compounds which enhance or allow growth of the cellular network can be added between the heterogenous polylayers.
[0051] After the collagen polylayer is established, an elastin polylayer can be created using a suspension of an elastin-secreting cell population (e.g. smooth muscle cells, chondrocytes, and fibroblasts.) Cells of the elastin-secreting cells are incubated until the cells develop and proliferate to produce at least a monolayer of cells. A second suspension of the elastin-secreting cells are then deposited on the first layer, and the cells are incubated until they develop and proliferate to produce a bilayer. The process is repeated to produce a polylayer of elastin-secreting cells.
[0052] A chimeric interface is produced where two or more heterogenous polylayers are in mutual contact with each other. This enables unhindered interaction to occur between the cells of the polylayers. Extensive interactions between different cell populations results in the production of a interstitial material, which can develop into an interstitial biomaterial that is different from each of the polylayers. The interstitial biomaterial can provide unique biological and functional properties to the artificial sling.
[0053] The skilled artisan will appreciate that any interstitial biomaterial produced when two or more heterogenous polylayers comprising different cell populations interact, is within the scope of the invention. The different interstitial biomaterial produced will depend on the type of cells in the heterogenous polylayer.
[0054] In another embodiment, at least two surfaces of the biocompatible substrate are used to produce the artificial sling. This can be performed by depositing a suspension of a collagen-secreting cells (e.g., mesenchymal cells such as, fibroblasts, chondroblasts, osteoblasts and ondoblasts.) on one surface of the biocompatible substrate. The collagen-secreting cells are incubated until the cells develop and proliferate to produce a monolayer of cells. The process is repeated to produce a polylayer of collagen-secreting cells. Next, a suspension of an elastin-secreting cells (e.g., smooth muscle cells, chondrocytes, and fibroblasts) can be deposited on a second surface that is opposite the first surface of a biocompatible substrate. The elastin-secreting cells are incubated until the cells develop and proliferate to produce a monolayer of cells. The process is repeated to produce a polylayer of elastin-secreting cells.
[0055] The skilled artisan will appreciate that the length and width of the artificial sling can be selected based on the size of the subject and the urinary structure which requires positioning to ameliorate urinary incontinence. The length and width of the artificial sling can easily be altered by shaping the biocompatible substrate to a desired length and width. In one embodiment, the artificial fascial sling has a biocompatible substrate with a length (defined by a first and second long end) of about 10 cm to about 30 cm. The artificial fascial sling can further have a length of about 15 cm to about 25 cm. In a preferred embodiment, the artificial fascial sling includes a biocompatible substrate with a length of about 20 cm. In another embodiment, the biocompatible substrate has a width (defined by a first and second short end) of about 0.5 cm to about 4.0 cm. The artificial fascial sling can further have a width of about 1.0 cm to about 3.0 cm. In a preferred embodiment, the artificial fascial sling has a biocompatible substrate with width of about 2.0 cm.
[0056] The artificial sling can be secured to a support structure in the subject. The support structure for securing the artificial sling can be selected based on the anatomy of the subject, for example, the support structure for a male subject may be different from the support structure of a female subject. Examples of support structures include, but are not limited to, the pubis bone, pelvic bone and inferior pubic arch.
[0057] The artificial sling can be secured to the support structure with a securing agent Examples of securing agents include, but are not limited to, felt matrix, mesh patch and for sutures. Techniques for attaching the artificial sling to the support structure are known in the art (See e.g., Horbach et al. (1988) Obst. and Gyn. 71: 648-652; Raz et al. (1988) J. Urol. 139:528-531; Mickey et al. (1990) Obst. and Gyn. 75: 461-463; Handa et al. (1996), Obst. and Gyn. 88: 1045-1049: Barbalias etal. (1997) Eur. UroL, 31: 394400; Govier et al. (1997) J. Urol. 157: 117-121; Jorion (1997) J. Urol. 157: 926-928; Wright et al. (1998) J. Urol. 160: 759-762, all incorporated herein by reference).
[0058] The tension of the artificial sling positioned around the urinary structure can also be adjusted to provide the required amelioration of incontinence. The can be performed, for example, by tacking the artificial fascial sling onto itself, which provides the ability to change the tension of the artificial sling in small increments and also moves the urinary structure to the desired position.
[0059] In another embodiment, the invention can also be used to produce an artificial fascial patch that can be attached to the base of the bladder and urethra. The artificial fascial patch can then be secured to a support structure in the subject to reposition the base of the bladder and urethra such that ameliorate urinary incontinence is ameliorated.
[0060] Urodynamic evaluations can be conducted to determine the extent of amelioration of urinary incontinence. Methods for urodynamic evaluation are known in the art and include for example, videourodynamics with intravascular and intraurethral pressure measurements (See e.g., Barbalias et al. (1997) Eur. Urol., 31: 394400).
[0061] One skilled in the art will appreciate further features and advantages of the invention based on the above-described embodiments. Accordingly, the invention is not to be limited by what has been particularly shown and described, except as indicated by the appended claims. All publications and references cited herein are expressly incorporated herein by reference in their entirety.
EXAMPLES
Example 1
In vitro Culturing of Fibroblast Cells
[0062] This example describes one of many possible methods of isolating and culturing fibroblast cells. Dermal tissue was isolated from foreskin and cut into 2-3 mm sized fragments. The fragments were placed onto a 100 mm cell culture plate and allowed to adhere to the plate for approximately 10 min. After the fragments had adhered to the plate, 15 ml of culture medium (Dulbecco's Modified Eagle Media (DMEM, HyClone Laboratories, Inc., Logan, Utah) with 10% fetal bovine serum (FBS, Gibco) and penicillin/streptomycin (Sigma, St. Louis, Mo.)), was added and the plates were incubated undisturbed for 5 days at 37° C. with 5% CO 2 . When small island of fibroblast cells appeared, the culture medium was changed and non-adherent tissue fragments were removed. Adhered fibroblast cells were incubated until a sufficient number of fibroblast cells had formed. These fibroblast cells were trypsinized, counted and plated onto 100 mm plates containing 10 ml media for further expansion. The media was changed every 3 days depending on the cell density. Fibroblast cells were cultured until they were approximately 80-90% confluent.
[0063] Fibroblast cells were passaged by removing the culture medium, adding 10 ml PBS/EDTA (1 liter of IX PBS containing 530 mL, 0.5M EDTA, with the pH adjusted to pH 7.2 with 1M HCl and filter sterilized) and incubating for 4 minutes. The separation of the cells was confirmed using a phase contrast microscope. After 4 minutes of incubation, the PBS/EDTA solution was removed and replaced with 5 ml Trypsin/EDTA (0.05% trypsin, 0.53 mM EDTA) to disperse the cells. The dispersed cells were plated into 10 ml culture dishes with a total cell and culture medium volume of 10 ml. The fibroblast cells were expanded until sufficient cell quantities were achieved. Cells were then trypsinized, collected, washed and counted for seeding.
Example 2
In vitro Culturing of Endothelial Cells
[0064] Endothelial cells, were isolated form a dissected vein. Perivenous heparin/papaverine solution (3 mg papaverine HCl diluted in 25 ml Hanks balanced salt solution (HBSS) containing 100 units of heparin (final conc. 4 u/ml)), was used to improve endothelial cell preservation. A proximal silk loop was placed around the vein and secured with a tie. A small venotomy was made proximal to the tie and the tip of vein cannula was inserted and secured in place with a second tie. A second small venotomy was made beyond the proximal tie and the vein was gently flushed with Medium 199/heparin solution Medium 199 (M-199) supplemented with 20% fetal bovine serum, ECGF (100 mg/ml), L-glutamine, heparin (Sigma, 17.5 u/ml) and antibioticantimycotic), to remove blood and blood clots. Approximately 1 ml of a collagenase solution (0.2% Worthington type I collagenase dissolved in 98 ml of M-199, 1 ml of FBS, 1 ml of PSF, at 37° C. for 15-30 min, and filter sterilized), was used to flush through the dissected vein. The collagenase solution was also used to gently distend the vein and the distended vein was placed into 50 ml tube containing Hank's Balanced Salt Solution (HBSS). The tube containing the collagenase distended vein was incubated for 12 minutes at 37° C. to digest the inner lining of the vein. After digestion, the contents of the vein, which contain the endothelial cells, were removed into a sterile 15 ml tube. The endothelial cell suspension was centrifuged at 125× g for 10 minutes. Endothelial cells were resuspended in 2 ml of Dulbec Co.'s Modified Eagle Media with 10% FBS and penicillin/streptomycin (DMEM/10%FBS) and plated into a 24 well plate coated with 1% difcogelatin. The endothelial cells were incubated overnight at 37° C.
[0065] After overnight incubation, the cells were rinsed with HBSS and placed in 1 ml of fresh DMEM/10%FBS. The media was changed 3 times a week. When cultures reached confluence (after 3-7 days), the confluent monolayers were subcultured by treatment with 0.05% trypsin, 0.53 mM EDTA, for 3-5 min until the cells dispersed. The dispersed cells were plated onto culture dishes coated with 0.1% difcogelatin at a 1:4- 1:6 split ratio. The endothelial cells were expanded until sufficient cell quantities were achieved. Cells were trypsinized, collected, washed and counted for seeding.
Example 3
Creation of an Artificial Fascial Sling
[0066] A synthetic polymer matrix of polyglycolic acid was cut to an average length of about 15 cm and a width of about 2 cm. The polyglycolic acid matrix was coated with a liquified copolymer, at a mixture of about 50% poly-DL-lactate-co-glucoside and about 50% 80 mg/ml methylene chloride, to obtain the desired mechanical characteristics. After sterilization, the polymer was stored in a desiccator until ready for use.
[0067] For each fascial sling, about 32 confluent 25 cm plates of each cell type, collagen-secreting cells, elastin-secreting cells and fibroblast cells, were processed for coating onto the polyglycolic acid matrix. The cells were resuspended in culture medium and applied at a cell density of about 107 cells/ml to one surface of the polymer matrix. The coated polymer was incubated in Dulbeccos's Modified Eagles Medium (DMEM, Sigma, St. Louis, Mo.) supplemented with 10% fetal calf serum (Biowhittaker Inc., Walkersville, Md.). The medium was changed at 12 hour intervals to ensure sufficient supply of nutrients. The cells were cultured until they attached to the surface of the polymer and began to grow and develop. A second suspension collagen-secreting cells was then coated onto the existing collagen layer. The cells were incubated until they grew and developed into a layer of collagen cells. The process was repeated until a polylayer of collagen developed.
[0068] The elastin-secreting cell population was coated onto the collagen polylayer. The cells were incubated until they formed an interface with the collagen polylayer and developed into a monolayer of elastin cells. A second suspension of elastin-secreting cells was then applied to the elastin monolayer and allowed to develop into a second monolayer. The process was repeated until a polylayer of elastin cells developed over the polylayer of collagen cells. Finally, a population of fibroblast cells was coated onto the polylayer of elastin-secreting cells. The cells were cultured until they developed into a monolayer of fibroblast cells. A second suspension of fibroblast cells was applied to the monolayer of fibroblast cells, and the cells were cultured until they grew and developed to form a second monolayer. The process was repeated until a polylayer of fibroblasts was formed.
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The present invention describes methods for producing artificial fascial slings and their subsequent use in treating subjects with urinary incontinence. The invention is based, in part, on the discovery that mesenchymal cells that secrete elastin and collagen, extracellular proteins responsible for elasticity and strength, respectively, can be used to engineer artificial fascia in vitro.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims benefit of and priority from the co-assigned German Application No. 10 2011 052 963.2 filed on Aug. 24, 2011. The disclosure of the above-mentioned Patent Application is incorporated herein by reference in its entirety.
TECHNICAL FIELD
The present invention relates to a slider unit for a tertiary air duct between a clinker cooler and a calciner of a clinker kiln plant.
RELATED ART
Cement clinker, also referred to herein as clinker, is usually produced in a rotary kiln. The clinker is discharged from the hot end of the rotary kiln onto a cooling grate of a clinker cooler. Resting on top of the cooling grate, the clinker is cooled by a gas or a mixture of gases, usually air. As a result, the air is strongly heated, at least in the area close to the kiln. This strongly heated air has a temperature of approximately 750-1300° C. and is highly dust-laden. The heated air is extracted from the clinker cooler at the kiln hood and/or the cooler roof and is dissipated through a so-called tertiary air duct. Accordingly, such air is referred to as tertiary air. This tertiary air is normally used for pre-processing of the raw meal and mostly fed to a calciner or an upstream combustion or gasification unit, such as a combustion chamber, for example. The term calciner is used in this application as a synonym for a “raw meal preprocessing unit” being fed with tertiary air as a source of heat and/or oxygen.
The raw materials necessary for the production of cement clinker are at least partly decarbonised in the calciner, using the thermal energy contained in the tertiary air directly, whereas the oxygen contained in the tertiary air is used for the combustion of the fuel in the secondary firing. The permanent optimisation of energy efficiency in cement producing plants results in an increase of tertiary air temperature. At the same time, the tertiary air volume per time unit decreases. The increasing use of secondary fuels, coal with high ash content, petrol coke and the like particularly increases the dust contingent, i.e. the dust load in the tertiary air. In order to prevent clinker dust from clogging the tertiary air duct in the long term, the flow speed inside the tertiary air duct is increased. The higher temperature and the high dust load, in combination with the higher flow speed, cause higher wear on the refractory lining inside the tertiary air duct.
When the clinker kiln line is started up, the tertiary air duct has to be initially closed. So called shutoff devices are used for this purpose. In the simplest case, these are plate-like sliders, which are inserted into the tertiary air duct orthogonally to the flow direction, thus closing the duct during start-up of the clinker kiln line. Foldable flaps are used as shutoff devices as well. After the start-up (or “ramp up”) the shutoff devices should be completely open. The present invention is based on the realization that the shutoff devices are, beyond their design, often used to control the amount of tertiary air per time unit, for example when the clinker kiln line is not operated at full production. In this case the shutoff devices are only inserted partly into the tertiary air duct, for example to split up the supply air for the combustion in the kiln and the calciner, thus ensuring oxidizing conditions at the kiln inlet.
When the shutoff devices do not close the tertiary air duct completely, they are subject to strong wear as the clinker dust contained in the tertiary air is highly abrasive. As a result, the shutoff element is abraded and thereby shortened to the extent that it cannot reliably seal the tertiary air duct. A normal restart of the clinker kiln line after an unscheduled shutdown is not possible without exchanging the shutoff device.
Another persisting problem is the deformation of the shutoff element caused by thermal stress, which can result in jamming of the shutoff device such that the adjustment of the same becomes impossible.
SUMMARY OF THE INVENTION
Embodiments of the present invention are directed to facilitate a reliable shutting-off of a tertiary air duct and control of the tertiary air flow.
This task is solved by a slider configured to be inserted into a tertiary air duct.
In particular, an embodiment of the slider unit can be inserted into a tertiary air duct of a clinker kiln line, hence it is located in the tertiary air flow between a clinker cooler and a calciner of the clinker kiln line. Accordingly, the slider unit can have a duct section, which can be inserted into the tertiary air duct. A preferably plate-like shut-off device can be inserted into the tertiary air duct in order to shut off the tertiary air duct, in other words close it completely. In addition to the shutoff device, the slider unit contains at least one control device that is insertable into the tertiary air duct in order to reduce the cross section of the duct. The slider unit is adapted to ensure that shutoff and control functionalities are separated. Therefore, the shutoff device is not subject to noteworthy wear, as it is only inserted into the tertiary air duct to close it completely. Hence its functioning is ensured permanently. The control device, however, can be inserted into the tertiary air duct in order to reduce its cross section and, when so inserted, is exposed to the tertiary air flow and should be designed accordingly. Preferably, the control device is at least on the side facing towards the tertiary air flow equipped with a heat resistant cladding of refractory bricks or similar material. Refractory here is not only stone-like, heat resistant material with 10 to 45 per cent alumina content but, according to the general linguistic usage, all heat resistant, in particular stone-like claddings, in particular claddings made of ceramics or ceramic elements. For simplification reasons there is no differentiation in the following text between air, a gas or a mixture of gases used as cooling agent for the clinker. The terms air or tertiary air are consequently not limited to the typical gaseous composition of air.
Preferably, the control device is supported by the shutoff device on its downwind side, that is the side facing away from the tertiary air flow. Therefore, the slider unit is particularly small. In one embodiment, the control device is located upwind, that is the side facing towards the tertiary air flow, of its guide. Hence, the guide is covered and therefore shielded against the tertiary air flow by the control device.
Preferably, the length of the control device is significantly less than the diameter of the duct section, as it does not have to shut off the tertiary air duct. To cover the usual control range a length of about ⅓ to about ⅔ of the duct diameter is sufficient. Consequently, it requires only a small amount of space next to the tertiary air duct when withdrawn completely from the tertiary air duct. In addition it takes less refractory material to protect the smaller slider, which reduces costs.
Preferably, the shutoff device has at least two parallel movable shutoff segments. In one embodiment, the length of each of the two shutoff segments is less than or equal to the length of the control device to ensure that the space required for the slider unit next to the tertiary air duct can be kept particularly small. For example, the shutoff device can have at least two plates, movable in parallel to each other, which can be inserted into the duct section.
It is preferred that at least a first shutoff segment is movable in a guidance of at least another shutoff segment. Therefore, the guidance of the first shutoff segment is not exposed to the tertiary air flow when the shutoff device is open and thus protected from damage through the tertiary air.
It is preferred that at least the first shutoff segment of a multi-segment shutoff device has at least one catch element for another shutoff segment of the shutoff device. Thus it is sufficient to actuate the first shutoff segment to open or close the tertiary air duct.
It is preferred that the shutoff device and the control device are mounted suspended above the tertiary air duct and can be lowered into the tertiary air duct. Therefore no thrust needs to be applied to close the shutoff device or to insert the control device. Flexible connecting elements such as chains or belts, for example, can be used instead of push rods, which further reduces the space required for the slider unit.
Preferably, the control device includes at least one carrier, which relates to a method of adjustment of the control device. For example, the at least one carrier may be suspended from at least one chain hoist. The carrier is preferably clad with refractory bricks, optionally with an isolating layer (such as, for example, insulating wool) that is located between the carrier and the refractory bricks. Preferably, the bricks can be bolted to the carrier, thereby securing the isolating layer. Such implementation of a control device has a good price/lifetime ratio.
Preferably the control device and/or the shutoff device has at least one channel adapted to contain a cooling agent. This further improves durability of the device.
The duct section of the tertiary air duct, in which the control device and/or the shutoff device are to be inserted, has preferably at least one slot adapted to accommodate the control device and/or the shutoff device therethrough. The duct section has preferably lateral guides, in the direction of movement, in which the shutoff device and/or the control device are movable.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, the invention will be described by way of examples, without limitation of the general inventive concept, of embodiments and with reference to the drawings.
FIG. 1 provides several views of a slider unit for a tertiary air duct according to an embodiment of the invention.
FIG. 2 is a perspective view of a partly assembled slider unit according to an embodiment of the invention.
FIG. 3 is a perspective view of a detail of a slider unit of FIG. 2 .
FIG. 4 is a perspective view of another detail of a slider unit of FIG. 2 .
FIG. 5 is a perspective view of a detail of an alternative embodiment of a shutoff device.
Various modifications and alternative forms of an embodiment of the invention are within the scope of the invention. The specific embodiments 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 related description are not intended to limit the invention to the particular form disclosed, but to 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
The slider unit 1 in FIG. 1 has a duct section 10 , configured to be installable in a tertiary air duct and is clad with refractory material 12 . Hence, the slider unit can be installed in a tertiary air duct as a module, which makes the assembly easier. A box-like carrier 20 with enough space to accommodate a control device 60 (shown inserted into the tertiary air duct) and a shutoff device 80 (shown partly inserted) is located on top of the duct section 10 . On the upper side of the carrier 20 drives 26 , 28 are located to withdraw the control device 60 or the shutoff device 80 , respectively, from the duct section 10 into the carrier 20 to open the tertiary air duct completely or to insert the shutoff device and the control device into the duct section 10 independently (see FIG. 2 ). To guide the control device 60 and the shutoff device 80 grooves 14 , 16 as guides are foreseen, in which the two devices 60 , 80 are movable (see FIG. 1 ). Additionally, the shutoff device is guided by the guides 18 on both sides. Simply speaking the guides include rails that extend to the inside through a slot in the refractory cladding of the carrier 20 .
The shutoff device 80 includes two shutoff segments that move parallel to each other, the example shown here is plate-shaped, further referred to as plates 82 , 83 . Plate 82 is located in front of plate 83 in a guide of the rear plate 83 (see FIG. 3 ). The front plate 82 has a lower edge 86 or lower narrow side 86 that is adapted to the contour of the lower part of the duct section 10 . Fastenings 84 holding the front plate 82 are attached on its upper narrow side 88 . This upper narrow side 88 is at least approximately horizontal. The lateral narrow sides 92 are at least approximately parallel to each other and have a vertical longitudinal axis. The rear plate 83 hangs on the upper narrow side of the front plate 82 . For this purpose the rear plate 83 is equipped with angle profiles 85 on its front side used as catch elements 85 , the free ends of which are angled downward at least approximately parallel to the front plate 82 . These catch elements 85 bear on the upper narrow side 88 of the front plate 82 .
In order to close the duct section 20 , the front plate 82 together with the rear plate 83 is lowered from the carrier 20 into the tertiary air duct until the rear plate 83 is located in the groove 16 and at least the lower part of the lateral narrow sides 93 bears on the groove. Consequently, the shapes of the lower part of the narrow sides 93 are adapted to the contour of the duct section 10 . When the rear plate 83 bears on the inner wall of the duct section 10 , the front plate 82 slides further downwards, being guided by the angle profiles 85 attached to the rear plate 83 . In its final position, the front plate also bears on the groove 16 . The duct section 10 is now sealed for tertiary air. To open the tertiary air duct the front plate 82 can be lifted upwards via the fastenings 84 . During such lifting, it is guided by the groove 16 in the wall of the duct section 10 as well as the lateral angle profiles 85 . Approximately halfway up, the front plate 82 attaches to the rear plate 83 or the upper angle profiles respectively from below and also lifts the rear plate, until both plates have reached their final position inside the carrier. The duct section 10 is now open (not shown). As both plates 82 , 83 are guided parallel to each other in a telescope-like manner, the minimum construction height of the carrier is significantly reduced. Therefore such a shutoff device 80 can be retrofitted even with reduced available space.
The control device 60 has a carrier plate 62 having fastening elements 64 attached to its upper end. The carrier plate 62 is suspended from the fastening elements 64 (see FIG. 4 ). Heat resistant isolating material 66 , for example mineral wool felt, is attached to the front and rear sides of the carrier plate 62 as well as to the narrow sides (at least the two lateral and the lower narrow side). The isolating material 66 is clad with refractory bricks 70 . The refractory bricks are bolted to the carrier plate 62 by bolts 68 . The refractory bricks 70 have through holes 72 , which have a larger diameter on the side facing away from the carrier plate 62 . The larger sections of the through holes 72 are used to receive nuts 69 , thus protecting the nuts and the projecting parts of the bolts 68 from abrasion by clinker dust. Preferably, the holes are sealed by a curing heat resistant matter.
Unlike the shutoff device 80 shown in FIGS. 1 to 3 , the shutoff device 80 depicted in FIG. 5 consists of only one plate 82 , which hangs from fastening elements 84 and can be lifted out of or lowered into a duct section 10 by a drive 28 . The shutoff device 80 has only one plate, which cannot cover the complete cross section of the tertiary air duct, but the plate is lowered behind the control device, so that it is sufficient to seal the remaining open part of the tertiary air duct below the control device with the single plate.
It will be appreciated to those skilled in the art having the benefit of this disclosure that embodiments of this invention are believed to provide a slider unit for a tertiary air duct of a cement clinker line. 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
1 slider unit
10 duct section
12 heat resistant material/cladding (i.e. refractory or ceramics)
14 groove
16 groove
18 guide
20 carrier
26 drive
28 drive
60 control device
62 carrier plate
64 fastening element
66 isolating material
68 bolt
69 nut
70 refractory bricks/heat resistant cladding
72 through hole
80 shutoff device
82 plate/shutoff segment
83 plate/shutoff segment
84 fastening element
85 catch/angle profile
86 lower edge/lower narrow side of the front plate
87 lower edge/lower narrow side of the rear plate
88 upper narrow side of the front plate
89 upper narrow side of the rear plate
92 lateral narrow sides of the front plate
93 lateral narrow sides of the rear plate
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A slider unit for a tertiary air duct between a clinker cooler and a calciner of a clinker kiln line. The slider unit has at least one shutoff device, which is insertable into a tertiary air duct to seal it without further reducing the cross section of the tertiary air duct, and provides reliable sealing of the tertiary air duct and control of the tertiary air flow, if the slider unit has at least one control device which is insertable into a section of the tertiary air duct to reduce its cross section.
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This application claims the benefit of U.S. Provisional application Ser. No. 60/126,020, filed Mar. 25, 1999, entitled “Window Treatment Holder System.”
BACKGROUND OF THE INVENTION
This invention relates generally to a system for mounting and retaining window treatments, such as horizontal blinds, vertical blinds, draperies, shades, shutters, sliding fabric panels, etc.
When installing window treatments in a new or existing structure, several options are available. With regard to installing horizontal blinds, for example, dedicated brackets provided by the manufacturer are generally fastened, such as with screws or other fasteners, to window frame or to wall or ceiling portions surrounding the corresponding window. Similarly, when installing draperies, drapery rods may also be directly fastened to window frame or to wall or ceiling surfaces surrounding the window with dedicated brackets using conventional fasteners.
Other installation conditions are common. One option involves the construction of an oversized pocket or soffit for concealing the upper portion of the window treatment. This pocket is typically built into the structure using wallboard, studs, etc. Another option is the use of a prefabricated pocket, which can be structured of metal such aluminum.
Another option is the use of a channel member, which also can be structured of metal such as aluminum, which may be provided by a manufacturer of the window treatment and which is configured specifically for that manufacturer's product.
Some of the foregoing options may be expensive, labor intensive to install, and/or of limited use for different types of window treatments.
Master Recessed Systems has offered pocket structures for holding venetian blinds, draperies and vertical blinds. Note in particular U.S. Pat. Nos. 3,678,636 and 3,708,927, both of which issued to Cohen. Note also U.S. Pat. Nos. 3,951,197 and 4,023,235, both of which issued to Cohen, et al. Concerning existing window treatment holders, other window treatment manufacturers offered brackets that twist into place using a tool and which hold window treatments, such as horizontal blinds, in place.
Other patented devices are disclosed in U.S. Pat. No. 4,886,102, issued to Debs which describes a support for a venetian blind, and also U.S. Pat. No. 3,715,776, issued to Tanaka, which discloses a curtain box. Australian Patent Document Nos. 54,837/90 and 57,823/73 disclose related devices.
Even in view of the foregoing devices, there still exists a need for advancements in window treatment holding systems. A particular need exists for a system which is easily installed with a minimal number of fasteners, and which finds more universal application among various types of window treatments produced by various manufacturers.
SUMMARY OF THE INVENTION
It is, therefore, the principal object of this invention to provide a window treatment holding system which can be used to install multiple types of window treatments produced by various manufacturers.
Another object of the present invention is to provide a window treatment holding system which can be incorporated in the top of the window mullion, mounted overhead, or surface mounted.
Yet another object of the present invention is to provide a window treatment holding system having a pocket member which finds widespread applicability for use in retaining various types and styles of window treatments.
Another object of the present invention is to provide a window treatment holding system having brackets tailored for specific window treatments, such brackets being usable in a particular embodiment of a pocket member constructed in accordance with the present invention.
A further object of the present invention is to provide brackets which position the window treatment within a pocket member.
A still further object of the present invention is to provide means for a given pocket configuration to allow various types of products to be installed using appropriate brackets of the present invention.
Yet a further object of the present invention is to provide a method of using a window treatment holding system constructed in accordance with the present invention.
Generally, the present invention includes an elongated pocket member defining a pocket profile, or structure, in which a bracket is received in a snap-fit arrangement. The bracket is designed to carry the head rail of a conventional horizontal or vertical blind, or a drapery rod or channel.
The pocket member can be of a variety of configurations and can be fastened over a window, in the ceiling, fastened to the wall or window frame adjacent the window, or incorporated into the window mullion head. Numerous pocket profiles are provided, some of which are designed to be concealed from view, and others having decorative external portions for providing an aesthetically appealing appearance. The pocket member is fixed to the desired location using conventional fasteners, such as screws, bolts, rivets or the like, or, in certain applications, could be molded or extruded as a part of a window frame or the window mullion head. Also, the pocket profile can be provided by a pocket adapter and snapped into place in a conventional mullion cavity.
The brackets also come in numerous designs, some of which are shown in the figures provided herewith. The brackets are “snapped” or “twisted” into place within a pocket member, allowing for a window treatment to be snapped into the pocket/bracket system. Alternately, the brackets can be attached to a window treatment head prior to its insertion into the pocket member. Neither screws, bolts nor other fasteners or tools are necessary in order to couple the window treatment to the pocket. Further, the brackets are preferably designed such that the window treatments may be removed or adjusted once coupled with the pocket member.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing, as well as other objects of the present invention, will be further apparent from the following detailed description of the preferred embodiment of the invention, when taken together with the accompanying specification and the drawings, in which:
FIG. 1 is a perspective view of a window treatment holding system constructed in accordance with the present invention, and illustrates a pocket member and bracket of the present invention holding a conventional set of horizontal blinds;
FIG. 2 is a partial perspective view of a window treatment holding system constructed in accordance with the present invention, illustrating an alternate embodiment pocket member and an alternate embodiment bracket of the present invention holding a conventional set of vertical blinds;
FIG. 3 is a partial perspective view of a pocket member and bracket constructed in accordance with the present invention;
FIG. 4 is a partial perspective view of a pocket member constructed in accordance with the present invention;
FIG. 5 is a perspective view of a bracket constructed in accordance with the present invention;
FIG. 6 is a perspective view of an alternate embodiment of a bracket constructed in accordance with the present invention;
FIG. 7 is a perspective view of an alternate embodiment of a pocket member constructed in accordance with the present invention having unitary decorative molding defined therein;
FIG. 8 is a partial perspective view of a pocket member constructed in accordance with the present invention having a separate decorative molding member attached hereto;
FIG. 9 is a sectional view of an alternate embodiment pocket member of the present invention in use with a horizontal blind;
FIG. 10 is a sectional view of the pocket member of FIG. 9 in use with a vertical blind set;
FIG. 11 is a sectional view of an alternate embodiment of a pocket member installed together with a bracket supporting a vertical blind;
FIG. 12 is a sectional view of a pocket member and bracket of the present invention, where the pocket member is installed and the bracket is supporting a vertical blind set;
FIG. 13A is a view of an alternate embodiment pocket member, and FIG. 13B is a side elevational view of a splicing member of the present invention illustrating use of the splicing member for adjoining adjacent pocket members;
FIGS. 14A is a view of the pocket member of FIG. 13A, and FIG. 14B is a side elevational view of a hanger member for use therewith;
FIG. 15 is a sectional view of the pocket member of FIG. 13 and bracket of the present invention in use with an S-fold drapery and track;
FIG. 16 is a sectional view of the pocket member of FIG. 13 and bracket of the present invention illustrating holding a cellular shade;
FIG. 17 is a sectional view of an alternate embodiment pocket member for use in mounting on a wall;
FIG. 18 is a sectional view of an alternate embodiment pocket member for use with a ceiling board or tile;
FIG. 19 is a sectional view of an alternate embodiment pocket member of the present invention for use with a vertical board, panel, or tile member;
FIGS. 20A, 20 B, 20 C, and 21 are various views of the bracket of FIG. 6;
FIG. 22 is a sectional view of the pocket member of FIG. 13 and bracket of the present invention in use with a roll shade;
FIG. 23 is a sectional view of an alternate embodiment pocket member of the present invention for use with a ceiling tile installation;
FIG. 24 is a sectional view of the pocket member of FIG. 13 and bracket of the present invention supporting a vertical blind set, the pocket member being attached to the face of a mullion and overhead, and additionally supporting a ceiling tile or panel;
FIG. 25 is a sectional view of pocket members and brackets of the present invention illustrating the mounting of a drapery set, a horizontal blind set, and a vertical blind set;
FIGS. 26A-26D are a series of views showing the steps of using the window treatment holding system of the present invention and involves inserting brackets of the present invention into a pocket of the present invention and then attaching the window treatment to the brackets;
FIG. 27 is a view showing use of the window treatment holding system of the present invention and involves attaching brackets of the present invention to a window treatment and then inserting the brackets into a pocket;
FIGS. 28A and 28B are a series of views showing the steps of removing a window treatment and bracket from a pocket of the present invention;
FIG. 29 is a sectional view of a pocket adapter constructed in accordance with the present invention for insertion into a cavity and for receiving a bracket constructed in accordance with the present invention;
FIG. 30 is a sectional view of an alternate embodiment bracket of the present invention constructed of a band of resilient material;
FIGS. 31A and 31B are a sectional view and a bottom plan view, respectively, of an alternate embodiment bracket of the present invention which can be twisted into place on a window treatment; and
FIGS. 32A-32E illustrate plan and side elevational views of a two-piece bracket constructed in accordance with the present invention for use in a pocket of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The accompanying drawings and the description which follows set forth this invention in its preferred embodiment. However, it is contemplated that persons generally familiar with window treatments will be able to apply the novel characteristics of the structures illustrated and described herein in other contexts by modification of certain details. Accordingly, the drawings and description are not to be taken as restrictive on the scope of this invention, but are to be understood as broad and general teachings.
Referring now to the drawings in detail, wherein like reference characters represent like elements or features throughout the various views, the window treatment holding system of the present invention is indicated generally in the figures by reference character 10 .
FIGS. 1 and 2 illustrate two of the fundamental configurations of the present invention. FIG. 1 illustrates window treatment holder system 10 supporting a set of horizontal blinds H. Pocket member, generally 12 , defines an elongated channel 14 for receipt of a bracket, generally 16 . It is to be noted at the outset that the configuration of pocket member 12 and bracket 16 can be varied significantly, while still not departing from the scope of the present invention.
Bracket 16 is preferably made of a flexible, resilient material such as plastic, although it is to be understood that metal, wood, or some other suitable material having sufficient resiliency and structural integrity could also be used. Bracket 16 includes downwardly extending arms 18 , 20 , each having a barb 22 at the end thereof. Each barb 22 receives and supports inwardly turned upper flange portions 24 , 26 of a head rail 27 of blinds H. Outer arms 28 , 30 are provided, and arm 28 rests on ledge 32 of pocket member 12 . Ledge 32 and a ledge 34 are formed by flanges 36 , 38 of pocket member 12 .
Pocket member 12 is preferably formed of extruded aluminum, although it is to be understood it could be fabricated in some other suitable manner and of some other material, such as another metal besides aluminum. Pocket member 12 , for example, could be potentially extruded or molded of plastic, if desired.
As shown in FIGS. 1 and 5, bracket 16 includes an elongated flexible catch member 40 which has a lower edge portion 42 which rests on ledge 34 when bracket and blinds H have been installed in pocket member 12 .
When it is desired to hang blinds H, bracket 16 , because it is flexible, is snapped onto head rail 27 such that barbs 22 engage flanges 24 , 26 of head rail 27 . Stops 44 , 46 limit upward movement of head rail 27 , once barbs 22 have engaged flanges 24 , 26 . Bracket 16 is then inserted into pocket channel 14 , and flexible catch is simultaneously pressed inwardly toward head rail 27 such that the lower edge 42 thereof clears flange 38 and edge 42 rests on ledge 34 . Once this occurs, flexible catch 40 is released, and bracket 16 , and accordingly, head rail 27 and blinds H, are securely held within pocket member 12 . If it is desired to remove blinds H, flexible catch 40 is depressed to the extent necessary that lower edge 42 clears flange 38 , thereby releasing bracket 16 from pocket member 12 . Although the present invention discloses numerous pocket and bracket configurations herein, the basic operation of the pocket and bracket designs of the present invention operate substantially the same as that just discussed.
Turning now to FIG. 2, alternate embodiments of the pocket member and bracket of the present invention will be discussed. In this embodiment, pocket member 12 A includes substantially the same inner “pocket structure,” as discussed above, i.e., the pocket structure including a channel 14 provided with support ledges 32 , 34 formed by inwardly extending flanges 36 , 38 , respectively. In the FIG. 2 embodiment, pocket member 12 A includes rearwardly extending flanges 50 , 52 which engage in an interlocking relationship with a bracket, generally 54 mounted on a wall W. Bracket 54 includes a lower barbed portion 56 which engages a corresponding barbed portion 58 of flange 52 in a snap fit relationship. Upper flange 50 includes a hook portion 60 which engages with a corresponding hook portion 62 of bracket 54 . On the other end of pocket member 12 A, a recess 64 is provided in which a support member 66 has a lip 68 for supporting a ceiling panel or tile, generally T. Support member 66 includes a hook portion 70 which corresponds with a hook portion 72 of pocket member 12 A. Support member 66 also includes a barbed edge 74 which is received in a barb/groove combination 76 defined in a flange 78 of pocket member 12 A. It is noted that pocket member 12 A can be securely retained to bracket 54 by the snap fit interaction of barbs 56 and 58 . Likewise, support member 66 is retained on pocket member 12 A by the snap fit arrangement of barb 74 with barb/groove combination 76 .
Bracket 16 A includes a flexible catch 40 A and snaps into place within pocket member 12 A upon a vertical blind V head rail 27 A being received by upstanding flexible arms 80 , 82 . Arms 80 , 82 have at their extreme end inwardly curved catches 84 , 86 , respectively, which engage outwardly extending lip portions 88 of head rail 27 . The lower end of catch 84 and the lower end of leg 90 of bracket 16 A rest on ledges of the pocket structure of pocket member 12 A.
FIG. 3 illustrates a pocket member 12 B having a front portion 92 and a rear upstanding portion 94 which can be used to attach pocket member 12 B to a wall using conventional fasteners (not shown). Bracket 16 A refers to a family of brackets, and in FIG. 3 bracket 16 A has been modified to eliminate cavity 95 (FIG. 2 ), and is provided in pocket member 12 B, but as compared with FIG. 2, the bracket 16 A is reversed, with the catch 40 A being adjacent the front 92 of pocket member 12 B, instead of the rear. Because bracket 16 A is asymmetric, reversing of the bracket 16 A, as shown in FIG. 6, allows for the distance between the window treatments, such as vertical blinds V from the wall W or window (not shown) to be varied for clearance, aesthetic, or other purposes.
FIG. 4 illustrates pocket member 12 C, which is similar to pocket member 12 and includes the basic pocket structure discussed above.
FIG. 5 illustrates bracket member 16 prior to insertion into a window treatment and also prior to insertion into pocket member 12 .
FIG. 6 illustrates bracket member 16 A prior to insertion into a window treatment and prior to insertion of bracket 16 A into pocket member 12 .
FIG. 7 illustrates a pocket member 12 D having a decorative crown molding profile 100 being integral therewith. In this embodiment, the pocket member and crown molding 100 could be extruded, or otherwise formed, as a single unit, thereby improving efficiency of construction and also providing increased aesthetic possibilities.
FIG. 8 illustrates pocket member 12 E having a separate crown molding member 102 attachable thereto. Crown molding 102 includes a hook portion 104 which engages hook portion 106 of pocket member 12 E. The lower end of molding 102 includes a flange 108 which rests upon flange 110 of member 12 E. Pocket member 12 E also includes a channel 112 , formed by legs 114 and 116 which can receive a joining, or splicing, member 118 (FIG. 13) when the plurality of pocket members 12 E are to be joined together in an end to end relationship.
FIG. 9 illustrates a pocket member 12 F having a channel 120 for receipt of a wall board member B, and the basic bracket 16 to support horizontal blinds H from the glass G of a window.
FIG. 10 illustrates pocket member 12 F being used with bracket 16 A in order to hold a set of vertical blinds V.
FIG. 11 illustrates pocket member 12 G which is similar to pocket member 12 F, except from the front portion thereof a lower flange 122 extends which supports a ceiling panel wallboard or tile T. Also, an upper flange 124 extends above lowered flange, together, flanges 122 , 124 form a channel for securely holding the tile T. In this embodiment the window treatment holder system 10 is substantially concealed within the ceiling of the structure.
FIG. 12 illustrates pocket member 12 H, which is similar to pocket member 12 G, except member 12 H includes a channel 127 in the front portion thereof for receipt of a joining member 118 , and also includes a barb 126 on an L-shaped ledge 128 for supporting the edge of a ceiling panel, such as wallboard, sheetrock, etc. or tile T. FIG. 13A illustrates a sectional view of pocket member 12 I having a joining member, or splices, 118 in channels 112 and 127 thereof, and FIG. 13B illustrates splice 118 in isolation.
FIGS. 14A and 14B illustrate pocket member 12 H with a hanger member 130 provided in channel 127 thereof for supporting the forward end of pocket member 12 H from above.
FIG. 15 illustrates pocket member 12 H with a bracket 16 A which has been modified to provide a wider recess between arms 80 and 82 in order to accept a track, generally T, for S-fold draperies 132 the draperies 132 and track T being of conventional design.
FIG. 16 illustrates a pocket member 12 H and a bracket 16 A which has been modified such that legs 80 and 82 engage with grooves 132 in the head rail 134 of a conventional cellular shade 136 .
FIG. 17 illustrates a pocket member 12 I, which is similar to pocket member 12 H, except that pocket member 12 I includes an upstanding rear flange 138 for allowing the rear portion of pocket member 12 I to be attached to a wall by the driving of fasteners through flange 138 .
FIG. 18 illustrates a pocket member 12 J having a rear wall attachment flange 140 and a channel 142 formed on the front portion thereof by an outwardly extending flange 144 which includes a channel 146 for receipt of a leg 148 of an L-shaped edge member 150 . Member 150 could provide an interface between the edge of a ceiling panel, such as wallboard, sheetrock, etc., or tile T and pocket member 12 J, with the interaction of leg 148 and channel 146 , being an interference fit.
FIG. 19 illustrates a pocket member 12 K having a channel 152 in the forward portion thereof for receipt of a vertical wall panel (not shown). Channel 152 is expandable by virtue of a fascia member 154 having legs 156 , 158 receivable in channel 160 of pocket member 12 K through an interference fit.
FIGS. 20A-20C and 21 illustrate various views of a bracket member 16 A which is similar to bracket 16 A of FIG. 2, except that chamber 95 found in bracket 16 A is eliminated.
FIG. 22 illustrates pocket member 12 L, having a bracket 16 C therein configured for holding a rail 161 of a conventional roll shade, generally S. Bracket 16 C includes a flexible catch 40 C and a flexible catch 41 C, one being provided at each end of bracket 16 C for releasably fastening roll shade within pocket member 12 L. Bracket 16 further includes flexible arms 162 for engaging grooves 163 of rail 161 .
FIG. 23 illustrates a pocket member 12 M having outwardly extending flanges 164 and 166 for supporting the edges of ceiling tile panels (not shown).
FIG. 24 illustrates installation of a pocket member 12 H having a bracket 16 A holding a set of vertical blinds V.
FIG. 25 is a composite figure illustrating a pocket member 12 M with a bracket member such as bracket member 16 A holding a set of draperies. Also illustrated in FIG. 25 is a pocket member 12 I having a bracket 16 supporting horizontal blinds H. Finally, FIG. 25 illustrates a pocket member 12 N which is formed integrally with the upper window frame. A bracket member such as a bracket 16 A is used to support vertical blinds V.
FIGS. 26A-26D illustrate a method of installing a window treatment, such as horizontal blinds, into a pocket member constructed in accordance with the present invention. The method includes installing a bracket into the pocket member and then snapping the headrail of the blinds into the bracket.
FIG. 27 illustrates another method of installing a window treatment, such as horizontal blinds referenced in FIGS. 26A-26D, into a pocket member. The method includes first installing one or more brackets onto the window treatment and then, inserting the window treatment into the pocket member and snapping the headrail of the blinds into the bracket.
FIGS. 28A and 28B illustrate a method of removing and window treatment/bracket combination from a pocket. Removal steps include depressing the resilient tab, such as catch, or tab, 40 A of bracket 16 A, such that it clears a ledge of the pocket member to allow withdrawal of the bracket and window treatment from the pocket.
FIG. 29 illustrates an additional element of the resent invention. Pocket adapter 168 can be inserted and snapped into place within a cavity 170 of a conventional mullion member 172 . Once in place, pocket adapter 168 provides a pocket profile in accordance with the present invention, having its own cavity 174 and support ledges 176 a and 176 b.
Pocket adapter 168 includes resilient arm 178 and lips 180 , 182 for engaging groove 184 and landing 186 , respectively of mullion 172 and may also include an elbow portion 188 for engaging recess 190 of mullion 172 . A bracket, such as bracket 16 A, is readily receivable in adapter 168 and includes tracks 191 for supporting a window treatment such as a vertical blind set V.
Although one embodiment of pocket adapter 168 has been shown in use with one particular style of mullion, it is to be understood that pocket adapter 168 could be changed and reconfigured as necessary to work in a variety of other mullion designs.
FIG. 30 illustrates another alternate embodiment of a bracket of the present invention. In this embodiment, bracket 16 D is formed of one or more bands of flexible, resilient material, such as a band of spring steel, plastic, etc. Bracket 16 D performs the same function as other brackets described herein in retaining a window treatment to a pocket.
Bracket 16 D could be stamped and bent into the shape illustrated in FIG. 30, or into a variety of other acceptable shapes (not shown) for snap-fit insertion into a pocket member. Bracket 16 D includes a generally S-shaped leg 192 terminating in a catch or tab 194 . Catch 194 engages a ledge of the pocket member, and bracket 16 D includes an angled leg 196 for engaging another ledge of the pocket member. Further, bracket 16 D includes tabs 198 , 200 for engaging recesses 202 of a conventional window treatment, and tabs 203 a and 203 b for limiting upward movement of the window treatment, which may include a vertical blind set as V shown in FIG. 30 .
Release of bracket 16 D from the pocket would be accomplished by depression of catch 194 such that catch 194 clears the ledge of the pocket member.
FIGS. 31A and 31B illustrate a sectional and bottom plan view of a further alternate embodiment of the present invention. Bracket 16 E is configured to allow for the headrail of a conventional window treatment to be twisted into place onto bracket 16 E. Bracket 16 E includes downwardly extending L-shaped tracks 204 , 206 having angled end portions 208 , 210 , respectively, which allow for the bracket 16 E to be twisted into place in the headrail of a window treatment, such as vertical blinds V shown in FIG. 30 . Once twisted into place, tracks 204 , 206 engage with flanges 212 , 214 , respectively to retain the window treatment to the pocket.
FIGS. 32A-32E include sectional and plan views of yet another alternate embodiment. In this embodiment, bracket 16 F is comprised of two portions 216 , 218 which connect to one another in an interlocking relationship. Portion 218 includes a tongue 220 which is received in passages 222 a and 222 b of portion 216 and once received therein, interlocks the portions 216 , 218 together. Tongue 220 include a channel 224 which receives a crossmember 226 of portion 216 in an interlocking relationship. Once locked together, the portions 216 , 218 form bracket 16 F which resembles and functions as do the other brackets disclosed herein to releasably support a window treatment in a pocket member of the present invention.
From the foregoing, it can be seen that the present invention provides a versatile window treatment holding system which can find widespread applicability with substantially all major categories of window treatment types and a wide variety of window frames and mullions.
While preferred embodiments of the invention have been described using specific terms, such description is for present illustrative purposes only, and it is to be understood that changes and variations to such embodiments, including but not limited to the substitution of equivalent features or parts, and the reversal of various features thereof, may be practiced by those of ordinary skill in the art without departing from the spirit or scope of the present invention.
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A window treatment holding system having an elongated pocket member defining a pocket profile, or structure, in which a bracket is received in a snap-fit arrangement. The system is capable of generally concealing the mechanical portion of a window treatment and includes the bracket being designed to carry the head rail of a conventional horizontal or vertical blind, or a drapery rod or channel. The pocket member can be of a variety of configurations and can be fastened over a window, in the ceiling, fastened to the wall or window frame adjacent the window, or incorporated into the window mullion head. Various pocket profiles are provided, some designed to be concealed from view, and others having decorative external portions for providing an aesthetically appealing appearance. The pocket member could be molded or extruded as a part of a window frame or the window mullion head. Also, the pocket profile can be created using a pocket adapter and snapped into place in a conventional mullion cavity.
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BACKGROUND OF INVENTION
This invention relates to improvements in and to hydraulic jacks, and in particular it relates to a support frame for a hydraulic jack which is lockable to support the load.
PRIOR ART
Hydraulic jacks according to the usual construction are so arranged that the jack must be positioned and operated to raise the load to the required height. The jack then remains in position to support the load and the jack is eventually lowered and removed, the jack thus being required while the load is supported.
It would be advantageous to be able to support the load without leaving the jack in place, and an object of this invention is to provide a mechanism for association with a jack which will achieve this.
It is a further object to increase the height to which a load can be raised by means of a standard jack.
It is a still further object to increase the rate of operation of a jack by having dual speed of lift which is actuated by the load.
This and other objects will be apparent from the description of the invention.
SUMMARY OF INVENTION
According to this invention the jack has associated with it a support frame which in use carries the jack but which supports the load so that the jack is used merely for raising and lowering the load, and a jack, for instance a hydraulic jack, can be removed while the support frame carries the load until the jack is again used to lower the load.
The jack support according to this invention comprises a pair of telescopic members, one of the telescopic members comprising a base plate and upstanding support means, the other member comprising a bridge and guide means, the guide means engaging the support means to guide the bridge toward and away from the base. A platform which supports a jack engages the support means to be movable along the support means to be variable in distance from the base, means being provided to lock the platform to the support means at a selected height, and there are also means to lock the guide means of the bridge to the support means, whereby the lifting jack can be positioned on the platform to have the lifting ram of the jack engage the bridge to raise and lower it in relation to the platform to give a multi-stage lift.
The locks for the platform and the bridge are preferably arranged to lock against movement in the direction of the said base plate only but are releasable.
In order however that the invention can be fully understood embodiments thereof will now be described with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1, 2, 3 and 4 show schematically how a jack and a supporting frame according to this invention can give different amounts of lift and leave the jack free so that it can be removed for other use, it being possible to provide a series of such support frames to be used with a common jack,
FIG. 5 is a perspective view of a jack support frame constructed according to the invention, the jack support frame being shown in extended position,
FIG. 6 is a transverse central section of same partly extended,
FIG. 7 is a section of same on line 7 -- 7 of FIG. 6, and
FIG. 8 is a side elevation of the jack support frame.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The means for supporting the jack comprise a pair of members 1 and 2 which are telescopic, the member 1 having a base plate 3 which has a pair of upwardly projecting support bars 4 on it which have a series of notches 5 therein. These support bars 4 engage and support an adjustable platform 6 on which the jack 7 actually rests when in use, it being possible to situate this at different heights as the lift progresses by having detents 8 on it which are disposed to engage the notches 5.
The member 2 is moved upwardly by the jack as the member is guided on the support bars 4 and has a bridge 9 which is engaged by the ram 10 of the jack 7. The member 2 has detents 11 associated therewith in such a way that the removable base plate can first be positioned and the load then lifted by operating the jack to raise the bridge 9 which engages the load, and the member 2 and bridge will then lock in position allowing the jack to be retracted and removed, whereupon the load will be supported by the bridge 9 on the member 2.
The first position prior to lift is shown in FIG. 1 and the position to which the load is lifted is shown in FIG. 2. The load will then be supported by the telescopic members 1 and 2, the detents 11 engaging the nearest of the notches 5 as the lift is released from the jack 7, the piston 10 of the jack being then retracted.
If the load is to be lifted to a new height the platform 6 is raised to the position shown in FIG. 3 and the jack with the piston lowered is placed on the platform 6 and when the jack is activated, the ram 10 will be extended to move the bridge 9 to the position shown in FIG. 4 where it will be held by the detents 11 engaging appropriate notches 5 in the support bars 4.
The ram 10 of the jack 7 can then be retracted and the load will be supported at the new level while the jack may be removed and used for other purposes such as with a further jack support.
Springs 15 pull the platform 6 toward the frame 2 so that unless prevented by the jack the platform 6 will be pulled against the bottom of the frame 2 in readiness for the next lift.
The detents 8 and 11 are provided with release means which pull them inwards to allow the platform 6 and the members 2 to be lowered when required.
Referring now particularly to FIGS. 5, 6, 7 and 8 it will be seen that the platform 3 has a guide frame 20 extending part-way around the support bars 4 which are of circular cross-section with the notches 5 extending around same, the detents 8 being positioned beneath the guide frame 20 so that the load is transferred from the platform 6 directly to the detents. The detents are connected to a release lever 21 which pulls them out of engagement with the support bars 4 when the platform is lowered. The posts 22 are merely added guides for the platform 6 which has a reinforcing frame 24 beneath it.
The guide frame 20 also has the lower ends of the springs 15 attached to it through rods 25, the upper ends of the springs engaging brackets 26 on the bridge 9.
The bridge 9 has a depending member 27 on it which engages the ram of the jack and if a jack of different size to that for which the frame is designed is used, this member 27 can be replaced by a member of different length.
The detents 11 are each formed by a split tubular member 30 which has the two halves of the member engaged in collars 31 on the member 2, each member 2 being of tubular form to encircle the support bars 4 and be guided thereby. The lower ends of the two parts of the tube 2 are turned in to form the actual engaging part of the detents 11 and the two parts are loaded into locking position by a spring circlip 32 but can be moved to swing the lower ends of the detents out to disengage from the notches of the support bars 4, a lever 34 with a cam 35 engaged between the two members of the split tubular member 30, thus allowing the detents to be released from the notched support bars 4.
In FIG. 8 is shown how a lower lift point can be achieved by using a fork member 37 having a foot 38 and a part 39 which engages over the bridge 9.
If a higher lift is required the device can be extended to its full height and the load taken on a support and the device can itself then be placed in a support to continue the lift.
The device thus comprises a first member 1 with a base 3 which is adapted to contact the ground and has upstanding support members 4 and a second member 2 which is telescopically movable on the first member but is lifted by the jack 7 resting on a platform 6 engaging the first member so that the telescopic portion can be given a series of lifts by appropriately repositioning the removable base plate each time the jack has completed a lift.
With the use of such a device the jack merely forms the operating means for the device so that the telescopic section can first be retracted to its minimum height and the jack then inserted to rest on the platform and when actuated lifts the telescopic portion for the first lift, after which the telescopic section is locked in that position and the jack can have the ram 10 retracted and the removable platform 6 raised for the second stage lift and so on until the required height has been reached.
Such a device also has the advantage that a number of these relatively simple jack support devices can be supplied with a single jack as once the telescopic member has been extended to lift a load, it will remain locked in position and the jack can be removed and associated with a second jack support which can then effect the required lift, and so on, thus enabling a single lifting jack to be used with a number of telescopic jack support members which will support the load at the height to which it was raised.
To lower the device it is only necessary to insert the jack 7 into the device and to disengage the detents after the weight has been taken by the jack, and to then lower the telescopic section by a required amount, whereupon the spring loaded detents of the telescopic section are again engaged to allow the base plate 6 to be lowered to its next position.
Instead of forming the jack support as illustrated it may comprise a tubular inner member attached to the base plate with grooves cut through the sides and open to the front to receive the jack. Over the outside is another tubular member open in front slidable with spring loaded wedges at the lower end. The platform inside the jack stand could be slidable in the inner member using spring loaded wedges and using the same grooves as the outer member. The platform could be spring loaded so that when released it would pull the platform up to reposition the jack.
Any form of jack may be used.
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A hydraulic jack support having a pair of telescopic members, one being a base and the other a bridge movable on the base, and an adjustable platform for supporting a jack engaging the base but adjustable thereon in height whereby the lifting jack is positioned on to the platform to lift the bridge in relation to the said platform and whereby the said platform can be raised for a multi-stage lift.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 10/827,141 filed Apr. 19, 2004, now U.S. Pat. No. 7,160,470 is a continuation-in-part of application Ser. No. 11/522,858 filed Sep. 18, 2006 now U.S. Pat. No. 7,291,275 and also claims priority from Provisional Application Ser. No. 60/833,968 filed Jul. 28, 2006.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
REFERENCE TO A MICROFICHE APPENDIX
Not Applicable.
TECHNICAL FIELD
This invention is directed to methods of clarifying industrial wastewater, specifically those wastewaters containing, soluble and insoluble organic compounds from a variety of sources including but not limited to industrial laundries, food manufacturing and processing, printing, and those industries where any organic matter is present in a wastewater matrix.
BACKGROUND OF THE INVENTION
In the industrial wastewater treatment field of solids/liquid separation, suspended and emulsified solids are removed from water by a variety of processes, including sedimentation, straining, flotation, filtration, coagulation, flocculation, and emulsion breaking among others. Additionally, after solids are removed from the wastewater they must often be dewatered. Liquids treated for solids removal often have as little as several parts per million (ppm) of soluble organic matter, or may contain several thousand ppm soluble organic matter. Solids being generated as sludge may contain anywhere from 0.1 to 6 weight percent solids prior to dewatering, and from 20 to 50 weight percent solids material after dewatering by a plate and frame press. Solids/liquid separation processes are designed to remove solids from liquids and the more solids generated in the process, the more costly its disposal.
While strictly mechanical means have been used to effect solids/liquid separation, the modern methods often rely on mechanical separation techniques that are augmented by synthetic and natural polymeric materials to accelerate the rate at which solids can be removed from water. These processes include the treatment of wastewater with cationic organic and inorganic coagulants that coagulate suspended particulates to form larger particles that then may be brought together by an anionic flocculent to create particles large enough to be removed from the waste stream by mechanical means, i.e., flotation or clarification. These methods have marginal success in the removal of soluble organic matter in the form of biochemical oxygen demand, semi-volatiles or volatile organic compounds without the addition of downstream treatment facilities or filters specifically designed for such removal to make the effluent suitable for industrial reuse or disposal in compliance with local permit discharge requirements.
In the industrial wastewater, the chemical treatment of wastewater to a typical municipal standard of 250 to 300 ppm of biochemical oxygen demand (BOD), (EPA method 304.5), 300 to 1200 chemical oxygen demand (COD), and the reduction of volatile and semi-volatile (henceforth called volatiles) compounds either individually or as an aggregate amount to the level of federal, state or local standards prior to the introduction of this invention has been: the hydraulic equalization of untreated wastewater followed by the metered flow of the wastewater through a pipe or tanks to provide for retention time for the injection of a variety of chemicals including combinations and individually, both organic and inorganic coagulants and aids, followed by an organic component flocculent to produce coagulation and flocculation. However after treatment by the above methods in streams containing sufficient amounts of influent BOD, COD and volatiles, treatment methods at times have not been sufficiently adequate to reduce these agents to acceptable discharge standards by either a surchargable or absolute standards.
Chemical treatment generally refers to the removal of non-settleable material by coagulation and flocculation. Chemical treatment for wastewater clarification is typically employed when colloidal and micro emulsified solids need to be removed so that the total petroleum hydrocarbons (TPH), fat, oil and grease (FOG), (BOD), (COD), volatiles total suspended solids (TSS), and other contaminants being discharged to a receiving stream need to be minimized. Typically, such treatment comprises using a cationic coagulant with one or more inorganic components, injected in combination or individually, followed by an anionic flocculent. Coagulation is the process of destabilization of the colloid waste particle by causing the coagulant (at 50-1000 ppm) to absorb by means of charge neutralization to form microfloc and impart residual cationic surface charge of the coagulated particles. The second step is to introduce a coagulant aid, i.e., ferric chloride, aluminum sulfate, ferrous sulfate, calcium chloride, polyaluminum chloride, typically at a rate of 75-700 ppm depending on the species, to increase the ability to form a more highly cationic surface that will cause the further adsorption of the coagulated particles onto the surface of an additional chemical, usually bentonite clay, at 200-900 ppm through a “sponge” effect. Flocculation occurs when the highly charged anionic flocculent bridges the previously formed cationic particles. Once neutralized, particles no longer repel each other and can come together to form larger agglomerated solids or sludge, which may then be removed from the water.
Clarification chemicals are typically utilized in conjunction with mechanical clarifiers including dissolved air flotation systems (DAF's) induced air flotation systems (IAFs), and settlers for the removal of solids from the treated water. The clarification chemicals coagulate and/or flocculate the suspended solids into larger particles, which can then be removed from the water by gravitational settling, flotation, or other mechanical means.
Processes for the preparation of high molecular weight cationic dispersion polymer flocculants are described in U.S. Pat. Nos. 5,006,590 and 4,929,655. High molecular weight, high active polymer cationic solution polymers for water clarification, dewatering and retention and drainage are disclosed in U.S. Pat. No. 6,171,505.
BRIEF SUMMARY OF THE INVENTION
The invention is directed to methods of clarifying industrial wastewater, specifically industrial laundry wastewater, to produce a compliant effluent reductions of COD, BOD and volatiles heretofore unrealized with only chemical treatment using a two part system of wastewater coagulants (blended and non-blended pDADMAC, polyamine or starch based coagulants) followed by a poly(acrylamide-co-acrylate) flocculent. Furthermore, the sludge produced using this invention will dewater in a typical plate and frame press, belt press or vacuum filter with or without the use of any other organic or inorganic compounds added to the waste stream or sludge. The use of substances such as slurried bentonite clay, ferric chloride or other stand alone metal salts can be used as a coagulant aids without departing from this invention.
This invention pertains to the use of a cationic aqueous coagulant solutions containing polydiallydimethylammonium chloride (pDADMAC), poly quaternary amine (poly amine), or starch based organic polymers non blended or blended with either each other or inorganic metal salts including but not limited to ferric chloride, ferrous sulfate, aluminum sulfate, aluminum chlorohydrate (also known by other names i.e. ACH, also known as partially neutralized polyaluminum chloride) and poly aluminum chloride. These inorganic metal salts may also be introduced into the wastewater matrix separately from the coagulants. These coagulants and metal salts are used to produce, in the chemical demulsification of industrial wastewater, cationic charged particles.
In accord with this invention powdered activated carbon (herein PAC) is also mixed in the coagulant solution. The PAC is utilized in the treatment of the wastewater to further treat in situ the wastewater for BOD, COD and volatile compound removal. The PAC does not interfere with the primary reaction created by the coagulants and metal salts for the primary treatment of the industrial wastewater. The PAC reacts with the BOD, COD, and volatile compounds remaining after the first microflocculation. It is the properties of PAC that permit it to reduce these pollutants through secondary absorption reaction with organic compounds.
Once these particles are created and the wastewater is initially cleaned in a charge neutralization and absorption reaction by the coagulants with or without the metal salts and the secondary removal is created by the PAC premixed in the coagulant solution, the wastewater is cleaned using a low to high molecular weight low to very highly charged cationic solution coagulant (polymer) premixed with an inorganic aluminum species as one product, followed by a low to very high molecular weight anionic flocculent, i.e., poly(acrylamide-co-acrylate), (also known herein as sodium acrylate flocculent) with a 5% charge or higher (preferably 50% or higher), added in solution to produce particulate of sufficient size to be removed by physical means. The wastewaters, to which this invention is directed, may be produced by the food, ink & printing, pulp and paper processing industries along with the industrial cleaning of products, including but not limited to: uniforms, shop towels, ink towels, mats, rugs, bar mops, aprons, coveralls and coats, used to protect personnel from manufacturing or commercial wastes.
The creation of the wastewater stream can be through the use of all available commercial equipment that is used by the above industries. These streams must then be collected in such a way as to promote the batch collection or intermittent or continuous flow of the stream. This collection of wastewater then may be further treated by batch or flow proportion as to allow for the injection and mixing of treatment chemicals by primary coagulation and flocculation only. This invention cleans the wastewater and increases the ability of the coagulant solution to remove BOD, COD and semi-volatile compounds by as much as 300% (depending on the analyte of concern). Furthermore, at the proper doses, this invention allows the sludge to be dewatered in equipment pertinent to this function with or without coagulant aids heretofore mentioned for improving dewatering characteristics
The specific invention herein relates to the wastewater batch, or the in-stream use of the coagulant polymers (non-blended or blended with each other or metal salts) with PAC (blended coagulant with PAC which may be called a paculant) mixed directly into the coagulant solution as a finished product ready for field distribution. The field use paculant is injected into the wastewater stream in a diluted or an undiluted form, at any point prior to the sodium acrylate acrylamide flocculent injection with approximately ten (10) seconds interval (or more) between the injections. The paculant must be injected in the correct empirical quantity and given a sufficient predetermined time to begin and complete the microcoagulation of the waste particles, during the time the highly water miscible coagulant is “washed off” the PAC particle in the coagulant solution. The reaction time necessary for this to be accomplished varies depending on the various types of wastewater streams being treated, and also may be accomplished by the strength and/or dilution of coagulant solution by water. The PAC is then left in a state able to absorb remaining amounts of organic pollutant as to be of a reduction of these pollutants in the treated wastewater effluent. This reaction needs at least two (2) seconds and the flocculent must be injected in the correct empirical quantity and given sufficient time to begin and complete the flocculation of the coagulated particles prior to dewatering. The paculant and flocculent must be injected in sufficient quantity to create the appropriate conditions in the sludge that allow for the dewatering of the sludge generated by this process. These injection or dosing ratios are critical to the overall performance of the invention.
The liquid, emulsified, or dry anionic flocculent is made into any solution strength (commonly between 0.05-0.5%, 0.2% being preferred), and injected post coagulant by at least a two (2) second interval (10 seconds being preferred) and in sufficient empirical quantities as to cause coagulated wastewater to form flocculated waste particles of sufficient size to settle in clarification or rise by flotation, as by dissolved/induced air or other means.
The combination of the paculant and the flocculent in the wastewater stream produces an effluent that has been demonstrated to reduce organic compounds as much 300% from typical treatment schemes depending on the analyte of concern. The process testing of this invention has shown these reductions to be typical of the specific application of the invention disclosed herein.
The flocculants of this invention must be of sufficient charge density, molecular weight and added in sufficient quantities, as to aid in all dewatering mechanisms, typically being a plate and frame press often found in typical plants.
BRIEF DESCRIPTION OF THE DRAWING
The novel features which are believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawing, which illustrates schematically an industrial laundry wastewater treatment system embodying features of this invention.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the present invention, methods are provided for removing contaminants from an aqueous solution.
Methods are provided for removing: surfactants, phenolics, total petroleum hydrocarbons, fats oil and grease, TSS contributors, BOD contributors, COD contributors, TOC contributors, and organic soluble material from an aqueous solution. The surfactants, phenolics, total petroleum hydrocarbons, fats, oil and grease (FOG), TSS contributors, BOD contributors, COD contributors, and TOC contributors from an aqueous solution are removed by adsorption onto a carrier precipitate which is formed in situ within the aqueous solution. In each of the embodiments of the invention the preferred method involves rapidly forming the precipitate.
The method of the invention can be used to remove the following contaminants from the industrial wastewater stream: TSS contributors, BOD contributors, COD contributors, TOC contributors, and/or fats, oil and grease (FOG). The invention will now be described first with respect to FOG, TSS contributors, BOD contributors, COD contributors, and TOC contributors. Unless otherwise stated, all process and apparatus parameters disclosed for FOG removal are equally effective for the removal of the other contaminants as well. Likewise, unless otherwise stated, all process and apparatus parameters disclosed for the removal of the other non-volatile contaminants are equally effective for heavy metal removal as well.
“Coprecipitation” as used with respect to the invention described herein refers to the chemical phenomenon where, within an aqueous solution containing a cationic carrier precipitate precursor, an anionic carrier precipitate precursor, and one or more coprecipitant precursors, the cationic and anionic carrier precipitate precursors are caused to chemically react and precipitate out of the aqueous solution as carrier precipitate particles; and, as the carrier precipitate particles are formed, coprecipitant precursors are removed from the aqueous solution by adsorption onto the surface of the carrier precipitate particle and/or by occlusion within the interior of the carrier precipitate particle.
The coprecipitant reaction is very rapid. Typically, more than 85 weight percent, and usually more than ninety-nine (99) weight percent, of the oil and grease are removed from the waste solution within about 10 seconds after the formation of the agglomerated particle.
Finally, the methods of the invention are superior to conventional precipitation methods in that these methods treat the organic soluble material remaining in the water after the initial microflocculation has taken place. The aqueous polymeric coagulants and metal salts used in creating blends used in the methods of this invention are made by several manufacturers. The PAC used in the methods of this invention is manufactured by several manufacturers. The first chemical used in the invention is mixed in controlled conditions with a percent by weight of PAC ranging from 0.5% to 25%.
By accepted definition, powdered activated carbon is activated carbon that is smaller than 80 mesh. Representative sizes for the activated carbons sold include 50-60% 200 mesh to 600 mesh, 60% less than 325 mesh, and 90% less than 325 mesh. Though even finer grinds can be used, its source can be any of the materials used to make activated carbon-wood, sawdust, bituminous and sub bituminous coals, anthracite, coconuts, lignite, peat, or petroleum stocks. The characteristics of the activated carbon are the direct result of the type of material used. The majority of powdered carbons sold in the world are those derived from wood, lignite, and coals. On the basis of the source for the activated carbon, the carbons are made into powder and will vary according to their density, ash content, pore volume distributions, and adsorptive properties, representative of their total surface areas. For this invention one such property of the carbon is the iodine number, which measures surface area and pores less than 28 angstroms in size, and it is used to grade carbons used in the water field. Another such property is the molasses number, which is a measure of macroporosity and the availability of transport pores. The materials used to make the powder can also be acid washed to lessen their ash content prior to grinding. Acid washed materials generally show a slight increase in apparent density, and a lessening of their iodine number of between 50 and 100 points. For the purpose of this invention the PAC used may have the characteristic properties of being both water-soluble and non-water soluble.
The size of the pores on the PAC allow it to be placed in the coagulant mixture without the coagulant being absorbed in a quantity to render the PAC ineffective in the absorption of soluble organic material remaining after reaction. The larger size organic molecules (>1000 angstroms) of the coagulant are too large in size to fill the pores of the PAC particles. This then allows the PAC particle to remain in suspension in the primary coagulant mixture without significant change of the PAC soluble organic reduction properties.
This completed PAC and coagulant mixture or paculant is injected into the waste stream in empirical quantities of typically 50-700 parts per million (ppm), depending primarily on stream flow rate, mix times, or strength, to cause the coagulation of negatively charged waste particles. The characteristic of water-soluble coagulants to disperse within an aqueous solution rapidly causes release of the surrounded PAC particle by allowing it to be “washed” of coagulant by the surrounding wastewater. As the pore sites on the PAC become available, these sites then are able to become the locations at which soluble organic compounds are then attached.
The resulting coagulated particle then has sufficient mass and residual cationic charge to react with the subsequent addition of the pre-described, water dispersed anionic flocculent to create an agglomerated particle of sufficient size for removal by mechanical means. It is during the step of flocculation that the pollutant laden PAC particle is caught in a sweep reaction during this agglomeration. The flocculent is injected into the waste stream after a predetermined time to permit the cationic blend to substantially complete the coagulation of the particles by at least two (2) seconds after the injection of the coagulant blend in empirical quantities of 1-50 ppm. The time interval for the coagulant to sufficiently absorb the waste particles prior to injection of the flocculent must be no less than two (2) seconds but longer time may be required. Sufficient passive or active mechanical action must take place between the wastewater and the coagulant to allow the intimate commingling of the waste particles with the coagulant prior to addition to the flocculent.
The anionic flocculent must be of a molecular weight, as termed in the industry, low to “very high” and of a charge density of no less than five percent (5%) and up to 100% but usually around fifty percent (50%). Again depending on wastewater stream strength the preferred range of 7-30 ppm of flocculent is needed to flocculate the coagulated particles to a level where the additional use of other coagulant aids and/or dewatering aids is not necessary, but may be used if desired.
Using this invention has shown to aid in the reduction of soluble organic compounds by as much as 300% depending of the analyte of concern.
The following examples are set forth to illustrate this invention and render same more understandable but are not intended to limit the scope of the herein disclosed and claimed invention.
EXAMPLE ONE
Laundry plant #1 has a daily average water usage of 65,000 gallons per day with 50% of the input product being shop towels, mats, ink wipers and other heavy soils. The prior existing program being used for industrial pretreatment was a poly (diallydimethylammonium chloride) mixed with aluminum chlorohydrate solution with a dose rate of 200-500 ppm residence time for each chemical being 15-20 seconds at 125 gpm flow. This created coagulated particles that were then flocculated with a 0.2% polyacrylate flocculent at 6-8 ppm to produce particles able to be floated through mechanical means. The plate and frame press produced dewatered sludge cakes amounting to 60 cubic feet per day. Typical BOD results from effluent analysis ranged from 450 ppm to over 2000 mg/l.
The method of this invention was used to replace the prior existing program with a dose rate of 200-400 ppm of paculant [PAC and a poly (diallydimethylammonium chloride) mixed with aluminum chlorohydrate solution being the primary coagulant] using a mix time of approximately 20 seconds, and the application of the flocculent at 20-30 ppm using a mix time of approximately 40 seconds, resulting in floc that was floated through mechanical means.
Effluent COD analysis showed that during operation effluent COD ranged from >150 to 295 mg/l. No change in the amount of sludge generated was seen nor degradation in other effluent quality parameters.
EXAMPLE TWO
Laundry plant #2 with a daily average water usage of 80,000 gallons per day with 40% of the input product being shop towels, mats, ink wipers and other heavy soils. The prior existing program being used for industrial pretreatment was a poly (diallydimethylammonium chloride) mixed with aluminum chlorohydrate solution with a dose rate of 200-700 ppm residence time for each chemical was approximately six minutes for the first chemical and 10 seconds for the second chemical at 60 gpm flow. This created coagulated particles that were then flocculated with a “wetted” 0.2% polyacrylate flocculent at 6-8 ppm to produce particles able to be floated through mechanical means. Typical COD results from effluent analysis ranged from 800ppm to over 2000 mg/l.
The method of this invention was used to replace the then existing program with a dose rate of 200-700 ppm of paculant using a mix time of approximately six minutes, and the application of the flocculent at 20-30 ppm using a mix time of approximately 40 seconds, resulting in floc that was floated through mechanical means.
Effluent COD analysis showed that during operation effluent COD ranged from >150 to 295 mg/l. No change in the amount of sludge generated was seen nor degradation in other effluent quality parameters.
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A method is provided for clarifying wastewater containing contaminants including soluble organic compounds and insoluble organic compounds. The wastewater is treated with a paculant admixture including a cationic coagulant polymer and powdered activated carbon. The cationic coagulant polymer is polydiallydimethylammonium chloride, poly quaternary amine, and/or a starch-based organic polymer. After an at least 2 second delay, a flocculent is added to the wastewater to achieve (i) microcoagulation of the cationic coagulant polymer with the contaminants to form coagulated particles having an effective mass and cationic charge to react with an anionic flocculent to be added thereafter, and (ii) absorption of the soluble organic compounds on the powdered activated carbon. The anionic flocculent as added and reacted with the coagulated particles to form a sludge, containing agglomerated particles including the coagulated particles and powdered activated carbon, of sufficient size for mechanical removal. The sludge is removed to provide clarified wastewater.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to the cell configuration and fabrication process of Power MOSFET devices. More particularly, this invention relates to a novel and improved trench MOSFET cell structure, and improved process of fabricating a trench MOSFET with shallow trench structures.
[0003] 2. The Prior Arts
[0004] In order to resolve restrict of high gate charge introduced in trench MOSFET of conventional configurations, shallow trench structure was disclosed by decreasing trench depth, please refer to FIG. 1A for an N-channel trench MOSFET of prior art. However, when etching the shallow trench during fabrication process, the trenched gate contact 109 into shallow trenched gate may penetrate through gate oxide and short to drain because the Cdpoly (trenched gate contact depth, as shown in FIG. 1A ) is about 1.5 times deeper than Cdsi (trenched source-body contact depth into epitaxial layer, as shown in FIG. 1A ) as the result of faster etching rate in doped poly than in silicon region.
[0005] Another disadvantage of prior art is that, as illustrated in FIG. 2 (the upper curve), to prevent the increase of Rds (Resistance between Drain and Source), a difference between Td (Trench Depth, FIG. 1A ) and Pd (P body depth, FIG. 1A ) must be kept larger than 0.4 μm, thus forming a large overlap region between gate and epitaxial layer, therefore greatly increasing Qgd (gate to drain charge, FIG. 1A ).
[0006] To further reduce Qgd, a trench MOSFET with thick bottom oxide of prior art (U.S. Pat. No. 5,126,807) was disclosed, as shown in FIG. 1B . However, according to the prior art, the thick bottom oxide 129 is formed by LOCOS (Local Oxidation of Silicon underneath trench bottom) having a bird's beak region 131 with nitride layer 130 on the sidewalls, resulting in deterioration of breakdown voltage as result of weak corner oxide formed in trench bottom.
[0007] Accordingly, it would be desirable to provide a novel trench MOSFET with shallow trench structure and improved fabrication process to maintain lower Rds, lower Qgd and higher breakdown voltage.
SUMMARY OF THE INVENTION
[0008] It is therefore an object of the present invention to provide new and improved power MOSFET with shallow trench structure and fabrication process to resolve the problems mentioned above.
[0009] One aspect of the present invention is that, an additional ion implantation region with the same conductivity doping type as epitaxial layer and higher concentration is formed wrapping the shallow trenched gate bottoms to achieve lower Rds. Please refer to FIG. 2 again for two different simulated relationship of an N-channel trench MOSFET, from which we can see that, the Rds of said N-channel trench MOSFET is significantly reduced with introduction of As ion implantation underneath shallow trenched gate bottoms. In FIG. 3 , the dashed line represents the concentration along channel region of said N-channel trench MOSFET, indicating that the concentration of said As ion implantation (n* area) of said N-channel trench MOSFET is heavier than that of the epitaxial layer.
[0010] Another aspect of the present invention is that, shallow trenched gates are formed with thick bottom insulation layer, for example, with thick bottom oxide by oxidizing un-doped poly silicon (deposited at 650° C. or above) or amorphous silicon (deposited below 650° C.) on top of gate oxide at trench bottom. By employing this structure, the Qgd of the trench MOSFET can be further reduced without having degradation of breakdown voltage due to the bird's beak effect of the prior art.
[0011] Another aspect of the present invention is that, in fabrication process, source-body contact trenches and gate contact trenches are defined by two different contact masks to avoid over-etching issue which happens when using single contact mask for source-body contact trenches and gate contact trenches, thus preventing the gate/drain shortage from happening.
[0012] Another aspect of the present invention is that, in some preferred embodiment, when carrying out the ion implantation for said additional ion implantation region wrapping the shallow trenched gates bottoms, a hard mask is used to block said ion implantation in termination area to avoid degradation of breakdown voltage.
[0013] Another aspect of the present invention is that, in some preferred embodiment, a guard ring ion implantation with dose less than body region ion implantation is added in termination area to further avoid the degradation of breakdown voltage.
[0014] Briefly, in a preferred embodiment, as shown in FIG. 4 , the present invention discloses a shallow trench MOSFET with trench bottom wrapped by additional heavier doping concentration than epitaxial layer. Said shallow trench MOSFET is formed on a heavily doped substrate of a first conductivity doping type onto which a lightly doped epitaxial layer of a same first conductivity doping type is grown. A plurality of shallow trenched gates and at least a wider shallow trenched gate for gate connection are formed within said epitaxial layer and filled with doped poly wherein padded by a first insulation layer, for example, gate oxide layer. Especially, oxide layer on trench bottom portion is thicker than that along trench sidewalls to further reduce Qgd. Around the bottom of each shallow trenched gate, a doped region of said first conductivity doping type is formed within said epitaxial layer, furthermore, said doped region has a heavier doping concentration than said epitaxial layer. Between every two adjacent shallow trenched gates, body regions of a second conductivity doping type are formed below source region heavily doped with said first conductivity doping type. Through a second insulation layer deposited over said epitaxial layer, trenched source-body contacts are formed by penetrating said source region and extending into said body region to connect said body region, said source region to source metal, while at least a trenched gate contact is formed extending into said wider shallow trenched gate to connect said wider shallow trenched gate to gate metal. Underneath the bottom of each said trenched source-body contact, a body contact region is formed heavily doped with said second conductivity doping type to further reduce contact resistance. At the same time, said gate metal is serving as metal field plate for termination area which is beyond body region and overlap the epitaxial layer surface ranging from 2 to 10 um.
[0015] Briefly, in another preferred embodiment, as shown in FIG. 5 , the invention discloses a shallow trench MOSFET similar to that in FIG. 4 except that, in FIG. 5 , the termination area has trench bottom ion implantation dopant region near the top surface, and the metal field plate is beyond body and overlap the epitaxial layer surface ranging from 2 to 10 um, which can alleviate the BV degradation caused by said trench bottom ion implantation on top surface of epitaxial layer in termination area.
[0016] Briefly, in another preferred embodiment, as shown in FIG. 6 , the invention discloses a shallow trench MOSFET similar to that in FIG. 5 except that, the termination area in FIG. 6 has a guard ring which is lightly doped with said second conductivity doping type between said body region and said trench bottom ion implantation dopant region underneath said metal field plate.
[0017] This invention further comprises method for making trench MOSFET with shallow trench structures with thick trench bottom wherein the method further comprising: depositing a first insulation layer along the inner surface of shallow gate trenches and the top surface of said epitaxial layer; depositing a layer of un-doped poly or amorphous silicon onto said first insulation layer; depositing a layer of nitride onto said un-doped poly or amorphous silicon and carrying out nitride anisotropic etch to leave said nitride only on sidewalls of said shallow gate trenches; oxidizing said un-doped poly or amorphous silicon on bottom of said shallow gate trenches and the top surface of said epitaxial layer. In some preferred embodiment, the method further comprises method for making guard ring after the formation of said shallow trenched gates and before applying body mask for the formation of body region. In some preferred embodiment, the method further comprises method for making trench bottom ion implantation region only around the bottom of each shallow trenched gate by applying a hard mask before the formation of shallow trenches and removing after the trench bottom ion implantation. In some preferred embodiment, the method further comprises method for making trench bottom ion implantation region around the bottom of each shallow trenched gate and near the top surface of said epitaxial layer in termination area by applying a hard mask before the formation of shallow trenches and removing before the trench bottom ion implantation.
[0018] These and other objects and advantages of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiment, which is illustrated in the various drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The present invention can be more fully understood by reading the following detailed description of the preferred embodiments, with reference made to the accompanying drawings, wherein:
[0020] FIG. 1A is a side cross-sectional view of a trench MOSFET of prior art.
[0021] FIG. 1B is a side cross-sectional view of a trench MOSFET with thick trench bottom of prior art.
[0022] FIG. 2 is a profile showing the dependence of Rds on difference between trench depth and P body depth in an N-channel MOSFET. The upper curve indicates the condition with no As implantation at the bottom of the trench, while the lower one indicates the condition with heavier As implantation around the bottom of the trench for an N-channel trench MOSFET.
[0023] FIG. 3 is a profile illustrating the doping concentration distributed along channel region from silicon surface in an N-channel MOSFET.
[0024] FIG. 4 is a side cross-sectional view of a shallow trench MOSFET of an embodiment according to the present invention.
[0025] FIG. 5 is a side cross-sectional view of a shallow trench MOSFET of another embodiment according to the present invention.
[0026] FIG. 6 is a side cross-sectional view of a shallow trench MOSFET of another embodiment according to the present invention.
[0027] FIGS. 7A to 7H are a serial of side cross sectional views for showing the processing steps for fabricating a shallow trench MOSFET as shown in FIG. 4 .
[0028] FIGS. 8A to 8B are a serial of side cross sectional views for showing a few processing steps for fabricating a shallow trench MOSFET as shown in FIG. 5 .
[0029] FIG. 9 is a side cross sectional view for showing a few processing steps for fabricating a shallow trench MOSFET as shown in FIG. 6 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0030] Please refer to FIG. 4 for a preferred embodiment of this invention where an N-channel trench MOSFET with shallow trench structures is formed on a heavily N+ doped substrate 200 onto which a lightly N doped epitaxial layer 201 is grown. A plurality of shallow trenched gates are formed within said epitaxial layer and filled with doped poly onto gate oxide 202 to form shallow trenched gates 210 and at least a wider shallow trenched gate 211 for gate connection. What should be noticed is that, oxide layer on the bottom of each of trenched gates 210 and 211 is thicker than that along the sidewalls. Around the bottom of each trenched gate 210 and 211 , an n* is formed with heavier concentration than said epitaxial layer. N+ source region 205 is formed near the top surface of P body region 204 between every two adjacent shallow trenched gates 210 . The shallow trench MOSFET further comprises: trenched source-body contact filled with tungsten plug 208 penetrating through an insulation layer 206 , said source region 205 and extending into said body region 204 ; trenched gate contact filled with tungsten plug 209 penetrating through said insulation layer 206 and extending into doped poly filled in said shallow trenched gate 211 ; p+ body contact region 207 underneath each trenched source-body contact. Source metal 212 is connected to said source region 205 and said body region 204 via said trenched source-body contact metal plug 208 , while gate metal 212 ′ is connected to said shallow trenched gate 211 via said trenched gate contact metal plug 209 , said gate metal also serves as field metal plate for termination area and overlap the epitaxial layer 201 surface ranging from 2 to 10 um.
[0031] FIG. 5 shows another preferred embodiment of the present invention. Compared to FIG. 4 , the termination area in FIG. 5 has additional n* region 203 ′ next to body region 204 near the top surface of said epitaxial layer 201 . Said n* region 203 ′ is formed due to the ion implantation for trench bottom doping region 203 .
[0032] FIG. 6 shows another preferred embodiment of the present invention. Compared to FIG. 5 , the termination area in FIG. 6 has a p− guard ring 214 between n* region 203 ′ and P body region 204 underneath field metal plate which also serving as gate metal 212 ′.
[0033] FIGS. 7A to 7H show a series of exemplary steps that are performed to form the inventive shallow trench MOSFET shown in FIG. 4 . In FIG. 7A , an N doped epitaxial layer 201 is grown on an N+ doped substrate 200 . A hard mask (oxide or oxide/nitride/oxide) is deposited onto said epitaxial layer 201 . Thereafter, a trench mask (not shown) is applied onto said hard mask for the formation of a plurality of shallow gate trenches 210 a and at least a wider shallow gate trench 211 a by a successively hard mask etching, photo-resist removing and dry silicon etching. After all the shallow trenches are opened to a certain depth, in FIG. 7B , a sacrificial oxide (not shown) is grown and then removed to eliminate the plasma damage introduced during opening those shallow gate trenches. Then, a layer of screen oxide is grown for the followed As ion implantation to form n* region 203 underneath each of shallow gate trenches with doping concentration heavier than that of said epitaxial layer 201 to further reduce Rds. Next, in FIG. 7C , after the screen oxide and the hard mask removal, gate oxide 202 a , a layer of un-doped poly or amorphous silicon 202 b and nitride layer 202 c are successively deposited along the front surface of epitaxial layer 201 and the inner surface of said shallow gate trenches 210 a and 211 a . Then, nitride anisotropic etch is carried out to leave said nitride layer 202 c only on the sidewalls of said shallow gate trenches 210 a and 211 a.
[0034] In FIG. 7D , a step of oxidation is performed to oxidizing un-doped poly or amorphous silicon 202 b only on shallow gate trench bottoms and the top surface of said epitaxial layer due to blocking by said nitride layer 202 c on sidewalls of said shallow gate trenches. Thus, the gate oxide layer 202 with thick trench bottom is implemented. In FIG. 7E , after removing said nitride layer 202 c , all trenches are filled with doped poly or combination of doped poly and non-doped poly and followed by poly CMP (Chemical Mechanical Polishing) or plasma etching back to form shallow trenched gates 210 and at least a wider shallow trenched gate 211 for gate connection on which a layer of silicide (not shown) are formed as alternative for low Rg (gate resistance). Then, after applying a body mask, an ion implantation of a second conductivity doping type is carried out to form P-body region 204 . After that, the oxide along the top surface of said epitaxial layer is etched back to 100˜400 Å. Then, the process continues by applying an N+ source mask, and carrying out an ion implantation of said first conductivity doping type and driving in (or no driving in as alternative for shallower source) for the formation of N+ source region 205 near the top surface of said P body region 204 .
[0035] In FIG. 7F , a second insulation layer 206 , for example, oxide layer, is deposited covering the top surface of said epitaxial layer 201 and said shallow trenched gates 210 and said at least a wider shallow trenched gate 211 . Then, by applying a source-body contact mask, a dry oxide etch and dry silicon etch through the second insulation layer and the N+ source region are carried out successively to form source-body contact trenches 208 a into P− body region. In FIG. 7G , after the removal of said source-body contact mask, a gate contact mask is applied and followed by a successively dry oxide etch and dry poly-silicon etch to form gate contact trench 209 a extending into said at least a wider shallow trenched gate 211 . Then, above said second insulation layer 206 , a BF2 ion implantation is carried out to form p+ body contact region 207 underneath each source-body contact trench 208 a and followed by RTA (Rapid Thermal Annealing) to active BF2. In FIG. 7H , a barrier layer of Ti/TiN or Co/TiN or Ta/TiN are deposited along the inner surface of contact trenches and the top surface of said second insulation layer 206 , on which metal W is deposited to fill said contact trenches and then etched back to form trenched source-body contact metal plug 208 and trenched gate contact metal plug 209 . Then, Al alloys padded with a resistance-reduction layer Ti or Ti/TiN is deposited covering the top surface of said second insulation layer 206 , said trenched source-body contact metal plug 208 and said trenched gate contact metal plug 209 and then patterned by a metal mask to form source metal 212 and gate metal 212 ′.
[0036] FIGS. 8A to 8B show a few steps for showing the processing steps for fabricating shallow trench MOSFET in FIG. 5 . In FIG. 8A , an N doped epitaxial layer 201 is grown on an N+ doped substrate 200 . A hard mask (oxide or oxide/Nitride/oxide) is deposited onto said epitaxial layer 201 . Then, a trench mask (not shown) is applied onto said hard mask for the formation of a plurality of shallow gate trenches 210 a and at least a wider shallow gate trench 211 a by a successively hard mask etching, photo-resist removing and dry silicon etching. Thereafter, said hard mask is removed, which is different from process flow of structure in FIG. 4 . Then, a sacrificial oxide (not shown) is grown and then removed to eliminate the plasma damage introduced during opening those shallow gate trenches. Then, a layer of screen oxide is grown for the followed As ion implantation to form n* region 203 underneath each shallow gate trenches and n* region 203 ′ on the top surface of epitaxial layer with doping concentration heavier than that of said epitaxial layer 201 .
[0037] Next, in FIG. 8B , after the screen oxide removal, the process flow is similar to that of structure in FIG. 4 till the formation of metal pad layer. Said n* region 203 ′ is left in termination area due to hard mask removal before screen oxide grown.
[0038] FIG. 9 shows a few steps for fabricating structure in FIG. 6 . Compared to FIG. 8B , after the formation of shallow trenched gates, a guard ring mask is applied to define guard ring and followed by a guard ring ion implantation for the formation of P− guard ring 214 between body region 204 and n* region 203 ′ before applying P− body mask.
[0039] Although the present invention has been described in terms of the presently preferred embodiments, it is to be understood that such disclosure is not to be interpreted as limiting. Various alternations and modifications will no doubt become apparent to those skilled in the art after reading the above disclosure. Accordingly, it is intended that the appended claims be interpreted as covering all alternations and modifications as fall within the true spirit and scope of the invention.
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A method for making trench MOSFET with shallow trench structures with thick trench bottom is disclosed. The improved method resolves the problem of deterioration of breakdown voltage resulted by LOCOS having a bird's beak shape introduced in prior art, and at the same time, the inventive device has a lower Qgd and lower Rds.
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FIELD OF THE INVENTION
[0001] The present invention relates to computer software in general, and, more particularly, to safety-critical systems.
BACKGROUND OF THE INVENTION
[0002] Software systems typically maintain configuration data outside of the source code, as opposed to hard-coded within source code, in order to provide maximum flexibility and extensibility. This approach, however, introduces the risk that configuration data might be corrupted or changed in some other unwanted fashion. Moreover, in a system that supports concurrency, there is the risk that two or more applications, processes, threads, etc. will not have a consistent view of the configuration data.
[0003] In a safety-critical system, configuration data is considered vital, and the foregoing risks are unacceptable. What is needed, therefore, is a mechanism that offers the advantages of maintaining configuration data outside of source code, but that guarantees that (1) no corruption of configuration data occurs prior to initialization, and (2) any change to configuration data that occurs during execution is detected.
SUMMARY OF THE INVENTION
[0004] The present invention provides a mechanism in which a safety-critical system can maintain configuration or other vital data outside of source code, without the potential risks associated with techniques of the prior art. In particular, a data manager software component is employed that serves as an interface between an external configuration data store and one or more applications, processes, and threads of the safety-critical system. In accordance with the illustrative embodiment, the data manager component is an object class that implements the Singleton design pattern, which restricts instantiation of the class to a single object. In accordance with the Singleton pattern, the data manager class has a public method getInstance( ) that provides access to the single object, and a constructor that is declared private, thereby preventing the creation of additional objects from outside the class.
[0005] In accordance with the illustrative embodiment, the data manager class also comprises code for obtaining configuration data from an external eXtensible Markup Language (XML) document, where the code is inaccessible from outside of the class. In addition, the data manager class comprises one or more public methods for accessing values of the configuration data, but lacks any public methods for updating the configuration data.
[0006] The illustrative embodiment comprises: a software component for maintaining one or more configuration data across one or more processes, threads, and applications, the software component comprising: code for obtaining one or more values for the configuration data from outside the software component; one or more public methods for accessing values of the configuration data; and a method that returns a singleton instance of the software component; wherein the code is inaccessible from outside of the software component; and wherein the code is the only means in the software component for obtaining a value for the configuration data; and wherein the software component has no public method for updating a value of the configuration data; and wherein the software component has no public constructor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 depicts a schematic diagram of the salient elements of a safety-critical software system, in accordance with the illustrative embodiment of the present invention.
[0008] FIG. 2 depicts illustrative contents of configuration data store 102 , as shown in FIG. 1 , in accordance with the illustrative embodiment of the present invention.
[0009] FIG. 3 depicts a conceptual representation of application 103 - i during its execution, in accordance with the illustrative embodiment of the present invention.
[0010] FIG. 4 depicts a conceptual representation of process 304 - j during its execution, in accordance with the illustrative embodiment of the present invention.
[0011] FIG. 5 depicts illustrative code for data manager 101 , as shown in FIG. 1 , in accordance with the illustrative embodiment of the present invention.
[0012] FIG. 6 depicts illustrative code for application 103 - i , as shown in FIG. 1 , in accordance with the illustrative embodiment of the present invention.
DETAILED DESCRIPTION
[0013] FIG. 1 depicts a schematic diagram of the salient elements of safety-critical software system 100 , in accordance with the illustrative embodiment of the present invention. As shown in FIG. 1 , software system 100 comprises data manager 101 , configuration data store 102 , and applications 103 - 1 through 103 -N, where N is a positive integer.
[0014] Data manager 101 is a software component that is capable of obtaining configuration data values from configuration data store 102 , and of controlling access to these values, and is described in detail below and with respect to FIG. 5 .
[0015] Configuration data store 102 is one of a database, an unstructured file system, a data structure stored in main memory, etc. that is capable of storing configuration data values. In accordance with the illustrative embodiment, configuration data store 102 stores the configuration data values in an eXtensible Markup Language (XML) document, as is described below and with respect to FIG. 2 .
[0016] Each of applications 103 - 1 through 103 -N, where N is a positive integer, is a computer program that performs a well-defined set of functions in safety-critical system 100 , as is well-known in the art.
[0017] FIG. 2 depicts illustrative contents of configuration data store 102 , in accordance with the illustrative embodiment of the present invention. In the illustrative embodiment, configuration data values are stored in an eXtensible Markup Language (XML) document, a type of document well-known in the art. FIG. 2 depicts illustrative XML document 200 , in which the configuration data are represented as a set of properties and values.
[0018] As will be appreciated by those skilled in the art, in some other embodiments of the present invention, configuration data values might be stored in an alternative fashion in XML document 200 , while in still other embodiments, configuration data values might be stored in a different kind of document or data structure, rather than an XML document. In any case, it will be clear to those skilled in the art, after reading this disclosure, how to make and use such alternative embodiments of the present invention.
[0019] FIG. 3 depicts a conceptual representation of application 103 - i during its execution, where i is an integer between 1 and N inclusive, in accordance with the illustrative embodiment of the present invention. As shown in FIG. 3 , application 103 - i comprises processes 304 - 1 through 304 -M, where M is a positive integer.
[0020] Each process 304 - j , where j is an integer between 1 and M inclusive, is an instance of a computer program that is spawned during the execution of application 103 - i , as is well-known in the art.
[0021] FIG. 4 depicts a conceptual representation of process 304 - j during its execution, where j is an integer between 1 and M inclusive, in accordance with the illustrative embodiment of the present invention. As shown in FIG. 4 , process 304 - j comprises threads 405 - 1 through 405 -P, where P is a positive integer.
[0022] Each thread 405 - k , where k is an integer between 1 and P inclusive, is a thread of execution within process 304 - j , as is well-known in the art.
[0023] FIG. 5 depicts illustrative code for data manager 101 , in accordance with the illustrative embodiment of the present invention. In accordance with the illustrative embodiment, data manager 101 is a single object class called DataManager. As shown in FIG. 5 , class DataManager implements the Singleton design pattern, which restricts instantiation of the class to a single object. In particular, class DataManager has a public method getInstance( ) that provides access to the single object, and restricts external access to the class constructor by declaring it private, thereby preventing the creation of additional objects from outside the class.
[0024] The configuration data values are stored in a property list data structure called configData. Class DataManager has two public methods getConfigValue( ) for accessing the configuration data values: one accepts the datum name as its single input parameter, and the other accepts the datum name and a default value. In addition, class DataManager has a private method loadConfigValues( ) that reads the configuration data values from XML document 200 ; this method is invoked by a static initialization block that is automatically executed when the class is loaded. Because data structure configData is declared private, and because the code for reading the configuration data values is encapsulated in a private method, the configuration data values cannot be directly accessed or changed by any of applications 103 - 1 through 103 -N, processes 304 - 1 through 304 -M, or threads 405 - 1 through 405 -P.
[0025] As will be appreciated by those skilled in the art, in some other embodiments of the present invention, data manager 101 might comprise code that is specified in some other object-oriented programming language (e.g., C#, Smalltalk, etc.), or might comprise a plurality of object classes rather than a single object class, or might in fact be specified in a programming language that is not object-oriented (e.g., C, Perl, etc.). In any case, it will be clear to those skilled in the art, after reading this disclosure, how to make and use such alternative embodiments of data manager 101 .
[0026] FIG. 6 depicts illustrative code for application 103 - i , where i is an integer between 1 and N inclusive, in accordance with the illustrative embodiment of the present invention. As shown in FIG. 6 , the singleton DataManager object is obtained by the public getInstance( ) method, and the configuration data values are obtained by the public getConfigValue( ) methods. As will be appreciated by those skilled in the art, in some embodiments of the present invention, the code depicted in FIG. 6 might belong to one of processes 304 - 1 through 304 -M spawned by application 103 - i , while in some other embodiments, the code of application 103 - i depicted in FIG. 6 might not belong to any of these processes. Moreover, when the code depicted in FIG. 6 does belong to one of processes 304 - 1 through 304 -M (say process 304 - j ), then in some embodiments of the present invention this code might belong to one of threads 405 - 1 through 405 -P, while in some other embodiments, the code of process 304 - j depicted in FIG. 6 might not belong to any of these threads.
[0027] As will be appreciated by those skilled in the art, the specification of safety-critical system 100 as described above and with respect to FIGS. 1 through 6 guarantees that the values of the configuration data will not be corrupted prior to initialization, and that during execution, any corruption or changes to configuration data values are automatically detected. Consequently, safety-critical software system 100 is said to maintain the vitality of the configuration data. As will be further appreciated by those skilled in the art, in some other embodiments of the present invention, the techniques of the illustrative embodiment might be employed for maintaining the vitality of other kinds of data (i.e., data that might not be related to system configuration).
[0028] It is to be understood that the disclosure teaches just one example of the illustrative embodiment and that many variations of the invention can easily be devised by those skilled in the art after reading this disclosure and that the scope of the present invention is to be determined by the following claims.
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A mechanism for maintaining configuration or other vital data outside of source code is disclosed. In accordance with the illustrative embodiment of the present invention, a data manager software component serves as an interface between an external configuration data store and one or more applications, processes, and threads. In contrast with techniques of the prior art, the illustrative embodiment does not suffer from the risk of undetected corruption of vital data, and therefore is especially advantageous in safety-critical systems.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority from Japanese Patent Application No. 2013-065499 filed on Mar. 27, 2013, the entire contents of which are hereby incorporated by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates to a diagnostic device for an actuator which controls hydraulic pressure to be supplied to controlled objects of a transmission provided in a vehicle such as an automobile, and particularly to a diagnostic device which can properly determine fixation of the actuator to a high pressure position or a low pressure position.
[0004] 2. Related Art
[0005] In a transmission such as continuously variable transmission (CVT) to be mounted on a vehicle such as an automobile, hydraulic oil is pressurized by a mechanical hydraulic pump driven by an engine output, then a line hydraulic pressure is regulated within a predetermined range, for example, by a hydraulic control unit having e.g., a solenoid valve, and is supplied to various hydraulic devices which are to be controlled.
[0006] It is demanded to make a proper diagnosis of a failure such as fixation to ON position or OFF position of an actuator for line pressure control of the above-mentioned transmission. For example, Japanese Unexamined Patent Application Publication (JP-A) No. H9-250370 describes a conventional technology related to diagnosis of an actuator for line pressure control, in which a failure of a line pressure control system is determined when a line pressure indication value is other than a maximum value and the line pressure in reality is higher than or equal to the maximum value. In addition, JP-A No. 2004-124960 describes a technology in which a failure of a line pressure control system is determined when a minimum line pressure is indicated at the time of vehicle stop and the line pressure in reality is high.
[0007] However, when a hydraulic pump of a transmission is coordinated, for example, with a crankshaft of an engine, and the driving revolution rate of the hydraulic pump is changing during running of a vehicle, regardless of fixation of a line pressure control valve to a high pressure position or a low pressure position, the line pressure, which has been regulated, increases as the number of revolutions of the engine is increased. Thus, the line pressure is not fixed to a constant value. For this reason, when a failure is diagnosed using a constant threshold value as in the above-described conventional technology, diagnosis may not be properly made.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide a diagnostic device for a hydraulic pressure control actuator, the diagnostic device being capable of properly determining fixation of the actuator to a high pressure position or a low pressure position.
[0009] An aspect of the present invention provides a diagnostic device for a hydraulic pressure control actuator which drives a line pressure control valve to regulate a pressure of hydraulic oil between an upper limit line pressure and a lower limit line pressure, so that the pressure approaches a predetermined target line pressure, the hydraulic oil being discharged by a hydraulic pump which discharges hydraulic oil in an amount according to a driving revolution rate, the diagnostic device including: an actual hydraulic pressure detection unit configured to detect an actual hydraulic pressure after the pressure is regulated by the line pressure control valve; a determination value setting unit configured to set a high pressure fixation determination value which is increased as the driving revolution rate is increased so as to substantially match a characteristic of the hydraulic pressure control actuator at a time of high pressure fixation; and a fixation determination unit configured to determine high pressure fixation of the hydraulic pressure control actuator when the actual hydraulic pressure substantially matches the high pressure fixation determination value with a difference between the target line pressure and the upper limit line pressure higher than or equal to a predetermined value.
[0010] The determination value setting unit may set a low pressure fixation determination value which is increased as the driving revolution rate is increased so as to substantially match a characteristic of the hydraulic pressure control actuator at a time of low pressure fixation, and the fixation determination unit may be configured to determine low pressure fixation of the hydraulic pressure control actuator when the actual hydraulic pressure substantially matches the low pressure fixation determination value with a difference between the target line pressure and the lower limit line pressure higher than or equal to a predetermined value.
[0011] Another aspect of the invention provides a diagnostic device for a hydraulic pressure control actuator which drives a line pressure control valve to regulate a pressure of hydraulic oil between an upper limit line pressure and a lower limit line pressure, so that the pressure approaches a predetermined target line pressure, the hydraulic oil being discharged by a hydraulic pump which discharges hydraulic oil in an amount according to a driving revolution rate, the diagnostic device including: an actual hydraulic pressure detection unit configured to detect an actual hydraulic pressure after the pressure is regulated by the line pressure control valve; a determination value setting unit configured to set a low pressure fixation determination value which is increased as the driving revolution rate is increased so as to substantially match a characteristic of the hydraulic pressure control actuator at a time of low pressure fixation; and a fixation determination unit configured to determine low pressure fixation of the hydraulic pressure control actuator when the actual hydraulic pressure substantially matches the low pressure fixation determination value with a difference between the target line pressure and the lower limit line pressure higher than or equal to a predetermined value.
[0012] The determination value setting unit may correct a determination value such that the determination value is increased as a hydraulic temperature decreases.
[0013] The determination value setting unit may be configured to determine fixation only when an amount of control performed by the hydraulic pressure control actuator, the amount of control being set based on the target line pressure, and an amount of control actually commanded to the hydraulic pressure control actuator are both within a predetermined range.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic diagram illustrating a configuration of a hydraulic control system of a continuously variable transmission, the hydraulic control system including an implementation of a diagnostic device for a hydraulic pressure control actuator according to the present invention;
[0015] FIG. 2 is a graph schematically illustrating an example of correlation between a current value of a hydraulic pressure control actuator (solenoid), an engine revolution rate, and a line hydraulic pressure;
[0016] FIG. 3 is a flow chart illustrating diagnosis of high pressure fixation in the diagnostic device for a hydraulic pressure control actuator in the implementation;
[0017] FIG. 4 is a flow chart illustrating diagnosis of low pressure fixation in the diagnostic device for a hydraulic pressure control actuator in the implementation; and
[0018] FIG. 5 is a graph schematically illustrating an example of correlation between an oil temperature, an engine revolution rate, and a line hydraulic pressure.
DETAILED DESCRIPTION
[0019] An object of the present invention is to provide a diagnostic device for a hydraulic pressure control actuator, the diagnostic device being capable of properly determining fixation of the actuator to a high pressure position or a low pressure position. The present invention achieves the object by setting a determination value which is increased as the driving revolution rate of the hydraulic pump increases, according to the characteristic of line pressure at the time of fixation of the hydraulic pressure control actuator.
[Implementation]
[0020] An implementation of a diagnostic device for a hydraulic pressure control actuator (hereinafter referred to simply as a “diagnostic device”) according to the present invention will be described in the following. The diagnostic device in the implementation makes diagnosis of fixation of a solenoid (hydraulic pressure control actuator) for controlling line pressure to a maximum position and a minimum pressure position, the solenoid being configured to drive a hydraulic control valve which regulates a hydraulic pressure (primary pressure) to a predetermined line pressure (secondary pressure), the hydraulic pressure being discharged by an oil pump of a continuously variable transmission (CVT) which is mounted on a vehicle such as an automobile.
[0021] FIG. 1 is a schematic diagram illustrating a configuration of a hydraulic control system of a continuously variable transmission, the hydraulic control system including a diagnostic device for a hydraulic pressure control actuator in the implementation. As illustrated in FIG. 1 , the continuously variable transmission includes an oil pump 20 driven by an engine 10 , a line pressure control solenoid valve 30 , controlled objects 40 , a line pressure sensor 50 , and a transmission control unit 100 .
[0022] The engine 10 is, for example, an internal combustion engine such as a gasoline engine or a diesel engine which is used as a power source for driving a vehicle. The continuously variable transmission increases or decreases the revolution output of the engine 10 , and transmits the increased or decreased output to a power transmission mechanism which provides a driving force to the driving wheels of the vehicle.
[0023] The oil pump 20 pressurizes the hydraulic oil (CVT fluid) of the continuously variable transmission up to the primary pressure, and discharges the pressurized hydraulic oil. The oil pump 20 is driven to rotate via a chain which connects from a sprocket provided on a crankshaft of the engine 10 to a sprocket provided on an input shaft. For this reason, the driving revolution rate of the oil pump 20 has a predetermined direct proportional relationship with the crankshaft revolution rate of the engine 10 . The oil pump 20 is configured to have a discharge amount and a discharge pressure which increase as the driving revolution rate increases.
[0024] The line pressure control solenoid valve 30 is a pressure regulating valve driven by a solenoid which is a hydraulic pressure control actuator. The line pressure control solenoid valve 30 drains part of hydraulic oil supplied from the oil pump 20 as necessary, thereby regulating the line pressure (secondary pressure) which is supplied to the controlled objects 40 .
[0025] FIG. 2 is a graph schematically illustrating an example of correlation between a current value of the solenoid, an engine revolution rate, and a line hydraulic pressure. When the solenoid is not energized (control current is 0 A), the line pressure control solenoid valve 30 substantially does not drain the hydraulic oil, and the line pressure then is the upper limit of a controllable range. The amount of oil drained by the line pressure control solenoid valve 30 is increased as the control current of the solenoid is increased, thereby reducing the line pressure. For example, when the control current is 1 A, the drained oil has a maximum amount, and the line pressure then is the lower limit of the controllable range.
[0026] As illustrated in FIG. 2 , in any of the values of the control current, the line pressure tends to increase as the engine revolution rate is increased. This demonstrates that even when fixation of the solenoid to a high pressure position (0 A position) or a low pressure position (1 A position) occurs, the line pressure is not constant. Thus, the diagnostic device in the present implementation uses a characteristic as a high pressure fixation determination value, the characteristic corresponding to a line pressure which is slightly lower than the line pressure for the characteristic at the time of 0 A in consideration of a maximum of variation and a degree of margin. In addition, the diagnostic device uses a characteristic as a low pressure fixation determination value, the characteristic corresponding to a line pressure which is slightly higher than the line pressure for the characteristic at the time of 1 A in consideration of a maximum of variation and a degree of margin. In FIG. 2 , a dashed line illustrates the characteristics of the high pressure fixation determination value and the low pressure fixation determination value. The transmission control unit 100 holds the high pressure fixation determination value and the low pressure fixation determination value as a map in a storage device such as a ROM, the map being figured out from the engine revolution rate. The diagnosis using the determination values will be described in detail below.
[0027] The controlled objects 40 are various hydraulic devices which are operated with supplied hydraulic oil having a line pressure regulated by the line pressure control solenoid valve 30 . The controlled objects 40 include, for example, a gear shift control actuator, a forward and backward switching clutch, and a lock-up clutch.
[0028] The line pressure sensor 50 is a hydraulic sensor which measures a line pressure which has been regulated by the line pressure control valve 30 . The output of the line pressure sensor 50 is transmitted to the transmission control unit 100 .
[0029] The transmission control unit 100 performs centralized control over the continuously variable transmission and its auxiliary devices. The transmission control unit 100 includes an information processing device such as a CPU, a storage device such as a RAM or a ROM, an input/output interface, and a bus for connecting these devices. The transmission control unit 100 performs, for example, line pressure control, forward and backward switching control, transmission gear control, and lock-up control.
[0030] The transmission control unit 100 includes a target line pressure calculation unit 110 , an actual line pressure calculation unit 120 , and a feedback control unit 130 . The target line pressure calculation unit 110 calculates a target line pressure based on a running state of the vehicle. The actual line pressure calculation unit 120 calculates a line pressure in reality (actual line pressure) based on an output of the line pressure sensor 50 . The feedback control unit 130 performs feedback control over the line pressure control solenoid valve 30 so that the actual line pressure approaches the target line pressure, based on a difference between the target line pressure calculated by the target line pressure calculation unit 110 and the actual line pressure calculated by the actual line pressure calculation unit 120 .
[0031] The transmission control unit 100 serves also as a diagnostic device which makes diagnosis of high pressure fixation and low pressure fixation of the solenoid of the line pressure control solenoid valve 30 . FIG. 3 is a flow chart illustrating diagnosis of high pressure (0 A) fixation in the diagnostic device for a hydraulic pressure control actuator in the implementation. Hereinafter, description will be given for each step sequentially.
<Step S 01 : Diagnosis Execution Condition Determination>
[0032] The transmission control unit 100 determines whether or not all the following conditions described below are satisfied. When all the conditions are satisfied, the flow proceeds to step S 02 , otherwise when at least one condition is not satisfied, the flow proceeds to step S 03 . The conditions are as described below. These conditions are set in the consideration that risk of making wrong diagnosis is reduced by making no diagnosis in a state where the operational condition of the transmission is transitional, and a command for regulating the pressure to a high pressure is not issued to the line pressure control solenoid valve 30 .
a) Engine revolution rate≧a predetermined value (for example, 1000 rpm). b) Oil temperature≧a predetermined value (for example, 0° C.) c) Line pressure control solenoid target current value≧a predetermined value (for example, 0.5 A). d) Line pressure control solenoid actual current value≧a predetermined value (for example, 0.5 A). Here, the conditions c) and d) indicate that the target line pressure is sufficiently small with respect to the line pressure (0 A) as the upper limit of the controllable range. The condition is set such that the actual current value and the target current value are within the same range, and this is because to prevent making wrong diagnosis which is due to a failure of a current control system which does not actually output the target current value. e) Target line pressure−actual line pressure≦a predetermined value (for example, −0.5 MPa). f) Elapse of a predetermined time (for example, 1 second) with condition that lock-up clutch pressure control solenoid duty≧a predetermined value (for example, 90% or 0%). g) Elapse of a predetermined time (for example, 1 second) with condition that FR clutch pressure control solenoid current value≦a predetermined value (for example, −0.7 A), and |amount of change in FR clutch pressure control solenoid target current value|≦a predetermined value (for example, 0.1 A/s). h) Elapse of a predetermined time (for example, 1 second) with condition that up shift control solenoid duty≦a predetermined value (for example, 30%). i) Elapse of a predetermined time (for example, 1 second) with condition that down shift control solenoid duty≦a predetermined value (for example, 30%). j) Elapse of a predetermined time (for example, 1 second) with condition that |amount of change in target transmission gear ratio|≦a predetermined value (0.3 [1/s]).
<Step S 02 : Diagnostic Execution Condition Satisfied>
[0043] Because the execution condition for diagnosis of high pressure fixation of the line pressure control solenoid valve 30 is satisfied, the operational flow of the transmission control unit 100 proceeds to step S 04 .
<Step S 03 : Diagnostic Execution Condition Not Satisfied>
[0044] Because the execution condition for diagnosis of high pressure fixation of the line pressure control solenoid valve 30 is not satisfied, the transmission control unit 100 terminates (returns) a series of processes.
<Step S 04 : Diagnostic Condition Determination>
[0045] The transmission control unit 100 compares the actual line pressure detected by the line pressure sensor 50 with the above-described high pressure fixation determination value according to the current revolution rate of the engine 10 . When the actual line pressure is higher than or equal to the high pressure fixation determination value (when the actual line pressure is substantially the same as the line pressure characteristic at the time of high pressure fixation), the operational flow proceeds to step S 05 , otherwise, a series of processes is terminated (returned).
<Step S 05 : Failure Determination Flag Set>
[0046] The transmission control unit 100 sets a high pressure fixation failure determination flag for the line pressure control solenoid valve 30 , and a series of processes is terminated (returned).
[0047] FIG. 4 is a flow chart illustrating diagnosis of low pressure (1 A) fixation in the diagnostic device for the hydraulic pressure control actuator in the implementation. Hereinafter, description will be given for each step sequentially.
<Step S 11 : Diagnosis Execution Condition Determination>
[0048] The transmission control unit 100 determines whether or not all the following conditions described below are satisfied. When all the conditions are satisfied, the flow proceeds to step S 12 , otherwise when at least one condition is not satisfied, the flow proceeds to step S 13 . The conditions are as described below. These conditions are set in the consideration that risk of making wrong diagnosis is reduced by making no diagnosis in a state where the operational condition of the transmission is transitional, and a command for regulating the pressure to a low pressure is not issued to the line pressure control solenoid valve 30 .
a) Engine revolution rate≧a predetermined value (for example, 1000 rpm). b) Oil temperature a predetermined value (for example, 0° C.) c) Line pressure control solenoid target current value≦a predetermined value (for example, 0.5 A). d) Line pressure control solenoid actual current value≦a predetermined value (for example, 0.5 A). Here, the conditions c) and d) indicate that the target line pressure is sufficiently large with respect to the line pressure (1 A) as the lower limit of the controllable range. The condition is set such that the actual current value and the target current value are within the same range, and this is because to prevent making wrong diagnosis which is due to a failure of the current control system which does not actually output the target current value. e) Target line pressure−actual line pressure a predetermined value (for example, −0.5 MPa). f) Elapse of a predetermined time (for example, 1 second) with condition that lock-up clutch pressure control solenoid duty≧a predetermined value (for example, 90% or 0%). g) Elapse of a predetermined time (for example, 1 second) with condition that FR clutch pressure control solenoid current value≦a predetermined value (for example, −0.7 A), and |amount of change in FR clutch pressure control solenoid target current value|≦a predetermined value (for example, 0.1 A/s). h) Elapse of a predetermined time (for example, 1 second) with condition that up shift control solenoid duty≦a predetermined value (for example, 30%). i) Elapse of a predetermined time (for example, 1 second) with condition that down shift control solenoid duty≦a predetermined value (for example, 30%). j) Elapse of a predetermined time (for example, 1 second) with condition that |amount of change in target transmission gear ratio|≦a predetermined value (0.3 [1/s]).
<Step S 12 : Diagnostic Execution Condition Satisfied>
[0059] Because the execution condition for diagnosis of low pressure fixation of the line pressure control solenoid valve 30 is satisfied, the operational flow of the transmission control unit 100 proceeds to step S 14 .
<Step S 13 : Diagnostic Execution Condition Not Satisfied>
[0060] Because the execution condition for diagnosis of low pressure fixation of the line pressure control solenoid valve 30 is not satisfied, the transmission control unit 100 terminates (returns) a series of processes.
<Step S 14 : Diagnostic Condition Determination>
[0061] The transmission control unit 100 compares the actual line pressure detected by the line pressure sensor 50 with the above-described low pressure fixation determination value according to the current revolution rate of the engine 10 . When the actual line pressure is lower than or equal to the low pressure fixation determination value (when the actual line pressure is substantially the same as the line pressure characteristic at the time of low pressure fixation), the operational flow proceeds to step S 15 , otherwise, a series of processes is terminated (returned).
<Step S 15 : Failure Determination Flag Set>
[0062] The transmission control unit 100 sets a low pressure fixation failure determination flag for the line pressure control solenoid valve 30 , and a series of processes is terminated (returned).
[0063] The diagnostic device in the implementation corrects the high pressure fixation determination value and the low pressure fixation determination value according to an oil temperature. FIG. 5 is a graph schematically illustrating an example of correlation between the oil temperature, the engine revolution rate, and the line hydraulic pressure. In FIG. 5 , it can be seen that although the control current value of the line pressure control solenoid valve 30 is constant, the line pressure increases as the oil temperature decreases and the viscosity increases accordingly. In the implementation, such an influence of the oil temperature on the line pressure characteristic is taken into consideration, and the high pressure fixation determination value and the low pressure fixation determination value are corrected such that the determination values are increased as the oil temperature decreases. The transmission control units 100 holds the high pressure fixation determination value and the low pressure fixation determination value, for example, as map data base which is read from the engine revolution rate and the oil temperature.
[0064] In the above-described implementation, the following effects can be obtained.
(1) The high pressure fixation determination value is set to be increased as the driving revolution rate increases so as to substantially match the characteristic of the line pressure control solenoid at the time of fixation to 0 A position, and when the actual line pressure is higher than or equal to the high pressure fixation determination value irrespective of the target current value of the line pressure control solenoid being greater than or equal to 0.5A, fixation to 0 A position of the line pressure control solenoid is determined, thereby allowing proper diagnosis to be made even when the actual line pressure is changing according to the driving revolution rate of the hydraulic pump. (2) The low pressure fixation determination value is set to be increased as the driving revolution rate increases so as to substantially match the characteristic of the line pressure control solenoid at the time of fixation to 1 A position, and when the actual line pressure is lower than or equal to the low pressure fixation determination value irrespective of the target current value of the line pressure control solenoid being less than or equal to 0.5A, fixation to 0 A position of the line pressure control solenoid is determined, thereby allowing proper diagnosis to be made even when the actual line pressure is changing according to the driving revolution rate of the hydraulic pump. (3) The high pressure fixation determination value and the low pressure fixation determination value are corrected according to the oil temperature, thus accurate determination can be made by reducing the influence of a change in the viscosity of the hydraulic oil due to a change in the hydraulic temperature. (4) Only when the line pressure control solenoid target current value which is set based on the target line pressure, and the actual line pressure control solenoid current value are both within a predetermined range, determination of fixation is made, and thus wrong diagnosis due to failure of the control system can be prevented.
(Modifications)
[0069] The present invention is not limited to the above-described implementation and various modifications and alterations may be made, and the modified or altered implementation s are also in the technical scope of the present invention. For example, the transmission in the implementation is a chain-type continuously variable transmission which uses a pair of variable pulley and chain as a variator. In addition, the present invention may be applied to a continuously variable transmission having a variator in another type such as a belt variator or a toroidal variator, and to a transmission in another type such as a stepped automatic transmission using a planetary gear set. The transmission in the implementation uses a solenoid as a hydraulic pressure control actuator. Alternatively, an actuator in another type such as a stepping motor may be used. Various types of numerical parameters above are just examples and may be altered as needed.
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A diagnostic device diagnoses a hydraulic pressure control actuator which drives a line pressure control valve to regulate a pressure of hydraulic oil between upper and lower limit line pressures, so that the pressure approaches a predetermined target line pressure. The diagnostic device includes: an actual hydraulic pressure detection unit to detect an actual hydraulic pressure; a determination value setting unit to set a high pressure fixation determination value which is increased as the driving revolution rate is increased so as to substantially match a characteristic of the actuator at a time of high pressure fixation; and a fixation determination unit to determine high pressure fixation of the actuator when the actual hydraulic pressure substantially matches the high pressure fixation determination value with a difference between the target line pressure and the upper limit line pressure not lower than a predetermined value.
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[0001] This application is a continuation of application Ser. No. 09/804,407 filed Mar. 12, 2001, which is a continuation of application Ser. No. 09/535,221 filed Mar. 27, 2000, now U.S. Pat. No. 6,229,276, which is a division-of application Ser. No. 09/161,840 filed Sep. 28, 1998, now U.S. Pat. No. 6,172,475, which are all incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to movable barrier operators for operating movable barriers or doors. More particularly, it relates to garage door operators having improved safety and energy efficiency features.
[0003] Garage door operators have become more sophisticated over the years providing users with increased convenience and security. However, users continue to desire further improvements and new features such as increased energy efficiency, ease of installation, automatic configuration, and aesthetic features, such as quiet, smooth operation.
[0004] In some markets energy costs are significant. Thus energy efficiency options such as lower horsepower motors and user control over the worklight functions are important to garage door operator owners. For example, most garage door operators have a worklight which turns on when the operator is commanded to move the door and shuts off a fixed period of time after the door stops. In the United States, an illumination period of 4½ minutes is considered adequate. In markets outside the United States, 4½ minutes is considered too long. Some garage door operators have special safety features, for example, which enable the worklight whenever the obstacle detection beam is broken by an intruder passing through an open garage door. Some users may wish to disable the worklight in this situation. There is a need for a garage door operator which can be automatically configured for predefined energy saving features, such as worklight shut-off time.
[0005] Some movable barrier operators include a flasher module which causes a small light to flash or blink whenever the barrier is commanded to move. The flasher module provides some warning when the barrier is moving. There is a need for an improved flasher unit which provides even greater warning to the user when the barrier is commanded to move.
[0006] Another feature desired in many markets is a smooth, quiet motor and transmission. Most garage door operators have AC motors because they are less expensive than DC motors. However, AC motors are generally noisier than DC motors.
[0007] Most garage door operators employ only one or two speeds of travel. Single speed operation, i.e., the motor immediately ramps up to full operating speed, can create a jarring start to the door. Then during closing, when the door approaches the floor at full operating speed, whether a DC or AC motor is used, the door closes abruptly with a high amount of tension on it from the inertia of the system. This jarring is hard on the transmission and the door and is annoying to the user.
[0008] If two operating speeds are used, the motor would be started at a slow speed, usually 20 percent of full operating speed, then after a fixed period of time, the motor speed would increase to full operating speed. Similarly, when the door reaches a fixed point above/below the close/open limit, the operator would decrease the motor speed to 20 percent of the maximum operating speed. While this two speed operation may eliminate some of the hard starts and stops, the speed changes can be noisy and do not occur smoothly, causing stress on the transmission. There is a need for a garage door operator which opens the door smoothly and quietly, with no abruptly apparent sign of speed change during operation.
[0009] Garage doors come in many types and sizes and thus different travel speeds are required for them. For example, a one-piece door will be movable through a shorter total travel distance and need to travel slower for safety reasons than a segmented door with a longer total travel distance. To accommodate the two door types, many garage door operators include two sprockets for driving the transmission. At installation, the installer must determine what type of door is to be driven, then select the appropriate sprocket to attach to the transmission. This takes additional time and if the installer is the user, may require several attempts before matching the correct sprocket for the door. There is a need for a garage door operator which automatically configures travel speed depending on size and weight of the door.
[0010] National safety standards dictate that a garage door operator perform a safety reversal (auto-reverse) when an object is detected only one inch above the DOWN limit or floor. To satisfy these safety requirements, most garage door operators include an obstacle detection system, located near the bottom of the door travel. This prevents the door from closing on objects or persons that may be in the door path. Such obstacle detection systems often include an infrared source and detector located on opposite sides of the door frame. The obstacle detector sends a signal when the infrared beam between the source and detector is broken, indicating an obstacle is detected. In response to the obstacle signal, the operator causes an automatic safety reversal. The door stops and begins traveling up, away from the obstacle.
[0011] There are two different “forces” used in the operation of the garage door operator. The first “force” is usually preset or setable at two force levels: the UP force level setting used to determine the speed at which the door travels in the UP direction and the DOWN force level setting used to determine the speed at which the door travels in the DOWN direction. The second “force” is the force level determined by the decrease in motor speed due to an external force applied to the door, i.e., from an obstacle or the floor. This external force level is also preset or setable and is any set-point type force against which the feedback force signal is compared. When the system determines the set point force has been met, an auto-reverse or stop is commanded.
[0012] To overcome differences in door installations, i.e. stickiness and resistance to movement and other varying frictional-type forces, some garage door operators permit the maximum force (the second force) used to drive the speed of travel to be varied manually. This, however, affects the system's auto-reverse operation based on force. The auto-reverse system based on force initiates an auto-reverse if the force on the door exceeds the maximum force setting (the second force) by some predetermined amount. If the user increases the force setting to drive the door through a “sticky” section of travel, the user may inadvertently affect the force to a much greater value than is safe for the unit to operate during normal use. For example, if the DOWN force setting is set so high that it is only a small incremental value less than the force setting which initiates an auto-reverse due to force, this causes the door to engage objects at a higher speed before reaching the auto-reverse force setting. While the obstacle detection system will cause the door to auto-reverse, the speed and force at which the door hits the obstacle may cause harm to the obstacle and/or the door.
[0013] Barrier movement operators should perform a safety reversal off an obstruction which is only marginally higher than the floor, yet still close the door safely against the floor. In operator systems where the door moves at a high speed, the relatively large momentum of the moving parts, including the door, accomplishes complete closure. In systems with a soft closure, where the door speed decreases from full maximum to a small percentage of full maximum when closing, there may be insufficient momentum in the door or system to accomplish a full closure. For example, even if the door is positioned at the floor, there is sometimes sufficient play in the trolley of the operator to allow the door to move if the user were to try to open it. In particular, in systems employing a DC motor, when the DC motor is shut off, it becomes a dynamic brake. If the door isn't quite at the floor when the DOWN travel limit is reached and the DC motor is shut off, the door and associated moving parts may not have sufficient momentum to overcome the braking force of the DC motor. There is a need for a garage door operator which closes the door completely, eliminating play in the door after closure.
[0014] Many garage door operator installations are made to existing garage doors. The amount of force needed to drive the door varies depending on type of door and the quality of the door frame and installation. As a result, some doors are “stickier” than others, requiring greater force to move them through the entire length of travel. If the door is started and stopped using the full operating speed, stickiness is not usually a problem. However, if the garage door operator is capable of operation at two speeds, stickiness becomes a larger problem at the lower speed. In some installations, a force sufficient to run at 20 percent of normal speed is too small to start some doors moving. There is a need for a garage door operator which automatically controls force output and thus start and stop speeds.
SUMMARY OF THE INVENTION
[0015] A movable barrier operator having an electric motor for driving a garage door, a gate or other barrier is operated from a source of AC current. The movable barrier operator includes circuitry for automatically detecting the incoming AC line voltage and frequency of the alternating current. By automatically detecting the incoming AC line voltage and determining the frequency, the operator can automatically configure itself to certain user preferences. This occurs without either the user or the installer having to adjust or program the operator. The movable barrier operator includes a worklight for illuminating its immediate surroundings such as the interior of a garage. The barrier operator senses the power line frequency (typically 50 Hz or 60 Hz) to automatically set an appropriate shut-off time for a worklight. Because the power line frequency in Europe is 50 Hz and in the U.S. is 60 Hz, sensing the power line frequency enables the operator to configure itself for either a European or a U.S. market with no user or installer modifications. For U.S. users, the worklight shut-off time is set to preferably 4½ minutes; for European users, the worklight shut-off time is set to preferably 2½ minutes. Thus, a single barrier movement operator can be sold in two different markets with automatic setup, saving installation time.
[0016] The movable barrier operator of the present invention automatically detects if an optional flasher module is present. If the module is present, when the door is commanded to move, the operator causes the flasher module to operate. With the flasher module present, the operator also delays operation of the motor for a brief period, say one or two seconds. This delay period with the flasher module blinking before door movement provides an added safety feature to users which warns them of impending door travel (e.g. if activated by an unseen transmitter).
[0017] The movable barrier operator of the present invention drives the barrier, which may be a door or a gate, at a variable speed. After motor start, the electric motor reaches a preferred initial speed of 20 percent of the full operating speed. The motor speed then increases slowly in a linearly continuous fashion from 20 percent to 100 percent of full operating speed. This provides a smooth, soft start without jarring the transmission or the door or gate. The motor moves the barrier at maximum speed for the largest portion of its travel, after which the operator slowly decreases speed from 100 percent to 20 percent as the barrier approaches the limit of travel, providing a soft, smooth and quiet stop. A slow, smooth start and stop provides a safer barrier movement operator for the user because there is less momentum to apply an impulse force in the event of an obstruction. In a fast system, relatively high momentum of the door changes to zero at the obstruction before the system can actually detect the obstruction. This leads to the application of a high impulse force. With the system of the invention, a slower stop speed means the system has less momentum to overcome, and therefore a softer, more forgiving force reversal. A slow, smooth start and stop also provide a more aesthetically pleasing effect to the user, and when coupled with a quieter DC motor, a barrier movement operator which operates very quietly.
[0018] The operator includes two relays and a pair of field effect transistors (FETs) for controlling the motor. The relays are used to control direction of travel. The FET's, with phase controlled, pulse width modulation, control start up and speed. Speed is responsive to the duration of the pulses applied to the FETs. A longer pulse causes the FETs to be on longer causing the barrier speed to increase. Shorter pulses result in a slower speed. This provides a very fine ramp control and more gentle starts and stops.
[0019] The movable barrier operator provides for the automatic measurement and calculation of the total distance the door is to travel. The total door travel distance is the distance between the UP and the DOWN limits (which depend on the type of door). The automatic measurement of door travel distance is a measure of the length of the door. Since shorter doors must travel at slower speeds than normal doors (for safety reasons), this enables the operator to automatically adjust the motor speed so the speed of door travel is the same regardless of door size. The total door travel distance in turn determines the maximum speed at which the operator will travel. By determining the total distance traveled, travel speeds can be automatically changed without having to modify the hardware.
[0020] The movable barrier operator provides full door or gate closure, i.e. a firm closure of the door to the floor so that the door is not movable in place after it stops. The operator includes a digital control or processor, specifically a microcontroller which has an internal microprocessor, an internal RAM and an internal ROM and an external EEPROM. The microcontroller executes instructions stored in its internal ROM and provides motor direction control signals to the relays and speed control signals to the FETs. The operator is first operated in a learn mode to store a DOWN limit position for the door. The DOWN limit position of the door is used as an approximation of the location of the floor (or as a minimum reversal point, below which no auto-reverse will occur). When the door reaches the DOWN limit position, the microcontroller causes the electric motor to drive the door past the DOWN limit a small distance, say for one or two inches. This causes the door to close solidly on the floor.
[0021] The operator embodying the present invention provides variable door or gate output speed, i.e., the user can vary the minimum speed at which the motor starts and stops the door. This enables the user to overcome differences in door installations, i.e. stickiness and resistance to movement and other varying functional-type forces. The minimum barrier speeds in the UP and DOWN directions are determined by the user-configured force settings, which are adjusted using UP and DOWN force potentiometers. The force potentiometers set the lengths of the pulses to the FETs, which translate to variable speeds. The user gains a greater force output and a higher minimum starting speed to overcome differences in door installations, i.e. stickiness and resistance to movement and other varying functional-type forces speed, without affecting the maximum speed of travel for the door. The user can configure the door to start at a speed greater than a default value, say 20 percent. This greater start up and slow down speed is transferred to the linearly variable speed function in that instead of traveling at 20 percent speed, increasing to 100 percent speed, then decreasing to 20 percent speed, the door may, for instance, travel at 40 percent speed to 100 percent speed and back down to 40 percent speed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a perspective view of a garage having mounted within it a garage door operator embodying the present invention;
[0023] FIG. 2 is an exploded perspective view of a head unit of the garage door operator shown in FIG. 1 ;
[0024] FIG. 3 is an exploded perspective view of a portion of a transmission unit of the garage door operator shown in FIG. 1 ;
[0025] FIG. 4 is a block diagram of a controller and motor mounted within the head unit of the garage door operator shown in FIG. 1 ;
[0026] FIGS. 5A-5D are a schematic diagram of the controller shown in block format in FIG. 4 ;
[0027] FIGS. 6A-6B are a flow chart of an overall routine that executes in a microprocessor of the controller shown in FIGS. 5A-5D ;
[0028] FIGS. 7A-7H are a flow chart of the main routine executed in the microprocessor;
[0029] FIG. 8 is a flow chart of a set variable light shut-off timer routine executed by the microprocessor;
[0030] FIGS. 9A-9C are a flow chart of a hardware timer interrupt routine executed in the microprocessor;
[0031] FIGS. 10A-10C are a flow chart of a 1 millisecond timer routine executed in the microprocessor;
[0032] FIGS. 11A-11C are a flow chart of a 125 millisecond timer routine executed in the microprocessor;
[0033] FIGS. 12A-12B are a flow chart of a 4 millisecond timer routine executed in the microprocessor;
[0034] FIGS. 13A-13B are a flow chart of an RPM interrupt routine executed in the microprocessor;
[0035] FIG. 14 is a flow chart of a motor state machine routine executed in the microprocessor;
[0036] FIG. 15 is a flow chart of a stop in midtravel routine executed in the microprocessor;
[0037] FIG. 16 is a flow chart of a DOWN position routine executed in the microprocessor;
[0038] FIGS. 17A-17C are a flow chart of an UP direction routine executed in the microprocessor;
[0039] FIG. 18 is a flow chart of an auto-reverse routine executed in the microprocessor;
[0040] FIG. 19 is a flow chart of an UP position routine executed in the microprocessor;
[0041] FIGS. 20A-20D are a flow chart of the DOWN direction routine executed in the microprocessor;
[0042] FIG. 21 is an exploded perspective view of a pass point detector and motor of the operator shown in FIG. 2 ;
[0043] FIG. 22A is a plan view of the pass point detector shown in FIG. 21 ; and
[0044] FIG. 22B is a partial plan view of the pass point detector shown in FIG. 21 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0045] Referring now to the drawings and especially to FIG. 1 , a movable barrier or garage door operator system is generally shown therein and referred to by numeral 8 . The system 8 includes a movable barrier operator or garage door operator 10 having a head unit 12 mounted within a garage 14 . More specifically, the head unit 12 is mounted to a ceiling 15 of the garage 14 . The operator 10 includes a transmission 18 extending from the head unit 12 with a releasable trolley 20 attached. The releasable trolley 20 releasably connects an arm 22 extending to a single panel garage door 24 positioned for movement along a pair of door rails 26 and 28 .
[0046] The system 8 includes a hand-held RF transmitter unit 30 adapted to send signals to an antenna 32 (see FIG. 4 ) positioned on the head unit 12 and coupled to a receiver within the head unit 12 as will appear hereinafter. A switch module 39 is mounted on the head unit 12 . Switch module 39 includes switches for each of the commands available from a remote transmitter or from an optional wall-mounted switch (not shown). Switch module 39 enables an installer to conveniently request the various learn modes during installation of the head unit 12 . The switch module 39 includes a learn switch, a light switch, a lock switch and a command switch, which are described below. Switch module 39 may also include terminals for wiring a pedestrian door state sensor comprising a pair of contacts 13 and 15 for a pedestrian door 11 , as well as wiring for an optional wall switch (not shown).
[0047] The garage door 24 includes the pedestrian door 11 . Contact 13 is mounted to door 24 for contact with contact 15 mounted to pedestrian door 11 . Both contacts 13 and 15 are connected via a wire 17 to head unit 12 . As will be described further below, when the pedestrian door 11 is closed, electrical contact is made between the contacts 13 and 15 closing a pedestrian door circuit in the receiver in head unit 12 and signalling that the pedestriam door state is closed. This circuit must be closed before the receiver will permit other portions of the operator to move the door 24 . If circuit is open, indicating that the pedestrian door state is open, the system will not permit door 24 to move.
[0048] The head unit 12 includes a housing comprising four sections: a bottom section 102 , a front section 106 , a back section 108 and a top section 110 , which are held together by screws 112 as shown in FIG. 2 . Cover 104 fits into front section 106 and provides a cover for a worklight. External AC power is supplied to the operator 10 through a power cord 112 . The AC power is applied to a step-down transformer 120 . An electric motor 118 is selectively energized by rectified AC power and drives a sprocket 125 in sprocket assembly 124 . The sprocket 125 drives chain 144 (see FIG. 3 ). A printed circuit board 114 includes a controller 200 and other electronics for operating the head unit 12 . A cable 116 provides input and output connections on signal paths between the printed circuit board 114 and switch module 39 . The transmission 18 , as shown in FIG. 3 , includes a rail 142 which holds chain 144 within a rail and chain housing 140 and holds the chain in tension to transfer mechanical energy from the motor to the door.
[0049] A block diagram of the controller and motor connections is shown in FIG. 4 . Controller 200 includes an RF receiver 80 , a microprocessor 300 and an EEPROM 302 . RF receiver 80 of controller 200 receives a command to move the door and actuate the motor either from remote transmitter 30 , which transmits an RF signal which is received by antenna 32 , or from a user command switch 250 . User command switch 250 can be a switch on switch panel 39 , mounted on the head unit, or a switch from an optional wall switch. Upon receipt of a door movement command signal from either antenna 32 or user switch 250 , the controller 200 sends a power enable signal via line 240 to AC hot connection 206 which provides AC line current to transformer 212 and power to work light 210 . Rectified AC is provided from rectifier 214 via line 236 to relays 232 and 234 . Depending on the commanded direction of travel, controller 200 provides a signal to either relay 232 or relay 234 . Relays 232 and 234 are used to control the direction of rotation of motor 118 by controlling the direction of current flow through the windings. One relay is used for clockwise rotation; the other is used for counterclockwise rotation.
[0050] Upon receipt of the door movement command signal, controller 200 sends a signal via line 230 to power-control FET 252 . Motor speed is determined by the duration or length of the pulses in the signal to a gate electrode of FET 252 . The shorter the pulses, the slower the speed. This completes the circuit between relay 232 and FET 252 providing power to motor 118 via line 254 . If the door had been commanded to move in the opposite direction, relay 234 would have been enabled, completing the circuit with FET 252 and providing power to motor 118 via line 238 .
[0051] With power provided, the motor 118 drives the output shaft 216 which provides drive power to transmission sprocket 125 . Gear reduction housing 260 includes an internal pass point system which sends a pass point signal via line 220 to controller 220 whenever the pass point is reached. The pass point signal is provided to controller 200 via current limiting resistor 226 to protect controller 200 from electrostatic discharge (ESD). An RPM interrupt signal is provided via line 224 , via current limiting resistor 228 , to controller 200 . Lead 222 provides a plus five volts supply for the Hall effect sensors in the RPM module. Commanded force is input by two force potentiometers 202 , 204 . Force potentiometer 202 is used to set the commanded force for UP travel; force potentiometer 204 is used to set the commanded force for DOWN travel. Force potentiometers 202 and 204 provide commanded inputs to controller 200 which are used to adjust the length of the pulsed signal provided to FET 252 .
[0052] The pass point for this system is provided internally in the motor 118 . Referring to FIG. 22 , the pass point module 40 is attached to gear reduction housing 260 of motor 118 . Pass point module 40 includes upper plate 42 which covers the three internal gears and switch within lower housing 50 . Lower housing 50 includes recess 62 having two pins 61 which position switch assembly 52 in recess 62 . Housing 50 also includes three cutouts which are sized to support and provide for rotation of the three geared elements. Outer gear 44 fits rotatably within cutout 64 . Outer gear includes a smooth outer surface for rotating within housing 50 and inner gear teeth for rotating middle gear 46 . Middle gear 46 fits rotatably within inner cutout 66 . Middle gear 46 includes a smooth outer surface and a raised portion with gear teeth for being driven by the gear teeth of outer ring gear 44 . Inner gear 48 fits within middle gear 46 and is driven by an extension of shaft 216 . Rotation of the motor 118 causes shaft 216 to rotate and drive inner gear 48 .
[0053] Outer gear 44 includes a notch 74 in the outer periphery. Middle gear includes a notch 76 in the outer periphery. Referring to FIG. 22A , rotation of inner gear 48 rotates middle gear 46 in the same direction. Rotation of middle gear 46 rotates outer gear 44 in the same direction. Gears 46 and 44 are sized such that pass point indications comprising switch release cutouts 74 and 76 line up only once during the entire travel distance of the door. As seen in FIG. 22A , when switch release cutouts 74 and 76 line up, switch 72 is open generating a pass point presence signal. The location where switch release cutouts 74 and 76 line up is the pass point. At all other times, at least one of the two gears holds switch 72 closed generating a signal indicating that the pass point has not been reached.
[0054] The receiver portion 80 of controller 200 is shown in FIG. 5A . RF signals may be received by the controller 200 at the antenna 32 and fed to the receiver 80 . The receiver 80 includes variable inductor L 1 and a pair of capacitors C 2 and C 3 that provide impedance matching between the antenna 32 and other portions of the receiver. An NPN transistor Q 4 is connected in common-base configuration as a buffer amplifier. Bias to the buffer amplifier transistor Q 4 is provided by resistors R 2 , R 3 . The buffered RF output signal is supplied to a second NPN transistor Q 5 . The radio frequency signal is coupled to a bandpass amplifier 280 to an average detector 282 which feeds a comparator 284 . Referring to FIGS. 5C and 5B , the analog output signal A, B is applied to noise reduction capacitors C 19 , C 20 and C 21 then provided to pins P 32 and P 33 of the microcontroller 300 . Microcontroller 300 may be a Z86733 microprocessor.
[0055] An external transformer 212 receives AC power from a source such as a utility and steps down the AC voltage to the power supply 90 circuit of controller 200 . Transformer 212 provides AC current to full-wave bridge circuit 214 , which produces a 28 volt full wave rectified signal across capacitor C 35 . The AC power may have a frequency of 50 Hz or 60 Hz. An external transformer is especially important when motor 118 is a DC motor. The 28 volt rectified signal is used to drive a wall control switch, a obstacle detector circuit, a door-in-door switch and to power FETs Q 11 and Q 12 used to start the motor. Zener diode D 18 protects against overvoltage due to the pulsed current, in particular, from the FETs rapidly switching off inductive load of the motor. The potential of the full-wave rectified signal is further reduced to provide 5 volts at capacitor C 38 , which is used to power the microprocessor 300 , the receiver circuit 80 and other logic functions.
[0056] The 28 volt rectified power supply signal indicated by reference numeral T in FIG. 5C is voltage divided down by resistors R 61 and R 62 , then applied to an input pin P 24 of microprocessor 300 . This signal is used to provide the phase of the power line current to microprocessor 300 . Microprocessor 300 constantly checks for the phase of the line voltage in order to determine if the frequency of the line voltage is 50 Hz or 60 Hz. This information is used to establish the worklight time-out period and to select the look-up table stored in the ROM in the microcontroller for converting pulse width to door speed.
[0057] When the door is commanded to move, either through a signal from a remote transmitter received through antenna 32 and processed by receiver 80 , or through an optional wall switch, the microprocessor 300 commands the work light to turn on. Microprocessor 300 sends a worklight enable signal from pin P 07 . The worklight enable signal is applied to the base of transistor Q 3 , which drives relay K 3 . AC power from a signal U provides power for operating the worklight 210 .
[0058] Microprocessor 300 reads from and writes data to an EEPROM 302 via its pins P 25 , P 26 and P 27 . EEPROM 302 may be a 93C46. Microprocessor 300 provides a light enable signal at pin P 21 which is used to enable a learn mode indicator yellow LED D 15 . LED D 15 is enabled or lit when the receiver is in the learn mode. Pin P 26 provides double duty. When the user selects switch S 1 , a learn enable signal is provided to both microprocessor 300 and EEPROM 302 . Switch S 1 is mounted on the head unit 12 and is part of switch module 39 , which is used by the installer to operate the system.
[0059] An optional flasher module provides an additional level of safety for users and is controlled by microprocessor 300 at pin P 22 . The optional flasher module is connected between terminals 308 and 310 . In the optional flasher module, after receipt of a door command, the microprocessor 300 sends a signal from P 22 which causes the flasher light to blink for 2 seconds. The door does not move during that 2 second period, giving the user notice that the door has been commanded to move and will start to move in 2 seconds. After expiration of the 2 second period, the door moves and the flasher light module blinks during the entire period of door movement. If the operator does not have a flasher module installed in the head unit, when the door is commanded to move, there is no time delay before the door begins to move.
[0060] Microprocessor 300 provides the signals which start motor 116 , control its direction of rotation (and thus the direction of movement of the door) and the speed of rotation (speed of door travel). FETs Q 11 and Q 12 are used to start motor 118 . Microprocessor 300 applies a pulsed output signal to the gates of FETs Q 11 and Q 12 . The lengths of the pulses determine the time the FETs conduct and thus the amount of time current is applied to start and run the motor 118 . The longer the pulse, the longer current is applied, the greater the speed of rotation the motor 118 will develop. Diode D 11 is coupled between the 28 volt power supply and is used to clean up flyback voltage to the input bridge D 4 when the FETs are conducting. Similarly, Zener diode D 19 (see FIG. 5A ) is used to protect against overvoltage when the FETs are conducting.
[0061] Control of the direction of rotation of motor 118 (and thus direction of travel of the door) is accomplished with two relays, K 1 and K 2 . Relay K 1 supplies current to cause the motor to rotate clockwise in an opening direction (door moves UP); relay K 2 supplies current to cause the motor to rotate counterclockwise in a closing direction (door moves DOWN). When the door is commanded to move UP, the microprocessor 300 sends an enable signal from pin P 05 to the base of transistor Q 1 , which drives relay K 1 . When the door is commanded to move DOWN, the microprocessor 300 sends an enable signal from pin P 06 to the base of transistor Q 2 , which drives relay K 2 .
[0062] Door-in-door contacts 13 and 15 are connected to terminals 304 and 306 . Terminals 304 and 306 are connected to relays K 1 and K 2 . If the signal between contacts 13 and 15 is broken, the signal across terminals 304 and 306 is open, preventing relays K 1 and K 2 from energizing. The motor 118 will not rotate and the door 24 will not move until the user closes pedestrian door 11 , making contact between contacts 13 and 15 .
[0063] The pass point signal 220 from the pass point module 40 (see FIG. 21 ) of motor 118 is applied to pin P 23 of microprocessor 300 . The RPM signal 224 from the RPM sensor module in motor 118 is applied to pin P 31 of microprocessor 300 . Application of the pass point signal and the RPM signal is described with reference to the flow charts.
[0064] An optional wall control, which duplicates the switches on remote transmitter 30 , may be connected to controller 200 at terminals 312 and 314 . When the user presses the door command switch 39 , a dead short is made to ground, which the microprocessor 300 detects by the failure to detect voltage. Capacitor C 22 is provided for RF noise reduction. The dead short to ground is sensed at pins P 02 and P 03 , for redundancy.
[0065] Switches S 1 and S 2 are part of switch module 39 mounted on head unit 12 and used by the installer for operating the system. As stated above, S 1 is the learn switch. S 2 is the door command switch. When S 2 is pressed, microprocessor 300 detects the dead short at pins P 02 and P 03 .
[0066] Input from an obstacle detector (not shown) is provided at terminal 316 . This signal is voltage divided down and provided to microprocessor 300 at pins P 20 and P 30 , for redundancy. Except when the door is moving and less than an inch above the floor, when the obstacle detector senses an object in the doorway, the microprocessor executes the auto-reverse routine causing the door to stop and/or reverse depending on the state of the door movement.
[0067] Force and speed of door travel are determined by two potentiometers. Potentiometer R 33 adjusts the force and speed of UP travel; potentiometer R 34 adjusts the force and speed of DOWN travel. Potentiometers R 33 and R 34 act as analog voltage dividers. The analog signal from R 33 , R 34 is further divided down by voltage divider R 35 /R 37 , R 36 /R 38 before it is applied to the input of comparators 320 and 322 . Reference pulses from pins P 34 and P 35 of microprocessor 300 are compared with the force input from potentiometers R 33 and R 34 in comparators 320 and 322 . The output of comparators 320 and 322 is applied to pins P 01 and P 00 .
[0068] To perform the A/D conversion, the microprocessor 300 samples the output of the comparators 320 and 322 at pins P 00 and P 01 to determine which voltage is higher: the voltage from the potentiometer R 33 or R 34 (IN) or the voltage from the reference pin P 34 or P 35 (REF). If the potentiometer voltage is higher than the reference, then the microprocessor outputs a pulse. If not, the output voltage is held low. The RC filter (R 39 , C 29 /R 40 , C 30 ) converts the pulses into a DC voltage equivalent to the duty cycle of the pulses. By outputting the pulses in the manner described above, the microprocessor creates a voltage at REF which dithers around the voltage at IN. The microprocessor then calculates the duty cycle of the pulse output which directly correlates to the voltage seen at IN.
[0069] When power is applied to the head unit 12 including controller 200 , microprocessor 300 executes a series of routines. With power applied, microprocessor 300 executes the main routines shown in FIGS. 6A and 6B . The main loop 400 includes three basic functions, which are looped continuously until power is removed. In block 402 the microprocessor 300 handles all non-radio EEPROM communications and disables radio access to the EEPROM 302 when communicating. This ensures that during normal operation, i.e., when the garage door operator is not being programmed, the remote transmitter does not have access to the EEPROM, where transmitter codes are stored. Radio transmissions are processed upon receipt of a radio interrupt (see below).
[0070] In block 404 , microprocessor 300 maintains all low priority tasks, such as calculating new force levels and minimum speed. Preferably, a set of redundant RAM registers is provided. In the event of an unforeseen event (e.g., an ESD event) which corrupts regular RAM, the main RAM registers and the redundant RAM registers will not match. Thus, when the values in RAM do not match, the routine knows the regular RAM has been corrupted. (See block 504 below.) In block 406 , microprocessor 300 tests redundant RAM registers. Several interrupt routines can take priority over blocks 402 , 404 and 406 .
[0071] The infrared obstacle detector generates an asynchronous IR interrupt signal which is a series of pulses. The absence of the obstacle detector pulses indicates an obstruction in the beam. After processing the IR interrupt, microprocessor 300 sets the status of the obstacle detector as unobstructed at block 416 .
[0072] Receipt of a transmission from remote transmitter 30 generates an asynchronous radio interrupt at block 410 . At block 418 , if in the door command mode, microprocessor 300 parses incoming radio signals and sets a flag if the signal matches a stored code. If in the learn mode, microprocessor 300 stores the new transmitter codes in the EEPROM.
[0073] An asynchronous interrupt is generated if a remote communications unit is connected to an optional RS-232 communications port located on the head unit. Upon receipt of the hardware interrupt, microprocessor 300 executes a serial data communications routine for transferring and storing data from the remote hardware.
[0074] Hardware timer 0 interrupt is shown in block 422 . In block 422 , microprocessor 300 reads the incoming AC line signal from pin P 24 and handles the motor phase control output. The incoming line signal is used to determine if the line voltage is 50 Hz for the foreign market or 60 Hz for the domestic market. With each interrupt, microprocessor 300 , at block 426 , task switches among three tasks. In block 428 , microprocessor 300 updates software timers. In block 430 , microprocessor 300 debounces wall control switch signals. In block 432 , microprocessor 300 controls the motor state, including motor direction relay outputs and motor safety systems.
[0075] When the motor 118 is running, it generates an asynchronous RPM interrupt at block 434 . When microprocessor 300 receives the asynchronous RPM interrupt at pin P 31 , it calculates the motor RPM period at block 436 , then updates the position of the door at block 438 .
[0076] Further details of main loop 400 are shown in FIGS. 7A through 7H . The first step executed in main loop 400 is block 450 , where the microprocessor checks to see if the pass point has been passed since the last update. If it has, the routine branches to block 452 , where the microprocessor 300 updates the position of the door relative to the pass point in EEPROM 302 or non-volatile memory. The routine then continues at block 454 . An optional safety feature of the garage door operator system enables the worklight, when the door is open and stopped and the infrared beam in the obstacle detector is broken.
[0077] At block 454 , the microprocessor checks if the enable/disable of the worklight for this feature has been changed. Some users want the added safety feature; others prefer to save the electricity used. If new input has been provided, the routine branches to block 456 and sets the status of the obstacle detector-controlled worklight in non-volatile memory in accordance with the new input. Then the routine continues to block 458 where the routine checks to determine if the worklight has been turned on without the timer. A separate switch is provided on both the remote transmitter 30 and the head unit at module 39 to enable the user to switch on the worklight without operating the door command switch. If no, the routine skips to block 470 .
[0078] If yes, the routine checks at block 460 to see if the one-shot flag has been set for an obstacle detector beam break. If no, the routine skips to block 470 . If yes, the routine checks if the obstacle detector controlled worklight is enabled at block 462 . If not, the routine skips to block 470 . If it is, the routine checks if the door is stopped in the fully open position at block 464 . If no, the routine skips to block 470 . If yes, the routine calls the SetVarLight subroutine (see FIG. 8 ) to enable the appropriate turn off time (4.5 minutes for 60 Hz systems or 2.5 minutes for 50 Hz systems). At block 468 , the routine turns on the worklight.
[0079] At block 470 , the microprocessor 300 clears the one-shot flag for the infrared beam break. This resets the obstacle detector, so that a later beam break can generate an interrupt. At block 472 , if the user has installed a temporary password usable for a fixed period of time, the microprocessor 300 updates the non-volatile timer for the radio temporary password. At block 474 , the microprocessor 300 refreshes the RAM registers for radio mode from non-volatile memory (EEPROM 302 ). At block 476 , the microprocessor 300 refreshes I/O port directions, i.e., whether each of the ports is to be input or output. At block 478 , the microprocessor 300 updates the status of the radio lockout flag, if necessary. The radio lockout flag prevents the microprocessor from responding to a signal from a remote transmitter. A radio interrupt (described below) will disable the radio lockout flag and enable the remote transmitter to communicate with the receiver.
[0080] At block 480 , the microprocessor 300 checks if the door is about to travel. If not, the routine skips to block 502 . If the door is about to travel, the microprocessor 300 checks if the limits are being trained at block 482 . If they are, the routine skips to block 502 . If not, the routine asks at block 484 if travel is UP or DOWN. If DOWN, the routine refreshes the DOWN limit from non-volatile memory (EEPROM 302 ) at block 486 . If UP, the routine refreshes the UP limit from non-volatile memory (EEPROM 302 ) at block 488 . The routine updates the current operating state and position relative to the pass point in non-volatile memory at block 490 . This is a redundant read for stability of the system.
[0081] At block 492 , the routine checks for completion of a limit training cycle. If training is complete, the routine branches to block 494 where the new limit settings and position relative to the pass point are written to non-volatile memory.
[0082] The routine then updates the counter for the number of operating cycles at block 496 . This information can be downloaded at a later time and used to determine when certain parts need to be replaced. At block 498 the routine checks if the number of cycles is a multiple of 256. Limiting the storage of this information to multiples of 256 limits the number of times the system has to write to that register. If yes it updates the history of force settings at block 500 . If not, the routine continues to block 502 .
[0083] At block 502 the routine updates the learn switch debouncer. At block 504 the routine performs a continuity check by comparing the backup (redundant) RAM registers with the main registers. If they do not match, the routine branches to block 506 . If the registers do not match, the RAM memory has been corrupted and the system is not safe to operate, so a reset is commanded. At this point, the system powers up as if power had been removed and reapplied and the first step is a self test of the system (all installation settings are unchanged).
[0084] If the answer to block 504 is yes, the routine continues to block 508 where the routine services any incoming serial messages from the optional wall control (serial messages might be user input start or stop commands). The routine then loads the UP force timing from the ROM look-up table, using the user setting as an index at block 510 . Force potentiometers R 33 and R 34 are set by the user. The analog values set by the user are converted to digital values. The digital values are used as an index to the look-up table stored in memory. The value indexed from the look-up table is then used as the minimum motor speed measurement. When the motor runs, the routine compares the selected value from the look-up table with the digital timing from the RPM routine to ensure the force is acceptable.
[0085] Instead of calculating the force each time the force potentiometers are set, a look-up table is provided for each potentiometer. The range of values based on the range of user inputs is stored in ROM and used to save microprocessor processing time. The system includes two force limits: one for the UP force and one for the DOWN force. Two force limits provide a safer system. A heavy door may require more UP force to lift, but need a lower DOWN force setting (and therefore a slower closing speed) to provide a soft closure. A light door will need less UP force to open the door and possibly a greater DOWN force to provide a full closure.
[0086] Next the force timing is divided by power level of the motor for the door to scale the maximum force timeout at block 512 . This step scales the force reversal point based on the maximum force for the door. The maximum force for the door is determined based on the size of the door, i.e. the distance the door travels. Single piece doors travel a greater distance than segmented doors. Short doors require less force to move than normal doors. The maximum force for a short door is scaled down to 60 percent of the maximum force available for a normal door. So, at block 512 , if the force setting is set by the user, for example at 40 percent, and the door is a normal door (i.e., a segmented door or multi-paneled door), the force is scaled to 40 percent of 100 percent. If the door is a short door (i.e., a single panel door), the force is scaled to 40 percent of 60 percent, or 24 percent.
[0087] At block 514 , the routine loads the DOWN force timing from the ROM look-up table, using the user setting as an index. At block 516 , the routine divides the force timing by the power level of the motor for the door to scale the force to the speed.
[0088] At block 518 the routine checks if the door is traveling DOWN. If yes, the routine disables use of the MinSpeed Register at block 524 and loads the MinSpeed Register with the DOWN force setting, i.e., the value read from the DOWN force potentiometer at block 526 . If not, the routine disables use of the MinSpeed Register at block 520 and loads the MinSpeed Register with the UP force setting from the force potentiometer at block 522 .
[0089] The routine continues at block 528 where the routine subtracts 20 from the MinSpeed value. The MinSpeed value ranges from 0 to 63. The system uses 64 levels of force. If the result is negative at block 530 , the routine clears the MinSpeed Register at block 532 to effectively truncate the lower 38 percent of the force settings. If no, the routine divides the minimum speed by 4 to scale 8 speeds to 32 force settings at block 534 . At block 536 , the routine adds 4 into the minimum speed to correct the offset, and clips the result to a maximum of 12. At block 538 the routine enables use of the MinSpeed Register.
[0090] At block 540 the routine checks if the period of the rectified AC line signal (input to microprocessor 300 at pin P 24 ) is less than 9 milliseconds (indicating the line frequency is 60 Hz). If it is, the routine skips to block 548 . If not, the routine checks if the light shut-off timer is active at block 542 . If not, the routine skips to block 548 . If yes, the routine checks if the light time value is greater than 2.5 minutes at block 544 . If no, the routine skips to block 548 . If yes, the routine calls the SetVarLight subroutine (see FIG. 8 ), to correct the light timing setting, at block 546 .
[0091] At block 548 the routine checks if the radio signal has been clear for 100 milliseconds or more. If not, the routine skips to block 552 . If yes, the routine clears the radio at block 550 . At block 552 , the routine resets the watchdog timer. At block 554 , the routine loops to the beginning of the main loop.
[0092] The SetVarLight subroutine, FIG. 8 , is called whenever the door is commanded to move and the worklight is to be turned on. When the SetVarLight subroutine, block 558 is called, the subroutine checks if the period of the rectified power line signal (pin P 24 of microprocessor 300 ) is greater than or equal to 9 milliseconds. If yes, the line frequency is 50 Hz, and the timer is set to 2.5 minutes at block 564 . If no, the line frequency is 60 Hz and the timer is set to 4.5 minutes at block 562 . After setting, the subroutine returns to the call point at block 566 .
[0093] The hardware timer interrupt subroutine operated by microprocessor 300 , shown at block 422 , runs every 0.256 milliseconds. Referring to FIGS. 9A-9C , when the subroutine is first called, it sets the radio interrupt status as indicated by the software flags at block 580 . At block 582 , the subroutine updates the software timer extension. The next series of steps monitor the AC power line frequency (pin P 24 of microprocessor 300 ). At step 584 , the subroutine checks if the rectified power line input is high (checks for a leading edge). If yes, the subroutine skips to block 594 , where it increments the power line high time counter, then continues to block 596 . If no, the subroutine checks if the high time counter is below 2 milliseconds at block 586 . If yes, the subroutine skips to block 594 . If no, the subroutine sets the measured power line time in RAM at block 588 . The subroutine then resets the power line high time counter at block 590 and resets the phase timer register in block 592 .
[0094] At block 596 , the subroutine checks if the motor power level is set at 100 percent. If yes, the subroutine turns on the motor phase control output at block 606 . If no, the subroutine checks if the motor power level is set at 0 percent at block 598 . If yes, the subroutine turns off the motor phase control output at block 604 . If no, the phase timer register is decremented at block 600 and the result is checked for sign. If positive the subroutine branches to block 606 ; if negative the subroutine branches to block 604 .
[0095] The subroutine continues at block 608 where the incoming RPM signal (at pin P 31 of microprocessor 300 ) is digitally filtered. Then the time prescaling task switcher (which loops through 8 tasks identified at blocks 620 , 630 , 640 , 650 ) is incremented at block 610 . The task switcher varies from 0 to 7. At block 612 , the subroutine branches to the proper task depending on the value of the task switcher.
[0096] If the task switcher is at value 2 (this occurs every 4 milliseconds), the execute motor state machine subroutine is called at block 620 . If the task is value 0 or 4 (this occurs every 2 milliseconds), the wall control switches are debounced at block 630 . If the task value is 6 (this occurs every 4 milliseconds), the execute 4 ms timer subroutine is called at block 640 . If the task is value 1, 3, 5 or 7, the 1 millisecond timer subroutine is called at block 650 . Upon completion of the called subroutine, the 0.256 millisecond timer subroutine returns at block 614 .
[0097] Details of the 1 ms timer subroutine (block 650 ) are shown in FIGS. 10A-10C . When this subroutine is called, the first step is to update the A/D converters on the UP and DOWN force setting potentiometers (P 34 and P 35 of microprocessor 300 ) at block 652 . At block 654 , the subroutine checks if the A/D conversion (comparison at comparators 320 and 322 ) is complete. If yes, the measured potentiometer values are stored at block 656 . Then the stored values (which vary from 0 to 127) are divided by 2 to obtain the 64 level force setting at block 658 . If no, the subroutine decrements the infrared obstacle detector timeout timer at block 660 . In block 662 , the subroutine checks if the timer has reached zero. If no, the subroutine skips to block 672 . If yes, the subroutine resets the infrared obstacle detector timeout timer at block 664 . The flag setting for the obstacle detector signal is checked at block 666 . If no, the one-shot break flag is set at block 668 . If yes, the flag is set indicating the obstacle detector signal is absent at block 670 .
[0098] At block 672 , the subroutine increments the radio time out register. Then the infrared obstacle detector reversal timer is decremented at block 674 . The pass point input is debounced at block 676 . The 125 millisecond prescaler is incremented at block 678 . Then the prescaler is checked if it has reached 63 milliseconds at block 680 . If yes, the fault blinking LED is updated at block 682 . If no, the prescaler is checked if it has reached 125 ms at block 684 . If yes, the 125 ms timer subroutine is executed at block 686 . If no, the routine returns at block 688 .
[0099] The 125 millisecond timer subroutine (block 690 ) is used to manage the power level of the motor 118 . At block 692 , the subroutine updates the RS-232 mode timer and exits the RS-232 mode timer if necessary. The same pair of wires is used for both wall control switches and RS-232 communication. If RS-232 communication is received while in the wall control mode, the RS-232 mode is entered. If four seconds passes since the last RS-232 word was received, then the RS-232 timer times out and reverts to the wall control mode. At block 694 the subroutine checks if the motor is set to be stopped. If yes, the subroutine skips to block 716 and sets the motor's power level to 0 percent. If no, the subroutine checks if the pre-travel safety light is flashing at block 696 (if the optional flasher module has been installed, a light will flash for 2 seconds before the motor is permitted to travel and then flash at a predetermined interval during motor travel). If yes, the subroutine skips to block 716 and sets the motor's power level to 0 percent.
[0100] If no, the subroutine checks if the microprocessor 300 is in the last phase of a limit training mode at block 698 . If yes, the subroutine skips to block 710 . If no, the subroutine checks if the microprocessor 300 is in another part of the limit training mode at block 700 . If no, the subroutine skips to block 710 . If yes, the subroutine checks if the minimum speed (as determined by the force settings) is greater than 40 percent at block 704 . If no, the power level is set to 40 percent at block 708 . If yes, the power level is set equal to the minimum speed stored in MinSpeed Register at block 706 .
[0101] At block 710 the subroutine checks if the flag is set to slow down. If yes, the subroutine checks if the motor is running above or below minimum speed at block 714 . If above minimum speed, the power level of the motor is decremented one step increment (one step increment is preferably 5% of maximum motor speed) at block 722 . If below the minimum speed, the power level of the motor is incremented one step increment (which is preferably 5% of maximum motor speed) to minimum speed at block 720 .
[0102] If the flag is not set to slow down at block 710 , the subroutine checks if the motor is running at maximum allowable speed at block 712 . If no, the power level of the motor is incremented one step increment (which is preferably 5% of maximum motor speed) at block 720 . If yes, the flag is set for motor ramp-up speed complete.
[0103] The subroutine continues at block 724 where it checks if the period of the rectified AC power line (pin P 24 of microprocessor 300 ) is greater than or equal to 9 ms. If no, the subroutine fetches the motor's phase control information (indexed from the power level) from the 60 Hz look-up table stored in ROM at block 728 . If yes, the subroutine fetches the motor's phase control information (indexed from the power level) from the 50 Hz look-up table stored in ROM at block 726 .
[0104] The subroutine tests for a user enable/disable of the infrared obstacle detector-controlled worklight feature at block 730 . Then the user radio learning timers, ZZWIN (at the wall keypad if installed) and AUXLEARNSW (radio on air and worklight command) are updated at block 732 . The software watchdog timer is updated at block 734 and the fault blinking LED is updated at block 736 . The subroutine returns at block 738 .
[0105] The 4 millisecond timer subroutine is used to check on various systems which do not require updating as often as more critical systems. Referring to FIGS. 12A and 12B , the subroutine is called at block 640 . At block 750 , the RPM safety timers are updated. These timers are used to determine if the door has engaged the floor. The RPM safety timer is a one second delay before the operator begins to look for a falling door, i.e., one second after stopping. There are two different forces used in the garage door operator. The first type force are the forces determined by the UP and DOWN force potentiometers. These force levels determine the speed at which the door travels in the UP and DOWN directions. The second type of force is determined by the decrease in motor speed due to an external force being applied to the door (an obstacle or the floor). This programmed or pre-selected external force is the maximum force that the system will accept before an auto-reverse or stop is commanded.
[0106] At block 752 the 0.5 second RPM timer is checked to see if it has expired. If yes, the 0.5 second timer is reset at block 754 . At block 756 safety checks are performed on the RPM seen during the last 0.5 seconds to prevent the door from falling. The 0.5 second timer is chosen so the maximum force achieved at the trolley will reach 50 kilograms in 0.5 seconds if the motor is operating at 100 percent of power.
[0107] At block 758 , the subroutine updates the 1 second timer for the optional light flasher module. In this embodiment, the preferred flash period is 1 second. At block 760 the radio dead time and dropout timers are updated. At block 762 the learn switch is debounced. At block 764 the status of the worklight is updated in accordance with the various light timers. At block 766 the optional wall control blink timer is updated. The optional wall control includes a light which blinks when the door is being commanded to auto-reverse in response to an infrared obstacle detector signal break. At block 768 the subroutine returns.
[0108] Further details of the asynchronous RPM signal interrupt, block 434 , are shown in FIGS. 13A and 13B . This signal, which is provided to microprocessor 300 at pin P 31 , is used to control the motor speed and the position detector. Door position is determined by a value relative to the pass point. The pass point is set at 0. Positions above the pass point are negative; positions below the pass point are positive. When the door travels to the UP limit, the position detector (or counter) determines the position based on the number of RPM pulses to the UP limit number. When the door travels DOWN to the DOWN limit, the position detector counts the number of RPM pulses to the DOWN limit number. The UP and DOWN limit numbers are stored in a register.
[0109] At block 782 the RPM interrupt subroutine calculates the period of the incoming RPM signal. If the door is traveling UP, the subroutine calculates the difference between two successive pulses. If the door is traveling DOWN, the subroutine calculates the difference between two successive pulses. At block 784 , the subroutine divides the period by 8 to fit into a binary word. At block 786 the subroutine checks if the motor speed is ramping up. This is the max force mode. RPM timeout will vary from 10 to 500 milliseconds. Note that these times are recommended for a DC motor. If an AC motor is used, the maximum time would be scaled down to typically 24 milliseconds. A 24 millisecond period is slower than the breakdown RPM of the motor and therefore beyond the maximum possible force of most preferred motors. If yes, the RPM timeout is set at 500 milliseconds (0.5 seconds) at block 790 . If no, the subroutine sets the RPM timeout as the rounded-up value of the force setting in block 788 .
[0110] At block 792 the subroutine checks for the direction of travel. This is found in the state machine register. If the door is traveling DOWN, the position counter is incremented at block 796 and the pass point debouncer is sampled at block 800 . At block 804 , the subroutine checks for the falling edge of the pass point signal. If the falling edge is present, the subroutine returns at block 814 . If there is a pass point falling edge, the subroutine checks for the lowest pass point (in cases where more than one pass point is used). If this is not the lowest pass point, the subroutine returns at block 814 . If it is the only pass point or the lowest pass point, the position counter is zeroed and the subroutine returns at block 814 .
[0111] If the door is traveling UP, the subroutine decrements the position counter at block 794 and samples the pass point debouncer at block 798 . Then it checks for the rising edge of the pass point signal at block 802 . If there is no pass point signal rising edge, the subroutine returns at block 814 . If there is, it checks for the lowest pass point at block 806 . If no the subroutine returns at block 814 . If yes, the subroutine zeroes the position counter and returns at block 814 .
[0112] The motor state machine subroutine, block 620 , is shown in FIG. 14 . It keeps track of the state of the motor. At block 820 , the subroutine updates the false obstacle detector signal output, which is used in systems that do not require an infrared obstacle detector. At block 822 , the subroutine checks if the software watchdog timer has reached too high a value. If yes, a system reset is commanded at block 824 . If no, at block 826 , it checks the state of the motor stored in the motor state register located in EEPROM 302 and executes the appropriate subroutine.
[0113] If the door is traveling UP, the UP direction subroutine at block 832 is executed. If the door is traveling DOWN, the DOWN direction subroutine is executed at block 828 . If the door is stopped in the middle of the travel path, the stop in midtravel subroutine is executed at block 838 . If the door is fully closed, the DOWN position subroutine is executed at block 830 . If the door is fully open, the UP position subroutine is executed at block 834 . If the door is reversing, the auto-reverse subroutine is executed at block 836 .
[0114] When the door is stopped in midtravel, the subroutine at block 838 is called, as shown in FIG. 15 . In block 840 the subroutine updates the relay safety system (ensuring that relays K 1 and K 2 are open). The subroutine checks for a received wall command or radio command. If there is no received command, the subroutine updates the worklight status and returns. If yes, the motor power is set to 20 percent at block 844 and the motor state is set to traveling DOWN at block 846 . The worklight status is updated and the subroutine returns at block 850 . If the door is stopped in midtravel and a door command is received, the door is set to close. The next time the system calls the motor state machine subroutine, the motor state machine will call the DOWN direction subroutine. The door must close to the DOWN limit before it can be opened to the full UP limit.
[0115] If the state machine indicates the door is in the DOWN position (i.e. the DOWN limit position), the DOWN position subroutine, block 830 , at FIG. 16 is called. When the door is in the DOWN position, the subroutine checks if a wall control or radio command has been received. If no, the subroutine updates the light and returns at block 858 . If yes, the motor power is set to 20 percent at block 854 and the motor state register is set to show the state is traveling UP at block 856 . The subroutine then updates the light and returns at block 858 .
[0116] The UP direction subroutine, block 832 , is shown in FIGS. 17A-17C . At block 860 the subroutine waits until the main loop refreshes the UP limit from EEPROM 302 . Then it checks if 40 milliseconds have passed since closing of the light relay K 3 at block 862 . If not, the subroutine returns. If yes, the subroutine checks for flashing the warning light prior to travel at block 866 (only if the optional flasher module is installed). If the light is flashing, the status of the blinking light is updated and the subroutine returns at block 868 . If not, the flashing is terminated, the motor UP relay is turned on at block 870 . Then the subroutine waits until 1 second has passed after the motor was turned on at block 872 . If no, the subroutine skips to block 888 . If yes, the subroutine checks for the RPM signal timeout. If no, the subroutine checks if the motor speed is ramping up at block 876 by checking the value of the RAMPFLAG register in RAM (i.e., UP, DOWN, FULLSPEED, STOP). If yes, the subroutine skips to block 888 . If no, the subroutine checks if the measured RPM is longer than the allowable RPM period at block 878 . If no, the subroutine continues at block 888 .
[0117] If the RPM signal has timed out at block 874 or the measured time period is longer than allowable at block 878 , the subroutine branches to block 880 . At block 880 , the reason is set as force obstruction. At block 882 , if the training limits are being set, the training status is updated. At block 884 the motor power is set to zero and the state is set as stopped in midtravel. At block 886 the subroutine returns.
[0118] At block 888 the subroutine checks if the door's exact position is known. If it is not, the door's distance from the UP limit is updated in block 890 by subtracting the UP limit stored in RAM from the position of the door also stored in RAM. Then the subroutine checks at block 892 if the door is beyond its UP limit. If yes, the subroutine sets the reason as reaching the limit in block 894 . Then the subroutine checks if the limits are being trained. If yes, the limit training machine is updated at block 898 . If no, the motor's power is set as zero and the motor state is set at the UP position in block 900 . Then the subroutine returns at block 902 .
[0119] If the door is not beyond its UP limit, the subroutine checks if the door is being manually positioned in the training cycle at block 904 . If not, the door position within the slowdown distance of the limit is checked at block 906 . If yes, the motor slow down flag is set at block 910 . If the door is being positioned manually at block 904 or the door is not within the slow down distance, the subroutine skips to block 912 . At block 912 the subroutine checks if a wall control or radio command has been received. If yes, the motor power is set at zero and the state is set at stopped in midtravel at block 916 . If no, the system checks if the motor has been running for over 27 seconds at block 914 . If yes, the motor power is set at zero and the motor state is set at stopped in midtravel at block 916 . Then the subroutine returns at block 918 .
[0120] Referring to FIG. 18 , the auto-reverse subroutine block 836 is described. (Force reversal is stopping the motor for 0.5 seconds, then traveling UP.) At block 920 the subroutine updates the 0.5 second reversal timer (the force reversal timer described above). Then the subroutine checks at block 922 for expiration of the force-reversal timer. If yes, the motor power is set to 20 percent at block 924 and the motor state is set to traveling UP at block 926 and the subroutine returns at block 932 . If the timer has not expired, the subroutine checks for receipt of a wall command or radio command at block 928 . If yes, the motor power is set to zero and the state is set at stopped in midtravel at block 930 , then the subroutine returns at block 932 . If no, the subroutine returns at block 932 .
[0121] The UP position routine, block 834 , is shown in FIG. 19 . Door travel limits training is started with the door in the UP position. At block 934 , the subroutine updates the relay safety system. Then the subroutine checks for receipt of a wall command or radio command at block 936 indicating an intervening user command. If yes, the motor power is set to 20 percent at block 938 and the state is set at traveling DOWN in block 940 . Then the light is updated and the subroutine returns at block 950 . If no wall command has been received, the subroutine checks for training the limits at block 942 . If no, the light is updated and the subroutine returns at block 950 . If yes, the limit training state machine is updated at block 944 . Then the subroutine checks if it is time to travel DOWN at block 946 . If no, the subroutine updates the light and returns at block 950 . If it is time to travel DOWN, the state is set at traveling DOWN at block 948 and the system returns at block 950 .
[0122] The DOWN direction subroutine, block 828 , is shown in FIGS. 20A-20D . At block 952 , the subroutine waits until the main loop routine refreshes the DOWN limit from EEPROM 302 . For safety purposes, only the main loop or the remote transmitter (radio) can access data stored in or written to the EEPROM 302 . Because EEPROM communication is handled within software, it is necessary to ensure that two software routines do not try to communicate with the EEPROM at the same time (and have a data collision). Therefore, EEPROM communication is allowed only in the Main Loop and in the Radio routine, with the Main loop having a busy flag to prevent the radio from communicating with the EEPROM at the same time. At block 954 , the subroutine checks if 40 milliseconds has passed since closing of the light relay K 3 . If no, the subroutine returns at block 956 . If yes, the subroutine checks if the warning light is flashing (for 2 seconds if the optional flasher module is installed) prior to travel at block 958 . If yes, the subroutine updates the status of the flashing light and returns at block 960 . If no, or the flashing is completed, the subroutine turns on the DOWN motor relay K 2 at block 962 . At block 964 the subroutine checks if one second has passed since the motor is first turned on. The system ignores the force on the motor for the first one second. This allows the motor time to overcome the inertia of the door (and exceed the programmed force settings) without having to adjust the programmed force settings for ramp up, normal travel and slow down. Force is effectively set to maximum during ramp up to overcome sticky doors.
[0123] If the one second time has not passed, the subroutine skips to block 984 . If the one second time limit has passed, the subroutine checks for the RPM signal time out at block 966 . If no, the subroutine checks if the motor speed is currently being ramped up at block 968 (this is a maximum force condition). If yes, the routine skips to block 984 . If no, the subroutine checks if the measured RPM period is longer than the allowable RPM period. If no, the subroutine continues at block 984 .
[0124] If either the RPM signal has timed out (block 966 ) or the RPM period is longer than allowable (block 970 ), this is an indication of an obstruction or the door has reached the DOWN limit position, and the subroutine skips to block 972 . At block 972 , the subroutine checks if the door is positioned beyond the DOWN limit setting. If it is, the subroutine skips to block 990 where it checks if the motor has been powered for at least one second. This one second power period after the DOWN limit has been reached provides for the door to close fully against the floor. This is especially important when DC motors are used. The one second period overcomes the internal braking effect of the DC motor on shut-off. Auto-reverse is disabled after the position detector reaches the DOWN limit.
[0125] If the motor has been running for one second, at block 990 , the subroutine sets the reason as reaching the limit at block 994 . The subroutine then checks if the limits are being trained at block 998 . If yes, the limit training machine is updated at block 1002 . If no, the motor's power is set to zero and the motor state is set at the DOWN position in block 1006 . In block 1008 the subroutine returns.
[0126] If the motor has not been running for at least one second at block 990 , the subroutine sets the reason as early limit at block 1026 . Then the subroutine sets the motor power at zero and the motor state as auto-reverse at block 1028 and returns at block 1030 .
[0127] Returning to block 984 , the subroutine checks if the door's position is currently unknown. If yes, the subroutine skips to block 1004 . If no, the subroutine updates the door's distance from the DOWN limit using internal RAM in microprocessor 300 in block 986 . Then the subroutine checks at block 988 if the door is three inches beyond the DOWN limit. If yes, the subroutine skips to block 990 . If no, the subroutine checks if the door is being positioned manually in the training cycle at block 992 . If yes, the subroutine skips to block 1004 . If no, the subroutine checks if the door is within the slow DOWN distance of the limit at block 996 . If no, the subroutine skips to block 1004 . If yes, the subroutine sets the motor slow down flag at block 1000 .
[0128] At block 1004 , the subroutine checks if a wall control command or radio command has been received. If yes, the subroutine sets the motor power at zero and the state as auto-reverse at block 1012 . If no, the subroutine checks if the motor has been running for over 27 seconds at block 1010 . If yes, the subroutine sets the motor power at zero and the state at auto-reverse. If no, the subroutine checks if the obstacle detector signal has been missing for 12 milliseconds or more at block 1014 indicating the presence of the obstacle or the failure of the detector. If no, the subroutine returns at block 1018 . If yes, the subroutine checks if the wall control or radio signal is being held to override the infrared obstacle detector at block 1016 . If yes, the subroutine returns at block 1018 . If no, the subroutine sets the reason as infrared obstacle detector obstruction at block 1020 . The subroutine then sets the motor power at zero and the state as auto-reverse at block 1022 and returns at block 1024 . (The auto-reverse routine stops the motor for 0.5 seconds then causes the door to travel up.) The appendix attached hereto includes a source listing of a series of routines used to operate a movable barrier operator in accordance with the present invention.
[0129] While there has been illustrated and described a particular embodiment of the present invention, it will be appreciated that numerous changes and modifications will occur to those skilled in the art, and it is intended in the appended claims to cover all those changes and modifications which followed in the true spirit and scope of the present invention.
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A movable barrier operator having improved safety and energy efficiency features automatically detects line voltage frequency and uses that information to set a worklight shut-off time. The operator automatically detects the type of door (single panel or segmented) and uses that information to set a maximum speed of door travel. The operator moves the door with a linearly variable speed from start of travel to stop for smooth and quiet performance. The operator provides for full door closure by driving the door into the floor when the DOWN limit is reached and no auto-reverse condition has been detected. The operator provides for user selection of a minimum stop speed for easy starting and stopping of sticky or binding doors.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority under 35 USC 119 to Japanese Patent Application No. 2005-69366 filed on Mar. 11, 2005 the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a Rankine cycle system that includes an evaporator for heating a liquid-phase working medium with thermal energy of exhaust gas of an engine so as to generate a gas-phase working medium, an expander for converting the thermal energy of the gas-phase working medium generated by the evaporator into mechanical energy, and temperature control means for manipulating the amount of liquid-phase working medium supplied to the evaporator in order to make the temperature of the gas-phase working medium supplied from the evaporator to the expander coincide with a target temperature.
[0004] 2. Description of Background Art
[0005] Japanese Utility Model Registration Publication No. 2-38162 discloses an arrangement in which the temperature of steam generated by a waste heat once-through boiler using, as a heat source, exhaust gas of an engine rotating at a constant speed is compared with a target temperature. When a water supply signal obtained from this deviation is used in a feedback control of the amount of water supplied to the waste heat once-through boiler, a feedforward signal, that is obtained by correcting with steam pressure a degree of throttle opening signal of the engine, is added to the above-mentioned feedback signal, thus compensating for variation in the load of the engine to improve the precision of control.
[0006] In the above-mentioned conventional arrangement, since the steam temperature is controlled only by manipulating the amount of water supplied to the evaporator, in the case where the load of the engine changes suddenly and the thermal energy of the exhaust gas increases rapidly, there is a possibility that a response lag might occur in the steam temperature due to the length of a water supply pipe or the heat capacity of the evaporator. Thus, the steam temperature might overshoot the target temperature to deteriorate the operating efficiency of the expander.
[0007] As another method for preventing the steam temperature from overshooting the target temperature when the load of the engine changes suddenly, cylinder shut-off in the engine could be considered. However, if cylinder shut-off is carried out, since the engine output itself changes, there is a problem that this Rankine cycle system mounted in an automobile gives an uncomfortable feeling to the driver.
SUMMARY OF THE INVENTION
[0008] The present invention has been accomplished under the above-mentioned circumstances, and it is an object thereof to carry out control with good responsiveness so that the temperature of steam generated in an evaporator does not overshoot a target temperature even when the operating conditions of the engine change and the energy of the exhaust gas increases rapidly.
[0009] In order to achieve the above object, according to a first feature of the present invention, there is provided a Rankine cycle system comprising: an evaporator for heating a liquid-phase working medium with thermal energy of exhaust gas of an engine so as to generate a gas-phase working medium with an expander for converting the thermal energy of the gas-phase working medium generated by the evaporator into mechanical energy. Temperature control means are provided for manipulating the amount of liquid-phase working medium supplied to the evaporator in order to make the temperature of the gas-phase working medium supplied from the evaporator to the expander coincide with a target temperature, wherein the temperature control means controls a distribution ratio between the amount of liquid-phase working medium supplied to the entrance of the evaporator and the amount of liquid-phase working medium supplied to a portion partway along the evaporator.
[0010] With the first feature, the temperature control means for manipulating the amount of liquid-phase working medium supplied to the evaporator controls the distribution ratio of the amount of liquid-phase working medium supplied to the entrance of the evaporator and the amount of liquid-phase working medium supplied to the portion partway along the evaporator in order to make the temperature of the gas-phase working medium supplied from the evaporator to the expander of the Rankine cycle system coincide with the target temperature. Therefore, it is possible to suppress an overshoot in the temperature of the gas-phase working medium due to a sudden increase in the thermal energy of the exhaust gas by supplying the liquid- phase working medium to a portion partway along the evaporator.
[0011] According to a second feature of the present invention, the temperature control means supplies the liquid-phase working medium to a portion partway along the evaporator at a predetermined distribution ratio when the thermal energy of the exhaust gas changes suddenly accompanying a change in load of the engine and the temperature of the gas-phase working medium cannot be controlled at the target temperature by supplying the liquid-phase working medium only from the entrance of the evaporator.
[0012] With the second feature, when the temperature of the gas-phase working medium cannot be controlled at the target temperature by supplying the liquid-phase working medium only from the entrance of the evaporator due to a sudden change in the thermal energy of the exhaust gas, part of the liquid-phase working medium that has been supplied to the entrance of the evaporator until then is supplied to the portion partway along the evaporator. Therefore, it is possible to decrease the temperature of the gas-phase working medium and reliably prevent the occurrence of overshooting.
[0013] According to a third feature of the present invention, the temperature control means supplies the liquid-phase working medium to a portion partway along the evaporator at a predetermined distribution ratio when the temperature of the gas-phase working medium supplied from the evaporator to the expander is higher than the target temperature.
[0014] With the third feature, when the temperature of the gas-phase working medium supplied from the evaporator to the expander is higher than the target temperature, part of the liquid-phase working medium that has been supplied to the entrance of the evaporator until then is supplied to the portion partway along the evaporator. Therefore, it is possible to decrease the temperature of the gas-phase working medium and reliably prevent the occurrence of overshooting.
[0015] According to a fourth feature of the present invention, the temperature control means supplies the liquid-phase working medium to a portion partway along the evaporator at a predetermined distribution ratio according to an air/fuel ratio.
[0016] According to a fifth feature of the present invention, at least when the air/fuel ratio is stoichiometric, the temperature control means increases the distribution ratio of the liquid-phase working medium to a portion partway along the evaporator as compared with the case of another air/fuel ratio.
[0017] With the fourth and fifth features, when the air/fuel ratio is stoichiometric the temperature of exhaust gas rises and the thermal energy increases as compared with when it is rich or lean, but in this case the liquid-phase working medium is supplied to the portion partway along the evaporator at the predetermined distribution ratio according to the air/fuel ratio, that is, the distribution ratio of the liquid-phase working medium supplied to the portion partway along the evaporator is increased at least when the air/fuel ratio is stoichiometric as compared with when it is another air/fuel ratio. Therefore, it is possible to suppress an excessive increase in the temperature of the gas-phase working medium supplied from the evaporator to the expander, and it is also possible to suppress an excessive decrease in the temperature of the gas-phase working medium supplied from the evaporator to the expander when the air/fuel ratio is rich or lean, thereby making the temperature of the gas-phase working medium coincide with the target temperature with good precision.
[0018] The above-mentioned object, other objects, characteristics, and advantages of the present invention will become apparent from a preferred embodiment that will be described in detail below by reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
[0020] FIG. 1 is a diagram showing the overall arrangement of a Rankine cycle system;
[0021] FIG. 2 is a control block diagram of temperature control means;
[0022] FIG. 3 is a graph showing the relationship between optimum steam temperature and maximum efficiency of an evaporator and an expander;
[0023] FIG. 4 is a flowchart of steam temperature control;
[0024] FIG. 5 is a map in which the total water supply amount is looked up from exhaust gas energy;
[0025] FIG. 6 is a map in which an intermediate position water supply amount distribution ratio is looked up from an air/fuel ratio;
[0026] FIG. 7 is a graph showing the relationship between exhaust gas energy, intermediate position water supply amount distribution ratio, and air/fuel ratio;
[0027] FIGS. 8A and 8B are time charts for explaining the effect of the intermediate position water supply;
[0028] FIG. 9 is a graph showing temperature distribution in the direction of steam flow of the evaporator; and
[0029] FIG. 10 is a graph showing parameter changes when engine operating conditions change.
DESCRIPTION OF PREFERRED EMBODIMENT
[0030] FIG. 1 shows the overall arrangement of a Rankine cycle system R to which the present invention is applied. The Rankine cycle system R recovers thermal energy of exhaust gas of an engine E and converts it into mechanical energy. The Rankine cycle system R includes: an evaporator 11 ; an expander 12 ; a condenser 13 ; a water supply pump 14 ; and a distribution device 15 for water supplied from the pump 14 to the evaporator 11 . The evaporator 11 heats water with the exhaust gas discharged by the engine E so as to generate high temperature, high pressure steam. The expander 12 is operated by the high temperature, high pressure steam generated by the evaporator 1 1 so as to generate mechanical energy. The condenser 13 cools decreased temperature, decreased pressure steam that has completed work in the expander 12 so as to turn it back into water. The water supply pump 14 pressurizes water discharged from the condenser 13 and supplies it to the evaporator 11 again. Supply of water to the evaporator 11 can be carried out not only via main water supply from the upstream end of the evaporator 11 , but also via intermediate position water supply from a portion partway along that is close to the downstream end of the evaporator 11 . The distribution device 15 can freely control the ratio of the amount of water of the main water supply and the amount of water of the intermediate position water supply by means of a distribution valve that is duty-controlled.
[0031] The intermediate position water supply may be independent from the main water supply, and may optionally involve supplying water via another route and pump, etc.
[0032] FIG. 2 shows the arrangement of temperature control means 21 included in the Rankine cycle system R. The temperature control means 21 includes: feedforward water supply amount calculation means 22 ; feedback water supply amount calculation means 23 ; comparison means 24 ; and intermediate position water supply amount calculation means 25 . The feedforward water supply amount calculation means 22 calculates a feedforward water supply amount for the evaporator 11 based on a parameter such as engine rotational speed, intake negative pressure, fuel injection quantity, or exhaust gas temperature. The feedback water supply amount calculation means 23 calculates a feedback water supply amount by multiplying a deviation, from a target temperature for steam at the entrance of the expander 12 , of the steam temperature at the exit of the evaporator 11 by a predetermined gain. A total water supply amount, which is the sum of the main water supply amount and the intermediate position water supply amount, is calculated by subtracting the feedback water supply amount calculated by the feedback water supply amount calculation means 23 from the feedforward water supply amount calculated by the feedforward water supply amount calculation means 22 .
[0033] The target steam temperature is determined as follows. That is, as shown in FIG. 3 , the efficiency of the evaporator 11 and of the expander 12 of the Rankine cycle system R, which are represented by the efficiency of each element on the left-hand ordinate, change according to the steam temperature; when the steam temperature increases, the efficiency of the evaporator decreases and the efficiency of the expander increases, whereas when the steam temperature decreases, the efficiency of the evaporator increases and the efficiency of the expander decreases. Therefore, there is an optimum steam temperature (a target temperature) at which the overall efficiency of the two, which is represented by the overall efficiency on the right-hand ordinate, becomes a maximum.
[0034] Returning to FIG. 2 , the comparison means 24 compares the steam temperature at the exit of the evaporator 11 with the target temperature for steam at the entrance of the expander 12 , and if the result is that the steam temperature at the exit of the evaporator 11 is higher than the target temperature for steam at the entrance of the expander 12 , the intermediate position water supply amount calculation means 25 calculates an intermediate position water supply amount by map lookup. When the intermediate position water supply amount is calculated in this way, the main water supply amount is calculated by subtracting the intermediate position water supply amount from the total water supply amount. While maintaining the total water supply amount, the distribution valve of the distribution device 15 is duty-controlled so that the main water supply amount and the intermediate position water supply amount satisfy the predetermined ratio.
[0035] The above-mentioned operation is now explained in further detail by reference to the flowchart of FIG. 4 .
[0036] In step S 1 , the main water supply amount, the intermediate position water supply amount, and the total water supply amount are all set at 0. In the subsequent step S 2 , the engine rotational speed, intake negative pressure, fuel injection quantity, and exhaust gas temperature are detected, in step S 3 an air/fuel ratio A/F is calculated from the engine rotational speed, the intake negative pressure, and the fuel injection quantity, and in step S 4 the exhaust gas energy is estimated. Subsequently, in step S 5 , the total water supply amount (a feedforward value) is looked up in the map of FIG. 5 from the exhaust gas energy. The total water supply amount is set so as to increase in response to an increase in the exhaust gas energy.
[0037] In the subsequent step S 6 , the steam temperature at the exit of the evaporator 11 is measured; if in step S 7 the exit steam temperature is higher than the target steam temperature, then in step S 8 a distribution ratio (intermediate position water supply amount/total water supply amount) of the intermediate position water supply amount is looked up in the map of FIG. 6 from the air/fuel ratio A/F. Switchover of the distribution ratio shown in FIG. 6 is not limited to a stepwise form (ref. the solid line), and it may be in a curved form (ref. the dashed line) in order to moderate a sudden change in steam temperature.
[0038] In the case where the air/fuel ratio A/F is rich, since the temperature of the exhaust gas decreases as compared with the case where it is stoichiometric (theoretical air/fuel ratio), and the temperature of steam at the exit of the evaporator 11 also decreases, the proportion of the intermediate position water supply amount (intermediate position water supply amount distribution ratio) for decreasing the exit steam temperature is set low. Also in the case where it is lean, in the same manner as in the case where it is rich, the exhaust gas temperature decreases as compared with the case where it is stoichiometric. Therefore, the proportion of the intermediate position water supply amount is set low as in the case of rich. Thus, in the case where it is stoichiometric, the proportion of the intermediate position water supply amount is set high. In step S 9 an intermediate position water supply amount (feedforward value) is calculated by multiplying the total water supply amount by the intermediate position water supply amount distribution ratio.
[0039] The reason why the intermediate position water supply amount distribution ratio is set based on the air/fuel ratio is explained below. As shown in FIG. 7 , there is no correlation found between exhaust gas energy and intermediate position water supply amount distribution ratio, but instead the intermediate position water supply amount distribution ratio becomes substantially constant depending on the air/fuel ratio being stoichiometric or rich (or lean, although it is not illustrated). If the intermediate position water supply amount distribution ratio is set according to the air/fuel ratio, the intermediate position water supply amount distribution ratio can be calculated instantaneously from the fuel injection quantity and the intake air amount. Thus, an advantage is obtained in that the responsiveness is improved as compared with the case where the intermediate position water supply amount distribution ratio is calculated using the exhaust gas temperature and the steam temperature.
[0040] Returning to the flowchart of FIG. 4 , in step S 10 a PID control amount (feedback value) is calculated by multiplying a deviation, from a target steam temperature, of the exit steam temperature by a gain, in step S 1 a total water supply amount is calculated by subtracting the feedback value from the feedforward value, in step S 12 the main water supply amount is calculated by subtracting the intermediate position water supply amount from the total water supply amount, in step S 13 the water supply amount of the water supply pump 14 is controlled based on the total water supply amount, and the operation of the distribution valve of the distribution device 15 is controlled based on the main water supply amount and the intermediate position water supply amount.
[0041] As shown in FIG. 8A , in the case where no intermediate position water supply is carried out, when a driver depresses an accelerator pedal and the exhaust gas energy increases, only the main water supply amount calculated from the exhaust gas energy is controlled. Therefore, the steam temperature overshoots and it becomes difficult to converge it on the target temperature. On the other hand, as shown in FIG. 8B , when both the main water supply amount and the intermediate position water supply amount are controlled, it is possible to suppress the overshooting of the steam temperature and quickly converge it on the target temperature. In this process, since the output of the engine E is not changed unlike the case of cylinder shut-off, the Rankine cycle system R mounted on an automobile gives no disagreeable sensation to the driver.
[0042] FIG. 9 shows changes in the steam (water) temperature corresponding to each position from the upstream end to the downstream end in the direction of steam (water) supply for the evaporator 11 , and it can be seen that carrying out intermediate position water supply makes the steam temperature converge on the target temperature at the exit of the evaporator 11 .
[0043] FIG. 10 shows changes in the engine rotational speed, the total water supply amount, the intermediate position water supply amount distribution ratio, and the steam temperature when the operating conditions of the engine E change from an idling state to a high load state, and then to a fuel-cut state, and it can be seen that variation in the steam temperature can be suppressed to a low level by increasing the intermediate position water supply amount distribution ratio in the high load state.
[0044] Although one embodiment of the present invention is explained above, the present invention can be modified in a variety of ways as long as the modifications do not depart from the spirit and scope of the present invention.
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A Rankine cycle system includes: an evaporator for heating water with thermal energy of exhaust gas of an engine so as to generate steam; an expander for converting the thermal energy of the steam generated by the evaporator into mechanical energy; and a distribution device for manipulating the amount of water supplied to the evaporator in order to make the temperature of the steam supplied from the evaporator to the expander coincide with a target temperature. The distribution device controls a distribution ratio between the amount of water supplied to the entrance of the evaporator and the amount of water supplied to a portion partway along the evaporator, thereby suppressing an overshoot in the temperature of the gas-phase working medium due to a sudden increase in the thermal energy of the exhaust gas.
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This is a continuation of application Ser. No. 08/838,905 filed Apr. 11, 1997 now abandoned.
FIELD OF THE INVENTION
This invention relates to laminated magnetic assemblies such as may be employed in transformers or other electrical apparatus.
BACKGROUND OF THE INVENTION
As is well known, laminations made of sheets of ferrous material are employed in various electrical apparatus and provide a magnetic path. In transformers, the laminations provide a magnetic path around an electric current developed in a winding or other electrical conductor.
In some uses, as when the laminated assembly is employed as an electric sensor core in an overload relay and is required to respond linearly at low currents and continue a linear output throughout the desired current range while having an adequate high saturation level, the laminated assembly requires a large cross sectional area with minimal air gaps. Conventionally, this has been achieved through the use of laminations of relatively thin, sheets of ferrous material configured generally in the form of a "U" or a "D". The laminations are achieved by "U-U" or "D-U" laminations stacked in a sequence. This type of construction tends to require extra width on the ends of the laminations to compensate for the air gaps left between groups of laminations. Also typically, the laminations are riveted together or adhesively assembled using varnish or epoxy resin, or even held together with spring clips. If the extra width is not permitted because of spacial requirements of a given use, then two laminations are used per layer so as to minimize the air gap. However, as the extra width is eliminated and the assembly becomes narrower, it becomes increasingly difficult to utilize rivets to secure the laminations together. Moreover, as the assembly becomes thicker, spring clips lose their effectiveness and the use of varnish and/or epoxy as an adhesive tends to be messy and time consuming.
As a consequence, magnetic assemblies made up of laminations for use in transformers and the like have either been bulky, i.e. undesirably large, with a consequence that the volume of the equipment in which they are employed is increased or, if of an appropriate size matched to the requisite magnetic efficiency for the particular use, undesirably expensive to fabricate.
The present invention is directed to providing a compact magnetic assembly of the type that may be used in a transformer and which is economical to manufacture.
SUMMARY OF THE INVENTION
It is the an object of the invention to provide a new and improved magnetic assembly for use in a transformer or the like. More specifically, it is an object of the invention to provide such an assembly that is economically manufactured and yet may be of small volume so as to reduce the space occupied by the same in a given particular piece of electrical equipment.
An exemplary embodiment of the invention achieves the foregoing object in a magnetic assembly for a transformer of the like that includes a first series of substantially identical laminations, each made up of a thin sheet of ferrous material, and abutted against one another in aligned relation. The laminations of the first series include a first open area flanked by spaced, opposed first surfaces. First holding means hold the first series in assembled relation. A second series of substantially identical laminations are provided and each is made up of a thin sheet of ferrous material and they are abutted against one another in aligned relation. A second holding means hold the second series in assembled relation. The laminations of the second series are configured to be assembled to the laminations of the first series and define therewith a closed loop of the ferrous material. The laminations of the second series have spaced, opposed second surfaces configured to be complementary to a corresponding one of the first surfaces and abutting the same. The distance between the first surfaces, before assembly of the first series to the second series, is slightly more or slightly less than the distance between the second surfaces so that upon assembly of the first series and the second series to one another, an interference fit exists between the first and second series at the first and second surfaces to hold the first and second series in assembled relation. An electrical winding is disposed about at least one of the first and second series and at least partially occupies the open area.
In a preferred embodiment, the first surfaces face one another while the second surfaces face oppositely of one another.
In a preferred embodiment, one of the first and second surfaces is concave and the other of the first and second surfaces is convex.
In another preferred embodiment, the first and second surfaces are generally parallel to one another.
A highly preferred embodiment includes a third series of substantially identical laminations, each made up of a thin sheet of ferrous material and abutted against one another in aligned relation. The laminations of the third series include a second open area flanked by spaced, opposed third surfaces. A fourth series of substantially identical laminations is included and each is made up of a thin sheet of ferrous material and abutted against one another in aligned relation. The laminations of the fourth series are configured to be assembled to the laminations of the third series and define therewith a closed loop of the ferrous material. The laminations of the fourth series have spaced, opposed surfaces configured to be complimentary to a corresponding one of the third surfaces and abutting the same. The distance between the third surfaces, before assembly of the third series and the fourth series is slightly greater or slightly less than the distance between the fourth surfaces so that upon assembly of the third series and the fourth series to one another, an interference fit exists between the third and fourth series at the third and fourth surfaces to hold the third and fourth series in assembled relation. Means hold the laminations of the third series in abutting relation and means are provided to hold the laminations of the fourth series in abutting relation. The laminations of the third series have a different configuration than the laminations of the first series while the laminations of the second series have a different configuration than the laminations of the fourth series. Means assemble the first and second series to the assembled third and fourth series with the first and second open areas aligned. The electrical winding at least partially occupies both the open areas so that the magnetic assembly comprises two closed loops of ferrous material, each of two series of laminations, with the laminations of one loop overlapping the laminations of the other loop to achieve a desired magnetic efficiency.
In one embodiment, the first and fourth series of laminations have the same configuration and the second and third series of laminations have the same configuration. In this embodiment of the invention, the first and third series are assembled in abutting relation and the second and fourth series are in abutting relation to minimize the existence of significant air gaps.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate a presently preferred embodiment of the invention, and together with the general description given above and the detailed description of the preferred embodiment given below, serve to explain the principles of the invention.
FIG. 1 is a perspective view of a sensing transformer embodying the invention;
FIG. 2 is an exploded view of the sensing core with its coil removed;
FIG. 3 is an enlarged, fragmentary, sectional view of a so called "partial perfing" or stake locking construction utilized to hold laminations together;
FIG. 4 is a side elevation of a first and second series of laminations employed in the embodiment of FIG. 1;
FIG. 5 is a side elevation of third and fourth series of laminations employed in the embodiment of FIG. 1;
FIG. 6 is a perspective view of another embodiment of the invention;
FIG. 7 is an exploded view of the embodiment shown in FIG. 6;
FIG. 8 is a view of two lamination assemblies utilized in the embodiment shown in FIG. 6 and 7;
FIG. 9 is a side elevation of one lamination configuration used in the embodiment of FIG. 6;
FIG. 10 is a side elevation of another lamination configuration used in the embodiment of FIG. 6;
FIG. 11 is a side elevation of one assembly configuration of the laminations of FIGS. 9 and 10; and
FIG. 12 is a side elevation of another assembly configuration of the laminations of FIGS. 9 and 10.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An exemplary embodiment of a magnetic assembly for use in, for example, a sensing core transformer as employed in an overload relay, is illustrated in FIGS. 1, 2, 4 and 5. The same is seen to include a first lamination assembly, generally designated 10, a second lamination assembly, generally designated 12 and abutted to one side of the lamination assembly 10, and an electrical coil assembly, generally designated 14 mounted thereto. As is well known, in a sensing core transformer, another conductor will typically be employed as, for example, a conventional bus bar (not shown) disposed to extend through the lamination assemblies 10 and 12 in a conventional fashion.
The coil assembly 14 is conventional and includes a bobbin 16 made of a conventional insulating material as, for example, a plastic. An electrical conductor 18 is wound about the bobbin 16 to form an electrical coil.
As seen in FIG. 4, the lamination assembly 10 is made up of a series of U-shaped laminations 20 having opposed, generally parallel legs 22 and 24 connected by a bight 26. As a result, a central open area 28 is defined. As illustrated, the open area 28 has a somewhat enlarged upper end 30. As can be seen in FIG. 1, the bobbin 16 is impaled on the leg 24 and is such is to substantially fill the central area 28 except for the enlarged area 30. The latter is reserved for the bus bar (not shown) mentioned earlier.
The legs 22 terminate in facing concave surfaces 32 and 34 respectively. The ends of the legs 22 and 24 are also provided with notches 36 for purposes to be disclosed.
Extending between the concave surfaces 32 and 34 is a second series of laminations 38 which, with the first series 20, defines a closed loop of the ferrous material. The laminations 38 terminate in oppositely directed convex surfaces 40 and 42 which are complimentary with and engage the surfaces 32 and 34 as best seen in FIG. 4.
The second lamination assembly 12, as best seen in FIG. 5, also includes a series of generally U-shaped laminations 50 having an open central area 28 with an enlarged open end 30 as before. The open area 28 may be closed by a fourth series of laminations 52 which bridges the legs 54, 56 of the laminations 50 again to form a closed loop of the ferrous material.
It is important to note that the distance between the facing surfaces 32 and 34 of the lamination assembly 10 is slightly less than the distance between the opposed, oppositely directed surfaces 40, 42 of the laminations 38. Typically, the difference in distance will be on the order of 0.020 inches. This provides a means whereby when the surface 32 is abutted to the surface 40 and the surface 34 is abutted to the surface 42, an interference fit will result to hold the laminations 38 assembled to the laminations 20.
To hold individual laminations 20 in assembled and aligned relation, they are typically held by a construction known as partial perfing or stake locking. An example of stake locking is illustrated in FIG. 3 and the endmost lamination 60 in a stack includes an opening 62. The adjacent laminations 64, 66, 68 and 70 all have respective perforations displaced into the adjacent lamination. Thus, the lamination 64 has a perforation 72 displaced into the opening 62 while the lamination 66 includes a perforation 74 displaced into the perforation 72. The lamination 68 includes a perforation 76 displaced into perforation 74 while the lamination 70 includes a perforation 78 displaced into the perforation 76. This type of construction is known in the art and will not be described further herein. Equipment for forming the partial perforations or stake holding structure may be obtained, for example, from Swanbro Corporation of Elk Grove Village, Ill. or L. H. Carbide of Fort Wayne, Ind.
As can be seen in FIG. 2, the laminations 50 making up the part of the second lamination assembly 12 are assembled together, and to the laminations 20 making up part of the first lamination assembly 10 and are all held in place by locking means of the sort just described at locations such as illustrated at 80. Similar structure, also shown at 80, may be used to fasten the laminations 52 to one another and to the laminations 38.
In the embodiment illustrated in FIGS. 1-5, inclusive, the legs 22 and 24 of the first lamination assembly 10 may be spread slightly by placing a tool in the notches 36 and applying an expanding force thereto. This allows that part of the lamination assembly 10 made up of the laminations 38 and that part of the lamination assembly 12 made up of the laminations 52 to be inserted laterally in place after, of course, the winding assembly 14 has been impaled on the lamination assemblies. When the expanding force applied to the notches 36 is released, an interference fit results.
It is to be particularly observed that in this embodiment of the invention, the configuration of the laminations 20 is different from that of laminations 50, which in turn is different from that of the laminations 38, which in turn is different from that of laminations 52. When assembled, the laminations 38 will be generally aligned with the laminations 52 while the laminations 20 will be aligned with the laminations 50. However, because of their difference in configuration, there will be considerable overlap to prevent any single continuous air gap which could interfere with the magnetic efficiency of the assembly. By appropriately selecting the number of laminations in each of the assemblies 10 and 12, the air gaps that are present can be adjusted to set the system for a range of amperage that is desired for the particular piece of equipment with which the cores are to be used.
A further, and highly preferred embodiment is illustrated in FIGS. 6-12, inclusive. In this embodiment, the coil assembly 14 is again employed and includes the bobbin 16 along with an electrical winding 18 thereon. Two lamination assemblies, generally designated 100 and 102, are employed in this embodiment of the invention. Each is made up of a plurality of laminations 104 that are interferenced fitted in assembled relation with a plurality of laminations 106. As illustrated, the number of laminations employed in each of the assemblies 100 and 102 is the same and as with all the laminations, each is made up of a thin sheet of ferrous material, usually steel. However, on some instances, a different number of lamination, and/or differing thickness of the assemblies 100 and 102 may be used to develop particular magnetic characteristics.
Each of the assemblies 100 and 102 in turn is made up of a series of the laminations 104 together with a series of the laminations 106. The configuration of the laminations 104 is shown in FIG. 9 and is basically that of a shallow U-shape having a central bight 110 flanked by legs 112 and 114. The legs 112 and 114 have facing, generally parallel surfaces 116 and 118 respectively.
The space between the legs 112 and 114 defines a central open area 120 as seen in FIG. 11 and which may be closed off by assembly of the laminations 106 to the laminations 104 as illustrated in FIG. 11 to form a closed loop of magnetic material. Again, the open area of 120 has an enlarged upper end 122 for receipt of a bus bar or the like while the remainder of the open area 112 receives one part of the bobbin 16.
Each lamination 106 is also somewhat U-shaped but in this case, the two legs 124 are located somewhat closer to one another than the legs 112 and dimensioned so that they nest within the legs 112 and 114. In this regard, the legs 124 and 126 have oppositely facing, generally parallel surfaces 128 and 130 that are adapted to interference fit with the surfaces 116 and 118 on the legs 112 and 114 of the laminations 104. Preferably, the surfaces 128 and 130 are approximately 0.020 inches further apart than the surfaces 116 and 118 to achieve the desired interference fit.
The bight 132 of each of the laminations 106 is extended somewhat past the legs 124 and 126 to provide extensions 134 and 136 which, together with the outer surfaces of the legs 112 and 114, form a rectangular peripheral shape as seen in FIGS. 11 and 12.
FIG. 11 illustrates how the laminations 104 and 106 are arranged to provide the first lamination assembly 100 while FIG. 12 illustrates the arrangement of the laminations 104 and 106 to form the second lamination assembly 102.
Preferably, the outer most corners of the legs 124 and 126 may be slightly chamfered as at 140. A similar chamfer 142, may be located on the inner corners of the legs 112 and 114 to aid in assembly so that the legs 112, 114 may be cammed somewhat apart by the legs 124 and 126 to achieve the desired interference fit between the surfaces 116 and 128 and the surfaces 118 and 130.
Typically, stake holding formations as shown at 144 and are generally as described in connection with the first embodiment are used as a holding means. They are not only used to hold the laminations 104 and the laminations 106 in abutting relation to each other, but also may be used at the interface of the assemblies 100 and 102 to hold them in assembled relation as well.
The embodiment shown in FIGS. 6-12 is a preferred embodiment in the sense that only two different lamination configurations are required, that is, only the lamination shapes of the laminations 104 and 106 are needed. In contrast, four different lamination shapes are required for the embodiment of FIGS. 1-5, which in turn means it is more expensive to tool.
In the embodiment shown in FIGS. 6-12, overlaps to control air gap losses are achieved simply by making the laminations 104 and 106 of a different configuration but then reversing their side to side arrangement as they are stacked by abutting the assembly 100 to the assembly 102 as illustrated in the drawings.
From the foregoing, it will be appreciated that a core for a transformer or the like made according to the invention can be made of relatively small size. Wide parts of the laminations heretofore required so as to allow the laminations to be assembled by rivets are avoided. The use of the stake holding means to assemble the individual laminations in a given series to one another also provides a means of eliminating other securing methods such as spring clips or adhesives heretofore employed. At the same time, the use of an interference fit to secure lamination parts to one another to define a closed loop of ferrous material which is at least partially occupied by the coil provides a further means whereby conventional fastening methods may be avoided. Ultimately, the unique structures and methods employed result in a sensing coil of economical construction and yet of relatively small bulk so that it may be readily and advantageously incorporated in electrical apparatus requiring small size.
Furthermore, the unique arrangement of laminations of differing configurations allows one to control air gaps within the overall assembly to achieve a desired magnetic effectiveness, dependent upon the ultimate use to which the sensing cores are to be put.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in the broader aspects is not limited to the specific details, and representative devices, shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
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Size constraints imposed by riveting of the laminations of a sensing core transformer that cost constraint imposed through the use of adhesive in assembling laminations together in a sensing core along with the use of additional fasteners are eliminated through the use of two lamination assemblies, that are interference fitted at complementary surfaces to form a series of lamination assemblies to which a coil assembly may be applied. Individual laminations may be held together by stake holding structure.
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TECHNICAL FIELD
[0001] The present invention relates to modular wooden decking for patios, balconies or terraces.
BACKGROUND OF THE INVENTION
[0002] It has become increasingly common for some types of work, traditionally done by craftsmen, to be done now by do-it-yourself enthusiasts. One type of work often done by owners of houses, summer holiday cottages and the like is the construction of wooden decking for patios, terraces, balconies and the like. At the places where the construction elements for wooden decking are sold, for example at DIY stores, sawmills or the like, the boards and joists forming the main components of wooden decking are sold in lengths which make it difficult to transport the elements needed for the wooden decking in a car or on the roof rack of a car. It is often necessary to shorten some of the building elements in order to be able to take them away. Another problem is that it may be difficult to calculate how many joists and boards need to be purchased to be able to construct a certain size of wooden decking, as it is necessary to take into account that a certain amount of material may be wasted. This difficulty is accentuated if the joists and boards available at the point of sale do not have the same length, which they often do not have. The result is that the purchaser often buys more construction elements than are actually needed, so as to avoid having to buy further construction elements at a later time. This in turn leads to more material being wasted and then having to be dealt with.
[0003] Even work as simple as constructing wooden decking with the construction elements presently available at DIY stores requires a certain level of craftsmanship. The joists have to be sliced, and the boards have to be sawn and secured to the joists. For the wooden decking to be esthetically pleasing, the joins between the joists have to be neat, and the saw cuts made in the boards have to be at right angles both transversely and in depth. This can be a difficult task for the average do-it-yourself enthusiast, and it means that the end result may be wooden decking that is functionally satisfactory but esthetically unattractive.
[0004] There is therefore a need to permit wooden decking construction in which the building components are easy to transport by car, and the wooden decking can be easily constructed without requiring skilled craftsmanship.
[0005] The objects of the present invention are to satisfy this requirement and at the same time to provide a construction which eliminates waste or at least to a large extent reduces waste.
SUMMARY OF THE INVENTION
[0006] According to the invention, these objects are achieved by means of modular wooden decking for patios, balconies or terraces, characterized by a framework made up of a plurality of identical rectangular frames which are arranged alongside one another and whose sides have lengths which are a multiple of the length of the shortest side, and boards laid on top of the frames and secured to them, said boards having a length which is a multiple of the length of the shortest side of the frame. Wooden decking of this type is very easy to assemble and involves simply laying the frames alongside one another across the surface that the wooden decking is to cover, and then securing the boards to the frames. The only tool needed for joining the boards and the frames together is a screwdriver or a hammer, depending on the type of securing element used. There is normally no need for any sawing of joists or boards.
[0007] In a preferred embodiment, the boards have the same width and are secured to the frames with a spacing a between adjacent boards, and a multiple of the sum of the width of a board and the spacing a between adjacent boards is equal to the length of the longest side of the frames. The frames can advantageously be square and made up of four identical joists which have a width greater than the spacing a between the boards.
[0008] In a preferred variant, each frame has a central joist arranged midway between the two shortest sides of the frame, and the boards are screwed securely to the frames, with screw holes being pre-drilled in the boards in order to make assembly easier.
[0009] The invention also relates to a package for a unit forming part of the modular wooden decking described above, characterized in that the package contains all the components included in a modular unit of frame(s), central joist(s), boards, angle irons and screws.
[0010] In one variant, the invention also relates to a package for a unit forming part of the modular wooden decking described above, characterized in that it comprises angle irons and screws for one or more modules. Such a package can be included inside a package for one or more module units.
BRIEF DESCRIPTION OF THE DRAWING
[0011] The invention will now be described with reference to the attached figures, in which:
[0012] FIG. 1 shows a schematic perspective view of a frame according to a preferred embodiment of the invention,
[0013] FIG. 2 shows a schematic perspective view of the frame from FIG. 1 , with boards fitted onto it,
[0014] FIG. 3 shows a schematic top view of the frame from FIG. 1 ,
[0015] FIG. 4 is a schematic illustration of how two frames according to FIG. 1 are joined together,
[0016] FIG. 5 shows the frames from FIG. 4 joined together and with boards fitted onto them, and
[0017] FIGS. 6-8 show schematic perspective views of different combinations of frames and boards.
DESCRIPTION OF EMBODIMENTS
[0018] FIGS. 1 and 3 show a square frame 1 made up of four identical wooden joists 2 whose end areas are secured to one another in a suitable manner, for example with the aid of angle irons 3 screwed into the ends of the joists. The frame 1 constitutes a modular unit of the wooden decking according to the invention and is advantageously of such a size that it can be carried in the luggage compartment of a car or on a roof rack of a car. In the embodiment shown, the sides of the frame have a length l of ca. 1200 mm, and a central joist 4 is arranged midway between two opposite sides of the frame 1 so that the boards to be fitted onto the frame will be mounted with a suitable central spacing between the supports. The central joist 4 is secured to the frame in a suitable manner, for example with the aid of angle irons 3 , as in the embodiment shown in FIGS. 1 to 3 .
[0019] The frame configured as a modular unit can of course have a different length than the one mentioned above; for example, it can be rectangular, with long sides having a length which is a multiple of the length of the short sides, e.g. twice as long as the short sides. For example, the short sides can have a length of ca. 600 mm. With such a configuration, no central joist is needed to obtain a suitable central spacing between the supports for the fitted boards. However, the short sides should not be shorter than 500-600 mm, so as to avoid an unnecessarily large number of joists being included in the finished wooden decking. It is also possible to imagine a rectangular frame with short sides having a length of ca. 1200 mm and long sides which are twice as long. If the long sides are longer than ca. 2400 mm, it may be difficult to transport the frames in a car, and for this reason the length of the long sides is preferably at most ca. 2400 mm.
[0020] FIG. 2 shows a schematic view of the frame from FIG. 1 , provided with boards 5 laid on top of it. In FIG. 3 , broken lines indicate the boundaries 6 , 7 of the different boards. As can best be seen from FIG. 3 , the boards 5 are separated from one another by a spacing a which, for example, can be between 6 and 10 mm. The length of the boards 5 in FIG. 2 is equal to the length l of the sides of the square frame 1 , and a multiple of the sum of the width of each board 5 and the abovementioned spacing a is equal to the length l of a frame side. Such a configuration ensures that the boards 5 of units 8 composed of frame and fitted boards according to FIG. 2 and adjacent to one another in the transverse direction of the boards can be arranged with a spacing a between them. The thickness of the joists 2 is preferably greater than the spacing a. In the longitudinal direction of the boards, the board ends lie against one another in longitudinally adjacent units according to FIG. 2 .
[0021] FIG. 5 shows a second unit 10 made up of two frames according to FIG. 1 and with fitted boards 9 . This unit differs from the embodiment shown in FIG. 2 in that the boards 9 are twice as long as the boards 5 . Otherwise, the embodiment is the same as the one described above. As is indicated in FIG. 4 , the unit 10 is constructed from two frames 1 which are brought together as indicated by arrows in FIG. 4 and are then preferably secured to one another, for example by being screwed together. The boards 9 are then fitted on top and secured to the joists 2 and central joists 4 lying in the transverse direction of the boards.
[0022] FIG. 6 shows two units 10 according to FIG. 5 joined together to form a square unit, and FIG. 7 shows four units 8 joined together to form a square unit with the same size as the unit in FIG. 6 . It will be seen from FIGS. 6 and 7 that wooden decking of different patterns can be constructed depending on which module length of the boards is used.
[0023] FIG. 8 shows a unit made up of five frames, where boards 5 of module length l have been used for the frame 1 extending out to the right in FIG. 8 from the square made up of four frames 1 , and boards 9 of twice the module length have been used for the frames in the square made up of four frames.
[0024] For the system according to the invention to have the necessary flexibility, boards 5 , 9 of different length should therefore be included in the system, and the lengths of the boards will constitute a multiple of the module length l.
[0025] In the embodiment shown in FIG. 8 , identical frames have been used. However, this is not necessary for wooden decking according to the invention, and it will be appreciated that the boards 9 can cooperate with a frame of twice the module length.
[0026] By means of the above-described system of frames and boards, wooden decking can be constructed by first laying the frames out so that they completely or partially cover the surface area to be provided with wooden decking. The frames are then secured to one another, for example by means of screws, after which the boards are laid on top of the respective frame or pair of frames depending on whether the boards have the length l or 2l. The boards are then secured to the frames, preferably by screwing. It is therefore very easy for a do-it-yourself enthusiast to construct wooden decking by means of the above-described system of frames and boards.
[0027] It is not entirely necessary to connect the frames to one another, but such connection is preferred from the point of view of stability. The frames included in a unit 10 according to FIG. 5 , however, do not need to be connected directly to one another, and instead they can be indirectly connected to one another via the boards 9 . It is also possible to surround the whole of the wooden decking with side pieces which are secured round the edge of the wooden decking and avoid horizontal shifting of the units of frames and boards included in the wooden decking. These side pieces preferably have a width or height which at least corresponds to the sum of the frame height, i.e. the width of joists included in the frame, and the thickness of the boards.
[0028] The only tool needed for constructing wooden decking by means of the described system of frames and boards is a screwdriver if screws are used as securing elements, or a hammer if nails are used as securing elements. To make it easier to secure the boards, they can be provided with pre-drilled holes at the level of the joists and central joists. The fact that all the boards, central joists and joists have been cut by machine at the time of purchase means that even the average do-it-yourself enthusiast will achieve a satisfactory result on assembling the described wooden decking. Machine cutting means that exact lengths are obtained, something which is difficult to achieve when cutting by hand.
[0029] So that the frames take up less room and are easier to transport, they can be supplied in a disassembled state and then put together on site by the do-it-yourself enthusiast or someone else. To facilitate the purchase of the components and the calculation of the amount of timber needed, it may be advantageous for all the components included in a unit 8 , 10 of frame(s) 1 , central joist(s) 4 , boards 5 or 9 , angle irons 3 and screws to be supplied in individual packages.
[0030] It is moreover advantageous if the fittings, i.e. angle irons or the like and screws or nails, for one or more modules are packed in a bag or the like which can be included in a package for one or more modules according to the above or can be supplied separately.
[0031] The described embodiments can of course be modified within the scope of the invention. The modules forming part of the wooden decking can have other dimensions than those indicated, and the spacing between the boards can be different than stated. The boards can be profiled on one side or on both sides. Moreover, elements other than angle irons can be used for connecting the joist ends to one another, for example wooden corner blocks to which the joist ends are secured, or just screws or nails. The invention is therefore limited only by the content of the attached patent claims.
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The present invention relates to modular wooden decking for patios, balconies or terraces. According to the invention, the wooden decking comprises a framework made up of a plurality of rectangular frames ( 1 ) which are arranged alongside one another and whose sides have lengths which are a multiple of the length of the shortest side (l), and boards ( 5, 9 ) laid on top of the frames and secured to them, said boards having a length which is a multiple of the length (l) of the shortest side of the frame.
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BACKGROUND OF THE INVENTION
[0001] NPB (n-propyl bromide) has been used in the metal parts degreasing industry, particularly in vapor degreasers for years. Now according to the invention it has been discovered to have a very useful and desired purpose in other industries. Many substrates, for example, home textiles, carpets, upholstery acquire oil-,water- and soil-repellant properties by treatment with fluorocarbons.
[0002] These chemicals are now applied to substrates with water based (aqueous) carriers requiring other auxiliary chemicals i.e.: emulsifiers and dispersing agents to keep organics in suspension. These auxiliary chemicals needed for aqueous application often lesson the intended benefit of the applied chemical to the substrate. These aqueous carriers require high temperatures and expensive drying systems to evaporate the water. Chlorinated hydrocarbons have been used in the past as carrier mediums to apply organic chemicals to substrates when an aqueous carrier could not be used. Chlorinated hydrocarbons are being phased out by mandate of the Environmental Protection Agency (EPA).
BRIEF SUMMERY OF THE INVENTION
[0003] By this invention, NPB has shown an excellent alternative to current aqueous and chlorinated hydrocarbons as a carrier medium for application of organics to substrates. NPB is non-regulated, non-toxic and has no ozone pollution properties. NPB is economical and environmentally friendly.
[0004] After extensive study, it has been found that the use of NPB as a carrier dramatically improves the performances and durability of benefits achieved by application of organics to substrate and that this invention is superior to current methods and chemistry.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0005] The invention relates to methods and formulations to provide substrates with treatment to include oil and water repellant treatment, for example; the treatment of home textiles and apparel, which achieve desired effects with significantly smaller amounts of expensive fluorocarbon compounds as Compared to available current technology, as illustrated in Example 2 Compared to Example 4.
[0006] The following description, taken in conjunction with the referenced examples, is presented to enable one of ordinary skill in the art to make and use the invention. Various modifications will be readily apparent to those Skilled in the art, and the general principles defined herein may be applied to a wide range of aspects. Thus, the present invention is not intended to be limited to the aspects presented, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. Furthermore, the compositions according to the invention should furthermore impart to the substrates, in particular the home textiles, water-repellant actions that meet increased requirements. Another object comprises providing treatment compositions with which the heat treatment can be carried out at the lowest temperature or, preferably, no heat treatment is necessary (Example 3).
[0007] In one aspect, invention relates to substrates from the group consisting of naturally occurring and synthetic textiles and their mixtures, leather, mineral substances, thermoplastic and thermosetting polymers and paper, which are treated with fluorine-containing compositions of the type mentioned below in an amount of 10 to 10,000 ppm, preferably 50 to 5,000 ppm, particularly preferably 100 to 2,000 ppm, calculated as fluorine and based on the total weight of substrates provided with an oil-, water- and soil-repellant treatment.
[0008] In another aspect, other textile auxiliary chemicals can be added during preparation of the treatment formula as according to the invention, or subsequently. Such additives are crease-proofing and soft handle agents, melamine, flame retardant, oleophobizing agents, hydrophobizing agents, Urethane, finishing agents, extenders for textile auxiliaries and others.
[0009] Substrates which are suitable for imparting oil-, water- and soil-repellant properties according to the invention are: linen, cotton, wool, silk, jute, polyamide, polyester, polyacrylonitrile and mixtures thereof, leather, stone slabs, floor tiles, glazed tiles, roof tiles, glass, ground surfaces of silicon, foils and films and compact workpieces of polyolefins, polyesters, polyamides, polycarbonates, polyurethane, polyacetals, polyethers, polysulphides, polysulphones, polyamides and other thermoplastics, as well as of phenol/formaldehyde resins, urea/formaldehyde resins, melamine/formaldehyde resins and other thermosetting resins, paper and paper-like materials, such as paperboard. Preferred base substrates are home textiles based on naturally occurring and synthetic textiles and their mixtures, which are employed, for example, as carpets, curtains, decorative materials or coverings for upholstered furniture.
[0010] Processes for the treatment of such base substrates and therefore for application of the fluorine-containing compositions according to the invention are known to the expert and are, for example, foaming, dipping or spraying of the base substrates; the compositions according to the invention furthermore can be employed during the production of the base substrates, for example the pulp.
[0011] Textiles as base substrates, preferably home textiles and apparel can be treated, for example, in the padding, spraying or foaming process. The padder consists of a liquor trough (chassis) and at least one pair of rubber rolls (Example 2). The textiles to be treated are impregnated with the treatment liquor in the chassis and squeezed off between the rolls; the liquor runs back into the chassis. It is very important that a uniform liquor pick-up is achieved over the entire width of the goods during squeezing-off.
[0012] In the padding process, the liquor pick-up is stated in percentage of the weight of goods, and for normal textile constructions can be between 30 and 300%, depending on the quality of the goods and the padder pressure used.
[0013] In the spraying process, (Example 3) the textile is sprayed with the treatment liquor. The treatment liquor is finely divided by nozzles and applied uniformly. An amount of treatment liquor precisely defined beforehand is applied to one square meter of textile goods.
[0014] In the foaming process, the treatment liquor is continuously foamed mechanically in a commercially available mixer with out the addition of a foaming agent. The foam is produced in the mixing head by mixing the liquor with air. The foam, which emerges, is conveyed via a foam line to a discharge slot in the applicator. The goods are pressed against the slot and taken off via a separate unit, for example a stenter frame. In example 1, a concentration of 98% NPB and 2% Perfluoroalkyl polyacrylate were used. The experiments were carried out on the Gaston Systems, Inc. Foam Applicator, Stanly, N.C.
[0015] By the invention, it has been discovered surprisingly that a mixture of NPB and Perfluoroalkyl polyacrylate can be foamed with or without the aid of a foaming agent (Example 1). Not using foaming agents greatly improves the benefit of the applied fluorine composition to the substrate and reduces the amount of compound added to fabric to achieve water and oil repellency.
[0016] In another aspect, this invention involves the surprising discovery that the use of NPB applied in 100% concentration via dipping and squeezing with pressure rollers (Padding) and the NPB being evaporated away imparts a much improved softness and luster to textile substrates, especially home furnishing, apparel fabrics and upholstery fabrics.
[0017] After the treatment, the textiles, preferably home textiles, are dried, it being possible to use temperatures of 120.degree. to 170.degree. C. to achieve the desired treatment effect according to the known procedure. However, good oil-, water- and soil-repellant treatments can also be obtained with the new compositions according to the invention at significantly lower drying temperatures, for example at 25.degree. C. (Example 3).
[0018] Samples of the materials thus pretreated were taken for testing of the following effects:
[0019] Oil-repellency (according to AATCC 118-1972): The test sample is placed on a horizontal, smooth surface, a small drop (drop diameter about 5 mm) of he test liquids is applied to the test sample with the aid of a dropping pipette, In addition, the sample is evaluated as specified.
[0020] The AATCC oil-repellency level of a test fabric is the highest number of that test liquid which does not wet or penetrate into the test material within a time span of 30 seconds. The test liquids and mixtures for the test method are: No. 1: Nujol or paraffin oil DAB 8; No. 2: 65% by volume of Nujol and 35% by volume of n-hexadecane; No. 3: n-hexadecane; No. 4: n-tetradecane; No. 5: n-dodecane; No. 6: n-decane; No. 7: n-octane; No. 8: n-heptane.
[0021] Repellency towards a water/alcohol mixture (hydrophobicity): Drops of water/isopropanol mixtures (ratio 90/10 to 10/90) are applied to the test sample. The test result corresponds to the mixture with the highest isopropanol content which remains on the test sample in unchanged form for at least 20 seconds (the value 80/20, for example, is better than 20/80).
EXAMPLES
[0022] Compositions which are not according to the invention (Example 4) and which represent the prior art are the following: Nuva HPU (Clariant Corporation). Scotchgard.RTM. FC 396 (3M Comp.) according to DE-A 2 149 292 Baygard.RTM. SF-A. (Bayer AG) according to DE-A 3 307 420 and Zonyl (E. I. Dupont)
[0023] The compositions according to the invention (Examples 1, 2 & 3) are non-aqueous solutions contents of which comprise a mixture of NPB (component A) and one or more poly (meth) acrylates (component B).
Use of the Compositions According to the Invention
Example 1
[0024] A solution of 98% NPB and 2% Perfluoroalkyl polyacrylate were mixed and applied to the foam generator which imparts the solution to a high speed mixer that generates the solution into foam. The foam was then dispensed to the substrates listed in below via an applicator at 30%-wet pickup. The substrates were then dried at 170 deg C. for 1-minute dwell time with the following results:
Initial After 10 Home Laundries Example 1 Oil IPA Spray Fluoride Oil IPA Spray Fluoride Cotton 5 85 100 2160 ppm 2 60 70 1600 ppm Polyester 6 90 100 1170 ppm 5 90 90 980 ppm Pes/Rayon 6 80 100 5 60 70
Example 2
[0025] A solution of 99.6% NPB and 0.4% Perfluoroalkyl polyacrylate were mixed and applied to the substrates listed below via a pad applicator at 3.5 bars pressure. The solution was applied at noted wet pickup. Again, the substrates were dried at 170 deg C. with a 1-minute dwell.
Initial After 10 Home Laundries Example 2 Oil IPA Spray Fluoride Oil IPA Spray Fluoride Cotton 6 100 100 2480 ppm 3 90 80 2200 ppm Polyester 8 90 100 1270 ppm 6 90 90 1100 ppm Pes/Rayon 8 80 100 6 80 80
Example 3
[0026] A solution of 99.6% NPB and 2% Perfluoroalkyl polyacrylate were mixed and applied to the substrates listed below via a Spray at 1.5 bars pressure. The solution was applied at noted wet pickup. Again, the substrates were dried at 170 deg C. with a 1-minute dwell.
Initial After 10 Home Laundries Example 3 Oil IPA Spray Fluoride Oil IPA Spray Fluoride Cotton 6 85 100 2260 ppm 2 60 70 1690 ppm Polyester 6 90 100 1170 ppm 5 90 90 1080 ppm Pes/Rayon 6 80 100 5 60 70
Use of the Compositions Not According to the Invention
Example 4
[0027] An aqueous Perfluoroalkyl polyacrylate dispersion using Nuva HPU at 2% concentration was prepared and applied via a padding applicator at 3.5 bars pressure. The solution was applied at noted wet pickup. Again, the substrates were dried at 170 deg C. with a 1-minute dwell.
Initial After 10 H me Laundries Example 4 Oil IPA Spray Fluoride Oil IPA Spray Fluoride Cotton 7 100 100 2460 7 90 80 2210 ppm ppm Polyester 6 60 100 1270 4-5 45-50 90 1100 ppm ppm Pes/Rayon 5 60 100 2 35-40 70
[0028] In all examples, the substrates used were (1) White Polyester 8 oz/sq yd (PES), (2) 100% Cotton interlock and (3) 60/40 PES and Rayon Blend.
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The present invention relates to methods and chemical formulations utilizing NPB(n-propyl bromide) also called 1-bromopropane or propyl bromide or 1-BP or N-Bromopropane as non-aqueous carrier mediums to apply fluorocarbons and other chemicals to substrates, whereby the NPB is evaporated away leaving the remaining chemicals on the substrate. The present invention offers formula and method for applying organic chemicals to substrates that perform superior to current water based technology. Additional, the invention offers a more economical and environmental friendly alternative to current chlorinated hydrocarbons carriers that are being phased out by mandate of the Environmental Protection Agency (EPA).
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a national stage application under 35 U.S.C. §371(c) prior-filed, co-pending PCT patent application serial number PCT/EP2010/069347, filed on Dec. 10, 2010, which claims priority to Italian Patent Application No. CO2009A000067, filed on Dec. 17, 2009, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the present invention relate generally to compressors and, more specifically, to a mid-span gas bearing in a multistage compressor.
[0004] 2. Description of the Prior Art
[0005] A compressor is a machine which increases the pressure of a compressible fluid, e.g., a gas, through the use of mechanical energy. Compressors are used in a number of different applications and in a large number of industrial processes, including power generation, natural gas liquification and other processes. Among the various types of compressors used in such processes and process plants are the so-called centrifugal compressors, in which the mechanical energy operates on gas input to the compressor by way of centrifugal acceleration, for example, by rotating a centrifugal impeller.
[0006] Centrifugal compressors can be fitted with a single impeller, i.e., a single stage configuration, or with a plurality of centrifugal stages in series, in which case they are frequently referred to as multistage compressors. Each of the stages of a centrifugal compressor typically includes an inlet volute for gas to be compressed, a rotor which is capable of providing kinetic energy to the input gas and a diffuser which converts the kinetic energy of the gas leaving the impeller into pressure energy.
[0007] A multistage compressor 100 is illustrated in FIG. 1 . Compressor 100 includes a shaft 120 and a plurality of impellers 130 - 136 (only three of the seven impellers are labeled). The shaft 120 and impellers 130 - 136 are included in a rotor assembly that is supported through bearings 150 and 155 .
[0008] Each of the impellers 130 - 136 , which are arranged in sequence, increase the pressure of the process gas. That is, impeller 130 may increase the pressure from that of gas in inlet duct 160 , impeller 131 may increase the pressure of the gas from impeller 130 , impeller 132 may increase the pressure of the gas from impeller 131 , etc. Each of these impellers 130 - 136 may be considered to be one stage of the multistage compressor 100 .
[0009] The multistage centrifugal compressor 100 operates to take an input process gas from inlet duct 160 at an input pressure (P in ), to increase the process gas pressure through operation of the rotor assembly, and to subsequently expel the process gas through outlet duct 170 at an output pressure (P out1 )which is higher than its input pressure. The process gas may, for example, be any one of carbon dioxide, hydrogen sulfide, butane, methane, ethane, propane, liquefied natural gas, or a combination thereof
[0010] The pressurized working fluid within the machine (between impellers 130 and 136 ) is sealed from the bearings 150 and 155 using seals 180 and 185 . A dry gas seal may be one example of a seal that can be used. Seals 180 and 185 prevent the process gas from flowing through the assembly to bearings 150 and 155 and leaking out into the atmosphere. A casing 110 of the compressor is configured so as to cover both the bearings and the seals, and to prevent the escape of gas from the compressor 100 .
[0011] While additional stages can provide an increase in the ratio of output pressure to input pressure (i.e. between inlet 160 and outlet 170 ), the number of stages cannot simply be increased to obtain a higher ratio.
[0012] An increase in the number of stages in a centrifugal compressor leads to multiple problems. The bearings which support the shaft are outside a sealed area that includes the impellers. An increase in the number of stages necessitates a longer shaft. A longer shaft cannot be safely supported by the bearings for the same operating speed, which become further apart as the shaft length increases making the shaft more flexible.
[0013] As the rotor assembly gets longer, the shaft becomes flexible therefore decreasing the rotor natural frequencies. When operating at higher speeds, the decrease in the fundamental natural frequencies of the rotor assembly tends to make the system more susceptible to rotor-dynamic instability, which can limit the operating speed and output of the machine.
[0014] The other issue is the forced response due to synchronous rotor imbalance. When the operating speed coincides with a rotor natural frequency, the machine is defined to be operating at a critical speed, which is a result of rotor imbalance. The compressor must pass through several of these natural frequencies or critical speeds before reaching the design operating speed.
[0015] As the compressor passes through critical speeds, the vibration amplitude of the rotor must be bounded by damping from bearings. However, with a long shaft, the majority of the rotor-dynamic energy is transferred to bend the rotor instead of energy dissipation at the bearings. This results in low damped rotor modes and high amplification factors at rotor resonances that can lead to casing and impeller rubs and even catastrophic failure of the machine.
[0016] At higher speeds past the rotor critical speeds, fluid induced forces are generated between the rotor assembly and the casing (i.e. fluid induced rotor dynamic instability). These pulsations, stemming from fluid forces can excite destructive or even catastrophic vibrations if not adequately dampened. Rotor-dynamic instability is a different mechanism from critical speeds or imbalance response and often time is much more difficult to address.
[0017] It would be desirable to design and provide a multistage centrifugal compressor which includes additional stages without increasing the diameter of the shaft and other design parameters that would drastically change the size and cost of the machine.
BRIEF SUMMARY OF THE INVENTION
[0018] Systems and methods according to these exemplary embodiments provide for an increase in the number of stages in a centrifugal compressor while overcoming problems typically associated with such an increase.
[0019] According to an exemplary embodiment, a centrifugal compressor includes a rotor assembly having a shaft and a plurality of impellers, a pair of bearings located at ends of the shaft and configured to support the rotor assembly, a sealing mechanism disposed between the rotor assembly and the bearings, and a first gas bearing disposed between the plurality of impellers and configured to support the shaft. The first gas bearing receives a working gas from an impeller located downstream from the location of the first gas bearing.
[0020] According to another exemplary embodiment, a method of processing a working gas in a centrifugal compressor includes providing the working gas to an inlet duct of the compressor, processing the gas through a plurality of compression stages with each stage increasing the speed of the gas, bleeding a portion of the accelerated gas after a stage that is downstream from a midway point of the compression stages, providing the bled gas to a bearing, reintroducing the gas from the bearing to the working gas flowing in the compressor, and expelling the working gas from an outlet duct of the compressor.
[0021] According to a further embodiment, a centrifugal compressor includes a rotor assembly having a shaft and a plurality of impellers, a pair of bearings located at ends of the shaft and configured to support the rotor assembly, a sealing mechanism disposed between the rotor assembly and the bearings, and a plurality of gas bearings disposed between the plurality of impellers and configured to support the shaft. The gas bearings receive a working gas from respective impellers located downstream from a location of the gas bearings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The accompanying drawings illustrate exemplary embodiments, wherein:
[0023] FIG. 1 illustrates a multistage centrifugal compressor;
[0024] FIG. 2 illustrates a multistage centrifugal compressor according to exemplary embodiments; and
[0025] FIG. 3 illustrates a method in accordance with exemplary embodiments.
DETAILED DESCRIPTION
[0026] The following detailed description of the exemplary embodiments refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. Also, the following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims.
[0027] In exemplary embodiments, a mid-span bearing may be utilized to provide additional stiffness to the rotor assembly with a longer shaft to overcome the critical speed issue highlighted above. Such a bearing makes the rotor assembly less flexible and therefore allows the rotor-dynamic energy (due to synchronous rotor imbalance forces) to be transmitted to the bearings.
[0028] This three-bearing configuration increases the damping in the rotor modes and lowers amplification factors as the rotor traverses through the critical speed allowing for safe operation of the rotor assembly. A mid-span bearing may, therefore, be provided within the casing for facilitating an increased number of stages (i.e. longer shaft) and overcoming the rotor dynamic instability.
[0029] Surface speed of a shaft (such as shaft 120 ) is a function of its diameter. The diameter in the middle portion of the shaft is greater than the diameter at the end portions. The difference in speeds between these portions (i.e. between middle and end) may be in the order of 2 to 3 times. Therefore, the surface speed of a shaft is greater (by a factor of 2 to 3) at the center portion of the shaft than it is at the end portions.
[0030] Bearings, such as bearing 150 and 155 of FIG. 1 , may typically be oil bearings. Oil bearings, however, are limited to usage where surface speed is typically closer to the surface speed at end portions of the shaft.
[0031] A mid-span bearing according to exemplary embodiments may be a gas bearing. Gas bearings can be used where surface speed is closer to the surface speeds at middle portions of a shaft.
[0032] In existing systems, highly corrosive working fluids such as hydrogen disulfide can damage conventional oil lubricated journal bearings. Such damage, greatly limits the life of the machine as oil lubricated bearings are not resistant to corrosive gases. A process gas lubricated bearing, however, does not require such sealing and can operate even in this corrosive environment while maintaining the life of the machine.
[0033] In addition to having ultra high surface speed viscous fluid capability, there is negligible power loss with gas bearings relative to oil bearings. Oil bearings also require sealing systems for preventing leakage of oil into the gas being processed by the compressor. Gas bearings obviate this need for sealing systems.
[0034] FIG. 2 illustrates a compressor according to exemplary embodiments. Compressor 200 includes a shaft 220 , a plurality of impellers 230 - 239 (only some of these impellers are labeled), bearings 250 and 255 , seals 280 and 285 , inlet duct 260 for taking an input process gas at an input pressure (P in ) and outlet duct 270 for expelling the process gas at an output pressure (P out2 ). A casing 210 of the compressor 200 covers both the bearings and the seals and prevents the escape of gas from the compressor 200 .
[0035] Compressor 200 also includes bearing 290 . Bearing 290 may be located near the middle between the first and last impellers 230 and 239 in exemplary embodiments. The number of impellers 230 - 239 may be increased with the mid-span bearing according to exemplary embodiments than is currently possible for the additional reasons described herein further.
[0036] Currently, a limiting factor in the number of stages that can be included in a compressor is the ratio between the length and the diameter of a shaft. This ratio is referred to as the flexibility ratio. In order to operate effectively, a compressor may have a maximum flexibility ratio. This ratio can be increased with a longer shaft and a mid-span gas bearing according to exemplary embodiments.
[0037] The gas used in gas bearing 290 may be the gas being processed by compressor 200 . The placement of gas bearing 290 may be at a location where the rotor displacement for a nearest natural frequency may be most pronounced. This location may be of optimal effectiveness from a rotor dynamic point of view.
[0038] The gas being processed may be “bled” from an output of an impeller that is “downstream” from gas bearing 290 using known elements/components and methods. The term downstream is used in this case as it relates to the direction of the gas flow and higher pressure in the case of compressors. That is, pressure is higher downstream and lower upstream relative to a particular location. For example, as illustrated in FIG. 2 , gas bearing 290 is “upstream” relative to impeller 235 but is “downstream” relative to impeller 234 .
[0039] The pressure of the working gas coming into bearing 290 has to be at a higher pressure than the pressure of the working gas in “bounding” or “adjacent” stages to the gas bearing so that the gas flow is out of the bearing pad and not into the bearing pads.
[0040] The working gas, therefore, has to be bled from a stage that is beyond the location of gas bearing 290 . If bearing 290 is placed after five stages (i.e. impeller 234 ) for example, then the working gas has to be bled from a stage after the sixth stage (i.e. impeller 235 ). In one embodiment, the working gas may be bled from at least two stages downstream from the location of the mid-span gas bearing (i.e. after impeller 236 ). The high pressure is needed by bearing 290 to work in a stable manner.
[0041] The working gas that is bled from a downstream compression stage may be processed through filter 240 and provided to gas bearing 290 in some embodiments. Filter 240 may remove any impurities and particulates in the gas being processed. The rotor assembly may be flushed with gas via gas bearing 290 to remove heat from the assembly. The percent of working gas mass flow going to the bearing 290 may be less than 0.1% of the core flow.
[0042] Small bore channels may be provided between bearing 290 and the working flow path. The gas from bearing 290 may be lead into the flow path by the bore channel to the proper pressure.
[0043] An increase in the length of the shaft leads to an increase in a ratio of the length to the diameter of the compressor bundle/casing. This facilitates the addition of compression stages within the same casing.
[0044] Thus, according to an exemplary embodiment, a method for processing a gas 300 through a multistage compressor having a mid-span gas bearing includes the method steps in the flowchart of FIG. 3 . At 310 , a working gas may be supplied to an inlet duct of a compressor. The working gas may be processed by a plurality of compression stages to increase the pressure (and speed) at 320 . A portion of the working gas may be bled from its flow through the compression stages after it has been processed by a number of compression stages at 330 . This number of stages may be greater than one half of the compression stages in the compressor.
[0045] The gas may be supplied to a gas bearing at 340 to flush and remove heat from the rotor assembly, the gas bearing being located upstream of the filter. The gas supplied to the gas bearing may be reintroduced into the flow of the working gas at 350 . Gas from the final stage of compression may be expelled via the outlet duct at 360 . In some embodiments, the gas that has been bled may be processed by a filter to remove any impurities before being provided to the gas bearing.
[0046] The number of mid-span gas bearings may be greater than one. Additional (or, multiple) mid-span gas bearings may be included in some embodiments utilizing the principles described above. Also, a mid-span bearing may not be exactly in the center—it may be offset depending on the particular design and specifications such as having an odd number of stages. Each of the multiple gas bearings may receive working gas from a separate impeller downstream.
[0047] If multiple gas bearings are implemented within a compressor, the number of (compression) stages between the input and the first of the gas bearings may be the same as the number stages between the last of the gas bearings and the output. The multiple gas bearings may also be spaced apart by the same number of stages. Therefore, the number of stages between the input and the first gas bearing may be the same as the number stages between the first and the second gas bearings (and between each of the subsequent gas bearings) which may also be the same as the number of stages between the last gas bearing and the output, etc.
[0048] A first of the gas bearings may receive compressed gas from a stage that is both downstream from the first gas bearing and upstream from a second of the gas bearings. That is, the first gas bearing may receive compressed gas from a stage that is between the first and the second gas bearings.
[0049] Those skilled in the art will appreciate that the specific number of impellers described above and illustrated in FIG. 2 are purely exemplary and that other number of impellers may be used. There may be a greater or a lesser number impellers depending on the application. The shaft may be a single shaft.
[0050] Exemplary embodiments as described herein provide multiple advantages over compressors that are in use at present. Additional impellers (and longer rotor assembly) may be placed within one casing as opposed to having a series of casings for increasing pressure. Efficiency within each casing (having longer rotor assembly for example) is increased as well. Space requirements for compressors to achieve a particular ratio of output pressure to input pressure are reduced. The flexibility ratio is increased to facilitate additional impellers.
[0051] Length (L 2 ) of shaft 220 in compressor 200 ( FIG. 2 ) according to exemplary embodiments is greater than the length (L 1 ) of shaft 120 in compressor 100 ( FIG. 1 ).
[0052] In addition, the use of gas bearings also obviates the need for elaborate sealing systems within the casing as oil does not enter the casing. The cost is also dramatically reduced as a result of the design as described.
[0053] The above-described exemplary embodiments are intended to be illustrative in all respects, rather than restrictive, of the present invention. Thus the present invention is capable of many variations in detailed implementation that can be derived from the description contained herein by a person skilled in the art. All such variations and modifications are considered to be within the scope and spirit of the present invention as defined by the following claims. No element, act, or instruction used in the description of the present application should be construed as critical or essential to the invention unless explicitly described as such. Also, as used herein, the article “a” is intended to include one or more items.
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A centrifugal compressor includes a rotor assembly with a shaft and a plurality of impellers, bearings located at ends of the shaft and configured to support the rotor assembly, a sealing mechanism disposed between the rotor assembly and the bearings, and a gas bearing disposed between the plurality of impellers for supporting the shaft and receiving a working gas from an impeller downstream from a location of the gas bearing.
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BACKGROUND OF THE INVENTION
The present invention relates to an ignition apparatus of low-voltage wiring type for an engine using gasoline as a fuel.
In an automotive gasoline engine, it is widely utilized to supply lean mixture into the engine and combust it completely in order to meet the restrictions against environmental pollution. In the engine using the lean mixture, therefore, an accurate timing advance control is required over a wide range of ignition timing. In order to meet this requirement, a low-voltage wiring system has been put into practical use. In the low voltage wiring system, a distributor is eliminated and the ignition apparatus is arranged in each cylinder. Another advantage of the low-voltage wiring system is that the absence of a high-voltage wiring leads to a reduced trouble of the electrical system, and the wiring is simplified.
For an independent ignition apparatus to be arranged in each cylinder of a multicylinder engine, the ignition apparatus is required to be compact and slim. Under the circumstances, however, a conventional ignition apparatus which was combined with the distributor was used by reducing the size. Therefore, the efficiency was low and the reliability was not high.
A first prior art ignition apparatus will be explained with reference to a circuit configuration of the first prior art ignition apparatus shown in FIG. 10 .
A primary winding 31 of a transformer (ignition coil) 3 is connected to a battery 1 through a switching element 2 . An end of the secondary winding 32 of the transformer 3 is connected to the negative electrode of the battery 1 , and the other end thereof is connected to a spark plug 33 . FIG. 11A shows the current flowing in the switching element 2 , and FIG. 11B a current in the secondary winding 32 .
The switching element 2 is turned on/off by a control signal applied thereto from a controller not shown. Upon turning on of the switching element 2 , a current flows through the battery 1 , the primary winding 31 and the switching element 2 so that an electromagnetic energy is stored in the transformer 3 . An on-period of the switching element is designated as T on . At the time when the switching element 2 is turned off, the electromagnetic energy stored in the transformer 3 is represented by (Cs·Vs 2 )/2, where Cs is a distributed capacity of the secondary winding 32 and Vs is a secondary voltage. And when the switching element 2 turns off, the stored energy is transferred to the secondary side. As a result, the secondary voltage Vs rises to such an extent that plug gap 34 of a spark plug 34 breaks down and a discharge current flows. A transistor or a FET is generally used as the switching element 2 .
A capacitor discharge ignitor (CDI) disclosed in JP-A-60-252168 is shown in FIG. 12 as a second prior art. FIG. 12 shows a circuit configuration of the CDI. A battery 1 and a spark plug 33 are substantially identical to those shown in FIG. 10. A DC-DC converter 4 in series with a capacitor 5 is connected between the positive terminal of the battery 1 and the primary winding 31 of the transformer 3 . A switching element 2 A is inserted between the junction point between the DC-DC converter 4 and the capacitor 5 and the negative terminal of the battery 1 . The switching element 2 A requires a high allowable pulse current value, and therefore generally is composed of a thyristor. FIG. 13A shows a current flowing in the switching element 2 A, and FIG. 13B a discharge current flowing in the secondary winding 32 .
In FIG. 12, the voltage across the battery 1 is converted to a high DC voltage (e.g. 400 v) by the DC-DC converter 4 and charges the capacitor 5 . A pulse signal responding to an ignition timing is supplied to the gate of the switching element 2 A from a controller not shown, and the switching element 2 A turns on. A charge stored in the capacitor 5 is discharged through the switching element 2 A and the primary winding 31 of the transformer 3 . Thus, a high voltage is generated across the secondary winding 32 , and a discharge current of FIG. 13B flows. The discharge current from the capacitor 5 assumes a resonance waveform determined by an equivalent inductance as viewed from the primary side of the transformer 3 and the capacitance of the capacitor 5 . In order to turn off the thyristor positively in preparation for the next firing, it is a general practice to turn on the thyristor only during the positive half cycle and turn it off during the next negative half cycle. In the first conventional ignition apparatus, the transformer 3 has dual functions of storing the electromagnetic energy and boosting the voltage. As regards the energy storage, however, an inductance device have a low volume ratio as described below. The number of turns of the primary winding 31 is determined by the inductance required for the electromagnetic energy storage. Further, the requirement for a large step-up ratio greatly increases the number of turns of the secondary winding 32 . As a result, the distributed inductance and the distributed capacitance are increased, thereby adversely affecting the energy transfer efficiency of the transformer.
Further, it is necessary to turn on the switching element 2 before the desired ignition timing. This timing is determined based on the information on the previous cycle. It is therefore difficult to control the turn-on timing accurately following the sudden change of the engine speed.
In the CDI system of the second prior art, the energy storage element is the capacitor 5 . The capacitor 5 is smaller than the transformer 3 for the same energy storage, and therefore the energy storage element can be reduced in size. The transformer 3 is not required to store energy, and can be greatly reduced in size, because the magnetic saturation due to the exciting current is the sole matter of consideration. For example, the number of turns of the primary winding of the transformer in the second prior art is about one third of that in the first prior art. Thus the energy transfer efficiency is high. In view of the fact that the thyristor is used for the switching element 2 A, however, the discharge time has to be shortened in order to prevent a firing error. Furthermore, since the switching element 2 A is connected across the output terminal of the DC-DC converter 4 and the negative terminal of the battery 1 , the battery 1 is shortcircuited by the on-state of the switching element 2 A. Therefore, the on-period of the switching element 2 A can not be extended. The low ignition accuracy, therefore, has been the problem for the lean mixture requiring a long discharge time, 0.5 milliseconds for example.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to improve the capacitor discharge ignitor (CDI) and to provide a compact and highly reliable ignition apparatus of low-voltage wiring type which is long in discharge time and high in efficiency.
The ignition apparatus according to the present invention comprises a DC-DC converter connected to a DC power supply for converting the input DC voltage to a high DC voltage (e.g. 400 v), a capacitor connected to the output terminal of the DC-DC converter and charged by the output voltage of the DC-DC converter, a transformer including a primary winding with an end thereof connected to an end of the capacitor and a secondary winding connected to a spark plug, and switching means including an insulated gate bipolar transistor (IGBT) and a diode connected in inverse-parallelism and inserted between the other end of the primary winding and the other end of the capacitor.
When the switching means including the IGBT and the diode turns on, a resonance current of a frequency determined by the capacitance of the capacitor connected in parallel to the DC power supply and the inductance of the primary winding of the transformer flows in the capacitor and the primary winding of the transformer. The resonance current is gradually decreased in a time determined by the capacitance of the capacitor. A voltage generated in the secondary winding by the resonance current causes discharge at the spark plug. According to the present invention, the switching means is conneted between the afore-mentioned other end of the primary winding and the afore-mentioned other end of the capacitor. Therefore, the battery is not shortcircuited by on-state of the switching means, and the time length of on-period of the switching means is not restricted. Moreover, the time during which the resonance current decreases gradually can be set to the desired length by selecting the capacitance of the capacitor.
According to the present invention, the extension of the sustained discharge time which has been difficult in the conventional CDI system is made possible, and the efficiency of the ignition apparatus is improved. Thus, the system is improved in reliability and reduced in size and cost.
Further, since the on-period of the switching element can be adjusted, the ignition energy can be supplied to the spark plug at the required time in the required amount thereby further improving the efficiency. The prior art system has been configured such that the energy is not regulated but a very much large margin of energy was always provided in anticipation of the worst operating conditions, and therefore, extraneous energy is consumed in normal state. In contrast, according to this invention, minimum required energy is secured for a higher efficiency, and the system can be remarkably reduced in size.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a circuit diagram of an ignition apparatus according to a first embodiment of the invention;
FIG. 2 A and FIG. 2B are waveform diagrams showing the operation of the first embodiment of the invention;
FIG. 3 is a circuit diagram showing an ignition apparatus according to a second embodiment of the invention;
FIG. 4A is a diagram showing a configuration of the transformer according to the second embodiment of the invention, and FIG. 4B is a diagram showing an equivalent circuit thereof;
FIG. 5 is a circuit diagram showing an ignition apparatus according to a third embodiment of the invention;
FIG. 6A to FIG. 6D are waveform diagrams showing the operation of the third embodiment;
FIG. 7 is a circuit diagram showing an ignition apparatus according to a fourth embodiment of the invention; FIG. 8 is a circuit diagram showing an ignition apparatus according to a fifth embodiment of the invention;
FIG. 9A to FIG. 9D are waveform diagrams showing the operation according to a fifth embodiment;
FIG. 10 is a circuit diagram of a first prior art ignition apparatus;
FIG. 11 A and FIG. 11B are waveform diagrams showing the operation of the first prior art ignition apparatus;
FIG. 12 is a circuit diagram showing a second prior art ignition apparatus; and
FIG. 13 A and FIG. 13B are waveform diagrams showing the operation of the second prior art ignition apparatus.
DETAILED DESCRIPTION OF THE INVENTION
Hereafter, preferred embodiments of the present invention will be explained with reference to FIG. 1 to FIG. 9 D.
[First Embodiment]
FIG. 1 is a circuit diagram of an ignition apparatus according to the first embodiment of the present invention. In FIG. 1, the positive electrode of a battery 1 is connected to an end of a primary winding 31 of a transformer (ignition coil) 3 through a DC-DC converter 4 for converting the input DC voltage to a high DC voltage (e.g. 400 v). The other end of the primary winding 31 is connected to the negative electrode of the battery 1 through a bi-directional switching element 20 . The switching element 20 includes an IGBT 21 and a diode 22 connected in inverse-parallelism to the IGBT 21 . The gate of the IGBT 21 is connected to a control unit 25 , and a control signal is applied from the control unit 25 to the IGBT 21 . A capacitor 5 is connected between the junction point between the DC-DC converter 4 and the primary winding 31 and the negative electrode of the battery 1 . An end of a secondary winding 32 of the transformer 3 is connected to the negative electrode of the battery 1 and the other end thereof is connected to a spark plug 33 . The turns of the secondary winding 32 is more than that of the primary winding 31 . FIG. 2A shows a current flowing in the primary winding 31 through the switching element 20 , and FIG. 2B shows a current flowing in the secondary winding 32 .
In FIG. 1, as long as the gate of the IGBT 21 of the switching element 20 is supplied with an on-signal from the control unit 25 , the switching element 20 is conducting in two directions. As a result, as shown in FIG. 2A, a discharge current at a resonance frequency determined by the capacitance of the capacitor 5 and an inductance as viewed from the primary side of the transformer 3 flows in the primary winding 31 . The discharge begins when the voltage across the secondary winding 32 exceeds the breakdown voltage of a discharge gap 34 of the spark plug 33 . During a time period (hereinafter is referred to as duration) when the voltage across the secondary winding 32 of the transformer 3 is not lower than the breakdown voltage of the discharge gap 34 , the currents flowing in the primary winding 31 and the secondary winding 32 becomes a gradually-attenuating resonance waveform as shown in FIGS. 2A, 2 B, respectively. The duration of the resonance waveform is dependent on the capacitance of the capacitor 5 . Therefore, by appropriately selecting the capacitance, a desired duration is obtained. Consequently, the discharge time can be extended in the ignition apparatus for the engine using lean mixture. The electromagnetic energy in the transformer 3 is transmitted from the primary winding 31 to the secondary winding 32 and is consumed as discharge energy in the spark plug 33 . When the voltage across the secondary winding 32 of the transformer 3 drops below the breakdown voltage of the discharge gap 34 , the discharge ceases. According to the first embodiment, the discharge time period can be selected in the range of 0.4 to 0.6 msec. The lean mixture, therefore, can be ignited accurately.
[Second Embodiment]
A second embodiment of the invention will be described with reference to FIG. 3 and FIG. 4 .
The discharge time can be further extended if the electromagnetic energy generated in the secondary winding 32 can be issued in the secondary side including the secondary winding 32 to a longer length of time. The inventor has found that this is possible by inserting a choke coil 37 in series with the secondary winding 32 . FIG. 3 is a specific circuit diagram of the second embodiment of the invention comprising the choke coil 37 . The configuration other than the choke coil 37 is identical to that of the first embodiment shown in FIG. 1 and will not be described. The provision of the choke coil 37 increases the discharge time by about 80 to 100%.
In the case where it is difficult to arrange the choke coil 37 independently on the high-voltage side including the secondary winding 32 , the same effect as if the choke coil 37 is inserted in the secondary side can be equivalently realized to some degree by changing the structure of the transformer 3 . A specific example of such a structure is shown in FIG. 4A, and an equivalent circuit is shown in FIG. 4 B. In FIG. 4A, the primary winding 31 and the greater proportion of the secondary winding 32 of a transformer 36 are wound in mutually overlapping relation to each other on an iron core 39 with the same winding width as far as possible in order to obtain a high coupling coefficient. A part 32 A of the secondary winding 32 is wound on another iron core 40 disposed apart with an air gap G from the iron core 39 .
The air gap G prevents the secondary winding 32 and the winding 32 A from being totally coupled with each other magnetically, and has the same effect as if an independent choke coil is connected in series to the secondary winding 32 . In such part of the iron core whereon the winding 32 A only is wound is not always necessary. For instance, an air core has some effect in the case where the electromagnetic energy is sufficiently large.
In the equivalent circuit of FIG. 4B, “L 1 ” represents a leakage inductance of the primary winding 31 , “L 2 ” represents a leakage inductance of the secondary winding 32 , and “M” represents a mutual inductance. “C 1 ” and “C 2 ” represent stray capacitances. By adding the winding 32 , the inductance L 2 becomes larger in comparison with the inductance L 1 . An electromagnetic energy once transmitted to the secondary winding 32 does not easily transferred to the primary winding 31 by the action of the choke coil equivalently arranged in the secondary side. And consequently, the duration of discharge retention is extended.
According to the second embodiment, the CDI system having a very high energy transfer efficiency is combined with a transformer (ignition coil) having a large leakage inductance which is increased by the choke coil of the secondary side. Consequently, a compact and highly efficient ignition apparatus with a long discharge time can be realized. According to an experiment and a simulation test conducted by the inventor, the efficiency becomes about twice as high as that of the prior art shown in FIG. 12 with the same output energy and the discharge duration time.
[Third Embodiment]
FIG. 5 is a circuit diagram of an ignition apparatus according to a third embodiment of the invention. FIG. 6A shows waveform of a current flowing in a switching element 20 in FIG. 5, FIG. 6B waveform of a voltage across a capacitor 5 , FIG. 6C a discharge waveform of a current flowing in a secondary winding 32 , and FIG. 6D an input current waveform supplied from a battery 1 . In the third embodiment, the DC-DC converter 4 of the first embodiment is replaced by a diode 7 connected in series with a choke coil 6 . A temperature sensor 26 for detecting an ambient temperature is connected to the control unit 25 . The configurations of the remaining component parts are similar to those of the first embodiment and will not be described.
Upon turning on the switching element 20 , the capacitor 5 begins to discharge. As shown in FIG. 6A, a discharge current flows for an on-period T on (in one example, 1-2 msec) while being attenuated as a resonance current determined by the capacitance of the capacitor 5 and the equivalent primary inductance of the transformer 3 . The on-period T on is decided by a pulse width of a pulse signal which is applied to the gate of the IGBT 21 from the control unit 25 . At the same time, a current flows also in the choke coil 6 so that an electromagnetic energy is stored therein. When the switching element 20 turns off at t 1 , the electromagnetic energy in the choke coil 6 is discharged so as to charge the capacitor 5 , and the voltage across the capacitor 5 increases to a predetermined level L 1 as shown in FIG. 6 B. An experiment by the inventor shows that a voltage of about 350 V is generated by using the battery 1 of 13V, the choke coil 6 of 1 mH and the capacitor 5 of 1 μF with the switching element 20 having an on-period T on of 1 ms.
When the switching element 20 turns off, a high voltage is generated across the secondary winding 32 by a flyback effect due to the current flowing in the primary winding 31 of the transformer 3 . When the high voltage exceeds the breakdown voltage of the spark plug 33 , as shown in FIG. 6C, a DC discharge current i flows again in the secondary winding 32 of the transformer 3 . As a result, a long discharge time is obtained which is the sum of the on-period T on of the switching element 20 and a period T d during which the discharge current flows in the secondary winding 32 by the flyback effect.
The third embodiment is based on the substantially same principle as that of the second embodiment from the view point that the electromagnetic energy is stored in the choke coil 6 . The choke coil 37 in the second embodiment has a great number of turns for a high tension and therefore, a complicated insulation construction. On the contrary, the choke coil 6 in the third embodiment has a simple insulation construction because of a low operation voltage. Since a power loss in the choke coil 6 for the low operation voltage is smaller than that of the choke coil 37 for the high operation voltage, a high efficiency is realized in the third embodiment in comparison with the second embodiment.
In the ignition apparatus according to the third embodiment, the ignition energy is determined by the voltage across the capacitor 5 . The voltage across the capacitor 5 depends on the current value of the choke coil 6 immediately before the switching element 20 turns off. Until the choke coil 6 is saturated, therefore, the current value is proportional to the on-period T on of the switching element 20 . Specifically, the ignition energy can be regulated by controlling the on-period T on . It is possible to maintain a constant ignition energy, for example, by controlling the on-period T on in accordance with the variations of the out put voltage of the battery 1 . In the case where the energy required for ignition undergoes a change under the effect of an ambient temperature, the on-period T on is controlled to a suitable value in accordance with the ambient temperature detected by the temperature sensor 26 . The on-period T on can be controlled responding to a rotation speed of an engine. As a result, extraneous energy consumption is suppressed while at the same time improving the reliability.
[Fourth Embodiment]
FIG. 7 and FIG. 8 are circuit diagrams of an ignition apparatus according to a fourth embodiment of the invention. In the fourth embodiment, as described in detail below, an AC current flows continuously in the secondary winding 32 of the transformer 3 during both an on-period T on and an off-period T off of the switching element 20 . Therefore, the discharge sustain time period can be freely set by repeating the on-off operation of the switching element 20 for a predetermined time period.
In the fourth embodiment, the on-off operation of the switching element 20 is repeated by 20 to 30 times for one ignition operation. FIG. 9A shows waveform of a current flowing in the switching element 20 . FIG. 9B shows waveform of a discharge current flowing in the secondary winding 32 . Each on-period T on in FIG. 9B is about 100 μsec, and is one twentieth or one thirtieth of the on-period T on in FIG. 6 A. FIG. 9C shows a voltage waveform across the capacitor 5 , and FIG. 9D shows an input current waveform. According to FIG. 7, a diode 8 is connected in inverse-parallelism to the capacitor 5 , and further, a switch 9 is connected across the junction between the choke coil 6 and the diode 7 and the negative electrode of the battery 1 . The configurations and operations of the remaining parts are substantially similar to those of the third embodiment, and therefore the superposed descriptions thereof are omitted.
The switching element 20 and the switch 9 are turned on/off at the same time, namely in synchronism. Upon turning on of the switching element 20 at time t0, the capacitor 5 begins to discharge, so that a current flowing in the switching element 20 assumes the waveform as shown in FIG. 9 A. After the current in the capacitor 5 reaches a peak, the current in the switching element 20 is gradually decreased due to clamping operation of the series circuit of the diode 8 and the switch 9 . A discharge occurs and energy is discharged in the spark gap 34 connected to the secondary winding 32 of the transformer 3 . As a result, a negative discharge current as shown in FIG. 9B flows for the on-period T on in the secondary winding 32 of the transformer 3 . At a time point t1 while the absolute value of the current in the primary winding 31 of the transformer 3 gradually decreases, assume that the switching element 20 and the switch 9 turn off. The excitation energy remaining in the transformer 3 is discharged, and therefore a flyback voltage is generated in the secondary winding 32 . Consequently, as shown in FIG. 9B, a gradually-decreasing positive discharge current flows during an off-period T off in opposite polarity to the on-period T on . Also, the electromagnetic energy stored during the on-period T on of the switch 9 by the current flowing in the choke coil 6 is discharged when the switch 9 turns off. The capacitor 5 is charged again by the discharged energy. In this way, the voltage across the capacitor 5 rises to a predetermined level as shown in FIG. 9 C.
By repeating this operation, the AC current can be continuously outputted in the secondary winding 32 of the transformer 3 . It is also possible to freely select the sustained discharge time of the spark plug 33 connected to the secondary winding 32 of the transformer 3 by controlling the duration of the on-off operation of the switching element 20 and the switch 9 .
Also, the electromagnetic energy stored in the choke coil 6 can be regulated by adjusting the on-period T on of the switching element 20 and the switch 9 . In this way, the charge voltage of the capacitor 5 can be changed, thereby making it possible to control the discharge energy of the spark plug 33 connected to the secondary winding 32 of the transformer 3 .
The on/off timings of the switching element 20 and the switch 9 are synchronized in the above-mentioned description. It does not necessarily require the synchronization of the switching element 20 and the switch 9 . Specifically, the Switch 9 can be turned on either before or after turn-on of the switching element 20 . Similarly, the switch 9 can be turned off at the same time as or after the switching element 20 is turned off. The discharge current waveform in the secondary winding 32 of the transformer 3 can be optimized by adjusting the on-period T on of the switching element 20 . Also, both the excitation energy stored in the choke coil 6 and the charge voltage of the capacitor 5 can be regulated by adjusting the on-period T on of the switch 9 .
In the case where the turning on/off of the switching element 20 and the switch 9 are completely synchronized with each other, as shown in FIG. 8, the diode 10 can be connected in forward direction across the junction point between the choke coil 6 and the diode 7 and the junction point between the secondary winding 31 and the switching element 20 , instead of the switch 9 . When connected in this way, the current in the choke coil 6 flows through the diode 10 and the switching element 20 . As a result, a voltage drop occurs by an amount equal to the forward voltage of the diode 10 , thereby unavoidably reducing the efficiency somewhat as compared with the circuit of FIG. 7 . Since the control circuit for controlling the switch 9 is eliminated, however, the whole circuit can be simplified.
Although the present invention has been described in terms of the presently preferred embodiments, it is to be understood that such disclosure is not to be interpreted as limiting. Various alterations and modifications will no doubt become apparent to those skilled in the art to which the present invention pertains, after having read the above disclosure. Accordingly, it is intended that the appended claims be interpreted as covering all alterations and modifications as fall within the true spirit and scope of the invention.
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An ignition apparatus for a gasoline engine of independent cylinder type with low-voltage wiring has no distributor, and a CDI (Capacitor Discharge Ignitor) is employed to improve the ignition characteristic of lean mixture. In order to lengthen a discharge time of the ignition apparatus of CDI type, the primary winding of a transformer in series with a switching element is connected in parallel to a capacitor, the ends of which are connected to a DC power supply. The switching element includes an IGBT and a diode connected in parallel to each other.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of international PCT application No. PCT/JP2005/005036 filed on Mar. 18, 2005.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a display apparatus using a cholesteric liquid crystal with an image memory function that the apparatus is capable of retaining a display state without requiring electric power (noted as “power” hereinafter), and particularly to a background color forming method for a cholesteric liquid crystal display (LCD) element.
[0004] 2. Description of the Related Art
[0005] Recent years have been witnessing a use of a cholesteric LCD element capable of retaining a display state without requiring the electricity, that is, capable of performing an image memory display, as a segment type display apparatus, et cetera. The cholesteric liquid crystal noted here is precisely defined as a selective reflection type cholesteric liquid crystal which has two stable states, i.e., an interference reflection state (i.e., a color reflection) for reflecting only a specific color and a transparent state (i.e., black) for transmitting light and which has a characteristic, namely a bistability, of being capable of retaining respective display states without requiring a power after being electrically driven. The cholesteric liquid crystal has a spiral molecular structure and a property of selective reflection reflecting only a light of a wavelength corresponding to the pitch of the spiral in the interference reflection state. Therefore, a use of a cholesteric liquid crystal having a spiral of a pitch corresponding to a wavelength of a color to be desirably reflected enables a desired color display.
[0006] Meanwhile, the cholesteric liquid crystal also has a property of mutual transition between the interference reflection state and transparent state which is caused by an external pressure and/or a thermal environment. Because of this, there is a problem of being very difficult to revert back to an initial state if an external action results in a change of states in a part in which a counter electrode does not exist, such as an outer circumferential part of a segment and in between electrode wirings.
[0007] Therefore, in an LCD apparatus, such as a conventional segment type display apparatus, a background color has been limited to black even though the segment part is a color display as shown in FIG. 1 . In the technical fields, such as clock, marker display, et cetera, putting emphasis on an industrial design, however, a colorful background is highly desired as shown in FIG. 2 .
[0008] The following is a description of reason for a background color being limited to black in a conventional display element using a conventional cholesteric liquid crystal by referring to FIGS. 3 and 4 .
[0009] FIG. 3 is a diagram of a conventional cholesteric liquid crystal display element 10 when looking at it from the display surface side. FIG. 3 shows an example of a segment display of the number “35” in color with black as the background. Also shown are segment lead wires 12 for applying a voltage to each segment electrode 11 .
[0010] FIG. 4 shows a cross-section of the conventional cholesteric LCD element 10 .
[0011] What are shown here are, from the display surface side, a layer of segment electrodes 11 and light-shield film 13 , a liquid crystal unit (i.e., a cell) 14 filled with a cholesteric liquid crystal, a light absorption layer 15 , a common electrode (i.e., a flat type electrode) 16 and a glass substrate 17 , while segment lead wires 12 are omitted. The segment electrodes 11 are transparent, while the light-shield film 13 and light absorption layer 15 are black.
[0012] In the conventional cholesteric LCD element 10 , a part which is a background part other than a segment part where there is no counter electrode pair part such as the segment electrode 11 and common electrode 16 is made black by forming the light-shield film 13 shielding a cell 14 of which the state can possibly be changed by an external action so as to make a reflection color of a segment as an On display and a black color of a transparent state, which is the same as the background color, as an Off display. This accordingly limits the background color to black.
[0013] It is of course easily possible to conceive a method for making a colorful background by coloring the light-shield film 13 to form a background color, and reversibly displaying negative (On) and positive (Off) displays; which, however, requires a segment reflection color to be exactly identical with a background color in order to bury the display color completely in the background. The reflection color of a segment is an interference reflection color of a liquid crystal expressing a special shade dependent on a view angle and it is therefore very difficult to make it identical with the background color which is colored with a pigment or dye.
[0014] Meanwhile, it is possible to form a background color by using a liquid crystal by comprising a background-use electrode; an inter-electrode space of tens micrometers needs to be formed for insulating a border with a display pattern electrode, however. Because of this space, it is not possible to bury the display color completely in the background.
[0015] As an example, each of the following reference patent documents 1 and 2 notes an LCD element forming a background color by comprising a background-use electrode; either of them, however, has not been able to bury the display color completely in the background since there is a gap, although it may be very small, between the electrode for the display pattern and that for the background.
[0016] As a configuration colorizing a background, the following reference patent document 3 notes a display element filling display cell with a liquid crystal, in which a transition from a cholesteric phase to a nematic phase is caused by applying an electrical field, added with a multi-color dye, and controlling a hue by applying an electrical field, thereby performing a display. This display element, however, has no image memory function and therefore a constant application of the electrical field is required for maintaining a display state.
[0017] Patent document 1: Japanese Published Patent Application No. H11-337672
[0018] Patent document 2: Japanese Published Patent Application No. 2002-229051
[0019] Patent document 3: Japanese Published Patent Application No. S53-35564
SUMMARY OF THE INVENTION
[0020] The problem for the present invention to be solved is to provide a cholesteric LCD element of a structure which is capable of forming a color background by using a low cost electrode structure and burying an Off display color completely in a background color.
[0021] For that purpose, the present invention is contrived to form a display part and a background part of the display element by means of a color reflection state and a transparent state of the cholesteric liquid crystal. The background is fixed to the color reflection state by employing a mechanical pressure for example. An alternative configuration is to make an electrode for the background and that for the display part as two-layer structure and allow no gap between both of the aforementioned electrodes when viewed from the front face of the display element. Furthermore, a configuration is to form a film of a pattern feature for displaying on one of counter electrodes within a cell and give a difference of drive voltages for changing states of the liquid crystal in regions of the pattern and on the outside thereof, thereby turning On-Off the display only in one zone of the pattern and outside thereof.
[0022] The adoption of the above described method makes it possible to form a color so as to bury an Off display color completely in the background color by using a low cost electrode structure in a display of a cholesteric liquid crystal, thereby improving a suitability to an industrial design and accomplishing a display of a high visibility.
BRIEF DESCRIPTION OF DRAWINGS
[0023] FIG. 1 is a diagram showing a conventional display element of which a background is black;
[0024] FIG. 2 is a diagram exemplifying a display element colorizing a background;
[0025] FIG. 3 is a diagram of a conventional cholesteric LCD element viewed from the front;
[0026] FIG. 4 is a cross-sectional diagram of a conventional cholesteric LCD element;
[0027] FIG. 5 is a front view diagram of a cholesteric LCD element according to a first embodiment;
[0028] FIG. 6 is a diagram describing an electrode pattern of a cholesteric LCD element according to a first embodiment;
[0029] FIG. 7 is a diagram describing a transparent state, a reflection state generated by applying an electrical field, and a reflection state generated by a mechanical action, in a cholesteric liquid crystal;
[0030] FIG. 8 is a front view diagram of a cholesteric LCD element according to a second embodiment;
[0031] FIG. 9 is a diagram showing a structure of an outer circumference electrode of a cholesteric LCD element according to the second embodiment;
[0032] FIG. 10 is a diagram showing a cross-section of a cholesteric LCD element according to the second embodiment;
[0033] FIG. 11A is a diagram showing a cross-section of a cholesteric LCD element according to a third embodiment;
[0034] FIG. 11B is a diagram of a cholesteric LCD element, viewed from a display surface side, according to the third embodiment;
[0035] FIG. 11C is a diagram showing a color combination of a pattern and a flat type pattern and of a cholesteric LCD element according to the third embodiment;
[0036] FIG. 12 is a diagram describing a method for driving a cholesteric LCD element according to the third embodiment;
[0037] FIG. 13 is a diagram describing an example of performing a segment display by using a cholesteric LCD element according to the third embodiment;
[0038] FIG. 14 is a diagram showing a cross-section of a cholesteric LCD element according to a fourth embodiment; and
[0039] FIG. 15 is a diagram describing a method for driving a cholesteric LCD element according to the fourth embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] The following is a description of the preferred embodiment of a cholesteric LCD element (sometimes noted as “display element” hereinafter) according to the present invention by referring to the accompanying drawings.
[0041] FIGS. 5 through 7 are diagrams for describing a first embodiment of the present invention.
[0042] FIG. 5 is a front view diagram of a display element 100 according to the first embodiment, in which the liquid crystal at a background part is fixed to a color reflection state by using a mechanical pressure including a part on a segment wiring. Therefore, an Off display color is buried in the background. The mechanical pressure is applied to the entire surface of the display surface by using a roller apparatus (i.e., a laminator apparatus), or a press apparatus, after injecting the liquid crystal into the cell during the production process of the display element.
[0043] FIG. 6 is a diagram describing a segment electrode pattern 110 and a common electrode pattern 160 according to the first embodiment. The common electrode pattern 160 is configured to be opposite to the segment electrode pattern 110 and so as to prevent a display change in the area on the wiring of segment lead wires 120 as shown in the drawing. Therefore, a counter electrode does not exist in the background including a part on the segment wiring, thereby making a state of the background part staying in a color refection state, which is fixed during the production, even after a usage start.
[0044] Note here that there is no longer a necessity of the light-shield film 13 equipped in the display element 10 of a conventional example noted in FIGS. 3 and 4 , for all embodiments put forth herein.
[0045] FIG. 7 is a diagram describing a transparent state, a reflection state generated by applying an electrical field, and a reflection state generated by a mechanical action, in a cholesteric liquid crystal. As shown in the drawing, the reflection state generated by applying an electrical field has a little difference in the state of the liquid crystal from the reflection state generated by a mechanical action. This sometimes makes a hue of the background different from that of the display color (i.e., an Off display color), causing a little dissatisfaction in the visibility.
[0046] The next is a description of a second embodiment by referring to FIGS. 8 through 10 .
[0047] FIG. 8 is a front view diagram of a display element 200 according to the second embodiment. The second embodiment is configured to use an outer circumference electrode 280 (shown in FIG. 9 ) for a background color use, and therefore FIG. 8 differs from the front view of FIG. 5 , showing the first embodiment, where there is an outer circumference electrode lead wire 285 .
[0048] FIG. 9 is a diagram showing a structure of the outer circumference electrode 280 . The structure of the outer circumference electrode 280 is a rectangle for example and is a result of coring out the part of a position, where a segment electrode exists, from an electrode having no particular pattern (i.e., a flat type electrode).
[0049] FIG. 10 is a diagram showing a cross-section of a display element 200 according to the second embodiment. A common electrode 260 is formed on a glass substrate 270 , and a light absorption layer 250 is formed on the common electrode 260 . Formed on the display surface side is an electrode pattern of a two-layer structure, i.e., a layer comprising a segment electrode 210 and a lead electrode 215 and a layer of the outer circumference electrode 280 , by way of an insulation film 290 , and a gap with the common electrode 260 side is featured with a liquid crystal unit 240 which is filled with a cholesteric liquid crystal. On the glass substrate 270 of the common electrode 260 side, a flat type electrode pattern is generated. The state of the liquid crystal is transparent (i.e., black) at the time of an On display of the segment, and is the same reflection color as the background color at the time of an Off display. In the second embodiment, an Off reflection color and background color of the segment are completely identical, thereby improving a visibility. And a reversing changeover between negative and positive displays can easily be implemented by choosing an electrode to apply an electrical field between the segment electrode ( 210 ) and outer circumference electrode ( 280 ). Because the outer circumference electrode 280 is in the inner layer of the lead electrode 215 , the background is not affected by the lead electrode.
[0050] Therefore, a various application can be conceived, such as reversing negative and positive displays at a set time or between the morning and afternoon.
[0051] The next is a description of a third embodiment by referring to FIGS. 11A through 13 .
[0052] The third embodiment is configured to form a film of a pattern feature to be displayed on one of counter electrodes within a cell in a display element using a cholesteric liquid crystal, give a difference of drive voltages under which a liquid crystal changes a state in regions of the pattern and outside thereof, and cause a transition from the color reflection state to transparent state, or vice versa, either only in the pattern or outside thereof. Therefore, this enable an On-Off of the display either only in the pattern or outside thereof.
[0053] The next is a description of a configuration of the display element according to the third embodiment by referring to FIGS. 11A through 11C .
[0054] FIG. 11A is a diagram showing a cross-section of a display element 300 according to the third embodiment. Layered are, from the display surface side, an upper substrate 310 , an upper flat type electrode 320 , a liquid crystal unit 330 , a pattern 340 , a flat type pattern 350 , a lower flat type electrode 360 , a lower substrate 370 and a light absorption layer 380 .
[0055] FIG. 11B is a diagram of the display element, viewed from a display surface side, according to the third embodiment, exemplifying a key mark as a pattern 340 .
[0056] FIG. 11C is a diagram showing a combination of color tones of the pattern 340 and the flat type pattern 350 . A combination of both black of (1) shows a clear contrast, enabling an elimination of a light absorption layer 380 . In terms of design, however, four combination between black and transparent can be adopted, enabling a utilization of an oriented film or insulation film as a transparent layer. The transparent layer may be configured by not forming a film, or, if both of the pattern 340 and periodical pattern 350 are transparent, either one of them may be configured by not forming a film.
[0057] The next is a description of a drive method, and a display state, of the cholesteric LCD element 300 according to the third embodiment by referring to FIG. 12 . The initial state prior to an application of a voltage is assumed to be a color reflection state. The graph noted as “single layer BK” shows a relationship of an applied voltage with a reflectance of a liquid crystal in the part of the flat type pattern 350 constituted by one layer of black, and the graph noted as “two-layer BK” shows a relationship of an applied voltage with a reflectance of a liquid crystal in the part constituted by two layers of black with the pattern 340 being protruded.
[0058] When an applied voltage is at V 1 , the part of the single layer BK is transparent (i.e., black) and the part of the two-layer BK is a reflection color, thus becoming a positive On state; and when the applied voltage is at V 2 , both of the part of the single layer BK and two-layer BK is transparent (i.e., black), thus becoming a positive Off state. When the applied voltage is at V 3 , the part of the single layer BK is a reflection color and the part of the two-layer BK is transparent (i.e., black), thus becoming a negative On state and displaying a key mark in the color background. When the applied voltage is at V 4 , both of the part of the single layer BK and two-layer BK is a reflection color, becoming a negative Off state.
[0059] The above embodiment has been described by assuming the mark display part as two layers and the background part as one layer; it is, however, apparent that a configuration of the mark display part being one layer and the background part being two layers makes it possible to display the same. In the case of configuring the transparent layer as not forming a film, a mark display part becomes one layer or a background part becomes one layer.
[0060] FIG. 13 is a diagram describing an example of performing a segment display in seven segments by using a cholesteric LCD element according to the third embodiment. The use of the cholesteric LCD element according to the third embodiment for each segment enables a segment display as shown in FIG. 13 . The flat type electrode can be configured to conceal a segment border by making a two-layer structure likewise the segment electrode 210 and outer circumference electrode 280 of the second embodiment.
[0061] The next is a description of a fourth embodiment of the present invention by referring to FIGS. 14 and 15 .
[0062] FIG. 14 is a diagram showing a cross-section of a cholesteric LCD element 400 according to the fourth embodiment. As compared to the cholesteric LCD element of the third embodiment shown in FIG. 11A , the difference lies in printing a pattern on the flat type pattern in multiple stage thicknesses. FIG. 14 exemplifies the case of three patterns, i.e., the pattern A 410 , pattern B 420 and pattern C 430 .
[0063] FIG. 15 is a diagram describing a method for driving the cholesteric LCD element 400 according to the fourth embodiment configured as described above. Since the present configuration is printed with three kinds of patterns A, B and C, eight kinds of display patterns can exist in terms of mathematics as combinations of On and Off; in actuality, however, the display pattern 3 in which only the pattern B 420 is turned Off can not be implemented, and the display pattern 6 in which only the pattern B 420 is turned On requires some devising.
[0064] Assuming that the initial state prior to applying a voltage is a color reflection state, a drive starts with the state of the display pattern 1 . Increasing the applied voltage initially constitutes the state of the display pattern 5 as a result of the pattern A 410 becoming transparent, that is, turned Off. Then, as the applied voltage is increased, the display patterns transits from the pattern 7 to 8 to 4 to 2 , followed by returning to the display pattern 1 . In order to carry out a display of the display pattern 6 , the power is turned off in the state of the display pattern 2 , followed by applying the voltage in the state of the display pattern 2 , in which only the pattern C 430 is transparent, as the initial state. This turns the part of the pattern A 410 into transparent ahead of the part of the pattern B, and the display pattern 6 in which only the pattern B 420 is a color reflection state can be achieved.
[0065] Therefore, a positive display can be achieved by switching over three ways of display patterns by using the display patterns 4 , 6 and 7 .
[0066] As described above, the present invention is contrived to make it possible to bury an Off display color in a colorized background, thereby enabling a positive response to a requirement of an industrial design suitability by utilizing a display element according the present invention in industrial fields putting emphasis on an industrial design suitability such as clocks, marker displays, et cetera, which require a colorful background as background colors.
[0067] The first embodiment is configured to be able to fix a background color by using a mechanical pressure, thereby eliminating a necessity of an electrode for a background color. This accordingly eliminates a necessity of controlling a voltage of a background color-use electrode.
[0068] The second embodiment is configured to make it possible to drive a background part including a part on the segment wiring, thereby making an Off reflection color of the segment completely identical with the background color and improving the visibility. Also a reversing changeover between negative and positive displays can easily be implemented by selecting an electrode for applying the electrical field between the segment electrode and outer circumference electrode.
[0069] The third embodiment is configured to make an electrode pattern as a flat type pattern and make it possible to form a display pattern such as a mark by employing a simple process for forming a flat type pattern and a pattern on the aforementioned flat type pattern of the electrode.
[0070] The fourth embodiment provides benefit of obtaining a more complex display effect in addition to the benefit of the third embodiment.
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In order to provide a cholesteric liquid crystal display element of a structure capable of forming a color in the background by means of a low cost electrode structure and burying an Off display color completely in the background color, the color of the display part and background part of the display element is formed by a color reflection state and a transparent state. This configuration makes it possible to form a color in the background so as to bury the Off display color completely in the background by employing a low cost electrode structure, thereby improving a suitability to an industrial design and accomplish a display of a good visibility.
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FIELD OF THE INVENTION
The present invention provides an improved method for detecting poor hole cleaning and stuck pipe during rotary drilling of a well. The present invention provides an improved method of preventing drilling delays, losses and hazards by early detection of conditions favorable for stuck pipe during rotary drilling of a well.
BACKGROUND OF THE RELATED ART
Wells are generally drilled to recover natural deposits of hydrocarbons and other desirable, naturally occurring, materials trapped in geological formations in the earth's crust. A slender well is drilled into the ground and directed to the targeted geological location from a drilling rig at the surface. In conventional “rotary drilling” operations, the drilling rig rotates a drillstring comprised of tubular joints of steel drill pipe connected together to turn a bottom hole assembly (BHA) and a drill bit that is connected to the lower end of the drillstring. During drilling operations, a drilling fluid, commonly referred to as drilling mud, is pumped and circulated down the interior of the drillpipe, through the BHA and the drill bit, and back to the surface in the annulus. It is also well known in the art to utilize a downhole mud-driven motor, located just above the drill bit, that converts hydraulic energy stored in the pressurized drilling mud into mechanical power to rotate the drill bit. The mud circulating pumps that pump the drilling mud and thereby power the mud-driven motor are sealably connected to the surface end of the drillstring through the standpipe and a flexible hose-like connection called a kelly.
When drilling has progressed as far as the drillstring can extend without an additional joint of drillpipe, the mud circulating pumps are deactivated and the end of the drillstring is set in holding slips that support the weight of the drillstring, the BHA and the drill bit. The kelly is then disconnected from the end of the drillstring, an additional joint of drillpipe is threaded and torqued onto the exposed, surface end of the drillstring, and the kelly is then reconnected to the top end of the newly connected joint of drillpipe. Once the connection is made, the mud pumps are reactivated to power the drill motor and drilling resumes.
To isolate porous geologic formations from the wellbore and to prevent collapse of the well, the well is generally cased with tubular steel pipe joints connected together to form a casing string. Casing is set in progressively smaller diameter sections as drilling progresses. Downhole conditions and the physical properties of drilled formations determine when a section of casing must be set in order to isolate exposed wellbore. During drilling operations, the drilling rig extends the drillstring through the casing and into the open wellbore and rotates the drill bit against rock and geologic formations lying in the trajectory of the drilling bit.
The fluid pressure in porous and permeable geologic formations penetrated by the wellbore is generally balanced by the hydrostatic pressure of the column of drilling mud in the well. Pressurized drilling mud is pumped into the surface end of the tubular drillstring by mud pumps that circulate mud down through the interior of the drillstring, through the BHA and drill bit and back up to the surface through the casing/drillstring annulus. Drilling mud is specially designed to not only balance formation pressure, but also to cool and lubricate the drillstring and drill bit, and to suspend and transport drill cuttings to the surface for removal. The process of using drilling mud to suspend and transport cuttings out of the wellbore is often called “hole cleaning.”
Efficient hole cleaning greatly benefits the overall drilling process. A smooth and uniform flow of drilling mud promotes easy and cost-effective drilling. It is desirable for the cuttings to be uniformly dispersed and suspended in the flowing drilling mud as they are carried to the surface through the annulus. The flow rate, flow regime and viscosity of the drilling mud are key factors that determine the capacity of the drilling mud to suspend and transport drill cuttings to the surface. Slender, intermediate deviations (40°-60°) and horizontal wellbores are more subject to poor hole cleaning and stuck pipe than are larger, vertical wells because drill cuttings settling out of drilling mud tend to accumulate on the lower or downward side of the well. The unwanted accumulation of a stationary bed of drill cuttings interferes with the drilling process by resisting reciprocation and rotation of the drillstring. Poor hole cleaning results in high torque (resistance to rotation) and excessive drag (resistance to reciprocation) on the drill string, hole pack-off (resistance to drilling mud circulation) and, ultimately, stuck pipe. These conditions may cause well control problems, delays in drilling and poor drilling efficiency, adversely impacting the well economics and possibly resulting in the equipment loss or damage or even a loss of the wellbore.
A method has been devised for early detection of poor hole cleaning and stuck pipe using measured wellbore data. U.S. Pat. No. 5,454,436, issued to Jardine et al., describes a method of diagnosing and warning of pipe sticking during drilling operations and is incorporated herein by reference. The Jardine method mathematically analyzes the standpipe pressure (SPP) trace and the surface torque trace comprising a series of standpipe drilling mud pressures and surface torque measurements over the same time period, respectively. The input SPP trace and surface torque trace can be seen in FIGS. 1 (A) and 1 (B), respectively. Jardine's method determines the SPP skew of the SPP trace and the normalized standard deviation of the surface torque trace as shown in FIGS. 2 (A) and 2 (B), respectively. This attenuates and enables correlation of increases in the SPP and surface drillstring torque that are characteristic signatures of accumulated drill cuttings obstructing mud flow and packing off around the drill string. Jardine's method then determines the product of the SPP skew and the normalized standard deviation of the drill string torque trace to further attenuate the data to indicate events causing simultaneous spikes in the SPP skew and the surface torque normalized standard deviation as shown in FIG. 3 (A). Finally, Jardine's method integrates the product of the SPP skew and the normalized standard deviation of the surface torque to produce the diagnostic shown in FIG. 3 (B). The integrated value is a more reliable diagnostic than the product because the skew should oscillate between positive and negative values for normal drilling conditions, in other words, pressure fluctuations will be both positive and negative, and hence the integral should be close to zero. However, the integrated value will exhibit an increasing positive trend in the presence of positive pressure fluctuations indicative of poor hole cleaning or stuck pipe. Trend analysis or a simple thresholding technique can then be used to identify when this positive trend occurs.
The method disclosed by Jardine is, however, hindered by extraneous influences (besides poor hole cleaning) that contribute to the SPP trace, and therefore interfere with detection of poor hole cleaning and retard the accuracy of the wellbore diagnosis.
What is needed is a method of detecting poor hole cleaning or conditions favorable for the occurrence of stuck pipe that is not hindered by extraneous influences. What is needed is a method of detecting poor hole cleaning or conditions favorable for the occurrence of stuck pipe using data that is already generally available on drilling rigs, or with reliable and inexpensive additional downhole equipment. What is needed is a method of raising an alarm at the onset of poor hole cleaning or stuck pipe to alert persons operating the drilling rig to take timely remedial measures.
SUMMARY OF THE INVENTION
The present invention provides a method for early detection of poor hole cleaning or conditions favorable for the onset of stuck pipe during rotary drilling. The method provides early detection by inventive analysis and use of drill string torque data and downhole annular fluid pressure data, preferably on a real-time or near real-time basis. The annular fluid pressure is continuously measured downhole at the BHA (and possibly other depths) and communicated to the surface using telemetry, and is correlated with either surface or downhole torque measurements to attenuate certain signature responses. The method enables drilling rig operators to observe and recognize attenuated signature responses in downhole annular fluid pressure and surface or downhole torque data that arise from poor hole cleaning or stuck pipe in time to take preventive and remedial measures. The method uses generally available data to prevent the unwanted delays, hazards and losses that result from poor hole cleaning and stuck pipe.
Downhole annular fluid pressure is typically measured by the bottom hole assembly (BHA) and communicated to the surface during periods of active mud circulation. At the surface, the measured downhole annular fluid pressure trace is analyzed along with a simultaneously measured trace of the surface torque applied to rotate the drillstring. This correlation, enabled by mathematical manipulation of the data, enables the drilling rig operator to detect recognizable responses characteristic of poor hole cleaning and stuck pipe.
The downhole pressure trace commonly available to facilitate use of the improved method is measured at the BHA and communicated to the surface using telemetry, preferably mud-pulse telemetry. The telemetry data capacity of the drilling mud may allow additional downhole devices to transmit additional data to the surface. Optionally, the method may utilize additional downhole pressure traces or other data measured at instruments and sensors strategically placed along intervals of interest in the drillstring. The method may use correlation of one “local” annular fluid pressure trace to others measured at the BHA or other depths to diagnose the exact location and nature of poor hole cleaning or stuck pipe.
Optionally, the method may comprise correlating measured downhole drill string torque with the measured downhole annular fluid pressure trace(s).
DESCRIPTION OF DRAWINGS
So that the features and advantages of the present invention 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.
FIGS. 1 (A and B) are graphs of the measured standpipe pressure trace and drillstring surface torque trace, respectively, during an interval of time of erratic well behavior.
FIGS. 2 (A and B) are graphs of the skew of the standpipe pressure and the normalized standard deviation of the surface drillstring torque, respectively, during an interval of time of erratic well behavior.
FIG. 3 (A) is a graph of the product of the skew of the downhole annular fluid pressure trace and the normalized standard deviation of the surface torque trace. FIG. 3 (B) is a graph of the integral of the product shown in FIG. 3 (A).
FIG. 4 is a drawing of a wellbore having a horizontal section near its terminus.
FIG. 5 is a depiction of dispersed and suspended drill cuttings being transported to the surface in drilling mud flowing uphole in the annular flow area formed between the drill string and the side wall of the well.
FIG. 6 is depiction of an accumulated bed of settled drill cuttings building from the downward side of a horizontal section of the wellbore.
FIG. 7 is a schematic representation of the behavior of an asymmetric suspension of cuttings in drilling mud within a range of pressure gradient and flow velocity.
FIG. 8 (A) is a graph showing the position of the drilling rig block height and FIG. 8 (B) is a graph showing the downhole annular pressure trace (in terms of the equivalent circulating density of drilling mud), both during the same interval of time with of erratic well behavior.
FIG. 9 shows the typical location of the BHA, and the primary downhole annular pressure sensor, in a typical drill string.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a method for monitoring and detecting poor hole cleaning or conditions favorable for the occurrence of stuck pipe during rotary drilling. The method provides for recurrent mathematical analysis of data to determine when poor hole cleaning or stuck pipe is likely to occur, preferably with the analysis being performed on an ongoing basis. The present invention may be integrated with visual, audible or other alarm systems to alert drilling rig operators of poor hole cleaning or stuck pipe so that timely remedial action can be taken to prevent hazards and delays and to decrease drilling costs.
The present invention utilizes a telemetry communication system. A mud pulse telemetry communication system is presently preferred for reliably communicating data from the BHA to the surface and has gained widespread acceptance in the industry. Mud pulse telemetry systems use no cables or wires for carrying downhole data to the surface, but instead it uses a series of decipherable pressure pulses that are transmitted to the surface through flowing, pressurized drilling fluid. One such system is described in U.S. Pat. No. 4,120,097, which is incorporated by reference. Mud pulse telemetry systems provide the drilling rig access to almost continuous real time data, including annular fluid pressure and drill string torque. Other telemetry systems, such as electromagnetic systems or EMAG telemetry, may also be used to advantage with the present invention.
The present invention provides a method of analyzing continuous real time annular fluid pressure and drill string torque data to detect poor hole cleaning and stuck pipe.
FIG. 4 is a drawing of a wellbore 10 having a horizontal section 15 near its terminus 16 . The slender drillstring 12 is received into the wellbore 10 to turn the drill bit 17 against the bottom of the wellbore 16 . The drilling mud is pumped down the interior of the tubular drillstring 12 through the bit 17 and back to the surface in the annulus 14 formed by the exterior of the drillstring 12 and the side wall 18 of the wellbore. FIG. 5 is an enlargement of a portion of the horizontal section 15 of the wellbore 10 and shows drill cuttings 19 being transported by drilling mud flowing in the uphole direction 13 towards the surface.
Like many downhole conditions that occur during rotary drilling, poor hole cleaning and stuck pipe provide a “signature” wellbore response. FIG. 6 depicts drill cuttings settling out of suspension from the drilling mud and accumulating in a bed 22 to form an obstacle to drilling mud flow in the annulus. This “bottleneck” causes all upstream pressures in the circulation loop, from the mud pumps through the standpipe and drill bit to the annulus immediately downhole of the obstruction 23 , to increase with diminishing cross sectional area for annular mud flow.
For a given mud of fixed rheological properties, the pressure gradient and the flow velocity physically determine the capacity of the mud to transport drill cuttings to the surface. The relationship between pressure gradient, mud flow velocity and flow regime of a drilling mud/drill cuttings mixture is shown in FIG. 7 . As velocity is decreased, a moving bed of accumulated settled drill cuttings moves uphole along the annulus towards the surface. Further decreases in velocity promotes stationary beds of accumulated drill cuttings in the annulus around the drillstring and resistance to reciprocation and rotation of the drillstring.
FIG. 8 (B) shows one signature response of poor hole cleaning and stuck pipe. The downhole annular fluid pressure measured at the BHA is expressed in FIG. 8 (B) in terms of equivalent circulating density (ECD). At the onset of the time interval recorded and depicted in FIG. 8 (A), the ECD had been gradually increasing, ultimately peaking at the onset to well instability 32 at 60 minutes. Attempts to reduce the ECD by suspending drilling and circulating drilling mud led to large pressure oscillations 34 from 80 minutes to 200 minutes, then resulting in the first of the two ECD spikes 36 and 38 at 200 and 440 minutes, respectively. These two spikes each reflect obstructed flow in the annulus resulting from accumulated settled drill cuttings. Each spike subsides as increased downhole pressure forcibly displaces, or “blows through,” the obstruction and dislodges the accumulated stationary or slow moving bed of drill cuttings.
Drilling progress is usually disrupted as the drilling rig takes remedial actions to address the well instability and hazards indicated by erratic ECD behavior. FIG. 8 (A) shows the height of the block supporting the drillstring at all times during the time interval for the ECD plot showing erratic well behavior shown in FIG. 8 (B). Drilling progresses smoothly, as indicated by the steadily descending block height, until the onset of well instability 32 at 80 minutes. Drilling progress is suspended during circulation 34 , 36 and 38 , and reciprocation 37 of the drill string within the wellbore. Suspended drilling operations cause substantial increases in well cost, and each ECD spike 36 , 38 brings an increased risk of inadvertent fracturing of exposed formations, drilling mud loss from the well and potential well control problems.
The standpipe pressure (SPP) trace includes information related to the mud pressure throughout the entire circulating system. As such, increases in the SPP may be attributed to poor hole cleaning when in reality such increases could be caused by fluctuations in the pressure drop across the mud motor, back pressure in the MWD tool, blocked nozzles in the drill bit, or other factors upstream from the annulus. Thus, wellbore mechanics unrelated to poor hole cleaning influence the SPP trace, and adversely affects the approximation of downhole annular pressure that's based on SPP. The present invention eliminates these factors and provides a more reliable diagnosis of poor hole cleaning by using real time downhole annular fluid pressure trace measured at or near to the zone of interest and communicated by mud telemetry to the surface. The present invention thereby improves early diagnosis and detection of poor hole cleaning and conditions favorable for the occurrence of stuck pipe.
The present invention eliminates friction losses attributable to physical interference by the side wall, mechanical losses at pipe joint connections and frictional drag on pipe rotation in viscous drilling mud by using real time downhole torque data. Using real time torque data dramatically improves early diagnosis and detection of poor hole cleaning and conditions favorable for the occurrence of stuck pipe.
Some mud circulation obstructions will not result in corresponding spikes in both the SPP and the normalized standard deviation of the surface torque. FIG. 9 shows that poor hole cleaning or stuck pipe can occur within the sub-BHA depth interval 40 between the BHA 21 and the drill bit 17 . In this instance, the signature response 36 , 38 of the downhole annular pressure trace will not spike as shown in FIG. 8 (B) because the downhole annular pressure being monitored by the BHA 21 is downstream from the flow obstruction in the sub-BHA depth interval 40 . The SPP trace would exhibit a surge in response to this type of obstruction that may be correlated under Jardine's method to either the normalized standard deviation of the torque or to the product of the SPP skew and the normalized standard deviation of the torque. Either of these correlations under Jardine's method may provide for early detection of poor hole cleaning or stuck pipe in this sub-BHA depth interval 40 . Similarly, an obstruction in the interior of the drill string 12 will result in a surge in SPP without a corresponding increase in either the downhole annular pressure or the torque on the drill string.
While obtaining a reliable mathematical analysis, data that provides advance warning of conditions favorable for the occurrence of stuck pipe is the primary focus of this invention, it is an option, within the scope of the present invention, to automatically initiate remedial measures to alleviate or eliminate the conditions. A closed loop feedback system may be used to automatically decrease weight on bit, increase mud pump flow rate or to circulate a viscous “pill” to better suspend and remove drill cuttings from the wellbore whenever conditions favorable for pipe sticking are detected.
While the 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 provides a method of monitoring a well to detect and provide warning of pipe sticking. The method includes 1) monitoring the downhole annular fluid pressure of a drilling fluid being pumped through the drill string during drilling over predetermined intervals of time to obtain a series of pressure measurements, 2) monitoring the torque required to rotate the drill string during said periods to obtain a series of torque measurements, and 3) comparing the series of downhole annular fluid pressure measurements with the series of torque measurements so as to identify corresponding changes in both, and 4) raising an alarm when the magnitude of the changes passes predetermined alarm values.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority, under 35 U.S.C. §119, of German application DE 10 2010 043 496.5, filed Nov. 5, 2010; the prior application is herewith incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0002] The invention relates to hearing aid with a hearing aid housing and with at least one humidity sensor and to a method for operating a hearing aid with determination of at least one ambient humidity.
[0003] Hearing aids are wearable hearing devices serving to aid persons with impaired hearing. In order to meet the numerous individual requirements, different forms of hearing aid such as behind-the-ear hearing aids, hearing aids with external earpieces and in-the-ear hearing aids, e.g. also Concha hearing aids or in-canal hearing aids, are provided. The hearing aids given by way of example are worn on the outer ear or in the auditory canal. In addition there are also bone-conduction hearing aids, implantable or vibrotactile hearing aids available on the market. In such cases the damaged hearing is stimulated either mechanically or electrically.
[0004] In principle hearing aids possess an input transducer, an amplifier and an output transducer as their major components. The input transducer is generally a sound receiver, e.g. a microphone and/or an electromagnetic receiver, e.g. an induction coil. The output transducer is mainly implemented as an electro-acoustic converter, e.g. miniature loudspeaker or as electro-mechanical converter, e.g. bone conduction earpiece. The amplifier is usually integrated into a signal processing unit. This basic structure is shown in FIG. 1 , using a behind-the-ear hearing aid 1 as an example. Two microphones 3 for receiving the sound from the environment are usually built into a hearing aid housing 2 for wearing behind the ear. Microphone openings 7 are embodied in the hearing aid housing 2 above the microphones 3 . The sound can reach the microphones 3 within the hearing aid housing through the sound openings 7 . A signal processing unit 4 , which is likewise integrated into the hearing aid housing 2 , processes the microphone signals and amplifies them. The output signal of the signal processing unit 4 is transmitted to a loudspeaker or earpiece 5 , which outputs an acoustic signal. The sound is transmitted to the eardrum of the hearing aid wearer if necessary via a sound tube not shown in the FIG. 1 , which is fixed to an otoplastic in the auditory canal. Energy is supplied to the hearing aid 1 and especially to the signal processing unit 4 by a battery 6 likewise integrated into the hearing aid housing 2 .
[0005] With hearing aids the problem often occurs of moisture collecting within the hearing aid housing. This can penetrate into the device from outside or condensation water forms within the device. The moisture in the device can adversely affect the function of the sensitive electrical and mechanical components of the hearing aid. German patent DE 10 2007 044 205 B3, corresponding to U.S. patent publication No. 2009/0074219, thus discloses the method of removing the moisture in the housing by use of an electrical heating device.
[0006] Moisture sensors are known for the detection of moisture. For example published European patent application EP 2136975 A1 specifies a Cochlea implant which includes a moisture sensor for generating a signal. The signal indicates moisture within the implant.
[0007] International patent disclosure WO 2010/120243 A1 specifies a hearing aid with a measurement sensor arranged on a hearing aid housing for detection of environmental parameters such as moisture for example, on the basis of which measured values at least one hearing a parameter can be modified.
[0008] German patent DE 101 41 800 C1, corresponding to U.S. Pat. No. 6,819,770, discloses an in-the-ear hearing aid with a sensor for detecting the air humidity in an enclosed auditory canal volume.
SUMMARY OF THE INVENTION
[0009] It is accordingly an object of the invention to provide a hearing aid and a method for operating a hearing aid with a humidity sensor which overcome the above-mentioned disadvantages of the prior art methods and devices of this general type, which take account of the influence of humidity on the hearing aid.
[0010] The invention claims a hearing aid with a hearing aid housing, a first humidity sensor which measures a first ambient humidity and a modification unit which modifies an operating state and/or an operating parameter of the hearing aid in dependence on the first ambient humidity determined. In addition the hearing aid includes a second humidity sensor arranged within the hearing aid housing which determines a second level of ambient humidity inside the hearing aid housing. The invention offers the advantage of being able to take account of the effect of humidity within and outside the hearing aid on the hearing aid properties and of allowing compensation measures to be taken.
[0011] In a development the modification unit can modify at least one hearing aid parameter as a function of the first ambient humidity determined. This has the advantage of enabling the hearing aid properties to be adapted to the ambient humidity.
[0012] In a further form of embodiment the modification unit can switch to another hearing aid program in dependence on the first ambient humidity determined. This offers the advantage of enabling the program preset in accordance with the humidity currently obtaining to be used.
[0013] Furthermore the modification unit can switch the hearing aid on or off in dependence on the first ambient humidity determined. A feedback level that is too high can typically be avoided in this way. In a development of the invention the first humidity sensor can be arranged outside on the hearing aid housing or integrated into the hearing aid housing and can determine the first ambient humidity outside the hearing aid.
[0014] Furthermore the hearing aid can include a signal generation unit which generates a warning signal when the second ambient humidity exceeds a predeterminable threshold.
[0015] In a further embodiment the hearing aid can include an earpiece which acoustically outputs the generated warning signal.
[0016] Furthermore the hearing aid can transmit the warning signal electromagnetically to a remote control.
[0017] In a development the hearing aid can have a salt content measurement sensor which determines the salt content outside the hearing aid housing. This enables critical corrosion states to be detected.
[0018] Preferably the salt content measurement sensor can be arranged outside on the hearing aid housing or can be integrated into the hearing aid housing.
[0019] The invention also recites a method for operating a hearing aid, with the following steps: determining a first ambient humidity, modifying an operating state and/or an operating parameter of the hearing aid in dependence on the first ambient humidity determined and determining a second ambient humidity within the hearing aid.
[0020] In a further form of embodiment the modification modifies a hearing aid parameter, switches into another hearing aid program and/or switching off or switching on the hearing aid in dependence on the first ambient humidity determined.
[0021] In a development the first ambient humidity can be determined outside the hearing aid housing.
[0022] The method can also include issuing a warning signal if the second ambient humidity exceeds a predeterminable threshold value.
[0023] Preferably the warning signal can be issued acoustically by an earpiece of the hearing aid and/or transmitted electromagnetically to a remote control.
[0024] In a development a salt content can be determined on or in the hearing aid housing. Damaging salt from perspiration can be detected in this way.
[0025] Furthermore a salt warning signal can be output if the salt content determined exceeds a predeterminable salt content threshold.
[0026] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0027] Although the invention is illustrated and described herein as embodied in a hearing aid and a method for operating a hearing aid with a humidity sensor, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0028] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0029] FIG. 1 is an illustration of a behind-the-ear hearing aid according to the prior art;
[0030] FIG. 2 is an illustration of a hearing aid housing with a first exterior humidity sensor according to the invention;
[0031] FIG. 3 is an illustration of the hearing aid housing with a first and a second humidity sensor; and
[0032] FIG. 4 is a flowchart of a method for operating a hearing aid with humidity measurement.
DETAILED DESCRIPTION OF THE INVENTION
[0033] Referring now to the figures of the drawing in detail and first, particularly, to FIG. 2 thereof, there is shown a behind-the-ear hearing aid 1 with a hearing aid housing 2 . Arranged in the hearing aid housing 2 are a microphone 3 , an earpiece 5 , a signal processing unit 4 and a modification unit 12 . In accordance with the invention a first humidity sensor 10 which detects a first ambient humidity UF 1 sits on the hearing aid housing 2 .
[0034] Since the first humidity sensor 10 is arranged outside the hearing aid housing 2 , the first ambient humidity UF 1 corresponds to the humidity outside the hearing aid 1 . A high first humidity UF 1 influences the acoustic properties of the hearing aid 1 so that counter measures have to be taken. For this purpose the first humidity sensor 10 is connected to the modification unit 12 which modifies the operating state or an operating parameter of the hearing aid 1 in accordance with the first ambient humidity UF 1 determined. For this purpose the modification unit 12 is connected to the signal processing unit 4 .
[0035] For example, depending on the first ambient humidity UF 1 , a hearing aid parameter, such as the amplification, can be modified. Or the hearing aid 1 is switched to another hearing aid program. With high humidity, which spells danger for the hearing aid 1 , the hearing aid 1 can also be automatically switched off. On the other hand, if the ambient humidity UF 1 drops, the hearing aid 1 can be automatically switched back on again.
[0036] FIG. 3 shows a behind-the-ear hearing aid 1 with a hearing aid housing 2 . Arranged in the hearing aid housing 2 are the microphone 3 , the earpiece 5 , the signal processing unit 4 and the modification unit 12 . In accordance with the invention the first humidity sensor 10 which determines the first ambient humidity UF 1 sits on the hearing aid housing 2 . Furthermore a second humidity sensor 11 , a comparator unit 13 and a signal output unit 14 are arranged inside the hearing aid housing 2 .
[0037] Since the first humidity sensor 10 is arranged outside the hearing aid housing 2 , the first ambient humidity UF 1 corresponds to the humility outside the hearing aid 1 . A high first ambient humidity UF 1 influences the acoustic properties of the hearing aid 1 , so that measures have to be taken to counter this. For this purpose the first humidity sensor 10 is connected to the modification unit 12 , which in accordance with the measured first ambient humidity UF 1 , modifies the operating state and/or an operating parameter of the hearing aid 1 . To this end the modification unit 12 is connected to the signal processing unit 4 .
[0038] For example a hearing aid parameter, such as the amplification, can be modified in dependence on the first ambient humidity UF 1 . Or the hearing aid 1 is switched to another hearing aid program. With high humidity, which represents a danger for the hearing aid 1 , the hearing aid 1 can also be automatically switched off. On the other hand, if the first ambient humidity UF 1 drops, the hearing aid 1 can be automatically switched back on again.
[0039] The second humidity sensor 11 inside the hearing aid 1 measures the second ambient humidity UF 2 , which corresponds to the humidity obtaining inside the hearing aid housing 2 . A high humidity inside the hearing aid 1 can lead to damage to the hearing aid 1 . Thus the second humidity sensor 11 is connected to the comparator unit 13 which compares a measured second ambient humidity UF 2 with a threshold value. If the threshold value is exceeded the signal generation unit 14 will be made to output an electrical and/or an electromagnetic warning signal. The electrical warning signal is processed in the signal processing unit 4 and is transferred to the earpiece 5 where it is converted into an acoustic warning signal and as such can be heard by a hearing aid wearer. In addition or as an alternative the warning signal is transmitted wirelessly to a remote control 15 , where it can be shown on a display for example. The threshold value is selected so that the warning signal detects humidity that endangers the operation of the hearing aid 1 and for example advises a visit to a hearing aid acoustician or requests that the hearing aid be dried or does this automatically.
[0040] Too much salt in the environment of the hearing aid 1 can also be damaging for the hearing aid 1 . The salt can typically be deposited by perspiration of the hearing aid wearer. Therefore a salt content measurement sensor 16 measures the salt concentration outside the hearing aid housing 2 and passes on this information to the comparator unit 13 . If the threshold value is exceeded, on exceeding the threshold value for the second ambient humidity UF 2 a corresponding warning signal is generated by the signal generation unit 14 .
[0041] FIG. 4 shows a flow diagram of a method for inventive operation of a hearing aid. In step 100 a first ambient humidity UF 1 is determined, which corresponds to the humidity outside the hearing aid. The measured first ambient humidity UF 1 is used in step 101 to modify an operating state or to modify an operating parameter. For example, for a high first ambient humidity UF 1 the amplification of the hearing aid can be reduced.
[0042] In parallel to steps 100 and 101 , in step 102 a second ambient humidity UF 2 is determined, which corresponds to the humidity within the hearing aid. In step 103 the second ambient humidity UF 2 is compared to a threshold value and the warning signal is generated if the threshold is exceeded. In step 104 the warning signal is output via an earpiece of the hearing aid and/or is transmitted wirelessly to a remote control where a corresponding warning can be displayed. The acoustic warning signal of the earpiece can include both a signal tone and also a voice message.
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A hearing aid has a hearing aid housing and an associated method for operating the hearing aid. The hearing aid contains a first humidity sensor which determines a first ambient humidity and a modification unit, which modifies an operating state and/or an operating parameter of the hearing aid in dependence on the first ambient humidity detected. The hearing aid takes account of the effect of the humidity of the environment on the hearing aid properties and takes measures to compensate for the humidity.
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CROSS-REFERENCE TO A RELATED APPLICATION
[0001] The present application is a Divisional Application of U.S. patent application Ser. No. 11/900,081 filed on Sep. 10, 2007, and claims priority from U.S. Provisional Application No. 60/843,934, filed Sep. 12, 2006, the contents of which are incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to a process for making allyloxytrifluoropropenes and homopolymers and copolymers thereof starting from fluoro olefins. More particularly, the present invention relates to a process for making compounds, such as, CF 3 CH═CHOCH 2 CH═CH 2 , CF 3 CH═CFOCH 2 CH═CH 2 , CF 3 CH═C(OCH 2 CH═CH 2 ) 2 and methallyl derivatives thereof from CF 3 CH═CHF or CF 3 CH═CF 2 and allyl or methallyl alcohol.
[0004] 2. Description of the Prior Art
[0005] Compounds containing allyloxy group are typically used as monomers for preparing siloxane polymers or as a CF 3 building block. See, for example, Polymer Chemistry, (1995) 33(14), 2415-23 , J. Polymer Sci. A: Polym. Chem (1997) 35, 1593-1604 and Chem. Commun., (1996), 57-58.
[0006] Uses of polymers derived from allyl ethers for UV curing, to films on various surfaces, for adhesives, coating, cladding and the like are described in J. Polym. Sci., Part A, Polym. Chem., 2002, 40, 2583-2590.
[0007] Allyloxypropene of the formula CF 3 CH 2 CFHOCH 2 —CH═CH 2 is used as a monomer for making siloxane polymers, as described in the German Patent DE 3,138,235 A1 and in J. Fluorine Chem., (2005), 126, 281-288.
[0008] Relatively little is known about allyloxypropene polymers in general. U.S. Pat. No. 6,930,159 B1 describes some fluorinated allyl ether polymers. However, the structure of monomers used in the preparation of the polymers described in this patent is quite different from the allyloxypropene monomers described in the present invention.
[0009] Relatively little is known about allyloxypropenes described by the present invention. The only known example in this group is 1-allyloxy-3,3,3-trifluoropropene of the formula CF 3 CH═CH(OCH 2 CH═CH 2 ) which is made from CF 3 CBr═CH 2 with a base and catalytic amount of water.
[0010] This reaction proceeds by an elimination-addition mechanism through the formation of trifluoromethylpropyne as an intermediate followed by the addition of allyl alcohol to the so formed trifluoromethylpropyne (See Chem. Commun., (1996), 57-58).
[0011] However, large-scale preparation of allyloxytrifluoropropenes using this approach requires the use of CF 3 CBr═CH 2 as a starting material, which is expensive and cumbersome to manufacture.
[0012] Compounds such as CF 3 CH═C(OCH 2 CH═CH 2 ) 2 with two allyloxy groups and polymers derived therefrom are unknown in the art.
[0013] Consequently, there is a need in industry to develop commercially feasible processes for making such compounds and exploring their properties and uses in various applications.
[0014] To achieve this objective, the present invention provides a process, which is practical and, as such, it is potentially useful commercially.
SUMMARY OF THE INVENTION
[0015] The present invention provides a process for the preparation of an allyloxytrifluoropropene derivative represented by the formula:
[0000] CF 3 CH═CR 1 (OCH 2 CR═CH 2 )
[0000] wherein:
[0016] R 1 is selected from hydrogen, fluoro, and allyloxy group represented by the formula:
[0000] —OCH 2 CR═CH 2
[0017] wherein R is hydrogen or methyl.
[0018] The process includes the steps of:
[0019] contacting:
[0020] (i) a compound represented by the formula:
[0000] CF 3 CH═CR 2 R 3
[0021] wherein R 2 is selected from the group consisting of hydrogen, chloro, and fluoro and wherein R 3 is chloro or fluoro; and
[0022] (ii) an allyl alcohol derivative represented by the formula:
[0000] HOCH 2 CR═CH 2
[0023] wherein R is hydrogen or methyl;
[0024] wherein the contacting is carried out in the presence of a base and optionally a solvent at a temperature and length of time sufficient to produce the allyloxytrifluoropropene derivative.
[0025] The present invention further provides allyloxytrifluoropropene derivatives, including compounds of the following formula:
[0000] CF 3 CH═C(OCH 2 CH═CH 2 ) 2 ;
[0000] CF 3 CH═C(OCH 2 C(CH 3 )═CH 2 ) 2 ;
[0000] CF 3 CH═CH(OCH 2 C(CH 3 )═CH 2 ); and
[0000] CF 3 CH═CF(OCH 2 CR═CH 2 );
[0026] wherein R is hydrogen or methyl.
[0027] The present invention still further provides process for preparing a polymer including the step of:
[0028] polymerizing:
[0029] (iii) an allyloxytrifluoropropene derivative selected from compounds represented by the formula:
[0000] CF 3 CH═CH(OCH 2 CR═CH 2 );
[0000] CF 3 CH═C(OCH 2 CR═CH 2 ) 2 ;
[0000] CF 3 CH═CF(OCH 2 CR═CH 2 ); and
[0030] any mixtures thereof;
[0031] wherein R is hydrogen or methyl; and optionally
[0032] (iv) an ethylenically unsaturated comonomer;
[0033] wherein the copolymerizing step is carried out in the presence of a catalyst, preferably including methylphenylsilane and CO 2 (CO) 8 , under conditions sufficient to produce the copolymer.
[0034] The present invention also provides homopolymers and copolymers of these allyloxytrifluoropropene derivatives prepared by the polymerization process according to the present invention.
[0035] The process according to the present invention is practical and, as such, it is potentially useful commercially.
[0036] These and other benefits of the present invention will become more evident from detailed description of the preferred embodiments that follow.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] When CF 3 CH═CF 2 is reacted with allyl alcohol or methallyl alcohol at 25° C. to 35° C. with catalytic amount of a base, such as, Cs 2 CO 3 , in a polar solvent, quite unexpectedly, the major product formed was the fluoride substitution produce, rather than the expected product of addition to the carbon-carbon double bond, to form CF 3 CH═C(OCH 2 —CH═CH 2 ) 2 (IA).
[0038] Even with only catalytic amount of a base being present, both of the vinylidene fluorines in CF 3 CH═CF 2 can be replaced by allyloxy group. This is an unknown reaction of vinylidene fluorides and, as such, it is an unexpected reaction.
[0039] Temperature appears to play an important role in these reactions. At lower temperatures, such as, for example, at temperatures from about 20° C. to about 5° C., one can predominantly obtain the addition product of the formal CF 3 CH 2 CF 2 OCH 2 —CH═CH 2 (IC).
[0040] In contrast, when a temperature from about 25° C. to about 35° C. is used, the major product formed is CF 3 CH═C(OCH 2 —CH═CH 2 ) 2 (IA); the minor being CF 3 CH═CF(OCH 2 —CH═CH 2 ) (IB) (˜5 to 20%) as shown in Scheme 1 below. Thus, under these experimental conditions, only trace amount of the expected addition product (IC) was seen.
[0041] This above reactions are depicted in the Scheme 1 below.
[0000]
[0042] In large scale preparations, the volatiles generated in the reaction can be trapped in a cold trap/scrubber and thereafter neutralized and the HF generated can be neutralized via washing with aqueous NaOH solution.
[0043] Alternately, if the exclusive preparation of IA is desired, one can employ two equivalents of base to neutralize the HF generated during the reaction.
[0044] As mentioned before, the reparation of Compound IIA CF 3 CH═CH(OCH 2 CH═CH 2 ) has been reported in the literature using a method which employs CF 3 CBr═CH 2 as a starting material.
[0045] This approach is described in greater detail in Chem. Commun., 1996, 57-58 and is depicted in Scheme 2 herein below.
[0000]
[0046] In the present invention, this problem can be overcome by the use of commercially available CF 3 CH═CHF with a base, as depicted in Scheme 3 below.
[0000]
[0047] Alternately, CF 3 CH═CHCl can also be used in place of CF 3 CH═CHF which is commercially available. Typically, bases such as Cs 2 CO 3 , K 2 CO 3 , and sodium or potassium tertiary butoxide can be used in Schemes 1 and 2.
[0048] The starting material CF 3 CH═CHF can be made in large scale from commercially available CF 3 CH 2 CF 2 H according to methods described in U.S. Pat. No. 6,548,719 B1. CF 3 CH 2 CF 2 H is produced by and is available from Honeywell International, Inc., Morristown, N.J.
[0049] Preferably, CF 3 CH═CF 2 is formed from CF 3 CH 2 CF 2 H by chlorination followed by dehydrochlorination and CF 3 CH═CHF is formed from CF 3 CH 2 CF 2 H by dehydrofluorination.
[0050] The step of contacting is carried out at a temperature sufficient to produce the allyloxytrifluoropropene derivative. Contacting is preferably carried out at a temperature of about 25° C. to about 100° C., more preferably about 25° C. to about 50° C., and most preferably about 25° C. to about 35° C.
[0051] The step of contacting is carried out at a pressure sufficient to produce the allyloxytrifluoropropene derivative. Contacting is preferably carried out at a pressure of about 0.5 to about 1 atm and most preferably about 1 atm.
[0052] The step of contacting is carried out for a length of time sufficient to produce the allyloxytrifluoropropene derivative. Contacting is preferably carried out for a length of time of about 5 minutes to about 300 hours, more preferably about 30 minutes to about 5 hours, still more preferably about 30 minutes to about 2 hours, and most preferably about 2 hours.
[0053] The step of contacting is preferably carried out at a temperature from about 25° C. to about 50° C., at a pressure of about 0.5 atm to about 1 atm, and for a length of time from about 30 minutes to about 5 hours.
[0054] More preferably, the step of contacting is carried out at a temperature from about 25° C. to about 35° C., at a pressure from about 1 atm, and for a length of time from about 30 minutes to about 2 hours.
[0055] The process can be either a batch process or it can be a continuous process.
[0056] The reactor can further include a diluent, such as, a solvent or mixture of solvents. Preferably, polar, non-protic solvents, such as, acetonitrile, dimethylformamide (DMF), dimethylsulfoxide (DMSO), are used as the reaction medium. However, other solvents, such as, mono- and di-ethers of glycols, mono- and di-esters thereof, glymes, diglymes, triglymes, and tetraglymes can also be employed.
[0057] The process can further include one or more of the following steps:
[0058] (1) isolating the product from the reaction mixture by pouring the crude reaction mixture onto cold water at about 5° C. whereby the product separates out the lower layer; and
[0059] (2) purifying the reaction product via distillation under reduced pressure to obtain the product in substantially pure form.
[0060] In operation, preferably at least 10 wt % of the reactants are converted to the product. More preferably, up to at least 80 wt % of the reactants are converted to the product, and most preferably, at least 90 wt % of the reactants are converted to the product. Accordingly, operation of the process of the present invention under high conversion conditions is preferred.
[0061] Polymerization can be carried out essentially the same way as the methods known and described in the art, such as, the methods described in J. Polymer Sci. A: Polym. Chem . (1997) 35, 1593-1604 and U.S. Pat. No. 6,930,159 B1. Thus, both monomers can be readily polymerized to form homopolymers under standard polymerization conditions known to a person skilled in the art.
[0000] Alternatively, these monomers can be also readily polymerized to copolymers if an ethylenically unsaturated comonomer is present.
[0062] Depending on the polymerization conditions, the polymers can be obtained as transparent or white powders.
[0063] The allyloxytrifluoropropenes according to the present invention are suitable for use as monomers in the preparation of polymers and copolymers, including preparation of coatings, and particularly UV cured coatings.
[0064] The following non-limiting examples are illustrative of the various embodiments of the present invention. It is within the ability of a person of ordinary skill in the art to select other variable from amongst the many known in the art without departing from the scope of the present invention. Accordingly, these examples shall serve to further illustrate the present invention, not to limit them.
EXPERIMENTAL DETAILS
[0065] Unless otherwise indicated, all parts and percentages are on a weight basis.
Example 1
1,1-Bis-allyloxy-3,3,3-trifluoropropene (CF 3 CH═C(OCH 2 CH═CH 2 ) 2 )
[0066] To a stirred mixture of acetonitrile (100 mL), allylalcohol, CH 2 ═CHCH 2 OH, (20 g, 0.34 mol) and catalytic amount cesium carbonate (1.5 g, 4.6 mmol) was added, CF 3 CH═CF 2 (0.40 mol) via a gas sparger. The addition of CF 3 CH═CF 2 was such that the temperature of the reaction was not more than 36° C. After complete addition (30 minutes), the reaction mixture was stirred for 1 hour, poured into 400 mL cold water, mixed well and the upper layer was separated. Separated organic layer was mixed with water (400 mL), allowed to settle. The lower layer was separated, washed with water (50 ml), dried (MgSO 4 ) and filtered to afford crude product CF 3 CH═C(OCH 2 CH═CH 2 ) 2 . Pure product was obtained on distillation under reduced pressure (50 to 55° C./8-9 mm Hg) as a colorless liquid (25 g, 35% yield).
[0067] The structure of the product is consistent with the following spectroscopic data:
[0068] GC/MS data: m/e 208 (M + for C 9 H 11 F 3 O 2 );
[0069] 19 F NMR (CDCl 3 ) δ=−68.6 (3F, d, J HF =8 Hz) ppm; and
[0070] 1 H NMR (CDCl 3 ) δ=5.87 (1H, m), 5.71 (1H, m), 5.36-5.09 (4H, m), 4.65 (2H, dt, J=6 and 2 Hz), 3.2 (1H, m), 2.6 (2H, m) ppm.
[0071] The other product formed in this reaction is CF 3 CH═CF(OCH 2 CH═CH 2 ).
Example 2
1-Allyloxy-3,3,3-trifluoropropene (CF 3 CH═CH(OCH 2 CH═CH 2 ))
[0072] To a stirred mixture of acetonitrile (240 mL), allylalcohol, CH 2 ═CHCH 2 OH, (20 g, 0.34 mol) and sodium tertiarybutoxide (34.5 g, 0.36 mol) was added, CF 3 CH═CFH via a gas sparger. The addition CF 3 CH═CFH was such that the temperature of the reaction was not more than 35° C. After complete addition (about 45 minutes), the reaction mixture was stirred for 1 hour, poured into 400 mL cold water, mixed well and the upper layer was separated. Separated organic layer was mixed with water (400 mL), allowed to settle. The lower layer was separated, washed with water (50 ml), dried (MgSO 4 ) and filtered to afford 42 g product characterized to be CF 3 CH═CHOCH 2 CH═CH 2 , which was 86% pure, by GC. Pure product was obtained on distillation under reduced pressure (36 to 42° C./68 mm Hg) to afford the pure product as a colorless liquid (32 g, yield=62%). The ratio of cis- to trans-isomer is 96:2.
[0073] The structure of the product is consistent with the following spectroscopic data:
[0074] GC/MS data: m/e 152 for M + (M=C 6 H 7 F 3 O);
[0075] NMR data for trans: 19 F NMR (CDCl 3 ), δ=−59.1 (3F, m) ppm; and
[0076] 1 H NMR (CDCl 3 ) δ=7.03 (1H, dq, overlaps J=12 and 2 Hz), 5.92 (m, 1H), 5.28-5.40 (m, 2H), 5.0 (1H, dq, overlaps, J=12 and 6 Hz) and 4.3 (2H, dm, J=5 Hz) ppm.
Example 3
[0077] The reaction was carried out in the same manner as described in the Example 2 except that CF 3 CH═CHCl was used in place of CF 3 CH═CHF. CF 3 CH═CHOCH 2 CH═CH 2 was obtained in 50% yield.
Example 4
Polymerization of CF 3 CH═CH(OCH 2 CH═CH 2 )
[0078] Polymerization was conducted essentially the same way as described in J. Polymer Sci. A: Polym. Chem . (1997) 35, 1593-1604.
[0079] To a clean vial containing a Teflon coated magnetic stirbar and a Teflon backed septa was added 15 mg (4.5×10 −5 mol) of CO 2 (CO) 8 in an Argon-filled dry box. To this was added 2.6 mL of dry Toluene followed by 20 uL (1.1×10-4 mol) of dry diphenylsilane. This was mixed, and, after 15 minutes, the 1-allyloxy-3,3,3-trifluoropropene (0.65 mL, 5.0×10 −3 mol) was added via syringe. The vial was placed on a hot plate at 110° C. for 2 hrs while stirring. The reaction was quenched with a few drops of triethylamine (TEA) and then the polymer was precipitated in methanol. The polymer was then dried under vacuum at 80° C. for overnight.
[0080] The remaining polymer was determined by 1 H, 19 F NMR to contain the CH 3 groups in the main chain with characteristic broad peaks associated alkyl CH groups and phenyl silyl peaks as endgroups along with characteristic CF 3 groups. The resulting polymer was shown by GPC using polystyrene standards to have a MW=2,171 (weight average molecular weight) and Dp=3.01 (degree of polymerization).
Example 5
Polymerization of CF 3 CH═C(OCH 2 CH═CH 2 ) 2
[0081] Polymerization is conducted in essentially the same manner as in Example 3, with the exception that CF 3 CH═C(OCH 2 CH═CH 2 ) 2 was used instead of 1-allyloxy-3,3,3-trifluoropropene.
[0082] The present invention has been described with particular reference to the preferred embodiments. It should be understood that variations and modifications thereof can be devised by those skilled in the art without departing from the spirit and scope of the present invention. Accordingly, the present invention embraces all such alternatives, modifications and variations that fall within the scope of the appended claims.
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A process for preparing a polymer comprising the step of: polymerizing:
(i) an allyloxytrifluoropropene derivative selected from the group consisting of compounds represented by the formula:
CF 3 CH═CH(OCH 2 CR═CH 2 );
CF 3 CH═C(OCH 2 CR═CH 2 ) 2 ;
CF 3 CH═CF(OCH 2 CR═CH 2 ); and any mixtures thereof; wherein R is selected from the group consisting of: hydrogen and methyl; and optionally (ii) an ethylenically unsaturated comonomer;
wherein the copolymerizing step is carried out in the presence of a catalyst, under conditions sufficient to produce the copolymer.
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FIELD OF THE INVENTION
[0001] This invention relates to improvements in preventing heat- and moisture-shrink problems in specific polypropylene fibers. Such fibers require the presence of certain compounds that quickly and effectively provide rigidity to the target polypropylene fiber after heat-setting. Generally, these compounds include any structure that nucleates polymer crystals within the target polypropylene after exposure to sufficient heat to melt the initial pelletized polymer and upon allowing such a melt to cool. The compounds must nucleate polymer crystals at a higher temperature than the target polypropylene without the nucleating agent during cooling. In such a manner, the “rigidifying” nucleator compounds provide nucleation sites for polypropylene crystal growth. After drawing the nucleated composition into fiber form, the fiber is then exposed to sufficient heat to grow the crystalline network, thus holding the fiber in a desired position. The preferred “rigidifying” compounds include dibenzylidene sorbitol based compounds, as well as less preferred compounds, such as sodium benzoate, certain sodium and lithium phosphate salts (such as sodium 2,2′-methylene-bis-(4,6-di-tert-butylphenyl)phosphate, otherwise known as NA-11). Specific methods of manufacture of such fibers, as well as fabric articles made therefrom, are also encompassed within this invention.
DISCUSSION OF THE PRIOR ART
[0002] There has been a continued desire to utilize polypropylene fibers in various different products, ranging from apparel to carpet backings (as well as carpet pile fabrics) to reinforcement fabrics, and so on. Polypropylene fibers exhibit excellent strength characteristics, highly desirable hand and feel, and do not easily degrade or erode when exposed to certain “destructive” chemicals. However, even with such impressive and beneficial properties and an abundance of polypropylene, which is relatively inexpensive to manufacture and readily available as a petroleum refinery byproduct, such fibers are not widely utilized in products that are exposed to relatively high temperatures during use, cleaning, and the like. This is due primarily to the high and generally non-uniform heat- and moisture-shrink characteristics exhibited by typical polypropylene fibers. Such fibers are not heat stable and when exposed to standard temperatures (such as 150° C. and 130° C. temperatures), the shrinkage range from about 5% (in boiling water) to about 7-8% (for hot air exposure) to 12-13% (for higher temperature hot air). These extremely high and varied shrink rates thus render the utilization and processability of highly desirable polypropylene fibers very low, particularly for end-uses that require heat stability (such as apparel, carpet pile, carpet backings, molded pieces, and the like). To date, there has been no simple solution to such a problem. Some ideas have included narrowing and controlling the molecular weight distribution of the polypropylene components themselves in each fiber or mechanically working the target fibers prior to and during heat-setting. Unfortunately, molecular weight control is extremely difficult to accomplish initially, and has only provided the above-listed shrink rates (which are still too high for widespread utilization within the fabric industry). Furthermore, the utilization of very high heat-setting temperatures during mechanical treatment has, in most instances, resulted in the loss of good hand and feel to the subject fibers. Another solution to this problem is preshrinking the fibers, which involves winding the fiber on a crushable paper package, allowing the fiber to sit in the oven and shrink for long times, (crushing the paper package), and then rewinding on a package acceptable for further processing. This process, while yielding an acceptable yarn, is expensive, making the resulting fiber uncompetitive as compared to polyester and nylon fibers. As a result, there has not been any teaching or disclosure within the pertinent prior art providing any heat- and/or moisture-shrink improvements in polypropylene fiber technology.
DESCRIPTION OF THE INVENTION
[0003] It is thus an object of the invention to provide improved shrink rates for standard polypropylene fibers. A further object of the invention is to provide a class of additives that, in a range of concentrations, will give low shrinkage. A further object of the invention is to provide a specific method for the production of nucleator-containing polypropylene fibers permitting the ultimate production of such low-shrink fabrics therewith. Accordingly, this invention encompasses a polypropylene fiber possessing at most 5,000 denier per filament and exhibiting a heat-shrinkage in at least 150° C. hot air of at most 11%, wherein said fiber further comprises at least one nucleating agent. Also, this invention encompasses a polypropylene fiber possessing at most 5,000 denier per filament and exhibiting a heat-shrinkage in at least 150° C. hot air of at most 11%, wherein said fiber further comprises at least one nucleating agent, and wherein said fiber further exhibits a long period of at least 20 nm as measured by small-angle x-ray scattering. Furthermore, this invention encompasses a polypropylene fiber possessing at most 5,000 denier per filament and comprising at least one nucleating agent, and wherein said fiber further exhibits a long period of at least 20 nm as measured by small-angle x-ray diffraction spectroscopy. Additionally, this invention encompasses a polypropylene fiber possessing at most 5,000 denier per filament and exhibiting a peak crystallization temperature of at least 115° C. as measured by differential scanning calorimetry in accordance with a modified ASTM Test Method D3417-99 at a cooling rate of 20° C./min, and wherein said fiber further exhibits a long period of at least 20 nm as measured by small-angle x-ray scattering. Certain yarns and fabric articles comprising such inventive fibers are also encompassed within this invention.
[0004] Furthermore, this invention also concerns a method of producing such fibers comprising the sequential steps of a) providing a polypropylene composition in pellet or liquid form comprising at least 100 ppm by weight of a nucleator compound; b) melting and mixing said polypropylene composition of step “a” to form a substantially homogeneous molten plastic formulation; c) extruding said plastic formulation to form a fiber structure; d) mechanically drawing said extruded fiber (optionally while exposing said fiber to a temperature of at most 105° C.); and e) exposing said drawn fiber of step “d” to a subsequent heat-setting temperature of at least 110° C. Preferably, step “b” will be performed at a temperature sufficient to effectuate the melting of all polymer constituent (e.g., polypropylene), and possibly the remaining compounds, including the nucleating agent, as well (melting of the nucleating agent is not a requirement since some nucleating agents do not melt upon exposure to such high temepratures). Thus, temperatures within the range of from about 175 to about 300° C., as an example (preferably from about 200 to about 275°, and most preferably from about 220 to about 250° C., are proper for this purpose. The extrusion step (“c”) should be performed while exposing the polypropylene formulation to a temperature of from about 185 to about 300° C., preferably from about 210 to about 275° C., and most preferably from about 230 to about 250° C., basically sufficient to perform the extrusion of a liquefied polymer without permitting breaking of any of the fibers themselves during such an extrusion procedure. The drawing step may be performed at a temperature which is cooler than normal for a standard polypropylene (or other polymer) fiber drawing process. Thus, if a cold-drawing step is followed, such a temperature should be below about 105° C., more preferably below about 100° C., and most preferably below about 90° C. Of course, higher temperatures may be used if no such cold drawing step is followed. The final heat-setting temperature is necessary to “lock” the polypropylene crystalline structure in place after extruding and drawing. Such a heat-setting step generally lasts for a portion of a second, up to potentially a couple of minutes (i.e., from about {fraction (1/10)} th of a second, preferably about ½ of a second, up to about 3 minutes, preferably greater than ½ of a second). The heat-setting temperature must be greater than the drawing temperature and must be at least 110° C., more preferably at least about 115°, and most preferably at least about 125° C. The term “mechanically drawing” is intended to encompass any number of procedures which basically involve placing an extensional force on fibers in order to elongate the polymer therein. Such a procedure may be accomplished with any number of apparatus, including, without limitation, godet rolls, nip rolls, steam cans, hot or cold gaseous jets (air or steam), and other like mechanical means.
[0005] In another embodiment of the method of making such inventive fibers, step “c” noted above may be further separated into two distinct steps. A first during which the polymer is extruded as a sheet or tube, and a second during which the sheet or tube is slit into narrow fibers of less than 5000 deniers per filament (dpf).
[0006] All shrinkage values discussed as they pertain to the inventive fibers and methods of making thereof correspond to exposure times for each test (hot air and boiling water) of about 5 minutes. The heat-shrinkage at about 150° C. in hot air is, as noted above, at most 11% for the inventive fiber; preferably, this heat-shrinkage is at most 9%; more preferably at most 8%; and most preferably at most 7%. Also, the amount of nucleating agent present within the inventive fiber is at least 10 ppm; preferably this amount is at least 100 ppm; and most preferably is at least 1250 ppm. Any amount of such a nucleating agent should suffice to provide the desired shrinkage rates after heat-setting of the fiber itself; however, excessive amounts (e.g., above about 10,000 ppm and even as low as about 6,000 ppm) should be avoided, primarily due to costs, but also due to potential processing problems with greater amounts of additives present within the target fibers.
[0007] The term “polypropylene” is intended to encompass any polymeric composition comprising propylene monomers, either alone or in mixture or copolymer with other randomly selected and oriented polyolefins, dienes, or other monomers (such as ethylene, butylene, and the like). Such a term also encompasses any different configuration and arrangement of the constituent monomers (such as syndiotactic, isotactic, and the like). Thus, the term as applied to fibers is intended to encompass actual long strands, tapes, threads, and the like, of drawn polymer. The polypropylene may be of any standard melt flow (by testing); however, standard fiber grade polypropylene resins possess ranges of Melt Flow Indices between about 2 and 50. Contrary to standard plaques, containers, sheets, and the like (such as taught within U.S. Pat. No. 4,016,118 to Hamada et al., for example), fibers clearly differ in structure since they must exhibit a length that far exceeds its cross-sectional area (such, for example, its diameter for round fibers). Fibers are extruded and drawn; articles are blow-molded or injection molded, to name two alternative production methods. Also, the crystalline morphology of polypropylene within fibers is different than that of standard articles, plaques, sheets, and the like. For instance, the dpf of such polypropylene fibers is at most about 5000; whereas the dpf of these other articles is much greater. Polypropylene articles generally exhibit spherulitic crystals while fibers exhibit elongated, extended crystal structures. Thus, there is a great difference in structure between fibers and polypropylene articles such that any predictions made for spherulitic particles (crystals) of nucleated polypropylene do not provide any basis for determining the effectiveness of such nucleators as additives within polypropylene fibers.
[0008] The terms “nucleators”, “nucleator compound(s)”, “nucleating agent”, and “nucleating agents” are intended to generally encompass, singularly or in combination, any additive to polypropylene that produces nucleation sites for polypropylene crystals from transition from its molten state to a solid, cooled structure. Hence, since the polypropylene composition (including nucleator compounds) must be molten to eventually extrude the fiber itself, the nucleator compound will provide such nucleation sites upon cooling of the polypropylene from its molten state. The only way in which such compounds provide the necessary nucleation sites is if such sites form prior to polypropylene recrystallization itself. Thus, any compound that exhibits such a beneficial effect and property is included within this definition. Such nucleator compounds more specifically include dibenzylidene sorbitol types, including, without limitation, dibenzylidene sorbitol (DBS), monomethyldibenzylidene sorbitol, such as 1,3:2,4-bis(p-methylbenzylidene) sorbitol (p-MDBS), dimethyl dibenzylidene sorbitol, such as 1,3:2,4-bis(3,4-dimethylbenzylidene) sorbitol (3,4-DMDBS); other compounds of this type include, again, without limitation, sodium benzoate, NA-11, and the like. The concentration of such nucleating agents (in total) within the target polypropylene fiber is at least 100 ppm, preferably at least 1250 ppm. Thus, from about 100 to about 5000 ppm, preferably from about 500 ppm to about 4000 ppm, more preferably from about 1000 ppm to about 3500 ppm, still more preferably from about 1500 ppm to about 3000 ppm, even more preferably from about 2000 ppm to about 3000 ppm, and most preferably from about 2500 to about 3000 ppm. Furthermore, fibers may be produced by the extrusion and drawing of a single strand of polypropylene as described above, or also by extrusion of a sheet, then cutting the sheet into fibers, then following the steps as described above to draw, heat-set, and collect the resultant fibers. In addition, other methods to make fibers, such as fibrillation, and the like, are envisioned for the same purpose.
[0009] Also, without being limited by any specific scientific theory, it appears that the shrink-reducing nucleators which perform the best are those which exhibit relatively high solubility within the propylene itself. Thus, compounds which are readily soluble, such as 1,3:2,4-bis(p-methylbenzylidene) sorbitol provides the lowest shrinkage rate for the desired polypropylene fibers. The DBS derivative compounds are considered the best shrink-reducing nucleators within this invention due to the low crystalline sizes produced by such compounds. Other nucleators, such as NA-11, also provide good low-shrink characteristics to the target polypropylene fiber; however, apparently due to poor dispersion of NA-11 in polypropylene and the large and varied crystal sizes of NA-11 within the fiber itself, the shrink rates are noticeably higher than for the highly soluble, low crystal-size polypropylene produced by well-dispersed MDBS.
[0010] One manner of testing for the presence of a nucleating agent within the target fibers is preferably through differential scanning calorimetry to determine the peak crystallization temperature exhibited by the resultant polypropylene. The fiber is melted and placed between two plates under high temperature and pressure to form a sheet of sample plastic. A sample of this plastic is then melted and subjected to a differential scanning calorimetry analytical procedure in accordance with modified ASTM Test Method D3417-99 at a cooling rate of 20° C./minute. A sufficiently high peak crystallization temperature (above about 115° C., more preferably above about 116° C., and most preferably above about 116.5° C.), well above that exhibited by the unnucleated polypropylene itself, shall indicate the presence of a nucleating agent since attaining such a high peak crystallization without a nucleating agent is not generally possible.
[0011] It has been determined that the nucleator compounds that exhibit good solubility in the target molten polypropylene resins (and thus are liquid in nature during that stage in the fiber-production process) provide more effective low-shrink characteristics. Thus, low substituted DBS compounds (including DBS, p-MDBS) appear to provide fewer manufacturing issues as well as lower shrink properties within the finished polypropylene fibers themselves. Although p-MDBS is preferred, however, any of the above-mentioned nucleators may be utilized within this invention as long as the long period (SAXS) measurements are met or the low shrink requirements are achieved through utilization of such compounds. Mixtures of such nucleators may also be used during processing in order to provide such low-shrink properties as well as possible organoleptic improvements, facilitation of processing, or cost.
[0012] In addition to those compounds noted above, sodium benzoate and NA-11 are well known as nucleating agents for standard polypropylene compositions (such as the aforementioned plaques, containers, films, sheets, and the like) and exhibit excellent recrystallization temperatures and very quick injection molding cycle times for those purposes. The dibenzylidene sorbitol types exhibit the same types of properties as well as excellent clarity within such standard polypropylene forms (plaques, sheets, etc.). For the purposes of this invention, it has been found that the dibenzylidene sorbitol types are preferred as nucleator compounds within the target polypropylene fibers. Of interest, as well, is the ability to provide a purely liquid formulation of the dibenzylidene sorbitol compounds for introduction within the target polypropylene compositions. Such liquid DBS formulations comprise certain nonionic surfactants that can be selected both for their liquefying and stability-providing benefits to the DBS compounds themselves, but also potentially for their lubricating properties for the eventual fiber. In such a manner, the amount of lubricant generally required for and added to the target fiber may be reduced or eliminated, thus reducing costs associated with such additives. Thus, the surfactants required for such a liquid nucleator composition of 3,4-DMDBS (or other types of nucleating agents), include those which are nonionic and which are ethoxylated to the extent that their hydrophilic-lipophilic balance (HLB) is greater than about 8.5. HLB is a measure of the solubility of a surfactant both in oil and in water and is approximated as one-fifth (⅕) the weight percent of ethoxy groups present on the particular surfactant backbone. More specifically, such surfactants exhibit a HLB value of more preferably greater than about 12, and most preferably greater than about 13, and must possess at least some degree of ethoxylation, more preferably greater than about 4 molar equivalents of ethylene oxide (EO) per molecule, and most preferably greater than about 9.5 molar equivalents of EO per molecule.
[0013] Of these preferred surfactants, the most preferred for utilization within the potential fluid nucleating agent dispersion for purposes of this invention include, in tabulated form:
TABLE SURFACTANT Preferred Diluent Surfactants (with Tradenames) Ex. Surfactant Available as and From HLB # 1 sorbitan monooleate (20 EO) Tween 80 ®; Imperial Chemical (ICI) 15.0 2 sorbitan monostearate (20 EO) Tween 60 ®; ICI 14.9 3 sorbitan monopalmitate (20 EO) Tween 40 ®; ICI 15.6 4 sorbitan monolaurate (20 EO) Tween 20 ®; ICI 16.7 5 dinonylphenol ether (7 EO) Igepal ® DM 430; Rhône-Poulenc (RP) 9.5 6 nonylphenol ether (6 EO) Igepal ® CO 530; RP 10.8 7 nonylphenol ether (12 EO) Igepal ® CO 720; RP 14.2 8 dinonylphenol ether (9 EO) Igepal ® DM 530; RP 10.6 9 nonylphenol ether (9 EO) Igepal ® CO 630; RP 13.0 10 nonylphenol ether (4 EO) Igepal ® CO 430; RP 8.8 11 dodecylphenol ether (5.5 EO) Igepal ® RC 520; RP 430 9.6 12 dodecylphenol ether (9.5 EO) Igepal ® RC 620; RP 12.3 13 dodecylphenol ether (11 EO) Igepal ® RC 630; RP 13.0 14 nonylphenol ether (9.5 EO) Syn Fac ® 905; Milliken & Company ˜13 15 octylphenol ether (10 EO) Triton ® X-100; Rohm & Haas 13.5
[0014] This list is not exhaustive as these are merely the preferred surfactants for use within the potential fluid nucleating agent dispersion for utilization within this invention. In such a fluid dispersion, then, the nucleating agent, such as preferably 3,4-DMDBS, comprises at most 40% by weight, preferably about 30% by weight, of the entire inventive fluid dispersion. Any higher amount will deleteriously affect the viscosity of the dispersion. Preferably the amount of surfactant is from about 70% to about 99.9%, more preferably from about 70% to about 85%; and most preferably, from about 70% to about 75% of the entire inventive fluid dispersion. A certain amount of water may also be present in order to effectively lower the viscosity of the overall liquid dispersion. Optional additives may include plasticizers, antistatic agents, stabilizers, ultraviolet absorbers, and other similar standard polyolefin thermoplastic additives. Other additives may also be present within this composition, most notably antioxidants, antistatic compounds, perfumes, chlorine scavengers, and the like. As noted above, this type of fluid dispersion is disclosed in greater detail within U.S. Pat. Nos. 6,102,999 and 6,127,440, both herein entirely incorporated by reference. Most preferred is a composition of 30% by weight of 3,4-DMDBS and 70% by weight of Tween® 80. This mixture is listed in the Preferred Embodiments section below as “Liquid 3,4-DMDBS”.
[0015] The closest prior art references teach the addition of nucleator compounds to general polypropylene compositions (such as in U.S. Pat. No. 4,016,118, referenced above). However, some teachings include the utilization of certain DBS compounds within limited portions of fibers in a multicomponent polypropylene textile structure. For example, U.S. Patent Nos. 5,798,167 to Connor et al. and 5,811,045 to Pike, both teach the addition of DBS compounds to polypropylene in fiber form; however, there are vital differences between those disclosures and the present invention. For example, both patents require the aforementioned multicomponent structures of fibers. Thus, even with DBS compounds in some polypropylene fiber components within each fiber type, the shrink rate for each is dominated by the other polypropylene fiber components which do not have the benefit of the nucleating agent. Also, there are no lamellae that give a long period (as measured by small-angle X-ray scattering) thicker than 20 nm formed within the polypropylene fibers due to the lack of a post-heatsetting step being performed. Again, these thick lamellae provide the desired inventive higher heat-shrink fiber. Also of importance is the fact that, for instance, Connor et al. require a nonwoven polypropylene fabric laminate containing a DBS additive situated around a polypropylene internal fabric layer which contained no nucleating agent additive. The internal layer, being polypropylene without the aid of a nucleating agent additive, dictates the shrink rate for this structure. Furthermore, the patentees do not expose their yarns and fibers to heat-setting procedures in order to permanently configure the crystalline fiber structures of the yarns themselves as low-shrink is not their objective.
[0016] In addition, Spruiell, et al, Journal of Applied Polymer Science, Vol. 62, pp. 1965-75 (1996), reveal using a nucleating agent, MDBS, at 0.1%, to increase the nucleation rate during spinning. However, after crystallizing and drawing the fiber, Spruiell et al. do not expose the nucleated fiber to any heat, which is necessary to impart the very best shrinkage properties, therefore the shrinkage of their fibers was similar to conventional polypropylene fibers without a nucleating agent additive. In the examples below, yarn made with similar levels of nucleating agent additives included and no further heat exposure showed worse shrinkage (at all measured temperatures after the standard 5 minute exposure time) than commercial fibers, and fibers which contained no additive and were exposed to the same conditions. Thus, in addition to the presence of the nucleating agent additive, exposure to heat after mechanical drawing is a crucial step in the invention.
[0017] Of particular interest and which has been determined to be of primary importance in the production of such inventive low-shrink polypropylene fibers, is the discovery that, at the very least, the presence of nucleating agent within heat-set polypropylene fibers (as discussed herein), provides high long period measurements for the crystalline lamellae of the polypropylene itself. This discovery is best explained by the following:
[0018] Polymers, when crystallized from a melt under dynamic temperature and stress conditions, first supercool and then crystallize with the crystallization rate dependent on the number of nucleation sites, and the growth rate of the polymer, which are both in turn related to the thermal and mechanical working that the polymer is subjected to as it cools. These processes are particularly complex in a normal fiber drawing line. The results of this complex crystallization, however, can be measured using small angle x-ray scattering (SAXS), with the measured SAXS long period representative of an average crystallization temperature. A higher SAXS long period corresponds to thicker lamellae (which are the plate-like polymer crystals characteristic of semi-crystalline polymers like PP). The higher the crystallization temperature of the average crystal, the thicker the measured SAXS long period will be. Further, higher SAXS long periods are characteristic of more thermally stable polymeric crystals. Crystals with shorter SAXS long periods will “melt”, or relax and recrystallize into new, thicker crystals, at a lower temperature than those with higher SAXS long periods. Crystals with higher SAXS long periods remain stable to higher temperatures, requiring more heat to destabilize the crystalline structure.
[0019] In highly oriented polymeric samples such as fibers, those with higher SAXS long periods will remain stable to higher temperatures. Thus the shrinkage, which is a normal effect of the relaxation of the highly oriented polymeric samples, remains low to higher temperatures than in those highly oriented polymeric samples with lower SAXS long periods. In this invention, as is evident from these measurements, the nucleating additive is used in conjunction with a thermal treatment to create fibers with extremely high SAXS long periods of at least 20 nm, or preferably at least 22 nm, which in turn are very stable and exhibit low shrinkage up to very high temperatures.
[0020] Furthermore, such fibers may also be colored to provide other aesthetic features for the end user. Thus, the fibers may also comprise coloring agents, such as, for example, pigments, with fixing agents for lightfastness purposes. For this reason, it is desirable to utilize nucleating agents that do not impart visible color or colors to the target fibers. Other additives may also be present, including antistatic agents, brightening compounds, clarifying agents, antioxidants, antimicrobials (preferably silver-based ion-exchange compounds, such as ALPHASAN® antimicrobials available from Milliken & Company), UV stabilizers, fillers, and the like. Furthermore, any fabrics made from such inventive fibers may be, without limitation, woven, knit, non-woven, in-laid scrim, any combination thereof, and the like. Additionally, such fabrics may include fibers other than the inventive polypropylene fibers, including, without limitation, natural fibers, such as cotton, wool, abaca, hemp, ramie, and the like; synthetic fibers, such as polyesters, polyamides, polyaramids, other polyolefins (including non-low-shrink polypropylene), polylactic acids, and the like; inorganic fibers such as glass, boron-containing fibers, and the like; and any blends thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate a potentially preferred embodiment of producing the inventive low-shrink polypropylene fibers and together with the description serve to explain the principles of the invention wherein:
[0022] [0022]FIG. 1 is a schematic of the potentially preferred method of producing low-shrink polypropylene.
[0023] [0023]FIG. 2 is described in greater detail below with regard to small angle X-ray scattering and is a graphical representation of the integrated intensity data I(q) as a function of 2θ in order to determine the long period spacing of the target fibers.
[0024] [0024]FIG. 3 is also described in greater detail below with regard to small angle X-ray scattering and is a graphical representation of the K(z) function to aid in the ultimate determination of long period spacing.
DETAILED DESCRIPTION OF THE DRAWING AND OF THE PREFERRED EMBODIMENT
[0025] [0025]FIG. 1 depicts the non-limiting preferred procedure followed in producing the inventive low-shrink polypropylene fibers. The entire fiber production assembly 10 comprises an extruder 11 comprising four different zones 12 , 14 , 16 , 18 through which the polymer (not illustrated) passes at different, increasing temperatures. The molten polymer is mixed with the nucleator compound (also molten) within a mixer zone 20 . Basically, the polymer (not illustrated) is introduced within the fiber production assembly 10 , in particular within the extruder 11 . The temperatures, as noted above, of the individual extruder zones 12 , 14 , 16 , 18 and the mixing zone 20 are as follows: first extruder zone 12 at 205° C., second extruder zone 14 at 215° C., third extruder zone 16 at 225° C., fourth extruder zone 18 at 235° C., and mixing zone 20 at 245° C. The molten polymer (not illustrated) then moves into a spin head area 22 set at a temperature of 250° C. which is then moved into the spinneret 24 (also set at a temperature of 250° C.) for strand extrusion. The fibrous strands 28 then pass through a heated shroud 26 having an exposure temperature of 180° C. The speed at which the polymer strands (not illustrated) pass through the extruder 11 , spin pack 22 , and spinneret 24 is relatively slow until the fibrous strands 28 are pulled through by the draw rolls 32 , 34 , 38 . The fibrous strands 28 extend in length due to a greater pulling speed in excess of the initial extrusion speed within the extruder 11 . The fibrous strands 28 are thus collected after such extension by a take-up roll 32 (set at a speed of 370 meters per minute) into a larger bundle 30 which is drawn by the aforementioned draw rolls 34 , 38 into a single yarn 33 . The draw rolls are heated to a very low level as follows: first draw roll 34 68° C. and second draw roll 38 88° C., as compared with the remaining areas of high temperature exposure as well as comparative fiber drawing processes. The first draw roll 34 rotates at a speed of about 377 meters per minute and is able to hold fifteen wraps of the polypropylene fiber 33 through the utilization of a casting angle between the draw roll 34 and the idle roll 36 . The second draw roll 38 rotates at a higher speed of about 785 meters per minute and holds eight wraps of fiber 33 , and thus requires its own idle roll 40 . After drawing by these cold temperature rolls 34 , 38 , the fiber is then heat-set by a combination of two different heat-set rolls 42 , 44 configured in a return scheme such that eighteen wraps of fiber 33 are permitted to reside on the rolls 42 , 44 at any one time. The time of such heat-setting is very low due to a low amount of time in contact with either of the actual rolls 42 , 44 , so a total time of about 0.5 seconds is standard. The temperatures of such rolls 42 , 44 are varied below to determine the best overall temperature selection for such a purpose. The speed of the combination of rolls 42 , 44 is about 1290 meters per minute. The fiber 33 then moves to a relax roll 46 holding up to eight wraps of fiber 33 and thus also having its own feed roll 48 . The speed of the relax roll 46 is lower than the heat-set roll (1280 meters per minute) in order to release some tension on the heat-set fiber 33 . From there, the fiber 33 moves to a winder 50 and is placed on a spool (not illustrated).
Inventive Fiber and Yarn Production
[0026] The following non-limiting examples are indicative of the preferred embodiment of this invention:
[0027] Yarn Production
[0028] Yarn was made by compounding Amoco 7550 fiber grade polypropylene resin (melt flow of 18) with a nucleator additive and a standard polymer stabilization package consisting of 500 ppm of Irganox® 1010, 1000 ppm of Irgafos® 168 (both antioxidants available from Ciba), and 800 ppm of calcium stearate. The base mixture was compounded at 2500 ppm in a twin screw extruder (at 220° C. in all zones) and made into pellets. The additive was selected from the group of three polypropylene clarifiers commercially available from Milliken & Company, Millad® 3905 (DBS), Millad® 3940 (p-MDBS sorbitol), Millad® 3988 (3,4-DMDBS), two polypropylene nucleators commercially available from Asahi-Denka Chemical Company (NA-11 and NA-21), sodium benzoate, Liquid 3,4-DMDBS, and 1,3:2,4-bis(2,4,5-trimethylbenzylidene) sorbitol (2,4,5-TMDBS).
[0029] The pellets were then fed into the extruder on an Alex James & Associates fiber extrusion line as noted above in FIG. 1. Yarn was spun with the extrusion line conditions shown in Table 1 using a 68 hole spinneret, giving a yarn of nominally 150 denier. For each additive, four yarns were spun with heat-set temperatures of 100°, 110°, 120°, and 130° C. respectively. These temperatures are the set temperatures for the controller for the rolls 42 , 44 . In practice, a variation is found to exist over the surface of the rolls 42 , 44 , up to as much as 10° C. Pellets with no nucleator additive were used to make control fibers.
[0030] The yarns were tested for shrinkage in boiling water by cutting a length of yarn, marking the ends of a “10” section with tape, placing the yarn in boiling water for 5 minutes, then taking the yarn out and measuring the length of the section between the tape marks. Measurements were taken on five pieces of each yarn, and the average change in dimension is divided by the initial length (10 inches) to give % shrinkage. Also, the measurements below have a statistical error of ±0.4 percentage units.
[0031] The yarns were similarly tested for shrinkage in hot air at 150° C. and 130° C. by marking a “10” section of yarn, placing it in an oven for five minutes at the measurement temperature, and similarly measuring the % shrinkage after removing the yarn from the oven. Again, five samples were measured, and the average shrinkage results are reported for each sample in Table 1. The shrink measurements are listed below the tested nucleators for each yarn sample. The yarn samples were as follows:
POLYPROPYLENE YARN COMPOSITION TABLE Yarn Samples with Specific Nucleators Added Yarn Sample Nucleator Added A NA-11 B NA-21 C Sodium Benzoate D DBS E p-MDBS F 3,4-DMDBS G Liquid 3,4-DMDBS H 2,4,5-TMDBS I(Comparative) None (Control)
Fiber and Yarn Physical Analyses
[0032] These sample yarns were then tested for shrink characteristics with a number of different variables including heat-set temperatures differences (on the heat-set rolls) during manufacture and different heat-exposure conditions (hot air at various temperatures and boiling water exposure at temperatures in excess of 100° C.). The results are tabulated below:
TABLE 1 EXPERIMENTAL Experimental Shrink Measurements for Sample Yarns Shrinkage Test Sample Yarn Heatset Temp.(° C.) and Temp.(° C.) Shrinkage A 100 150 Hot air 9.5% A 110 150 Hot air 9.4% A 120 150 Hot air 8.1% A 130 150 Hot air 6.7% A 100 130 Hot air 7.4% A 110 130 Hot air 5.9% A 120 130 Hot air 4.9% A 130 130 Hot air 4.0% A 100 Boiling water 4.9% A 110 Boiling water 4.1% A 120 Boiling water 3.6% A 130 Boiling water 2.7% B 100 150 Hot air 11.1% B 110 150 Hot air 10.1% B 120 150 Hot air 9.3% B 130 150 Hot air 6.7% B 100 130 Hot air 8.1% B 110 130 Hot air 7.3% B 120 130 Hot air 6.3% B 130 130 Hot air 3.4% B 100 Boiling water 5.6% B 110 Boiling water 4.7% B 120 Boiling water 2.7% B 130 Boiling water 2.3% C 100 150 Hot air 10.9% C 110 150 Hot air 11.2% C 120 150 Hot air 9.5% C 130 150 Hot air 7.1% C 100 130 Hot air 7.8% C 110 130 Hot air 7.4% C 120 130 Hot air 6.2% C 130 130 Hot air 4.5% C 100 Boiling water 6.0% C 110 Boiling water 5.0% C 120 Boiling water 3.9% C 130 Boiling water 2.6% D 100 150 Hot air 9.8% D 110 150 Hot air 9.7% D 120 150 Hot air 9.5% D 130 150 Hot air 5.8% D 100 130 Hot air 7.4% D 110 130 Hot air 6.9% D 120 130 Hot air 6.2% D 130 130 Hot air 2.9% D 100 Boiling water 5.6% D 110 Boiling water 4.5% D 120 Boiling water 3.1% D 130 Boiling water 2.1% E 100 150 Hot air 10.9% E 110 150 Hot air 9.2% E 120 150 Hot air 8.0% E 130 150 Hot air 4.0% E 100 130 Hot air 7.5% E 110 130 Hot air 6.1% E 120 130 Hot air 4.5% E 130 130 Hot air 2.7% E 100 Boiling water 4.6% E 110 Boiling water 4.0% E 120 Boiling water 2.4% E 130 Boiling water 1.9% F 100 150 Hot air 13.6% F 110 150 Hot air 12.4% F 120 150 Hot air 7.3% F 130 150 Hot air 7.2% F 100 130 Hot air 9.2% F 110 130 Hot air 8.0% F 120 130 Hot air 3.7% F 130 130 Hot air 3.4% F 100 Boiling water 6.5% F 110 Boiling water 4.0% F 120 Boiling water 2.6% F 130 Boiling water 2.7% G 100 150 Hot air 12.9% G 110 150 Hot air 11.7% G 120 150 Hot air 9.3% G 130 150 Hot air 7.6% G 100 130 Hot air 9.2% G 110 130 Hot air 8.8% G 120 130 Hot air 6.5% G 130 130 Hot air 4.3% G 100 Boiling water 6.0% G 110 Boiling water 5.3% G 120 Boiling water 3.9% G 130 Boiling water 2.8% H 100 150 Hot air 12.2% H 110 150 Hot air 10.9% H 120 150 Hot air 9.6% H 130 150 Hot air 6.8% H 100 130 Hot air 8.9% H 110 130 Hot air 8.0% H 120 130 Hot air 6.3% H 130 130 Hot air 3.0% H 100 Boiling water 5.5% H 110 Boiling water 4.7% H 120 Boiling water 3.3% H 130 Boiling water 2.1% I 100 150 Hot air 21.3% I 110 150 Hot air 19.3% I 120 150 Hot air 17.4% I 130 150 Hot air 13.4% I 100 130 Hot air 12.5% I 110 130 Hot air 10.7% I 120 130 Hot air 8.6% I 130 130 Hot air 5.3% I 100 Boiling water 6.8% I 110 Boiling water 5.2% I 120 Boiling water 3.2% I 130 Boiling water 3.2%
[0033] In addition, two commercial yarns were obtained from Filament Fiber Technology and tested in each of the three tests, with the results shown in Table 3. Commercial Yarn #1 is an air jet textured yarn with a black pigment. Commercial Yarn #2 is an air jet textured yarn with a white pigment.
TABLE 2 EXPERIMENTAL Experimental Data for Comparative Commercial Polypropylene Yarns Test Comm. Yarn #1 Comm. Yarn #2 150° C. Hot air shrinkage 13.0% 12.1% 130° C. Hot air shrinkage 7.8% 7.0% Boiling water shrinkage 4.8% 5.5%
[0034] It is evident from these two TABLEs that the inventive polypropylene yarns (including those made from the inventive method described above) exhibit vastly improved shrinkage rates for all three test methods and thus are clearly improvements over the commercially available prior art yarns as well as those yarns lacking nucleating agent and heat-set.
[0035] Additive Level Dependence
[0036] To test the dependence on nucleator additive level, additional yarns were spun in accordance with the method described above with varying levels of additive using Amoco 7550 resin. The additive was compounded into the resin and the fibers spun under the same conditions as in the previous examples. The yarns were similarly tested, with the results shown in Table 5.
TABLE POLYPROPYLENE YARN SAMPLE Yarn Samples with Specific Nucleators Added Yarn Sample Nucleator Added (Amount ppm) J NA-11 (1000) K 3,4-DMDBS (1250) L 2,4,5-TMDBS (1250)
[0037] [0037] TABLE 3 EXPERIMENTAL Experimental Data for Different Nucleator Levels in Polypropylene Yarns Shrinkage Test Sample Yarn Heatset Temp.(° C.) and Temp.(° C.) Shrinkage J 100 150 Hot air 18.1% J 110 150 Hot air 16.6% J 120 150 Hot air 16.7% J 130 150 Hot air 9.0% J 100 130 Hot air 10.4% J 110 130 Hot air 9.0% J 120 130 Hot air 6.8% J 130 130 Hot air 4.5% J 100 Boiling water 5.4% J 110 Boiling water 4.8% J 120 Boiling water 3.3% J 130 Boiling water 2.6% K 100 150 Hot air 15.7% K 110 150 Hot air 17.1% K 120 150 Hot air 13.0% K 130 150 Hot air 8.8% K 100 130 Hot air 9.3% K 110 130 Hot air 8.6% K 120 130 Hot air 5.5% K 130 130 Hot air 4.0% K 100 Boiling water 6.8% K 110 Boiling water 4.5% K 120 Boiling water 3.3% K 130 Boiling water 2.5% L 100 150 Hot air 16.9% L 110 150 Hot air 15.8% L 120 150 Hot air 13.2% L 130 150 Hot air 8.7% L 100 130 Hot air 11.1% L 110 130 Hot air 9.2% L 120 130 Hot air 6.8% L 130 130 Hot air 4.5% L 100 Boiling water 6.8% L 110 Boiling water 4.3% L 120 Boiling water 3.3% L 130 Boiling water 2.3%
[0038] Thus, additive levels are important to providing overall good low shrinkage characteristics for the target polypropylene yarns. Higher levels appear to provide better shrinkage properties.
[0039] X-Ray Scattering Analysis
[0040] The long period spacing of several of the above yarns was tested by small angle x-ray scattering (SAXS). The small angle x-ray scattering data was collected on a Bruker AXS (Madison, Wis.) Hi-Star multi-wire detector placed at a distance of 105 cm from the sample in an Anton-Paar vacuum chamber where the chamber was evacuated to a pressure of not more than 100 mTorr. X-rays (λ1.54178 Å) were generated with a MacScience rotating anode (40 kV, 40 mA) and focused through three pinholes to a size of 0.2 mm. The entire system (generator, detector, beampath, sample holder, and software) is commercially available as a single unit from Bruker AXS. The detector was calibrated per manufacturer recommendation using a sample of silver behenate.
[0041] A typical data collection was conducted as follows. To prepare the sample, the yarn was wrapped around a 3 mm brass tube with a 2 mm hole drilled in it, and then the tube was placed in an Anton-Paar vacuum sample chamber on the x-ray equipment such that the yarn was exposed to the x-ray beam through the hole. The path length of the x-ray beam through the sample was between 2-3 mm. The sample chamber and beam path was evacuated to less than 100 mTorr and the sample was exposed to the X-ray beam for one hour. Two-dimensional data frames were collected by the detector and unwarped automatically by the system software. The data were smoothed within the system software using a 2-pixel convolution prior to integration. To obtain the intensity scattering data [I(q)] as a function of scattering angle [2θ] the data were integrated over ø with the manufacturer's software set to give a 2θ range of 0.2°-2.5° in increments of 0.01° using the method of bin summation. These raw scattering data were then transformed into a real space correlation function K(z) using a FORTRAN program written in house to evaluate the integral:
K ( z ) = ∫ 0 ∞ 4 π q 2 I ( q ) cos ( 2 π q z ) q where q = 4 πsin ( θ ) / λ .
[0042] The integral was evaluated by direct summation over all values 2θ in the data range (0.2°-2.50) and over the real space values from 0 nm-50 nm. This follows the method of G. Strobl (Strobl G. The Physics of Polymers; Springer: Berlin 1997, pp. 408-14), entirely incorporated by reference. From the one-dimensional correlation function, K(z), one can extract the morphological data of interest, in this case long period spacing (L). The integrated intensity data I(q) as a function of 2θ demonstrates a broad hump corresponding to the long period spacing (FIG. 2). The K(z) function has a characteristic shape (FIG. 3). The relevant extractable data points are indicated. Long-period spacing is extracted from K(z) data as the global maximum of the function occurring at a higher z value than the global minimum.
[0043] These data are collected in Table 6. Also included in Table 6 are the measurements as a result of 150° C. hot air exposure (to test for shrinkage). As can be clearly seen, a longer SAXS long period corresponds to a lower shrinkage. In addition, samples prepared with the additive, but without sufficient heat in the process (represented in this case by a 130° C. heatset), gave a smaller SAXS long period and a correspondingly higher 150° C. hot air shrinkage. The following TABLE thus shows the correlation between SAXS long period measurements with 150° C. hot air exposure (for shrinkage of the target yarns), as well as the correlation between heat-set temperatures with such characteristics.
TABLE 4 EXPERIMENTAL SAXS and 150° C. Hot Air Shrinkage Data For Yarn Samples Sample Yarn Heat-set Temp. (° C.) Shrinkage SAXS Long Period A 130 6.7% 26.45 B 130 6.7% 22.35 C 130 7.1% 21 D 130 5.8% 23.2 E 130 4.0% 26.4 E 120 8.0% 21 E 110 9.2% 18.4 F 130 7.2% 21.55 H 130 6.8% 22.4 Comm. Yarn 1 — 12.1% 16.95 Comm. Yarn 2 — 13.0% 15.6
[0044] It is thus evident that the higher the long period as measured by small-angle X-ray scattering, the lower the shrinkage exhibited by the target polypropylene yarn.
[0045] Peak Crystallization Temperatures
[0046] As noted above, in order to provide the desired low-shrink characteristics to the target yarns and/or fibers, a nucleating agent should be added. Although the presence of a nucleating agent or agents is necessary to accord such low-shrink properties in tandem with a proper heat-setting of the fiber and/or yarn, it is not a requirement that all nucleating agents present within the target yarn and/or fiber exhibit a relatively high peak crystallization temperature. There are certain instances, however, wherein the nucleating agent does induce such high peak crystallization temperatures and thus their presence may be determined through differential scanning calorimetry analysis. For those nucleating agents that do not induce the target polymer to exhibit such high peak crystallization temperatures, other methods of analysis (gas chromatography/mass spectroscopy, as one example) may be utilized to determine their presence. For example, although sodium benzoate is well known as a polyolefin nucleating agent (as defined above), peak crystallization results within polypropylene yarns and/or fibers are not consistent with accepted results for sodium benzoate within other types of polypropylene articles (such as plaques, containers, and the like). Some peak crystallization measurements for sodium benzoate within polypropylene fibers have been nearly as low as the measurements for the polypropylene itself. Again, since sodium benzoate provides effective low-shrink characteristics for such fibers and/or yarns, the lack of high peak crystallization temperatures for such sodium benzoate-containing polypropylene fiber samples does not remove sodium benzoate from the definition of nucleating agent for the purposes of this invention.
[0047] Thus, for the polypropylene samples including the remaining types of nucleating agents, peak crystallization was measured by the following method (a modified version of ASTM D3417-99 including a manner of creating a proper measurable sample of the test fibers themselves): A Perkin-Elmer DSC7 calibrated with an indium metal standard at a heating rate of 20° C./min was used to measure the peak crystallization temperature of the polypropylene fibers. Bundles of polypropylene fibers were heated to 220° C. for 1 minute and then compressed into thin disks approximately 250 μm thick. The specific polyolefin/DBS mixture composition was heated from 60° C. to 220° C. at a rate of 20° C. per minute to produce a molten formulation and held at the peak temperature for 2 minutes. At that time, the temperature was then lowered at a rate of 20° C. per minute until it reached the starting temperature of 60° C. The peak crystallization temperature of the polymer was thus measured as the peak maximum during the crystallization exotherm. This entire procedure of first preparing fibers into plaques followed by DSC analysis in accordance with the modified ASTM D-3417-99 test is herein referred to as “fiber peak crystallization temperature measurement(s)” for the purposes of this invention. The results for the fiber peak crystallization temperature measurements for the samples from Table 1, above, are tabulated below (with a standard deviation of ±0.5° C.):
TABLE 5 EXPERIMENTAL Peak Crystallization Temperatures For Yarn Samples Peak Crystallization Sample Yarn Heat-set Temp. (° C.) Temperature (Tc)(° C.) A 120 124.3 B 130 124.6 D 130 117.0 E 130 123.7 F 130 124.5 H 130 122.2 I(Comparative) 130 109.9
[0048] Thus, the presence of certain nucleating agents provided relatively high peak crystallization temperatures for the sample yarns (at least above 115° C., and as high as a low level of about 117.0° C.).
Fabric Article Production and Analyses
[0049] Woven Fabric Comprising the Inventive Yarn
[0050] Fabric was woven using the inventive yarns and a 150 denier, 34 filament polyester warp, and weaving a square weave with 84 picks/inch using five yarns: a control made as above with no additive with final draw roll 3 A and 3 B temperatures of 110° C. and 130° C. Three experimental yarns were made having 2500 ppm 3,4-DMDBS (Sample yarns F, from above) and a final draw roll 3 A and 3 B temperature of 110° C., 130° C., and 140° C. respectively. These sample fabrics were separated into 18 inch squares. A 12″ box was drawn in the center of the piece of fabric, and the fabric was washed five times in either hot (60° C.) or cold (20° C.) water, and dried for 30 minutes in a conventional dryer (at about 70° C. for 20 minutes). The dimensional change of the 12″ box was measured, and is reported in Table 6 as % shrinkage.
TABLE 6 EXPERIMENTAL Fabric Sample Shrinkage Data Sample Fabric (corresponding Yarn Heat-set Cold Wash Hot Wash to TABLE 1, above) Roll Temp. (° C.) Shrinkage Shrinkage F 110 2.4% 5.8% F 130 2.9% 3.7% F 140 2.4% 3.7% I(Comparative) 110 8.9% 14.9% I(Comparative) 130 5.0% 6.8%
[0051] Thus, it is evident that the fabric samples comprising the inventive yarns exhibit lower shrinkage rates as well.
[0052] Knit Fabric Construction Comprising the Inventive Yarn
[0053] Yarns from TABLE 1 were produced with a heat-set roll temperature of 130° C. and were subsequently knit into socks on a Lawson Hemphill FAK Knitter 36 gage knitting machine using 160 needles (needle no. 71.70) at speed setting 4 using 40 PSI of air pressure. The fabric was laid flat, and a 2.75″×10″ section of sock was marked (10″ in the course direction, 2.75″ in the wales direction). The socks were placed in an oven at 150° C. (hot air) for five minutes, and then the dimensions of the marked section were measured. The shrinkage in each direction and the area shrinkage are reported in TABLE 8, below. The area shrinkage is the product of the measured dimensions (the area) divided by 27.5 sq. inches (the original area), reported as a percentage.
TABLE 7 EXPERIMENTAL 150° C. Hot Air Shrinkage Data For Knit Fabric Samples Sample Yarn Course Shrinkage Wales Shrinkage Area Shrinkage A 5.3% 2.8% 8.0% B 7.2% 2.8% 9.8% C 8.8% 2.2% 10.8% D 0.6% 3.4% 4.0% E 1.6% 1.6% 3.2% F 5.6% 2.8% 8.2% H 7.2% 2.2% 9.2% I(Comparative) 11.3% 4.4% 15.2% Comm. Yarn 1 20.6% 5.3% 24.8% Comm. Yarn 2 20.0% 3.8% 23.0%
[0054] Therefore, it is evident that the inventive knit fabrics exhibit far better shrinkage characteristics than the commercial yarn-containing fabric samples as well as the control without any nucleator compound present. The control yarn gave very high area shrinkage, which was eclipsed by the air jet textured commercial yarns. Yarns with DBS and p-MDBS gave very low shrinkage, easily acceptable within the apparel industry.
[0055] Non-Woven Fabric Construction Comprising the Inventive Yarn
[0056] Yarns from Sample E of TABLE 1 were produced with a heat-set roll temperature of 130° C. and were extruded at a pump rate of 87.6 cc/min with a 68 hole spinneret, to give a total yarn denier of 680 and a denier per filament of 10. The fibers were combined by plying such into 5 yarns of 2720 denier, which were then combined into a single tow of 13600 denier, which was heated at ˜90° C. in steam, crimped in a stuffer box, and then cut to a staple length of 3.25 inches. The staple was then carded, lapped using a Fiber Locker manufactured by James Hunter Machine Company, and then needled with a Di-Lour-6 manufactured by Dilo, Inc. into a bat approximately 12×24 inches. Boxes of 130.3 cm 2 were marked on the bat. The bat was then molded by heating with an IR lamp for 60 seconds to temperatures reaching 120-150° C. and then compressing in a 10° C. mold. The boxes showed average shrinkage of 3.2%.
[0057] A control yarn of 10 DPF with no additive was obtained. It was then crimped and cut into staple, carded, lapped, and needled in the same manner. Boxes were again marked prior to molding. When molded under the same conditions, the boxes showed an average shrinkage of 11.7%.
[0058] It is thus evident that the non-woven fabrics made from the inventive low-shrink propylene yarns also exhibit excellent low-shrink characteristics in comparison with control samples.
[0059] There are, of course, many alternative embodiments and modifications of the present invention which are intended to be included within the spirit and scope of the following claims.
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Improved polypropylene fibers exhibiting greatly reduced heat- and moisture-shrink problems are provided. Such fibers require the presence of certain compounds that quickly and effectively provide rigidity to the target polypropylene fiber after heat-setting. Generally, these compounds include any structure that nucleates polymer crystals within the target polypropylene after exposure to sufficient heat to melt the initial pelletized polymer and upon allowing such a melt to cool. The compounds must nucleate polymer crystals at a higher temperature than the target polypropylene without the nucleating agent during cooling. In such a manner, the “rigidifying” nucleator compounds provide nucleation sites for polypropylene crystal growth. After drawing the nucleated composition into fiber form, the fiber is then exposed to sufficient heat to grow the crystalline network, thus holding the fiber in a desired position. The preferred “rigidifying” compounds include dibenzylidene sorbitol based compounds, as well as less preferred compounds, such as sodium benzoate, certain sodium and lithium phosphate salts (such as sodium 2,2′-methylene-bis-(4,6-di-tert-butylphenyl)phosphate, otherwise known as NA-11). Specific methods of manufacture of such fibers, as well as fabric articles made therefrom, are also encompassed within this invention.
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