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REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of copending application Serial No. 1,744 filed Jan. 8, 1979, now abandoned, a continuation-in-part of Serial No. 843,001 filed Oct. 17, 1977, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to wipers for industrial and other applications involving the absorption of water and/or oily materials. The many uses for such wipers include auto repair cleanup, lithographic plate processing, hand wiping, and many others. For such uses it is desirable to have a single material that wipes well for both oil and water residues. Further, since wiping is, in many cases, a hand labor step, it is also desired to obtain a wiper that wipes clean with a minimum effort, preferably on the first application. Finally, cloth wipers, which are most prevalent in industrial applications today, must be reused for economy and, as a result, are subject to pilferage and laundry costs. It is, therefore, desirable to obtain an improved wiper at a cost consistent with single use and disposability.
2. Description of the Prior Art
Many forms of wipers are available for various applications. In general, however, prior wipers can be classified as either paper or cloth. The paper wipers, while inexpensive, are suited primarily for use in wiping aqueous materials and not entirely satisfactory for use with oil. On the other hand, cloth wipers, while suitable for wiping both oils and water, are expensive and must be laundered. In addition, unless care is taken in laundering, water absorption rates for cloth wipers can be adversely affected. Some nonwoven wipers made from rayon which may also include other ingredients such as pulp, for example, and other synthetic materials have been available, but, in general, fail to provide good wiping properties with both oil and water and may entail a cost that prevents disposability except in special applications. Finally, sponges, both natural and synthetic, are in widespread use for wiping but are even more expensive.
Examples of prior wipers within these broad classifications are contained in the following U.S. patents which are intended to be representative and not exhaustive: U.S. Pat. No. 3,477,084 to Thomas, U.S. Pat. No. 3,520,016 to Meitner, U.S. Pat. No. 3,546,056 to Thomas, U.S. Pat. No. 3,650,882 to Thomas, and U.S. Pat. No. Re. 27,820 to Politzer et al.
The preparation of polyolefin microfiber webs is also known and described in Wente, Industrial and Engineering Chemistry, Volume 48, Number 8 (1965) pages 1342 through 1346 as well as U.S. Pat. No. 3,978,185 to Buntin et al, U.S. Pat. No. 3,795,571 to Prentice and U.S. Pat. No. 3,811,957 to Buntin. The Buntin et al patent further discloses that mats of meltblown polyolefins are useful as wiping cloths and hydrocarbon absorption material. However, the wipers as described in these publications each are deficient to a significant degree in one or more of the following properties: cost, combined oil and water wiping, clean wiping, or physical properties.
SUMMARY
The present invention provides a unique, low cost wiper having an improved combination of water and oil wiping properties. It is formed from a low basis weight web of synthetic, thermoplastic microfibers treated with a wetting agent and may be pattern bonded. The type and amount of wetting agent as well as the particular bonding patterns are selected to result in an unexpected degree of water and oil absorption while producing a unique ability to wipe clean in most cases with a single wiping action. This contrasts with wipers of the prior art which display usefulness primarily with respect to either water or oil and which require multiple wipings to remove all residue. In a particularly preferred embodiment the wipers are produced by embossing at a pressure of at least 20 psi and a temperature in the range of 180° F. to 245° F. The wipers of the present invention find particular application in industrial uses such as lithographic plate processing, machine maintenance and repair, and food handling, but many other applications will be apparent to those skilled in this art.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph of capillary sorption comparisons for known wiping materials and various wipers of the present invention;
FIG. 2 is a capillary sorption graph comparing bond patterns;
FIG. 3 is a capillary sorption graph comparing basis weights;
FIG. 4 is a capillary sorption graph comparing polyester webs; and
FIG. 5 is a graph comparing water wiping film residue properties.
DESCRIPTION OF THE PREFERRED EMBODIMENT
While the invention will be described in connection with preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
The invention will be described in reference to certain tests carried out on the material of the invention as well as conventional wipers. These tests are performed as follows:
Trapezoidal tear results were obtained essentially in accordance with ASTM D2263 #34, page 483, part 24, ASTM Test Methods. An Instrom tester was used equipped with a 1 inch by 3 inch jaw grip with the longer dimension perpendicular to the direction of load application. A trapezoidal template was used having parallel sides 1 inch and 4 inches long with a 3 inch height and a 15 mm cut in the 1 inch side. Five 3 inch by 6 inch samples are prepared with a tear in the "machine" direction and five with a tear in the "cross" or opposite direction. The tear is made by cutting as in the template. The Instron load range is selected such that the break will normally occur between 10% and 90% of full scale load, and the sample is clamped along nonparallel sides with the cut midway between. The crosshead is moved until the sample ruptures or the return limit is reached. The maximum and minimum tearing loads are reported for each sample group of five, and the average reported as the tearing load.
Oil absorbency rate results were obtained essentially in accordance with Federal Specification UU-P-316, Mar. 3, 1949, Method 180 and UU-T-5956 dated Apr. 4, 1967. A 4 inch square specimen is placed on a wire screen and a syringe filled with white mineral oil at about 73° F. is held at an angle of about 30° from horizontal with its tip nearly touching the specimen. Exactly 0.1 ml of oil is applied to the center of the specimen keeping the syringe tip in drop and the time measured from start of flow to the point when the sample no longer reflects light when viewed at an angle. Five measurements were taken and the average reported.
Tensile results were obtained essentially in accordance with ASTM D-1117-74. Samples 4 inches by 6 inches are prepared with 5 each having at its length in the "machine" and "cross" directions. An Instron machine is used having one jaw face 1 inch square and the other 1 inch by 2 inches or larger with the longer dimension perpendicular to the direction of load. At a crosshead speed of 12 inches per minute, the full scale load was recorded and multiplied by a factor as follows: Readings (lbs.): 2, 5, 10, 20, 50; factors (respectively): 0.0048, 0.012, 0.024, 0.048, 0.120. The results were reported in energy (inches/lbs.).
Softness results were obtained by Handle-O-Meter readings under standard conditions of about 50% relative humidity and 73.5° F. The instrument was calibrated and two 6 inch square samples prepared. Using the 0.50 inch slot with curved plates and with the opening and blade aligned, each sample was centered and the maximum reading recorded as grams of force per specimen width. Readings were taken in "machine" and "cross" directions on each sample and averaged.
Capillary sorption pressure results were obtained essentially as described in Burgeni and Kapur, "Capillary Sorption Equilibria in Fiber Masses", Textile Research Journal, May 1967, pp. 356-366. A filter funnel was movably attached to a calibrated vertical post. The funnel was movable and connected to about 8 inches of capillary glass tubing held in a vertical position. A flat, ground 150 ml. Buchner form fitted glass medium Pyrex filter disc having a maximum pore diameter in the range of 10-15 microns supported the weighed sample within the funnel. The funnel was filled with Blandol white mineral oil having a specific gravity in the range of 0.845 to 0.860 at 60° F. from Whitco Chemical, Sonneborn Division, and the sample was weighed and placed under 0.4 psi pressure on the filter. After one hour during which the meniscus is maintained constant at a given height starting at 35 cm., the sample was removed, weighed, and grams per gram absorbed calculated. The height was adjusted and the process repeated with a new sample until a height of 1 cm. was reached. The results were plotted as in FIGS. 1-4. In general, results obtained below 10 cm. oil indicate oil contained within large web voids and are not characteristic of wiper performance. Results obtained above 15 cm. oil are most significant as representing oil absorbed within the fibers which will be retained and is an important measure of wiper performance.
Oil residue removal was determined by applying several drops of Blandol white mineral oil including 0.5% duPont oil red to a Lucite bar 18 inches by 2-9/16 inches by 3/4 inch fitted with a 4 inch by 2-9/16 inch top slide. Using a roller the oil was spread until evenly distributed. The 21/2 inch by 8 inch sample was wrapped about the slide and a 0.4 lb/in 2 weight placed on top. The sample and slide were pulled across the bar at a uniform rate, and the oil remaining on the bar washed off with mineral spirits into a 600 ml. beaker. The residue was then transferred quantitively into a 50 ml. volumetric flask and the volume adjusted to 50 ml. with mineral spirits. The flask was then placed in a colorimeter absorption cell and the percent transmittance measured at a wavelength of 5250 A°. The amount of oil residue was obtained from a calibration curve derived from tests run using known oil weights. The procedure was repeated five times and an average taken.
Water residue results were obtained using a Lucite slide 3.2 inches wide by 4 inches in length with a notched bottom adapted to receive a sample and slide along a 2 inch wide glass plate of 17.8 inches length. In carrying out the test a 2.5 inch by 8 inch strip of the material to be tested was wrapped around the Lucite slide and taped in place. The notched slide was then positioned at one end of the glass slide, and a 5 pound weight placed on top. Using a 0.5% water solution of diphenyl fast scarlet 4 Ban dye, from Geigy Dyestuff, the plate surface was wetted by pipetting about three 0.4 ml. drops spaced about two inches apart and centered along the remaining length of the plate. The slide plus the weight and sample was then pulled along the plate in a smooth, continuous motion. The dye solution remaining on the plate was then rinsed into a beaker using distilled water and diluted to 50 ml. in a volumetric flask. The residue was then determined by transmittance at 525 mμ using a Bausch & Lomb Spectronic 20 or calculated as follows:
residue (g.)=log (% T)-2.0079/-3.5108
Except where indicated otherwise, meltblown polyolefin webs produced for the wipers of the present invention were manufactured in accordance with the process described in U.S. Pat. No. 3,978,185 to Buntin et al which is incorporated herein by reference in its entirety and to which reference may be made for details of the meltblowing process.
The invention will now be described in terms of specific examples illustrating the various embodiments.
EXAMPLES 1-10
Meltblown microfiber webs were formed in accordance with the process described in U.S. Pat. No. 3,978,185 to Buntin et al as follows: for Examples 1-8, polypropylene resin having a melt index of 14-16, measured at 190° C. using 2161 g load and identified as Hercules PC 973 was used. For all but Examples 7 and 8, production was at a rate of 2.5 lbs. per hour, and collected at a distance of 14 inches on a forming screen. Examples 7 and 8 were produced at a rate of 2.0 lbs. per hour and collected at 21 inches. For Examples 9 and 10, polyethylene terephthalate polyester resin having an inherent viscosity of 0.45-0.64 and melting point of 252° C. with 0.1% TiO 2 by weight and identified as Eastman Chemical Products T-2 was used. In Examples 1, 4, 7, and 9, the meltblown filaments were integrated into a web as formed. Examples 2, 3, 5, 6, 8, and 10 include pattern bonding steps. In Examples 1-6, dioctylester of sodium sulfosuccinic acid wetting agent was applied to the web in a quench spray as the web was formed in an amount of 0.3% by weight. The timing and manner of wetting agent addition are not considered critical. The webs are further described in the following Table I that also includes the results of physical tests performed on the webs.
TABLE I__________________________________________________________________________Example 1 2 3 4 5 6 7 8 9 10__________________________________________________________________________Resin PP PP PP PP PP PP PP PP PE PEBasis Weight (oz/yd.sup.2) 2.5 2.5 2.5 3.5 3.5 3.5 3.0 3.0 2.0 2.0Bonding U RHT* D** U RHT* D** U RHT* U RHT*% Bond Area -- 10.2 11.8 -- 10.2 11.8 -- 10.2 -- 10.2Pins/in.sup.2 -- 153 100 -- 153 100 -- 153 -- 153Temp °F. -- 190 190 -- 190 190 -- 190 -- 190Pin Height (in.) -- 0.045 0.030 -- 0.045 0.030 -- 0.045 -- 0.045PropertiesTrap. Tear (lbs) 2.0 2.0 2.2 2.7 3.9 3.4 1.5 1.2 1.0 0.8Bulk (in.) 0.040 0.035 0.030 0.054 0.043 0.041 0.072 0.041 0.030 0.024Grab Tensile (lbs) 6.4 12.8 10.8 4.7 15.9 17.0 3.9 12.7 3.1 4.3SoftnessMD (-) 23.6, 30.0, 16.2, 44.0, 61.0, 78.2, 46.8, 56.0, 9.8, 6.8, 32.2 39.6 24.8 50.0 63.2 83.0 30.2 30.0 9.8 9.2CD (-) 16.0, 32.0, 30.0, 29.2, 61.5, 43.8, 24.0, 20.8, 11.8, 14.4, 33.0 15.6 15.2 47.8 65.2 42.0 41.2 50.0 9.8 13.6__________________________________________________________________________ *Pattern as illustrated in U.S. Design Pat. No. 239,566 **Pattern as illustrated in U.S. Pat. No. 3,855,046
The various materials produced in the foregoing examples were tested for oil absorbency rate, water absorbency rate, and residue removal as were the following materials representative of conventional wipers: a conventional cotton cloth wiper having a basis weight of 6.3 oz/yd 2 . an air formed rayon and cellulose fiber nonwoven wiper having a basis weight of 4.2 oz/yd 2 , and a paper wiper having a basis weight of 2.5 oz/yd 2 available under the trademark KIMTOWELS. The results of these tests are shown in the following Table II.
TABLE II__________________________________________________________________________Sample Ex Ex Ex Ex Ex Ex Ex Ex Ex Ex Cotton RayonProperties 1 2 3 4 5 6 7 8 9 10 Cloth NW Paper__________________________________________________________________________Oil 3.5 4.9 7.4 3.6 5.8 4.7 2.6 6.3 4.5 5.6 1.3 1.2 3.2Absorbency sec. sec. sec. sec. sec. sec. sec. sec. sec. sec. sec. sec. sec.RateOil 0.026 0.021 0.021 0.026 0.023 NA NA NA 0.032 0.032 0.039 0.089 0.035Residue g. g. g. g. g. g. g. g. g. g.Water 0 3.4 3.0 0 0 0 2 2 2 2 4.7 4.5 1.4Absorbency sec. sec. sec. sec. sec. sec. min.+ min.+ min.+ min.+ sec. sec. sec.Rate__________________________________________________________________________
The results of capillary sorption tests are shown in FIG. 1 which illustrates the improvement obtained with the wiper of the present invention. FIG. 2 illustrates oil capillary sorption tests comparing bonding patterns. As shown, pattern bonding has a slight adverse effect on capillary sorption, but, in many cases, this is acceptable in view of the benefits obtained in improved appearance, grab tensile, and other properties such as abrasion resistance, particularly since performance is still improved over other wiping materials. The RHT pattern is preferred as resulting in improved appearance and physical properties. FIG. 3 demonstrates the effect of increased basis weight on capillary sorption. As shown, at higher basis weights the gram per gram absorbency is somewhat lower. FIG. 4 illustrates capillary sorption results for polyester showing that the benefits are not as great as with polypropylene but that the adverse effects of pattern bonding are less pronounced. Polypropylene is, therefore, a preferred material for the wipers of the present invention.
The comparison of oil absorbency and water absorbency rates demonstrates that the use of a wetting agent has a remarkable effect on water absorbency rates while having only a slight effect on oil absorbency. To obtain the benefits of the invention the wetting agent is preferably applied in an amount to produce 0.1 to 0.6% by weight on the finished web although the range of 0.1 to 1.0% is useful. Thus, in accordance with the invention, the advantages of a synthetic polymer oil wipe can be retained in a wiper that is water absorbent as well.
FIG. 5 illustrates the improved water wiping characteristics of the wiper of the present invention in terms of water residue as measured by the test procedure described above. As shown, the wiper of the present invention was superior to the cloth and another nonwoven wiper, both of which left water residue several times greater than that left by the wiper of the present invention. FIG. 5 also demonstrates that little improvement is obtained by addition of surfactant (Aerosol OT) in excess of the preferred range.
The comparison of capillary sorption tests demonstrates the dramatic improvement in absorbency obtainable in accordance with the invention. For example, FIG. 1 shows that at 15 cm. pressure of oil, wipers of the invention contain at least about double and up to 15 times as much oil as conventional wiping products on an equal weight basis. As a result, wipers can be fabricated either on a lower basis weight to contain equal amounts of wiping capacity or at equal basis weights to conventional wipers with higher wiping capacity.
The comparison of residue removal demonstrates that the wiper of the present invention provides a remarkably clean oil wiping material and can result in significantly reduced wiping times and labor costs especially in industrial uses. Similar results are obtainable with water.
To obtain the advantages of the present invention the wetting agent is preferably selected from the following surface active agents: anionic compositions such as dioctylester of sodium sulfosuccinic acid (Aerosol OT). and nonionic compositions such as isooctyl phenypolyethoxy ethanol (Triton X-100 and X-102). Also the fibers are preferably polyolefin microfibers having an average diameter in the range of up to about 10 microns. The bond pattern comprises a density of the range of from about 20 to 250 pins/in 2 and preferably within 50 to 225 pins/in 2 with a percent area bond coverage in the range of from about 5 to 25%. For optimum cost/performance combinations the wipers of the invention preferably have a basis weight in the range of from about 1.5 to 3.5 oz/yd 2 although the range of from about 1 to 4.5 oz/yd 2 is useful. As shown, a wipe with these characteristics produces the highly unexpected beneficial results in addition to its economy of manufacture and use.
To demonstrate the effect of embossing conditions, material produced as in Example 2 was embossed under the temperature conditions of 160° F., 200° F., 245° F. and 280° F. at pressures of 10 psi, 30 psi, and 50 psi for each temperature. Test results for absorbency abrasion (5=low abrasion, 1=high abrasion resistance), grab tensile, trapezoidal tear and bulk were as follows:
TABLE III__________________________________________________________________________Capillary Suction Pressure-Oil @ 10 cmGrams Oil/Gram Fiber Comparative Abrasion Resistance Grab Tensile-PoundsTemp. 10 psi 30 psi 50 psi Temp. 10 psi 30 psi 50 psi Temp. 10 psi 30 psi 50 psi__________________________________________________________________________160° F. 4.61 4.55 4.61 160° F. 5 4 3 160° F. 4.6 8.5 9.5200° F. 4.15 4.26 4.17 200° F. 5 3 3 200° F. 7.8 9.7 9.5245° F. 3.63 3.73 3.74 245° F. 4 2 2 245° F. 9.5 9.8 9.9280° F. 3.77 3.82 3.69 280° F. 2 1 1 280° F. 9.7 10.0 9.5__________________________________________________________________________ 5 4 3 2 1 Low High Abrasion Abrasion Resistance Resistance__________________________________________________________________________ Trap Tear-Pounds Ames Bulk-Inches Temp. 10 psi 30 psi 50 psi Temp. 10 psi 30 psi 50 psi__________________________________________________________________________ 160° F. 1.76 2.05 2.18 160° F. 0.037 0.036 0.035 200° F. 1.95 1.70 1.92 200° F. 0.034 0.034 0.034 245° F. 1.71 1.85 1.89 245° F. 0.031 0.032 0.032 280° F. 1.27 1.31 1.34 280° F. 0.030 0.031 0.031__________________________________________________________________________
The foregoing shows that best results are obtained under embossing conditions of at least 20 psi and 180° F. to 245° F.
While other nonwoven wipers have achieved satisfactory performance with either oil or water, the wiper of the present invention is excellent in both applications. The addition of a wetting agent to a wiper of thermoplastic hydrophobic fibers would be expected to increase wetting out of the surface being wiped of water. This is extremely undesirable in, for example, restaurant applications where customers may be faced with a wet counter even after wiping. In contrast, the wiper of the present invention wipes clean both oily and aqueous substances with a minimum of residue making it useful for many applications in diverse areas such as restaurants and auto repair shops. While it is not desired to limit the invention to any theory, it is believed that the pore size of the microfiber webs of the invention reduces the adverse effect of wetting agent addition by retaining aqueous liquids with a minimum effect on the oil wiping capability of the webs. The results are particularly apparent in wiping surfaces such as stainless steel that are especially subject to spotting and streaking. As shown by the residue tests, dramatic improvement in residue removal is obtained with the wipers of the invention.
Thus it is apparent that there has been provided, in accordance with the invention, a wipe material that fully satisfies the objects, aims and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit and broad scope of the appended claims.
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Low cost wiper material for industrial and other applications having improved water and oil wiping properties. A base material of meltblown synthetic, thermoplastic microfibers is treated with a wetting agent and may be pattern bonded in a configuration to provide strength and abrasion resistance properties while promoting high absorbency for both water and oil. The wiper of the invention displays a remarkable and unexpected ability to wipe surfaces clean of both oil and water residues without streaking. It may be produced in a continuous process at a low cost consistent with the convenience of single use disposability.
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GROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority under 35 U.S.C. 119 to U.S. Provisional Patent Application No. 60/801,016 filed on May 16, 2006, the entire content of which is hereby incorporated by reference.
BACKGROUND
[0002] 1. Field of Art
[0003] Provided is a method that relates to the recovery of hydrocarbons in subsurface formations, particularly the recovery of heavy oil from reservoirs in which steam fracturing operations have been conducted.
[0004] 2. Background of the Related Art
[0005] Unconventional, heavy oil reserves, such as, for example, Miocene diatomite (Opal A), can be recovered through “steam fracturing”. Steam fracturing takes place through a cyclic process with characteristics that include injection pressures of approximately 1000 psi and temperatures of +/−500-550° F. Commonly assigned U.S. Pat. Nos. 5,085,276 and 5,305,829 disclose process(es) for cyclic steaming that are applicable to diatomite formations. Such processing generally includes:
Steaming. Injection takes place for 2-3 days (approximately 1000-1500 Barrels of Steam Per Day or BSPD) until a target volume of steam (e.g., 3000-5000 barrels of steam) is achieved. The steam is injected at approximately 1000 psi, which typically serves to exceed the fracture gradient of the subsurface rock, fracture the low-permeability reservoir (5 millidarcy or mD), and create secondary fracture permeability. Soak Period. After steaming the well, the well is shut in and “soaked” for approximately 2 days. The high temperature provides necessary viscosity reduction for the 13° API oil and allows the oil to flow more easily. In addition, a process known as imbibition takes place, in which condensed steam vapor is preferentially imbibed by the (hydrophilic) diatomite rock and oil is displaced into fractures and the well bore. Production. After “soaking” the well, the well is produced for approximately 20 or more days. The production causes a pressure drop, which induces “flashing” of hot water to steam, which provides lift energy for the fluid column. As a result, the wells flow and do not have to be artificially lifted, as long as the wells are subsequently steamed. Typically, a flowing wellhead configuration is used for cyclic steaming at a heavy oil field. After a well dies, the well is prepared for the next steam job.
SUMMARY
[0009] In an embodiment, provided is a method of drilling a wellbore useful for the recovery of hydrocarbons from a subsurface reservoir, the method comprising drilling a wellbore having a substantially horizontal productive portion lying within the subsurface reservoir. The subsurface reservoir is penetrated by one or more wellbores previously injected with steam.
[0010] In an embodiment, provided is a method of drilling a wellbore useful for the recovery of hydrocarbons from a subsurface reservoir, the method comprising drilling a wellbore having a substantially horizontal productive portion lying within the subsurface reservoir, drilling one or more substantially vertical wellbores; and perforating the one or more substantially vertical wellbores according to a depth of the substantially horizontal productive portion of the wellbore.
BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS
[0011] The appended drawings illustrate typical embodiments and are not to be considered limiting in scope.
[0012] FIG. 1 shows a cross-section of the first horizontal well of the Example. The productive interval (slotted liner) for the first horizontal well of the Example intersects intervals above top perforations of vertical wells. The intervals above the top perforations of the vertical wells are interpreted to be heated and highly fractured, due to steaming of the vertical wells: (prior to abandonment).
[0013] FIG. 2 shows a cross-section through an oil saturation model depicting the lateral section of the first horizontal well of the Example. The view is looking to the north-northwest direction at the steep dips of the formation, and the schematic indicates that gravity drainage could be a significant component of the producing mechanism for the first horizontal well of the Example.
DETAILED DESCRIPTION
[0014] While heavy oil reserves can be recovered through known “steam fracturing” processes, it has been discovered, as indicated by data acquired through the use of surface tiltmeters, that, during some steam cycles, fugitive steam migration can occur in the overburden (i.e., above the reservoir). The fugitive steam migration is believed to be caused by shallow casing damage or out-of-zone fracturing and result in higher than normal pressures in the overburden. The higher than normal pressures are believed to cause surface expressions, drilling issues, workover difficulties and surface uplift. As used herein, “surface expressions” refer to high-pressure volumes of steam and oil that breach the surface and result in recordable spills. Recordable spills are not only costly from an HES (health-environmental-safety) standpoint, but can also lead to significant lost production/revenue if steaming is curtailed as a result. In particular, surface expressions can lead to the abandonment of damaged (or assumed damaged) wellbores.
[0015] A surface expression can lead to a moratorium on drilling/steaming new replacement or infill wells in the area of the surface expression, as well as a moratorium on operating remaining wells around the surface expression by conventional cyclic steaming means, for fear of agitating the surface expression. It was surprisingly discovered that such remaining wells, when converted to artificial lift (rod-pump) without active steam injection, in order to help reduce surface dilation and continue to recover reserves in close proximity to the surface expression, produced at rates exceeding expectations.
[0016] Thus, high oil production from the post-steam, artificial lift (rod-pump) wells, without direct cyclic steam injection, led to the exploration of whether the performance of rod-pump wells could be duplicated with a horizontal well. It was discovered that a horizontal well could intersect the cyclic-steam induced fractures of abandoned vertical wells and still be productive without steam injection. Without wishing to be bound by any theory, it is believed that the production mechanisms for artificial lift wells in the reservoir are three-fold. First, gravity drainage likely assists in areas of steeply-dipping beds and thus oil can migrate within a single pattern. Second, established, open-fractures (both steam-induced and natural) play a major role in providing migration pathways for the oil in the low-permeability matrix rock. Third, the remaining heat from prior cyclic steaming, along with steaming on the periphery of the area, both play an important role in the heating and viscosity reduction of the oil.
[0017] The area near a surface expression can be characterized as one that has both steam-induced fractures as well as existing natural fractures. The high frequency of natural fractures can be documented near surface expressions through a detailed FMI/EMI (electromagnetic interference) study. Without wishing to be bound by any theory, it is believed that the natural fractures, along with steam-induced fractures, likely create a network that can be supplied with steam and can become “pressured”, as well as further heated, which allows for the production of oil through an artificial lift mechanism and does not necessarily require active injection in the producing wellbore. While not clear how far steam and pressure can propagate through existing fractures in the area of a field near a surface expression, rod-pump response to aggressive steaming suggests that the methods disclosed herein are a viable mechanism for continual resurgence in production.
[0018] As used herein, the phrase “substantially vertical” refers to an orientation of approximately 30° or less from vertical, while the phrase “substantially horizontal” refers to an orientation of approximately 30° or less from the horizontal.
[0019] From a strictly subsurface standpoint, there are a few basic criteria to be followed when planning a wellpath of a horizontal well. The criteria are used to create a “best-fit” line for a lateral section of the well. Exemplary criteria include:
[0020] 1) The path should be within approximately 50 feet of targeted abandoned wells.
[0021] 2) The path should pass by the abandoned wells at an elevation no greater than approximately 160 feet above (in TVDSS) top perforations of the abandoned wells.
[0022] 3) The path should pass by the abandoned wells at a TVDSS elevation that would be no lower than bottom perforations for the abandoned wells.
[0023] 4) The interpreted fracture networks from abandoned wells was targeted with greater than 150,000 barrels (CWE) of cumulative steam injection.
[0024] As disclosed herein, horizontal rod-pump wells are viable options to cyclic steaming in thermally mature areas, by taking advantage of a combination of steam-induced and natural fractures and gravity drainage of hot, mobile oil. Exemplary uses include:
[0025] 1) Drilling horizontal Wells to supplement existing vertical wells or replace vertical abandoned wells, when the vertical wells have previously been injected with greater than 50,000 cumulative barrels of steam (Cold Water Equivalent or CWE) and the lateral (production) section of the horizontal well is generally between the depths (total vertical depth subsea or TVDSS) of top and bottom perforations of offset vertical wells (when passing by the vertical wells). In one embodiment, the depth range is within approximately 200 feet TVDSS (height) from the top perforation of the vertical wells or approximately 50 feet TVDSS (depth) below bottom perforation of the vertical wells.
[0026] 2) Drilling horizontal wells in a thermal diatomite field such that a productive portion of the horizontal well lies within approximately 100 feet from all existing or abandoned wells that have previously been injected with greater than 50,000 barrels of steam (OWE), in accordance with the aforementioned parameters for depth relative to perforations of offset vertical wells. In an embodiment, the productive portion of the horizontal well can be defined as any well completion (perforated or slotted liner) that is at an angle of 90°, or higher, and is used for inflow of oil and water.
[0027] 3) Drilling horizontal wells in thermal diatomite, followed by drilling and completing vertical wells according to the aforementioned parameters for depths of perforations, relative to the productive portion of the horizontal well.
[0028] Essentially, the horizontal well disclosed herein employs a “fracture/heat salvage” approach for production in heavy oil fields such as, for example, thermal diatomite settings.
EXAMPLE
[0029] The following illustrative example is intended to be non-limiting.
[0030] A surface expression led to a moratorium on drilling/steaming new replacement or infill wells, within a 500 feet radius of the surface expression. The great number (i.e., twenty two) of abandoned wells and the restricted steaming policy led to significant loss of production (on the order of approximately 1000 Barrels Per Day or BPD) in the area of the surface expression.
[0031] Despite the abandonment of several active wells around the surface expression, there were several wells that remained. The several remaining wells were not operated by conventional cyclic steaming means, for fear of agitating the surface expression. Thus, one well was converted to artificial lift (rod-pump) in order to increase Antelope withdrawal, help reduce surface dilation, and continue to recover reserves in close proximity to the surface expression. Surprisingly, without active steam injection, the well produced at rates exceeding expectations (on the order of hundreds of BPD), until casing damage necessitated the abandonment of the converted well. Shortly after the conversion to rod-pump, four other producing wells were also equipped with rod-pumps. The four additional converted wells also responded positively.
[0032] When planning the first horizontal well, the exemplary well planning criteria as disclosed herein were focused on to ensure that the wellpath would be close enough to the abandoned wells, so as to capitalize on steam-induced fracturing and heating (see FIG. 1 ). Specifically, the productive portion, or productive interval (slotted liner), for the first horizontal well intersected intervals above the top perforations of the vertical wells. The intersected intervals above the top perforations were interpreted to be heated and highly fractured, due to steaming of the vertical wells (prior to abandonment).
[0033] The path of the first horizontal well targeted four previously abandoned wells in the area of the surface expression. The first horizontal well took a little over a week to drill and complete. The well was put on production with an initial production (IP) exceeding 1000 Barrels of Oil Per Day (BOPD). The first horizontal well had sustained production exceeding the average well production in the field by a factor of ten.
[0034] Prior to drilling the first horizontal well, the hypothesized mechanism for production was that the horizontal well would take advantage of the years of historic steam injection in the area by intersecting both steam-induced and natural fractures and also benefit from gravity drainage in the reservoir and wellbore (heel-to-toe elevation change rises 12°). The performance of the first horizontal well substantiates the hypotheses and suggests contribution from the majority of lateral section.
[0035] In addition to the first horizontal well, two additional horizontal well opportunities in the field were identified and capitalized on. The two additional horizontal wells were planned and drilled parallel to the first horizontal well, with the path of the second and third additional horizontal wells targeting six and five previously abandoned wells in the area of the surface expression, respectively.
[0036] FIG. 2 is a cross section through an oil saturation model for the oil field in which the surface expression occurred, showing the steep dips of the formation. Without wishing to be bound by any theory, it is believed that steep dips of the formation of the oil field in which the surface expression occurred, along with natural and steam-induced fractures, allow for the likelihood that gravity drainage could have been a significant component of the production mechanism for some horizontal wells at the oil field. Bedding dips can exceed 45° in the part of the field where the three horizontal wells were drilled and hot, mobile oil can drain down the steep beds. If a gravity drainage mechanism was taking place, then lateral portions of the three horizontal wells were in favorable position to capture the hot, mobile oil.
[0037] Previous near-wellbore volumetric calculations indicated that a considerable portion of the oil in the first horizontal well path was drained within 25 feet of the abandoned wellbores. However, the same study also concluded similar results for the aforementioned vertical rod-pump producers. The actual performance of the first horizontal well (discussed below), along with the rod-pump production response to offset steaming, suggests that oil production can be contributed from further than 25 feet away (from bottomhole location), which suggests that a fracture network exists in the mature area of the surface expression and the fracture network likely allows for the migration of steam and oil.
[0038] Many modifications of the exemplary embodiments disclosed herein will readily occur to those of skill in the art. The present disclosure is intended for purposes of illustration only and should not be construed in a limiting sense. Accordingly, the present disclosure is to be construed as including all structure and methods that fall within the scope of the appended claims. The term “comprising” within the claims is intended to mean “including at least” such that the recited listing of elements in a claim are an open set or group. Similarly, the terms “containing,” having,” and “including” are all intended to mean an open set or group of elements. “A,” “an” and other singular terms are intended to include the plural forms thereof unless specifically excluded.
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A method of drilling a wellbore useful for the recovery of hydrocarbons from a subsurface reservoir, penetrated by one or more wellbores previously injected with steam, comprises drilling a wellbore having a substantially horizontal productive portion lying within the subsurface reservoir.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] Applicants claim priority of German Patent Application No. 10 2007 015 950.3, filed Apr. 3, 2007.
FIELD OF THE INVENTION
[0002] The invention relates generally to automotive fuel supply systems, and more particularly to fuel pump housings used in automotive fuel supply systems.
BACKGROUND OF THE INVENTION
[0003] Many automotive fuel supply systems include a fuel tank for storing fuel. In one arrangement, a fuel delivery module including, among other things, a housing, a fuel pump, and a fuel filter may be suspended within the fuel tank. In another arrangement, the fuel pump may be arranged in-line with one or more fuel delivery lines. In operation, fuel typically travels through the fuel filter, into the fuel pump, and to an internal combustion engine. The traveling fuel often creates static electricity in the fuel filter.
SUMMARY OF THE INVENTION
[0004] One embodiment of a fuel pump housing may include a body, a fuel filter, and a ground connection. The body may have a bottom portion. The fuel filter may be located at or near the bottom portion where it can be in contact with the body so that electricity, such as static electricity, is conducted between the fuel filter and the body. The ground connection may help dissipate electricity that may be present in both the body and the fuel filter.
[0005] One embodiment of an assembly may include a housing and a fuel pump. The housing may include a body with a bottom portion, and may include a fuel filter. The fuel filter may be located at or near the bottom portion, and may conduct electricity, such as static electricity, to the housing. The housing, the fuel filter, or both may also include a single ground connection in order to dissipate electricity that may be present in both the housing and the fuel filter. The fuel pump may be held at least partially within the housing.
[0006] One embodiment of an assembly may include a housing and a fuel pump. The housing may include a body with a bottom portion, and may include a fuel filter. The fuel filter may be located at or near the bottom portion, and may conduct electricity, such as static electricity, to the body. The housing may also include a single ground connection in order to dissipate static electricity that may be present in both the body and the fuel filter. The housing may further include a connecting device that may extend between the body and the ground connection. The connecting device may conduct electricity between the body and the ground connection. The fuel pump may be held at least partially within the housing
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The following detailed description of preferred embodiments and best mode will be set forth with reference to the accompanying drawings, in which:
[0008] FIG. 1 is a cross-section of an embodiment of a fuel pump housing;
[0009] FIG. 2 is a cross-section of an embodiment of a fuel pump housing; and
[0010] FIG. 3 is a cross-section of an embodiment of a fuel pump housing having a fuel pump therein.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0011] In general, and before referring to the drawing figures, various example embodiments of a holder or housing 10 are shown and described. The housing 10 may be used in a fuel delivery module or sender unit of an automotive fuel supply system, and may be disposed in communication with or in a fuel tank. The housing 10 may have a simple design and a compact structure. A fuel filter 12 and a body 14 of the housing 10 may conduct electricity between each other, and a ground connection 16 may help dissipate electricity present in both the fuel filter and the body.
[0012] As shown in FIG. 3 , a fuel pump 18 can be secured in the housing 10 , or the housing can secure parts of the fuel pump. The fuel pump 18 provides the suction and drive needed to take fuel out of the fuel tank and deliver fuel to an internal combustion engine. The fuel pump 18 may be of the in-tank type, and the electric type having an electric motor that is powered by a vehicle power supply, such as a battery 20 . The fuel pump 18 may have an inlet 22 for drawing-in fuel, and may have an outlet 24 for discharging fuel out of an outlet or discharge line 26 . One or more retaining devices 28 may hold the fuel pump 18 in-place inside of the housing 10 , or a fitting (not shown) around the discharge line 26 may suspend the fuel pump in the housing. A negative terminal 30 may be located on the fuel pump 18 . A connecting device 32 may connect the fuel pump 18 with the body 14 , such as by a terminal lug. The connecting device 32 may ground the fuel pump 18 to the body 14 .
[0013] The body 14 receives the fuel pump 18 or parts of the fuel pump, and may provide the structure of the housing 10 . In one example, the body 14 may be composed of an electrically conductive material such as a metal like steel or aluminum. The body 14 may be formed by various metal forming processes such as by deep-drawing a metal sheet into a generally cylindrical shape. Referring to FIG. 1 , the body 14 may have a top portion 34 that may define an opening 36 for the discharge line 26 and for electrical wires providing power to the fuel pump 18 . The body may also have a bottom portion 38 that may define an opening (not shown) for a feed line (also not shown). The top portion 34 may define other openings for other lines or for the electrical wires, or the top portion may define an open top. In other embodiments, the top portion 34 and the bottom portion 38 may be separate components that are subsequently attached together. In this case, the top portion 34 and the bottom portion 38 may be in contact with each other such that electricity conducts through and between the portions.
[0014] The fuel filter 12 helps screen out contaminants that may otherwise enter into the fuel pump 18 or into the housing 10 . The fuel filter 12 may have various embodiments. In the example of FIG. 1 , the fuel filter 12 may be integral with, or may be a part of, the body 14 ; that is, the fuel filter may not necessarily be a component that is separate from the body. A plurality of pores or openings 42 may be formed in the bottom portion 38 by a punching process, a laser cutting process, or by any other suitable forming process. The openings 42 may be disposed about a majority of the area of the bottom portion 38 , may be disposed on only a section of the bottom portion, or may be disposed partly on a side wall adjacent the bottom portion. The openings 42 may be sized and dimensioned to allow fuel to enter into the housing 10 , and to exclude other larger particles. When in use, static electricity may build-up or accumulate in the fuel filter 12 by fuel flowing through it. Such static electricity may be dissipated, or dispersed, through the body 14 . This may limit electricity build-up in the fuel filter 12 and may help prevent static discharge at the fuel filter.
[0015] In the example of FIG. 2 , the fuel filter 12 may constitute an insert in the sense that the fuel filter may be a separate component that is subsequently attached to the bottom portion 38 . For example, a larger opening 44 may be formed in the bottom portion 38 by a punching process, a laser cutting process, or by any other suitable forming process. The opening 44 may be a single opening or may have more than one opening. The opening 44 may extend over a majority of the area of the bottom portion 38 , may extend over only a section of the bottom portion, or may extend partly on the side wall adjacent the bottom portion. A mesh-like material, such as a film or a screen 46 , may be attached to the bottom portion 38 and may extend over the opening 44 in order to separate contaminants out of the fuel flowing through it. The screen 46 may be attached to the bottom portion 38 by caulking, crimping, overmolding its perimeter, welding (e.g., by weld spots 48 ), or other suitable attaching methods. In at least some of these examples, the screen 46 may be inserted in notches (not shown) defined in a surface of the opening 44 . The screen 46 may be composed of an electrically conductive material such as a metal like steel or aluminum. When in use, static electricity may build-up or accumulate in the screen 46 by fuel flowing through it. Such static electricity may be dissipated, or dispersed, through the body 14 as the screen may be in contact with the body at its attachment points. This may limit electricity build-up in the fuel filter 12 and may help prevent static discharge at the fuel filter.
[0016] The ground connection 16 may help limit the build-up of static electricity in the housing 10 , and in both the fuel filter 12 and the body 14 . The ground connection 16 may dissipate, or disperse, static electricity through itself and to whatever the ground connection is connected to. The ground connection 16 may be a single ground connection, and may constitute the only ground connection for the housing 10 . That is, there may be no need to have a separate ground for each of the body 14 and the fuel filter 12 .
[0017] The ground connection 16 may have various embodiments. In the example of FIGS. 1 and 2 , the ground connection 16 may include the connecting device 32 in order to link the housing 10 or the fuel filter 12 with another component. For example, the connecting device 32 may have a metal screw 50 , one or more terminal lugs, and an electric wire 52 ; in another embodiment, the connecting device may include a stainless steel strip or sheet. The metal screw 50 may be fastened to the body 14 , and the electric wire 52 may extend to another component. Static electricity may travel from the body 14 , through the metal screw 50 and the electric wire 52 , and to the particular component. For example, the connecting device 32 may extend to the vehicle power supply, such as the battery 20 , and the ground connection 16 may be formed where the battery is ground. As another example, the connecting device 32 may extend to a body of the vehicle, and the ground connection 16 may be formed thereat. In another example, the connecting device 32 may extend to a negative terminal of a vehicle accumulator. Still in other examples, the ground connection 16 may be formed without the connecting device 32 , where the body 14 may be directly contacting a component such as the body of the vehicle. In this case, static electricity may travel between an interface of the body 14 and the vehicle body.
[0018] In another embodiment, the housing 10 may constitute the outer housing or casing of the fuel pump 18 . In this case, the impeller or running gears and other internals of the fuel pump 18 may be directly supported in the housing 10 without any other intermediate housing. The variously described fuel filters 12 and ground connections 16 may be used in this embodiment.
[0019] While the forms of the invention herein disclosed constitute presently preferred embodiments, many others are possible. It is not intended herein to mention all the possible equivalent forms or ramifications of the invention. It is understood that the terms used herein are merely descriptive, rather than limiting, and that various changes may be made without departing from the spirit or scope of the invention.
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A fuel pump housing includes a body that has a bottom portion. A fuel filter is located adjacent the bottom portion, and contacts the body so that electricity, such as static electricity, is conducted between the body and the fuel filter. A ground connection dissipates, or limits, electricity in both the body and the fuel filter.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority of Korea patent Application No. 10-2000-0055108, filed on Sep. 20, 2000.
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The present invention relates to a method for controlling a glow plug, and more particularly, to a method for controlling power supplied to the glow plug by dividing an engine starting step into a cranking step and an idling step, and operating the glow plug even after successfully entering into a running state in the case of entering into an abnormal engine state based on an amount of injected fuel, an engine speed and a coolant temperature, and thereby controlling the glow plug from before the engine starts through after it is running.
(b) Description of the Related Art
A conventional diesel engine is a compression-ignition type engine, which ignites fuel by injecting it into a combustion chamber heated to a high temperature by compressing air in a cylinder. Ignition of the conventional diesel engine may be unstable when the engine is at a low temperature in an early state of engine starting in which the engine is cold, because compression heat is not sufficient.
To enhance startability of a diesel engine when it is cold, a glow plug is installed in each cylinder and operated before starting the engine in order to heat air around the glow plug.
A conventional method for controlling a glow plug by prior art is simply to heat the glow plug for a given period of time according to coolant temperature.
According to the prior art, there is a problem of high power consumption. For example, the glow plug heating is continued in an unnecessary situation because the heating time is unchangeably determined by data acquired during starting. Therefore the battery may be frequently discharged because of high power consumption and the engine can be stalled in the process of starting because too much electrical power stored in the battery can be consumed by heating the glow plug.
SUMMARY OF THE INVENTION
Therefore, the present invention has been made in an effort to solve the above problem. An object of the present invention is to provide a method for controlling power supplied to a glow plug by dividing an engine starting step into a cranking step and an idling step, and operating the glow plug in the case of entering into an abnormal engine state even after successfully entering into a running state, based on an amount of injected fuel, engine speed and coolant temperature, and thereby controlling the glow plug from before the engine starts through after it is running, and stopping the process of control for a short time when a battery voltage is low.
Generally, a starter motor is rotated by operating a start switch, and thereby starting begins. The process of engine starting is made up of a cranking step in which the engine starts to rotate and an idling step in which the engine idles immediately after the engine is started.
Therefore, to achieve the above object, the method for controlling the glow plug according to the present invention controls power supplied to the glow plug by dividing the engine starting step into the cranking step and the idling step. Furthermore, the glow plug is operated even after the engine successfully starts, when the engine is in an abnormal state based on an amount of injected fuel, engine speed and coolant temperature.
A preheating system using a method for controlling a glow plug according to the present invention includes the glow plug being fixed on one side of a cylinder head, a battery supplying power to the glow plug, a control unit controlling power supply from the battery to the glow plug through a relay, a coolant temperature sensor measuring the temperature of the coolant, a battery voltage sensor measuring the voltage of the battery, and means for measuring an amount of injected fuel.
A method for controlling the glow plug of the present invention applies power to the glow plug until a power supply time exceeds a predetermined initial preheating time, or the engine is cranked, at which time the power supply to the glow plug is maintained until the power supply time exceeds a predetermined main preheating time, the engine enters into the idling state, or the coolant temperature is higher than a predetermined target value, and then the power supply to the glow plug is cut off.
The initial preheating time and the main preheating time are determined by tables that use the battery voltage and the coolant temperature as variables.
When the engine speed is greater than a predetermined speed for a predetermined time, the engine is determined to be cranking. When the engine speed reaches a predetermined speed, the engine is determined to be idling.
As the engine starts idling, the amount of injected fuel and the engine speed are measured. When the amount of injected fuel is greater than a predetermined fuel injection reference amount, or the engine speed is greater than a predetermined reference speed, the glow plug is preheated until the amount of fuel being injected and the engine speed become respectively lower than the fuel injection reference amount and the reference speed.
After engine starting is complete, when the coolant temperature is lower than a determined critical temperature, or the amount of injected fuel is less than a determined critical amount of injected fuel, or the engine speed is lower than a determined critical speed, the glow plug is again preheated until the coolant temperature, the amount of injected fuel and the engine speed are respectively greater than the critical values.
In each control step, when the battery voltage being measured is lower than a predetermined critical voltage, the power supply to the glow plug and the execution of the detailed steps are stopped. The power supply to the glow plug and the execution of the detailed steps remain stopped until the battery voltage is higher than the critical voltage, and then the power supply to the glow plug and the execution of the detailed steps are resumed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a glow plug system in which a method for controlling glow plugs by an embodiment of the present invention is used.
FIG. 2 is a flowchart showing an embodiment of a method for controlling a glow plug of the present invention.
FIG. 3 and FIG. 4 are flowcharts showing respectively a detailed step of a starting glow plug control step and a running glow plug control step.
FIG. 5 and FIG. 6 are flowcharts showing respectively a detailed step of a post-preheating step and an instantaneous preheating step.
FIG. 7 and FIG. 8 are drawings showing respectively an example of a table that determines an initial preheating time and an example of a table that determines a main preheating time.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic view of a glow plug system in which a method for controlling glow plugs by an embodiment of the present invention is used.
As shown in FIG. 1, the glow plug system according to the embodiment of the preset invention includes a glow plug 110 being fixed on one side of a cylinder head 150 , a battery 135 supplying power to the glow plug, a relay 115 being connected to the glow plug 110 and switching a power supply from the battery 135 to the glow plug 110 , a glow plug control unit 120 being connected to the relay 115 and controlling an operation of the relay 115 , a coolant temperature sensor 125 inputting a variable with which the glow plug control unit 120 controls an operation of the relay 115 , a battery voltage sensor 130 , and a fuel volume sensor 145 for measuring an amount of injected fuel, and it further comprises a start switch 140 controlling the power supply to the glow plug control unit 120 .
The glow plug 110 can be an arbitrary heating device that transforms electrical energy into thermal energy, and the fuel volume sensor 145 for measuring the amount of injected fuel can be any arbitrary device that performs the function.
The start switch 140 includes an ‘on’ position for supplying power to sensors attached to the engine and a ‘start’ position for supplying power to a starter motor and thereby rotating the starter motor.
Though the control unit 120 can be a singular control unit controlling the relay 115 by signal inputs from the above sensors 125 , 130 and 145 , it is preferable that the control unit is an electronic control unit (ECU) also controlling actuators of the engine.
FIG. 2 is a flowchart showing an embodiment of a method for controlling a glow plug of the present invention.
As shown in FIG. 2, a method for controlling the glow plug of the present invention comprises a starting glow plug control step S 210 controlling the glow plug for engine starting, and a running glow plug control step S 220 controlling the glow plug after engine starting.
Generally, the starter motor is rotated by operating the start switch of the engine, and thereby starting begins. In the starting glow plug control step S 210 , the engine-starting step is divided into a cranking step in which the engine rotates and an idling step in which the engine starts to idle after the engine is started, and power supplied to the glow plug is controlled from the point of operating the start switch to the point of entering into the idling state. Furthermore, it is determined whether the engine is stable when entering the idling state, and when the engine is determined to be unstable, the glow plug is again actuated.
In the running glow plug control step S 220 , when the engine is unstable based on the amount of injected fuel, the engine speed and the coolant temperature even after the engine starts idling, the glow plug is operated, and thereby the glow plug can be controlled after engine starting.
While the engine normally operates, running glow plug control step S 220 is executed continuously. When the engine start switch 140 is turned off, the running control step S 220 ends.
FIG. 3 and FIG. 4 are flowcharts showing respectively a detailed step of a starting glow plug control step and a running glow plug control step.
FIG. 3 is a flowchart showing detailed steps of the starting control step in an embodiment of a method for controlling the glow plug of the present invention.
If the start switch is turned to an ‘on’ or a ‘start’ state, the starting glow plug control step S 210 is initiated.
If the starting glow plug control step S 210 starts, the control unit 120 determines whether the coolant temperature sensor is working properly, in step S 310 . The determination is made by ordinary logic of an electronic control unit (ECU).
If the coolant temperature sensor is determined to be working properly in step S 310 , the temperature detected from the coolant temperature sensor 125 is fixed as the coolant temperature (S 320 ). If the coolant temperature sensor is determined to be malfunctioning in step S 310 , a default temperature is fixed as the coolant temperature (S 315 ). The default temperature can be fixed as a sufficiently low temperature with reference to an ordinary cold starting situation of the engine. For example, the default temperature can be fixed as −25° C.
The control unit 120 , after fixing the coolant temperature, operates the relay 115 such that power is applied to the glow plug 110 from the battery 135 (S 325 ).
After applying power to the glow plug 110 , the control unit 120 measures an elapsed time of power application, and then the control unit 120 determines whether the measured time exceeds a predetermined preheating time (hereinafter called an initial preheating time) (S 330 ).
The initial preheating time is determined by a table that uses the battery voltage and the coolant temperature as variables.
FIG. 7 is a drawing showing an example of a table that determines the initial preheating time. The initial preheating time is determined according to the coolant temperature and the battery voltage as shown in FIG. 7 . The initial preheating time for a coolant temperature and a battery voltage not given in FIG. 7 can be determined by linear approximation based on the coolant temperatures and battery voltages given in FIG. 7 .
As shown in FIG. 3, when the control unit 120 determines that the elapsed time for the power application is not greater than the initial preheating time, the control unit 120 determines whether the engine is being cranked (S 335 ).
In step S 335 , the engine is determined to be cranking when the engine speed is greater than a predetermined speed for more than a predetermined time. The predetermined time and the predetermined speed can be set respectively as an elapsed time in which the starter motor rotates normally and an arbitrary RPM (Revolutions per Minute). By way of example, the predetermined time can be 0.5 seconds, and the predetermined speed can be 450 RPM.
If the engine is determined to be not cranking in step S 335 , step S 330 is executed again.
If the measured time is determined to be greater than the initial preheating time in step S 330 , or if the engine is determined to be cranking in step S 335 , the initial preheating in the cranking step ends, and the preheating in the idling entrance step (hereinafter called main preheating) starts.
If the main preheating starts, the control unit 120 determines whether the measured time from power-apply start time exceeds the main preheating time (S 340 ).
The main preheating time is determined by using a table with the coolant temperature and the battery voltage as variables, as shown in FIG. 8 . The main preheating time for a coolant temperature and a battery voltage not given in FIG. 8 can be determined by linear approximation based on the coolant temperatures and the battery voltages given in FIG. 8 .
As shown in FIG. 3, if, in the step of determining whether the measured time from the power-apply start time is greater than the main preheating time, the measured time is determined to be not greater than the main preheating time, the control unit 120 determines whether the engine has started idling (S 345 ).
In the determination of entrance to the idling state (S 345 ), if the engine speed becomes a predetermined speed, it is determined to be idling. The predetermined engine speed can be an arbitrary speed of the engine at which the electronic control unit (ECU) recognizes that starting is completed, and by way of example, the predetermined engine speed can be 800 RPM.
If the engine is determined to have not entered the idling state in step S 345 , the control unit 120 measures the coolant temperature and determines whether the coolant temperature is higher than a predetermined target value (S 350 ).
The predetermined target value can be an arbitrary coolant temperature, and for example it can be 50° C.
If the coolant temperature is determined to be not higher than the predetermined target value, the step determining whether the measured time is greater than the main preheating time (S 340 ) is executed again.
If the measured time is determined to be greater than the main preheating time in step S 340 , or if the engine is determined to be idling, or if the coolant temperature is determined to be higher than the predetermined target value in the step determining the coolant temperature, the control unit 120 cuts off power supplied to the relay 115 such that the power supply from the battery 135 to the glow plug 110 is cut off (S 355 ).
After the power supply to the glow plug 110 is cut off, the control unit 120 determines whether the amount of injected fuel from an injector is greater than a predetermined fuel injection reference amount (S 360 ).
The fuel injection reference amount can be set as a maximum amount of fuel that can be injected in a normal engine speed range, and it can be set using a fuel control device of the engine. By way of example, in an engine in which the amount of injected fuel is less than 70 mm 3 in all normal driving circumstances, the fuel injection reference amount can be set as 75 mm 3 .
Generally, the amount of fuel that can normally be injected into an engine has a maximum value. Therefore, if the amount of injected fuel is determined to be greater than the fuel injection reference amount, it can be determined that the engine is cranking or it is malfunctioning.
If the amount of injected fuel is determined to be not greater than the fuel injection reference amount in step S 360 , it is determined whether the engine speed is greater than a predetermined reference engine speed (S 365 ).
The reference engine speed can be set as a maximum engine speed at which the engine operates normally, and it can be set at a fuel cutoff RPM in which the electronic control unit (ECU) cuts off the fuel supply. By way of example, generally in diesel engines the reference engine speed is set at 4500 RPM.
If the engine speed is determined to be not higher than the reference engine speed in step S 365 , the starting control step (S 210 ) ends.
If the amount of injected fuel is determined to be greater than the fuel injection reference amount in step S 360 , or if the engine speed is determined to be greater than the reference engine speed in step S 365 , a post-preheating step (S 370 ) is executed.
FIG. 5 is a flowchart showing detailed steps of the post-preheating step (S 370 ).
As shown in FIG. 5, if the post-preheating step (S 370 ) starts, the control unit 120 operates the relay 115 such that power is applied to the glow plug 110 from the battery 135 (S 510 ).
After power is applied to the glow plug 110 , the control unit 120 determines whether the amount of injected fuel from the injector is greater than the predetermined fuel injection reference amount (S 515 ).
If the amount of injected fuel is determined to be not greater than the fuel injection reference amount in step S 515 , the control unit 120 determines whether the engine speed is greater than the predetermined reference engine speed (S 520 ).
If the amount of injected fuel is determined to be greater than the fuel injection reference amount in step S 515 , or if the engine speed is determined to be greater than the reference engine speed in step S 520 , the step determining if the amount of injected fuel is greater than the fuel injection reference amount (S 515 ) is executed again.
If the engine speed is determined to be not greater than the reference engine speed in the step S 520 , the control unit 120 cuts off power supplied to the relay 115 such that the power supply from the battery 135 to the glow plug 110 is cut off.
After the power supply to the glow plug 110 is cut off, the post-preheating step (S 370 ) ends, at which point the starting control step (S 210 ) ends, and if the starting glow plug control step (S 210 ) ends, the running glow plug control step (S 220 ) is executed as shown in FIG. 2 .
FIG. 4 is a flowchart showing detailed steps of the running glow plug control step (S 220 ) in an embodiment of the present invention.
If the running glow plug control step (S 220 ) starts, the control unit 120 detects the coolant temperature and determines whether the coolant temperature is lower than a predetermined critical coolant temperature (S 410 ).
The predetermined critical coolant temperature can be set as an arbitrary temperature by which the engine is determined to be abnormally cool. By way of example, the predetermined critical temperature can be set as −20° C.
If the coolant temperature is determined to be not lower than the critical coolant temperature in step S 410 , the amount of injected fuel is measured and the control unit 120 determines whether the amount of injected fuel is less than the fuel injection critical amount (S 415 ).
The fuel injection critical amount can be set as a minimum value of the amount of fuel that can be injected at a normal engine speed range, and it can be set using a fuel control device of the engine. By way of example, the critical amount of injected fuel can be set as 10 mm 3 .
If the amount of injected fuel is determined to be not less than the critical amount of injected fuel in step S 415 , the control unit 120 determines whether the engine speed is less than the critical engine speed (S 420 ).
The critical engine speed can be set as a minimum engine speed at which the engine operates normally. By way of example, the critical engine speed can be set at 800 RPM.
If the engine speed is determined to be not less than the critical engine speed in step S 420 , the step determining if the coolant temperature is less than the critical coolant temperature (S 410 ) is executed again.
If the coolant temperature is determined to be less than the critical coolant temperature in step S 410 , or if the amount of injected fuel is determined to be less than the fuel injection critical amount in step S 415 , or if the engine speed is determined to be less than the critical engine speed in the step S 420 , an instantaneous preheating step (S 425 ) is executed.
FIG. 6 is a flowchart showing detailed steps of the instantaneous preheating step (S 425 ).
As shown in FIG. 6, if the instantaneous preheating step (S 425 ) starts, the control unit 120 applies power to the relay 115 such that power is supplied to the glow plug 110 from the battery 135 .
After power is applied to the glow plug 110 , the control unit 120 measures the coolant temperature and determines whether the coolant temperature is less than the predetermined critical coolant temperature (S 615 ).
If the coolant temperature is determined to be not lower than the critical coolant temperature in step S 615 , the control unit 120 determines whether the amount of injected fuel is less than the fuel injection critical amount (S 620 ).
If the amount of injected fuel is determined to be not less than the critical amount of injected fuel in step S 620 , the control unit 120 determines whether the engine speed is less than the predetermined critical engine speed (S 625 ).
If the coolant temperature is determined to be lower than the critical coolant temperature in step S 615 , or if the amount of injected fuel is determined to be less than the fuel injection critical amount (S 620 ), or if the engine speed is determined to be less than the predetermined critical engine speed (S 625 ), the step of evaluating the coolant temperature (S 615 ) is executed again.
If the engine speed is determined to be not less than the predetermined critical engine speed in step S 625 , the control unit 120 cuts off the power supplied to the relay 115 such that the power supply from the battery 135 to the glow plug 110 is cut off, at which point the instantaneous preheating step (S 425 ) ends.
If the instantaneous preheating step (S 425 ) ends, the step of evaluating the coolant temperature (S 410 ) is executed again as shown in FIG. 4 .
Therefore, while the engine operates, continuous detection of whether instantaneous preheating is needed is performed, and in the case when instantaneous preheating is needed the instantaneous preheating can be executed.
In the detailed steps S 330 ˜S 350 , S 410 ˜S 420 , S 515 ˜S 520 and S 615 ˜S 625 , being executed while power is supplied to the glow plug 110 in the starting glow plug control step (S 210 ) and the running glow plug control step (S 220 ), if the battery voltage being measured is lower than a predetermined critical voltage it is preferable that the control unit 120 stops both the power supply to the glow plug and execution of the detailed steps, and stands by until the battery voltage is higher than the critical voltage. Once it is, the control unit can resume the power supply to the glow plug and execution of the detailed steps, and it thereby allows the battery to charge when it is becomes low due to operation of the glow plug.
The critical voltage can be set as a minimum value of the battery voltage in which the starter motor of the engine can be rotated stably. By way of example, the critical voltage can be set as 8V.
The above-described preferable embodiments of the present invention are to be considered in all respects to be illustrative and not restrictive. Thus, various improvements and modifications to this invention may occur to those skilled in the art, and such improvements and modifications will fall within the scope of the present invention.
According to the embodiment of the present invention, during cold starting of an engine, the control unit divides the starting of the engine into several steps and then precisely controls starting of the engine. In addition, the control unit precisely controls the power supply to the glow plug, and thereby unnecessary power consumption can be decreased. Furthermore, if the charge of the battery is low, the control logic stops for a short time and thereby prevents an engine stall.
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For the purpose of precisely controlling a power supply to the glow plug and thereby reducing unnecessary power consumption, and stopping a control logic for a time when a battery voltage is low and thereby preventing a engine stall, the present invention provides a method for dividing an engine starting step into a cranking step and an idling step, controlling power supplied to the glow plug, and operating the glow plug even after successfully entering into a running state in the case of entering into an abnormal engine state based on an amount of injected fuel, an engine speed and a coolant temperature, and thereby controlling the glow plug from before the engine starts through after it is running.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a system for splitting and spreading existing underground utility pipe and pipe fittings and pulling new pipe through the bore of the utility pipe and pipe fittings.
2. Description of the Background Art
Throughout the United States steps are being taken to improve methods of replacing existing underground utility pipe and pipe fittings. In many municipalities, the utility pipes have been installed long ago and must be replaced on a regular scheduled basis to maintain vital utility services to its customers. Also, where rapid growth has occurred, the utility pipes are now undersized with respect to the desired capacity and must be replaced with larger capacity pipe. Initial replacement methods involved excavating the entire length of pipe and replacing it with new pipe in the excavated trench. This was very expensive and time consuming. Further, other vital utility services (telephone, electric) were also disrupted because the conduits carrying those services were usually in the same trench.
Trenchless replacement of utility pipe initially focused on slipping smaller diameter pipe through the bore of the utility pipe. This reduced the installation time and expense dramatically. However, the smaller diameter slipped pipe also reduced the utility system capacity. This is unacceptable to most municipalities.
U.S. Pat. No. 2,983,042 issued to Frantz et al. discloses a tube splitting apparatus having a plurality of cutter wheels for cutting a tube (pipe) that is stuck in a sleeve into two halves. The cutter wheels shape the edge of the split halves inwardly. U.S. Pat. No. '042 teaches away from only one path for the cutter wheels to traverse. Further, U.S. Pat. No. '042 is silent on scoring and cutting the utility pipe fittings.
U.S. Pat. No. 1,001,205 issued to Lovell discloses a well casing splitter and perforator for admitting water or oil through a group of slits into the casing. U.S. Pat. No. '205 teaches away from making a continuous cut through the pipe. U.S. Pat. No. '205 is silent on scoring and cutting the utility pipe fittings.
U.S. Pat. No. 4,106,561 issued to Jerome et al. discloses a well casing perforator adapted for use with pneumatically powered rotary drilling equipment commonly found in the oil exploration field. U.S. Pat. No. '561 teaches the intermittent engagement of a cam shaped perforating wheel with the well casing. U.S. Pat. No. '561 teaches away from a plurality of circular cutting wheels in continuous engagement with the interior of the utility pipe wall. Further, U.S. Pat. No. '561 teaches away from hydraulic means to pull the cutter assembly through the bore of the underground utility pipe and pipe fittings.
U.S. Pat. No. 3,181,302 issued to Lindsay discloses a pipe splitter and spreader that cuts the existing pipe into two halves and spreads the halves apart. U.S. Pat. No. '302 teaches away from a plurality of cutter wheels making only one cut in the existing pipe and maintaining the cut pipe as one whole pipe, even after the cut is made. U.S. Pat. No. '302 teaches away from equal diameter cutter wheels. U.S. Pat. No. 5,171,106 issued to Rockower et al. discloses a cutting tool having a plurality of cutter wheels of unequal diameter. U.S. Pat. No. '106 also discloses a pair of guide rollers for rotational engagement with the interior wall of the pipe. U.S. Pat. No. '106 teaches away from equal diameter cutter wheels and further teaches away from a plurality of paired pipe expanders to loosen and scrape built-up debris from the interior wall of the existing pipe and pipe fittings.
U.S. Pat. No. 4,455,107 issued to Schosek discloses a hydraulic apparatus for forcing a rod through undisturbed earth with axial force exerted through a set of jaws. U.S. Pat. No. '107 teaches the installation of new plastic pipe only in the bore created by the rod traversing the undisturbed soil. U.S. Pat. No. '107 teaches away from a plurality of rods forming a train. U.S. Pat. No. '107 is silent on replacing existing utility pipe and pipe fittings.
U.S. Pat. No. 4,903,406 issued to Schosek et al. teaches the use of a pipe splitter apparatus having a single cutting wheel having a circular diameter greater than the bore of the pipe to be split. U.S. Pat. No. '406 teaches the use of side wheels to rotatably engage the interior wall of the pipe. U.S. Pat. No. '406 teaches away from a plurality of cutter wheels.
None of these previous efforts, however, provide the benefits intended with the present invention. Additionally, prior techniques do not suggest, the present inventive combination of component elements as disclosed and claimed herein. The present invention achieves its intended purposes, objectives and advantages over the prior art devices through a new, useful and unobvious combination of component elements, which is simple to use, with the utilization of a minimum number of functioning parts, at a reasonable cost to manufacture, assemble, test and by employing only readily available material.
Therefore, it is an object of the present invention to provide a trenchless system to replace existing worn out utility pipe and pipe fittings with new pipe of equal or greater diameter.
It is a further object to provide a system to cut the pipe and the pipe fittings along a continuous longitudinal line on an upper hemispheric section of the pipe and pipe fittings.
It is another object of the invention to provide a pipe cutting system that maintains its vertical orientation through the entire traverse of the existing pipe to be replaced.
It is yet another object of the invention to provide a system that has equal diameter cutter wheels to minimize the inventory of cutter wheels in the field.
It is still another object of the invention to provide a system that loosens and scrapes built up debris from the interior wall of the existing pipe and pipe fittings as the cut is made.
It is yet another object of the invention to provide a hydraulic apparatus that can force a rod through undisturbed earth using only axial forces through a set of split jaws.
It is yet another object of the invention to provide a system that requires only two men to operate in the field.
It is still yet another object of the invention to provide a pipe spreading and splitting system that does not separate the existing pipe into two equal sized sections.
It is another object of the invention to provide a pipe splitting and spreading system that works equally well with either plastic or steel walled pipe.
It is yet another object of the invention to provide a pipe splitting and spreading system which operates with a minimum of force necessary to propel the invention through the existing pipe and pipe fittings and to ensure that the existing pipe and pipe fittings remain in place during the splitting/spreading process.
It is another object of the invention to provide a pipe splitting and spreading system which forms a single longitudinal cut along a longitudinal path of the pipe and pipe fittings to be split.
A final object of this invention to be specifically enumerated herein is to provide a pipe splitting and spreading system in accordance with the proceeding objects and which will conform to conventional forms of manufacture, be of simple construction and easy to use so as to provide a device that would be economically feasible, long lasting and relatively trouble free in operation.
Although there have been many inventions related to pipe splitting and spreading systems, none of the inventions have become sufficiently compact, low cost and reliable enough to become commonly used. The present invention meets the requirements of the simplified design, compact size, low initial cost, low operating cost, ease of installation and maintainability, and minimal amount of training to successfully employ the invention.
The foregoing has outlined the more pertinent objects of the invention. These objects should be construed to be merely illustrative of the more prominent features and applications of the intended invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiments in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
The invention is defined by the appended claims with the specific embodiment shown in the attached drawings. For the purpose of summarizing the invention, the invention may be incorporated into a pipe splitting and spreading system for replacing underground utility pipe and pipe fittings with new pipe. The system comprises a cutter assembly having a plurality of co-aligned cutter wheels and a plurality of pipe expanders, a mandrel having a first section sized for expanding the cut existing pipe and a second section adapted for engaging a pipe adapter, and means (either a cable and winch, or a hydraulic apparatus) for towing the cutter assembly and the mandrel and the pipe adapter and the new pipe through the bore of the existing utility pipe and pipe fittings.
An alternative embodiment of the invention uses the hydraulic apparatus and a plurality of steel rods coupled together in a train to form a tunnel through new, undisturbed soil, and roads or driveways or the like. A coupling attaches the new pipe to the foremost steel rod in the train. Then, the hydraulic apparatus is reversed and the new pipe is pulled through the newly created tunnel.
The hydraulic means is mounted in a first trench pit. A plurality of steel rods are coupled together to form a train. Each steel rod is dispatched into the bore of the existing utility pipe and pipe fittings by a plurality of split jaws exerting an axial force on the steel rod.
A second trench pit is oriented to receive the foremost steel rod after it traverses the bore of the existing utility pipe and pipe fittings. The cutter assembly, the mandrel, the pipe adapter and the new pipe are coupled one to the other in serial communication. The leading end of the cutter assembly is coupled to the foremost steel rod in the train and then the hydraulic apparatus is reversed. The train tows the cutter assembly and mandrel and pipe adapter and new pipe through the bore of the existing utility pipe and pipe fittings. As each steel rod returns to the first trench pit, it is uncoupled from the train until finally, the cutter assembly and mandrel and pipe adapter, arrive at the first trench pit. Thereupon, the cutter assembly and mandrel and pipe adapter are uncoupled from the new pipe.
The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood so that the present contribution to the art can be more fully appreciated. Additional features of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent structures do not depart from the spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:
FIG. 1 is a perspective drawing showing the general layout and operation of the invention in the field.
FIG. 2 is a perspective drawing of the cutter assembly.
FIG. 3 is a perspective drawing of the hydraulic apparatus.
FIG. 4A is a perspective drawing of the pipe adapter for plastic wall pipe.
FIG. 4B is a right hand side elevational view of the plastic pipe adapter.
FIG. 5 is a perspective drawing of the pipe adapter for steel wall pipe.
FIG. 6 is a front elevational view of the hydraulic apparatus showing the split jaws.
FIG. 6A is a front elevational view of the planetary balls gripping a steel rod.
FIG. 6B is a cross-sectional view of the planetary balls gripping a steel rod.
FIGS. 7A-7C are top plan views of the hydraulic apparatus showing its three functions of releasing/retracting, pushing and pulling the train.
FIG. 8A is a cross-sectional elevational view of the pipe and pipe joint taken along line 8A--8A of FIG. 1.
FIG. 8B is a cross-sectional elevational view of the cutter cutting the pipe taken along line 8B--8B of FIG. 1.
FIG. 8C is a cross-sectional elevational view of the cutter assembly passing through the cut pipe along line 8C-8C of FIG. 1.
FIG. 8D is a cross-sectional elevational view of the cutter cutting the pipe fitting taken along line 8D-8D of FIG. 1.
Similar reference characters refer to similar parts throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, the invention generally comprises a cutter assembly 10 having an elongated frame and a leading end and a trailing end. A plurality of cutter wheels 11 and 12 are mounted longitudinally in the cutter assembly with journals 11A and 12A, respectively. Each cutter wheel 11, 12 is mounted on a transverse axle in the journal 11A, 12A to provide unencumbered rotational movement of each cutter wheel, as best seen in FIG. 2. The cutter wheels 11, 12 are co-aligned along the longitudinal axis of the cutter assembly 10. The first cutter wheel 11 cuts through the existing utility pipe 13 and scribes a scoring line on the existing utility pipe fittings 14. The second cutter wheel 12 cuttably engages the existing utility pipe fittings 14 within the scoring line and cuts the existing utility pipe fittings 14 along the scoring line. The second cutter wheel 12 does not cut through the utility pipe 13, but only cuts through the utility pipe fitting 14. The cutter assembly 10 also includes a plurality of pipe expanders 15 and 16 that fractionally and frictionally contact the interior wall of the utility pipe. The distance between the extremities of at least one of the pipe expanders 16 is greater than an inside diameter of the existing pipe, as best seen in FIG. 8C. The distance between the extremities of the second pipe expander 15 is approximately equal to the inside diameter of the existing pipe.
As best seen in FIG. 1, a mandrel 17 has a first end adapted for coupling to the trailing end of the cutter assembly 10. Further, the second end of the mandrel is adapted for coupling to a pipe adapter 18. The pipe adapter 18 is adapted to receive a foremost section of the new replacement pipe 20. The mandrel 17 is sufficiently sized to spread the existing underground pipe and pipe fittings as it traverses through the bore of the existing underground utility pipe and pipe fittings.
Pulling means 30 are provided to engage the cutter assembly 10 at its leading end and pull the elongated cutter assembly 10 and mandrel 17 and pipe adapter 18 and new pipe 20 through the bore of the existing utility pipe and pipe fittings.
The pipe expanders 15 and 16 frictionally contact the interior wall of the existing underground utility pipe. In this manner, the pipe expanders maintain the plurality of cutter wheels 11 and 12 in a vertical orientation and are sufficiently sized to maintain the frictional contact with an interior surface of the pipe wall during the entire traverse of the existing underground utility pipe and pipe fittings. Each of pipe expanders 15, 16 is oriented on an outer periphery of the elongated frame of the cutter assembly 10 forward of each one of the cutting wheels, as best seen in FIG. 2. For example, pipe expander 15 is oriented forward of the first cutter wheel 11 and protects the journal 11A of the first cutter wheel 11.
Further, pipe expander 15 is designed to be horizontally disposed and frictionally contact and continuously engage the interior surface of the pipe wall along a horizontal path for urging the first cutter wheel 11 to maintain a vertical orientation throughout the entire traverse of the existing underground utility. The first and second pipe expanders 15 and 16 are designed and sufficiently sized to loosen built-up scale and debris on the interior surface of the pipe wall 13 as they frictionally contact the interior of the pipe wall throughout the entire traverse of the existing underground utility pipe and pipe fittings. The second pipe expander 16 is oriented forward of the second cutter wheel 12 and protects its journal 12A of the second cutter wheel. As best seen in FIG. 2, plurality of steel rods which form a train 22. Each steel rod pipe expanders 16 is vertically disposed for frictionally contacting and continuously engaging the interior surface of the pipe wall along a swath wider than the inside diameter of pipe 13 for urging the second cutter wheel to maintain a vertical orientation in the scoring line described by the first set of paired pipe expanders 15 throughout the entire traverse of the existing underground utility pipe and pipe fittings. Further, the second set of paired pipe expanders 16 are designed and sufficiently sized to scrape the loosened built-up scale and debris from the interior surface of the wall of the pipe along the entire traverse of the existing underground utility pipe and pipe fittings. Still further, the second set of pipe expanders 16 spreads the wall of the existing underground utility pipe and pipe fittings.
The first cutter wheel 11 is mounted in an upper portion of the elongated frame in proximity to the leading end of the cutter assembly 10 and the second cutter wheel is also mounted in an upper portion of the elongated frame in proximity to the trailing end of the cutter assembly, as best seen in FIG. 2. This arrangement facilitates the cutting of the pipe 13 and pipe fittings 14 cleanly and efficiently.
As an alternative embodiment, a third cutter wheel is mounted longitudinally in the elongated frame of the cutter assembly. The third cutter wheel engages a bottom section of the interior wall of the pipe and cuts through any built up scale and debris and perforates the pipe. The third cutter wheel is disposed within the elongated frame of the cutter assembly to urge the third cutter wheel to pass freely through the pipe fittings without cuttably engaging the pipe fittings. The third cutter wheel is positioned rearwardly of the second cutter wheel and journaled for rotational movement around a transverse axis within the elongated frame of the cutter assembly. The third cutter wheel facilitates cutting and perforating the lower section of the pipe, but passes freely through the pipe fittings.
An important feature of the invention is the fact that the cutter wheels all have the same diameter. That is, the diameter of the first cutter wheel is equal to the diameter of the second cutter wheel and is equal to the diameter of the third cutter wheel, if used. This significantly reduces the inventory of parts when the system is deployed for use and operation in the field.
As best seen in FIG. 2, the mandrel 17 has a front section having a frustro-conical outer periphery that spreads the existing underground utility pipe fittings as the mandrel 17 traverses through the existing underground utility pipe and pipe fittings. The mandrel 17 comes in an assortment of sizes, each mandrel being sized for spreading the existing utility underground pipe and fittings, according to the pipe diameter. Likewise, the cutter assembly 10 is available in an assortment of sizes accommodate various pipe diameters encountered in the field.
In the preferred embodiment of the invention, the means for pulling the cutter assembly and mandrel and new pipe through the bore of the existing underground utility pipe and pipe fittings is a plurality of steel rods which form a train 22. Each steel rod has a threadable end adapted for attachment to a rod coupling which in turn is coupled to a succeeding steel rod for forming the train to guide the cutter assembly and mandrel and new pipe through the bore of the existing underground utility pipe and pipe fittings. A foremost steel rod has a first end adapted for removable attachment to the leading end of the cutter assembly. Each steel rod is fabricated from a high strength steel, preferably alloy steel to reduce the chance of breakage when the train is traversing the bore of the existing underground utility pipe and pipe fittings. The high strength alloy steel is necessary to eliminate any chance of breakage when the train is pulling the cutter assembly 10 and mandrel 17 and new pipe 20 through the bore of the existing underground utility pipe and pipe fittings.
The mandrel 17 has a first end that is adapted for coupling to the trailing end of the cutter assembly 10 and a second end adapted to receive a pipe adapter 18, 19. The pipe adapter 18 is adapted to receive a foremost section of the new pipe. In one embodiment shown in FIGS. 4A and 4B, the pipe adapter has a plurality of threaded apertures radially oriented on an outer periphery, each aperture for receiving a threaded fastener 18a to threadably engage the pipe adapter 18 and the foremost section of new plastic pipe 20 in threadable communication. In another form the pipe adapter 19 has a recess that is threaded and properly sized to receive a threaded steel wall pipe as best seen in FIG. 5. The first section of mandrel 17 has a frustro-conical shape for expanding the bore of the existing underground utility pipe and pipe fittings in a progressive manner as the mandrel 17 traverses the bore. The pipe adapter 18, 19 is securely attached to the foremost section of new pipe 20 prior to pull the new pipe through the bore of the existing underground utility pipe and pipe fittings.
A less preferred embodiment of the pulling means has a cable and winch apparatus to engage the cutter assembly 10. The cable has a first end attached to the winch and a second end adapted for removable attachment to the leading end of the cutter assembly 10. The leading end of the cutter assembly is adapted to receive the first end of the winch cable by means of a rotatable screw eye or the like.
The preferred embodiment of the invention has a hydraulic apparatus 30 to engage the train and pull the cutter assembly and mandrel and new pipe through the bore of the existing utility pipe and pipe fittings, as best seen in FIG. 3. The hydraulic apparatus intermittently engages each steel rod of train 22 in axial communication and pull the train and cutter assembly 10 and mandrel 17 and new pipe 20 through the existing underground utility pipe 13 and pipe fittings 14. A plurality of rod guides 33, each having a plurality of spherical balls 33A arranged in a planetary relationship urge the rods to remain in axial alignment with the hydraulic apparatus. Cross-bars 33B urge the rod guides 33 to maintain axial communication with the rod throughout the releasing/retracting, pushing, and pulling phases of the hydraulic apparatus 30 with the steel rods.
The hydraulic means are mounted in a first trench pit 40 oriented in general alignment and elevation with the existing underground utility pipe and pipe fittings section to be replaced. The hydraulic means dispatches each steel rod through the existing underground utility pipe and pipe fittings to a second trench pit 41 where the cutter assembly and mandrel and pipe adapter and new pipe are threadably engaged to the foremost steel rod.
The second trench pit 41 is oriented in general alignment and elevation with the existing underground utility pipe and pipe fittings to be replaced and is at a second end of the underground existing utility pipe and pipe fittings opposite the first trench pit 40. The system allows a crew of only two people to deploy the invention and operate the system. This provides a significant labor savings over other methods of replacing worn out underground pipe and pipe fittings. The first crew member is located in the first trench pit 40 and threadably couples each steel rod to form the train. The hydraulic means then dispatches each steel rod through the bore of the existing pipe and pipe fittings to the second trench pit 41. The second crew member is located in the second trench pit 41 and upon receipt of the foremost steel rod, threadably engages the leading end of the cutter assembly 10 to the foremost steel rod. Then the second crew member sequentially couples the mandrel 17 to the trailing end of the cutter assembly, the pipe adapter 18, 19 to the mandrel, and engages the foremost section of the new pipe 20 to the pipe adapter.
Upon the appropriate signal, the hydraulic means 30 in the first trench pit 40 is reversed and pulls the train and cutter assembly 10 and mandrel 17 and pipe adapter 18, 19 and new pipe 20 through the bore of the existing utility pipe and pipe fittings. The first trench pit 40 is sufficiently sized to allow docking of the cutter assembly 10 after a complete traverse of the existing pipe and pipe fittings. In this manner, the first crew member can uncouple in a sequential manner, each steel rod 22 from the train, the cutter assembly 10, the mandrel 17, and the pipe adapter 18, 19.
The hydraulic means intermittently engage each steel rod with a plurality of split jaws such as 34 and 35 as seen in FIG. 6. Each set of split jaws is horizontally disposed to engage each steel rod axially and pull each steel rod without twisting or turning the steel rod. If twisting or turning were to occur, the resultant forces would missalign the cutter assembly and mandrel and pipe adapter and new pipe within the bore of the existing utility pipe and pipe fittings and generate great resistance to traverse that the hydraulic means would not be able to overcome.
The hydraulic means include a pair of hydraulic cylinders 31 and 32. Each hydraulic cylinder can be co-aligned in a common horizontal plane or a common vertical plane for providing simultaneous engagement and disengagement of each set of split jaws with each steel rod. The preferred relationship is horizontal disposition of the split jaws as shown in FIG. 6. In the vertical plane arrangement, the jaws are vertically oriented in an upper/lower relationship.
It has been found in the field that the hydraulic means must generate a force of about between 60,000 to 100,000 pounds in order to successfully split and spread most existing underground utility pipe and pipe fittings and pull the new pipe through the existing underground utility pipe and pipe fittings, regardless of the soil condition or type.
Also, it has been found that each trench pit 40, 41 should be about between five to seven feet in length to accommodate the two man crew and allow them to set up and operate the system and dock the cutter assembly after a complete traverse of the existing utility pipe and pipe fittings.
As shown in FIGS. 2, 8B and 8D, the cutter wheels include a cutting edge and are of a sufficient diameter to cut completely through a pipe wall. However, pipe fittings have larger wall thicknesses than pipe. Accordingly, first cutter wheel 11 is oriented to scribe a scoring line on the pipe fittings. The second cutter wheel 12, although it is the same diameter as the first cutter wheel, is oriented within the cutter assembly to cuttably engage the scoring line in the pipe fittings and cut completely through the pipe fittings. The invention is unique in the fact that although it uses equal diameter cutting wheels, it achieves its intended purpose of having a first cutter wheel cut through the pipe body and the second cutter wheel cut through the pipe fittings by positioning each cutter wheel within a section of the cutter frame assembly so that the cutting edge is predispositioned to cuttably engage the wall of the pipe, or in the case of the second cutting wheel, the wall of the pipe fittings, respectively.
The first cutter wheel and the second cutter wheel cuttably engage the pipe and the pipe fittings respectively in an upper portion of the pipe and the pipe fittings. In this manner, the pipe retains its structural integrity below a cut path and precludes separating the pipe into two halves. If this condition were to occur, dirt, refuse, loose rock, and other material could interfere with the new pipe traversing through the bore of the existing utility pipe and pipe fittings.
In yet another embodiment of the invention, the hydraulic system can be used to create a tunnel through undisturbed soil and facilitate pulling the new utility pipe and pipe fittings through the tunnel. This approach eliminates the necessity to dig up and excavate the street to install the utility pipe, which eliminates the obstruction to vehicular traffic. Excavation is also time consuming and expensive.
The system creates the tunnel by pushing the plurality of steel rods that form the train through the undisturbed soil and forms a tunnel, under a road or the like. A rod push pipe cap is threadably coupled to an end of the foremost steel rod. The first trench pit houses the hydraulic means and dispatches the plurality of steel rods that form the train through the undisturbed soil to form the tunnel for the new underground utility pipe and pipe fittings to traverse.
A second trench pit receives the foremost steel rod and the rod push pipe cap after the tunnel is formed. The rod push pipe cap is uncoupled and then a first section of the mandrel is threadably attached to an end of the foremost steel rod. The mandrel has a first section that is adapted for threadable coupling to a trailing end of the train. The mandrel further has a second section that is adapted for coupling to a pipe adapter which in turn is coupled to a foremost section of the new pipe. After the connections are established, and upon the appropriate signal, the hydraulic means is reversed in the first trench pit and the process is reversed. Thereupon, the train is pulled through the tunnel and consequently pulls the mandrel and the pipe adapter and the new pipe through the bore of the tunnel. Both the first trench pit and the second trench pit are in general alignment and elevation with the tunnel and with each other. The mandrel is properly sized to guide the pipe adapter, pipe and pipe fittings through a bore of the tunnel, according to the pipe diameter.
The present disclosure includes that contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred forms with a certain degree of particularity, it is understood that the present disclosure of the preferred forms have been made only by way of example and that numerous changes in the details of structures and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as set forth in the following claims.
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The invention discloses a system for splitting and spreading existing underground pipe and pipe fittings. A plurality of cutter wheels are positioned within a cutter assembly frame. A first cutter wheel cuts the pipe and scores the pipe fittings. A second cutter wheel rides in the path cut in the pipe by the first cutter wheel and cuts the pipe fittings. A plurality of paired pipe expanders are formed on the outer periphery of the cutter assembly frame. Pipe expanders contact the inner surface of the pipe wall and keep the cross section of the pipe circular while the cutter wheels cut through the pipe and pipe fittings. Also, the paired pipe expanders keep the cutter wheels in a vertical alignment and thirdly, they loosen and scrape residue and built-up material from the inner wall of the pipe. A mandrel is connected to the trailing end of the cutter assembly and to a pipe adapter which in turn is connected to a foremost section of new pipe. The mandrel spreads the cut pipe and fittings and pulls the pipe adapter and the new pipe through the bore of the existing pipe. A train comprised of multiple sections of steel rods is connected to a leading end of the cutter assembly and pulls the cutter assembly and mandrel and pipe adapter and the new pipe through the bore of the existing pipe and pipe fittings. Cable/winching means or hydraulic means supply the motive power to use and operate the system.
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RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 10/077,233, filed Feb. 15, 2002, now U.S. Pat. No. 7,297,142 which is a continuation-in-part of U.S. application Ser. No. 10/034,871, filed Dec. 21, 2001 (now U.S. Pat. No. 6,810,281), U.S. application Ser. No. 09/827,503, filed Apr. 6, 2001 (now U.S. Pat. No. 6,432,112), which is a continuation of U.S. application Ser. No. 09/746,853, filed Dec. 21, 2000 (now U.S. Pat. No. 6,692,485), which is a divisional of U.S. application Ser. No. 09/375,666, filed Aug. 17, 1999 (now U.S. Pat. No. 6,197,017), which is a continuation of U.S. application Ser. No. 09/028,550, filed Feb. 24, 1998 (now abandoned). The application Ser. No. 10/077,233 is also a continuation-in-part of U.S. application Ser. No. 09/783,637, filed Feb. 14, 2001 (now abandoned), which is a continuation of PCT/US00/12553, filed May 9, 2000, which claims the benefit of priority from U.S. Application Ser. No. 60/133,407, filed May 10, 1999. The application Ser. No. 10/077,233 is also a continuation-in-part of PCT/US01/11376, filed Apr. 6, 2001, which claims priority from U.S. application Ser. No. 09/746,853, filed Dec. 21, 2000 (now U.S. Pat. No. 6,692,485, and Ser. No. 09/827,503, filed Apr. 6, 2001 (now U.S. Pat. No. 6,432,112). The application Ser. No. 10/077,233 is also a continuation-in-part of U.S. application Ser. No. 09/746,853, filed Dec. 21, 2000 (now U.S. Pat. No. 6,692,485), and 09/827,503, filed Apr. 6, 2001 (now U.S. Pat. No. 6,432,112). The application Ser. No. 10/077,233 is also a continuation-in-part of U.S. application Ser. No. 09/827,643, filed Apr. 6, 2001 (now U.S. Pat. No. 6,554,844), which claims priority to U.S. Application Ser. Nos. 60/257,869, filed Dec. 21, 2000, and 60/195,264, filed Apr. 7, 2000, and is also a continuation-in-part of PCT/US00/12553, filed May 9, 2000, from which U.S. application Ser. No. 09/783,637, filed Feb. 14, 2001 (now abandoned), claims priority.
The application Ser. No. 10/077,233 also claims the benefit of priority from U.S. Application Ser. Nos. 60/332,287, filed Nov. 21, 2001, 60/344,124, filed Dec. 21, 2001, 60/293,346, filed May 24, 2001, 60/279,087, filed Mar. 27, 2001, 60/313,496, filed Aug. 21, 2001, 60/313,497, filed Aug. 21, 2001, 60/313,495, filed Aug. 21, 2001, 60/269,203, filed Feb. 15, 2001, 60/269,200, filed Feb. 15, 2001, 60/276,151, filed Mar. 15, 2001, 60/276,217, filed Mar. 15, 2001, 60/276,086, filed Mar. 15, 2001, 60/276,152, filed Mar. 15, 2001, 60/257,816, filed Dec. 21, 2000, 60/257,868, filed Dec. 21, 2000, 60/257,867, filed Dec. 21, 2000, and 60/257,869, filed Dec. 21, 2000.
The application Ser. No. 10/077,233 further is a continuation-in-part of U.S. Application Ser. Nos. 10/014,143 (now abandoned), 10/012,845 (now U.S. Pat. No. 7,169,141), U.S. Ser. No. 10/008,964 (now abandoned), 10/013,046 (now abandoned), 10/011,450 (now abandoned), 10/008,457 (now U.S. Pat. No. 6,949,106), 10/008,871 (now U.S. Pat. No. 6,843,793), 10/023,024 (now abandoned), 10/011,371 (now U.S. Pat. No. 7,090,683, 10/011,449 (now abandoned); 10/010,150 (now U.S. Pat. No. 7,214,230), 10/022,038 (now abandoned), and 10/012,586, all filed on Nov. 16, 2001 now U.S. Pat. No. 7,371,210.
This application is also related to copending application Ser. No. 11/762,758. The entire disclosures of the above applications are expressly incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
The present invention relates in general to medical instrumentation. More particularly, the present invention relates to a surgical instrumentation system that enables the interchange of any one of a number of different surgical instruments at an operative site.
In open surgery a surgeon uses a variety of different surgical implements with the total number that are used being a function of the particular operation being performed. For the most part these instruments or implements are hand held devices directly held and manipulated by the surgeon through the open incision. Typical surgical instruments include forceps, needle drivers, scissors, scalpels, etc. A number of different instruments or implements may be used during an operation depending upon the complexity of the medical procedure being performed, and even a greater number of instrument exchanges occur. Thus, a great deal of time may be spent during the surgery simply in exchanging between different types of instruments.
In minimally invasive surgery (MIS) there is likewise a requirement, depending upon the particular surgical procedure, to exchange instruments or implements during a medical procedure. The primary difference in minimally invasive surgery is that the incision or incisions are relatively small, typically 5 mm to 10 mm in diameter, in comparison to open surgery. Also, in current MIS instrumentation, such instruments as forceps, scissors, etc., are inserted into the body at the end of long slender push rods actuated by the surgeon from outside the patient. Due to the size and increased complexity of these instruments it may be even more difficult to carry out an exchange due to the need to extract and re-insert through a relatively small incision.
Both open and MIS procedures involve control of the instrument directly by the human hand. In the case of open surgery, of course, the surgeon directly holds and manipulates the instrument, while in MIS the operable tool (scalpel, scissors, etc.) is controlled by hand, but through some type of mechanical transmission that intercouples from outside the patient to an internal operative site.
In more recent years computer control of instrumentation systems has come into being, typically referred to as robotic surgical systems, in which a surgeon controls an instrument carrying an end effector from a remote site, and through an electronic controller or the like. These robotic systems do provide an improvement in the dexterity with which medical procedures can be performed. However, even in these more advanced systems there is still a need to manually exchange instruments during a procedure.
Accordingly, it is an objective of the present invention to provide a system and associated method for the ready exchange or interchange between a plurality of different instruments at an operative site, whether it be in connection with open, MIS, robotic, or other types of surgical systems, apparatus, or procedures.
BRIEF SUMMARY OF THE INVENTION
In accordance with a first aspect of the present inventions, a medical instrument assembly is provided. The medical instrument assembly comprises an instrument driver having a driver shaft, a driver cable slidably disposed through the driver shaft, and a driver coupling member (e.g., a hook) respectively mounted to the driver cable. In one embodiment, the instrument driver has at least one slot on the driver shaft in which the driver coupling member is disposed. The medical instrument assembly further comprises an instrument configured for being mated with the instrument driver. The instrument has an instrument shaft, an end effector (e.g., an articulating tool), an instrument cable slidably disposed through the instrument shaft for actuating the end effector, and an instrument coupling member (e.g., a hook) respectively mounted to the instrument cable. The driver coupling member and the instrument coupling member are configured for being interlocked together.
In one embodiment, the instrument driver has a plurality of driver cables slidably disposed through the driver shaft, and a plurality of driver coupling members respectively mounted to the driver cables. In this case, the instrument has a plurality of instrument cables slidably disposed through the instrument shaft, and a plurality of instrument coupling members respectively mounted to the instrument cables, and the driver coupling members and the instrument coupling members are configured for being respectively interlocked together. In another embodiment, the instrument driver has one of a post and a recess located on a distal surface of the driver shaft, and the instrument has another of the post and the recess on a proximal surface of the instrument shaft, in which case, the post and recess are configured for being mated together to align the driver coupling member with the instrument coupling member.
In still another embodiment, the medical instrument assembly further comprises a storage chamber having a passage, in which case, the instrument driver may be configured for being distally advanced within the passage to engage the instrument and for being proximally retracted within the passage to disengage the instrument. In this case, the instrument coupling member may be configured for being biased radially outward, and the passage may have a small diameter distal section and a large diameter proximal section, such that the small diameter distal section deflects the instrument coupling member radially inward to engage driver coupling member when the instrument driver is distally advanced within the passage, and the large diameter proximal section allows the instrument coupling member to deflect radially outward to disengage the driver coupling member when the instrument driver is proximally retracted within the passage.
In accordance with a second aspect of the present inventions, a robotic medical system is provided. The robotic medical system comprises the instrument driver, instrument, and storage chamber described above. The robotic medical system further comprises a user interface configured for generating at least one command signal, and a drive unit (e.g., one that has a motor array) coupled to the instrument driver. The robotic medical system further comprises an electric controller configured, in response to the at least one command signal, for directing the drive unit to distally advance the instrument driver within the passage of the storage chamber, such that the driver coupling member engages the instrument coupling member, and for directing the drive unit to proximally retract the instrument driver within the passage of the storage chamber, such that the driver coupling member disengages the instrument coupling member. In one embodiment, the user interface is located remotely from the drive unit, and the electrical controller is coupled to the drive unit via external cabling. In another embodiment, robotic medical system further comprises a carriage on which the instrument driver is slidably disposed. In another embodiment, the electric controller is configured, in response to the command signal(s), for directing the drive unit to linearly translate the driver cable within the driver shaft to actuate the end effector.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the present invention are described in greater detail in the following detailed description, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a perspective view of one embodiment of a robotic surgical system in which the interchangeable instrument principles of the present invention are applied;
FIG. 2 is a perspective view showing a portion of the system of FIG. 1 , particularly the storage chamber and the driving mechanism;
FIG. 3 is a cross-sectional view illustrating the storage chamber, the driver and the associated positioning of components, and as taken along line 3 - 3 of FIG. 2 ;
FIG. 4 is a perspective view showing some further detail of the instrument in this first embodiment;
FIG. 5 is a partial cross-sectional view showing further details of the driver and instrument in this first embodiment;
FIG. 6 is a further cross-sectional view similar to that illustrated in FIG. 5 but showing the driver and instrument in an interlocked position;
FIG. 7 is a schematic cross-sectional perspective view that illustrates details of the instrument of the present invention;
FIGS. 8A and 8B are perspective views of the tool component of the surgical instrument illustrating the cabling scheme;
FIG. 9 is a perspective view of an alternate embodiment of the present invention, providing linear registration rather than rotational registration;
FIG. 10 is a perspective view of another embodiment of a robotic surgical system in which the interchangeable instrument principles of the present invention are applied;
FIG. 11 is a perspective view at the slave station of the system of FIG. 10 illustrating the interchangeable instrument concepts;
FIG. 12 is a cross-sectional view through the storage chamber and as taken along line 12 - 12 of FIG. 11 ;
FIG. 13 is a longitudinal cross-sectional view, as taken along line 13 - 13 of FIG. 11 ;
FIG. 14 is a perspective schematic view of the indexing mechanism used in the embodiment illustrated in FIGS. 10-13 ;
FIG. 15 is a block diagram illustrating the steps taken to provide indexing for instrument interchange; and
FIG. 16 is a schematic diagram of another alternate embodiment of the invention using a serial storage concept.
DETAILED DESCRIPTION
In this detailed description there is described an apparatus for enabling the interchange, at an operative site, between different types of surgical instruments and in an automated fashion. In this way a substitution of one instrument for another can be readily accomplished, without manually withdrawing one instrument followed by manual insertion of another instrument. Further, with this apparatus, and the associated use of a guide tube, or the like, for receiving and guiding the instrument, the interchange can be carried out quickly and safely, thus enabling medical procedures to be performed in a far shorter period of time. The guide tube preferably extends to the operative site OS (see FIG. 7 ) so that the instrument can transition safely thereto. Also, the guide tube preferably remains at the operative site even as the instruments are exchanged in the guide tube, so as to avoid any tissue or organ damage during an instrument exchange. The operative site may be defined as the general area in close proximity to where movement of the tool occurs in performing a surgical procedure, usually in the viewing area of the endoscope and away from the incision.
In this description the instrument interchange principles are illustrated in association with two separate surgical systems, both of which are robotic systems, sometimes also referred to as telerobotic systems. However, the principles of this invention also apply to other surgical instrumentation, such as used in minimally invasive surgery (MIS), where a number of instrument exchanges are typical in performing a medical or surgical procedure.
It is assumed, by way of example, that the systems disclosed herein are for use in laparoscopic surgery. Thus, one system is disclosed in FIGS. 1 through 8A and 8 B, while a second system is disclosed in FIGS. 10-14 . A variation of the first system is illustrated in FIG. 9 . It is noted that in FIG. 9 , the instrument-to-driver registration is accomplished with a linear arrangement, while in the other versions described herein a rotating arrangement is employed, all to be described in further detail later. Also, in the embodiments described herein the driver has only linear translation while the instrument storage chamber rotates ( FIGS. 1 and 10 ) or slides ( FIG. 9 ). In an alternate embodiment the driver may rotate or otherwise move to different registration positions, as the instrument storage chamber remains stationary, as long as there is relative motion between the instrument driver and instrument storage chamber.
Before reference is made to the detailed embodiments described herein, consideration is given to co-pending applications that are hereby incorporated by reference herein in their entirety, and that describe in further detail aspects of the several components that make up the overall robotic surgery system. In connection with descriptions set forth herein reference is made to the applications set forth in the related application part of this application as well as to pending U.S. application Ser. No. 09/783,637 filed Feb. 14, 2001; U.S. application Ser. No. 10/014,143 filed Nov. 11, 2001; as well as issued U.S. Pat. No. 6,197,017.
The first embodiment of the invention is illustrated in FIGS. 1-8 . FIG. 1 shows a surgical instrument system 10 that performs surgical procedures. The system may be used to perform minimally invasive procedures. The system may also be used to perform open or endoscopic surgical procedures. The system 10 includes a surgeon interface 11 , computation system 12 , and drive unit 13 . The system controls the instrument so as to position the end effector (tool) 18 of the instrument 20 at the very distal end of and extending through the outlet guide tube 24 . During use, a surgeon may manipulate the handles 30 of the surgeon interface 11 , to effect desired motion of the end effector 18 within the patient, at the operative site which is schematically illustrated in FIG. 7 . The movement of a handle 30 is interpreted by the computation system 12 to control the movement of the end effector (tool) 18 .
The system may also include an endoscope with a camera to remotely view the operative site. The camera may be mounted on the distal end of the instrument, or may be positioned away from the site to provide additional perspective on the surgical operation. In certain situations, it may be desirable to provide the endoscope through an opening other than the one used by the instrument.
The entire assembly illustrated in FIG. 1 is shown supported over the surgical table 27 , and in a position so that the guide tube 24 can be inserted through an incision in the patient and directed to the operative site of the patient. The incision is represented in FIG. 1 by the dashed line L. The surgical instrument system 10 of the present invention is preferably mounted on rigid post 19 which may be movably affixed to the surgical table 27 , at bracket 28 .
The surgical system 10 includes two mechanical cable-in-conduit bundles 21 and 22 . These cable bundles 21 and 22 terminate at one end at the two connection modules (couplers) 23 A and 23 B, which removably attach to the drive unit 13 . The drive unit 13 is preferably located outside the sterile field, although it may be draped with a sterile barrier so that it may be operated within the sterile field. The other end of the bundles terminate at the surgical system 10 . These terminations are shown in further detail in the description of the second embodiment that is described later. Basically cables in the bundle 21 may control; the indexing for controlled rotation of the instrument storage chamber 40 ; rotation of the guide tube 24 ; as well as motion of the carriage 54 for control of the linear translation of the driver 50 . On the other hand the bundle 22 may control, for example, rotation of the instrument within the guide tube 24 , as well as actuation of the tool 18 . The instrument storage chamber is also referred to herein as an instrument retainer.
FIG. 1 also shows the instrument storage chamber 40 that is illustrated as supported over the base piece 51 , which, in turn, is supported from the rigid post 19 . The cable bundle 21 couples to the base piece 51 and controls motion of the instrument storage chamber 40 , as well as the driver 50 . The guide tube 24 is supported at the outlet port side of the instrument storage chamber 40 , and is controlled for rotation relative to the instrument storage chamber 40 . Rotation of the guide tube 24 provides a corresponding rotation of the instrument and tool. The instrument storage chamber 40 has at its inlet side a port for receiving the driver 50 , and for permitting engagement of the driver with the one of the instruments in the instrument storage chamber 40 that is in registration with the driver 50 . The driver 50 is supported from the carriage 54 which transitions on rails 55 , and is controlled from cable bundle 22 . The driver may also be referred to herein as an instrument transporter.
In accordance with the setup of the system of FIG. 1 , the guide tube 24 of the surgical instrument system 10 is inserted into the patient usually through an incision. Usually, a cannula is positioned in the incision, is maintained in position and receives the guide tube 24 . This incision is illustrated in FIG. 1 by the dashed line L. The system is then mounted to the rigid post 19 . The cable bundles 21 and 22 are then coupled to the drive unit 13 . The connection modules or couplers 23 A and 23 B at the end of respective cable bundles 21 and 22 are then engaged into the drive unit 13 . The system is then ready for use and control from the master station side at surgeon interface 11 . For further details of the entire slave side of the system, including the drive unit, detachability at the drive unit, the cabling and cable couplers, refer to U.S. Ser. Nos. 09/783,637; and 10/014,143, previously mentioned.
Now, reference is made, not only to FIG. 1 but also to FIGS. 2 through 6 that illustrate further details depicting the interchangeable instrument concepts of the present invention. FIG. 7 illustrates schematically a cabling scheme that may be used in the instrument. FIG. 9 illustrates an alternative to the revolving chamber construction, in the form of a linearly translatable housing or chamber arrangement.
The revolving instrument storage chamber 40 includes a base 42 , opposite end walls 43 and a cylindrical chamber or magazine 44 . In the embodiment illustrated herein, chamber 44 has six elongated passages 46 each for receiving an instrument. The chamber 44 is supported by a centrally disposed support rod 47 , such as illustrated in FIG. 5 . The support rod 47 may be supported in bearings (not shown) at the opposite end walls 43 . The instrument storage chamber 40 has its rotation controlled at base piece 51 (see FIG. 1 ) so that when an operator at interface 11 wants to change instruments, a command can be sent from the master to the slave side to rotate the magazine 44 so that a different instrument is in alignment with the driver 50 . Of course, this exchange only occurs when the driver has been withdrawn to its rest (disengaged) position. Specific sequences of the interchange action are described later. The command that is sent may be initiated by any one of several means, some of which are described in some detail later.
FIGS. 2 and 3 also illustrate the outlet guide tube 24 . The tube 24 is secured to one of the end walls 43 and is essentially fixed in axial position relative to that end wall 43 of the rotating instrument storage chamber 40 , but is capable of rotation on its own axis, and relative to the chamber 40 . Details of this rotational support are described further in connection with the second embodiment described in FIGS. 10-14 . The end walls 43 supporting the magazine 44 are fixed to the base 42 , which is supported over the base piece 51 which, in turn, is fixed to the rigid post 19 . Thus, in this particular embodiment the instrument storage chamber 40 rotates but does not have any significant linear movement toward or away from the operative site. Thus, in this first embodiment the instrument control has a somewhat limited number of degrees-of-freedom. The degrees-of-freedom can be increased by providing the guide tube with a curved distal end, like that illustrated in the second embodiment of the invention in FIGS. 10-14 .
FIGS. 1 through 6 also illustrates the instrument driver 50 . The instrument driver 50 is adapted to enter an end inlet port 49 in the wall 43 of the rotating chamber 40 . In this regard, refer to FIG. 3 for the inlet port 49 . Also, as discussed previously in connection with FIG. 1 , in the base piece 51 there is an indexing mechanism that controls the rotation of the rotating storage chamber 44 so that different ones of the passages 46 are adapted to be aligned with the input driver port 49 . This registration control may be carried out using a detent mechanism so that the proper instrument is aligned and selected from the chamber by the instrument driver 50 . Refer to FIG. 2 and the cable bundle 21 that interconnects with the chamber 44 for selective and registered rotation thereof. Also, refer to FIG. 14 for an example of an indexing mechanism.
In a similar manner, at the opposite end wall 43 of the chamber 40 , there is provided an outlet port 48 , such as illustrated in FIG. 3 , and that aligns with the outlet guide tube 24 . Also, in FIGS. 2 and 3 there is illustrated the carriage 54 that carries the instrument driver 50 and that transitions along the support rails 55 to enable the driver to selectively engage with and drive the instrument forward through the guide tube 24 and toward the operative site.
FIG. 3 illustrates a cross-sectional view of one embodiment of the interchangeable instrument apparatus of the present invention. An instrument 20 with its end effector (tool) 18 is illustrated disposed in one of the elongated chambers 46 of the rotating chamber 44 . In practice, each of the other passages 46 can contain other types of instruments, with a variety of different tool or end effectors. For the sake of clarity, only one of the instruments is illustrated in FIG. 3 , it being understood that up to six other instruments of different types may be disposed in other ones of the elongated passages 46 . Also, the magazine 44 may be constructed with fewer or more instrument-receiving passages. FIG. 3 also illustrates the driver 50 in a position where the end 56 thereof is positioned just entering the inlet port 49 with the end 56 about to engage the end 25 of the instrument 20 . The position of the instrument driver 50 is considered as a “rest position” when the end 57 is disposed in wall 43 , but has not yet entered the magazine 44 so that the magazine 44 is free to rotate. To interlock and align the driver and the instrument, there is provided a post 58 (see FIG. 5 ) on the driver 50 and an accommodating recess 26 (see FIG. 5 ) in the instrument end 25 .
As mentioned previously, there are mechanical cables extending in bundles 21 and 22 illustrated in FIG. 1 . The cables in bundle 22 , in particular, couple by way of pulleys and then extend the length of the driver 50 to the instrument 20 . The cabling and control pulley arrangements are disclosed in further detail in the second embodiment as shown in FIGS. 10-14 . This cabling is for operating the end effector 18 illustrated in FIG. 1 . To provide continuity of this mechanical control cabling, both the instrument driver as well as the instrument carry interconnecting cable connections. These are illustrated clearly in FIGS. 4 through 6 . Also refer to the schematic perspective view of FIG. 7 showing the manner in which the cables couple about pulleys 29 and extend through the driver to intercouple with cabling of the instrument 20 . These cable connections between the driver and instrument may also be considered as defining a coupling section or coupling interface 59 where the driver and instrument are releasably engageable. One may also consider the driver and instrument, such as illustrated in FIGS. 1-6 , as collectively being an instrument member including a work section (instrument 20 and tool 18 ), and a driver section (driver 50 ).
The instrument driver 50 has passages 61 (see FIG. 4 ) for receiving a cable 62 (see FIGS. 4 , 5 and 6 ). As illustrated in FIGS. 4 , 5 and 6 the end of cable 62 terminates in a hook 64 . The hook 64 is adapted to engage with a similar-configuration hook 66 at the end of cable 68 as illustrated in FIG. 6 . FIG. 4 illustrates a series of slots or passages 61 , which in the illustrated embodiment comprise six such slots 61 . Each of these slots receives a cable 62 with its end hook 64 .
Referring further to FIG. 4 , this illustrates the end 25 of the instrument 20 . Also illustrated are the elongated slots 61 in the driver (transporter) 50 . FIG. 4 illustrates the cables 68 and their associated hooks 66 associated with the instrument 20 . Also shown is the cable 62 with its hook 64 disposed in slot 61 .
FIG. 5 illustrates the end 56 of the instrument driver 50 as the driver 50 is transitioning through the port 49 for engagement with the instrument 20 . The driver 50 has not yet engaged the instrument 20 , but has just left its rest position. The “rest” (disengaged) position for the instrument driver 50 is one in which the end 56 of the driver 50 is disposed in the end wall 43 and out of the passage 46 so that the chamber 44 is free to rotate. In the position of FIG. 5 , the hook 66 associated with the instrument 20 is preferably biased to a somewhat outward deflected position. In this regard, it is noted that the passage 46 has an enlarged section 46 A that permits the hook 66 to deflect outwardly, as illustrated. The hooks are essentially spring biased outwardly so as to contact the inner wall surface of enlarged section 46 A. This enables the driver to pass by the hooks 66 for engagement with the instrument 20 .
As the driver 50 proceeds from the position illustrated in FIG. 5 , toward the position illustrated in FIG. 6 , the hook 64 passes under the hook 66 and as the driver is driven further to the left, as viewed in FIG. 3 , the hooks 64 and 66 become interlocked in the position illustrated in FIG. 6 and there is thus cable continuity from cable 62 to cable 68 . As is discussed in further detail hereinafter, the operation of these cables provide operation of certain actions of the end effector 18 . As the driver end 56 engages the instrument end 25 , the post 58 engages with the recess 26 so as to properly align the driver and instrument. At the initial point of contact the hooks 66 are still out of engagement with the hooks 64 . However, as the driver moves further to the left the instrument starts to transition out of the storage chamber passage 46 , and the hooks 66 transition into the smaller diameter section of the passage 46 , causing them to deflect into engagement with the hooks 64 , such as illustrated in FIG. 6 . The coupling interface 59 formed essentially between the hooks 64 and 66 is maintained as the instrument transitions out of the instrument storage chamber 40 . Refer to FIG. 7 .
The driver 50 is of a sufficient length so that the selected instrument 20 is driven out of the chamber 44 and into the outlet guide tube 24 . The instrument is then transitioned through the guide tube 24 to the position illustrated in FIG. 1 where the end effector or tool 18 of the instrument extends from the distal end of the guide tube 24 at a position inside the body cavity (operative site). All the while that the instrument is being transitioned to the end of the guide tube 24 , the interconnecting cables are maintained in an interlocked position such as illustrated by the engaged hooks 64 and 66 in FIG. 6 .
When it is desired to change to a different instrument, the driver 50 is withdrawn or in other words is moved in a direction to the right in FIG. 3 . This carries the instrument with the instrument driver to the right and when the instrument reaches a position approximately as illustrated in FIG. 5 , because of the increased diameter of the section 46 A illustrated in FIG. 5 , the hooks 66 are biased outwardly and disengage from the hooks 64 . This essentially disengages the driver from the instrument and the driver is then in a position to be withdrawn through the port 49 , no longer engaging with the instrument. This also leaves the instrument 20 in place in the instrument storage chamber 44 in readiness for a subsequent usage.
With the driver disengaged from the instrument, the instrument storage chamber can then be rotated to align a different instrument with the driver. The cabling in bundle 21 , via base piece 51 , controls the position of chamber 40 so as to select a different instrument by rotating the chamber 44 so that a different instrument registers with the driver 50 . For an example of a registration mechanism refer to FIG. 14 . A different instrument would also carry cabling similar to that illustrated in FIG. 5 . Once the new instrument is in-line with the instrument driver 50 then the driver 50 may be engaged once again to pass through the port 49 engaging the new instrument and thus transitioning the new instrument out the outlet guide tube 24 to a position where the tool of the instrument is at the operative site in readiness for use and control from the master station surgeon interface.
A wide variety of different instruments may be supported in the instrument storage chamber 40 . Tool 18 may include a variety of articulated tools, such as jaws, scissors, graspers, needle holders, micro dissectors, staple appliers, tackers, suction irrigation tools, clip appliers, that have end effectors driven by wire links, eccentric cams, push-rods or other mechanisms. In addition, tool 18 may comprise a non-articulated instrument, such as cutting blades, probes, irrigators, catheters or suction orifices. Alternatively, tool 18 may comprise an electrosurgical probe for ablating, resecting, cutting or coagulating tissue.
To provide proper alignment of the instrument 20 in the chamber 40 and with the driver 50 there are preferably provided interlocking surfaces such as a tongue and groove (not shown) between the walls of the chamber passage and the outer surface off the instrument and/or driver. Interlocking or guiding surfaces may also be provided within the guide tube 24 . Thus, as the different instruments are moved in and out of the rotating chamber they will always be properly aligned with the driver so that the proper cabling is provided to control the instrument.
Reference is now made to FIG. 7 for a schematic illustration of the cabling as it extends from the bundle 22 , through the driver 50 , to the instrument 20 , and the tool 18 . The cabling extends about pulleys 29 and into the slots 61 in the instrument driver 50 . FIG. 7 illustrates the driver 50 in a position in which it has entered the guide tube 24 and transitions to a location essentially at the end of the guide tube where the tool 18 is located and at the operative site OS. At the end of the driver where the cable hooks engage, such as illustrated in FIGS. 5 and 6 , there is the coupling or interface section 59 . FIG. 7 also illustrates the passages 46 and another non-selected tool within the instrument storage chamber.
The construction of one form of tool is illustrated in FIGS. 8A and 8B . This is in the form of a set of jaws or grippers. This tool is shown for the purpose of illustration, it being understood that a variety of other tool may be used. FIG. 8A is a perspective view showing the tool pivoted at the wrist while FIG. 8B is an exploded view of the tool. The tool 18 is comprised of four members including the base 600 , link 601 , upper grip or jaw 602 and lower grip or jaw 603 . The base 600 is affixed to the flexible stem section 302 . This flexible section may be constructed of a ribbed plastic. This flexible section may be used when a curved end guide tube (see FIG. 11 ) is used so that the instrument will readily bend through the curved actuator tube 24 .
The link 601 is rotatably connected to the base 600 about axis 604 . FIG. 8B illustrates a pivot pin at 620 . The upper and lower jaws 602 and 603 are rotatably connected to the link about axis 605 , where axis 605 is essentially perpendicular to axis 604 . FIG. 8B illustrates another pivot pin at 624 .
Six cables 606 - 611 , shown schematically in FIG. 8A and FIG. 8B , actuate the four members 600 - 603 of the tool. Cable 606 travels through the insert stem (section 302 ) and through a hole in the base 600 , wraps around curved surface 626 on link 601 , and then attaches on link 601 at 630 . Tension on cable 606 rotates the link 601 , and attached upper and lower grips 602 and 603 , about axis 604 (wrist pivot). Cable 607 provides the opposing action to cable 606 , and goes through the same routing pathway, but on the opposite sides of the insert. Cable 607 may also attach to link 601 generally at 630 . Cables 606 and 607 may be one continuous cable secured at 630 .
Cables 608 and 610 also travel through the stem 302 and though holes in the base 600 . The cables 608 and 610 then pass between two fixed posts 612 . These posts constrain the cables to pass substantially through the axis 604 , which defines rotation of the link 601 . This construction essentially allows free rotation of the link 601 with minimal length changes in cables 608 - 611 . In other words, the cables 608 - 611 , which actuate the grips 602 and 623 , are essentially decoupled from the motion of link 601 . Cables 608 and 610 pass over rounded sections and terminate on grips 602 and 603 , respectively. Tension on cables 608 and 610 rotate grips 602 and 603 counter-clockwise about axis 605 . Finally, as shown in FIG. 8B , the cables 609 and 611 pass through the same routing pathway as cables 608 and 610 , but on the opposite side of the instrument. These cables 609 and 611 provide the clockwise motion to grips or jaws 602 and 603 , respectively. At the jaws 602 and 603 , as depicted in FIG. 8B , the ends of cables 608 - 611 may be secured at 635 . This securing may occur with the use of an adhesive such as an epoxy glue or the cables could be crimped to the jaw.
Reference is now made to FIG. 9 . FIG. 9 schematically illustrated an alternate embodiment of the present invention. In FIGS. 1-8 the different instruments are selected by means of a rotating arrangement. In FIG. 9 the selection is made on an essentially linear basis. Thus, instead of the rotating member illustrated in FIGS. 1-8 , there is a flat array 70 also having a series of elongated passages 72 extending therethrough. Each of these passages accommodates an instrument. FIG. 9 also schematically illustrates, by the same reference characters, the instrument driver 50 and the outlet guide tube 24 such as previously illustrated in FIGS. 1-8 . The flat array 70 may be driven selectively in the direction of arrow 74 so as to align different ones of the passages 72 with the driver 50 and guide tube 24 . Mechanisms for selective linear drive are well known, as are mechanisms for registration so as to provide proper alignment between the instrument and instrument driver.
In connection with the aforementioned description of the cables/hooks, it is noted that the interchange system is designed preferably to have all cabling maintained in tension. In this way, as an instrument is engaged, all of the cabling running therethrough is in tension and properly operative to control the end effector whether it be a set of jaws as illustrated in FIGS. 8A and 8B or some other type of instrument. If an end effector has less degrees of movement than that illustrated in FIGS. 8A and 8B this is still effectively controlled, but with the use of fewer cable control signals (fewer cables will actually be activated).
Reference is now made to the second robotic surgical system depicted in FIGS. 10-14 , and that discloses a system having a greater number of degrees-of-freedom than the system described in FIGS. 1-8 . In FIGS. 10-14 the same reference characters are used for similar components as depicted in FIGS. 1-8 .
The surgical robotic system, as illustrated in FIGS. 10-14 , although preferably used to perform minimally invasive surgery, may also be used to perform other procedures as well, such as open or endoscopic surgical procedures. FIG. 10 illustrates a surgical instrument system 10 that includes a master station M at which a surgeon 2 manipulates an input device, and a slave station S at which is disposed a surgical instrument. In FIG. 1 the input device is illustrated at 3 being manipulated by the hand or hands of the surgeon. The surgeon is illustrated as seated in a comfortable chair 4 . The forearms of the surgeon are typically resting upon armrests 5 .
FIG. 10 illustrates a master assembly 7 associated with the master station M and a slave assembly 8 associated with the slave station S. Assembly 8 may also be referred to as a drive unit. Assemblies 7 and 8 are interconnected by means of cabling 6 with a controller 9 . As illustrated in FIG. 10 , controller 9 typically has associated therewith one or more displays and a keyboard. Reference is also made to, for example, the aforementioned U.S. Ser. No. 10/014,143, for further detailed descriptions of the robotic controller operation and associated algorithm.
As noted in FIG. 10 , the drive unit 8 is remote from the operative site and is preferably positioned a distance away from the sterile field. The drive unit 8 is controlled by a computer system, part of the controller 9 . The master station M may also be referred to as a user interface vis-vis the controller 9 . Commands issued at the user interface are translated by the computer into an electronically driven motion in the drive unit 8 . The surgical instrument, which is tethered to the drive unit through the cabling connections, produces the desired replicated motion. FIG. 10 , of course, also illustrates an operating table T upon which the patient P is placed.
Thus, the controller couples between the master station M and the slave station S and is operated in accordance with a computer algorithm. The controller receives a command from the input device 3 and controls the movement of the surgical instrument so as to replicate the input manipulation.
With further reference to FIG. 10 , associated with the patient P is the surgical instrument 14 , which in the illustrated embodiment actually comprises two separate instruments one on either side of an endoscope E. The endoscope includes a camera to remotely view the operative site. The camera may be mounted on the distal end of the instrument insert, or may be positioned away from the site to provide additional perspective on the surgical operation. In certain situations, it may be desirable to provide the endoscope through an opening other than the one used by the surgical instrument 14 . In this regard, in FIG. 10 three separate incisions are shown, two for accommodating the surgical instruments and a centrally disposed incision that accommodates the viewing endoscope. A drape is also shown with a single opening.
The surgical instrument 14 is generally comprised of two basic components including a surgical adaptor or guide 15 and an instrument 14 . FIG. 10 illustrates the surgical adaptor 15 , which is comprised primarily of the guide tube 24 . In FIG. 10 the instrument 14 is not clearly illustrated but extends through the guide tube 24 . The instrument 14 carries at its distal end the tool 18 . Descriptions of the surgical instrument are found hereinafter in additional drawings, particularly FIG. 11 . The surgical adaptor 15 is basically a passive mechanical device, driven by the attached cable array.
In FIG. 10 there is illustrated cabling 22 coupling from the instrument 14 to the drive unit 18 . The cabling 22 is preferably detachable from the drive unit 8 . Furthermore, the surgical adaptor 15 may be of relatively simple construction. It may thus be designed for particular surgical applications such as abdominal, cardiac, spinal, arthroscopic, sinus, neural, etc. As indicated previously, the instrument 14 couples to the adaptor 15 and essentially provides a means for exchanging the instrument tools. The tools may include, for example, forceps, scissors, needle drivers, electrocautery etc.
Referring still to FIG. 10 , the surgical system 10 may preferably be used to perform minimally invasive procedures, although it is to be understood that the system may also be used to perform other procedures, such as open or endoscopic surgical procedures. The system 10 includes a surgeon's interface 11 , computation system or controller 9 , drive unit 8 and the surgical instrument 14 . The surgical system 10 , as mentioned previously, is comprised of an adaptor or guide 15 and the instrument 14 . The system is used by positioning a tool 18 of the instrument, which is inserted through the surgical adaptor or guide 15 . During use, a surgeon may manipulate the input device 3 at the surgeon's interface 11 , to effect desired motion of the tool 18 within the patient. The movement of the handle or hand assembly at input device 3 is interpreted by the controller 9 to control the movement of the guide tube 24 , instrument, and tool 18 .
The surgical instrument 14 , along with the guide tube 24 is mounted on a rigid post 19 which is illustrated in FIG. 10 as removably affixed to the surgical table T. This mounting arrangement permits the instrument to remain fixed relative to the patient even if the table is repositioned. Although, in FIG. 10 there are illustrated two such instruments, even a single surgical instrument may be used.
As indicated previously, connecting between the surgical instrument 14 and the drive unit 8 , are cablings. These include two mechanical cable-in-conduit bundles 21 and 22 . These cable bundles 21 and 22 may terminate at two connection modules, not illustrated in FIG. 10 (see FIG. 1 ), which removably attach to the drive unit 8 . Although two cable bundles are described here, it is to be understood that more or fewer cable bundles may be used. Also, the drive unit 8 is preferably located outside the sterile field, although it may be draped with a sterile barrier so that it may be operated within the sterile field.
In the preferred technique for setting up the system, and with reference to FIG. 10 , the surgical instrument 14 is inserted into the patient through an incision or opening. The instrument 14 is then mounted to the rigid post 19 using a mounting bracket 31 . The cable bundles 21 and 22 are then passed away from the operative area to the drive unit 8 . The connection modules of the cable bundles are then engaged into the drive unit 8 . The separate instrument members of instrument 14 are then selectively passed through the guide tube 24 . This action is in accordance with the interchangeable instrument concepts of this invention.
The instrument 14 is controlled by the input device 3 , which is be manipulated by the surgeon. Movement of the hand assembly produces proportional movement of the instrument 14 through the coordinating action of the controller 9 . It is typical for the movement of a single hand control to control movement of a single instrument. However, FIG. 10 shows a second input device that is used to control an additional instrument. Accordingly, in FIG. 10 two input devices are illustrated and two corresponding instruments. These input devices are usually for left and right hand control by the surgeon.
The surgeon's interface 11 is in electrical communication with the controller 9 . This electrical control is primarily by way of the cabling 6 illustrated in FIG. 10 coupling from the bottom of the master assembly 7 . Cabling 6 also couples from the controller 9 to the actuation or drive unit 8 . This cabling 6 is electrical cabling. The actuation or drive unit 8 , however, is in mechanical communication with the instrument 14 . The mechanical communication with the instrument allows the electromechanical components to be removed from the operative region, and preferably from the sterile field. The surgical instrument 14 provides a number of independent motions, or degrees-of-freedom, to the tool 18 . These degrees-of-freedom are provided by both the guide tube 24 and the instrument 14 .
FIG. 10 shows primarily the overall surgical system. FIGS. 11-14 show further details particularly of the interchangeable instrument concepts as applied to this system. FIG. 15 illustrates a control algorithm for the system. The system of FIG. 10 is adapted to provide seven degrees-of-freedom at the tool 18 . Three of the degrees-of-freedom are provided by motions of the adaptor 15 , while four degrees-of-freedom may be provided by motions of the instrument 14 . As will be described in detail later, the adaptor is remotely controllable so that it pivots, translates linearly, and has its guide tube rotate. The instrument also rotates (through the instrument driver), pivots at its wrist, and has two jaw motions at the tool.
Now, reference is made to the more detailed drawings of FIGS. 11-14 . FIG. 11 is a perspective view at the slave station of the system of FIG. 10 illustrating the interchangeable instrument concepts. FIG. 12 is a cross-sectional view through the storage chamber and as taken along line 12 - 12 of FIG. 11 . FIG. 13 is a longitudinal cross-sectional view, as taken along line 13 - 13 of FIG. 11 . FIG. 14 is a perspective schematic view of the indexing and registration mechanism used in the embodiment illustrated in FIGS. 10-13 .
Reference is now made to FIG. 11 which is a perspective view illustrating the instrument 14 and the adaptor 15 at the slave station S. This instrument system is secured in the manner illustrated in FIG. 10 to the rigid post 19 that supports the surgical instrument by way of the mounting bracket 31 illustrated in FIG. 10 , but not shown in FIG. 11 . FIG. 11 also shows several cables that may be separated into five sets for controlling different motions and actions at the slave station. These are individual cables of the aforementioned bundles 21 and 22 referred to in FIG. 10 . FIG. 11 also illustrates the support yoke 220 that is secured to the mounting bracket 31 , the pivot piece 222 , and support rails 224 for the carriage 226 . The rails are supported in end pieces 241 and 262 with the end piece 241 attached to the pivot piece 222 . The pivot piece 222 pivots relative to the support yoke 220 about pivot pin 225 . A base piece 234 is supported under the carriage 226 by means of the support post 228 . The support post 228 in essence supports the entire instrument assembly, including the adaptor 15 and the instrument 14 .
As indicated previously, the support yoke 220 is supported in a fixed position from the mounting bracket 31 . The support yoke 220 may be considered as having an upper leg 236 and a lower leg 238 . In the opening 239 between these legs 236 and 238 is arranged the pivot piece 222 . Cabling extends into the support yoke 220 . This is illustrated in FIG. 11 by the cable set 501 . Associated with the pivot piece 222 and the carriage 226 are pulleys (not shown) that receive the cabling for control of two degrees-of-freedom. This control from the cable set 501 includes pivoting of the entire instrument assembly about the pivot pin 225 . This action pivots the guide tube 24 essentially in a single plane. This pivoting is preferably about an incision of the patient which is placed directly under, and in line with, the pivot pin 225 . Other cables of set 501 control the carriage 226 in a linear path in the direction of the arrow 227 . See also the cables 229 extending between the carriage 226 and the end pieces 241 and 262 . The carriage moves the instrument and guide tube 24 back and forth in the direction of the operative site OS. Incidentally, in FIG. 11 the instrument is in its fully advanced state with the tool at the operative site OS.
The base piece 234 is the main support for the interchangeable instrument apparatus of the invention. Refer to FIGS. 11-14 . The base piece 234 supports the guide tube 24 , the instrument storage chamber 540 , and the instrument driver 550 . The instrument driver 550 is supported from another carriage, depicted in FIGS. 11 and 13 as the carriage 552 , and that, in turn, is supported for translation on the carriage rails 554 . The rails 554 are supported at opposite ends at end pieces 556 and 558 , in a manner similar to the support for the other carriage 226 . A support post 560 interconnects the carriage 552 with the instrument driver housing 570 .
With further reference to FIG. 11 , and as mentioned previously, there are a number of cable sets from bundles 21 and 22 coupled to and for controlling certain actions of the instrument system. Mention has been made of the cable set 501 for controlling instrument pivoting and translation, as previously explained. In addition, FIG. 11 depicts four other cable sets 503 , 505 , 507 , and 509 . Cable set 503 controls rotation of the guide tube 24 . Cable set 505 controls the carriage 552 , and, in turn, the extending and retracting of the instrument driver for instrument exchange. Cable set 507 controls rotation of the instrument through rotation of the instrument driver. Finally, cable set 509 controls the tool via the instrument driver and instrument. There is also one other set of control cables not specifically illustrated in FIG. 11 that controls the indexing motor 565 , to be discussed in further detail later.
FIG. 13 shows a cross-sectional view through the interchangeable instrument portion of the overall instrument system. This clearly illustrates the internal cable and pulley arrangement for the various motion controls. There is a pulley 301 driven from the cable set 503 that controls rotation of the guide tube 24 . There is also a pulley 303 driven from cable set 505 , along with a companion pulley 305 that provides control for the carriage 552 . FIG. 13 also illustrates another pulley 307 driven from cable set 507 , and for controlling the rotation of the instrument driver 550 , and, in turn, the selected instrument.
FIG. 13 illustrates the guide tube 24 supported from the base piece 234 . The guide tube 24 is hollow and is adapted to receive the individual instruments or work sections 541 disposed in the instrument storage chamber 540 , as well as the instrument driver 550 . Refer to FIG. 7 for an illustration of the instrument and instrument driver positioned in the guide tube 24 . FIG. 13 shows the instrument driver 550 in its rest or disengaged position. The proximal end 24 A of the guide tube 24 is supported in the base piece 234 by means of a pair of bearings 235 so that the guide tube 24 is free to rotate in the base piece 234 . This rotation is controlled from the pulley 237 which is secured to the outer surface of the guide tube 24 by means of a set screw 231 . The pulley 237 is controlled to rotate by means of the cabling 310 that intercouples the pulleys 301 and 237 and that is an extension of the cabling 503 . Thus, by means of the cable and pulley arrangement, and by means of the rotational support of the guide tube 24 , the rotational position of the guide tube 24 is controlled from cable set 503 . Of course, this controlled rotation is effected from the master station via the controller 9 , as depicted in the system view of FIG. 10 , and as a function of the movements made by the surgeon at the user interface 11 .
As indicated before the proximal end 24 A of the guide tube 24 is supported from the base piece 234 . The distal end of the guide tube 24 , which is adapted to extend through the patient incision, and is disposed at the operative site OS illustrated about the tool 18 in FIG. 11 , and where a medical or surgical procedure is to be performed. In the system shown in FIG. 11 the distal end of the guide tube 24 is curved at 24 B. In this way by rotating the guide tube 24 about its longitudinal axis there is provided a further degree-of-freedom so as to place the end tool at any position in three-dimensional space. The rotation of the guide tube 24 enables an orbiting of the end tool about the axis of the guide tube 24 . The guide tube 24 is preferably rigid and constructed of a metal such as aluminum. The tool 18 illustrated in FIG. 11 may be the same tool as illustrated in FIGS. 8A and 8B . Also, when the instrument is fully engaged, as in FIG. 11 , the cabling and cable interface is as illustrated in FIG. 7 .
FIG. 13 also illustrates a cross-section of the instrument storage chamber 540 including the storage magazine 549 , and showing two of the six instrument passages 542 in the storage magazine 549 . The instrument storage chamber may also be referred to herein as an instrument retainer. In FIG. 13 one of the instruments 541 is about to be engaged by the instrument driver 550 . The other instrument 541 is in place (storage or rest position) in the instrument storage chamber 540 , and out of the path of the instrument driver 550 . One of the instruments 541 carries a gripper tool illustrated at 543 , while the other instrument carries a scissors 544 . Because these instruments are adapted to pass to the guide tube 24 and be positioned at the distal end 24 B thereof, the body 548 of the instrument is flexible so as to be able to curve with the curvature of the guide tube 24 .
Although reference is made herein to the separate instrument and instrument driver, such as illustrated in FIG. 13 , once they are engaged they function as a single piece instrument member. Accordingly reference is also made herein to the instrument driver 550 as a “driver section” of the overall one piece instrument member, and the instrument 541 as a “working” section of the instrument member. The instrument member has also been previously discussed as having a “coupling section” or “interface section”, which is defined between the working section and the driver section where the cables interlock by means of the engaging hook arrangement, such as clearly depicted in FIGS. 5 and 6 . This is shown in FIG. 13 at 559 . This is analogous to the interface 59 illustrated in FIG. 7 .
The carriage 552 illustrated in FIG. 13 is moved linearly by the cables 555 that extend between pulleys 303 and 305 . These cables attach to the carriage 552 . The carriage movement is controlled from cable set 505 . It is the movement of the carriage 552 that drives the instrument driver (driver section) 550 . The instrument driver 550 , in its rest or disengaged position, is supported between the instrument driver housing 570 and the wall 562 that is used for support of the instrument storage chamber 540 . The instrument magazine 549 is rotationally supported by means of the axle or shaft 547 , with the use of bushings or bearings, not shown. This support is between walls 562 and 563 .
FIG. 13 shows the very distal end 525 of the instrument driver (transporter) 550 supported at wall 562 . In the rest position of the instrument driver 550 the driver is out of engagement with the instruments and the magazine 549 , thus permitting rotation of the instrument storage chamber 540 . The proximal end 526 of the instrument driver 550 is supported at the instrument driver housing 570 . It may be rotationally supported by means of a bushing 527 . The instrument driver 550 is supported for rotation, but rotation is only enabled once the driver has engaged the instrument and preferably is at the operative site. The rotation of the instrument driver 550 is controlled from cable set 503 by way of the pulley 307 .
In FIG. 11 the cable set 509 is illustrated as controlling the instrument motions including tool actuation. These cables control a series of pulleys shown in FIG. 13 as pulleys 529 . As indicted in FIG. 13 these pulleys control cabling that extends through the instrument driver and the instrument for control of instrument and tool motions. The cables that are controlled from these pulleys may control three degrees-of-freedom of the instrument, including pivoting at the wrist and two for gripper action. For the details of the interlocking of the instrument and instrument driver refer to FIGS. 5 and 6 . The same engagement arrangement can be used in this second embodiment of the invention including the mating hook arrangement, interlocked at interface 559 when the instrument driver and instrument are engaged.
Reference has been made before to the indexing motor 565 . This motor is illustrated in FIG. 11 positioned next to the base piece 234 , and is further illustrated in FIG. 14 located for interaction with the instrument storage chamber 540 . The indexing motor 565 is controlled from the master station side, and accordingly there is another cable set (not shown) that actuates the indexing motor 565 . The indexing motor 565 may be a stepper motor having a degree of rotation that corresponds to the desired rotation of the instrument storage chamber 540 . The stepper motor may be designed to provide 60 degrees of rotation for each actuation, corresponding to an instrument storage chamber 540 having six passages (360 degrees divided by 6) for receiving instruments.
In FIG. 14 the stepper motor 565 has an output shaft 566 that supports an indexing disk 567 , shown also in dashed line in FIG. 12 . The indexing disk 567 is fixed to the shaft 566 and so rotates with the shaft 566 . FIG. 12 illustrates the disk 567 carrying four pins 568 disposed at the periphery of the disk 567 . FIG. 14 also shows these pins 568 . The pins 568 selectively engage in indexing slots 569 in an end wall of the magazine 549 . To insure that the rotating chamber stays in proper registration with the instrument driver a spring and ball detent arrangement is employed. Refer to FIGS. 11-14 illustrating a standard ball and spring member 575 supported in the wall 563 . The ball of member 575 is urged against an end wall surface 576 of the magazine 549 . This end wall has a series of detent dimples 577 (see FIG. 14 ) disposed at locations corresponding to the passages in the magazine 549 . The stepper motor 565 is selectively operated under surgeon control from the master station. Each step rotates the disk 567 through 90 degrees. The engagement of the pins 568 with the slots 569 causes a corresponding rotation of the magazine 549 through 60 degrees. Each subsequent rotation of the stepper motor 565 causes a further 60 degree rotation of the magazine 549 . The stepper motor 565 is controllable in a manner so that, with proper decoding, there may be multiple step actuations to get from one instrument to the next selected instrument.
The operation of the slave instrument is in a robotic manner from the master station, such as illustrated in FIG. 10 . The surgeon can control several degrees-of-freedom of the instrument system. In addition, when the surgeon wishes to exchange instruments this can be done directly from the master station from an actuation member and at the proper time in the surgical procedure. One type of actuation member may be by means of a foot switch 410 illustrated in FIG. 10 within access of the surgeon. The foot switch 410 couples to the controller 9 . Appropriate electrical signals are coupled from the master station to the slave station basically to control the stepper motor 565 for indexing the magazine 549 .
The sequence of operation for the indexing is demonstrated in the flow chart of FIG. 15 . This block diagram indicates the sequence of steps performed commencing with a rest position of the system in which the instruments are all in place in the storage chamber 540 , and the instrument driver is in the position substantially as illustrated in FIG. 13 , just out of contact with the registered instrument and with the driver end 525 disposed in the wall 562 . It is this position that is illustrated in FIG. 15 by box 420 . The next step is to check the registration of the instrument driver with the instrument itself. This is depicted by the box 422 . This step may involve the use of some known registration system, such as one using an optical sensing arrangement to determine proper registration between the instrument driver 550 and each of the passages in the magazine 549 , along with the instrument 541 . If proper registration is detected then the system proceeds to the next step indicated in FIG. 15 by box 426 , which activates the instrument driver 550 . This starts the process of driving the instrument to the operative site OS. This involves mechanical control signals on the cable set 505 controlling the carriage 552 , and in turn, the instrument driver 550 . If an improper registration is detected then box 424 indicates the step of correcting the registration. This may be carried out in a well known manner with the use of an optical system to provide slight rotation to the instrument storage chamber 540 so as to obtain proper registration. This system may also use some type of a feedback system.
The next step in the system is indicated in FIG. 15 by the box 428 which simply detects the fully engaged position of the instrument driver and instrument. This is the position illustrated in FIG. 11 . Again, this position can be readily detected by optical means. The next step illustrated in FIG. 15 by box 430 is one that commences the interchange process. The intercoupled instrument and instrument driver are withdrawn. This involved movement of the carriage 552 in the opposite direction. Next, indicated by box 432 , is where the instrument and instrument driver have reached the position illustrated in FIG. 13 previously referred to as the “rest position”. In that position the instrument driver (transporter) 550 is clear of the instrument storage chamber 540 , and thus the instrument storage chamber 540 can be indexed (rotated). This is shown in FIG. 15 by the box 434 . Following these steps, from FIG. 15 it is seen that there may be another registration check (box 436 ), and a correction (box 438 ), in a manner similar to the operation previously discussed regarding boxes 422 and 424 . The process can then repeat at a time determined by the surgeon's instrument selection sequence.
There has to be some correlation between the indexing, what and where particular instruments are stored, and how the indexing is controlled from the master station. As indicated previously a foot switch can be used, such as the switch 410 illustrated in FIG. 10 . In one version of the control the switch 410 may be comprised of six separate actuation buttons, each one corresponding to one of the six instruments disposed in the instrument storage chamber 540 . Indicia may be provided associated with the storage chamber to indicate what particular instrument is disposed in what particular instrument passage. In this way the surgeon would know what button to actuate to select the desired instrument. There could be corresponding indicia associated with the switch buttons so the surgeon knows what button corresponds exactly to what instrument.
The control system for indexing may also include a decoding scheme so that when the surgeon makes a selection the decoder determines the number of rotations (such as of the stepper motor 565 ) necessary to bring the instrument driver into proper registration with the selected instrument. Because it may not always be clear as to the specific instrument sequence that the surgeon will use, the system has to determine how to index from one instrument to the next one selected. This selection process involves more than just sequencing from one instrument to an adjacent instrument. The process will have to accommodate a selection process in which the next selected instrument is not the adjacent instrument. Thus a simple decoder can be used to determine the number of stepper motor steps necessary to move the storage chamber to the next selected instrument.
Another aid that can be provided to the surgeon is a visible display illustrated in FIG. 10 , and on which there can be a diagram that matches the storage chamber pattern showing to the surgeon exactly where each instrument is placed including the type of instrument. This could be set up when the instruments are first selected the disposed in the instrument storage chamber 540 . In association with this display one could also provide, in place of the switch 410 , a voice activated system so that the surgeon simply indices by voice which instrument to select. This may be done by simply numbering the instruments, such as one through six. A further variation may use a touch screen so that the surgeon simply touches an area on the screen corresponding to the displayed image of the storage chamber with the stored instruments. In all of the above instances, there are electrical signals generated from the master station, through a touch screen, switch, etc. that are conveyed to the controller 9 and from there to the slave side. The activating signals at the slave side basically control the stepper motor 565 via a cable set not specifically shown in the drawings but that would couple to the stepper motor 565 illustrated in FIGS. 11 , 12 and 14 .
Reference is now made to FIG. 16 for a schematic representation of a further alternate embodiment of the invention. In FIGS. 1 and 10 it is noted that the instruments are contained in a parallel array. In accordance with the invention the instruments may also be disposed in a series array, as depicted in the schematic diagram of FIG. 16 . This embodiment includes a retainer 580 that is adapted to store a series of instruments 581 in a serial array, also referred to herein as a linear chamber or linear retainer. Means are provided to enable the array to move laterally in the directions indicated by arrows 585 . This movement can be of either the retainer or the instruments themselves. There is an alignment that occurs so that a selected instrument may align with a port 584 from which the instrument may then be moved to location 583 . This is by a lateral or transverse movement of the instrument out of the retainer 580 . This movement is indicated in FIG. 16 by the arrow 587 . The instrument, once moved, is then in registration with the driver or transporter 580 which is moveable in the direction of arrow 588 . The driver is controlled as in previous embodiments to transition the instrument to the operative site, through the represented output port 586 .
Although reference is made herein to “surgical instrument” it is contemplated that the principles of this invention also apply to other medical instruments, not necessarily for surgery, and including, but not limited to, such other implements as catheters, as well as diagnostic and therapeutic instruments and implements.
Having now described certain embodiments of the present invention, it should be apparent to one skilled in the art that numerous other embodiments and modifications thereof can be made, some of which have already been described, and all of which are intended to fall within the scope of the present invention. For example, the coupling sections or interface sections have been disclosed as intercoupled cables with hook arrangements, such as shown in FIG. 6 . In another arrangement a different mechanical coupling scheme may be employed using a different interlock between cables. Also, in place of mechanical couplings other technologies may be used for coupling action to the instrument and tool, such as SMA technology. Regarding the tool itself, one has been illustrated with a wrist pivot. Instead the tool may include a bendable section at or near its distal end. In place of the stepper motor other indexing arrangements can be used, such as a ratchet and pawl system. Also, encoders can be used at the rotating storage chamber to detect motions to provide feedback for controlling the overall system.
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A robotic medical system comprises an instrument driver having a driver shaft, a driver cable slidably disposed through the shaft, and a driver coupling member respectively mounted to the driver cable, and an instrument having an instrument shaft, an end effector, an instrument cable slidably disposed through the shaft for actuating the end effector, and an instrument coupling member mounted to the instrument cable. The robotic medical system further comprises a storage chamber having a passage that stores the instrument, a drive unit coupled to the instrument driver, and an electric controller configured for directing the drive unit to distally advance the instrument driver within the passage of the storage chamber and engage the driver coupling member and instrument coupling member, and for directing the drive unit to proximally retract the instrument driver within the passage of the storage chamber and disengage the driver coupling member and instrument coupling member.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a national stage §371 application of PCT/US00/27056 filed Sep. 29, 2000, and claims priority to provisional application 60/157,580 filed in the United States on Oct. 4, 1999.
STATEMENT REGARDING FEDERALLY-SPONSORED R&D
Not Applicable
REFERENCE TO MICROFICHE APPENDIX
Not Applicable
FIELD OF THE INVENTION
This invention relates to the genes and enzymes involved in cell wall synthesis in bacteria.
BACKGROUND OF THE INVENTION
The pathway of peptidoglycan (PG) biosynthesis is both essential and unique to bacteria and the responsible enzymes are present in both Gram-negative and Gram-positive bacteria. Thus, inhibitors of these enzymes are likely to be broad spectrum and safe antibiotics. In fact, several enzymes in this pathway are molecular targets of naturally occurring antibiotics such as fosfomycin, cycloserine, β-lactams and vancomycin (Bugg & Walsh, 192 Nat. Prod. Rep. 9:199-215).
One enzyme intrinsic to the peptidoglycan biosynthesis is MraY. To date, no MraY sequences have been disclosed for Pseudomonas aeruginosa , an opportunistic pathogen causing infections in patients with burns or neutropenia. More serious is its involvement in respiratory tracts of cystic fibrosis patients.
It would be desirable to have polynucleotides and polypeptides encoding the MraY protein of Pseudomonas aeruginosa in order to further screen compounds for antibiotic activity against this enzyme catalytically active in the first step of the membrane cycle of peptidoglycan biosynthesis. Inhibitors of this enzyme would be particularly helpful in preventing the growth of Pseudomonads and other G+C rich bacteria.
Possession of this information would also greatly facilitate determinations as to the role of the encoded enzyme, Phospho-N-Acetylmurmoyl-Pentapeptide-Translocase, in the pathogenesis of infection and disease.
SUMMARY OF THE INVENTION
Polynucleotides and polypeptides of Pseudonmonas aeruginosa MraY, an enzyme involved in bacterial cell wall biosynthesis, are provided. The recombinant MraY enzyme is catalytically active in the first step of the membrane cycle of peptidoglycan biosynthesis, transferring the N-acetylmuramic acid pentapeptide to a bactoprenol phosphate carrier molecule. The enzyme is useful in in vitro assays to screen for antibacterial compounds that target cell wall biosynthesis. The invention includes the polynucleotides, proteins encoded by the polynucleotides, and host cells expressing the recombinant enzyme, probes and primers, and the use of these molecules in assays.
An aspect of this invention is an isolated polynucleotide having a sequence encoding a Pseudomonas aeruginosa MraY protein, or a complementary sequence. In a particular embodiment the encoded protein has a sequence corresponding to SEQ ID NO:2. In preferred embodiments the polynucleotide can be DNA, RNA or a mixture of both, and can be single or double stranded. In a most preferred embodiment, the polynucleotide has a sequence shown in SEQ ID NO:1.
An aspect of this invention is a probe having a sequence of at least about 25 contiguous nucleotides that is specific for a naturally occurring polynucleotide encoding a Pseudomonas aeruginosa MraY protein. Probes in accordance with this description are useful for the specific detection of the presence of a polynucleotide encoding a Pseudomonas aeruginosa MraY protein. In preferred embodiments, the probes of this aspect can have additional components including, but not limited to, compounds, isotopes, proteins or sequences for ready detection.
An aspect of this invention is a primer having a sequence of at least about 25 contiguous nucleotides that is specific for a naturally occurring polynucleotide encoding a Pseudomonas aeruginosa MraY protein. Primers in accordance with this description are useful in nucleic acid amplification-based assays for the specific detection of the presence of a polynucleotide encoding a Pseudonmonas aeruginosa MraY protein. In preferred embodiments, the primers of this aspect can have additional components including, but not limited to, compounds, isotopes, proteins or sequences for ready detection.
An aspect of this invention is an expression vector including a polynucleotide encoding a Pseudomonas aeruginosa MraY protein, or a complementary sequence, and regulatory regions. In a particular embodiment the encoded protein has a sequence corresponding to SEQ ID NO:2. In particular embodiments, the vector can have any of a variety of regulatory regions known and used in the art as appropriate for the types of host cells the vector can be used in. In a most preferred embodiment, the vector has regulatory regions appropriate for the expression of the encoded protein in gram-negative prokaryotic host cells. In other embodiments, the vector has regulatory regions appropriate for expression of the encoded protein in gram-positive host cells, yeasts, cyanobacteria or actinomycetes. In some preferred embodiments the regulatory regions provide for inducible expression while in other preferred embodiments the regulatory regions provide for constitutive expression. Finally, according to this aspect, the expression vector can be derived from a plasmid, phage, virus or a combination thereof.
An aspect of this invention is a host cell comprising an expression vector including a polynucleotide encoding a Pseudomonas aeruginosa MraY protein, or a complementary sequence, and regulatory regions. In a particular embodiment the encoded protein has a sequence corresponding to SEQ ID NO:2. In preferred embodiments, the host cell is a yeast, gram-positive bacterium, cyanobacterium or actinomycete. In a most preferred embodiment, the host cell is a gram-negative bacterium.
An aspect of this invention is a process for expressing a MraY protein of P. aeruginosa in a host cell. In this aspect a host cell is transformed or transfected with an expression vector including a polynucleotide encoding a Pseudomonas aeruginosa MraY protein, or a complementary sequence. According to this aspect, the host cell is cultured under conditions conducive to the expression of the encoded MraY protein. In particular embodiments the expression is inducible or constitutive. In a particular embodiment the encoded protein has a sequence corresponding to SEQ ID NO:2.
An aspect of this invention is a purified polypeptide having an amino acid sequence of SEQ ID NO:2. Cellular extracts comprising a polypeptide having the above amino acid sequence are also included within the instant invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 . Nucleotide sequence (SEQ ID NO:1) and the predicted amino acid sequence (SEQ ID NO:2) of P. aeruginosa MraY. The amino acid sequence (SEQ ID NO:2) is presented in a three-letter code below the nucleotide sequence (nucleotides 34 to 1113 of SEQ ID NO:1).
DETAILED DESCRIPTION OF THE INVENTION
This invention provides polynucleotides and polypeptides of a cell wall biosynthesis gene from Pseudomonas aeruginosa , referred to herein as MraY. The polynucleotides and polypeptides are used to further provide expression vectors, host cells comprising the vectors, probes and primers, and assays for the presence or expression of MraY.
Bacterial mraY encodes for phoshpo-N-acetylmuramoyl-pentapeptide translocase, an enzyme responsible for catalyzing the first step of the membrane cycle of peptidoglycan biosynthesis, transfer of the N-acetylmuramic acid pentapeptide to a bactoprenol phosphate carrier molecule.
The mraY gene was cloned from Pseudomonas aeruginosa . Sequence analysis of the P. aeruginosa mraY gene revealed an open reading frame of 361 amino acids.
Nucleic acids encoding MraY from Pseudomonas aeruginosa are useful in the expression and production of the P. aeruginosa MraY protein. The nucleic acids are also useful in providing probes for detecting the presence of P. aeruginosa MraY.
As used herein, the following definitions apply:
The term “about” in the specification means within approximately 10-20% greater or lesser than particularly stated.
The term “polynucleotide” means a nucleic acid of more than one nucleotide. A polynucleotide can be made up of multiple polynucleotide units that are referred to by description of the unit. For example, a polynucleotide can comprise within its bounds a polynucleotide(s) having a coding sequence(s), a polynucleotide(s) that is a regulatory region(s) and/or other polynucleotide units commonly used in the art.
The term “expression vector” means a polynucleotide having regulatory regions operably linked to a coding region such that, when in a host cell, the regulatory regions can direct the expression of the coding sequence. The use of expression vectors is well known in the art. Expression vectors can be used in a variety of host c ells and, therefore, the regulatory regions are preferably chosen as appropriate for the particular host cell.
The term “regulatory region” means a polynucleotide that can promote or enhance the initiation or termination of transcription or translation of a coding sequence. A regulatory region includes a sequence that is recognized by the RNA polymerase, ribosome, or associated transcription or translation initiation or termination factors of a host cell. Regulatory regions that direct the initiation of transcription or translation can direct constitutive or inducible expression of a coding sequence.
The terms “purified” and “isolated” are utilized interchangeably to stand for the proposition that the polynucleotide, protein and polypeptide, or respective fragments thereof in question have been removed from the in vivo environment so that they exist in a form or purity not found in nature. This, however, is not mandated of cDNA as understood by one of ordinary skill in the art.
The term “substantially pure” with regard to a polynucleotide means it is obtained purified from cellular components by standard methods at a concentration of at least about 100-fold higher than that found in nature. A polynucleotide is considered essentially pure if it is obtained at a concentration of at least about 1000-fold higher than that found in nature.
Polynucleotides
Polynucleotides useful in the present invention include those described herein and those that one of skill in the art will be able to derive therefrom following the teachings of this specification.
An aspect of the present invention is a polynucleotide encoding a MraY protein of Pseudomonas aeruginosa . It is known that there is a substantial amount of redundancy in the various codons which code for specific amino acids. Therefore, this invention is also directed to those DNA sequences that encode RNA comprising alternative codons which code for the eventual translation of the identical amino acid. The present invention, thus, discloses codon redundancy which can result in different DNA molecules encoding an identical protein. For purposes of this specification, a sequence bearing one or more replaced codons will be defined asa degenerate variation.
A further aspect of the present invention is a cDNA encoding a MraY protein of Pseudomonas aeruginosa.
A preferred aspect of the present invention is an isolated nucleic acid encoding a MraY protein of Pseudomonas aeruginosa . A preferred embodiment is a nucleic acid having the sequence disclosed in FIG. 1 , SEQ ID NO:1.
The isolated nucleic acid molecule of the present invention can include a ribonucleic or deoxyribonucleic acid molecule, which can be single (coding or noncoding strand) or double stranded, as well as synthetic nucleic acid, such as a synthesized, single stranded polynucleotide.
Noncoding or antisense strands can be useful as modulators of the gene by interacting with RNA encoding the MraY protein. Antisense strands are preferably less than full length strands having sequences unique or specific for RNA encoding the polypeptide.
Also included in the present invention are polynucleotides that hybridize to P. aeruginosa mraY sequences under stringent conditions. By way of example, and not limitation, a procedure using conditions of high stringency is as follows: Prehybridization of filters containing DNA is carried out for 2 hr. to overnight at 65° C. in buffer composed of 6×SSC, 5× Denhardt's solution, and 100 μg/ml denatured salmon sperm DNA. Filters are hybridized for 12 to 48 hrs at 65° C. in prehybridization mixture containing 100 μl/ml denatured salmon sperm DNA and 5-20×10 6 cpm of 32 P-labeled probe. Washing of filters is done at 37° C. for 1 hr in a solution containing 2×SSC, 0.1% SDS. This is followed by a wash in 0.1×SSC, 0.1% SDS at 50° C. for 45 min. before autoradiography.
Other procedures using conditions of high stringency would include either a hybridization step carried out in 5×SSC, 5× Denhardt's solution, 50% formamide at 42° C. for 12 to 48 hours or a washing step carried out in 0.2×SSPE, 0.2% SDS at 65° C. for 30 to 60 minutes.
Reagents mentioned in the foregoing procedures for carrying out high stringency hybridization are well known in the art. Details of the composition of these reagents can be found in, e.g., Sambrook, el al., 1989, Molecular Cloning: A Laboratory Manual, second edition, Cold Spring Harbor Laboratory Press. In addition to the foregoing, other conditions of high stringency which may be used are well known in the art.
Polypeptides
A preferred aspect of the present invention is a substantially purified form of the MraY protein from Pseudomonas aeruginosa . A preferred embodiment is a protein that has the amino acid sequence which is shown in FIG. 1 , in SEQ ID NO:2.
Probes and Primers
Probes comprising full length or partial sequences of SEQ ID NO:1 can be used to determine whether a cell or sample contains P. aeruginosa mraY DNA or RNA. A preferred probe is a single stranded antisense probe having at least the full length of the coding sequence of MraY. It is also preferred to use probes that have less than the full length sequence, and contain sequences specific for P. aeruginosa mraY DNA or RNA. The identification of a sequence(s) for use as a specific probe is well known in the art and involves choosing a sequence(s) that is unique to the target sequence, or is specific thereto. It is preferred that probes have at least about 25 nucleotides, more preferably about 30 to 35 nucleotides. The longer probes are believed to be more specific for P. aeruginosa mraY gene(s) and RNAs and can be used under more stringent hybridization conditions. Longer probes can be used but can be more difficult to prepare synthetically, or can result in lower yields from synthesis.
Examples of sequences that are useful as probes or primers for P. aeruginosa mraY gene(s) are Primer A (sense) 5′-T CAT ATG CTC CTG CTG CTG GCC GAA TAC-3′ (SEQ ID NO:3) and Primer B (antisense) 5′-TT GGA TCC TCA ACG CAG CTT CAA GGT G-3′ (SEQ ID NO:4). Restriction sites, underlined, for NdeI and BamHI are added to the 5′ ends of the primers to allow cloning between the NdeI and BamHI sites of the expression vector pET-11a. However, one skilled in the art will recognize that these are only a few of the useful probe or primer sequences that can be derived from SEQ ID NO:1.
Polynucleotides having sequences that are unique or specific for P. aeruginosa MraY can be used as primers in amplification reaction assays. These assays can be used in tissue typing as described herein. Additionally, amplification reactions employing primers derived from P. aeruginosa MraY sequences can be used to obtain amplified P. aeruginosa mraY DNA using the mraY DNA of the cells as an initial template. Many types of amplification reactions are known in the art and include, without limitation, Polymerase Chain Reaction, Reverse Transcriptase Polymerase Chain Reaction, Strand Displacement Amplification and Self-Sustained Sequence Reaction. Any of these or like reactions can be used with primers derived from SEQ ID NO:11.
Expression of MraY
A variety of expression vectors can be used to express recombinant MraY in host cells. Expression vectors are defined herein as nucleic acid sequences that include regulatory sequences for the transcription of cloned DNA and the translation of their mRNAs in an appropriate host. Such vectors can be used to express a bacterial gene in a variety of hosts such as bacteria, bluegreen algae, plant cells, insect cells and animal cells. Specifically designed vectors allow the shuttling of genes between hosts such as bacteria-yeast or bacteria-animal cells. An appropriately constructed expression vector should contain: an origin of replication for autonomous replication in host cells, selectable markers, a limited number of useful restriction enzyme sites, a potential for high copy number, and regulatory sequences. Expression vectors can include, but are not limited to, cloning vectors, modified cloning vectors, specifically designed plasmids or viruses.
In particular, a variety of bacterial expression vectors can be used to express recombinant MraY in bacterial cells. Commercially available bacterial expression vectors which are suitable for recombinant MraY expression include, but are not limited to pQE (QIAGEN), pET11a (NOVAGEN), lambda gt11 (INVITROGEN), and pKK223-3 PHARMACIA).
Alternatively, one can express mraY DNA in cell-free transcription-translation systems, or mraY RNA in cell-free translation systems. Cell-free synthesis of MraY can be in batch or continuous formats known in the art.
One can also synthesize MraY chemically, although this method is not preferred.
A variety of host cells can be employed with expression vectors to synthesize MraY protein. These can include E. coli, Bacillus , and Salmonella . Insect and yeast cells can also be appropriate.
Following expression of MraY in a host cell, MraY polypeptides can be recovered. Several protein purification procedures are available and suitable for use. MraY protein and polypeptides can be purified from cell lysates and extracts, or from culture medium, by various combinations of, or individual application of methods including ultrafiltration, acid extraction, alcohol precipitation, salt fractionation, ionic exchange chromatography, phosphocellulose chromatography, lecithin chromatography, affinity (e.g., antibody or His-Ni) chromatography, size exclusion chromatography, hydroxylapatite adsorption chromatography and chromatography based on hydrophobic or hydrophillic interactions. In some instances, protein denaturation and refolding steps can be employed. High performance liquid chromatography (HPLC) and reversed phase HPLC can also be useful. Dialysis can be used to adjust the final buffer composition.
The following examples are presented in order to illustrate the instant invention.
EXAMPLE 1
General Materials and Methods
All reagents were purchased from SIGMA CHEMICAL CO., St. Louis, Mo., unless otherwise indicated. DNA manipulations reagents and techniques.
Restriction endonucleases and T4 ligase were obtained from Gibco-BRL. Agarose gel electrophoresis and plasmid DNA preparations were performed according to published procedures (Sambrook, J., E. F. Fritsch, and T. Maniatis, 1989, Molecular cloning: a Laboratory Manual, 2nd ed. Cold Spring Harbor, N.Y.: Cold Spring Harbor Laboratory). Recombinant plasmids containing P. aeruginosa mraY were propagated in E. coli DH5α (GIBCO-BRL, Rockville, Md.) prior to protein expression in E. coli BL21(DE3)/plysS (NOVAGEN, Madison, Wis.). SDS-PAGE was performed with precast gels (NOVAGEN). DNA sequences were determined using an automated ABI PRISM™ DNA sequencer (PERKIN-ELMER ABI, Foster City, Calif.).
EXAMPLE 2
Cloning of Pseudomonas aeruginosa mraY
Genomic DNA from P. aeruginosa (strain MB4439) was prepared from 100 ml late stationary phase culture in Brain Heart Infusion broth (DIFCO, Detroit, Mich.). Cells were washed with 0.2 M sodium acetate, suspended in 10 ml of TEG (100 mM Tris, pH 7, containing 10 mM EDTA and 25% glucose) and lysed by incubation with 200 μg of N-acetylmuramidase (SIGMA) for 1 h at 37° C. Chromosomal DNA was purified from the cell lysate using a QIAGEN (Santa Clarita, Calif.) genomic DNA preparation kit following the manufacturers' protocol. Briefly, the cell lysate was treated with protease K at 50° C. for 45 min, loaded onto an equilibrated QIAGEN genomic tip, and entered into the resin by centrifugation at 3000 rpm for 2 min. Following washing the genomic tip, the genomic DNA was eluted in distilled water and kept at 4° C. Approximately 50 ng genomic DNA was used as a template in PCR reactions to clone mraY.
Two oligonucleotide primers (GIBCO/BRL, Bethesda, Md.) complementary to sequences at the 5′ and the 3′ ends of P. aeruginosa mraY were used to clone this gene using KLENTAQ ADVANTAGE™ polymerase (CLONTECH, Palo Alto, Calif.). The primer nucleotide sequences were as follows: 5′-TT CAT ATG CTC CTG CTG CTG GCC GAA TAC-3, (SEQ ID NO:3) and 5′-TT GGA TCC TCA ACG CAG CTT CAA GGT G-3′ (SEQ ID NO:4). A PCR product representing P. aeruginosa mraY was verified by nucleotide sequence, digested with NdeI and BamHI, and cloned between the NdeI and BamHI sites of pET-11a, creating plasmid pPaeMraY. This plasmid was used for expression of the mraY gene in E. coli.
EXAMPLE 3
Overexpression and Enzymatic Activity of Pseudomonas aeruginosa MraY
mraY was cloned into the expression vector pET-11a (NOVAGEN) as described above to create plasmid pPaeMraY. The pET-11a vector allows expression of authentic, non-fusion, proteins. The pET (Plasmids for Expression by T7 RNA polymerase) plasmids are derived from pBR322 and designed for protein over-production in E. coli . The vector pET-11a contains the ampicillin resistance gene, and ColE1 origin of replication, in addition to T7 phage promoter and terminator. The T7 promoter is recognized by the phage T7 RNA polymerase but not by the E. coli RNA polymerase. A host E. coli strain such as BL21(DE3)pLysS is engineered to contain integrated copies of T7 RNA polymerase under the control of lacUV5 that is inducible by IPTG. Production of a recombinant protein in the E. coli strain BL21(DE3)pLysS occurs after expression of T7RNA polymerase is induced.
The pPaeMraY plasmid was introduced into the host strain BL21 DE3/pLysS (NOVAGEN) for expression of MraY. Colonies were grown at 37° C. in 100 ml of LB broth containing 100 mg/ml ampicillin and 32 μg/ml chloramphenicol. When cultures reached a cell density of A 600 =0.5, cells were pelleted and then resuspended in M9ZB medium (NOVAGEN) containing 1 mM IPTG. Cells were induced for 3 h at 30° C., pelleted at 3000 g, and frozen at −80° C.
Cultures containing either the recombinant plasmid pPaeMraY or the control plasmid vector, pET-11a, were grown at 30° C. and induced with IPTG. Lysates of cells transformed with pPaeMraY exhibited some 10.3 fold increase in MraY activity over uninduced cell lysates or induced lysates from cells containing the plasmid vector.
Assay for Activity of MraY Enzyme.
The MraY (translocase I) assay was performed using the butanol extraction method described by Brandish and coworkers (Brandish et al., 1996 J. Biol. Chem. 271(13):7609-7614). The assay was performed at room temperature with assay components held at concentrations of: 100 mM TRIS, pH 7.5; 30 mM MgCl 2 ; 60.2 nCi [ 14 C]UDP-MurNAc-pentapeptide (14 μM); 40 μM Decaprenol phosphate (SIGMA CHEMICAL CORP.); 0.15% Triton X-100 (w/v); and 100 mg/mL phosphatidyl glycerol SIGMA CHEMICAL CORP.). Enzyme concentration was varied in order to obtain linear kinetics. Aliquots (50 μl) were removed at varying time points and transferred to a fresh tube containing 50 μl of 6M pyridinium acetate, pH 4.2. The mixture was then extracted with 100 μl butanol and 50 μl water. After brief centrifugation, 80 μl of the top butanol layer was quantitated in a Packard TriCarb PACKARD TRICARB™ scintillation counter to determine the amount of Lipid I product produced.
Table 1
Specific Activity of Recombinant MraY
from P. aeruginosa .
TABLE 1
Specific activity of recombinant MraY
from P. aeruginosa .
Fold Increase in
Recombinant MraY
Specific Activity
Specific Activity
P. aeruginosa mraY in
1428.2
10.3
pET-11a vector
Host E. coli cells
139.3
1
containing pET-11a
(empty vector-Control)
|
Polynucleotides and polypeptides of Pseudomonas aeruginosa MraY, an enzyme involved in bacterial cell wall biosynthesis, are provided. The recombinant MraY enzyme is catalytically active in the first step of the membrane cycle of peptidoglycan biosynthesis. Also provided are proteins encoded by the sequences, host cells expressing the recombinant enzyme, and probes and primers.
| 2
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BACKGROUND OF THE INVENTION
Composite materials which comprise an organic resin and an inorganic filler have been known and used for a number of years. Adhesion stability between the filler and the resinous mixture has been recognized as a source of degradation and failure of these materials for nearly as long as composite materials have been known. Coupling agents are additives which promote adhesion between the filler and resin and improve the hydrolytic stability of the bond between the two. Coupling agents in general have been known and used commercially since the introduction of chromium based coupling agents in the 1950s. Since the introduction of these coupling agents, there has been a steady development of new coupling agents which provide better strength and/or hydrolytic stability with various resin/filler combinations. The actual coupling capability of state of the art coupling agents is quite satisfactory. However, in general the best coupling agents in regards to adhesion and hydrolytic stability are also the most expensive coupling agents. Therefore, any coupling agent composition which gives premium performance at lower costs must be considered an advance in the art.
Surprisingly, it has been found that the addition of maleic anhydride, in certain proportions, to diamino functional silane coupling agents improves the performance of these silanes as coupling agents. Thus, a more effective coupling agent is provided which has the added advantage of being comprised of a substantial proportion of a low cost component (the maleic anhydride).
Aminofunctional silanes are well known in the art as effective coupling agents for epoxide, phenolic, melamine, furane, isocyanate, and other thermosettable resins. The reaction products of organic acids with aminofunctional silanes is also known in the art. For instance, U.S. Pat. No. 3,249,461 granted to Grotenhuis May 3, 1966 teaches the reaction product of an aminofunctional silane coupling agent with an acid chloride or anhydride in one to one amino to acid ratios. All of Grotenhuis's products are 1 to 1 amino radical to carboxy radical products, and are taught to be effective primers or coupling agents for olefinic resins.
U.S. Pat. No. 3,558,741 issued to Holub, et al. Jan. 26, 1971 teaches curable imido substituted organopolysiloxane compositions. Holub's compositions are the reaction product of one mole part aminofunctional silane and one mole part of an unsaturated anhydride such as maleic anhydride. The reaction is run to completion to form imides which Holub teaches are curable compositions.
U.S. Pat. No. 3,773,607 issued to Marzocchi Nov. 20, 1973 teaches silyl amides as "binding agents" between glass fibers or fillers and elastomers. Marzocchi's "anchoring agents" are the reaction product of a carboxy functional silane and an organic amine or an amino functional silane, where the ratio of carboxy groups to amine groups is between 0.8 and 3. Marzocchi does not mention stabilizing the resulting coupling agent composition.
SUMMARY OF THE INVENTION
The present invention is a coupling agent composition comprised of the reaction product of (a) about two mole parts of maleic anhydride; with (b) about one mole part of a diamine functional silane compound of the general formula ##STR2## where R denotes an alkyl radical with 1 to 6 carbon atoms or an alkoxyalkyl radical with 2 to 8 carbons, R' denotes an alkyl radical with 1 to 6 carbon atoms, R" and R'" denote alkylene radicals with 1 to 6 carbon atoms, or arylalkylene radicals, alkylarylene radicals or arylene radicals with 6 to 10 carbon atoms, and x is 0 or 1; and a solvent in sufficient quantity to solubilize (a) and (b). R" and R" radicals include divalent radical represented by the following formula:
--CH.sub.2 C.sub.6 H.sub.4 CH.sub.2 --,
--C.sub.6 H.sub.4 --,
--(CH.sub.2).sub.2 C.sub.6 H.sub.4 --
--(CH.sub.2).sub.2 C.sub.6 H.sub.4 (CH.sub.2).sub.2 --, and
--C.sub.6 H.sub.4 (CH.sub.2).sub.2 --
These radicals can be ortho, meta or para isomers of the above formulae.
These compositions are particularly useful as coupling agents in the production of thermoplastic composite materials and unsaturated polyester composite materials. The compositions can also be used as primers in adhering thermoplastic resins or unsaturated polyester resins to various substrates.
DETAILED DESCRIPTION OF THE INVENTION
The silane compounds used in the present invention include the following silanes; N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltris(2-ethylhexoxy)silane, p(2-trimethoxysilylethyl)-N-(2-aminoethyl)benzylamine, and N-(3-aminopropyl)-3-aminopropyltrimethoxysilane. These silanes are available commercially. Maleic anhydride is, of course, widely available in commercial quantities, as are the solvents used in the present invention.
Solvents which have been found useful in the present invention include dimethylsulfoxide, sulfolane, butyrolactone, 2-nitropropane, dimethylformamide, methylbutenol, methylbutynol, t-butanol, isopropylalcohol, methyl pyrrolidone, diethylcarbonate, and water. Other solvents may be used as long as they provide sufficient compatibility with the substrate to allow uniform coatings to be formed on the substrate, and provide a solvent which keeps the amine groups of the silane from adding across the double bond of the maleic anhydride. Such addition results in gelation of the composition and reduced effectiveness of the composition as a coupling agent.
The mole ratio of maleic anhydride to diaminofunctional silane is critical in the present invention. If a molar excess of anhydride is not present addition across the maleic anhydride's double biond by the amine functionality of the silane occurs with the result that the mixture gels. As a practical matter, gelation prevents the mixture from being an effective coupling agent. Thus, to avoid the addition across the double bond, sufficient maleic anhydride must be present to form amide-acid products with each of the amino groups of the diamino functional silane. In general, it was found that the anhydride to silane mole ratio should be about 1.7 to about 2.
The compositions of the present invention can be used as coupling agents in composite materials, or as primers in the production of film laminates and such. As will be appreciated by those skilled in the art, the manner in which the present compositions are applied to the substrates can vary depending upon the particular application. For instance, when the present compositions are used as a coupling agent in the production of fiberglass laminates, the compositions can be applied to the fiberglass as dilute solutions, which are then dried before the resin is applied to the treated glass. Alternately, a concentrated solution of the coupling agent composition could be added to the resin which would then be applied to the glass fiber to form the desired composite.
When the compositions of the present invention are used to treat fillers in the production of composites, the amount of the composition used, based upon combined weight of the silane and maleic anhydride, can range from about 0.01 to 2 weight percent based upon the weight of the filler. When used as an additive in filled composites, the composition should comprise between 0.1 and 2 weight percent of the filler. When used as a primer the composition can be applied effectively as a 0.1 to 10 wt% solids solution to the solid substrate.
The compositions of the present application are useful as primers and coupling agents for widely varied combinations of thermoplastics and substrates. These thermoplastics include polyethylene, polypropylene, polycarbonate, polystyrene, acrylonitrile butadiene styrene terpolymer, modified polyethylene, polyurethane, nylon and various copolymers. The compositions of the present invention can also be used effectively as coupling agents for unsaturated polyester resins.
The substrates and fillers which can be effectively coupled or bonded to the aforementioned resins include inorganic fillers such as glass, quartz, ceramic, asbestos, silicone resin and glass fibers, metals such as aluminum, steel, copper, nickel, magnesium, and titanium, metal oxides such as MgO, Fe 2 O 3 , and Al 2 O 3 , and metal fibers and metal coated glass fibers. Substrates which can be effectively primed using the present compositions include metal foils and glass.
As mentioned, the mixture of maleic anhydride and diamino functional silane of the present application will react to some extent in solution. Where the silane used is N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, the reaction products expected are represented by the formulae: ##STR3##
The solutions will be comprised predominantly of the amide represented by Formula 1, with a small proportion of the imide product represented by Formula 2, also present.
EXAMPLES
The following examples illustrate the effectiveness of the present invention relative to state of the art coupling agents and primers. The examples do not fully illustrate the scope of the invention and should not be understood as delineating the limits of the invention.
EXAMPLE 1
This example illustrates the criticality of the mole ratio of maleic anhydride to N-(2-aminoethyl)-3-aminopropyltrimethoxysilane to the stability of the reaction product. Several 20 wt% solutions of maleic anhydride and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane in isopropanol were made which varied in their anhydride to silane ratio as indicated in Table 1. As can be seen from the solution stability tests performed on these solutions only the 2:1 anhydride:silane solution was stable for a significant period. The other solutions formed either gels or precipitates, neither of which would be effective coupling agents.
TABLE 1______________________________________Maleic AnhydrideSilane Ratio Gelation Time______________________________________1:1 3 days1.5:1 7 days2:1 stable after three months______________________________________
Solution stability tests were also conducted in isopropanol under accelerated aging conditions. The various solutions were kept at 50° C. These results indicated that the most stable maleic anhydride/N-(2-aminoethyl)-3-aminopropyltrimethoxysilane solutions were those with an anhydride to silane ratio greater than or equal to 1.75/1.
EXAMPLE 2
This example demonstrates the effectiveness of the present product as a coupling agent in micro Novacite filled polyester composites. Novacite, a form of low quartz, was treated with various coupling agents at the level of 0.25 wt% coupling agent based upon the weight of the treated Novacite. The coupling agents used were (1) a 2:1 mole mixture of maleic anhydride and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane; (2) vinyltrimethoxysilane; (3) 3-methacryloxypropyltrimethoxysilane; (4) 3[2(vinyl-benzylamino)ethylamino]propyltrimethoxysilane; and (5) a control using no coupling agent. The fillers were compounded with equal weight parts of an unsaturated polyester resin (CoResyn® 5500 sold by Interplastics Corp. of Minneapolis, Minn.). The compounded mixtures were cast into rods, cured at 100° C. for 24 hours, cooled, and the flexural strength of each sample rod was measured over a two inch span according to standard test procedures. New samples were made and their flexural strength was measured after being boiled for 24 hours in water. The test results are presented in Table 2.
TABLE 2______________________________________ Flexural Strength (psi)Coupling Agent Dry 24 Hr. Boil______________________________________1 20100 149002 15400 119003 18800 147004 20700 165005 12800 9800______________________________________
These results indicate the invention composition (#1) is a more effective coupling agent than the commercial coupling agents, except for coupling agent (4) a premium silane which costs more than #1. The inventive coupling agent was nearly as effective as the premium cost coupling agent.
EXAMPLE 3
This example demonstrates the effectiveness of the present invention as a primer for various thermoplastics to glass. Glass slides were coated with 20 wt% solutions of various coupling agents, and dried to form primed slides. Molten thermoplastics were then applied to the primed surfaces and cooled. The cooled slides were then immersed in water until the thermoplastic film no longer adhered to the slide. Since hydrolytic stability is an accurate indicator of the strength of the bond between the thermoplastic and the glass, the samples which had the longest time to failure upon immersion in water were considered to have the best adhesion.
The various silane coupling agent compositions used in this example were:
1. N-(2-aminoethyl)-3-aminopropyltrimethoxysilane;
2. 3-methacryloxypropyltrimethoxysilane;
3. 3[2-(vinylbenzylamino)ethylamino]propyltrimethoxysilane;
4. 3-glycidoxypropyltrimethoxysilane;
5. 3-aminopropyltrimethoxysilane; and
6. the reaction product of 2 mole parts maleic anhydride with 1 mole part N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.
The various types of thermoplastics used in this example were polyethylene (P.E.), polypropylene (P.P.), polystyrene (P.S.), acrylonitrile-butadiene-styrene terpolymer (ABS), modified polyethylene (sold as Plexar-6® by Chemplex Company, Rolling Meadows, IL). (MPE), polyurethane (PU), polybutylene terephthalate (PBT), nylon, polycarbonate (PC), and polyether ether ketone (PEEK). The results of the tests are summarized in Table 3a and 3b.
Each of the thermoplastics had a unique capacity to bond to the primed glass samples. Therefore, each set of ratings is relative to the type of thermoplastic used in the sample. Within each type of thermoplastic the samples were rated based upon the strength and hydrolytic stability of the bond between the thermoplastic. Samples with the best adhesion and stability were rated +++, samples with the worst adhesion and stability were rated -. The relative performance of each sample was based upon comparisons with the other listed coupling agent compositions. For instance, in the case of an SBR block copolymer, Kraton® sold by Shell Chemicals of Houston, TX the following results were achieved.
______________________________________ Peel Strength (N/cm) Upon Immersion in Boiling WaterCoupling Agent 1 hr. 2 hrs. 6 hrs. 10 hrs.______________________________________1 c 3.5 nil --2 c 12 5.2 nil3 c 1.7 nil --4 0.5 nil -- --5 0.5 nil -- --6 c c c c______________________________________ Note: c denotes cohesive failure of the thermoplastic, ie. the bond was stronge than the thermoplastic itself.
These results correspond to the following ratings: coupling agents 1, 2 and 3 would be rated +; coupling agents 4 and 5 would be rated -; and coupling agent 6 would be rated +++.
TABLE 3a______________________________________ ThermoplasticCoupling Agent PE PP PS ABS MPE______________________________________1 - - - +2 + - - - -3 ++ ++ ++ ++ +4 - - - - +5 - - + - -6 ++ + + ++ +______________________________________
TABLE 3b______________________________________ ThermoplasticCoupling Agent PU PBT Nylon PC PEEK______________________________________1 - - - + -2 - - + + -3 ++ ++ + + +4 ++ ++ + + -5 - - - + -6 ++ ++ + ++ ++______________________________________
The results of the tests indicate that the invention composition is an effective primer for a variety of types of thermoplastics. Only 3[2-(vinylbenzylamino)ethylamino]-propyltrimethoxysilane is as widely effective as a primer as the invention composition per the test method employed.
EXAMPLE 4
This example demonstrates the effectiveness of the present invention as a primer for epoxy resin to glass. Glass slides were coated with 20 wt% solutions of various coupling agent compositions, and dried. A film of an epoxy adhesive (Magnabond-6388-3 sold by Magnolia Plastics of Chamblee, GA) was applied to the primed slides and cured at 70° C. for 2 hours. After cooling, the samples were immersed in 60° C. water and the time until failure of the bond between the resin and the glass slide was measured. The results are presented in Table 4.
TABLE 4______________________________________ Time toPrimer Adhesive Failure______________________________________none 1 hr.3-aminopropyl ctrimethoxysilaneN--(2-aminoethyl)-3-amino- 8 hr.propyltrimethoxysilane3[2(vinylbenzylamino) cethylamino]propyltrimethoxy silane3-glycidoxypropyltrimethoxysilane 2 hr.reaction product of 2 m maleic anhydride cwith 1 m N--(2-aminoethyl)-3-amino-propyltrimethoxysilane______________________________________ Note: c denotes that the epoxy was adhered to the glass slide even after 24 hours of immersion in water.
The results of this comparison show that the reaction product of 2 mole parts maleic anhydride with 1 part N-(2-aminoethyl)-3-amino-propyltrimethoxysilane adheres the epoxy resin to the glass slide more effectively than N-(2-aminoethyl)-3-amino-propyltrimethoxysilane alone, or 3-glycidoxypropyltrimethoxysilane.
EXAMPLE 5
This example demonstrates the effectiveness of the present invention as a primer for unsaturated polyester resin to glass. Glass slides were primed using 20 wt% solutions of the silanes described in Example 3. An unsaturated polyester resin with 0.5 wt% dicumyl peroxide (CoResyn® 5500 sold by Interplastic Corp. of Minneapolis, Minn.) was applied to the various primed slides and cured at 100° C. for 24 hours. The slides were cooled, then immersed in 70° C. water until the polyester resin film no longer adhered to the slide. The 2 maleic anhydride: 1N-(2-aminoethyl)-3-amino-propyltrimethoxysilane product gave the most effective and hydrolytically stable adhesion of the polyester resin to the glass slide.
______________________________________CoResyn ® 5500 Adhesive to Primed Glass(time to failure in 70° C. H.sub.2 O in hours)Primer on Glass Time to Failure (hrs)______________________________________None <1vinyltrimethoxysilane 33[2(vinylbenzylanimo)- 6ethylamino] propyltri-methoxysilane3-methacryloxypropyl 12trimethoxysilane3-glycidoxypropyl- 6trimethoxysilaneN--(2-aminoethyl)-3- 10aminopropyltri-methoxysilane +2 mole parts maleicanhydride______________________________________
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A coupling agent composition comprised of the reaction product of (a) about two mole parts of maleic anhydride with (b) about one mole part of a diamine functional silane compound of the general formula ##STR1## where R denotes an alkyl radical, R' denotes an alkyl radical, R" and R'" denote alkylene radicals and x is 0 or 1; and (c) sufficient solvent to solubilize (a) and (b).
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to modification of surface properties, particularly surface wetting properties, of various materials, including polymer films, textile fibers, cellulose. Such treatments are typically carried out in preparation to further processing or treatment of the materials, such as dyeing or impregnation of fibers and fabrics.
It is known that surface properties of materials such as textile fabrics, polymer films, paper, cellulose, etc. can be modified by exposure of the material to either a low temperature, low pressure gas plasma or to a corona discharge. The processes performed at low pressure are more efficient than those performed in the corona discharge. Unlike corona discharge treatment, exposure to low pressure plasma discharge does not significantly raise the temperature of the treated material, thereby preserving the physical condition and properties of the material.
2. State of the Prior Art
Previous methods of improving absorbency of strips made of fibers include treatment in a corona discharge, as exemplified by French patent 2,333,084. A disadvantage of this method is that the corona discharge is substantially less effective than low pressure plasma, and relatively prolonged treatment times are necessary to sufficiently improve the capillary absorption of the fabrics.
In U.S. Pat. No. 4,338,420 improved wetting of low pressure polyethylene films is obtained by treatment in a low temperature plasma of inorganic gas such as O 2 , Ar, N 2 , or air. The effect of the plasma on the film is weak, however. After plasma treatment the wetting angle is 43 to 60 degrees for polyethylene and 55 to 65 degrees for polypropylene.
Japanese patent 61-247740 describes polyolefine activation before dyeing by treatment in oxygen plasma activated by radiofrequency power at 10 Mhz, at a pressure of 0.3-0.5 Torr, with a treatment time of 5-30 sec. The effect of the plasma treatment on the subject material is insufficient, however.
USSR patent 1030445 addresses the treatment of textile materials containing polyester fibers, including treatment in a solution containing 5-25 g/l metal hydroxide for 2-5 minutes; followed by treatment in a glow discharge plasma with density 0.014-0.27 A/cm2, pressure=0.02-0.04 Torr, T=60-90 sec to achieve enhanced hydrophilic properties. However, the pretreatment in solution considerably increases total treatment time, and the plasma effect on the treated material is insufficient.
SUMMARY OF THE INVENTION
This invention is an improved method for enhancing the hydrophilic surface properties of materials including polymer films, fabrics of natural and synthetic fibers, flax based fabrics and materials of cellulose fiber including paper by treatment in a low temperature plasma of inorganic gas, the improvement comprising addition of water vapor to the primary inorganic gas at a concentration of between 0.05 and 0.5% and a pressure of 0.01-10 Torr. The primary inorganic gas forming the plasma is selected from, but not limited to, the group comprised of the gases O 2 , Ar, N 2 , NO, and air, and mixtures thereof. Treatment time may range from 3 seconds to 600 seconds. It is preferred to generate the plasma by means of an alternating frequency power source between 1 MHz and 40 MHz, at a specific power of the plasma of between 0.003 and 3.0 Wt/cm3.
In the case of previously impregnated fabrics, the novel method includes the step of first treating the fabrics in a plasma produced by igniting a glow discharge in a plasma chamber at a pressure of between 0.05 and 0.1 Torr without supplying gas to said chamber. The low pressure encourages evaporation of impregnating substance from the surface of the subject fabric, which impregnating substance would otherwise contaminate the inorganic gas/water vapor plasma and interfere with the surface activation treatment.
The added water vapor has been found to substantially shorten the treatment time required to obtain the desired modified surface properties of the treated materials. Results include increased receptivity of dyestuffs, increased efficiency of viscose impregnation of the fibers, and reduced wetting angle compared to existing treatment methods. Increased capillary absorption of fabrics and decreased wetting angle of polymer films is obtained with substantially reduced treatment times, a significant factor where commercial application of such treatments in large scale continuous processes is contemplated. Benefits include greatly simplified and shortened conditioning of fabrics for dyeing, and shortened times for impregnation of fabrics with viscose, resins and other substances.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic illustration of a low pressure gas plasma chamber used for material treatment according to the improved processes of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
It is known to use low pressure gas plasmas for treatment of materials. A main characteristic of this type of plasma is its non-isotermicity, i.e., Te>>Ti--Tg, where
Te--Temperature of electrons
Ti--Temperature of ions
Tg--Temperature of gas
and typically: Te=30,000 degrees K., Tg=375 degrees K.
In the plasma atmosphere, the basic activation effect is caused by free electrons. For instance, the following processes take place in an oxygen plasma:
O.sub.2 +e→O.sub.2 (.sup.1 Δg)+e
O.sub.2 +e→O (.sup.3 Σu)+e
O.sub.2 (.sup.3 Σu)+e→O (.sup.3 p)+O (.sup.1 D)+e
O (.sup.3 p)+O.sub.2+M→O.sub.3 +M
Surface+(O(.sup.3 p), O (.sup.1 Δg), O.sub.3)→surface modification
The components O 2 , ( 1 Δg), O( 3 p), O 3 have increased chemical activity at lower temperatures. In this case, chemical interaction with the surface leads to formation of open chemical bonds at the surface. The surface is activated by this treatment, resulting in modification of the surface properties, in particular, its susceptibility to wetting by water and other liquids. In the case of treatment in argon plasma, the surface activation is induced by physical rather than chemical processes, chiefly by the recombination of ionized argon with electrons at the surface, releasing energy which creates open bonds on the surface, activating the same.
Water vapor when added to the inorganic gas generates various processes which operate in different directions. On the one hand, active components are formed which promote the modification of surface properties, i.e. operate to increase hydrophylicity of the surface:
H.sub.2 O+e→H+OH+e
H+O.sub.2 →OH+O (.sup.3 p)
O (.sup.3 p)+surface→modification
On the other hand, the concentration of negative ions of water molecules increases:
H.sub.2 O+e→(H.sub.2 O).sup.-
This latter effect leads to a gradual decrease in free electron concentration and to a general reduction of the intensity of the plasma discharge. It has been found therefore, that water vapor concentrations of 0.05 to 0.5% at discharge parameters indicated below yield the best results. Further increase of water vapor concentration lowers the intensity of surface activation and can lead to total extinction of the discharge.
Activation processes in low pressure plasma turn out to be more efficient than those of corona discharge. The temperature the process is very low compared to corona discharge treatment, eliminating the risk of overprocessing or damage to the subject material.
The apparatus employed for the low pressure plasma treatment is schematically illustrated in FIG. 1 of the attached drawing. The plasma treatment is as follows. Material to be processed, indicated by the numeral 1, is placed in a vacuum chamber 2. Three gas bottles 4, separately containing one or more inorganic gases and water vapor, are connected through suitable valves and conduits to the chamber 2. The chamber 2 is evacuated by means of vacuum pump 3 until the interior pressure of chamber 2 reaches approximately 0.01 Torr. The vacuum system then is flushed with oxygen gas from one of bottles 4, and the chamber is again evacuated. Oxygen gas and water vapor are then fed, in metered amounts, into the system to a pressure from 0.01 to 10.00 Torr. Two cylindrical electrodes 6 are mounted to the exterior of the chamber 2 in axially spaced apart relationship. A high frequency electrical power generator 5 connected between the electrodes 6 lights a plasma generating glow discharge in the chamber 2 between the electrodes. The preferred specific power of the discharge is 0.003 to 3 Wt/cm3, and the discharge is sustained for 1 to 300 seconds. Then both the vacuum pump 3 and the generator 5 are turned off. The interior of chamber 2 is brought to atmospheric pressure and the treated material 1 is removed from the chamber by opening end closure 7.
As a result of such treatment, film surfaces exhibit reduced wetting angle, while fabrics better absorb water and other liquids. Hygroscopicity is increased.
The attached Tables 1 through 11, together with examples 1 through 7 given below illustrate the improved method and the results obtained by the same. In all Tables, the analogue is a reference treatment carried out in plasma without water vapor, in accordance with prior practice.
Table 1 shows the wetting angle obtained as a function of water vapor concentration, all other parameters remaining constant, in plasma treatment of a polymer film, specifically low pressure polyethylene. The first line in Table 1 is the initial condition of the sample prior to treatment. Treatment in a plasma of inorganic gases with water vapor added to a concentration of 0.05-0.5% results in reduced wetting angle of the film surface for equal treatment time compared to existing methods. At a H 2 O vapor concentration of 0.6% the angle of wetness increases to 44 degrees, which is greater than achieved by the reference treatment. Minimum wetting angle was obtained at H 2 O concentrations of approximately 0.10 to 0.15%, while improved results over the reference were obtained for an H 2 O concentration range of 0.05 through 0.5.
Table 2 shows treatment time as a function of H 2 O concentration to achieve a given wetting angle at constant input power. Table 3 lists input power required as a function of H 2 O concentration to achieve a given wetting angle for a fixed treatment time. Both Tables 2 and 3 show that presence of H 2 O a concentration of 0.05 to 0.5% decreases processing time as well as the specific power needed to obtain the wetting angle of 43 degrees obtained in the reference treatment.
Table 4 shows data obtained at an optimal concentration of water vapor equal to 0.1%, showing wetting angle Q obtained as a function of input power for treatment without H 2 O vapor (column Q, (H 2 O)=0.0) and treatment with 0.1% H 2 O (column Q(H 2 O)). Table 5 makes a similar comparison for treatments of varying duration at a constant specific power input. Tables 4 and 5 show that for polyethylene film treatment, optimal specific power is 1.5 to 2.0 wt/cm3 and optimal treatment time is 2.5 to 3.5 minutes.
Similar results were obtained for treatment of polypropylene film as shown in Table 6. In each instance the results can be compared to the results obtained in the absence of water vapor the plasma.
Table 7 shows the effect of water vapor added to the plasma on modification of capillary absorption properties of non-impregnated cotton fabric before dyeing. Power input and treatment time are fixed. Water vapor concentration in the plasma was varied and resulting capillary absorption was measured in millimeters of height lifted along a vertical strip of the treated fabric in a 10 minute interval. As one can see from the table, maximum absorption of 54 was obtained at an H 2 O concentration of 0.20 to 0.25, compared to absorption of 28 for a reference sample treated without water vapor under otherwise similar conditions.
Table 8 shows how treatment time affects the properties of a non-impregnated fabric sample. The longer the treatment time the greater the capillary absorption of the sample. However, the incremental improvement in absorption diminishes with increasing treatment time, as shown.
Table 9 shows plasma treatment data for impregnated fabrics. Column 3 lists capillary absorption obtained by a 10 minute plasma treatment with water vapor present in the indicated concentration. Column 4 lists capillary absorption obtained where the sample was first subjected to a 10 minute plasma treatment stage without water vapor, and then to plasma treatment with water vapor present in the concentration indicated. It is clear that pretreatment in the absence of water vapor is of great importance. The capillary absorption of all samples not subject to the 1st stage pretreatment was actually less than that of the untreated sample, except at relatively long treatment times. In other words, the plasma treatment had improved the hydrophobic properties of the sample, which became more water repellent. It is believed that these results can be explained as follows. Under near vacuum conditions in the treatment chamber, partial evaporation of the fabric impregnating material occurs. These extraneous vapors contaminate the plasma and have a negative influence on the desired results of the plasma treatment. This may lead to the increase of the water-repellent properties of fabrics which, for example, makes subsequent coloring or dyeing of the fabric more difficult. It is believed that pretreatment by an electrical discharge in the evacuated chamber without supplying gas to the chamber helps to eliminate and to decompose the vapors of the impregnating substance. During the subsequent plasma treatment stage, in the presence of H 2 O vapor, the extraneous vapors will no longer interfere with the treatment, yielding the considerably increased capillary absorption figures shown in column 6 of Table 9.
Table 10 shows resulting capillary absorption as a function of specific power input and treatment time in relation to an untreated sample and reference analogue treatment without H 2 O vapor.
Table 11 shows the results obtained for flax based fabrics, of the type which are impregnated for use as industrial belting The Table gives separate results for a) non-impregnated fabrics, b) for fabrics pre-impregnated with viscose and c) for fabrics pre-impregnated with resin. The samples were treated at constant specific power and treatment time with varying concentrations of H 2 O vapor. The criterion used for comparing effectiveness of the treatment is the time required for absorption of liquid (viscose and water) to a height of 25 mm in a treated sample suspended over the liquid. The results show that, also for these materials, the presence of water vapor in the inorganic gas plasma enhances the surface property modification process in comparison to the analogue samples treated without water vapor.
EXAMPLES
Example 1
A 150=150 mm sample of wool fabric with specific density 820 g/m2 was placed into a plasma discharge chamber equipped with external cylindrical electrodes. Air was extracted by a vacuum pump to a pressure of 0.005 Torr. Oxygen gas with water vapor added to a concentration of 0.1% was then introduced into the chamber to a pressure 0.5 Torr. A glow discharge was ignited by supplying high frequency voltage (at 6.25 Mhz) to the electrodes for 120 sec with specific power input of 0.35 wt/cm3. The discharge was then extinguished and vacuum pumping stopped. Air was admitted into the system and the sample removed from the discharge chamber. The sample subjected to testing after treatment showed substantially unimpaired mechanical properties. Air penetration of the untreated sample was measured as 24.9 cm3/cm2.sec. Air penetration of the sample following the plasma treatment was 26.1 cm3/cm2.sec. Wear testing of the initial sample was measured at 1,200 revolutions. Wear testing of the treated sample was measured at 1,500 revolutions. Capillary absorption of untreated sample was 11 mm/10 min. Capillary absorption of treated sample was found to be 24 mm/10 min. Capillary absorption of a similar sample treated without water vapor ([H 2 O]=0.0) in the plasma was 19 mm/10 min.
Example 2
A 150×150 mm sample of wool fabric with specific density 830 g/m2 was placed into a gas discharge chamber between parallel plate electrodes placed longitudinally and diametrically opposite to each other on the exterior of the tubular plasma treatment chamber, and treated for 15 seconds under conditions indicated in example 1, but with the specific power of the electrical discharge adjusted to 2 wt/cm3. Mechanical strength and deformation properties and air penetration characteristics of the sample were not significantly affected by the treatment. Wear testing of the untreated sample was measured at 850 revolutions. Wear testing of the sample treated in the presence of water vapor was 1,130 revolutions. Capillary absorption of the untreated sample was 0.7 mm/10 min. Capillary absorption of a sample treated without water vapor ([H 2 O]=0.0) was 13 mm/10 min. Capillary absorption of the sample treated with water vapor present in the chamber at the concentration indicated in Example 1 was 18 mm/10 min.
Example 3
A 200×400 mm sample of paper with a thickness of 142 μm was placed in a discharge unit with parallel plate electrodes and treated under conditions indicated in example 2, but the concentration of water vapor was adjusted to 0.2% and treatment time was 60 sec. Subsequent examination revealed no detrimental effect to the mechanical strength and deformation characteristics of the sample. Capillary absorption of the untreated sample was 12 mm/10 min. Capillary absorption of a sample treated without water vapor ([H 2 O]=0.0) was 69 mm/10 min. Capillary absorption of the treated sample with water vapor present ([H 2 O]=0.2%) was 107 mm/10 min.
Example 4
A 50×50 mm sample of polyethylene film was placed into a glow discharge unit with external cylindrical electrodes, and treated under conditions indicated in example 3 for 5 minutes. The wetting angle of the untreated sample was 90 degrees. The wetting angle of a sample treated without water vapor ([H 2 O]=0.0) was 44 degrees. The wetting angle of the sample treated in the presence of water vapor was 17 degrees.
Example 5
A sample of flax based fabric was placed into a glow discharge unit with external cylindrical electrodes, and treated under the conditions of example 3 for 5 minutes. The untreated sample showed a time of 5.3 sec for lifting water to a height of 25 mm by capillary absorption; time for lifting viscose to the same height was 46.3 sec. A sample treated without water vapor ([H 2 O]=0.0) showed a water lifting time of 3.1 sec, and a viscose lifting time of 31.3 sec. The water lifting time for a sample treated with H 2 O vapor present was 0.7 sec, and the viscose lifting time for the same sample was 22.3 sec.
By comparison, a similar sample treated in a corona discharge, in accordance with prior art practice, showed a time of 4.4 sec for lifting water to 25 mm, and 32.4 sec for lifting viscose to the same height.
Example 6
A sample of flax based fabric as in Example 5 but preimpregnated with viscose was placed in a glow discharge chamber with external electrodes, and treated under the conditions of example 3 for 160 sec. The untreated sample showed a water lifting time to 25 mm of 12.2 sec, and a viscose lifting time to the same height of 37.4 sec. A similar sample treated without water vapor ([H 2 O]=0.0) showed a water lifting time of 5.4 sec and a viscose lifting time of 4.5 sec. A similar sample treated with water vapor present in the chamber showed a water lifting time of 4.2 sec and a viscose lifting time of 19.8 sec.
By comparison, a similar sample treated in a corona discharge in accordance with prior art practice showed a lifting time of 7.6 sec for water and 31.7 sec for viscose.
Example 7
A 150×150 mm sample of cotton fabric preimpregnated with an anti-wrinkling agent was placed in a glow discharge chamber with external cylindrical electrodes. Air was evacuated from the chamber to a pressure of 0.05 Torr. In a 1st treatment stage a glow discharge was ignited by supplying high frequency voltage (f=6.25 Mhz) to the electrodes, without introducing gases into the chamber. Specific power of the discharge was 0.35 wt/cm3 and time of treatment was 30 sec during this first stage.
This was followed by a second treatment stage where oxygen gas with water vapor added ([H 2 O]=0.15%) was introduced into the chamber to a pressure of 1.5 Torr. The glow discharge was reignited for 120 seconds with a specific power of 0.35 wt/cm3 during this second stage. The discharge was then extinguished and vacuum pumping was stopped. Air was admitted into the system and the sample removed from the discharge chamber. The capillary absorption of the untreated sample was 12 mm/10 min. After the two stage treatment capillary absorption of the treated sample increased to 21 mm/10 min. Capillary absorption of a sample subjected only to the second stage treatment, without 1st stage treatment, was found to be 14 mm/min.
TABLE 1______________________________________EFFECT OF WATER VAPORCONCENTRATION ON WETTING ANGLE(FOR LOW PRESSURE POLYETHYLENE) Time of Specific Power Treatment Wetting angle(H.sub.2 O), % Wsp, Wt/cm3 t, min Q-degrees______________________________________initial 0 0 90analogue 3 5 430.05 3 5 42.50.075 3 5 370.10 3 5 320.15 3 5 320.2 3 5 350.25 3 5 370.3 3 5 390.4 3 5 400.5 3 5 420.6 3 5 44______________________________________
TABLE 2______________________________________EFFECT OF WATER VAPOR ON TREATMENT TIMEFOR OBTAINING WETTING ANGLEQ = 43 DEGREES(FOR LOW PRESSURE POLYETHYLENE) Time of Specific Power Wetting Angle Treatment(H.sub.2 O), % W sp, Wt/cm3 Q-Degrees t, sec.______________________________________Analogue 3 43 3000.05 3 43 2970.075 3 43 2580.1 3 43 2230.15 3 43 2230.2 3 43 2440.25 3 43 2580.3 3 43 2720.4 3 43 2790.5 3 43 2930.6 3 43 314______________________________________
TABLE 3______________________________________EFFECT OF WATER VAPOR ON SPECIFIC POWERFOR OBTAINING WETTING ANGLEQ = 43 DEGREES(FOR LOW PRESSURE POLYETHYLENE) Time of Treatment, Wetting Angle Specific Power(H.sub.2 O), % t, min Q-Degrees W sp, Wt/cm3______________________________________Analogue 0 5 43 30.05 5 43 2.930.075 5 43 2.630.1 5 43 2.340.15 5 43 2.350.2 5 43 2.510.25 5 43 2.630.3 5 43 2.750.4 5 43 2.810.5 5 43 2.980.6 5 43 3.22______________________________________
TABLE 4______________________________________EFFECT OF SPECIFIC POWER ON WETTING ANGLEAT BOTH MOST EFFICIENT CONCENTRATION OFWATER VAPOR AND AT FIXED TIME OF TREATMENT(FOR LOW PRESSURE POLYETHYLENE)Time of SpecificTreatment Power (H.sub.2 O) =t, min W sp, Wt/cm3 0.0 (H.sub.2 O), % Q (H.sub.2 O)______________________________________0 0 90 0 90initial5 0.5 65 0.1 43.55 1.0 52 0.1 255 1.5 48 0.1 175 2.0 44 0.1 185 2.5 43.5 0.1 225 3.0 43.0 0.1 325 3.5 43.0 0.1 56______________________________________
TABLE 5______________________________________EFFECT OF TREATMENT TIME ON ANGLEOF WETNESS AT MOST EFFICIENT CONCENTRATIONOF WATER VAPOR AND FIXED SPECIFIC POWER(FOR LOW PRESSURE POLYETHYLENE)Wsp, Wt/cm3 t, min. Q, (H.sub.2 O) = 0.0 (H.sub.2 O), % Q (H.sub.2 O)______________________________________0 0 90 0 90initial3 1 72 0.1 433 2 60 0.1 243 3 52 0.1 173 4 47 0.1 233 5 43 0.1 323 6 43 0.1 46______________________________________
TABLE 6______________________________________FOR POLYPROPYLENE Specific Time of Wetting Power W sp Treatment Angle(H.sub.2 O), % Wt/cm3 t, min Q-Degrees______________________________________Initial 0 0 0 90Analogue 0 3 5 550.05 3 5 53.50.075 3 5 480.1 3 5 450.15 3 5 430.2 3 5 440.25 3 5 460.3 3 5 520.4 3 5 530.5 3 5 540.6 3 5 57 (H.sub.2 O) = 0.00.1 0.5 5 72 780.1 1.0 5 56 690.1 1.5 5 44 630.1 2.0 5 39 580.1 2.5 5 40 570.1 3 5 45 550.1 3 5 55 55______________________________________
TABLE 7______________________________________EFFECT OF WATER VAPORCONCENTRATION ON CAPILLARY ABSORPTIONUNDER FIXED TREATMENT CONDITIONS(FOR NON-IMPREGNATED FABRICS) Specific Time of Capillary Power Treatment Absorption1st Stage Wt/cm3 Sec. (H.sub.2 O), % mm/10 min.______________________________________Initial 0 0 0 21Analogue 3.0 600 0 28+ 3.0 600 0.05 34+ 3.0 600 0.1 41+ 3.0 600 0.15 49+ 3.0 600 0.20 54+ 3.0 600 0.25 54+ 3.0 600 0.30 49+ 3.0 600 0.40 46+ 3.0 600 0.50 41+ 3.0 600 0.60 28______________________________________
TABLE 8______________________________________EFFECT OF TREATMENT TIME ON CAPILLARYABSORPTION AT MOST EFFICIENT CONCENTRATIONOF WATER VAPOR AND FIXED SPECIFIC POWER(FOR NON-IMPREGNATED FABRICS) CapillarySpecific Time of Absorption CapillaryPower Treatment, at (H.sub.2 O) = 0.0 (H.sub.2 O), AbsorptionWt/cm3 Sec. mm/10 min. % mm/10 min.______________________________________0 0 21 0 213.0 60 24 0.2 303.0 120 26 0.2 383.0 180 28 0.2 443.0 240 28.5 0.2 483.0 300 28.5 0.2 50.53.0 360 29 0.2 523.0 420 29 0.2 52.53.0 480 29 0.2 533.0 540 39.5 0.2 53.53.0 600 29.5 0.2 54______________________________________
TABLE 9__________________________________________________________________________EFFECT OF TREATMENT TIME ON CAPILLARYABSORPTION AT MOST EFFICIENT CONCENTRATIONOF WATER VAPOR AND FIXED SPECIFIC POWER(FOR IMPREGNATED FABRICS) Capillary CapillarySpecificTime of Absorption mm/10 min Absorption mm/10 min CapillaryPowerTreatment without Ist stage with Ist stage (H.sub.2 O), AbsorptionWt/cm3t, Sec. at (H.sub.2 O) = 0.0 at (H.sub.2 O) = 0.0 % mm/10 min__________________________________________________________________________3.0 0 12 12 0 123.0 60 6.5 8.2 0.2 173.0 120 3.0 6.0 0.2 213.0 180 0.5 3.5 0.2 213.0 240 1.0 4.5 0.2 243.0 300 3.0 6.0 0.2 263.0 360 4.0 8.5 0.2 293.0 420 6.0 12.0 0.2 313.0 480 8.0 16.0 0.2 31.53.0 540 10.0 18.0 0.2 323.0 600 12.0 20.0 0.2 33__________________________________________________________________________
TABLE 10______________________________________EFFECT OF SPECIFIC POWER ORTREATMENT TIME ON CAPILLARY ABSORPTIONAT FIXED CONCENTRATION OF WATER VAPOR(FOR NON-IMPREGNATED FABRICS) CapillarySpecific Power Time of AbsorptionWt, Wt/cm3 Treatment (H.sub.2 O), % mm/10 min.______________________________________0.003 600 0.3 30.53.0 600 0.3 490.002 600 0.3 213.1 600 0.3 54 change of properties1.5 3 0.3 311.5 600 0.3 491.5 2 0.3 21.51.5 610 0.3 52 change of properties0 0 0 21 initial3.0 600 0 28 analogue1.5 600 0 25 analogue______________________________________
TABLE 11______________________________________EFFECT OF WATER VAPOR CONCENTRATION ONFLUID LIFTING TIME THROUGH 25 MM(FOR FLAX BASED FABRICS) Specific Time of Time of liftingImpreg- power, W Treatment (H.sub.2 O), through 25 mmnation Wt/cm3 t, Sec. % visc. water______________________________________Without 0 0 0 initial 46.3 5.31st 3.0 600 0 analog 39.7 4.4stage 3.0 600 0.05 32.4 4.0 3.0 600 0.1 27.3 1.5 3.0 600 0.15 22.5 0.5 3.0 600 0.2 21.1 <0.5 3.0 600 0.3 25.4 <0.5 3.0 600 0.4 30.1 1.1 3.0 600 0.5 37.8 2.5 3.0 600 0.6 42.3 4.5Prelim. 0 0 0 initial 37.4 12.2Viscose 3.0 600 0 analog 31.7 7.6Impreg- 3.0 600 0.05 30.1 7.2nation 3.0 600 0.1 22.5 5.7 3.0 600 0.2 18.5 4.2 3.0 600 0.3 21.2 3.8 3.0 600 0.4 23.1 5.4 3.0 600 0.5 24.5 5.2 3.0 600 0.6 31.8 7.8Prelim. 0 0 0 initial 49.1 25.3Resin 3.0 600 0 analog 31.6 13.5Impreg- 3.0 600 0.05 30.4 12.4nation 3.0 600 0.1 23.1 10.3 3.0 600 0.2 19.1 8.3 3.0 600 0.3 22.7 7.9 3.0 600 0.4 23.4 9.1 3.0 600 0.5 25.3 11.2 3.0 600 0.6 32.3 14.1______________________________________
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Efficiency of low pressure gas plasma processes is increased by addition of small quantities of water vapor to the primary gas constituting the plasma. Treated fabrics and polymer films show decreased wetting angle and increased capillary absorption, which beneficially affects the material's susceptibility to dyeing and impregnation.
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FIELD OF INVENTION
The present invention relates generally to shutters, blinds and other coverings, collectively referred to as shades, for windows, doorways and other permanent and temporary apertures and openings.
BACKGROUND OF THE INVENTION
Shutters and blinds typically have a plurality of horizontally oriented rotatably adjustable slats. Typically, such shades comprise an assembly of plural individual slats. Each slat must be individually replaced if it is desired to change a slat due to any reason, such as damage, soiling, etc. The slats are vertically spaced apart and hang from a plurality of depending drawstrings. The drawstrings must be threaded through each individual slat. By “thread” or “threading”,it is meant that the hole in the shade or attachment is circumscribed by a solid periphery, and the drawstring is necessarily inserted through the hole in a direction generally perpendicular to the plane of such hole. In contrast, according to the present invention, the drawstring may be inserted without threading. Instead of threading, the drawstring may be inserted into the attachment in a lateral or radial direction, providing speed and convenience to the user. Shades having vertically oriented slats are also known in the art, and suffer from much of the same disadvantages, as shades having horizontally oriented slats.
Shades also include cellular and single panel embodiments. Such shades typically are suspended from a header by a plurality of drawstrings. These shades often comprise a plurality of horizontal pleats, through which the drawstrings are threaded. These shades provide the benefit that a unitary assembly can be inserted and removed to cover the opening, but also have the disadvantage of requiring threading of the drawstrings through individual pleats.
Frequently, the user will wish to provide a pattern, coloring or aesthetically pleasing indicia on the shade. For example, U.S. Pat. No. 5,263,529, iss. Nov. 23, 1993 to Landis, teaches individual decals being applied to the slats of horizontally oriented blinds. Each decal contains a portion of the desired design. When the individual slats are viewed together, an entire design is formed. U.S. Pat. No. 5,443,563, iss. Aug. 22, 1995 to Hindel et al., teaches a shade secured to a roller and having a high definition print applied to the face of the shade. The shade is treated to make it non-stretchable. U.S. Pat. No. 3,580,323, iss. May 25, 1971 to Gossling et al., teaches a blind having a decorative scalloped edge. However, these references fail to teach a shade having a design which is conveniently removable and replaceable. Each of these attempts in the art requires complex disassembly and reassembly if the user wishes to change the color, pattern, or other aesthetic effect of the shade. Disassembly/reassembly are equally complex if one wishes to change another feature of the shade, such as its size or position on the opening.
U.S. Pat. No. 6,033,504, iss. Mar. 7, 2000 to Judkins, teaches an exemplary honeycomb type of cellular window covering suspended from two pairs of cords. Another attempt in the art is U.S. Pat. No. 6,056,035, iss. May 2, 2000 to Laster-Bivens. Laster-Bivens teaches an apparatus for hanging various styles of shades, and comprising four depending draw cords. The individual draw cords are threaded through a hanging grid at discrete predetermined locations. To “simplify” the installation process, the draw cords may be secured with quick release stops. However, both of these attempts in the art still require the time consuming task of threading cords or strings through individual holes in the shades.
An attempt to overcome threading individual cords or strings through individual holes is given by U.S. Pat. No. 6,192,962 B1, iss. Feb. 27, 2001 to Glover. Glover teaches a telescoping support bar and window treatment panels which are joined together by hook and loop fasteners. When the consumer desires to change the panel, the hook and loop attachment means are released and a new panel applied. However, Glover does not teach easily replaceable pleated shades which are raised and lowered by the user.
Another attempt to forego threading drawstrings through individual holes is found in U.S. Pat. No. 5,158,127, iss. Oct. 27, 1992 to Schumacher. Schumacher teaches a temporary covering fastened to the top of the window frame by an adhesive fastening strip and adjusted to length by a pair of clipping means. Schumacher's adhesive does not allow for permanent or even long term attachment of the temporary covering. Yet, another attempt is found in U.S. Pat. No. 4,880,045, iss. Nov. 14, 1989 to Stahler. Stahler teaches a flexible window shade assembly having a pair of guide tracks 30 which receive and support the window shade assembly. Stahler is not suitable for use with the existing infrastructure, which primarily relies upon the draw cords disclosed above. U.S. Pat. No. 6,196,292 B1, iss. Mar. 6, 2001 to Jackson, discloses a venetian blind window covering comprising two individual blinds. The individual blinds are detachably secured together, one on top of the other. The blinds may be individually changed or independently controlled by the user. However, the Jackson blinds are not suitable for relatively short windows, and, more significantly, do not allow the user to conveniently change the size or appearance of the entire blind system.
U.S. Pat. No. 4,655,003, iss. Apr. 7, 1987 to Henley, Sr., teaches a shutter assembly with individually removable slats. Henley does not require the assembly to be threaded through drawstrings. Instead, each slat is provided with a dowel at each end. The dowel fits into vertically spaced sockets in the side rails. The Henley assembly does not allow for removal and insertion of a new assembly all at once, nor is Henley usable with the pleated shades so popular today.
U.S. Pat. No. 4,539,238, iss., Sep. 3, 1985 to Markowitz also teaches a window shade comprising strips connected by severable connecting threads. The strips may be torn from each other if one wishes to remove an individual strip for sizing. Markowitz, like Henley, fails to teach a way to conveniently change the entirety of a window shade.
Accordingly, there is a need in the art to accommodate convenient removal and insertion of window shades. Particularly, there is a need to provide removal and insertion of shades which do not require threading individual strings or cords through individual holes in a shade. Further, the need exists for convenient insertion and removal of the popular pleated shades in use today.
SUMMARY OF THE INVENTION
The invention comprises an apparatus for at least partially obscuring or covering an opening. The apparatus comprises a header. The header is attachable to the periphery of the opening and particularly may be attachable to the frame of the opening, if provided. The apparatus further comprises at least one drawstring extending away from the header and in operative association with the header. Also provided is a shade. The shade has a proximal end juxtaposed with the header and a distal end opposed thereto. The shade has a plurality of attachments attachable to the drawstring. The shade is operatively associated with the drawstring without threading the drawstring through holes in the shade. In operation, the distal end of the shade may be moved towards or away from the header by operation of the drawstring.
If desired, the shade may be pleated and/or cellular. Multiple drawstrings and/or an external motor for automated operation of the shade may be provided. The shade is conveniently removable from the balance of the apparatus in order that the user may easily replace the shade, as desired.
All documents cited are, in relevant part, incorporated herein by reference; the citation of any document is not to be construed as an admission that it is prior art with respect to the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a broken perspective view of a pleated shade according to the present invention, having unequally sized pleats in the upper half, within internally facing slots on the attachments and equally sized pleats with externally facing slots on the lower half.
FIG. 2 is a broken side elevational view of a shade similar to that shown in FIG. 1, and being cellular.
FIGS. 3A-3D are top plan views of externally extending attachments usable with the present invention.
FIGS. 3E-3G are top plan views of internally extending attachments usable with the present invention.
FIG. 4 is a frontal view of a shade according to the present invention being disposed on tracks.
FIGS. 5A-5B are fragmentary vertical sectional views taken along line 5 — 5 of FIG. 4, showing two different possible constructions, each usable with the shade of FIG. 4 .
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, the apparatus 10 comprises a header 12 . The header 12 is attachable to the frame of an opening 40 . At least one, and preferably a plurality, of drawstrings 14 extend away from the header 12 . A shade 16 is suspended from the header 12 by the drawstrings 14 .
The header 12 may be horizontally oriented and attached to or juxtaposed with the top of the opening 40 . The opening 40 may comprise a window, door, aperture, portal, access panel or any other blind or through hole, as desired. The drawstring(s) 14 depend downwardly from the header 12 . The drawstring 14 supports and controls the shade 16 . The shade 16 may be pleated. If the shade 16 is pleated, it may have Z-pleats of equal or unequal size. Joined to or otherwise operatively associated with the shade 16 is a plurality of attachments 19 , as described below. The attachments 19 are typically juxtaposed with the vertex of the pleat 18 , although other locations on the pleat 18 , as well as other positions on the shade 16 , may be suitable.
The pleated shade 16 is operatively associated with the drawstring 14 in known manner, which will not be repeated here, so that the shade 16 may be moved relative to the opening 40 . Particularly, the shade 16 has a proximal end 20 juxtaposed with the header 12 and a distal end 22 remote therefrom. When the shade 16 is moved, typically the distal end 22 is moved towards and away from the header 12 . The drawstring 14 and shade 16 are operatively associated in a known manner so that the drawstring 14 can operate the shade 16 to obscure and reveal, or cover and uncover, more or less of the opening 40 as desired. In extreme situations, the shade 16 may totally obscure the opening 40 , or not obscure it at all. Alternatively, the portion of the opening 40 obscured/revealed by the shade 16 may remain constant while the absolute position of the shade 16 is moved towards and away from different portions of the frame.
The length of the shade 16 is taken from the proximal end 20 to the distal end 22 . The width of the shade 16 is perpendicular to its length and lies within the plane of the shade 16 . The length and width directions define the plane of the shade 16 .
The apparatus 10 is useful for partially or totally obscuring/revealing an opening 40 . If the opening 40 is large, the user may not wish to totally obscure the opening 40 . For example, if the opening 40 is a large, tall window, the upper portion of the window may remain uncovered and transparent while the lower portion is covered to provide sufficient privacy for the users. The user may wish to allow portions on one side of the window or around the periphery of the window to always remain uncovered, for example, to allow for light entry. It is to be understood that depending upon the needs of the user and the geometry of the opening 40 , the apparatus 10 of the present invention may be used to partially or totally obscure/reveal the opening 40 .
The opening 40 has a geometry defined by a periphery. The geometry may have any desired shape/aspect ratio, and comprise a periphery having straight sides, curved sides, or combinations thereof. The periphery of the opening 40 is typically bounded by a frame, although it is to be recognized that openings 40 may have one or more undefined sides as, for example, occurs when the top of the opening 40 is not bounded. The frame may only be disposed on one side of the opening 40 , may traverse the opening 40 , and may be continuous or discontinuous, as desired. The frame of the opening 40 need only be usable for attachment 19 of the apparatus 10 as set forth below. Thus, the frame includes the walls and other members 32 juxtaposed with the opening 40 and suitable for mounting of the apparatus 10 . The frame may be integral with the periphery of the opening 40 or may be a separate element.
The drawstring 14 is any flexible element 32 which can operate the shade 16 to obscure/reveal more or less of the opening 40 as desired, or which may serve to change the position of the shade 16 relative to the periphery of the opening 40 . Drawstrings 14 are inclusive of strings, cords, chains, belts, and bands which can operate the shade 16 as known in the art. Drawstrings 14 are also inclusive of rigid members 32 flexibly attached to the shade 16 and provide for its operation and movement, such as rotatable handles and articulable levers.
Referring to FIG. 2, the shade 16 may optionally comprise at least one, and preferably a plurality of cells, Z pleats, and other known folds. The pleats 18 allow for accumulation of the material forming the shade 16 as it is compressed to reveal more of the opening 40 , and also allow for extension of the material to obscure more of the opening 40 . The material forming the shade 16 may be elastic or inelastic, as desired. Also, the material forming the shade 16 may be opaque to varying degrees, translucent, or even transparent. If desired, the shade 16 may comprise one or more holes therethrough for viewing, communicating with persons on the opposite side of the shade 16 , etc. The shade 16 may be formed of a single piece of material or may comprise at least two pieces of material disposed 180 degrees out of phase. The at least two pieces of material may be alternatingly opaque and transparent and disposed such that when the shade 16 is transposed the amount of light transmitted through the shade 16 can be varied. The pitch and opacity differences between the transparent and opaque areas can be varied, as desired.
If desired, the shade 16 may comprise a flexible panel without pleats 18 . Such a panel would be comprised of any flaccid material which can be accumulated or gathered by known means to reveal more or less of the opening 40 as desired. For example, a flat panel embodiment of the shade 16 may be rolled around a tube in known fashion, as illustrated, for example, by U.S. Pat. No. 4,951,730, iss. Aug. 28, 1990 to Hsu.
The attachments 19 are disposed on the shade 16 in any pattern which allows for operation and movement of the shade 16 . Preferably, the attachments 19 are spaced apart along the length of the shade 16 in a straight line. This disposition not only accommodates convenient attachment 19 of the drawstrings 14 to the attachments 19 , but also allows for simple operation of the drawstrings 14 in known fashion. If a Z pleated or cellular shade 16 is selected, the attachments 19 may be disposed on the vertex of each pleat 18 or cell. Alternatively, attachments 19 may be disposed at other positions on the shade 16 . It is not necessary that each pleat 18 of the shade 16 have an attachment 19 . It is only necessary that the number of attachments 19 be sufficient to move the distal end 22 of the shade 16 towards and away from the header 12 . In an extreme case, a single attachment 19 juxtaposed with the distal end 22 of the shade 16 may be utilized. If the pleats 18 are of unequal size the attachments 19 may be only disposed on the larger pleats 18 , which typically extend further outwardly from the plane of the shade 16 . Further, a Z pleated or cellular shade 16 may have pleats 18 disposed of in two oppositely facing arrays, a first array oriented towards the opening 40 and a second array of pleats 18 oppositely oriented and facing away from the opening 40 . The attachments 19 may be disposed on either the first array, the second array, or both.
Referring to FIGS. 3A-3G, attachments 19 provide for operatively associating the shade 16 with the drawstring 14 . Preferably, the attachments 19 do not comprise holes, and thereby avoid the necessity and inconvenience of threading the drawstrings 14 through holes in the attachments 19 or in the shade 16 . Instead, the attachment 19 may connect the drawstring 14 to the shade 16 by mechanical engagement, frictional forces, or any other releasably attachable method or mechanism which does not require the inconvenience of threading the drawstrings 14 through holes in the attachment 19 or the shade 16 . The attachments 19 may be made of plastic, metal, paper, sheet stock, wire, or any other suitable material.
Referring particularly to FIGS. 3A-3D, the attachments 19 may extend outwardly from the shade 16 . Each attachment 19 may comprise an open loop. The open loop has a narrow slot through which the drawstring 14 is inserted for attachment 19 of the shade 16 , as illustrated in FIGS. 3A-3B. The slot is narrow enough that it is unlikely that and reasonably difficult for the drawstring 14 to become detached from that attachment 19 . Alternatively, the attachment 19 may comprise wire loops, clips, and compliant geometries—similar to an “owl clip” style paper clip, as illustrated in FIGS. 3C-3D. The open area of the geometry of the attachment 19 preferably provides for smooth operation of the shade 16 . The attachment 19 may be joined to the shade 16 by adhesion, crimping, heat sealing, or various other means known to one of skill in the art. Alternatively, the attachment 19 and shade 16 may be integrally formed at the time of manufacture. Referring to FIGS. 3E-3G, if desired, the attachments 19 may be internal to the shade 16 , such as a slot, notch, or other feature cut from or into the shade 16 .
FIGS. 3A, 3 C, 3 E, and 3 G show attachments 19 extending perpendicular to the plane of the shade 16 . FIGS. 3B, 3 D, and 3 F show attachments 19 extending outwardly from or internally into the end of the shade 16 . FIG. 3E shows a J-shaped slot extending generally perpendicular to the plane of the shade 16 . FIG. 3G shows an attachment 19 comprising an open slot terminating at an enlarged hole.
One of skill will recognize that many permutations, combinations, and variations of the foregoing attachments 19 are feasible and within the scope of the claimed invention. For example, the slot type attachments 19 need not have an enlarged hole at the distal end 22 of the slot. Slots may be convergently and divergently tapered. Overlapping type clips, such as the owl type clips illustrated may overlap or not overlap, as desired.
Additionally, one of skill will recognize that variations and combinations in the type of attachments 19 used on a particular shade 16 are feasible. For example, a first type of attachment 19 may be used near the proximal end 20 of the shade 16 while a different type of attachment 19 may be used near the distal end 22 of the shade 16 . The same pleat 18 may have plural attachments 19 on it, a single attachment 19 , or no attachments 19 . If plural attachments 19 are selected for a given pleat 18 , the attachments 19 may be alike or different.
Referring back to FIGS. 1-2, the shade 16 may be joined to the header 12 and/or footer using temporary or permanent means well known in the art, including, but not limited to, magnetic attraction, hook-and-loop fasteners, adhesive, etc. The same joining method need not be used for both the header 12 and footer. A greater holding force is required at the header 12 than the footer.
If desired, the shade 16 may have indicia provided thereon. The indicia may comprise any aesthetic pattern, print, or recognizable feature sought by the user. For example, the indicia may be coordinated with the season (Christmas, Easter, Fall, etc.), may comprise sports figures, cartoons for children, color coordinate with the rest of the room or environment in which the shade 16 /opening 40 are used, may provide printed instructions for activities carried out in the vicinity of the shade 16 , may comprise memorabilia unique to the user, photographs of family, local sites of interest, etc.
The indicia may comprise ink, dye, or any visually aesthetically discernible pattern, including three-dimensional topographies, such as embossments or debossments. Inks or dyes may be applied to the sheet in any number of ways, including, but not limited to: dipping the sheet into the ink or dye, spraying a solution onto the sheet, or preferably by printing. Suitable printing processes include, but are not limited: lithography, letter press, elcography, laser printing, gravure, screen printing, intaglio, flexography, and preferably inkjet printing. The indicia may be a single color image or multi-colored. Inks and devices suitable for printing of the indicia are found in commonly assigned U.S. Pat. No. 6,096,412, iss. Aug. 1, 2000 to McFarland, et al. and U.S. Pat. No. 5,123,037, iss. May 25, 1993 to Leopardi, II, respectively. Embossing may be accomplished according to commonly assigned U.S. Pat. No. 5,294,475. iss. Mar. 15, 1994 to McNeil, or using other well known methods. The image may be centered on the shade 16 as illustrated in the aforementioned U.S. Pat. No. 3,580,323. The indicia may be applied during manufacture and prior to purchase by the user. Alternatively, the image may be applied by the user after purchase. If a symmetrical image is desired, the image should have a border feature which allows for trimming of the shade 16 to the desired size. A single shade 16 may have indicia on both sides, if desired.
In another embodiment (not shown), the shade 16 may comprise alternating rigid elements and flexible joints. The rigid elements are spaced apart by the flexible joints and may have a major dimension disposed parallel to the width and substantially transverse to the length of the shade 16 . If desired, the rigid members 32 may span the entire width of the shade 16 . The flexible joints may comprise suitable springs. The flexible joints allow for alternating collapse of the space separating the rigid members 32 as the distal end 22 of the shade 16 is retracted towards the header 12 . This embodiment is similar to the well known Roman shade which has rigid joints/bars and the material between the bars which is flexible as the bars are raised and lowered, such a shade 16 is attached to the header 12 and optionally a footer. Opposite the shade 16 are the attachments 19 which are operatively associated with the drawstrings 14 . The attachments 19 may be connected to the flexible joints or, alternatively, to the rigid members 32 . By alternating the rigid members 32 and flexible joints, the shade 16 will preferentially buckle at the flexible joints when the distal end 22 of the shade 16 is retracted towards the header 12 .
If desired, a pair of shades 16 may be disposed in parallel and facing each other. This arrangement increases the opacity and thermal barrier provided by the shades 16 . Each shade 16 of the pair may be provided with indicia. The indicia may be mutually different or the same. Of course, three or more shades 16 may be disposed in parallel in this manner. Each such shade 16 may have a portion of the total indicia disposed thereon, with the indicia becoming visually clearer as the shade 16 closest to the viewer is seen.
Referring to FIG. 4, the header 12 may be movable, rather than fixed to the frame. For example, tracks 30 may be provided on the sides of the opening 40 . One or more members 32 are juxtaposed with the ends of the header 12 and footer (if provided) and attached to tracks 30 to move up and down the tracks 30 to the desired position. This arrangement provides the benefit that more flexibility is available in obscuring/revealing different portions of the opening 40 . A particular benefit to this embodiment is that the top of the opening 40 may remain uncovered without drawstrings 14 hanging from the movable header 12 across the opening 40 to the shade 16 , as occurs in the prior art.
Referring to FIGS. 5A-5B, in such an arrangement, the shade 16 may be attached to the track by a compliant member 32 or by any other method or mechanism which engages the track 30 to hold the shade 16 in the desired position. Such a member 32 may be magnetic, biased or spring loaded, as desired, to provide frictional/mechanical engagement. Alternatively, in such an embodiment the drawstring 14 may be eliminated. A plurality of members 32 may be provided, including one disposed on each end of each pleat 18 of the shade 16 . If desired, the members 32 may be integral with and cut into the ends of each pleat 18 of the shade 16 .
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
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A shade for covering and uncovering an opening. The shade is attachable to drawstrings which raise and lower or otherwise move the end of the shade to obscure/reveal more or less of the opening, as desired. The shade is attachable to the drawstrings through attachments which comprise slots, etc. The attachments do not require threading of the drawstrings through holes in the shade. The shades are conveniently removable from the drawstrings and optionally disposable so that different shades may be coordinated with room colors, seasonal events, etc.
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BACKGROUND OF THE INVENTION
The invention relates to a trench wall cutter with at least two oppositely rotating cutting wheels mounted on a cutting frame and circumferentially provided with soil-breaking tools.
Such cutters are used for making trench walls in the case of foundation trenches, dikes and foundations. In the known trench wall cutters, the cutting wheels are equipped with tearing teeth, which cut or break the ground and transport inwards crushed soil fragments where they are sucked away with a supporting liquid. The cutter is lowered vertically under continuous rotation of the cutting wheels and depths of 100 m and more can be reached. The advance is brought about by the weight of the cutting wheels and the cutting frame, which is hung by means of a cable line to a crawler crane.
Although the presently used trench wall cutters, in which the soil or ground is cut with tearing teeth, can be used in the case of almost all soil types in such a way as to achieve good boring or drilling results, it has been found that considerable wear to the tearing teeth is unavoidable in the case of very hard rocks.
SUMMARY OF THE INVENTION
The problem of the invention is to provide a trench wall cutter of the aforementioned type, in which also in the case of high resistance to rocks, a good boring advance and good free-cutting of the cutting wheels is achieved.
This problem is solved in that the cutting wheels are equipped with rolling tools, which are oriented axially parallel to the cutting wheel axes with a one-sided mounting in order to obtain the free-cut.
The effect of the rolling tools is that as a result of the rolling engagement with the bottom of the bore hole under an applied load, it is possible to locally exceed the rock strength and to split off the rock into small fragments. The tools are consequently only temporarily in engagement with the ground, each tool being exposed to substantially the same loading during rotation. However, the force for detaching the soil is determined not only by the applied load, but by the torque acting on the cutting wheels, as a function of the position of the particular tool in the worked trench semicircle.
As the boring advance, which is determined by the contact pressure per tool and the number of engagements per surface unit, is substantially independent of the diameter of the trench to be produced or the projection surface of the cutting wheel on the trench bottom, the applied load does not have to be increased in the same way with increasing trench diameter. Therefore the dead load to be moved in the case of a location change can be kept relatively small.
According to a preferred further development of the invention, the tools are constructed as cutting rolls, which are mounted on one side with an axial projection with respect to the cutting wheel. Thus, they can be mounted in simple manner on the particular cutting wheel and can, if necessary, be replaced when worn. It is particularly advantageous to axially stagger the tools on the cutting wheels.
Good boring results can be obtained in that the cutting rolls are constructed as at least a single-ring roll with a ring tooth. In addition, the ring tooth can be constructed as a button or stud ring tooth.
In a particularly appropriate manner the cutting rolls have a frustum shape or in axial section a trapezoidal shape. The one-sided mounting of these cutting rolls is preferably provided in the extention of the radial outer face of the cutting wheel. Considered over the circumference, on one side of the cutting wheel roughly four cutting rolls are fitted and on the opposite side thereof an equal number of cutting rolls, but they are circumferentially staggered. The circumferential surface of the frustrum shape of the cutting rolls and the rotation axis of the cutting rolls or their inclination with respect to the axis of the cutting wheels are matched in such a way that with respect to the bottom of the bore hole a roughly parallel cutting face to the axis of the cutting wheels is obtained. The cutting rolls are mounted by means of an approximately triangular bearing block, which can be roughly aligned with the radial outer face of the cutting wheels. However, the cutting rolls are mounted in such a way that their wider base, i.e. the corner region on the bottom of the bore hole projects axially at least slightly over the outer face of the associated cutting wheel. This construction of the roughly axially parallel cutting faces and the axial projection advantageously leads on the one hand to a free-cutting of the cutting wheels and on the other hand in a vertical sectional view a substantially rectangular bore, also in the vicinity of the bottom of the bore hole.
The design and arrangement of the cutting rolls in the aforementioned form during the drilling or boring process leads to a pressing and grinding effect with respect to the bottom region in the vicinity of the bottom of the bore hole, said effect being further increased by the one-sided mounting with a better force transfer to the cutting rolls.
The cutting rolls have on the circumferential surface of the frustrum shape in the corner regions preferably rounded and almost hemispherical studs made from hard metal, e.g. a hardened steel. Between these studs are provided in the circumferential surface further breaking tools in the form of tips and, if possible, the breaking tools are reciprocally displaced. With a view to an easy replacement, both the studs and the tips can be inserted into the circumferential surface of the cutting roll.
In the case of a pairwise, coaxial arrangement of the cutting wheels, in which between the two cutting wheels is provided a bearing plate or bracket receiving the spindles and the gear, it is very appropriate to arrange on those edges of the cutting wheels which face the bearing bracket, in the axial direction pivotable bearings for the cutting rolls, so that upstream of the bearing bracket the cutting rolls can be pivoted in the feed direction. This prevents a ridge building up between the cutting wheels on which the bearing bracket is mounted, so that sinking is prevented.
In order to assist the transporting away of the loosened soil, it is advantageous to position brushes on the cutting wheels. These brushes are used for cleaning the bottom of the bore hole and the bored material can be transported away for suction.
According to a further preferred development of the invention further brushes are arranged over the width of the cutting wheels on the cutting frame and engage with the tools. This measure has the advantage that the tools are cleaned during each rotation of the cutting wheels and it is possible to prevent any sticking together, e.g. in the case of clayish material.
DESCRIPTION OF THE DRAWINGS
The invention is described in greater detail hereinafter relative to non-limitative embodiments and the attached drawings, wherein show:
FIG. 1 diagrammatically a view of a trench wall cutter.
FIG. 2 diagrammatically an axial view on the cutting frame and cutting wheels of a trench wall cutter according to FIG. 1.
FIG. 3 diagrammatically a view at right angles to the axial direction of the cutting frame and cutting wheels according to FIG. 2.
FIG. 4 and 5 in each case an example of a cutting roll.
FIG. 6 a frustum-shaped cutting roll with one-sided mounting on the circumferential wall of a cutting wheel shown in fragmentary form, the bottom the bore hole being shown in the upper part of the drawing.
FIG. 7 an axial section through a comparable cutting roll to that of FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a trench wall cutter 10. It comprises a cutting frame 1, which is suspended by means of a cable line 2 on a cantilever arm 3 of a carrier means 4 equipped with a crawler chassis. Cutting frame 1 carries oppositely rotating cutting wheels 5, 6 and 7, 8 arranged in pairwise manner. In FIG. 1 the cutting wheels are oriented in the plane of the drawing, i.e. in each case one cutting wheel of each pair is concealed by another cutting wheel. The opposite rotation is indicated by arrow 9.
A trench is made in that the cutting frame 1 is vertically lowered, accompanied by the continuous rotation of cutting wheels 5 to 8, the advance being produced by the weight of the cutting wheels 5 to 8 and the cutting frame 1. The loosened soil is transported inwards by the cutting wheels 5 to 8 to a suction means 11, where it is sucked off with a supporting liquid by means of a hose line 12.
FIG. 2 makes it clear that the cutting wheels are equipped over the circumference of their hubs 13 with rolling tools 14 and brushes 15. The tools 14 in each case comprise cutting rolls 16, which are mounted in rotary manner in fork-like mounting supports 17. The rotation axis or spindle of the cutting roll 16 is substantially parallel to the rotation axes or spindles 18 of cutting wheels 5 to 8.
During sinking, as a result of the rotation of cutting wheels 5 to 8, tools 14 temporarily engage with the bottom of the bore hole in the vicinity of the semicircle located in the advance direction. As a result of the applied load G, as well as the torque M acting on the cutting wheels 5 to 8, the soil is loosened. The crushed material is conveyed inwards by brushes 15 to the suction means 11. In place of brushes 15, it would also be possible to use other means, e.g. ribs or the like for the lateral transporting away of the bored material.
Further brushes 19 are arranged in fixed manner on the cutting frame 1 in such a way that during the rotation of wheels 5 to 8, the tools 14 necessarily come into engagement therewith, so that any soil adhering thereto is removed.
FIG. 3 clearly shows the pairwise arrangement of the cutting wheels with particular reference to the pair comprising wheels 5,6. The following description applies accordingly to the two other cutting wheels 7,8. The cutting wheels 5,6 are mounted coaxially on a bearing bracket 20, via which the drive is also introduced into wheels 5,6.
In the represented embodiment, the cutting rolls 16 are staggered in several rows running in the circumferential direction of the cutting wheels 5,6. Between them are located the brushes 15, which if possible are also staggered. On the edges of the cutting wheels 5,6 adjacent to the bearing bracket 20 are pivotably articulated the mounting supports 17' of the cutting rolls 16' in the direction of arrow 22, so that they can flap in laterally and in the advance direction upstream of the bearing bracket 20. In this pivoted down position indicated at 23, the particular cutting rolls 16' act on the rock 24 located between the two cutting wheels 5,6 and prevent the formation of a ridge. The pivot axis of the mounting supports 17' is directed substantially tangentially to the wheels 5,6.
Pivoting in can be initiated on the one hand automatically as a result of the resistance offered by the bottom 21 of the bore to the cutting rolls 16', or on the other hand by a forced control (not shown). The pivoting back takes place by means of a not shown control ledge constructed on the bearing bracket 20 and with which the cutting rolls 16' engage.
FIG. 4 shows a cutting roll constructed as a single-ring roll 26. It comprises a substantially cylindrical body 27 with journals 28 and a ring tooth 29.
FIG. 5 shows a cutting roll 16 constructed as a two-ring roll 30, whose body 27 carries two stud or button-like ring teeth 31.
If it proves advantageous and necessary for the rock to be worked, it is also possible to fit more than two ring teeth, which may be constructed either smooth or provided with studs, teeth and the like. The individual ring teeth can also have different external diameters and cross-sections.
FIG. 6 is a side view of a cutting roll 40, which is substantially frustum-shaped notably the roll has a frusto-conical surface 60. This cutting roll 40 is so positioned with respect to the axis of the cutting wheel 5 by inclining its rotation axis or spindle 43 by an angle ∝, that the cutting line defined by surface 60 at the top in the drawing is roughly parallel to the rotation axis of the cutting wheel 5 with respect to the bottom of the bore 21. Apart from this parallelism, it is particularly important that the right-hand upper, projecting area 50 has a small, axial projection over the outer face 48 of a corresponding bearing block and the outer face 68 of the cutting wheel. As a result of this projecting area 50, it is ensured that there is "free-cutting" of the cutting wheels during sinking.
The cutting roll 40, which is frustum-shaped or approximately trapezoidal in section, is mounted in rotary manner on a bearing block 42. The inclination of the rotation axis 43 and the arrangement of the circumferential surface of the frustum jacket are such that the cutting face 60 is roughly parallel to the axis of the cutting wheel 5. In this circumferential surface of the frustum jacket are provided first and second rim portions 69 each with circumferentially disposed breaking tools in the form of hemispherical studs 46 or 47 made from hard metal. Hard metal tips or spikes 51 are provided between them on the frusto-conical surface 60. These breaking tools 46 and 51 are designed to permit easy replacement.
These breaking tools 46,51 are normally arranged in circular, but reciprocally displaced manner over the circumference.
It is particularly noteworthy that stud 47, which comes into engagement with the soil 36 in corner area 37 permits an almost rectangular bore and as a result of the projecting area 50 prevents any rubbing of the cutting wheels with respect to the soil 36.
As a result of the frustum-shaped design of the cutting roll, it is appropriate to provide a groove-like recess 52 in the circumferential surface 67 of the cutting wheel 5 and this is roughly complimentary to the outer circumference of studs 47 in corner area 69.
Cutting roll 40 is mounted in the vicinity of its side 41 by means of an approximately triangular bearing block 42, whilst the opposite side 44 is so-to-speak kept free.
As FIG. 6 only shows a cutting wheel 5 is fragmentary manner, it is pointed out that a homologous addition to the left is necessary, in order to be able to conceive the complete function of a cutting wheel. The then facing cutting rolls 40 are then staggered over the circumference and on both outer faces of the cutting wheel the projecting area 50 can be present.
FIG. 7 is a sectional representation of an embodiment of a cutting roll 40 according to FIG. 6 further illustrating the mounting thereof. The cutting roll 40 comprises an outer roll jacket 55, which is rotatable by means of roller bearings 62 and a central ball bearing 64 on an inner jacket 56. A frustum-shaped cone or taper sleeve 57 engages with press fit in said inner jacket 56. The taper sleeve 57 is fixed by means of a screw 58 in FIG. 7 to the bearing block 42. The thread of the front region of the screw 58 engages in the inner jacket 56. The remaining reference numerals correspond to the embodiment of FIG. 6.
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In particular for the production of trenches in medium hard to hard rock, the cutting wheels of the trench wall cutter are equipped with rolling tools, whose cutting faces are parallel to the bore axis. The cleaning of the bottom of the bore and the transportation of the material to the suction point preferably takes place with the aid of brushes. Further brushes arranged on the cutting frame are used for cleaning the tools.
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FIELD OF THE INVENTION
The invention relates to a refrigerating cabinet, and more particularly, to an arrangement of a condenser tube in a refrigerator of a refrigerating cabinet.
In the refrigerator of a refrigerating cabinet, a refrigerant is converted into an overhead, high pressure gas by means of a compressor and fed into a condenser where it is cooled down and liquidified. Subsequently, the pressure is reduced in a capillary tube to be supplied to an evaporator which is located within the cabinet. The condenser normally comprises a sufficient length of tube which is required for the cooling and liquefaction of the overheated gas. This condenser tube is disposed in a serpentine form with a suitable spacing between adjacent lengths on the outside of the rear plate of an external casing for the cabinet, and thus remains exposed to the atmosphere. When the condenser tube is exposed to the exterior, it is necessary to provide a suitable clearance between the condenser tube and the wall surface of a room in which the cabinet is located in order to dissipate heat produced by the tube. This disadvantageously increases the area or the space required for the installation of a refrigerating cabinet. In addition, the condenser tube may be subject to a breakage or a bending during the time the cabinet is being shipped or installed.
DESCRIPTION OF THE PRIOR ART
In order to overcome the described disadvantages, U.S. Pat. No. 2,484,310 issued Oct. 11, 1949 to Lawrence A. Philipp discloses a refrigerating cabinet having a double-walled box including an external and an internal casing wherein a condenser tube is disposed inside and in contact with the rear plate of the external casing in order to dissipate the heat from the tube to the external atmosphere through the rear plate. This eliminates the condenser tube from the back of the refrigerating cabinet, reducing the space required for its provision at least by an amount corresponding to the clearance which has been heretofore required between the condenser tube and the rear plate, and also preventing any likelihood of damage to the tube. However, because the condenser tube is disposed in the region of the rear plate in a concentrated manner with this construction, it is possible that part of the heat produced by the tube may leak to the internal casing through a heat insulating material. To accommodate for this, there must be provided an increased spacing between the rear plate of the external casing and its facing well, namely, the wall of the internal casing, and also the thickness of the layer of heat insulating material must be increased. As a result, when compared with a refrigerating cabinet of the type in which the condenser tube is externally exposed and which has the same volume, the refrigerating cabinet disclosed in the patent has a reduced internal volume. In addition, because the condenser tube must be tightly held against the rear plate, special retaining means is required, which prevents a difficulty in the assembly of the casing.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a refrigerating cabinet having a double-walled box formed by an external and an internal casing and in which a major portion of a condenser tube having an increased length is disposed so that the heat from the tube may be dissipated by diffusion to the exterior through the external casing.
It is another object of the invention to provide a refrigerating cabinet of the type described in which the condenser tube can be held in place by retainers which are simply formed by folding part of the external casing, without requiring the use of a special retaining means.
In accordance with the invention there is provided a refrigerating cabinet comprising a metallic external casing including a front wall, a rear wall, a left- and a right-hand sidewall, a top wall and a bottom wall with an opening formed in the front wall, an internal casing fitted into the external casing and having a plurality of walls which are disposed in opposing relationship with the rear wall, the left- and the right-hand sidewall, the top wall and the bottom wall of the external casing with suitable clearances therebetween, a pack of a heat insulating material filling the space created between the external and the internal casing, a compressor disposed on the outside of the external casing, an evaporator disposed within the internal casing, and a condenser unit including a condenser tube for cooling down and reducing the pressure of a refrigerant from the compressor before it is fed to the evaporator, the condenser tube extending from the compressor to the evaporator by-passing a space created between the external and the internal casing, the condenser tube passing through the space along the inside of a plurality of corners defined by selected adjoining walls of the external casing.
In the refrigerating cabinet according to the invention, a condenser tube extends from a compressor initially along the inside of a corner defined by the rear plate and the bottomplate of an external casing and then along the inside of another corner defined by one of sideplates of the external casing and the bottomplate so as to reach the front face of the external casing. From the front face of the external casing, the condenser tube extends upwardly along the inside of a corner defined by the front face of the external casing and said one sideplate and then extends to the other sideplate along the inside of a corner formed by the top plate of the external casing and the front face. The condenser tube then extends from the other sideplate downwardly along the inside of a corner defined by the front face and the other sideplate until the bottomplate is reached where it then extends toward the rear plate along the inside of a corner defined by the bottomplate and the other sideplate. After extending along corners defined by the rear plate, the sideplates and the top plate, the condenser tube is connected with an evaporator. Vertical runs of the condenser tube are firmly held by condenser retainers which are formed integrally with the opposite ends of the sideplates by a simple folding operation, so that the heat from the condenser tube can be transmitted through the retainers to the sideplates and then to the external atmosphere. By disposing the condenser tube within the external casing, the rear surface of the refrigerating cabinet remains flat, reducing the space are area required for its installation. Since the condenser tube extends along the corners of the external casing which are located remote from the internal casing, and since it is not disposed on a concentrated manner on one surface thereof, the heat transfer from the condenser tube to the internal casing can be reduced to a negligibly small value.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal section of a refrigerating cabinet according to one embodiment of the invention;
FIG. 2 is a perspective view of the cabinet, illustrating the disposition of the condenser tube;
FIG. 3 is a transverse section taken along the line 3--3 shown in FIG. 1;
FIG. 4 is an enlarged cross section of a junction between the sideplate and the rear plate;
FIG. 5 is an enlarged cross section of a junction defined by the front face of the external casing and the front face of the internal casing; and
FIG. 6 is a perspective view showing another disposition of the condenser tube.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIGS. 1 to 5, there is shown one embodiment of the invention. The refrigerating cabinet of this embodiment includes a metallic external casing which is generally indicated by a reference numeral 11. The external casing includes a left- and a right-hand sideplate 12, 13, a bottomplate 14, a rear plate 15 and a top plate 16. It should be noted that the front side of the external casing, namely, the left-hand side as viewed in FIG. 1 or the lower side as viewed in FIG. 3, is open. A partitioning plate 19 is disposed in the lower corner of the external casing which is defined by the sideplates 12, 13, the bottomplate 14 and the rear plate 15 in order to define a machine room 18 in which a compressor 17 or the like is contained. The front ends of sideplates 12, 13 are formed with front flanges 20, 21 which are folded at right angles to the respective sideplates. The front end of the bottomplate 14 is also formed with an upright, front flange 22 which is also bent at right angles to the bottomplate. A strip-shaped upper front flanges 23 extends across the upper ends of the front flanges 20, 21. An internal casing 25 which has an open front side is fitted into the external casing 11. The internal casing 25 includes a left- and a right-hand sideplate 26, 27, a bottomplate 28, a rear plate 29, a top plate 30 and a stepped plate 31, all of which are formed of a metal or synthetic resin material and which are disposed at suitable spacings from the sideplates 12, 13, the bottomplate 14, the rear plate 15, the top plate 16 and the partitioning plate 19 of the external casing 11, respectively. An evaporator 32 is mounted on the underside of the top plate 30 of the internal casing 25. The left- and right-hand sideplate 26, 27 and the rear plate 29 are integrally formed with a plurality of ledges 33 which are used in fixing shelf plates (not shown) thereon. Around its full periphery, the front edge of the internal casing 25 which defines its front opening is folded outwardly at right angles so as to be aligned with the individual flanges 20, 21, 22 and 23 of the external casing 11, thus defining a front flange 34 of the refrigerating cabinet.
As shown in detail in FIG. 2, a condenser tube 35 is disposed between the external and the internal casing 11, 21 so as to extend along the inside of the corners of the external casing 11. The purpose of the condenser tube is to cool down a refrigerant such as ammonia or freon gas which is compressed by the compressor 17 into an overheated, high pressure gas. Specifically, one end of the condenser tube 35 is connected to the compressor 17. It includes a plurality of runs including a first run 36 extending to the right (as viewed in FIG. 2) along the inside of a corner defined by the bottomplate 14 and the rear plate 15, a second run 37 extending forwardly along the inside of a corner defined by the right-hand sideplate 13 and the bottomplate 14 and contiguous with the first run 36, a third run 38 contiguous with the second run and extending upwardly along the inside of a corner defined by the right-hand sideplate 13 and the front flange 21, a fourth run 39 contiguous with the third run and extending to the left along the inside of a corner defined by the top plate 16 and the upper front flange 23, a fifth run 40 contiguous with the fourth run and extending downwardly along the inside of a corner defined by the left-hand sideplate 12 and the front flange 20, a sixth run 41 contiguous with the fifth run and extending rearwardly along the inside of a corner defined by the left-hand sideplate 12 and the bottomplate 14, a seventh run 42 contiguous with the sixth run 41 and extending upwardly along the inside of a corner defined by the left-hand sideplate 12 and the rear plate 15, and an eighth run 43 contiguous with the seventh run and extending to the right along the inside of a corner defined by the rear plate 15 and the top plate 16 and a ninth run 44 contiguous with the eighth run 43 and extending downwardly along the inside of a corner defined by the right-hand sideplate 13 and the rear plate 15. The other end of the ninth run 44 is connected to a capillary tube 46 which serves reducing the pressure through a strainer 45. After its pressure is reduced by the capillary tube 46, the refrigerant is fed to the evaporator 32. The evaporator supplies the refrigerant through a piping 47 to the compressor 17 where it is compressed and fed into the condenser tube 35 again.
Referring to FIGS. 1 and 3 to 5, the assembly of the external and the internal casing 11, 25 and the manner of fixing the condenser tube 35 in place will now be described. Referring to FIG. 5, it will be noted that the left-hand front flange 22 of the external casing 11 has its end folded back inwardly and then again folded back outwardly to define a retainer 51 which is substantially U-shaped in horizontal section. The retainer 51 has a bottom 52 which receives the fifth run 40 of the condenser tube 35 in tight engagement therewith. It is to be noted that the spacing between the oppositely located limbs of the U-shaped retainer 51 is less than the thickness of the flange 34 of the internal casing 25, so that when the flange 34 is inserted into the clearance therebetween, it is a tight fit therein. The right-hand front flange 21 of the external casing 11 is similarly formed with another retainer 51 having a bottom 52 which receives the third run 38 of the condenser tube 35 in tight engagement therewith. The flange 34 on the right-hand side 27 of the internal casing 25 is inserted into the oppositely located limbs of the retainer. Referring to FIG. 4, the left-hand sideplate 12 of the external casing 11 has its rear end initially folded inwardly with an internal diameter substantially corresponding to the outer diameter of the condenser tube 35 to define a condenser retainer 53 in which to hold the seventh run 42 therein, and then folded back outwardly to define a rear plate retainer 54 which is substantially U-shaped in horizontal section. It is to be noted that the rear plate retainer 54 is formed with a step 55 therein which extends toward the condenser tube 35 and hence has an increased width in the deep end thereof than in the entrance thereof. The right-hand sideplate 13 of the external casing 11 is similarly formed with a condenser retainer 53, a rear plate retainer 54 and a step 55. The condenser retainer 53 holds the ninth run 44 of the condenser tube 35 in tight engagement therewith. Along its opposite lateral sides, the rear plate 15 is formed with folded pieces 56 which are inserted into the left- and right-hand rear plate retainers 54, with a barb 57 formed on each folded piece 56 to engage the step 55 to prevent an unintended withdrawal of the rear plate 15 from the retainers 54. It will be appreciated that the opposite ends of the lower front flange 22 formed on the bottomplate 14 of the external casing 11 are similarly formed with inwardly extending retainers 58 which are substantially U-shaped in vertical section to receiver the flange 34 on the bottomplate 28 of the internal casing 25 therein. When the external and the internal casings 11, 25 are assembled together in this manner, a foamed, heat insulating material 59 such as liquid urethane may be injected into the clearance between the both casings to define a heat insulating layer.
It will be understood from the foregoing description that the third, the fifth, the seventh and the ninth runs 38, 40, 42 and 44 of the condenser tube 35 are firmly held in tight engagement with the external casing 11 by the retainers 51, 53 which are formed integrally with the sideplates 11, 12. Consequently, the heat from the refrigerant produced in these regions 38, 40, 42, 44 of the condenser tube 35 can be transferred to the entire external casing 11 through these retainers and then dissipated to the external atmosphere. It is to be noted that the second, the fourth, the sixth and the eighth runs 37, 39, 41 and 43 of the condenser tube 35 communicate with the third, the fifth, the seventh and the ninth runs 38, 40, 42 and 44, respectively, through notches (not shown) formed in the upper and lower ends of the respective condenser tube retainers. It will also be noted that the first, the second, the fourth, the sixth and the eighth runs 36, 37, 39, 41 and 43 of the condenser tube 35 are not positively carried by the retainers as mentioned above while partly contacting the external casing 11. However, it is recognized that the contact between the condenser tube 35 and the external casing is sufficient to provide a heat dissipating effect. Nevertheless, it is possible to provide a wrapping of a heat insulating tape around these regions, as indicated at 60 for the second run 37 in FIG. 2, to prevent a flow of heat from these regions to the internal casing 25.
When the condenser tube 35 is disposed to extend along the individual corners of the external casing 11 as mentioned above, the spacing between the condenser tube 35 and the internal casing 25 can be increased, thus presenting an increased resistance to the flow of heat from the condenser tube 35 to the internal casing 25. As compared with the provisions of a serpentine condenser tube on the back side of the rear plate of the external casing, the thickness of the heat insulating material can be reduced. It is to be noted that when the refrigerant from the compressor 17 which is heated to a relatively high temperature is initially fed to the front side of the external casing 11 as in the present embodiment, such heat can be efficiently utilized to prevent condensation of moisture adjacent a door 61 which is indicated in phantom line in FIG. 1.
FIG. 6 shows a modification of the described arrangement which permits the length of the condenser tube to be increased. In this instance, a condenser tube 62 from the compressor 17 extends to and along the inside of a corner defined by one of the sideplates and the rear plate, then along the inside of a corner defined by the top plate and the rear plate, along the inside of another corner defined by the top plate and the other sideplate until it reaches the front side of the external casing where it passes along the inside of all of four corners formed on the front side of the external casing. The condenser tube 62 then extends along the inside of a corner defined by the top plate and the other sideplate, and along the inside of a corner defined by the rear plate and the other sideplate for connection with a strainer 45. It will be noted that the resulting arrangement is greater in length than the piping system of FIG. 2 by a length which corresponds to one side of the front of the external casing, thus enhancing the cooling effect upon the refrigerant passing through the condenser tube. In this embodiment, the condenser tube extends along the inside of the corner defined by the top plate and the other sideplate once in one direction and another time in the opposite direction. However, a local heating of this corner cannot occur since the refrigerant is considerably cooled down after it has passed along the four front corners of the external casing.
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A refrigerating cabinet comprises a metallic external casing including a front wall, a rear wall, a left- and a right-hand sidewall, a top wall and a bottom wall with an opening formed in the front wall, an internal casing fitted into the external casing and having a plurality of walls which are disposed in opposing relationship with the individual walls of the external casing with suitable clearances therebetween, a pack of a heat insulating material filling the space created between the external and the internal casing, and a condenser tube for cooling down a refrigerant from a compressor before it is fed to pressure reduction means. The condenser tube extends from the compressor to the pressure reduction means by passing through the space between the external and the internal casing, and is disposed along the inside of selected corners each defined by adjoining two walls of the external casing.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims from the benefit of U.S. Provisional Application Ser. No. 61/897,360, entitled “Automated Authentic Listening Passage Selection System for the Language Proficiency Test,” filed Oct. 30, 2013, the entirety of which is hereby incorporated by reference.
FIELD
[0002] This disclosure is related generally to automated information retrieval and more particularly to automated retrieval and selection of media appropriate for developing test items.
BACKGROUND
[0003] Developing test items, such as those for reading and listening proficiency tests, may be labor-intensive and time-intensive. Test developers often spend hours browsing for examples online to get inspiration for new test items, as real-life examples could help developers diversify the genre or topic of test items and make the language used sound more natural. Typically, test developers query for audios and videos using conventional search engines (e.g., Google.com), review the search results, and select examples as seed materials for developing new test items. The process of reviewing search results is especially time consuming since the results are audio and/or video clips.
SUMMARY
[0004] Test designers looking for test ideas often search online for audio/video materials. Unfortunately, they often have to spend considerable time sifting through materials that are unsuitable or inappropriate for test-item development. To minimize the time wasted, this invention describes a system, apparatus, and method of retrieving media materials for generating test items. In one example, the system may query one or more data sources based on a search criteria for retrieving media materials, and receive candidate media materials based on the query, each of which including an audio portion. The system may obtain a transcription of the audio portion of each of the candidate media materials. The system may analyze the transcription for each candidate media material to identify characteristics of the associated candidate media material. The candidate media materials may be filtered based on the identified characteristics to derive a subset of the candidate media materials. A report may then be generated for the user identifying one or more of the candidate media materials in the subset. Exemplary systems comprising a processing system and a memory for carrying out the method are also described. Exemplary non-transitory computer readable media having instructions adapted to cause a processing system to execute the method are also described.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a block diagram depicting an embodiment of an audio/video retrieval system.
[0006] FIG. 2 is a flow diagram depicting an implementation of an audio/video retrieval system.
[0007] FIG. 3 is a flow diagram depicting an implementation of an audio-quality filter module for filtering retrieved audio/video materials.
[0008] FIG. 4 is a flow diagram depicting an implementation of a transcription-quality filter module for filtering retrieved audio/video materials.
[0009] FIG. 5 is a flow diagram depicting an implementation of a topic filter module for filtering retrieved audio/video materials.
[0010] FIG. 6 is a flow diagram depicting an implementation of a text-type filter module for filtering retrieved audio/video materials
[0011] FIG. 7 is a flow diagram depicting an implementation of a linguistic filter module for filtering retrieved audio/video materials
[0012] FIGS. 8A , 8 B, and 8 C depict example systems for use in implementing a system for retrieving materials for test-item development.
DETAILED DESCRIPTION
[0013] The technology described herein relates to systems and methods for retrieving and selecting appropriate media materials (e.g., containing audio and/or video in addition to text) for developing test items, such as for language proficiency tests. In some implementations, the system may receive a keyword query from a user (e.g., a test developer) and use it to retrieve media materials that include speech audio. The retrieved materials may differ substantially in terms of audio quality (if they are audio or video files), vocabulary difficulty, syntactic complexity, distribution of technical terms and proper names, and/or other content and linguistic features that may influence the materials' usefulness to the user. Rather than returning all the retrieved materials to the user, the system may automatically filter out the materials with undesirable characteristics and only return a selected set that is more likely to be of use to the user. The information retrieval system described herein may therefore significantly reduce the amount of time spent by a test developer reviewing inadequate materials.
[0014] FIG. 1 shows a block diagram of an embodiment of the retrieval system. A user 100 , such as a test developer, may enter a query into a computer 110 to specify the desired characteristics of materials in which he is interested. In some implementations, the entry may include any combination of keywords and selections from predetermined options (e.g., lists of predetermined topics, text types, etc.). In some implementations, the user 100 may also specify the threshold requirements for any retrieved materials' audio/video quality, the accuracy of their transcriptions, the level of similarity between their contents and the desired content (e.g., as indicated by the user's keywords), the linguistic features of interest, and/or the like. In some implementations, the computer 110 may query one or more databases, information repositories or any source on the World Wide Web generally based on the user's 100 input and transmit it to a server 120 through a network (e.g., Internet, LAN, etc.), and the server 120 may in turn carry out the user's 100 requests. In some other implementations, the operation may be performed by the computer 110 itself, or by a distributed system.
[0015] In an exemplary implementation where the server 120 carries out the operations, the server 120 may retrieve relevant media materials (e.g., containing audio, video, and/or text) based on the user's specification (e.g., keyword entry or selection). The materials may be retrieved from any source 130 , such as the World Wide Web, a specific third-party source (e.g., YouTube.com), a repository of previously collected materials hosted remotely or locally, and/or the like. The server 120 may also retrieve training materials from a repository 140 (local or remote). The training materials may be existing test items similar to what that the test developer wishes to develop, or they may be samples selected by experts. As will be described in further detail below, the retrieved materials may undergo a variety of filtering and selection operations, some of which may utilize the training materials, to identify materials that are most likely to be useful to the user 100 . The server 120 may then return the results to the user's computer 110 , which may in turn display the results to the user 100 . The user 100 may review and use the returned materials to develop new test items.
[0016] FIG. 2 depicts a flow diagram of an exemplary retrieval system for selecting appropriate materials based on a user's search criteria. The system may receive user inputs (e.g., keywords, selections, and/or the like) that specify one or more desired characteristics of a media material 200 . For example, the user may specify topics (e.g., finance, health, sports, manufacturing, purchasing, etc.) and/or text types (e.g., presentation, advertising, local announcement, journal article, etc.) of interest.
[0017] The system may generate a query based on the user input 200 and use it to retrieve relevant media materials (e.g., audio, video, and/or text) 210 . In addition to using the user input 200 , the system in some implementations may also automatically add synonyms and closely related terms as search parameters (e.g., if the user entered the keyword “film,” the system may also search for “movies”). The system may query any combination of data sources, including the World Wide Web, private networks, specific databases, etc. The retrieval may be carried out by using Application Programming Interfaces (APIs) provided by online service providers, web scraping algorithms, audio/video search engines, and/or the like. For example, in some implementations the search may be based on a comparison of the user-entered keywords to a media's title, file name, metadata, hyperlink, contextual information (e.g., the content of the webpage where the media is found), user remarks, audiovisual indexes created by the hosting service, and other indicia of content. The retrieved materials may be considered as candidates for the final set of materials presented to the user.
[0018] The retrieved media materials are then filtered based on any number and combination of characteristics associated with the materials, such as, but not limited to, audio quality, transcription quality, content relevance to the user's search criteria, appropriateness of the linguistic features used, etc. The filtering modules described in detail below provide additional examples of how some characteristics are identified and analyzed for purposes of filtering out undesirable media materials.
[0019] The audio quality of some of the retrieved candidate media materials may be unacceptably poor since the retrieval algorithm may not have taken into consideration audio quality. A material with poor audio quality may be unsuitable for use by the test developer or by the system (e.g., poor audio quality may hamper the system's ability to use speech recognition technology to transcribe the content). Therefore, in some embodiments the system may filter the retrieved materials based on audio quality 220 . FIG. 3 shows an example of an audio quality filter module 300 . The module may use any combination of audio metrics to extract features from each audio/video material 310 and determine whether to filter out the material based on those features. One exemplary audio metric is based on energy distributions and spectrum characteristics of audio/video materials 320 . Since intelligible human speech is roughly between the frequency spectrum of 300 Hz and 3.4 kHz, the metric 320 may extract a material's acoustic spectral energy distribution to determine whether human speech (the sound within the speech spectrum) is sufficiently detectable. In some implementations, Mel-Frequency Cepstrum (MFC) may be used to represent the material's audio as a sequence of cepstral vectors. As will be described in more detail below (e.g., with respect to 350 ), in some implementations the cepstral vectors may be used as features in a statistical model for determining the sufficiency of audio quality.
[0020] Another audio feature that may be used for assessing audio quality is based on jitter measurements (i.e., irregularities/deviations in pitch periods), which is undesirable if excessive. Any conventional method for extracting jitter information from audio may be used. For example, the speech analysis software, PRAAT (developed by the University of Amsterdam), may be used to measure jitter information 330 from each of the audio/video materials 310 . In some implementations, local frame-to-frame jitter may be measured, which in general is the average absolute difference between consecutive periods, divided by the average period. The jitter measurement may, in some implementations, be used as a feature in the statistical model for determining sufficiency of audio quality (e.g., at 350 ).
[0021] In addition to the above, any other conventionally known measures of audio or speech features may be employed. For example, the pitch contour 340 of each audio/video material 310 may be measured. In some implementations, the pitch contour may be compared to sample human pitch contours in the target language of the test items (e.g., English, Spanish, etc.). A similarity measure may be calculated based on, e.g., the root-mean-square deviations between the measured pitch contour and the sample pitch contours. The similarity measure of the pitch contours may also be used as a feature in the statistical model for assessing audio quality 350 .
[0022] As another example, estimations of the signal-to-noise ratio 345 of each audio/video material 310 may be used. In situations where separate measurements of the “signal” and the “noise” for the audio/video materials are unavailable, the signal-to-noise ratio of the materials may be estimated based on assumptions about signal behavior and noise behavior. For example, the NIST STNR utility (National Institute of Standards and Technology Signal-to-Noise Ratio), developed by Columbia University, and the WADA method (Waveform Amplitude Distribution Analysis), developed by Carnegie Mellon University, may be used to estimate the signal-to-noise ratio of the audio/video materials. The estimated signal-to-noise ratio may again be used as a feature in the statistical model 350 .
[0023] The audio feature measurements (e.g., 320 , 330 , 340 , 345 ) for each audio/video material 310 may be input into a statistical model 350 to determine whether the material 310 should be filtered out or kept as a candidate for further analysis. In some implementations, the statistical model may be trained using training audio/video materials of known quality (e.g., as determined by human reviewers). For example, a model may be represented by a linear combination of weighted audio feature measurements (i.e., the independent variables) that predicts a value representing audio quality (i.e., the dependent variable). During training, the known quality of each training material, which may be represented numerically, would replace the dependent variable of the model, and the training material's audio feature measurements (e.g., obtained using the aforementioned audio metrics) would replace the independent variables. The goal of the training is to find weights for the independent variables that would optimize the predictability of the dependent variable. Regression analysis or any other model-training processes known to one of ordinary skill in the art may be used to determine the proper weights for the independent variables in the model. Once the model has been trained, the audio feature measurements of an audio/video material may be input into the model to obtain an audio quality score 350 . Based on the score, the audio/video material may be retained as a candidate or filtered out 360 . For example, if a audio quality score fails to meet a predetermined threshold, then the corresponding audio/video material may be filtered out of the group of candidate materials. The predetermined threshold may be based on empirical observations or be specified by the user.
[0024] Rather than training and using a model to analyze the audio measurements (e.g., at 350 ), an assessment of audio quality may be performed by directly comparing the audio measurements (e.g., 320 , 330 , 340 , 345 ) to benchmark characteristics or values. Based on the comparison of the audio measurements to their respective benchmarks, the corresponding audio/video material may be retained or discarded. For example, in some implementations a material may be discarded for having any substandard audio measurement (e.g., a material may be filtered out if its estimated signal-to-noise ratio fail to meet a predetermined threshold).
[0025] Referring again to FIG. 2 , the audio portions of the candidate materials may be transcribed 230 using automated speech recognition technology (ASR), well known in the art. Alternatively, the system may attempt to retrieve existing transcriptions of the materials. For example, the candidate materials may have been previously transcribed by the retrieval system (e.g., by using ASR or by human). In some cases, the data source from where the materials was retrieved may also provide transcriptions (e.g., using YouTube's API to automatically obtain transcriptions). The transcriptions enable text-based analysis tools to be used to assess the contents of the retrieved materials.
[0026] In some implementations, an initial screening of the transcriptions may be used to filter out unsuitable materials 240 . FIG. 4 provides an example of a transcription-quality filter module 400 where filtering is based on a transcription's quality and/or inclusion of inappropriate terms. The Transcription-Correctness Filter 410 aims to filter out audio/video materials whose corresponding transcriptions contain excessive ASR-generated transcription errors. The approach taken by the Transcription-Correctness Filter 410 may depend on whether an audio/video material has an existing transcription (e.g., downloaded along with the material itself) or if a new transcription has to be generated using ASR technology 415 . If a material has an existing transcription, a conventionally-known transcription quality metric may be used to assess how well the existing transcription matches the associated audio. For example, a speech-text alignment metric may be used to generate a score to represent the degree of alignment between the speech audio and transcription text. Based on the alignment score, the corresponding audio/video material may be removed or retained 430 . For example, transcriptions with an alignment score below a predetermined threshold may warrant the removal of the corresponding audio/video material. The threshold may be empirically determined by human.
[0027] In cases where no existing transcription is available, the accuracy of an ASR-generated transcription may be scrutinized by using any confidence measure (CM) algorithm 440 , such as the normalized acoustic score and N-best based confidence score, as described in L. Chase, “Word and Acoustic Confidence Annotation for Large Vocabulary Speech Recognition” (1997) and T. J. Hazen et. al, “Recognition Confidence Scoring and Its Use in Speech Understanding Systems” (2002), both of which are expressly incorporated by reference herein. Depending on the CM, the corresponding candidate material may be filtered out or retained 445 . For example, if the CM of an ASR-generated transcription fails to meet a predetermined threshold (e.g., the CM is too low), then the corresponding material may be filtered out from the candidate group.
[0028] The candidate materials may also be scrutinized for including excessive undesirable/inappropriate terms. FIG. 4 depicts an exemplary Language Model Filter 450 that identifies transcriptions with unnatural word sequences (which may be caused by speech recognition errors), overly specialized terms/jargons targeted at specific audiences, expressions lacking elaboration. In some implementations, the system may generate a language model for each material's transcription 460 . For example, the language model may be based on n-grams (e.g., of words, phonemes, syllables, etc.). The language model may then be compared to one or more representative language models of native speakers 470 (e.g., English, Spanish, etc., depending on the target language of interest) to estimate how natural the underlying language is. In some implementations, the representative language models may be pre-existing language models such as Google N-grams, Gigawords N-gram, and/or the like. Alternatively, the representative language model may also be built using pre-existing corpora such as the LDC corpora. The comparison of the language models may be performed by any conventional model-comparison algorithms, such by calculating the cross entropy between a generated language model for a material and the representative language model. In some implementations, the comparison may output a similarity measure 480 . In implementations where the similarity measure is derived from cross entropy calculations, a small entropy may indicate that the generated language model is predictable (in light of the representative language model) and therefore more “natural” and desirable. Conversely, a large cross entropy may indicate, e.g., that the audio/video material includes unnatural or overly specialized language, and therefore may be unsuitable to be used for developing test-items. Based on a similarity measures, a corresponding audio/video material may be filtered out or retained 490 . For example, if the similarity measure fails to meet a predetermined threshold, the corresponding audio/video material may be filtered out; conversely, if the similarity measure satisfies a predetermined threshold, the corresponding material may be retained for further consideration. The similarity threshold may be determined by, e.g., generating language models for training materials of known quality (e.g., obtained from pre-existing test items or selected by experts) and calculating the similarity measures between them and the representative language model. In some implementations, the similarity measures of the training material may be averaged, and that average measure may be used as the predetermined similarity threshold. In some other implementations, rather than using a predetermined threshold as the cut-off, the similarity scores of the candidate materials may be ranked, and the n materials with the best similarity scores may be retained and the rest filtered out.
[0029] In addition to filtering based on audio quality and transcription quality, the content of the materials may be compared against the user-entered search criteria to identify materials with the best match. In some implementations, the system may first parse the user's search criteria (e.g., from step 200 ) and determine whether the user has specified a desired topic or text type 250 . For example, the words in the user's search criteria may be classified by comparing them to a collection of topic labels and a collection of text-type words. Alternatively, the system's user interface may allow the user to enter keywords or make selections in separate topic and text-type forms. Based on the classification of the user's search criteria, an appropriate filter module may be invoked. For example, if the search criteria specify a topic, a topic filter module 260 may be invoked to identify audio/video materials that are sufficiently similar to the user-specified topic.
[0030] FIG. 5 depicts an exemplary flow diagram for a topic filter module 500 . In some implementations, the system may analyze each audio/video material's transcription to determine a set of relevant topic labels 510 . This may be performed by any topic modeling or topic classification algorithms known to one of ordinary skill in the art. For example, generative modeling, such as Latent Dirichlet Allocation (LDA), or topic modeling toolkits, such as Gensim, may be used to automatically and statistically identity potential topics for each transcription. As another example, a set of topics may be predetermined, and conventional clustering and/or classification algorithms may be used to determine in which of the set of predetermined topics a transcription belongs (e.g., based on a training set of transcriptions whose topic categorization is known). Then, the identified topic labels may be compared with the user-specified topic keyword(s) to calculate a similarity measure 520 , which represents the topic similarity between the corresponding audio/video material and the topic(s) specified by the user. Any conventional semantic similarity measure may be used, such as latent semantic analysis (LSA), generalized latent semantic analysis (GLSA), pointwise mutual information (PMI), and/or the like. In another example, the similarity between topic labels may be determined based on their relationship within a lexical database, such as WordNet, developed by Princeton University. Any conventional similarity algorithms utilizing such lexical database may be used. For example, a similarity algorithm may locate the topic labels within WordNet's hierarchical word structure and count the number of edges (distance) between them and calculate a similarity score accordingly (e.g., shorter distances may indicate higher degrees of similarity, and longer distances may indicate higher degrees of dissimilarity). Based on the similarity measure 520 , the corresponding audio/video material may be removed or retained accordingly 530 . For example, if the similarity measure exceeds a predetermined threshold, which indicates that the topic labels derived from the transcription of the audio/video material are sufficiently similar to the user-specified topic(s), then the audio/video material may continue to be a candidate material. On the other hand, if the similarity measure does not meet a minimum threshold, then the corresponding audio/video material may be filtered out from the candidate materials. The appropriate threshold may be determined from empirical observations.
[0031] Referring again to FIG. 2 , if the user-specified criteria indicates a desired text type, a text-type filter module 270 may be invoked. FIG. 6 illustrates an exemplary flow diagram for a text-type filter module 600 that utilizes one or both of a classification algorithm and a clustering algorithm. Supervised text classification algorithms may be used to identify materials that match the user-specified text type. In some implementations, the system may retrieve a collection of training materials that have been manually labeled/classified by text-type 610 . The training materials may be separated into two categories: those having text types matching the user-specified text type (referred to as the target group) and those that do not (referred to as the garbage group) 620 . In some implementations, the matching algorithm used for comparing the user-specified text type to the training materials' text types may be based on word distances within WordNet, as described above. In some other implementations where the scope of possible text types is limited by the user interface (e.g., the user can only select text types from a pre-determined list), each of the available text types may have an associated set of training materials, in which case there may be no need to use a matching algorithm.
[0032] The training materials in the target group and the garbage group may be used to train a classification model for classifying a given material's transcription into either of the groups 630 . In some implementations, the classification model may use TF-IDF (Term Frequency-Inverse Document Frequency) values of words in a transcription as features for predicting whether the transcription belongs in the target or garbage group (TF-IDF is a numerical statistic that is intended to reflect how important a word is to the document). In other words, the classification model's independent variables may correspond to the TF-IDF values and the dependent variable may correspond to an indication of whether a transcription belongs in the target group or garbage group. Once the model has been trained, it can be applied to the collection of candidate materials to identify those that match the user-specified text type (i.e., those that fall into the target group) 640 . The ones matching the user-specified text type may remain a candidate, and the ones that do not (i.e., those that fall into the garbage group) may be discarded 650 .
[0033] In cases where the user's search criteria only includes a topic but not a text type, it may be desirable to return a collection of topic-relevant audio/video materials categorized by text type. For example, if the user is interested in materials relating to finance, he may be presented with categories of financial materials that are from lectures, presentations, news, etc. This may be implemented using a classification method similar to the one described above, but instead of training the classification model based on two categories (i.e., a target group and a garbage group), the training would be based on the training materials' text-type labels (e.g., lecture, conference article, journal, etc.). Thus, when the classification model is applied to a audio/video material, it would output a prediction of which text type the material would likely fall under.
[0034] The text-type filter module 600 may also use clustering algorithms to determine whether a material's text type matches the user-specified text type. For example, k-mean clustering (e.g., as implemented by Apache Mahout) and/or Expectation-Maximization algorithms may be used to automatically cluster the remaining candidate audio/video materials into groups. As known by persons of ordinary skill in the art, k-mean clustering algorithm iteratively cluster data around k closest cluster centers. In general, the algorithm is given a number k and a set of data (e.g., text documents) represented by numeric features in n dimensional space 660 . Where the data is text, the numeric features may be TF-IDF vector values, as previously mentioned. Typically, the algorithm begins by randomly selecting k cluster centers in the n dimensional space and then clustering the given data around those k cluster centers (e.g., based on the calculated distances between the data points to the centers). However, since the goal of the text-type filter module 600 is to find materials of a specific user-specified text type, in some implementations the initial k cluster centers may be explicitly set, rather than randomly selected. For example, each of the initial k cluster centers may correspond to a known text type 670 (e.g., one cluster center may be derived from a collection of lectures, another cluster center may be derived from a collection of presentations, etc.). Having provided initial cluster centers that correspond to text types, the algorithm may then cluster the transcriptions of the audio/video materials around those cluster centers 680 . The clustering algorithm may then recalculate each cluster's center based on the data clustered around it 685 , and again cluster the data around the new centers 680 . This process may iterate for a specified number of times or until the cluster centers stabilize 690 . In some implementations, the audio/video materials represented by the final cluster associated with the user-specified text type would be retained 695 .
[0035] In other implementations, the aforementioned k cluster centers may be randomly selected, and the transcriptions would be placed into k clusters according to the k-mean algorithm. After the k clusters of transcriptions have been determined, any cluster labeling algorithm may be used to pick descriptive labels for each of the clusters. In one example, cluster labeling may be based on external knowledge such as pre-categorized documents (e.g., human-assigned labels to existing test items or training documents). The process in some implementations may start by extracting linguistic features from the transcriptions in each cluster. The features may then be used to retrieve and rank n-nearest pre-categorized documents (e.g., pre-categorized documents with similar linguistic features). One of the n-nearest pre-categorized documents may be selected (e.g., the one with the best rank), and the pre-determined words (e.g., the category titles) used to describe that document may be used as the cluster label for the corresponding cluster of transcriptions. Each cluster of transcriptions may be labeled in this manner. Thereafter, the cluster labels may be compared to the user-specified text type, using any conventional semantics similarity algorithm, to identify the best-matching cluster. The final materials presented to the user may be selected from the best-matching cluster.
[0036] Referring again to FIG. 2 , the candidate materials may be further filtered based on the complexity of the language used 280 . In some implementations, complexity may be assessed based on linguistic features extracted from the transcriptions of the audio/video materials. For example, the Text Evaluator, developed by Education Testing Service, may be used to assess the linguistic complexity of the transcriptions (the associated U.S. Pat. No. 8,517,738 is hereby incorporated by reference). The scores output by the Text Evaluator may be compared to a predetermined threshold, which may be specified by the user. The audio/video materials with corresponding complexity scores failing to meet the threshold may be filtered out.
[0037] FIG. 7 illustrates an embodiment of a linguistic filter module 700 for filtering materials based on text complexity or other text characteristics. A statistical model, represented by, e.g., a linear combination of linguistic features, may be used to predict a complexity score for each transcription. To build the model, a collection of training texts with predetermined complexity levels (e.g., as determined by human reviewers) may be obtained 710 . Various linguistic features of the training texts may then be extracted from each of the training texts 720 . The linguistic features may include, but not limited to: (1) difficulty of vocabulary (e.g., based on the number of abstract nouns, ratio of academic words to content words, average frequency of words appearing in familiar word lists, and/or the like); (2) syntactic characteristics (e.g., based on the depth of parsed trees, the average sentence length, the number of long sentences, the number of dependent clauses per sentence, the number of relative clauses and/or concatenated clauses, and/or the like); (3) distribution of proper nouns, technical terms, and abbreviations; (4) level of concreteness; (5) cohesion; and/or the like. The model may then be trained using the extracted linguistic features as values for the model's independent variables and the predetermined complexity levels of the training texts as values for the dependent variable 730 . In some implementations, linear regression may be used to determine the optimal weights/coefficients for the independent variables. The set of optimal weights/coefficients may then be incorporated into the model for predicting text complexity. To use the model to assess a candidate audio/video material's transcription, the first step in some implementations may be to extract the aforementioned linguistic features from the transcription 740 , and then input the feature values into the model as the values for the independent variables 750 . The output of the model may be a numerical complexity score that represents the text complexity of the transcription 760 . If the complexity score fails to reach a predetermined threshold (e.g., which may be specified by the user), then the corresponding audio/video material may be filtered out; otherwise, the material may remain a candidate 770 .
[0038] In another implementation, candidate audio/video materials may be filtered based on the formality level of the speech therein. For example, some materials may use speech that is overly formal (e.g., in news reporting or business presentations) or overly informal (e.g., conversations at a playground or bar) for purposes of test item generation. In one implementation, a model for predicting formality level may be trained, similar to the process described above with respect to complexity levels. For example, a collection of training materials with predetermined formality levels (e.g., as labeled by human) may be retrieved, and various linguistic features of the training materials may be extracted. A model (e.g., represented by a linear combination of variables) may then be trained using the extracted linguistic features as values for the independent variables and the predetermined formality levels as values for the dependent variable. In some implementations, linear regression may be used to determine the optimal weights/coefficients for the independent variables. The set of optimal weights/coefficients may then be incorporated into the model for predicting formality levels. The model may be applied to the transcriptions (specifically, the linguistic features of the transcriptions) of the candidate audio/video materials to predict the formality level of the speech contained therein. The candidate audio/video materials may then be filtered based on the formality levels and a predetermined selection criteria (e.g., formality levels above and/or below a certain threshold may be filtered out).
[0039] In some instances it may also be desirable to filter out audio/video materials based on the level of inclusion of inappropriate words, such as offensive words or words indicating that the topic relates to religion or politics. In some implementations, a list of predetermined inappropriate words may be retrieved. Each transcript may then be analyzed to calculate the frequency in which the inappropriate words appear. Based on the frequency of inappropriate-word occurrences (e.g., as compared to a predetermined threshold), the corresponding candidate audio/video material may be filtered out.
[0040] Referring again to FIG. 2 , once filtering is complete, a report (e.g., an web page, a document, a graphical user interface, etc.) may be generated based on the remaining subset of candidate materials 290 . In some cases, the subset could be the entire set of media materials retrieved (e.g., if nothing was filtered out). In some implementations, a ranking score may be calculated for each candidate material in the subset based on, e.g., the scores it obtained from any combination of the filter modules. For example, the ranking score may be a weighted sum of the output from the audio-quality filter module ( FIG. 3 ), the transcription-quality filter module ( FIG. 4 ) the topic filter module ( FIG. 5 ), the text-type filter module ( FIG. 6 ), and/or the linguistic filter module (e.g., FIG. 7 ). The report of materials presented to the user may be generated based on the ranking scores. For example, the materials may be sorted based on their ranking scores, or only the materials with the n highest ranking scores would be presented.
[0041] As one of ordinary skill in the art would recognize, the filters described herein may be applied in any sequence and are not limited to any of the exemplary embodiments. For example, the linguistic filter module may be applied first, followed by the transcription-quality filter, followed by the audio-quality filter, and followed by the text-type filter and topic filter. In addition, one or more of the filters may be processed concurrently using parallel processing. For example, each of the filters may be processed on a separate computer/server and the end results (e.g., similarity scores, model outputs, filter recommendations, etc.) may collectively be analyzed (e.g., using a model) to determine whether a media material ought to be filtered out. Furthermore, the retrieval system may utilize a subset or all of the filters described herein.
[0042] Additional examples will now be described with regard to additional exemplary aspects of implementation of the approaches described herein. FIGS. 8A , 8 B, and 8 C depict example systems for use in implementing a retrieval system described herein. For example, FIG. 8A depicts an exemplary system 800 that includes a standalone computer architecture where a processing system 802 (e.g., one or more computer processors located in a given computer or in multiple computers that may be separate and distinct from one another) includes a retrieval engine 804 being executed on it. The processing system 802 has access to a computer-readable memory 806 in addition to one or more data stores 808 . The one or more data stores 808 may include the retrieved materials (e.g., audio, video) 810 as well as pre-annotated/labeled training data 812 .
[0043] FIG. 8B depicts a system 820 that includes a client server architecture. One or more user PCs 822 access one or more servers 824 running a retrieval engine 826 on a processing system 827 via one or more networks 828 . The one or more servers 824 may access a computer readable memory 830 as well as one or more data stores 832 . The one or more data stores 832 may contain retrieved materials 834 as well as training data 836 .
[0044] FIG. 8C shows a block diagram of exemplary hardware for a standalone computer architecture 850 , such as the architecture depicted in FIG. 8A that may be used to contain and/or implement the program instructions of system embodiments of the present invention. A bus 852 may serve as the information highway interconnecting the other illustrated components of the hardware. A processing system 854 labeled CPU (central processing unit) (e.g., one or more computer processors at a given computer or at multiple computers), may perform calculations and logic operations required to execute a program. A non-transitory processor-readable storage medium, such as read only memory (ROM) 856 and random access memory (RAM) 858 , may be in communication with the processing system 854 and may contain one or more programming instructions for performing the method of implementing a scoring model generator. Optionally, program instructions may be stored on a non-transitory computer readable storage medium such as a magnetic disk, optical disk, recordable memory device, flash memory, or other physical storage medium.
[0045] A disk controller 860 interfaces one or more optional disk drives to the system bus 852 . These disk drives may be external or internal floppy disk drives such as 862 , external or internal CD-ROM, CD-R, CD-RW or DVD drives such as 864 , or external or internal hard drives 866 . As indicated previously, these various disk drives and disk controllers are optional devices.
[0046] Each of the element managers, real-time data buffer, conveyors, file input processor, database index shared access memory loader, reference data buffer and data managers may include a software application stored in one or more of the disk drives connected to the disk controller 860 , the ROM 856 and/or the RAM 858 . Preferably, the processor 854 may access each component as required.
[0047] A display interface 868 may permit information from the bus 852 to be displayed on a display 870 in audio, graphic, or alphanumeric format. Communication with external devices may optionally occur using various communication ports 873 .
[0048] In addition to the standard computer-type components, the hardware may also include data input devices, such as a keyboard 872 , or other input device 874 , such as a microphone, remote control, pointer, mouse and/or joystick.
[0049] Additionally, the methods and systems described herein may be implemented on many different types of processing devices by program code comprising program instructions that are executable by the device processing subsystem. The software program instructions may include source code, object code, machine code, or any other stored data that is operable to cause a processing system to perform the methods and operations described herein and may be provided in any suitable language such as C, C++, JAVA, for example, or any other suitable programming language. Other implementations may also be used, however, such as firmware or even appropriately designed hardware configured to carry out the methods and systems described herein.
[0050] The systems' and methods' data (e.g., associations, mappings, data input, data output, intermediate data results, final data results, etc.) may be stored and implemented in one or more different types of computer-implemented data stores, such as different types of storage devices and programming constructs (e.g., RAM, ROM, Flash memory, flat files, databases, programming data structures, programming variables, IF-THEN (or similar type) statement constructs, etc.). It is noted that data structures describe formats for use in organizing and storing data in databases, programs, memory, or other computer-readable media for use by a computer program.
[0051] The computer components, software modules, functions, data stores and data structures described herein may be connected directly or indirectly to each other in order to allow the flow of data needed for their operations. It is also noted that a module or processor includes but is not limited to a unit of code that performs a software operation, and can be implemented for example as a subroutine unit of code, or as a software function unit of code, or as an object (as in an object-oriented paradigm), or as an applet, or in a computer script language, or as another type of computer code. The software components and/or functionality may be located on a single computer or distributed across multiple computers depending upon the situation at hand.
[0052] It should be understood that as used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein and throughout the claims that follow, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise. Further, as used in the description herein and throughout the claims that follow, the meaning of “each” does not require “each and every” unless the context clearly dictates otherwise. Finally, as used in the description herein and throughout the claims that follow, the meanings of “and” and “or” include both the conjunctive and disjunctive and may be used interchangeably unless the context expressly dictates otherwise; the phrase “exclusive or” may be used to indicate situation where only the disjunctive meaning may apply.
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Test designers looking for test ideas often search online for audio/video materials. To minimize the time wasted on irrelevant/inappropriate materials, this invention describes a system, apparatus, and method of retrieving media materials for generating test items. In one example, the system may query one or more data sources based on a search criteria for retrieving media materials, and receive candidate media materials based on the query, each of which including an audio portion. The system may obtain a transcription of the audio portion of each of the candidate media materials. The system may analyze the transcription for each candidate media material to identify associated characteristics. The candidate media materials may be filtered based on the identified characteristics to derive a subset of the candidate media materials. A report may then be generated for the user identifying one or more of the candidate media materials in the subset.
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RELATED APPLICATION
This is a continuation, of application Ser. No. 221,408 filed Jan. 27, 1972, now abandoned which is a continuation-in-part of U.S. patent application Ser. No. 885,353, filed Dec. 15, 1969, now abandoned, the benefit of the date of which is hereby claimed.
BACKGROUND OF THE INVENTION
Liquid crystalline materials have properties that are intermediate those of a true liquid and a true crystal since they have an ordered structure while also having fluidity. These materials are known and are characterized or identified by one of three phases or structures known as the smectic phase, the nematic phase, and the cholesteric phase (a special form of the nematic phase). The present invention is concerned with materials exhibiting a cholesteric liquid crystalline phase.
Compounds with the cholesteric liquid crystalline structure exhibit certain characteristics which are markedly different from those having the smectic or the nematic structures. The characteristic properties of compounds with the cholesteric liquid crystalline structure may be summarized as follows: (1) they are optically negative, in contrast to the smectic and nematic structures which are optically positive; (2) the cholesteric liquid crystalline structure is optically active and shows strong optical rotatory power; (3) when illuminated with white light, the most striking property of the compounds with the cholesteric liquid crystalline structure is that they scatter light selectively to give vivid colors. The color and intensity of the scattered light depends upon the temperature of the scattering material and upon the degree of incidence of illumination. A cholesteric material exhibits a scattering peak having a band width of about 200 angstroms that occurs in or between the infrared and ultraviolet portions of the spectrum; (4) in the cholesteric structure, one circular polar component of the incident beam is completely unaffected. For the dextro cholesteric structure, it is only the circular polarized beam with counterclockwise rotating electric vector which is reflected. (The sign of rotation refers to an observer who looks in the direction of the incident light.) Levo cholesteric structures have the reverse effect; (5) when circular polarized light is scattered from these materials, the sense of polarization is unchanged. In ordinary materials, the sense of circular polarization is reversed; (6) the mean wave length of the reflected band depends upon the angle of incidence of the beam. The relationship can be roughly approximated by the Bragg difraction equation for birefringent materials. These enumerated properties effectively define cholesteric liquid crystals.
Thin films of cholesteric liquid crystals exhibit a property upon interaction with light, which may be termed "selective scattering". The term "scattering" is used rather than "reflection" in order to distinguish from the effect occurring on mirror surfaces wherein light is reflected at an angle equal to the angle of incident light. A scattered light ray may leave the scattering material at an angle unrelated to the angle of the incident light. A selectively scattering film, when observed with light impinging the film on the same side as that which is viewed, has an apparent color which is a complement of the color of the light transmitted through the film.
The terms "light" and "color" as used herein have a broad connotation of referring to electromagnetic radiation generally, rather than to solely visible radiation.
The phenomenon of selective scattering as exhibited by cholesteric liquid crystalline films is independent of whether the light illuminating the film is polarized or not. The color and intensity of the scattered light depends upon the temperature of the scattering material and upon the angle of incidence of illumination.
Because of the thermochromic properties of cholesteric liquid crystals, films containing them are useful for detecting temperature patterns on various objects, i.e., thermography and/or themometry. This temperature pattern is manifested by an irredescent color pattern exhibited by compounds in their cholesteric liquid crystalline phase.
Compounds capable of existing in the cholesteric liquid crystalline phase exhibit thermochromic properties at temperature ranges which are unique for that compound. Therefore, the particular cholesteric liquid crystalline compound or mixtures of compounds utilized to detect a temperature pattern can be varied to result in color sensitivity at the particular temperature range being measured. At the lower temperature within the range, which can be varied from fractions of a degree to several degrees of temperature, the color exhibited is in the red end of the spectrum and at the higher temperature within the range, the color is in the violet end of the spectrum. Intermediate temperatures result in intermediate colors, e.g., green. Thus, for example, if it is desired to measure and detect the temperature pattern of a particular portion of the anatomy of a person suspected of having a blood circulatory disorder or a tumor, a composition which shows a color change at the appropriate temperature can be formulated. Furthermore, cholesteric liquid crystals have been utilized to determine faults of metal parts of machines and airplanes by non-destructive testing techniques.
Previously, it has been found that in order to more easily visualize the colors exhibited by cholesteric liquid crystals, it is advantageous to utilize a black background. However, the use of a black background gives rise to problems which make the use of cholesteric liquid crystals for detecting temperature patterns difficult and uneconomical. One problem is that the black background must be painted on in the form of a paint or a spray and then the liquid crystals must be applied to the black background so the colors can be readily observed. Because of the problems involved, the adaptability of these systems is limited. Further, these methods are disadvantageous since the oily cholesteric liquid crystals must be applied to the black background as a solution in a volatile solvent, thus causing obvious dangers. Furthermore, the removal of the background and particularly the liquid crystals themselves is difficult particularly where large areas are concerned. These methods are also disadvantageous since it is very difficult if not impossible to get a uniformly even coating of the liquid crystals upon the background, thus rendering the pattern unreliable. Furthermore, by the known methods, the re-use of the liquid crystals is, for practical purposes, impossible.
In instances wherein the black background is painted or sprayed on a plastic film prior to the application of liquid crystals, as well as wherein no plastic film is utilized, problems arise since the liquid crystals age and are unstable when exposed to the atmosphere causing partial decomposition of the compounds and loss of color intensity and either a shift in the color-temperature response or complete loss of the color-temperature response. Even in the case wherein the liquid crystals are protected from the atmosphere, e.g., minute transparent liquid walled capsules, aging and other problems arise. This is true since films formed containing these materials tend to be rough and the protected liquid crystalline material can be rubbed off, thus causing losses of color intensity and thermographic reliability. Furthermore, the thin walls of the capsules can shatter under pressure, thus exposing unprotected liquid crystals to the atmosphere.
It is more advantageous to use a film of the cholesteric liquid crystals, preferably on a flexible substrate blackened prior to the application of liquid crystals, since the utilization of a black paint or spray to serve as a background is particularly troublesome when dealing with human patients since these black paints are very difficult to apply as a uniform film, are uncomfortable on a patient and difficult to remove.
There is thus a need for a stable cholesteric liquid crystalline composition that is amenable to re-use, exhibits good color properties at desired temperature ranges, can be formed into or onto a film and is easy to apply as a uniformly thick film, is easy to remove from the thermography subject and permits the use of an easily handled black or dark background.
The problem of the prior art can be overcome to some extent by using film forming emulsions containing cholesteric liquid crystal materials. These emulsions are generally satisfactory for protecting and stabilizing the liquid crystal compositions, however, they do not prevent aging of the liquid crystals during storage.
SUMMARY OF THE INVENTION
This invention relates to stable emulsions and films formed from them which contain cholesteric liquid crystals homogeneously distributed throughout the films, processes for forming the films and the emulsions and methods for stabilizing the cholesteric liquid crystals used therein against aging by the use of antioxidants. The film-forming stable emulsions utilized in the process of this invention contain cholesteric liquid crystalline materials and an antioxidant and can be applied as a uniformly thick film to a film substrate and/or can form a self-supporting uniformly thick film. The improved emulsions containing antioxidants provide a means by which the cholesteric liquid crystals contained in them as well as the films formed from them are stabilized against aging and the effect of the atmosphere as well as mechanical abrasion.
DETAILED DESCRIPTION OF THE INVENTION
The stable emulsions used in forming the films of this invention are made from two phases, the first phase is a hydrophobic oil or organic phase, and the second phase is an aqueous phase.
The first phase contains oily cholesteric liquid crystalline materials and an antioxidant. Optionally, an oil soluble yellow dye can be included in the first phase.
The particular cholesteric liquid crystalline material or mixtures thereof as well as their proportions included in the first phase are determined by the particular temperature response required for the intended thermographic and/or thermometric use. Thus, if it is desired to have a temperature response manifested by a green color between 36° C. and 37.5° C., a homogeneous mixture of 46.0 parts of cholesteryl nonanoate, 8.0 parts cholesteryl oleyl carbonate and 6.0 parts cholesteryl chloride can be used.
The antioxidants useful in this invention are those which do not adversely affect the color-temperature response of the cholesteric liquid crystals and which also do not mask the colors. Typical suitable antioxidants are butylated hydroxytoluene (BHT), butylated hydroxy anisole (BHA), nordihydroguaiaretic acid (NDGA), 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline (EMQ), dl-α-tocopherol, tertiary butylhydroquinone (TBHQ), 1,5-dihydroxynaphthalene (1,5-DHN) or mixtures thereof. The amount and identity of antioxidant used can vary, however, preferably from about 0.2% to about 1.75% based on the weight of the cholesteric liquid crystals is suitable. The antioxidant has no particular affect on the abrasion resistance of the finally formed film but has the affect of stabilizing the temperature vs. color response as well as improvement in the brightness of the color developed by the films.
Optionally, an oil soluble yellow dye can be added to the first phase. The purpose of the dye is to enhance the intensity of the green color response. Usually, based on the weight of the cholesteric liquid crystals, about 0.04% to 0.06% of a yellow dye is used. A typical suitable yellow dye is Ext. D & C Yellow No. 11.
The first phase is formed by heating the cholesteric liquid crystalline material, antioxidant and remaining ingredients, if any, until a uniformly clear homogeneous liquid melt is obtained. Generally, the temperature at which this occurs depends upon the particular cholesteric liquid crystals or mixtures thereof which are used. The temperatures which are suitable for forming the melt are generally between about 40° C. and about 130° C.
It should be understood this invention comprehends the use of any cholesteric liquid crystalline material with thermochromic properties for forming the emulsions. Examples of typical cholesteric liquid crystalline materials which are suitable for use in this invention are mixed esters of cholesterol and inorganic acids, such as, cholesteryl chloride, cholesteryl bromide, cholesteryl nitrate, etc.; organic ester of cholesterol such as cholesteryl benzoate, cholesteryl crotonate, cholesteryl nonanoate, cholesteryl formate, cholesteryl acetate, cholesteryl propionate, cholesteryl valerate, cholesteryl hexanoate, cholesteryl-2-ethylhexanoate, cholesteryl octonoate, cholesteryl docosonoate, cholesteryl vaccenate, cholesteryl chloroformate, cholesteryl linolate, cholesteryl linolenate, cholesteryl oleate, cholesteryl erucate, cholesteryl butyrate, cholesteryl caprate, cholesteryl laurate, cholesteryl myristrate, cholesteryl clupanodonate, cholesteryl phenyl propionate, cholesteryl 2,4-dichlorobenzoate, etc.; ethers of cholesterol such as cholesteryl decyl ether, cholesteryl lauryl ether, cholesteryl dodecyl ether, etc.; carbonates and carbamates of cholesterol such as cholesteryl decyl carbonate, cholesteryl methyl carbonate, cholesteryl ethyl carbonate, cholesteryl butyl carbonate, cholesteryl docosonyl carbonate, cholesteryl cetyl carbonate, cholesteryl oleyl carbonate, cholesteryl p-n-butoxyphenyl carbonate, cholesteryl nonyl carbonate, cholesteryl 2-ethylhexyl carbonate, cholesteryl heptyl carbamates, etc.; alkyl amides and aliphatic secondary amines derived from 3-β-amino-Δ-5-cholestene, the corresponding esters noted above of cholestanol and the like.
The second phase, i.e., the aqueous phase, is comprised of film-formers. In the preferred embodiments, the aqueous phase additionally contains a plasticizer. An added plasticizer, however, is not necessary in all cases since the cholesteric liquid crystalline materials in the first hydrophobic phase can act as plasticizers, e.g., cholesteryl oleyl carbonate. The film-formers preferably are those which exhibit surface active properties. Additional preferred optional ingredients which can be used in the aqueous phase include bacteriastatic agents which are particularly needed if the emulsion is to be stored for a length period.
Suitable types of film-formers which can be used are organic, water-soluble, film-forming polymers of plant or animal origin, typical of which are the protein-type of film formers such as zein, gelatin and hydrolyzed collagen; cellulose derivatives such as ethylcellulose, methylcellulose, hydroxy propylcellulose, hydroxy ethylcellulose, sodium carboxymethylcellulose; natural products such as acacia and starches; modified starches and polymer such as polyvinyl alcohol and polyvinyl pyrrolidone.
The preferred film-formers for use in this invention are the proteins, of which gelatin if most suitable. Of the suitable gelatins, high bloom Type A gelatin is preferred.
Since the desired use of the films formed from a particular emulsion determines the required characteristics of both the emulsion and the film eventually formed from it, the film-forming components of the aqueous phase can be varied to produce the desired results. Thus, mixtures of the aforesaid film-formers can be used in required proportions, which proportions can be ascertained by simple laboratory experiments
The amount and identity of film-former utilized in the emulsions is variable but generally the total is from about 25% to about 75% by weight based on the dry weight of the finished film with about 35% to about 60% by weight preferred for most uses of the finished film.
If more than 75% of film-former by weight based on the weight of the dry film is used, then an insufficient amount of cholesteric liquid crystalline material will be in the film, resulting in poor color intensity. If less than 25% of film-former by weight is used, then there is so much cholesteric liquid crystalline material present that the resulting film becomes undesirably greasy to the feel. A greasy feel is indicative of the bleeding of cholesteric liquid crystals from the film. The presence of an excess greasy feel is, therefore, an indication of insufficient gelatin in the matrix to contain the liquid crystals homogeneously throughout the film. Hence, the film-former content in the emulsion is critical within the stated limits since an insufficient film-former content cannot prevent bleeding of the liquid crystals from the film and consequent loss of film stability and thermographic utility while an excess of film-former results in the presence of a lesser amount of liquid crystals with the consequent loss in color intensity.
The identity, amount and type of plasticizer, when used in the aqueous phase, is dependent upon the particular film properties desired. Thus, in order to obtain a flexible film, sufficient amount of a plasticizer should be used to provide on a dry weight basis about one-tenth the weight of the film-former. Howevr, in the event a cholesteric liquid crystalline material which is suitable as a plasticizer is used, no added plasticizer is needed. Generally, if a harder film is desired, no plasticizer is necessary. The amount and identity of the plasticizer will determine the flexibility of the films and this is in turn determined by the requirements of the intended use of the materials. Generally from about 0% to 7.5% by weight based on the dry film weight is suitable with about 4% preferred.
Suitable plasticizers for use in this invention are carbohydrates and polyhydric alcohols. Suitable typical carbohydrates are sugars such as sucrose, dextrose, levulose, invert sugars and sorbitol. Suitable typical polyhydric alcohols are glycols, glycerine and the like. The preferred plasticizer, when one is used in the composition of this invention, is glycerine.
Preferably, the relative proportions by weight of the cholesteric liquid crystal containing phase to the aqueous film-forming phase in the emulsion composition is about 35% to about 60% by weight of cholesteric liquid crystals to about 40% to about 65% of film-formers based on the dry weight of the finished film. These proportions can vary so long as they are within ranges which form stable emulsions and films. Generally, the most preferred emulsions contain about 50% by weight of cholesteric liquid crystals based on the dry weight of the film. The relative proportions of the film-formers and the liquid crystals in the emulsion are calculated on a dry weight basis and these proportions depend upon the end use of the composition and the methods of applying them to substrates. The relative proportions are calculated on a dry weight basis since dilution of the two phases can be made to suit convenience. The emulsion is formed by mixing to homogeniety, the aqueous solution with a homogeneous melt of the cholesteric liquid crystalline materials. Temperatures of about 40° C. to about 80° C. have been found suitable and convenient for mixing to homogeniety the components of the emulsion. There is thus formed an oil-in-water emulsion in which the cholesteric liquid crystal component is present as a distinct entity in the form of discrete particles. No chemical reaction or complexation occurs between the components of the emulsion.
These emulsions can be stored at 5° C. for periods in excess of 4 weeks without any emulsion breakdown or deterioration in the thermographic response of the crystals.
The particle sizes of the cholesteric liquid crystalline materials dispersed in the emulsion can vary, but in order to achieve a satisfactory film, particle sizes in the range of about 2 to about 10 microns are preferred because in this range the most intense colors are produced. If the particle size of the dispersed cholesteric liquid crystals is too small, the intensity of the color response is diminished and if the particle size of the cholesteric liquid crystals is too large, the emulsion is physically unstable and is not formable into a suitable film wherein the cholesteric liquid crystals are uniformly dispersed throughout (homogeneous).
The emulsion can be applied with uniform thickness to the surface of the thermography and/or thermometry subject and allowed to dry into a continuous film which is easily removable. Alternatively, the film can be formed on a non-adhering surface, e.g., Teflon, then removed and used by applying to the surface of the subject. The film can also be formed by applying the emulsion by coating by suitable means on a supportive matrix to which it will adhere such as paper, cellulose acetate or other plastic film base. After the emulsion dries as a film on the supportive matrix material, it can be cut into desired shapes or sizes prior to use and, if desired, it can be further water proofed by coating with a clear vinyl lacquer.
As previously indicated, the properties of the film or supportive matrix are modified by variations in the formulations in order to give them the properties required for a specific use. In any event, the film formed when the emulsion dries contains the cholesteric liquid crystalline material and the antioxidant permanently imbedded therein, dispersed uniformly throughout (homogeneous) and thus stabilized against aging, the atmosphere and physical abrasion. If the optional oil soluble yellow dye is included in the formulation, it too is dispersed uniformly throughout (homogeneous) the film. In many cases, the black background which is needed to better visualize the colors developed by the cholesteric liquid crystals in response to temperature is painted either on the supportive matrix or the thermographic subject before the emulsion is applied, preferably the supportive matrix serves as the black background. It is also suitable to coat a transparent supportive matrix on one side with the black background and the other side with the emulsion. Another alternative is to apply the emulsion to a transparent supportive matrix film and, after the emulsion is thoroughly dry, to paint the emulsion black and to view the color response through the transparent film. It is further advantageous to utilize a supportive matrix having a black pigment or dye dispersed therein.
In instances where it is necessary to adhere the liquid crystalline containing film to the thermographic subject, it is advantageous to coat the back of the film or supportive matrix with a pressure sensitive adhesive. Generally, the liquid crystal containing film formed from the emulsion is somewhat thicker than a monomolecular layer, but is uniformly thick throughout and is continuous. Films of from about 0.05 to about 0.15 mm. thick are suitable when on a supportive matrix. Films of the emulsion wherein no supportive matrix is used are suitable from about 0.1 to about 1.0 mm. thick, with about 0.2 mm. generally preferred. Unsupported films less than 0.10 mm. thick can be made but they are too fragile for practical purposes. As indicated previously, the films, whether supported on a matrix or not, can be rigid, brittle, flexible and/or elastic, depending on the intended uses.
In some cases, it is necessary to prepare the supportive matrix to receive the emulsion and insure its adherence. For example, if Saran (a vinylidene polymer plastic) is used, it must be first coated with a primary layer, generally a self-reacting vinyl acrylic polymer. Preferred are the types known as X-Link marketed by National Starch Company and described as self-reactive vinyl acrylic terpolymer latexes. Other similar solvent soluble resin materials known to the art which adhere to the supportive matrices and the gelatin film are also suitable, e.g., vinylidene chloride copolymer latex (Vynaclor 3623), vinyl acrylic copolymer latex (Resyn 78-3346) and vinyl acetate copolymer latex (Resyn 1103), all marketed by National Starch Company.
The following examples illustrate the invention and are not intended to be a limitation thereon. All temperatures are in ° C.
EXAMPLE 1
37.25 Parts by weight of cholesteryl nonanoate, 12.75 parts by weight cholesteryl oleyl carbonate, 10.0 parts by weight cholesteryl chloride, 0.50 parts by weight butylated hydroxytoluene and 0.66 parts by weight Ext. D & C Yellow No. 11 were mixed together and heated to about 120°-125° until a clear solution is formed.
A solution containing 500.0 parts by weight of 300 Bloom Type A gelatin, 4.0 parts by weight of sorbic acid and sufficient water to form a solution weighing 4000 parts by weight are heated to 70°-75°. This is a 12.5% gelatin solution by weight.
60.66 Parts by weight of the liquid crystal containing melt is added to 400 parts by weight of the gelatin solution and homogenized with an Eppenbach Homo-Rod.
The particle size of the dispersed liquid crystal phase is in the range of 2-10 microns.
The completed emulsion can be stored in suitable containers or cast into a film and allowed to dry. It displays a temperature color response having a green mid-point at 7.5°-10.5°.
EXAMPLES 2 TO 5
Following the procedures of Example 1, emulsions containing the following ingredients are formed using the same gelatin compositions and cast into films. The films have the color-temperature responses as noted.
______________________________________ Example Nos. 2 3 4 5Ingredients Parts by Weight______________________________________Cholesteryl Nonanoate 29.0 46.0 47.0 46.0CholesterylOleyl Carbonate 24.0 8.0 5.0 6.0Cholesteryl Chloride 7.0 6.0 8.0 8.0BHT 0.50 0.50 0.05 0.50Ext. D & CYellow No. 11 0.06 0.02 0.02 0.02Gelatin Composition 400 400 400 400Midpoint Temperature 12.5° - 36° - 33° - 30 ° -Response(Green Color) 14.5° 37.5° 36° 33°______________________________________
EXAMPLES 6 AND 7
Following the procedures of Example 1, emulsion containing the following ingredients are formed, using the same gelatin composition and cast into films:
______________________________________ Example Nos. 6 7Ingredients Parts by Weight______________________________________Cholesteryl Nonanoate 43.98 33.48Cholesteryl Oleyl Carbonate 10.02 20.52Cholesteryl Chloride 6.00 6.00BHT 0.50 0.50Gelatin Composition 400 400Midpoint TemperatureResponse (Green Color) 31.75 33.0______________________________________
The following tables indicate the stability upon storge at various temperatures of the temperature-color response of the formulations of Examples 6 and 7 using as a control, the identical formulation without antioxidants.
Table I______________________________________ Storage Change Storage Time in ResponseFormulation Temp. ° C. Months ° C.______________________________________Example 6 Room Temp. 1 0 2 0 3 0 4 +0.25 37° 1 0 2 -0.25 3 -0.25 4 -0.25 45° 1 -0.25 2 -0.25 3 -0.25 4 -0.25 55° 1 -0.50 2 -0.25 3 -0.50 4 -0.25Control Room Temp. 1 0 2 0 3 0 4 +0.25 37° 1 -0.25 2 -0.75 3 -0.50 4 -0.75 45° 1 -0.25 no color 1.5 response 55° 1 -1.25 no color 1.25 responseExample 7 Room Temp. 1 0 2 0 3 0 4 0 37° 1 0 2 0 3 0 4 0 45° 1 -0.25 2 -0.25 3 -0.25 4 -0.25 55° 1 -0.5 2 -0.25 3 -0.25 4 -0.25Control Room Temp. 1 0 2 0 3 +0.25 4 +0.25 37° 1 -0.50 no color 1.75 response no color 45° 0.75 response no color 55° 0.25 response______________________________________
The following table illustrates the effect of various amounts of antioxidants using the cholesteric liquid crystal formulation of Example 7 with the only changes being in the amount and identity of antioxidant:
Table II______________________________________ Amount Initial Color/ Parts by Temp. Response ColorAntioxidants Weight (Green) Stability Intensity______________________________________BHT 0.24 34.25 Excellent Satisfactory 0.48 33.0 Excellent Satisfactory 0.72 31.25 Excellent SatisfactoryBHA 0.24 33.0 Excellent Satisfactory 0.48 30.8 Excellent Satisfactory 0.72 26.0 Excellent SatisfactoryBHA & BHT 0.24 34.25 Good Satisfactory1:1 0.48 32.25 Good SatisfactoryEMQ 0.24 33.5 Excellent Satisfactory 0.48 29.75 Excellent Satisfactory 1.2 27.5 Excellent SatisfactoryTocopherol 0.24 32.0 Good Satisfactory 0.48 31.25 Good Satisfactory 1.2 27.75 Good SatisfactoryTBHQ 0.24 36.0 Good Satisfactory 0.48 35.25 Excellent Satisfactory 1.2 35.0 Excellent Satisfactory1-5 DHN 0.24 36.0 Good Excellent 0.48 35.25 Good Excellent 0.72 35.5 Good ExcellentNone -- 36.25 Poor Poor (After Storage Test)______________________________________
EXAMPLE 8
This example illustrates that no chemical reaction or complexation occurs when the cholesteric liquid crystals and the film-former are combined but that an oil-in-water emulsion forms in which both components exist as distinct entities.
440 Grams of cholesteryl pelargonate, 90 grams of cholesteryl oleyl carbonate, 70 grams of cholesteryl chloride, 5 grams of butylated hydroxy toluene and 0.1 grams of D & C Yellow No. 11 Dye are heated until a uniformly clear liquid forms. 4,000 Grams of a 121/2 % by weight aqueous solution of gelatin are heated to 50°-60° C. and added to the molten cholesteryl esters. The emulsion is formed by mixing to homogeneity with an Eppenbach Homo Rod.
Four 10 gram samples of the emulsion prepared as described above, containing 1.08 grams of gelatin and 1.30 grams of the cholesteric liquid crystalline material, are diluted into 100 ml. of water. To overcome viscosity and/or gelation problems and to improve the extraction efficiency the emulsions are further diluted with a 50/50 alcohol-water mixture except in Test 2. The samples are then exhaustively extracted with either petroleum ether, ethyl ether or ethyl ether and chloroform as follows:
______________________________________Test Method of Extraction______________________________________1 Six 100 ml. portions of petroleum ether from 50/50 alcohol-water dilution2 Six 100 ml. portions of ethyl ether from water dilution3 Six 100 ml. portions of ethyl ether from 50/50 alcohol-water dilution4 Two 100 ml. portions of ethyl ether, two 100 ml. portions of chloroform and two 100 ml. portions of ethyl ether from 50/50 alcohol- water dilution.______________________________________
For each sample, the extracts are then combined and evaporated to dryness on a steambath. In the case of the ethyl ether extracts (Tests 2 and 3), the extracts are washed with water before evaporation to remove any alcohol solubilized therein. In Test 4, the extracts are first evaporated to dryness on the steambath. The residue is then redissolved in chloroform and washed with water to remove any water soluble products. The resulting samples are dried in a desiccator, using calcium chloride as the desiccant for approximately 3 hours. The amount of cholesteric liquid crystalline material is then determined gravimetrically. The results are tabulated below.
______________________________________ % of CholestericTest Material Recovered______________________________________1 97.72 99.43 99.44 99.8______________________________________
These results show that from 97% to over 99% of the cholesteric liquid crystalline material utilized in the reaction was recovered chemically intact and, therefore, no sterol/protein reaction or complexation occurred. Hence, the emulsion compositions of this application comprise both discrete cholesteric liquid crystalline materials and discreet protein entities. The somewhat lower results in Test 1 are attributed to the fact that petroleum ether is not as efficient a solvent as ethyl ether or chloroform.
EXAMPLE 9
This example illustrates the criticality of the minimum amount of a film-former in the cholesteric liquid crystal-film-former emulsion.
20.0 Parts by weight of cholesteryl oleyl carbonate and 80 parts by weight of cholesteryl nonanoate are mixed together and heated to about 120°-125° C. until a clear solution forms.
A solution containing 500 parts by weight of 300 Bloom Type A gelatin, 4.0 parts by weight of sorbic acid and sufficient water to form a solution weighing 4000 parts by weight is heated to 70°-75° C. This is a 12.5% gelatin solution by weight.
Aliquots of the liquid crystal containing melt are added to 40 parts by weight of the 12.5% gelatin solution and homogenized with an Eppenbach Homo-Rod.
In this manner, the following emulsions are prepared, all weights are on a dry weight basis.
______________________________________ LiquidEmulsion Crystals Gelatin % GelatinNo. grams grams (By weight on Dry Basis)______________________________________1 6.0 5.0 45.42 9.0 5.0 35.73 11.5 5.0 30.34 15.0 5.0 25.05 20.0 5.0 20.0______________________________________
Aliquots of each of the emulsions as described are cast into films on pre-coated black Saran substrates using a Meier Rod. Each emulsion is applied three times to a Saran substrate with air drying between applications. The film coatings are then dried overnight at room temperature.
Tactile evaluation of the coated substrates is based on the greasiness or oiliness of the film as evidenced by a resistance to rubbing and greasy feel. The greater resistance to rubbing and greasiness of feel, the less satisfactory the film. The following is a tabulation of the results.
______________________________________Film, Rubbing Greasy% Gelatin Resistance Feel Film Rating______________________________________45.4 + + Satisfactory35.7 + + Satisfactory30.3 + + Satisfactory25.0 ± ± Satisfactory Borderline20.0 - - Unsatisfactory______________________________________
In the preceding table the symbols have the following meanings:
+ = satisfactory characteristics, i.e., minimal rubbing resistance and minimal greasy feel.
± = Borderline characteristic -- barely satisfactory, i.e., some rubbing resistance and some greasy feed.
- = unsatisfactory characteristics, i.e., substantial rubbing resistance and excess greasy feel.
A greasy feel and rubbing resistance are manifestations of the bleeding of the cholesteric liquid crystals from the film. The presence of an excess greasy feel is, therefore, an indication of insufficient gelatin in the matrix to contain the liquid crystals homogeneously throughout the film.
Therefore, the gelatin content of the liquid crystal/gelatin emulsion is of importance since an emulsion having an insufficient gelatin content cannot prevent bleeding of the liquid crystals from the film and consequent loss of film stability and thermographic utility.
The antioxidant was not included in the emulsion formulations since it has no effect on any physical characteristics of the film including rubbing resistance and greasy feel.
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Improved temperature monitoring films formed from stable emulsions containing compounds capable of existing in the cholesteric liquid crystalline phase which are protected and stabilized against aging, and the atmosphere by the inclusion of an antioxidant are provided. The thus-formed film materials are used in thermography and/or thermometry.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 61/570,882 filed Dec. 15, 2011.
FIELD OF THE INVENTION
This invention pertains to a process for the manufacture of fluoroelastomer compositions filled with fluoroplastic fibrils.
BACKGROUND OF THE INVENTION
Fluoroelastomers are well known in the art; see for example U.S. Pat. Nos. 4,214,060; 4,281,092; 5,789,489; 6,512,063 and 6,924,344 B2. They may be partially fluorinated (i.e. contain copolymerized units of at least one monomer having C—H bonds such as vinylidene fluoride, ethylene or propylene) or be perfluorinated (i.e. contain copolymerized units of monomers not having C—H bonds). Examples of fluoroelastomers include, but are not limited to copolymers of i) vinylidene fluoride, hexafluoropropylene and, optionally, tetrafluoroethylene; ii) vinylidene fluoride, perfluoro(methyl vinyl ether) and, optionally, tetrafluoroethylene; iii) tetrafluoroethylene and propylene; and iv) tetrafluoroethylene and perfluoro(methyl vinyl ether). Optionally, the fluoroelastomer may further comprise copolymerized units of a cure site monomer to assist in the crosslinking of the elastomer.
Shaped fluoroelastomer articles (e.g. seals, gaskets, tubing, etc.) are typically made by first compounding the fluoroelastomer with other ingredients such as filler, curative, process aids, colorants, etc., shaping the compound (e.g. by extrusion though a die or by molding) and then curing the shaped article.
Non-fibrillating fluoroplastic particles are often employed as fillers in fluoroelastomers. However, high loading of non-fibrillating fluoroplastics is required in order to achieve a modulus or hardness suitable for some end uses. High loading can cause the compression set resistance to undesirably increase.
Fibrillatable fluoroplastic fillers for fluoroelastomers have been disclosed previously, e.g. U.S. Pat. No. 4,520,170. However, the compositions are made by a cumbersome cryogenic pulverization process. It would be desirable to have a more commercially feasible process for introducing fibrillating fluoroplastic filler into a fluoroelastomer composition.
SUMMARY OF THE INVENTION
One aspect of the present invention is a process comprising:
A) applying shear to a fluoroelastomer gum in a mixer; B) adding a liquid dispersion of fibrillatable fluoroplastic particles to said fluoroelastomer gum while applying shear in said mixer, thereby forming a fluoroelastomer composition containing fluoroplastic fibrils dispersed therein.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed to a process for manufacturing a fluoroelastomer composition that contains fluoroplastic fibrils.
The fluoroelastomer that may be employed in the process of the invention may be partially fluorinated or perfluorinated. Fluoroelastomers preferably contain between 25 and 70 weight percent, based on the total weight of the fluoroelastomer, of copolymerized units of a first monomer which may be vinylidene fluoride (VF 2 ) or tetrafluoroethylene (TFE). The remaining units in the fluoroelastomers are comprised of one or more additional copolymerized monomers, different from said first monomer, selected from the group consisting of fluoromonomers, hydrocarbon olefins and mixtures thereof. Fluoromonomers include fluorine-containing olefins and fluorine-containing vinyl ethers.
Fluorine-containing olefins which may be employed to make fluoroelastomers include, but are not limited to vinylidene fluoride (VF 2 ), hexafluoropropylene (HFP), tetrafluoroethylene (TFE), 1,2,3,3,3-pentafluoropropene (1-HPFP), 1,1,3,3,3-pentafluoropropene (2-HPFP), chlorotrifluoroethylene (CTFE) and vinyl fluoride.
Fluorine-containing vinyl ethers that may be employed to make fluoroelastomers include, but are not limited to perfluoro(alkyl vinyl)ethers. Perfluoro(alkyl vinyl)ethers (PAVE) suitable for use as monomers include those of the formula
CF 2 ═CFO(R f′ O) n (R f″ O) m R f (I)
where R f′ and R f″ are different linear or branched perfluoroalkylene groups of 2-6 carbon atoms, m and n are independently 0-10, and R f is a perfluoroalkyl group of 1-6 carbon atoms.
A preferred class of perfluoro(alkyl vinyl)ethers includes compositions of the formula
CF 2 ═CFO(CF 2 CFXO) n R f (II)
where X is F or CF 3 , n is 0-5, and R f is a perfluoroalkyl group of 1-6 carbon atoms.
A most preferred class of perfluoro(alkyl vinyl)ethers includes those ethers wherein n is 0 or 1 and R f contains 1-3 carbon atoms. Examples of such perfluorinated ethers include perfluoro(methyl vinyl ether) (PMVE), perfluoro(ethyl vinyl ether) (PEVE) and perfluoro(propyl vinyl ether) (PPVE). Other useful monomers include those of the formula
CF 2 ═CFO[(CF 2 ) m CF 2 CFZO] n R f (III)
where R f is a perfluoroalkyl group having 1-6 carbon atoms, m=0 or 1, n=0-5, and Z=F or CF 3 . Preferred members of this class are those in which R f is C 3 F 7 , m=0, and n=1.
Additional perfluoro(alkyl vinyl)ether monomers include compounds of the formula
CF 2 ═CFO[(CF 2 CF{CF 3 }O) n (CF 2 CF 2 CF 2 O) m (CF 2 ) p ]C x F 2x+1 (IV)
where m and n independently=0-10, p=0-3, and x=1-5. Preferred members of this class include compounds where n=0-1, m=0-1, and x=1.
Other examples of useful perfluoro(alkyl vinyl ethers) include
CF 2 ═CFOCF 2 CF(CF 3 )O(CF 2 O) m C n F 2n+1 (V)
where n=1-5, m=1-3, and where, preferably, n=1.
If copolymerized units of PAVE are present in fluoroelastomers employed in the process of the invention, the PAVE content generally ranges from 25 to 75 weight percent, based on the total weight of the fluoroelastomer. If perfluoro(methyl vinyl ether) is used, then the fluoroelastomer preferably contains between 30 and 65 wt. % copolymerized PMVE units.
Hydrocarbon olefins useful in the fluoroelastomers employed in the invention include, but are not limited to ethylene and propylene. If copolymerized units of a hydrocarbon olefin are present in the fluoroelastomers, hydrocarbon olefin content is generally 4 to 30 weight percent.
The fluoroelastomers employed in the process of the present invention may also, optionally, comprise units of one or more cure site monomers. Examples of suitable cure site monomers include, but are not limited to: i) bromine-containing olefins; ii) iodine-containing olefins; iii) bromine-containing vinyl ethers; iv) iodine-containing vinyl ethers; v) fluorine-containing olefins having a nitrile group; vi) fluorine-containing vinyl ethers having a nitrile group; vii) 1,1,3,3,3-pentafluoropropene (2-HPFP); viii) perfluoro(2-phenoxypropyl vinyl)ether; and ix) non-conjugated dienes.
Units of cure site monomer, when present in the fluoroelastomers employed in this invention, are typically present at a level of 0.05-10 wt. % (based on the total weight of fluoroelastomer), preferably 0.05-5 wt. % and most preferably between 0.05 and 3 wt. %.
Alternatively, or in addition to units of a cure site monomer, fluoroelastomers employed in this invention may contain cure sites (e.g. Br or I) at chain ends.
Fluoroplastics that may be employed in this invention are semi-crystalline fluoropolymers and include, but are not limited to polytetrafluoroethylene (PTFE), modified PTFE (e.g. acrylic modified PTFE) and copolymers of tetrafluoroethylene (e.g. tetrafluoroethylene/perfluoro(propyl vinyl ether)). PTFE is preferred. Fibrillatable fluoroplastic refers to fluoroplastic that forms nanosized in at least one dimension (i.e. <100 nm width) fibrils which can vary in length from submicron to several microns in length when exposed to shear during mixing with the fluoroelastomer. The amount of fluoroplastic (dry weight) added to the fluoroelastomer composition is generally between 0.01 and 20 (preferably between 0.5 and 15) parts by weight per hundred parts by weight fluoroelastomer.
The fluoroplastic is in the form of a liquid dispersion when added to the fluoroelastomer composition. The dispersion contains fluoroplastic particles having a d90 (d90 is defined as 90 volume % have diameters of this value or less) of less than 5 microns, preferably less than 1 micron, most preferably a d90 less than 0.5 microns and a d50 (d50 is defined as 50 volume % have diameters of this value or less) less than 0.3 microns. The fluoroplastic particles are distributed within a polar or non-polar liquid. The concentration of the fluoroplastic particles may vary from 0.1 wt % to 70 wt %, based on total weight of dispersion. Preferably, the fluoroplastic particles are dispersed in a polar liquid within a concentration range of 10 to 70 wt %, most preferably 50 to 70 wt %. Preferably, the dispersion is an aqueous dispersion that may optionally contain one or more surfactants.
In the process of this invention, shear is first applied to a fluoroelastomer gum in a mixer. The fluoroelastomer gum is not in the form of a latex. Instead, it is substantially dry (i.e. contains less than 1 wt. % water, preferably less than 5000 ppm water). Any mixer typically employed in the rubber industry may be used. A 2-roll rubber mill is preferred. Optionally, other ingredients commonly employed in the rubber industry (e.g. curative packages, process aids, colorants, etc.) may be incorporated into the fluoroelastomer gum, either before or after addition of the fluoroplastic dispersion.
The liquid dispersion of fibrillatable fluoroplastic is added slowly to the mixer containing the fluoroelastomer gum that is under shear. The shear applied during mixing fibrillates the fluoroplastic. Mixing is continued until the fluoroplastic fibrils are well dispersed in the fluoroelastomer gum. The liquid (e.g. water) in the fluoroplastic dispersion evaporates from the composition during mixing. If necessary, the mixing temperature may be adjusted in order to volatilize the liquid.
The resulting fluoroelastomer compositions contain well dispersed fibrils of fluoroplastic. Fibrils have a width less than 100 nm and vary in length from submicron to micron. Aggregates of unfibrillated fluoroplastic structures are reduced by the process of the invention, compared with conventional processing methods such as dry blending, so that there are no unfibrillated aggregates having a diameter greater than 500 nm present in the compositions. These aggregates and non-fibrillar structures are typically observed when unfibrillated fluoroplastic powders having d90 of 5 microns or greater are employed. Other processes for making fluoroelastomer compositions containing fibrillatable fluoroplastic typically result in regions of fluoroplastic fibrils and regions of large (>500 nm) fluoroplastic aggregates within the fluoroelastomer composition.
The fluoroelastomer compositions made by the process of this invention form cured articles that are useful in many industrial applications including seals, wire coatings, tubing and laminates. The cured articles exhibit improved tear strength vs. similar articles absent the fluoroplastic fibrils.
Cured articles of the invention have a tear resistance (measured at 200° C. according to ASTM 1938-08) of at least 0.15 (preferably at least 0.2) N/mm and a modulus at 50% elongation (measured at 25° C. according to ASTM D 412) of at least 0.9 (preferably at least 1.15, most preferably at least 1.55) MPa.
EXAMPLES
Test Methods
M 50 , modulus at 50% elongation (MPa) was measured according to ASTM D 412 at 25° C.
Tear resistance (force required to propagate a tear divided by sample thickness, N/mm) was performed at 200° C. according to ASTM D1938-08.
Particle Size Measurement: Volume-weighted particle size distributions were measured on a Malvern Instruments Ltd. Zetasizer nano-S, which uses the Dynamic Light Scattering (DLS) technique that is described in ISO 22412:2008. The vendor's software (version 4.10) was set to record 36 runs of 10 seconds each, with an equilibration time of 4 minutes at a temperature of 25° C. The “general purpose” (i.e. multi-modal) data inversion routine was selected. Samples were diluted with filtered, deionized water to 0.1% by volume before measurement.
Transmission Electron Microscope (TEM) Imaging of O-ring Samples was performed by the following procedure.
To prepare ultrathin specimens, a diamond knife was used to cut sections by low temperature ultramicrotomy. The knife boat employed to accumulate sections was filled with absolute ethanol to prevent freezing at the operating temperature of −90° C. A specimen block was trimmed with single edge razor blades. The block was secured in the flat jaws of the cryoultramicrotome sample holder and sectioned to nominal thickness 90 nm. After sectioning was complete, the boat fluid with sections was poured into a shallow dish of water. The sections floating on the water/alcohol mixture were retrieved on copper mesh grids, and blotted on filter paper.
Unstained sections were examined in a Transmission Electron Microscope (TEM) operated at 200 KV accelerating voltage. Images of magnification 1000-20,000× were recorded on a digital camera.
The fluoroelastomer gum employed in the examples was a copolymer of tetrafluoroethylene, perfluoro(methyl vinyl ether) and perfluoro(8-cyano-5-methyl-3,6-dioxa-1-octene) and was prepared according to the general process described in U.S. Pat. No. 5,789,489.
Diphenylguanidine (phthalic acid salt) was employed as the curative.
Example 1
The fluoroplastic dispersion employed in this example was a 60 wt % aqueous dispersion of fine (d50=200-220 nm, d90=300-320 nm) fibrillatable PTFE particles having a standard specific gravity (SSG) of 2.218-2.222 as measured according to ASTM D4895.
Fluoroelastomer gum (427.92 g) was blended or banded on a 2-roll mill along with curative (4.96 g). To this composition was added 28.53 g of fluoroplastic dispersion by slowly dripping the fluoroplastic dispersion onto the fluoroelastomer composition while blending on the mill. The mill was maintained at about 80° C. and the water present in the fluoroplastic dispersion evaporated during mixing. This resulted in a fluoroelastomer composition that contained 4 parts by weight PTFE per hundred parts by weight fluoroelastomer (dry weights).
The resulting fluoroelastomer composition containing fluoroplastic fibrils was molded into o-rings or slabs and cured at 190° C. for 11 minutes. The articles were than post cured under nitrogen at 305° C. for 26 hours, after a slow ramp up in temperature from room temperature.
Modulus at 50% elongation (M 50 ) at 25° C. was measured on o-rings. Tear resistance was measured at 200° C. using ASTM 1938-08 for tear propagation resistance of a film measuring 2.3-2.6 mm in thickness which is cut with the appropriate die (“trouser tear”). Results are shown in the Table.
Example 2
A procedure similar to that described in Example 1 was employed except that 419.93 g of fluoroelastomer was combined with 4.87 g of curative on a 2-roll mill and 41.99 g of the PTFE dispersion was added by slow dripping. This resulted in a fluoroelastomer composition that contained 6 parts by weight PTFE per hundred parts by weight fluoroelastomer (dry weights).
Modulus at 50% elongation (M 50 ) at 25° C. was measured on o-rings. Tear resistance was measured at 200° C. using ASTM 1938-08 for tear propagation resistance of a film measuring 2.3-2.6 mm in thickness which is cut with the appropriate die (“trouser tear”). Results are shown in the Table.
No unfibrillated fluoroplastic aggregates having a diameter greater than 500 nm were observed in the TEM images. Fluoroplastic fibrils had a width less than 100 nm.
Example 3
A procedure similar to that described in Example 1 was employed except that 412.24 g of fluoroelastomer was combined with 4.78 g of curative on a 2-roll mill and 54.97 g of the PTFE dispersion was added by slow dripping. This resulted in a fluoroelastomer composition that contained 8 parts by weight PTFE per hundred parts by weight fluoroelastomer (dry weights).
Modulus at 50% elongation (M 50 ) at 25° C. was measured on o-rings. Tear resistance was measured at 200° C. using ASTM 1938-08 for tear propagation resistance of a film measuring 2.3-2.6 mm in thickness which is cut with the appropriate die (“trouser tear”). Results are shown in the Table.
Example 4
A procedure similar to that described in Example 1 was employed except that 404.82 g of fluoroelastomer was combined with 4.70 g of curative on a 2-roll mill and 67.47 g of the PTFE dispersion was added by slow dripping. This resulted in a fluoroelastomer composition that contained 10 parts by weight PTFE per hundred parts by weight fluoroelastomer (dry weights).
Modulus at 50% elongation (M 50 ) at 25° C. was measured on o-rings. Tear resistance was measured at 200° C. using ASTM 1938-08 for tear propagation resistance of a film measuring 2.3-2.6 mm in thickness which is cut with the appropriate die (“trouser tear”). Results are shown in the Table.
Example 5
The fluoroplastic dispersion employed in this example was a 60 wt % aqueous dispersion of fine (d50=240-250 nm, d90<500 nm) fibrillatable PTFE particles having an SSG of 2.218-2.222.
A procedure which was similar to that described in Example 1 was used, except that the above fluoroplastic dispersion was employed. This resulted in a fluoroelastomer composition that contained 4 parts by weight PTFE per hundred parts by weight fluoroelastomer (dry weights).
Modulus at 50% elongation (M 50 ) at 25° C. was measured on o-rings. Tear resistance was measured at 200° C. using ASTM 1938-08 for tear propagation resistance of a film measuring 2.3-2.6 mm in thickness which is cut with the appropriate die (“trouser tear”). Results are shown in the Table.
Example 6
The fluoroplastic dispersion employed in this example was a 60 wt % aqueous dispersion of fine (d50=240-250 nm, d90<500 nm) fibrillatable PTFE particles having an SSG of 2.218-2.222.
A procedure which was similar to that described in Example 2 was used, except that the above fluoroplastic dispersion was employed. This resulted in a fluoroelastomer composition that contained 6 parts by weight PTFE per hundred parts by weight fluoroelastomer (dry weights).
Modulus at 50% elongation (M 50 ) at 25° C. was measured on o-rings. Tear resistance was measured at 200° C. using ASTM 1938-08 for tear propagation resistance of a film measuring 2.3-2.6 mm in thickness which is cut with the appropriate die (“trouser tear”). Results are shown in the Table.
No unfibrillated fluoroplastic aggregates having a diameter greater than 500 nm were observed in the TEM images. Fluoroplastic fibrils had a width less than 100 nm.
Example 7
The fluoroplastic dispersion employed in this example was a 60 wt % aqueous dispersion of fine (d50=240-250 nm, d90<500 nm) fibrillatable PTFE particles having an SSG of 2.218-2.222.
A procedure which was similar to that described in Example 3 was used, except that the above fluoroplastic dispersion was employed. This resulted in a fluoroelastomer composition that contained 8 parts by weight PTFE per hundred parts by weight fluoroelastomer (dry weights).
Modulus at 50% elongation (M 50 ) at 25° C. was measured on o-rings. Tear resistance was measured at 200° C. using ASTM 1938-08 for tear propagation resistance of a film measuring 2.3-2.6 mm in thickness which is cut with the appropriate die (“trouser tear”). Results are shown in the Table.
Example 8
The fluoroplastic dispersion employed in this example was a 60 wt % aqueous dispersion of fine (d50=240-250 nm, d90<500 nm) fibrillatable PTFE particles having an SSG of 2.218-2.222.
A procedure which was similar to that described in Example 4 was used, except that the above fluoroplastic dispersion was employed. This resulted in a fluoroelastomer composition that contained 10 parts by weight PTFE per hundred parts by weight fluoroelastomer (dry weights).
Modulus at 50% elongation (M 50 ) at 25° C. was measured on o-rings. Tear resistance was measured at 200° C. using ASTM 1938-08 for tear propagation resistance of a film measuring 2.3-2.6 mm in thickness which is cut with the appropriate die (“trouser tear”). Results are shown in the Table.
Comparative Example A
In this example, carbon black was used in place of a fluoroplastic dispersion. Fluoroelastomer (343.09 g) was blended or banded on a 2-roll mill along with 102.93 g N990 MT carbon (Cancarb Ltd.) and 3.98 g curative.
The resulting fluoroelastomer composition containing 30 parts by weight per hundred parts by weight fluoroelastomer of carbon black instead of fluoroplastic fibrils was molded into o-rings or slabs and cured at 190° C. for 11 minutes. The articles were than post cured under nitrogen at 305° C. for 26 hours after a slow ramp up from room temperature.
Modulus at 50% elongation (M 50 ) at 25 C was measured on o-rings and tear resistance was measured at 200° C. using ASTM 1938-08 for tear propagation resistance of a film measuring 2.3-2.6 mm in thickness which is cut with the appropriate die (“trouser tear”) Results are shown in the Table.
TABLE
Comp.
Ex. 1
Ex. 2
Ex. 3
Ex. 4
Ex. 5
Ex. 6
Ex. 7
Ex. 8
Ex. A
M 50 , MPa,
0.95
1.25
1.65
2.11
0.99
1.16
1.55
2.25
1.58
at 25° C.
Tear resistance,
0.16
0.39
0.39
0.55
0.03
0.21
0.22
0.74
0.06
200° C., N/mm
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Disclosed herein is a process for the manufacture of a fluoroelastomer composition containing fluoropolymer fibrils. The process comprises applying shear to a fluoroelastomer gum in a mixer while adding a liquid dispersion of fibrillatable fluoropolymer.
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FIELD OF THE INVENTION
[0001] The invention relates generally to methods of improving health and nutrition. In particular, embodiments of the present invention relate to compositions and methods increasing the shelf-life of food articles and for stabilizing micronutrients, phytochemicals, nutraceuticals, and other beneficial compounds in food additives and food articles for enteric digestion and absorption rather than digestion in the stomach.
BACKGROUND
[0002] Society has become increasingly aware of the importance of maintaining proper nutritional habits. As the average diet increasingly utilizes processed foods, it has become more important for processed foods to provide the same good nutritional benefits of natural foods.
[0003] Nutrients necessary to support life include proteins, carbohydrates, fats, minerals, and vitamins. Processed food products are often supplemented by the addition of synthetic nutrients to help replace natural nutrients that may have been rendered inactive or otherwise damaged during processing of the food product. Elevated temperatures during cooking, for example, may damage the natural nutrients that are present in foods. The freeze drying process by which food products are dehydrated also may damage the natural nutrients that are present in foods.
[0004] Besides nutrients, other non-nutritive compounds found in, for example, fruits and vegetables may have beneficial effects when consumed. Nutraceuticals, for example, are chemical compounds in foods that may aid in preventing or treating diseases and other medical conditions when consumed even though they are not traditionally recognized to possess nutritive value.
[0005] Phytochemicals are chemical compounds in plants that also may aid in preventing or treating diseases and other medical conditions when consumed even though they also are not traditionally recognized to possess nutritive value. Nutraceuticals and phytochemicals, like nutrients, may be damaged by subsequent processing of food products to which they are added.
[0006] Heating processes for stabilizing and preserving nutrients, particularly phytochemicals, that involve application of a colloid plant extract selected from vegetable gums, hydroscopic phosphatides, vegetable albumin, and pectin are not entirely satisfactory from the standpoint of maintaining the nutritional value of the original foodstuffs, since a relatively large percentage of the nutritional value still may be lost during subsequent processing.
[0007] Conventional nutraceutical and phytochemical food additives are often ineffective in promoting good health and nutrition because they are digested in the stomach, which effectively breaks down the additives into compounds that provide less advantage to the body from a health and nutrition viewpoint. The highly acidic conditions present in the stomach prevent many nutraceutical and phytochemical food additives from reaching the intestines, and particularly the small intestine, where the additives may be absorbed for use by the body to provide a nutritional benefit to the consumer.
SUMMARY
[0008] The invention relates to compositions and methods that promote health and increase the shelf-life of foods. The compositions can include mixtures of fatty acids, vegetable gums, and oligosaccharides. When compounded with a food article, the compositions can act as a protective barrier for micronutrients, phytochemicals, and nutraceuticals such as may be found in food products, for example food additives, as the food products are stored and as the food products are being digested. The compositions can stabilize food products during prolonged storage and as ingested food products move through the digestive tract so that nutrients are available for absorption in a consumer's intestines. Methods for producing food additives using the compositions are also described.
[0009] What is needed is a composition that stabilizes and protects micronutrients, phytochemicals, nutraceuticals, and other beneficial compounds in food additives and food articles from degradation during processing.
[0010] Therefore, in accordance with a feature of an embodiment of the present invention, there is provided a composition for stabilizing and protecting micronutrients, phytochemicals, nutraceuticals, and other beneficial compounds in food additives and food articles. The composition may comprise a mixture of vegetable gums, oligosaccharides, and at least one fatty acid.
[0011] In accordance with still another embodiment of the present invention there is provided a process for producing a food additive. A food article may be chopped or granulated; sprayed with a mixture of vegetable gums, oligosaccharides, and fatty acid; and then freeze dried to provide a stabilized freeze dried food article suitable for subsequent processing into a food additive, for example by grinding into a powder.
[0012] Still further features and advantages of the present invention are identified in the ensuing description.
[0013] Accordingly, the invention features a composition for improving health and nutrition. The composition can feature an enteric coating that includes a fatty acid, an oligosaccharide, and a vegetable gum.
[0014] In another aspect, the invention can feature the fatty acid including at least one fatty acid selected from among: oleic acid, lauric acid, linoleic acid, palmitoleic acid, caprylic acid, capric acid, myristic acid, palmitic acid, margaric acid, margaroleic acid, stearic acid, alpha-linoleic acid, arachidic acid, eicosanic acid, behenic acid, erucic acid, and combinations and mixtures thereof.
[0015] In another aspect, the invention can feature the fatty acid being oleic acid.
[0016] In another aspect, the invention can feature the oligosaccharide including at least one oligosaccharide selected from among: a fructo-oligosaccharide, a galacto-oligosaccharide, an inulin, and combinations and mixtures thereof.
[0017] In another aspect, the invention can feature the vegetable gum including at least one vegetable gum selected from among: konjac root extract, gellan, xanthan, carrageenan, and combinations and mixtures thereof.
[0018] In another aspect, the invention can feature the vegetable gum being a natural vegetable gum, a modified vegetable gum, or combinations and mixtures thereof.
[0019] In another aspect, the invention can feature the natural vegetable gum being at least one gum selected from among: gum arabic, guar gum, agar, carrageenan gum, karaya gum, gum ghatti, locust agar, algin, pectin, xanthan gum, locust bean gum, gum tragacanth, tamarind gum, and combinations and mixtures thereof.
[0020] In another aspect, the invention can feature the modified vegetable gum being at least one gum selected from among: chelated agar; a pectin derivative; low-methoxyl pectin; high-methoxyl pectin; an alginate; a cellulose derivative; microcrystalline cellulose; methylcellulose; sodium carboxymethyl cellulose; carboxymethylcellulose; hydroxypropyl cellulose; hydroxypropyl methyl cellulose; sodium hydroxymethyl cellulose; carboxymethyl locust bean gum; gellan gum; carboxymethyl guar gum; and combinations and mixtures thereof.
[0021] In another aspect, the invention can feature the alginate being propylene glycol alginate.
[0022] In another aspect, the invention can feature the enteric coating including at least one soluble anionic fiber selected from among: all forms of alginates, pectin, carrageenan, polygeenan, and gellan including protonated and salt forms; protonated alginic acid; and salts of alginic acid.
[0023] A method of the invention can be used for stabilizing and protecting a food additive to enhance enteric nutrient absorption. The method can include the step of applying to the food additive an enteric coating composition that features a fatty acid, an oligosaccharide, and a vegetable gum.
[0024] Another method of the invention can be used for producing an enterically coated food article. The method can include the step of coating a food article with an enteric coating composition that is resistant to break down at a pH of 1 but begins to break down at a pH of greater than 7.
[0025] Another method of the invention can include the food article being a fruit or vegetable.
[0026] Another method of the invention can be used for producing a food additive for improving the shelf-life of a food article. The method can include the steps of: (a) shredding a first food article; (b) sanitizing the first food article; (c) applying to the first food article a composition featuring a fatty acid, an oligosaccharide, and a vegetable gum; (d) freeze drying the first food article; and (e) grinding the first food article into a powder to form a food additive.
[0027] Another method of the invention can include the step of applying the food additive to a second food article.
[0028] Unless otherwise defined, all technical 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 the case of conflict, the present specification, including definitions will control.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 is a graph showing the dissolution profiles for sodium ascorbate tablets using waxy cornstarch as an enteric coating.
[0030] FIG. 2 is a graph showing, for purposes of comparison with the results of testing shown in FIG. 1 , the dissolution profiles for sodium ascorbate tablets using whey-derived lactose as an enteric coating
DETAILED DESCRIPTION
[0031] The invention provides compositions for coating a food article to preserve nutrients in the food article for enteric absorption. These compositions improve health and nutrition of consumers. These compositions can also be added to a food article to increase the food article's shelf-life.
[0032] As used throughout this description, “nutrients” can refer to compounds generally recognized as necessary to support human life. These compounds can include proteins, carbohydrates, fats, minerals, and vitamins. Mineral and vitamins, because they are generally required in much smaller amounts than the other nutrients, may be referred to as “micronutrients.”
[0033] “Nutraceuticals,” as used herein, can refer to non-nutritive compounds that nonetheless may produce beneficial effects, for example medicinal effects, when consumed. Exemplary nutraceuticals include, but are not limited to, phytochemicals, glucosamine, methylsulfonylmethane, chondroitin, ruscus, bromlein, boswellin, carnitine, hydroxycitric acid, chitosan, acetyl-L-carnitine, phosphatidylserine, huperzine-A, S-adenosylmethione, vinceptine, dimethylaminoethanol (DMAE), lecithins, ginseng, ashwagandha, ipriflavone, NADH, magnesium malate, and D-ribose. “Nutraceuticals” also include as yet unknown or unidentified compounds that may produce beneficial effects when consumed.
[0034] “Phytochemicals,” as used herein, can refer to non-nutritive plant chemicals that nonetheless may produce beneficial effects when consumed. For example, some phytochemicals have been implicated as anti-cancer compounds or may possess other medicinal qualities. Exemplary phytochemicals include, but are not limited to, ajoene, allyl sulfides, beta-carotene, butyl phthalide, calcium pectate, capsaicin, carotenoids, catechin hydrate, coumarin, coumesterol, ellagic acid, flavonoids and isoflavones such as quercetin, genistein, gingerols, glycyrrhizin catechins, heliotropin, indoles and glucosinolates, isothiocyanates and thiocyanates, kaempferol, lutein, lycopene, monoterpenes such as limonene, para-coumaric acid, phenols, phthalides, phytic acid, polyacetylenes, quercetin, saponin, silymarin, sulfaforaphane, thiols, and zeaxanthin. “Phytochemicals” also include as yet unknown or unidentified plant chemicals that may produce beneficial effects when consumed.
[0035] In one embodiment, the composition can feature an enteric coating. The enteric coating can include a fatty acid, an oligosaccharide, and a vegetable gum. The fatty acid can be selected from among: oleic acid, lauric acid, linoleic acid, palmitoleic acid, caprylic acid, capric acid, myristic acid, palmitic acid, margaric acid, margaroleic acid, stearic acid, alpha-linoleic acid, arachidic acid, eicosanic acid, behenic acid, erucic acid, and combinations and mixtures thereof. In an exemplary embodiment, the fatty acid can be oleic acid.
[0036] The oligosaccharide of the composition can be selected from among: a fructo-oligosaccharide, a galacto-oligosaccharide, an inulin, and combinations and mixtures thereof. The composition can include one or more inulins, as well as the methods for producing such inulins, such as, for example, those described in U.S. Pat. No. 6,203,797, which is incorporated herein by reference.
[0037] The vegetable gum can be selected from among: konjac root extract, gellan, xanthan, carrageenan, and combinations and mixtures thereof. The vegetable gum can also be either a natural vegetable gum, a modified vegetable gum, or combinations and mixtures thereof.
[0038] In embodiments in which a natural gum is selected as an ingredient of the composition, the natural vegetable gum can be selected from among: gum arabic, guar gum, agar, carrageenan gum, karaya gum, gum ghatti, locust agar, algin, pectin, xanthan gum, locust bean gum, gum tragacanth, tamarind gum, and combinations and mixtures thereof.
[0039] In embodiments in which a modified gum is selected as an ingredient of the composition, the modified gum can be selected from among: a chelated agar; a pectin derivative; low-methoxyl pectin; high-methoxyl pectin; an alginate; a cellulose derivative; microcrystalline cellulose; methylcellulose; sodium carboxymethyl cellulose; carboxymethylcellulose; hydroxypropyl cellulose; hydroxypropyl methyl cellulose; sodium hydroxymethyl cellulose; carboxymethyl locust bean gum; gellan gum; carboxymethyl guar gum; and combinations and mixtures thereof. In an exemplary embodiment, the alginate can be propylene glycol alginate.
[0040] In an embodiment of the invention, there is provided a composition for stabilizing and protecting micronutrients, phytochemicals, nutraceuticals, and other beneficial compounds in food additives and food articles. The composition may include vegetable gums, oligosaccharides, and at least one fatty acid. An exemplary use of the composition is to protect micronutrients, phytochemicals, nutraceuticals, and other beneficial compounds in food additives and articles from degradation when subjected to low or high temperatures.
[0041] Any applicable vegetable gum may be used in the composition, following the guidelines provided herein. Vegetable gums contemplated for use in the invention include, but are not limited to, the following: gum arabic (acacia gum), guar gum (guar flour), agar (agar-agar), carrageenan gum (alpha, kappa and all other types), karaya gum (sterculia gum, India tragacanth, kadaya gum), gum ghatti, locust agar, algin, pectin, xanthan gum, locust bean gum, gum tragacanth, tamarind gum, and combinations and mixtures thereof. Additionally, modified vegetable gums may be used in accordance with the present invention. Modified vegetable gums contemplated for use in the invention include, but are not limited to, the following: chelated agar; pectin derivatives including both low- and high-methoxyl pectin; alginates such as propylene glycol alginate; cellulose derivatives such as microcrystalline cellulose, methylcellulose, sodium carboxymethyl cellulose, carboxymethylcellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, and sodium hydroxymethyl cellulose; carboxymethyl locust bean gum; gellan gum; carboxymethyl guar gum; and combinations and mixtures thereof.
[0042] In one exemplary embodiment, the vegetable gum is gellan gum. Gellan gum is a polysaccharide of repeating tetrasaccharide units. Each tetrasaccharide unit has two glucose residues, one glucuronic acid, and one rhamnose residue. Additionally, the tetrasaccharide units may be substituted with acyl (glyceryl and acetyl) groups at the O-glycosidically-linked esters. Gellan gum is commonly obtained from fermentation of a carbohydrate by the bacteria Pseudomonas elodea , although gellan gum obtained from other sources also is applicable in the invention.
[0043] In another exemplary embodiment, the vegetable gum is xanthan gum. Xanthan gum is a polysaccharide composed of glucose, mannose, and glucuronic acid and has a backbone similar to the backbone of cellulose but with additional trisaccharide sidechains. Xanthan gum is commonly used in food products to control viscosity because of its hydration and gelling capabilities. Additionally, its relatively good hydration ability at low temperatures may make xanthan gum useful in hindering ice recrystallization in freeze-thaw situations. Xanthan gum is commonly obtained from fermentation of corn sugar by the bacteria Xanthomonas campestris , although gellan gum obtained from other sources also is applicable in the invention.
[0044] In yet another exemplary embodiment, the vegetable gum is carrageenan gum. “Carrageenan” refers collectively to a group of polysaccharides consisting of long chains of galactose derivatives obtained by alkaline extraction from red seaweed, commonly of the genus Chondrus, Eucheuma, Gigartina and Iridaea . The three most common carrageenan gums (i.e., κ-carrageenan, ι-carrageenan, and λ-carrageenan) are commonly used as gels and thickeners in food products.
[0045] In a preferred embodiment, the composition can include about 1% to about 50% vegetable gums. In a more preferred embodiment, the composition can include about 1% to about 25% vegetable gums. In a most preferred embodiment, the composition can include about 1% to about 10% by weight vegetable gums.
[0046] Any applicable oligosaccharides may be used in the composition, following the guidelines provided herein. Oligosaccharides are short chains of sugar molecules. Common oligosaccharides include fructo-oligosaccharides (FOS), galacto-oligosaccharides (GOS), and inulins. Vegetables are common sources of oligosaccharides, though oligosaccharides obtained from other sources also are contemplated for use in the invention.
[0047] In a preferred embodiment, the composition can include about 5% to about 45% by weight oligosaccharides. In a more preferred embodiment, the composition can include about 5% to about 25% by weight oligosaccharides. In a most preferred embodiment, the composition can include about 5% to about 10% by weight oligosaccharides.
[0048] Application of the composition to a food additive or food article may act as a protective barrier at the molecular level to increase the temperature resistant qualities of the food additive or article, particularly the temperature resistant qualities of micronutrients, phytochemicals, and nutraceuticals that may be present in the food additive or article. For example, addition of the composition may help a food additive or article to withstand the 150° F. to 180° F. temperature changes commonly associated with the freeze drying process. Food additives and articles treated with the natural composition may experience less degradation of their natural nutritional and extra-nutritional content when cooked or frozen by consumers and manufacturers. Application of the natural composition, therefore, may help to reduce reliance upon synthetic nutritional supplements in processed food products. Additionally, application of the natural composition may increase the shelf life of treated food additives and articles.
[0049] In another embodiment, there is provided a process for preparing a food additive. A food article may be shredded and sanitized. A composition comprising vegetable gums, oligosaccharides, and at least one fatty acid as described herein may be applied to the food article. The food article may be freeze dried and ground into a powder. A stabilizing composition optionally may be applied to the powder. The food additive may be mixed with processed foods to enhance the nutritional and extra-nutritional content of the food.
[0050] The food article may be any applicable raw material useful as a food additive, as will be appreciated by one skilled in the art. Raw fruits and vegetables, for example, are contemplated as food articles. Phytochemical-rich foods are preferred food articles. Phytochemical-rich foods include, but are not limited to, tomatoes, broccoli, garlic, Brussels sprouts, cabbage, bok choi, and other cruciferous vegetables. Additionally, fruit such as apples and oranges are useful as food articles. The raw fruits and vegetables preferably may be selected, for example, to ensure freshness and stored at reduced temperatures. The food articles may be shredded to a particle size of about 6.2 mm (0.25 inches). Preferably, the food article may be shredded to a particle size of about 3.2 mm (0.125 inches). If desired, the shredded food articles may be selected by weight.
[0051] A mixture of vegetable gums, oligosaccharides, and at least one fatty acid as described herein may be applied to the food article, for example by dusting or spraying. The mixture may help to prevent degradation of nutraceuticals and phytochemicals present in the food article during subsequent processing, for example freeze drying. Preferably, the vegetable gum is selected from gellan, xanthan, carrageenan, and combinations and mixtures thereof. A mixture of about 1% to about 50% by weight vegetable gums, about 5% to about 45% by weight oligosaccharides, and about 1% to about 20% by weight fatty acid is preferred. A mixture of about 1% to about 25% by weight vegetable gums, about 5% to about 25% by weight oligosaccharides, and about 5% to about 15% by weight fatty acid is more preferred. A mixture of about 1% to about 10% by weight vegetable gums, about 5% to about 10% by weight oligosaccharides, and about 5% to about 10% by weight fatty acid is most preferred. The mixture may be applied in a liquid form or a dry powdered form. It may be preferable to apply the mixture in a temperature controlled manner so as to maximize the adhesion between the mixture and the food article. Also, it may be preferable to mix the vegetable gum and oligosaccharide components first, thereby forming a sticky product, and then add the fatty acid to the sticky product and mix until homogenous.
[0052] The food article may be freeze dried to reduce the moisture content of the article. Freeze drying may proceed in any applicable manner, as will be appreciated by one skilled in the art. In an exemplary embodiment, the food article may be cooled to about 0° C. (32° F.) before being introduced to a rotary type freeze dryer. After introduction of the food article, the pressure in the freeze dryer may be reduced to about 500 microns of Hg (0.5 torr), which may aid in removing moisture from the food article. The evaporation of water from the food article due to the low pressure in the freeze dryer may further reduce the temperature of the food article, for example, to about −18° C. (0° F.). The low pressure may be maintained for about 8 to about 12 hours. Thereafter, the temperature of the freeze dryer may be allowed to increase to about 30° C. (86° F.). Freeze drying the food article may preferably reduce the moisture content, which is typically about 85% before freeze drying, to within the range of about 2% to about 5%.
[0053] The food article may be ground to a powder. Preferably, the size of the powder is about 60 mesh to about 100 mesh. The mesh size of the powder may be determined by sifting the powder through a screen with appropriately sized orifices. A sifting process also may be used to separate powders of different sizes in order to obtain a powder of a desired mesh size. A stabilizing composition may optionally be added to the food article. The stabilizing composition, if used, may help to further prevent degradation of micronutrients, nutraceuticals, and phytochemicals present in the food article during subsequent processes, for example cooking. In a preferred embodiment, a stabilizing composition comprising a second mixture of vegetable gums, oligosaccharides, and at least one fatty acid as described herein is added to the food article.
[0054] The food additives made according to this process may exhibit superior resistance to degradation and deactivation of constituent nutraceuticals, phytochemicals, and micronutrients during subsequent processing of food products supplemented with the food additives. For example, the phytochemicals of the food additives made according to this process may resist temperatures up to about 80° C. (180° F.). More preferably, food additives made according to this process may maintain 97% of their natural nutritional content at temperatures up to 205° C. (400° F.).
[0055] The invention now will be described in more detail with reference to the following non-limiting example.
Example 1
[0056] Tests were conducted using the composition which determined that vegetable gums containing polysaccharides such as, for example, oligosaccharides, are preferred for inclusion in the composition over saccharides such as, for example, lactose. In these tests, sodium ascorbate, a freely water-soluble compound, was used as a detectable marker. Microcrystalline cellulose (“MCC”) and waxy cornstarch were used as the excipients in a first set of tablets. In a second set of tablets, lactose monohydrate was used as a reference cofiller instead of the waxy cornstarch. Lactose is the primary saccharide complex found in whey protein materials. Purified water was used as a granulation liquid in these tests.
[0057] Preparation of Tablets
[0058] As ingredients, the first set of tablets contained: 0.1% sodium ascorbate; 70.6% microcrystalline cellulose; and 29.3% waxy cornstarch. The second set of tablets contained: 0.1% sodium ascorbate; 70.6% microcrystalline cellulose; and 29.3% lactose.
[0059] Each set of tablets was made using the extrusion/spheronization technique using a mixer/granulator, an extruder, and a spheronizer. The tablets were prepared in batches of 2.5 kg. The speed of the powder feeder was 35 rpm and the speed of the liquid input pump was 195 rpm for formulation I (i.e., the first set of tablets) and 158 rpm for formulation II (i.e., the second set of tablets). The spheronization times for formulations I and II were 6 minutes and 2 minutes, respectively. The tablets were dried for 24 hours at ambient temperature.
[0060] Dissolution Tests
[0061] In vitro release tests were performed using a USP (U.S.A. Pharmacopoeia, 1995) apparatus I (basket method). The dissolution medium was 500 mL of 0.1 N hydrochloride acid and simulated intestinal fluid (SIF) without enzyme (pH 7.4, USP) maintained at 37±0.5° C. The basket rotation speed was maintained at 100 rpm. Samples were assayed by UV spectrophotometry at 444 nm for sodium ascorbate.
[0062] Confocal Laser Scanning Microscopy (CLSM) and Image Analysis
[0063] Observations were made with a Bio-Rad Lasersharp MRC-1024 attached to a microscope using a Zeiss Plan-Neofluar 10×/0.30 NA air lens. A 488-nm line of a krypton-argon laser and a laser power of 0.15 mW were used. The iris, black, gain control, and all other settings were kept constant during all experiments. Kalman for N=6 frames per Z level was set prior to initiation of Z series. Images were recorded at intervals of 5 μm in the Z direction.
[0064] Each set of photographs was evaluated using an image analysis system. The image was measured by determination of fluorescence intensity of sodium ascorbate in the film. The measurements were made in triplicate. Exactly the same size of image was determined for images at different sections.
[0065] Results of the Dissolution Test
[0066] To investigate the enteric properties of the tablets, a dissolution test was performed in 0.1 N HCl for 1 hour, and subsequently in SIF. The results showed that the 29.3% enteric-coated waxy cornstarch tablets had a good acidic resistance in 0.1 N HCl solution for at least 1 hour, while the lactose tablets failed the test. The waxy cornstarch-containing enteric tablets dissolved in SIF in less than 10 minutes. The lactose pellets gave no acidic resistance. As regards tablet performance, waxy cornstarch-containing tablets released the marker material slower than the lactose pellets.
CONCLUSION
[0067] Clear differences were found in dissolution between the waxy cornstarch- and lactose-containing tablets. Waxy cornstarch contains almost entirely the polysaccharide amylopectin, with no amylose. Amylopectin is a branched D-glucose (alpha 1-6) chain. This chain also contains alpha 1-4, 1 of the 2 polysaccharides that make up a starch. The branched structure of waxy cornstarch with all its attached chains yielded a large molecule and gave steric hindrance. Obviously, this large branched molecule of waxy cornstarch is able to better control premature sodium ascorbate release from the tablets than when lactose is used as a cofiller (lactose is additionally more water soluble than waxy cornstarch).
[0068] Lactose is a disaccharide that consists of galactose and glucose fragments bonded through a β-1→4 glycosidic linkage. Lactose's systematic name is β-D-galactopyranosyl-(1→4)-D-glucose. The reasons mentioned above explain why lactose-containing tablets dissolved faster and, consequently, were poorer candidates for than the waxy cornstarch tablets. FIG. 1 shows the dissolution profiles for sodium ascorbate tablets using waxy cornstarch as an enteric coating, which delays the dissolution of the tablets for a much longer period than does whey-derived lactose, as shown in FIG. 2 .
[0069] While the description of the embodiments presented above has been described with reference to particularly preferred embodiments, it is recognized that similar advantages may be obtained by other embodiments. The foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. It will be evident to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention, and all such aspects, advantages and modifications are within the scope of this invention and the following claims.
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Compositions and methods are described that promote health and increase a shelf-life of foods. The compositions may feature mixtures of fatty acids, vegetable gums, and oligosaccharides. When introduced into a food article, the compositions can act as a protective barrier for micronutrients, phytochemicals, and nutraceuticals such as may be found in food products, for example food additives, as the food products are stored and as the food products are being digested. The compositions can stabilize food products during prolonged storage and as ingested food products move through the digestive tract so that nutrients are available for absorption in a consumer's intestines. Methods for producing food additives using the compositions are also described.
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STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
(Not Applicable).
CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a Section 371 application based upon PCT/GB97/02708 filed Oct. 8, 1997, and United Kingdom application 9620934.1, filed Aug. 10, 1996.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to apparatus and to a method for conducting assays and, in particular, to multi-well plate structures for receiving and holding, in separate wells, volumes of liquid for the purpose of conducting chemical or biochemical assays. Multi-well trays or plates having a 2-dimensional array of small wells are commonly used in medicine and science to facilitate testing of a liquid analyte. One particular area of use is blood screening where blood or blood products are introduced into the wells to test for viruses such as HIV, heptitis etc.
2. Description of the Related Art
Such tests (immunoassays) typically involve an antigen-antibody interaction, where the surfaces of the wells are coated with specific antigen itself. This approach detects circulating antibodies to that specific antigen. Alternatively the wells can be coated with a specific antibody which captures circulating antigen which is, in turn, identified by a second antibody directed against a second epitope on the captured antigen. These two approaches are just two of the large number of variants developed in immunoassay (review Principles and Practice of Immunoassay Price & Newman 1997 ISBN 1-56159-145-0).
In an immunoassays sample must be applied and in most cases subsequent addition of reagents or washing buffer is required. Typically the well is exposed to blood or blood product and the well is rinsed clean and a further reactant, which binds either to exposed antibodies or captured antigens is introduced into the wells, to create an observable reaction. These reactions may produce a colour or some other observable change. This enables the wells containing specific antigen antibody reactions to be identified and the extent of these reactions quantified.
It is often necessary to fill each well of a multi-well tray with a precisely defined volume of analyte. This is normally achieved using a single or multi-headed micro-pipette. However, this process is often time consuming and, particularly where a large number of wells are to be filled can lead to a number of wells being missed.
BRIEF SUMMARY OF THE INVENTION
In certain circumstances it is necessary that the wells of a tray be contained within a substantially closed container, e.g. to avoid the risk of contamination of the wells and of leakage of contaminated material. With trays such as this, it may be difficult or impossible to gain access to the wells to enable them to be filled using a micro-pipette.
It is an object of the present invention to overcome or at least mitigate the disadvantages of known multi-well trays.
This is achieved by providing a multi-well assay plate structure which defines a relatively shallow substantially enclosed space above a plurality of wells, with the enclosed space having an inlet and an outlet separate from the inlet. Fluid introduced via the inlet flows into the space, and covers the wells, by displacing air. Withdrawal of the fluid from the space via the inlet or outlet leaves fluid in the wells allowing various tests to be performed.
According to a first aspect of the present invention there is defined a multi-well assay plate structure comprising:
a first upper surface, a second lower surface having a plurality of wells disposed therein, the first and second surfaces defining a chamber having an inlet and an outlet, the inlet and outlet allowing fluid to be introduced and withdrawn from the chamber, the wells being proportioned and dimensioned to retain a volume of fluid in each well following withdrawal of the liquid.
Preferably, the chamber is shallow enough to allow fluid to fill the wells and the chamber. The wells are deep enough to retain a volume of fluid following withdrawal of fluid in the space above the wells.
The plate structure can be of any convenient shape but, advantageously, is sector-shaped with a detachable handle at the longer arc-portion to facilitate locating the sector on a disc. Conveniently, a plurality of sector-shaped structures are located on the disc.
Conveniently, also the sectors and discs are made of plastic and the sectors can be snap-fitted onto the disc. The sectors and the disc include lock and key portions to allow the sectors to be snap-fitted in the correct orientation only.
Alternatively, a disc with a plurality of separate sections can be manufactured or moulded in one piece instead of snap-in sectors.
The composite structure may be snap-fitted onto a compact disk.
The disk structure may have a circumferential gutter extending around its periphery to facilitate collection of fluid following fluid introduction/withdrawal from the chamber.
The wells are dimensioned and proportioned in terms of diameter and depth to receive and retain fluid containing the analyte or part of the reagent under test. The exact dimensions are a matter of choice and depend on a number of parameters such as the type of material of the surfaces of the chamber and wells; viscosity of the fluid and the depth (height) of the space between the first and second surfaces.
Advantageously, the dimensions of the structure are such that the wells fill to retain sufficient fluid the space is flooded and withdrawal to allow a measurable reaction to be measured within an individual well without contribution from adjacent wells. The overall process of sequential steps of flood and fill is advantageous in that it allows both discrete measurements within individual wells when filled and efficient washing of an array of wells (flood) which is useful in multistep procedures, such as immunoassays, which requires sequential application of reagents interspersed with rigorous washing steps. This permits the wells to be cleaned or rinsed in the same way as filling to allow subsequent tests to be carried out within an individual well whilst avoiding cross-contamination between adjacent wells.
The structure is preferably made of transparent or otherwise optically transmissive plastic to facilitate optical reading of the wells to determine the results of the tests. Conveniently, the structure is integrated with automatic fluid handling apparatus and an optical reader of allow automatic fluid handling and optical assessment of the results of the reactions. Alternatively, fluid handling can be manually controlled and the results of the reactions within the structure can be assessed by an optical reader or be scored by visual assessment.
According to a second aspect of the present invention there is provided a multi-well assay structure comprising an upper surface and a lower closely spaced opposed surface, said upper and lower surfaces defining a relatively shallow space therebetween, the lower surface having a plurality of wells therein, at least two spaced apart openings providing access to said space from an external location, wherein a fluid introduced into said space through one of said openings fills substantially all of the space and covers of the wells and said fluid, when subsequently withdrawn through the same or the other opening, leaves the wells filled with liquid.
The volume of fluid introduced into each well when using the structure of the present invention is substantially defined by the volume of the well. The accuracy and precision with which the wells can be filled is therefore defined by the accuracy and precision with which the wells can be fabricated and which is generally high. Furthermore, the multiplicity of wells can be filled by way of a single injection and withdrawal of fluid through an opening into the space containing the wells, so that the wells can be filled extremely rapidly.
The structure of the present invention provides for the filling of a plurality of wells in a substantially closed chamber, the only openings into that container being the fluid injection opening and a second ‘vent’ opening.
The structure of the present invention simplifies the process of cleaning or rinsing previously filled wells as this can be achieved by repeatedly injecting and withdrawing fluid through one of said openings.
Conveniently, the spacing between said upper and lower surfaces is sufficiently small to facilitate the flow of fluid in said space by capillary or capillary like action. Typically, the spacing is less than 1 mm and preferably less than 0.5 mm.
Preferably, said upper and lower surfaces are substantially planer.
The wells may have any suitable geometry. For example, the wells may be provided in said lower surface by blind circular holes with a semi-spherical termination. Alternatively, the wells may have substantially straight sidewalls, e.g. so that the sidewalls extend substantially vertically and terminate in a flat base. Vertical sidewalls assist in preventing the transfer of fluid between adjacent wells.
The surfaces may be provided by respective upper and lower plates which are spaced apart by one or more spacer walls.
Preferably, the opening through which fluid is introduced into said space is provided through either the upper or lower surface and, more preferably, through the upper surface. The additional opening may be provided through said upper or lower surface or through a side surface.
Preferably, said opening for introducing a fluid comprises a relatively small opening arranged to receive the end of a syringe or similar liquid injecting device, where the opening forms a substantially air-tight seal around said end.
Preferably, said lower surface of the container is treated to increase the hydrophobicity to facilitate smooth flow of liquid across the sector and hydrophilicity to aid movement of liquid into desired locations, e.g. wells. This helps to prevent the formation of air pockets in the space and aids filling of the wells. The treatment may comprise for example exposing the surface to a wetting agent, e.g. poly-1-lysine, or exposing the surface to a gas plasma.
In one embodiment of the present invention, the multi-well structure is embodied in a disc. The disc effectively comprises upper and lower circular plates, the internal surfaces of which respectively define said upper and lower opposed surfaces. Preferably, said opening for introducing liquid into the space is a hole passing through the upper circular plate. Preferably, the second opening is provided at the peripheral edge of the disc. The space between the upper and lower plates is subdivided, by one or more dividing walls, to provide a plurality of multi-well plates in which case each space is provided with an opening and a vent to enable each space to be independently filled. The dividing walls may extend radially and/or may be concentric to one another.
Preferably, at least one of the upper and lower plates forming the container are transparent to enable optical inspection of the wells from outside the container. The other of the upper and lower plates may comprise a reflecting surface so that radiation entering into the container through the transparent plate transverses the container in both directions, resulting in an improved signal detection for optical inspection.
In an alterative embodiment of the present invention there is provided a disc arranged to receive a plurality of sector (pie) shaped inserts each of which comprises a generally planar upper surface having a plurality of wells provided therein. For each insert, the disc comprises a substantially planar surface arranged, in use, to oppose said substantially planar insert surface and means for retaining the insert in position so that the respective planar surfaces are in closely spaced opposition to one another, and said at least two openings.
Preferably, the opening for filling the container is provided through the planar surface of the disc. The vent opening is preferably provided at, or adjacent to, the peripheral edge of the disc.
The disc preferably comprises upper and lower circular plates separated by radially extending spacers. The spacers define slots between the plates for receiving said inserts. Preferably, said planar surface of each insert comprises upstanding walls around at least a portion of its periphery for the purpose of sealing the inner edges of the insert to the opposed planar surface of the disc, thereby to prevent seepage of liquid around the insert.
According to a third aspect of the present invention there is provided a method of filling the wells of the multi-well structure of the above first aspect of the present invention, said method comprising the steps of:
introducing a fluid into said chamber through one of said openings to substantially flood the chamber;
and subsequently withdrawing the fluid from the chamber through the same or the other opening to leave liquid in the wells.
Preferably, the method further includes the step of forming an air tight seal between the fluid inlet and an end region of a syringe or similar liquid injecting device, and injecting fluid through the opening into the chamber and subsequently sucking liquid out of the space through the opening.
According to a fourth aspect of the present invention there is provided a method of conducting a chemical or biochemical assay said method comprising the steps of:
providing a surface within a substantially enclosed chamber having a plurality of wells at spaced locations sufficient to allow a reaction at each well location,
treating each well with a first reagent, flooding the enclosed chamber and covering the wells with a fluid carrying at least a second reagent,
removing excess fluid from said chamber to leave a mixture of said first and second reagents in each well, and
optically assessing each well and determining if a reaction occurred and correlating the reaction results to provide an assay of the chemical or biochemical reactions under test.
Preferably, the step of optical assessment is carried out automatically using optical reading apparatus.
Preferably also, the surfaces with the wells having first fluid carrying reagents are prior prepared for loading into the structure.
Conveniently, the fluid carrying at least the second reagent is introduced into the structure and withdrawn from the structure using suitable automatic fluid handling apparatus.
Conveniently also, after optical assessment of the results of the assay, the automated fluid handling apparatus is used to inject and withdraw rinsing fluid a predetermined number of times from the well tray to clean the wells for receiving subsequent samples for assay.
According to a fifth aspect of the present invention, there is provided chemical/biochemical assay apparatus comprising an assay plate structure defined in said first aspect and having a plurality of wells for receiving samples to be assayed,
fluid handling means for introducing and removing fluid reagents into said assay plate structure to allow a fluid reagent mixture to be retained in each well, and
optical assessment means for measuring optical result of the reaction in each well.
Preferably, the fluid handling means and the optical assessment means are automated.
According to a sixth aspect of the present invention there is provided an assay plate structure for use in conducting optical assays of a fluid analyte, the plate structure comprising:
a disc for rotation about a central axis, the disc having upper and lower plates and a plurality of substantially radially extending walls disposed between the plate, wherein said walls sub-divide the disc into a plurality of disc sectors; and
a plurality of disc inserts arranged to be received by respective disk sectors and to be retained therein,
the structure further having a plurality of openings through the upper surface, at least one opening above each disc sector for introducing a liquid analyte into the sector space between the plate and the disc insert.
Preferably, the disc further comprises a lower plate, spaced apart from said upper plate by said radially extending walls. More preferably, the upper and lower plates are circular.
Preferably, the upper surface of each disc insert and the opposed surface of the plate are substantially planar, and, more preferably, are in a closely spaced arrangement.
Preferably, a vent opening is provided for each disc segment around the periphery thereof, between the radially outer edge of the upper plate and each disc insert.
These and other aspects of the present invention will now be described with reference to the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a diagrammatic representation of a multi-well assay plate structure according to a first embodiment of the present invention;
FIGS. 2 a to 2 c illustrate the steps involved in filling the wells of the container of FIG. 1 ;
FIG. 2 d is an enlarged detail of part of the structure of FIGS. 2 a to 2 c;
FIG. 3 shows a multi-well assay plate structure according to a second embodiment of the present invention;
FIG. 4 a shows a third embodiment of a disc-style structure for conducting multi-tests;
FIG. 4 b shows an enlarged cross-sectional detail of FIG. 4 a to allow snap-fitting of the plates in the disc sectors;
FIG. 4 c is a fourth embodiment of a disc-style structure for conducting multi-tests;
FIG. 4 d shows a modification of the outer disc with hinged sectors and which is applicable to the previous embodiments;
FIG. 5 depicts chemical/biochemical assay apparatus for conducting an assay on reactions carried out using the multi-well assay plate structures shown in FIG. 3 or FIGS. 4 a, b, c and d, and
FIGS. 6 a and 6 b depict the data and graphs respectively of antigen/antibody biochemical assays carried out using the apparatus of FIG. 5 on the assay plate shown in FIG. 4 a, b, c and d.
FIG. 7 shows a plate structure including digitally encoded address information.
FIG. 8 corresponds to FIG. 2 d with the location of lenses 90 shown.
DETAILED DESCRIPTION OF THE INVENTION
Reference is first made to FIG. 1 which shows a multi-well assay plate, generally indicated by reference numeral 10 , having a box-like construction with a rectangular cross-section. The assay plate 10 comprises an upper plate 12 , a lower plate 14 , and side and rear spacers 16 , 18 , 20 all of which are made of a transparent polycarbonate. The front of the box, indicated generally by the reference numeral 22 , is open to the surrounding space.
The spacers 16 , 18 , 20 are dimensioned to produce a space 21 of uniform spacing d between the opposed inner surfaces 12 a, 14 a of the upper and lower plates 12 , 12 . Spacing d is chosen such that a selected liquid is able to flow through the space 21 between the upper and lower plates 12 , 14 in a controlled manner by capillary or capillary-like action. Generally, d is less than 0.5 mm.
A small opening 23 extends through the upper plate 12 to communicate the inner space 21 with the exterior space surrounding the container. Opening 23 is located close to the rear wall 20 in order to prevent air-locks forming in the container during filling as will be described in more detail below.
A regular array of wells or depressions 24 are formed in the upper surface 14 a of the lower plate 14 . Typically, the polycarbonate assay plate with wells 24 is produced by suitably moulding the lower plate 14 or by etching or pressing. The wells 24 are 2 mm in diameter and 1 mm deep and typically have a volume of 5 μl and any suitable number of wells may be provided. The wells are spaced 4 mm apart (centre or centre).
FIGS. 2 a to 2 c illustrate the process by which the wells 24 of the assay plate 10 are filled with a liquid analyte 25 . The end 26 of a syringe 28 containing the liquid analyte 25 is pressed into the opening 23 provided in the upper plate 12 of the container 10 ( FIG. 2 a ) so as to form an air-tight seal between the periphery of the syringe and the inner surface of the opening 23 . The plunger 30 of the syringe 28 is then depressed to force the liquid 25 through the opening 23 into the space 21 within the plate 10 . As best seen in FIG. 2 b, due to the capillary or capillary like flow of liquid through the space 21 , the entire space 21 is filled and wells 24 are covered before liquid 25 beings to flow through the front open face 22 of the container 10 . When it is observed that all of the space 21 is filled and the wells 24 are covered with liquid, and preferably prior to liquid flowing out through the front face 22 , the plunger 30 of the syringe 28 is withdrawn. This action empties the space 21 of liquid, but results in the wells 24 being filled with liquid 25 as shown in FIG. 2 c. FIG. 2 d shows an enlarged cross-sectional view through part of the assay plate structure and showing how liquid is retained in wells 24 up to the meniscus. As with the filling process, liquid flows from the space 21 in a controlled manner. No puddles or drops of liquid remain in the space 21 , other than in the wells 24 .
It will be appreciated that prior to introducing the liquid analyte 25 into the space 21 , for example during the manufacture of the assay plate 10 , the wells 24 of the plate 10 may be coated with an appropriate reactant. For example, if it is desired to conduct antigen-antibody reactions, the wells 24 are coated with an antigen. The remainder of the surface 14 a is coated with a blocking agent to prevent antigen and antibodies from binding to surface 14 a. Once the wells 24 have been filled with the liquid analyte 25 , any antibodies present in the liquid analyte 25 will bind with the antigens contained in the wells 24 . There is no binding of the antibodies to surface 14 a. If it is necessary to conduct a further reaction in the wells 24 , e.g. to bind a coloured or fluorescent label to the bound antibodies or exposed antigens, it is possible to repeat the steps of FIGS. 2 a to 2 c in order to introduce the labelled components into the wells 24 . Prior to introducing the labelled components, if it is necessary to rinse the wells 24 and the inner surfaces 12 a, 14 a of the plate 10 , this is again easily achieved by repeating steps 2 a to 2 c with the syringe 28 containing, for example, distilled water.
There is illustrated in FIG. 3 a second embodiment of the present invention which depicts a multi-well assay plate in the form of a disk 32 designed for use with a rotating scanning device having a CD player type format. One such device is described for example in WO96/09548. The disk 32 shown in FIG. 3 comprises a pair of upper and lower circular plates 34 , 36 sandwiched together to provide a cylindrical space 38 therebetween. This space 38 is divided into eight sectors 40 by radially extending spacers 42 . A plurality of wells 44 are provided in each sector 40 (one set of which is shown in broken outline) by forming the upper surface 36 a of the lower circular plate 36 as described with reference to FIG. 1 . The wells 44 are of the same size and are spaced as for FIG. 1 .
Each sector 40 provides a chamber or space 46 which can be filled independently via openings 48 provided through the top surface of each sector 40 . The peripheral edge 50 of each sector 40 is open to the surrounding space to provide a vent for the sector 40 to allow liquid to flow through the space or chamber 46 by displacing air therefrom.
In order to enable the disk 32 to be compatible with scanning devices such as are described in WO 96/09548, the upper and/or lower plates 34 , 36 are made of transparent polycarbonate to enable a liquid beam to be scanned across the disk surface. The disk 32 is provided with a central hole 52 to enable the disk 32 to be mounted on a rotatable shaft.
As is described in W/O96/09548, one of the surfaces of the upper of lower plates 34 , 36 may be provided with digitally encoded address information, as indicated at 39 in FIG. 7 , which can be read by the scanned light beam. This information may be encoded by way of “pits” and “lans” pressed or moulded into one of the plates. This address information can be used to provide accurate location information on the part of the disk which is being scanned by the light beam.
There is shown in FIG. 4 a third embodiment of a disk assay plate 54 which comprises upper and lower circular transparent polycarbonate plates 56 , 58 which are spaced apart by a number of radially extending spacer walls 60 to create a plurality of disk sectors 62 . The inner surfaces 56 a, 58 a of the circular plates 56 , 58 are both planar.
Each disk sector 62 is arranged to receive a sector plate insert 64 which is a transparent polycarbonate plate with a detachable handle 66 on the outer side to facilitate entry and removal of the plate insert 64 in the sector 62 . The plate insert 64 and spacer wall 60 have respective recesses/projections (not shown in the interest of clarity) which allow the plate insert 64 to be inserted only in the correct orientation. The plate insert 64 has a groove 68 , as shown in FIG. 4 b for example, which allows the inset to be snap-fitted over a projection 70 upstanding from plate 58 into the sector. The thickness of the sector plate insert 64 is marginally less than the spacing provided between the upper and lower plates 56 , 58 so that the plate insert 64 can be pressed/fitted into one of the disk sector 62 to define a liquid receiving chamber or space 73 between the upper surface 64 a of the plate insert 64 and the lower surface 56 a of the upper disk plate 56 . Openings 72 are provided through the upper disk plate 56 into each disk sector 64 whilst the space 70 between the radially outermost peripheral edge 74 of the insert plate 64 and the upper plate 56 provides a further vent or filling opening into the disk sector 62 .
The surface 64 a of the insert plate 64 is provided with a plurality of wells 76 as described with respect to FIG. 1 . The wells are 2 mm in diameter, 1 mm in depth and 4 mm apart (spaced between centres). These wells are filled by introducing liquid into the disk sector 64 through the upper opening 72 to fill space 70 and subsequently withdrawing the liquid through the same opening as previously described.
Reference is now made to FIG. 5 of the drawings which depicts assay apparatus for conducting an assay on reactions carried out using the assay plate structures of the already described embodiments. However, for convenience, the assay apparatus will be described in combination with the preferred embodiment shown in FIGS. 4 a,b with like numerals referring to like parts.
In this case the plate 54 is mounted on a shaft 74 carried by a turntable 77 . The apparatus includes a suitable automatic fluid filling/withdrawal system, generally indicated by reference numeral 80 , which operates a syringe 82 to dispense/retrieve fluid from a reservoir 84 via the openings 72 into the space 70 between the plate surface 56 a and the surface 64 a of each sector plate 64 . The fluid can of course be dispensed and retained manually if desired. This is achieved for each sector by rotating the disk plate 54 to a suitable position to allow fluid filling/withdrawal. It will be appreciated that the plates are pre-prepared with various reagents, e.g. antigens, and they are inserted in the appropriate wells 76 , as described with reference to FIGS. 4 a, 4 b. The plates are first flooded with fluid carrying antibodies and withdrawal of the fluid leaves the antibody/antigen reagents filling the wells 76 resulting in a reaction.
The following example of an assay within the embodiment shown in FIG. 4 b is described to provide a better understanding of the steps involved:
Multi-Antigen Elisa Using Sectors
1. The underside of upper surface ( 56 a ) of is coated with silicone spray to aid fluid movement. Sector plates 64 are also coated including wells 76 . Any excess silicone is removed.
2. Sectors wells 76 are loaded by hand with a panel of seven antigens—Human Serum Albumin, Antitrypsin, Macroglobulin, Antithrombin III, Catalase, Antichymotrypsin and Plasminogen at a concentration of 20 ug/ml in PBS and a volume of 2 ul/well. Control wells contain PBS only. Antigens can be arranged in blocks of the same on the sector plate 64 in a series giving a panel of tests evenly distributed over the sector. Incubate at room temperature for 15 minutes.
3. Wash with 0.05% PBS-Tween using flood/fill technique—1 ml is flooded across the sector plate via holes 72 in the top plate using a 1 ml pipette. This pipetted up and down three times then withdrawn and the washing discarded. This repeated a further three times to ensure complete washing.
4. Blocking is carried out to prevent reactions occurring other than at well sites with 50 mg/ml Bovine Serum Albumin (BSA) (in PBS) using flood/fill. 1 ml of BSA/PBS is flooded across the sector, pipetted up and down three times, withdrawn and discarded. This allows all wells 76 to be filled simultaneously. Incubate for 15 minutes at room temperature.
5. Wash as before.
6. Primary antibodies are applied to the sector plate 64 as a mixture using flood/fill with each individual antibody at the following concentrations: anti-Human Serum Albumin 1/1000, anti-Antitrypsin 1/2000, anti-Macroglobulin 1/2000, anti-Antithrombin III 1/1000, anti-Catalase 1,1000, anti-Antichymotrypsin 1/1000, anti-Plasminogen 1/1000. Antibodies are diluted in 0.5 mg/ml BSA/PBS. Incubate for 10 minutes at room temperature.
7. Wash as before.
8. Second antibody is Amdex anti-IgG (peroxidase conjugate) at a concentration of 1/1000 in 0.5 mg/ml BSA/PGS. After washing this is applied to the sector using flood/fill. Incubate at room temperature for 10 minutes.
9. Wash as before.
10. The substrate is insoluble Tetramethylbenzidine (TMB). This reacts with the peroxidase on the second antibody to produce an intense blue colour. After washing this is applied to the sector plate 64 by flood/fill but is left flooded across the sector plate 64 after pipetting up and down several times. Incubate for 10 minutes at room temperature.
11. Remove TMB and discard. Wash out the wells with distilled water four times by flood/fill. A blue precipitate will be evident in wells with a positive reaction. No colour is produced in negative wells. Store sections in dark as TMB will slowly fade in daylight. The date for the above assay is shown in FIG. 6 a and is graphically represented in FIG. 6 b which is reproducible and is representative of a large number of experiments ( 712 ).
It will be seen that there is a significant measurable change for each antibody/antigen reaction compared with the background level. The reaction results in an optical change, from transparent to coloured (blue) and which is measured using an optical detector which measures light transmissivity through the disk and wells. In this case optical assessment was carried out using the apparatus as shown in FIG. 5 by locating the plate 64 in a light transmissive microscope 80 (Zeiss Axiophot fitted with a JVC video camera 83 (Model No. TK-1280E)) and sensing the change in optical signal. The output of the video camera is connected to Macintosh IICx 85 with video frame capture. The results can be displayed via the MAC display 87 or a hard copy provided by printer 86 . Analysis was carried out by measuring means grayscale values in centre of wells quantified by NIH Image software. Background levels taken from sectors which had not been exposed to immuno-chemicals or chromogen were subtracted from all experimental wells. Experimental wells contained array or seven separate antigens listed above. In addition, experimental controls were carried out in which specific antigen was omitted wells and wells exposed to the same regime of blocking, antibody binding and exposure to chromogenis substrate. The average reading from these experimental controls minus mean reading from the sector alone was defined as the background level of straining. Experimental readings from the seven specific antigens providing signals of approximately five to six times greater than this background. It will be observed that there is no cross-contamination between wells 76 become of the efficiency of withdrawal and because the substrate in this case is insoluble. However, this assay would also work satisfactorily for soluble substrates because of fluid withdrawal from the sector plate 64 leaving fluid in the wells 76 only, not on surface 64 a.
In a modification, if it was unnecessary to withdraw all of the liquid to leave a film on surface 64 , the assay would still work with an insoluble substrate in each well, cross-contamination would still not occur. However, this arrangement would be unsatisfactory for soluble substrates in the wells as the film could cause dispersal to other locations and provide contamination of other wells.
With the embodiment shown in FIGS. 4 a, 4 b the disk sector plate 54 is more suitable for conducting a variety of different assays, e.g. antigen/antibody assays for different patients, i.e. one patient/sector.
It will be appreciated that modification may be made to the above described embodiments without departing from the scope of the present invention. For example, the opening through which a liquid analyte is introduced may be provided through the lower plate of the multi-well container. More than one opening can be used for faster flooding. This opening may be arranged to receive the tip of a syringe needle. The vent opening may also be provided in any one of the walls of the container although it is preferably provided in a peripheral wall. The opening 22 may be provided by a single opening 22 or by a series of openings or vents as shown in FIG. 4 d for example. A laser may be used with CD optics instead of the microscope and video camera for the embodiment of FIG. 4 . The top plate in the embodiment of FIGS. 3 and 4 may be snap-fitted to the lower plate and may be snap-fitted onto a CD base plate which would receive sections and provide the advantage of positioned information. As shown in FIG. 4 c the upper plant surface 56 can have sector covers connected to a lower surface or central boss by a hinge, for example integrated living hinge 90 at the inner radius to allow each disk sector 62 to be pivotally raised and lowered and allow sector plates 64 to be inserted into each sector. The well size and spacing may be varied as required, for example the wells could be 3 mm in diameter; 1.5 mm apart and spaced 5.5 mm between centre. The exact size and spacing is a matter of choice consistent with the requirement that fluid is retained in the wells after withdrawal as described above. However, the wells could also be filled during flooding of the space depending on the well size, type of plastic and fluid properties. However, liquid will still be retained in the wells upon withdrawal of the liquid. Also, the structure and inserts made may be of any suitable optical transmissive plastic, such as polystyrene or perspex™. The handle 66 may be integrated with or detachable from plate 64 . As shown in FIG. 4 a the radially extending ribs may have radial shoulders 92 to define a recess 94 for receiving the plate 64 also defining the spacing height between the surface 64 a of the plate 64 and the underside 56 a for receiving the liquid. Suitable materials may be used to coat the interior of the sectors to aid fluid movement as described with reference to silicone above. This may be applied to the underside of the top surface and to the top surface of the plats as for the other embodiments. Suitable materials may be used to increase the hydrophobicity of liquid across the sector and hydrophilicity to the movement of liquid into the desired location, e.g. wells. The wells may be coated by a suitable optical reflective material to enhance the reflection of light and observation of reactions occurring within the wells and, similarly, lenses 90 may be located in the top or bottom light transmissive plates 12 and 14 as seen in FIG. 8 , to improve optical assessment of the reaction. These lenses may be mounded into the upper or lower plates of the exemplary embodiments during the manufacture as is well known in plastic moulding processes. Separate optical elements may be used instead, if appropriate.
In a modification to the embodiments described, the wells are absent from the upper surface of the plate and that plate retains its planar surface to enable a thin, uniform layer of liquid to be introduced into the space between the upper disk plate and the insert plate. An insoluble substrate with reagent or reagents (e.g. an antigen) may be applied directly to the planar surface of the insert plate by for example applying spots of reagent thereto.
For certain applications, it may be appropriate to provide each insert with a lid which can be slid into the space between the insert and the upper plate 22 of the disk following filling of the wells. The lower surface of the lid may be arrange to be flush with the surface of the insert so as to close off each well. This prevents liquid from being thrown out of the wells during spinning of the disk during automated reading and analysis. The invention has use in immunoassay applications including tests for sexually transmitted diseases, parasites, allergens, cancer markers and cardiac markers, either in laboratories or at point-of-care locations, for example medical practitioners offices or the like. Other applications of the invention are in chemical and biochemical assays. Examples of such assays include immunoassay, clinical biochemistry tests, nucleic acid analysis and receptor ligand interactions. Examples of clinical biochemistry uses would be in measurement of serum analytes such as glucose, urea, creatinine and enzymes such as alkaline phosphatase. Immunoassay application include tests designed to detect infections organisms, viruses, parasites as well as endogenous analytes such as circulating hormone levels and cancer markers. Examples of chemical analysis include measure of phosphate and nitrate levels in water, environmental and industrial monitoring including potable and waste water and process monitoring. The system could be used in a variety of settings including clinical laboratories, doctor's and veterinary surgeries as well as industrial and research laboratories.
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A multi-well assay plate structure ( 54 ) and assay apparatus and a method for performing chemical biochemical assays is described. The multi-well assay plate structure ( 54 ) defines a relatively shallow substantially enclosed space ( 71 ) above a plurality of wells ( 76 ), with the enclosed space ( 71 ) having an inlet ( 72 ) and an outlet ( 22 ) separate from the inlet. Fluid introduced via the inlet ( 72 ) flows into the space ( 71 ) and/or wells ( 76 ) by displacing air. Withdrawal of the fluid via the inlet ( 72 ) or outlet leaves fluid in the wells ( 76 ) allowing various tests to be performed. Various embodiments of the structure are described. The preferred arrangement embodies the structure on a transparent plastic disk which can be used with automatic fluid handling apparatus ( 80 ) and the results assessed using optical assessment apparatus ( 81 ). The apparatus can be used to perform a variety of assays but, in particular, biochemical/chemical assay, immunoassays and genetic (DNA) assays and it can be used in a laboratory for multiple sample testing or at a point-of-care, i.e. in a surgery or clinic.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of German patent application 102005036485.3 filed Aug. 3, 2005, herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The invention relates to an open end rotor spinning machine with plural workstations each having a spinning device for producing a yarn, a yarn take-off mechanism and a winding device for producing a cross-wound bobbin rotatably held in a creel. More particularly, the spinning device has a spinning rotor circulating in a spinning housing at a high speed, a fiber band opening roller and a fiber band draw-in cylinder driven by a single drive, and the yarn take-off mechanism is loadable by a single drive.
[0003] Open end rotor spinning machines of this type, as known and described, for example, in German Patent Publication DE 198 36 065 A1, have a plurality of similar workstations arranged next to one another in a row, on which a fiber band preferably presented in a spinning can is spun to form a yarn and then wound to form a cross-wound bobbin. The individual workstations, in each case, for this purpose have a spinning device and a winding device, both the working members of the spinning device and the working members of the winding device generally being loaded via drive means along the length of the machine. In other words, arranged in the region of the spinning devices, are tangential belts to drive the spinning rotors and the fiber band opening rollers as well as a drive shaft along the length of the machine for loading the fiber band draw-in cylinder. The drive of the bobbin drive roller arranged in the region of the winding devices is also implemented via a drive shaft along the length of the machine. A yarn guide rod going back and forth is also present, which is loaded by a traversing gearing arranged at the end of the machine, and on which the yarn guides are fixed.
[0004] Furthermore, yarn take-off mechanisms are present, the driven take-off rollers of which are a component of a continuous drive shaft.
[0005] The workstations of such open end rotor spinning machines are attended to by service units, which patrol and automatically intervene, for example, along the workstations when a failure, for example, a yarn break, has occurred at one of the workstations. In such a case, the service unit runs to the relevant workstation, is locked thereat and with a pivotably mounted suction nozzle, which can be vacuum-loaded, seeks the yarn which has run onto the cross-wound bobbin after a yarn break. Apart from the suction nozzle, such service units also have a series of further yarn handling elements, which allow the yarn taken up by the suction nozzle, after a corresponding preparation in the open end rotor spinning device of the relevant workstation, to be repieced on a fiber ring circulating there with the spinning rotor. The individual yarn handling elements of the service unit, including the suction nozzle, are preferably driven by an electric motor which drives a cam disc pack which is connected via special lever rods to the yarn handling elements.
[0006] Service units of this type, which are described in relative detail, for example in German Patent Publication DE 198 27 605 A1, are relatively complicated, however, with respect to their design structure and therefore relatively cost-intensive.
[0007] Rotor spinning machines, which were still driven without such moveable service units, are also known from the past from German Patent Publications DE-OS 22 03 198 or DE-OS 25 34 816.
[0008] In the region of the yarn take-off tubes of their spinning devices, these open end rotor spinning machines, in each case, have a piecing aid, which makes it possible to shorten a yarn retrieved from a cross-wound bobbin to a specific length, to prepare it, convey it back to the rotor groove of a spinning rotor rotating in a spinning housing which can be loaded with a vacuum and to piece it there on a circulating fiber ring.
[0009] However, it is disadvantageous in these mechanisms that piecing a new yarn on the fiber ring circulating in the rotor groove takes place in a substantially uncontrolled manner. In other words, in these known mechanisms, there is neither an exact matching of the yarn feed into the spinning rotor nor an exact time matching of the yarn take-off to the speed of the spinning rotor and this leads to the fact that the yarn splices or piecings generated with these known mechanisms do not at all correspond to current quality standards.
[0010] Furthermore, open end rotor spinning devices are known which have various single drives in the region of their workstations.
[0011] Open end rotor spinning devices are described, for example in German Patent Publication DE 43 09 947 A1, in which the fiber band draw-in cylinder and/or the fiber band opening roller are driven, in each case, via a single drive.
[0012] An open end spinning machine is also known from German Patent Publication DE 100 62 096 A1, in which various single drives are arranged, in each case, in the region of the workstations. The workstations of this rotor spinning machine, for example, have an open end rotor spinning device with a single motor-driven fiber band draw-in cylinder, a single motor-driven yarn take-off mechanism and a single drive for the bobbin drive roller.
[0013] Furthermore, an open end rotor spinning machine, the workstations of which are configured such that they can automatically eliminate failures, in particular yarn breaks, is described in European Patent Publication EP 1 283 288 A2. The very substantially self-sufficient workstations of this known open end rotor spinning machine, apart from the spinning station's own suction nozzle, also inter alia have single drives for the bobbin drive roller and the yam take-off mechanism. The workstations also, in each case, have a piecing aid device which is arranged in the region of the open end rotor spinning device and in which the yarn provided by the suction nozzle is prepared for re-piecing.
SUMMARY OF THE INVENTION
[0014] Proceeding from the above prior art, the invention is based on the object of providing an economical open end rotor spinning machine, which is configured such that the workstations can be restarted without problems after a failure, without a special service unit being necessary for such purpose, wherein the quality of the piecer being produced should correspond to current high quality standards.
[0015] This object is achieved according to the invention by an open end rotor spinning machine having plural workstations each having a spinning device for producing a yarn, a yarn take-off mechanism and a winding device for producing a cross-wound bobbin rotatably held in a creel. The spinning device has a spinning rotor circulating in a spinning housing at a high speed, a fiber band opening roller and a fiber band draw-in cylinder driven by a single drive. The yarn take-off mechanism is loadable by a single drive. According to the present invention, each workstation has a mechanism for the defined cutting to length of a yarn retrieved manually from the cross-wound bobbin, a storage mechanism for receiving a specific yarn quantity, and a drive mechanism which can be activated in a targeted manner for lifting the cross-wound bobbin from the bobbin drive roller. The drive of the yarn take-off mechanism is reversibly driven. A manually activatable control mechanism is operable, during a piecing process, to activate the drive of the yarn take-off mechanism, the drive of the fiber band draw-in cylinder and the drive mechanism to lift the cross-wound bobbin according to a predetermined piecing program.
[0016] Advantageous further configurations and features according to preferred embodiments of the invention are discussed hereinbelow.
[0017] The embodiment of an open end rotor spinning machine as above-described has the advantage, in particular, that it is economical to implement, on the one hand, and, on the other hand, allows splices to be produced, which correspond to current high quality standards. In other words, splices produced after a failure, for example a yarn break, are comparable with splices such as are produced by automatically operating service units with regard to their appearance and their strength. The number of unrecognised “out-of-standard” splices can also be significantly reduced with the mechanism according to the invention, as such splices, when the yarn is taken off from the spinning device, already lead to a yarn break, in particular owing to the high rotor speed. In other words, on average, the quality of the splices produced with the mechanism according to the invention is better than splices which are produced with a service unit. Overall, open end rotor spinning machines with the features described in claim 1 are distinguished by a very favourable price/performance ratio.
[0018] In an advantageous embodiment, a stationary mechanism is arranged in the region of the open end rotor spinning device and allows a yarn manually retrieved from the cross-wound bobbin to be cut to length precisely in a simple manner. The yarn that has been cut to length can then immediately be properly prepared for refeeding into the open end rotor spinning device by a manual yarn preparation apparatus which the operator preferably carries on him. In other words, the yarn end is made as far as possible twist-free. The manual yarn preparation has the advantage that the operator can visually check the result of his preparation and optionally correct it. In this manner, it can be ensured that only properly prepared yarn ends are conveyed back into the spinning device for repiecing and this has a very positive affect on the quality of the splices.
[0019] It is advantageous that the control mechanism of the workstation is configured and connected to the yarn take-off mechanism in such a way that, on manual activation of the control mechanism, feeding of fibers into the spinning rotor is immediately started and in addition the return of the yarn end that has been cut to length in to the spinning rotor rotating at operating speed is initiated in a manner so as to be precise in terms of time and length. The control mechanism in this case ensures an extremely precise yarn return feed, in other words, the prepared yarn is conveyed back in to the spinning rotor according to instructions and placed on the fiber ring rotating there.
[0020] The spinning rotor is either rotated by a tangential belt along the length of the machine or by a single drive. The fiber band opening roller can either be driven by a tangential belt along the length of the machine or by a single drive, which is preferably configured as a so-called external rotor drive.
[0021] An embodiment with a tangential belt drive is an economical and proven type of drive, in each case, while a variant with a single drive offers the advantage that a drive of this type can be adapted individually at any time to the respective work situation if necessary.
[0022] It is also provided in an advantageous embodiment that a drive mechanism to lift the cross-wound bobbin from the bobbin drive roller is provided in the region of the creel. The drive mechanism is preferably configured here as a sliding piston gearing, which loads the creel, in which the cross-wound bobbin is held and which can be activated in a defined manner via an electromagnetic valve by the control mechanism.
[0023] Thus, the cross-wound bobbin can be placed in a targeted manner on the rotating bobbin drive roller during the piecing process and after the repiecing of the yarn can rapidly be accelerated at least to a speed in which the peripheral speed of the cross-wound bobbin corresponds to the yarn take-off speed.
[0024] As the acceleration of the cross-wound bobbin, in particular in the case of large bobbins, initially remains slightly behind the yarn take-off, the excess yarn thus occurring is initially compensated by means of a storage mechanism, which operates at this time as a passing yarn store. In other words, a yarn loop is initially formed in a pneumatically loaded yarn store and is slowly released again in the course of the spinning process.
[0025] The pneumatic yarn store thus also takes up the yarn length, which is required at the beginning of the piecing process in conjunction with the yarn refeeding.
[0026] The creel also has a braking mechanism via which the cross-wound bobbin can be fixed to prevent rotation if necessary. Thus, after the yarn has been manually retrieved, the braking device prevents further yarn material impairing the piecing process from being unwound inadvertantly from the cross-wound bobbin, in addition to the yarn length required in conjunction with the forming of the yarn length for the piecing process.
[0027] Further details of the invention can be inferred with the aid of the embodiment described hereinafter in the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 shows a side view of a first embodiment of a workstation of an open end rotor spinning machine according to the invention,
[0029] FIG. 2 schematically shows the activation of the single drives of a workstation in a further embodiment of the invention,
[0030] FIG. 3 shows a manual yarn preparation apparatus for treating the yarn end of the yarn that has been cut to length and retrieved by the operators from the cross-wound bobbin.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0031] FIG. 1 shows one half of a semi-automatic open end rotor spinning machine 1 according to the invention. Spinning machines of this type have a plurality of workstations 2 , which are equipped, in each case, with a spinning device 3 and a winding mechanism 33 . In the spinning devices 3 , the fiber band 34 presented in spinning cans 28 is spun, in each case, to form a yarn 30 , which is wound on the winding mechanism 33 to form a cross-wound bobbin 22 . The winding mechanisms 33 have, as known per se, a creel 21 , in each case, for rotatably holding the tube of a cross-wound bobbin 22 , a bobbin drive roller 23 , a yarn traversing mechanism 26 and a mechanism 7 for lifting the cross-wound bobbin 22 from the bobbin drive roller 23 .
[0032] The mechanism 7 is configured for example as a sliding piston gearing, which is connected to an excess pressure source (not shown) via a pneumatic line 24 , into which an electromagnetic valve 17 is inserted.
[0033] Furthermore, a braking mechanism 50 , by means of which free rotation of the cross-wound bobbin 22 lifted from the bobbin drive roller 23 can be prevented, if necessary, is arranged on the creel 21 .
[0034] In the present embodiment, the bobbin drive roller 23 is driven as a group drive. In other words, a drive shaft along the length of the machine is provided, on which the individual bobbin drive rollers 23 are fixed. In an alternative embodiment, however, a single motor drive of the bobbin drive roller 23 is also possible. In a case such as this, the drive of the bobbin drive roller is connected via a corresponding control line to the spinning station's own control mechanism 9 .
[0035] A yarn lifting mechanism (not shown), known per se, can also be installed in the region of the winding mechanism 33 . A yarn lifting mechanism of this type prevents the yarn being able to be grasped inadvertently by the traversing yarn traversing mechanism 26 during the piecing process. In other words, the yarn lifting mechanism configured as a foldable plate, for example, initially holds the yarn during the actual piecing process at a spacing above the yarn traversing mechanism 26 going back and forth.
[0036] The spinning device 3 substantially has, as known, a spinning rotor 4 , a yarn band opening roller 12 and a yarn band draw-in cylinder 14 .
[0037] According to the embodiment of FIG. 1 , the spinning rotor 4 is mounted in a support disc bearing 5 , for example, and is driven via a tangential belt 6 along the length of the machine.
[0038] To detect the speed of the spinning rotor 4 , a sensor mechanism 8 may also be provided, which is then connected to the control device 9 via a signal line 40 . The fiber band opening roller 12 is preferably also loaded via a tangential belt 13 along the length of the machine, while the fiber band draw-in cylinder 14 is driven by a single motor via a drive 15 . The drive of the fiber band draw-in cylinder 14 , for example a stepping motor 15 is also connected to the control mechanism 9 via a control line 16 .
[0039] Furthermore, the workstations 2 each have a yarn take-off mechanism 18 , the drive 19 of which is connected via a control line 20 to the control mechanism 9 .
[0040] Viewed in the yarn running direction, a yarn storage mechanism 37 , preferably a pneumatically loadable storage nozzle, is provided downstream from the yarn take-off mechanism 18 . The storage nozzle 37 is connected, in this case, via a pneumatic line 38 to a vacuum source (not shown).
[0041] Finally, a stationary device 10 is arranged in the region of the spinning device 3 and allows defined cutting to length of a yarn retrieved manually from the cross-wound bobbin 22 , the yarn end of which can then be treated by the operators by the yarn preparation mechanism 25 shown in FIG. 3 .
[0042] This yarn preparation mechanism 25 for manually preparing the yarn substantially consists of a handle 36 and a yarn handling region 35 for processing the yarn end.
[0043] As indicated in FIG. 1 , the control mechanism 9 which controls the drive of the mechanism 7 for lifting the cross-wound bobbin, the drive 16 of the yarn take-off mechanism 18 and the drive 15 of the fiber band draw-in cylinder 14 , is connected via a signal line 29 to a switching element 27 . In other words, the control mechanism 9 can be activated manually via the switching element 27 .
[0044] In an alternative embodiment, which is shown in FIG. 2 , the spinning rotor 4 is not supported in a support disc bearing 5 , but in a magnetic bearing, indicated only schematically. The spinning rotor 4 , in a case such as this, is preferably loaded by a single drive 31 .
[0045] The spinning rotor drive 31 is connected, in this case, via a control line 45 to the control mechanism 9 . As also shown in the embodiment according to FIG. 2 , the fiber band opening roller 12 can also be driven by a single motor. In other words, arranged inside the clothing ring of the opening roller, is an external rotor drive 59 , for example, which is also connected to the control mechanism 9 via a control line 32 .
[0046] Operation of the open end rotor spinning machine according to the invention occurs as follows:
[0047] During the regular spinning process, the yarn 30 produced in the spinning device 3 is taken off by the yarn take-off mechanism 18 and wound on the winding device 33 to form a cross-wound bobbin 22 . The cross-wound bobbin 22 , which is rotatably mounted between the arms of a creel 21 , rests, in this case, with its surface on the bobbin drive roller 23 and is driven by it in the winding direction via frictional engagement. At the same time, the yarn 30 running onto the bobbin is transferred by means of the yarn traversing mechanism 26 in such a way that it runs in crossing layers on to the lateral surface of the cross-wound bobbin 22 .
[0048] If there is a failure, for example a yarn break, at one of the workstations 2 of the open end rotor spinning machine 1 , which may preferably be detected by a stop motion (not shown), the control mechanism 9 ensures that the relevant workstation 2 is stopped.
[0049] In other words, the drive 15 of the fiber band draw-in cylinder 14 is firstly switched off in the region of the spinning device 3 and further fiber supply to the spinning rotor 4 is stopped. Simultaneously, the drive 19 of the yarn take-off mechanism 18 is simultaneously switched off and the cross-wound bobbin 22 is lifted from the bobbin drive roller 23 by the mechanism 7 . The spinning rotor 4 driven by a tangential belt 6 or the opening roller 12 driven by a tangential belt 13 firstly continue to rotate at operating speed.
[0050] When, as shown in the embodiment according to FIG. 2 , single drives 31 or 59 are provided for the spinning rotor 4 or the fiber band opening roller 12 , in the event of a yarn break, these drives are generally immediately switched off. After a yarn break there are different procedures for repiecing the yarn.
[0051] For example there is the possibility of repiecing without clearing the spinning rotor. However, the generally practised method is more probable, in which the spinning device 3 is firstly cleared before repiecing.
[0052] If repiecing is to take place immediately without prior cleaning of the spinning rotor, the cross-wound bobbin 22 lifted from the bobbin drive roller 23 is initially rotated manually in the unwinding direction, the yarn 30 which has run on to the lateral surface of the cross-wound bobbin 22 after the yarn break is picked up by the operator and returned to the region of the spinning device 3 . The cross-wound bobbin 22 is then fixed by the braking mechanism 50 to prevent rotation and the tightly drawn yarn 30 is placed by the operator in the yarn take-off mechanism 18 . By actuating the control mechanism 9 , the operator then ensures that the yarn take-off mechanism 18 briefly starts to run counter to the yarn take-off direction, with a precisely predetermined yarn quantity being sucked into the pneumatic yarn store 37 of the workstation 2 and stored there.
[0053] In the case of a generally practised, prophylactic or necessary clearing of the spinning rotor, the spinning device 3 has to be initially opened by the operator. If the spinning device 3 has a spinning rotor 4 driven by a tangential belt 6 and a fiber band opening roller 12 driven by a tangential belt 13 , (embodiment FIG. 1 ), these are automatically separated from their drive means on opening the spinning device 3 and run down to a standstill. The spinning rotor 4 is preferably additionally braked by a rotor brake. These rotatable components are also initially braked to a standstill in the embodiment according to FIG. 2 , in which the spinning rotor 4 and the opening roller 12 are loaded by single drives.
[0054] After clearing, the spinning device 3 is closed again and, for example, the spinning rotor 4 and the opening roller 12 placed on their associated tangential belts 6 or 13 .
[0055] The spinning rotor 4 and the opening roller 12 then run up to their operating speed. At the same time, as explained above, the yarn 30 is retrieved manually from the cross-wound bobbin 22 , the tightly drawn yarn 30 is placed in the yarn take-off mechanism 18 , the yarn take-off mechanism 18 is briefly driven counter to the yarn take-off direction and a yarn loop is formed in this case in the pneumatic yarn store 37 .
[0056] In the two cases, the yarn 30 is then cut to length at the stationary device 10 which is arranged in the region of the spinning device 3 and the yarn end is manually prepared for repiecing by means of a preparation mechanism 25 which in each case is in the possession of the operator. The prepared yarn end is finally yarned into the yarn take-off tube 11 of the spinning device and the control mechanism 9 is activated via the switching element 27 .
[0057] The control mechanism 9 then initiates the drive 15 of the fiber band draw-in cylinder 14 , so, in conjunction with the fiber band opening roller 12 , which is rotating at operating speed, in the spinning rotor 4 , a fiber ring is produced.
[0058] With a small, defined time delay, the control mechanism 9 also activates the drive 19 of the yarn take-off mechanism 18 in such a way that a targeted yarn return of the prepared yarn end of the yarn 30 into the spinning device 3 takes place. In other words, the yarn end, in the spinning device 3 , is placed on the fiber ring circulating with the spinning rotor 4 in manner so as to be precise in terms of time and length, the fiber ring is broken open and the yarn 30 being newly produced is taken off from the spinning device 3 via the yarn take-off mechanism 18 , which was switched over to forward speed at a precise time by the control mechanism 9 . At the same time, the cross-wound bobbin 22 is lowered via the mechanism 7 onto the rotating bobbin drive roller 23 and the yarn 30 is wound on the winding device 33 to form a cross-wound bobbin 22 . The speeds with which the fiber band draw-in cylinder 14 and the yarn take-off mechanism 18 operate are thus matched precisely to the speeds of the spinning rotor 4 , fiber band opening roller 12 and bobbin drive roller 23 very substantially predetermined by the group drives.
[0059] It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.
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An open end rotor spinning machine with plural workstations each having a spinning device for producing a yarn, a yarn take-off mechanism and a winding device for producing a cross-wound bobbin. The spinning device has a spinning rotor circulating in a spinning housing at high speed, a fiber band opening roller and a single motor-driven fiber band feed cylinder. The yarn take-off mechanism can be loaded by a single drive. Each workstation ( 2 ) has a mechanism ( 10 ) for defined cutting to length of a yarn ( 30 ) retrieved from the cross-wound bobbin ( 22 ), a storage mechanism ( 37 ) for receiving a specific yarn quantity and a drive mechanism ( 7 ) for lifting the cross-wound bobbin ( 22 ) from the bobbin drive roller ( 23 ). The drive ( 19 ) of the yarn take-off mechanism ( 18 ) can be reversibly driven. During the piecing process, a manually activatable control mechanism ( 9 ) activates the drive ( 19 ) of the yarn take-off mechanism ( 18 ), the drive ( 15 ) of the fiber band draw-in cylinder ( 14 ) and the drive mechanism ( 7 ) to lift the cross-wound bobbin ( 22 ) according to a predetermined piecing program.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a national application for International Application No. PCT/DE00/4266 which was filed on Nov. 30, 2000 and which published in German on Jun. 7, 2001 which in turn claims priority from 199 58 251.3, which was filed on Dec. 3, 1999 of which the following is a of which the following is a specification.
FIELD OF THE INVENTION
The invention relates to a force sensor which is integrated into an actuator for generating or transmitting a force in the force flux and has an actuator bottom that is transverse to the force flux.
BACKGROUND OF THE INVENTION
In motor vehicles, the braking function is implemented nowadays by means of hydraulically activated actuators. In the method designated as “brake-by-wire”, electrically operated braking devices are used. In said braking devices, actuators, (i.e. elements in which the braking force is generated and by means of which the braking force is transmitted), are activated by means of electromotive step-down drives. The resulting advantages are the individual and variable configuration of the braking process and the possibility of simultaneously performing further functions, for example the ABS function (Anti-lock Braking System). As an electromechanical braking system will generally operate with controlled braking force, the precise measurement of the braking force is essential to the performance of the overall system. High demands are made on the precision of the system due to the synchronous operation. For example, fault tolerances should be <1% even if the braking force is, for example, 5 t. The measuring task is additionally made considerably more difficult as a result of limited accessibility to relevant measurement locations, the small amount of free space in the direction of force and the extremely high spatial, and chronological temperature gradients. These aspects rule out the use of known force sensors such as, for example, strain gauges.
SUMMARY OF THE INVENTION
The present invention is based on the object of enabling precise and unambiguous sensing of braking forces as close as possible to the location where the braking force acts. More specifically, the invention is based on the recognition that a force sensor can easily be integrated into an actuator. The deflection of an actuator bottom or of a braking piston bottom (a designation by analogy with hydraulic systems) can be used as a measurement variable for the braking force. The actuator bottom is appropriately configured for this purpose. The actuator is generally constructed in the form of a hollow cylinder, having an actuator bottom, and also containing a supporting ring by which it bears directly or indirectly on the brake lining of a brake. The braking force is generated centrally and applied to the actuator bottom.
The deformation of the actuator bottom is advantageously determined by means of various measuring methods. One method which is suitable for series production is the capacitive measuring method, whereby the actuator bottom constitutes an electrode of a capacitor and the capacitance which is changed with the deformation is determined. The capacitor will therefore generally be a plate capacitor. The electrode which lies opposite the actuator bottom is embodied as a plate and which is pressed onto a base with spring support so that the high temperature gradients do not cause any mechanical stresses to be transmitted to the insulator of the electrode. Thus this ensures a defined electrode spacing, as is described in the European patent EP 0 849 576 B1.
The connecting point between the actuator bottom, namely the rear part of the actuator which is generally of cylindrical construction, and the supporting ring, is embodied so as to be relatively rigid, since the braking force can cause torques to be transmitted to the supporting ring at this point and said torques cause the measurement to be subject to a hysteresis due to friction effects. For this reason, the material cross section at this connecting point is advantageously reduced by an internal peripheral groove, an external peripheral groove, or by means of a combination thereof so that only minimum torques are transmitted.
The measures which are provided for minimized hysteresis are likewise suitable for suppressing in the axial direction a temperature gradient in the actuator bottom due to largely radial introduction of heat. Axial temperature gradients can cause the actuator bottom to bulge in the direction of the force to be measured and result in an incorrect measurement.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the present invention are described below with reference to drawings, in which
FIG. 1 illustrates an actuator bottom with supporting ring, isotherms and the heat flow being indicated;
FIG. 2 illustrates an actuator bottom in the state of rest and in the deformed state;
FIG. 3 illustrates an actuator with grooves provided on the inner and outer peripheries in order to reduce the material cross section between the actuator bottom and supporting rings;
FIG. 4 illustrates shows a view corresponding to FIG. 2, but with a hysteresis-free deformation path of the actuator bottom;
FIG. 5 illustrates an actuator with measuring elements for the deformation ΔZ; and
FIG. 6 illustrates an actuator with capacitive measuring device for the deformation ΔZ; and
FIG. 7 illustrates a schematic sectional view of a motor vehicle braking system with a sensor integrated in the frictional engagement and in the actuator.
DETAILED DESCRIPTION OF THE INVENTION
A significant aspect of the invention consists in the integration of the force sensor in the actuator, the actuator bottom being used as a measuring element. The elastic deformation of the actuator bottom with corresponding application of a force is thus the measurement variable at this deformation element. The magnitude of the force can be inferred from the deformation.
In order to prevent temperature-induced deformation at the actuator bottom in the measuring direction, i.e. in the direction of force, it is ensured that at the connecting point between the actuator bottom and supporting ring the application of the temperature or the introduction of the heat is such that temperature gradients are minimized in the direction of force, which is equivalent to an approximately axial profile of the isotherms formed in the direction of force. The heat flow will thus run inwards almost exclusively in the radial direction.
In order to prevent hysteresis effects during various load changes in which the force is increased and decreased, the generation or torques and their transmission to the supporting ring are minimized in a targeted fashion. This leads to the connecting point between the actuator and the supporting ring being embodied in a way similar to a joint. As the actuator bottom serves as a diaphragm-like deformation element, when force is applied to the connecting point between the actuator bottom and external cylinder or supporting ring, a torque will be generated which has a center of rotation positioned within a T connection. This leads to a radial migration of the supporting face of the supporting ring on the brake lining. As a result of friction forces present at the supporting point, when the load is reduced the original supporting position is no longer reached, so that hysteresis effects arise which prevent reproducible measurements. As a result of appropriately formed grooves which are constructed on the periphery, the transmission of torques at the point in question is prevented.
FIG. 1 shows a section through actuator 1 , the actuator bottom 2 being arranged perpendicularly with respect to the direction of force. The direction of force is illustrated in FIG. 2 . In addition, FIG. 1 shows a base plane 12 as an application point for the force, a supporting ring 3 , a brake lining 18 , and the direction of the heat flow. The actuator 1 has an overall cylindrical shapes for the most part is a hollow cylinder shape. The supporting ring 3 is arranged in the region of the outer periphery of the actuator bottom 2 , in the direction of force behind the actuator bottom 2 . In order to guide the actuator bottom, the hollow-cylinder form is extended opposite the supporting ring 3 , beyond the actuator bottom 2 and counter to the direction of force. Furthermore, isotherms 11 , which characterize various temperatures T 1 to T 4 , are entered in the actuator bottom 2 . The construction corresponding to FIG. 1 does not contain any sensor elements and does not have any features which can prevent temperature effects, or hysteresis effects. The central feature in FIG. 1 is that the heat flow Q, starting from the brake system with the brake lining 18 on which the supporting ring 3 rests, is introduced into the actuator bottom 2 in such a way that temperature gradients occur in the direction of force in the actuator bottom 2 . This leads to temperature-induced deformations of the actuator bottom, which results in incorrect measurement of the force.
FIG. 2 shows a view corresponding to FIG. 1 wherein the force F, and the braking force, are shown schematically, as is the deformation of the actuator bottom 2 in the form of the deflected actuator bottom 2 . The maximum deflection ΔZ will occur in the center of the usually radially symmetrical component. The deformation which is shown will generate a torque at the connecting point between the actuator bottom 2 and the supporting ring 3 . The center of rotation 10 of said torque is designated. As a result of this torque, the surface of the supporting ring 3 which rests on the brake lining 18 will be displaced outward when force is applied. The torques M are indicated schematically.
FIG. 3 s is a view corresponding to FIG. 1, wherein the heat flow is introduced into the actuator bottom 2 virtually perpendicularly to the direction of force, i.e. radially from the outside to the inside, by means of an inner peripheral groove 8 and an outer peripheral groove 9 . This gives rise to isotherms 11 which are approximately parallel to the force. As a result, no temperature-induced deformations occur.
FIG. 4 shows an arrangement corresponding to FIG. 2, in which measures to eliminate torques M occurring when force is applied also take the form of peripheral grooves 8 and 9 between the actuator bottom 2 and supporting ring 3 . Here, the actuator bottom 2 can be deflected by a maximum absolute value of ΔZ without torques occurring at its outer edges which act on the supporting ring 3 and which cause its supporting face on the brake lining 18 to migrate outward. The material cross section is correspondingly reduced by the grooves 8 and 9 so that a joint-like construction is achieved.
FIG. 5 shows an actuator arrangement with a measurement of the actuator bottom deflection ΔZ by different sensors. On the one hand, the deflection of the actuator bottom 2 can be measured inductively or optically with a contactless distance sensor 13 . The contactless sensor is, for this purpose, mounted on the base plane 12 which is oriented perpendicularly with respect to the direction of force, and is thus displaced by ΔZ in accordance with the central region of the actuator bottom 2 . This displacement is carried out in a contactless way by moving the sensor close to the actuator bottom 2 .
A further measuring method includes the use of strain sensors 6 which are suitable for higher temperatures. These sensors measure, as their designation suggests, a strain ε, which occurs when a force F acts on the actuator bottom 2 . Metallic, semiconductor, or piezoresistive strain gauges, as well as capacitive strain sensors with silicon surface micromechanics can be used as strain sensors. As before, the peripheral grooves 8 and 9 are illustrated in FIG. 5, together with the bearing of the supporting ring 3 on the brake lining 18 .
FIG. 6 shows the actuator 1 with a capacitive measuring arrangement, whereby ΔZ is again measured. The capacitive measuring arrangement contains an electrode 5 which is positioned on an electrode mount 7 . The electrode mount is pressed in its outer region onto a base 14 with spring support. The base 14 will remain fixed, even when force is applied. The spring support is brought about by means of the spring 15 which is supported on the rear cover 22 . This ensures that the electrode 5 is oriented approximately plane-parallel with respect to the actuator bottom 2 in the position of rest. The actuator bottom 2 thus constitutes the opposite electrode corresponding to the electrode 5 . A change in the distance between these two electrodes generates a signal which is proportional to ΔZ.
FIG. 7 shows the entire arrangement of a brake system which engages a brake disc 17 . The brake linings 18 which are held together by the brake caliper 16 are pressed on both sides against the brake disc 17 if a spindle 20 exerts a braking force on the actuator 1 by electromotive means via the motor 19 . The electromotive drive is usually connected to a step-down gear mechanism. The spindle 20 transmits the braking force centrally onto the actuator bottom 2 , the motor 19 being supported at the rear on a part of the brake caliper 16 . In addition, the capacitive sensor 24 is shown schematically. In the illustration corresponding to FIG. 7, it is possible to see the heat flow which is introduced starting from the contact faces between the brake disc 17 and brake lining 18 rearward via the brake lining into the supporting ring 3 and via the latter into the actuator bottom 2 . As temperature differences of several 100° C. can occur here, it becomes clear that temperature-induced deformations can prevent reproducible measurements.
The following is to be noted with respect to the influence of temperature and hysteresis. The influence of temperature on a brake can be enormous as the actuator 1 is heated up considerably in several seconds during the braking operation. The heat flow Q occurs here exclusively via the supporting ring 3 , and is then distributed into the actuator bottom 2 . In the process, considerable axial temperature gradients occur in the actuator bottom, which is illustrated in FIG. 1 . This leads to temperature-dependent bulging ΔZ of the actuator bottom 2 , and thus to an incorrect measurement. However, if a turning, in the form of a peripheral groove 8 , is made in the interior of the supporting ring 3 , the heat flow is introduced virtually radially into the actuator bottom 2 , and a temperature-induced axial bulging ΔZ is thus precluded.
The hysteresis phenomena on the described actuator occur as a result of a relatively rigid connection of the actuator bottom 2 to the supporting ring 3 . The centrally introduced braking force not only causes a deflection ΔZ at the actuator bottom 2 but also generates a torque M corresponding to FIG. 2 . This torque ensures radial migration of the supporting face of the supporting ring 3 . However, when the loading ceases, a considerable hysteresis effect then occurs owing to the considerable frictional effects, and said hysteresis prevents, to a certain extent, the deformation ΔZ from being reversed in proportion to the force F. According to the present inventions hysteresis is avoided in that the rigid connection between the actuator bottom 2 and supporting ring is considerably reduced in cross section. Furthermore, the connection between these two parts is arranged approximately centrally with respect to the supporting face, as illustrated in FIG. 4 . Moreover, a material with a low hysteresis is used to manufacture the sensor. Special stainless special steels which can be precipitation-hardened, for example of the type 17 - 4 PH, are preferably used. The measurement of the deformation ΔZ which is proportional to the braking force is expediently carried out in relation to the edge of the actuator. For this purpose, inductive or optical methods can be used. Capacitive measuring principles, as illustrated in FIG. 6, are also particularly suitable owing to the high temperatures. The corresponding change in capacitance arises due to a braking-force-dependent change in the electrode spacing with respect to the actuator bottom 2 . A measurement signal is proportional to the deformation ΔZ, and thus to the braking force F, results from the radial strain ε of the actuator bottom 2 . In this case, high-temperature measuring gauges, piezoresistive sensors, or capacitive micromechanical strain sensors are suitable as strain sensors.
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The present invention is based on an use of the already existing actuator bottom as a deformation element for a direct measurement of braking force, and on its geometric configuration in order to measure a force in a way which is largely independent of temperature and free of hysteresis. Accordingly, a force sensor is integrated into an actuator for generally or transmitting a force in the force flux. The actuator bottom is transverse to the force flux.
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BACKGROUND OF THE INVENTION
1. Field Of The Invention
The invention relates to a method of upsetting the working of a metal slug, to a sleeve for implementing the method and to a sleeve and lid assembly for implementing the method.
2. Description Of The Related Art
Metal forgings are generally obtained by forging slugs, or billets, which are part-finished rough blanks of metal parts, generally in the form of bars, used as basic elements for forging the part that is to be obtained, their volume corresponding to the volume of the latter increased by the volume lost during forging. For example, in a jet engine, the fan discs or the compressor drums are obtained by forging metal slugs.
The invention applies particularly to the working of metal slugs resulting from powder metallurgy, but relates more generally to the working of metal slugs. It is above all recognized for the working of materials that are difficult to forge, particularly as a result of small acceptable temperature ranges.
Metal slugs originating from powder metallurgy are generally obtained by extruding a container containing the powdered material. During the extrusion, the container is forced, by a press, to pass through an orifice of a cross section smaller than its own, during which operation the material forms a dense bar. Machining the container enveloping the material—and to which it has become welded during the extrusion operation—yields the slug ready for working. Current constraints dictate a maximum diameter smaller than 300 mm, typically of the order of 230 mm, for a metal slug obtained from powder metallurgy.
Furthermore, in the field of aeronautical engineering, the safety criteria are very strict and dictate checks at all stages of manufacture. The slugs have, in particular, to be inspected, for example using ultrasound, in order to detect whether any inclusions or defects are present in the metal, as a result of cracks that have appeared during forging and possibly breaks in the finished part. The requirements governing the maximum permissible defect size in the billets as dictated by the engine manufacturers are becoming increasingly strict. Slug suppliers therefore limit the diameter of the slugs in order to be able to perform quality control using ultrasound and meet the criteria dictated by the constructors. Typically, once again, this diameter is smaller than 300 mm, for nickel-based or cobalt-based metal slugs originating from powder metallurgy.
If the finished parts of the jet engine are of large volume, then the slugs have to have a high slenderness ratio, typically in excess of 2.8, often of the order of 7 to 10, in order to compensate for their small cross section.
The term “working” is intended to cover hot deformation of a metal part in order to obtain an increase in its diameter and reduction in its length, for equal volumes. The working may be done by upsetting, that is to say by applying stress in lengthwise direction of the metal slug.
In the case of metal slugs originating from powder metallurgy, a slenderness ratio in excess of 2.8 means continuous upsetting of the slugs in order to work them so as to obtain slugs in which the ratio of length to diameter is small. The ratio is brought down to a value at which they can be forged, stamped or alternatively upset again without being contained laterally, without the risk of buckling or of imperfections being created within the fibre of the metal.
Contained upsetting means upsetting in which the slug is laterally protected, none of its surfaces being in contact with the open air. The alloys resulting from powder metallurgy require the most isothermal upsetting possible, it being typically necessary for the temperature not to drop by more than 50 or 100° C. during upsetting, otherwise deep cracks or tears will appear in the material. The operating temperature lies between the plastic deformation temperature and the melting point of the alloy, thus allowing the alloy to be forged, and is limited by a maximum value defined to ensure control over the microstructure of the alloy. Furthermore, the diameter of the worked mass must not be too small, otherwise imperfections may be created in the material. It needs to be arranged such that the slenderness ratio is below 2.8.
To achieve this, the prior art teaches cladding the slug in a steel tube, which increases its diameter and affords thermal protection. The slug and tube assembly is then upset in the open air, because it has sufficient diameter. During such upsetting, the slug and the steel tube will establish a metallic bond between them, comparable to a seized connection. It is therefore necessary, after upsetting, to machine the assembly, for example machining it on a lathe, so as to remove the steel in order to find a slug that contains only the alloy originating from the powder metallurgy. Firstly, such machining is expensive, and secondly leads to a loss in slug material. This loss of material is all the greater since, in general, the interface between the slug and the tube is relatively irregular, which means that more machining has to be done as a safety measure.
It would be desirable not to use a steel sheath. However, in such a case, it would be necessary to use very hot tooling, which would cause cracks and fissures in the slug, which would then have to be eliminated, in so far as they were accessible, by grinding.
BRIEF SUMMARY OF THE INVENTION
The invention aims to alleviate these disadvantages.
To this end, the invention relates to an upsetting method for working a metal slug of cylindrical shape and provided with a coating, characterized in that the slug is placed, lengthwise, in a sleeve the internal wall of which leaves a space with respect to the lateral surface of the slug, the slug and sleeve assembly is placed in an upsetting container, and upsetting force is exerted on the slug on at least one of its transverse surfaces until a determined slenderness ratio has been obtained, and the slug is separated from the sleeve.
By virtue of the invention, the slug is upset continuously but only the slug is upset, this being permitted because of the space formed by the internal wall of the sleeve. By virtue of the coating and the difference in cross section, the material of the sleeve, for example made of steel, is not welded or seized to the slug, which means that it need not be machined in order to separate the two after the operation. Thus there is no loss of slug material nor is there any additional cost associated with subsequent machining. The upset slug obtained thus has a very good surface finish and a very high metallurgical quality.
Advantageously, the slug is of cylindrical shape.
Obtaining an upset slug of cylindrical shape is advantageous because it makes subsequent forging, upsetting or stamping easier.
The invention also relates, for the implementation of the method described hereinabove, to the use of a sleeve of cylindrical shape intended to accommodate a metal slug, comprising an end wall from which there rises a cylindrical side wall, the end wall comprising an imprint for centering and preforming a slug.
The invention also relates to a sleeve and lid assembly comprising a sleeve as described hereinabove and a lid in the form of a plate of circular shape, the cross section of which is more or less equal to the internal cross section of the sleeve, very slightly smaller.
The invention applies particularly well to the upsetting of slugs made of alloy resulting from powder metallurgy, but also applies more generally to the upsetting of any metal slug.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood with the aid of the following description of the preferred embodiment of the invention, with reference to the attached plates in which:
FIG. 1 depicts a schematic sectional view of a metal slug housed in the sleeve of the invention;
FIG. 2 depicts a schematic sectional view of the slug and of the sleeve of FIG. 1 , both housed in an upsetting container before the slug is upset;
FIG. 3 depicts a schematic sectional view of the slug and of the sleeve of FIG. 1 , both housed in an upsetting container, at the end of the upsetting of the slug, and
FIG. 4 depicts a schematic sectional view of the slug and of the sleeve of FIG. 1 after the slug has been upset.
DETAILED DESCRIPTION OF THE INVENTION
The object of the method of the invention is to upset a metal slug 1 , in this instance a slug 1 made of a nickel-based or cobalt-based alloy obtaining using powder metallurgy. This slug 1 is of cylindrical shape. It has a given cross section and a given length. Its slenderness ratio, that is to say the ratio of its length to the diameter of its cross section in this instance is in excess of 2.8 and may be of the order of 10 or higher. The slug 1 is coated, by vitrification, with a coat of enamel.
The slug 1 is housed in a sleeve 2 of cylindrical shape. This sleeve 2 comprises an end wall 3 from which there rises a cylindrical side wall 4 of relatively small thickness by comparison with the diameter of the sleeve. The cross section of the cylinder formed by the internal surface of the side wall 4 is greater than the cross section of the slug 1 . In this instance, in the case of a slug 1 with a cross-sectional diameter of about 235 mm, the internal cross-sectional diameter of the sleeve 2 is approximately 300 mm while the thickness of its side wall 4 is approximately 20 mm. The sleeve 2 in this instance comprises, and here consists of a mild steel, which is fairly strong for the application for which it is intended. Such a steel is inexpensive, which may be preferable given the fact that the sleeve 2 is intended to be destroyed. Furthermore, it could be recycled, once the sleeve 2 has been destroyed. In the particular case considered, the sleeve 2 is formed by welding its cylindrical side wall 4 , in this instance made of mild steel, to the end wall 3 , in this instance made of a nickel alloy.
The slug 1 is inserted in the sleeve 2 via its open end. The end wall 3 of the sleeve 2 comprises an imprint 5 for centering the slug 1 . A lid 6 in the form of a plate of circular shape, the cross section of which is more or less equal to the internal cross section of the sleeve 2 , very slightly smaller, is inserted via the open end of the sleeve 2 to cover the slug 1 . The lid 6 here is made of a nickel alloy. This lid 6 also comprises, on its underside, that is to say on its surface in contact with the slug 1 , an imprint 7 for centering the slug 1 . The lid 6 is then held in position by a weld 8 made between its top surface and the internal wall of the sleeve 2 . This weld 8 is not designed to be very strong because its function is merely to hold the lid in position rather than to seal it; this weld may also be in the form of spot welds. The assembly 9 comprising the slug 1 , the sleeve 2 and the lid 6 is therefore held together, the weld 8 being breakable through application of sufficient force. This assembly 9 is ready to be used and can be temporarily stored in this state. It can also be handled.
Prior to the upsetting operation, the assembly 9 is placed in an oven in which it is heated to the temperature required for upsetting. Determining this temperature makes it possible to control the deformation of the material and the microstructure of the alloy of the slug 1 during the upsetting operation described hereinafter. In this particular instance, for a slug 1 made of nickel-based alloy, this temperature may range between 900° C. and 1200° C. and for example be of the order of 1100° C.
The assembly 9 is then placed in an upsetting container 10 made of steel and comprising a cylindrical housing 11 the cross section of which corresponds to the external cross section of the sleeve 2 . During handling, the mechanical strength of the steel of the sleeve 2 will admittedly have reduced on account of the temperature, but still remains sufficient for the geometry to be maintained. The upsetting container 10 has also been preheated, in this instance to a temperature of the order of 400 to 500° C. It is installed on a hydraulic press comprising a punch 12 which is set to bear against the upper surface of the lid 6 of the assembly 9 . This punch 12 is able to move in vertical translation, driven by the mobile upper platen of the hydraulic press. Its area of contact with the lid 6 is identical to, or of slightly smaller dimensions than, the cross-sectional area of this lid.
The operation of upsetting the slug 1 is then carried out. The punch 12 is driven by a conventional hydraulic mechanism of the hydraulic press platen to be lowered at a determined rate and thus exert stress on the slug 1 , in its lengthwise direction, via the lid 6 which descends with the punch 12 , the weld 8 having been broken by the stress exerted by the punch 12 . Since the slug 1 is at a temperature higher than its plastic deformation temperature (but below its melting point), plastic deformation of the material of the slug 1 ensues, this being manifested by a reduction in its length and an increase in its cross section. The rate of descent of the punch 12 is determined, in collaboration with the choice of the temperature of the material, in such a way as to control the deformation of the material and the change in its microstructure. In this particular instance, for a nickel-based alloy, it is chosen to be of the order of 10 mm/sec. This rate may vary during the course of the upsetting operation.
During the upsetting, since the diameter of the lid 6 is slightly smaller than the internal diameter of the sleeve 2 , the air filling the gap between the slug 1 and the internal wall of the sleeve 2 is expelled via the gap between the lid 6 and the sleeve 2 .
The enamel with which the slug 1 is coated performs three functions: lubricating the device; protecting against oxidation; and forming protection between the slug 1 and the sleeve 2 . Thus, during upsetting, the enamel forms a pasty interface which, at the end of upsetting, when the walls of the slug 1 come into contact with the internal wall of the sleeve 2 , prevents the slug 1 from welding itself to this wall. Furthermore, the same function is performed throughout the upsetting operation at the lid 6 and at the end wall 3 of the sleeve 2 .
It will be noted that, unlike the methods of the prior art, only the slug 1 is upset here. The sleeve 2 is not deformed by the operation and performs a function of containing the slug 1 and of acting as a thermal barrier or buffer between the slug 1 and the upsetting container 10 . Thus, even if the temperature of the upsetting container 10 decreases, the temperature of the slug 1 is not appreciably affected thereby. Furthermore, the slug 1 is kept centred by the imprints 5 , 7 of the end wall 3 of the sleeve 2 and of the underside of the lid 6 , respectively. These imprints 5 , 7 can thus perform a function of preforming the slug 1 and thus be designed to preform the ends of the slug 1 according to the shape that is to be given to the finished part, through a further upsetting and/or stamping and/or forging operation on the slug 1 , once this upsetting operation has been completed.
The upsetting operation is halted when a certain force is reached on the slug 1 . The slug 1 then fills practically the entire cross section of the sleeve 2 , its cross section having increased and its length having reduced accordingly, since there is no change in volume. In this situation, the punch 12 is in the lowered position as can be seen in FIG. 3 . The slug 1 has indeed been worked by upsetting.
At the end of upsetting, the punch 12 can sustain additional pressure on the assembly, for example for 10 seconds or so, in order to ensure that the geometry of the worked slug is correct, particularly that the material is correctly filling the entire housing 11 , especially the corners thereof.
With reference to FIG. 4 , the assembly 9 comprising the slug 1 , the sleeve 2 and the lid 6 , in the lowered position, with the slug 1 upset, is then extracted from the upsetting container 10 . This operation is performed in an entirely conventional way. To this end, an actuator may, for example, form the end wall of the housing 11 of the upsetting container 10 and be driven upwards after the upsetting operation, with the punch 12 having previously been driven upwards, so that the assembly 9 can be extracted from the housing 11 . Any other method of extraction is conceivable.
The assembly 9 is then cooled. To do this, it may simply be left to cool in the open air. Once a desired temperature has been reached, the slug 1 is removed from the sleeve 2 . Since these two elements have not welded themselves together, this operation is very easy. For example, once the upper portion of the sleeve 2 has been cut off above the lid 6 , it is possible to make two opposed longitudinal slots, by milling, along the side wall of the sleeve 2 , insert a wedge into this slot in order to separate the two wall portions from one another and thus be able to extract the slug 1 from the sleeve 2 . The slot may also be made at the level of the lid 6 or of the end wall 3 of the sleeve 2 , in order to remove one of these ends it then being possible for the slug 1 to be slid freely in its lengthwise direction and extracted from the sleeve 2 thus opened. However, such a slot is not generally needed because, on account of the enamel, the slug 1 is secured neither to the end wall 3 nor to the lid 6 .
The slug 1 is just then processed in order to remove the remains of its enamel coating. This treatment may be a mechanical treatment, for example by shot peening or steel wire, or chemical treatment, for example using a soda bath.
The slug 1 thus worked by upsetting may either be upset again using the same method if necessary, or upset without being contained, stamped or forged, or may undergo several of these operations in order to obtain the finished part.
It may be noted that separating the slug 1 from the sleeve 2 is made very much easier here by the difference in the values of the coefficients of expansion of the materials employed. Thus, during cooling, the volume of a slug 1 made of nickel alloy will reduce more than that of a sleeve 2 made of steel, thus creating a gap between the two and making them easier to separate.
By virtue of the method of the invention, the slug is indeed upset in a contained manner, this being advantageous in certain applications, for example when upsetting a slug of relatively small diameter originating from powder metallurgy. Only the slug is upset and this is easily removed from its protective sleeve at the end of the method. The worked slug is obtained without any loss of material or any additional cost associated with subsequent machining and thus exhibits a very good surface finish and a very good metallurgical quality. Various cross sections of slug can be obtained by adapting the cross section of the sleeve and of the upsetting container.
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An upsetting method for working a metal slug of cylindrical shape and provided with a coating is disclosed. The slug is placed, lengthwise, in a sleeve the internal wall of which leaves a space with respect to the lateral surface of the slug, the slug and sleeve assembly is placed in an upsetting container, and an upsetting force is exerted on the slug on at least one of its transverse surfaces until a determined slenderness ratio has been obtained, and the slug is separated from the sleeve. The slug is upset continuously but only the slug is upset because of the space formed by the internal wall of the sleeve. The material of the sleeve, for example made of steel, is not welded or seized to the slug, which means that it need not be machined in order to separate the two after the operation.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from U.S. Provisional Patent Application Ser. No. 60/889,764 entitled “High Impedance, high Parallelism, High Temperature Memory Test System Architecture” filed Feb. 14, 2007 which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention is related generally to automated test systems; more specifically, the invention is related to driver/receiver-type circuits employed in testing memory and similar high speed electronic devices.
BACKGROUND
[0003] Complexity levels of electronic device testing vary tremendously, from simple manual low-volume/low-complexity testing performed with perhaps an oscilloscope and voltmeter, to personal computer-based medium-scale testing, to large-scale/high-complexity automated test equipment (ATE). Manual and personal computer-based testing are typically applied when testing discrete devices, specific components of an integrated circuit, or portions of a printed circuit board. In contrast, ATE testing is used to test functionality of a plurality of complex integrated circuits (ICs) such as memory circuits or hundreds of dice on a wafer prior to sawing and packaging.
[0004] FIG. 1 shows a block diagram of an automated test system 100 of the prior art. The test system 100 includes a test system controller 101 , a test head 105 , and a test prober 107 . The test system controller 101 is frequently a microprocessor-based computer and is electrically connected to the test head 105 by a communication cable 103 . The test prober 107 includes a stage 109 on which a semiconductor wafer 111 may be mounted and a probe card 113 for testing devices under test (DUTs) on the semiconductor wafer 111 . The stage 109 is movable to contact the wafer 111 with a plurality of test probes 115 on the probe card 113 . The probe card 113 communicates with the test head 105 through a plurality of channel communications cables 117 .
[0005] In operation, the test system controller 101 generates test data which are transmitted through the communication cable 103 to the test head 105 . The test head in turn transmits the test data to the probe card 113 through the plurality of communications cables 117 . The probe card then uses these data to probe DUTs (not shown explicitly) on the wafer 111 through the plurality of test probes 115 . Test results are then provided from the DUTs on the wafer 111 back through the probe card 113 to the test head 105 for transmission back to the test system controller 101 . Once testing is completed and known good dice are identified, the wafer 111 is diced.
[0006] Test data provided from the test system controller 101 are divided into individual test channels provided through the communications cable 103 and separated in the test head 105 so that each channel is carried to a separate one of the plurality of test probes 115 . Channels from the test head 105 are linked by the channel communications cables 117 to the probe card 113 . The probe card 113 then links each channel to a separate one of the plurality of test probes 115 .
[0007] With reference to FIG. 2 , a prior art tester portion 200 of a typical ATE system designed for high speed testing, such as memory applications, has a driver 201 and comparator 203 pair electrically connected through a transmission line 205 to a single pin on a device under test (DUT) 207 . The driver 201 sends write signals to the DUT 207 through a resistive element 211 while the comparator 203 acts as a receiver for reading signals generated by the DUT 207 . When the tester portion 200 is writing a signal to the DUT 207 , the driver 201 is enabled by closing a write switch 209 and the comparator 203 is disabled by opening a read switch 213 . During a read operation, the driver 201 is disabled by opening the write switch 209 and the comparator 203 is enabled by closing the read switch 213 .
[0008] The physical length of the transmission line 205 is roughly four feet long in a typical ATE test cell used for wafer sort and three feet long in an ATE system used for package test. Since the transmission line 205 is so long, when the tester 200 is reading from the DUT 207 , a 50 ohm parallel termination resistor 217 is added into the circuit by closing a termination switch 215 . The 50 ohm termination resistor 217 is used to avoid reflections along the transmission line 205 .
[0009] With reference to FIG. 3 and continued reference to FIG. 2 , a typical 100 MHz waveform 300 produced by the prior art tester portion 200 is displayed. Closing the termination switch 215 during a read operation reduces an amplitude of the signal received by the comparator 203 to approximately 2.1 V compared with a 3.0 V output from the DUT 207 . The amplitude is reduced since the 50 ohm termination resistor 217 creates a voltage divider. If the termination switch 215 is left open, the voltage divider effect is eliminated but reflections on the transmission line 205 produce a distorted waveform 400 ( FIG. 4 ). For comparison, an actual waveform 500 ( FIG. 5 ) emanating from the DUT 207 is shown in FIG. 5 .
[0010] As is readily discernible by one skilled in the art with reference to the waveforms in FIGS. 3-5 , to test the DUT 207 with a data rate of greater than 100 MHz during a read cycle, the termination switch 215 must be closed to prevent significant distortion of the read signal. The disadvantage of closing the termination switch 215 is that the DUT 207 must source enough current to drive the 50 ohm termination resistor 217 . In today's handheld consumer electronics markets, customers demand several days of usage of their products (such as iPods® and other MP3 devices, cellular phones, digital cameras, etc.) before having to recharge batteries internal to the product. Consequently, more and more memory devices are being designed such that the output buffers conserve power (i.e., battery life). Hence, many memory devices increasingly cannot source the current to drive the 50 ohm termination resistor 217 required during ATE applications. Consequently, a maximum data rate for the testing the DUT 207 cannot be optimized.
[0011] For example, a typical memory device inside a contemporary cell phone runs at a frequency of 100 MHz. If the memory device cannot source enough current to drive the 50 ohm termination during ATE testing, the maximum test frequency will be only approximately 10 MHz. Furthermore, most memory devices are intended to be used in applications that do not require a 50 ohm termination since other devices are typically located in close proximity. When the memory device, or any other DUT, sources sufficient current to drive the 50 ohm termination during ATE testing, the electrical characteristics of the device change. Most notably, the 50 ohm termination creates a voltage divider and the DC levels measured at the comparator are attenuated.
[0012] Once of the key reasons that the driver/receiver pair has been located physically far away from the DUT in prior art applications is due to the wide temperature range over which a DUT is tested. A common temperature test range is from −40° C. to +150° C. The prior art driver/receiver pair typically cannot operate over this large temperature range while maintaining performance specifications. The performance specifications are especially critical for parametric tests such as I CC and other leakage current tests.
[0013] Therefore, what is needed is a means to test a large plurality of DUTs in high speed applications while maintaining signal integrity read from the DUTs while ensuring that a full range of temperature testing can still occur.
SUMMARY OF THE INVENTION
[0014] In an exemplary embodiment, the invention is an electronic device for use with a probe head in automated test equipment. The device includes a plurality of semiconductor devices arranged to provide at least one driver/receiver pair where the driver portion of the driver/receiver pair is configured to transmit a signal to at least one device under test and the receiver portion of the driver/receiver pair is configured to receive a signal from the at least one device under test. Each of the plurality of semiconductor devices is fabricated using metal-on-insulator technology and has a thickness less than about 300 μm exclusive of any electrical interconnects. The at least one driver/receiver pair is adapted to mount directly to the probe head.
[0015] In another exemplary embodiment, the invention is an electronic device for use with a probe head in automated test equipment. The device includes a plurality of semiconductor devices arranged to provide at least one driver/receiver pair where the driver portion of the driver/receiver pair is configured to transmit a signal to at least one device under test and the receiver portion of the driver/receiver pair is configured to receive a signal from the at least one device under test. Each of the plurality of semiconductor devices is fabricated using silicon-on-insulator technology and has a thickness less than about 300 μm exclusive of any electrical interconnects. The at least one driver/receiver pair is adapted to mount directly to the probe head.
[0016] In another exemplary embodiment, the invention is an electronic device for use with a probe head in automated test equipment. The device includes a first plurality of semiconductor devices arranged to form at least one driver arranged to couple and transmit a signal to a device under test. A second plurality of semiconductor devices is arranged to form at least one receiver arranged to couple and receive a signal from the device under test. Each of the second plurality of semiconductor devices has a thickness less than about 300 μm exclusive of any electrical interconnects. The at least one receiver is adapted to mount directly to the probe head.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a block diagram of an ATE system of the prior art.
[0018] FIG. 2 is a block diagram of a DUT driver/receiver testing apparatus employed in the ATE system of FIG. 1 .
[0019] FIG. 3 is a typical prior art reduced-amplitude waveform of a DUT during a read operation using the testing apparatus of FIG. 2 with appropriate parallel termination.
[0020] FIG. 4 is a typical prior art waveform of a DUT during a read operating using the testing apparatus of FIG. 2 without parallel termination.
[0021] FIG. 5 is a typical prior art waveform originating at and generated by the DUT.
[0022] FIG. 6 is an cross-sectional view of an exemplary semiconductor fabrication process used to produce semiconductor-based transconducting devices utilized in the present invention.
[0023] FIG. 7 is a block diagram of an exemplary probe card using transconducting devices fabricated in accord with FIG. 6 .
[0024] FIG. 8 is a schematic representation of an exemplary embodiment of the present invention replacing a single comparator with multiple comparators.
DETAILED DESCRIPTION
[0025] In an exemplary embodiment, a driver/receiver pair is fabricated that can be mounted physically close to the DUT, thereby eliminating detrimental effects of the prior art related to long transmission lines and termination networks. Using a metal-on-insulator (MOI) fabrication or silicon-on-insulator (SOI) fabrication process, the MOI-based driver/receiver pair may be fabricated to maintain low leakage currents (e.g., less than 5 nA), even at 150° C., due to a silicon dioxide layer incorporated between a base substrate and an active semiconductor layer.
[0026] In FIG. 6 , an exemplary four-terminal FET 600 is fabricated in a metal-on-insulator (MOI) or silicon-on-insulator (SOI) process where an isolated bulk semiconducting material is actively driven by a control signal. The exemplary FET 600 includes a base substrate 601 , a first dielectric layer 603 , a semiconductor layer 605 , a second dielectric layer 609 , and a silicided control gate 611 . A dopant material is, for example, implanted or diffused into the semiconducting layer 605 to form source and drain regions 607 . An electrode (not shown) added in later process steps allows access to the semiconductor layer 605 through a body terminal.
[0027] In a specific exemplary embodiment, the semiconducting layer 605 is approximately 2 μm (2000 nm) in thickness and is bonded to the first dielectric layer 603 . The base substrate 601 may be a silicon wafer. Alternatively, another elemental group IV semiconductor or compound semiconductor (e.g., Groups III-V or II-VI) may be selected for the base substrate 601 . In lightweight applications or flexible circuit applications, such as those employed in a cellular telephone or personal data assistant (PDA), the FET may be formed on a polyethyleneterephthalate (PET) substrate deposited with silicon dioxide and polysilicon followed by an excimer laser annealing (ELA) anneal step. In still other applications, the base substrate 601 may be comprised of a dielectric material directly, such as a quartz photomask, thereby obviating a need for the first dielectric layer 603 . In this case, the semiconducting layer 605 may be formed directly over the photomask.
[0028] In a case where the base substrate 601 is a semiconductor wafer, the wafer may contain a buried oxide layer (not shown) placed below a polysilicon layer (not shown) to prevent transport of carriers through the underlying bulk semiconducting material. The polysilicon is then treated at an elevated temperature to reform crystalline (i.e., non-amorphous) silicon. In still another embodiment, the base substrate 601 is formed from intrinsic silicon, thereby effectively limiting transport of carriers due to the high resistivity of intrinsic silicon.
[0029] If either the substrate 601 or the semiconductor layer 605 is chosen to be comprised of silicon, the second dielectric layer 609 may be a thermally-grown silicon dioxide layer. Alternatively, the second dielectric layer 609 may be a deposited layer, for example, a silicon dioxide, silicon nitride, or oxynitride layer deposited by atomic layer deposition (ALD) or chemical vapor deposition (CVD) techniques. In a specific exemplary embodiment, the second dielectric layer is comprised of silicon dioxide, 100 Å to 500 Å in thickness.
[0030] Regardless of the fabrication techniques employed, either deep or shallow trenches (not shown) may be subsequently etched into the semiconducting layer 605 to isolate either adjacent devices or adjacent circuits. Any silicon-containing layers may be etched, for example, with potassium hydroxide (KOH) or tetra-methyl ammonium hydroxide (TMAH). an edge wall angle of the shallow trench formed within the semiconducting layer 605 will depend on several factors such as a crystallographic orientation of the semiconducting layer 605 and the type of etchant employed. The edge wall angle determines, to some extent, how densely transistor may be fabricated and still remain electrically isolated from one another.
[0031] Deep trench isolation techniques are frequently employed to isolate device elements laterally. Formation of deep trench isolation can be partially accomplished with low-cost dielectric films. Low-cost dielectric films typically have less desirable electrical characteristics (e.g., dielectric breakdown strength or higher shrinkage values) than a high-quality film. However, a high-quality film is a better choice for filling shallow trench isolation (STI) regions and for producing cap layers over a deep trench fill layer. A skilled artisan can readily envision how either deep or shallow trenches may be beneficial to portions of the present invention described herein.
[0032] In the case of an ATE wafer sort operation, a bare die fabricated using MOI or SOI fabrication techniques may be soldered directly to a probe head of the probe card. With reference to FIG. 7 , an exemplary probe card test arrangement 700 includes a probe printed circuit board (PCB) 701 , a multilayer ceramic probe head 705 , and a test structure 709 containing a plurality of DUTs (not shown directly). The multilayer ceramic probe head 705 is in electrical communication with the probe PCB 701 through a plurality of electrical interconnects 703 . A plurality of probe contact points 711 allows electrical communications with an ATE system (not shown) once the plurality of probe contact points 711 is brought into contact with the test structure 709 .
[0033] The multilayer ceramic probe head 705 is typically a multilayer low- or high-temperature co-fired ceramic (LTCC or HTCC). Various mounting techniques known in the art may be used for attaching a plurality of MOI-based driver/receiver dice 707 directly to an underside of the multilayer ceramic probe head 705 . For example, a series of ball-grid arrays (BGA) solder balls, electroplated bumps, controlled collapse chip connection (C4) bump technology, or other types of bonding features known in the art may be used to electrically and mechanically connect the plurality of MOI-based driver/receiver dice 707 to the multilayer ceramic probe head 705 .
[0034] Using ordinary fabrication techniques of the prior art, the plurality of MOI-based driver/receiver dice 707 ordinarily cannot be mounted directly to the multilayer ceramic probe head 705 since the plurality of probe contact points is generally too short to allow compression onto the test structure 709 . Typically, probe contact points are approximately 750 μm long and require about 100 μm of compression onto a test surface. thus, any mounted dice must be substantially less than 650 μm in thickness. The 650 μm thickness includes the thickness of any mounting structures, such as C4 columns after collapse. Therefore, the plurality of MOI-based driver/receiver dice 707 are thinned to approximately 300 μm or less exclusive of the mounting structures or electrical interconnects. The MOI-based dice 707 may be thinned by a variety of techniques. In a specific exemplary embodiment, a backside of the base substrate 601 ( FIG. 6 ) containing the MOI-based dice 707 is lapped after device fabrication is completed. Lapping techniques are known in the art.
[0035] Another thinning technique involves using a thinned wafer bonded to a thicker base substrate for processing. In a specific exemplary embodiment, a base substrate (not shown) is comprised of five layers prior to device processing. The five layers include, for example, a thick base substrate (e.g., a 750 μm thick silicon wafer), a dielectric bonding layer, a thinned wafer (e.g., a 50 μm thick silicon wafer), an SOI dielectric, and a epitaxial layer upon which the MOI-based dice are produced. Thinned semiconductor wafers (e.g., thinned to 30 μm or less) are commercially available (e.g., Silicon Valley Microelectronics, Inc, Santa Clara, Calif.). Processing may then proceed in accordance with the exemplary method described with relation to FIG. 6 . After processing, the thick base substrate is removed from the dielectric bonding layer by de-bonding techniques. Thus, a plurality of thin MOI-based semiconductor devices remains.
[0036] In another exemplary embodiment of the invention (not shown), the driver/receiver pair describe with reference to FIG. 7 may be split into multiple functional dice. Thus, driver dice may be placed far from the DUT, for instance, located physically inside the ATE system, and receiver dice remain mounted on the probe head. Advantages of this mounting arrangement include having a much greater density of DUTs tested in parallel as the receiver dice mounted on the probe head are roughly only one-half the size of the driver/receiver combination, thereby allowing more possible connections to more DUTs.
[0037] In yet another exemplary embodiment described with reference to FIG. 8 , the single comparator may be replaced by multiple comparators and a logic circuit that will compare expectant data to multiple DUTs simultaneously. The exemplary test arrangement 800 includes an ATE system component 801 and a semiconductor testing component 851 . The ATE system component 801 includes a driver 803 A and comparator 803 B pair electrically connected through a transmission line 805 to the semiconductor testing component 851 . The semiconductor testing component 851 may be mounted to the probe head (not shown) to eliminate any deleterious transmission line effects associated with the prior art. Individual components on the semiconductor testing component 851 may be fabricated in accordance with fabrication methods described with reference to FIG. 6 . Further, the individual components may be contained on a single die or may be fabricated on a plurality of dice.
[0038] The driver 803 A sends write signals through a resistive element 811 to the semiconductor testing component 851 while the comparator 803 B acts as a receiver for reading signals received from the testing component 851 . A value of the resistive element 811 is chosen to match the characteristic impedance of the transmission line. An input impedance to a typical DUT is usually quite high (e.g., greater than 10 megaohms). Consequently, to avoid multiple reflections and standing waves from being created along the transmission line, one reflection is allowed at the DUT and the reflected waveform is terminated at the resistive element 811 . When the DUT is driving the ATE (e.g., during a read cycle), the termination element 817 is used to terminate the transmission to avoid reflections.
[0039] When the driver 803 A is writing a signal to the testing component 851 , a signal from the driver 803 A is enabled by closing a write switch 809 and any signal passing to the comparator 803 is disabled by opening a read switch 813 . During a read operation, the driver 803 A is disabled by opening the write switch 809 and closing the read switch 813 . The comparator 803 is now enabled to read signals passing from the testing component 851 .
[0040] The physical length of the transmission line 805 is roughly four feet long in a typical ATE test cell used for wafer sort and three feet long in an ATE system used for package test. When the exemplary test arrangement 800 is configured to read from the testing component 851 , a 50 ohm parallel termination element 817 , coupled on one end to a termination voltage, V T , is coupled into the circuit by closing a termination switch 815 coupled to the opposite end of the termination element 817 . The 50 ohm termination element 815 is used to avoid reflections along the transmission line 805 .
[0041] The semiconductor testing component 851 includes a write switch 853 and a read switch 855 . A plurality of comparators 859 A- 859 n provide input to an exclusive nor (XNOR) gate 857 . A plurality of DUTs 865 A- 865 n is coupled to the semiconductor testing component 851 and may be selected for writing or reading operational testing through a series of write switches 861 A- 861 n is coupled to the semiconductor testing component 851 and may be selected for writing or reading operational testing through a series of write switches 861 A- 861 n and a series of read switches 863 A- 863 n, respectively. When one or more of the series of read switches 859 A- 859 n is closed, selected ones of the plurality of DUTs 865 A- 865 n are electrically coupled to associated comparators 859 A- 859 n. Each of the plurality of comparators 859 A- 859 n can source sufficient current to avoid significant amplitude reduction of propagated signals found in the prior art. Alternatively, the XNOR gate 857 can source sufficient current to supply the ATE system component 801 once the read switch 855 is closed.
[0042] For a write operation, the write switch 853 and one or more of the series of write switches 861 A- 861 n is closed in order to drive a signal to one or more of the plurality of DUTs 865 A- 865 N. The write signals are transmitted from the driver 803 A in the ATE system component through the write switch 809 (in a closed position) and the transmission line 805 . In a specific exemplary embodiment, all switches used in the exemplary test arrangement 800 are semiconductor-based transconducting devices (e.g., an FET transistor) which may also be used to passively fan-out signals transferred to or from a plurality of DUTs. The passive fan-out avoids the necessity for an active buffer, thus reducing power dissipation. An additional advantage in not employing an active buffer is that all voltage and timing signals from the plurality of DUTs may be parametrically tested directly (e.g., no analog information will be lost (such as voltage levels and timing) as would be the case with an active buffer arrangement). Also, high DC current fan-outs of 400 mA or more are possible due to the four-terminal technology employed herein.
[0043] In the foregoing specification, the present invention has been described with reference to specific embodiments thereof. It will, however, be evident to a skilled artisan that various modifications and changes can be made thereto without departing from the broader spirit and scope of the present invention as set forth in the appended claims. For example, a skilled artisan will recognize that alternative techniques and methods may be utilized to form or deposit certain layers described herein. The alternative techniques and methods are still included within a scope of the appended claims. For example, there are frequently several techniques used for forming a material in addition to CVD deposition or thermal growth techniques (e.g., plasma-enhanced vapor deposition, epitaxy, sputtering etc.). Although not all techniques are amenable to all material types described herein, one skilled in the art will recognize that multiple methods for fabricating a material may be used. Also, various alloys, compounds, and multiple layers of stacked materials may be used, such as with conductive materials formed within the vias. For example, other types of semiconductors may be substituted for an epitaxial layer in the SOI. Additionally, various circuit components and elements produced by fabrication techniques described are exemplary only and illustrative in a functional sense more than a strict component selection sense. A skilled artisan will recognize other circuit elements which may be used instead of or in addition to circuit components described herein.
[0044] Additionally, various embodiments described herein describe specific exemplary embodiments of the present invention. In addition to embodiments already described, the present invention has several additional advantages. For example, a read cycle data rate can be optimized for devices that cannot drive 50 ohm terminations or for devices that are intended to be used to drive other devices that are in close physical proximity. Memory and other devices may be tested without using an impedance balancing termination and run at the same frequency that the device would in its intended application These and various other embodiments and techniques are all within a scope of the present invention. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.
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An electronic device for use with a probe head in automated test equipment. The device includes a plurality of semiconductor devices arranged to provide at least one driver/receiver pair where the driver portion of the driver/receiver pair is configured to transmit a signal to at least one device under test and the receiver portion of the driver/receiver pair is configured to receive a signal from the at least one device under test. Each of the plurality of semiconductor devices is fabricated using either a silicon-on-insulator (SOI) or metal-on-insulator (MOI) technology and has a thickness less than about 300 μm exclusive of any electrical interconnects. The at least one driver/receiver pair is adapted to mount directly to the probe head.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of U.S. Provisional Patent Application 62/284,324 filed on Sep. 28, 2015, the entire content and substance of which is also incorporated herein by reference.
TECHNICAL FIELD OF THE INVENTION
[0002] This invention relates to the field of liquid food dispensing apparatus, and in particular to food dispensing involving mixing of food components within a dispensing container and which may be subject to spoilage based on extended exposure to environmental conditions. The invention has particular benefit for mixing and monitoring of baby formula in a baby bottle.
BACKGROUND OF THE INVENTION
[0003] There are many situations where it is desirable to store the components of liquid food in separate containers or compartments within a container until the time when it is desired to consume them. One of the most common of these situations involves feeding babies with baby formula mixed with water. In the past, it has been common to fill a baby bottle with water, open a package of powdered formula and pour it into the bottle, and then agitate the contents until the ingredients are thoroughly mixed. However, once mixed, the liquid formula must be consumed within a short period of time, typically within two hours, or the mixture will be spoiled. The length of time that the mixture can be stored depends, in part, on the temperature of the mixture during the course of being used, which can in turn vary depending on ambient environmental conditions. For example, it is common to heat the water either before mixing or after mixing to bring the temperature closer to the body temperature of the baby. Or, the bottle may be set down for a period of time, or placed in a refrigerator for a period of time. In addition, when the bottle is not in use, the ambient air temperature around the bottle may vary, for example if the baby is fed inside the house or outside on a cold or hot day. Because pathogens grow faster in warmer temperatures, these varying and unpredictable temperatures can affect the length of time for which the mixture is usable.
[0004] Unfortunately, it is difficult to know the point in time when the mixture becomes spoiled and should be discarded, because it is relatively easy to forget exactly when the formula was mixed, and how much time has elapsed since then, and also because it is also difficult to factor in the variable temperatures that the bottle has experienced during that time. Accordingly, as a precaution, unused food may be unnecessarily disposed of too early, or worse, a baby may be exposed to spoiled formula if the acceptable usage time is overestimated.
[0005] In the past, the desire to have more accurate awareness of the time that baby milk remains in the bottle has led to a number of inventions relating to timers associated with baby bottles. An example of the prior art may be seen in U.S. Pat. No. 9,244,440 to Pantchenko, the entire contents of which is herein incorporated by reference. This patent teaches a device that may be affixed to the outside of a bottle by a band or the like, for monitoring the time and temperature that the bottle experiences since the most recent time that the device was reset. The device calculates various display values, such as the current time, current temperature, current expiration time, etc. and may selectively display these values on a display screen. The device may further take a temperature measurement and calculate a time interval corresponding to the temperature reading, and may trigger an alarm based on the elapsed time or the temperature or change in temperature.
[0006] The problem of accurately assessing the expiration date of perishable goods has been widespread throughout the food industry. An example of the prior art with respect to temperature and time monitoring of perishable food items may be found in U.S. Pat. No. 6,795,376 to Quine, the entire contents of which is herein incorporated by reference. The system taught in this patent is an LCD device mountable on a package of perishable food, and including a controller and one or more sensors, which may monitor temperature, humidity, pressure, pH, ambient light, or mechanical situations using trip wires or switches. Based on the sensor signals, the controller adjusts the expiration date shown on the LCD display, by determining whether an environmental triggering condition has occurred that necessitates an adjustment to the expiration date, or by causing the expiration clock to run backwards at a rate that is determined in accordance with tables and/or logic preprogrammed into the controller. The rate of change of the expiration date can be made to be proportional to, or otherwise a function of, the magnitude of the measured environmental condition away from a preferred environmental condition, which for simplicity may be taken to be a linear correlation. In operation, the expiration date is initially set to be the maximum amount, and various environmental conditions may then cause the controller to alter the expiration date to an earlier value. One such condition is whether a seal on the package has been opened, exposing the contents of the package to outside air (and biological contaminants). As taught in this patent, a conductive wire may be broken when the package is opened. The controller may then take appropriate action, such as shifting the expiration date to an earlier expiration date, and may subsequently use a different table or algorithm for computing further adjustments to the expiration date based on environmental conditions experienced later.
[0007] Another example of a prior art monitor designed to be attached to a perishable food product and which calculates an expiration date in part based on ongoing environmental conditions such as temperature, is U.S. Pat. No. 7,495,558 to Pope et al, the entire contents of which is herein incorporated by reference. The calculation of expiration date may be based in part on a spoilage curve derived from the Arrhenius kinetic equation, for example wherein spoilage rate is equal to a linear function of inverse exponential temperature. The monitor is configured to periodically measure one or more average or estimated temperatures over a time period since a previous measurement. The temperature measurements are then used to determine whether the product remains fresh, for example from a table of data and including an integration calculation over time.
[0008] With respect to baby bottles that are designed to enable rapid mixing of powdered baby formula with water, the prior art includes specialized bottles that have a main chamber holding water, and a second chamber holding the powdered formula to be mixed, which is initially maintained closed with respect to the first chamber. Mixing occurs by moving an external actuating element that breaks a seal or opens a valve enabling the powder and water to come in contact. For example, in U.S. Pat. No. 2,786,769 to Greenspan (the entire contents of which are herein incorporated by reference), the actuating element is a plunger which forces open a seal; and for U.S. Pat. No. 8,413,803 to Questad et al (the entire contents of which are also herein incorporated by reference), the actuating element is a plunger which can be moved by pressing on the flexible bottom of the bottle, thereby forcing open a valve at the other end of the plunger. Other examples of patents teaching bottles designed to allow isolated storage and subsequent mixing of contents, using a variety of storage chamber means and sealing means, are the following, the entire contents of which are also herein incorporated by reference:
[0000]
D606661
Elizabeth Colombo
20040149599
Young Cho
9067715
Jeong-min Lee et al
9004301
Matthew Wahlstrom
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Christopher Estrada
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SUMMARY OF THE INVENTION
[0009] The present invention comprises in its principal embodiments, a system and method for enabling accurate spoilage monitoring of a liquid food product from the moment it is created, until the time it is either consumed or needs to be discarded. In a preferred embodiment of the invention, a container for the food product, or a device desired to be attached to a container, is equipped with a switch, thermometer and/or other environmental sensors, controller and alarm. The switch is activated automatically or manually at the moment when the liquid food product is created, and then the temperature and possible other environmental parameters of the food product are monitored during the subsequent course of time, all the while keeping track of the temperature history of the product throughout the period, until the controller calculates that the maximum safe period has expired; whereupon an alarm is activated to warn the user to discard the product.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 shows in a preferred embodiment the mixing and spoilage monitor of the instant invention installed on a conventional baby bottle.
[0011] FIG. 2 shows in a preferred embodiment the electrical components of the mixing and spoilage monitor of the instant invention.
DETAILED DESCRIPTION
[0012] FIG. 1 shows a preferred embodiment of the instant invention, wherein the mixer and spoilage monitor is presented in the form of an enhanced bottle ring 101 that can be installed along with a conventional nipple 102 on a conventional baby bottle 103 (shown in outline), thereby forming a container that can hold a liquid such as water. However, unlike a conventional baby bottle ring, the enhanced ring of the instant invention includes an interior compartment 104 extending within at least a portion of the general area indicated as 105 in FIG. 1 , and capable of holding formula (not shown) ready to be mixed with the liquid that is held in bottle 103 . Prior to mixing, the formula and liquid are held isolated by seal means 106 shown in cutaway view, and further illustrated here by way of example as a butterfly valve. Although a butterfly valve is shown, any other suitable seal means can be employed in the instant invention, including without limitation, poppet valves, pivoting members with aligning holes, frangible elements, etc. Indeed, as will be readily understood by those skilled in the art, although a particular construction for the storage chamber, seal and liquid chamber is illustrated in FIG. 1 , the invention can work with many other sealing means, such as the diverse arrangements disclosed by example in the prior art listed above. Also shown in the particular embodiment of FIG. 1 is an external actuating element 107 , which may be any type of mechanical element, including without limitation, a push button, sliding lever, etc. In some embodiments, external member 107 is linked internally to the seal 106 to cause the seal to be broken (in other words, in the case of a valve, for the valve to be opened, or in the case of a frangible element, for the element to be pierced or torn) when it is desired to mix the formula contents retained in compartment 104 with the liquid in bottle 103 . In some embodiments, external member 107 may be replaced with just an electrical switch if the seal 106 is electrically actuated, as will be discussed hereinafter.
[0013] The mixer and spoilage monitor of a preferred embodiment of the instant invention may be further understood with reference to FIG. 2 in association with FIG. 1 , wherein FIG. 2 shows in detail the electrical components for the preferred embodiment. The mixer and spoilage monitor includes digital controller 200 and associated user interface 210 , also shown generally as 110 in FIG. 1 . Also shown in FIGS. 2 and 1 are display ( 211 , 111 , respectively), which may comprise an LCD display or other electronic display, Start/Stop button ( 212 , 112 ), Formula content selector ( 213 , 113 ), Reset button ( 214 , 114 ), and Status indicator ( 215 , 115 ), which may be a multicolor LED or may be simply another display portion of LCD ( 211 , 111 ), or other type of electronic display. FIG. 2 also shows audible alarm 230 which in some embodiments may be actuated when the controller indicates that the contents of the bottle are spoiled, and may also give audible feedback as the buttons 212 , 214 , etc. are pressed. Also shown is battery means 250 to provide power to the controller and other electronic components, and one or more environmental sensors 220 such as temperature 221 , light 222 , pH 223 , etc. for providing a signal that the controller may use to more accurately determine spoilage. FIG. 2 also shows motor means 240 which may be used to automatically actuate seal 106 and switch 216 which may be used to sense movement of mechanical member 107 in the case where seal 106 is manually actuated. Also shown in FIG. 2 is wireless link means 260 to enable communication with an external device using well-known Wi-Fi, Bluetooth, etc. wireless communication means, if desired. There may also be an electrical socket (not shown) to allow connecting a source of electrical power to recharge battery 250 or provide electronic communication to an external device.
[0014] The operation of the preferred embodiment of the instant invention may be further understood with reference to FIGS. 2 and 1 . Before ring 101 is installed on a baby bottle, compartment 104 is filled with the required amount of formula by first opening seal 106 either manually with actuator 107 , or by actuating one or more electrical buttons (e.g., Start Button 212 combined with Reset Button 214 ) on the controller's user interface, or by filling from the top prior to installing nipple 102 . Formula selector ( 213 , 113 ) may be actuated to inform controller 200 about the particular formula contents installed. Then, bottle 103 is filled with the required amount of liquid, and ring 101 is installed on the bottle (usually by screwing it onto the opening, depending on the type of bottle to which it is designed to be attached). Seal 106 is then closed, either by pressing Reset Button 214 or by manually closing the seal, or in the case of a frangible seal, by installing a new frangible seal member. At this point, seal 106 maintains the liquid and formula in total isolation. This condition may be retained for a considerable period of time without worry of spoilage. However, it is also possible to place the controller in a first standby shelf-mode status to allow the controller to keep track of the length of time (and of environmental conditions—to be explained later), of the isolated formula/liquid compartments, if the condition is to be maintained for a sufficiently long time that shelf spoilage should be considered. This shelf mode may be indicated to the user by changing status indicator 115 for example to “blue” (by actuating the “B” LED), or by changing the display on LCD display ( 211 , 111 ). The controller may then monitor the time and environmental conditions of the separated formula and liquid prior to the time they are mixed, and issue alarms in a manner similar to the process described below for monitoring the contents once mixing has occurred.
[0015] When it is desired to mix the formula, either external member 107 is actuated (for those embodiments that have a manual actuating member) to cause seal 106 to open; or start/stop button ( 212 , 112 ) is actuated to cause the controller to actuate motor 240 , thereby opening seal 106 or otherwise breaking the seal, for example by piercing or tearing it if a frangible seal. In the case of actuation by external member 107 , electrical switch 216 may also be actuated, automatically sending a “commencement of mixing” signal to the controller, or start/stop button ( 212 , 112 ) may be actuated by the user to send the “commencement of mixing” signal.
[0016] Once seal 106 is opened, the liquid in bottle 103 and the formula in compartment 104 are no longer maintained in isolation, but are now in mutual association so that the formula may travel to the liquid and/or the liquid travel to the formula, and mixing can occur. To enhance mixing, the bottle may be agitated manually by shaking the entire bottle, or the internal movement may be imparted by further back-forth operation of seal 106 , or if desired, by motion of additional internal elements such as mixing vanes (not shown). Responsive to the “commencement of mixing” signal, the controller is now placed in “active” mode, and status indicator 115 may change color (e.g., to “green” by actuating the “G” LED) to indicate the active mode status. Further, controller 200 now initiates a timer (which may be internal to controller 200 ), and actively monitors the timer and additional environmental parameters 220 to determine the safety of the mixed contents. During this time, the LCD display ( 211 , 111 ) may display the allowable time left until spoilage, or may display other parameters, such as the temperature, formula content, etc. This display of various parameters can occur on a rotating basis, or may be selected by suitable user controls, such as combinations of the switches already described, or by additional switches (not shown) for selecting the parameter to display.
[0017] Eventually, either the contents of bottle 103 are consumed, in which case the user can press Reset button 214 to stop the controller and cancel further monitoring, or the controller reaches the point in its spoilage calculation where it believes the contents are in danger. This can occur because the calculated elapsed growth of pathogens within the container has reached a threshold, or because a particular condition is measured (e.g., pH or other chemical sensor, beyond limits). The controller may then actuate alarm 230 , change the color of status indicator ( 215 , 115 ), e.g. to “red” (by actuating the “R” LED), and set the LCD to zero or some other suitable indicator of spoilage. Preferably, prior to reaching the status of “spoiled”, the controller may reach a point in its calculation where it believes the contents are “nearly spoiled”. In such case, it can issue a preliminary warning alarm (e.g., short beeps) on alarm 230 and change the status indicator ( 215 , 115 ), e.g., to “yellow” (for example, by actuating both the R and G LEDs simultaneously). Thus, in preferred operation, the status indicator ( 215 , 115 ) can change from “green” to “yellow” to “red” to indicate sequentially that the contents are “good”, “nearly spoiled”, or “spoiled”. Of course, other visual indicators are within the scope of the invention, such as a spaced series of three independent lights for these conditions, or particular indicia on the LCD screen, as is well-known by those skilled in the art of electronic user interfaces.
[0018] That environmental parameters may affect spoilage time for perishable goods is discussed above in reference to the prior art spoilage monitors. Of primary importance to the instant invention are temperature, light, and pH (and other chemical measurements), which may be derived from suitable electrical sensors 220 - 223 appropriately disposed with respect to the ring and bottle. The temperature measurement may be obtained from a temperature sensor 221 near the exterior of the bottle, or may be an internal sensor having a housing that contacts the mixed contents within the bottle. Similarly, the pH sensor 223 may comprise an electrical contact that can measure the pH within the bottle. Once in active mode (or while in stand-by shelf mode for those embodiments that make use of it) the controller uses the environmental measurements to calculate on a rapid and periodic basis (i.e., pseudo-continuously) the expected spoilage time for the current contents. The particular algorithm or table look-up used to calculate the spoilage as a function of environmental parameters will also vary depending on the contents in the bottle. Therefore, in a preferred embodiment, a communication link, such as wireless link 260 (or a wired link, not shown) may be used to establish communication with a smart phone, tablet, PC, etc. or other external device to enable programming of possible formula contents and algorithms into controller 200 . The desired formula actually installed in the compartment may then be selected by using the Formula selector ( 213 , 113 ) in conjunction with LCD display ( 211 , 111 ). It is also within the scope of the invention to include one or more “non-mixed” formula settings, to allow the Monitor of the instant invention to be used also in cases where it is not intended to mix ingredients, a common example being when it is desired to place pure breast milk in the bottle without any additional formula supplement. In such case, formula selector ( 213 , 113 ) is set to indicate the “breast milk” non-formula setting, and immediately after filling bottle 103 with breast milk, the user presses start button ( 212 , 112 ) to cause controller 200 to begin monitoring environmental conditions in the same fashion as in the mixing case, except using a different spoilage calculation corresponding to the different ingredient in the bottle.
[0019] The user interface may include an additional button or other means to lock the settings of the buttons to prevent accidental actuation (especially by a baby). For example, pressing a particular combination of the buttons already disclosed in the preferred embodiment may cause a visual or audible signal to the user that the buttons are locked. Further actuation of the buttons then will have no effect on the previously-described operation of the device until the device becomes unlocked by actuating another particular combination of the buttons or by actuating an unlocking button (not shown).
[0020] For embodiments that include wireless link 260 capable of communicating with an external computer, smart phone or other external device, the user may want to authorize uploading of operating parameters from controller 200 , either in real time or in batch, in order to monitor the operation of the mixing device. For example, when the controller switches from “active” mode to “nearly spoiled” or to “spoiled”, the controller can also issue an alarm to the external device to indicate a change in status. As a further example, if a tilt or other “bottle position” sensor (not shown) is included in the device, the controller can monitor whether the baby is properly holding the bottle, and issue an alarm and/or send a signal to the external device in case the bottle is not positioned properly. The controller can also send data corresponding to the various sensors (e.g., temperature, pH, etc.) to the external device.
[0021] Other information may be communicated between the mixing device and an external device. The mixing device may be equipped with a sensor capable of measuring the volume of mixed liquid, and send this data to the external device, along with alarms when the level of remaining liquid runs low. The controller may also monitor the overall consumption of liquid just by counting the number of uses, and may send these or other cumulative statistics to the external device. Additionally, the controller, either by itself, or in conjunction with an app running on the external device, may keep track of the frequency of usage, and issue alarms if too much time has passed since the previous feeding of the baby or if the baby has received either too little or too much feeding. The monitoring and data sent by the controller may also include the composition of the formula and liquid within the mixing device, so that the controller and/or external device may keep track of the overall nutritional content that a baby is receiving. The app running on the external device may receive identifying data such as a serial number from the mixing device to keep track of which device is sending the data in case several such mixing devices are available for use. The mixing device may be programmed to allow the user to identify which baby is receiving the mixture, and this data may be automatically transmitted to the external device to enable the app to keep track of consumption when a plurality of babies can be fed by the mixing devices.
[0022] In another embodiment, the mixing device of the instant invention may include programming to actuate audible and/or visual indicators (e.g., sound generator 230 , indicator 215 ) or other audible and/or visual indicators (not shown) in order to sooth a baby while consuming the mixed contents, or to be used in other situations such as to keep a baby's attention times other than when being used for feeding.
[0023] The above description and appended drawings show only preferred embodiments of the present invention, and not all of the numerous variations and modifications that will become apparent to those skilled in the art of designing electronic consumer products, after having benefit of reading the disclosed invention. For example, but not by way of limitation, although only one compartment is described for holding powdered formula, there may be multiple compartments and multiple seals corresponding to seal 106 , if it is desired to keep multiple ingredients in isolation prior to use, and the controller may actuate the multiple seals according to a timed sequence so that the components be mixed in succession according to a mixing algorithm. Also, although the Mixing and Spoilage Monitor of the instant invention has been described in the context of a ring that is installed on a conventional baby bottle, it is also within the scope of the invention to have the active parts of the device installed as integral elements of a baby bottle container itself, either disposed near the top of the bottle or at the bottom (or anywhere else along the bottle, or distributed at multiple positions throughout the bottle). Some examples of possible variations in design of mixing chambers that could be used in the present invention may be found in the documents listed in the background section. To use these designs with the present invention, it is only necessary to include a switch 216 to be actuated when the seals are broken, or alternatively, to add motor 240 and appropriate linkage to cause the seals to be broken in response to the user pressing an electrical switch.
[0024] Further, some or all of the electronic components, such as Controller 200 , User Interface 210 , etc. may be placed in a removable module that may be removed from the remainder of the device prior to washing the device after use. Moreover, although the description has focused on the application for baby bottles, it is obviously within the scope of the invention to use this for any container (can, bottle, jug, etc.) or portion thereof, wherein it is desired to maintain two or more ingredients in isolation prior to use, and then to track the spoilage point once mixed, possibly based in part on environmental exposure. Thus, many variations to the preferred embodiments presented as examples in this specification are possible, so that the scope of the instant invention should be limited only by the subject matter covered in the claims appended herewith.
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System and method for enabling accurate spoilage monitoring of a liquid food product or the like from the moment it is created, until the time it is either consumed or needs to be discarded. In a preferred embodiment of the invention, a container for the food product, or a device to be attached to a container, is equipped with a switch, thermometer, other environmental sensors, controller and alarm. The switch is activated automatically or manually at the moment when the liquid food product is created, and then the temperature and other environmental parameters of the food product are monitored during the subsequent course of time, all the while keeping track of the temperature history of the product throughout the period, until the controller calculates that the maximum safe period has expired; whereupon an alarm is activated to warn the user to discard the product.
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TECHNICAL FIELD
[0001] The present invention relates to energy storage systems incorporating battery packs utilized in hybrid motor vehicles, and more particularly to the thermal conditioning thereof. Still more particularly, the present invention relates to thermal conditioning by selectively employing various air sources of the motor vehicle.
BACKGROUND OF THE INVENTION
[0002] Hybrid motor vehicles utilize a propulsion system which incorporates both an internal combustion engine and an electrical system which is used typically for propulsion and regenerative braking. The electrical system includes at least one electrical motor mechanically connected to one or more axles of the motor vehicle and a battery pack of cells which is an integrated component of an energy storage system (ESS) that is electrically connected to the at least one motor. When the at least one motor propels the motor vehicle, electrical energy is extracted from the ESS (the battery pack discharges). During regenerative braking the motor acts as a generator, and the electrical energy generated is delivered to the ESS (the battery pack charges).
[0003] FIGS. 1 and 2 schematically depict aspects of a conventional hybrid ESS and the prior art thermal conditioning arrangement therefor.
[0004] Within the passenger cabin 10 of the hybrid motor vehicle is disposed the ESS 12 , which may, for example, rest on the vehicle floor 14 above the fore-aft floor “tunnel” 16 . The ESS 12 is thermally conditioned by the movement of cabin air A C via an ESS blower 18 , whereby the cabin air is circulated through the ESS, originating at least one permanently open entry vent 20 and exiting at least one permanently open exit vent 22 , both vents being permanently open in the sense of being in permanently and completely open fluidic communication with the passenger cabin. The prior art has sometimes placed the entry vent near the output of the HVAC ducting, whereby cabin air A C and HVAC air A H can comingle before unselectively entering the entry vent. Operation of the ESS blower 18 is controlled by a hybrid vehicle integration control module (VICM) 24 , utilizing temperature data from (among others) an inlet duct sensor 26 a , an outlet duct sensor 26 b , and an ESS temperature sensor 26 c . The VICM 24 is connected to inputs and outputs by various data lines (see for example dashed lines in FIG. 2 ). These components are subject to an on-board diagnostics (OBD) requirement, whereby a signal is provided to the driver if a fault is detected in any of the components.
[0005] The passenger cabin includes a heating, ventilation and air conditioning (HVAC) module 28 , which typically includes passenger input instruments 30 and an HVAC controller 32 which operates the HVAC module in response to the passenger input. Typically, the HVAC module includes an HVAC blower 34 , an evaporator 36 for cooling the HVAC air to the cabin and a heater core 38 for heating the HVAC air to the cabin via HVAC ducting 40 . These components are not subject to an OBD requirement.
[0006] Utilizing the cabin environment in the prior art to provide air for thermal conditioning of the ESS is effective only when the cabin air is not too hot nor too cold. For example, after a soak in hot sun or frigid cold, the ESS will be similarly either hot or cold, and the cabin air used to thermally condition the ESS will also be likewise hot or cold. This has problematic implications for the electrical charge/discharge performance of the ESS, which is temperature dependent. As discussed hereinbelow with respect to FIG. 3 , there is an optimal ESS performance temperature range, and the cabin air temperature extremes can easily be outside (both above and below) this range.
[0007] And, this problem of administering ESS thermal conditioning in the prior art is not “solved” by merely placing the entry vent someplace near the outlet of the HVAC ducting, as the commingling of cabin air with HVAC air is haphazard, unselectable and takes too much time.
[0008] Accordingly, what remains needed in the art is a thermal conditioning system of hybrid vehicle ESS which does more than simply utilize cabin air therefor.
SUMMARY OF THE INVENTION
[0009] The present invention is an ESS thermal conditioning system which selectively utilizes air from at least one auxiliary air source (other than the at least one permanently open entry vent of the prior art), as for example one or more passenger cabin areas, the trunk, an exterior vent, and, most preferably, the HVAC ducting.
[0010] Interfaced with each auxiliary air source is a selectively operable actuator door which either connects or disconnects the auxiliary air source to the ESS blower. By way of example, VICM utilizes temperature sensors associated with each of the various auxiliary air sources to open, close, or partly open each of the respective actuator doors so that the ESS is optimally temperature conditioned. In this regard, if there are more than one auxiliary air sources available, then the VICM will select the actuator door opening amount appropriate to any of them based upon, for example, the sensed temperature at the auxiliary air source in relation to the sensed temperature of the cabin air, and either or both of the ESS and/or the ESS inlet. It should be noted that the VICM does not have any control of change in temperature available at any of the air sources.
[0011] In the most preferred form of the ESS thermal conditioning system according to the present invention, the selective auxiliary air source is the HVAC ducting. An HVAC ESS duct is interfaced with the HVAC ducting of the HVAC module. An actuator door, or “bleed” door, is fitted to the HVAC ESS duct, and is electrically operated anywhere between a closed position to an open position responsive to the VICM. The VICM operates the bleed door based upon its programming and data from temperature sensors on either side of the bleed door, and for example, other temperature sensors. In this manner, the temperature of the ESS can be kept within the optimal performance temperature range, or brought thereinto as quickly as possible. It should be noted that the VICM does not have any control of the HVAC module.
[0012] In operation, if the motor vehicle has experienced a cold soak, then the driver would be expected to select a heating mode for the HVAC module. The VICM would sense the temperature rise of the HVAC air in the HVAC ducting and thereupon open the bleed door to allow the ESS blower to duct-in (bleed) a selected portion of the HVAC conditioned air from the HVAC ducting. On the other hand, if the motor vehicle has experienced a hot soak, then the driver would be expected to select a cooling mode for the HVAC module. Now, the VICM would sense the temperature decline in the HVAC air and thereupon open the bleed door to allow the ESS blower to duct-in (bleed) a selected portion of the HVAC conditioned air from the HVAC ducting. When the optimal ESS performance temperature range of the ESS (and the passenger cabin) is present, the VICM will detect there is no need for HVAC air to assist thermal conditioning of the ESS and will close the bleed door, opening the door as needed to keep the temperature of the ESS within its optimal temperature range.
[0013] Accordingly, it is an object of the present invention to provide an ESS thermal conditioning system which selectively utilizes air from at least one auxiliary air source, most preferably the HVAC ducting.
[0014] This and additional objects, features and advantages of the present invention will become clearer from the following specification of a preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a schematic side view of a passenger cabin, showing an HVAC module and components associated with prior art thermal conditioning of a hybrid vehicle ESS.
[0016] FIG. 2 is a schematic diagram of an HVAC module and components associated with prior art thermal conditioning of a hybrid vehicle ESS.
[0017] FIG. 3 is a graph of available ESS power as a function of battery pack cell temperature, showing plots for charge and discharge.
[0018] FIG. 4 is a schematic side view of a passenger cabin, showing an HVAC module interfaced with components associated with the thermal conditioning of a hybrid vehicle ESS according to a preferred example of the present invention.
[0019] FIG. 5 is a schematic diagram of an HVAC module interfaced selectively with components associated with thermal conditioning of a hybrid vehicle ESS according to the present invention.
[0020] FIG. 6A is a schematic plan view of an HVAC ESS duct with the bleed door in its closed position.
[0021] FIG. 6B is a schematic view seen along line 6 B- 6 B of FIG. 6A .
[0022] FIG. 6C is a schematic plan view of an HVAC ESS duct with the bleed door in its open position.
[0023] FIG. 6D is a schematic view seen along line 6 D- 6 D of FIG. 6C .
[0024] FIG. 7 is an exemplar algorithm for carrying out the ESS thermal conditioning system according to the present invention, wherein the HVAC ducting is the selective auxiliary air source.
[0025] FIG. 8 is a graph of inlet air temperature versus time, including plots of selected proportions of HVAC conditioned air.
[0026] FIG. 9 is a graph of battery pack cell temperature versus time, including plots of selected proportions of HVAC conditioned air with respect to a selected motor vehicle operation event profile.
[0027] FIG. 10 is an exemplar schematic representation of a plurality of selective air sources in accordance with a second example of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0028] Referring now to the Drawings, FIG. 3 depicts a graph 200 of power versus battery pack cell temperature of a typical hybrid vehicle ESS. Plot 202 depicts the available discharge power, and plot 204 depicts the available charge power. It is seen that there is a temperature range at which both plots 202 , 204 plateau at a maximum, from temperature T 1 to temperature T 2 , wherein this plateau defines an optimal ESS performance temperature range 206 (any particular ESS and its battery pack will have its particular optimal ESS performance temperature range which may vary from that shown in FIG. 3 ). For temperatures below T 1 , the power availability of the battery pack in both charge and discharge modes decreases rapidly with decreasing temperature, and for temperatures above T 2 , the power availability of the battery pack in both charge and discharge modes also decreases rapidly with increasing temperature. Therefore, it is highly desirable to keep the ESS within the optimal ESS performance temperature range (i.e., for the example of FIG. 3 , the range 206 between T 1 and T 2 ), and indeed to keep the ESS from approaching even the limits of the range (i.e., for the example of FIG. 3 , keeping the temperature of the ESS within about T 1 +ΔT and T 2 -ΔT, where +ΔT may be, for example, about 5 C), if at all possible.
[0029] The ESS thermal conditioning system according to the present invention performs the function of keeping the ESS temperature within the optimal ESS performance temperature range, or bringing the ESS temperature into this range as quickly as possible.
[0030] A preferred example of the ESS temperature conditioning system 100 is shown at FIGS. 4 through 7 .
[0031] As mentioned, the passenger cabin includes a heating, ventilation and air conditioning (HVAC) module 104 , which typically includes passenger input instruments 130 and an HVAC controller 132 which operates the HVAC module in response to the passenger input. Typically, the HVAC module includes an HVAC blower 134 , an evaporator 136 for cooling the HVAC air to the cabin and a heater core 138 for heating the HVAC air to the cabin via the HVAC ducting 108 . These components are not subject to an OBD requirement, being not controlled or influenced by the hybrid vehicle integration control module (VICM) 124 .
[0032] The ESS 102 and the HVAC module 104 are generally as described with respect to FIGS. 1 and 2 , except now an HVAC ESS duct 106 is provided which communicates with the HVAC ducting 108 so that HVAC air A′ H can be made selectively available to the ESS blower 110 and be mixed with the cabin air A′ C , which is always available.
[0033] As in FIGS. 1 and 2 , within the passenger cabin 112 of the hybrid motor vehicle is disposed the ESS 102 , which may, for example, rest on the vehicle floor 114 above the fore-aft floor “tunnel” 116 . The ESS 102 is thermally conditioned, at least in part, by the movement of cabin air via an ESS blower 118 , whereby the cabin air is circulated through the ESS, originating at least one permanently open entry vent 120 and exiting at least one permanently open exit vent 122 , both vents being permanently open in the sense of being in permanently and completely open fluidic communication with the passenger cabin. Operation of the ESS blower 118 is controlled by the VICM 124 , utilizing temperature data from (among others) an inlet duct temperature sensor 126 a , an outlet duct temperature sensor 126 b , and an ESS temperature sensor 126 c . The VICM 124 is connected to inputs and outputs by various data lines (see for example dashed lines in FIG. 5 ).
[0034] The HVAC ESS duct 106 intersects the HVAC ducting 108 of the HVAC module 104 such that the HVAC air may bleed from the HVAC ducting into the HVAC ESS duct. An actuator door, or “bleed” door, 144 is fitted to the HVAC ESS duct 106 , and is electrically operated selectively to position anywhere between a closed position to an open position responsive to the VICM 124 . The VICM 124 operates the bleed door 144 based upon its programming and data from temperature upstream and downstream sensors 146 a , 146 b disposed on either side of the bleed door, and may for example, utilize other temperature sensors.
[0035] The VICM 124 , its associated data lines, the system sensors, including inlet and outlet duct temperature sensors 126 a , 126 b , and upstream and downstream temperature sensors 146 a , 146 b , and any actuator door position sensor (which can be incorporated into the actuator, i.e., as shown at 144 c of FIGS. 6A and 6C ), all constitute an electronic control system 142 .
[0036] These non-HVAC module components are subject to an on-board diagnostics (OBD) requirement, whereby a signal is provided to the driver if a fault is detected in any of the components.
[0037] By way of example as shown at FIGS. 6A through 6D , the bleed door 144 may be a panel 144 a having an area which matches the cross-sectional area of the HVAC ESS duct 106 , which is nonotatably mounted to an axle 144 b which is, itself, rotatably mounted to the HVAC ESS duct. The axle 144 b is rotated by an actuator 144 c which is electrically connected to the VICM 124 .
[0038] In operation, if the motor vehicle has experienced a cold soak, for example sitting outside on a very cold night, then the driver would be expected to select a heating mode for the HVAC module 128 . The VICM 124 would sense the temperature rise of the HVAC air in the HVAC ducting via the temperature sensor 146 a and thereupon open the bleed door 144 (as for example shown at FIGS. 6C and 6D ) to allow the ESS blower to duct-in (bleed) a selected portion of the HVAC air A′ H from the HVAC ducting to blend or mix with the cabin air A′ C , wherein the proportion of the HVAC air to cabin air is selected by the VICM and is effected by the selected position of the bleed door (i.e., being positioned more or less open). On the other hand, if the motor vehicle has experienced a hot soak, for example sitting outside on a hot, sunny day, then the driver would be expected to select a cooling mode for the HVAC module. Now, the VICM would sense the temperature decline in the HVAC air via the temperature sensor 146 a , and thereupon open the bleed door to allow the ESS blower to duct-in (bleed) a selected a portion of the HVAC conditioned air from the HVAC ducting to blend or mix with the cabin air A′ C , wherein, as mentioned above, the proportion of the HVAC air to cabin air is selected by the VICM and is effected by the selected position of the bleed door (i.e., being positioned more or less open).
[0039] In the mode where the bleed door 144 is open, the VICM 124 receives data from the downstream temperature sensor 146 b , and compares to the data from the upstream temperature sensor 146 a to ascertain that the bleed door is open and air is flowing (bleeding) properly from the HVAC ducting. If it is detected that there is a fault, then an OBD fault signal is provided to the driver.
[0040] When the optimal ESS performance temperature range of the ESS 102 (and the passenger cabin) is present, the VICM 124 will detect there is no need for HVAC air to assist thermal conditioning of the ESS and will close the bleed door 144 . The re-opening of the bleed door is effected periodically as needed to keep the temperature of the ESS within its optimal temperature range and avoid as best as possible the extremes of the optimal temperature range.
[0041] Turning attention now to FIG. 7 , an exemplar algorithm 300 for carrying out the preferred example of the ESS temperature conditioning system 100 will be described.
[0042] The algorithm is initiated at Block 302 and passes to Decision Block 304 , whereat inquiry is made as to whether the engine ignition is on. If the answer to the inquiry is no, then the algorithm proceeds to Block 306 , whereat the ESS blower is turned off and the bleed door is closed. The algorithm then returns to Decision Block 304 .
[0043] Reconsidering Decision Block 304 , if the answer to the inquiry thereat is yes, then the algorithm proceeds to decision block 308 , whereat inquiry is made as to whether the cells of the battery pack of the ESS are cold or trending toward becoming cold, that is, below a predetermined temperature or trending theretoward, as for example a temperature almost at yet above, at, or below a lowest temperature at which available charge/discharge power is optimum (see discussion of FIG. 3 , hereinabove). If the answer to the inquiry is yes, then the algorithm proceeds to Decision Block 310 , whereat inquiry is made as to whether the HVAC air temperature is greater than or equal to the ESS inlet air temperature (i.e., the VICM compares the temperature data from the upstream sensor 146 a and the inlet duct sensor 126 a ). If the answer to the inquiry is no, then the algorithm proceeds to Block 312 whereat the bleed door is closed, and the algorithm then proceeds back to Decision Block 304 .
[0044] However, if the answer to the inquiry at Decision Block 310 is yes, then the algorithm proceeds to Block 314 , whereat the bleed door is opened, and then proceeds to Block 316 , whereat the VICM operates the ESS blower based for example upon a predetermined look-up table stored in the VICM. The algorithm then returns to Decision Block 304 .
[0045] Reconsidering Decision Block 308 , if the answer to the inquiry thereat is no, then the algorithm proceeds to Decision Block 318 , whereat inquiry is made as to whether the cells of the battery pack of the ESS are hot or trending toward becoming hot, being above a predetermined temperature or trending theretoward, as for example a temperature almost at yet below, at, or above a highest temperature at which available charge/discharge power is optimum (see discussion of FIG. 3 , hereinabove). If the answer to the inquiry is no, then the algorithm proceeds to Block 306 , whereat the ESS blower is turned off and the bleed door is closed. The algorithm then proceeds back to Decision Block 304 .
[0046] However, if the answer to the inquiry at Decision Block 318 is yes, then the algorithm proceeds to Decision Block 320 , whereat inquiry is made as to whether the HVAC duct air temperature is less than the ESS inlet temperature (i.e., the VICM compares the temperature data from the upstream sensor 146 a and the inlet duct sensor 126 a ). If the answer to the inquiry is no, then the algorithm proceeds to Block 312 , whereat the bleed door is closed, and the algorithm then returns to Decision Block 304 .
[0047] However, if the answer to the inquiry at Decision Block 320 is yes, then the algorithm proceeds to Block 322 , whereat the bleed door is opened, and then proceeds to Block 316 , whereat the VICM operates the ESS blower based for example upon a predetermined look-up table stored in the VCIM. The algorithm then returns to Decision Block 304 .
[0048] Temperature conditioning benefits to the ESS as a result of implementation of the above described preferred form of the present invention are graphically depicted at FIGS. 8 and 9 .
[0049] FIG. 8 is a graph 400 of inlet air temperature versus time, depicting four plots, all with an initial temperature of 60 C at initial time. The first plot 402 is indicative of change in HVAC air as a function of time. The second plot 404 is indicative of the change in ESS inlet temperature as a function of time, wherein the air delivery to the ESS is proportionally 75% HVAC air and 25% cabin air. The third plot 406 is indicative of the change in ESS inlet temperature as a function of time, wherein the air delivery to the ESS is proportionally 50% HVAC air and 50% cabin air. The fourth plot 408 is indicative of the change in ESS inlet temperature as a function of time, wherein the air delivery to the ESS is 100% cabin air. It is clear that the blending of HVAC air provides a quicker reduction in temperature of the ESS inlet air over that of only cabin air.
[0050] FIG. 9 is a graph 500 of ESS average cell temperature versus time, showing 5 plots after a hot solar soak. The start ESS inlet temperature (the cabin temperature) is 60 C, and the ESS cell temperature is 41 C. The first plot 502 is indicative of the speed of the motor vehicle during a driving event. The second plot 504 is indicative of the change in ESS cell temperature as a function of time, wherein the air delivery to the ESS is proportionally 75% HVAC air and 25% cabin air. The third plot 506 is indicative of the change in ESS cell temperature as a function of time, wherein the air delivery to the ESS is proportionally 50% HVAC air and 50% cabin air. The fourth plot 508 is indicative of the change in ESS cell temperature as a function of time, wherein the air delivery to the ESS is 100% cabin air at a base rate of flow. The fifth plot 510 is indicative of the change in ESS cell temperature as a function of time, wherein the air delivery to the ESS is 100% cabin air at a rate 30% higher than the base rate of flow. As in FIG. 8 , it is clear that the blending of HVAC air provides a quicker reduction in temperature of the ESS over that of conventional cabin air.
[0051] Table I provides exemplar operational conditions of the ESS temperature conditioning system 100 .
[0000]
TABLE I
Condition
HVAC Bleed
Cabin Inlet
ESS Min.
100%
0%
City driving
75%
25%
Hwy. Driving
50%
50%
ESS Max.
40%
60%
[0052] Table II provides exemplar responses to certain fault conditions of operation by the ESS temperature conditioning system 100 .
[0000]
TABLE II
System Condition
System Response
Bleed door stuck closed
OBD indicator on
Bleed door stuck midway
OBD indicator on, poss. lower ESS
blower speed
Bleed door stuck open
OBD indicator on, poss. lower ESS
blower speed
Bleed temp. sensor failure
OBD indicator on, switch to ESS
inlet sensor
Bleed duct blocked/dislodged
OBD indicator on, command bleed door
closed
[0053] FIG. 10 depicts a schematic diagram of a non-limiting example of possible selective air sources of the ESS temperature conditioning system 600 according to the present invention, wherein other selective air sources may be utilized other than those illustrated.
[0054] Air source 602 is a conventional prior art air source, as for example shown at FIGS. 1 and 2 and discussed hereinabove. Selective air source 604 selectively draws air from a selected location of the cabin other than the conventional location of the one or more entry vents used by the conventional air source 602 , as for example at the floor or the roof of the vehicle, wherein the selectivity depends upon the open or closed position of its actuator door per the VICM. Selective air source 606 draws air from another selected location of the cabin other than the conventional location of the one or more entry vents used by the conventional air source 602 , as for example at the cargo area of a SUV, station wagon or van, wherein the selectivity depends upon the open or closed position of its actuator door per the VICM. Selective air source 608 selectively bleeds air from the HVAC, being the ESS thermal conditioning system 100 as described hereinabove. Selective air source 610 draws air from the trunk of the vehicle, wherein the selectivity depends upon the open or closed position of its actuator door per the VICM. Selective air source 612 draws air from an exterior vent, as for example at the engine compartment, wheel well or near the exhaust (safely away from exhaust gases), wherein the selectivity depends upon the open or closed position of its actuator door per the VICM. Since a plurality of auxiliary air sources are available, the VICM will select the actuator door opening amount which is most appropriate to any of them, respectively, based upon, for example, the sensed temperature at the auxiliary air source in relation to the sensed temperature of the cabin air, and either or both of the ESS and/or the ESS inlet.
[0055] To those skilled in the art to which this invention appertains, the above described preferred embodiment may be subject to change or modification. Such change or modification can be carried out without departing from the scope of the invention, which is intended to be limited only by the scope of the appended claims.
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A thermal conditioning system for the energy storage system of a hybrid vehicle. At least one auxiliary air source, other than a permanently open air source, has a selectively operable actuator door which either connects or disconnects the auxiliary air source to the energy storage system blower, the air flow being selected to optimally temperature condition the energy storage system. The auxiliary air source preferably includes the HVAC ducting.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2001-371372 filed on Dec. 5, 2001, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to an engine starting control apparatus that cranks an engine by means of a starter motor to start the engine, and more particularly to an engine starting control apparatus that cranks, upon starting of an engine, a crankshaft in the reverse direction to a predetermined position to improve the startability of the engine.
[0004] 2. Description of Background Art
[0005] The official gazette of Japanese Patent Laid-open No. Sho 63-75323 discloses an engine stopping and starting control apparatus which controls an engine so that the engine is automatically stopped when a vehicle stops and re-started. Starting control is accomplished when a throttle grip is operated in the stopping state of the vehicle to issue an instruction to start the vehicle, and has the effect of reducing the production of exhaust gas or consumption of the fuel, particularly during idling. As a result, this device provides some environmental and energy saving benefits.
[0006] Another device is disclosed, for example, in the official gazette of Japanese Patent Laid-open No. Hei 6-64451, or the official gazette of Japanese Patent Laid-open No. Hei 71350. This device uses a technique of rotating a crankshaft reversely to a predetermined position before an engine is started, and then starting the engine from the reversely rotated position. As such, this device helps to reduce the cranking torque upon starting of the engine, thus enhancing the startability of the engine
[0007] However, the above devices are not without problems.
[0008] In a four-cycle engine, it is sufficient if ignition is performed at the compression top dead center, and ignition is not necessary at the exhaust top dead center. However, for the reason that it is necessary to discriminate a stroke in order to cause ignition to occur only at the compression top dead center and that there is no actual loss even if ignition occurs at the exhaust top dead center, ignition is usually performed as useless ignition at the exhaust top dead center.
[0009] However, if the reverse rotation control described above is applied, since fuel air mixture remaining in the exhaust pipe is sucked into the cylinder in the exhaust stroke upon the reverse rotation, there is the possibility that the air fuel mixture may be fired by useless ignition at the exhaust top dead center upon subsequent forward rotation.
SUMMARY AND OBJECTS OF THE INVENTION
[0010] It is an object of the present invention to solve the problems of the prior art described above by providing an engine starting control apparatus which is capable of preventing firing by useless ignition with a simple and inexpensive configuration that does not need a system for discrimination of a stroke, or the like.
[0011] In order to attain the object described above, the present invention adopts the following countermeasures for an engine starting control apparatus; namely, upon starting of an engine, a crankshaft is caused to rotate reversely to a predetermined position, and then rotate forwardly.
[0012] Several characteristics of the present invention are described below:
[0013] (1) The engine starting control apparatus of the present invention includes a starter motor connected to the crankshaft, ignition means for igniting the engine in the proximity of the top dead center of a piston, and ignition suppression means for inhibiting the ignition of the engine for a predetermined period of time after the forward rotation of the engine.
[0014] (2) In the engine starting control apparatus of the present invention the reverse rotation control means causes the crankshaft to rotate reversely until the piston runs over the exhaust top dead center.
[0015] (3) In the engine starting control apparatus of the present invention the engine has a valve overlap period within which an intake valve and an exhaust valve communicate with each other in the proximity of the exhaust top dead center, and the ignition means performs ignition as useless ignition at a position in the proximity of the exhaust top dead center.
[0016] (4) In the engine starting control apparatus of the present invention the ignition suppression means inhibits ignition of the engine only for the first ignition timing after the engine is rotated forwardly.
[0017] (5) Further, the engine starting control apparatus of the present invention includes a kick starting means for causing the crankshaft to rotate forwardly using man-power, and an ignition suppression cancellation means for canceling the inhibition of the ignition of the engine by the ignition suppression means when the engine is started by man-power.
[0018] With the characteristic (1) described above, even if air fuel mixture remaining in the exhaust pipe is sucked into the cylinder in an exhaust stroke during the reverse rotation and is compressed at the exhaust top dead center during the forward rotation thereafter, since ignition is inhibited at the timing, firing of the air fuel mixture is prevented. Accordingly, firing by useless ignition is prevented by using a simple and inexpensive ignition means. Moreover, the apparatus has high flexibility and avoids the need to perform a stroke discrimination operation.
[0019] With the characteristic (2) described above, since the crankshaft always is rotated forwardly and reversely on reaching the boundary of the exhaust top dead center, the running start distance upon forward rotation can be assured sufficiently. Accordingly, firing by useless ignition can be prevented while maintaining good startability.
[0020] With the characteristic (3) described above, firing by useless ignition can also be prevented in a structure wherein, when the crankshaft stops in the proximity of the exhaust top dead center, the intake system, the combustion chamber and the exhaust system communicate with each other, which makes it likely that the combustible air fuel mixture flows into the exhaust system, as with a high output power engine having a valve overlap period.
[0021] With the characteristic (4) described above, since ignition is inhibited only with regard to the first useless ignition, rapid firing by normal ignition can be achieved. Accordingly, firing by useless ignition can be prevented without sacrificing the startability.
[0022] With the characteristic (5) described above, since misfiring is not inhibited upon cranking from a state wherein the crankshaft is not rotated reversely as upon kick starting, the startability upon kick starting is not disturbed by unnecessary inhibition of ignition.
[0023] Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
[0025] [0025]FIG. 1 is a general side elevational view of a scooter type motorcycle to which the present invention is applied;
[0026] [0026]FIG. 2 is a sectional view of a swing unit of FIG. 1 taken along a crankshaft;
[0027] [0027]FIG. 3 is a partial enlarged view of FIG. 2;
[0028] [0028]FIG. 4 is a block diagram of a control system for an ACG starter;
[0029] [0029]FIG. 5 is a view illustrating transition conditions of an operation mode and an operation pattern in stop & go control;
[0030] [0030]FIG. 6 is a view illustrating principal operations in the stop & go control as a table;
[0031] [0031]FIG. 7 is a view illustrating a relationship between the crank angle position and the run-over torque;
[0032] [0032]FIG. 8 is a view illustrating a relationship between the target reverse rotation time period and the water temperature;
[0033] [0033]FIG. 9 is a timing chart of engine starting control;
[0034] [0034]FIG. 10 is a flow chart of the engine starting control;
[0035] [0035]FIG. 11 is a flow chart of starting reverse rotation control;
[0036] [0036]FIG. 12 is a flow chart of ignition suppression control;
[0037] [0037]FIG. 13 is a flow chart of stopping reverse rotation control;
[0038] [0038]FIG. 14 is a functional block diagram of a stopping reverse rotation control section; and
[0039] FIGS. 15 ( a )-( c ) are diagrams illustrating operation of the stopping reverse rotation control.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] In the following, a preferred embodiment of the present invention is described in detail with reference to the drawings. FIG. 1 is a general side elevational view of a scooter type motorcycle to which an engine starting control apparatus of the present invention is applied. The vehicle further has an engine automatic stopping and starting function of automatically stopping an engine if the vehicle is stopped but driving, such that when a throttle grip is opened or a starter switch is operated into an on-state is performed thereafter, a starter motor automatically to re-start the engine.
[0041] A vehicle body front part and a vehicle body rear part are connected to each other by a low floor member 4 , and a vehicle body frame which forms a skeleton of the vehicle body is generally formed from a down tube 6 and a main pipe 7 . A fuel tank and an accommodation box (both not shown) are supported by the main pipe 7 , and a seat 8 is disposed above the fuel tank and the accommodation box.
[0042] On the vehicle body front part, a handle bar 11 is provided for pivotal motion by and above a steering head 5 , and a front fork 12 extends downwardly and a front wheel FW is supported for rotation at a lower end of the front fork 12 . A handle bar cover 13 serving also as an instrument panel covers the handle bar 11 from above. A bracket 15 is provided in a projecting manner at a lower end of a rising portion of the main pipe 7 , and a hanger bracket 18 of a swing unit 2 is connected to and supported by the bracket 15 for rocking motion through a link member 16 .
[0043] A single-cylinder four-cycle engine E is carried at a front portion of the swing unit 2 . A belt type non-stage transmission 10 extends rearwardly from the engine E, and a rear wheel RW is supported for rotation on a reduction gear mechanism 9 , which is provided at a rear portion of the belt type non-stage transmission 10 with a centrifugal clutch interposed therebetween. A rear cushion 3 is interposed between an upper end of the reduction gear mechanism 9 and an upper bent portion of the main pipe 7 . A carburetor 17 connected to an intake pipe 19 extending from the engine E and an air cleaner 14 connected to the carburetor 17 are disposed at a front portion of the swing unit 2 .
[0044] [0044]FIG. 2 is a sectional view of the swing unit 2 taken along a crankshaft 201 , and FIG. 3 is a partial enlarged view of the swing unit 2 , and like reference characters to those appearing as above denote like or equivalent elements.
[0045] The swing unit 2 is covered with a crankcase 202 formed from left and right crankcase halves 202 L, 202 R joined together, and the crankshaft 201 is supported for rotation by bearings 208 , 209 secured to the crankcase half 202 R. A connecting rod (not shown) is connected to the crankshaft 201 through a crank pin 213 .
[0046] The left crankcase 202 L serves also as a belt type non-stage transmission case, and a belt driving pulley 210 is provided for rotation on the crankshaft 201 , which extends to the left crankcase 202 L. The belt driving pulley 210 is composed of a fixed side pulley half 210 L and a variable side pulley half 210 R. The fixed side pulley half 210 L is securely mounted at a left end portion of the crankshaft 201 through a boss 211 , and the variable side pulley half 210 R is spline-fitted with the crankshaft 201 on the right side of the fixed side pulley half 210 L such that the variable side pulley half 210 R can move toward and away from the fixed side pulley half 210 L. A V belt 212 is wound between the pulley halves 210 L, 210 R.
[0047] On the right side of the variable side pulley half 210 R, a cam plate 215 is secured to the crankshaft 201 , and a slide piece 215 a provided at an outer circumferential end of the cam plate 215 is held in sliding engagement with a cam plate sliding boss portion 210 Ra formed in an axial direction at an outer circumferential end of the variable side pulley half 210 R. The cam plate 215 of the variable side pulley half 210 R has a tapering face which is inclined such that a portion near to an outer circumference thereof approaches the cam plate 215 side, and a dry weight pole 216 is accommodated in a space defined between the tapering face and the variable side pulley half 210 R.
[0048] As the speed of rotation of the crankshaft 201 increases, the dry weight pole 216 which is positioned between and rotate together with the variable side pulley half 210 R and the cam plate 215 is moved in a centrifugal direction by centrifugal force, and the variable side pulley half 210 R is pressed by the dry weight pole 216 to move leftwardly toward the fixed side pulley half 210 L. As a result, the V belt 212 held between the pulley halves 210 L, 210 R is moved in a centrifugal direction so that the wrapping diameter thereof increases.
[0049] A driven pulley (not shown) corresponding to the belt driving pulley 210 is provided at the rear portion of the vehicle, and the V belt 212 is wrapped around the driven pulley. By this belt transmission mechanism, power of the engine E is automatically adjusted and transmitted to the centrifugal clutch and drives the rear wheel RW through the reduction gear mechanism 9 and so forth.
[0050] An ACG starter 1 that is a combination of a starter motor and an AC generator is disposed in the right crankcase half 202 R. In the ACG starter 1 , an outer rotor 60 is secured to the tapering end portion of the crankshaft 201 by a screw 253 .
[0051] A stator 50 disposed on the inner circumference side of the outer rotor 60 is secured to the crankcase 202 by a bolt 279 . A fan 280 secured by a bolt 246 is provided on the outer rotor 60 . A radiator 282 is provided adjacent the fan 280 and is covered with a fan cover 281 .
[0052] As shown in an enlarged scale in FIG. 3, a sensor case 28 is fitted in the inner circumference of the stator 50 . Rotor angle sensors (magnetic pole sensors) 29 and a pulser sensor (ignition pulsers) 30 are provided at equal distances along an outer circumference of a boss 60 a of the outer rotor 60 in the sensor case 28 . The rotor angle sensors 29 are provided for energization control of stator coils of the ACG starter 1 and are provided in a one-by-one corresponding relationship for the U phase, V phase, and W phase of the ACG starter 1 . The pulser sensor 30 is provided for ignition control of the engine and provided singly. The rotor angle sensors 29 and the pulser sensor 30 can each be formed from a Hall IC or a magnetic resistance (MR) element.
[0053] Leads of the rotor angle sensors 29 and the pulser sensor 30 are connected to a board 31 , and further, a wire harness 32 is coupled to the board 31 . A magnet ring 33 magnetized in two stages is fitted with an outer periphery of the boss 60 a of the outer rotor 60 so that the magnet ring 33 may exert a magnetic action to the rotor angle sensors 29 and the pulser sensor 30 .
[0054] The N poles and the S poles disposed alternately at distances of 30° in a circumferential direction corresponding to the magnetic poles of the stator 50 are formed on one of the magnetized zones of the magnet ring 33 corresponding to the rotor angle sensors 29 , and a magnetized portion is formed over a range of 15° to 40° at one location in a circumferential direction on the other magnetized zone of the magnet ring 33 corresponding to the ignition pulser 30 .
[0055] Upon starting of the engine, the ACG starter 1 functions as a starter motor (synchronous motor) and is driven with current supplied from a battery to rotate the crankshaft 201 to start the engine. After the engine is started, the ACG starter 1 functions as a synchronous motor charges the battery with current generated thereby and besides supplies current to various electric accessory elements.
[0056] Referring back to FIG. 2, a sprocket wheel 231 is secured to the crankshaft 201 between the ACG starter 1 and a bearing 209 , and a chain for driving a camshaft (not shown) from the crankshaft 201 is wrapped around the sprocket wheel 231 . It is to be noted that the sprocket wheel 231 is formed integrally with a gear wheel 232 for transmitting power to a pump for circulating lubricating oil.
[0057] [0057]FIG. 4 is a block diagram of principal elements of an electric accessory system including the ACG starter 1 . An ECU 80 includes a full wave rectification bridge circuit 81 for full wave rectifying three-phase ac current generated by the ACG starter 1 , a regulator 82 for limiting an output of the full wave rectification bridge circuit 81 to a predetermined regulated voltage (for example, 14.5 V), and a stop & go control section 84 for automatically stopping the engine when the vehicle stops and automatically re-starting the engine when predetermined starting conditions are satisfied. The ECU 80 also includes a starting reverse rotation control section 85 for rotating, upon starting of the engine by a starter switch 35 , the crankshaft 201 reversely to a predetermined position and then rotating the engine forwardly, a stopping reverse rotation control section 86 for rotating the crankshaft 201 to a predetermined position after the engine is automatically stopped by the stop & go control, and an ignition suppression control section 87 for causing the engine to misfire by a predetermined number of times at ignition timings upon starting of the engine.
[0058] An ignition coil 21 is connected to the ECU 80 , and an ignition plug 22 is connected to the secondary side of the ignition coil 21 . Further, a throttle sensor 23 , a fuel sensor 24 , a seat switch 25 , an idling switch 26 , a cooling water temperature sensor 27 , a throttle switch 47 , a warning buzzer 48 , the rotor angle sensors 29 , and the ignition pulser 30 are connected to the ECU 80 so that detection signals from the various element are inputted to the ECU 80 .
[0059] Furthermore, a starter relay 34 , the starter switch 35 , stop switches 36 , 37 , a standby indicator 38 , a fuel indicator 39 , a speed sensor 40 , an auto-by starter 41 , and a headlamp 42 are connected to the ECU 80 . A dimmer switch 43 is provided for the headlamp 42 .
[0060] Current is supplied from a battery 46 to the various elements mentioned above through a main fuse 44 and a main switch 45 . It is to be noted that, while the battery 46 is connected directly to the ECU 80 by the starter relay 34 , it has a circuit by which it is connected to the ECU 80 only through the main fuse 44 without through the main switch 45 .
[0061] As seen in FIG. 5, the stop & go control section 84 of the ECU 80 controls the components of the vehicle in one of a “starting mode”, an “idling switch mode” and a “stop & go mode” in response to the state of the idling switch 26 and the state of the vehicle. In the “stop & go mode”, one of a first operation pattern (hereinafter referred to as “first pattern”) wherein idling is inhibited at all and a second operation pattern (hereinafter referred to as “second pattern”) wherein idling is permitted exceptionally under a predetermined condition is selected.
[0062] In the “starting mode”, idling is permitted only for a certain period of time after the engine is started in order to perform warming up upon starting of the engine or the like. In the “idling switch mode”, idling is permitted any time in accordance with the will of the driver by switching the idling switch 26 on. In the “stop & go mode”, when the vehicle is stopped from its running state, the engine is stopped automatically, and if the accelerator pedal is operated in a stopping state, then the engine is re-started automatically.
[0063] In FIG. 5, changeover conditions of the operation mode and the operation pattern are illustrated schematically, and if the idling switch 26 is OFF when the main switch 45 is switched ON (the condition [1] is satisfied), then the “starting mode” is selected.
[0064] Further, if a vehicle speed equal to or higher than a predetermined speed is detected for a predetermined period of time or more in the “starting mode” (the condition [2] is satisfied), then transition to the “stop & go mode” is performed. In the “stop & go mode”, immediately after the transition thereto from the “starting mode”, the “first pattern” is selected and idling is inhibited. If, in the “first pattern”, an ignition OFF state continues for three minutes or more (the condition [3] is satisfied), then transition to the “second pattern” is performed. If the condition [2] described above is satisfied in the “second pattern”, then transition to the “first pattern” is performed.
[0065] On the other hand, if the idling switch 26 is ON when the main switch 45 is switched ON (the condition [6] is satisfied), then the “idling switch mode” is selected. It is to be noted that, if, in the “stop & go mode”, the idling switch 26 is switched ON and the condition [4] is satisfied irrespective of the “first pattern” and the “second pattern”, then transition to the “idling switch mode” is performed. Further, if the idling switch 26 is switched OFF in the “idling switch mode” (the condition [5] is satisfied), then transition to the “first pattern of the stop & go mode” is performed.
[0066] [0066]FIG. 6 is a view illustrating contents of individual control of the stop & go control section 84 for each of the operation modes and operation patterns.
[0067] In the “engine starting control” (first row of FIG. 6), when predetermined conditions are satisfied for each of the operation modes and the operation patterns, an engine starting instruction is issued to drive the ACG starter 1 .
[0068] More particularly, in the “starting mode” and the “idling switch mode”, an engine starting instruction is issued when the starter switch 35 is ON and the stop switches 36 , 37 are ON, and besides the engine speed is a predetermined idling speed or lower.
[0069] In the “first pattern of the stop & go mode”, an engine starting instruction is issued when the throttle switch 47 is ON, the seat switch 25 is ON, and besides the engine speed is the predetermined idling speed or lower.
[0070] In the “second pattern of the stop & go mode”, an engine starting instruction is issued when the starter switch 35 is ON, the stop switches 36 , 37 are ON, and besides the engine speed is the predetermined idling speed or lower, or when the throttle switch 47 is ON, the seat switch 25 is ON, and besides the engine speed is the predetermined idling speed or lower.
[0071] In the “standby indicator control”(second row of FIG. 6), ON/OFF of the standby indicator 38 is controlled. The standby indicator blinks in a state wherein, even if the engine is in a stopping state, if the throttle is opened, then the engine can be started immediately to start the vehicle, and a warning of this is given to the driver. The standby indicator 38 is always unlit in the “starting mode”, “idling switch mode”, and “second pattern of the stop & go mode”. In the “first pattern of the stop & go mode”, the standby indicator 38 blinks when the seat switch 25 is ON and the engine speed is a predetermined speed or lower.
[0072] In the “ignition control”(third row of FIG. 6), ignition of the engine is permitted or inhibited. More particularly, in the “starting mode”, “idling switch mode”, and “second pattern of the stop & go mode”, ignition of the engine is always permitted. In the “first pattern of the stop & go mode”, ignition of the engine is permitted when the throttle switch is ON, or the vehicle speed is higher than zero, but in any other case, ignition of the engine is inhibited.
[0073] In the “headlamp control” (fourth row of FIG. 6), ON/OFF the headlamp 42 is controlled. More particularly, in the “idling switch mode”, “first pattern of the stop & go mode”, and “second pattern of the stop & go mode”, the headlamp 42 is always controlled ON. In the “starting mode”, the headlamp 42 is controlled ON when the engine speed is equal to or higher than a predetermined speed or the vehicle speed is higher than zero.
[0074] In the “warning buzzer control” (fifth row of FIG. 6), ON/OFF of the warning buzzer 48 is controlled. More particularly, in the “starting mode”, the warning buzzer 48 is always controlled OFF. In the “idling switch mode”, the warning buzzer 48 is switched ON if a non-seated state continues for one second or more while the ignition is OFF. In the “first pattern of the stop & go mode”, warning sound is generated if a non-seated state continues for equal to or more than one second while the ignition is OFF or the ignition OFF state continues for three minutes or more. In the “second pattern of the stop & go mode”, warning sound is generated when the ignition is OFF, the throttle switch is OFF, and besides the vehicle speed is zero.
[0075] In the “charging control” (sixth row of FIG. 6), upon sudden acceleration when the driver suddenly opens the throttle or upon starting of the vehicle from its stopping state, the charging voltage is lowered from 14.5 V in a normal state to 12.0 V irrespective of the operation mode or the operation pattern. More particularly, if the vehicle speed is higher than 0 km and the period of time within which the throttle is opened from its fully closed state to its fully open state is, for example, 0.3 second or less, then it is recognized that the operation is an acceleration operation, and the charging control is started. Similarly, if the throttle switch is switched ON when the vehicle speed is zero and the engine speed is a predetermined speed or lower, then this is recognized as starting of the vehicle from its stopping state, and the charging control is started. Consequently, the electric load of the ACG starter 1 is temporarily lowered to raise the acceleration performance. This control is ended by providing that six seconds elapse after the control is started, the engine speed is equal to or higher than the predetermined speed, or else the throttle opening decreases.
[0076] Referring back to FIG. 4, upon starting of the engine by the starter switch 35 , the starting reverse rotation control section 85 of the ECU 80 first rotates the crankshaft 201 reversely once to a position at which the load torque upon forward rotation is low and then drives the ACG starter in the forward rotation direction to start, the engine. However, only if the ACG starter 1 is rotated reversely for a fixed period of time, forward rotation cannot be started from a desired crank angle position due to a difference in rotational friction of the engine. Therefore, in the present embodiment, before the engine is rotated reversely, the temperature of cooling water is detected, and the ACG starter 1 is rotated reversely for a period of time corresponding to the water temperature. By the countermeasure, upon re-starting when the engine is stopped once, the engine can be immediately started to start the vehicle by avoiding an influence of the load torque.
[0077] [0077]FIG. 7 illustrates a relationship between the crank angle position and the run-over torque, that is, torque necessary for the top dead center to be run over, upon starting of the engine. Where the crank angle position is within a range of 450 degrees to 630 degrees forwardly of the compression top dead center C/T, that is, within a range of 90 degrees to 270 degrees (low load range) forwardly of the exhaust top dead center O/T, the run-over torque is low. Meanwhile, where the crank angle position is within another range of 90 degrees to 450 degrees (high load range) forwardly of the compression top dead center C/T, the run-over torque is high, and particularly at 180 degrees forwardly of the compression top dead center C/T, the run-over torque is highest. In other words, the run-over torque is generally high before the compression top dead center C/T, but is generally low before the exhaust top dead center O/T.
[0078] Therefore, in the present embodiment, the energization time period, when the ACG starter 1 is energized in the reverse direction of the crankshaft 201 is determined so that the crankshaft 201 is stopped within the low load range described above. Where the crankshaft 201 is rotated reversely to the low load range and the ACG starter 1 is energized in the forward rotation direction from this position, then the compression top dead center C/T can be run over with low run-over torque.
[0079] Incidentally, when the engine is stopped, the crank does not stop in the proximity of the compression top dead center C/T (on the reverse rotation direction side, the range from the compression top dead center C/T to 140 degrees forwardly of the compression top dead center C/T) in most cases (range indicated by hatching). Therefore, the ACG starter 1 is energized in the reverse rotation direction for a period of time required to vary the crank angle position from 140 degrees forwardly of the compression top dead center C/T to a leading end of the low load range, that is, to 90 degrees forwardly of the exhaust top dead center O/T.
[0080] Particularly, if the ACG starter 1 is rotated reversely for a time period required or more for the crankshaft 201 to rotate between the compression top dead center C/T and the exhaust top dead center O/T, that is, for a time period or more which the crank angle position varies by 360 degrees, then at whichever position the crankshaft 201 is positioned upon starting of the reverse rotation, the crank angle position after the crankshaft 201 is rotated reversely by 360 degrees or more is forwardly of the exhaust top dead center O/T, that is, is included in the low load range.
[0081] [0081]FIG. 8 is a diagram illustrating a relationship between the target reverse rotation time period “Trev” of the ACG starter 1 and the cooling water temperature of the engine. In the present embodiment, the target reverse rotation time period Trev is set so as to decrease as the temperature of cooling water of the engine rises, that is, as the rotational friction decreases.
[0082] Now, operation of the present embodiment is described in detail with reference to a timing chart of FIG. 9 and flow charts of FIGS. 10 to 13 .
[0083] If the starter switch 35 is switched on at time “t0” of FIG. 9, then the stop & go control section 84 is started up in the “starting mode” or the “idling switch mode”. If the engine starting instruction described hereinabove is issued at time “t1” and this is detected at step S 10 , then “starting reverse rotation control” is executed at step S 11 to reversely rotate the crankshaft 201 to a predetermined position.
[0084] [0084]FIG. 11 is a flow chart illustrating operation of the “starting reverse rotation control”, and this is executed by the starting reverse rotation control section 85 of the ECU 80 .
[0085] At step S 1101 , the temperature of cooling water of the engine is detected based on an output of the cooling water sensor 27 . At step S 1102 , a target reverse rotation time period Trev corresponding to the detected water temperature is read out from a data table. In the present embodiment, the target reverse rotation time period Trev is given as a function of the cooling water temperature as described hereinabove with reference to FIG. 8.
[0086] At step S 1103 , reverse rotation energization is started to start reverse rotation of the crankshaft 201 , and simultaneously, an “n” th misfire control flag “Fncut” representing whether or not the ignition suppression control by the ignition suppression control section 87 described hereinabove is proceeding is reset (the control is not proceeding) and a reverse rotation time period timer “T1” for counting the period of time of reverse rotation is started.
[0087] At step S 1104 , the reverse rotation time period timer T 1 and the target reverse rotation time period Trev are compared with each other, and the reverse rotation energization is continued until the reverse rotation time period timer T 1 reaches the target reverse rotation time period Trev. Thereafter, when the reverse rotation time period timer T 1 reaches the target reverse rotation time period Trev at time “t2” of FIG. 9, the reverse rotation energization is stopped at step S 1105 . At step S 1106 , the ignition suppression control by the ignition control suppression section 87 is started.
[0088] [0088]FIG. 12 is a flow chart illustrating the “ignition suppression control”. At step S 1201 , the “n” th misfire control flag Fncut representing whether or not the ignition suppression control is proceeding is set (the control is proceeding), and an ignition suppression cancellation timer “Tncut” for limiting the ignition suppression control only to a predetermined period of time is started. Then, after waiting for the predetermined period of time at step S 1202 , the processing advances to step S 1203 , at which forward rotation energization is started at time “t3” of FIG. 9 and the reverse rotation time period timer T 1 is cleared.
[0089] At step S 1204 , reference is made to the “n” th misfire control flag Fncut. Since the “n” th misfire control flag Fncut initially is in a set state (under the ignition suppression control), the processing advances to step S 1205 . When an ignition timing is reached at time “t4” of FIG. 9 and a pulser signal is detected at step S 1205 , the ignition timing counter Np is incremented at step S 1206 . Accordingly, the ignition timing counter Np represents the number of times by which an ignition timing comes upon starting of the engine. At step S 1207 , the value of the ignition timing counter Np is compared with the value Nx of the ignition inhibition counter.
[0090] A number of times by which ignition should be inhibited upon starting of the engine is registered in advance in the ignition inhibition counter Nx. In the present embodiment, “1” is registered in the ignition inhibition counter Nx. Accordingly, the discrimination at step S 1207 now is in the affirmative, and the processing advances to step S 1208 . At step S 1208 , ignition in the current cycle is inhibited and the engine misfires.
[0091] At step S 1209 , it is discriminated whether or not the starter switch 35 is switched OFF. Since the starter switch 35 initially remains in an ON state, the processing advances to step S 1211 . At step S 1211 , the ignition suppression cancellation timer Tncut is compared with the ignition suppression cancellation time “Tend”. Since Tncut <Tend at the present point of time, in order to continue the ignition suppression control, the processing returns to step S 1204 so that the processes described above are repeated.
[0092] Thereafter, second and third ignition timings come at times “t5” and “t6”. If this is detected at step S 1205 , the ignition timing counter Np is incremented at step S 1206 every time, and at step S 1207 , the value of the ignition timing counter Np is compared with the value Nx of the ignition inhibition counter. In the present embodiment, since the value Nx of the ignition inhibition counter is “1” and it is discriminated that Np >Nx, the processing advances to step S 1209 et seq. by skipping the step S 1208 . Accordingly, the engine is ignited normally at the ignition timings of times “t5” and “t6”.
[0093] Thereafter, when the ignition suppression cancellation timer Tncut reaches the ignition suppression cancellation time Tend at time “t7” of FIG. 9 and this is detected at step S 1211 , the “n” th misfire control flag Fncut is reset at step S 1212 . Accordingly, since thereafter the steps S 1205 to S 1208 are skipped, ignition at any ignition timing is not inhibited at all irrespective of the value of the ignition inhibition counter Nx.
[0094] Thereafter, the starter switch 35 is switched OFF at time “t8”, and when this is detected at step S 1209 , the energization for forward rotation is stopped at step S 1210 .
[0095] In this manner, with the present embodiment, even if air fuel mixture remaining in the exhaust pipe is sucked into the cylinder in an exhaust stroke upon reverse rotation and is compressed at the exhaust top dead center upon forward rotation after then, since ignition is inhibited at the timing, the air fuel mixture is not fired.
[0096] Referring back to FIG. 10, when the engine automatically stops in the stop & go mode after the engine is started and this is detected at step S 12 , a “stopping reverse rotation control” for rotating the crankshaft 201 reversely to a predetermined position in advance is executed at step S 13 .
[0097] [0097]FIG. 14 is a functional block diagram of the “stopping reverse rotation control”. In the stopping reverse rotation control section 86 , a stage discrimination section 863 divides the rotational position of the crankshaft 201 to 36 stages of stages #0 to #35 based on output signals of the rotor angle sensors 29 and discriminates a present stage sing a detection timing of a pulse signal generated by the ignition pulser 30 as a reference stage (stage #0).
[0098] A stage pass time detection section 864 detects a pass time .tn of the current stage based on a period of time after the stage discrimination section 863 discriminates a new stage until it discriminates a next stage. A reverse rotation control section 865 generates a reverse driving instruction based on the discrimination result by the stage discrimination section 863 and the pass time .tn detected by the stage pass time detection section 864 .
[0099] A duty ratio setting section 862 dynamically controls the duty ratio of the gate voltage to be supplied to each power FET of the full wave rectification bridge circuit 81 based on the discrimination result by the stage discrimination section 863 . A driver 88 supplies a driving pulse of the thus set duty ratio to each power FET of the full wave rectification bridge circuit 81 .
[0100] Subsequently, operation of the stopping reverse rotation control section 86 described above is described with reference to a flow chart of FIG. 13 and the diagrammatic views of the operation shown in FIGS. 15 ( a )-( c ).
[0101] [0101]FIG. 15( a ) indicates a relationship between the cranking torque (reverse rotation load) required to rotate the crankshaft 201 reversely and the crank angle, and the cranking torque increases suddenly immediately before the compression top dead center is reached (upon reverse rotation). FIG. 15( b ) indicates a relationship between the crank angle and the stage, and FIG. 15( c ) shows a variation of the angular velocity of the crankshaft upon reverse rotation.
[0102] When stopping of the engine is detected, the present stage discriminated already by the stage discrimination section 863 is referred to at steps S 1301 and 1302 . Here, if the current stage is one of the stages #0 to #11, then the processing advances to step S 1303 , but if the current stage is one of the stages #12 to #32, then the processing advances to step S 1304 , and in any other case (one of the stages #33 to #35), the processing advances to step S 1305 . At steps S 1303 and S 1305 , the duty ratio of the driving pulse is set to 70% by the duty ratio setting section 862 , but at step S 1304 , the duty ratio of the driving pulse is set to 80% by the duty ratio setting section 862 .
[0103] As described above, dynamic control of the duty ratio is performed in order to sufficiently lower the angular velocity of the crankshaft 201 upon reverse rotation before an angle corresponding to the compression top dead center at which the cranking torque is high is reached (upon reverse rotation), but also to permit rapid reverse rotation driving at any other angle. This will be described later.
[0104] At step S 1306 , the driver 88 controls each power FET of the full wave rectification bridge circuit 81 with the set duty ratio described above to start reverse rotation energization. At step S 1307 , the pass time .tn of the passed stage #n is measured by the stage pass time detection section 864 .
[0105] At step S 1308 , the reverse rotation control section 865 discriminates whether or not the crankshaft 201 passes the stage #0, that is, the position in the proximity of the top dead center. If the stage #0 is not passed, then the ratio [.tn/.tn−1] between the pass time .tn of the stage #n passed last and the pass time tn−1 of the stage #(n−1) passed before the last is compared with a reference value “Rref” (in the present embodiment, 4 / 3 ). If the pass time ratio [.tn/.tn−1] is not higher than the reference value Rref, then the processing returns to step S 1301 to continue the reverse rotation driving, and the processes described above are repeated in parallel to the continued reverse rotation driving.
[0106] Here, if the engine stopping position, that is, the reverse rotation starting position, is on the side nearer to the compression top dead center in a next cycle than a middle position between the compression top dead centers in the preceding and next cycles as shown by the curve A in FIG. 15( c ), or in other words, is in the course of rotation after the exhaust top dead center is passed (upon forward rotation) until the compression top dead center is reached, the crankshaft can pass the stage #0 (exhaust top dead center) although the ACG starter 1 is driven to rotate reversely with the duty ratio of 70%. Accordingly, this is detected at step S 1308 , and the processing advances to step S 1309 , at which it is discriminated whether or not the crankshaft 201 reaches the stage #32. If it is discriminated that the crankshaft 201 reaches the stage #32, then the reverse rotation energization is stopped at step S 1311 , and therefore, the crankshaft stops after it is further rotated reversely by inertial force.
[0107] On the other hand, if the reverse rotation starting position is on the side nearer to the compression top dead center in a preceding cycle than a middle position between the compression top dead centers in the preceding and next cycles as shown by the curve B in FIG. 15( c ), or in other words, is in the course of rotation after the compression top dead center is passed (upon forward rotation) until the exhaust top dead center is reached, since the ACG starter 1 is driven to rotate reversely with the duty ratio of 70%, when the reverse rotation load increases forwardly of the stage #0 (upon reverse rotation), the angular velocity of the crankshaft 201 drops suddenly as seen in FIG. 15( a ). Then, when it is discriminated at step S 1310 that the pass time ratio [.tn/.tn−1] is higher than 4/3 of the reference value, the reverse rotation energization is stopped at step S 1311 , and the reverse rotation of the crankshaft stops substantially simultaneously with the stopping of energization.
[0108] In this manner, upon reverse rotation driving after the engine stops, the apparatus of the present invention supervises whether or not the crankshaft passes an angle corresponding to the top dead center, and whether or not the angular velocity of the crankshaft drops. When the crankshaft passes the top dead center upon reverse rotation, reverse rotation energization is ended immediately thereafter and reverse rotation energization is ended also when the angular velocity of the crankshaft drops as a result of increase of the reverse rotation load, the crankshaft can be returned to a position forwardly of the last compression top dead center (upon reverse rotation) at which the compression reactive force is low irrespective of the reverse rotation starting position.
[0109] Further, in the present embodiment, since the angular velocity of the crankshaft 201 is detected based on the outputs of the rotor angle sensors 29 which detect the rotor angle (that is, the stage) of the ACG starter 1 , there is no need to provide a separate sensor for detecting the angle of the crankshaft 201 .
[0110] Referring back to FIG. 10, at step S 14 , it is discriminated whether or not the engine starting conditions are satisfied. If the engine starting conditions are satisfied, then forward rotation energization is started to crank the engine in the forward rotation direction at step S 15 . At step S 16 , it is discriminated, for example, based on the engine speed whether or not the starting of the engine is completed. If it is discriminated that the starting of the engine is completed, then the forward rotation energization is stopped at step S 17 .
[0111] It is to be noted that, in the embodiment described above, while the ignition suppression control is carried out only upon starting of the engine by an operation of the starter switch in the “starting mode” and the “idling switch mode”, it can be carried out similarly also upon starting of the vehicle after the engine stops in the “stop & go mode”.
[0112] Further, in the embodiment described above, while it is described that “1” is registered into the ignition inhibition counter Nx and ignition of the engine is inhibited only once for the first time after forward rotation, if the value of 2, 3, . . . is registered into the ignition inhibition counter Nx, then ignition of the engine can be inhibited by a plural number of times after the engine is rotated forwardly.
[0113] Further, in the embodiment described above, while a vehicle that includes only an ACG starter as engine starting means is described as an example, the present invention can be applied similarly also to a vehicle that additionally includes starting means by a kick pedal. However, in order that the ignition suppression control for causing the engine to misfire by a predetermined number of times upon starting of the engine may function only upon starting by the ACG starter but may not function upon kick starting wherein the crankshaft is not rotated reversely in advance, it is preferable to include means for selectively canceling the suppression function upon kick starting.
[0114] According to the present invention, in an engine starting control apparatus that includes reverse rotation control means for causing, upon starting of an engine, a crankshaft of the engine to rotate reversely to a predetermined position, an ignition suppression means is provided for inhibiting ignition of the engine for a predetermined period of time after forward rotation of the engine. As a result, the following positive effect is produced: even if the air fuel mixture remaining in the exhaust pipe is sucked into the cylinder in an exhaust stroke during the reverse rotation and is compressed at the exhaust top dead center during the forward rotation thereafter, since ignition is inhibited at this time, the air fuel mixture is not fired at all.
[0115] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
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An engine starting control apparatus that causes a crankshaft of an engine to rotate reversely to a predetermined position immediately after the engine is stopped to make preparations for next starting of the engine. This action is performed in order to prevent firing by useless ignition upon forward rotation of the crankshaft when the engine is started again. When the engine restarted, the engine starting control apparatus causes the engine to rotate forwardly from the predetermined position. The apparatus includes a starter motor connected to the crankshaft, a reverse rotation means capable of rotating the engine reversely to a predetermined position, an ignition device for igniting the engine in the proximity of the top dead center of a piston, and an ignition suppression device for inhibiting the ignition of the engine for a predetermined period of time after the forward rotation of the engine.
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This application was filed in the PCT as PCT/US94/02497 on Mar. 8, 1994 designating among other countries the USA and is a continuation in part of U.S. Ser. No. 08/037,217 filed Mar. 26, 1993, now abandoned.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 4,925,481, U.S. Pat. No. 4,213,773 and U.S. Pat. No. 4,881,967 disclose herbicidal tetrahydrotriazolopyridin-3-ones and methods for preparation, but do not disclose the instant process.
SUMMARY OF THE INVENTION
The invention pertains to a process to prepare compounds of Formula I ##STR2## R 1 is H, halogen, OH, C 1 -C 6 alkyl, C 1 -C.sub. haloallcyl, C 1 -C.sub. alkoxy, C 1 -C 6 haloalkoxy, C 1 -C 6 alkylthio, C 1 -C 6 haloalkylthio, C 2 -C 6 alkenyloxy, C 2 -C 6 alkenylthio, C 2 -C 6 haloalkenyloxy, C 2 -C 6 haloalkenylthio, C 3 -C 6 alkynyloxy, C 3 -C 6 alkynylthio, C 3 -C 6 haloalkynyloxy, C 3 -C 6 haloalkynylthio, C 2 -C 6 alkylcarbonyl, C 2 -C 6 alkoxycarbonyl, C 4 -C 8 alkenyloxycarbonyl, C 3 -C 8 alkylcarbonylalkoxy, C 3 -C 8 alkylcarbonylalkylthio, C 3 -C 8 alkoxycarbonylalkoxy, C 3 -C 8 alkoxycarbonylalkylthio, C 5 -C 8 alkenyloxycarbonylalkoxy, C 5 -C 8 alkenyloxycarbonylalkylthio, phenoxy and phenylthio where the phenyl groups are optionally substituted with halogen;
R 3 is H, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 2 -C 6 alkoxyalkyl, C 3 -C 6 alkenyl, C 3 -C 6 alkynyl and ##STR3## R 4 is H, C 1 -C 3 alkyl and halogen; R 5 is H, halogen, C 1 -C 3 alkyl, C 1 -C 3 haloalkyl, cyclopropyl, vinyl, C 2 alkynyl, CN, C(O)R 6 , C(O) 2 R 6 , C(O)NR 6 R 7 , CR 8 R 9 CN, CR 8 R 9 C(O)R 6 , CR 8 R 9 C(O) 2 R 6 , CR 8 R 9 C(O)NR 6 R 7 , CHR 8 OH, CHR 8 OC(O)R 6 and OCHR 8 OC(O)NR 6 R 7 ;
R 6 and R 7 are independently H and C 1 -C 4 alkyl;
R 8 and R 9 are independently H and C 1 -C 4 alkyl;
W is O and S;
Z is CH 2 and);
m is 1-5; and
n is 1-3; when m or n are greater than 1, R 1 may be the same or independently selected from the defined substituents;
which involves the following reactions:
first, reacting compounds of Formula V ##STR4## wherein R 2 is C 1 -C 6 alkyl; with an anhydrous acid to produce compounds of Formula IV ##STR5## wherein X is Cl or Br and R 2 is described above; second, reacting compounds of Formula IV with Formula III hydrazines or salts thereof
Q--NHNH.sub.2 (III)
wherein Q is defined above;
to produce compounds of Formula II ##STR6## wherein R 2 is defined above; and third, heating compounds of Formula II in liquid form optionally in the presence of an acid to produce Formula I compounds at 0°-150° C. with or without a solvent ##STR7## wherein Q and Z are defined above.
This invention further pertains to novel Formulae II and IV intermediates ##STR8## wherein Q, R 2 , and X are defined above.
In the above definitions, the term "alkyl", used either alone or in compound words such as "alkylthio" or "haloalkyl", includes straight chain or branched alkyl, such as methyl, ethyl, n-propyl, isopropyl and the different butyl, pentyl, and hexyl isomers. "Alkoxy" used either alone or in compound words such as "haloalkoxy" includes methoxy, ethoxy, n-propoxy, isopropoxy, and the different butoxy, pentoxy, and hexyloxy isomers. "Alkenyl" used either alone or in compound words such as "haloalkenyl" or "alkenylthio" includes straight chain or branched alkenes, such as vinyl, 1-propenyl, 2-propenyl, 3-propenyl and the different butenyl, pentenyl, and hexenyl isomers. "Alkynyl" used either alone or in compound words such as "haloalkynyl" or "alkynylthio" includes straight or branched alkynes, such as 1-propynyl, 3-propynyl, and the different butynyl, pentynyl, and hexynyl isomers. "Alkylthio" includes methylthio, ethylthio, and the different propylthio, butylthio, pentylthio, and hexylthio isomers.
The term "halogen", used either alone or in compound words such as "haloalkyl", means fluorine, chlorine, bromine or iodine. Further, when used in compound words such as "haloalkyl" said alkyl can be partially or fully substituted with halogen atoms, which can be the same or different. Examples of haloalkyl include CF 3 , CH 2 CH 2 F, CF 2 CF 3 , CH 2 CHFCl, and CHBrCH 3 . The terms "haloalkenyl" and "haloalkynyl" are defined analogously to the term "haloalkyl".
The total number of carbon atoms in a substituent group is indicated by the "C i -C j " prefix where i and j are numbers from 1 to 8. For example, C 3 alkynyloxy designates OCH 2 C═CH, and C 4 alkynyloxy includes OCH 2 C═CCH 3 , OCH 2 CH 2 C═CH and OCH(CH 3 )C═CH; C 2 alkylcarbonyl designates C(O)CH 3 , and C 4 alkylcarbonyl includes C(O)CH 2 CH 2 CH 3 and C(O)CH(CH 3 ) 2 ; C 2 alkoxycarbonyl designates C(O) 2 CH 3 , and C 4 alkoxycarbonyl includes C(O) 2 CH 2 CH 2 CH 3 and C(O) 2 CH(CH 3 ) 2 ; C 3 alkylcarbonylalkoxy designates OCH 2 C(O)CH 3 , and C 4 alkylcarbonylalkoxy includes OCH 2 C(O)CH 2 CH 3 , OCH(CH 3 )C(O)CH 3 , and OCH 2 CH 2 C(O)CH 3 ; C 3 alkoxycarbonylalkoxy designates OCH 2 C(O) 2 CH 3 , and C 4 alkoxycarbonylalkoxy includes OCH 2 C(O) 2 CH 2 CH 3 , OCH(CH 3 )C(O) 2 CH 3 , and OCH 2 CH 2 C(O) 2 CH 3 ; C 3 alkylcarbonylalkylthio designates SCH 2 C(O)CH 3 , and C 4 alkylcarbonylalkylthio includes SCH 2 C(O)CH 2 CH 3 , SCH(CH 3 )C(O)CH 3 , and SCH 2 CH 2 C(O)CH 3 ; and as a final example C 3 alkylcarbonylalkylthio designates SCH 2 C(O) 2 CH 3 , and C 4 alkylcarbonylalkylthio includes SCH 2 C(O) 2 CH 2 CH 3 , SCH(CH 3 )C(O) 2 CH 3 , and SCH 2 CH 2 C(O) 2 CH 3 .
When a compound is substituted with a substituent bearing a subscript that indicates the number of said substituents can exceed 1, said substituents (when they exceed 1) are independently selected from the group of defined substituents.
Specifically preferred processes for the greatest utility of their products are:
A) The process to prepare Formula I compounds wherein Q is Q-1.
B) The process of Preferred A to prepare Formula I compounds selected from the group:
2- 2,4-dichloro-5-(2-propynyloxy)phenyl!-5,6,7,8-tetrahydro-1,2,4-triazolo4,3-a!pyridin-3(2H)-one;
ethyl 2-chloro4-fluoro-5-(5,6,7,8-tetrahydro-3-oxo-1,2,4-triazolo 4,3-a!pyridin-2(3H)-yl)phenyl!thio!acetate; and
2-(2,4-dichloro-5-hydroxyphenyl)-5,6,7,8-tetrahydro-1,2,4-triazolo 4,3a!pyridin-3(2H)-one.
C) The process to prepare Formula I compounds wherein Q is Q-2.
D) The process of Preferred C to prepare the Formula I compound:
2-(5,7-dichloro-2,3-dihydro-2-methyl-4-benzofuranyl)-5,6,7,8-tetrahydro-1,2,4-triazolo 4,3-a!-pyridin-3(2H)-one.
E) The process to prepare Formula I compounds wherein Q is Q-3.
F) The process to prepare Formula I compounds wherein Q is Q-4.
G) The process of Preferred F to prepare the Formula I compound:
6-(5,6,7,8-tetrahydro-3-oxo-1,2,4-triazolo 4,3-a!pyridin-2(3H)-yl)4-(2-propynyl)-2H-1,4-benzoxazin-3(4H)-one.
Compounds produced by the process of the invention are active herbicides for selective and/or general broadleaf and grass weeds control in all plantation crops which include coffee, cocoa, oil palm, rubber, sugar cane, citrus, grapes, fruit trees, nut trees, banana, plantain, pineapple, conifers, e.g., loblolly pine, and turf species Kentucky bluegrass, St. Augustine grass, Kentucky fescue and bermudagrass.
The intermediates of the present invention are useful as such in the process of the invention to produce the active herbicides.
DETAILED DESCRIPTION OF THE INVENTION
The first stage (a) of the process (Scheme I) is as a rule carried out by contacting one or more equivalents of an anhydrous hydrogen halide, preferably 2 to 2.5 equivalents of hydrogen chloride, at a temperature between -40° C. and 40° C., preferably at 5°-15° C., with a compound of Formula V, preferably the methyl carbamate, either in an inert hydrocarbon, chlorinated hydrocarbon, or ethereal solvent, preferably toluene, with or without solvent. The solvent is advantageously used in an mount from 100 to 2000 percent by weight, based on starting material V, and the reaction may be conducted at atmospheric or superatmospheric pressure in either a continuous or a batchwise mode. The products of Formula IV are generally isolated by removal of excess hydrogen halide under reduced pressure followed by removal of solvent or filtration and washing with a suitable oxygenated solvent such as tetrahydrofuran. Alternatively, they may be used without purification following the purge of excess hydrogen halide. Carbamates of Formula V are either known or can be prepared by various methods known to one skilled in the art. For example, Synthesis, (1984) 831 describes the preparation of Formula V carbamates by amidomercuration-reductive alkylation of alkenes and amides. ##STR9## wherein R 2 , X, and Z are as described previously.
The second stage (b) of the process, illustrated in Scheme II, is as a rule carried out by contacting the hydrohalide salt of Formula IV with an approximately equivalent molar amount of a hydrazinc compound of Formula III or a salt thereof and a sufficient amount of acid binding agent to maintain an effective pH of 3.5 to 7.0, preferably at 4.5 to 5.5, in a suitable non-reactive solvent, preferably, but not limited to, acetonitrile or alcohols such as methanol, at a temperature between -40° and 80° C., preferably at -20° C. to 30° C. The acid-binding agent used may be any weakly-basic anhydrous material but is preferably a weak tertiary amine base such as pyridine or an alkali metal carboxylic acid salt such as sodium acetate, and is preferably used in amounts of between 0.5 to 1.5 equivalents, based on the total amount of acid bound in the compounds of Formulae III and IV. Hydrazincs of Formula III are either known or can be prepared by various methods known to one skilled in the art. For example, U.S. Pat. No. 4,881,967 and references cited therein, describe the preparation of hydrazincs by diazotization of appropriately substituted amines known in the art. ##STR10## wherein Q is as described previously.
Preparation of Formula I compounds (Stage (c)) is as a rule carried out by allowing a compound of Formula II to react, optionally with a solvent, at a temperature between 0° and 150° C., advantageously in the presence of an acidic catalyst, either at atmospheric, subatmospheric, or superatmospheric pressures (Scheme III). A wide range of solvents may be used, but are preferably non-ketonic, neutral or only weakly acidic. Especially preferred are toluene, acetone, ethyl acetate, and isopropyl acetate, preferably used in amounts of between 100 and 2000 percent. The reaction is optionally acid-catalyzed, and 0.01 to 100 molar equivalents of formic, acetic, propionic acid and the like may be used, preferably using 0.1 to 3 equivalents, preferably operating the process at temperatures from 25°-100° C. The end product of the process, a compound of Formula I, is then isolated by cooling the reaction mixture, optionally adding a non-polar solvent, such as hexanes, and filtering the precipitated product. ##STR11##
Alternatively, Formula I compounds may be prepared by heating the reaction mixture of Stage (b) from 25°-150° C., but is preferably carried out by first isolating the intermediate compounds of Formula II and conducting the reaction as described for Stage (c).
EXAMPLE 1
Step A
Preparation of methyl 2-imino-1-piperidinecarboxylate hydrochloride
Bromine (6.5 kg) is added subsurface to a solution of 5.1 kg of 5-cyano-valeramide and 4.45 kg of sodium methylate in 27.5 kg of methanol at 0°-5 ° C. The resulting mixture is transferred slowly to 24 kg of hot (60° C.) methanol to maintain the temperature at 50°-65 ° C. The majority of the methanol is removed by distillation, toluene (30 kg) is added, and the distillation is continued until all of the methanol is removed. The mixture is then filtered to obtain an approximately 18% (wt/wt) solution of methyl 4-cyanobutyl carbamate in toluene. A portion of this solution (259 g) is maintained at 15°-20° C. while 33 g of anhydrous hydrogen chloride is bubbled in during two hours. The two-phase mixture is then purged of excess HCl at 150 torr and 100 mL of tetrahydrofuran is added. The product is filtered and washed with tetrahydrofuran to remove residual HCl. The title compound is thus obtained as 53 g (95%) of a white crystalline solid, m.p. 118°-119 ° C. (dec). 1 H NMR (CDCl 3 )δ1.7 (t, 2H), 1.8 (t, 2H), 3.15 (t, 2H). 3.8 (t,2H), 3.82 (s, 3H), 10.2 (br s, 1H), 12.75 (br s, 1H).
Step B
Preparation of methyl 2- 2,4-dichloro-5-(2-propynyloxy)phenyl!-hydrazono!-1-piperidinecarboxylate
To a mixture of 12.3 g of anhydrous sodium acetate and 80 mL of acetonitrile is added 13.3 g of 91% 2,4-dichloro-5-(propargyloxy)phenyl-hydrazine hydrochloride and, after 30 minutes of vigorous stirring, the mixture is cooled to 0°-5° C. before adding 10.0 g of the product from Step A. The mixture is stirred vigorously for 1 h at 5°-10 ° C. and is then poured into 200 mL of cold water. The product is filtered, washed with 30 mL of cold water and then with 30 mL of cold isopropanol, and dried to provide 16.0 g (95%) of the title compound as a solid, m.p. 137°-138° C. 1 H NMR (CDCl 3 ) δ5 1.74 (m, 2H), 1.82 (m, 2H), 2.46 (t, 2H, J=6Hz), 2.52 (d, 1H, J=2.4Hz), 3.68 (t, 2H, J=6Hz), 3.73 (s, 3H), 4.75 (d, 2H, J=2.4Hz), 7.13 (s, 1H), 7.23 (s, 1H), 7.26 (br s, 1H).
Step C
Preparation of 2- 2,4-dichloro-5-(2-propynyloxy)phenyl!-5,6,7,8-tetrahydro-1,2,4-triazolo 4,3-a!-pyridin-3(2H)-one
A mixture of 10.0 g of the product from Step B and 0.50 g of glacial acetic acid in 50 mL of toluene is heated at 100° C. for 2 h while removing methanol vapor with a stream of nitrogen. Hexane (50 mL) is added at 70° C. and the product is filtered at 25° C. and washed with hexanes to provide 8.0 g (94%) of the title compound, m.p. 168°-169° C. 1 H NMR (CDCl 3 ) δ1.9 (m, 4H), 2.55 (t, 1H, J=2.4Hz), 2.74 (t, 2H, J=6Hz), 3.67 (t, 2H, J=6Hz), 4.74 (d, 2H, J=2.4Hz), 7.13 (s, 1H), 7.50 (s, 1H).
EXAMPLE 2
Step A
Preparation of methyl 2- 2,4-dichloro-5-hydroxyphenyl)hydrazonol-1piperidinecarboxylate
A mixture of 18.5 g of sodium acetate and 320 mL of dry methanol is cooled to -20° C. and 28.8 g of the product from Example 1, Step A is added, followed by 34.8 g of 96% pure 2,4-dichloro-5-hydrazinophenol hydrochloride. The mixture is stirred for 1 h at -10° to 0° C. and then is poured into 500 mL of ice water. The product is filtered, washed with three 100 mL portions of water and dried in vacuo to provide 44.6 g of the title compound as an orange solid, m.p. 158°-159° C. 1 H NMR (DMSO-d 6 ) δ1.7 (m, 4H), 2.5 (t, 2H, J=5.4Hz), 3.57 (t, 2H, J=5.4Hz). 3.64 (s, 3H), 7.00 (s, 1H), 7.25 (s, 1H), 8.15 (br s, 1H), 10.3 (br s, 1H).
Step B
Preparation of 2-(2,4-dichloro-5-hydroxyphenyl)-5,6,7,8-tetrahydro-1,2,4-triazolo 4,3-a!pyridin-3(2H)-one
A mixture of 50 g of the product from Step A and 100 mL of a 5% solution of acetic acid in toluene is heated at 65°-70° C. for 3 h with removal of methanol by a stream of nitrogen. Hexanes (50 mL) is then added and the mixture is filtered at ambient temperature, washed sequentially with 50 mL of hexanes and two 50-mL portions of cold isopropanol, and dried to provide 37 g of the title compound, m.p. 214°-216 ° C. (218°-219 ° C. recrystallized from aq. EtOH). 1 H NMR (DMSO-d 6 ) δ1.8 (m, 4H), 2.6 (t, 2H, J=6Hz), 3.50 (t, 2H, J=6Hz), 7.09 (s, 1H), 10.9 (br s, 1H).
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This invention includes compounds of Formula II and IV and a process for preparing Formula I compounds by first preparing the compounds of Formula IV and then further reacting to form the compounds of Formula II and further reacting to prepare the compounds of Formula I wherein Q, Z, R 2 are as defined within. ##STR1##
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FIELD OF THE INVENTION
[0001] The invention relates in general to a handle device for operating doors, windows, gates, hatches and the like. The invention relates in particular to such a handle device comprising a first element which is rotatable about an axis of rotation, a second element, and a coupling device for selectively allowing or preventing relative rotation about the axis of rotation between the first and the second element.
BACKGROUND OF THE INVENTION
[0002] In the case of many doors, windows and other such elements provided with a rotatable handle, it is desirable to be able to selectively couple a part that can be turned or rotated by means of the handle to another part, or to disengage it therefrom. The other part may consist either of a similarly rotatable part or of a fixed part.
[0003] Where both of the parts are rotatable, it may be desirable in a disengaged state, for example, to allow the handle to be turned without affecting the other part and in a coupled state to allow a rotational movement of the handle to be transmitted to the other part. The other part may then consist, for example of a swivel pin, such as a handle shank, which is in turn capable of transmitting the rotational movement to a tumbler, a bolt, an espagnolette bolt, a lock or some other device for influencing the state of the door or the window. In the coupled position, operation therefore occurs in the normal way by means of the handle. In the disengaged position, on the other hand, the state of the door or window remains unaffected if the handle is turned. Such selective disengagement may be used, for example, as a child safeguard, in order to prevent an external door or a window being opened from the inside or in order to prevent damage to a lock or the like coupled to the handle if excessive forces are applied to the handle when the lock is in the locked position.
[0004] Where the second part consists of a fixed, non-rotatable part, the rotatable handle can be conventionally fixed or continuously coupled by means of a handle shank to a bolt, an espagnolette bolt, or a lock, for example, or some other device for influencing the state of the door or the window. Disengagement and coupling between the rotatable handle and the fixed part can then be used, in the disengaged position, to allow operation and, in the coupled position, to lock the handle and thereby prevent operation of the door or the window. The coupling between the handle and the fixed part can in this respect be said to constitute a lock. Such selective disengagement and coupling between the rotatable handle and the fixed part can be used as a child safeguard, for example, or in order to prevent unauthorized operation of a door or a window.
[0005] In both cases the disengagement and coupling between the rotatable handle and the other part can be achieved manually, for example by operating a mechanical button, a lock cylinder or the like. Recently, however, it has become increasingly more common to bring about such a disengagement and coupling by electromechanical means. This allows disengagement and/or coupling, for example, only if an authorized user has first entered a code via a keypad or entered an identification via an electronic card reader.
PRIOR ART
[0006] EP 0 861 959 B1 shows a device which allows selective disengagement and coupling between a rotatable handle and a likewise rotatable square shank, which is coupled to a lock. The device comprises two concentric tubes, which are coupled to the handle and the square shank respectively. The tubes each have a hole in their walls. A radially displaceable pin is arranged in the inner tube. By means of a spring, which is supported against the inner tube, the pin can be shot out through the two holes, thereby coupling these together. A depressor element is arranged radially outside the two tubes. In order to disengage them, the depressor element is made, by means of a pivoted arm driven by a motor, to press the pin radially inwards, so that it is no longer engaged in the hole through the outer tube. This device is not only relatively complicated with many moving parts, but takes up a lot of space and furthermore requires the assembly of a relatively large handle escutcheon or handle plate, which encloses necessary parts required for the disengagement. A further disadvantage with this device is that disengagement can only take place once both of the tubes have assumed a predefined rotational position, in which the pin is aligned with the depressor element.
[0007] In order to achieve selective disengagement and coupling of a rotatable handle and a fixed part, the prior art encompasses devices which work on two different basic principles. A known handle device comprises a rotatable handle which is rotatably fixed to a handle escutcheon or handle plate, which can be fixed to a door, a window or the like. A handle spindle or handle shank, usually in the form of a square shank, is rotationally fixed to the handle. In order to lock the handle, the latter comprises a pin, which is axially displaceable parallel to the axis of rotation of the handle and which in a projecting position engages in a corresponding hole in the handle escutcheon. The pin is operated, for example, by a pushbutton or a pressure cylinder for a key. Another known device which works on the second basic principle also comprises a handle which is rotatable relative to a handle escutcheon and a handle shank, which is fixed to the handle. For locking the handle, the handle escutcheon comprises a turning cylinder for a key, the turning cylinder interacting with a pin, radially displaceable in the handle escutcheon relative to the axis of rotation of the handle. The pin can be brought into locking engagement with a recess in the handle or square shank by means of the turning cylinder.
[0008] In both of these devices for achieving selective disengagement and coupling between a rotatable handle and a fixed part, a relatively big pin taking up a lot of space is needed in order to achieve a satisfactory locking of the handle. A further disadvantage with both these solutions is that they are unsuited to electrical control of the disengagement and coupling.
SUMMARY OF THE INVENTION
[0009] An object of the invention is therefore to provide an improved handle device which allows selective disengagement and coupling between a first rotatable element and a second element.
[0010] Another object is to provide such a device which is simple with few moving parts, which is compact and which also allows a very solid coupling between the two elements.
[0011] A further object is to provide such a device which readily allows disengagement and coupling from either side or both sides of a door, a window or the like to which the device is fitted.
[0012] Yet another object is to provide such a device which facilitates electrical control of the disengagement and coupling.
[0013] Yet a further object is to provide such a device in which all components for controlling the disengagement and coupling, whether this is done mechanically or electrically, can be located in the handle grip.
[0014] These and other objects are achieved by a handle device of the type specified in the introductory part of claim 1 and which has the special technical features specified in the characterizing part. The handle device according to the invention is suitable for operating doors, windows and the like. The handle device comprises a first element which is rotatable about an axis of rotation, a second element, and a coupling device which is connected to the first and the second element and is designed to selectively allow or prevent relative rotation about the axis of rotation between the first and the second element. The coupling device comprises an outer coupling member and an inner coupling member, which is concentrically accommodated, rotatable about the axis of rotation, in the outer coupling member. At least one engaging member is radially displaceable in the inner coupling member. An activating member is accommodated in the inner coupling member and axially displaceable therein, parallel to the axis of rotation.
[0015] The engaging member and the activating member have interacting contact surfaces in order, during the axial displacement of the activating member, to press the engaging member into a radially projecting position for simultaneous engagement with the inner and outer coupling member.
[0016] The handle device according to the invention allows selective disengagement and coupling between the first and the second element. The first element may comprise a part of the handle or be rotationally fixed thereto, the invention therefore allowing selective disengagement and coupling between the handle and the second element. The other element may be rotatable or non-rotatable. The engaging member may assume a retracted position, in which it does not engage with the outer coupling member. In this position relative rotation is therefore allowed between the inner and outer coupling members and hence between the first and second elements. Displacement of the axially moveable activating member allows the engaging member to be pressed radially outwards, so that it engages with both the inner and the outer coupling members, thereby achieving a coupling of these two members and hence of the first and second element. The device according to the invention affords a very compact embodiment of the coupling device with few moving parts. The axially moveable activating member means that control of the selective disengagement and coupling can readily be achieved from a handle which is located on either side of the door or the window to which the device is fitted. The coupling device with the interacting, axially moveable activating member and radially moveable engaging member means that only a slight force needs to be applied to the activating member in order to achieve the coupling between the two elements. A further advantage is that it is possible to obtain the requisite radial projection of the engaging member with only a short axial movement of the activating member. The stroke length of the activating member can therefore be kept small. The axial movement can therefore advantageously be achieved with a relatively small and energy-saving electrical activator, such as a solenoid, a motor or a piezo-electric activator. If so desired, such a small and energy-saving electric activator can be located in the handle together with an adequate power source, without the need to make this larger than is otherwise usual. In reality the invention means that all parts and components for allowing an electrically controlled selective disengagement and coupling of desired elements can be accommodated in a handle of normal size. The axially displaceable activating member moreover means that a selective disengagement and coupling of a handle with a desired element located on one side of a door or a window can readily be controlled by electrical components which are located exclusively in a handle located on the other side of the door.
[0017] The engaging member may advantageously comprise a ball, which is received in a radial, cylindrical hole in the inner coupling member. Alternatively the engaging member may comprise a circular cylindrical pin, which is located in a recess in the inner coupling member, so that its axis extends parallel to the axis of rotation. Regardless of the embodiment of the engaging members, the handle device may comprise more than one engaging member.
[0018] The outer coupling member suitably comprises a substantially circular cylindrical bore, in which the inner coupling member is received and in the circumferential surface of which a radially curved and axially elongated groove is located. The radially curved shape of the groove interacts with the spherical or cylindrical shape of the engaging member in order to press the engaging member back into its retracted position when the activating member is in a position that allows this and when a torsional moment is applied to either the inner or outer coupling member. This obviates the need for any spring device or the like for returning the engaging member to the disengaged position when the activating member is situated in a corresponding position.
[0019] If the inner coupling element is fixed to the handle and the outer coupling member is fixed to or consists of a handle escutcheon, the handle device readily allows immobilization or locking of the handle. The strong, solid coupling achieved between the inner and the outer coupling member means that such an immobilization of the handle can for many applications constitute full locking of a door or a window, for example.
[0020] The handle device can also be designed to allow selective disengagement and coupling between two rotatable parts, this type of selective coupling sometimes being known as free swivelling. In order to achieve such a selective coupling, the inner coupling member is suitably fixed to or consists of a rotatable swivel pin and the outer coupling member is suitably fixed to the handle.
[0021] In order to allow a reliable and smooth-running transmission of movement with low friction, the activating member suitably has a surface inclined in its axial displacement direction, which in contact with the engaging member presses this radially outwards when the activating member is displaced axially.
[0022] The handle device may comprise means for manual actuation of the activating member.
[0023] Owing to its smooth running and compactness, however, the handle device is even better suited to electrical control and therefore comprises suitable means for electrically acting upon the activating member. These means may comprise an electric motor or preferably a solenoid, which is designed to produce axial displacement of the activating member.
[0024] In the case of such electrical control, the handle device also suitably comprises an electrical control circuit for controlling the means of electrically acting upon the activating member and a keypad which is electrically connected to the control circuit. In this embodiment the selective disengagement and/or coupling can be achieved only after entering a correct authorization code. The electrical control circuit can additionally or alternatively be connected to an electronic card reader or some other similar authorization-verifying equipment. Again, the effective coupling device, by means of which an axial movement of the activating member can be translated by a slight force into a radial engaging movement of the engaging member, means that all parts and components for such authorization verification and electrical control of the device can be accommodated in a handle. This handle may be either the handle, coupling of which to another element is being controlled, or also the second of two handles fitted to a door or the like.
[0025] Further objects and advantages of the invention are set forth in the following description of exemplary embodiments, and in the patent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] There follows a detailed description of exemplary embodiments, referring to the drawings attached, in which:
[0027] FIG. 1 is a schematic perspective view of a partially disassembled handle device according to a first embodiment of the invention.
[0028] FIG. 2 is a rear plan view of the handle device shown in FIG. 1 when this is assembled.
[0029] FIG. 3 is a plan view from above of the handle device shown in FIG. 3 .
[0030] FIGS. 4 a and 4 b show schematic sections through the handle device shown in FIGS. 2 and 3 when this is in a disengaged and a coupled state respectively.
[0031] FIG. 5 is a schematic perspective view of a partially disassembled handle device according to a second embodiment of the invention.
[0032] FIG. 6 is a plan view from above of the handle device shown in FIG. 1 when this is assembled.
[0033] FIGS. 7 a and 7 b show schematic sections through the handle device shown in FIG. 6 when this is in a disengaged and a coupled state respectively.
[0034] FIG. 8 a is a schematic section along the line I-I in FIG. 4 a.
[0035] FIG. 8 b is a schematic section along the line II-II in FIG. 4 b.
[0036] FIG. 9 a is a schematic section along the line in FIG. 7 a.
[0037] FIG. 9 b is a schematic section along the line IV-IV in FIG. 7 b.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0038] FIGS. 1 , 2 , 3 , 4 a , 4 b , 8 a and 8 b show a handle device according to a first embodiment of the invention. This handle device is designed to allow selective disengagement and coupling between the handle grip and a fixed part. In the disengaged position, rotation of the handle grip is therefore allowed and in the coupled position the handle grip is prevented from being turned.
[0039] The handle device comprises a handle grip 1 , a handle neck 2 , a handle escutcheon 3 or plate and a swivel pin or handle spindle 4 in the form of a square shank.
[0040] The handle escutcheon 3 comprises fixing holes for receiving screws or the like, by means of which it can be fixed to a door, a window, a gate, a hatch (not shown) or a similar element. The handle escutcheon 3 further comprises a central through-hole 7 , the central axis of which defines an axis of rotation for the handle grip. Two opposing grooves 7 a are made in the central hole 7 of the handle escutcheon 3 . The grooves 7 a are formed as axially running, radial, outwardly curved recesses in the circumferential surface of the central hole 7 .
[0041] A boss 5 is received in the handle neck 2 . In the embodiment shown in FIGS. 1-4 b and 8 a - b the boss 5 consists of an inner coupling member for achieving a selective disengagement and coupling of the handle grip 1 in relation to the handle escutcheon 3 . For fitting the boss 5 in the handle neck 2 , the handle grip 1 comprises two separable parts 1 a , 1 b . Detaching the part 1 b from the part 1 a gives access to the internal cavity in the handle neck 2 , so that the boss 5 can be threaded into the neck from the side of the handle grip 1 remote from the handle escutcheon 3 . The boss 5 has a part 6 projecting from the handle neck and extending through the hole passing through the handle escutcheon 3 . The boss 5 comprises a radially projecting pin 8 , which is received in a corresponding inner groove 9 in the internal cavity of the handle neck 2 . The engagement of the pin 8 in the groove 9 prevents relative rotation between the boss and the handle neck 2 . In the part of the boss 5 projecting from the handle neck 2 is an axial square hole, in which the handle spindle 4 is received. The longitudinal axis of the handle spindle 4 defines an axis of rotation, about which the handle grip 1 is rotatable relative to the handle escutcheon 3 .
[0042] The boss 5 furthermore has two opposing radial, cylindrical through-holes 10 . Each of these holes 10 receives an engaging member in form of a ball 20 . An axially displaceable activating member 11 is arranged inside the boss 5 . The activating member is rotationally symmetrical and has a front cylindrical section 12 a with a smaller diameter, a rear cylindrical section 12 b with a larger diameter and an intermediate conical section 12 c . In the embodiment shown the conical section has a cone angle of 45°. The conical section 12 c forms an outer curved surface which is inclined in the axial direction of movement of the activating member 11 . For driving the activating member 11 , an electrically powered solenoid 13 is arranged in the handle grip 1 . The solenoid comprises a fixed part 13 a and a part 13 b axially moveable in relation to the fixed part. The moveable part 13 b is fixed to the activating member 11 . Delivering a current pulse to the fixed part of the solenoid enables the moveable part 13 b to be moved axially in either direction.
[0043] In the position shown in FIGS. 4 a and 8 a , the moveable part 13 b of the solenoid and hence the activating member 11 are in a retracted position. The front cylindrical section 12 a of the activating member 11 is situated directly in front of the balls 20 . The distance between the outer surface of the cylindrical section 12 a and the outer surface of the boss 5 around the hole 10 is substantially equal to the diameter of the balls 20 . In this position, therefore, the balls are allowed to assume a position in which they do not protrude from the boss 5 . The boss 5 is therefore allowed to rotate inside the handle escutcheon 3 , so that the handle grip is released and can be freely turned in relation to the handle escutcheon 3 . In this position the handle grip can therefore be used normally in order to transmit a rotational movement to a tumbler, an espagnolette bolt or some other member via the handle spindle 4 in the usual way.
[0044] When the handle grip 1 is to be locked, it is first turned into a position in which the two balls 20 align with the two opposing grooves 7 a in the handle escutcheon 3 . It will be appreciated that the handle grip can therefore be locked in two rotational positions with an 180° offset. The solenoid 13 is then supplied with a current pulse, thereby displacing the moveable part 13 b thereof axially outwards from the fixed part 13 a . The activating member 11 is thereby also displaced to the position shown in FIGS. 4 b and 8 b . In the course of this axial displacement movement, the conical surface 12 c of the activating member in contact with the balls 20 will press these radially outwards, so that they are received in and engage with the grooves 7 a in the handle escutcheon 3 , which in this exemplary embodiment constitutes an outer coupling member. When the engaging member 11 has assumed the full axially projecting position shown in FIGS. 4 b and 8 b , the balls 20 will be supported against and held in the radially projecting position by the cylindrical surface 12 of the activating member having a larger diameter. The balls 20 hereby engage simultaneously in the holes 10 and the grooves 7 a , thereby preventing rotation of the boss 5 and hence the handle neck 2 and the handle grip 1 .
[0045] When the handle grip is to be disengaged again, the solenoid 13 is supplied with a current pulse, which causes the moveable part 13 b and thereby the activating member 11 to be displaced to the retracted position shown in FIGS. 4 a and 8 a . The part 12 a of the activating member 11 with a smaller diameter will thereby come to lie directly in front of the holes 10 , so that the balls 20 are allowed to assume the retracted position not protruding from the activating member 11 . This retracting movement of the balls can be achieved entirely without the action of any spring device or the like. Instead, the balls are brought into their seated position in the holes 10 not protruding from the activating member in that the spherical surface of the balls 20 interacts with the radially curved surface of the grooves 7 a , since the handle grip is being turned when the balls are not locked by the part 12 b of the activating member having a larger diameter.
[0046] As can be seen from FIG. 1 , the handle grip 1 is provided with a keypad. In the handle grip 1 there is also an electronic control circuit (not shown) and a battery (not shown) for powering the control circuit and the solenoid 13 . The electronic control circuit is designed to emit a current pulse adjusting the state of the solenoid only if a correct authorization code has first been entered via the keypad. In this way the handle device shown in FIGS. 1-4 b and 8 a - b can be used as a lock for the door or the window in which it is arranged.
[0047] FIGS. 5 , 6 , 7 a - b and 9 a - b show a second embodiment of the handle device according to the invention. In the further description, the parts corresponding to those in the embodiment described above will be given the same reference numerals as above. With this second embodiment it is possible to achieve selective disengagement and coupling between the handle grip 1 and a rotatably moveable part. In the example shown this rotatably moveable part consists of handle spindle 30 . The handle spindle 30 is capable of transmitting a rotational movement to a tumbler, an espagnolette bolt (not shown) or some other member in the usual way.
[0048] Among other things, this embodiment differs from that described above in that the handle spindle 30 comprises a circular cylindrical end section 31 , which is firmly connected to a square shank 32 . The end section 31 is rotatably accommodated in a boss 50 , which is in turn received in the handle neck 2 ′.
[0049] As in the embodiment described above, the boss 50 can be introduced into the handle neck 2 ′ when a part 1 ′ b of the handle grip 1 ′ is released from another part 1 ′ a of the handle grip. The boss 50 comprises a radially projecting pin 51 , which is received in a corresponding groove 9 in the handle neck 2 ′. The boss 50 is therefore prevented from turning in relation to the handle neck 2 ′ and the handle grip 1 ′. The boss 50 has a central axial through-bore, in the circumferential surface of which a radial, outwardly curved groove 52 is arranged, extending axially parallel to the bore. According to this embodiment the boss 50 constitutes an outer coupling member.
[0050] The circular cylindrical end section 31 of the handle spindle is concentrically received in the axial bore of the boss 50 and constitutes an inner coupling member. The end section 31 has a radially extending circular cylindrical hole 33 , in which a ball 20 is displaceably seated. The end section 31 also has a central circular cylindrical recess, in which an axially displaceable activating member 60 is located.
[0051] The activating member 60 comprises two sections 61 having a larger diameter and a waist section 62 of smaller diameter located between them. Conical sections 63 having a cone angle of 45° are located between the waist section 62 and the two sections 61 . The activating member 60 is firmly connected to a moveable part 13 b of a solenoid 13 , which also comprises a fixed part 13 a.
[0052] In the position shown in FIGS. 7 a and 9 a the moveable part 13 b of the solenoid and hence the activating member 60 are in a projecting position in relation to the fixed part 13 a of the solenoid. The activating member 60 is here situated in a position in which the waist section 62 is directly in front of the hole 33 in the end section 31 of the handle spindle. The distance between the surface of the waist section 62 and the outer surface of the end section 31 around the hole 33 is substantially equal to the diameter of the ball, so that the ball 20 , which rests against the waist section, is situated in a position not projecting radially from the end section 31 . Under the rotation of the handle grip 1 ′, the handle neck 2 ′ and the boss 50 also turn. On the other hand, the rotational movement is not transmitted to the handle spindle 30 in this position of the activating member 60 and the ball 20 . The handle grip 1 ′ is therefore disengaged from the handle spindle 30 and in this position is therefore allowed to turn freely in relation to the handle spindle 30 , thereby affording a so-called free-swivelling function. In this position it is therefore not possible, by means of the handle grip 1 ′, to operate a tumbler, an espagnolette bolt or any other device to which the square shank 32 of the handle spindle 30 may be coupled.
[0053] In order to couple the handle grip 1 ′ to the handle spindle 30 , the handle grip is first turned to a position in which the groove 52 is aligned with the hole 33 . It will be appreciated that this relative position between the boss 50 and the handle spindle 30 can be assumed regardless of which rotational position these two parts occupy in relation to the handle escutcheon 40 . As in the embodiment described above, the solenoid 13 is then supplied with a current pulse, which causes the moveable part 13 b to be displaced towards the fixed part 13 a . The activating member 60 is thereby displaced towards the solenoid 13 , so that the upper conical surface 62 in FIG. 7 a , in contact with the ball 20 , presses the ball radially outwards in the hole 33 until it comes into engagement with the groove 52 in the boss 50 . The ball 20 is then in simultaneous engagement with the boss 50 and with the end section 31 of the handle spindle 30 , so that a rotational movement which is imparted to the handle grip 1 ′ is transmitted to the handle spindle 30 , via the boss 50 with its pin 51 and its groove 52 , the ball 20 and the end section 31 of the handle spindle 30 with its hole 33 . In this way the handle grip 1 ′, in the position shown in FIGS. 7 b and 9 b , is coupled to the handle spindle 30 and can therefore be used to operate a tumbler, an espagnolette bolt or some other member or device to which the handle spindle 30 is coupled.
[0054] As in the embodiment demonstrated with reference to FIGS. 1-4 , no spring or the like is needed in order to return the ball 20 to its retracted position not projecting radially from the end section 31 . Such a return movement of the ball is instead achieved through the interaction between the spherical surface of the balls 20 and the outwardly curved surface of the groove 52 . In the embodiment shown in FIGS. 5-7 and 9 the solenoid 13 can also be controlled by an electric control circuit (not shown), to which a keypad (not shown) and a battery (not shown) may be connected. All of these parts can be accommodated in the handle grip.
[0055] An advantage of the handle device according to the invention is that it requires only a very slight force in order to produce the axial movement of the activating member, the axial movement bringing the engaging member in the form of a ball into or out of engagement in order to achieve coupling or disengagement. A further advantage is that the activating member only requires a very small stroke length. In an embodiment in which the ball has a diameter of 4 mm, and the inclined or conical surface of the activating member that comes to bear against the ball in transmitting movement has an angle of 45° to the direction of movement of the activating member, a stroke length of 2.1 mm is sufficient to displace the ball between its respective coupled and disengaged positions. Both of these advantages mean that the drive and control members can be made very compact, so that they can in this way be accommodated in a handle grip of conventional dimensions.
[0056] Exemplary embodiments of the invention have been described above. It will be appreciated, however, that the invention is not limited to these embodiments but can be modified without departing from the scope of the following patent claims. For example, the axially displaceable activating member, instead of being powered by an electrical solenoid, may be coupled to a mechanical pushbutton or some other mechanical member for manually operating the activating member. Such a mechanical member is advantageously arranged in the handle grip, preferably axially in line with the direction of movement of the activating member.
[0057] The solenoid forming part of the embodiments described above may comprise a permanent magnet (not shown), which is designed to draw the moveable part into the retracted position shown in FIGS. 4 a and 7 b . The solenoid may also be provided with a spring (not shown), which is designed to displace the moveable part to the projecting position shown in FIGS. 4 b and 7 a . Such a magnet and spring provide a bistable solenoid, in which the moveable part maintains an assumed retracted or projecting position without the need for a continuous supply of current to the solenoid. In such an embodiment it is therefore sufficient to supply a brief current pulse to the solenoid when it is to switch between its two possible positions. This affords a very energy-saving device, which in turn helps in allowing the use of a small battery, which can advantageously be accommodated in the handle grip. Instead of using a solenoid to electrically bring about axial movement of the activating member, it is also possible to use an electric motor, a piezo-electric member or some other device capable of electrically powering an axial movement. Instead of an authorization-verifying keypad, which is connected to the control circuit for controlling the movement of the activating member, other equipment may be used in order to verify a user's authorization. Examples of such equipment are so-called RFID equipment, which by radio transmission can read off a coded identification card or a coded identification badge or the like, which a user holds up close to an RFID reader that may preferably be located in the handle grip. It is naturally also possible to use a system with a so-called “i-button”, in which the RFID reader is activated only when the identification badge is brought into physical contact with a contact surface which is connected to the RFID reader. Such an arrangement draws current only when the RFID reader is activated for reading and is therefore well suited to fitting in the handle grip where the limited space places a limit on the size of the current source that can be used. It is also possible for the control circuit to comprise an RF receiver for remote operation from a remote station, which communicates with the control circuit of the handle device via long-range radio waves.
[0058] In the embodiments described above the solenoid for powering the activating member is located in the handle grip, which is to have the facility for disengagement from and coupling to another part of the device. Since the activating member moves axially, however, it is easy to control the activating member with an electrical or mechanical device which is arranged, for example, in a handle grip, a knob or some other element which is fixed to the opposite side of the door on which the handle device is arranged. The axial activation movement means that it is easy, by means of an axially displaceable through-member, such as bar or a shank that is centrally received in the handle spindle, to operate the activating member from either side of the door.
[0059] In an embodiment not shown, one or more engaging members, instead of being designed as balls, may consist of an elongate pin, which is arranged parallel to the direction of movement of the activating member and which preferably has a radial, outwardly curved surface and conically tapering ends. One or more such pins may be located in corresponding recesses in the inner coupling member and like the ball may be acted upon by an axially moveable activating member, which is accommodated in the inner coupling member.
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Handle device for operating doors, windows and the like, comprising a first element, which is rotatable about an axis of rotation, a second element, and a coupling device which is connected to the first and the second element and is designed to selectively allow or prevent relative rotation about the axis of rotation between the first and the second element, the coupling device comprising an outer coupling member ( 3, 50 ) and an inner coupling member ( 5, 31 ), which is concentrically accommodated, rotatable about the axis of rotation, in the outer coupling member. The handle device comprises at least one engaging member ( 20 ), which is radially displaceable in the inner coupling member ( 5, 31 ), and an activating member ( 12, 60 ) which is accommodated in the inner coupling member and axially displaceable therein, parallel to the axis of rotation. The engaging member and the activating member have interacting contact surfaces ( 12 b, 12 c, 61, 63 ) in order, during axial displacement of the activating member, to press the engaging member into a radially projecting position for simultaneous engagement with the inner and outer coupling member.
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[0001] (This application is a continuation of U.S. patent application Ser. No. 10/310,059 filed Dec. 5, 2002 which is a division of U.S. patent application Ser. No. 10/300,849 filed Nov. 21, 2002. All of these application are incorporated herein by reference.)
FIELD OF THE INVENTION
[0002] The present invention relates to the field of video coding, more particularly it relates to a method of reducing blocking artifacts inherent in hybrid block-based video coding.
BACKGROUND OF THE INVENTION
[0003] Video compression is used in many current and emerging products. It has found applications in video-conferencing, video streaming, serial storage media, high definition television (HDTV), and broadcast television. These applications benefit from video compression in the fact that they may require less storage space for archived video information, less bandwidth for the transmission of the video information from one point to another, or a combination of both.
[0004] Over the years, several standards for video compression have emerged; such as the Telecommunication Standardization Sector of the International Telecommunication Union (ITU-T) recommended video-coding standards: H.261, H.262, H.263 and the emerging H.264 standard and the International Standardization Organization and International Electrotechnical Commission (ISO/IEC) recommended standards MPEG-1, MPEG-2 and MPEG-4. These standards allow interoperability between systems designed by different manufacturers.
[0005] Video is composed of a stream of individual pictures (or frames) made up of discrete areas known as picture elements or pixels. The pixels are organised into lines for display on a CRT or the like. Each pixel is represented as a set of values corresponding to the intensity levels of the luminance and chrominance components of a particular area of the picture. Compression is based mainly on the recognition that much of the information in one frame is present in the next frame and, therefore, by providing a signal based on the changes from frame to frame a much reduced bandwidth is required. For the purpose of efficient coding of video, the pictures or frames can be partitioned into individual blocks of 16 by 16 luminance pixels called “macroblocks”. This practice simplifies the processing which needs to be done at each stage of the algorithm by an encoder or decoded. To encode a macroblock (or sub-macroblock partition) using motion-compensated prediction, an estimation is made of the amount of motion that is present in the block relative to the decoded pixel data in one or more reference frames, usually recently decoded frames, and the appropriate manner in which to convey the information from which the current frame may be reconstructed. The residual signal, which is the difference between the original pixel data for the macroblock and its prediction, is spatially transformed and the resulting transform coefficients are quantized before being entropy coded. The basic processing blocks of an encoder are a motion estimator/compensator/predictor, a transform, a quantizer and an entropy coder. Due to the quantization of the transformed coefficients of the residual signal, the reconstructed pixel values are generally not identical to those of the original frame. Since the coding is block-based, the errors that are introduced by the quantization process tend to produce artifacts in the form of sharp transitions in image intensity across transform block boundaries in the reconstructed frame. Such artifacts are referred to as “blocking artifacts”. The appearance of blocking significantly affects the natural smoothness seen in video images and leads to a degradation of the overall video image quality.
[0006] Blocking artifacts are inherent in hybrid block-based video coders, especially in low bit rate video applications. A number of solutions have been presented to alleviate the degradation in visual quality due to the presence of blocking artifacts. Two general approaches have been proposed to deal with blocking artifacts. The first approach is based on using a deblocking filter in the decoder only as a post-processing stage, and applying the deblocking filter on the decoded and reconstructed video frames before they are displayed. The purpose of the filter is to modify the sample values around the block boundaries in order to smooth unnatural sharp transitions that have been introduced by the block-based coding process. Having a deblocking filter applied outside of the motion-compensation loop can be viewed as an optional process for the decoder, placing no requirements on the video encoder. However, this scheme has a disadvantage in that the reference frames that are used for generating predictions for the coding of subsequent frames will contain blocking artifacts. This can lead to reduced coding efficiency and degraded visual quality. The second approach to reduce the visibility of blocking artifacts is to apply a deblocking filter inside the motion-compensation loop. In this case, the reference frames that are used for generating predictions for subsequent encoded frames represent filtered reconstructed frames, generally providing improved predictions and improved compression and visual quality. In order to create identical predictions at both the encoder and decoder, the deblocking filter (sometimes referred to as a “loop filter” if it is inside the motion-compensation loop) must be applied in both the encoder and the decoder.
[0007] In order to reduce the appearance of blocking artifacts, a number of video coding standards, including H.263 version 2, and most recently the emerging H.264 video coding standard specify the use of a deblocking filter inside the motion-compensation loop. In particular, the H.264 video coding standard fully specifies a deblocking filter that is to be used inside the motion-compensation loop in both the encoder and decoder.
[0008] One of the known prior art methods is described in a document “Working Draft Number 2, Revision 2 (WD-2)” by the Joint Video Team (JVT) of ISO/IEC MPEG and ITU-T VCEG. In this prior art method, filtering occurs on the edges of 4×4 blocks in both the luminance and chrominance components of each reconstructed video frame. The filtering takes place on one 16×16 macroblock at a time, with macroblocks processed in raster-scan order throughout the frame. Within each macroblock, vertical edges are filtered first from left to right, followed by filtering of the horizontal edges, from top to bottom. The filtering of samples for one line-based filtering operation occurs along the boundary separating unfiltered samples p 0 , p 1 , p 2 , and p 3 on one side of the boundary, and unfiltered samples q 0 , q 1 , q 2 , and q 3 on the other side, as illustrated in FIG. 3 a . The block boundary lies between samples p 0 and q 0 . In some cases p 1 , p 2 may indicate samples that have been modified by filtering of a previous block edge. For each line-based filtering operation, unfiltered samples will be referred to with lower-case letters, and filtered samples with upper-case letters. For each block boundary segment (consisting of 4 rows or columns of samples), a “Boundary strength” parameter, referred to as “Bs”, is computed before filtering. The calculation of Bs is based on parameters that are used in encoding the bounding blocks of each segment. Each segment is assigned a Bs value from zero to four, with a value of zero indicating that no filtering will take place, and a value of 4 indicating that the strongest filtering mode will be used.
[0009] The process for determining Bs is as follows. For each boundary, a determination is made as to whether either one of the two blocks that neighbour the boundary is intra-coded. If either block is intra-coded, then a further determination is made as to whether the block boundary is also a macroblock boundary. If the block boundary is also a macroblock boundary, then Bs=4, else Bs=3.
[0010] Otherwise, if neither block is intra-coded then a further determination is made as to whether either block contains non-zero transform coefficients. If either block contains non-zero coefficients then Bs=2; otherwise if a prediction of the two blocks is formed using different reference frames or a different number of frames and if a pair of motion vectors from the two blocks reference the same frame and either component of this pair has a difference of more than one sample, then Bs=1; else Bs=0, in which case no filtering is performed on this boundary. The value of boundary strength, Bs, for a specific block boundary is determined by the encoding characteristics of the two 4×4 blocks along the boundary. Therefore, the control of the filtering process for each individual block boundary is well localized. The block boundary is filtered only when it is necessary, based on whether the coding modes used for the neighbouring blocks are likely to produce a visible blocking artifact.
[0011] The known filtering process starts with the step of filtering each 4×4 block edge in a reconstructed macroblock. The filtering “Boundary strength” parameter, Bs, is computed and assigned based on the coding parameters used for luma. Block boundaries of chroma blocks correspond to block boundaries of luma blocks, therefore, the corresponding Bs for luma is also used for chroma boundaries.
[0012] Filtering takes place in the order described above on all boundary segments with non-zero value for Bs. The following describes the process that takes place for each line-based filtering operation.
TABLE 1 QP av dependent activity threshold parameters α and β QP av 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 α 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 4 5 6 7 9 10 12 β 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 3 3 4 4 4 6 6 QP av 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 α 14 17 20 24 28 33 39 46 55 65 76 90 106 126 148 175 207 245 255 255 255 255 255 255 β 7 7 8 8 9 9 10 10 11 11 12 12 13 13 14 14 15 15 16 16 17 17 18 18
[0013] A content activity check is performed. If the check is passed, filtering continues; otherwise, the sample values are not modified on this line of the boundary segment. The activity check makes use of a pair of activity threshold parameters, ALPHA (α) and BETA (β), whose particular values are selected from the above Table 1, based on the average quantization parameter (QP av ) used in coding each boundary segment. It is noted that QP av represents the average value of the quantization parameter values used in encoding the two blocks that neighbour the boundary, with rounding of the average by truncation of any fractional part. Accordingly, the content activity check is passed if
| p 0 −q 0 |<ALPHA(α) AND | p 1 −p 0 |<BETA(β) AND | q 1 −q 0 <BETA(β).
[0014] Further, if this first content activity check is passed, and Bs is not equal to 4, default mode filtering is performed. Otherwise, if the check is passed and Bs is equal to 4, a second, stricter activity check is performed. This activity check involves the evaluation of the condition
1<| p 0 −q 0 |<( QP av >>2) AND | p 2 −p 0 |<BETA(β) AND | q 2 −q 0 |<BETA(β).
If this second condition is true on a particular line of samples, a strong mode filtering is used on this line of samples. Otherwise, a default mode filtering is used on this line of samples. It should be noted the symbol “>>” is used to represent the operation of bit-wise shifting to the right.
[0015] Among the disadvantages of the above described known method is that it permits switching between two filtering modes with very different characteristics at the level of each line of samples within a boundary segment. This switching adds complexity to the filtering process and can significantly increase the worst-case critical path for processing on many architectures.
[0016] Further disadvantages include the particular values in the tables of filtering parameters, ALPHA (α) and BETA (β), which are not optimized to produce the best subjective viewing quality of reconstructed and filtered video. Further, the characteristics of the deblocking filter in terms of the threshold parameters used in the activity checks and equations used for generating filtered sample values are fixed in the known method, providing the encoder with little or no flexibility to control the properties of the deblocking filter. This hinders optimization of the subjective quality of the decoded video for different types of video content and displays.
[0017] In the default mode of the above identified filtering method, the value Δ, which represents the change from the unfiltered values of p 0 and q 0 to their respective filtered values is computed using:
Δ=Clip(− C,C ,((( q 0 −p 0 )<<2+( p 1 −q 1 )+4)>>3)),
where C is determined as specified below and the function “Clip” is defined as:
Clip( a,b,c )=IF( c<a )THEN a ELSE IF( c>b ) THEN b ELSE c
Further, the filtered values P 0 and Q 0 are computed where
P 0 =Clip(0,255 ,p 0 +Δ) and Q 0 =Clip(0,255 ,q 0 −Δ).
[0018] In order to compute the clipping value, C, that is used to determine Δ, and also determine whether the values of p 1 and q 1 will be modified on this set of samples, two intermediate variables, a p and a q are computed, where:
a p =|p 2 −p 0 | and a q =|q 2 −q 0 |.
[0019] If a p <β for a luminance edge, a filtered sample P 1 is produced as specified by:
P 1 =p 1 +Clip(− C 0 ,C 0, ( p 2 +P 0 −( p 1 <<1))>>1).
[0020] If a q <β for a luminance edge, a filtered sample Q 1 is produced as specified by Q 1 =q 1 +Clip(−C0,C0,(q 2 +Q 0 −(q 1 <<1))>>1) where C0 is specified in Table 2 (see below), based on Bs and QP av for the block boundary. For both luma and chroma, C is determined by setting it equal to C0 and then incrementing it by one if a p <β, and again by one if a q <β.
TABLE 2 Value of filter clipping parameter C0 as a function of QP av and Bs QP av 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Bs = 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 Bs = 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 Bs = 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 QP av 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 Bs = 1 1 1 1 1 1 1 1 2 2 2 2 3 3 3 4 4 4 5 6 6 7 8 9 10 11 13 Bs = 2 1 1 1 1 1 2 2 2 2 3 3 3 4 4 5 5 6 7 8 8 10 11 12 13 15 17 Bs = 3 1 2 2 2 2 3 3 3 4 4 4 5 6 6 7 8 9 10 11 13 14 16 18 20 23 25
[0021] It is important to note that the computation of the filtered values P 1 and Q 1 require as an input to the filtering equation the filtered values of P 0 and Q 0 from the current line of samples. This recursive filtering method presents a disadvantage as the values of P 0 and Q 0 must be computed before the computation of P 1 and Q 1 can begin. This design can impede parallel processing of the different samples and thereby increases the critical path for the default mode filtering on most hardware architectures.
[0022] An additional disadvantage in the default mode filtering process of the known method is that the calculation of the clipping parameter, C, for chroma samples is unnecessarily complex. The chroma samples p 1 and q 1 are never filtered in the default mode and, therefore, the computation of the variables a p and a q is only necessary to determine the C parameter that is used to clip the value of Δ. These computations could be avoided by specifying a simpler method to compute C for chroma filtering.
[0023] For strong mode filtering in the known method, the following equations are applied to calculate the filtered sample values:
P 0 =( p 2 +2 *p 1 +2 *p 0 +2 *q 0 +q 1 +4)>>3,
P 1 =( p 3 +2 *p 2 +2 *p 1 +2 *p 0 +q 0 +4)>>3,
Q 0 =( p 1 +2 *p 0 +2 *q 0 +2 *q 1 +q 2 +4)>>3 and
Q 1 =( p 0 +2 *q 0 +2 *q 1 +2 *q 2 +q 3 +4)>>3.
For the luminance component only, p 2 and q 2 are also filtered as specified by:
P 2 =(2 *p 3 +3 *p 2 +p 1 +p 0 +q 2 +4)>>3 and
Q 2 =(2 *q 3 +3 *q 2 +q 1 +q 0 +p 0 +4)>>3.
[0024] Filtering with this set of equations can lead to insufficient reduction in the visibility of blocking artifacts. It is therefore an object of the present invention to obviate or mitigate the above-mentioned disadvantages.
SUMMARY OF THE INVENTION
[0025] In accordance with one aspect of the present invention there is provided a method of filtering samples to minimise coding artifacts introduced at a block boundary in a block-based video encoder, the method having the steps of:
[0026] (a) calculating a pair of indices used to access a table of a pair of corresponding activity threshold values, the indices calculated using an average quantization parameter and an offset parameter;
[0027] (b) determining the activity threshold values based on the pair of indicies;
[0028] (c) confirming whether the filtering process will modify the sample values on every line of samples for the block boundary by checking a content activity for the every line of samples for the block boundary, the content activity based on the determined activity threshold values; and
[0029] (d) filtering the confirmed samples when a block on either side of the block boundary was coded using inter prediction.
[0030] The determination of whether the filtering process will modify the sample values on each particular line is based on a content activity check which makes use of a set of adaptively selected thresholds whose values are determined using Variable-Shift Table Indexing (VSTI). The method is also operated on a system including tables for the various activity thresholds accessed through the calculated indicies.
[0031] In another aspect of the invention there is provided a method of controlling filter properties to adjust the properties of said filter at a block boundary, the method having the steps of:
[0032] (a) computing an average quantization parameter value (QP av ) at the block boundary;
[0033] (b) adding offset values Filter_Offset_A and Filter_Offset_B to the average quantization parameter value QP av and clipping these values within a given range to determine table indices Index A and Index B ; and
[0034] (c) accessing an ALPHA (α) table, a BETA (β) table, and a Clipping (C0) table using the indices computed based on the filter offsets and the average quantization parameter value such that:
ALPHA=ALPHA_TABLE[Index A ]
BETA=BETA_TABLE[Index B ]
C0=CLIP_TABLE[Bs][Index A ]
[0035] In a still further aspect of the invention there is provided a method of filtering samples to minimise coding artifacts introduced at a block boundary in a block-based video encoder, the method having the steps of checking content activity on every line of samples belonging to the boundary to be filtered and determining whether the filtering process will modify the sample values on said line of samples based on content activity thresholds that are dependent on a quantization parameter and determined using a filter offset parameter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] These and other features of the preferred embodiments of the invention will become more apparent in the following detailed description in which reference is made to the appended drawings wherein:
[0037] FIG. 1 is a schematic representation of a data transmission system;
[0038] FIG. 2 is a schematic representation of hierarchy of levels of an H.264 conformant bitstream;
[0039] FIG. 3 a is schematic representation of a macroblock and a block;
[0040] FIG. 3 b is a diagram showing relationship between unfiltered samples and activity thresholds;
[0041] FIG. 4 is a block diagram of a hybrid block-based video decoder including a deblocking filter inside the motion compensation loop of the system of FIG. 1 ;
[0042] FIG. 5 is a flowchart of the operation of the deblocking filter process for the decoder of FIG. 4 ;
[0043] FIG. 6 is the dependency graph for default mode filter for the decoder of FIG. 4 ; and
[0044] FIG. 7 is flowchart for the process of calculating the boundary strength for the decoder of FIG. 4 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0045] Referring to FIG. 1 , a video conferencing system 10 used as an example of a video transmission system has participants A and B that exchange video data 12 between monitors 13 , formatted as a compressed bit stream 15 over a network 14 (such as but not limited to the Internet). Each participant A, B has a video processor 16 having an encoder 18 for encoding transmitted video data 12 and a decoder 20 for decoding the received bit stream 15 . Each image frame 22 displayed on the monitors 13 is made of a series of macroblocks 24 , such as but not limited to a block of 16×16 pixels, representing (for example) an object 26 which moves over a background 28 (for example a person giving a presentation while standing in front of a backdrop). Accordingly, the processors 16 coordinate the display of successive frames 22 on the monitors 13 , as the video data 12 is communicated between the participants A, B, which can include applications such as video conferencing. It will be appreciated recognised that the system 10 may also involve the exchange of video data 12 in the compressed bit stream 15 in either one direction or both and on peer-to-peer basis or broadcast.
[0046] The video data 12 is a temporal sequence of pictures, each referred to as a frame or field 22 . Each picture 22 is organized as a matrix of macroblocks 24 . Each macroblock 24 has a size of 16 by 16 pixels and the macroblocks 24 are stored from left to right and from top to bottom and groups of macroblocks 24 are combined in a slice 32 (see FIG. 2 ). Generally, a slice 32 contains macroblocks 24 and each macroblock 24 consists of blocks 25 (see FIG. 3 ). Generally, each macroblock 24 is composed of three images; one red (R), one green (G), and one blue (B). However, for compatibility with non-coloured media, the RGB model is represented as an equivalent YCbCr model, where Y is a luminance (luma) component, and Cb and Cr are chrominance (chroma) components, such that typically Y=0.299R+0.587G+0.114B, Cb=B−Y, and Cr=R−Y. Therefore, each frame 22 of the video data 12 is generically referred to as containing one luma image, one Cb chroma image, and one Cr chroma image. Standard formats have 8 bits per pixel to digitally represent each of the three components, where Cb and Cr images are typically downsampled by 2 in each dimension due to the sensitivity of human vision. Generally, each block 25 consists of four pixels for the luma components and one pixel for each chroma component of the 4:2:0 color data. The blocks 25 are processed and compressed for transmission as the bit stream 15 over the network 14 (see FIG. 1 ).
[0047] Generally, one of three fundamental coding modes can be selected for each macroblock 24 , with the choice of coding mode determining how the prediction of a macroblock 24 is formed. Intra-coded (I) macroblocks 24 make use of intra-prediction, in which the prediction is formed using only the current picture. In predictive (P), or inter-coded, macroblocks 24 the prediction of each sample is formed by referring to one block 25 in the set of previously decoded and stored reference pictures 22 . In bi-predictive (B) macroblocks 24 , predictions can be formed in this way, but can also be formed by computing a weighted average of two different blocks 25 in the set of previously decoded reference pictures 22 . It will be noted that some of the previously decoded pictures 22 are typically temporally subsequent to the current picture in terms of their intended display order when bi-predictive coding is used. Depending on the mode of each slice 32 , which is indicated in the slice header 27 , P- and B-macroblocks 24 may not be permitted within certain slices 32 .
[0048] Referring again to FIG. 2 , the bitstream 15 is organized into a hierarchy of syntax levels, with the 3 main levels being a sequence level 17 , a picture (or frame) level 19 , and slice level 21 . A concept know as “parameter sets” allows efficient transmission of infrequently changing data at the sequence 17 and picture level 19 in the H.264 standard. A sequence parameter set 29 in the first level 17 includes values of parameters that will remain unchanged for an entire video sequence, or from one instantaneous decoder refresh (IDR) picture to the next. (IDR pictures are used to provide points of random access into the bitstream). Examples of parameters in a sequence parameter set 29 include frame dimensions and the maximum number of reference frames. A unique ID number “N” identifies each sequence parameter set 29 .
[0049] A picture parameter set 31 in the second level 21 includes values of parameters that will remain unchanged within a coded representation of a picture (frame or field) 22 . Examples of parameters in the picture parameter set 31 include the entropy coding mode and a flag that specifies whether deblocking filter parameters will be transmitted in the slice headers 27 of the picture 22 (see FIG. 1 ). Each picture parameter set 31 , labeled as “M”, refers to the unique ID of a valid sequence parameter set 29 , which selects the active sequence parameters that are used when decoding coded pictures 22 that use the particular picture parameter set 31 . The unique ID number “M” identifies each picture parameter set 31 .
[0050] A slice 32 in the bit stream 15 contains a picture data 35 representing a sub-set of the macroblocks 24 of the complete picture 22 . The macroblocks 24 in a slice 32 are ordered contiguously in raster scan order. The coded slice 32 includes the slice header 27 and the slice data 35 (coded macroblocks 24 ). The slice header 27 contains a coded representation of data elements 35 that pertain to the decoding of the slice data that follow the slice header 27 . One of these data elements contains a reference to a valid picture parameter set 31 , which specifies the picture parameter values (and indirectly the sequence parameter values) to be used when decoding the slice data 35 . Each slice header 27 within the same picture 22 must refer to the same picture parameter set 31 . Other data elements in the slice header 27 include the initial quantization parameter for the first macroblock 24 in the slice 32 and deblocking filter offset parameters 39 (as further explained below), if the transmission of such offset parameters 39 is specified in the active picture parameter set.
[0051] Thus, the filter offsets 39 are transmitted in the slice header 27 , and therefore the offsets 39 can be different for each slice 32 within the picture 22 . However, depending on the value of a flag in the picture parameter set 31 (“filter_parameters_flag”), the transmission of these offsets 39 in the slice header 27 might be disabled. In the case that offsets 39 are not transmitted, a default value of zero is used for both filter offsets 39 for example. Further, each picture parameter set 31 contains parameter values that pertain to the decoding of the pictures 22 for which the particular parameter set 31 is active (i.e. selected in the slice headers 27 of the picture 22 ). The parameter sets 31 also contain a reference to the sequence parameter sets 29 , which are active for decoding of the pictures 22 . The choice of sequence parameter sets 29 and picture parameter sets 31 can be chosen by the encoder 18 (see FIG. 1 ), or set at the time of system 10 setup for sequential operation of the encoder 18 , decoder 20 pair.
[0052] Referring further to FIG. 2 , each of the pictures 22 can select individual picture parameter sets that specify the picture structure and the picture coding type. For exemplary purposes only, FIG. 3 a contains the macroblock 24 each consisting of a grouping of pixels, such as a 16×16 luma block 25 with the two associated 8×8 chroma blocks 25 . However, it is recognized that other sizes of blocks 24 could be used to represent the frames 22 , if desired. Each slice 32 of the frame 22 is encoded by the encoder 18 (see FIG. 1 ), independently from the other slices 32 in the frame 22 . Each of the slices 32 has the slice header 27 that provides information, such as but not limited to the position of the respective slice 32 in the frame 22 as well as the initial quantization parameter; and the slice data which provides information for reconstructing the macroblocks 24 of a slice 32 , such as but not limited to the prediction modes and quantised coefficients for each of the respective macroblocks 24 .
[0053] Referring to FIG. 4 , the decoder 20 processes the received bit stream 15 and then reconstructs the predicted frame 46 , using a stored copy of the reference frame(s) 48 , the transmitted motion vectors 23 , and the decompressed or reassembled prediction error 54 contained in the bit stream 15 .
[0054] The bit stream 15 generated by the encoder 18 is processed by the decoder 20 to produce the reconstructed video images 55 . Referring to FIG. 4 , the video decoder 20 is based on functional units or components similar to those found in other hybrid block-based video decoders. The functional units include a buffering unit 33 that receives the compressed bitstream 15 , an entropy decoder 34 which decodes the received bit stream 15 to produce syntax elements used in subsequent processing by the other decoder 20 components, a motion compensated prediction 36 to produce the predicted frame, an inverse scanning and quantization unit 38 , and inverse transform units 40 to reproduce the coded prediction error 54 . A reconstruction unit 42 adds the prediction error 54 to the predicted pixels 57 to produce the reconstructed frame 56 , and a deblocking filter 44 that smoothes the edges of sub-blocks within the reconstructed frame 56 to produce the filtered reconstructed frame 56 . Each of the above mentioned components is discussed in more detail in the following.
[0055] The incoming video bitstream 15 is stored in a buffer 33 at the input to the decoder 20 . The first stage in the decoding process includes the parsing and decoding of the entropy coded bitstream symbols that are stored in a buffer 46 to produce the syntax elements used by the other decoder 20 components.
[0056] The various syntax elements in the bitstream 15 are de-multiplexed for use in different processes within the decoder 20 . High-level syntax elements include temporal information for each frame, frame coding types and frame dimensions. The coding can be based primarily on macroblocks 24 consisting of 16×16 luminance-pixel blocks 25 and 2 8×8 chrominance pixel blocks 25 . On the macroblock 24 level, syntax elements include the coding mode of the macroblock 24 , information required for forming the prediction, such as motion vectors 23 and spatial prediction modes, and the coded information of the residual (difference) blocks, such as the coded block pattern (CBP) for each macroblock 24 and quantized transform coefficients for each of the underlying blocks 24 .
[0057] Depending on the coding mode of each macroblock 24 , the predicted macroblock 24 can be generated either temporally (inter prediction) or spatially (intra prediction). The prediction for an inter-coded macroblock 24 is specified by the motion vectors 23 that are associated with that macroblock 24 . The motion vectors 23 indicate the position within the set of previously decoded frames from which each block of pixels will be predicted. Each inter-coded macroblock 24 can be partitioned in a number of different ways, using blocks of seven different sizes, with luminance block sizes ranging from 16×16 pixels to 4×4 pixels. Also, a special SKIP mode exists in which no motion vector difference values 23 (or coded residual blocks) are transmitted and the prediction is taken from a location in the previous picture that is predicted by the values of previously decoded motion vectors 23 of macroblocks 24 neighbouring the current macroblock 24 . Thus, 0 to 16 motion vectors 23 can be transmitted for each inter-coded macroblock 24 . Additional predictive modes in which two different motion vectors 23 correspond to each pixel and the sample values are computed using a weighted average are supported when bi-predictive macroblock types are employed.
[0058] For each motion vector 23 , a predicted block 25 must be computed by the decoder 20 and then arranged with other blocks 24 to form the predicted macroblock 24 . Motion vectors 23 in H.264 are specified generally with quarter-pixel accuracy. Interpolation of the reference video frames is necessary to determine the predicted macroblock 24 using sub-pixel accurate motion vectors 23 .
[0059] Multiple (previous for P-pictures) reference pictures 22 can also be used for motion-compensated prediction. Selection of a particular reference pictures 22 is made on an 8×8 sub-macroblock 24 basis, or larger if a larger sub-macroblock partition size is used for generating the motion-compensated prediction. This feature can improve coding efficiency by providing a larger set of options from which to generate a prediction signal.
[0060] Two different modes are supported in intra prediction and coding of macroblocks 24 . In the 4×4 Intra mode, each 4×4 block within a macroblock 24 can use a different prediction mode. In the 16×16 Intra mode, a single prediction mode is used for the entire macroblock 24 . The prediction of intra-coded blocks 25 is always based on neighboring pixel values that have already been decoded and reconstructed.
[0061] The decoding of a residual (difference) macroblock 24 requires that a number of transforms be performed on any blocks for which non-zero transform coefficients were transmitted in the bitstream, along with associated scanning and coefficient scaling operations. The transforms that are required for each macroblock 24 are determined based on the coding mode and the coded block pattern (CBP) of the macroblock 24 . The decoding of a difference macroblock 24 is based primarily on the transformation of 4×4 blocks 25 of both the luminance and chrominance pixels, although in some circumstances, a second-level transform must be performed on the DC coefficients of a group of 4×4 blocks 25 for macroblocks 24 that are coded in the 16×16 Intra prediction mode. Additionally, a special 2×2 transform is applied to the 4 DC coefficients of the chrominance residual blocks 25 of a macroblock 24 .
[0062] The values of the quantized coefficients are parsed and decoded by the entropy decoder 34 . These are put into their correct order based on the run values through the scanning process and then the levels, which represent quantized transform coefficients, are scaled via multiplication by a scaling factor. Finally, the necessary transform to reconstruct the coded residual signal for a block is performed on the scaled coefficients. The result of the transforms for each macroblock 24 is added to the predicted macroblock 24 and stored in the reconstructed frame buffer 48 .
[0063] In the final stage of the decoding process, the decoder 20 applies the normative de-blocking filtering process, which reduces blocking artifacts that are introduced by the coding process. The filter 44 is applied within the motion compensation loop, so both the encoder 18 and decoder 20 must perform this filtering. The filtering is performed on the 4×4 block edges of both luminance and chrominance components. The type of filter 44 used, the length of the filter and its strength are dependent on several coding parameters as well as picture content on both sides of each edge. A stronger filtering mode is used if the edge lies on a macroblock boundary 49 where the block on one or both sides of the edge is coded using intra prediction. The length of the filtering is also determined by the sample values over the edge, which determine the so-called “activity measures”. These activity measures determine whether 0, 1, or 2 samples on either side of the edge are modified by the filter.
[0064] Filtering is applied across the 4×4 block edges of both luminance and chrominance components. Looking at FIG. 3 a , the blocks 25 are separated by boundaries or block edges 47 , with unfiltered samples p 0 , p 1 , p 2 and p 3 on one side of the boundary 47 and unfiltered samples q 0 , q 1 , q 2 and q 3 on the other side, such that the boundary 47 lies between p 0 and q 0 . In some cases p 1 , p 2 may indicate samples that have been modified by filtering of the previous block edge 47 . The deblocking filter 44 (see FIG. 4 ) is applied on the block boundaries 47 of each reconstructed frame 56 , which helps to reduce the visibility of coding artifacts that can be introduced at those block boundaries 49 . The filter 44 includes a control function that determines the appropriate filtering to apply. The control algorithm is illustrated by FIG. 5 .
[0065] One of the parameters used to control the filtering process of all the block boundaries 47 is the boundary strength, Bs. The procedure for determining the boundary strength, Bs, for the block boundary 47 between two neighbouring blocks j and k is illustrated in FIG. 7 . For each edge 47 , a determination is made as to whether either one of the two blocks j and k across the boundary 47 is intra-coded, in step 140 . If either block j or k is intra-coded then a further determination is made as to whether the block boundary 47 is also a macroblock boundary 49 , in step 152 . If the block boundary 47 is also a macroblock boundary 49 , then Bs=4 (step 154 ), else Bs=3 (step 156 ).
[0066] Otherwise, if neither block j or k is intra-coded then a further determination is made as to whether either block 25 contains non-zero coefficients, in step 142 . If either block 25 contains non-zero coefficients then
[0067] Bs=2 (step 144 ), otherwise the following condition is applied:
[0068] R(j)≠R(k) or|V(j, x)−V(k, x)|≧1 pixel or |V(j, y)−V(k, y)|≧1 pixel, where R(j) is the reference picture 22 used for predicting block j, and V(j) is the motion vector 23 used for predicting block j, consisting of x and y (horizontal and vertical) components. Therefore, if a prediction of the two blocks 25 is formed using different reference frames 22 or a different number of frames 22 or if a pair of motion vectors 23 from the two blocks 25 reference the same frame and either component of this pair has a difference if more than one sample distance, then this condition holds true and
[0069] Bs=1 (step 148 );
[0000] else,
[0070] Bs=0 (step 150 ), in which case no filtering is performed.
[0071] The value of boundary strength, Bs, for a specific block boundary 47 is determined solely by characteristics of the two 4×4 blocks 24 across the boundary 47 . Therefore, the control of the filtering process for each individual block boundary 47 is well localized. A block boundary 47 is filtered only when it is necessary, so that unneeded computation and blurring can be effectively avoided.
[0072] The flowchart of FIG. 5 describes the filtering process starting with step 100 for the purposes of filtering each 4×4 block edge 47 in a reconstructed macroblock 24 . The filtering “Boundary strength” parameter, Bs, is computed ( 102 ) and assigned for luma. Block boundaries 47 of chroma blocks 25 always correspond to block boundaries 47 of luma blocks 25 , therefore, the corresponding Bs for luma is also used for chroma boundaries 47 . The boundary strength is based on the parameters that are used in encoding the bounding blocks 25 of each segment ( 104 ). Each segment is assigned a Bs value from 0 to 4, with a value of zero indicating that no filtering will take place ( 108 ), and a value of 4 indicating that the strongest filtering mode will be used.
[0073] In step 110 , the filtering process takes place for each line of samples on the block boundary 47 . The set of filtering operations that take place on one line of a block boundary is referred to as a line-based filtering operation. A content activity check at the boundary 47 between the two blocks 25 is performed in step 112 . The content activity measure is derived from the absolute value of the separation between sample values of p 0 , p 1 , q 0 , q 1 on either side of the boundary 47 . The activity check is based on two activity threshold parameters ALPHA (α) and BETA (β), whose particular values are selected based on the average quantization parameter (QP av ) used in coding each boundary segment, as well as upon a pair of encoder 18 selected parameter values, referred to as Filter_Offset_A and Filter_Offset_B (referred to as 39 in FIG. 2 ). QP av represents the average of the quantization parameter values used in coding the two blocks 25 that neighbour the boundary 47 , with rounding of the average by truncation of any fractional part. Thus, the content activity check is done by comparing difference in the unfiltered sample values p 0 and q 0 across the boundary 47 against the activity threshold ALPHA (α), and the difference in the unfiltered sample values p 0 and p 1 on one side of the boundary 47 and unfiltered sample values q 0 and q 1 on the other side of the boundary 47 against the activity threshold and BETA (β), as shown in FIG. 3 b . A determination is made to discover whether the activity on the line is above or below the activity threshold. If the activity is above the threshold, the sample values are not modified, otherwise filtering continues. The ALPHA (α) and BETA (β) values are considered as activity thresholds for the difference in magnitude between sample values along the line of samples being filtered.
[0074] Referring to FIG. 3 , the ALPHA (α) and BETA (β) parameters represent the activity thresholds for the difference in the values of unfiltered samples p 0 , p 1 , q 0 , q 1 across the boundary 47 . The content activity check is passed if:
p 0 −q 0 |<ALPHA(α) AND | p 1 −p 0 |<BETA(β) AND | q 1 −q 0 |<BETA(β)
[0075] The sets of samples p 0 , p 1 , q 0 , q 1 across this edge 46 are only filtered if Bs is not equal to zero and the content activity check expressed in the above condition is passed.
[0076] The values in the ALPHA (α)- and BETA (β)-tables used in the loop filter are optimal in terms of the resulting video visual quality and allow some flexibility in the encoder 18 in terms of adjusting the filter parameters, such as the activity threshold parameters and maximum change in a sample value produced by the default filter, through control of the indexing of these tables. The strength of the deblocking filter 44 refers to the magnitude of the change in sample intensities that is caused by the filtering process. Generally, the strength of the filter 44 varies with the coding mode, as well as the step-size used for quantization of the transform coefficients. Stronger filtering is applied when the quantization step-size (and its corresponding “quantization parameter”, QP) are larger, since it is more likely that large block artifacts are created when the quantization is coarse. Thus, flexibility in the properties of the loop filter 44 is provided by allowing the encoder 18 to select offsets 39 to the QP-based indices used to address these tables. This adds flexibility to the filter 44 , help making it more robust to different content, resolutions, display types, and other encoder 18 decision characteristics.
[0077] The α- and β-tables of the loop filter 44 are QP-dependent thresholds that define the maximum amount of activity at an edge for which the edge will still be filtered. The modified α-table of the preferred embodiment is based on the subjective evaluation of a number of sequences over the entire QP scale. In the preferred embodiment, the value of a doubles every 6 QP as it is related directly to the quantization step size, which also doubles every 6 QP in the H.264 standard.
[0078] A determination is made to find the QP value below which a should be zero, such that the filter is no longer used for values of a which equal zero. Looking at Table 1, in sequences with smooth areas, blocking artifacts are clearly visible using QP=19, which is the largest QP for which a is equal to zero. Based on Table 3, filtering will take place for QP values as low as 16, since blocking artifacts are still visible in smooth areas. The β-table is also extended at the low QP end in order to permit filtering at these lower QP values.
[0079] The content activity check ( 112 ) determines whether each sample line is to be filtered and uses the following specific values for a and β ( 114 ) as shown in Table 3 below, where the index used to access the tables is clipped to be within the range of valid QP values (0 to 51).
TABLE 3 Index A (for α) or Index B (for β) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 α 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 4 5 6 7 8 9 10 12 13 15 β 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 2 2 3 3 3 3 4 4 4 6 Index A (for α) or Index B (for β) 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 α 17 20 22 25 28 32 36 40 45 50 56 63 71 80 90 101 113 127 144 162 182 203 226 255 255 β 6 7 7 8 8 9 9 10 10 11 11 12 12 13 13 14 14 15 15 16 16 17 17 18 18
[0080] Further, the particular values for a and β to be used on each block boundary 47 do not only depend on QP, but additionally upon a pair of parameter values, referred to as Filter_Offset_A and Filter_Offset_B, (referenced 39 in FIG. 2 ) that are transmitted in the higher-level syntax (sequence 17 , picture 19 , or preferably the slice level 21 ) within the video bitstream 15 . These offsets 39 are added to the average QP value between the blocks 24 in order to calculate the indices that are used to access the tables of ALPHA (α) and BETA (β) values ( 114 ), as well as the C0 table:
Index A =Clip( QP min ,QP max ,QP av +Filter — Offset — A )
Index B =Clip( QP min ,QP max ,QP av +Filter — Offset — B )
[0081] The variables QP min and QP max in the above equations represent the minimum and maximum permitted values, respectively, of the quantization parameter QP, and for example can be such that but not limited to the values 0 and 51, respectively.
[0082] However, because the values Index B and Index A are limited to lie in a predetermined interval, if any of the computed coefficients lie outside the interval, those values are limited to the permitted range by the “clip” function. The function “clip” is defined as:
clip( a,b,c )=IF( c<a )THEN a ELSE IF( c>b )THEN b ELSE c
[0083] By default, Filter_Offset_A and Filter_Offset_B values 39 are both assumed to have a value of zero. Further, within the default filtering, Index A is also used to access the table of C0 values. Transmission of the Filter_Offset_A and Filter_Offset_B values 39 in the slice header 27 (see FIG. 2 ) provides a means of adapting the properties of the deblocking filter 44 in terms of the magnitude of the thresholds used in the activity checks and the maximum change in sample values that can be produced by the default filter 44 . This flexibility helps to allow the encoder to achieve the optimal visual quality of the decoded and filtered video. Typically, the semantic in the slice header 27 slice_alpha_c0_offset_div2 specifies the offset 39 used in accessing the ALPHA (α) and C0 deblocking filter tables for filtering operations controlled by the macroblocks 24 within the slice 32 . The decoded value of this parameter is in the range from +6 to −6, inclusive. From this value, the offset 39 that shall be applied when addressing these tables is computed as:
Filter_Offset — A =slice_alpha — c 0_offset — div 2<<1
[0084] If this value is not present in the slice header 27 , then the value of this field shall be inferred to be zero.
[0085] Correspondingly, the semantic in the slice header 27 slice_beta_offset div2 specifies the offset 39 used in accessing the BETA (β) deblocking filter tables for filtering operations controlled by the macroblocks 24 within the slice 32 . The decoded value of this parameter is in the range from +6 to −6, inclusive. From this value, the offset 39 that shall be applied when addressing these tables is computed as:
Filter_Offset — B =slice_beta_offset — div 2<<1.
[0086] If this value 39 is not present in the slice header 27 , then the value of this field shall be inferred to be zero. The resulting Variable-Shift Table Indexing (VSTI) method (using the offsets 39 to shift selection of the α-, β-, and clipping (C0) values) allows the decoder 20 to make use of the offset 39 that is specified on the individual slice 32 basis and that will be added to the QP value used in indexing the α-, β-, and clipping (C0) tables. Thus,
Alpha(α)=ALPHA_TABLE[Index A ]
Beta(β)=BETA_TABLE[Index B ]
C0=CLIP_TABLE[Bs][Index A ]
[0087] The offset 39 for indexing the clipping table is always the same as for the α-table. In general, it is desired have α and the clipping values remain in sync, although a different offset 39 for β can be beneficial. The implementation of this method can be simplified even further by applying the offset 39 to the base pointers that are used to access the tables. This way, the extra addition only occurs as often as the offset 39 can be changed (on a per-slice basis), not every time the table is accessed. Clipping of the index can be avoided by extending the tables with the last value in the valid range of indices at each end of the table.
[0088] A positive offset 39 results in more filtering by shifting a curve (of α, β, or C0 values) to the left on a horizontal QP scale, while a negative offset 39 results in less filtering by shifting a curve to the right. The range of permitted offsets 39 is −12 to +12, in increments of 2. This range is large enough to allow properties of the filter 44 to vary as widely, but is limited to limit additional memory requirements and/or added complexity. This variable-shift method provides both stronger and weaker filtering, and there is sufficient flexibility in the range of values, with reasonable constraints on the amount of variation permitted in the filtering, while maintaining the doubling rate of 6 QP's for α, consistent with the quantization step size. Also, the clipping (C0) and α values remain in sync with each other.
[0089] The specific decision on the choice of offsets 39 is varied, and dependent upon the content, resolution, and opinion of the viewer. Generally, less filtering is needed for slowly changing, detailed areas and for high-resolution pictures 22 , while more filtering (using positive offsets 39 ) is preferable for lower resolution pictures 22 , especially with smooth areas and human faces. More filtering can provide the viewer with a feeling of smoother motion.
[0090] Referring again to FIG. 5 , if the check is not passed in step 116 , the sample values are not modified on this line ( 118 ), otherwise filtering continues. The selection of the filtering mode occurs at the block boundary 47 level. More specifically, switching between the default-mode filtering and the strong-mode filtering does not occur on a line-to-line basis, and default-mode filtering is not used for intra-coded macroblock boundaries 47 . In step 120 , a further determination is made as to whether the macroblocks 24 are intra-coded. If the macroblocks 24 are not intracoded, then a default filter is applied in step 122 , in which the edges 47 with Bs<4 are filtered by computing the filtered samples P 0 and Q 0 based on the DELTA (Δ). The variable Δ represents the difference the between the unfiltered samples p 0 and q 0 and their respective filtered samples, P 0 and Q 0 , according to the following relation:
Δ=Clip(− C,C ,((( q 0 −p 0 )<<2+( p 1 −q 1 )+4)>>3))
P 0 =Clip(0,255, p 0 +Δ)
Q 0 =Clip(0,255 ,q 0 −Δ)
[0091] The two intermediate threshold variables a p and a q are used to determine the clipping value for the default filtering of luminance samples, as well as the choice of one of the two sub-modes of the strong mode filter, where
a p =|p 2 −p 0 | and a q =|q 2 −q 0 |.
[0092] Thus, for default-mode filtering ( 122 ), the calculations of filtered samples P 1 and Q 1 are modified from the prior art to increase the parallelism of the filtering process. If a p <β for a luma edge, a filtered P 1 sample generated as specified by:
P 1 =p 1 +Clip(− C 0 ,C 0,( p 2 +( p 0 +q 0 )>>1−( p 1 <<1))>>1).
[0093] While if a q <β for a luma edge, a filtered Q 1 sample generated as specified by:
Q 1 =q 1 +Clip(− C 0 ,C 0,( q 2 +( p 0 +q 0 )>>1−( q 1 <<1))>>1)
where C0 is specified in Table 4. However, the adaptable parameter Index A is used to address the table, rather than QP av .
[0094] A dependency graph for the default mode filter with reduced critical path as shown in FIG. 6 shows that the complexity can be reduced significantly. By shortening the critical path, a reduced cost of default filtering can be achieved and opportunities for parallel processing can be substantially increased, leading to reduced computational requirements. Also, from this figure, the complexity of Bs=4 filtering is potentially reduced by not permitting the filter 44 to switch between default and strong filter modes on a line-by-line basis to help minimise branching stalls and control logic.
[0095] For luminance only, C, which represents the maximum change in the level of intensity that the default filter can apply to the p 0 and q 0 samples, is determined by setting it equal to C0 and then incrementing it by one if a p <β, and again by one if a q <β. In the default luma filtering, P 1 and Q 1 are filtered only if a p <β and a q <β, respectively, evaluate to true, while P 1 and Q 1 are never filtered for chroma. Therefore, for chrominance filtering, instead of doing these calculations, C can be defined with the basic relationship:
C=C 0+1
[0096] Thus, there is a no need to perform the calculations of a p and a q for chrominance and therefore no need to load the sample values p 2 and q 2 . This can reduce the complexity of the default chroma filtering by approximately 20%. There is no reduction in quality, either objective or subjective, introduced by this simplification.
TABLE 4 Index A 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Bs = 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 Bs = 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 Bs = 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 Index A 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 Bs = 1 1 1 1 1 1 1 1 2 2 2 2 3 3 3 4 4 4 5 6 6 7 8 9 10 11 13 Bs = 2 1 1 1 1 1 2 2 2 2 3 3 3 4 4 5 5 6 7 8 8 10 11 12 13 15 17 Bs = 3 1 2 2 2 2 3 3 3 4 4 4 5 6 6 7 8 9 10 11 13 14 16 18 20 23 25
[0097] For strong mode filtering where Bs=4 and the initial activity threshold check 112 has been passed, a further determination to check whether each side of the boundary 47 meets an additional smoothness criteria is performed in steps 124 and 126 . The smoothness criteria for the left/upper side of the boundary 47 is checked in step 124 , while the smoothness criteria for the right/lower side is checked in step 126 . Thus, a choice between a 3-tap filter or a 5-tap filter for the left/upper (P) or the right/lower (Q) side of the boundary 47 is made. If the smoothness criterion is not met on a particular side, a 3-tap filter is used to filter only a single pixel on that side of the boundary 47 .
[0098] Specifically, for strong-mode filtering:
a p =|p 2 −p 0 |
a q =|q 2 −q 0 |
[0099] Therefore, in step 124 , for filtering of edges with Bs=4 if the following condition holds true
a p <BETA(β) AND | p 0 −q 0 |<((ALPHA(α)>>2)+2),
then filtering of the left/upper side of the block edge is specified by the equations ( 130 )
P 0 =( p 2 +2 *p 1 +2 *p 0 +2 *q 0 +q 1 +4)>>3
P 1 =( p 2 +p 1 +p 0 +q 0 +2)>>2
[0100] In the case of luminance filtering, then ( 130 )
P 2 =(2 *p 3 +3 *p 2 +p 1 +p 0 +q 0 +4)>>3
[0101] Otherwise, if the above condition does not hold, then filter only P0 using the 3-tap filter ( 128 )
P 0 =(2 *p 1 +p 0 +q 1 +2)>>2
[0102] Identical but mirrored filters are applied to the right/lower side of the boundary 47 , substituting q and Q for p and P, respectively, in the above description (and vice-versa) ( 132 , 134 ).
[0103] Therefore, if the following condition holds true ( 126 ):
a p <BETA(β) AND | p 0 −q 0 |<((ALPHA(α)>>2)+2)
filtering of the right/lower side of the block edge ( 134 ) is specified by the equations
Q 0 =( p 1 +2 *p 0 +2 *q 0 +2 *q 1 +q 2 +4)>>3
Q 1 =( p 0 +q 0 +q 1 +q 2 +2)>>2
[0104] In the case of luminance filtering, then ( 134 )
Q 2 =(2 *q 3 +3 *q 2 +q 1 +q 0 +p 0 +4)>>3
[0105] Otherwise, if the above condition does not hold, then only P0 is filtered with the 3-tap filter ( 132 )
Q 0 =(2 *q 1 +q 0 +p 1 +2)>>2
[0106] The system 10 thus includes a set of equations for the strong mode filtering to generate samples P 1 and Q 1 that can provide a greater reduction in the visibility of blocking artifacts than alternative equations that were used in the prior known method. Typically, the filters for samples P 1 and Q 1 consist of only 4 taps, as opposed to the 5 taps used for the other filtered samples in this strongest filtering mode. However, this is referred to as a 5-tap filter, since 5 taps is the maximum used for any sample. In addition to providing an improved reduction in blocking artifacts, these equations for filtering P 1 and Q 1 are simpler than those used in the prior art method, potentially reducing the complexity of the filter by a small amount.
[0107] The system 10 includes tables for ALPHA (α) and BETA (β) that can improve the subjective quality of the filtered video and can also specify an efficient method to allow the encoder 18 to control the characteristics of the deblocking filter 44 by transmitting variable offsets 39 that affect the QP-based indexing of these tables.
[0108] Although the invention has been described with reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art without departing from the spirit and scope of the invention as outlined in the claims appended hereto.
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A method of filtering to remove coding artifacts introduced at block edges in a block-based video coder, the method having the steps of: checking the content activity on every line of samples belonging to a boundary to be filtered and where content activity is based on a set of adaptively selected thresholds determined using Variable-Shift Table Indexing (VSTI); determining whether the filtering process will modify the sample values on that particular line based on said content activity; and selecting a filtering mode between at least two filtering modes to apply on a block boundary basis, implying that there would be no switching between the two primary modes on a line by line basis along a given block boundary. The two filtering modes include a default mode based on a non-recursive filter, and a strong filtering mode which features two strong filtering sub-modes and a new selection criterion that is one-sided with respect to the block boundary to determine which of the two strong filtering sub-modes to use. The two strong filtering sub-modes include a new 3-tap filter sub-mode and a 5-tap filter sub-mode that permits a more efficient implementation of the filter.
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BACKGROUND OF THE INVENTION
The present invention relates to the use of Echinacea as a cancer chemopreventive agent to block the formation of and to detoxify cancer-causing agents, or carcinogens. More particularly, the present invention relates to the induction of phase II enzymes by Echinacea, and specifically by lipid-soluble fractions isolated from Echinacea. The present invention relates to the use of lipid-soluble fractions isolated from Echinacea as nutritional supplements. The present invention also contemplates a novel method of extracting the desired lipid-soluble fractions from Echinacea.
Phase II enzymes are involved in the detoxification of cancer-causing agents by converting carcinogenic substances into products that are no longer harmful. Unexpectedly, certain fractions of Echinacea, particularly the lipid-soluble fractions, show a greater induction of phase II enzymes than other fractions. It is desirable to use these lipid-soluble fractions as a dietary supplement because they are the most potent and can yield the greatest benefit for cancer prevention.
Echinacea contains numerous active phytochemicals that have immunomodulatory and other beneficial activities. There is a long tradition of the use of Echinacea preparations in the adjuvant therapy of inflammations (see, Tragni et al., Evidence from two classic irritation tests for an anti-inflammatory action of a natural extract, Echinacea B., Food Chem. Toxicol., 23(2): 317–319 (1985); and Facino et al., Direct characterization of caffeoyl esters with antihyaluronidase activity in crude extracts from Echinacea angustifolia roots by fast atom bombardment tandem mass spectrometry, Farmaco, 48(10): 1447–1461 (1993)), skin damage (see, Facino et al., Echinacoside and caffeoyl conjugates protect collagen from free radical-induced degradation: a potential use of Echinacea extracts in the prevention of skin photodamage, Planta Med., 61(6): 510–514 (1995)), and, more typically, infections (see, Steinmuller et al., Polysaccharides isolated from plant cell cultures of Echinacea purpurea enhance the resistance of immunosuppressed mice against systemic infections with Candida albicans and Listeria monocytogenes, Int. J. Immunopharmacol., 15(5): 605–614 (1993)). The Echinacea plant is a popular herbal immunostimulant. The ability of Echinacea to stimulate the immune system in a nonspecific manner is exemplified in the enhancement of phagocytosis seen in cells treated with Echinacea (see, Sun et al., The American coneflower: a prophylactic role involving nonspecific immunity, J. Altern. Complement Med., 5(5): 437–446 (1999)). Echinacea 's immunomodulatory activity has been attributed to various actives, including alkylamides, phenolics, polysaccharides, alkaloids, glycoproteins, and flavonoids (see, Bauer, R. and Wagner, H., Echinacea species as potential immunostimulatory drugs, in Economic and Medicinal Plant Research, Ch. 8, p. 253, Wagner, H. and Farnsworth, N. R. (Editors), Academic Press Limited, New York, N.Y., (1991)).
Phase II enzymes are a class of enzymes that detoxify cancer-causing agents and protect cells against neoplasia and mutagenesis. Phase II enzymes are thought to act by detoxifying highly reactive intermediates of carcinogens activated by Phase I enzymes. Phase II enzymes include NAD(P)H quinone reductase (quinone reductase or QR) and glutathione S-transferases (GST). The consumption of vegetables, especially crucifers, such as broccoli (Zhang et al., A major inducer of anticarcinogenic protective enzymes from broccoli: isolation and elucidation of structure, Proc. Natl. Acad. Sci., USA., 89(6): 2399–2403 (1992)) and broccoli sprouts (Fahey, et al., Broccoli sprouts: an exceptionally rich source of inducers of enzymes that protect against chemical carcinogens, Proc. Natl. Acad. Sci. USA, 94: 10367–10372 (1997)) has been associated with the induction of phase II enzymes. Broccoli contains high levels of the compound sulforaphane which has been shown to be a potent inducer of phase II enzymes.
The ability of a compound or compounds to induce phase II enzymes can be measured by monitoring the increase in the activity of the phase II enzyme quinone reductase (QR). The induction of quinone reductase can be tested using a cell culture system similar to that developed by Prochaska et al. (Prochaska, H. J. and Santamaria, A. B., Direct Measurement of NAD(P)H:quinone reductase from cells cultured in microtiter wells: a screening assay for anticarcinogenic enzyme inducers, Anal. Biochem., 169(2): 328–336 (1988)) which is incorporated herein by reference. This system measures the elevation of quinone reductase, thus detecting the potency of the phase II enzyme inducers.
SUMMARY OF THE INVENTION
The present invention is directed to the use of Echinacea as a cancer chemopreventive agent, and more particularly to the induction of phase II enzymes by various Echinacea fractions. More specifically, the present invention relates to the use of lipid-soluble fractions isolated from Echinacea as nutritional supplements. The present invention also contemplates a novel method of extracting the desired lipid-soluble fractions from Echinacea.
The term “ Echinacea” is used to refer to any species of Echinacea. Presently preferred, however, is Echinacea purpurea which is used in the experiments described herein. Nevertheless, the contemplated scope of present invention includes any Echinacea species.
The terms “induction” and “induce” (e.g., induction of phase II enzymes) refer to an increase of the total measurable activity of an enzyme. The induction may occur at one level or multiple levels of gene expression or regulation. For example, induction may occur through increased transcription or translation which may lead to an increase in the total amount of an enzyme. Alternatively, induction may occur at the level of enzyme activity, where the total amount of protein does not change substantially, but the activity of the enzyme increases.
The terms “phase II enzyme” and “phase II enzymes” refer to a class of enzymes that are coupled with Phase I enzymes in detoxify cancer-causing agents. Examples of phase II enzymes include, but are not limited to, NAD(P)H quinone reductase (quinone reductase or QR), glutathione S-transferases, and UDP-glucuronosyltransferases.
The term “quinone reductase” refers to NAD(P)H quinone reductase and is abbreviated “QR”. These terms refer to the same enzyme and are used interchangeably.
The term “MTT” is an abbreviation for 3-(4,5-dimethylthiazo-2-yl)-2,5-diphenyltetrazolium bromide.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow chart of the extraction procedure.
FIG. 2 is a bar graph of the Quinone Reductase Activity of Echinacea purpurea Root and Aerial Fractions.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the present invention, a cancer chemopreventive agent comprising Echinacea extract is provided to induce phase II enzymes. The present invention further provides a method of inducing phase II enzymes with Echinacea fractions. The induction of phase II enzymes has extremely important implications for human health due to the activity of these enzymes in the detoxification of potential carcinogens. The detection of phase II enzyme induction is used as a method to screen for anticarcinogenic compounds.
Echinacea purpurea fractions have been found to induce the expression of phase II enzymes. Phase II enzymes are a class of enzymes that detoxify cancer-causing agents and protect cells against neoplasia and mutagenesis. Induction of phase II enzymes is correlated with cancer chemopreventive activity. The potency of a compound or compounds for induction of phase II enzymes can be quantified by measuring the increased activity of the phase II enzyme, quinone reductase.
Studies were conducted to test for the induction of a phase II enzyme by extracted fractions of Enchinacea purpurea in normal rat liver cells. The cell line used was ATCC CRL-1439, obtained from the American Type Culture Collection. The CRL-1439 cell line is generally used for in vitro studies of carcinogenesis and for screening of nutritional supplements.
A compound's ability to induce phase II enzymes in vitro is indicative of the compound's activity for the induction of such enzymes in vivo. Compounds are generally screened for anti-cancer activity in vitro by growing established cell lines in the presence of the compound to be screened.
In summary, fractions from both the roots and the aerial parts of Echinacea were tested for induction of quinone reductase, and both root fractions and aerial part fractions induced the phase II enzyme, quinone reductase. The fractions that showed the greatest induction of quinone reductase for both the roots and the aerial parts were the lipid-soluble fractions. For the roots, the fraction with the greatest induction activity was chloroform fraction ( 1 ). (See FIG. 2 ). For the aerial parts, the fraction with the greatest induction activity is acidic chloroform fraction ( 2 ). (See FIG. 2 ).
For the roots, the level of enzyme activity in the root chloroform fraction ( 1 ) was 35% higher than the root 80% methanol fraction. Likewise, for the aerial parts, the level of enzyme activity in the acidic chloroform fraction ( 2 ) was 87% higher than the more polar fraction extracted with 80% methanol. The fractions that showed the greatest induction of phase II enzymes for Echinacea were, therefore, the lipid soluble fractions.
Extraction Procedure
Generally, the extraction procedure provides a method of producing lipid-soluble solids of harvested Echinacea plant material. Echinacea plant material is chopped and dehydrated. The dehydrated plant material is then extracted with aqueous methanol, filtered, and dried to produce a dried methanol extract. At least a portion of the dried methanol extract is mixed with water to provide an aqueous suspension. The aqueous suspension is fractionated with petroleum ether to provide a petroleum ether fractionated aqueous layer and an organic petroleum ether layer. The organic petroleum ether layer is collected and dried to provide a dried petroleum ether fraction. The petroleum ether fractionated aqueous layer is further fractionated with chloroform to provide a chloroform fractionated aqueous layer and an organic chloroform layer. The organic chloroform layer is collected and dried to provide a dried chloroform fraction (chloroform fraction ( 1 ) in FIG. 2 ). The chloroform fractionated aqueous layer is then adjusted to a pH level of about pH 2 to provide a pH-adjusted chloroform fractionated aqueous layer. The pH-adjusted chloroform fractionated aqueous layer is further fractionated with chloroform to provide an acidic chloroform fractionated aqueous layer and an acidic organic chloroform layer. The acidic organic chloroform layer is collected and dried to provide a dried acidic chloroform fraction (acidic chloroform fraction ( 2 ) in FIG. 2 ). The acidic chloroform fractionated aqueous layer is further fractionated with ethyl acetate to provide an ethyl acetate fractionated aqueous layer and an organic ethyl acetate layer. The organic ethyl acetate layer is collected and dried to provide a dried ethyl acetate fraction. The ethyl acetate fractionated aqueous layer is further fractionated with butanol to provide a butanol fractionated aqueous layer and an organic butanol layer. The organic butanol layer is collected and dried to provide a dried butanol fraction.
In greater detail, the extraction procedure was carried out as follows. Whole full-bloom plants of Echinacea purpurea were manually harvested. After harvesting, the roots and the aerial parts were separated, chopped by hand, and dehydrated at 60° C. Samples were stored separately in cool, dark conditions until the extraction was carried out.
The roots and the aerial parts of the plant were separated and were kept separate throughout the extraction procedure. Therefore, each sample discussed is either a root sample or an aerial part sample, not a mixture of root and aerial parts. The same procedure, as described below and as shown in FIG. 1 , was used for the extraction and fractionation of the roots and the aerial parts of Echinacea purpurea.
Dehydrated roots or aerial parts of Echinacea purpurea were blended with a Warning commercial laboratory blender (Warning model 34BL79). 100 g of blended material then was extracted with 500 ml of 80% methanol under reflux in a water bath for 50 minutes. The extraction solution was filtered immediately. The 80% methanol extraction procedure was then repeated. The two 80% methanol root extraction solutions were combined and the two 80% methanol aerial extraction solutions were combined. Each was evaporated to dryness by a vacuum rotary evaporator at about 30° to 40° C.
The total amount of dried extract obtained from the 80% methanol extraction was approximately 11.7 g of roots and approximately 20.5 g of aerial parts. From these total amounts of dried extract, 5.8 g of the root extract and 10.3 g of the aerial part extract were used to continue the fractionation procedure. These gram amounts of extract (5.8 g of root extract and 10.3 g of aerial part extract) were designated as 100% for the purpose of calculating the percentage yield from subsequent fractionation steps.
The 5.8 g of root extract and the 10.3 g of aerial part extract were each suspended in 100 ml of water. The suspensions were fractionated, in sequence, three times with 100 ml of petroleum ether, and then three times with 100 ml of chloroform (referred to as “chloroform ( 1 )” fraction). The organic layers from the fractionations were collected and combined as described below. The aqueous layers were used for the subsequent fractionation. The three petroleum ether root fractions were combined, and the three chloroform ( 1 ) root fractions were combined. Similarly, the three petroleum ether aerial fractions were combined, and the three neutral chloroform aerial fractions were combined. The fractions were then dried over anhydrous sodium sulfate, then filtered, and evaporated to dryness. The yield from the petroleum ether fractions was 0.100 g roots (1.71%) and 0.158 g aerial parts (1.55%). The yield from the chloroform ( 1 ) fractions was 0.238 g roots (4.11%) and 0.219 g aerial parts (2.14%).
The aqueous layers of the root extract and the aerial part extract were adjusted to pH 2 with 2N HCl and were re-extracted, in sequence, three times with 100 ml of chloroform (referred to as the “acidic chloroform ( 2 )” fraction), three times with 100 ml of ethyl acetate, and three times with 100 ml of butanol. The three acidic chloroform ( 2 ) root fractions were combined, the three ethyl acetate root fractions were combined, and the three butanol root fractions were combined. Similarly, the three acidic chloroform ( 2 ) aerial fractions were combined, the three ethyl acetate aerial fractions were combined, and the three butanol aerial fractions were combined.
The collected organic layers were washed twice with water using 50 ml of water for each wash. The washed organic layers were then dried over anhydrous sodium sulfate, then filtered, and evaporated to dryness by a vacuum rotary evaporator at about 30 to 40° C. The yield from the acidic chloroform ( 2 ) fraction was 0.054 g roots (0.92%) and 0.044 g aerial parts (0.43%). The yield from the ethyl acetate fraction was 0.619 g roots (10.7%) and 0.330 g aerial parts (3.23%). The yield from the butanol fraction was 0.061 g roots (1.05%) and 0.063 g aerial parts (0.62%).
The six fractions, or test extracts, (80% methanol, petroleum ether, chloroform ( 1 ), acidic chloroform ( 2 ), ethyl acetate, and butanol) were stored in a refrigerator at approximately 4° C. until the enzyme assays were performed. The test extracts were redissolved with α-MEM prior to analysis and their concentrations were recorded in mg/ml.
Quinone Reductase Assay
The quinone reductase assay is modified from the method described by Prochaska, H. J. and Santamaria, A. B., Direct Measurement of NAD(P)H:Quinone Reductase from Cells Cultured in Microtiter Wells: A Screening Assay for Anticarcinogenic Enzyme Inducers, Analytical Biochemistry, 169: 328–336 (1988), which is incorporated herein by reference.
Generally, the assay measures quinone reductase activity in catalyzing a NADPH-dependent menadiol-mediated reduction of MTT to a blue formazan dye. Liver cells are exposed to a test extract in medium or, in the case of the controls, the cells are exposed to medium only. When the cells are subsequently broken, the quinone reductase is released. A reaction cocktail containing glucose-6-phosphate and glucose-6-phosphate dehydrogenase, which together continually generate NADPH, is added to the cell samples. Quinone reductase, which is the only rate limiting step, uses NADPH to transfer electrons to menadione converting it to menadiol. The menadiol then reduces MTT to form the blue formazan dye. This blue tint is measured at 610 nm on a Microtiterplate Reader equipped with a data processor (Model # Vmax Kinetic Microplate Reader—Molecular Devices equipped w/Softmax software).
More specifically, normal rat liver cells (ATCC CRL-1439) were cultured in a α-MEM (minimal essential medium) at 37° C. in a 6% CO 2 incubator with 98% humidity. Cells were trypsinized and plated in 96-well microtiter plates at a density of about 3000 cells per well. The cells were grown for 24 hours and were attached to the bottom of the well. The medium was changed when the test extracts were added. In the case of the controls, only medium was added. After growing for 48 hours, the medium was shaken off of the 96 well plates. Then the cells were lysed by incubation with a 0.4% digitonin solution. The reaction cocktail was then added to the cells and the blue color was allowed to develop. The reaction was arrested, and the optical density of the samples was read at 610 nm. The quinone reductase activity of the samples was calculated by dividing the optical density of the cells treated with test extracts by the optical density of the untreated cells, also known as control cells. Each concentration of extract was tested four times, so four wells were used for each concentration of extract (Note: This protocol is modified from the Prochaska et al. protocol in which cells are exposed to test compounds for 24 hours.)
The results of the quinone reductase induction experiments are shown in FIG. 2 . FIG. 2 is a bar graph that illustrates the quinone reductase induction activity of each of the six fractions for both roots and aerial parts at a set concentration of 0.09 mg/ml extract. In FIG. 2 , each data point represents the mean of 4 replications, plus or minus the standard error of the mean. At this concentration of extract, the root fraction with the greatest quinone reductase induction activity was the chloroform ( 1 ) fraction with activity at 1.86 times the level of the control. The aerial parts fraction with the greatest quinone reductase induction activity was the acidic chloroform ( 2 ) fraction with activity at 1.74 times that of control. For the roots, the level of enzyme activity in the root chloroform ( 1 ) fraction was 35% higher than the root 80% methanol fraction. Likewise, for the aerial parts, the level of enzyme activity in the acidic chloroform ( 2 ) fraction was 86% higher than the more polar fraction extracted with 80% methanol.
The fractions that showed the greatest induction of quinone reductase for both the roots and the aerial parts are lipid soluble fractions. These fractions have the greatest potency for the induction of phase II enzymes and for chemopreventive activity.
Administration of therapeutic compositions according to the present invention can be via any common route, including, for example, oral, nasal, or topical. Alternatively, administration can be by orthotopic, intradermal, subcutaneous, intramuscular, intraperitoneal or intravenous injection. Dosage forms include, but are not limited to, tablets, capsules, caplets, dietary bar, solution, suspension gel, powder, cream, transdermal patch, and implanting reservoir. Such compositions can normally be administered as nutritionally acceptable compositions that include physiologically acceptable carriers, buffers, or other excipients. Compositions for oral administration may contain acceptable carriers, for example, mannitol, lactose, starch, magnesium stearate, sodium saccharine, cellulose, magnesium carbonate, and the like.
The nutritional supplements of the present invention may be formulated using any pharmaceutically acceptable forms of the extracts discussed above, including their salts. Preferred forms include calcium carbonate, magnesium hydroxide or magnesium sulfate, sodium tetraborate, cupric oxide, manganese sulfate, zinc sulfate, cholecalciferol, ferrous fumarate, pyridoxine hydrochloride, chromium picolinate, and ascorbic acid. The dietary supplements may be formulated for mixing with consumable liquids such as milk, juice, water or consumable gels or syrups for mixing into other dietary liquids or foods. The dietary supplements of this invention may be formulated with other foods or liquids to provide premeasured supplemental foods, such as single serving bars, for example. Flavorings, binders, protein, complex carbohydrates, and the like may be added as needed.
The dietary supplements of the present invention can be formulated for once-daily administration. Alternatively, they can be formulated in multiple portions or as time release compositions for more or less frequent administration.
Although the description above contains many specifics, these should not be construed as limiting the scope of the invention, but as merely providing illustrations of some of the presently preferred embodiments of this invention. Thus the scope of this invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.
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The present invention relates to the use of Echinacea as a cancer chemopreventive agent to block the formation of and to detoxify cancer-causing agents, or carcinogens. More particularly, the present invention relates to the induction of phase II enzymes by Echinacea, and specifically by lipid-soluble fractions isolated from Echinacea. The present invention also contemplates a novel method of extracting the desired lipid-soluble fractions from Echinacea.
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FIELD OF THE INVENTION
The present invention relates to a laundry appliance such as a washing machine or washer-dryer and to a control apparatus for such a machine.
BACKGROUND OF THE INVENTION
Conventional washing machines operate by agitating textile articles within a rotating drum in the presence of water and detergent so that dirt is released from the fibres of the textile articles into the water. The agitation is caused, in the case of front-loading washing machines, by the rotation of the drum about a generally horizontal axis so that the textile articles tumble over one another and rub against each other and against the walls of the drum. However, the rotational speed of the drum is limited because, if the speed is too high, the textile articles will merely be pressed under centrifugal forces against the interior walls of the drum. The articles then rotate with the drum and no agitation with respect to the drum or with respect to other articles is achieved. The amount of agitation which can be applied to the textile articles by front-loading washing machines is therefore limited. This means that, in order to achieve a specific standard of cleanliness, the machine must operate for a minimum period of time.
International Patent Application WO99/58753 describes a washing machine in which the drum comprises two rotatable drum portions which are driven in such a way that relative rotation is produced between the drum portions. The relative rotation between the drum portions gives a more vigorous agitation of the articles within the drum, treating them more intensively than they would be in conventional apparatus and consequently dirt is released from the textile articles at a higher rate than in other machines.
SUMMARY OF THE INVENTION
The present invention seeks to provide an improved laundry apparatus.
Accordingly, a first aspect of the invention provides a laundry appliance comprising a drum for receiving articles to be laundered, the drum comprising at least two rotatable drum portions and a drive capable of operating the drum in a plurality of different drum modes, including a drum mode in which the rotatable drum portions are driven so as to cause relative rotation between the adjacent rotatable drum portions, and a controller which is capable of controlling the appliance to perform a plurality of different wash programmes, each wash programme having an associated drum mode.
This has the advantage that each wash programme uses a drum mode which is appropriate for the type of load that is to be washed during that wash programme.
Preferably, in one of the wash programmes, the controller controls the drive to operate in a drum mode in which the drum portions are not rotated relative to one another at any point during the wash programme. This has the advantage that the drum can accommodate a load of the type which would not normally be suited to this type of appliance, such as a duvet.
The portions of the drum can be rotated in opposite directions at the same or different speeds. Alternatively, each of the portions of the drum can be rotated at a different speed in the same direction.
Preferably the appliance has a control panel for allowing a user to select an intensity for the chosen wash programme, such as when clothes are more heavily or more lightly soiled than normal. The controller is arranged to vary, in use, the intensity of the wash programme in accordance with the selection made by a user. The intensity of the wash programme can be varied by varying the length of the wash portion of the wash programme, varying the ratio of time during which the drum portions are rotated relative to one another compared to the time during which the drum portions are not rotated or varying the speed of relative rotation between the drum portions. The latter two options have the advantage of allowing the wash intensity to be varied without increasing the length of the wash programme.
BRIEF DESCRIPTION OF THE DRAWINGS
A further aspect of the invention provides a control apparatus for the laundry appliance.
Embodiments of the invention will now be described with reference to the accompanying drawings, in which:
FIG. 1 is a cross-sectional view of a washing machine embodying the present invention;
FIG. 2 shows a control system for the machine of FIG. 1 ;
FIG. 3 shows one form of control panel for the, machine of FIG. 1 ;
FIGS. 4A-4C show one drum mode performed by the machine of FIG. 1 ;
FIGS. 5A-5C show another drum mode performed by the machine of FIG. 1 ;
FIGS. 6 and 7 are tables which give details of the wash programmes performed by the machine of FIG. 1 and FIG. 8 is a key for these tables.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a washing machine 10 which includes an outer casing 12 in which a stationary tub 40 is located. A drum 50 is mounted inside the tub 40 so as to be rotatable about an axis 85 . The tub 40 is watertight except for an inlet 21 and outlet 22 . The washing machine 10 includes a soap tray 20 capable of receiving detergent in a known manner. At least one water inlet 23 communicates with the soap tray 20 and is provided with suitable means for connection to a water supply within the environment in which the washing machine 10 is to be used. A conduit 21 is provided between the soap tray 20 and the tub 40 so as to allow water introduced via the inlet 23 to enter the tub 40 . The tub 40 has a sump 26 located beneath the drum 50 . A drainage pipe 28 communicates with the sump 26 and leads to a water outlet 30 via which water can be discharged from the washing machine 10 . A pump 42 is provided to allow water to be pumped from the sump 26 to the water outlet 30 at appropriate stages of the washing cycle carried out by the washing machine 10 .
The drum 50 is rotatably mounted about the axis 85 by way of a shaft 80 . The shaft 80 is mounted in a known manner, allowing the tub 40 to remain stationary whilst the drum 50 is rotatable with the shaft 80 . The shaft 80 is rotatably driven by a motor (not shown) mounted within the outer casing 12 of the washing machine 10 . A door 66 is located in the front panel 12 a of the outer casing 12 to allow access to the interior of the drum 50 . It is via the door 66 that a wash load can be deposited within the drum 50 before a wash cycle commences and removed from the drum 50 at the end of the wash cycle.
Drum 50 comprises two portions 60 , 70 which are mounted such that they can be rotated with respect to one another. A drum of this type is described more fully in International Patent Application WO99/58753. Typically the drum portions 60 , 70 are rotated in opposite directions to one another, i.e. one portion clockwise, one counter-clockwise, but they can also be rotated together in the same direction. The drum 50 is mounted in a cantilever fashion on the wall of the tub 40 remote from the door 66 . The first outer rotatable portion 60 , is supported on a hollow cylindrical shaft 81 . An angular contact bearing 82 is located between the rear wall of the tub 40 and the hollow cylindrical shaft 81 . The outer rotatable portion 60 is dimensioned so as to substantially fill the interior of the tub 40 . More specifically, the outer rotatable portion 60 has a generally circular rear wall 63 extending from the hollow cylindrical shaft 81 towards the cylindrical wall of the tub 40 , a generally cylindrical wall 61 extending generally parallel to the cylindrical walls of the tub 40 from the rear wall 63 towards the front wall of the tub 40 , and a generally annular front face 64 extending from the cylindrical wall 61 towards the door 66 . Sufficient clearance is allowed between the walls 61 , 63 , 64 of the outer rotatable portion 60 and the tub 40 to prevent the outer rotatable portion 60 from coming into contact with the tub 40 when the drum 50 is made to spin.
An inner cylindrical wall 62 is also provided on the interior of the cylindrical wall 61 of the outer rotatable portion 60 . The inner cylindrical wall 62 extends from a point which is substantially midway between the rear wall 63 and the front face 64 to the front face 565 . The space between the interior cylindrical wall 62 and the cylindrical wall 61 is hollow but, if desired, could be filled with a strengthening material. In this event, the strengthening material must be lightweight. The provision of parallel cylindrical walls 61 , 62 in the portion of the outer rotatable portion 60 closest to the front face 64 provides strength to the whole of the outer rotatable portion 60 whilst reducing the internal diameter of the outer rotatable portion 60 in this region.
The inner rotatable portion 70 is supported on a central shaft 80 , which in turn, is supported by deep groove bearings 83 located between the central shaft 80 and the hollow cylindrical shaft 81 . The inner rotatable portion 70 essentially comprises a generally circular rear wall 71 extending from the central shaft 80 towards the cylindrical wall of the tub 40 , and a cylindrical wall 74 extending from the periphery of the rear wall 71 towards the front wall of the tub 40 . The diameter of the cylindrical wall 74 of the inner rotatable portion 70 is substantially the same as the diameter of the inner cylindrical wall 62 of the outer rotatable portion 60 . The cylindrical wall 74 of the inner rotatable portion 70 is dimensioned so that its distal end approaches the end of the cylindrical wall 62 closest to it. It is advantageous to keep the gap between these two cylindrical walls 62 , 74 as small as possible. An annular sealing ring 76 is located on the cylindrical wall 61 of the outer cylindrical portion 60 immediately adjacent to the end of the inner cylindrical wall 62 closest to the inner cylindrical portion 70 so as to provide support for the distal end of the cylindrical wall 76 thereof.
FIG. 2 shows part of the control system of the machine 10 . A controller 100 operates according to a control program stored on a non-volatile memory 105 . The controller 100 is preferably implemented in the form of a microcontroller but other ways of implementing the controller, such as an implementation entirely in hardware, will be apparent to the reader and are intended to fall within the scope of this invention.
An interface 110 interfaces the controller 100 to other parts of the machine 10 . Sensors placed on the machine return signals to the interface 110 . The sensors include a water temperature sensor for monitoring temperature of the wash water in the sump of the machine 10 and a motor speed sensor. The interface 110 also outputs signals to control operation of the display 220 to display text messages and signals to control the illumination of indicator lamps 215 , 265 on the control panel 120 . Interface 110 also receives inputs from each of the control buttons 210 , 230 , 240 , 250 , 260 on the control panel 120 which allows the controller 100 to determine what button a user has pressed. The interface 110 also outputs a set of control signals 140 to control the operating state of various parts of the machine, such as the door lock, water inlet valves, and the motor M. In a well-known manner, the control software 105 controls operation of the machine according to the inputs it receives and issues outputs 140 for controlling various parts of the machine.
The speed of motor M is controlled on the basis of the monitored supply voltage and motor speed inputs to the interface and an output signal 145 to motor drive 130 . Control signal 145 controls the firing angle of the triac (or other power switching device) in the motor drive circuit 130 . Another output signal 144 controls the direction of rotation of the motor M and a further output signal 146 controls the state of the gearbox. The state of the gearbox determines whether the drum portions 60 , 70 are rotated in unison or whether they are rotated relative to one another. Motor M can be used to drive both drum portions 60 , 70 or two separate motors may be provided, one motor being used to drive each of the drum portions 60 , 70 .
FIG. 3 shows one embodiment of control panel 120 in more detail. It will be appreciated that the control panel can vary from the one shown here. For example, the control panel 120 may provide a different range of options, the type of control may vary e.g. push button, touch-sensitive control, switch, rotatable control knob or slider. Also, the range and type of visual indicators can vary, e.g. the indicators can include LEDs, an LCD or electroluminescent display.
The control panel of FIG. 3 includes an on/off button 201 to turn the mains power supply to the machine on/off; a set of control buttons 210 and associated indicators 215 for selecting the wash programme (cotton, synthetics, wool, delicates etc.); a control button 230 and an associated set of indicators for selecting the wash temperature (20-85° C.); a control button 240 and an associated set of indicators for selecting spin speed (0-1600 rpm); a control button 250 and an associated set of indicators for selecting wash intensity (light, normal, heavy); a set of control buttons 260 and an associated set of indicators 265 for selecting special features (minimum crease, pre-wash, extra rinse etc.); a plurality of memory buttons 270 , 271 , 272 for selecting a combination of stored settings; a start button 280 for starting the machine according to the settings programme by a user, and a cancel button 282 . A further indicator 283 indicates when the door 30 of the machine is locked and indicator 284 indicates when the child lock mode is active.
An LCD display 220 displays text messages at various stages during operation of the machine to help a user select programme settings and to indicate the progress of the machine through the wash cycle.
There are two basic types of drum mode: a counter-rotating mode in which the drum portions 60 , 70 are rotated relative to one another and a normal mode in which the drum portions 60 , 70 are rotated in unison in the same direction in a conventional manner.
The following table gives details of five drum modes. Each drum mode comprises a repeated sequence of four steps. For example, the ‘Counter Rotation’ operation performs: a first step which counter-rotates the drum portions 60 , 70 with respect to one another for 13 s ; a second step which rests for 6 s with no drum action; a third step which counter-rotates the drum portions 60 , 70 with respect to one another for 13 s in the opposite direction to that used in action 1 ; and a fourth step which rests for 6 s with no drum action. Clearly, any of the parameters of the drum operations defined here could be varied as appropriate.
Drum Mode
Step no.
Duration (s)
Drum speed (rpm)
Counter Rotation
1
13
52
(CR)
2
6
0
3
13
−52
4
6
0
Counter Rotation
1
10
52
Normal
2
32
0
(CRN)
3
10
−52
4
32
0
Normal Action
1
11
52
(NA)
2
5
0
3
11
−52
4
5
0
Gentle Action
1
6
52
(GA)
2
12
0
3
6
−52
4
12
0
Super Gentle Action
1
6
52
(SGA)
2
27
0
3
6
−52
4
27
0
FIGS. 4A-4C illustrate steps numbers 1 - 3 for the counter-rotating drum modes. The drum portions 50 , 60 firstly rotate in opposite directions (FIG. 4 A), then rest (FIG. 4 B), then rotate in opposite directions ( FIG. 4C ) with each drum portion 60 , 70 rotating in a different direction to that in FIG. 4 A and finally rest (not shown.) FIGS. 5A-5C illustrate actions for the normal drum modes. The drum portions 60 , 70 firstly rotate in unison in the same direction (FIG. 5 A), then rest (FIG. 5 B), then rotate in unison ( FIG. 5C ) in the opposite direction to that in FIG. 5 A and finally rest (not shown.)
In the above table, the Counter Rotations (CR) and Counter Rotation Normal (CRN) modes differ in the ratio of time when the drums are rotating (and therefore agitating the load) and when the drums are at rest. In the CR mode the drums are rotating for roughly twice the time that they are at rest whereas in the CRN mode the drums are at rest for roughly three times the time that they are rotating. Similarly, with the normal modes, the modes differ in the ratio of time when the drums are rotating (and therefore agitating the load) and when the drums are at rest. While the modes detailed above all operate at the same drum speed of 52 rpm it is possible to vary the drum speed between modes to vary the amount of agitation that these modes provide.
FIGS. 6 and 7 are tables which give full details of a set of wash programmes performed by the machine 10 and FIG. 8 is a key for these tables. A complete wash cycle comprises the following stages: prewash (if the user has selected this), main wash, rinse, final rinse and final spin. Each of these stages comprises a number of steps. During each step the machine operates with a combination of an amount of water, a water temperature and a drum mode 400 detailed in the tables. As is well-known with conventional wash programmes, the water temperature that is used during the wash programme varies according to the type of fabric being washed, with robust fabrics such as cotton being washed at a higher temperature than delicates.
During the stages of the wash cycle, and particularly during the main wash (see “Main Wash” step no. 3 , FIG. 6 ) the machine operates with a drum mode which is dependent on the wash programme. The most robust fabric types such as cottons, synthetics and dedicates use the CR drum mode (long burst of counter-rotation followed by a short rest); wool and care+ use the CRN drum mode (short burst of counter-rotation followed by a long rest) and the duvet programme does not use counter-rotation at all, since the load comprises one large article which is expected to fill the drum, conditions which are not suited to the use of a counter-rotating drum mode. The length of the wash step (see “Main Wash” step no. 3 , FIG. 6 ) varies according to the amount of soiling of the articles in the wash load: 4 minutes for light soiling, 6 minutes for normal soiling and 10 minutes for heavy soiling. A user selects the intensity of the wash via control 250 on the control panel 120 . However, as an alternative to varying the length of time for the wash step, the controller can vary the amount of agitation by varying the drum mode. Increased agitation can be provided by using a drum mode which rotates the drum portions 60 , 70 at a higher speed relative to one another or with a longer ratio of rotation time to rest time.
Variations to the described embodiments are intended to fall within the scope of the present invention. While five drum modes are described here, it is possible to provide more modes which vary in the amount of agitation they apply to the wash load. The modes can vary in the ratio of rotating time to rest time and/or speed of rotation. The drum 50 can comprise more than just the two rotatable portions 60 , 70 . Three or more separately rotatable portions can be provided, all lying alongside one another along the axis of rotation.
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A laundry appliance comprises a drum for receiving articles to be laundered, the drum comprising at least two rotatable drum portions and a drive capable of operating the drum in a plurality of different drum modes. The drum modes include a mode in which the rotatable drum portions are driven so as to cause relative rotation between them. A controller ( 100 ) controls the appliance to perform a plurality of different wash programs, each wash program having an associated drum mode. Each wash program comprises a sequence of stages, with a drum mode being associated with each stage. The drum modes can differ in respect of (a) use (or non-use) of relative rotation between the drum portions (b) the ratio of time that the drum portions rotate compared to the time that they are at rest, and (c) the speed at which the drum portions are rotated. The intensity of a wash program can be varied, inter alia, by varying the length of the wash stage.
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BACKGROUND INFORMATION
[0001] 1. Field of the Invention
[0002] The field of the invention relates to gutters on residential and commercial buildings. More particularly, the invention relates to a retractable gutter.
[0003] 2. Discussion of the Prior Art
[0004] Gutters are typically attached to the fascia under the eaves of a structure, to collect rainwater that drains from the roof. The fascia is a trim board that is fixed vertically on edge to the rafter ends or wall which conventionally carries the gutter around the eaves of the roof. In many regions that experience cold winters, snow falls on the roof of the structure and eventually melts, either due to heat loss through the roof, rain, or an ambient temperature that is above freezing. The melting snow water runs to the eaves and then into the gutter. The eave, however, is colder than the roof, so, as the water reaches the gutter, it begins to freeze. The gutter then fills up with ice and may eventually cause an ice dam to form under the eave, which may then cause water to run back up under the shingles, resulting in damage to the structure because of water leaking into the interior of the structure.
[0005] Tree debris is another source of failure of the conventional gutter system. Leaves and needles from trees often end up in gutters, carried there by wind and rain. This debris can plug up the entry to the downspout, and, as a result, force water to leak back into the facia area of the roof.
[0006] FIG. 1 (prior art) illustrates the problem with the conventional gutter system resulting from a plugged gutter.
[0007] What is needed therefore is a gutter system that can quickly and easily be moved away from the normal functional position to a protected position, so as to protect the gutter from ice build-up and/or tree debris.
BRIEF SUMMARY OF THE INVENTION
[0008] The invention is a retractable gutter system that includes a retractable support means that is mounted under the eaves of a structure and a gutter mounted on the retractable support means. In its gutter functional position, the retractable support means is pulled out, so that rainwater drains from the roof into the gutter. In regions that experience cold winters or in locations in which tree debris is copious at certain times of the year, it is desirable to avoid the build-up of ice and/or tree debris in the gutter. To that end, the retractable support means is constructed to be movable between a stowed position and its functional position, so that the gutter may be pushed in under the eaves in times of freezing temperatures or tree debris. On residential structures, the eaves overhang, i.e., the distance from the drip edge of the eaves to the outer surface of the wall, is typically 12 inches. The bottom face of this overhang is typically covered with a board, referred to as the soffit. The telescoping slides are not fastened to the fascia, but rather, are either mounted on cross brackets that are fastened to the soffit, or are fastened to the soffit directly.
[0009] During the spring and summer, the gutter is pulled out, so as to catch rainwater as it runs from the roof. In the fall, when leaves are coming down, and in the months when the temperature is frequently below freezing, the retractable support means may be pushed in to the stowed position, so that the gutter is under the eaves and, thus, protected from debris and ice.
[0010] The downspout on a gutter system includes a gutter downspout and a structure downspout. The gutter downspout is attached to the gutter and, in the conventional gutter system, is fitted into the top of the structure downspout from above. In the retractable gutter system according to the invention, the structure downspout has a cut-out at the top, on the wall that faces the structure. This allows the gutter downspout, when the gutter is pulled out to its functional position, to slide into the upper end of the structure downspout, so as to provide an enclosed conduit for the water to drain from the gutter into the spout.
[0011] The retractable gutter system according to the invention is adaptable to various types of structures. The gutters may be constructed of vinyl or metal gutter section, or be seamless metal lengths.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. The drawings are not drawn to scale.
[0013] FIG. 1 illustrates a conventional gutter system (prior art).
[0014] FIG. 2 illustrates the retractable gutter system according to the invention.
[0015] FIG. 3 illustrates the gutter of FIG. 2 mounted on the retractable slide and pulled out to the drip edge of the fascia.
[0016] FIG. 3A illustrates a second means of mounting the gutter to the extension slide.
[0017] FIG. 4 illustrates the gutter of FIG. 2 , mounted on the eaves of a structure and retracted.
[0018] FIG. 5 shows a structure downspout with a cut-out.
[0019] FIG. 6 illustrates how the gutter downspout fits into the structure downspout.
[0020] FIG. 7 illustrates the mounting means for an open-style eave.
[0021] FIG. 7A shows a wall-mounting bracket.
[0022] FIG. 8 illustrates a long-handled tool for manipulating the retractable gutter system.
[0023] FIG. 9 illustrates a modified downspout.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The present invention will now be described more fully in detail with reference to the accompanying drawings, in which the preferred embodiments of the invention are shown. This invention should not, however, be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be complete and will fully convey the scope of the invention to those skilled in the art.
[0025] FIG. 1 illustrates a conventional gutter system. Snow is lying on the roof and the gutter is clogged with debris and/or ice. As a result, an ice dam has formed at the drip edge, which is forcing water back up under the roof shingles and into the interior of the structure.
[0026] Note: The reference designation D shown in the figures shall refer to debris, which term shall encompass leaves, ice, and any other matter that may clog a gutter.
[0027] FIG. 2 illustrates a retractable gutter system 100 according to the invention that is in its functional position. The figure is a top plan view of the system attached to a soffit S. For illustration purposes, roof shingles and fascia that are part of a roof system are not shown. The soffit S is the board that forms the underside of the eaves E, as shown in FIGS. 1 and 3 . The retractable gutter system 100 comprises a gutter 10 , at least two retractable slides 20 , mounting means 30 , and a downspout 40 . Any conventional gutter may be used. The retractable slides 20 may be any type of telescoping slide or bracket that is suitable for this purpose. Drawer runner hardware is quite suitable, because the ball bearings in the runners ensure smooth motion. An example of suitable hardware are the Ball Bearing Side-Mount Drawer Slides Do-It-Yourself D806, made by Liberty Hardware Manufacturing Corp. Ideally, the retractable slide 20 is made of a metal or alloy that does not rust readily.
[0028] In the embodiment shown in FIG. 3 , the gutter 10 is attached to the extension slide 20 C of the retractable slide 20 by a gutter-fastening means 22 , which, in this embodiment is a bolt that passes through a hole in the retractable slide 20 and through the bottom of the gutter 10 and is secured with a rubber washer and a nut. Other means of attaching the gutter 10 to the slide 20 are within the scope of the invention. For example, FIG. 3A illustrates a second embodiment, in which a brace 24 that is dimensioned to extend approximately the largest cross-sectional dimension transverse to axial direction of the gutter trough is attached to the underside of the extension slide 20 C by means of the gutter fastening means 22 , which is now a shortened bolt that passes through the slide 20 and the brace 24 , but not through the bottom of the gutter 10 . Fastening means 26 fasten the brace 24 to the front and rear walls of the gutter 10 . The fastening means 26 may be screws, wing nuts, pins, or other suitable means. A particularly suitable material for the brace 24 is ultra high molecular weight polyethylene (UHMW PE), because it will not change dimensions to any significant extent as a function of temperature and humidity and is very rugged. Other suitable materials, however, may also be used.
[0029] FIGS. 2 , 3 , and 3 A illustrate the mounting means 30 . There are various suitable mounting means 30 and the following descriptions are not intended to be limiting. In the embodiment shown in these figures, the mounting means 30 includes at least two cross brackets 34 that extend the length of the eaves E that is to be fitted with the retractable gutter system 100 . A front cross bracket 34 A is affixed to the soffit S at a position closer to the structure and a rear cross bracket 34 B affixed to the soffit closer to the fascia F. The cross brackets 34 may be provided as wooden or metal straps, but preferably, UHMW PE straps are used. In the embodiment shown, two cross brackets 34 are fastened through the soffit S to the rafters R. A rafter R is shown in dashed lines in FIG. 3A . The retractable slides 20 has a slide retainer 20 A and an extension slide 20 C captured in the slide retainer 20 A, as shown in FIG. 2 . The slide retainer 20 A has a distal end that is mounted to the cross bracket 34 A closer to the structure wall and a proximal end that is mounted to the cross bracket 34 B closer to the fascia F. The retractable gutter system 100 is shown truncated, but it is understood that the gutter 10 extends the entire length of the eaves E and that a plurality of retractable slides 20 may used with the retractable gutter system 100 , sufficient in number and evenly spaced apart to ensure a substantially even sliding motion of the entire length of gutter 10 . An even sliding motion is particularly important if the gutter 10 along a single run is constructed in sections, as any “snaking” along the length of the gutter 10 may cause seams to open. For this reason, seamless gutters are preferred, as a long single gutter can withstand some snaking, without damaging the gutter.
[0030] Another example of the mounting means 30 includes the front cross-bracket 34 B mounted to the soffit S closer to the fascia edge F of the eaves E. At each location where the retractable slide 20 is to be mounted, a transverse bracket that extends generally transverse to the axial direction of the front cross bracket 34 B is affixed at a first end to the front cross bracket 34 B and at a second end to the wall W. This mounting means 30 provides support for the retractable slide 20 from front to back and facilitates adjusting the position of the retractable slide 20 so that the gutter 10 is positioned directly under the drip edge of the eaves E. This particular mounting means 30 is not shown, but it is understood that a person of ordinary skill in the art will know how to place and secure the transverse brackets.
[0031] FIG. 4 illustrates the retractable gutter system 100 , retracted under the eaves E. FIGS. 4 and 5 illustrate details of the downspout 40 , which includes a gutter downspout 42 and a structure downspout 44 . A rear wall 44 A in the structure downspout 44 has a cut-out 44 B, that is dimensioned to receive the gutter downspout 42 . FIG. 6 is a plan view of the downspout 40 , viewed from the wall of the structure, showing how the gutter downspout 42 fits into the structure downspout 44 when the retractable gutter system 100 is extended out to its functional position.
[0032] Gutters are installed with a slope toward the downspout end of the gutter, to ensure proper drainage of water from the gutter. The retractable gutter system 100 according to the invention is mounted to the soffit S, which provides a horizontal plane, so the retractable gutter system requires some means to ensure the slope of the gutter. To maintain the desired slope, spacers or washers are used when mounting the retractable slides 20 to the soffit S. For example, assuming the retractable slides 20 are mounted to the soffit S spaced five feet apart, then a series of spacers with increasing thicknesses may be used to provide the desired slope. At the end opposite the downspout end, at the first retractable slide 20 , no spacer is used, but then, at every mounting point toward the downspout end, a spacer with a slightly greater thickness is used, thereby achieving the desired slope of the gutter 10 . The spacers may be provided with increasing thickness, or multiple spacers may be used to achieve the desired thickness. A suggested increment in thickness is ⅛-inch. Over a 40-foot span, spacers ranging from ⅛-inch to 1-inch may be used to achieve a ¼-inch drop per every ten feet of span. As with the cross brackets 34 , the spacers may be stamped from UHMW PE. Metal washers or spacers made of other materials may also be suitable for this purpose.
[0033] FIG. 7 illustrates a suitable mounting means 30 for an eaves that does not have a soffit. A cross bracket 34 is attached close to the leading edge of the eaves and wall-mounting brackets 36 are fastened to the outer wall at spaced intervals. The distal end 20 B of the slide 20 is supported by the wall-mounting bracket 36 and a proximal end 20 A of the retractable slide 20 , shown in FIG. 2 , is then fastened to the cross bracket 34 and. The wall-mounting bracket 36 may be any suitable means to affix the distal end of 20 B of the retractable slide 20 to the wall of the structure. FIG. 7A is an enlarged view of a simple bracket 36 that provides sufficient support to hold the retractable slide 20 firmly in place. The bracket 36 is, for example, stamped or machined from a piece of UHMW PE, having two through-bores 36 A for mounting fasteners and a retainer bore 36 B that is dimensioned to receive the distal end of the retractable slide 20 . The distal end 20 B is inserted into the retainer bore 36 B and the proximal end 20 A of the slide 20 then mounted to the cross bracket 34 . Although the inventor has used UHMW PE for this bracket 36 , because of the ability of the dense material to hold a threaded fastener, it is understood that other materials and other types of brackets may be used for the wall-mounting bracket 36 .
[0034] FIG. 8 illustrates a device 200 for manipulating the retractable gutter system 100 . The device 200 has a handle 210 and, at its upper end, a C-shaped bracket 220 for engaging the body of the gutter 10 , when retracting the retractable gutter system and a hook 230 for engaging an upper edge of the gutter 10 when pulling the retractable gutter system to its functional position. The handle 210 may have extensions, to obtain the necessary height to engage the gutter 10 and move it between the protected and the functional positions.
[0035] The retractable gutter system 100 according to the invention will typically extend across a long expanse on a face of a structure, 20, 30, 40 feet or more. To ensure that the retractable gutter system 100 operates smoothly and easily, the retractable slides 20 are mounted on the cross brackets 34 at suitable distances apart, for example, every five feet or so. When a seamed gutter system is used, the inventor suggests strengthening the span of the gutter, to prevent cracks and, thus, leaks, from forming at the seams. One way to do this is to provide a reinforcing strip along the gutter 10 , to ensure that the various segments of the gutter remain aligned when the gutter is being deployed or stowed away. For example, a one-inch strip of perforated steel may be affixed to the gutter 10 , extending in the longitudinal direction of the gutter 10 , to provide the desired stiffness. Another method is to reinforce the joints between gutters with fiberglass. This misalignment when extending/retracting the retractable gutter system is not a concern with seamless gutters, because there are no seams that will open up if the length of gutter span “snakes” a bit.
[0036] FIG. 9 illustrates a modified downspout 50 . It may be desirable to prevent snow, ice, debris from collecting in the upper part of the structure downspout 44 described above. The modified downspout 50 includes a structure downspout 54 , a gutter downspout 52 , and an extension trough 55 . The structure downspout 54 has shortened upper end 54 A that extends at an angle from the wall of the structure, whereby the end of the upper end 54 A is still under the eaves E. The gutter downspout 52 has a lower end 52 A that is angled toward the wall of the structure. The extension trough 55 is adjustable in length and connects the lower end 52 A of the gutter downspout 52 to the upper end 54 A of the structure downspout 54 , to provide a continuous trough to guide water from the gutter 10 into the structure downspout 54 . The extension trough 55 has a first rough section 55 A that is affixed to the gutter downspout 52 and a second trough section affixed to the structure downspout 54 . The first and second trough sections 55 A and 55 B are dimensioned such, that the free end of the first section is slidably held in the free end of the second section. When the gutter 10 is moved to the stowed position, the first section 55 A slides into the second section 55 B of the extension trough, so that the entire downspout system is now under the eaves E. When the gutter 10 is moved to its functional position, the extension trough 55 slidably accommodates the greater distance between the gutter 10 and the structure downspout 54 . The lengths of the first and second trough sections 55 A, 55 B are variable and are dictated by the specific depth dimension of the eaves E.
[0037] As a safety measure, a tether means may be provided to securely connect the gutter to the structure. It is conceivable that a gutter filled with leaves, ice, or snow could become so heavy, that its weight exceeds the weight limit to be supported by the gutter fastening means 22 that connects the gutter 10 to the slides 20 . The risk is such a situation is that the gutter 10 could inadvertently detach from the retractable slides 20 . If that were to happen, the gutter 10 could drop away from the retractable gutter system, which could result in damage to the gutter, to the structure, and/or to something that the gutter drops onto. To reduce this risk, the tether means is constructed to prevent the gutter from dropping away into a free fall. The tether means includes a cable that is attached at one end to the structure and at the other end to the gutter. One or more of such cables may be attached to a length of gutter.
[0038] It is understood that the embodiments described herein are merely illustrative of the present invention. Variations in the construction of the retractable gutter system may be contemplated by one skilled in the art without limiting the intended scope of the invention herein disclosed and as defined by the following claims.
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The invention is a retractable gutter system that allows the gutter to be moved under the eaves in climates that are typically below freezing, to prevent an ice dam from forming under the eaves, and at times when leaf debris risks clogging the gutter. Slide retainers are affixed to the soffit and the gutter affixed to the extendible slides held in the slide retainers. The gutter is slidable between a first position in which the gutter is placed at the drip edge and a second position in which the gutter is stowed away under the eaves.
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FIELD OF THE INVENTION
The present invention relates to a graft capable of replacing a blocked, occluded or damaged portion of a small diameter artery and more particularly, to a small bore biologic graft with a therapeutic drug delivery system that give it an improved resistance to occlusion by platelets, thrombi or smooth muscle cell proliferation. Still more particularly, the present invention relates to a two-part graft comprising an inner vessel and an outer sleeve and a drug delivery composition in the annulus therebetween.
BACKGROUND OF THE INVENTION
Coronary artery bypass graft (CABG) surgery is a surgical procedure intended to restore blood flow to ischemic heart muscle whose blood supply has been compromised by occlusion or stenosis of one or more of the coronary arteries. One method for performing CABG surgery entails using a length of graft material to bypass the blockage or narrowing. The graft is typically an autologous graft, such as a portion of the saphenous vein or internal mammary artery, or a synthetic graft, such as one made of Dacron or Gore-Tex tubing.
Atherosclerosis is the major disease that affects the blood vessels. This disease may have its beginnings early in life and is first noted as a thickening of the arterial walls. This thickening is an accumulation of fat, fibrin, cellular debris and calcium. The resultant narrowing of the lumen of the vessel is called stenosis. Vessel stenosis impedes and reduces blood flow. Hypertension and dysfunction of the organ or area of the body that suffers the impaired blood flow can result. As the buildup on the inner wall of a vessel thickens, the vessel wall loses the ability to expand and contract. Also, the vessel loses its viability and becomes weakened and susceptible to bulging, also known as aneurysm. In the presence of hypertension or elevated blood pressure, aneurysms will frequently dissect and ultimately rupture.
Small vessels, such as the arteries that supply blood to the heart, legs, intestines and other areas of the body, are particularly susceptible to atherosclerotic narrowing. When an artery in the leg or intestine is affected, the resultant loss of blood supply to the leg or segment of the intestine may result in gangrene. Atherosclerotic narrowing of one or more of the coronary arteries limits and in some instances prevents blood flow to portions of the heart muscle. Depending upon the severity of the occlusion and its location within the coronary circulation system, pain, cardiac dysfunction or death may result.
It is preferable to correct aneurysms and stenosis of major arteries using plastic reconstruction that does not require any synthetic graft or patch materials. However, if the disease is extensive and the vessel is no longer reliable, the blocked or weakened portion is usually replaced with a graft. In such case, the involved vessel section is transected and removed and a synthetic patch, conduit or graft is sewn into place.
Patients with coronary artery disease, in which blood flow to part of the heart muscle has been compromised, receive significant benefit from CABG surgery. Because the coronary arteries are relatively small, CABG surgery requires the use of small diameter grafts, typically less than 3-5 mm in diameter. Because they cause more problems than biologic grafts, as discussed below, synthetic grafts are used in CABG surgery only on infrequent occasions. Thus, in a patient who undergoes coronary artery bypass surgery, a non-critical artery or vein of small diameter is harvested from elsewhere in the body and sewn into place in a manner that reestablishes flow to the area of the heart that earlier lost its blood supply because of atherosclerotic blockage. This is referred to as an autograft. When no suitable artery or vein can be harvested from the patient, an allograft (from the same species) or xenograft (from another species) vessel may be employed. However, experience with allografts and xenografts is limited and not typically satisfactory.
In CABG cases where an autograft is available, the saphenous vein (SV) in the leg and the internal mammary artery (IMA) are the vessels most commonly harvested for use as a bypass graft. It has been found that most saphenous vein bypass grafts, in time, exhibit a narrowing of the lumen that is different from atherosclerosis. It is believed this is a pathologic response of the vein because it is of different cellular construction and composition than an artery, thus making it unsuitable for use as an artery. Current estimates of the life expectancy of saphenous vein bypass grafts do not exceed 7 years. In addition, harvesting a saphenous vein autograft is a tedious surgical task and not always rewarded with the best quality graft. Further, removal of the saphenous vein disrupts the natural venous blood return from the leg and is not therapeutically recommended except for certain cases, such as in a patient with advanced venous disease. Finally, harvesting an autograft in the operating room requires additional surgical time and expense.
While the patency rate is better when the internal mammary artery is used, use of the internal mammary artery as autograft material may lead to sternal nonunion and mediastinitis. Furthermore, if multiple bypasses are indicated, the internal mammary artery may not provide sufficient graft material.
Hence, there is a desire to provide a small bore synthetic graft material for coronary artery bypass. Clinical experience with small diameter synthetic grafts for coronary artery bypass dates back to the mid 1970's, with limited success. When a synthetic vascular prosthesis (graft) is implanted, the fine pores of the vessel are clogged by clotted blood, and the inside surface of the vessel is covered by a layer of the clotted blood. The clotted blood layer is composed largely of fibrin, and the thickness of the fibrin layer varies, depending on the material and surface structure of the blood vessel. When a knitted or woven fabric such as polyester or polytetrafluoroethylene (PTFE) is used, the fibrin thickness typically approaches about 0.5 to about 1 mm. Also, overproliferation of smooth muscle cells (SMC) as part of the natural repair process may contribute to luminal occlusion. Despite the different methods and techniques of graft construction however, such as woven or knit, velour, texturized or nontexturized, tight or loose, fine or coarse, expanded or non-expanded, variations in fiber diameter and wall thickness, etc., no graft of small lumen diameter has shown a satisfactory resistance to blockage resulting from fibrin deposition and cellular adhesion. It is believed that the tendency of synthetic grafts to become occluded is due in part to the thrombogenic nature of the nude, i.e., nonendothelialized, surface of the implanted prostheses. Furthermore, in instances where the vessel, and hence the replacement graft, are of small diameter, handling and surgical placement of the graft is difficult. Thus, the internal diameter may be compromised due either to surgical technique or biological response. In some cases, the graft may become entirely occluded shortly after surgery.
Accordingly, synthetic vascular grafts are successful only with blood vessels having a large enough inside diameter that occlusion due to cell growth on the inner surface does not occur. This typically requires arteries having an inside diameter of 5 to 6 mm or more. Generally, vascular prostheses made of woven or knitted fabrics are not successful when the inside diameter is less than approximately 5 mm, and particularly not when the inside diameter is less than 4 mm.
Hence, it is desired to provide a small bore biologic graft that resists blocking due to fibrin deposition and cellular adhesion. The desired graft must be readily available, easily manipulated by the surgeon and effective at containing blood flowing through it.
BRIEF SUMMARY OF THE INVENTION
The present invention is a synthetic vascular graft that is particularly suited for use in small bore applications. The graft of the present invention comprises a biologic graft vessel comprising cross-linked collagen, surrounded by a structural sleeve comprising synthetic fiber. According to the present invention, an amount of an occlusion-preventing agent is positioned in the annulus between the graft and the sleeve. The occlusion-preventing agent preferably comprises a drug or combination of drugs that reduce thrombosis, help prevent intimal hyperplasia and help prevent smooth muscle cell proliferation. The occlusion-preventing agent is preferably carried in a time-release vehicle. The time-release vehicle is adjacent the outer surface of the biologic vessel and can be carried in either a viscous carrier medium, on a sleeve coating, or forming part of the sleeve material itself.
The components of the present graft are implanted sequentially in a series of steps that produce the fully assembled graft. After one end of the biologic graft vessel is attached to the first bypass point, the sleeve is placed over it and the second end of the biologic graft vessel is attached to the second bypass point. Both ends of the structural sleeve are sutured to the organ supporting the graft adjacent the anastomoses of the biologic graft vessel. The mixture containing the bioactive compound(s) is provided in a time-release mechanism, such as polymeric microspheres, and is injected through the sleeve into the annulus between the sleeve and the vessel.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more detailed description of the present invention, reference will now be made to the accompanying Figures, wherein:
FIG. 1 is a drawing of a human heart showing the relative sizes of the various arteries;
FIG. 2 shows the biologic graft vessel and the sleeve of the present invention, prior to anastomosis of the second end of the vessel to the bypassed vessel; and
FIG. 3 shows the injection of the bioactive compound(s) into the sleeve of the present invention following attachment of the biologic graft vessel and the sleeve to the bypassed vessel.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring initially to FIG. 1, it can be seen that the coronary arteries are relatively small in size and lie along the surface of the heart. The coronary arteries provide the heart muscle with oxygen and nutrients. Thus, any occlusion or dysfunction of the coronary arteries can detrimentally affect the functioning of the heart. Depending upon the severity of the occlusion and its location within the coronary circulation system, pain, cardiac dysfunction or death may result.
Referring now to FIG. 2, a small bore composite graft 10 constructed in accordance with the present invention comprises an inner vascular graft 12 , around which is an outer sleeve 14 . Between vascular graft 10 and sleeve 14 is a narrow annulus 16 , which is filled with a bioactive compound following anastomosis, according to a preferred embodiment described below. According to the present invention, the bioactive compound is preferably carried in a timerelease vehicle, and can, in various embodiments, be coated on the inside of the sleeve or incorporated into the sleeve material itself.
According to a preferred embodiment, vascular graft 12 comprises a crosslinked, non-synthetic collagenic vessel. An example of a preferred vascular graft 12 is an ovine carotid artery that has been stabilized so as to resist enzymatic degradation following implantation. Vessels having any suitable diameter can be used, however, the present technique is particularly advantageous in that it eliminates the problems typically associated with very small diameter grafts, such as those having diameters less than 5 mm, and more particularly less than 4 mm.
According to a preferred technique, cross-linked, biologic, collagenic vessels are prepared using the following steps: a vessel is harvested, collected into neutral buffer, dissected from adjacent tissue, dipped in a high osmolarity (HO) solution so as to remove the cellular contents by osmotic pressure, placed in an HO solution with a photoreactive catalyst, and exposed to light from a light source while being washed with a solution of photoreactive catalyst. The exposure to light is preferably carried out at reduced temperature (10° C.) and preferably lasts about two days. Following treatment in this manner, the vessel is preferably placed in a de-staining solution (50% EtOH). This series of steps causes the collagen to become cross-linked and chemically modified. Collagen that is prepared in this manner is stabilized against enzymatic degradation and thus is better suited for implantation in living body. A more detailed discussion of the photofixing process can be found in U.S. Pat. Nos. 5,147,514 and 5,332,475, which are incorporated herein by reference in their entireties. While other techniques for cross-linking and chemically modifying collagen are known, photofixing is preferred because it renders the collagen sufficiently resistant to degradation by the host, without increasing the stiffness of the tissue to an unacceptable level.
Following the stabilization process; if the tissue is vascular, its branches are sutured shut, and it is leak tested, packaged and sterilized. For CAB surgery, the preferred graft will have an inside diameter of approximately 3-5 mm and a length of at least approximately 15 cm. Other possible sources for vascular graft 12 include the carotid artery of ostriches and cows. In addition, it will be understood by those skilled in the art that other sources of collagenic tissue can be used. For example, the bovine or porcine pericardium can be stabilized in the manner described above, formed into a tubular vessel and used as vascular graft 12 .
Sleeve 14 preferably comprises a knitted, ribbed polyester sleeve having an inside diameter slightly larger than the outside diameter of vascular graft 12 , such as are generally commercially available. For the preferred vessel described above the sleeve has an inside diameter of approximately 6-8 mm. The preferred sleeve is a knitted, ribbed polyester material having a pore size smaller than the diameter of the desired microspheres (described below). Material having the desired characteristics is available from Sulzer Vascutek, of Renfrewshire, Scotland. It will be understood that other materials and configurations for sleeve 14 , both synthetic and of natural origin, can be used in place of the knitted, ribbed polyester sleeve and are within the scope of the invention.
The graft 10 of the present invention further includes an amount of a bioactive compound(s) contained in a time-release mechanism. The bioactive compound may be a compound having any desired bioactivity, including antithrombotic, antibiotic, and/or antiproliferative properties. The time-release mechanism may be of any type sufficient to slowly release the bioactive compound(s), such as the ethylene vinyl acetate system described in Edelman et al., “Effect of controlled adventitial heparin delivery on smooth muscle cell proliferation following endothelial injury”, Vol. 87, pp. 3773-3777, May 1990. In one preferred embodiment, the bioactive compound is mixed into a resorbable polymer, which is formed into microspheres. The microspheres in turn are carried in a carrier 30 . Thus, an example of one preferred form of bioactive material comprises heparin-loaded poly lactic-co-glycolic acid 75:25 (PLGA) polymer microspheres having an average diameter of approximately between 0.5 μm and 2.5 μm. Heparin is both a potent anticoagulant and an inhibitor of smooth muscle cell proliferation. Other suitable occlusion-preventing agents, such as warfarin and protamine sulfate, could be used in place of heparin. Alternatively, separate drugs could be used to provide the desired anticoagulant and cell growth inhibitive properties. Identification of suitable occlusion-preventing agents is within the ability of those skilled in the art. Similarly, other resorbable polymers, such as poly-caprolactone, polydioxanone and polyanhydride could be used in place of the PLGA, so long as they are capable of retaining and gradually releasing the occlusion-preventing agent and do not interfere with its effectiveness.
One technique for forming the preferred heparin-loaded PLGA microspheres is spray drying. This entails dissolving the heparin in water, and dissolving the PLGA in a suitable solvent, such as ethyl formate. The heparin and PLGA solutions are then sonicated to emulsify them and pumped into a spray dryer. This produces microspheres of a suitable size. The microspheres loaded with heparin agent are preferably sterilized using any suitable conventional sterilization technique. Spray drying is preferred because the concentration of heparin in the microspheres can be controlled. Microspheres containing other bioactive agents can be formed in this manner, or by any other technique that produces the desired time-release effect. The period over which the bioactive compound is released from the time-release mechanism is preferably varied by varying the composition of the polymer in which the bioactive compound is dispersed.
The occlusion-preventing agent of the present invention need not be carried on microspheres, but can instead be carried on a time-release vehicle having any other suitable configuration including, but not limited to particles, film and fibers. Likewise, the time-release vehicle can be incorporated into the fiber(s) forming the sleeve itself.
A preferred fluid carrier for the microspheres preferably comprises a solution of polyvinylpyrrolidone (PVP) in water. The PVP solution effectively manages the static charge associated with dry PLGA microspheres. The carrier must be thin enough to allow it to flow into and fill annulus 16 , yet viscous enough to be easily emplaced and to remain in the annulus during the suturing of opening 15 . A slightly viscous carrier is also less likely to seep out of annulus 16 through the pores of the sleeve or any small opening that may remain between vascular graft 12 or sleeve 14 and the organ itself. PVP is used in one preferred embodiment because it is biologically inactive, successfully wets microspheres made of PLGA (necessary for dissolution of the heparin), does not dissolve the microspheres, and does not adversely affect the performance of the heparin. Other suitable carriers include, but are not limited to, solutions of glycerol and solutions of Pluronic®. The carrier is preferably steam sterilized.
When it is desired to replace a portion of a coronary artery or other vessel with the biologic graft of the present invention, the preferred microspheres are mixed with the preferred carrier and the vascular graft 12 is soaked in an anticoagulant solution prior to commencing the bypass surgery.
One common CABG bypass technique involves using the graft material to bypass an occluded portion of a coronary artery as shown in FIGS. 2 and 3. This technique uses end-to-side anastomoses, in which the end of the graft is connected to the side of the host vessel(s). The steps for surgically implanting the small bore graft 10 of the present invention according to this technique are as follows:
a plug is removed from the host vessel(s) at each of the two bypass connection points 23 , 25 (located on aorta 22 and a coronary artery 24 , respectively, in this embodiment);
one end of the vascular graft 12 is sutured to the proximal bypass connection point 23 ; sleeve 14 is placed over the vascular graft 12 ;
the free end of vascular graft 12 is sutured to the distal bypass connection point 25 ;
the sleeve ends are sutured over the graft anastomoses;
sleeve 14 is nicked as at 15 (FIG. 3 );
a preselected amount of the microsphere/carrier mixture is injected into the space between the vascular graft and the sleeve, using a suitable injector 30 ; and
the nick in the sleeve is sutured closed.
Another preferred technique includes the application of the bioactive compound (in a suitable time release mechanism) to the interior surface of the sleeve 14 prior to packaging of sleeve 14 . An advantage of this technique is that the separate step of emplacing the bioactive compound in the annulus can be eliminated.
An alternative, similar technique (not illustrated) uses end-to-end anastomoses and includes removal of the bypassed portion of the original vessel.
EXAMPLE
In an illustrative procedure, the foregoing process and preferred components were used in a canine coronary lab bypass model. A mass of 0.8-1.0 grams per 10 cm of vascular graft length were used. The microspheres were PLGA 75:25 spray dried with 2-2.5 wt. % heparin. The vascular graft was soaked in 0.9% saline/10,000 U/ml heparin for 15 minutes prior to implantation. The microsphere/carrier mixture was injected using a 5 cc syringe. Three out of four grafts implanted according to this procedure had not failed or become inoperable due to occlusion after 270 days. It is believed that after approximately two months sufficient endothelialization has occurred at the anastomoses to inhibit thrombosis and SMC proliferation, even following depletion of the occlusion-preventing agent. The endothelial layer secretes nitrous oxide (NO) and prostacyclin, among other things.
The rate of release of the anti-coagulant and cell growth inhibitor was measured in vitro in a laboratory setup designed to simulate an in vivo application. Measurements taken in this apparatus showed that the composite graft described above released heparin in an initial burst of 15%, followed by approximately 1.5%/day for approximately 60 days.
By using a biologic graft vessel, the tendency of the graft to become occluded due to thrombosis and intimal hyperplasia is reduced. The sleeve of the present invention surrounds the biologic graft vessel and provides a means for maintaining an occlusion-preventing agent in the vicinity of the graft, which further reduces the tendency of the graft to become occluded. The occlusion-preventing agent in turn is released in a controlled manner over time through the vessel wall and further reduces the tendency of the vessel to occlude. The advantage of using the local modulator delivery of the present invention is that therapeutic levels of modulator can be maintained at the required site while keeping systemic levels nearly undetectable. The sleeve of the present invention further provides a mechanical support for the graft material, which can help prevent aneurysm.
While the present biologic graft has been described according to a preferred embodiment, it will be understood that departures can be made from some aspects of the foregoing description without departing from the scope of the invention. For example, the occlusion-preventing agent, the configuration of the drug delivery system, the polymer from which the time release vehicle is formed, the means for maintaining the occlusion preventing agent in the vicinity of the graft, the sleeve material, and the vessel material can all be varied, so long as the resultant graft is within the scope of the claims that follow. It is contemplated that stabilized ostrich carotid artery may be suitable for use as the biologic graft vessel, because of its length and relatively small diameter. Likewise, stabilized tissue from other sources is contemplated, including bovine and porcine pericardium. It is further contemplated that the bioactive compound can be affixed to the inner surface of the sleeve member, rather than carried in a fluid in the annulus. As such, the bioactive compound can be carried in resorbable microspheres, or in any other suitable vehicle, such as fiber, film or the like.
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A composite graft for a fluid-carrying vessel in a living body, comprising: an inner vessel comprising a biologic collagenic material that has been stabilized, an outer member surrounding at least a segment of the inner vessel and defining an annulus between the inner vessel and the sleeve, the outer member comprising a polymeric fabric, and a bioactive compound in said annulus, said bioactive compound being carried on a time-release vehicle. The bioactive compound is preferably an occlusion-preventing agent. Alternatively, the sleeve includes the bioactive compound, either on its inner surface or integrally as part of its fibers.
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BACKGROUND OF THE INVENTION
This invention relates to a thread supply device for textile machines, comprising a drum on which the thread issuing from a supply bobbin can be wound tangentially and withdrawn over the end either by rotation of the drum or, in the case of a stationary drum, by means of a disc-shaped or ring-shaped winding element rotating adjacent a free front drum rim while forming at least one thread winding such that the thread is withdrawn over a removal edge of the drum in the case of a rotating drum and over a sliding edge of the winding element in the case of a stationary drum, and that a thread control element is provided which is arranged stationary adjacent the removal edge in the case of a rotating drum and which serves as a lateral stop for the unwinding thread opposite the direction of movement of the removal edge, and which is located on the winding element adjacent the sliding edge in the case of a stationary drum and which limits the peripheral velocity of the thread unwinding about the sliding edge to the peripheral speed thereof.
A thread supply device of this type is already known from German laid-open print DT-OS 2,312,267 with a rotating drum and from German laid-open print DT-OS 2,345,986 having a stationary drum. In both cases the thread control element prevents the thread removal speed from exceeding the unwinding speed as the thread is unwound from the drum in the direction of the drum axis. Since an off-the-end removal of the thread from the drum is normally used in the case of an intermittent thread supply, the thread control element ensures that a device which is suitable per se for intermittent thread supply can be employed for strictly positive thread supply.
The supply of thread is especially problematical in the case of small-scale jacquard machines. A strict positive thread supply is not expedient for such machines because the thread consumption varies within each repetition of the pattern. For this reason it was hitherto common to use an intermittent thread supply in these machines, but this is not ideal either because the amount of thread consumed for each repetition of the pattern cannot be held constant as would be desired.
The object of the present invention is therefore to develop a thread supply device of the type stated at the outset in which the thread is removed from the drum over the end similar to an intermittent thread supply device, but whose speed of removal is limited to the unwinding speed by a thread control element which laterally engages the unwinding thread in such a manner that in the case of small jacquard machines the amount of thread available to the machine is maintained respectively at a constant level through the repetition of the pattern, but in which fluctuations of thread consumption are possible in narrow limits within the repetition in order to form the pattern.
In accordance with the invention this object is accomplished in that order to use the thread supply device in small jacquard machines, a brake means acting progressively on the unwinding thread in the peripheral direction of the same is disposed in front of the thread control element in the sense of the thread rotating about the removal or sliding edge during the thread removal such that the braking effect is amplified as the thread approaches the thread control element and is decreased as it moves away from the thread control element.
In the case of the thread supply device in accordance with the invention, the maximum amount of thread per unit time which the knitting machine can take up is limited by the thread control element to that amount of thread which is wound on the drum per unit time. In this way the amount of thread consumed per repetition of pattern cannot exceed a specific maximum limit in any case. The thread supply device in accordance with the invention is normally operated on small jacquard machines, however, such that the thread is removed from the drum with a certain amount of angular spacing from the thread control element. If the thread consumption increases, it can approach the thread control element somewhat against the increasing resistance of the braking device, whereas it moves away from the thread control element in the direction of winding with a reduction of the braking effect if the thread consumption decreases. The thread consumption can thus vary somewhat about an average value, these fluctuations being dampened by the increasing and decreasing braking effect and is limited on the one hand by the control element and on the other hand by a common switch-off means if it exceeds the permissible limit. The thread control device in accordance with the invention is thus an intermediate between a purely positive and a purely intermittent thread control device which permits the thread requirements which fluctuate over the small pattern within narrow limits to be met in small jacquard machines, but to strictly limit the amount of thread to a maximum amount over the repetition of pattern.
It is provided in the preferred embodiment of the invention that the brake means have a constant braking effect over an operation angle section of the thread rotation, and that the braking effect increase from the operating angle section toward the thread control element and decrease away from said thread control element. This ensures that in that area in which the thread is noramlly withdrawn from the drum a constant thread tension is exerted on the thread. The braking effect is increased or decreased only when the thread attempts to mvoe out of this normal operating area in order to compensate in this manner for undesired large fluctuation in thread consumption or thread tension.
The brake means is expediently a curved guide part over which the thread passes and is deflected farther out of its path the closer it approaches the thread control element in the direction of thread rotation about the removal or sliding edge during thread removal. The braking effect is achieved in this case with simple structural means by a greater or lesser deflection of the thread out of its path and by corresponding greater or lesser friction exerted on the curved guide part. This is simpler than if another type of brake means were provided, e.g. a spring-action rotatably supported guide arm supporting a guide eye for the thread, although the latter would also be possible.
An especially simple structural design results if the curved guide part is a loop-shaped wire bracket positioned adjacent the removal or sliding edge, through whole interior the unwinding thread passes and which extends the more radially within the removal or sliding edge over its entire effective area the more it approaches the thread control element in the direction of thread rotation about the removal or sliding edge during thread removal. The brake means in this case is a simple wire bracket along whose peripheral the measure of thread deflection and thus the braking effect is varied without any additional structural means by making its radial spacing from the removal or sliding edge greater or smaller.
In the preferred embodiment of the invention, it is provided that the wire bracket has the shaped of a closed loop which forms a stop section forming the thread control element and extending radially relative to the removal or sliding edge and a first brake section connected thereto contrary to the direction of thread rotation during thread removal and having a radial spacing relative to the removal or sliding edge which is reduced as the distance from the stop section increases, an operating section with a constant radial spacing from the removal or sliding edge and a second brake section with a radial spacing from the removal or sliding edge which decreases even further as the distance from the stop section increases, a shut-off section extending externally of the removal or sliding edge and a connecting section between the shut-off and stop sections which is not contacted by the thread in any normally occuring operational phase. In this case, all control functions which affect the thread after its removal from the drum are combined on a simple, loop-shaped wire bracket. The stop section forms the control element which limits the speed of removal to the unwinding speed. Two brake sections extend on both sides of an operational section which the thread passes during normal operation with a constant radial spacing from the removal or sliding edge, a switch-off section being connected to the one brake section. This functions simply in that the braking effect is completely neutralized by reducing the radial spacing of the wire bracket relative to the removal or sliding edge to zero or to a negative value so that a conventional shut-off device can bring the the thread supply device or the textile machine to a standstill. Hence, all control functions are met in this case using the simplest structural means.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a thread supply device with a drum which can be set in rotation,
FIG. 2 is a thread supply device with a stationary drum,
FIG. 3 is a schematic view of a brake means, FIG. 4A is a fragmentary side view illustrating the effect of the braking means on the withdrawal thread in the normal operational position, and FIG. 4B diagrammatically illustrates the positional relationship depicted in FIG. 4A, and
FIGS. 5A-5B and 6A-6B schematically illustrate in different positions the action of the braking means on the course of the thread.
DETAILED DESCRIPTION
The thread supply device according to FIG. 1 includes a drum which is rotatably supported in a housing 2. The housing 2 is secured by means (not shown) to a textile machine, in particular a knitting machine, a plurality of supply devices being provided in the knitting machines according to the number of knitting systems. The drum 1 is driven by a pin wheel 3 and a perforated belt (not shown) which cooperates with the pin wheel and which is driven synchronously with the textile machine. The thread F issues from a supply bobbin (not shown), passes through a preliminary brake 4, a disc brake 5 and a thread monitor 6 to be wound tangentially on the drum 1 which rotates in the direction of the arrow P. The thread drum 1 is associated with an inclined advance disc 7 which pushes the forming thread windings in the axial direction of the drum so that an intermediate thread supply V is formed on the drum. The thread is removed from the intermediate thread supply V through a braking ring 8 with elastic fingers and is drawn over the end over a lower removal edge 1a of the drum. It subsequently passes through a wire bracket 10 which forms a closed loop and which is secured to a support arm 9 in a stationary manner. A removal eye 11 and a pivotally supported thread monitor 12 are also attached to the support arm 9 coaxial to the axis of the drum 1. The support arm 9 extends external to the thread drum 1 and parallel to its axis and is supported in the housing 2 at one end.
FIG. 3 shows a schematic view of the wire bracket 10 as seen from the bottom, i.e. without mounting elements and in its correct position with respect to the removal edge 1a of the drum 1 which is indicated by a circle. The wire bracket constitutes a brake means for the unwinding thread and has separate sections of differing form and mode of function. A stop section 10a extends radially relative to the removal edge 1a. This is followed in the direction of rotation of the drum by a first braking section 10b which has a radial spacing relative to the removal edge 1a which is decreased as the distance from the stop section increases. The next is an operating section 10c with a constant radial spacing from the removal edge and a second braking section which continuously approaches the removal edge in a radial manner. This is followed by a switchoff section 10e extending external to the removal edge 1a as well as a connecting section 10f between the shut-off and the stop section.
The mode of action of the brake means, i.e. the loop-shaped wire bracket 10, during knitting of small jacquard patterns is described in the following with reference to the schematic drawing in FIGS. 4A-6B which illustrate specific positions. It should be noted in this context that the wire bracket 10 is illustrated in FIGS. 4A-6B from the top, i.e. as seen from the side of the drum, and the removal edge 1a of the drum is only shown to illustrate the relative position. The direction of rotation P of the drum is counterclockwise (anticlockwise). The point of thread removal on the removal edge and thus the point of thread contact on the wire bracket migrate in response to the thread requirements of the knitting machine, i.e. the thread tension, such that if requirements are reduced, i.e. the tension decreases, these points migrate in the same sense of direction as the rotation of the drum, whereas if thread requirements increase, i.e. increased tension, these points rotate contrary to the direction of drum rotaton, i.e. counterclockwise. When knitting small jacquard patterns, the thread passes over the point of removal A 1 of the removal edge during normal knitting operation and thus passes over the point of contact B 1 on the wire bracket 10 which lies in the center of the operating section 10c. This position is shown in FIGS. 4A-4B. Migrational movements of the point of removal in the or contrary to the direction of drum rotation caused by small changes in requirements, i.e. tension, are possible without changing the braking force as long as their magnitude is within the area of the operating section. If thread consumption and thus the tension become considerably larger, the thread migrates out of the operational sections 10c contrary to the direction of drum rotation into the first braking section 10b, e.g. at the point of contact B 2 shown in FIGS. 5A-5B which corresponds to a removal point A 2 . FIG. 5A shows clearly the great extent to which the thread curvature is increased thereby between the removal edge 1a and the wire bracket 10, while simultaneously the area of contact on the bracket 10. The braking effect on the thread is increased thereby. Another increase in thread consumption moves the point of thread contact with bracket 10 to the stop section 10a where the thread is intercepted and supplied at an unwinding speed corresponding exactly to the winding speed. Thread consumption exceeding this value is thus impossible. On the contrary, if the thread F' unwinding in the operating section 10c is under less tension because the machine is consuming less than corresponds to the winding speed of the drum, the point of removal migrates and thus the point of contact migrates also relative to the drum in the direction of rotation until it arrives at the second braking section 10d, e.g. at points A 3 and B 3 in FIGS. 6A-6B. The reversal of the thread between points A 3 and B 3 are close together, the thread is reversed only a bit and makes contact with the wire bracket 10 only in a small area. The braking effect diminishes. As soon as the thread requirements decrease further or stop completely, the thread moves into the stop section 10e in which no braking occurs so that the thread supply device or the textile machine can be shut off by a conventional shut-off device. The connecting section 10f between sections 10a and 10e merely serves to close the loop and is normally not in contact with the thread in any operating position.
FIG. 2 shows a thread supply device with a stationary drum 1' which is non-rotatably affixed to a housing 2'. The housing 2' is adapted to be mounted on the support ring of a textile machine by means of a clamping device indicated schematically at 2'a. The drum 1' and the housing 2' are traversed by a hollow shaft 13 onto which a pin wheel 3' is wedged by means of a key. The pin wheel 3' operates together with a perforated drive belt (not shown) in order to set the hollow shaft 13 in rotation. At the lower free end of the hollow shaft 13 a disc 14 is non-rotatably secured which supports on its outer rim a flange-like ring 15 which surrounds the lower free edge of the drum 1'. The ring 15 contains a thread eye 16. Parts 14 to 16 form a rotating winding element for winding the thread F issuing from a supply bobbin (not shown). The thread passes through the hollow shaft 13, is then diverted radially outwardly, passes through the thread eye 16 and from here is wound on the drum 1' tangentially. A ball bearing 17 is supported in an inclined position on the hub 14a of the disc 14. An advance disc 7' rotates about said ball bearing and engages outwardly in the jacket of the drum 1' by arms 18 extending through longitudinal slots 19. The arms 18 are interconnected externally by a ring 20. The arrangement is selected such that the advance disc 7' maintains its inclined spacial position so that it advances the thread windings wound upon the drum 1' upwardly in the axial direction of the drum so that an intermediate thread storage V is provided on the drum. From this intermediate thread storage, the thread is removed from the drum 1' over the end as indicated at F'. In so doing, it passes over the outer surface of the ring 15 which forms a sliding edge 1'a, through a wire bracket 10 to a central removal eye 11'. The wire bracket 10 has the same shape as that illustrated in FIG. 3. It is secured to the disc 14 by means of mounting elements 21 in such a spaced relation that it does not impede the course of the thread between the hollow shaft 13 and the thread eye 16. The mode of function of the wire bracket 10 as a braking means for the thread removal during knitting of small jacquard patterns is the same as the mode of functon already described with reference to FIGS. 4A-6B, irrespective of the fact that the relative movement between the drum 1' and the wire bracket 10 is produced by the drum 1' remaining stationary and the wire bracket 10 rotating together with the winding element 14.
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A thread supply device for a textile machine, which device includes a drum on which a thread is wound to form an intermediate thread storage, and from which the thread is withdrawn over one end of the drum for supply to the textile machine. A brake means is disposed adjacent the withdrawal end of the drum and acts on the unwinding thread for imposing a braking effect thereon. The braking means acts progressively on the unwinding thread as it moves peripherally relative to the drum for either increasing or decreasing the braking effect on the thread, depending upon the relative peripheral direction of movement of the thread.
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REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Patent Application No. 60/474,842 filed Jun. 2, 2003, incorporated herein by reference for all purposes.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND
Natural gas, as it comes from the ground, may contain impurities. One impurity that is often found in natural gas is sulfur, particularly sulfur in the form of H 2 S. It may be desirable to remove the sulfur from a natural gas stream because, for example, it may prematurely corrode pipelines and it also may act as a poison to catalysts in downstream processes. One method of removing sulfur from a natural gas process is the Claus Process. The Claus Process generally consists of several steps: (1) oxidizing a portion of the H 2 S to form some elemental sulfur and some SO 2 and (2) reacting some of the remaining H 2 S and SO 2 to form elemental sulfur and water. The sulfur produced in the Claus Process is generally produced at near atmospheric pressure (e.g., less than about 15 psig).
Another method of removing sulfur from a gas stream is through the direct partial oxidation of the H 2 S to produce water and elemental sulfur. Generally, in this partial oxidation process, a stream containing up to about 3% H 2 S is partially oxidized over a catalyst to produce, inter alia, elemental sulfur at elevated pressures (e.g., greater than about 15 psig). See generally, U.S. Pat. Nos. 5,271,907 and 6,099,819, incorporated herein by reference. The methods of processing sulfur at near atmospheric pressure may not work properly when handling elemental sulfur at elevated pressures. Additionally, other high pressure treatment processes may be capital intensive, may require many moveable parts, which may require frequent maintenance and/or possibly expose workers and operators to high pressure sulfur. Thus, there is a need for a process for processing sulfur at elevated pressures which alleviates or eliminates one or more of these concerns.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing of a system for treating sulfur in accordance with embodiments of the present invention.
FIG. 2 is a schematic drawing of a second system for treating sulfur in accordance with embodiments of the present invention.
FIG. 3 is a schematic drawing of a third system for treating sulfur in accordance with embodiments of the present invention.
SUMMARY
Disclosed herein is a process for treating sulfur at elevated pressures wherein the sulfur may be separated from the process gas, sent to a transfer vessel, and the transfer vessel is vented to depressurize the sulfur to near atmospheric pressure. The sulfur may then be transferred to ambient storage or any other desirable use.
DETAILED DESCRIPTION
Referring now to FIG. 1 , there is shown a system comprising a product separator 100 , a pressurized sulfur storage vessel 110 , a sulfur transfer vessel 120 , and valves V 1 , V 2 , V 3 , V 4 , V 5 , V 6 , and V 7 . In operation, sulfur and process gas (e.g., H 2 O and/or H 2 ) at elevated pressure (e.g., above about 15 psig) flow continuously or semi-continuously into process separator 100 through inlet line 190 . Most of the process gas exits separator 100 through gas outlet 200 . Likewise, most of the sulfur exits separator 100 through sulfur outlet 210 , through valve V 1 and into sulfur storage vessel 110 .
At steady state, the pressure of storage vessel 110 is maintained equal to the pressure of separator 100 (e.g., about 70 psig) less the hydrostatic head of the sulfur as it rises through elevation A before entering storage vessel 110 . In some embodiments the pressure of storage vessel 110 may be about 65 psig. Elevation A may be adjusted as desired to provide the desired pressure drop between vessels 100 and 110 . In some embodiments, elevation A may be about 7.7 feet. Pressurized gas may be injected or released through gas lines 230 and 220 respectively so as to maintain the desired pressure in storage vessel 110 . For example, an automatic or manual level control sensors 280 and 290 may be introduced into vessel 100 . If the level of sulfur in separator 100 increases above a desired level, as indicated by level sensor 280 , valve V 2 may be opened and gas released to decrease the pressure in vessel 110 , thereby increasing the flow rate of sulfur from the separator through sulfur line 210 . Likewise, if the level of sulfur in separator 100 decreases below a desired level, as indicated by level sensor 290 , valve V 3 may be opened and gas injected so as to increase the pressure in vessel 110 , thereby decreasing the flow rate of sulfur from the separator through sulfur line 210 . Similarly, if the operating pressure in separator 100 changes, as indicated by pressure sensor 300 it may be necessary to increase or decrease the pressure in vessel 110 correspondingly.
As the level of sulfur in storage vessel 110 reaches a desired level, as indicated, e.g., by level sensor 310 , the pressure in transfer vessel 120 may be increased (automatically by a control device or manually) to just below that of storage vessel 110 . For example, if storage vessel 110 is at 100 psig, transfer vessel 120 may be brought to, e.g., 50 psig (via, e.g., high pressure gas line 260 ) and valve V 4 opened to allow sulfur to flow from storage vessel 110 to transfer vessel 120 . Additionally, vessel 120 may be vented through, e.g., valve V 5 as vessel 120 is filled. Valve V 4 can be closed when the sulfur level in vessel 110 reaches a desired lower level (e.g., its minimum safe operating level). This closure of valve V 4 can occur manually or via an automated device that closes V 4 in response to a signal from a level indicator 320 in vessel 110 . Once the sulfur has been transferred from vessel 110 into transfer vessel 120 and valve V 4 has been closed, the pressure in vessel 120 may be reduced to near atmospheric pressure (e.g., through gas release line 250 ) and the sulfur transferred to atmospheric or near atmospheric storage (e.g., 0 to about 5 psig) through sulfur removal line 270 . Once the sulfur level in vessel 120 reaches its desired lower level, valve V 7 may be closed and vessel 120 may then be repressurized to receive sulfur from storage vessel 110 , and the sequence may be repeated. The closure and repressurization may be manual or automatic via a control device. In some embodiments, sulfur production may be about 10 tons/day.
In some embodiments, either or both of vessels 110 and 120 may have a diameter of about 4 feet and a height of about 20 feet.
Referring now to FIG. 2 , there is shown a separator 400 , a sulfur transfer vessel 410 , and valves V 21 , V 22 , V 23 , and V 24 . In operation, sulfur and process gas (e.g., H 2 O and/or H 2 ) at elevated pressure (e.g., above about 15 psig) flow continuously or semi-continuously into process separator 400 through inlet line 490 . Most of the process gas exits separator 400 through gas outlet 500 . Likewise, most of the sulfur exits separator 400 through sulfur outlet 510 , through valve V 21 and into sulfur storage vessel 410 .
In operation, when the sulfur level of separator 400 reaches the desired level, valve 21 may be opened to allow sulfur to flow from separator 400 to vessel 410 . During transfer of sulfur from separator 400 to vessel 410 , it is desirable to keep the pressure of vessel 410 just below that of separator 400 . Pressurized gas may be injected or released through gas lines 530 and 520 respectively so as to maintain the desired pressure in storage vessel 410 . So long as the pressure of vessel 410 is less than the pressure of separator 400 less the hydrostatic head of the sulfur in transfer line 510 , sulfur will flow from separator 400 to vessel 410 . For example, automatic or manual level control sensors 580 and 590 maybe introduced into vessel 400 . If the level of sulfur in separator 400 increases above a desired level, as indicated by level sensor 580 , valve V 22 may be opened and gas released to decrease the pressure in vessel 410 , thereby increasing the flow rate of sulfur from the separator through sulfur line 510 . Likewise, if the level of sulfur in separator 400 decreases below a desired level, as indicated by level sensor 590 , valve V 23 may be opened and gas injected so as to increase the pressure in vessel 410 , thereby decreasing the flow rate of sulfur from the separator through sulfur line 510 . Similarly, if the operating pressure in separator 400 changes, as indicated by pressure sensor 600 it may be necessary to increase or decrease the pressure in vessel 410 correspondingly.
As the level of sulfur in vessel 410 reaches a desired level, valve V 21 may be closed and the pressurized sulfur in vessel 410 vented through gas release line 520 to the desired pressure (e.g., atmospheric) and the sulfur transferred to atmospheric or near atmospheric storage (e.g., 0 to about 5 psig) through sulfur removal line 640 . Once the sulfur level in vessel 410 reaches its desired lower level, valve V 24 may be closed and vessel 410 may then be repressurized to receive sulfur from separator 400 , and the sequence may be repeated. The closure and repressurization may be manual or automatic via a control device.
Referring now to FIG. 3 , there is shown an embodiment in which two transfer vessels may be operated alternately in parallel. There is shown separator 700 , first transfer vessel 710 , second transfer vessel 720 , and valves V 31 , V 32 , V 33 , V 34 , V 35 , V 36 , V 37 , and V 38 . In short, one vessel is filled with sulfur from separator 700 , the valve between the filled vessel and the separator is closed, and the sulfur in the filled vessel is vented to the desired pressure (i.e., atmospheric or near atmospheric). Once the pressure of the sulfur is reduced as desired, the sulfur can be transferred to its destination (e.g., storage or a process). For the purpose of this disclosure, vessel 720 will be filled first, however, the order of the steps may be changed such that another vessel is filled first. Additionally, in some embodiments, it may be desirable to allow sulfur to transfer to both vessels simultaneously. p In operation, sulfur and process gas are injected into separator 700 , sulfur exits separator 700 trough sulfur outlet 810 and gas exits through gas outlet 800 . Valves V 38 is open and the pressure of vessel 720 may be just below that of the separator 700 less the hydrostatic head of the sulfur flowing from the separator 700 to vessel 720 . The flow of sulfur flowing from separator 700 to vessel 720 may be controlled by controlling the pressure in vessel 720 by injecting or venting gas through valves V 35 or V 37 respectively. To increase the rate of sulfur transfer, gas may be vented. Conversely, to decrease the rate of sulfur transfer, high pressure gas may be injected. Once the amount of sulfur in vessel 720 reaches its desired upper level, valve V 38 is closed, valve V 31 is opened, and the high pressure sulfur in vessel 720 is vented until the sulfur reaches its desired pressure. The sulfur may then be transferred to storage or any other desirable use. While the sulfur in vessel 720 is brought to atmospheric pressure, vessel 710 may be filled with sulfur from separator 700 , and the same process repeated.
The above discussion is meant to be illustrative of the principles and various embodiments of the present invention. Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. For example, the embodiments of FIG. 1 and/or FIG. 3 may be modified to include 3 or more vessels. It is intended that the following claims be interpreted to embrace all such variations and modifications.
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A process for treating sulfur at elevated pressures by which the sulfur may be separated from a process gas in a separation vessel, sent to one or more transfer vessels, and the transfer vessel(s) vented to depressurize the sulfur to near atmospheric pressure. The sulfur may subsequently be transferred to ambient storage or other desirable use. The sulfur exiting the separation vessel may also be transferred to an intermediate vessel. The rate of transfer of the sulfur throughout the process may be controlled by controlling the pressure differentials between the various vessels.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of priority to U.S. provisional patent application No. 61/961,304 entitled “Method and Apparatus for Melting and Resolidifying ZBLAN Optical Fiber Under Microgravity Conditions” filed Oct. 10, 2013.
FIELD
This disclosure relates generally to the production of fiberoptic waveguides utilizing a novel melting and resolidifying apparatus and method while under microgravity conditions.
BACKGROUND
It is well known in prior art of the superior light transmission properties of ZBLAN fiberoptic waveguides (a.k.a. fiber) as well as its application in fiber lasers and amplifiers. Unfortunately, all ZBLAN fiber-forming methods involve fabrication from a melt, which creates inherent problems such as the formation of bubbles, core-clad interface irregularities and inclusions. The ZBLAN fiber drawing process generally occurs at 310° C. in a controlled atmosphere (to minimize contamination by moisture or oxygen impurities which significantly weaken the fiber) using a narrow heat zone compared to silica glass. Drawing is complicated by a small difference (only 124° C.) between the glass transition temperature (approximately 260° C.) and the melting temperature (approximately 310° C.). As a result, ZBLAN fibers often contain undesired crystallites. It is known that the crystallite concentration can be reduced or eliminated by melting and resolidifying ZBLAN in zero gravity (a.k.a. microgravity). The theory is that microgravity conditions reduce convection processes that cause crystallite formation in ZBLAN glasses.
The disclosed subject matter helps to avoid this and other problems.
Known art, such as French patent application Nos. 76.18878 and 77.09618, discloses fabricating a ZBLAN optical fiber in 1 G (normal gravity). However, such known methods of fabricating ZBLAN optical fibers often contain undesired crystallites. These optical fibers may suffer from reduced light transmission and, in the case of use in fiber lasers, undesirable heat generation and an associated upper power limit.
Known art, such as U.S. Pat. No. 2,749,255 by Nack, et. al., discloses cladding a glass fiber with a higher melting temperature cladding via a cladding system comprised of a fiber metalizing system employing nickel carbonyl or gas plating methods. The advantage of this gas plating method is that the metallic cladding (e.g. nickel plating) deposition occurs at a lower temperature (approximately 180-250° C.) than, for example, the ZBLAN glass transition temperature (approximately 260° C.) and the melting point of the ZBLAN glass material (approximately 310° C.)
Additional known art, such as U.S. Pat. No. 5,991,486 by Braglia, discloses an optical fiber that has the core made of a rare earth doped non-oxide glass and cladding made of an oxide glass. The glass of the core has a melting temperature lower than that of the glass of the cladding and lying within the range of the softening temperatures of the cladding. To produce the fiber, a preform, obtained by introducing an element made of the non-oxide glass into the hole of a capillary tube made of the oxide glass, is brought to a temperature lying within the range of softening temperatures of the oxide glass and not lower than the melting temperature of the non-oxide glass, and is drawn. The capillary tube, during the drawing process, serves as a container for the molten glass of the core.
SUMMARY
The disclosure relates to an improved apparatus and method for the production of transparent fiberoptic waveguide materials (e.g. ZBLAN) utilizing a novel melting and resolidifying process while under microgravity conditions, and to this end the apparatus is provided with means for manufacturing specially clad optical fiber under normally controlled conditions and, while under the influence of microgravity (e.g. free fall or on-orbit conditions), melting and resolidifying the optical fiber core to eliminate any imperfections in said optical fiber core caused by solidification in a gravity environment.
The advantage of using the invention is the provision of a novel means of cladding an optical fiber core with a higher melting temperature cladding to permit easy handling (e.g. spooling or bundling) and optical fiber core melting/re-solidification of a compact and contained assembly under microgravity conditions.
An additional advantage is that the optical fiber can be clad during conventional controlled condition fabrication (i.e. fiber drawing) with a cladding that is of a higher melting temperature than the core ZBLAN material, it being a particular feature of the invention that the cladding is either a glass cladding of higher melting temperature or a vapor deposited higher melting temperature metal cladding or a combination of the two. After cladding is accomplished, the fiber may be wound on a spool, stretched out in strands, bundled in strands, etc., placed in a furnace assembly and exposed to microgravity conditions. While under microgravity conditions, the furnace is activated and the temperature applied is just enough to melt the ZBLAN fiber core but not enough to melt the outer cladding layer(s). The furnace is then allowed to cool over a period of time, while still under microgravity conditions, thus permitting the ZBLAN fiber core to resolidify under microgravity conditions. This method provides a superior transparent ZBLAN product, eliminating any imperfections in said optical fiber caused by solidification in a gravity environment.
Another advantage offered by the inventive means is the provision of manufacturing the ZBLAN fiber under controlled conditions, exposing it to microgravity conditions, melting, resolidifying and stripping the cladding material from the core ZBLAN fiber without harming the core ZBLAN fiber or exposing it to harmful moisture.
A further advantage of this method is that it permits individual samples (e.g. 1 meter lengths) of fiber to be processed by first melting the core material and exposing the fiber to microgravity conditions (i.e. a drop tower, aircraft parabolic flight or suborbital flight) for a very short period (e.g. on the order of 1 second to 5 minutes) and rapidly (e.g. on the order of 1 second to 5 minutes) resolidifying the core material under microgravity conditions. This is possible due to the low thermal mass of each piece of fiber. The rapid cooling may be accomplished by some well-known means of quenching (e.g. air blast, refrigerant blast, liquid immersion, etc.). Thus, the fiber samples may be processed under microgravity conditions without the need for transporting to orbit.
DETAILED DESCRIPTION
In one embodiment, the apparatus of the invention includes fabricating a ZBLAN fiber on Earth via many well-known means in the prior art (e.g. French patent application Nos. 76.18878 and 77.09618) and then cladding the fiber with a higher melting temperature cladding via a cladding system comprised of a fiber metalizing system described for example in U.S. Pat. No. 2,749,255 and other systems well known in the art employing nickel carbonyl or gas plating methods. The advantage of this gas plating method is that the metallic cladding (e.g. nickel plating) occurs at a lower temperature (approximately 180-250° C.) than the ZBLAN glass transition temperature (approximately 260° C.) and the melting point of the ZBLAN core material (approximately 310° C.). This plating method provides a cladding that permits the fiber to be wound on a spool, individual strands can be bundled and heated en masse or the fiber can be transported past a zone heater (e.g. in the fashion of a reel to reel magnetic tape recorder) to melt the ZBLAN core at a temperature of 310° C. without melting the cladding material (e.g. nickel with a melting temperature of 1455° C.) thus preventing the ZBLAN fiber from adhering to itself while coiled on a spool and melted under microgravity conditions in any simple furnace well known in the art.
The advantage of spooling/bundling the clad optical fiber and melting the optical fiber core on the same spool/bundle versus drawing the fiber from a preform under microgravity conditions is that it provides the highest packing density (i.e. most processed material in the least amount of volume) possible as well as providing an extremely simple and totally automatic on-orbit processing (i.e. melting and cooling system) apparatus. Both advantages are critical for processing under microgravity conditions since volume and mass as well as time are limited resources for space missions or free fall situations.
Another advantage of this process is that the metallic cladding can be removed by simply exposing the metallic clad fiber to an atmosphere of carbon monoxide gas heated to approximately 130° C., whereupon the nickel cladding combines with the carbon monoxide to form nickel carbonyl gas and is stripped from the optical fiber. After removal of the metallic cladding, the remaining optical fiber can then be clad with any material desired (e.g. a UV curable polymer).
While nickel carbonyl is cited as the preferred metallic cladding material, other metallic plating materials that are useful in the plating or metallization of the materials described include copper acetyl acetonate; the nitrosyls (nitrosyl carbonyls, for example); cobalt nitrosyl carbonyl; hydrides (such as antimonyhydride or tin hydride); metal alkyls; chromyl chloride; and carbonyl halogens (for example, osmiumcarbonyl broniide, ruthenium carbonyl chloride, and the like).
In another embodiment, an optical fiber is provided whose core is made of a rare earth doped, non-oxide glass (e.g. ZBLAN), wherein the cladding is made of an oxide glass and wherein, furthermore, the core is made of a glass whose melting temperature is lower than that of the cladding glass and lies within the range of softening temperatures of the latter.
The term “range of softening temperatures” means, in this description, the temperature range between the glass transition temperature Tg (where the glass has a viscosity of 10 12 Pa·s) and the temperature at which the glass has a viscosity of 10 4 Pa·s (viscosity at which the “gob” falls down by gravity and the fiber can be drawn with minimum force).
A fiber of this kind eliminates the cladding melting issue, mechanical resistance and chemical inertia problems of fibers completely made of non-oxide glass, since the cladding (which, for example, makes up most of the material of the single mode fiber) is made of an oxide glass.
Important aspects to be taken into account in choosing the two glasses to be used in a fiber of this kind are given by the thermal expansion coefficient and by the refractive index of the glasses themselves. Specifically, the two glasses must have, at temperatures lower than the glass transition temperature, essentially similar thermal expansion coefficients as well as compatible viscosities, in order to prevent the cladding from inducing stresses on the core or vice versa while the fiber being drawn cools off. In regard to refractive indexes, they must be such that the numerical aperture allows obtaining cores whose radius is in the required order of magnitude. The numerical aperture is given by NA=(n 1 2 −n 2 2 ) 1/2 , with n 1 , n 2 being the refractive indexes of the core and of the cladding respectively, and it is linked to radius r of the core and to wavelength λ by the relation λ=2 πr·NA/2.405. Suitable numerical apertures range between 0.3 and 0.5.
Non-oxide glasses which can be used in the presence of an oxide glass cladding can be, for instance, ZBLAN glasses, chalcogenide glasses, aluminum fluoride glasses, or phosphate-fluoride glasses.
These glasses have glass transition temperatures Tg ranging from a minimum of about 265° C. (for ZBLAN) to a maximum of about 475° C. (for glasses containing Ba), melting temperatures in the order of 700-740° C., thermal expansion coefficients α (for temperatures lower than Tg, particularly temperatures in the range 30 to 300° C.) ranging from a minimum of about 11·10 −6 ° C. −1 (for glasses containing Ba or As) and a maximum of about 19·10 −6 ° C. (for ZBLAN), and refractive index ranging from 2 to about 2.5.
Oxide glasses with glass transition and melting temperatures, thermal expansion coefficients, viscosities and refractive indexes compatible, for the purposes of the present invention, with those of the aforesaid non-oxide glasses are specifically lead silicate glasses with high lead oxide content, preferably between 30% and 70% (molar percentages), whose refractive index varies from 1.69 to 2.14. In choosing the specific composition, it should be kept in mind that glasses whose lead oxide content is close to the upper limits of the range have thermal expansion coefficients which are very similar to those of chalcogenide or ZBLAN glasses and refractive indexes yielding the required numerical aperture for the fiber, but they may have excessively low glass transition temperatures. By contrast, glasses whose lead oxide content is close to the lower limits of the range have suitable glass transition temperatures but may have excessively low thermal expansion coefficients and refractive indexes. Glasses whose lead oxide content is within the preferred range represent, in any case, a good compromise solution, also taking into account that any stresses induced in the drawing process can be eliminated with an annealing operation at temperature lower than the glass transition temperature Tg of the core glass.
Alternatively, instead of binary SiO 2 —PbO glasses, lead silicate glasses also containing minor percentages of additional oxides, e.g. TiO 2 , can be used. The presence of these additional oxides allows, as is well known to the person skilled in the art, modifying the characteristics of a lead silicate glass in order to obtain the required compatibility of all parameters of interest in the two glasses.
Glasses containing oxides of the M 2 O 5 type, where M is Nb or Ta, instead of PbO, are also suitable. The refractive indexes of said glasses also exceed 2.
Further details of other suitable glasses can be found in U.S. Pat. No. 5,991,486.
The invention also provides a method for the fabrication of the aforesaid fiber, wherein a preform comprising a cladding and a core is drawn, in which the ratio between the diameters corresponds to that required to obtain the desired optical fiber. According to the invention for preform production an oxide glass capillary tube is used as cladding, into the interior of which there is introduced an element of non-oxide glass (e.g. ZBLAN), whose melting temperature is lower than that of the oxide glass and lies within the range of softening temperatures of the latter, and, for the drawing process, the preform is brought to a temperature lying within said range and not lower than the melting temperature of the non-oxide glass.
The non-oxide glass element can be introduced into the capillary in its molten state, by capillarity or by pouring, or in its solid state, in the form of a rod.
As can be clearly seen, with the described method the fiber is obtained either by starting from the non-oxide glass already in its molten state, or by drawing a cold-formed preform.
The glasses used have preferably melting temperatures (for the non-oxide glass) and softening temperatures (for the oxide glass) ranging between about 700° and 750° C., and such refraction indexes as to give rise, in the drawn fiber, to a numerical aperture ranging between 0.3 and 0.5. Further prior art details of drawing glass clad fibers using this method can be found in U.S. Pat. No. 5,991,486.
Additionally, the aforementioned method of coating the fiber with metal may be used to apply metal over the aforementioned glass cladding to completely eliminate the possibility of glass cladding adhering to itself during the core melting operation. As stated earlier, the metallic cladding can be removed by simply exposing the metallic clad fiber to an atmosphere of carbon monoxide gas heated to approximately 130° C. whereupon the nickel cladding combines with the carbon monoxide to form nickel carbonyl gas and is stripped from the optical fiber. After removal of the metallic cladding, the remaining optical fiber can then be clad with any material desired (e.g. a UV curable polymer).
The aforementioned processes also have the advantage of eliminating any exposure to water, water vapor or aqueous solutions, all of which will potentially damage the fiber core.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.
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An apparatus used for the fabrication of fiberoptic waveguides utilizing a novel melting and resolidifying apparatus and method while under microgravity conditions is disclosed. In one embodiment, the optical fiber core has a lower melting point than the cladding and the core is melted and resolidified under microgravity conditions. The molten lower melting point core is thus contained by the higher melting point cladding while under microgravity conditions.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an improved device for preventing a drag adjusting knob from loosening in a spinning reel for fishing, which reliably prevents the nob from loosening and which is compactly constructed.
2. Prior Art
Means for preventing the drag adjusting knob from loosening in a spinning reel for fishing has been disclosed in Japanese Utility Model Publication No. 58948/1982, according to which a set plate having teeth along the periphery thereof is engaged with the upper portion of a brake plate that is slidably supported by a spool shaft at a front portion thereof but without being allowed to rotate, and an engaging pawl provided on the knob is resiliently engaged with a tooth of the seat plate. When the knob is turned, the engaging pawl simply swings toward the right or left to engage with the tooth. In this case, however, the engagement is not strong due to the nature of the mechanism. In other words, the knob has a weak holding force and tends to be loosened, and the engaging pawl and the teeth lack durability, too. When the knob is turned, furthermore, sharp and vivid sound is not produced. Moreover, the knob has a shape that protrudes greatly toward the front of the spool, causing the spinning reel to become bulky.
A system has also been disclosed in Japanese Utility Model Publication No. 32290/1984, in which a ball is urged by an annular spring to engage with a gear that is fitted to a spool shaft to freely slide only in the axial direction thereof. According to this system in which the ball engages with the gear, the degree of engagement is small. Further, since the ball is brought into engagement while being rotated, the engaging force is weak, i.e., the holding force of the knob is weak like the above-mentioned device. Moreover, the annular spring, ball and gear that are arranged in the portion of the drag adjusting knob cause it to greadly protrude toward the front of the spool, i.e., make it difficult to compactly construct the device. Furthermore, to incorporate the annular spring requires cumbersome operation in manufacturing the device.
SUMMARY OF THE INVENTION
The present invention was accomplished to improve these defects, and its first feature is to provide a spinning reel for fishing in which a drag adjusting knob produces an increased engaging force (holding force) so that it is prevented from escaping as may be caused when it is loosened, and which makes it possible to finely and reliably control the drag that may require a weak force of control.
A second feature of the present invention is to provide a spinning reel for fishing, in which an annular spring is inserted in a cylinder with a bottom that is secured to a drag adjusting knob, a folded protrusion at the center of the annular spring is protruded beyond a hole formed in the cylinder with a bottom so as to engage with a tongued and grooved face formed on an inner peripheral surface of a dish member that engages with the shaft member, to thereby produce a suitable holding force in turning the drag adjusting knob.
A third feature of the present invention is to provide a spinning reel for fishing in which a threaded rod screwed into the shaft, an annular spring and a spring are contained as a unitary structure in the cylinder with a bottom which is secured to a drag adjusting knob in order to facilitate the operation for assembling and disassembling the drag mechanism, and in order to reduce the amount of protrusion of the drag adjusting knob toward the front, such that the drag mechanism can be constructed in a compact size.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partly cut-away front view of the present invention;
FIG. 2 is a section view along the line A--A of FIG. 1; and
FIG. 3 is a perspective view showing a major portion of the invention in a disassembled manner.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An embodiment of the present invention will now be described in conjunction with the drawings. A spool 1 of a spinning reel is rotatably fitted to a shaft 3 of a partly cut-away circular shape in cross section, which is secured to the front end of a spool shaft 2 that slides reciprocally. Widely known brake members such as washers 5 that engage with the shaft 3, a washer 6 that engages with a groove 4' of a recessed portion 4 and that is rotatable on the shaft 3, and friction plates 7 that are interposed among them, are inserted in an overlapped manner in the recessed portion 4. Further, a dish member 9 that has a tongued and grooved face 8 formed on the inner peripheral surface thereof is engaged with the shaft 3 on the front side of the forefront washer 5 being stopped by a stop ring 10 so as not to escape from the recessed portion 4 of the spool 1.
A threaded rod 14 is screwed into the end of the shaft 3, the threaded rod 14 having a polygonal junction portion 11 at its front end to engage with a junction portion 13 of a drag adjusting knob 12. To the peripheral edge of the drag adjusting knob 12 is fastened a flange plate 16 of a cylinder 15 the bottom surface of which abuts to the inner bottom surface of the dish member 9. A coil spring 17 is loaded between the inner bottom surface of the cylinder 15 with bottom and the junction portion 11 of the threaded rod 14.
Through holes 18, 18 are formed in the periphery of the cylinder 15 in an opposing manner. Ends of an annular spring 19 inserted in the cylinder 15 are fitted to one through hole 18, and a central folded protrusion 20 of the annular spring 19 is allowed to protrude beyond another through hole 18 to come into engagement with the tongued and grooved face 8 of the dish member 9.
A rotor 22 is provided at the back of the spool 1 and is turned by a handle in front of a reel housing 21. A fishing line is wound on the spool 1 by a bail arm 23 that is attached to the rotor 22 in a customary manner.
The embodiment of the present invention is constructed as described above. When the drag of the spool 1 is to be controlled, therefore, the drag adjusting knob 12 is turned to turn and feed forward the threaded rod 14 that engages with the knob 12. The cylinder 15 fastened to the threaded rod 14, then, presses the dish member 9, so that the washers 5, 6 and friction plates 7, that are brake members, are pressed together. Depending upon the degree of pressing force, the power transmission varies between the spool 1 and the shaft 3. If the threaded rod 14 is turned and retracted, the power transmission decreases between the spool 1 and the shaft 3; i.e., the braking members undergo slip. In these cases, the central folded protrusion 20 of the annular spring 19 is brought into engagement with the tongued and grooved face of the dish member 9 as the drag adjusting knob 12 is turned, whereby a holding force is given to the turning operation so that the drag adjusting knob is prevented from loosening.
According to the present invention as described above, the annular spring is inserted in the cylinder with bottom which is secured to the drag adjusting knob, a central folded protrusion of the annular spring is protruded beyond a through hole to come into engagement with the tongued and grooved face of the dish member, and the drag adjusting knob, threaded rod, annular spring and spring are assembled together as a unitary structure in the cylinder with bottom. Therefore, the central folded protrusion of the annular spring smoothly and reliably engages with the tongued and grooved face of the dish member maintaining a strong engaging force to impart a suitable holding force to the turn of the drag adjusting knob so that it is prevented from loosening. The thus constructed drag mechanism exhibits increased durability and is formed as a unitary structure, enabling the drug mechanism to be easily assembled or disassembled. Moreover, the drag adjusting knob protrudes little toward the front, and the drag mechanism can be constructed in a compact size.
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A spinning reel for fishing in which a drag adjusting knob produces an increased engaging force (holding force) so that it is prevented from escaping that may be caused when it is loosened, and which makes it possible to finely and reliably control the drag that may require a weak force of control.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present invention claims priority to a U.S. provisional patent application entitled HANDS-FREE MULTI-FUNCTIONAL UTILITY ILLUMINATING DEVICE Ser. No. 60/682,656 filed on May 20, 2005 and said application is incorporated herein at least by rerefence.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention pertains to illuminating devices, and more particularly to a hands-free multi-functional utility illuminating apparatus adapted to be worn in different locations, such as about the wrist of a user, and having a variety of light-emitting devices, such as a diode and strobe light emitter.
[0004] 2. Discussion of the State of the Art
[0005] Whether for use in law enforcement or military, or by ordinary citizens, lighting devices, such as flashlights, are used to illuminate dark areas. However, the flashlight, while an adequate light source, occupies the hands and limits a person's ability to use both hands. Furthermore, the flashlight does not emit a strobe or other visual indicator that would be eye-catching for locating a person in distress in a variety of ambient lighting conditions.
[0006] In view of the above, there is a continuing need for a hands-free multi-functional utility illuminating module adapted to be worn about the wrist of a user or on a belt or vest worn by a user and having at least one light emitting diode and a separate strobe emitter.
[0007] As will be seen more fully below, the present invention is substantially different in structure, methodology and approach from that of other light sources.
SUMMARY OF THE INVENTION
[0008] According to an aspect of the invention, a system is provided for illuminating in a hands free manner. The system includes an illumination module including at least one independent light source and strobe emitter, and a material holder for supporting the illumination module for hands free use. In a preferred embodiment, the illumination module is secured to the holder using hook and loop connectors. In one embodiment, the at least one independent light source is a light emitting diode (LED). In a preferred embodiment, there is more than one LED each emitting a different color of light.
[0009] In one embodiment, the material holder is one of a wristband, a legband, or an armband. In one embodiment, the material holder is a material pocket having at least one flap to secure the module inside the pocket. In a variation of this embodiment, the material holder has an extension for looping around a belt. In another variation of the embodiment, the material holder has a belt loop or a belt clip attached thereto for securing to a belt.
[0010] According to another aspect of the invention, an illumination module is provided. The illumination module includes two or more LEDs each LED emitting a different color of light, a strobe emitter for producing a sequence of strobe flashes, and an input panel of buttons for activating and controlling the LEDs and the strobe emitter. In a preferred embodiment, there is one white LED and one red LED, the LEDs independently operable from the input panel. In a variation of this embodiment, the strobe emitter is a bulb.
[0011] In one embodiment, the illumination module further includes a magnetic strip for magnetic attachment to a metallic surface. In one embodiment, the illumination module further includes modular covers over the LEDs and the strobe emitter, the covers exchangeable for like covers of varying transparencies and light directing features. In a variation of this embodiment, the light direction features are transparent windows on otherwise non-transparent covers. In one embodiment, the LEDs are independently adjustable for direction of light emission.
[0012] According to a variation of the first embodiment of the invention, the material holder of the system includes a vest band. In a further variation of this embodiment, the material holder includes an animal collar. In one aspect of this embodiment, the animal collar is a dog collar.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0013] FIG. 1 is a perspective view of a hands free light and strobe emitting system according to an embodiment of the present invention.
[0014] FIG. 2A is a front view of the light and strobe emitting module of FIG. 1 .
[0015] FIG. 2B is a top view of the light and strobe emitting module of FIG. 2A .
[0016] FIG. 3A is a top view of the light and strobe emitting module supported by a material holder according to another embodiment of the present invention.
[0017] FIG. 3B is a side view of the module and holder of FIG. 3A .
[0018] FIG. 4 is a block diagram illustrating the basic components of the light and strobe-emitting module of FIG. 1 according to an embodiment of the present invention.
[0019] FIG. 5 is a perspective view of a light and strobe emitting module and a holder according to another embodiment of the invention.
[0020] FIG. 6 is an elevation view of a version of the module of FIG. 1 supported on a dog collar according to an embodiment of the invention.
[0021] FIG. 7 is an elevation view of the module of FIG. 1 supported on a vest band and a belt.
DETAILED DESCRIPTION OF THE INVENTION
[0022] FIG. 1 is a perspective view of a hands free light and strobe emitting system 100 according to an embodiment of the present invention. System 100 includes a light source and strobe-emitting module 101 . Module 101 is an electronics module and houses electronic circuitry and a power source. Module 101 has a base portion 105 generally rectangular in shape in this example. Base 105 may have one or more compartments (not illustrated) for housing batteries, power cells, or the like for powering the module. In one embodiment, the power source may be one or more AAA batteries. However, other power sources and batteries types, including re-chargeable batteries or cells may be used.
[0023] Module 101 has an upper body portion 106 provided to house electronic circuitry required to enable function of the module according to embodiments of the invention. Body 106 is rectangular in shape in this embodiment and is situated above and centered over base 105 . Base 105 and body 106 may be contiguously formed of molded plastic like ABS plastic, for example. Base 105 may have an access door provided on its underside (not visible) for enabling access to batteries or power cells.
[0024] Upper body portion 106 has a user interface panel of buttons or switches 109 for activating and controlling the functions of module 101 . The functions of module 101 include acting as an illumination module capable of producing a bright white light and an illumination module capable of producing a bright red light, such as in the infra-red spectrum. The illumination devices are light emitting diodes (LEDs) in a preferred embodiment. The diodes are housed within an LED compartment having a removable cover 107 situated strategically on top of upper body 106 . In this example, light is emitted in the general forward direction indicated by arrows. Module 101 comprises in this embodiment a strobe light that is capable of emitting a sequence of timed flashes of high intensity bright light. The strobe light is housed in this embodiment within a strobe compartment having a removable cover 108 . Strobe cover 108 may, in one embodiment, be transparent so that emitted flashes of bright light emanate through the cover. In another embodiment, strobe cover 108 may have a transparent opening in one end for focusing strobe flashes in one general direction.
[0025] A user interacting with one or more buttons or switches 109 controls module 101 . xxxxx For example, one button may control a bright white LED while another controls a red LED and the third button controls the strobe. In one example, depressing one button powers the associated LED or strobe on and pressing it a second time turn it off. In a preferred embodiment, the strobe flashes once every 0.75 seconds. However, other timing considerations may be implemented. Additionally, more than one timing sequence may be provided and implemented such as by repeatedly depressing the button 109 associated to the strobe function.
[0026] The functions of module 101 or more specifically, the LEDs and the strobe bulb communicate with the appropriate printed circuits housed in upper body 106 and with the battery compartment via appropriate power and signal trace. The amount of intelligence built into module 101 depends on the circuitry provided to drive the utilities.
[0027] System 100 includes a material arm or wrist support 102 for holding module 101 in a position that is stable for hands free operation. Wrist support 102 may be fabricated from a stiff or pliable material that may be wrapped around the arm or wrist of a user. Cordura, leather, canvas, or other materials may be used in fabricating wrist support 102 . Support 102 includes a portion 103 that fits over module 101 and secures it between the overlapping layers of wrist support 102 by way of a cutout 110 provided through the overlap portion 103 . Cutout 110 is rectangular in shape and is just large enough dimensionally to fit snuggly over upper body portion 106 of module 101 .
[0028] Wrist support 102 may be secured around the wrist of a user by hook and loop connection typical of wrap around belts and bands. With module 101 in position, portion 103 of wrist support 102 is urged down over the module against the upper surface of base 105 exposing the interface and body potion 106 through cutout 110 . The hook and loop connection is then secured to firmly hold module 101 in position on the wrist or arm of a user. Wrist support 102 has a material extension 104 having a loop formed at the free end for wrapping around a finger of a user to prevent wrist support 102 from slipping around the wrist of a user while being worn. The loop formed at the end of material extension 104 may be a solid loop or ring sized generally to fit a ring finger or little finger of the user. In one embodiment the finger loop is physically wrapped around a finger and secured using a hook and loop connection similar to the one used on support 102 .
[0029] The configuration of system 100 in this example enables a user to handle a weapon like a firearm, for example, with both hands remaining free to hold and brace the weapon for firing in traditional stance used by law enforcement and to have a high intensity light shining in the same direction as the weapon is being pointed. Persons engaging tools in dark areas such as underneath an automobile when performing repairs may use system 100 as a hands free light source. The direction of the light emitted from the LEDs of module 101 when powered on coincides generally with the angle at which the light is desired to illuminate the work area without having to hold and point a flashlight or other handheld light source.
[0030] Wrist support 102 may vary in design somewhat without departing from the spirit and scope of the present invention. For example, there may be a three sided rectangular pocket formed on the upper surface of overlap portion 103 wherein the pocket accepts module 101 by sliding the module into the pocket. In this case, the upper body portion may still be exposed through a cutout in the top of the pocket and a separate flap may be provided to secure module 101 within the pocket by hook and loop connection. There are many possibilities. In this example, system 100 is intended to be worn on a user's wrist and to be stabilized on the wrist via material extension 104 . However, similar designs without finger stabilizers may be provided for the upper arm of a user in some cases. For example, an emergency worker stacking sand bags at night to prevent flooding might wear an armband with module 101 instead of a wristband with module 101 in order to have a more general illumination area. Likewise, it is conceivable that a support like 102 may be provided for wrapping around the leg of a user. There are many possibilities.
[0031] In addition to the LED function, the strobe emitter may be activated on module 101 to produce a sequence of high intensity flashes that are visible from a relatively great distance. This is practical for search and rescue missions where the target of the search has system 100 and activates it to facilitate spotting during the search. The activated strobe can be spotted from a distance at night, underwater, under rubble, under snow, and in a variety of other rescue situations. In one embodiment, all of the utilities may be activated to run separately from one another or at the same time. Each utility has it's own circuitry in a preferred embodiment.
[0032] The red LED may be used in situations where some light is required but not enough that might attract attention. Undercover work, soldering, and the like are good situations where one may require some light but not intense brightness. Reading maps at night is a good example of such a use. Another is preparing demolitions under cover of darkness in a battle situation. There are many possibilities.
[0033] In one embodiment, the LEDs of module 101 may be set at differing levels of brightness of emission by toggling the associated buttons 109 . Likewise, the strobe emitter may be set to flash at a slower frequency or a faster frequency depending on need. In one embodiment wrist support 102 has a sewn pocket 111 for inserting therein a key or other small item.
[0034] FIG. 2A is a front view of the light and strobe emitting module 101 of FIG. 1 .
[0035] FIG. 2B is a top view of the light and strobe emitting module 101 of FIG. 2A .
[0036] Referring now to FIG. 2A , module 101 includes base 105 for housing batteries and serving as a flange for installing the module in a band as was previously described. Upper body 106 houses the driver circuitry enabling function of the module. Strobe bulb cover 108 and LED compartment cover 107 are removed in this example for clarity. In this view, an LED 201 and an LED 202 are mounted and directed to emit light in a uniform direction. Cover 107 may have a transparent window 207 through which light is emitted. The bottom of the LED compartment has openings provided to enable electrical communication traces 205 to connect the LEDs to a printed circuit board (PCB) mounted within upper body 106 . The circuit board, not visible in this example contains all of the required circuitry to enable the functions and features of the invention. In one embodiment, more than one circuit board may be provided.
[0037] Button panel 109 is located behind the LED compartment in this view and also has connection to appropriate gates on the PCB enabling activation and control of the utilities individually and in unison if desired. A strobe bulb 203 is provided in this example and has electrical communication to the PCB and associated circuitry via electrical communication paths 204 . Cover 108 may have a window 209 for directing strobe flashes. Cover 108 may also be transparent to expand visibility of the strobe. More than one cover may be provided for setting up different scenarios depending on circumstance. For example, if using the strobe as a rescue beacon then the transparent cover would be used. If using the strobe as a signaling device, then a non-transparent cover with a transparent window would be used.
[0038] Referring now to FIG. 2B , the geometric arrangement of LED 201 , LED 202 , strobe bulb 203 , and input panel 109 may vary significantly without departing from the spirit and scope of the present invention. In this example, LEDs 201 and 202 have back shielding and are constructed to focus light in one direction. LEDs 201 and 202 are fixed adjacently in this example. In one embodiment, LEDs 201 and 202 may be adjusted at the mounted positions to align or to change direction of light emission.
[0039] One with skill in the art of plastic molding will appreciate the use of the present invention does not depend on geometric shape of module 101 . Instead of rectangular shapes for base 105 and upper body portion 106 , elliptical or annular shapes may be incorporated into the design. Similarly for a rectangular configuration, corners and edges may be rounded or chamfered.
[0040] FIG. 3A is a top view of the light and strobe emitting module 101 of FIG. 1 supported by a material holder 300 according to another embodiment of the present invention. Material holder 300 may be provided of a durable cloth like cordura, or nylon 302 . Some other material like leather or canvas may also be used instead. In this example, holder 300 is sewn forming a rectangular pocket having three sewn walls, a cutout window to accommodate upper body portion 106 and a closeable flap 303 to form the fourth side. A hook and loop connection on the inner side of flap 303 and on the upper right surface of holder 300 in this view enable a user to secure module 101 within the holder.
[0041] Module 101 may be placed into pocket 300 by sliding the module in through the open end with flap 300 in an open position. When module 101 is secured in holder 300 with the window properly formed around the upper body portion of the module, flap 300 may be closed and secured using the hook and loop connection provided.
[0042] FIG. 3B is a side view of module 101 and holder 300 of FIG. 3A . In this view, material holder 300 has module 101 secured with flap 303 closed. Module 101 is entirely covered accept for the exposes utilities (LEDs, strobe bulb, and input panel). A belt loop 301 may be provided and sewn on to the underside of material holder 300 so that a user may install module 101 on a belt. In one embodiment, a hook or loop pad may be provided on the underside of holder 300 so that a user may secure holder 300 with module 101 inside to a hook or loop pad provided on a wristband or other band, or on some article of clothing such as a hunting jacket or the like. Industrial strength hook and loop materials may provide a secure one-stick installation without requiring an overlay flap or any other attachment mechanisms.
[0043] FIG. 4 is a block diagram illustrating the basic components 400 of the light and strobe-emitting module of FIG. 1 according to an embodiment of the present invention. The block diagram illustrating components 400 is a logical diagram only and does not strictly follow any geometric arrangements of components. Components 400 include a utility 405 that includes the LEDs and the strobe bulb or emitter described further above. A control (Ctrl,) block 406 includes the user input panel of buttons for activating and controlling functions and features of the module.
[0044] A block 402 illustrated PCB circuitry containing all of the necessary circuitry to operate and control the module. PCB circuitry 402 contains at least LED circuits 403 and a strobe circuit 404 . A power source block 401 includes the battery or power cell compartment and terminals connected to the PCB board to provide power to the module. In a preferred embodiment, module 101 uses a stacked form factor to lower the footprint of the module. The batteries are provided in the first level, the PCB circuitry at the second level, and the utilities and control buttons at the top level as illustrated in the previous embodiments.
[0045] FIG. 5 is a perspective view of light and strobe emitting module 101 and a material holder 503 according to another embodiment of the invention. In this example, a material holder 503 is provided to contain and secure module 101 . Material holder 503 has 3 sewn sidewalls and an open side for accepting the module. Holder 503 has a locking flap 501 with a window cutout dimensioned to fit over the upper body portion of module 101 . Locking flap 501 has a hook or loop provided on the undersurface. The material sidewall opposite the free end of flap 501 has a hook or loop connector 505 a provided on the outer surface. In this example, locking flap 501 is placed over module 101 in the pocket and is secured by connection of the hook and loop connectors 505 a and 505 b.
[0046] Material holder 503 has an outer extension 502 that can be used to secure the module from a belt or waistband, or some other support band using hook and loop connectors 504 a and 504 b . In this embodiment, while module 101 is being worn on a belt or being supported on a wrist band or the like, the user may easily remove dive 101 and replace it by un-securing flap 501 and sliding the module out from the pocket of holder 503 . In this way, the module may be moved from belt to wrist to vest, for example, when desired.
[0047] FIG. 6 is an elevation view of a version of the module of FIG. 1 supported on a dog collar according to an embodiment of the invention. In one embodiment of the present invention module 101 or a version of module 101 may be provided to a dog collar using the same material holder design described above. A dog 600 with a dog collar 601 has material holder 602 and a version of module 101 containing at least the strobe function. In this example, LEDs may not be desired. Rather, the dog may need to be found if lost during some operation or as a result of general circumstance. The strobe bulb of system 602 may be activated by remote, perhaps by a remote control device provided for the purpose. In one embodiment a telephone communications device like a cell phone may activate the bulb. In any case, activation of the strobe emitter on the dog collar causes intense strobe flashing to occur that is visible from a great distance (up to 4 miles) even in low visibility conditions like fog. Hunting dogs might use the collars so that their owner may quickly sight the dogs from a distance as they are working. Cattle herding dogs may also use the collar to provide an additional incentive (intense strobe flashing) for cattle or other herded animals to submit to the dog. There are many possibilities.
[0048] FIG. 7 is an elevation view of module 101 of FIG. 1 supported on a vest band and a belt. A vest 700 is illustrated having a vest cross-band 701 and a belt 702 . Vest 700 may be any type of clothing, but a vest is illustrated because of the existence of many types of uniform safety vests worn by various road crew, emergency personnel, rescue workers, miners, law enforcement, firemen and the like. Module 101 using a material holder like those already described may be attached securely to a vest band 701 or a belt 702 as is illustrated. Using the high intensity strobe feature on a vest provides an added safety factor for road crews and the like to increase their visibility to passing motorists. Likewise, firemen or miners may use them so that they may quickly locate one another in low visibility condition such as in a smoke-filled house or underground in a dust filled mine. Children at play or joggers and bike riders may also wear the module of the present invention for safety purposes to increase their visibility to others.
[0049] In one embodiment of the present invention module 101 of FIG. 1 may include a magnet glued to the rear battery cover so that the module may stuck on to a metal surface such as a refrigerator. Likewise, the material holder may also have a magnetic strip on the bottom side for magnetically attaching the module to a metal surface. The possible applications are virtually endless. The module of the present invention when supported by a wristband as shown in FIG. 1 may be positioned on the upper or lower side of the wrist of a user, or on either side of the wrist of a user without departing from the spirit and scope of the present invention. The module of the present invention may be provided using all of or some of the components described without departing from the spirit and scope of the present invention. For example, there may be more than two LEDs and/or more than one strobe emitter provided on a single module.
[0050] There may be fewer or more than three input buttons for activating and controlling the module. Specific versions of the module may also be provided wherein the features are dedicated to specific uses. For example, if used on a dog collar, the LED features of the module may not be applicable. Therefore the module may be provided with only the strobe feature without departing from the spirit and scope of the invention. Likewise, for a mechanic, a module may be provided without the strobe feature because it may not be required for hands free illumination of a work area.
[0051] The spirit and scope of the present invention should only be limited by the following claims.
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A system for illuminating and signaling in a hands free manner includes an illumination module comprising at least one independent light source and strobe emitter, and a material holder for supporting the illumination module for hands free use.
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FIELD OF THE INVENTION
[0001] The present invention refers to 3-aza-bicyclo[3.2.1]octane derivatives of general formula (I) useful in the treatment of infectious diseases and particularly pathologies caused by microbial pathogens expressing aspartyl-protease activity. Specifically, the invention refers to compounds of general formula (I), and their metabolites, as Candida albicans SAP2 inhibitors for treating fungus infections, as HIV protease inhibitors for treating HIV infections, or as plasmepsines or histo-aspartyl protease (HAP) inhibitors for treating malaria.
STATE OF THE ART
[0002] Aspartyl proteases are widely distributed in many organisms and tissues with different physiological and functional properties, and contain two aspartyl residues at the active site, one protonated and the other not, which work together as general acid-base catalysis. A water molecule bound between the two aspartate residues is believed to be the nucleophile for the amide bond hydrolysis, and it is activated by the deprotonated catalytic aspartic acid residue. To catalyse peptide hydrolysis, the two aspartic residues must be close enough in the tertiary structure of the molecule. Most of the aspartic proteases belong to the pepsin family, including digestive enzyme such as pepsin and chimotrypsin, as well as lysosomal cathepsins D and processing enzymes such as renin and certain fungal proteases (the Candida albicans SAPs, penicillopepsin etc). A second family comprises viral proteases such as the HIV, also called retropepsin. The active site of aspartic proteases does not in general contain groups that are sufficiently nucleophilic to be chemically modified by a selective irreversible inhibitor. Thus, most of the aspartic protease inhibitors developed to date binds to their target enzyme through non covalent interactions. These compounds are therefore reversible inhibitors and an effective inhibition results when the enzyme shows higher affinity for the inhibitor than for its natural substrate (Tacconelli, E. et al. Curr. Med. Chem. 2004, 4, 49).
[0003] It has been proposed that stable structures which resemble the transition state of an enzyme-catalysed reaction should bind the enzyme more tightly than the substrate. As a consequence, an approach that has been very successful for the design of efficient aspartyl protease inhibitors is based on the incorporation of a transition state isostere into a peptidomimetic structure.
[0004] Candida albicans is an opportunistic fungal pathogen that causes severe systemic infections especially in immunodeficient individuals. Although a certain number of antifungal agents are available, the need for new drugs against C. albicans is escalating due to both the widespread occurrence of mucosal and systemic infections caused by Candida , and the development of resistance against available drugs (Shao, P.-L. et al. Int. J. Antimicrob. Agents 2007, 30, 487). In fact, despite drug availability, Candida albicans ranks as a highly incident cause of morbility, cost of hospitalization and mortality (Pfaller M A & D: J: Diekema. Epidemiology of invasive Candidiasis: a persistent public health Problem. Clin.Microbiol.Rev. 2007; 20:133-163). Although the ability to cause disease is likely a complex process involving multiple interactions between Candida and the host, Secreted Aspartyl Proteases (SAPs) activity appears to be a major virulence factor and therefore offers a potential target for drug intervention in infections. The Candida strains express at least nine distinct genes (SAP1-9) during the course of the same disease but to different stages of infection, indicating that the different SAPs have different functions (Schaller, M. et al. J. Invest. Dermatol. 2000, 114, 712); particularly, among them SAP2 is one of the most expressed enzymes implicated in host persistent colonization and invasion.
[0005] Other strong evidence of the need of inhibitors of aspartyl protease activity are due to the following aspects:
Immunodeficient patients suffering of infections caused by Candida albicans can develop systemic candidiasis and also resistance to common therapeutics. HIV and HTVL viruses rely upon their aspartyl proteases for viral maturation. Plasmodium falciparum uses plasmepsines I and II for processing hemoglobin.
[0009] Recently, the inhibitory activity of HIV protease inhibitors (HIV-PI) against pathogenic microorganisms in which aspartyl proteases play a key role has been demonstrated (Tacconelli et al., Curr. Med. Chem., 2004, 4, 49). Particularly, HIV-PI show micromolar activity towards aspartyl proteases of both Candida albicans (Cassone et al., J. Infect. Dis., 1999, 180, 448), and malaria plasmepsines II and IV (Andrews et al., Antimicrob. Agents Chemother. 2006, 639). Such results are in agreement with the flexibility of these molecules and some structural analogy between aspartyl proteases of HIV-1 and SAP2 of Candida albicans.
[0010] Thus, new compounds having inhibitory activity towards aspartyl proteases can act as Candida albicans SAP2 inhibitors for treating fungus infections, as HIV protease inhibitors for treating HIV infections, as plasmepsines or histo-aspartyl protease (HAP) inhibitors for treating malaria.
[0000]
[0000] wherein:
[0011] R1 is chosen in the group consisting of H, benzyl, p-methoxybenzyl, benzhydryl; preferably benzyl;
[0012] R2 is a chosen in the group consisting of H, alkyl, aryl, alkylaryl; preferably H, benzyl, methyl, isobutyl.
[0013] R3 and R4 are independently chosen in the group consisting of H, alkyl, alkenyl, alkynyl, cycloalkyl, alkylaryl, aryl, hydroxyalkyl, alkoxyalkyl, alkoxycarbonyl, —CH(α-amino acid side chain)CH2OH; preferably H, hydroxyethyl, propargyl, —CH(Leu side chain)CH2OH;
[0014] R3 and R4 together with the nitrogen atom they are bonded to can form a cycle, eventually substituted; preferably piperidine, 4-hydroxyethyl-piperazine, 4-carboethoxy-piperazine, morpholine; including all the possible combinations of stereoisomers;
[0000] are known.
[0015] Their preparation has been reported in J. Org. Chem. 1999, 64, 7347 ; J. Org. Chem. 2002, 67, 7483 ; Bioorg. Med. Chem. 2001, 9, 1625 ; Eur. J. Org. Chem. 2002, 873 ; J. Org. Chem. 2002, 67, 7483 ; C. R. Chimie 2003, 631 ; J. Comb. Chem. 2007, 9, 454.
[0016] Their use in pharmaceutical compositions for the treatment of pathologies related to deficit of neurotrofines activity has been described in WO2004/000324.
[0017] Thus, aim of the present invention is to furnish alternative compounds for the preparation of medicaments for the treatment of pathologies related to aspartyl protease activity, and specifically of SAP2, and more specifically for the treatment of pharmaco-resistant systemic infections of Candida albicans in immunodepressed patients.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 —Vaginal infection with C. albicans SA40 in rats intravaginally treated with APG12 after challenge (1, 24, 48 hrs)
[0019] FIG. 2 —Vaginal infection with C. albicans AIDS 68 in rats intravaginally treated with APG12 after challenge (1, 24, 48 hrs)
DETAILED DESCRIPTION OF THE INVENTION
[0020] The present invention refers to compounds of formula (I)
[0000]
[0000] wherein:
[0021] R1 is a —CH(R)COR5;
[0022] R is a α-amino acid side chain, preferably said α-amino acid is chosen among the group consisting of Gly, Leu, Val, Ile, Ala, Phe, Phg, Nle, Nva;
[0023] R2 is H, alkyl, aryl, alkylaryl, preferably H, benzyl, methyl, isobutyl;
[0024] R3 and R4 are independently chosen in the group consisting of H, alkyl, alkenyl, alkynyl, cycloalkyl, alkylaryl, aryl, hydroxyalkyl, alkoxyalkyl, alkoxycarbonyl, —CH(α-amino acid side chain)CH2OH; preferably H, hydroxyethyl, propargyl, —CH(Leu side chain)CH2OH;
[0025] R3 and R4 together with the nitrogen atom they are bonded to can form a 5 to 8 membered cycle, eventually substituted; preferably piperidine, 4-hydroxyethyl-piperazine, 4-carboethoxy-piperazine, 4-benzyl-piperazine, 4-phenethyl-piperazine, morpholine;
[0026] R5 is chosen in the group consisting of —Oalkyl, —Oaryl, —NHalkyl, NHaryl, amino acid, peptide; preferably —OCH3, NHCH2CH(OH)CH2CONHBu;
[0000] including all the possible combinations of stereoisomers.
Surprisingly, it has been discovered that compounds of formula (I)
[0000]
[0000] wherein:
[0027] R1 is chosen in the group consisting of benzyl, phenyl, —CH(R)COR5; preferably benzyl, —CH(R)COR5;
[0028] R is a α-amino acid side chain; preferably said α-amino acid is chosen among the group consisting of Gly, Leu, Val, Ile, Ala, Phe, Phg, Nle, Nva;
[0029] R2 is H, alkyl, aryl, alkylaryl, preferably H, benzyl, methyl, isobutyl;
[0030] R3 and R4 are independently chosen in the group consisting of H, alkyl, alkenyl, alkynyl, cycloalkyl, alkylaryl, aryl, hydroxyalkyl, alkoxyalkyl, alkoxycarbonyl, —CH(α-amino acid side chain)CH2OH; preferably H, hydroxyethyl, propargyl, —CH(Leu side chain)CH2OH;
[0031] R3 and R4 together with the nitrogen atom they are bonded to can form a 5 to 8 membered cycle, eventually substituted; preferably piperidine, 4-hydroxyethyl-piperazine, 4-carboethoxy-piperazine;
[0032] R5 is chosen in the group consisting of —Oalkyl, —Oaryl, —NHalkyl, NHaryl, α-amino acid, peptide; preferably —OCH3, NHCH2CH(OH)CH2CONHBu;
[0000] including all the possible combinations of stereoisomers;
are potent inhibitors both in vitro and in vivo of SAP2, thus they can be used for the preparation of medicaments for treating infectious diseases, preferably related to Candida albicans , HIV, HTVL, Plasodium falciparum.
[0033] An aspect of the present invention relates to pharmaceutical compositions containing at least a compound of formula (I), wherein R1 is —CH(α-amino acid side chain)COR5; preferably such α-amino acid is chosen in the group consisting of Gly, Leu, Val, Ile, Ala, Phe, Phg, Nle, Nva; and at least another pharmaceutically acceptable ingredient, excipient, carrier or diluent.
[0034] According to the invention:
[0035] Alkyl means linear or branched radical chain, such as: methyl, ethyl, propyl, isopropyl, butyl, pentyl, hesyl, heptyl, octyl, ethenyl, propenyl, butenyl, isobutenyl, acetylenyl, propynyl, butynyl, etc. . . . ;
[0036] Aryl means aromatic or heteroaromatic ring containing heteroatoms like N, O, S. Amino acid side chain means diverse substitution as a side chain bound to an “amino acid”. The term “amino acid” includes every natural α-amino acids of the L or D series having as “side chain”: —H for glycine; —CH3 for alanine; —CH(CH3)2 for valine; —CH2CH(CH3)2 for leucine; —CH(CH3)CH2CH3 for isoleucine; —CH2OH for serine; —CH(OH)CH3 for threonine; —CH2SH for cysteine; —CH2CH2SCH3 for methionine; —CH2-(fenil) for phenylalanine; —CH2-(fenil)-OH for tyrosine; —CH2-(indole) for tryptophan; —CH2COOH for aspartic acid; —CH2C(O)(NH2) for asparagine; —CH2CH2COOH for glutamic acid; —CH2CH2C(O)NH2 for glutamine; —CH2CH2CH2—N(H)C(NH2)NH for arginine; —CH2-(imidazole) for hystidine; —CH2(CH2)3NH2 for lysine, comprising the same side chains of amino acids bearing suitable protecting groups. Moreover, the term “amino acid” includes non natural amino acids, such as ornitine (Orn), norleucine (Nle), norvaline (NVa), β-alanine, L or D α-phenylglycine (Phg), diaminopropionic acid, diaminobutyric acid, aminohydroxybutyric acid, and other well known in the state of the art of peptide chemistry.
[0037] Scheme 1 summarizes the synthetic preparation of compounds of formula (I) as described above, wherein R1 is —CH(R)COR5, R is a α-amino acid side chain, from commercially available or easily synthesizable α-amino-acid derivatives (II).
[0000]
[0038] Reductive alkylation of the amino acid derivative (II) with a commercially available or easily synthesisable dicarbonyl derivative, for example dimethoxy-acetaldehyde, in a protic solvent, preferably methanol, using a reducing agent, preferably H2 and a catalyst, preferably Pd/C, affords the secondary amine (III) after stirring at ambient temperature, preferably 16 h at 25° C. Alternatively, compound (II) is heated with a commercially available or easily synthesisable acetal derivative containing a good leaving group (X in Scheme 1), for example bromoacetaldehyde dimethylacetal, preferably at 120° C., in a polar solvent, preferably DMF, in the presence of a base, preferably NEt3, and in the presence of a catalyst, preferably KI. Amine (III) is successively converted into the amide (IV) through a coupling reaction with di-O-acetyl-tartaric anhydride. Treatment of crude (IV) with an acid in a polar solvent, preferably thionyl chloride in MeOH affords cyclic acetal (V) which is further heated in a non-polar solvent, preferably in refluxing toluene for 30 min, in the presence of an acid catalyst, preferably H2SO4 over silica gel, to yield (VI).
[0039] The synthesis of amides (I) is accomplished without using activating agents, by heating the methyl ester (VI) in the presence of the neat amine, preferably at 60° C. for 18 h.
[0040] The following examples are reported to give a non-limiting illustration of the present invention.
EXPERIMENTAL DETAILS
Example 1
(2S)-4-Methyl-2-[(1R,5S,7S)-2-oxo-7-(piperidine-1-carbonyl)-6,8-dioxa-3-aza-bicyclo[3.2.1]oct-3-yl]-pentanoic acid methyl ester [compound formula (I), where R1=—CH(Leu side chain)COOCH3, R2=H, R3 and R4=—CH2(CH2)3CH2-]
[0041] A solution containing L-leucine methyl ester hydrochloride (2.9 g, 16 mmol), 2-bromo-1,1-dimethoxy ethane (1.9 ml, 2.7 g, 16 mmol), NEt3 (6.7 ml, 48 mmol) and a catalytic amount of KI in DMF (190 ml) was stirred at 120° C. for 3 days. The reaction mixture was concentrated under reduced pressure, diluted with water and extracted with DCM. The organic layer was then washed with brine, dried over Na2SO4 and evaporated. The crude product was purified by column chromatography (silica gel, EtOAc/P.E. 1:1) to afford compound of formula (III), where R=Leu side chain, as a yellow oil (1.2 g, 32% yield).
[0042] [α] D 24 −3.32 (c 1.0, CHCl 3 ); 1 H-NMR (CDCl3, 200 MHz): δ 4.38 (t, J=6 Hz, 1H), 3.65 (s, 3H), 3.30 (s, 3H), 3.29 (s, 3H), 3.24 (t, J=6 Hz, 1H), 2.68 (dd, J 1 =J 2 =6 Hz, 1H), 2.52 (dd, J 1 =J 2 =6 Hz, 1H), 1.71-1.55 (m, 2H), 1.44-1.37 (m, 2H), 0.86 (d, J=4 Hz, 3H), 0.83 (d, J=4 Hz, 3H); 13 C-NMR (CDCl3, 200 MHz): δ 175.9 (s), 103.6 (d), 59.9 (d), 54.0 (q), 53.1 (q), 51.7 (q), 49.3 (t), 42.8 (t), 25.0 (d), 22.8 (q), 22.5 (q); MS m/z 233 (0.5), 202 (7.2), 174 (33), 158 (14), 75 (100); IR (CHCl3) 2915, 1729, 1130, 1065 cm −1 ; Anal. Calcd for C11H23NO4 (233.30): C, 56.63; H, 9.94; N, 6.00. Found: C, 57.49; H, 9.90; N, 6.24.
[0043] To a suspension of (S,S)-2,3-di-O-acetyl-tartaric anhydride (1 g, 4.7 mmol) in dry DCM (4.5 ml) was added, at 0° C. and under a nitrogen atmosphere, a solution of compound of formula (III), where R=Leu side chain, (1 g, 4.7 mmol) in dry DCM (2.5 ml). The reaction mixture was stirred at room temperature overnight. After evaporation of the solvent, the crude product of formula (IV), where R=Leu side chain, was dissolved in MeOH (8 ml) and thionyl chloride (292 μl 4 mmol) was added dropwise at 0° C. The mixture was then allowed to reach 60° C. and stirred for 2 h. The solvent was removed and the crude compound of formula (V), where R=Leu side chain, was isolated as a yellow oil and used without further purification in the next step.
[0044] A solution of (V), where R=Leu side chain, (1.63 g, 4.7 mmol) in toluene (8 ml) was quickly added to a refluxing suspension of SiO2/H2SO4 (1 g) in toluene (12 ml). The mixture was allowed to react for 30 min, and then one-third of the solvent was distilled off. The hot reaction mixture was filtered through a pad of NaHCO3 and, after evaporation of the solvent, the crude product was purified by flash chromatography (silica gel, EtOAc/P.E. 1:2) affording (VI), where R=Leu side chain, as a white solid (730 mg, 50% yield over three steps).
[0045] [α] D 24 22.0 (c 1.0, MeOH); 1 H-NMR (CDCl3, 200 MHz): δ 5.88 (d, J=2 Hz, 1H), 5.09 (t, J=8 Hz, 1H), 4.87 (s, 1H), 4.59 (s, 1H), 3.72 (s, 3H), 3.64 (s, 3H), 3.50 (dd, J 1 =12 Hz, J 2 =2 Hz, 1H), 3.11 (dd, J 1 =12 Hz, J 2 =2 Hz, 1H), 1.67-1.60 (m, 2H), 1.46-1.32 (m, 1H), 0.88 (s, 3H), 0.84 (s, 3H); 13 C-NMR (CDCl3, 200 MHz): δ 170.8 (s), 168.7 (s), 165.6 (s), 100.0 (d), 77.8 (d), 77.3 (d), 52.8 (d), 52.4 (q), 52.3 (q), 48.1 (t), 36.6 (t), 24.7 (d), 23.3 (q), 21.3 (q); MS m/z 315 (11), 256 (100), 240 (4); Anal. Calcd for C14H21NO7 (315.33): C, 53.33; H, 6.71; N, 4.44. Found: C, 52.99; H, 5.58; N, 4.79.
[0046] A solution containing (VI), where R=Leu side chain, (1 g, 3.2 mmol) and piperidine (6.3 ml, 63 mmol) was stirred at 60° C. overnight. The reaction mixture was then concentrated under reduced pressure, and the crude product was purified by column chromatography (silica gel, DCM/MeOH 20:1) to afford compound of formula (VII), where R=Leu side chain, R3 and R4=—CH2(CH2)3CH2— (corresponding to compound of formula (I), where R1=—CH(Leu side chain)COOCH3, R2=H, R3 and R4=—CH2(CH2)3CH2—), as a yellow oil (816 mg, 70% yield).
[0047] [α] D 22 33.6 (c 1.0, CHCl 3 ); 1 H-NMR (CDCl3, 200 MHz): (mixture of two rotamers) δ 5.79 (d, 1H, J=1.4 Hz), 5.06-4.94 (m, 1H), 5.02 (s, 1H), 4.82 (s, 1H, minor), 4.71 (s, 1H, major), 3.62 (s, 3H, minor), 3.61 (s, 3H, major), 3.55-3.20 (m, 5H), 3.09 (d, J=11.8 Hz, 1H), 1.67-1.34 (m, 9H), 0.86 (d, J=4.8 Hz, 3H), 0.84 (d, J=5.8 Hz, 3H); 13 C-NMR (CDCl3, 200 MHz) (mixture of two rotamers): δ 171.1 (s, minor), 170.8 (s, major), 167.6 (s, minor), 166.8 (s, major), 164.9 (s, minor), 164.8 (s, major), 99.6 (d, major), 99.5 (d, minor), 78.0 (d), 76.4 (d), 52.7 (q), 52.4 (d, major), 52.2 (d, minor), 48.6 (t, major), 47.7 (t, minor), 46.4 (t), 43.5 (t), 36.7 (t, major), 35.8 (t, minor), 26.4 (t), 25.5 (t), 24.7 (d), 24.5 (t), 23.2 (q), 21.5 (q); MS m/z 368 (M+), 309 (21), 312 (100); IR (CHCl3) 2935, 1739, 1666 cm −1 . Anal. Calcd. for C18H29N3O6 (368.43): C, 58.68; H, 7.66; N, 7.60. Found: C, 57.06; H, 7.50; N, 8.32
Example 2
(2S)-2-[(1R,5S,7S)-7-(4-methyl-piperazine-1-carbonyl)-2-oxo-6,8-dioxa-3-aza-bicyclo[3.2.1]oct-3-yl]-4-methyl-pentanoic acid methyl ester [compound of formula (I), where R1=—CH(Leu side chain)COOCH3, R2=H, R3 and R4=—CH2CH2N(CH3)CH2CH2-]
[0048] Compound (I), where R1=—CH(Leu side chain)COOCH3, R2=H, R3 and R4=—CH2CH2N(CH3)CH2CH2— was prepared according to the procedure described for compound (I), where R1=—CH(Leu side chain)COOCH3, R2=H, R3 and R4=—CH2(CH2)3CH2—, starting from compound (VI), where R=Leu side chain, (150 mg, 0.48 mmol) and 1-methyl piperazine (1.06 ml, 9.5 mmol). Pure compound (I), where R1=—CH(Leu side chain)COOCH3, R2=H, R3 and R4=—CH2CH2N(CH3)CH2CH2—, (128 mg, 72% yield) was obtained as yellow oil.
[0049] [α] D 25 28.1 (c 0.9, CHCl3); 1 H-NMR (CDCl3, 200 MHz): δ 5.85 (s, 1H), 5.12 (s, 1H), 5.05 (t, J=8 Hz, 1H), 4.77 (s, 1H), 3.68 (s, 3H), 3.62-3.51 (m, 5H), 3.14 (d, J=12 Hz, 1H), 2.42-2.33 (m, 4H), 2.72 (s, 3H), 1.73-1.65 (m, 2H), 1.49-1.42 (m, 1H), 0.92 (d, J=6 Hz, 3H), 0.90 (d, J=4 Hz, 3H); 13 C-NMR (CDCl3, 200 MHz): δ 170.8 (s), 166.8 (s), 165.0 (s), 99.7 (d), 78.0 (d), 76.4 (d), 55.0, 54.6 (t), 52.8 (q), 52.5 (d), 48.6 (t), 46.1 (q), 45.4 (t), 42.3 (t), 36.9 (t), 24.8 (d), 23.3 (q), 21.6 (q); MS m/z 383 (23), 352 (2.4), 324 (9), 99 (55), 70 (100); IR(CHCl3) 2866, 1738, 1670 cm −1 ; Anal. Calcd. for C18H29N3O6 (383.44): C, 56.38; H, 7.62; N, 10.96. Found: C, 55.12; H, 6.88; N, 12.01.
Example 3
4′-Methyl-(2′S)-2′-[(1R,5S,7S)-7-(morpholine-4-carbonyl)-2-oxo-6,8-dioxa-3-aza-bicyclo[3.2.1]oct-3-yl]-pentanoic acid methyl ester [compound of formula (I), where R1=—CH(Leu side chain)COOCH3, R2=H, R3 and R4=—CH2CH2OCH2CH2-]
[0050] Compound of formula (I), where R1=—CH(Leu side chain)COOCH3, R2=H, R3 and R4=—CH2CH2OCH2CH2— was prepared according to the procedure described for compound of formula (I), where R1=—CH(Leu side chain)COOCH3, R2=H, R3 and R4=—CH2(CH2)3CH2—, starting from compound (VI), where R=Leu side chain, (100 mg, 0.32 mmol) and morpholine (0.55 ml, 6.3 mmol). Pure compound of formula (I), where R1=—CH(Leu side chain)COOCH3, R2=H, R3 and R4=—CH2CH2OCH2CH2— (95 mg, 65% yield) was obtained as a yellow oil.
[0051] [α] D 22 29.0 (c 1.0, CHCl3); 1 H-NMR (CDCl3, 200 MHz): δ 5.86 (d, J=2 Hz, 1H), 5.16 (s, 1H), 5.06 (dd, J 1 =J 2 =8 Hz, 1H), 4.76 (s, 1H), 3.70 (s, 3H), 3.67-3.52 (m, 9H), 3.15 (d, J=12 Hz, 1H), 1.75-1.67 (m, 2H), 1.53-1.43 (m, 1H), 0.94 (d, J=6 Hz, 3H), 0.92 (d, J=6 Hz, 3H); 13 C-NMR (CDCl3, 200 MHz): δ 170.8 (s), 99.8 (d), 84.6 (d), 78.0 (d), 66.8 (t), 66.6 (t), 52.8 (q), 52.5 (d), 48.6 (t), 46.0 (t), 42.7 (t), 36.8 (t), 24.8 (d), 23.3 (q), 21.6 (q); MS m/z 370 (14), 311 (60), 283 (19), 168 (100); IR (CHCl3) 2932, 1735, 1668 cm −1 ; Anal. Calcd for C17H26N2O7 (370.41): C, 55.13; H, 7.08; N, 7.56. Found: C, 54.27; H, 6.40; N, 7.22.
Example 4
(2S)-2-[(1R,5S,7S)-7-(4-benzyl-piperazine-1-carbonyl)-2-oxo-6,8-dioxa-3-aza-bicyclo[3.2.1]oct-3-yl]-4-methyl-pentanoic acid methyl ester [compound of formula (I), where R1=—CH(Leu side chain)COOCH3, R2=H, R3 and R4=—CH2CH2N(benzyl)CH2CH2-]
[0052] Compound of formula (I), where R1=—CH(Leu side chain)COOCH3, R2=H, R3 and R4=—CH2CH2N(benzyl)CH2CH2— was prepared according to the procedure described for compound of formula (I), where R1=—CH(Leu side chain)COOCH3, R2=H, R3 and R4=—CH2(CH2)3CH2—, starting from compound of formula (VI), where R=Leu side chain, (100 mg, 0.32 mmol) and 1-benzyl piperazine (1.1 ml, 6.3 mmol). Pure compound of formula (I), where R1=—CH(Leu side chain)COOCH3, R2=H, R3 and R4=—CH2CH2N(benzyl)CH2CH2— (106 mg, 72% yield) was obtained as a yellow oil.
[0053] [α] D 23 20.1 (c 1.1, CHCl3); 1 H-NMR (CDCl3, 200 MHz): δ 7.42-7.27 (m, 5H), 5.88 (s, 1H), 5.25-5.05 (m, 2H), 4.79 (s, 1H), 3.71 (s, 3H), 3.63-3.53 (m, 7H), 3.16 (d, J=11.6 Hz, 1H), 2.51-2.45 (m, 4H), 1.76-1.68 (m, 2H), 1.55-1.25 (m, 1H), 0.96 (d, J=5, 3H), 0.93 (d, J=6.2 Hz, 3H); 13 C-NMR (CDCl3, 200 MHz): δ 170.8 (s), 166.8 (s), 165.0 (s), 129.1 (d), 128.3 (d), 127.3 (d), 99.7 (d), 78.0 (d), 76.4 (d), 62.9 (t), 52.9 (q), 52.7, 52.7 (t), 52.5 (d), 48.5 (t), 45.5, 42.4 (t), 36.8 (t), 24.8 (d), 23.3 (q), 21.6 (q); MS m/z 459 (10), 400 (1), 330 (1), 175 (19), 91 (100); IR(CHCl3) 2940, 1740, 1672 cm −1 ; Anal. Calcd for C24H33N3O6 (459.55): C, 62.73; H, 7.24; N, 9.14. Found: C, 61.34; H, 6.82; N, 8.50.
Example 5
(2S)-2-[(1R,5S,7S)-7-(4-phenylethyl-piperazine-1-carbonyl)-2-oxo-6,8-dioxa-3-aza-bicyclo[3.2.1]oct-3-yl]-4-methyl-pentanoic acid methyl ester [compound of formula (I), where R1=—CH(Leu side chain)COOCH3, R2=H, R3 and R4=—CH2CH2N(—CH2CH2Ph)CH2CH2-]
[0054] Compound of formula (I), where R1=—CH(Leu side chain)COOCH3, R2=H, R3 and R4=—CH2CH2N(—CH2CH2Ph)CH2CH2— was prepared according to the procedure described for compound of formula (I), where R1=—CH(Leu side chain)COOCH3, R2=H, R3 and R4=—CH2(CH2)3CH2—, starting from compound of formula (VI), where R=Leu side chain, (100 mg, 0.32 mmol) and 1-phenylethyl piperazine (1.2 ml, 6.3 mmol). Pure compound of formula (I), where R1=—CH(Leu side chain)COOCH3, R2=H, R3 and R4=—CH2CH2N(—CH2CH2Ph)CH2CH2— (89 mg, 59% yield) was obtained as a yellow oil.
[0055] [α] D 25 21.3 (c 0.9, CHCl 3 ); 1 H-NMR (CDCl3, 200 MHz): δ 7.33-7.18 (m, 5H), 5.88 (d, J=2 Hz, 1H), 5.17 (s, 1H), 5.09 (dd, J 1 =8 Hz, J 2 =6 Hz, 1H), 4.81 (s, 1H), 3.72 (s, 3H), 3.78-3.63 (m, 4H), 3.57 (dd, J 1 =12 Hz, J 2 =2 Hz, 1H), 3.18 (d, J=12 Hz, 1H), 2.88-2.80 (m, 2H), 2.70-2.58 (m, 6H), 1.78-1.70 (m, 2H), 1.53-1.25 (m, 1H), 0.98 (d, J=6 Hz, 3H), 0.94 (d, J=6 Hz, 3H); 13 C-NMR (CDCl3, 200 MHz): δ 170.6 (s), 166.5 (s), 164.8 (s), 138.5 (s), 128.4 (d), 128.3 (d), 126.1 (d), 99.5 (d), 77.7 (d), 76.9 (d), 59.5 (t), 52.6 (q), 52.4, 52.2 (t), 51.9 (d), 48.2, 44.3 (t), 41.3 (t), 36.5 (t), 32.4 (t), 24.4 (d), 22.8 (q), 21.2 (q); MS m/z 414 (1), 382 (95), 56(100); IR (CHCl 3 ) 2923, 1740, 1672 cm −1 ; Anal. Calcd. for C25H35N3O6 (473.57): C, 63.41; H, 7.45; N, 8.87. Found: C, 62.28; H, 7.01; N, 8.96.
Example 6
(2S)-4-Methyl-2-[(1R,5S,7S)-2-oxo-7-(piperidine-1-carbonyl)-6,8-dioxa-3-aza-bicyclo[3.2.1]oct-3-yl]-pentanoic acid (3-butylcarbamoyl-2-hydroxy-propyl)-amide [compound of formula (I), where R1=—CH(Leu side chain)COR5, R2=H, R3 and R4=—CH2CH2OCH2CH2—, R5=—NHCH2CH(OH)CH2CONHBu]
[0056] To a solution of 4-amino-3-hydroxy-butyric acid methyl ester hydrochloride salt, (37 mg, 0.22 mmol) in DCM (4 ml) were added, under a nitrogen atmosphere and at 0° C., PyBrOP (102 mg, 0.22 mmol), (2S)-4-methyl-2-[(1R,5S,7S)-2-oxo-7-(piperidine-1-carbonyl)-6,8-dioxa-3-aza-bicyclo[3.2.1]oct-3-yl]-pentanoic acid (80 mg, 0.22 mmol), previously obtained by basic ester hydrolysis of compound of formula (I), where R1=—CH(Leu side chain)COOCH3, R2=H, R3 and R4=—CH2(CH2)3CH2—, with LiOH, and DIPEA (85 μl, 0.5 mmol). The resulting solution was allowed to reach room temperature and was stirred overnight. The reaction mixture was then washed with a saturated solution of NaHCO3, aqueous 5% KHSO4, brine and dried over Na 2 SO 4 . After evaporation of the solvent the crude product was diluted in EtOAc and left for three hours at 4° C. in order to allow precipitation of the PyBrOP. After purification by flash chromatography, the resulting compound (40 mg, 0.08 mmol) was treated with n-butyl amine (168 μl, 1.7 mmol) in a mixture of THF (200 μl) and two drops of H2O at 50° C. for three days. Filtration of the reaction mixture on Amberlyst 15 and further purification by column chromatography (silica gel, DCM/MeOH 20:1) afforded 30 mg of compound of formula (I), where R1=—CH(Leu side chain)COR5, R2=H, R3 and R4=—CH2CH2OCH2CH2—, R5=—NHCH2CH(OH)CH2CONHBu as a colourless oil.
[0057] 1 H-NMR (CDCl3, 200 MHz): δ 6.81-6.68 (m, 1H), 6.41-6.22 (m, 1H), 5.90, 5.86 (s, 1H, mixture of two diastereoisomers), 5.14-4.81 (m, 3H), 4.13-3.92 (m, 1H), 3.66-3.35 (m, 6H), 3.36-3.02 (m, 4H), 2.28 (d, J=5.2 Hz, 2H), 1.88-1.20 (m, 13H), 0.97-0.87 (m, 9H); 13 C-NMR (CDCl3, 200 MHz): δ 171.5 (s), 170.2 (s), 168.0 (s), 164.8 (s), 99.6 (d), 77.9 (d), 67.9 (d), 54.1, 53.9 (d), 47.6 (t), 46.6 (t), 44.5 (t), 43.6 (t), 39.4 (t), 36.4 (t), 34.9 (t), 31.6 (t), 26.4 (t), 25.6 (t), 24.9 (d), 24.6 (t), 23.1 (q), 22.0 (q), 20.3 (t), 13.9 (q); MS m/z 510 (3), 309 (34), 112 (69), 84 (100).
[0058] The following examples are reported to give a non-limiting illustration of the in vitro and in vivo activity of selected compounds of the present invention.
Protease Enzyme Assay
[0059] Spectrophotometric method: protease activity of the various compounds of formula (I) was measured by a spectrophotometric assay with respect to pepstatin activity at the same concentration: each assay contained 50 μl of sample in 0.4 ml of 1% (w/v) BSA in 50 mM sodium citrate pH 3.2 and 50 μl of protease solution (1 μg/ml) After 30 min at 37° C. 1 ml 10% (w/v) trichloroacetic acid was added. The tubes were stored in ice for 30 min, and then centrifuged (3000 g) for 10 min. The absorbance of the supernatant was read at 280 nm. Control: 1% BSA in citrate buffer. One unit of the enzyme catalysed a ΔA 280 of 1 min −1 . With the pure protease the assay was proportional to enzyme concentration over the range ΔA 280 0.1-0.4 and a limit detection of 1 μg (De Bernardis F., Sullivan P. A., Cassone A. Medical Mycology 2001, 39, 303).
[0000]
TABLE 1
In vitro activity towards SAP2 of representative compounds of the present invention.
1% is the percent of inhibition with respect to pepstatin at the same concentration of 10 μm.
(I)
Cpd
R1
R2
R3
R4
R5
1%
1
—CH(Leu side chain)COR5
H
—CH2(CH2)3CH2—
OCH3
37
2
—CH(Leu side chain)COR5
H
—CH2CH2OCH2CH2—
OCH3
32
3
—CH(Leu side chain)COR5
H
—CH2(CH2)3CH2—
NHCH2CH(OH)
22
CH2CONHBu
4
—CH2Ph
H
H
—CH2CH2OH
—
36
5
—CH2Ph
H
H
—CH(Leu side chain)CH2OH
—
41
6
—CH2Ph
H
—CH2(CH2)3CH2—
—
42
7
—CH2Ph
H
—(CH2)2NCH2CH2OH(CH2)2—
—
34
8
—CH2Ph
H
—CH2CH2OCH2CH2—
—
31
9
—CH2Ph
H
—CH2CH2NC(O)OCH2CH3CH2CH2—
—
37
10
—CH2Ph
H
H
—(CH2)3OH
—
12
11
—CH2Ph
H
H
—CH(Pro side chain)CH2OH
—
24
12
—CH2Ph
H
H
—CH(D-Pro side chain)CH2OH
—
17
13
—CH2Ph
H
H
—CH(Phg side chain)CH2OH
—
16
14
—CH2Ph
H
H
—CH(Phe side chain)CH2OH
—
19
15
—CH2Ph
H
H
—CH(D-Phe side chain)CH2OH
—
15
16
—CH2Ph
—CH2Ph
H
—(CH2)3CH3
—
17
17
—CH2Ph
—CH2Ph
H
—(CH2)5CH3
—
21
18
—CH2Ph
—CH2Ph
H
—CH2CF3
—
17
19
—CH2Ph
—CH2Ph
—CH2CH2OCH2CH2—
—
25
20
—CH2Ph
—CH2Ph
—CH2CH2SCH2CH2—
—
28
21
—CH2Ph
—CH2Ph
—(CH2)2NCH2CH2OH(CH2)2—
—
31
In Vivo Assay
[0060] Experimental vaginal infection: for the experimental vaginal infection, a previously described rat vaginal model was adopted (De Bernardis, F.; Boccanera, M.; Adriani, D.; Spreghini, E.; Santoni, G.; Cassone, A. Infect. Immun., 1997, 65, 3399).
[0061] In brief, oophorectomized female Wistar rats (80-100 g; Charles River Calco, Italy) were injected subcutaneously with 0.5 mg of estradiol benzoate (Estradiolo, Amsa Farmaceutici srl, Rome, Italy). Six days after the first estradiol the animals were inoculated intravaginally with 107 yeast cells in 0.1 ml of saline solution of each C. albicans strain tested. The inoculum was dispensed into the vaginal cavity through a syringe equipped with a multipurpose calibrated tip (Combitip; PBI, Milan, Italy). The yeast cells had been previously grown in YPD broth (yeast extract 1%; peptone 2%; dextrose 2%) at 28° C. on a gyrator shaker (200 rpm), harvested by centrifugation (1500 g), washed, counted in a hemocytometer, and suspended to the required number in saline solution. The number of cells in the vaginal fluid was counted by culturing 100 μl samples (using a calibrated plastic loop, Disponoic, PBI, Milan, Italy) taken from each animals, on Sabouraud agar containing chloramphenicol (50 μg/ml) as previously described. The rat was considered infected when at least 1 CFU was present in the vaginal lavage, i.e. a count of >103 CFU/ml.
[0062] As a representative example for in vivo studies, one of the compounds of formula (I), as above described and hereinafter named APG12, corresponding to compound 6 of Table 1, was administered intravaginally at concentrations of 10 μM 1 h, 24 h and 48 h after intravaginal Candida albicans challenge with two different strains, namely SA40 and the pharmacoresistant AIDS68. Positive (pepstatin 10 μg; fluconazole 10 μg and negative (sterile saline solution) were similarly administered.
[0063] The profile of Candida albicans clearance in rats intravaginally treated with APG12 is similar to the acceleration observed in rats treated with the natural SAP2 inhibitor pepstatin, and in rats treated with fluconazole (Table 2 and FIG. 1 ). More importantly, the acceleration of Candida albicans clearance in the pharmacoresistant AIDS68 strain shows efficacy of both the natural SAP2 inhibitor pepstatin and of APG12, whereas the fluconazole is ineffective, showing a clearance profile similar to the untreated control (Table 3 and FIG. 2 ).
[0000]
TABLE 2
Acceleration of Candida SA40 clearance in rats intravaginally treated with
APG12 after challenge (1, 24, 48 hrs)
SA40 +
DAYS
SA40 + APG12
pepstatin
SA40
0
>100
>100
>100
1
70 ± 1.3
56.8 ± 2
>100
2
57.6 ± 1.4
51 ± 1.2
>100
5
39.2 ± 3
32.4 ± 2.5
80 ± 2.6
7
30.6 ± 1.8
28 ± 1.5
66 ± 2.1
14
14.4 ± 1.6
9.4 ± 1.4
26.2 ± 1.8
21
8 ± 1.5
5 ± 1.3
12.8 ± 1.2
28
1.2 ± 0.7
0
5.8 ± 1.6
[0064] All values×1000; SA40: untreated control; Starting day 1, all differences between APG12-treated and untreated control are statistically significant; (P<0.01, Mann-withney U test)
[0000]
TABLE 3
Acceleration of Candida AIDS68 clearance in rats intravaginally treated
with APG12 after challenge (1, 24, 48 hrs)
AIDS68 +
AIDS68 +
AIDS68 +
DAYS
APG12
pepstatin
fluconazole
AIDS68
0
>100 ± 0
>100 ± 0
>100 ± 0
>100 ± 0
1
71.8 ± 1.3
58.4 ± 1.0
100 ± 0
100 ± 0
2
62.6 ± 1.5
52.0 ± 1.3
93 ± 4.3
100 ± 0
5
40.6 ± 1.4
37.2 ± 1.6
61 ± 2.5
71 ± 1.6
7
23.2 ± 1.4
30.0 ± 1.2
44 ± 2.9
50 ± 3.5
14
12.8 ± 1.2
19.8 ± 0.8
18.7 ± 3.8
25 ± 1.6
21
3.4 ± 1.7
3.8 ± 1.9
11.7 ± 0.7
10.7 ± 1.6
28
0 ± 0
0 ± 0
0 ± 0
7.7 ± 3
[0065] All values×1000; AIDS68: untreated control; Starting day 1, all differences between APG12-treated and untreated control are statistically significant; (P<0.01, Mann-withney U test)
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The present invention refers to 3-aza-bicyclo[3.2.1]octane derivatives of general formula (I) their preparation, use and pharmaceutical compositions useful in the treatment of pathologies associated with microbial pathogens expressing aspartyl-protease activity.
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FIELD
[0001] The invention relates to a data processing method, a transmitter, a device, a network element and a base station.
BACKGROUND
[0002] Due to non-linear effects of analog components of a transmission chain, a transmitted signal is distorted in amplitude and phase. Such distortions usually depend on the signal magnitude.
[0003] The main cause for the distortions is a power amplifier of a transmitter. In addition to amplifying a desired signal, the power amplifier generates higher order harmonics of the original signal spectrum. The spread of the signal spectrum causes two major effects: a radio frequency spectrum mask does not fulfil the requirements for out-of-band radiated power, and detection of a distorted signal in a receiver suffers from errors.
[0004] The spread of the signal spectrum can be avoided (or at least diminished) by reducing the power of a power amplifier input signal. This is called “backing off”. However, such “backing off” leads to inefficient use of the amplification stage. Another option is to use a linearization technique. Several different prior art linearization techniques exist. The most effective of them are adaptive, since a plurality of factors, such as temperature, affect a transmission chain, making it unstable. Adaptation requires a reliable estimate of signal distortion. For the estimation, a feedback chain is typically used. A problem is that the feedback chain also generates distortion which sometimes makes the estimate of the signal distortion quite unreliable.
BRIEF DESCRIPTION OF THE INVENTION
[0005] According to an aspect of the invention, there is provided a data processing method in a transmitter, the method comprising: generating a feedback signal by using a feedback chain; setting a predetermined frequency shift to the feedback signal; evaluating distortion caused in a transmission chain based on the frequency shifted feedback signal; adapting quadrature modulation pre-distortion algorithms of the transmission chain; setting frequency of the feedback signal to an original frequency; evaluating distortion caused in the feedback chain based on the feedback signal having the original frequency; adapting quadrature demodulation pre-distortion algorithms of the feedback chain; adapting other pre-distortion algorithms.
[0006] According to another aspect of the invention, there is provided a data processing method in a transmitter, the method comprising: generating a feedback signal by using a feedback chain; setting a predetermined frequency shift to the feedback signal; evaluating distortion caused in a transmission chain based on the frequency shifted feedback signal; adapting pre-distortion algorithms of the transmission chain; setting frequency of the feedback signal to an original frequency; evaluating distortion caused in the feedback chain based on the feedback signal having the original frequency; and adapting pre-distortion algorithms of the feedback chain.
[0007] According to another aspect of the invention, there is provided a transmitter, comprising: generating unit configured to generate a feedback signal; setting unit configured to set a predetermined frequency shift to the feedback signal; evaluating unit configured to evaluate distortion caused in a transmission chain based on the frequency shifted feedback signal; adapting unit configured to adapt quadrature modulation pre-distortion algorithms of the transmission chain; wherein the setting unit is further configured to set frequency of the feedback signal to an original frequency; wherein evaluating the evaluating unit is further configured to evaluate distortion caused in the feedback chain based on the feedback signal having the original frequency; wherein the adapting unit is further configured to adapt quadrature demodulation pre-distortion algorithms of the feedback chain; and wherein the adapting unit is further configured to adapt other pre-distortion algorithms.
[0008] According to another aspect of the invention, there is provided a device, comprising: generating unit configured to generate a feedback signal; setting unit configured to set a predetermined frequency shift to the feedback signal; evaluating unit configured to evaluate distortion caused in a transmission chain based on the frequency shifted feedback signal; adapting unit configured to adapt quadrature modulation pre-distortion algorithms of the transmission chain; wherein the setting unit is further configured to set frequency of the feedback signal to an original frequency; wherein the evaluating unit is further configured to evaluate distortion caused in the feedback chain based on the feedback signal having the original frequency; wherein the adapting unit is further configured to adapt quadrature demodulation pre-distortion algorithms of the feedback chain; and wherein the adapting unit is further configured to adapt other pre-distortion algorithms.
[0009] According to another aspect of the invention, there is provided a network element, comprising: generating unit configured to generate a feedback signal; setting unit configured to set a predetermined frequency shift to the feedback signal; evaluating unit configured to evaluate distortion caused in a transmission chain based on the frequency shifted feedback signal; adapting unit configured to adapt quadrature modulation pre-distortion algorithms of the transmission chain; wherein the setting unit is further configured to set a frequency of the feedback signal to an original frequency wherein the evaluating unit is further configured to evaluate distortion caused in the feedback chain based on the basis of the feedback signal having the original frequency; wherein the adapting unit is further configured to adapt quadrature demodulation pre-distortion algorithms of the feedback chain; and wherein the adapting unit is further configured to adapt other pre-distortion algorithms.
[0010] According to another aspect of the invention, there is provided a base station comprising: generating unit configured to generate a feedback signal; setting unit configured to set a predetermined frequency shift to the feedback signal; evaluating unit configured to evaluate distortion caused in a transmission chain based on the frequency shifted feedback signal; adapting unit configured to adapt quadrature modulation pre-distortion algorithms of the transmission chain; wherein the setting unit is further configured to set a frequency of the feedback signal to an original frequency; wherein the evaluating unit is further configured to evaluate distortion caused in the feedback chain based on of the feedback signal having the original frequency; wherein the adapting unit is further configured to adapt quadrature demodulation pre-distortion algorithms of the feedback chain; and wherein the adapting unit is further configured to adapt other pre-distortion algorithms.
[0011] According to another aspect of the invention, there is provided a transmitter configured to: generate a feedback signal; set a predetermined frequency shift to the feedback signal; evaluate distortion caused in a transmission chain based on the frequency shifted feedback signal; adapt quadrature modulation pre-distortion algorithms of the transmission chain; set frequency of the feedback signal to an original frequency value; evaluate distortion caused in the feedback chain based on the feedback signal having the original frequency; adapt quadrature demodulation pre-distortion algorithms of the feedback chain; and adapt other pre-distortion algorithms.
[0012] According to another aspect of the invention, there is provided a device configured to: generate a feedback signal; set a predetermined frequency shift to the feedback signal; evaluate distortion caused in a transmission chain based on the frequency shifted feedback signal; adapt quadrature modulation pre-distortion algorithms of the transmission chain; set frequency of the feedback signal to an original frequency; evaluate distortion caused in the feedback chain based on the feedback signal having the original frequency; adapt quadrature demodulation pre-distortion algorithms of the feedback chain; and adapt other pre-distortion algorithms.
[0013] According to another aspect of the invention, there is provided a network element configured to: generate a feedback signal; set a predetermined frequency shift to the feedback signal; evaluate distortion caused in a transmission chain based on the frequency shifted feedback signal; adapt quadrature modulation pre-distortion algorithms of the transmission chain; set frequency of the feedback signal to an original frequency; evaluate distortion caused in the feedback chain based on the feedback signal having the original frequency; adapt quadrature demodulation pre-distortion algorithms of the feedback chain; and adapt other pre-distortion algorithms.
[0014] According to another aspect of the invention, there is provided a base station configured to: generate a feedback signal; set a predetermined frequency shift to the feedback signal; evaluate distortion caused in a transmission chain based on the frequency shifted feedback signal; adapt quadrature modulation pre-distortion algorithms of the transmission chain; set frequency of the feedback signal to an original frequency; evaluate distortion caused in the feedback chain based on the feedback signal having the original frequency; adapt quadrature demodulation pre-distortion algorithms of the feedback chain; and adapt other pre-distortion algorithms.
[0015] The invention provides several advantages.
[0016] In an embodiment of the invention, errors caused by the transmission chain can be separated from errors caused by the feedback chain, thus providing a reliable estimate of the signal distortion for pre-distortion.
LIST OF DRAWINGS
[0017] In the following, the invention will be described in greater detail with reference to embodiments and the accompanying drawings, in which
[0018] FIG. 1 shows an example of a communication system;
[0019] FIG. 2 is a flow chart; and
[0020] FIG. 3 illustrates a part of a transmitter including a feedback chain.
DESCRIPTION OF EMBODIMENTS
[0021] With reference to FIG. 1 , we examine an example of a communication system to which embodiments of the invention can be applied. The present invention can be applied to various communication systems. One example of such a communication system is a Universal Mobile Telecommunications System (UMTS) radio access network. It is a radio access network which includes wideband code division multiple access (WCDMA) technology and can also offer real-time circuit and packet switched services. Another example is a Global System for Mobile Communications (GSM). The embodiments are not, however, restricted to the systems given as examples but a person skilled in the art may apply the solution to other communication systems provided with the necessary properties.
[0022] It is clear to a person skilled in the art that the method according to the invention can be applied to systems utilizing different air interface standards or modulation methods, such as quadrature phase-shift keying (QPSK) or orthogonal frequency division multiplexing (OFDM).
[0023] FIG. 1 is a simplified illustration of a data transmission system to which the solution according to the invention is applicable. This is a part of a cellular radio system, which comprises a base station (or node B) 100 , which has bi-directional radio links 102 and 104 to subscriber terminals 106 and 108 . The subscriber terminals may be fixed, vehicle-mounted or portable. The base station includes transceivers, for instance. From the transceivers of the base station, there is a connection to an antenna unit that establishes the bi-directional radio links to the subscriber terminals. The base station is further connected to a controller 110 , a radio network controller (RNC) or a base station controller (BSC), which transmits the connections of the terminals to the other parts of the network. The base station controller of the radio network controller controls in a centralized manner several base stations connected to it. The base station controller or the radio network controller is further connected to a core network 112 (CN). Depending on the system, the counterpart on the CN side can be a mobile services switching centre (MSC), a media gateway (MGW) or a serving GPRS (general packet radio service) support node (SGSN) etc.
[0024] The radio system can also communicate with other networks, such as a public switched telephone network or the Internet.
[0025] Next, an embodiment of the data processing method is explained in further detail by means of FIG. 2 . In the embodiment, the feedback chain depicted in FIG. 3 may be used.
[0026] First, the principle of pre-distortion is clarified.
[0027] The main cause for distortions is non-linearity of a power amplifier. Power amplifiers are required in radio systems to amplify signals before transmission, because radio signals attenuate on the radio path. Unfortunately, high-power radio-frequency amplifiers tend to be non-linear devices and therefore they often cause distortion. This distortion is expressed, for example, as Inter-Symbol-Interference or out-off-band power in adjacent frequency bands. An ACLR (Adjacent Carrier Leakage Ratio) quantifies the out-off-band transmitted power and thus it must remain within specified limits.
[0028] Linear amplification is mostly needed when the transmitted signal contains both amplitude and phase modulation. Examples of these modulation methods include quadrature phase-shift keying (QPSK) and orthogonal frequency division multiplexing (OFDM).
[0029] Pre-distortion generates a non-linear transfer function which can be thought of as a reverse of the power amplifier's transfer function taking into account both amplitude and phase. In other words, pre-distortion is designed to provide distortion complementary to that of the power amplifier, prior to the input of the power amplifier, producing an overall linear transfer function.
[0030] Effective pre-distortion requires adaptation since changes in parameters, such as in signal phase, modulation, component characteristics or temperature, change the transfer function of the power amplifier. For the adaptation, feedback from the power amplifier's output signal is required. The feedback is usually generated by using a feedback chain to produce measurement results from the power amplifier's output signal.
[0031] Various techniques are used for producing information on the power amplifier's output signal characteristics for pre-distortion adaptation purposes. Examples of such techniques include carrier-to-inter-modulation (C/I) ratio, which compares the amplitude of the desired output carries to intermodulation-distortion (IMD) products; an adjacent channel power ratio (ACPR), which compares the power in an adjacent channel to that of the selected signal, a residual error signal, which relates to the complex error between transmit and feedback signals; and an error vector magnitude (EVM), which measures the deviation of the signal from the ideal waveform.
[0032] In the case of digital pre-distortion, complementary non-linearity is generated in the digital domain, typically at base-band or intermediate frequency. Therefore, it can be implemented in connection with digital signal processing (DSP) thus also providing a possibility to incorporate compensation for distortions caused by digital-to-analog conversion and frequency up-conversion.
[0033] A transmission chain modulator and a feedback chain demodulator generate similar kind of errors. Examples of modulator and demodulator errors include gain and phase imbalances manifesting themselves as an image frequency component of the desired signal. Another example is a DC-offset (direct current offset) which can be seen as a local oscillator component in transmitted and feedback signals.
[0034] The embodiment of the data processing method enables distortion caused by a transmitter modulator and distortion caused by a feedback demodulator to be separated, thus providing a possibility for more optimal adaptation of pre-distortion algorithms.
[0035] The embodiment begins in block 200 . In block 202 , a feedback signal is generated by using a feedback chain. A part of the output signal of the power amplifier is taken into the feedback chain for generating a feedback signal. One example of a feedback chain is depicted in FIG. 3 and will be explained later in this application.
[0036] In block 204 , a predetermined frequency shift is set to the feedback signal. The frequency shift is usually generated by using a local oscillator. The purpose of the frequency shift is to separate transmitter modulator errors and feedback demodulator errors by generating a frequency offset. The amount of frequency separation needed may vary according to the circumstances. A suitable frequency shift can be found for instance by simulations.
[0037] In block 206 , distortion caused in a transmission chain is evaluated on the basis of the frequency shifted feedback signal. The evaluation is typically based on measuring the feedback signal; the signal is usually measured after it has been returned from analog to digital form in a base-band frequency. It is also possible to measure a signal in another part of the feedback chain, for instance at an intermediate frequency.
[0038] Various techniques are used for producing measurement-based information on the distortion in the power amplifier's output signal characteristics. Examples of such techniques include a carrier-to-inter-modulation (C/I) ratio, which compares the amplitude of the desired output carries to intermodulation-distortion (IMD) products; an adjacent channel power ratio (ACPR), which compares the power in an adjacent channel to that of the selected signal, a residual error signal, which relates to the complex error between transmit and feedback signals; and an error vector magnitude (EVM), which measures the deviation of the signal from the ideal waveform.
[0039] Attention should be paid to the fact that the frequency shift (or the frequency offset) between the transmission chain and the down-conversion chain is removed with digital down-conversion in order to enable a transmitted signal and a frequency shifted feedback signal to be compared at the same frequency.
[0040] In block 208 , quadrature modulation (AQM) pre-distortion algorithms of the transmission chain are adapted. Several different prior art pre-distortion algorithms exist but they are not explained here in further detail. Basically, pre-distortion algorithms are designed to adapt one or more signal properties affected by transmission chain distortions, such as amplitude and phase.
[0041] In block 210 , the frequency of the feedback signal is set to an original frequency value. The frequency is usually returned to the original frequency by using the same local oscillator as was used for generating. A digital down-conversion frequency shift is also removed.
[0042] In block 212 , distortion caused in the feedback chain is evaluated on the basis of the feedback signal having the original frequency. The evaluation is typically based on measuring the feedback signal as described in connection to block 206 . The signal is usually measured after it has been returned from analog to digital form in a base-band frequency. It is also possible to measure a signal in another part of the feedback chain, for instance at an intermediate frequency.
[0043] Various techniques are used for producing measurement-based information on the distortion in the power amplifier's output signal characteristics. Examples of such techniques include a carrier-to-inter-modulation (C/I) ratio, which compares the amplitude of the desired output carries to intermodulation-distortion (IMD) products; an adjacent channel power ratio (ACPR), which compares the power in an adjacent channel to that of the selected signal, a residual error signal, which relates to the complex error between transmit and feedback signals; and an error vector magnitude (EVM), which measures the deviation of the signal from the ideal waveform.
[0044] In block 214 , quadrature demodulation (AQDeM) post-distortion algorithms of the feedback chain are adapted. Several different prior art pre-distortion algorithms exist but they are not explained here in further detail. Basically, pre-distortion algorithms are designed to adapt one or more signal properties affected by transmission chain distortions, such as amplitude and phase.
[0045] In block 216 , other pre-distortion algorithms are adapted. Examples of potential characteristics to be adjusted by the pre-distortion algorithms include time and frequency.
[0046] It is also possible to adapt pre-distortion algorithms compensating for transmitter modulator distortion by simultaneously taking into account distortion caused in the feedback chain instead of using separate pre-distortion phases for the transmission chain and for the feedback chain.
[0047] The embodiment ends in block 218 . Arrow 220 depicts that the embodiment is repeatable. The embodiment is typically repeated several times during transmission, using a predetermined measuring period.
[0048] In another embodiment, pre-distortion algorithms of the transmission chain are first adapted and pre-distortion algorithms of the feedback chain then are adapted. This embodiment is suitable for use with modulation methods other than quadrature amplitude modulation.
[0049] Next, an example of a part of a transmitter including a feedback chain is explained in greater detail by means of FIG. 3 . A transmitter is typically located in a network element such as a base station or a communication device without being restricted thereto. It is obvious to a person skilled in the art that the structure of the transmitter may vary according to the implementation. The part of a transmitter of FIG. 3 can also be thought to be a separate device placeable for instance in a transmitter.
[0050] In this example, the transmitter includes a digital adaptive pre-distortion (DAPD) block 314 .
[0051] A non-linear high-efficiency amplifier distorts both the amplitude and phase of a signal. Non-linearity also causes inter-modulation distortion and spectral re-growth. These cause adjacent channel interference due to which network performance deteriorates.
[0052] In principle, pre-distortion is designed to provide distortion complementary to that of the power amplifier, prior to the input of the power amplifier, producing an overall linear transfer function.
[0053] In the case of digital pre-distortion, the complementary non-linearity is generated in the digital domain, typically at base-band or intermediate frequency. Therefore it can be implemented in connection with digital signal processing (DSP) thus also providing a possibility to incorporate compensation for other distortion, such as distortion caused by digital-to-analog conversion and frequency up-conversion.
[0054] In DSP (Digital Signal Processing), the signal to be transmitted is processed in several ways, for instance it is encrypted and/or coded. The DSP may also include modulation and spreading, if the system is using a wide-band technique.
[0055] Digital adaptive pre-distortion is typically implemented by using a digital signal processing (DSP) device, typically a processor. The DSP device forms and updates the selected pre-distortion characteristics. Digital adaptive pre-distortion is typically implemented by using one or more look-up tables (LUT).
[0056] In a transmission chain, in quadrature amplitude modulation block 302 , a signal is modulated directly to a carrier frequency (in other words to a radio frequency) either via an intermediate frequency or directly to the carrier frequency by using a local oscillator signal from a local oscillator 304 .
[0057] Modulation means that a data stream modulates a carrier. In the example, a transmitter producing quadrature amplitude modulation (QAM) is depicted. QAM is a modulation technique that uses two amplitude modulated RF carriers that are out of phase by 90 degrees. Information transfer is achieved by accomplishing both phase and amplitude changes into the carriers.
[0058] Modulation methods are known in the art and therefore they are not explained here in greater detail.
[0059] Block 306 is a power amplifier which amplifies the signal for a radio path. High power amplifiers having high efficiency especially when used in systems using spectrally efficient modulation schemes, such as QPSK and OFDM, cause signal distortion. An amplifier may also be an amplifier chain including cascaded gain stages with different power gains.
[0060] The feedback chain includes a quadrature amplitude demodulation block 310 and a local oscillator 308 . The local oscillator 308 changes the frequency of the feedback signal by producing frequency offset offering a possibility to separate transmitter modulator errors and feedback demodulator errors.
[0061] In block 310 , the feedback signal is demodulated directly from a radio frequency to a digital base-band or an intermediate frequency. In the embodiment, block 310 also includes means for measuring the feedback signal.
[0062] In the embodiment, transmitter modulator compensator block 300 and feedback demodulator compensator block 312 are located in DAPD 314 .
[0063] The transmitter modulator compensator evaluates distortion caused in the transmission chain on the basis of the frequency shifted feedback signal.
[0064] The evaluation is typically based on measuring the feedback signal. Various techniques are used for producing measurement-based information on the distortion in the power amplifier's output signal characteristics. Examples of such techniques include a carrier-to-inter-modulation (C/I) ratio, which compares the amplitude of the desired output carries to intermodulation-distortion (IMD) products; an adjacent channel power ratio (ACPR), which compares the power in an adjacent channel to that of the selected signal, a residual error signal, which relates to the complex error between transmit and feedback signals; and an error vector magnitude (EVM), which measures the deviation of the signal from the ideal waveform.
[0065] The digital adaptive pre-distorter (DAPD) coupled with a modulator compensator 300 and a demodulator 312 compensator also adapts other required pre-distortion algorithms of the transmission chain. Several different prior art pre-distortion algorithms exist but they are not explained here in further detail. Basically, pre-distortion algorithms are designed to adapt one or more signal properties affected by transmission chain distortions, such as amplitude, phase and frequency.
[0066] The feedback demodulator compensator evaluates distortion caused in the feedback chain on the basis of the feedback signal having the original (typically base-band) frequency. The evaluation is typically based on measuring the feedback signal. Various techniques are used for producing measurement-based information on the distortion in the power amplifier's output signal characteristics. Examples of such techniques include a carrier-to-inter-modulation (C/I) ratio, which compares the amplitude of the desired output carries to inter-modulation-distortion (IMD) products; an adjacent channel power ratio (ACPR), which compares the power in an adjacent channel to that of the selected signal, a residual error signal, which relates to the complex error between transmit and feedback signals; and an error vector magnitude (EVM), which measures the deviation of the signal from the ideal waveform.
[0067] The feedback demodulator compensator also adapts required pre-distortion algorithms of the feedback chain. Several different prior art pre-distortion algorithms exist but they are not explained here in further detail. Basically, pre-distortion algorithms are designed to adapt one or more signal properties affect by transmission chain distortions, such as amplitude, phase and frequency.
[0068] Attention should be paid to the fact that the frequency shift (or the frequency offset) between the transmission chain and the local oscillator is removed with digital down-conversion in order to enable a transmitted signal (power amplifier's output signal) and a frequency shifted feedback signal to be compared at the same frequency. This is carried out either in the transmitter modulator compensator block or in the feedback demodulator compensator block in the DAPD.
[0069] It is also possible to adapt pre-distortion algorithms compensating for transmitter modulator distortion by simultaneously taking into account distortion caused in the feedback chain instead of using separate pre-distortion phases for the transmission chain and for the feedback chain.
[0070] The disclosed functionalities of the described embodiments of the data processing method can be advantageously implemented by means of software, typically being located in a Digital Signal Processor. The feedback information is provided with a feedback chain. The implementation solution can also be, for instance, an ASIC (Application Specific Integrated Circuit) component. A hybrid of these different implementations is also feasible.
[0071] Even though the invention has been described above with reference to an example according to the accompanying drawings, it is clear that the invention is not restricted thereto but it can be modified in several ways within the scope of the appended claims.
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The invention is related to a device comprising: generating unit configured to generate a feedback signal; setting unit configured to set a predetermined frequency shift to the feedback signal; evaluating unit configured to evaluate distortion caused in a transmission chain on the basis of the frequency shifted feedback signal; adapting unit configured to adapt quadrature modulation pre-distortion algorithms of the transmission chain; wherein the setting unit is further configured to set the frequency of the feedback signal to an original frequency value; wherein the evaluating unit is further configured to evaluate distortion caused in the feedback chain based on the feedback signal having the original frequency; wherein the adapting unit is further configured to adapt quadrature demodulation pre-distortion algorithms of the feedback chain; and wherein the adapting unit is further configured to adapt other pre-distortion algorithms.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims priority to and is a divisional of U.S. patent application Ser. No. 14/533,313 filed on Nov. 5, 2014, which claims priority to and is a divisional of abandoned U.S. patent application Ser. No. 12/850,166 filed on Aug. 4, 2010, all of which are hereby entirely incorporated by reference.
TECHNICAL FIELD
The present invention relates generally to an apparatus and method for forming one or more liquid streams having relatively small, well defined cross sectional areas which are normally directed to a target substrate, and for selectively interrupting and redirecting the flow of such liquid streams by application of gaseous fluid impingement jets transverse to the normal flow direction of the liquid streams. More specifically, the invention relates to an apparatus and method providing precise and substantially instantaneous switching between (i) a normal application mode in which a liquid stream is applied to a substrate and (ii) a diversion mode in which the liquid stream is redirected away from the substrate. Such switching is carried out in response to commands to develop desired fine scale treatment patterns across the substrate.
BACKGROUND OF THE INVENTION
Systems that provide relatively fine scale treatment patterns of liquid across a target substrate by interruption of the applied liquid streams are generally known. In prior systems, multiple liquid streams are expelled under pressure from orifice openings arranged in close, side-by-side relation. The orifice openings are surrounded circumferentially by walls defining the openings. The pressure liquid streams normally project towards a target substrate but are intermittently interrupted by application of a transverse gas jet which redirects the liquid stream away from the target substrate and into a collection reservoir to be reused. When application of the gas jet is discontinued, the liquid streams resume along the initial path. Such systems are used typically to apply intricate patterns of dye or other liquids to textile substrates, although other substrates may likewise be treated if desired.
While the prior systems work very well, it is a continuing challenge to provide improved definition in the applied pattern across the substrate while nonetheless delivering a sufficient quantity of dye or other liquid to the substrate to provide complete treatment. It is also a continuing challenge to provide reduced complexity in the system set-up as well as enhanced functionality in the collection of unused liquid.
SUMMARY OF THE INVENTION
The present invention provides advantages and alternatives over prior constructions and practices by providing an improved system for application of liquid streams to a substrate. The system of the present invention incorporates open face flow channels prior to discharge along an unconstrained flow path. The present invention further provides an improved self-aligning modular assembly for delivery of impingement stream to the liquid streams. The present invention further provides an improved arrangement for collection of the liquid stream in a diverted flow path in response to application of the impingement stream, without excess residue build-up.
In accordance with one exemplary aspect, the present invention provides an apparatus for intermittently applying one or more liquid streams to a target substrate. The apparatus includes a liquid supply in the form of a manifold for holding a liquid and a plurality of liquid conveyance channels in fluid communication with the liquid supply. The liquid conveyance channels are adapted to carry liquid away from the manifold and towards the target substrate. At least one of the liquid conveyance channels includes a first segment defining a substantially fully enclosed liquid passageway and a second segment downstream from the first segment. The second segment has an open-face flume configuration. The end of the second segment defines an open sided liquid outlet projecting towards the target substrate such that a liquid stream exiting the second segment is expelled towards the target substrate along a normal flow path substantially aligned with the liquid conveyance channel. A plurality of impingement jet directional passages are positioned at an elevation between the liquid conveyance channels and the target substrate. At least one of the impingement jet directional passages has a central axis oriented in an intersecting relation to the undisrupted flow path of a corresponding liquid stream expelled from the corresponding liquid conveyance channel. The impingement jet directional passages are adapted to selectively deliver an impingement stream to divert the corresponding liquid stream away from the undisrupted flow path into a diverted flow path. A liquid collection assembly captures the liquid stream in the diverted normal flow path.
In accordance with another exemplary aspect, the present invention provides an apparatus for intermittently applying one or more liquid streams to a target substrate. The apparatus includes a liquid supply in the form of a manifold for holding a liquid and a channel module with a plurality of liquid conveyance channels in fluid communication with the manifold. The liquid conveyance channels are adapted to carry liquid away from the manifold and towards the target substrate. The end of the liquid conveyance channel defines a liquid outlet projecting towards the target substrate such that a liquid stream exiting the liquid conveyance channel is expelled towards the target substrate along a normal flow path substantially aligned with the liquid conveyance channel. Below the liquid outlet, the channel module has a landing. The landing has impingement jet positioning apertures with central axis that align with the central axis of a corresponding liquid conveyance channel. The apparatus also includes an impingement jet module having a plurality of individually activatable impingement jet tubes mounted in an impingement jet body. The impingement jet tubes include distal ends extending from the impingement jet body, which are arranged in a pattern adapted for coaxial, plug-in into corresponding impingement jet positioning apertures in the landing of the channel module. The impingement jet tubes are adapted to selectively deliver the impingement stream to divert the corresponding liquid stream away from the undisrupted flow path into a diverted flow path. A liquid collection module captures the liquid diverted from the normal flow path.
In accordance with still another exemplary aspect, the present invention provides an apparatus for intermittently applying one or more liquid streams to a target substrate. The apparatus includes a liquid supply in the form of a manifold for holding a liquid and a channel module with a plurality of liquid conveyance channels in fluid communication with the manifold. The liquid conveyance channels are adapted to carry liquid away from the manifold and towards the target substrate. The end of the liquid conveyance channel defines a liquid outlet projecting towards the target substrate such that a liquid stream exiting the liquid conveyance channel is expelled towards the target substrate along a normal flow path substantially aligned with the liquid conveyance channel. A plurality of impingement jet directional passages are positioned at an elevation between the liquid conveyance channels and the target substrate. At least one of the impingement jet directional passages has a central axis oriented in an intersecting relation to the undisrupted flow path of a corresponding liquid stream expelled from the corresponding liquid conveyance channel. The impingement jet directional passages are adapted to selectively deliver an impingement stream to divert the corresponding liquid stream away from the undisrupted flow path into a diverted flow path. A liquid collection module captures the liquid diverted from the normal flow path. The liquid collection module having an entrance, funnel section, and an exit. The entrance is position for receiving the liquid stream in the diverted flow path, the funnel section is in fluid communication with the entrance and reduces in cross section as it progresses away from the entrance, and an the exit allows the fluid progressing through the liquid collection module to exit the collection module.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and which constitute a part of this specification, illustrate a potentially preferred embodiment of the present invention, and together with the general description above and the detailed description below, serve to explain the principles of the invention wherein:
FIG. 1 is a schematic cut-away view illustrating an exemplary apparatus in accordance with the present invention showing a liquid jet assembly projecting a single pressure liquid stream towards a carpet substrate;
FIG. 2 is a view similar to FIG. 1 showing application of an impinging gaseous deflection jet from an impingement jet assembly redirecting the liquid stream away from the substrate and into a collection tray assembly;
FIG. 3 is the schematic cut-away view of the liquid jet module showing the manifold component, the channel component, and the liquid streams projecting onto the carpet substrate;
FIG. 4 is a schematic view taken generally along the line 4 - 4 in FIG. 3 illustrating the channel liquid channels in the channel body, and the flow of liquid streams from the manifold chamber to the carpet substrate;
FIG. 5 is an expanded schematic view of a portion of FIG. 4 with an abutting channel body cover shown in phantom;
FIG. 6 is a schematic view taken generally along line 6 - 6 in FIG. 5 showing the grooves in the channel body of the liquid jet module;
FIG. 7 is a schematic view illustrating a impingement jet module in place with the channel body of the liquid jet module;
FIG. 8 is a view similar to FIG. 7 showing the impingement jet delivery module separated from the channel body;
FIG. 9 is a schematic cut-away view illustrating the collection module from FIGS. 1 and 2 for capture of a liquid stream in a diverted flow path; and
FIG. 10 is a side view of the collection module shown in FIG. 9 .
Before the embodiments of the invention are explained in detail, it is to be understood that the invention is in no way limited in its application to the details of construction and/or the arrangements of the components set forth in the following description or illustrated in the drawings. Rather, the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for purposes of description only and should not be regarded as limiting. The use herein of “including”, “comprising”, and variations thereof is meant to encompass the items listed thereafter and equivalents, as well as additional items and equivalents thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made to the drawings, wherein to the extent possible, like reference numerals designate like characters throughout the various views. Referring now to FIGS. 1 and 2 , there is shown a cross-sectional view of an exemplary liquid-jet application system 10 . As illustrated, the liquid-jet application system 10 generally includes a liquid jet module 100 , an impingement jet module 200 and a collection module 300 . A pressurized liquid supply 90 , holding a liquid, such as an ink, dye, or the like, under pressure, provides the liquid to the liquid jet module 100 . The pressurized liquid passes through the liquid jet module 100 and is emitted as pressurized, coherent liquid streams 11 . As shown in FIG. 1 , the liquid stream 11 may be applied as an undisrupted flow path 15 against the surface of a target substrate 20 . In the illustrated arrangement, the substrate 20 is a textile such as a carpet, pile fabric, or the like. However, it is likewise contemplated that the substrate may be virtually any material to which a liquid pattern may be applied. When it is desired that the liquid stream 11 does not reach the substrate 20 , the impingement jet module 200 provides an impingement stream 19 that engages the liquid stream 11 and creates a diverted flow path 16 for the liquid stream 11 into the collection module 300 , as shown in FIG. 2 .
As illustrated by the directional arrows in FIGS. 1 and 2 , the substrate 20 may move relative to the liquid jet application system 10 such that the undisrupted flow path 15 of the liquid stream 11 will apply a treatment pattern of the liquid as a line or line segment that is oriented generally parallel to the direction of travel for the substrate 20 . During periods when the impingement jet module 200 emits an impingement stream 19 creating the diverted flow path 16 , the liquid stream 11 is diverted from the substrate 20 and the portion of the substrate 20 passing under the liquid jet module 100 goes untreated by the liquid stream 11 . By way of example only, and not limitation, in the event that the substrate 20 is a carpet fabric and the liquid stream 11 is a dye, the undisrupted flow path 15 of the liquid stream 11 will dye the carpet substrate 20 with a line or line segment generally parallel to the direction of travel of the carpet substrate 20 . When the impingement jet module 200 emits the impingement stream 19 , the liquid stream 11 will have the diverted flow path 16 causing liquid stream 11 to divert into the collection module 300 and the portion of the carpet substrate 20 passing below the liquid stream 11 will remain undyed. By having a series of liquid jet application systems 10 perpendicular to the direction of travel of the carpet substrate 20 , the dye can be applied across the width of the carpet substrate 20 . By having a plurality of liquid jet application systems 10 in series in the direction of travel for the substrate 20 , each liquid jet application system 10 can apply liquid streams 11 of different liquids, such as different dye colors, across the surface of the substrate 20 to obtain different patterns of the different liquids (such as different colors) on the substrate 20 .
Referring now to FIG. 3 , the liquid jet module 100 generally includes a manifold component 120 and a liquid channel component 130 . In the embodiment illustrated, the liquid channel component 130 includes liquid channels 112 that are in fluid communication with a manifold chamber 111 in the manifold component 120 . Opposite to the manifold component 120 , the liquid channels 112 each have a liquid discharge end 116 that the liquid streams exit the channel component 130 . The liquid channels 112 are formed by groves 141 in a channel body 140 and a channel body cover 150 . In the embodiment illustrated, the manifold chamber 111 is primarily formed by a manifold body 120 , which is enclosed by the channel body 140 and the channel body cover 150 . The pressurized liquid supply 90 is in fluid communication with the manifold chamber 111 , and the manifold chamber 111 provides a supply source feeding the liquid through the liquid discharge ends 116 in the array of liquid channels 112 to create the liquid streams 11 that are emitted towards the substrate 20 .
It is contemplated that each liquid stream 11 will have a relatively small cross-sectional area to provide a finer pattern control on the application of liquid streams 11 across the substrate 20 . As will be appreciated and illustrated in FIG. 4 , such fine diameter streams may be arranged in a side-by-side arrangement to one another so as to define a substantially continuous curtain of liquid oriented transverse to the travel direction of the substrate 20 . Such an arrangement permits detailed liquid application patterns across the target substrate 20 by selectively discontinuing individual liquid streams 11 and/or groups of liquid streams 11 . By way of example only, and not limitation, the liquid streams 11 may have a diameter of less than about 150 mils, and more preferably less than about 100 mils, and most preferably about 3 to about 30 mils, although greater or lesser effective diameters may likewise be utilized. In order to provide fine-scale patterning across the substrate 20 , it is desirable to maintain the cross sectional integrity of the liquid stream 11 along the travel path between the liquid jet module 100 and the substrate 20 . The present invention provides a multi-stage liquid travel path for delivery of the liquid stream 11 from the manifold chamber 111 to the substrate 20 , which is believed to improve the cross sectional integrity of the liquid stream 11 from the liquid jet module 100 to the substrate 20 .
As illustrated in FIGS. 3 and 4 , the liquid streams 11 progress from the manifold chamber 111 into liquid channels 112 with an enclosed first stage 12 and then through a open directed second stage 13 , then exits the liquid channels 112 through liquid discharge ends 116 associated with individual liquid channels 112 along an unconstrained third stage 14 to the substrate 20 . In the enclosed first stage 12 , the liquid forming the liquid streams 11 passes through an enclosed first segment 114 of the liquid channel 112 created by the grooves 141 in the channel body 140 which are enclosed by the channel body cover 150 . As illustrated in FIG. 6 , the grooves 141 in the channel body 140 have a substantially rectangular shaped cross section, although other geometries may be used if desired, such as substantially circular or “U” shaped cross sections. Also the face the channel body cover 150 enclosing the grooves 141 in the embodiment illustrated is substantially flat, although it may include complementary grooves for alignment with the grooves 141 in the face of the channel body 140 . In the open directed second stage 13 , the liquid forming the liquid streams 11 passes through open flume second segment 115 created by the grooves 141 in the channel body 140 , which are not enclosed by the channel body cover 150 . That is, the liquid stream 11 is not bounded on all sides, such as being bounded by only two or three sides. In this area of the channel body 140 , the channel body cover 150 does not extend to cover the groves 141 , thereby creating the open flume-like configuration. Thus, the liquid streams 11 within the second segment 115 have an outer face which is free from an opposing constraining boundary surface and liquid traveling along the liquid channels 112 transitions from the enclosed first segment 114 in the first stage 12 to the open-faced second segment 115 second stage 13 . Following the second stage 13 created by the open faced second segment 115 , the liquid streams 11 exit the liquid channels 112 through associated liquid discharge ends 116 along an unconstrained third stage 14 of the liquid conveyance path in which the liquid streams 11 are normally substantially aligned with the liquid channels 112 , but no longer are bounded or guided by the liquid channels 112 . In this third stage 14 the liquid streams 11 are unconstrained and unguided by external boundary surfaces.
It is believed that transitioning from the enclosed first stage 12 to the open faced second stage 13 prior to discharge into the unbounded space of unconstrained third stage 14 is beneficial in promoting the coherency and overall stability of the liquid streams 11 . While not meaning to be constrained to a particular theory, it is believed that the open face of the second stage 13 allows the liquid stream 11 to dissipate static pressure before being released into an unconstrained or unguided stream. It is believed that a sudden abrupt change from a fully enclosed stream to a completely unenclosed stream may result in the expansion of the static pressure in the liquid stream to create cross sectional disruptions that will unpredictably expand the cross sectional size of the stream, or create uneven cross sections in the stream prior to being received by the substrate 20 . In practice, the length of the second stage 13 is preferably at least four (4) times the largest cross-sectional dimension of the liquid channels 112 provides an improved transition and guidance of the liquid stream that minimizes these disruptions. By way of example only, and not limitation, according to one practice the width dimension of the liquid channels 112 in the second segment 115 is about 14 mils. Accordingly, in that exemplary arrangement, the length of the second stage 13 is preferably about 56 mils or greater. Of course, larger and smaller effective diameters may likewise be utilized, if desired. As shown in FIG. 5 , the terminal ends of the second segment 115 define open sided outlets projecting towards the target substrate 20 .
The liquid streams 11 will travel from the liquid channels 112 to the substrate 20 as substantially cohesive and stable units. However, it is also desirable to have the capability to substantially instantaneously prevent the liquid stream 11 from being applied to the substrate 20 , followed by substantially instantaneous reapplication of the liquid stream 11 to the substrate 20 on demand so as to control the pattern application of the liquid onto the substrate 20 with a degree of definition and precision. To this end, the liquid streams 11 may be manipulated by the application of the gaseous impingement stream 19 from the impingement jet module 200 to provide manipulated patterning of the liquid stream 11 on the substrate 20 , as previously described and illustrated in FIG. 2 . The impingement jet module 200 includes an impingement stream directional passage 211 that emits and directs the impingement stream 19 . Each impingement stream directional passage 211 has a central directional axis that intersects a central directional axis of an associated the liquid channel 112 in the liquid jet module 100 , down stream from the liquid jet module 100 in the unconstrained third stage 14 of the liquid streams 11 . In the embodiment illustrated, the impingement stream directional passage 211 emits the impingement stream 19 towards a location on the liquid stream 11 at is opposite of the location on the liquid stream 11 that was unconstrained in the open directed second stage 13 of the liquid stream 11 .
Referring now to FIGS. 2, 3, 4, 5, 7 and 8 , the channel body 140 of the channel component 130 includes a recessed landing 142 at the end of the grooves 141 , which is spaced a short distance away from the liquid streams 11 exiting the liquid channel 112 . A series of impingement jet positioning apertures 143 are located in the recessed landing 142 , and the central axis of each impingement jet positioning aperture 143 intersects with the central axis of a corresponding liquid channel 112 below the liquid discharge end 116 of that liquid channel 112 . As illustrated, the impingement jet positioning apertures 143 may be arranged in side-by-side relation such that the impingement streams 19 are arranged to project along a substantially common plane. However, other arrangements may be used if desired. On the opposite side of the recess landing 142 from the exit of liquid stream 11 from the grooves 141 is an impingement jet mounting surface 144 .
Referring now to FIGS. 2, 7 and 8 , the impingement jet system 200 includes an impingement jet module body 220 housing an array of side-by-side gas tubes 230 . Each of the gas tubes 230 are spaced and positioned in the module body 220 at the same spacing and layout as the impingement jet positioning apertures 143 in the channel body 140 . The module body 220 has a mounting surface 221 , and each of the gas tubes 230 includes a distal end 231 extending from the mounting surface 221 . When the impingement jet module 200 is installed, the impingement jet module mounting surface 221 of the impingement jet delivery system 200 engages the impingement jet mounting surface 144 of the channel body 140 and the distal ends 231 of the gas tubes 230 project into the impingement jet positioning apertures 143 of the channel body 140 . The outer diameter of the gas tubes 230 will preferably correspond substantially with the inner diameter of the impingement jet positioning apertures 143 of the channel body 140 such that a secure plug-in relation is achieved upon insertion of the distal ends 231 . In order to accommodate the distal ends 231 of the gas tubes 230 , the impingement jet positioning apertures 133 in the channel body 140 are tapered with the wider end near the impingement jet mounting surface 143 and the narrower end near the landing 142 . Alternatively, or in addition, the distal ends 231 of the gas tubes 230 can be tapered with the larger end near the impingement jet body 220 and the narrower end near the proximal end 233 . It has also been found that, in a preferred arrangement, the distal ends 231 of the gas tubes 230 terminate flush with the surface of the landing 142 closest to the liquid streams 11 , thereby avoiding crevasses and corners that overspray liquid from the liquid streams 11 might accumulate and create errant drops.
The interior of the gas tubes 230 create the impingement stream directional passages 211 . As will be appreciated, since the gas tubes 230 plug into the corresponding impingement jet positioning apertures 143 , there is no need or ability to adjust the position of the gas tubes 230 . Rather, that position is pre-established and maintained by the position of the jet positioning apertures 143 . The position of the impingement stream directional passage 211 will have a central axis that intersects a central axis of the corresponding liquid channel 112 below the liquid discharge end 116 of that liquid channel 112 , and preferably in a perpendicular relationship.
According to the potentially preferred practice, the gas directional passages 211 in the impingement jet system 200 have a diameter which is greater than the width dimension of the corresponding liquid channel 112 in the liquid jet module 100 , and resultant liquid streams 11 . Most preferably, the cross sectional diameter of the gas directional passages 211 will be as large a possible while maintaining the substantially centered relation relative to the corresponding liquid streams 11 , and not allowing the impingement stream 19 therefrom to interfere with the adjacent liquid streams 11 or the adjacent impingement streams 19 . In this regard, it is desirable that the diameter of the gas directional passages 211 are at least as large as the diameter of the lines feeding into the gas tubes 230 such that the gas directional passages 211 do not create a flow restriction in the system. By way of example only, a diameter of about 43 mils for the gas directional passages 211 has been found to provide good performance when used with liquid channels 112 having a cross-section of about 14 mils, although larger or smaller diameters may be used if desired.
The impingement jet system 200 may be installed into, and removed from, the liquid jet module 100 as a single module. Of course, in actual practice, the impingement jet module 100 may be number of such modules disposed across the row of liquid streams 11 , each of which may incorporate a separate plurality of gas tubes 230 . In the event that one or more gas tubes 230 becomes damaged, the individual module containing that gas tube may simply be removed and replaced with minimal disruption.
The gas tubes 230 each may be operatively connected in fluid communication to a discreet supply line (not shown) which selectively delivers pressurized air or other gaseous fluid to the gas tube 230 . This selective delivery of pressurized gaseous fluid to individual gas tubes 230 is activated by valves which open and close based on instructions from a computer or other command device. As will be appreciated, during periods when a no pressurized gas is supplied to a gas tube 230 , the liquid stream 11 associated with that gas tube 230 passes in an undisrupted flow path 15 to the substrate 20 . Conversely, during periods when pressurized gas is supplied to a gas tube 230 , the resulting impingement stream 19 engages the liquid stream 11 which is then diverted away from the substrate 20 in a diverted flow path 16 and the portion of the substrate 20 in passing under the normal position of that liquid stream 11 goes untreated. As shown in FIG. 2 , the application of this diverting force is carried out within the unconstrained third stage 14 of the liquid stream 11 downstream from the open directed second stage 13 .
As shown in FIGS. 1 and 2 , the application system 10 includes a collection module designated generally as 300 . The collection module 300 from FIGS. 1 and 3 is illustrated in further detail in FIGS. 9 and 10 . The collection system 300 includes an angle body 320 and an opposing deflection blade 330 . The angle body 320 is mounted to the channel cover block 140 of the liquid jet module 100 and has a deflection surface 321 which is positioned near the liquid stream 11 exiting the liquid jet module 100 . The deflection surface 321 of the angle body 320 is oriented at an acute angle from the liquid stream 11 when measured from the downstream position of the liquid stream 11 . The position and angle of the deflection surface 321 is selected in a manner to hinder any mist or overspray of the liquid stream 11 from circling around in an eddy like current back out of the collection module 300 . The deflection blade 330 is mounted to the angled body 320 by standoffs 323 in a manner that creates a discharge passage 310 for the liquid stream 11 to pass through. The standoffs 323 are spaced intermittently along the cross machine length of the collection assembly 300 . This arrangement allows the deflected liquid stream 11 through the discharge passage 310 and into a recovery sump (not shown) for reuse. By way of example only, and not limitation, the slot openings between the standoffs 323 may have a height dimension of about 90 mils, although larger or smaller heights may be used, if desired.
As illustrated, the discharge passage 310 has a collection section 311 , a funnel section 314 , and an exit section 315 . The collection section 311 is positioned adjacent to the liquid stream 11 as the liquid stream 11 exits the liquid jet module 100 , and such that the diverted flow path 16 of the liquid stream 11 will enter the collection section 311 upon application of the impingement stream 19 . The collection section 311 is illustrated as having a short length before reaching the funnel section 314 , but could also be only the opening for the funnel section 314 . Inversely, the exit section 315 is illustrated as the opening for the funnel section 314 , but could have a short length extending away from the funnel section 314 . As illustrated, the liquid jet application system 10 is positioned with the liquid streams 11 progressing vertically to the substrate 20 . In this position, it is preferable that a vacuum be applied to the exit 315 of the discharge passage 310 to insure proper removal of the liquid stream 11 in the diverted flow path 16 . However, the liquid jet application system 10 can be positioned at an angle from the vertical in a manner that gravity will assist the progression of the liquid stream 11 in the diverted flow path 16 from the discharge passage 310 without a vacuum.
As illustrated, the deflection blade 330 includes leading edge 331 , a guidance surface 332 , and a contraction surface 333 . The deflection blade 330 is relatively thin. By way of example only, in one potentially preferred embodiment the deflection blade 330 may have a thickness of about 20 mils, although thicker or thinner blades may be used if desired. The leading edge 331 is position on the lower side of the entrance 311 adjacent to the undisrupted flow path 15 of the liquid stream 11 , and the surface of the leading edge 331 is flat and substantially parallel to the undisrupted flow path 15 of the liquid stream 11 . The guidance surface 332 progresses away from the leading edge 331 and angle between the leading edge 331 and the guidance surface 332 creates a knife edge adjacent to the undisrupted flow path 15 of the liquid stream 11 . Because of the closeness of the leading edge 331 to the liquid stream 11 , the knife edge will “cut off” any hook shape in the liquid stream 11 created when the liquid stream 11 transitions from the undisrupted flow path 15 to the diverted flow path 16 , or back. According to one potentially preferred practice, the spacing between the liquid stream 18 and the leading edge 331 is set at about 5 to about 15 mils although larger or smaller spacing levels may be used, if desired.
The guidance surface 332 leads away from the leading edge 331 and is preferably substantially parallel to a deflection surface 321 on the angled body 320 . This portion of the guide surface 332 that is substantially parallel to the deflection surface 321 creates the collection section 311 of the collection discharge passage 310 . At the rear of the guidance surface 331 of the deflection blade 330 , the deflection blade 330 away from the guidance surface 331 and angles towards the deflection surface 321 of the angled body 320 . The section of the deflection blade 330 that angles towards the deflection surface 321 of the angled body 320 is the contraction surface 333 . The space between the deflection surface 321 and the contraction surface 333 create the funnel section 314 of the discharge passage 310 . By way of example only, and not limitation, it has been found that an angle of about 150°-155° between the guidance surface 332 and the contraction surface 333 may be particularly desirable for the deflection blade 330 . This angle creates a constriction in the funnel section of about 25°-30° relative to the deflection surface 321 of the angle body 320 .
Upon the application of an impinging stream 19 from the gas directional passage 211 of the impingement jet module 200 , a diverted flow path 16 of the liquid stream 11 is created that passes through the discharge passage 310 . The disturbed flow of the liquid stream 11 enters the discharge passage 310 through the collection section 311 and is routed towards the funnel section 314 . Upon entering the collection section 311 , the knife edge of the deflection blade 330 cuts off any of the liquid stream 11 that might not follow the same path as the fully diverted stream 16 into the discharge passage 310 . The deflection surface 321 of the angled body 320 maintains a distance to the guidance surface 332 of the deflection blade 330 that helps prevent spray from the liquid stream 11 drifting back out of the discharge passage 310 due to circling currents onto parts of the equipment that might allow accumulated liquid to condensate and drop onto the substrate 20 below. The reducing cross sectional area of the funnel section 314 causes the disrupted flow path 16 of the liquid stream 11 and the impingement stream 19 to accelerate towards, and out of the exit section 315 of the discharge passage 310 where it can be collected by a liquid recovery system (not shown). When the impingement stream 19 is terminated, the liquid stream 11 resumes its normal undisrupted flow path 15 to the substrate 20 ( FIG. 1 ).
As will be appreciated, the present invention provides an application system which is highly functional and which can be set up and serviced relatively simply. In particular, due to the plug-in relation of the impingement jet delivery system 200 there is no need to engage in complex alignment of impingement jets with corresponding liquid streams 11 . Moreover, the incorporation of the open face transitional flow stage along the flow path is believed to substantially promote a cohesive and stable liquid stream which provides fine scale patterning across the substrate 20 . Further, the incorporation of the substantially parallel spaced-apart baffle and deflection blade arrangement promotes efficient and effective recovery of deflected liquid stream material. Such features, individually and in combination, promote substantially enhanced functionality and precision in the application of a spray pattern to the substrate 20 .
Of course, variations and modifications of the foregoing are within the scope of the present invention. Thus, it is to be understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention. the claims are to be construed to include alternative embodiments and equivalents to the extent permitted by the prior art. The term “about” means±10% when used in reference to distances.
Various features of the invention are set forth in the following claims.
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An improved system for application of liquid streams to a substrate. The system incorporates open face flow channels for carrying the liquid away from fully enclosed flow segments prior to discharge along an unconstrained flow path. The present invention further provides an improved, self-aligning modular assembly for delivery of impingement jet to the liquid streams for diverting the direction of the liquid streams. The present invention further provides an improved arrangement for collection of the deflected liquid in response to application of the impingement jet without excess residue build-up.
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BACKGROUND OF THE INVENTION
The present invention relates to a method for segregating relatively light weight materials from relatively heavy weight materials.
In the case where first materials of relatively equal weight are mixed with second materials which are heavier or lighter than the first materials, techniques for segregating the first and second materials using a sifter or a flow of air have usually been employed. Such techniques are effective when the first and second materials are greatly different in weight from each other and are different in absorptivity. However, such techniques are generally ineffective in the case where unwanted materials to be removed are mixed with articles such as vegetables or fish which are soft and are likely to be intermixed or where unwanted materials adhere to other articles such as caused by static electricity.
The inventor has previously disclosed an apparatus for segregating unwanted materials from such articles in Japanese Utility Model Application No. 102778/1978. This apparatus will be described with reference to FIG. 1. A number of rollers 2 having relatively large diameter and to which is applied to a high voltage are rotatably arranged above a vibrating conveyor 1. The mouths of a suction device are provided near the upper portions of the rollers so that unwanted materials mixed with articles are picked up on the lower surfaces of the rollers and are then sucked away so as to separate them from the articles.
The apparatus according to this utility model performs quite excellently in that its work efficiency is high and the apparatus can treat processed foods which cannot be treated by the above-described conventional segregation techniques which use a sifter or a flow of air. However, the apparatus is still disadvantageous in that the weight or range of properties of unwanted materials segregated by the apparatus are somewhat limited. More specifically, the material to be removed must be light in weight so that it may be sucked onto the surface of the roller 2. When a material such as yarn or soft hair having a simple configuration is picked up by the roller (removal of such a material being often required in the field of food manufacture), it tends to remain stuck to the roller surface and therefore it is difficult to remove by suction with the result that the work efficiency of the apparatus is very much lowered. Furthermore, light weight materials often float between the conveyor and the rollers. That is, they are not picked up on the roller surfaces and are therefore not removed.
SUMMARY OF THE INVENTION
Accordingly, an object of the invention is to thus provide a light weight material segregating method and apparatus in which all of the above-described difficulties accompanying conventional techniques have been eliminated and which is applicable to segregation of a variety of materials.
According to one aspect of the invention, a number of rollers having a relatively small diameter are arranged parallel to one another with a relatively short distance between them in such a manner as to form slits therebetween. The rollers are covered with suction ducts which generate flows of air rising from a conveyor toward the suction ducts whereby materials relatively light in weight are sucked in and segregated by the air flows. According to another aspect of the invention, high voltage is applied to the rollers to generate a force which attracts relatively light weight materials so as to assist the operation of the air flow in segregating the materials thereby to effectively segregate heavy or soft materials which cannot be segregated by only the air flow or by only the attractive force of the charged rollers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view showing a conventional apparatus for segregating light materials from heavy materials.
FIGS. 2 and 3 are side views showing a preferred embodiment of the invention.
FIG. 4 is a vertical sectional view showing a roller mounted in a cover according to the invention.
FIG. 5 is a front view showing a modification of a roller used with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the invention will be described with reference to FIGS. 2 through 5. FIG. 2 shows the fundamental arrangement of a light material segregating apparatus according to the invention. This includes a frame 4, a belt conveyor 5, rollers 6 and suction ducts 7. The rollers 6 are arranged parallel to one another with a relatively small spacing of about 5 to 30 mm therebetween. Each suction duct 7 has a large mouth at its lower end which covers corresponding ones of the rollers 6. In other words, the rollers 6 form a grid in the mouths of the suction duct 7 with the gaps between adjacent rollers serving as slits through which air flows. The ducts 7 are connected to a suction pump 8. Air sucked by the suction pump 8 is delivered into a collecting device, not shown. The rollers 6 are so designed and operated such that either all of the rollers are rotated in the same direction of the rotational direction of every other roller is opposite to that of its adjacent rollers. A high voltage is applied to the rollers. The conveyor 5 operates to convey articles from which unwanted materials lighter in weight than the other articles should be removed under the rollers thereby allowing the unwanted materials to separate from the articles. In order to improve the segregation performance, it is desirable that the conveyor be not only capable of conveying articles but also capable of vibrating the articles up and down so that the articles are detached from one another and the articles are set upside down. For this purpose, the conveyor is preferably a vibrating conveyor as shown in FIG. 2.
FIG. 2 shows also a preferred technique for vibrating the conveyor 5. The conveyor is supported on the frame 4 through several leaf springs 9 and is coupled to a crank mechanism 10 at one end. The conveyor is vibrated up and down by operation of the crank mechanism 10. As described before, the suction duct 7 has a large mouth designated by reference numeral 11 which extends over several rollers 6 in such a manner that the rollers are housed in the large mouth 11 and form a grid in the large mouth 11. Air sucked through the suction duct 7 passes through the gaps between rollers as a result of which the flow velocity of the air increases and accordingly the suction force is also increased.
The operation of the apparatus thus constructed will be described. First, the crank mechanism 10 is operated to vibrate the conveyor 5 while the suction pump 8 is operated to generate a flow of air moving upwardly from the surface of the conveyor. Under these conditions, articles to be treated are placed on the loading end of the conveyor 5. The articles are slowly moved forward while being vibrated and separated from one another by the conveyor. When they reach the region covered by the rollers 6, the light weight materials mixed with the articles are forced to move upwardly with the flow of air through the suction duct whereby the materials are segregated from the articles. In this connection, it goes without saying that the gap width between the conveyor 5 and the rollers 6 affects the segregation performance. As the rollers 6 are lowered decreasing the gap between the conveyor 5 and the rollers 6, the segregation efficiency is increased for heavier materials.
In the case where the materials to be segregated from articles have a relatively low water contact percentage such as powdered substances and hair, the segregation efficiency is remarkably improved by applying a high voltage to the rollers to provide an electrostatic force between the rollers and the conveyor, thus attracting the lighter materials. In the case where the materials to be segregated from articles have a relatively high water content percentage such as for instance vegetables or have relatively large volume, the segregation efficiency can be improved by jetting air from the surface of the conveyor. This will be described with reference to FIG. 3. Here, the conveyor 5 has been modified to be a hollow conveyor having a number of jetting holes 12 on the surface thereof. An air blower 13 is coupled to the hollow conveyor 5 and air is delivered under pressure into the hollow chamber formed in the conveyor 5 so as to be jetted upward through the jetting holes 12 and to thereby to blow upwards the light materials on the conveyor.
Even if, in this case, both of the materials lighter and heavier in weight being segregated are dry and are attracted to one another by static electricity, they will be moisturized by the air jetted through the holes and accordingly the attractive force therebetween will be released.
Next, an example of a mechanism for lifting the rollers 6 will be described. Each cover 11 adapted to cover the rollers is in the form of a box opened at the bottom. The rollers 6 are arranged in the box-shaped cover 11. Locking protrusions 14 are provided on the edges of the top of the cover 11. A hanging frame 15 is mounted on the apparatus frame 4 in such a manner that it can be moved up and down as desired. Accordingly, the rollers may be moved up and down by moving the hanging frame 15 up and down.
This mechanism will be described in more detail. Supporting shafts 17 are horizontally mounted at the upper portion of the frame 4 and arms 16 are rotably mounted on the supporting shafts 17. First ends of the arms 16 are coupled to the hanging frame 15 and the other ends of the arms 16 are connected to operating levers 18, respectively. The frame 15 may be moved vertically by turning the operating levers 18. Shafts 19 are horizontally mounted on the hanging frame 15 and engaging protrusions 20 are rotatably mounted on the shafts 19. An operating lever 21 is connected to and made integral with each engaging protrusion 20. Nuts 22 are secured to one side of the frame 15 and bolts 23 are screwed into the nuts 22 in such a manner that the ends of each of the bolts 23 is in engagement with a corresponding one of the operating levers 21. The covers 11 are coupled to the hanging frame 15 as follows. The locking protrusions 14 are held between the engaging protrusions 20 and the lower surface of the hanging frame 15. Then, the bolts 23 are rotated to turn the operating levers 21 thereby causing the engaging protrusions 20 to engage with the locking protrusions 14.
An example of the construction of the rollers 6 will be described with reference to FIG. 4. Insulating supporting members 25 and 26 are inserted into both end portions of a wire cylinder 24 which is assembled by covering the outer surface of a cylinder, formed by winding an electrical wire in the form of a coil, with an insulating material. A bearing 28 is secured at the center of the supporting member 26 and the bearing 28 is electrically connected to the wire cylinder 24 through a coil spring 29. Further, an insertion hole is formed in one side of the cover 11 which is made of an insulating material. A supporting protrusion 27 made of metal is provided on the inner surface of the opposite side of the cover 11 at a position opposite to the insertion hole with the protrusion 27 electrically extending outside of the cover 11.
The roller 6 can be mounted in the cover 11 as follows. The roller 6 is inserted into the cover 11 through the insertion hole formed in the side of the cover with the supporting protrusion 27 being thus inserted into the bearing 28. Still further, a bearing 30 is disposed between the insertion hole and the supporting member 25 so that the roller 6 is rotatably mounted in the cover 11 and removal of the roller is prevented. A gear 31 is secured to the supporting member 25. The gear 31 is engaged with a gear secured to the next adjacent roller 6 so that the rotational force is transmitted between rollers.
In the case where the materials to be separated from the articles are flexible, thin and long as for the case of hair, it may be difficult to segregate the materials from the articles because, even if one end of such a piece of material is sucked between the rollers, the other end may still adhere to the articles. This difficulty may be overcome by the use of rollers 6 which are formed as shown in FIG. 5. The rollers 6 have a number of protrusions 32 on their surfaces. The protrusions 32 are so arranged by cooperation with the intermeshing gears coupled to the rollers that the protrusions of adjacent rollers are always at symmetrical angular positions so that they are periodically brought into contact with each other. With the rollers thus formed, flexible, thin and long materials such as hair will be pinched between the protrusions 32 and thus pulled away from the articles.
As is apparent from the above description, in accordance with the invention, a number of relatively thin rollers are arranged in the form of a grid and are disposed inside covers which are connected to a suction pump so that air flows between the rollers at a relatively high speed whereby light materials mixed with articles which are transported by the conveyor are removed. That is, the light materials are segregated from the articles. In addition, the rollers are so designed that a high voltage is applied thereto to attract such light materials. Because of the combination of the attractive force due to the high voltage and the suction force produced by the flow of air at high velocity, the efficiency of segregating light materials from articles is considerably increased.
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An apparatus and method for separating light and heavy materials from one another. Materials to be separated are transported on a conveyer belt past a set of overhead rollers. Air is sucked through gaps between the rollers with covers surrounding groups of rollers which are coupled to a suction pump. Air is jetted through apertures in the conveyer belt to loosen adherence between lighter materials and larger articles. A high voltage is impressed upon the rollers to provide electrostatic attraction for light dry materials. The rollers may be provided with opposing protrusions which are used to pinch off certain materials.
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BACKGROUND OF THE INVENTION
The present invention relates to an industrial dust collector, and more particularly to an industrial dust collector having a prefiltering means.
As shown in FIG. 1, an industrial dust collector 10 of the prior art comprises mainly a base 11, support frames 12 arranged at upper portions of both ends of base 11, a guide box 13 disposed over the support frame 12, a motor 15, a suction hose 14, a filtering bag 18, a dust collecting bag 17, and a fan 16 driven by the motor 15.
The working of the prior art dust collector 10 is accomplished by the fan 16, which is driven by the motor 15 to bring about a stream of suction inside the suction hose 14 to draw the dust into the end of the suction hose 14 and then into the guide box 13, through which the air stream is released via the filtering bag 18 while the dust is collected in the dust bag 17.
Such dust collector 10 of the prior art described above is defective in design in that it is not provided with a filtering means between the suction hose 14 and the guide box 13. As a result, the sharp objects, such as nails, iron dusts, wood pieces, may be sucked into the guide box 13 in which the fan 16 is subjected to colliding abrasively with them. Furthermore, the dust bag 17 can be easily pierced by the sharp objects collected therein.
SUMMARY OF THE INVENTION
It is therefore the primary objective of the present invention to provide an industrial dust collector with a pre-filtering means intended to filter out the sharp objects so as to protect the fan and the dust bag of the dust collector.
In keeping with the principles of the present invention, the primary objective of the present invention is accomplished by an industrial dust collector provided with a pre-filtering means disposed between the guide box and the suction hose of the dust collector. In addition, the prefiltering means so provided is in communication with both guide box and suction hose so as to allow the objects considerably greater in size than dusts to be filtered out and deposited in the pre-filtering means. As a result, the air stream entering the guide box from the suction hose is free from any sharp object capable of doing damage to both suction fan and dust bag of the dust collector.
In addition, the effectiveness of industrial dust collector of the present invention is further enhanced by the pre-filtering means, which is arranged in such a way that it is spaced apart respectively a predetermined distance from the guide box and the suction hose so as to permit the objects carried by the air stream to fall in the space located therebetween in order to prevent the objects from being carried by the air stream all the way from the suction hose through the pre-filtering means and the guide box.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a three-dimensional view of an industrial dust collector of the prior art.
FIG. 2 shows a three-dimensional view of an industrial dust collector of the present invention.
FIG. 3 shows an exploded view of an industrial dust collector of the present invention.
FIG. 4 shows a sectional view of the first preferred embodiment of the present invention taken along the line 4--4 as shown in FIG. 2.
FIG. 5 shows a sectional view of the first preferred embodiment of the present invention taken along the line 5--5 as shown in FIG. 2.
FIG. 6 shows a sectional view of the second preferred embodiment of the present invention taken along the line 5--5 as shown in FIG. 2.
FIG. 7 shows a sectional view of the third preferred embodiment of the present invention taken along the line 5--5 as shown in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 2-5, the industrial dust collector 2 of the present invention is shown comprising a base 21, two pairs of support frames 22 attached respectively at the bottom thereof to the base 21, a guide box 23fastened to the top ends of the support frames 22 and provided with an air inlet 24 having a circular flange 241 and further provided with a pair of air outlets 25 arranged oppositely, a motor 26 fastened to the upper portion of the guide box 23 and provided with a driving shaft 27, a suction fan 28 fastened to the driving shaft 27, a pervious filtration bag291 fitted to the air outlet 25, and a dust bag 292 fitted to the air outlet 25 to collect the dust.
The industrial dust collector 2 of the present invention further comprises a pre-filtering device 20 provided with an upper housing 30, a lower housing 40, a suction hose 50, a pair of locking pieces 60, and three pairs of hooking pieces 70.
The upper housing 30 is of rectangular construction and is provided with anupper container 32 having an opening facing downwardly, and with a dust collecting port 34, and further with an air exit 36. The dust collecting port 34 and the air exit 36 are respectively provided at the peripheries thereof with a first circular sleeve 35 and a second circular sleeve 37. The dust collecting port 34 and the air exit 36 are arranged in such manners that they are axially perpendicular to each other and that they are spaced apart at a predetermined interval.
The lower housing 40 is rectangular in shape corresponding to that of the upper housing 30 and is composed of a lower container 42 having an openingfacing upwardly, and of a transparent window 44, and further of a flange 43disposed at the outer edge of the opening of the lower container 42.
The suction hose 50 has one end with an inner diameter corresponding to theouter diameter of the first circular sleeve 35 of the upper housing 30 so as to be fitted over the first circular sleeve 35 and to be fastened to the first circular sleeve 35 by means of a locking sleeve 52.
Each of the two locking pieces 60 is provided with a flat portion 62, whichis fastened to the external side of the upper housing 30, and with a curvedportion 64 fastened to the lower side of the guide box 24.
Each of the locking pieces 70 is composed of a body portion 72 fastened to the opening end of the upper housing 30 and of a hook portion 74 of a bowlike curved construction with a recess facing inwardly.
In the process of assembling the components described above, the second circular sleeve 37 of the upper housing 30 is fitted over the circular flange 241 of the air inlet 24 located at the lower end of the guide box 23 and is fastened to the circular flange 241 by means of a locking piece 60. The flange 43 of the lower housing 40 is inserted into the hook portion 74 of the hooking pieces 70.
The operation of the industrial dust collector 2 of the present invention is initiated by the onset of a stream of suction generated by means of rapid rotation of the suction fan 28 driven by the motor 26. The air outside the dust collector 2 is drawn into the suction hose 50 and then into the upper and the lower containers 32 and 42. Thereafter, the air stream flows out of the air exit 36 via the dust collecting port 34 in view of the facts that the dust collecting port 34 of the upper housing 30and the air exit 36 of the upper housing 30 are axially perpendicular to each other and that the dust collecting port 34 and the air exit 36 are spaced apart. The air stream is subsequently guided into the guide box 23 via the air inlet 24. At the time when such process is under way, an eddy of air is brought about in the upper container 32, thereby resulting in the larger and the heavier objects carried in the air stream to fall into the lower housing 40 by virtue of the law of gravity and of the fact that these objects are subjected to colliding with the inner wall of the upper housing 30 so as to lose their momentum. The industrial dust collector 2 of the present invention is provided with a window 44 for the convenience of the operator to be aware of the quantity of objects deposited in the lower housing 40.
Now referring to FIGS. 6 and 7, the upper housing 30 is provided therein with a curved surface 38 opposite to the dust collecting port 34, and witha plane surface 39. The curved surface 38 is designed in such a manner thatits axial center is parallel to the axis of the air exit 36 so as to permitthe air current, which has entered the upper container 32, to flow along the curved surface 38 to enter the guide box 23 via the air exit 36. Therefore, the objects are subjected to colliding with the bordering portion of the curved surface 38 and the plane surface 39 so as to fall into the lower container 42.
The embodiments of the present invention described above are to be considered in all respects as merely illustrations of principles of the present invention. Accordingly, the present invention is to be limited only by the scope of the hereinafter appended claims.
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An industrial dust collector comprises mainly a base, a guide box, a motor, a suction fan, a suction hose, a filtration bag, a dust bag, and a pre-filtering means disposed between the guide box and the suction hose so as to filter out the objects considerably greater in size and weight than the dust in order to prevent such objects from damaging the suction fan and the dust bag.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 61/392,768 filed on Oct. 13, 2010, entitled “Trash Hopper.”
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a portable garbage bag holder, or in the alternative a utility hopper for use in collecting debris or for the temporary storage of harvested items. More specifically, the present invention concerns a portable utility hopper designed to reduce the amount of strain placed on the user's wrist while the user collects items within the hopper.
[0004] 2. Description of the Prior Art
[0005] Many activities that require a user to collect small quantities of an item typically require temporary storage during the collection process for later transportation to a larger storage receptacle. To illustrate, consider the process of trash collection. When in the home, users place their trash in small trash cans around the house, which are then collected and their contents emptied into a larger trash receptacle that is taken out of the home where a trash service may collect the colocated quantity of garbage. A small quantity of trash is collected in home waste baskets and is then transferred to a larger trash receptacle, which in turn is transferred to the trash vehicle. Many harvesting industries operate in the same general way. The process of harvesting requires an individual to pick the harvested item, and collect it. Later the harvested items are transferred to larger storage containers for transport. There are many examples of industries that operate in this fashion.
[0006] A hopper is a temporary storage container for a bulk material such as harvested items, rocks or trash. While many hoppers are very large and stationary, as in mining or grain harvesting operations, hoppers can also be small and portable for used in applications such as berry harvesting, trash collecting or crabbing. Hoppers have also been suggested for use in trash collecting operations. A problem faced by many when collecting trash is the constant struggle to keep the trash bag open while depositing items therein.
[0007] A number of different devices are patented that claim rigid frames for keeping a trash bag open. Several patents have been granted for devices that attempt to provide a means of keeping a trash bag open so the user no longer has to place strain on his or her body while in operation. Many of the prior art patents describe a device with a handle to make the device portable. Some devices attach to a belt, while others can be supported by a strap around the shoulder. These prior art devices have several known drawbacks. Many of the prior art devices have a handle incorporated into their design that requires a user to occupy one hand while holding onto the device. As the hopper is filled with collected items, the hopper becomes increasingly heavier, causing unnecessary strain on the user's wrist. No patents exist for a device that incorporates a forearm support with a strap for bearing the weight of the device along the length of a user's forearm.
[0008] Included in the similar prior art are patents describing trash bag holders or utility hopper devices that hold a bag open so that a user can easily place items into the open bag. Several patents describe devices that have a frame for keeping the trash bag open that is attached to a handle. U.S. Pat. No. 3,733,099 to Szita describes such a device, wherein a triangular-shaped refuse bag support frame with a means of securing a refuse bag onto the triangular support frame is disclosed. The refuse bag is held open by the frame. The frame is attached to a handle which is used for manipulating the device. The handle, in conjunction with the triangular-shaped frame, can be adjusted to form a tri-pod-like stand to hold the refuse bag open and in an upright position so debris can be swept into the bag by a user. When the handle of the device is not in the stand position, the device requires a user to pick up the device by its handle.
[0009] Similarly, U.S. Pat. No. 4,012,067 to Travis describes a refuse collection device that comprises a hoop attached to an extendable handle. A refuse bag can be fastened, by a clamping means, to the hoop for the purpose of holding the bag open. The hoop has a D-shape configuration, with the extendable handle attached at the apex of the D curve. The attached handle has a telescopic construction and can be adjusted to an appropriate length based on the user's preferences and is designed to avoid the user having to stoop or bend over to pick up trash. The flat side of the D-shaped hoop can be placed against the ground so that debris can be swept into the attached trash bag easily. This device requires a user to pick up and carry the device by its handle.
[0010] U.S. Pat. No. 5,413,394 to Mitchell also describes a trash collecting device with a D-shaped hoop for keeping a trash bag open, attached to a handle. Similar to the Travis patent, the handle of the Mitchell device attaches at the apex of the D curve. The trash bag can be clamped to the D-shaped frame. The handle is connected to the D-shaped hoop by a rotating T-connector, which allows the user to adjust the angle of the handle in relation to the D-shaped hoop. The flat side of the D-shaped hoop can be placed against the ground so that debris can be swept into the attached trash bag. The Mitchell device also requires a user to hold and carry the device by its handle.
[0011] U.S. Pat. No. 5,050,920 to Potticary describes a device having a trapezoid-shaped rim with an attached handle. A handle is attached to the shorter parallel side while an attached lip is located on the lower, longer parallel edge of the rim. The lip is designed to help facilitate the collection of garbage when swept into the device. A refuse bag can be attached to the rim by utilizing a system of hooks along the rim. The hooks allow the user to attach bags of various sizes to the device since the multitude of hooks available as a fastening means can be utilized according to how tightly the user prefers the bag to fit on the device. The size of the attached bag will determine how much trash a user can collect. The device is designed to prevent a user from bending over to collect trash. To use this device, a user holds the device by its handle with one hand and as weight is added to the trash bag, it will place additional stress on the user's wrist.
[0012] U.S. Pat. No. 5,947,602 to Coxsey describes a trash collecting device with similar construction to the previously described prior art. A hoop that holds a trash bag open is attached to a short V-shaped handle. One leg of the V-shaped handle is a handle to be held by the user. The other leg of the V-shaped handle is placed within the attached trash bag to prevent the bag from collapsing. This device requires the user to hold the device by its handle, and offers no means of support for the user as the bag becomes heavier from the added trash.
[0013] U.S. Pat. No. 5,020,751 to Larkin describes a refuse bag holding system where the refuse bag is attached to a holding ring by an attachment means. A plate is attached to the holding ring which is designed to fit into a mounting bracket which can be attached to various surfaces. The device may also be detached from the mounting bracket and used as a hand-held bag holder. The preferred embodiment of the device is used as a trash storage device at sporting venues such as stadiums. The device can be attached to the backside of stadium seats for use by stadium patrons. The Larkin patent also describes an embodiment similar to the previously mentioned patents that incorporate a handle. This alternative embodiment comprises a refuse bag support frame that is rectangular in shape, with a handle attached to one of the longer sides of the support frame rectangle. A user can easily sweep debris or trash into the device, as the design of the device alleviates the need for a user to bend over and pick up trash. This particular embodiment of the device requires a user to hold the device by its handle and provides no support for the user's wrist.
[0014] Collectively, the previously mentioned prior art patents (U.S. Pat. No. 3,733,099 to Szita, U.S. Pat. No. 4,012,067 to Travis, U.S. Pat. No. 5,050,920 to Potticary, U.S. Pat. No. 5,413,394 to Mitchell, U.S. Pat. No. 5,947,602 to Coxsey and U.S. Pat. No. 5,020,751 to Larkin) all share a similar design flaw. Each device requires that a user hold the device by its handle in order to manipulate the device. The disadvantage of this design is that the user must bear the entire weight of the device at the wrist joint as the user picks up and/or carries the device with his or her hand. The present invention straps to the user's forearm, which eases the stress exerted on the user's wrist since the forearm is bearing a majority of the weight of the device when trash is collected in it. Another beneficial feature of the present invention is that the user may attach the device to a belt clip, leaving the user's hands and arms completely free. When attached to the belt clip, the user's body bears the weight of the device as trash is collected and placed into the attached bag.
[0015] Other patents have issued for trash holders that do not utilize a handle in their design. U.S. Pat. No. 6,604,717 to Stanfield describes a bag holder that has no handle. Instead, a user carries the device by pressing the hoop support frame of the device against their body with one hand. The edges of a trash bag are secured to the hoop support frame by a series of clamps, and the attached trash bag hangs close to the body of the user. This device exhibits the same disadvantage as the devices that incorporate a handle. While the user's body could support a majority of the weight of the device when it is in use, if the user were to pull the device away from their body—for example to set the device down—the user must bear the weight of the device with their wrist as they move the device way from their body.
[0016] U.S. Pat. No. 6,086,022 to Dalton describes an over-the-shoulder trash receptacle. The device has a ring support frame which the trash bag is attached to so that the trash bag stays open during use. The ring support frame is a pair of rings, wherein one snaps into the other. The edges of the trash bag are clamped in between the two rings when they are snapped together. A shoulder strap is attached to the ring support frame, allowing for a user to carry the device while keeping the user's hands free. This device has some disadvantages. For example, as the user adds weight to the trash bag, the weight of shoulder bag may become very heavy, or the added weight may cause the bag to shift as the user bends over to pick up trash. Unless the user is stabilizing the device with one hand, the shift in weight as the user bends over could disrupt the user's balance, or cause strain on the user's shoulder. The present invention aims to alleviate the unnecessary strain placed on the user's shoulder by providing a device that straps to the user's forearm, causing the user's forearm to help bear the weight of the device as trash is collected in it.
[0017] The present invention substantially diverges in design elements from the prior art and consequently it is clear that there is a need in the art for an improvement to existing utility hopper devices. There is a need to reduce the amount of stress that is placed on a user's wrist when using a utility hopper device for collecting items. In this regard the instant invention substantially fulfills this need.
SUMMARY OF THE INVENTION
[0018] In view of the foregoing disadvantages inherent in the known types of trash holders and utility hoppers now present in the prior art, the present invention provides a new means of securing the hopper device to a user's forearm that provides support for the user's wrist. The present invention can be utilized for providing convenience for the user in a variety of activities including, but not limited to, trash collecting and various types of harvesting applications. The device serves as a portable, temporary storage container for collected items, which at some later point in time will be transferred to a larger storage receptacle.
[0019] It is therefore an object of the present invention to provide a new and improved utility hopper that has all of the advantages of the prior art and none of the disadvantages.
[0020] Another object of the present invention to provide a means of reducing the stress placed on the user's wrist while using a utility hopper device by supporting the additional weight of the collected items via a forearm support and strapping device attachable to the user's forearm.
[0021] Another object of the present invention is to provide utility for activities related to item collection, harvesting, carrying and trash collection.
[0022] Other objects, features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTIONS OF THE DRAWINGS
[0023] Although the characteristic features of this invention will be particularly pointed out in the claims, the invention itself and manner in which it may be made and used may be better understood after a review of the following description, taken in connection with the accompanying drawings wherein like numeral annotations are provided throughout.
[0024] FIG. 1 is a perspective view of the supporting frame of the present invention without a bag or receptacle attached thereto.
[0025] FIG. 2 is a perspective view of the present invention fitted with a mesh bag and attachment clips.
[0026] FIG. 3 is a perspective view of the present invention fitted with a mesh bag and in a working position, attached to the forearm of a user.
[0027] FIG. 4 is a perspective view of the present invention fitted with a garbage bag and attached to a user's belt.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Referring now to FIG. 1 , there is shown a perspective view of the supporting frame 11 of the present invention without a bag attached thereto. The supporting frame 11 is comprised of a strong, rigid material that can support the weight of the collected items stored in a receptacle attached thereto without significant deflection. The device comprises a forearm support 14 that is strapped to a user's forearm in order to bear the weight of the device as items are collected and added thereto. An upstanding gripping handle 12 is located on the forearm support 14 near the bag support loop. The user grips the gripping handle 12 and holds the device flush with their forearm while securing the arm strap 13 tightly, but comfortably, around the circumference of the forearm. The straps 13 can be fastened around the user's arm by an attachment means, which includes, but is not limited to: snaps, hook and loop fasteners or a buckle, to ensure that the device remains securely fastened around the user's forearm.
[0029] Referring now to FIG. 2 , there is shown a perspective view of the present invention fitted with a mesh bag 16 . By strapping the device to a user's forearm, the device serves as an extension of the user's arm and a means to distribute the weight of the items placed within the mesh bag along the length of the forearm, as opposed to placing undue strain on the wrist joint during operation. Use of the gripping handle 12 provides the user with added stability and control when manipulating the device. The gripping handle 12 can be wrapped in a cushioning material, such as foam or rubber, for maximum comfort. Use of a mesh bag 16 is depicted here. Bags made of other materials may also be used if desired by the user, including trash bags, canvas bags or any similar containment article that is attachable to the rim of the supporting frame 11 . The bag 16 is preferably attached to the supporting frame 11 with a set of spring-loaded clips 15 . The clips 15 are evenly spaced along the perimeter of the supporting frame 11 to prevent dislocation or high stress areas. As weight is added to the attached bag 16 , strain will be exerted on the bag at the points where the bag 16 is connected to the supporting frame 11 , and in particular those areas connected by the clips 15 . Even spacing of the attachment clips 15 will ensure that the attached bag 16 remains open while in use and that the bag 16 does not tear or rip. If desired, an alternative means may be employed to connect the bag around the perimeter of the frame 11 , including folding the opening of the bag around the frame rim or using another attachment article to secure the bag thereto.
[0030] Referring now to FIG. 3 , there is shown a perspective view of the present invention in a working position, wherein the device has been strapped to the arm of a user 17 . The device can be strapped to either the right or left forearm. During typical use, the user 17 either places collected items into the bag 16 attached to the device, or a user 17 captures loose or falling items within the bag 16 , which is likely to occur when harvesting fruit from a tree or scooping fish, crabs or shrimp from a body of water. The items are placed in the attached bag 16 for temporary storage until the collected items can be transferred into a larger storage receptacle.
[0031] Referring now to FIG. 4 , there is shown a perspective view of the present invention, wherein the user 17 has secured the device to his belt 17 via an attachment clip 18 . This is a useful embodiment of the device as it leaves the user's 17 arms and hands completely free. A user 17 can attach a trash bag 16 to the device using clips 15 to fasten the bag 16 to the supporting frame 11 and use the device for article collection purposes. The device is easily detachable from the user's belt 17 if desired, or the device can be kept in this position while depositing items therein. To release the device so it can be used, a user 17 manipulates the belt clip 18 into an open position, freeing the rim of the frame from the clip and his belt. Rather than bending over to pick up an article, a user 17 can detach the device from the belt clip 18 , scoop up the item and then reattach the device to the belt clip 18 . The belt clip 18 has two configurations with respect to the user's belt. The first configuration orients the device in an upright and functional mode as depicted here in FIG. 4 . The supporting frame 11 extends outward from the user's body 17 and the trash bag 16 dangles out of the bottom of the device, ready to receive collected items. The second configuration allows the user 17 to carry the empty device when it is not in use by attaching it to the user's belt 17 while device hangs along the side of the user's body 17 so as to not to interfere with his activities, such as walking or otherwise moving position.
[0032] When used by an individual, the user can attach a trash bag to the supporting frame by pinching the bag with the attachment clips that are evenly spaced along the supporting frame. The user can then grip the device by the gripping handle and hold the device against their forearm while securing the arm strap. The straps should be secure, but not overly tight as to cut off the circulation of blood flow to the user's lower arm. Once the device is in place, the device serves as an improved structure for supporting the weight of collected items, or as an extension of the user's arm. The device can be used to scoop up trash, collect harvest items or capture fish, crabs or shrimp.
[0033] Another embodiment of the present invention involves the use of a mesh bag in place of a garbage bag. A mesh bag utility hopper can be used for storing harvested items temporarily until they can be transported to a larger storage container. This embodiment of the invention is very useful in agricultural harvesting applications. For example, if a user were attempting to gather peaches hanging in a peach tree, the user would fasten the device to their forearm and reach with the device to jostle the hanging fruit, with the goal being to catch the fruit in the mesh bag as it falls from the tree. If a peach is ripe for picking, but will not detach from the tree, the user will find the use of the gripping handle to be highly advantageous as it provides the user with additional control and improved dexterity over devices which do not act as an extension of the user's arm. With improved control, the user will be better able to manipulate the device and capture the desired peach. The user may also use a secondary tool to collect the items, such as a picker or trash picker, and deposit the items into the device after initial collection.
[0034] Other uses for the mesh bag embodiment of the device could include fishing and crabbing applications. Fishermen and bait dealers may use the device as one would use a net to scoop fish out of the water. Crabbers could also use the device to scoop crabs that have been lured into a crab trap. The advantage of this device is that a user does not have to extract the caught fish or crabs from the mesh bag as one would have to do when using a net. Instead, the user could simply unclip the mesh bag while keeping the caught fish or crabs inside.
[0035] The design of the device is such that the frame will not deflect or twist while supporting the load of collected items, while the forearm section and handle provided improved means of distributing this weight on a user's arm. Strain on the user is reduced, as the weight is distributed over the length of the forearm, as opposed to the wrist joint, which can tire and cause injury if overloaded. The device further provides an extension of the user's arm if desired by the user, which is helpful for reaching items or collecting items from an extended position. Overall, the device improves user safety and provides a high degree of novelty with respect to the collection or harvesting of items that are manually collected or picked.
[0036] To this point, the instant invention has been shown and described in what is considered to be the most practical and preferred embodiments. It is recognized, however, that departures may be made within the scope of the invention and that obvious modifications will occur to a person skilled in the art. With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
[0037] Therefore, the foregoing is considered as illustrative only of the principles of the invention. Since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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A device for holding a trash bag open while allowing a user to support and carry it with ease. The device comprises a rigid support frame and a plurality of clips that attach to, and hold open, a garbage bag. The support frame has a forearm support that extends from it, which the user secures to his or her forearm, along with a gripping handle that the user holds in his or her hand. The device keeps the bag open for easy trash placement thereinto. Alternatively, a netted, mesh bag can be used in place of the garbage bag to avoid waste associated with their disposal. The mesh bags can also serve as temporary storage space for items that will be later transferred to a larger storage receptacle. The device may also be attached to a user's belt with a clip for transport when not in use.
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BACKGROUND OF THE INVENTION
I. Field of the Invention
The present invention relates to digital communications. More particularly, the present invention relates to a novel and improved system and method for monitoring the load in a CDMA system.
II. Description of the Related Art
In the field of code division multiple access (CDMA) wireless communication, a wideband frequency channel is shared by multiple communication devices, with each communication device employing a different pseudorandom noise (PN) spreading code. In a typical CDMA wireless communication system, a first frequency band is used for forward channel communications (from the base station to the mobile station), while a second frequency band, different from the first frequency band, is used for reverse channel communications (from the mobile station to the base station). An example of such a system is given in U.S. Pat. No. 4,901,307 entitled “Spread Spectrum Multiple Access Communication System Using Satellite Or Terrestrial Repeaters,” issued Feb. 13, 1990, assigned to the assignee of the present invention, and incorporated herein by reference.
Fundamental to the concept of maximizing system capacity in a CDMA wireless communication system as described above is the process of power control. The output power of subscriber units must be controlled to guarantee that enough signal strength is received at the base station and to maintain good quality audio while minimizing the potential for interference. Since a CDMA wideband channel is reused in every cell, self interference caused by other users of the same cell and interference caused by users in other cells is the most limiting factor to the capacity of the system. Due to fading and other channel impairments, maximum capacity is achieved when the signal-to-noise ratio (SNR) for every user is, on the average, at the minimum point needed to support “acceptable” channel performance. Since noise spectral density is generated almost entirely by the interference from other users, all signals must arrive at the CDMA receiver with the same average power. In the mobile propagation environment, this is achieved by providing dynamic power control of the mobile station transceiver. Power control guards against changes in system loading, jamming, slow and fast variations in channel conditions, and sudden improvements or degradations in the channel (shadowing).
Power control of the mobile station transmitter consists of two elements: open loop estimation of transmit power by the mobile station, and closed loop correction of the errors in this estimate by the base station. In open loop power control, each mobile station estimates the total received power on the assigned CDMA frequency channel. Based on this measurement and a correction supplied by the base station, the mobile station transmitted power is adjusted to match the estimated path loss, to arrive at the base station at a predetermined level. All mobile stations use the same process and arrive with equal average power at the base station. However, uncontrolled differences in the forward and reverse channels, such as opposite fading that may occur due to the frequency difference and mismatches in the receive and transmit chains of the mobile station, can not be estimated by the mobile.
To reduce these residual errors, each mobile station corrects its transmit power with dosed loop power control information supplied by the base station via low rate data inserted into each forward traffic channel. The base station derives the correction information by monitoring the reverse CDMA Channel quality of each mobile station, compares this measurement to a threshold, and requests either an increase or decrease depending on the result. In this manner, the base station maintains each reverse channel, and thus all reverse channels, at the minimum received power needed to provide acceptable performance. An example of a communication system employing the open loop and closed loop power control methods described above is given in U.S. Pat. No. 5,056,109 entitled “Method And Apparatus For Controlling Transmission Power In A CDMA Cellular Mobile Telephone System,” assigned to the assignee of the present invention, and incorporated herein by reference.
In a CDMA wireless communication system as described above, a predetermined number of radio frequency resources, such as transceivers and channel modulator/demodulators (modems) are located at each base station. The amount of resources allocated to a base station depends upon the anticipated traffic loading conditions. For example, a system in a rural area may only have one omni-directional antenna at each base station, and enough channel modems to support eight simultaneous calls. On the other hand, a base station in a dense urban area may be co-located with other base stations, each having several highly directional antennas, and enough modems to handle forty or more simultaneous calls. It is in these more dense urban areas that cell site capacity is at a premium and must be monitored and managed closely in order to provide the most efficient allocation of limited resources while maintaining acceptable quality of communications.
Sector/cell loading is the ratio of the actual number of users in the sector to the maximum theoretical number that the sector can support. This ratio is proportional to total interference measured at the receiver of the sector/cell. The maximum number of users that the sector/cell can support is a function of the aggregate signal-to-noise ratio (SNR), voice activity, and interference from other cells. The individual subscriber unit SNR depends on subscriber unit speed, radio frequency propagation environment, and the number of users in the system. Interference from other cells depends on the number of users in these cells, radio frequency propagation losses and the way users are distributed. Typical calculations of the capacity assume equal SNR for all users and nominal values of voice activity and interference from other cells. However, in real systems, SNR changes from user to user and frequency reuse efficiency varies from sector to sector. Hence, there is a need to continuously monitor the loading of a sector or cell.
A conventional way to monitor cell site loading conditions is for a person, usually a network engineer or technician employed by a wireless communication service provider, to travel from cell to cell making loading condition readings using specially designed and expensive test equipment. The logged data is then returned to a central processing facility for post-processing and analysis. Some significant drawbacks to this method are that the data can not be evaluated in real-time, and that significant errors are introduced due to propagation effects between the base station and the measurement equipment. Thus, this monitoring method only be used in a time-delayed fashion to take corrective action, such as reassigning resources for the future. It does not enable the service provider to take any real-time action to improve loading conditions and their effect on system performance. Additionally, it requires a person to travel to each site serially, thus providing a discontinuous “hit or miss” estimate of the peak loading conditions and consequent system performance depending on whether the visit coincided with the actual (rather than assumed) peak usage times.
Another possible way of monitoring cell site loading conditions is accessing the performance data logged by the base station, or the base station controller. However, this method requires that scarce base station processing resources be diverted to collect and retrieve the loading data. Additionally, it suffers from the non-real time post-processing problems previously mentioned. It also requires that a person visit each cell site serially to retrieve the data.
One alternate method for monitoring loading in CDMA systems that is known in the prior art is the use of a dedicated channel. However, this solution is very expensive since the capacity of the dedicated channel can not be used for any other purposes. Consequently, a better way to monitor loading of CDMA communication systems is needed. These problems and deficiencies are clearly found in the art and are solved by the invention in the manner described below.
Thus it is desirable to provide a better way to perform load monitoring in CDMA systems wherein a base station determines the total amount of interference in its frequency band that it receives from all the other transmitters in the system. The load monitoring performed this way can be an important aspect of the operation and maintenance of CDMA systems. For example, load monitoring can be used to predict approaching system overloads. It can also be used to control the amount of loading in a system and to establish an admission policy for adding users to the system. The admission policy can apply to new users as well as to users already on the system and being handed off since admission of either kind of user can result in exceeding the system capacity. In addition to limiting the admission of users, steps can be taken to allocate more resources in response to load monitoring. Load monitoring can also be used to determine peak hour activities in CDMA systems.
SUMMARY OF THE INVENTION
The present invention is directed to a method and apparatus for monitoring the load on a CDMA communication system having a base station and a plurality of users. A measure of voice activity in the communication system is determined, and a current value of frequency reuse efficiency equal to an initial value of frequency reuse efficiency is provided. A power determination is made according to the determined voice activity and the current value of frequency reuse efficiency. The current value of frequency reuse efficiency is updated using the power determination to provide a new current value of frequency reuse efficiency. The power determination and the update of the frequency reuse efficiency are iteratively repeated until convergence to provide a converged value of frequency reuse efficiency. The load on the communication system is then determined in accordance with the converged frequency reuse efficiency value.
In one embodiment, after the load on the communication system is determined, the admission of new users to the communication system is controlled using the determined load value, e.g., admission of new users is denied when the load is above a threshold. Additionally, load values calculated in accordance with the present invention can be stored in order to collect peak hour activities relating to the communication system.
BRIEF DESCRIPTION OF THE DRAWINGS
The features, objects, and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly throughout and wherein:
FIG. 1 shows a high level overview of the system of the present invention;
FIGS. 2A, 2 B show graphical representations of possible loadings of a CDMA communication system;
FIG. 3 shows a flow diagram of the method of the present invention; and
FIG. 4 is a block diagram showing the components of an exemplary base station used for implementing the position tracking system of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, there is shown an overview of-communication system 9 of the present invention. Communication system 9 provides real time monitoring and management of system loading. Base station 4 of communication system 9 is in wireless communication with mobile stations 1 A- 1 D by way of antenna 2 . Mobile stations 1 A- 1 D can be power controlled CDMA cellular telephones as well known in the art. Base station 4 is also in communication with system management center 5 which can contain any personnel and network computers required to perform any monitoring or management functions required within base station 4 . Base station 4 and system management center 5 can communicate by any method known in the art.
In normal operation of system 9 , mobile stations 1 A- 1 D periodically communicate with base station 4 , either to originate a call, receive a call, or to send or receive various overhead messages to or from base station 4 . During peak usage hours, such as during the middle of the day, all four mobile stations 1 A- 1 D may be in simultaneous communication with base station 4 , thereby increasing system loading and interference on the reverse link. Conversely, during non-peak usage hours, such as during the middle of the night, fewer mobile stations 1 A- 1 D may be in communication with base station 4 at any time, thereby decreasing system loading. It will be understood that there may be fewer or many more than four mobile stations 1 A- 1 D simultaneously communicating with base station 4 depending on the capacity of base station 4 .
In practicing the system and method of the present invention, the system loading and the frequency reuse efficiency in an active CDMA communication system can be monitored. Information about system loading can then be used by a base station controller, a base station, or any other control device to control loading, establish admission policy to the system and collect peak hour activities. In order to obtain this information and perform these operations, traffic channel SNR information available to a cell site modem is used. In particular, the energy per bit (E b ) to noise power spectral density (N t ) of a reverse traffic channel i in a sector k of the CDMA system is used. This quantity is given by ( E b N t ) i = x i = ( W / R i ) C i N o W + 1 F k ∑ j ≠ i N v j C j ( 1 ) x i [ N o W + 1 F k ∑ j ≠ i N v j C j ] = W R i C i ( 2 ) x i [ N o W + 1 F k ∑ j = 1 N v j C j - 1 F k v i C i ) ] = W R i C i ( 3 ) x i [ N o W + 1 F k ∑ j = 1 N v j C j ] = W R i C i + 1 F k x i v i C i ( 4 ) C i = x i W / R i + 1 F k v i x i [ N o W + 1 F k ∑ j = 1 N v j C j ] ( 5 )
where N o W represents the thermal/background noise, C i is the power received at the antenna connector of the base station from user i, v i is the average voice activity of user i which the base already knows, N is the number of simultaneous users in the sector, W is the bandwidth of the CDMA waveform, R i is the data rate of user i, and F k is the frequency reuse efficiency of sector k.
As explained below, the voice activity v i is calculated over N frames based on the data rate(s) used for transmission of traffic information from the mobile station during the frames. For example, in a typical CDMA system frames may be transmitted to the base station using one of four rates (i.e., full rate, ½ rate, ¼ rate and ⅛ rate). In such systems, prior to transmission, the mobile station interleaver output stream is time gated to allow transmission of certain interleaver output symbols and deletion of others. The duty cycle of the transmission gate varies with the transmit data rate. When the transmit rate is 1 (full-rate), the transmission gate allows all interleave output symbols to be transmitted. When the transmit rate is ½, the transmission gate allows one-half of the interleaver output symbols to be transmitted, and so forth. For a given time interval that includes N 1 frames of rate 1, N 2 frames of rate ½, N 3 frames of rate ¼, and N 4 frames of rate ⅛, where N=N 1 +N 2 +N 3 +N 4 , the voice activity factor (v) averaged over N frames is calculated as follows: v = N 1 N + 1 2 N 2 N + 1 4 N 3 N + 1 8 N 4 N ( 6 )
The frequency reuse efficiency F k mentioned above can be represented as follows: F k = Interference from units within the cell Total interference from all cells ( 7 )
Multiplying by v i and summing Equation (5) over all values of i ∑ i = 1 N v i C i = [ N o W + 1 F k ∑ j = 1 N v j C j ] ∑ i = 1 N v i x i W / R i + 1 F k v i x i ( 8 )
Equation (8) can be rewritten as 1 F k ∑ i = 1 N v i C i [ N o W + 1 F k ∑ j = 1 N v j C j ] = 1 F k ∑ i = 1 N v i x i W / R i + 1 F k v i x i ( 9 )
The left side of Equation (9) represents the ratio of the CDMA power to the total received power. This ratio is defined as the percentage of loading of the CDMA communication system. On the right side of Equation (9), the frequency reuse efficiency F k is an estimated value. All of the other values of the right side of Equation (9) are known. Thus it is possible to calculate the percentage of loading of the communication system if a value of the frequency reuse efficiency F k is obtained.
Referring now to FIGS. 2A, 2 B, there are shown graphical representations 10 , 12 . Graphical representations 10 , 12 indicate possible loadings of CDMA sectors. In the CDMA sector represented by graphical representation 10 , approximately fifty percent of the received power is CDMA power and approximately fifty percent of the total received power is noise (N o W). In the CDMA sector represented by graphical representation 12 , approximately seventy-five percent of the total received power is CDMA power and approximately twenty-five percent of the received power is noise (N o W). Thus the percentages of loading of the sectors of FIGS. 2A, 2 B are fifty and seventy-five, respectively.
Referring now to FIG. 3, there is shown a flow chart representation of communication system control method 50 of the present invention for load monitoring and determining frequency reuse efficiency within communication system 9 . Method 50 is preferably implemented in software on a controller coupled to the cell site modem associated with the sector/cell under consideration.
When monitoring reverse RF link loading according to communication system control method 50 , a CDMA communication system can estimate the voice activity v i for each reverse traffic channel i in a sector k as shown in block 52 . It is known to those skilled in the art that the reverse traffic channel includes power control groups for transmitting power control information from a mobile station to the base station. At the end of each power control group a decision can be made by a channel element processor in the base station whether the transmitter of mobile i is on or off during the period of the power control group. This information can be used to determine the voice activity on traffic channel i as shown in equation (6).
For each reverse traffic channel in the sector, communication system 9 estimates the energy per bit to noise power spectral density x i =(E b /N t ) i as shown in block 54 . Depending on the implementation, either an average or instantaneous estimate of the energy per bit to noise power spectral density x i =(E b /N t ) i may be used. The ratio of the energy per bit to the noise power spectral density of CDMA communication systems can be determined in different ways. One way is to use instantaneous values of E b /N t . Another involves using set point values of E b /N t . In general, the instantaneous values of E b /N t are obtained from the base station controller and the set point values are obtained from a selector. If the instantaneous values are used, the base station processor can calculate the instantaneous loading using Equation (9) and pass the loading information to an admission control processor. If set point values from the selector are used, the base station controller can use Equation (9) to calculate the load corresponding to the determined set points. It will be understood that the value of the reverse link energy per bit to noise power spectral density required to sustain a specific frame error rate on the reverse traffic channel of user i can be represented as (E b /N t ) i .
The total received power P t = N o W + 1 F k ∑ j ≠ i N v j C j (10A)
is then measured as shown in block 56 . This quantity is readily available from the automatic gain control circuit of a conventional base station, or alternatively may be measured in other ways known in the art. As shown in block 58 , Equation (8) is used along with Equation 10(A) to calculate the CDMA power of sector k. This calculation is performed in accordance with equation 10(B) using a current value which is an estimated initial value of frequency reuse efficiency F k (0). A good initial value of F k (0) can be 0.66. P cdma ( 0 ) = ∑ i = 1 N v i C i = P t ∑ i = 1 N v i x i W / R i + 1 F k ( 0 ) v i x i (10B)
The frequency reuse efficiency is updated to produce a new current value as shown in block 60 . During each iteration the current value of frequency reuse efficiency is updated to provide a new current value of frequency reuse efficiency. The new current value is calculated as follows: F k ( 1 ) = P cdma ( 0 ) P t - N o W ( 11 )
The iteration of blocks 56 , 58 , 60 continues until the estimate of F k converges as determined in decision block 62 according to the following: P cdma ( n ) = ∑ i = 1 N v i C i = P t ∑ i = 1 N v i x i W / R i + 1 F k ( n ) v i x i ( 12 ) F k ( n + 1 ) = P cdma ( n ) P t - N o W ( 13 )
The final value of the frequency reuse efficiency is thus determined according to decision 62 . As shown in block 64 the sector loading is then calculated using the frequency reuse efficiency in the manner set forth in Equation (9). The operations of block 64 can be performed, for example, when two consecutive calculations of frequency reuse efficiency produce the same result within the precision of the processor performing the calculations or when two consecutive calculations of frequency reuse efficiency are within a predetermined threshold of each other. The CDMA communication system can then be controlled, for example, by a base station controller according to the system loading, the frequency reuse efficiency, or any other value obtained using communication system control method 50 as shown in block 66 . For example, the admission of new users to the communication system can be controlled according to the system loading. Alternatively, the system loading can be monitored in order collect information reflecting peak hour activities at a base station.
Referring now to FIG. 4, there is shown a block diagram of the components of an exemplary CDMA base station 400 used for implementing the load monitoring system of the present invention. At the base station, two receiver systems are utilized with each having a separate antenna and analog receiver for diversity reception. In each of the receiver systems, the signals are processed identically until the signals undergo a diversity combination process.
The elements within the dashed lines correspond to elements corresponding to the communications between the base station and one mobile station. Referring still to FIG. 4, the first receiver system is comprised of antenna 460 , analog receiver 462 , searcher receiver 464 and digital data receivers 466 and 468 . The second receiver system includes antenna 470 , analog receiver 472 , searcher receiver 474 and digital data receiver 476 . Cell-site control processor 478 is used for signal processing and control. Among other things, cell site processor 478 monitors the signals sent to and received from a mobile station and uses this information to perform the load monitoring calculations described above. Thus, the system of FIG. 3 is preferably implemented in software on cell site processor 478 .
Both receiver systems are coupled to diversity combiner and decoder circuitry 480 . A digital link 482 is used to communicate signals from and to a base station controller or data router under the control of control processor 478 . Signals received on antenna 460 are provided to analog receiver 462 , where the signals are amplified, frequency translated and digitized in a process identical to that described in connection with the mobile station analog receiver. The output from the analog receiver 462 is provided to digital data receivers 466 and 468 and searcher receiver 464 . The second receiver system (i.e., analog receiver 472 , searcher receiver 474 and digital data receiver 476 ) processes the received signals in a manner similar to the first receiver system. The outputs of the digital data receivers 466 , 476 are provided to diversity combiner and decoder circuitry 480 , which processes the signals in accordance with a decoding algorithm. Details concerning the operation of the first and second receiver systems and the diversity combiner and decoder 480 are described in U.S. Pat. No. 5,101,501 entitled “Method and Apparatus for Providing A Soft Handoff In Communications In A CDMA Cellular Telephone System”, incorporated above. Signals for transmission to mobile units are provided to a transmit modulator 484 under the control of processor 478 . Transmit modulator 484 modulates the data for transmission to the intended recipient mobile station.
The previous description of the preferred embodiments is provided to enable any person skilled in the art to make and use the present invention. The various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without the use of the inventive faculty. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
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A system and method for monitoring the load on a CDMA communication system having a base station and a plurality of users. A measure of voice activity in the communication system is determined, and a current value of frequency reuse efficiency equal to an initial value of frequency reuse efficiency is provided. A power determination is made according to the measured voice activity and the current value of frequency reuse efficiency. The current value of frequency reuse efficiency is updated using the power determination to provide a new current value of frequency reuse efficiency. The power determination and the update of the frequency reuse efficiency are iteratively repeated until convergence to provide a converged value of frequency reuse efficiency. The load on the communication system is then determined according to the converged frequency reuse efficiency value.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation-in-Part application of pending U.S. patent application Ser. No. 13/385,152, filed Feb. 6, 2012.
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to the field of decorative wristband bracelets and more specifically to a customizable elastic wristband.
[0003] Decorative wrist bands have been worn by people from all countries for thousands of years. They can be made out of rigid materials such as metal, wood or plastic, and may have a hinged portion and clasp to allow the user to fit the band around the wrist without needing to ride over the larger hand portion. Some wristbands are made of flexible material such as leather or fabric or rubber. Rubber is one of the materials that is elastic and can therefore by placed on a person's wrist without the need for a hinge or clasp. The band can simply be stretched to fit over the hand portion and then released once the band is in the area of the wrist.
[0004] In recent times, rubber bracelets have been used and worn to tell the world that you support a certain cause. For example, a person might wear a pink breast cancer bracelet to tell the world that you support breast cancer research. The bracelet may have lettering embossed into it that identifies the cause. Some bracelets are made of cast rubber or silicone, which is a form of rubber. However, there is a deficiency in the prior technology in that each bracelet must be manufactured for a specific purpose. A breast cancer bracelet can not also be set up to be a diabetes bracelet, or a bracelet that has a sports team logo printed on it. Therefore it would be ideal to have a universal elastic bracelet that can be adapted to include any graphic image of choice depending on the likes and interests of the user.
BRIEF SUMMARY OF THE INVENTION
[0005] The primary object of the invention is to provide an elastic wristband that allows a user to customize the band with insertable graphic panels.
[0006] Another object of the invention is to provide an elastic wristband where the graphic panels are removable and/or interchangeable.
[0007] Another object of the invention is to provide an elastic wristband that is translucent or substantially transparent to allow the graphic panels held within the band to be easily seen.
[0008] Another object of the invention is to provide an elastic wristband that is manufactured in strip form and then has its ends joined to form a continuous band.
[0009] Other objects and advantages of the present invention will become apparent from the following descriptions, taken in connection with the accompanying drawings, wherein, by way of illustration and example, an embodiment of the present invention is disclosed.
[0010] In accordance with a preferred embodiment of the invention, there is disclosed an elastic wristband having an elongate strip of injection molded translucent or almost transparent, resilient thermoplastic material and one or more graphic panels. The elongate strip includes an elongate center portion and an elongate left side and an elongate right side portions, wherein the right and left side portions are joined to the elongate center portion along its elongate edges by integral living hinge members, or other attachment. The central portion includes recessed areas for receiving and holding graphic panels. The central portion of the elongate strip includes end tabs which are suitable for being joined together by welding or other means, including gluing. Once the end tabs are joined together a continuous circular band is formed. As the band is elastic in nature, it is capable of fitting over a person's hand and onto a person's wrist to form a decorative wristband.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention.
[0012] FIG. 1 is a perspective view of the invention in bracelet form;
[0013] FIG. 2 is a perspective view of the invention in strip form;
[0014] FIG. 3 is a side section view of the invention;
[0015] FIG. 4 is a perspective view of a second embodiment of the invention in bracelet form;
[0016] FIG. 5 is a perspective view of the second embodiment in the invention when partially open before welding the opposite ends;
[0017] FIG. 6 is an outside view of the second embodiment in an open flat position;
[0018] FIG. 7 is a side view of the second embodiment shown in FIG. 6 ;
[0019] FIG. 8 is an inside view of the second embodiment shown in FIG. 6 ;
[0020] FIG. 9 is a cross-sectional view of a display portion of the second embodiment taken as shown in FIG. 6 ;
[0021] FIG. 10 is a cross-sectional view of a solid portion of the second embodiment taken as shown in FIG. 6 ;
[0022] FIG. 11 is a face view of a graphic panel;
[0023] FIG. 12 is a side view of a graphic panel.
[0024] FIG. 13 is a plan view of the wristband with a colored surface and extended flat before welding; and
[0025] FIG. 14 is a third embodiment of the wristband invention with releasable adhesive panels.
DETAILED DESCRIPTION OF THE INVENTION
[0026] Detailed descriptions of the preferred embodiment are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure or manner.
[0027] Referring now to FIG. 1 , we see a perspective view of the invention wristband 100 in the closed circular position. The circular band has an outside face and an inside face and includes a plurality of vertically oriented indentations 4 each extending transversely to the wristband elongate direction on the outside face eat at a position between recess locations 8 to allow for easier injection molding
[0028] An example of such a plastic is Versaflex CL 40 manufactured by GLS Corporation in McHenry Ill. However other manufacturers also make similar elastic moldable plastics. Because the plastic is almost transparent, a graphic panel 6 installed within the band 100 can be clearly seen. A seam line 2 is the edge of the tow folded left side and right side strips 18 , 20 , respectively.
[0029] FIG. 2 shows a perspective view of the invention wristband 100 in the open position just after being released from an injection mold. The elongate strip includes an integral elongate central strip 22 , an elongate left side strip 18 and an elongate right side strip 20 . The left side strip 18 is attached to the left elongate edge of the central strip 22 by living hinge 14 . The right side strip 20 is attached to the right elongate edge of the central strip 22 by a second living hinge 16 . The recessed areas for receiving the graphic panels are the depressions 8 which are positioned at plural successive locations on the central strip 22 to allow room for the insertion of a graphic panel 6 . After the graphic panels 6 are inserted, the left and right side strips 18 , 20 are folded over and the two opposite end tabs 10 , 12 are overlapped on each other and heat welded together forming a circular wrist band 100 as shown in FIG. 1 . The graphic panels 6 can be customized to show a sports team as shown in FIG. 1 , or a special cause, such as fighting breast cancer, or simply a decorative colorful design. The present design allows a user to fold open the two side strips 18 , 20 and change the decorative panels 6 stored inside the wristband 100 .
[0030] FIG. 3 shows a side section view that bisects the invention 100 when in the finished circular shape. Graphic panel 6 can be clearly seen trapped inside the outer central strip 22 and left side and right side inner strips 18 , 20 . The invention is economical to manufacture and can fit a variety of wrist sizes due to its elastic quality. Obviously various diameters of wristbands 100 can be manufactured for children or adults.
[0031] FIG. 4 is a perspective view of a wristband 200 having a top, i.e., outside strip 25 of stretchable plastic material, which has series, i.e., a plurality, of receiving indentations 27 , i.e., pockets, on its inner face, extending around the outside strip 25 . Each pocket 27 is used for holding a respective graphic panel 29 . The wristband 200 has an inside strip 31 of stretchable plastic material bonded to the outside strip 25 at their respective edges. This inside strip includes a longitudinal slit 33 which permits access to the inside area between the inside face of the outside strip 25 and the inside face of the inside strip 31 .
[0032] The individual graphic panel receiving indentations 27 , on the inner face of the outside strip 25 , are manually accessed through the slit 33 . With the inside strip 31 being of stretchable plastic material, slit 33 expands and stretches, whereby graphic panels 29 can be manually installed and removed from the respective receiving indentations 27 . When permitted to return to its original size and shape, the inside strip 31 holds each graphic panel 29 in place within its respective indentation 27 .
[0033] Each end of the outside strip 25 and inside strip 31 have a respective end tab 35 , 37 . These end tabs 35 , 37 are bonded together by heat welding to form the circular wristband.
[0034] The wristband 200 can be seen in a perspective view in FIG. 5 , in an open state, before the welding of the end tabs 35 , 37 . The inside strip 31 is bonded on its peripheral edges, by any of several means, including over-molding, to the peripheral edges of the outside strip 25 .
[0035] The outside strip 25 may be molded separately as an elongate member, FIG. 6 , with the series graphic panel indentations 27 , i.e., pockets 27 , formed into one side thereof. The panel indentations 27 defines the inside face 39 of the outside strip 25 .
[0036] The outside face 41 of the inside strip 31 is shown in FIG. 8 . The slit 33 extends longitudinally down the middle through the outside face 41 of the inside strip 31 to provide access to the series of panel indentations 27 .
[0037] The end tabs 35 , 37 face in opposite directions, FIG. 7 , which become juxtaposed when the elongate strips 25 , 31 sandwich is curved around to form the wristband 200 shape, FIG. 4 . Each end tab 35 , 37 extends entirely across the width of the elongate strips 25 , 31 .
[0038] The slit 33 provides access to a respective indentation pocket 27 in the inside face of the outside strip 25 , FIG. 9 . In a region of the outside strip 25 , without an indentation pocket 27 , FIG. 10 , inside strip 31 seats against the inside face of the outside strip 25 .
[0039] The graphic panel can be of any size and shape compatible with the size and shape of an indentation pocket. Conveniently, the graphic panels 29 can be rectangular in shape, FIG. 11 , and uniformly flat with a uniform thickness, FIG. 12 .
[0040] The wristband can be made in many sizes and size ratios. Changing sizes will contribute to a change in the looks of the finished wristband and its durability. As an example, the outside strip 25 and inside strip 31 can each be about 208 mm long and about 18 mm wide. The outside strip 25 can be about 2-7-3.3 mm thick with an indentation pocket being about 1.5-2.0 mm deep. Each indentation pocket can be about 26 mm long and about 12 mm wide when made rectangular. Each side edge from the edge of a pocket to the edge of the strip is about 3.5 mm. The pockets are spaced apart about 4 mm. The end pockets are spaced about 6 mm inward from the adjacent end of a strip, to allow a tab extension of about 3 mm. The thickness of each end tab is about 1.29-1.3 mm, with each tab extending across the width of the outside and inside strips.
[0041] The step between the thickness of an end tab and the sandwiched strips is about 1.5-2.0 mm. Thus, the thickness of the wristband is about 2.79-3.30 mm. The length and width of a rectangular graphic panel is slightly less than the length and width of an indentation pocket. This means that a graphic panel can be about 45 mm long, by about 11 mm wide, with a thickness of about 1.5-2.0 mm. The thickness of the inside strip is about 1.01-1.52 mm.
[0042] The outside strip 25 and inside strip 31 may also be made of transparent material with a stretch factor of about 150%. The length of the outside strip 25 is about 208 mm and its width is about 19 mm, with a total thickness of about 2.79-3.30 mm. Each window, i.e., indentation pocket 27 is about 45 mm in length, about 18 mm in width and about 2 mm id depth. The area 43 , FIG. 13 , of the outside strip 25 around each indentation pocket 27 may be transparent, or made translucent, or can be colored or tintied 43 , FIG. 13 . The inside strip 31 , FIG. 13 , is generally not seen when the wristband is on the wrist. It can be translucent or transparent, which would facilitate viewing a graphic panel and making the grasping of the graphic panel easier for removal or for insertion of the graphics. Alternatively, the inside strip can be tinted or colored to match the outside strip. The length and width of the inside strip are about 208 mm and about 19 mm, respectively, thereby matching the size of the outside strip. The thickness of the inside stip is about 1.01-1.52 mm. The width of the longitudinal slit is about 2-3 mm, with the longitudinal slit 33 terminating about 5-7 mm from each end of the inside strip.
[0043] A third embodiment of the wristband 300 has its outside strip 25 , FIG. 14 , made of a clear silicon rubber with a series of indentation pockets along its length. There is no inside strip. The graphic panels 29 have a releasable glue on the periphery of their front face. This releasable glue will permit a graphic panel to adhere to a respective outside strip indentation pocket. The graphic panel may then be removed by prying it free.
[0044] The graphic panels may be made of flexible material, or semi-flexible material and sufficiently stretchable so as not to break the adhesion when the wristband is stretched of the hand.
[0045] Regardless of the embodiment, the graphic panels may have the graphics embossed, or printed, or painted on the outside face which abuts the window or the indentation pocket.
[0046] Various materials may be used to construct the wristband. Polypropylene or other flexible, stretchable material that can be injection molded and over-molded, i.e., attached to a more transparent material which may be used for the inside strip.
[0047] The outside strip can be molded from TPE or a clear silicone rubber, or another transparent or highly translucent, flexible, stretchable material that can be over-molded (bonded to) a material like TPE.
[0048] VERSAFLEX CL 30 is also a material that may be used considered.
[0049] The TPE outside strip is injection molded. The polypropylene inside strip is first injection molded and then over-molded onto the outside strip. The longitudinal slit is cut into the inside strip by stamping or other means, generally before the over-mold operation.
[0050] The invention has been described in connection with several specific embodiments. However, many changes can be made in the above-described invention without departing from the intent and scope thereof. It is therefore intended that the above description be read in the illustrative sense and not in the limiting sense. Substitutions and changes can be made while still being within the scope and intent of the invention and of the appended claims.
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An elastic wristband with an elongate strip of injection molded resilient thermoplastic material and one or more graphic panels. The elongate strip includes a center portion, a left side portion and a right side portion joined by left and right living hinges. The central portion includes recessed areas for receiving the graphic panels which are visable through the molded thermoplastic material. The central portion of the elongate strip also includes end tabs that are welded together to form a continuous circular band. The band is elastic in nature and can fit over a person's hand and onto a person's wrist to form a decorative wristband.
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FIELD OF THE INVENTION
[0001] The mechanism described herein applies to systems where multiple independent initiators are sharing a dynamic random access memory (DRAM) subsystem.
BACKGROUND
[0002] In systems that are built on a single chip it is not uncommon that there are several independent initiators (such as microprocessors, signal processors, etc.) accessing a dynamic random access memory (DRAM) subsystem that for cost, board area, and power reasons is shared among these initiators. The system may require different qualities of service (QOS) to be delivered for each of the initiators. Secondly, the memory ordering model presented to the initiators is important. Ideally, the initiators want to use a memory model that is as strongly ordered as possible. At the same time, the order in which DRAM requests are presented to the DRAM subsystem can have a dramatic effect on DRAM performance. Yet re-ordering of requests for thread QOS or DRAM efficiency reasons can compromise a strongly ordered memory model. What is required is a unified DRAM scheduling mechanism that presents a strongly ordered memory model, gives differential quality of service to different initiators, and keeps DRAM efficiency as high as possible.
[0003] The request stream from each different initiator can be described as a thread. If a DRAM scheduler does not re-order requests from the same thread, intra-thread request order is maintained, and the overall DRAM request order is simply an interleaving of the sequential per-thread request streams. This is the definition of Sequential Consistency, the strongest memory ordering model available for systems that include multiple initiator components. [For further discussion regarding Sequential Consistency, see L. Lamport. How to Make a Multi-processing Computer That Correctly Executes Multiprocess Programs. IEEE Transaction on Computers C-28(9):241-248, September 1979.]
[0004] Existing systems either order the requests at a different point in the system than where the DRAM efficiency scheduling occurs (if any is done), and/or the systems re-order requests within a processing thread. For example, requests may be carried from the initiators to the DRAM Controller via a standard computer bus. Request order (between threads and within threads) is established at the time of access to the computer bus, and is not allowed to be changed by the DRAM controller. In this case, DRAM scheduling for efficiency is more constrained than it needs to be resulting in lower DRAM efficiency. In a different example, each initiator may have its own individual interface with the DRAM Controller, allowing the DRAM controller to schedule requests while maintaining thread ordering. This kind of system has the potential of achieving sufficient results, but it is wasteful of wires to the DRAM controller. It is possible, in such a system, to reorder DRAM requests within a thread. While this may result in higher DRAM efficiency, it also considerably loosens the memory model, i.e. it no longer presents a memory model of Sequential Consistency. It is important to retain a strong memory model while at the same time allowing a reordering of memory requests to achieve a high DRAM efficiency and QOS guarantees.
SUMMARY OF THE INVENTION
[0005] The present invention provides for the scheduling of requests to one resource, such as a DRAM subsystem, from a plurality of initiators. Each initiating thread is provided different quality-of-service while resource utilization is kept high and a strong ordering model is maintained.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] [0006]FIG. 1 illustrates one embodiment of the system of the present invention.
[0007] [0007]FIG. 2 is a simplified flow diagram illustrating one embodiment of combining thread scheduling and device scheduling.
[0008] [0008]FIG. 3 illustrates one embodiment of a DRAM and thread scheduler.
[0009] [0009]FIG. 4 is a simplified example illustrating the tradeoff of cost function scheduling.
[0010] [0010]FIG. 5 illustrates one embodiment of a cost function DRAM bus scheduler.
[0011] [0011]FIG. 6 is a flow diagram illustrating one embodiment of a cost function DRAM bus scheduling process.
[0012] [0012]FIG. 7 illustrates one embodiment of a scheduling component as a request filter.
[0013] [0013]FIG. 8 illustrates one embodiment of ordering of thread scheduling and device scheduling to achieve the desired results.
DETAILED DESCRIPTION
[0014] The mechanism described herein applies to systems where multiple independent initiators share a dynamic random access memory (DRAM) subsystem.
[0015] In one embodiment, the present invention allows different initiators to be given a pre-defined quality of service independent of one another while at the same time keeping DRAM efficiency as high as possible and presenting a strong memory ordering model to the initiators.
[0016] [0016]FIG. 1 shows a high-level block diagram of one embodiment of a DRAM scheduling system. Requests 10 from different initiators arrive over a multi-threaded interface 15 . An initiator may be embodied as a device or a process. Requests 10 from different initiators are communicated across different threads that are identified by different thread identifiers (“thread IDs”) at the interface. This allows requests to be split by thread (or initiator) into per-thread request queues, e.g. 20 , 25 , 30 . Requests from these thread queues 20 , 25 , 30 are presented in parallel to the DRAM and thread scheduler block 35 . The scheduler block 35 decides the order in which requests are presented to the DRAM Controller 40 , which in turn is responsible for sending the requests to the actual DRAM subsystem 45 . When responses 50 return from the DRAM controller 45 , they are sent back to the initiators via the multi-threaded interface 15 . The delivery of requests from the initiators was described using a multi-threaded interface and thread identifiers. An alternative embodiment uses individual single-threaded interfaces for each initiator.
[0017] The DRAM and Thread scheduler 35 acts as the synchronization point that establishes the order in which DRAM requests are processed. Even though requests can arrive over the multi-threaded interface in one order, the requests may be re-ordered by the scheduler block 35 in order to satisfy thread quality of service (QOS) guarantees, or in order to increase DRAM efficiency. Conversely, the DRAM Controller 40 block processes requests in order, so that the order established by the scheduler block 35 is indeed the order in which requests are committed. However, if the scheduler block 35 does not re-order requests from the same thread, intra-thread request order is maintained, and the overall DRAM request order is simply an interleaving of the sequential per-thread request streams.
[0018] One embodiment of the process is illustrated by the simplified flow diagram of FIG. 2. At step 205 , a preferred request order for QOS guarantees is identified or determined. The preferred order for processing requests for DRAM efficiency is determined at step 210 . In performing steps 205 and 210 the constraints of the memory ordering model are taken into account. If the preferred DRAM efficiency order satisfies QOS guarantees, step 215 , then a request is scheduled according to the DRAM efficiency order, step 220 . If the DRAM efficiency order does not satisfy QOS guarantees, step 215 , the next-best DRAM efficiency order is determined, step 225 . This step is repeated until the DRAM efficiency order meets QOS guarantees.
[0019] The process illustrated by FIG. 2 is only one embodiment. Other embodiments are also contemplated. For example, in one embodiment, a request order is determined that satisfies QOS guarantees and is then modified to optimize DRAM efficiency.
[0020] [0020]FIG. 3 offers a more detailed look at one embodiment of the DRAM and Thread Scheduler of FIG. 1. The requests 320 , 325 , 330 from different threads are presented and sequenced to the DRAM controller 310 . The scheduling decision for which request gets to proceed at any one time is derived using a combination of thread quality of service scheduling and DRAM scheduling.
[0021] The thread quality of service scheduler 340 keeps and uses thread state 350 to remember thread scheduling history and help it determine which thread should go next. For example, if threads are being guaranteed a certain amount of DRAM bandwidth, the thread scheduler 340 keeps track of which thread has used how much bandwidth and prioritizes threads accordingly. The DRAM scheduler 345 , on the other hand, attempts to sequence requests from different threads so as to maximize DRAM performance. For example, the scheduler 345 might attempt to schedule requests that access the same DRAM page close to each other so as to increase the chance of getting DRAM page hits. The DRAM scheduler 345 uses and keeps state 355 on the DRAM and access history to help with its scheduling decisions.
[0022] The thread quality of service scheduler 340 and the DRAM scheduler 345 are optimized for different behavior and may come up with conflicting schedules. Outputs of the two schedulers 340 , 345 have to be combined 360 or reconciled in order to achieve the promised thread quality of service while still achieving a high DRAM efficiency.
[0023] The DRAM scheduler 345 itself has to balance several different scheduling goals. In one embodiment, scheduling components can be categorized into two broad categories, referred to herein as absolute and cost-function scheduling.
[0024] Absolute scheduling refers to scheduling where a simple yes/no decision can be made about every individual request. An example is DRAM bank scheduling. Any given DRAM request has exactly one bank that it addresses. Either that bank is currently available to receive the request, or it is busy with other requests and there is no value in sending the request to DRAM at this time.
[0025] Cost-function scheduling is more subtle, in that there is no immediate yes/no answer to every request. At best it can be said that sending the request to DRAM at a certain time is more or less likely to yield a high DRAM efficiency.
[0026] An example of cost function scheduling is request scheduling based on the direction of a shared DRAM data bus. Typically, there is a cost associated with changing the DRAM data bus direction from read to write and vice versa. It is thus advantageous to collect requests that require the same data bus direction together rather than switching between every request. How many requests should be collected together depends on the expected request input pattern and a trade-off between efficiency and latency, an example of which is illustrated in FIG. 4. If the DRAM scheduling algorithm is set to switch frequently between directions, the expected efficiency is low because a lot of switches result in many wasted data bus cycles. On the other hand, the average waiting time (latency) of a request is low because it gets serviced as soon as it arrives.
[0027] If the DRAM scheduling algorithm is set to switch less frequently (i.e. to collect more requests of each direction together) the overall DRAM efficiency is likely to be higher but the average latency of requests is also higher. The best point for overall system performance is not easily determined and depends on the request pattern, the trade-off between latency and efficiency, and the cost of switching.
[0028] The example below uses bus direction as the basis for cost-function scheduling. However, it is contemplated that a variety of other criteria may be used to implement cost-function scheduling. Other examples of cost-function scheduling include deciding when to close one DRAM page and open another and deciding when to switch DRAM requests to use a different physical bank.
[0029] [0029]FIG. 5 illustrates one embodiment of a DRAM bus scheduler that is programmable so as to allow dynamic adjustment of the switch point for optimum performance. In one embodiment, the scheduler 505 keeps track of the last direction (read or write) of the data bus 510 , and a count 515 of the number of requests that had that direction. A register 520 is added to hold the switch point information. In one embodiment, this register 520 can be written from software 525 while the system is running in order to dynamically configure the DRAM scheduler for optimum performance. For example, it may be desirable to update the switch point dynamically according to the application and/or by the application. In one embodiment, the switchpoint is empirically determined based upon past and possibly current performance.
[0030] As requests are presented on the different threads, the scheduler 505 looks at the current direction of the DRAM data bus, the count of requests that have already been sent, the configurable switch point, and the direction of incoming new requests. Before the count reaches the switch point, requests that have the same direction as the current DRAM data bus are preferred over those going in the opposite direction. Once the switch point is reached, requests to the opposite direction are preferred. If only requests from one direction are presented, there is no choice in which direction the next request will go. In the present embodiment, a count and compare function is used to determine the switch point. However, it is contemplated that other functions may be used. Furthermore, although the example herein applies the count and compare function to bus direction, all types of measures for the count may be used.
[0031] One embodiment of the process is illustrated by FIG. 6. At step, 605 , considering that at least one request is available, it is determined whether there are any requests for the current direction of the bus. If there are not, the bus direction is changed, step 610 , the count resets step 615 , and the request is processed using the new direction of the bus 620 . The count keeping track of the number of requests performed in the current bus direction is incremented, step 625 . If there are requests for the current direction of the bus, it is then checked to see if the count has reached the switch point, step 630 . If the switch point has been reached then it is determined whether there are any requests for the opposite direction of the bus, step 635 . If there are not, then the request for the current direction is processed, step 620 , and the count incremented, step 625 . In addition, if the count has not reached the switch point, step 630 , then the process continues with the request for the current direction being processed and the count being incremented, steps 620 and 625 .
[0032] It is desirable, in one embodiment, to combine thread quality of service scheduling and DRAM scheduling to achieve a scheduling result that retains the desired quality of service for each thread while maximizing DRAM efficiency. One method for combining the different scheduling components is to express them as one or more request filters, one of which is shown in FIG. 7. Per-thread requests 705 enter, and are selectively filtered, so that only a subset of the requests filters through, i.e. exits, the filter 710 . The decision of which requests should be filtered out is made by the control unit 715 attached to the filter. The unit 715 bases its decision on the incoming requests and possibly some state of the unit 715 . For example, for a cost function filter that decides to switch the direction of the DRAM data bus, the decision is based on the current direction of the bus, the number of requests that have already passed in that direction since the last switch and the types of requests being presented from the different threads. The decision might be to continue with the same direction of the DRAM data bus, and so any requests that are for the opposite direction are filtered out.
[0033] Once the different scheduling components have been expressed as filters, the various filters can be stacked to combine the scheduling components. The order of stacking the filters determines the priority given to the different scheduling components.
[0034] [0034]FIG. 8 is a block diagram of one embodiment illustrating the ordering of the different portions of the two scheduling algorithms to achieve the desired results. Each of the blocks 810 , 820 , 830 , 840 shown in FIG. 8 acts like a filter for requests entering 805 and emerging 860 . For each filter, for example, 810 , 820 , 830 only requests that meet the criteria of that stage of scheduling are allowed to pass through. For example, DRAM bank scheduling 810 allows only requests to available banks to pass through and filters out those requests that do not meet the criteria. Thread quality of service scheduling 820 allows only threads that are in the desired priority groups to pass through. Data bus scheduling, an example of cost-function scheduling, 830 might preferentially allow only reads or writes to pass through to avoid data bus turnaround.
[0035] More particularly, in one embodiment, DRAM requests 805 from different threads enter and the absolute DRAM scheduling components 810 are exercised, so that requests that cannot be sent to DRAM are filtered out, and only requests that can be sent continue on to the thread scheduler 820 . The thread scheduler 820 schedules requests using the quality of service requirements for each thread. The scheduler 820 filters out requests from threads that should not receive service at this time. Any remaining requests are passed on to the cost-function DRAM scheduler 830 . Here, requests are removed according to cost-function scheduling. If there is more than one cost-function component to DRAM scheduling, the different components are ordered from highest switch cost to lowest. For example, if data bus turnaround costs 3 cycles and switching from one physical DRAM bank to another costs 1 cycle, then DRAM data bus scheduling is placed ahead of physical bank scheduling. If more than one request emerges from the bottom of the cost-function DRAM scheduler, they are priority ordered by arrival time. This last filter 840 prevents requests from getting starved within their thread priority group.
[0036] It is readily apparent that the above is just one implementation of a DRAM scheduling system. It is readily recognized that different filter types, having different thresholds, and switch points and/or different ordering of filters can be implemented to achieve desired results. Furthermore, although represented in the drawings as separate filter elements, the filters may be implemented by a single logic processor or process that performs the stages of the process representative of the filtering functions described above. The invention has been described in conjunction with one embodiment. It is evident that numerous alternatives, modifications, variations and uses will be apparent to those skilled in the art in light of the foregoing description.
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The present invention provides for the scheduling of requests to one resource from a plurality of initiator devices. In one embodiment, scheduling of requests within threads and scheduling of initiator device access is performed wherein requests are only reordered between threads.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Patent Application 62/203,160 filed Aug. 10, 2015, the entire contents of which are hereby incorporated by reference.
FIELD
This application relates to trailers, in particular to trailers for towing behind an agricultural implement.
BACKGROUND
Agricultural carts for transporting containers containing solid or liquid inputs are known in the industry. Such carts are typically designed for one type of application, lacking flexibility in the type of input to be carried or the conditions under which the input is to be distributed in a field. Carts with greater flexibility of operation are generally more desirable reducing the number of implements a farmer needs to purchase and reducing inventory that dealers may need to carry at any given time.
SUMMARY
There is provided a trailer comprising: a frame having frame-members configured to support a container; at least a pair of traction devices rotatably mounted on the frame; and, a tongue configured to be mounted on a transportation device or an implement being towed by a transportation device.
In one aspect, the frame-members may comprise a three-point mount configured to support a container.
In one aspect, the container may be configured to be interchangeable with another container.
In one aspect, the container may be an element of a seeding apparatus, the seeding apparatus mountable on the frame-members of the frame.
In one aspect, the trailer may comprise a steering mechanism for the traction devices.
In one aspect, the steering mechanism may be designed for row cropping applications.
In one aspect, the trailer may comprise a guidance control for a steering mechanism.
In one aspect, the trailer may be convertible between a steerable trailer and a non-steerable trailer.
In one aspect, a transverse distance between the traction devices in the pair of traction devices may be adjustable.
In one aspect, a height of the frame in relation to the ground may be adjustable.
The trailer comprises a frame. The frame has a longitudinal axis in the direction of motion of the trailer as it is being towed across the ground. The longitudinal axis runs from front to rear (or rear to front) of the frame. The frame has a transverse axis that is perpendicular to the longitudinal axis and runs left to right (or right to left) of the frame. The frame may have a plurality of connected frame-members, for example longitudinally and/or transversely spaced-apart frame-members, on which the traction devices, tongue, container and/or other elements may be mounted. The frame-members may comprise any suitably strong and/or rigid material (e.g. steel, aluminum alloy) in the form of elongated structures (e.g. tubes or bars). In one embodiment, frame-members may comprise rectangular tubes.
The trailer further comprises a tongue. The tongue may extend longitudinally forward of the frame and is configured to be mounted on a transportation device (e.g. a vehicle, for example a tractor) or an implement being towed by a transportation device. Such implements may include, for example, another trailer or any type of tillage or row cropping apparatus (e.g. a planter, a strip till bar, a fertilizer bar, etc.) The tongue may be a separate elongated structure rigidly mounted on the frame (for example by welding, bolting or the like) an integral extension of one or more of the frame-elements, or a combination thereof. The tongue comprises an attachment structure, preferably proximate or at a longitudinally forward end of the tongue, configured to mount the tongue on a corresponding attachment structure at a mounting point on the transportation device or implement. The attachment structure preferably provides for some degrees of freedom of motion at the mounting point. In a preferred embodiment, the tongue may comprise one or more ball hitches on pivoting knuckles.
Containers may be supported on the frame-members. The containers may be mounted at one or more points on the frame-members, for example two to five mounting points. The frame-members preferably comprise three mounting points, providing a good balance between secure mounting and easy interchangeability of containers. The mounts on the frame-members may comprise apertures through which pins on the containers may be fitted. The pins may be secured in the apertures by cotter pins, or in the case where the pins are bolts they may be secured in the apertures with nuts. Other types of mounts and securement devices may be utilized, for example pin and pocket, ridge and groove mounts and the like secured with clamps, spot welds and the like. Mounting containers on the frame may be aided by mounting guides to facilitate moving the container to the correct location on the frame for mounting. The mounts may further comprise weigh scales (e.g. load cells), preferably in electronic communication with a remote display device, computer or the like, to provide an indication of the weight of the container on the frame, which facilitates understanding the levels of product in the container at any given time. The frame-members may also comprise multiple sets of mounts for mounting more than one container.
Containers are preferably interchangeable on the frame to provide for a modular system. The containers may be directly and removably mounted on the frame or the containers may be mounted in a separate container retaining structure and the container retaining structure removably mounted on the frame. Container retaining structures may comprise, for example, interconnected struts configured to receive and secure the container within a network of the struts. It is an advantage of the present trailer that the containers may be a wide variety of types of containers, especially for agricultural product, and still be interchangeable on the same trailer. The containers may be for solid or liquid product, for example, bins, hoppers, boxes, tanks and the like. The product may be fertilizer, seed, anhydrous ammonia, pesticide, herbicide, lime or the like. The containers may be pressurized or non-pressurized. The containers may be accompanied by metering devices for metering product from the container into spreaders. Spreaders associated with the container may comprise liquid or solid product spreaders, for example liquid spray mechanisms, spinners for particulate materials or air delivery mechanisms (e.g. air lines and/or booms and the like) for particulate materials. In one embodiment, the container is a seed bin for cover seeding in association with other parts of a seeding apparatus, for example an air seeder. The trailer is particularly useful as an agricultural applicator cart.
The trailer further comprises at least a pair of traction devices rotatably mounted on the frame to permit movement of the trailer on the ground. The traction devices may comprise wheels, belts, tracks or the like and any combination thereof. Wheels are preferred. The traction devices are preferably located on either side of the frame. The traction devices may be mounted on one or more axles, the one or more axles mounted on the frame. One or more traction devices may be mounted on one axle on one side of the trailer. One traction device per axle per side of the trailer is common, but using two or more traction devices per axle per side may lower soil compaction and/or increase carrying capacity of the trailer. Preferably, the traction devices are mounted on stub axles and opposed stub axles mounted on an axle bar connecting the stub axles. The stub axles are preferably circular in cross-section so that the traction devices can readily rotate. The stub axles may comprise hubs onto which the traction devices, especially wheels, may be removably mounted. The axle bars may be of any cross-sectional shape and may be transversely in line or out of line with the stub axles when the traction devices are straight. The axle bars may be formed of one or more of the frame-members of the frame. The stub axles are preferably mounted on the axle bar such that the stub axles, traction devices and any mounting assembly for mounting the stub axles and traction devices on the axle bar may rotate thereby causing the trailer to turn. Such rotational motion assists with a steering mechanism as described below. Where the trailer comprises just two opposed traction devices, the container mounting points are preferably arranged on the frame-members so that the container's center of gravity is over the axle bar.
The trailer may be non-steerable or may comprise a steering mechanism for the traction devices. In one embodiment, a steering mechanism ensures that the traction devices stay between crop rows and track properly behind the transportation. Keeping the traction devices between crop rows is particularly important in row cropping applications. The steering mechanism may be entirely mechanical, or may further comprise hydraulic or electric actuators. In one embodiment, the steering mechanism is entirely mechanical comprising mechanical linkages.
Any suitable steering mechanism may be employed. For example, the traction devices on each side of the trailer may be steered by separate 4-bar linkage assemblies, where each 4-bar assembly comprises four linkages pivotally connected in a quadrilateral, and each 4-bar assembly is controlled by separate longitudinal control rods extending forward and connected to the transportation device or implement.
However, the steering mechanism preferably comprises a 5-bar linkage assembly in which five linkage arms are connected at pivot points so that the linkages may move relative to each other. In one embodiment, three of the five linkage arms are length adjustable. In one embodiment, two of the linkages comprise mounting assemblies for pivotally mounting the stub axles (and therefore the traction devices) on the axle bar. The stub axles on the mounting assemblies are able to pivot on the axle bar thereby turning the traction devices. One of the linkages comprises the axle bar, which is rigidly mounted on the frame or is a part of the frame. The other two linkages comprise tie rods, each tie rod pivotally mounted on respective mounting assemblies to permit pivoting of the mounting assemblies at the connection between the tie rods and the mounting assemblies. The tie rods may be pivotally connected at a pivot plate to form the 5-bar steering mechanism. The pivot plate may be pivotally connected to the transportation or an implement by one or more control rods, the one or more control rods pivotally connected to the pivot plate proximate first ends of the control rods and pivotally connected to the transportation or implement proximate second ends of the control rods. In such an arrangement, turning of the transportation or implement causes longitudinal movement of the one or more control rods, causing pivoting of the pivot plate. Pivoting of the pivot plate causes the tie rods to translate (e.g. by pushing one tie rod and pulling the other tie rod), causing the stub axles to pivot thereby turning the traction devices of the trailer in response to the turning of the transportation or implement.
The trailer may also be readily convertible between steerable and non-steerable modes by disabling the steering mechanism. In one embodiment, the 5-bar steering mechanism particularly facilitates the conversion by simply locking the pivot plate to prevent the pivot plate form turning. Locking the pivot plate may be accomplished, for example, with a pin-in-hole arrangement, a clamp arrangement or any other suitable arrangement. Disconnecting the one or more control rods from the pivot plate and/or the transportation or implement would further assist in the conversion from steerable to non-steerable mode. Where more than one control rod is used, disconnecting all of the control rods may be required. Unlocking the pivot plate and reconnecting the one or more control rods would return the trailer to steerable mode.
The trailer may also comprise guidance control of steering. Guidance control of steering may be accomplished in any suitable way, including methods known in the art. In one embodiment, a global navigation satellite system (GNSS), especially with real time kinematic (RTK) enhanced function, may be used. In one particular embodiment, a linear distance may be determined between a fixed point on the pivoting tongue of the trailer and a fixed point on the attachment structure of the transportation device or implement to which the tongue is attached. The linear distance may be correlated to the position of a global navigation satellite system (GNSS) receiver (e.g. a global positioning system (GPS) receiver) relative to a pre-mapped line of travel pre-programmed into both an auto-steer functionality of the transportation device and a secondary guidance system for the trailer itself. A controlled actuator (e.g. a servo-controlled hydraulic cylinder) may override pivoting of the tongue to return the trailer to tracking along the pre-mapped line of travel. The controlled actuator may be activated by a guidance system controller. To implement guidance control in the steering mechanism, actuators (e.g. hydraulic cylinders and/or electric actuators) may be used instead of linkage arms in the steering mechanism and the action of the actuators controlled according to GNSS input to steer the trailer on the pre-mapped line of travel. Alternatively, mechanical linkage arms in the steering mechanism may be equipped with in-line linkage compensating actuators (e.g. electric linear actuators and/or hydraulic cylinders), which may be activated to partially or completely move the traction devices in response to GNSS input or, for side hill tracking, provide a correction amount to keep the trailer on the pre-mapped line of travel.
In a particularly preferred embodiment, transverse distance between the traction devices (e.g. wheel-to-wheel distance) may be adjustable in order to accommodate differing axle lengths of the transportation or implement, or to more generally ensure that the traction devices of the trailer ride between crop rows. Adjustment of the transverse distance may be accomplished mechanically or by using hydraulic or electric actuator arrangements. In one embodiment, an axle may comprise one or more disconnectable connection points into and out of which one or more spacers may be inserted or removed to lengthen or shorten the axle. Where the trailer comprises a steering mechanism, certain connections in the steering mechanism may need to be lengthened or shortened to accommodate the change in transverse distance. Where the steering mechanism comprises actuators, the stroke length can be readily adjusted to accommodate the change in transverse distance, whereas with mechanical elements of the steering mechanism, length adjustable rods may be used to accommodate the change in transverse distance. Further, pivoting points in the steering system, for example the pivot plate in the 5-bar mechanism described above, may need to translate longitudinally to accommodate the change in transverse distance.
It is a particular advantage of a 5-bar steering mechanism that the tie rods may be pivotally connected to a common pivot plate and that arrangements for adjusting the transverse distance may be located between the pivot point of each tie rod on the pivot plate and the pivot point of each tie rod on the stub axle mounting assemblies. Therefore, the lengths of the tie rods may be changed to accommodate the change in transverse distance without affecting the ability of the trailer wheels to correctly track behind traction devices of the transportation or implement during a turn.
In another particularly preferred embodiment, height of the trailer in relation to the ground may be adjustable. Height adjustment may be conveniently accomplished by mounting one or more axles, and therefore the traction devices, at different vertically-spaced locations on the frame or by using hydraulic or electric actuators (e.g. hydraulic cylinders or liner actuators) to move an axle vertically. In one embodiment, stub axles to which the traction devices are mounted may be configured for mounting at different vertically-spaced locations on mounting plates proximate each end of a transverse axle bar rigidly mounted on the frame. As with any changes in the transverse distance, where the trailer comprises a steering mechanism, certain connections in the steering mechanism may need to be lengthened or shortened to accommodate the change in height of the trailer in relation to the ground.
Further features will be described or will become apparent in the course of the following detailed description. It should be understood that each feature described herein may be utilized in any combination with any one or more of the other described features, and that each feature does not necessarily rely on the presence of another feature except where evident to one of skill in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
For clearer understanding, preferred embodiments will now be described in detail by way of example, with reference to the accompanying drawings, in which:
FIG. 1A depicts a plan view of a trailer being towed behind an agricultural implement.
FIG. 1B depicts a side view of the trailer depicted in FIG. 1A .
FIG. 2 depicts a side view of the trailer depicted in FIG. 1A with a seed bin mounted on the trailer.
FIG. 3 depicts a side view of the trailer depicted in FIG. 1A with a liquid product tank mounted on the trailer.
FIG. 4 depicts a side view of the trailer depicted in FIG. 1A with a spinner spreader box mounted on the trailer.
FIG. 5A depicts a side view of the trailer depicted in FIG. 1A with a granular fertilizer bin mounted on the trailer.
FIG. 5B depicts is a rear perspective view of the trailer depicted in FIG. 5A further showing an air boom spreader for granular fertilizer in association with the granular fertilizer bin.
FIG. 6A depicts a plan view of a frame of a trailer.
FIG. 6B depicts a magnified view of a region A of the frame depicted in FIG. 6A .
FIG. 7 depicts a plan view illustrating how a tongue of the trailer depicted in FIG. 1A is hitched to an implement.
FIG. 8A depicts a rear isometric view of a trailer having a pair of opposed wheels separated by a shorter transverse distance.
FIG. 8B depicts a rear isometric view of the trailer of FIG. 8A where the opposed wheels are separated by a longer transverse distance.
FIG. 9A depicts a magnified view of one embodiment for extending transverse distance between opposed wheels of the trailer of FIG. 8A to the arrangement depicted in FIG. 8B .
FIG. 9B depicts a reverse view of the embodiment depicted in FIG. 9A including a wheel mounted on a hub.
FIG. 10A depicts a rear isometric view of a trailer having one wheel removed to illustrate where a height of the trailer frame in relation to the ground may be adjustable at an axle.
FIG. 10B depicts a magnified orthogonal view of a region B of the axle illustrated in FIG. 10A .
FIG. 11A depicts a side view of the trailer of FIG. 10A showing three positions to which the height of the frame may be adjusted in relation to the ground.
FIG. 11B depicts a rear view of the trailer of FIG. 10A showing three positions to which the height of the frame may be adjusted in relation to the ground.
FIG. 12A depicts a plan view of a trailer having one embodiment of a steering mechanism for a pair of opposed wheels on the trailer.
FIG. 12B depicts the trailer of FIG. 12A where transverse distance between the opposed wheels has been increased.
FIG. 13A depicts a plan view of the trailer of FIG. 12A in a ten degree turn.
FIG. 13B depicts a plan view of the trailer of FIG. 12A in a twenty degree turn.
FIG. 13C depicts a plan view of the trailer of FIG. 12A in a thirty degree turn.
FIG. 14A depicts a plan view of an overlay of the trailer of FIG. 12A when the trailer is tracking straight (solid lines) in comparison to when the trailer is turning (dashed lines).
FIG. 14B depicts a plan view of an overlay of the trailer of FIG. 12B when the trailer is tracking straight (solid lines) in comparison to when the trailer is turning (dashed lines).
FIG. 15A depicts a plan view of the trailer of FIG. 12A hitched to transportation while in a turn showing how the wheels of the trailer track with respect to the wheels of the transportation.
FIG. 15B depicts a plan view of the trailer of FIG. 12B hitched to transportation having a wider wheel base while in a turn showing how the wheels of the trailer track with respect to the wheels of the transportation.
FIG. 16A depicts a plan view of a trailer steerable with only one control rod.
FIG. 16B depicts a plan view of a trailer steerable with only one control rod and where transverse distance between the opposed wheels has been increased.
DETAILED DESCRIPTION
Referring to FIG. 1A and FIG. 1B , a trailer 100 is depicted being towed behind an agricultural implement 5 . The agricultural implement 5 is in turn being towed by a vehicle (not shown), for example a tractor. The trailer 100 comprises a frame 101 comprising longitudinally oriented rectangular tubes 102 and a transversely oriented rectangular tube 103 welded together to form a supporting structure for a container. The frame 101 further comprises an axle bar 105 welded to the longitudinally oriented rectangular tubes 102 , the axle bar 105 also comprising a rectangular tube and providing additional structural support for the frame 101 . A pair of opposed wheels 106 are rotatably mounted on the axle bar 105 . A tongue 104 is formed from a pair of converging longitudinally oriented rectangular tubes 107 meeting at hitch 108 . Each of the converging longitudinally oriented rectangular tubes 107 are rigidly connected (e.g. by welding, bolting or the like) to respective longitudinally oriented rectangular tubes 102 by angled braces 109 . Hitch 108 comprises a pair of ball hitch receivers, one at the end of each tube 107 , fitted with knurled knuckles to permit relative movement of the tongue 104 to the implement 5 .
The trailer 100 may be interchangeably equipped with a variety of containers as shown in FIG. 2 to FIG. 5 . FIG. 2 shows the trailer 100 outfitted with a seed bin 110 . The seed bin 110 is secured in a superstructure 111 designed to contain the seed bin 110 and to permit mounting of the superstructure 111 on the frame 101 of the trailer 100 . The seed bin 110 is accompanied by an air blower 112 , which is part of an air delivery system for delivering seed to seed applicators located on the agricultural implement 5 . Air lines which deliver the seed are not shown. FIG. 3 shows the trailer 100 outfitted with a liquid tank 120 . The liquid tank 120 is contained in a superstructure 121 configured to be mounted on the frame 101 of the trailer 100 . Liquid lines in fluid communication with the liquid in the liquid tank 120 are not shown. FIG. 4 shows the trailer 100 outfitted with a spinner spreader box 130 . The spinner spreader box 130 is mounted on the frame 101 and tongue 104 of the trailer 100 . The spinner spreader box 130 is associated with a spinner spreader 132 , which delivers granular product contained in the box 130 to the environment. FIG. 5A and FIG. 5B show the trailer 100 outfitted with a granular fertilizer bin 140 . The granular fertilizer bin 140 is contained on a superstructure 141 configured to be mounted on the frame 101 of the trailer 100 . As seen in FIG. 5B , air booms 142 associated with the granular fertilizer bin 140 may be configured to deliver granular fertilizer from the bin 140 to the environment.
FIG. 6A and FIG. 6B show the frame 101 of the trailer to further illustrate a three-point mount for supporting containers on the trailer and facilitating the interchange of containers. Each of the longitudinally oriented rectangular tubes 102 and the transversely oriented rectangular tube 103 of the frame 101 comprises a mounting tab 145 through which mounting apertures 146 are formed (only one of two mounting apertures 146 is labeled on each mounting tab 145 ). The mounting tabs 145 are fixedly secured to the rectangular tubes 102 , 103 , for example by welding, and the mounting apertures 146 are configured to receive downwardly depending pins or bolts attached to the container or the superstructure for the container. The mounting tabs 145 on the longitudinally oriented rectangular tubes 102 may be located at or proximate to the rear end of the tubes 102 , while the mounting tab 145 on the transversely oriented rectangular tube 103 may be conveniently located proximate a transversely central point to provide an approximately isosceles triangular three-point mount for the containers. The locations of the mounting apertures 146 and the pins or bolts on the container or superstructure are preferably selected so that the center of gravity of the container is over the axle bar 105 . Further, having more than one mounting aperture 146 per mounting tab 145 simplifies and provides flexibility in mounting the container on the frame 101 . While two mounting apertures 146 are shown, more than two apertures in any suitable pattern on the mounting tab 145 may be provided. The container may be mounted on the trailer with the aid of a mounting rack or a forklift, and guide structures may be associated with the mounting apertures 146 to guide the pins or bolts toward the mounting apertures 146 as the container is being mounted on the frame 101 . The pins or bolts may be secured in the mounting apertures 146 by any suitable device, for example cotter pins, nuts and the like.
FIG. 7 provides a magnified view of how the tongue 104 of the trailer is hitched to the implement 5 . The hitch 108 at the front ends of the converging longitudinally oriented rectangular tubes 107 comprises to ball receivers for receiving two hitch balls protruding upwardly form hitch plate 6 mounted on hitch tube 7 , where hitch tube 7 is removably mounted on two hitch struts 8 using brackets, which is in turn removably mounted on a rear bar 9 of implement 5 also using brackets. As discussed in more detail below, if the trailer in one embodiment comprises a 5-bar steering mechanism, control rods 451 of the steering mechanism may be pivotally mounted at pivot mount 10 on hitch plate 6 so that turning of the implement 5 will either cause the control rods 451 to translate longitudinally rearward or forward depending on whether the implement is turning left or right.
As shown in FIG. 8A and FIG. 8B , in one embodiment, transverse distance between opposed wheels 206 a , 206 b of a trailer 200 may be adjustable. In FIG. 8A where the wheels 206 a , 206 b are separated by a shorter transverse distance, opposed stub axles 211 a , 211 b are removably mounted directly on opposed ends of a transverse axle bar 205 . To increase the transverse distance between the wheels 206 a , 206 b , the stub axles 211 a , 211 b may be dismounted from the axle bar 205 and axle inserts 212 a , 212 b may be inserted between respective stub axles 211 a , 211 b and the axle bar 205 , as depicted in FIG. 8B . The axle inserts 212 a , 212 b may have the same length to extend the distance from the axle bar 205 to the stub axles 211 a , 211 b by the same amount, but in some applications it may be desirable for the axle inserts 212 a , 212 b to have different lengths. In some applications it may be desirable to insert an axle insert on one side of the trailer but not on the other side. Axle inserts of different lengths may be provided to be able to adjust the transverse distance between the opposed wheels by different amounts. In some embodiments, the axle inserts may be length adjustable actuators (e.g. hydraulic cylinders or linear actuators) so that the transverse distance between opposed wheels may be finely and/or independently controlled without the need to dismount the stub axles from the axle bar.
FIG. 9A and FIG. 9B show magnified views of one embodiment of an extended axle and wheel arrangement on one side of the trailer 200 . The other side of the trailer 200 may comprise a similar arrangement. In the extended arrangement depicted in FIG. 9A and FIG. 9B , the axle bar 205 is rigidly connected to the stub axle 211 a though the axle insert 212 a . An axle bar mounting plate 221 a may be rigidly attached to an end of the axle bar 205 , for example by welding or being formed integrally with the axle bar 205 , and the axle bar mounting plate 221 a may be removably mounted to a first insert mounting plate 222 a , for example by bolting. The first insert mounting plate 222 a may be rigidly attached to a first end of the axle insert 212 a , for example by welding or being formed integrally with the axle insert 212 a . A second end of the axle insert 212 a may comprise a second insert mounting plate 223 a , which may also be rigidly attached the axle insert 212 a . The second insert mounting plate 223 a may be removably attached, for example by bolting, to a stub axle mounting plate 224 a , which may be part of a stub axle assembly 225 a . In this embodiment, to change the distance between the wheels, the axle insert 212 a may be removed by unbolting the stub axle mounting plate 224 a from the second insert mounting plate 223 a and then unbolting the first insert mounting plate 222 a from the axle bar mounting plate 221 a . The stub axle mounting plate 224 a may then be bolted directly to the axle bar mounting plate 221 a , or an axle insert of different length may be bolted between the axle bar mounting plate 221 a and the stub axle mounting plate 224 a.
In addition to the stub axle mounting plate 224 a , stub axle assembly 225 a may comprise the stub axle 211 a housed and secured in axle collar 226 a by a bolt 227 a . The axle collar 226 a may be supported in apertures in collar support brackets 228 a and the bolt 227 a may further serve to prevent the axle collar 226 a from slipping out of the collar support brackets 228 a . The collar support brackets 228 a may be rigidly fixed to the stub axle assembly 225 a , or in the case where the trailer 200 comprises a steering mechanism, the collar support brackets 228 a may be mounted on a rotatable spindle 229 a rotatably mounted on the stub axle assembly 225 a . The rotatable spindle 229 a may be connected to the steering mechanism to permit turning the wheel 206 a , for example by connecting a tie rod to rotatable spindle 229 a . The wheel 206 a may be removably mounted on a wheel hub 231 a , which may be mounted on the stub axle 211 a in any usual way, preferably with the use of bearings in the wheel hub 231 a to permit easy rotation of the wheel hub 231 a on the stub axle 211 a.
FIG. 10A , FIG. 10B , FIG. 11A and FIG. 11B illustrates one embodiment of a trailer 300 in which a height of a frame 301 above the ground may be adjusted. Adjustment of the height in this embodiment may be accomplished by changing the relative heights of stub axles 311 a , 311 b to an axle bar 305 on the trailer 300 . While the stub axles 311 a , 311 b and wheels 306 remain at the same height, the axle bar 305 and the frame 301 of which the axle bar 305 is a part may be raised or lowered in relation to the stub axles 311 a , 311 b . Details of how height adjustment in this embodiment may be accomplished are best illustrated in FIG. 10B . FIG. 10B illustrates an axle arrangement on one side of the trailer 300 , but the other side of the trailer 300 may comprise a similar arrangement.
With reference to FIG. 10B , the stub axle 311 a may be mounted in a stub axle assembly 325 a , and a wheel removably mounted on a wheel hub 331 a rotatably mounted on the stub axle 311 a . The stub axle assembly 325 a may further comprise a stub axle mounting plate 324 a , the stub axle mounting plate 324 a comprising a plurality of bolt holes arranged in rows 331 , 332 , 333 . Three rows of bolt holes 331 , 332 , 333 are labeled and each row comprises three bolt holes. More or fewer rows of bolt holes and/or bolt holes per row may be used if desired, but at least two rows of bolt holes and two bolt holes per row are generally desirable. The stub axle mounting plate 324 a may be mounted on the axle bar 305 at an axle bar mounting plate 321 a . The axle bar mounting plate 321 a may also comprise a plurality of bolt holes arranged in rows 334 , 335 , 336 , 337 , 338 . Five rows of bolt holes 334 , 335 , 336 , 337 , 338 are labeled and each row comprises three bolt holes, although the rows of bolt holes 335 , 336 , 337 are not seen in FIG. 10B as they are hidden behind the stub axle mounting plate 324 a . More or fewer rows of bolt holes and/or bolt holes per row may be used if desired, but at least two bolt holes per row is generally desirable for security and the number of rows of bolt holes depends on the number of height settings that are desired. In FIG. 10B , five rows of bolt holes 334 , 335 , 336 , 337 , 338 on the axle bar mounting plate 321 a and three rows of bolt holes on the stub axle mounting plate 324 a provides for at least three height settings, although another two height settings for a total of five height settings are possible if only two rows of bolt holes are used to secure the stub axle mounting plate 324 a to the axle bar mounting plate 321 a . FIG. 11A and FIG. 11B illustrate three height settings achievable by the height adjustable axle arrangement depicted in FIG. 10B .
Securing of the two mounting plates 324 a , 321 a together may be accomplished by aligning the rows of bolt holes, inserting bolts through the aligned bolt holes and then using nuts to secure the bolts in the bolt holes. FIG. 10B illustrates an intermediate height setting where the rows of bolt holes 331 , 332 , 333 in the stub axle mounting plate 324 a are aligned with the rows of bolt holes 335 , 336 , 337 in the axle bar mounting plate 321 a . The axle bar 305 , and thus the frame of the trailer, may be raised in relation to the ground by bolting the rows of bolt holes 331 , 332 , 333 in the stub axle mounting plate 324 a to higher rows of bolt holes 336 , 337 , 338 in the axle bar mounting plate 321 a . The axle bar 305 , and thus the frame of the trailer, may be lowered in relation to the ground by bolting the rows of bolt holes 331 , 332 , 333 in the stub axle mounting plate 324 a to lower rows of bolt holes 334 , 335 , 336 in the axle bar mounting plate 321 a . Spacing between the rows of bolt holes in the stub axle mounting plate and between the rows of bolt holes in the axle bar mounting plate, as well as spacing between the individual bolt holes in the rows may be regularized to ensure that the bolt holes between the two mounting plates readily align at all desired height settings. While this embodiment has been described with reference to bolts and bolt holes, other structures may be used to mount the axle bar 305 at different heights in relation to the stub axle 311 a , for example clamps, unthreaded pins, and the like.
Comparing FIG. 10B to FIG. 9A it is evident that the same structures used for mounting the stub axles on the axle bar may facilitate both height adjustment ( FIG. 10B ) and adjustment of the transverse distance between the wheels ( FIG. 9A , ‘width’ adjustment). In a trailer that combines both height and width adjustment, the axle bar mounting plate and the first and second insert mounting plates may be the same in size and bolt hole configuration so that the stub axle mounting plate may be mounted at a desired height setting whether or not an axle insert is employed. Further, the stub axle assembly may be the same whether or not height and/or width adjustment is desired. Thus, the description related to the structure of the stub axle assembly in FIG. 9A is equally applicable to the stub axle assembly in FIG. 10B .
A trailer 400 having a steering mechanism 450 for the wheels 406 a , 406 b is depicted in FIG. 12A , FIG. 12B , FIG. 13A , FIG. 13B , FIG. 13C , FIG. 14A , FIG. 14B , FIG. 15A , FIG. 15B , FIG. 16A and FIG. 16B . The trailer 400 comprises a frame 401 , a tongue 404 a hitch 408 at a forward end of the tongue 404 for hitching to an agricultural implement, an axle bar 405 which is part of the frame 401 , first and second stub axle assemblies 425 a , 425 b removably mounted on the axle bar 405 and comprising stub axles 411 a , 411 b , and wheel hubs 431 a , 431 b rotatably mounted on the stub axles 411 a , 411 b and adapted to receive the wheels 406 a , 406 b . The stub axle assemblies 425 a , 425 b are the same as the stub axle assembly described in connection with FIG. 9A . In FIG. 12B , transverse distance between the wheels is increased by the insertion of two axle inserts 412 a , 412 b between the axle bar 405 and respective stub axle assemblies 425 a , 425 b in a manner as previously described.
The steering mechanism 450 may comprise five ‘bars’ linked into a pentagon at five locations and controlled by one or more control rods 451 . The one or more control rods 451 may extend longitudinally between a pivot plate 455 proximate a rear of the trailer 400 and the hitch plate 6 mounted on the hitch tube 7 of the transportation or implement towing the trailer 400 . The one or more control rods 451 may be pivotally mounted on the pivot plate 455 at one or more control rod pivot points 452 , and may be pivotally mounted on the hitch plate 6 at one or more pivot mounts 10 .
The ‘bars’ of the 5-bar mechanism may comprise a first tie rod 456 a , a second tie rod 456 b , a first stub axle linkage 457 a , a second stub axle linkage 457 b and a ‘bar’ comprising the axle bar 405 , stub axle assemblies 425 a , 425 b and any axle inserts 412 a , 412 b when taken all together may be considered a single rigid ‘bar’ in the 5-bar mechanism. The first tie rod 456 a and second tie rod 456 b are pivotally linked together at pivot points 454 on the pivot plate 455 . The first tie rod 456 a is pivotally linked to the first stub axle linkage 457 a at a pivot point 458 a . The second tie rod 456 b is pivotally linked to the second stub axle linkage 457 b at a pivot point 458 b . The first stub axle linkage 457 a is pivotally connected to the first stub axle assembly 425 a at a first spindle 429 a . The second stub axle linkage 457 b is pivotally connected to the second stub axle assembly 425 b at a second spindle 429 b.
With reference to FIG. 12A , FIG. 12B , FIG. 13A , FIG. 13B , FIG. 13C , FIG. 14A , FIG. 14B , FIG. 15A , FIG. 15B , FIG. 16A and FIG. 16B , operation of the steering mechanism 450 is as follows. When the implement is turning, hitch tube 7 on the implement acquires a non-orthogonal angle with the longitudinal axis of the trailer 400 causing the one or more control rods 451 to translate longitudinally. Longitudinal translation of the one or more control rods 451 is towards the rear of the trailer 400 for control rods 451 disposed to an inside of the turn with respect to a central longitudinal axis of the trailer, and is towards the front of the trailer 400 for control rods 451 disposed to an outside of the turn with respect to a central longitudinal axis of the trailer 400 . Translation of the one or more control rods 451 causes the pivot plate 455 to pivot about a vertical axis through the pivot plate 455 . Pivoting of the pivot plate 455 causes the tie rods 456 a , 456 b to translate transversely and somewhat longitudinally while pivoting about the pivot points 454 on the pivot plate 455 . Transverse translation of the tie rods 456 a , 456 b causes the stub axle linkages 457 a , 457 b to translate arcuately about vertical axes though spindles 429 a , 429 b thereby rotating the spindles 429 a , 429 b . As described in connection with FIG. 9A , the spindles 429 a , 429 b are ultimately connected to the stub axles 411 a , 411 b , therefore rotation of the spindles 429 a , 429 b causes the stub axles 411 a , 411 b and the wheels 406 a , 406 b thereon to turn in a direction opposite the turning of the hitch tube 7 , as best illustrated in FIG. 13A , FIG. 13B and FIG. 13C . Because the stub axle assemblies 425 a , 425 b and any axle inserts 412 a , 412 b are rigidly connected to the axle bar 405 , which is a part of the frame 401 of the trailer 400 , rotation of the spindles 429 a , 429 b must cause turning of the wheels 406 a , 406 b as the trailer 400 itself is much more difficult to move and acts essentially as a weight against which the rotating action of the spindles 429 a , 429 b can effect turning of the stub axles 411 a , 411 b and the wheels 406 a , 406 b.
The steering mechanism 450 described herein is easily adaptable to configurations of the trailer 400 having an increased transverse distance between the wheels 406 a , 406 b . As illustrated in FIG. 13B , the transverse distance between the wheels may be increased by inserting two axle inserts 412 a , 412 b between the axle bar 405 and respective stub axle assemblies 425 a , 425 b in a manner as previously described. To accommodate the effective increase in length of the axle, the length of the tie rods 456 a , 456 b may also be increased. Lengthening the tie rods may be accomplished by replacing the tie rods, by using hydraulic or linear actuators, or by using length adjustable tie rods, for example telescoping rods based on a threaded rod-in-tube arrangement. Stub axle linkages 457 a , 457 b remain a fixed length. Effective lengthening of the axle may also cause the pivot plate 455 to translate longitudinally in its position. Adjusting the length of the one or more control rods 451 may be required to accommodate translation of the pivot plate 455 . Adjusting the length of the one or more control rods 451 may be accomplished by replacing the control rods, by using hydraulic or linear actuators, or by using length adjustable control rods, for example telescoping rods based on a threaded rod-in-tube arrangement.
Changing the transverse distance between the trailer wheels is important for keeping the wheels between crop rows when crop row spacing changes and the transportation or implement has wheels that are spaced for the new spacing of the crop rows. In prior art steerable trailers, changing the effective length of the axle prevents the steering mechanism from properly tracking the trailer's wheels behind the wheels of the transportation or towing implement while the trailer is turning. Instead of properly and smoothly tracking behind the transportation's or implement's wheels, the wheels of the trailer tend to skid sideways in turns. Such behavior may arise from the way the steering linkages and pivot points are arranged in relation to the effective lengthening of the axle. With the steering mechanism 450 described herein, effective lengthening of the axle on one side of the trailer 400 occurs between the pivot points 458 a and 454 in the 5-bar mechanism and on the other side occurs between the pivot points 458 b and 454 in the 5-bar mechanism. As illustrated in FIG. 15A , FIG. 15B , FIG. 16A and FIG. 16B , the existence and generally central location of the pivot plate 455 permits adjusting the lengths of the tie rods 456 a , 456 b when the effective axle length is increased while maintaining the ability of the trailer wheels 406 a , 406 b to track properly behind wheels 16 a , 16 b of the transportation, even when only one control rod 451 is used in the steering mechanism 450 (see FIG. 16A and FIG. 16B ).
The trailer 400 may be readily convertible between a steerable trailer and a non-steerable trailer in a number of ways, for example by disconnecting the one or more control rods 451 from the pivot mounts 10 and reconnecting the one or more control rods 451 to a rigid portion of the trailer 400 (e.g. the tongue 404 ) to prevent the pivot plate 455 from pivoting, by disconnecting the one or more control rods 451 from the pivot plate 455 and securing the pivot plate 455 (e.g. to the frame 401 ) so that the pivot plate 455 cannot pivot, or by disconnecting the tie rods 456 a , 456 b from the pivot plate 455 and reconnecting the tie rods 456 a , 456 b to a non-movable portion of the trailer 400 (e.g. the frame 401 ).
The novel features will become apparent to those of skill in the art upon examination of the description. It should be understood, however, that the scope of the claims should not be limited by the embodiments, but should be given the broadest interpretation consistent with the wording of the claims and the specification as a whole.
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A trailer has a frame having frame-members configured to support a container, at least a pair of traction devices rotatably mounted on the frame, and a tongue configured to be mounted on a transportation device or an implement being towed by a transportation device. The frame-members may have a three-point mount configured to support a container. The container may be configured to be interchangeable with another container. The container may be an element of a seeding apparatus, the seeding apparatus mountable on the frame-members of the frame. The trailer may have a steering mechanism for the traction devices, and may be convertible between steerable and non-steerable modes. The steering mechanism may be guidance controlled. A transverse distance between the traction devices may be adjustable and/or height of the frame in relation to the ground may be adjustable. The trailer provides greater flexibility of operation under a greater variety of conditions.
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This application is a division of U.S. patent application Ser. No. 08/536,071, filed Sep. 29, 1995, which is a continuation of U.S. patent application Ser. No. 08/070,270, filed Jun. 2, 1993, now abandoned.
BACKGROUND OF THE INVENTION
1. Brief Description of the Invention
The invention is drawn toward absorbent, durable nonwoven articles, such as wipes, and methods for their manufacture.
2. Related Art
Synthetic wiping articles comprised of a nonwoven web made from polyvinyl alcohol (PVA) fibers and subsequently coated with covalently crosslinked PVA binder resins are known and have been sold as commercial products for many years. Chemically crosslinked PVAs provide distinct advantages in their usage in synthetic wipes. They increase and improve the elements of a dry wipe, non-linting of the wipe surface, mechanical strength, hydrophilic properties, and may also be cured in the presence of pigments to generate a colored wiping product. While their use has enjoyed considerable success, the currently known PVA binders used in synthetic wipes are chemically crosslinked in immersion baths containing potentially toxic materials, such as formaldehyde, various dialdehydes, methylolamines, and diisocyanates.
Glass and other fibers are sometimes sized (i.e., coated) with PVA coatings insolubilized with polyacrylic acid, or crosslinked with metal complexes, such as aluminum, titanium, silicon, or zirconium chelates, and the like.
U.S. Pat. No. 3,253,715 describes boil proof nonwoven filter media comprising a nonwoven fiber substrate and a binder comprising polyvinyl alcohol and polyacrylic acid. Although cellulosic fibers suitable for filters are described, there is no mention of polyvinyl alcohol fibers having utility. The polyvinyl alcohol fibers used in the present invention are prone to severe shrinkage under the pH and/or temperature conditions described in the '715 patent. In addition, the inventors herein have found that ratios of polyacrylic acid to polyvinyl alcohol in binders described in the '715 patent result in strong, but extremely rubbery, absorbent articles with poor "hand" and dry-wipe properties.
Natural chamois is a highly absorbent article derived from a goat-like antelope, and is commonly used to dry automobiles after washing. The absorbent properties of natural chamois have been emulated in several "synthetic chamois." Synthetic chamois commercially available may be formed from PVA fibers and a PVA binder crosslinked by formaldehyde, which undesirable for ecological reasons. Other synthetic chamois are known to be made from nonwoven fibers and an originally hydrophobic acrylic latex binder which has functional groups to make the binder, and thus the article, hydrophilic. These latter are inexpensive, but have very high drag property.
It would be desirous to develop a nonwoven article suitable for use in absorbing hydrophilic materials employing hydrophilic binders and fibers, without the use of formaldehyde. Such an article would allow the articles to exhibit high durability, good hand properties, low drag, and good dry-wiping properties (picks up water with no streaking) while maintaining absorption and "wet out" properties comparable to known articles. Such articles could be produced using ingredients and methods which are not as harmful to manufacturing personnel, users or the environment as are currently used ingredients. Finally, it would be advantageous if such binders could be cured in the presence of pigments to generate colored wiping products.
SUMMARY OF THE INVENTION
In accordance with the present invention, absorbent nonwoven articles are presented which can be produced using binder crosslinking agents which are less troublesome to handle, and which afford the inventive articles with as good or better absorbency and physical properties than known articles. In addition, certain preferred embodiments of the inventive articles may be made without the use of any chemical crosslinkers.
As used herein the term "absorbent" means the articles of the invention are hydrophilic (and therefore absorbent of aqueous materials).
Thus, a first aspect of the invention is an absorbent nonwoven article comprising:
(a) a nonwoven web comprised of organic fibers, the organic fibers comprised of polymers having a plurality of pendant fiber hydroxyl groups; and
(b) a binder comprising an at least partially crosslinked and at least partially hydrolyzed polymeric resin having a plurality of pendant resin hydroxyl groups, the resin crosslinked by a crosslinking agent, the crosslinking agent selected from the group consisting of organic titanates and amorphous metal oxides, the polymeric resin derived from monomers selected from the group consisting of monomers within the general formula ##STR2## wherein: X is selected from the group consisting of Si(OR 4 OR 5 OR 6 ) and O(CO)R 7 ; and
R 1 -R 7 inclusive are independently selected from the group consisting of hydrogen and organic radicals having from 1 to about 10 carbon atoms, inclusive, and combinations thereof.
Preferably, the binder is bonded to at least a portion of the organic fibers through bonds between the pendant fiber hydroxyl groups, a bonding agent, and the pendant resin hydroxyl groups, wherein the crosslinking agent and bonding agent are independently selected from the group consisting of organic titanates and amorphous metal oxides. Also preferred articles in accordance with this aspect of the invention are those wherein the crosslinking agent and bonding agent are the same compounds, and wherein R 4 -R 7 inclusive are methyl (--CH 3 ).
Two particularly preferred articles within this aspect of the invention are those in which the organic titanate crosslinking and/or bonding agent is dihydroxybis(ammonium lactato)titanium or a titanium complex with an alpha-hydroxy acid (e.g., lactic acid) and an alditol (e.g., D-glucitol).
As used herein the terms "bond" and "bonding" are meant to include hydrogen bonds, hydrophobic interactions, hydrophilic interactions, ionic bonds, and/or covalent bonds. The term "crosslinking" means chemical (covalent or ionic) crosslinking.
Especially preferred binders useful in this and other aspects of the invention are aqueous compositions comprising copolymers of vinyl trialkoxysilane and vinyl monomers such as vinyl/acetate, at least partially hydrolyzed with alkali, and at least partially crosslinked with inorganic ions and chelating organic titanates. The inorganic ions (e.g., aluminum, zirconium) react or otherwise coordinate with silanol groups, while the titanates react with secondary hydroxyl groups on the resin. This unique dual curing approach, with possibly different crosslinking chain lengths, allows intermolecular bonding between the PVA polymers of the binder and, theoretically, between the fiber hydroxyl groups and PVA polymers of the binder.
A second aspect of the invention is drawn toward nonwoven absorbent articles similar to those of the first aspect of the invention, wherein the crosslinking agent is selected from the group consisting of dialdehydes, titanates, and amorphous metal oxides.
A third aspect of the invention is an absorbent nonwoven article comprising:
(a) a nonwoven web comprised of a plurality of organic fibers comprising polymers having a plurality of pendant hydroxyl groups; and
(b) a binder coating at least a portion of the fibers, the binder comprising polyvinyl alcohol insolubilized with an effective amount of a polymeric polycarboxylic acid (preferably polyacrylic acid).
Preferred within this aspect of the invention are those articles wherein all of the polymers making up the fibers are at least partially hydrolyzed polymerized monomers selected from the group consisting of monomers within the general formula ##STR3## with the provisos mentioned above. The nonwoven web may further include a minor portion of fibers selected from the group consisting of cotton, viscose rayon, cuprammonium rayon, polyesters, polyvinyl alcohol, and combinations thereof.
In contrast to the articles described in the above-mentioned U.S. Pat. No. 3,253,715, we have found that very low amounts of polymeric polycarboxylic acid (in the range of 1 to 5 wt. % as weight of total binder weight) afford the best wiping properties while effectively eliminating binder washout. Further, we have found that pH (negative logarithm of the hydrogen ion concentration in aqueous compositions) ranging from 3 to 3.3 specified by the above-mentioned '715 patent is suitable for the present invention, but pH values up to 4.6 may be utilized, which is much more useful for reducing web shrinkage. The articles of this aspect of the invention employ a polymeric polycarboxylic acid to insolubilize aqueous polyvinyl alcohol, thereby providing absorbent articles with superior water absorption, dry-wipe, and improved strength compared to known articles.
A fourth aspect of the invention is an absorbent nonwoven article comprising:
(a) a nonwoven web comprised of organic fibers, the organic fibers comprised of polymers having a plurality of pendant hydroxyl groups; and
(b) a binder coated onto at least a portion of the fibers comprising syndiotactic polyvinyl alcohol, the syndiotactic polyvinyl alcohol having a syndiotacticity of at least 30%.
Articles employing the binder system mentioned in part (b) of this aspect of the invention employ syndiotactic polyvinyl alcohol (s-PVA) as a major (or only) component in the binder. The advantage of this binder is that s-PVA may be employed without a chemical crosslinking agent. This is because s-PVA tends to form microcrystalline regions. Chemical crosslinking through the use of titanates, inorganic ions, and dialdehydes may be employed, but they are rendered optional.
A fifth aspect of the invention is a method of making an absorbent nonwoven article, the method comprising:
(a) forming an open, lofty, three-dimensional nonwoven web comprised of organic fibers, the organic fibers comprised of polymers having a plurality of pendant hydroxyl groups;
(b) entangling the fibers of the web using means for entanglement to form an entangled fiber web;
(c) coating a major portion of the fibers of the entangled fiber web with a binder precursor composition to form a first coated web having first and second major surfaces, the binder precursor composition adapted to form the binder of the second aspect of the invention; and
(d) exposing the first coated web to energy sufficient to at least partially cure the binder precursor composition to form a nonwoven bonded web of fibers.
Preferred are those methods wherein the before step (c) the entangled fiber web is calendered, and those methods wherein after step (c) the first coated web is coated on at least one of its first and second major surfaces with a second binder precursor composition. Also preferred are those methods wherein the exposing step includes drying the second binder precursor composition uniformly to form a dried and cured nonwoven web having a surface coating, and those methods wherein the dried and cured nonwoven web is calendered, thereby smoothing and fusing the surface coating.
A sixth aspect of the invention is another method of making an absorbent nonwoven article comprised of a nonwoven web of fibers, at least a portion of the fibers having a binder coated thereon, the method comprising:
(a) forming a nonwoven web comprised of a plurality of organic fibers comprising polymers having a plurality of pendant fiber hydroxyl groups, a major portion of the polymers comprising polyvinyl alcohol;
(b) entangling the fibers of the web using means for entanglement to form an entangled fiber web;
(c) coating a major portion of the fibers of the entangled fiber web with a binder precursor composition to form a first coated web having first and second major surfaces, the binder precursor composition consisting essentially of polyvinyl alcohol and an effective amount of a polymeric polycarboxylic acid; and
(d) exposing the first coated web to energy sufficient to insolubilize the polyvinyl alcohol resin to form a nonwoven bonded web of fibers.
Optionally, bonding and crosslinking agents, as discussed herein, may be added to the binder precursor composition.
Finally, a seventh aspect of the invention is another method of making an absorbent nonwoven article comprised of a nonwoven web of fibers, at least a portion of the fibers having a binder coated thereon, the method comprising:
(a) forming a nonwoven web comprised of organic fibers, the organic fibers comprised of polymers having a plurality of pendant hydroxyl groups;
(b) entangling the fibers of the web using means for entanglement to form an entangled fiber web;
(c) coating a major portion of the fibers of the entangled fiber web with a binder precursor composition to form a first coated web having first and second major surfaces, the binder precursor composition consisting essentially of syndiotactic polyvinyl alcohol having a syndiotacticity of at least 30%; and
(d) exposing the first coated web to energy sufficient to at least partially cure the binder precursor composition to form a nonwoven bonded web of fibers.
An important aspect of the invention is that articles of the invention may employ inventive binders which allow the articles to exhibit high durability, good feel, reduced drag, and good dry wiping properties while maintaining comparable water absorption and "wet out" properties to existing wipes. In addition, wiping articles of the present invention may also be cured in the presence of pigments to generate colored wiping products.
Preferred articles within the invention may also include in the binder efficacious amounts of functional additives such as, for example, fillers, reinforcements, plasticizers, grinding aids, and/or conventional lubricants (of the type typically used in wiping articles) to further adjust the absorbance, durability, and/or hand properties.
The binders useful in the articles of the invention improve on conventional formaldehyde cross-linking agents which tend to embrittle the web fibers, reducing web strength, softness, and absorption, and which present chemical hazards.
Regarding the methods of the invention, in preferred methods the "exposing" step is preferably carried out in a fashion to afford uniform drying throughout the thickness of the web. Typically and preferably the exposing step is a two stage process wherein the coated web is first dried at a low temperature and subsequently exposed to a higher temperature to cure the binder precursor. In some embodiments, a third, higher temperature curing step is employed. As discussed herein below, to achieve uniformly dried and cured articles, both major surfaces of the uncured web are preferably exposed to a heat source simultaneously, or both major surfaces are sequentially exposed to the heat source. The methods of the invention may also encompass perforating and slitting the dried and cured bonded nonwoven into various finished products.
Further aspects and advantages of the invention will become apparent from the drawing figures and description of preferred embodiments which follows.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of a wipe made in accordance with the invention;
FIG. 2 is a cross-section along the lines 2--2 of the article of FIG. 1; and
FIG. 3 is a schematic diagram of a preferred method of making articles of the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
1. Articles Employing Chemically Crosslinked PVA Binders
Embodiments within this aspect of the invention include articles comprising a nonwoven web of fibers having coated thereon a binder comprising polyvinyl alcohol (preferably silanol modified) crosslinked with inorganic ions, chelating organic titanates, or combinations thereof.
The nonwoven web of fibers may be made from many types of hydrophilic fibers, and may include a minor portion of hydrophobic fibers, selected from the following fiber types: cellulosic-type fibers, such as PVA (including hydrolyzed copolymers of vinyl esters, particularly hydrolyzed copolymers of vinyl acetate), cotton, viscose rayon, cuprammonium rayon and the like, and thermoplastics such as polyesters, polypropylene, polyethylene and the like. The preferred cellulosic-type fibers are rayon and polyvinyl alcohol. Webs containing 100% PVA fibers, 100% rayon fibers, and blends of PVA fibers and rayon fibers in the wt. % range of 1:100 to 100:1 are within the invention, and those webs having PVA:rayon within the weight range of 30:70 to about 70:30 are particularly preferred in this aspect of the invention, since the coated products exhibit good hydrophilicity, strength, and hand.
Some aspects of the nonwoven fiber web are common to all article embodiments of the invention. The fibers employed typically and preferably have denier ranging from about 0.5 to about 10 (about 0.06 to about 11 tex), although higher denier fibers may also be employed. Fibers having denier from about 0.5 to 3 (0.06 to about 3.33 tex) are particularly preferred. ("Denier" means weight in grams of 9000 meters of fiber, whereas "tex" means weight in grams per kilometer of fiber.) Fiber stock having a length ranging from about 0.5 to about 10 cm is preferably employed as a starting material, particularly fiber lengths ranging from about 3 to about 8 cm.
Nonwoven webs of fibers for use in the articles of the invention may be made using methods well documented in the nonwoven literature (see for example Turbak, A. "Nonwovens: An Advanced Tutorial", Tappi Press, Atlanta, Ga., (1989). The uncoated (i.e., before application of any binder) web should have a thickness in the range of about 10 to 100 mils (0.254 to 2.54 mm), preferably 30 to 70 mils (0.762 to 1.778 mm), more preferably 40 to 60 mils (1.02 to 1.524 mm). These preferred thicknesses may be achieved either by the carding/crosslapping operation or via fiber entanglement (e.g., hydroentanglement, needling, and the like). The basis weight of the uncoated web preferably ranges from about 50 g/m 2 up to about 250 g/m 2 .
Binders within this aspect of the invention preferably are crosslinked via secondary hydroxyl groups on the PVA backbone with chelating organic titanates, and optionally with dialdehydes such as glyoxal. The resultant binder system will theoretically further react with hydroxyl groups on the fibers when cured at elevated temperatures to produce coated webs with excellent wiping properties.
Particularly preferred are "dual" crosslinked binders, wherein an amorphous metal oxide coordinates with silanol groups on the PVA backbone and titanates and/or glyoxal coordinate with secondary hydroxyl groups on the PVA backbone.
Silanol modified PVA's used in the present invention may be made via the copolymerization of any one of a number of ethylenically unsaturated monomers having hydrolyzable groups with an alkoxysilane-substituted ethylenically unsaturated monomer. Examples of the former are vinyl acetate, acetoxyethyl acrylate, acetoxyethylmethacrylate, and various propyl acrylate and methacrylate esters. Examples of alkoxysilane-substituted ethylenically unsaturated monomers include vinyl trialkoxysilanes such as vinyl trimethoxysilane and the like.
One particularly preferred silanol-modified PVA may be produced from the copolymerization of vinyl acetate and vinyl trialkoxysilane, followed by the direct hydrolysis of the copolymer in alkaline solution (see below). One commercially available product is that known under the trade designation "R1130" (Kuraray Chemical KK, Japan). This preferred base copolymer contains from about 0.5 to about 1.0 molar % of the silyl groups as vinylsilane units, a degree of polymerization of about 1700, and degree of hydrolysis of the vinyl acetate units preferably of 99+%.
The theoretical crosslink density may range from 1 to about 40 mole % based on mole of ethyleneically unsaturated monomer. This may be achieved by addition of one or more aqueous titanates and, optionally, dialdehyde/NH 4 Cl solutions to a polyvinyl alcohol binder resin. Though dialdehydes such as glyoxal and several classes of titanium complexes have been shown to crosslink aqueous compositions of polyvinyl alcohol, we have found that chelating titanates such as dihydroxybis(ammonium lactato) titanium (available under the trade designation "Tyzor LA" from du Pont) and titanium orthoesters such as Tyzor 131 provide excellent crosslinking for wiping articles described in this invention. It is desired that crosslinking be avoided until curing conditions (i.e., high temperatures) are present. Thus, organic acids, such as citric acid, may help to stabilize titanates such as dihydroxybis (ammonium lactato) titanium in aqueous compositions until the binder precursors are exposed to crosslinking and curing conditions.
To improve the tensile and tear strength of the inventive articles, and to reduce lint on the surface of the articles, it may be desirable to entangle (such as by needletacking, hydroentanglement, and the like) the uncoated web, or calender the uncoated and/or coated and cured nonwoven articles of the invention. Hydroentanglement may be employed in cases where fibers are water insoluble. Calendering of the binder coated web at temperatures from about 5° to about 40° C. below the melting point of the fiber may reduce the likelihood of lint attaching to the surface of the inventive articles and provide a smooth surface. Embossing of a textured pattern onto the wipe may be performed simultaneously with calendering, or in a subsequent step.
In addition to the above-mentioned components of the articles of this invention, it may also be desirable to add colorants (especially pigments), softeners (such as ethers and alcohols), fragrances, fillers (such as for example silica, alumina, and titanium dioxide particles), and bactericidal agents (for example iodine, quaternary ammonium salts, and the like) to add values and functions to the wiping articles described herein.
Coating of the binder resin may be accomplished by methods known in the art, including roll coating, spray coating, immersion coating, gravure coating, or transfer coating. The binder weight as a percentage of the total wiping article may be from about 1% to about 95%, preferably from about 10% to about 60%, more preferably 20 to 40%.
2. Articles Employing PVA-PA Blends as Binders
The absorbent nonwoven articles in accordance with this aspect of the invention comprise a nonwoven web of a plurality of organic fibers comprising polymers having a plurality of pendant hydroxyl groups, a major portion of the polymers being at least partially hydrolyzed polymerized monomers selected from the group consisting of monomers within the general formula ##STR4## wherein X is O(CO)R 7 the provisos mentioned above. A binder coats at least a portion of the fibers, the binder consisting essentially of polyvinyl alcohol insolubilized with an effective amount of polyacrylic acid. Optionally, chemical crosslinking agents and/or bonding agents may also be employed.
The nonwoven web of fibers is substantially the same as that described in Section 1 above. Any fiber type, such as polyesters, polyolefins, cellulosics, acrylics, and the like, may be employed, alone or in combination. Preferably, the nonwoven web of fibers comprises one or more of the following fibers: cotton, viscose rayon, cuprammonium rayon, polyvinyl alcohols including hydrolyzed copolymers of vinyl esters, particularly hydrolyzed copolymers of vinyl acetate and the like. Preferred cellulosic-type fibers are rayon and polyvinyl alcohol. Blends of rayon and polyvinyl alcohol fibers in the weight ranges given above in Section 1 are preferred.
The fiber denier and length are also as previously described in Section 1 above, as well as the preferred ranges for uncoated web thickness and weight.
Coating of the binder resin may accomplished by the previously mentioned methods, including roll coating, spray coating, immersion coating, transfer coating, gravure coating, and the like. The binder weight as a percentage of the total nonwoven article weight for this aspect of the invention may range from about 5% to about 95%, preferably from about 10% to about 60%, more preferably 20 to 40%.
Polymeric polycarboxylic acids useful in the invention include polyacrylic acid, polymethacrylic acid, copolymers of acrylic acid, methacrylic acid or maleic acid containing more than 10% acidic monomer, provided that such copolymers or their salts are water soluble the specified pH levels; and vinyl methyl ether/maleic anhydride copolymer.
Polyacrylic acid, the most preferred polymeric polycarboxylic acid useful in the present invention preferably has a weight average molecular weight ranging from about 60,000 to about 3,000,000. More preferably, the weight average molecular weight of polyacrylic acid employed ranges from 300,000 to about 1,000,000.
Optionally, small amounts (i.e., less than about 5 wt. % of the total weight of binder) of additional monomers (such as, for example, functionalized acrylate monomers like hydroxyethylmethacrylate, vinyl azlactone monomers, and the like) may be incorporated in the PVA binder polymer to reduce binder washout during repeated use.
As with previously described embodiments, chemical crosslinkers may be used. Preferred crosslinkers are titanates, dialdehydes, borates, and the like.
The nonwoven articles of this aspect of the invention may be calendered as previously described in Section 1 to reduce lint on the surface of the article and provide a smooth surface for printing. Embossing of a textured pattern onto the wipe may be performed simultaneously with calendering, or in a subsequent step.
The above-mentioned optional components (colorants, softeners, fragrances, fillers) may also be employed in the nonwoven articles of this aspect of the invention.
3. Articles Employing Binders Comprising Syndiotactic PVA
Triad syndiotacticity, as used herein, means that of a triad of three pendant hydroxyl groups, all three are on the same side of the polymer chain. This is opposed to atactic, which means that the hydroxyl groups are randomly arranged, and isotactic, meaning the hydroxyl groups are positioned in alternating pattern from side-to-side on the polymer chain.
Nonwoven absorbent articles within this aspect of the invention comprise a nonwoven web of fibers comprised of polymers having a plurality of pendant hydroxyl groups. The binder for articles within this aspect of the invention comprises polyvinyl alcohol having a syndiotacticity of at least 30%. Optionally, a chemical crosslinking agent may also be present.
The nonwoven web of fibers comprises fibers substantially the same as those described above as useful for the other articles of the invention. The fiber length and denier, and uncoated web thickness and weight are also as above-described in Section 1. Coating of the binder resin may be accomplished by the above-mentioned methods known in the art including roll coating, spray coating, immersion coating, transfer coating, gravure coating, and the like. The binder weight as a percentage of the total article weight for articles within this aspect of the invention may range from about 5% to about 95%, preferably from about 10% to about 60%, more preferably 20 to 40%.
For preparing syndiotactic PVA, vinyl trihaloacetoxy monomers are commonly employed, such as, vinyl trifluoroacetate, trifluoroacetoxyethyl acrylate, trifluoroacetoxyethyl methacrylate, and the like.
Polyvinyl trifluoroacetate is a preferred precursor ester for preparation of syndiotactic polyvinyl alcohol used in practice of the invention due to its high chemical reactivity making conversion to polyvinyl alcohol relatively facile. It may be hydrolyzed with alcoholic alkali, but is preferably hydrolyzed with methanolic ammonia (see Example 64 below). Polyvinyl trifluoroacetate is readily prepared by polymerization of vinyl trifluoroacetate.
Optionally, small amounts (i.e., less than about 5 wt. %) of additional monomers may be incorporated in the parent polymer to improve various properties of the polyvinyl alcohol derived therefrom. A particularly preferred syndiotactic PVA (and used in Examples 65-91 below) is poly(vinyl trifluoroacetate-co-[3-allyl-2,2'-dihydroxy-4,4'-dimethoxybenzophenone]) (99.95:0.05 by weight, abbreviated as PVTFA). The triad syndiotacticity measured by 1 H NMR was 51%, isotacticity =7%, atacticity =42%.
The syndiotacticity of the polyvinyl alcohol binder employed in this aspect of the invention typically and preferably ranges from about 45% to 100% syndiotacticity. It is known that increasing syndiotacticity at constant degree of polymerization results in increased melting point for the gel. (See Matsuzawa, S. et al., "Colloid Poly. Sci. 1981", 259 (12), pp. 1147-1150.) For this reason higher syndiotacticity is preferred since mechanical strength and thermal stability are improved, but aqueous compositions of polyvinyl alcohol become more viscous and/or thixotropic as syndiotacticity increases due to gel formation. For these reasons, and owing to methods of preparation, the preferred range of syndiotacticity when coated from aqueous compositions preferably ranges from about 25 to about 65% syndiotacticity. Although detrimental to the flexibility of the nonwoven articles of the invention, it may be advantageous to incorporate a small amount (e.g., up to about 10 mole %) of a chemical crosslinker such as those mentioned above in order to eliminate washout of the binder during use. Preferred crosslinkers are the above-mentioned titanates, with dialdehydes and the like being suitable but less preferred for ecological reasons.
The nonwoven articles of this aspect of the invention may be calendered at elevated temperature as above-described to reduce lint on the surface of the article and provide a smooth surface for printing. Embossing of a textured pattern onto the wipe may be performed simultaneously with calendering, or in a subsequent step. In addition, the above-mentioned colorants, softeners, fragrances, fillers, and the like may be employed.
4. Particularly Preferred Articles and Methods
Referring now to the drawing figures, FIG. 1 illustrates a perspective view of an absorbent nonwoven article 10 made in accordance with the invention. Article 10 has a plurality of fibers 12 at least partially coated with binder.
FIG. 2 is a cross-sectional view of the article of FIG. 1 taken through the section 2--2 of FIG. 1. FIG. 2 illustrates a preferred article wherein the major surfaces 14 and 16 (illustrated in exaggerated thickness) are comprise a combination of calendered and fused organic fibers and binder. Surfaces 14 and 16 form a sandwich with nonwoven material 18.
FIG. 3 illustrates a preferred method of producing the nonwoven articles illustrated in FIGS. 1 and 2. Staple fibers are fed via a hopper 20 or other means into a carding station 22, such devices being well known and not requiring further explanation. A moving conveyer transports a carded web 26 from carding station 22, typically to a crosslapper, not shown, which forms a layered web having fibers at various angles to machine direction. Carded web 26 then typically and preferably passes through a needling station 28 to form a needled web 30 which is passed through calender station 32. At this point the calendered web 34 is not more than about 60 mils (1.524 mm) thick. Calendered web 34 then passes through an immersion bath 36 where an aqueous binder precursor composition 37 is applied. Web 34 passes under rollers 38 and emerges as a coated web 40, which then passes through a drying station 42 to form a dried web 44. Drying station 42 typically and preferably exposes the web to a temperature and for a residence time which allows substantially all of the water to be removed from the binder precursor to form a dried web 44.
Depending on the composition of the binder precursor, type of crosslinking and/or bonding agent used, amount of water present, etc., web 44 may be suitable for use without further curing. In some embodiments, it is desirable to pass dried web 44 through a final curing station 46, which is at a temperature higher than the temperature of drying station 42, to form a dried and cured web 48.
Web 48 may then be passed through another set of calender rollers 50, which may used to emboss a pattern, fuse the surfaces, and impart other qualities to the article. Web 52 generally has a thickness of no more than 60 mils (1.524 mm), and a weight ranging from about 50 g/m 2 to about 250 g/m 2 .
Web 52 may then pass through a second needling station 54 to perforate the web for decorative or other purposes, after which the web is slit and wound onto take-up roll 56.
The features of the various aspects of the invention will be better understood in reference to the following Test Methods and Examples, wherein all parts and percentages are by weight. Names of ingredients in quotation marks indicate trade designations.
TEST METHODS
Tensile Strength
Tensile strength measurements were made on 1×3 inch (2.54×7.62 cm) wringer damp, die cut samples using an Instron Model "TM", essentially in accordance with ASTM test method D-5035. A constant rate of extension (CRE) was employed, and jaws were clamp-type. Rate of jaw separation was 9.3 inches/min. (23.6 cm/min).
Elmendorf Tear
Elmendorf tear tests were conducted on 2.5×11 inch (6.35×27.94 cm) damp, die-cut, notched (20 mm) samples, essentially in accordance with ASTM D-1424, using an Elmendorf Tear Tester model number 60-32, from Thwing-Albert Co., with a 3200 gram pendulum. An average of four measurement was used. A high value is desired.
Absorption
Absorption measurements were made on 6×8 inch (15.24×20.32 cm) samples which were die-cut in damp conditions. The absorption measurements are reported using the following terms:
(a) Dry Weight=the dried weight of the sample, in grams.
(b) No Drip Weight=the maximum total weight of the sample and water absorbed, in grams.
(c) With Drip Weight=the total weight of the sample, in grams, after dripping for 60 seconds.
(d) Damp Weight=the weight of the sample after passing through nip rollers.
(e) Wet Out=the time it takes for a droplet of water placed on the wipe surface to be completely absorbed into the sample.
(f) % Weight (H 2 O) Loss=(No Drip Weight--With Drip Weight)/No Drip Weight.
(g) Grams Water Absorbed per Square foot (grams/929 cm 2 )=3×(No Drip Weight-Dry Weight).
(h) Grams Water Absorbed per Gram Dry Weight=(No Drip Weight-Dry Weight)/Dry Weight.
(i) MD=machine direction, CD=cross direction, "abs" =absorbed, and "eff"=effective
(j) effective water absorption=3×(no drip weight-damp weight).
MATERIALS DESCRIPTION
The materials are used in the examples which follow:
"R1130" is the trade designation for a copolymer of vinyl silane and vinyl acetate containing from about 0.5 to about 1.0 molar % of the silyl groups as vinylsilane units, a degree of polymerization of about 1700, and degree of hydrolysis of the vinyl acetate units preferably of 99+ % (Kuraray Chemical KK, Japan).
"Tyzor LA" is the trade designation for dihydroxybis(ammonium lactato) titanium (50 wt. % aqueous solution, available from du Pont Company, Du Pont Company), glyoxal (40 wt. % aqueous solution, Aldrich Chemicals) are then added to the silanol modified PVA solution at various proportions and combinations as described in the examples to follow.
"Tyzor 131" is the trade designation for a mixture of titanium orthoester complexes (20 wt. % aqueous solution, also available from DuPont.
"Nalco 8676" is the trade designation for a nanoscale, amorphous aluminum hydrous oxide colloid (10 wt. % aqueous solution), available from Nalco Chemical Company.
glyoxal is a dialdehyde of formula HCOCOH, available as a 40 wt. % aqueous solution from Aldrich Chemicals, Co.
"Airvol 165" is the trade designation for a 99.5+ % hydrolyzed polyvinyl alcohol from Air Products and Chemicals, Inc.
EXAMPLES
General Procedure I for Preparing Inventive Articles
Nonwoven webs consisting of a blend of polyvinyl alcohol and rayon fibers (45% polyvinyl alcohol fiber having 1.5 denier and a length of 1.5 inch (3.81 cm) purchased from Kuraray, Japan, and 55% rayon fiber having 1.5 denier and a length of 1 and 9/16 inch (3.97 cm) purchased from BASF) were made using a web, making machine known under the trade designation "Rando-Webber". The resultant web had a nominal basis weight of 11.5 g/ft 2 (123.8 g/m 2 ) and an average thickness of 0.052 inch (0.132 cm).
Silanol modified polyvinyl alcohol granules ("R1130") were added to deionized water in proportions up to 10 wt. % solid in a stirred flask. The flask was then heated to 95° C. until reflux condition is achieved. The polymeric solution was then kept at reflux for a minimum of 45 minutes with adequate mixing. The solution was then cooled down to room temperature (about 25° C.). The silanol modified PVA solution was then diluted to 2.5 wt. % solid. Reactants such as Nalco 8676, Tyzor LA, Tyzor 131, and glyoxal were then added to the silanol modified PVA solution at various proportions and combinations as described in the examples to follow.
A 12×15 inch (30.48×38.1 cm) piece of this nonwoven web was placed in a pan and saturated with approximately 200 g of an aqueous coating solution containing 5.00 g of total polymer.
Saturated samples were then dried and cured in a flow-through oven at various conditions to be described in the examples below. When curing was completed, the samples were conditioned for 60 minutes in 60°-80° F. (140°-176° C.) tap water then dried. Samples were then analyzed for hydrophilicity, water retention and absorption, tensile strength, tear strength, and dry wiping properties.
Examples 1-10 and Comparative Example A
The results of testing on Comparative Example A, a nonwoven wipe originally 59 mils (0.149 cm) thick, and known under the trade designation "Brittex-11" (available from Vileda, a division of Freudenberg Co., Germany, and which is a PVA web coated with a PVA binder crosslinked with formaldehyde) were as follows:
Wet Out=3 sec.;
% Water Loss=12.8;
Total Water Absorption=137.5 g/ft 2 (1479 g/m 2 );
g of water absorbed/g of wipe=7.9;
tensile strength (machine direction)=273 lbs/in 2 (1882 KPa);
tensile strength (cross direction)=203 lbs/in 2 (1399 KPa);
Elmendorf Tear strength (machine direction and damp)=86.
Elmendorf Tear strength (cross direction and damp)=100+.
The test results for the inventive nonwovens of Examples 1-10 are presented in Tables 1 and 2. The nonwovens of Examples 1-10 were prepared as described in General Procedure I. For each example, 200 g of the polymeric solution (2.5 wt. % of R1130) was added with the reactants described below along with 0.1 g of Orcabrite Green BN 4009 pigment. The wt. % designated below represents the wt. % of active reactant (solid) over the R1130 polymer. The coated samples were dried at 150° F. (65.5° C.) for 2 hrs. then 250° F. (121.1° C.) for 2 hrs. and finally cured at 300° F. (148.8° C.) for 10 minutes. All samples had excellent dry wiping properties, low drag, and good feel.
TABLE 1______________________________________ g H2O Sample Wet out abs/g of g H2O % H2OEx. # Description (sec) Dry wipe abs/(ft.sup.2) Loss______________________________________1 Uncoated 0 11.37 148.7 24.78 nonwoven substrate COMPARATIVE2 R1130 0 8.90 158.6 18.553 R1130/0.5 0 8.37 159.7 17.2 wt. % Nalco 8676/5 wt. % Tyzor 1314 R1130/0.5 wt. 0 7.46 145.7 21.2 % Nalco 8676/ 15 wt. % Tyzor 1315 R1130/0.5 wt. 0 8.42 150.3 15.95 % Nalco 8676/5 wt. % Tyzor LA6 R1130/0.5 wt. 0 7.79 155.9 16.73 % Nalco 8676/15 wt. % Tyzor LA7 R1130/5 wt. % 0 8.26 145.5 15.71 Tyzor 1318 R1130/15 wt. % 0 7.83 150.4 17.11 Tyzor 1319 R1130/5 wt. % 0 8.52 151.1 16.47 Tyzor LA10 R1130/15 wt. % 0 8.06 136.6 12.93 Tyzor LA______________________________________
TABLE 2______________________________________ Tensile Strength (KPa) Elmendorf TearEx. # Sample Description MD CD MD CD______________________________________1 Uncoated nonwoven 1289 641 74.7 56.3 substrate COMPARATIVE2 R1120 2126 2011 85.5 93.03 R1130/0.5 wt. % 2555 2012 95.0 88.0 Nalco 8676/5 wt. % Tyzor 1314 R1130/0.5 wt. % Nalco 8696/15 wt. % 2770 2032 86.3 100 Tyzor 1315 R1130/0.5 wt. % 2543 2001 76.7 85.0 Nalco 8676/5 wt. % Tyzor LA6 R1130/0.5 wt. % 2802 1921 90.3 100 Nalco 8676/15 wt. % Tyzor LA7 R1130/5 wt. % 2481 2155 77.0 84.5 Tyzor 1318 R1130/15 wt. % 2327 2201 90.8 84.0 Tyzor 1319 R1130/5 wt. % 2356 1787 80.3 82.5 Tyzor LA10 R1130/5 wt. % 2769 2090 78.0 87.5 Tyzor LA______________________________________
Examples 11-20
The wipes of Example 11-20 were prepared as described in General Procedure I, and dried and cured as in Examples 1-10, except that the final 10 minute cure at 300° F. (121.1° C.) was eliminated. The absorbency, tensile strength and tear test results are presented in Tables 3 and 4.
It can be seen comparing the data of Tables 3 and 4 with the data of Tables 1 and 2 that addition of Tyzor LA or Tyzor 131, and the final 121.1° C. cure, gave immediate wet-out and consistently higher tensile strength and Elmendorf tear values.
TABLE 3______________________________________ g H2OSample Wet out abs/g of g H2O % H2OEx. #Description (sec) dry wipe abs/(ft.sup.2) Loss______________________________________11 R1130/0.5 wt. % 28 8.87 152.8 17.7Nalco 867612 R1130/1 wt. % 60+ 7.80 141.5 14.09Nalco 867613 R1130/1.5 wt. % 60+ 7.65 141.7 13.99Nalco 867614 R1130/2.0 wt. % 60+ 7.48 138.7 14.92Nalco 867615 R1130/0.5 wt. % 0 8.35 160.7 19.60Nalco 8676/1wt. % Tyzor LA16 R1130/0.5 wt. % 0 8.49 161.5 19.70Nalco 8676/5wt. % Tyzor LA17 R1130/0.5 wt. % 0 8.31 155.6 16.57Nalco 8676/10wt. % Tyzor LA18 R1130/0.5 wt. % 0 8.49 164.2 18.63Nalco 8676/1wt. % Tyzor 13119 R1130/0.5 wt. % 0 8.12 165.0 19.69Nalco 8676/5wt. % Tyzor 13120 R1130/0.5 wt. % 0 8.61 164.8 21.33Nalco 8696/10wt. % Tyzor 131______________________________________
TABLE 4______________________________________Sample Tensile strength (Kpa) Elmendorf TearEx. # Description MD CD MD CD______________________________________11 R1130/0.5 2218 2022 91.7 85.0 wt. % Nalco 867612 R1130/1 2212 1856 88.8 100.0 wt. % Nalco 867613 R1130/1.5 2678 1948 83.3 90.0 wt. % Nalco 867614 R1130/2.0 2961 2164 86.3 100.0 wt. % Nalco 867615 R1130/0.5 2425 1783 78.3 100.0 wt. % Nalco 8676/1 wt. % Tyzor LA16 R1130/0.5 2182 2086 74.5 100.0 wt. % Nalco 8676/ 5 wt. % Tyzor LA17 R1130/0.5 2379 2130 100.0 95.0 wt. % Nalco 8676/ 10 wt. % Tyzor LA18 R1130/0.5 2390 1959 90.3 92.0 wt. % Nalco 8676/ 1 wt. % Tyzor 13119 R1130/0.5 2295 1904 85.0 100.0 wt. % Nalco 8676/ 5 wt. % Tyzor 13120 R1130/0.5 2419 1837 78.0 100.0 wt. % Nalco 8676/ 10 wt. % Tyzor 131______________________________________
Examples 21-27
The inventive nonwovens of Examples 21-27 were prepared as described in General Procedure I. For each sample, 200 g of the polymeric solution (2.5 wt. % of R1130 ) was mixed with 1.54 g of glyoxal (40 wt. % aqueous solution) and 0.25 g of NH 4 Cl and then reacted with the reactants described below. The wt. % designated below represents the wt. % of active reactant (solid) over the R1130 polymer. The coated samples were dried at 110° F. (92.2° C.) for 4 hrs. All samples had excellent dry wiping properties, low drag, and good feel. The results of the absorbency, tensile strength, and tear strength are presented in Tables 5 and 6.
TABLE 5______________________________________ g H2O Sample Wet out abs/g of g H2O % H2OEx. # Description (sec) Dry wipe abs/(ft.sup.2) Loss______________________________________21 NONE: 0 7.40 127.9 15.27 COMPARATIVE22 1 wt. % 60+ 8.86 157.1 24.28 Nalco 867623 3 wt. % 60+ 9.39 162.9 26.12 Nalco 867624 5 wt. % 60+ 8.03 139.3 23.10 Nalco 867625 1 wt. % 31 8.25 148.7 19.70 Al2(SO4)3 (100% solid)26 3 wt. % 16 8.53 153.8 21.82 Al2(SO4)3(100 % solid)27 5 wt. % 60+ 8.54 147.1 21.32 Al2(SO4)3(100 % solid)______________________________________
TABLE 6______________________________________ Tensile Strength (KPa) Elmendorf TearEx. # Sample Description MD CD MD CD______________________________________21 NONE: 1717 2616 100.0 86.3 COMPARATIVE22 1 wt. % 1693 2639 94.0 94.3 Nalco 867623 3 wt. % 2509 1915 -- 91.0 Nalco 867624 5 wt. % 2248 3230 100.0 90.3 Nalco 867625 1 wt. % 1880 2202 100.0 82.7 Al2(SO4)3(100 % solid)26 3 wt. % 1813 2273 100.0 85.0 Al2(SO4)3 (100% solid)27 5 wt. % 2449 2030 100.0 96.0 Al2(SO4)3 (100% solid)______________________________________
Examples 28-29
Examples 28-29 demonstrated the use of nonwoven web containing 100% PVA fibers. The nonwoven web was made from 100% PVA fibers which were 1.5 denier and 1.5 inch long (3.81 cm), purchased from Kuraray, Japan, with a basis weight of 7.0 g/ft 2 (75.3 g/m 2 ) using a carding machine known under the trade designation "Rando-Webber." A 12×15 inch (30.48×38.1 cm) sample of this web was coated with a solution containing: 130 g of R1130 solution (2.5 wt. % solid), 0.16 g of Nalco 8676 (10% solid), 1.63 g of Tyzor 131 (20 wt. % in water), and 0.16 g of Orcobrite Royal blue pigment #R2008. The coated sample was dried at 150° F. (65.5° C.) for 2 hrs. then cured at 300° F. (148.9° C.) for an additional 15 minutes. The coated sample had a rubbery feel. The absorbency and tensile strength data are presented in Tables 7 and 8.
TABLE 7______________________________________ g H2O Sample Wet out abs/g of g H2O % H2OEx. # Description (sec) dry wipe abs/(ft.sup.2) Loss______________________________________28 Uncoated 0 12.74 159.3 30.71 100% PVA fiber web COMPARATIVE29 Coated 100% 7 4.74 81.3 13.32 PVA fiber web______________________________________
TABLE 8______________________________________ Tensile Strength (KPa)Ex. # Sample Description MD CD______________________________________28 Uncoated 100% PVA fiber 1751 2042 web COMPARATIVE29 Coated 100% PVA fiber web 2752 2352______________________________________
Examples 30-31
Examples 30-31 demonstrated the use of a nonwoven web containing a blend of PVA and cotton fibers. The nonwoven web was made from 50 wt. % PVA fibers which were 1.5 denier and 1.5 inch (3.81 cm) in length, purchased from Kuraray, Japan, and 50 wt. % cotton fibers with a resultant basis weight of 5.5 g/ft 2 (59.2 g/m 2 ) using a web making machine known under the trade designation "Rando-Webber." A 12×15 inch (30.48×38.1 cm) sample of this web was coated with a solution containing: 110 g of R1130 solution (2.5 wt. % solid in H 2 O), 0.13 g of Nalco 8676 (10% solid in H 2 O), 1.38 g of Tyzor 131 (20% solid in H 2 O), and 0.14 g of Orcobrite Royal blue pigment #R2008. The coated sample was dried at 150° F. (65.5° C.) for 2 hours, then cured at 300° F. (148.9° C.) for an additional 15 minutes. The coated sample had excellent dry wiping properties, low drag, and good feel. The absorbency and tensile strength data are presented in Tables 9 and 10.
TABLE 9______________________________________ g H2OSample Wet out abs/g of g H2O % H2OEx. #Description (sec) Dry wipe abs/(ft) Loss______________________________________30 Uncoated 50/50 0 22.27 170.4 50.16blend ofPVA/Cotton fibersweb: COMPARATIVE31 Coated 50/50 4 5.82 57.7 17.41blend ofPVA/Cotton fibersweb______________________________________
TABLE 10______________________________________ Tensile Strength (KPa)Ex. # Sample Description MD CD______________________________________30 Uncoated 50/50 blend of 384 411 of PVA/Cotton fibers web: COMPARATIVE31 Coated 50/50 blend of 3689 2919 PVA/Cotton fibers web______________________________________
Example 32
The nonwoven web used in Example 32 was made from rayon fibers which were 3.0 denier and 2.5 inches (6.35 cm) long from Courtaids Chemical Company, England, using a carding/crosslap/needletacking process. Its basis weight was 16.2 g/ft 2 (174.3 g/m 2 ). A 15×15 inch sample of this web (38.1×38.1 cm) was coated with a solution containing: 250 g of R1130 solution (2.5% solid in H 2 O), 0.31 g of Nalco 8676 (10% solid in H 2 O), 3.13 g of Tyzor 131 (20 wt. % in H 2 O), and 0.4 g of Orcobrite Royal blue pigment #R2008. The coated sample was dried at 150° F. (65.5° C.) for 2 hours and then at 250° F. (121.1° C.) for 2 hours, and finally at 300° F. (148.8° C.) for an additional 10 minutes. The coated sample had excellent dry wiping properties, low drag, and soft feel.
Example 33
Example 33 demonstrated the preparation of a bactericidal wipe based on iodine and the polyvinyl alcohol/polyiodide complex. A solution of 1.2 g potassium iodide, 0.64 g iodine crystals, and 50 g of water was prepared. This solution was then saturated on a wipe prepared using the procedure of Example 5. Initially, a brown color was observed where the sample had been treated. The brown color gradually changed to blue color which is a characteristic of the polyvinyl alcohol/polyiodide complex. When rinsed with water, iodine color and odor were plainly evident.
General Procedure II for Preparing Inventive Articles
Nonwoven webs consisting a blend of polyvinyl alcohol and rayon fibers (45% polyvinyl alcohol fiber having a denier of 1.5 and a length of 1.5 inch (3.81 cm) purchased from Kuraray KK, and 55% rayon fiber having a denier of 1.5 and a length of 1 and 9/16 inch (3.97 cm) purchased from BASF) were made using a web making machine known under the trade designation Rando-Webber. The resultant web had an average dry weight of 12 g/ft 2 (129 g/m 2 ) and nominal thickness of 0.056 inch (0.142 cm).
An aqueous binder precursor solution was prepared for each example containing various amounts of Airvol 165 (a 99.8% hydrolyzed polyvinyl alcohol with molecular weight 110,000 and degree of polymerization 2500, obtained from Air Products) reacted with Tyzor LA and/or Tyzor 131 and optionally, glyoxal as described in Examples 34-47 and NH 4 Cl, an acid catalyst. The binder precursor solutions also may have contained optional crosslinker(s) and pH modifiers as detailed in the Examples. A 12×15 inch (30.48×38.1 cm) piece of this nonwoven web was placed in a pan and saturated with approximately 200 g of an aqueous coating solution containing 5.00 g of total polymer.
Saturated samples were dried in a flow-through oven at 150° F. (65.5° C.), for between 30 minutes and 4 hours, and cured in a flow-through oven, preferably for greater than 10 minutes, at temperatures greater than 220° F. (104° C.). The samples were flipped every 10-30 minutes to aid in even drying conditions. When curing was completed, the samples were conditioned for 60 minutes in 60°-80° F. (15.6°-26.7° C.) tap water then dried. Samples were then analyzed for hydrophilicity, water retention and absorption, tensile strength, tear strength, and dry wiping properties.
Examples 34-38
Examples 34-38 illustrated the advantages of employing a titanate crosslinked PVA binder in wiping articles according to the invention. The wipes of Examples 34-38 were prepared as described in General Procedure II with the compositions described below at an initial coating weight of 5 g of polymeric material per 200 g solution and dried slowly at 150° F. (65.5° C.), followed by curing at 300° F. (148.9° C.). The absorbency, tensile strength, and tear data are presented in Tables 11 and 12, respectively.
TABLE 11______________________________________ Wet H.sub.2 O Eff gEx. Out % H.sub.2 O g H.sub.2 O Abs/Dry H.sub.2 O/# Description (sec.) Loss abs./ft.sup.2 wgt. (g/g) ft.sup.2______________________________________34 Airvol 165 0 20.49 157.62 6.20 116.22withoutTitanate35 Airvol 165 0 17.52 149.55 7.95 109.86with 5%Tyzor LA36 Airvol 16-5 0 13.10 142.83 7.51 101.49with 15%Tyzor LA37 Airvol 165 0 18.89 144.96 7.77 106.56with 5%Tyzor 13138 Airvol 165 0 15.79 133.47 7.21 96.06with 15%Tyzor 131______________________________________
TABLE 12______________________________________ Av. Tensile Stress Elmendorf Tear (KPa) (Damp)Ex. # Description Machine Cross Machine Cross______________________________________34 Airvol 165 2489 1999 100+ 88 without Titanate35 Airvol 165 2916 2330 100+ 69 with 5% Tyzor LA36 Airvol 165 2985 2489 83 96 with 15% Tyzor LA37 Airvol 165 2930 2296 86 93 with 5% Tyzor 13138 Airvol 165 3103 2530 75 88 with 15% Tyzor 131______________________________________
Examples 39-45
Examples 39-45 illustrated the advantages of employing a titanate, and optionally, glyoxal crosslinked PVA binder in wiping articles according to the invention. The wipes of Examples 39-45 were prepared at an initial coating weight of 5 g total PVA, 1.59 g glyoxal, and 0.25 g NH 4 Cl per 200 g solution and dried slowly at 150° F. (65.5°). The absorbency, tensile strength, and tear data are presented in Tables 13 and 14, respectively.
TABLE 13______________________________________ Wet g H.sub.2 O H.sub.2 O Eff gEx. Sample Out % H.sub.2 O Abs./ Abs/Dry H.sub.2 O/# Description (sec.) Loss ft.sup.2 wgt. (g/g) ft.sup.2______________________________________39 Airvol 165 1 14.47 125.37 7.42 88.11withGlyoxal,NH4Cl,w/outTitanate40 Airvol 165 1 14.91 124.62 7.39 87.81withGlyoxal,NH4Cl,and1% TyzorLA41 Airvol 165 1 14.65 128.88 7.34 92.64withGlyoxal,NH4Cl,and5% TyzorLA42 Airvol 165 1 14.75 130.53 7.35 93.33withGlyoxal,KH4Cl,and10% TyzorLA43 Airvol 165 1 to 25 13.83 121.05 7.34 84.36withGlyoxal,NH4Cl,and1% Tyzor13144 Airvol 165 1 to 20 15.27 128.61 7.48 91.23withGlyoxal,NR4Cl,and5% Tyzor13145 Airvol 165 1 14.58 121.92 7.27 83.97withGlyoxal,NH4Cl,and10% Tyzor131______________________________________
TABLE 14__________________________________________________________________________ Avg. Tensile Elmendorf Tear PVA Stress (KPa) (Damp)Ex. #Description Retention Machine Cross Machine Cross__________________________________________________________________________39 Airvol 165 80.5 2482 2255 98 100+withGlyoxal,NH4Cl, w/outTitanate40 Airvol 165 63 2709 2193 86 100withGlyoxal,NH4Cl, and1% Tyzor LA41 Airvol 165 91.2 2592 2055 86 96withGlyoxal,NH4Cl, and5% Tyzor LA42 Airvol 165 91.9 2758 2034 88 95withGlyoxal,NH4Cl, and10% Tyzor LA43 Airvol 165 78.2 2696 2455 97 100+with GlyoxalNH4Cl, and1% Tyzor 13144 Airvol 165 86.1 2772 2392 94 100+withGlyoxal,NH4Cl, and5% Tyzor 13145 Airvol 165 75.1 2558 2310 100+ 100+withGlyoxal,NH4Cl, and10% Tyzor131__________________________________________________________________________
Example 46
Example 46 demonstrated the ability to color the wiping articles of this invention made in accordance with General Procedure II in varying colors and shades. A binder binder precursor solution was prepared consisting of 100 g 5 wt. % Airvol 165, 1.68 g Tyzor LA, 0.03 g, 0.06 g, 0.13 g, 0.25 g, or 0.5 g pigment dispersion, and deionized water to achieve a total solution weight of 200 g for each run. The binder precursor solution was coated onto a 12×15 inch (30.48 cm×38.1 cm) piece of PVA/rayon nonwoven produced as described in General Procedure II, dried at 120° F. (48.9° C.) for 2 hours, and finally cured for one hour at 140° F. (57.0° C.). Upon completion of run, the samples were conditioned for 60 minutes in 60°-80° F. (140°-176° C.) water and dried. Results are shown below.
______________________________________Pigment, Amount Results______________________________________"Orcobrite Red BN", Good color and fastness.0.03 to 0.5 g"Orcobrite Yellow Good color and fastness.2GN", 0.03 to 0.5 g"Orcobrite Green BN", Good color and fastness0.03 to 0.5 g"Aqualor Green" Good color, binder washout."Aqualor Blue" Good color, binder washout.______________________________________
The aqueous pigment dispersions known under the trade designation "Aqualor" were obtained from Penn Color (Doylestown, Pa.), while those known under the trade designation Orcobrite aqueous pigment dispersions were obtained from Organic Dyestuffs (Concord, N.C.). Good results were obtained with a wide variety of the "Orcobrite" series of pigments. A major difference between the "Aqualor" and "Orcobrite" pigment dispersions, as supplied, was the substantially higher alkalinity of "Aqualor" pigment dispersions, perhaps leading to insufficient cure by the titanate crosslinking agent. Generally speaking it was found that the best results with regard to coloring were obtained at cure temperatures of 240°-250° F. (115.6°-121° C.), although higher temperatures were also useful.
Example 47
Example 47 demonstrated the ability to impregnate the synthetic wipes of the invention made in accordance with General Procedure II with a number of antibacterial, antifungal, and disinfecting solutions for use in the health care, business, and/or food service trades. A nonwoven produced in accordance with General Procedure II was saturated with an aqueous solution containing 1.2 g potassium iodide, 0.64 g solid iodine crystals, and 50 g deionized water.
Initially, a brown color was observed where the sample had been treated. The brown color gradually changed to blue, characteristic of the polyvinyl alcohol/polyiodide complex. When the article was rinsed with water, the iodine color and odor were plainly evident.
General Procedure III for Preparing Inventive Articles
A 12 by 15 inch (30.48×38.1 cm) piece of polyvinyl alcohol/rayon (45% polyvinyl alcohol fiber having a denier of 1.5 and a length of 1.5 inch (3.81 cm) purchased from Kuraray KK, and 55% rayon fiber having a denier of 1.5 and a length of 19/16 inch purchased from BASF) blended nonwoven fiber substrate (thickness=56 mil (0.142 cm), basis weight =11.5 g/ft 2 (123.8 g/m 2 ), prepared using a web marking of Rando-Webber) was placed in a pan and saturated with 200 g of an aqueous binder precursor solution containing 5.00 g total polyvinyl alcohol and polyacrylic acid, prepared by mixing a 5% aqueous solution of "Airvol 165" with a 2.5% aqueous solution of the polyacrylic acid. "Airvol 165" (a 99.8% hydrolyzed polyvinyl alcohol, MW=110,000, DP=2500 obtained from Air Products) was used in combination with polyacrylic acid (750,000 MW, Aldrich Chemical Co.). The binder precursor solution pH was adjusted with 85% phosphoric acid. The sample and tray were placed in a flow through drying oven at 120°-150° F. (48.9°-65.5° C.) for 2 hours followed by curing at 300° F. (148.9° C.) as specified in Table 15. The samples were flipped over after about 30 minutes and 60 minutes to aid in maintaining even drying. When curing was completed the samples were conditioned for 60 minutes in 60°-80° F. water then dried.
Examples 48-62
Example wipes 48-62 were made in accordance with General Procedure III at the conditions specified in Table 15, and subsequently analyzed for wet out, absorptivity, tensile strength, tear strength, and dry wiping properties. The test results are presented in Tables 16-17. Examples 48-62 each contained 0.1 g "Orcobrite Yellow 2GN 9000" (a yellow pigment, available from Organic Dyestuffs, Corp.).
TABLE 15__________________________________________________________________________ % Coating Conditioned Loss During Coat Wt.Ex. # Description Cure Conditions Conditioning (g/m.sup.2)__________________________________________________________________________48 Polyacrylic 2 HR 120° F. 4 40.5 Acid, pH = 3.0, (48.9° C.)/ COMPARATIVE 5 MIN 300° F. (148.9° C.)49 Airvol 165 2 HR 20° F. 1 48.4 (polyvinyl (48.9° C.)/ alcohol), 5 MIN 300° F. pH = 3.0, (148.9° C.) COMPARATIVE50 1 part 2 HR 120° F. 0 49.5 Polyacrylic (48.9° C.) acid/ 5 MIN 300° F. 2 parts Airvol (148.9° C.) 165, pH = 3.051 1 part 2 HR 120° F. 0 48.2 Polyacrylic (48.9° C.)/ acid/ 5 MIN 300° F. 3 parts Airvol (148.9° C.) 165, pH = 3.052 1 part 2 HR 120° F. 0 56.9 Polyacrylic (48.9° C.)/ acid/ 5 MIN 300° F. 5 Parts Airvol (148.9° C.) 165, pH = 3.053 1 part 2 HR 120° F. 0 58.5 Polyacrylic (48.9° F.)/ acid/ 5 MIN 300° F. 10 parts Airvol (148.9° C.) 165, pH = 3.054 1 part 2 HR 150° F. 0 52.4 Polyacrylic (65.6° C.)/ acid/ 5 MIN 300° F. 99 parts Airvol (148.9° C.) 165, pH = 3.555 1 part 2 HR 50° F. 0 51.6 Polyacrylic (65.6° C.)/ acid/ 15 MIN 300° F. 99 parts Airvol (148.9° C.) 165, pH = 3.556 1 part 2 HR 150° F. 0 55.4 Polyacrylic (65.6° C.)/ acid/ 25 MIN 300° F. 99 parts Airvol (148.9° C.) 165, pH = 3.557 0.1 part 2 HR 150° F. 1 49.5 Polyacrylic (65.6° C.)/ acid/ 5 MIN 300° F. 99 parts Airvol (148.9° C.) 165, pH = 3.558 0.5 part 2 HR 50° F. 1 53.5 Polyacrylic (65.6° C.)/ acid/ 5 MIN 300° F. 99 parts Airvol (148.9° C.) 165, pH = 3.559 1 part 2 HR 150° F. 0 55.4 Polyacrylic (65.6° C.)/ acid/ 5 MIN 300° F. 99 parts Airvol (148.9° C.) 165, pH = 3.560 1 part 2 HR 150° F. 0 49.7 Polyacrylic (65.6° C.)/ acid/ 5 MIN 300° F. 99 parts Airvol (148.9° C.) 165, pH = 4.061 1 part 2 HR 150° F. 0 52.3 Polyacrylic (65.6° C.)/ acid/ 5 MIN 300° F. 99 parts Airvol (148.9° C.) 165, pH = 4.662 1 part 2 HR 150° F. 1 48.3 Polyacrylic (65.6° C.)/ acid/ 5 MIN 300° F. 99 Parts Airvol (148.9° C.) 165, pH = 3.3__________________________________________________________________________
TABLE 16______________________________________Tensile TensileStrength Strength Elmendorf ElmendorfMachine Cross Web Tear Test Tear TestEx. Direction Direction (Machine (Cross Web % H.sub.2 O# (KPa) (KPa) Direction) Direction) Loss______________________________________48 1910 1014 65 73 1149 3054 2240 53 90 1150 2937 2420 54 100+ 1051 3296 2117 74 86 1152 2379 1751 87 100+ 1153 2779 1813 81 82 1354 2772 2737 96 100+ 1855 2958 2565 77 100+ 2056 2854 2399 79 90 2157 2758 2365 91 100+ 1658 2523 2324 88 100+ 1859 2723 2461 85 100+ 2060 2737 2392 89 100+ 2261 2785 2358 87 100+ 2262 2909 2275 90 100+ 19______________________________________
TABLE 17______________________________________ Total H.sub.2 O Abs. H.sub.2 O Abs./Dry Eff. H.sub.2 O Abs.Ex. # (g/ft.sup.2) Wt. (g/g) (g/ft.sup.2)______________________________________48 175.7 9.70 105.249 137.7 7.70 98.950 142.7 7.63 101.151 139.4 7.27 94.552 126.2 6.13 84.953 136.3 6.67 96.354 158.7 7.78 114.055 157.0 8.03 111.456 156.0 7.46 111.157 148.6 7.41 105.058 159.7 7.86 115.359 160.9 8.31 116.760 158.7 8.55 116.161 162.1 8.21 118.362 150.8 7.76 108.7______________________________________
Example 63
This example demonstrated the preparation of a bactericidal wipe based on iodine and a polyvinyl alcohol/polyiodide complex, and made in accordance with General Procedure III. A solution of 1.2 g potassium iodide, 0.64 g iodine crystals, and 50 g water was prepared. This solution was coated onto a sample of 1:2 polyacrylic acid/polyvinyl alcohol wipe prepared as in General Procedure III above. Initially, a brown color was observed where the sample had been treated. The brown color gradually changed to blue characteristic of the polyvinyl alcohol/polyiodide complex. When rinsed with water iodine color and odor were plainly evident.
General Procedure IV for Preparing Inventive Articles
A 12 by 15 inch (30.48×38.1 cm) piece of polyvinyl alcohol/rayon (45% polyvinyl alcohol fiber having a denier of 1.5 and a length of 1.5 in (3.81 cm) purchased from Kuraray KK, and 55% rayon fiber having a denier of 1.5 and a length of 1.56 inch (3.96 cm) purchased from BASF) blended nonwoven fiber substrate (thickness=56 mil (0.142 cm), basis weight 11.5 g/ft 2 (123.8 g/cm 2 ), prepared using a web making machine known under the trade designation "Rando-Webber") was placed in a pan and saturated with 200 g of an aqueous binder precursor solution containing 5.00 g total polyvinyl alcohol. "Airvol 165" (a 99.8% hydrolyzed polyvinyl alcohol, MW=110,000, DP=2500 obtained from Air Products) was used in combination with syndiotactic polyvinyl alcohol prepared in Example 64 to comprise the polyvinyl alcohol content in Examples 65-91. The binder precursor solutions may also have contained optional crosslinker(s), and pH modifiers depending on the Example. The sample and tray were placed in a flow through drying oven at 120°-50° F. (48.9°-65.6° C.) for 3 to 4 hours as specified. The samples were flipped over after about 30 minutes and 60 minutes to aid in maintaining even drying. When curing was completed the samples were conditioned for 60 minutes in 60°-80° F. (15.6°-26.7° C.) water then dried. Samples were then analyzed for wet out, absorptivity, tensile strength, tear strength, and dry wiping properties, with the results reported in Tables 18-27.
Example 64
Preparation of Syndiotactic PVA
This example illustrated the preparation of syndiotactic polyvinyl alcohol employed in Examples 65-91.
The polyvinyl trifluoroacetate (PVTFA) copolymer described above (300 g) was dissolved in 700 g acetone. This solution was slowly added to 1700 g of 10% methanolic ammonia that had been cooled in ice to 15° C. Despite vigorous mechanical stirring a large ball of solid material formed on the stirrer blade making stirring ineffective. After addition was complete the ball of material was broken up by hand and the mixture was shaken vigorously. The process was repeated twice more (elapsed time was about 3 hr). The divided mass was vigorously mechanically stirred for 20 minutes and allowed to stand at room temperature overnight.
The supernatant liquid was decanted off leaving a mixture of white powder and yellow fibrils. The solids were collected by filtration and spread in a tray at 15.6° C. to evaporate residual solvent. The solids were collected when constant weight over 2 hr was achieved. The solid was chopped in a blender to give 87.3 g of beige powder, 92% yield, referred to hereinafter as "Syn". Analysis of this material was carried out using IR and 1 H NMR spectroscopy, and Gel Permeation Chromatography. The results indicated the likely presence of traces of trifluoroacetate esters and salts. The triad syndiotacticity measured by 1 H NMR in DMSO-d 6 was 33%, atacticity=50%, isotacticity=17%, The difference between the hydrolyzed polymer and the trifluoroacetate precursor polymer may be due to acid catalyzed epimerization of hydroxyl groups during drying or solution in boiling water.
Examples 65-70
Examples 65-70 illustrated the advantages of employing syndiotactic polyvinyl alcohol alone or in blends with atactic polyvinyl alcohol in wiping articles according to the invention. The articles were prepared at an initial coating weight of 5 g total PVA/200 g solution. Curing conditions were 4 hr at 48.9° C.
TABLE 18__________________________________________________________________________ Tensile Tensile % Coating Strength Strength Weight Elmendorf Machine Cross Loss Tear Direct- Direct- During Machine ElmendorfEx. Descrip- ion ion Condition- Direc- Tear Cross# tion (KPa) (KPa) ing tion Direc-tion__________________________________________________________________________65 100% 2061 1131 10.1 63(5) 95(7) AIRVOL 16566 99% 2186 1496 8.9 79(2) 100+ AIRVOL 165:1% Syn67 95% 2029 1427 8.4 74(7) 89(0) AIRVOL 165:5% Syn68 90% 2475 1799 7.8 75(4) 86(7) AIRVOL 165:10% Syn69 80% 2109 1510 6.2 100+ 95(4) AIRVOL 165:20% Syn70 100% Syn 2661 1979 5.5 100+ 91(0)__________________________________________________________________________
TABLE 19__________________________________________________________________________ Water Total Absorption/ Effective Water Dry wt. WaterEx. Descrip- Wet Out % Water Absorption of Sample Absorption# tion (sec) Loss (g/ft.sup.2) (g/g) (g/ft.sup.2)__________________________________________________________________________65 100% 0 17.4 134.52 7.92 99.60 AIRVOL 16566 99% 0 20.0 150.09 8.38 112.50 AIRVOL 165:1% Syn67 95% 0 15.0 136.17 7.81 99.90 AIRVOL 165:5% Syn68 90% 0 14.8 130.50 7.63 95.40 AIRVOL 165:10% Syn69 80% 0 15.8 131.58 7.14 94.80 AIRVOL 165:20% Syn70 100 2 16.8 143.25 7.33 106.71 Syn__________________________________________________________________________
Examples 71-83
These examples demonstrated the use of syndiotactic polyvinyl alcohol with chemical crosslinkers (Tyzor LA and/or glyoxal) in wiping articles according to the invention. Curing conditions were 3.5 hr at 150° F. (65.5° C.). Mole % crosslinking amounts for Tyzor LA were based on four bonds between titanium and polyvinyl alcohol. Mole % crosslinking amounts for glyoxal were based on four bonds between glyoxal and polyvinyl alcohol.
TABLE 20__________________________________________________________________________ Water Total Absorption/ Effective Water Dry wt. WaterEx. Descrip- Wet Out % Water Absorption of Sample Absorption# tion (sec) Loss (g/ft.sup.2) (g/g) (g/ft.sup.2)__________________________________________________________________________71 1% Blend 0 25.1 129.2 8.65 119.49 of Syn in Airvol 165 with 20 mol % Tyzor LA crosslinking72 1% Blend 0 20.1 137.4 8.12 117.36 of Syn in Airvol 165 with 20 mol % Tyzor LA crosslinking73 5% Blend 0 16.9 134.7 7.71 106.92 of Syn in Airvol 165 with 20 mol % Tyzor LA crosslinking74 5% Blend 0 17.8 135.2 7.62 108.00 of Syn in Airvol 165 with 20 mol % Tyzor LA crosslinking75 10% Blend 0 21.7 128.4 7.96 110.28 of Syn in Airvol 165 with 20 mol % Tyzor LA crosslinking__________________________________________________________________________
TABLE 21__________________________________________________________________________ Water Total Absorption/ Effective Water Dry wt. WaterEx. Descrip- Wet Out % Water Absorption of Sample Absorption# tion (sec) Loss (g/ft.sup.2) (g/g) (g/ft.sup.2)__________________________________________________________________________76 10% Blend 0 18.2 133.8 7.70 108.2 of Syn in Airvol 165 with 20 mol % Tyzor LA crosslinking77 1% Blend 0 15.6 137.8 8.42 107.7 of Syn in Airvol 165 with 40 mol % Glyoxal crosslinking78 1% Blend 0 17 139.4 8.58 111.4 of Syndio- tactic in Airvol 165 with 40 mol % Glyoxal crosslinking79 5% Blend 0 15.8 145.4 8.35 114.7 of Syndio- tactic in Airvol 165 with 40 mol % Glyoxal crosslinking80 5% Blend 0 17.3 139.7 8.80 113.3 of Syndio- tactic in Airvol 165 with 40 mol % Glyoxal crosslinking81 10% Blend 0 11.2 144.5 8.40 107.1 of Syndio- tactic in Airvol 165 with 40 mol % Glyoxal crosslinking82 10% Blend 0 16.9 154.8 8.30 122.3 of Syndio- tactic in Airvol 165 with 40 mol % Glyoxal crosslinking83 10% Blend 0 13.1 141.9 7.46 105.2 of Syndio- tactic in Airvol 165__________________________________________________________________________
TABLE 22______________________________________ Tensile Tensile Strength Strength % Coating Machine Cross Weight Loss Direction Direction DuringEx. # Description (KPa) (KPa) Conditioning______________________________________71 1% Blend of 2158 2082 4.3 Syn in Airvol 165 with 20 mol % Tyzor LA crosslinking72 1% Blend of 2971 1724 4.2 Syn in Airvol 165 with 20 mol % Tyzor LA crosslinking73 5% Blend of 2572 2199 4.4 Syn in Airvol 165 with 20 mol 5 Tyzor LA crosslinking74 5% Blend of 2737 1979 4.5 Syn in Airvol 165 with 20 mol % Tyzor LA crosslinking______________________________________
TABLE 23______________________________________ Tensile Tensile Strength Strength % Coating Machine Cross Weight Loss Direction Direction DuringEx. # Description (KPa) (KPa) Conditioning______________________________________75 10% Blend of 2475 1944 5.1 Syn in Airvol 165 with 20 mol % Tyzor LA crosslinking76 10% Blend of 2910 2240 4.8 Syn in Airvol 165 with 20 mol % Tyzor LA crosslinking77 1% Blend of 2820 1889 3.3 Syn in Airvol 165 with 40 mol % Glyoxal crosslinking78 1% Blend of 2351 -- 3.5 Syndiotactic in Airvol 165 with 40 mol % Glyoxal crosslinking79 5% Blend of 2492 2006 3.2 Syndiotactic in Airvol 165 with 40 mol % Glyoxal crosslinking80 5% Blend of 2199 1841 3.5 Syndiotactic in Airvol 165 with 40 mol % Glyoxal crosslinking81 10% Blend of 2227 1696 3.5 Syndiotactic in Airvol 165 with 40 mol % Glyoxal crosslinking62 10% Blend of 2379 1786 3.0 Syndiotactic in Airvol 165 with 40 mol % glyoxal crosslinking83 10% Blend of 2365 1696 1.8 Syndiotactic in Airvol 165______________________________________
Examples 84-86
Examples 84-86 demonstrated the effect of coat weight on wiping parameters of articles made in accordance with General Procedure IV. A binder precursor solution consisting only of 30% syndiotactic PVA was coated onto nonwoven substrates at various coating weights (i.e., 1 g, 2 g, 5 g total PVA in coating solution) as indicated in Tables 24 and 25, which also present the absorbency and strength test results.
TABLE 24__________________________________________________________________________ Tensile Tensile % Strength Strength Weight Elmendorf Machine Cross Loss Tear Direct- Direct- During Machine ElmendorfEx. Descrip- ion ion Condition- Direc- Tear Cross# tion (KPa) (KPa) ing tion Direction__________________________________________________________________________84 5 g:100% 2661 ± 1979 ± 5.5 100+ 91 ± 0 Syn 117 6985 2 g:100% 2006 ± 1351 ± 3.3 75 ± 6 96 ± 2 Syn 131 3486 1 g:100% 1441 ± 1186 ± 2.9 84 ± 9 100+ Syn 138 89__________________________________________________________________________
TABLE 25__________________________________________________________________________ Water Total Absorption/ Effective Water Dry wt. WaterEx. Descrip- Wet Out % Water Absorption of Sample Absorption# tion (sec) Loss (g/ft.sup.2) (g/g) (g/ft.sup.2)__________________________________________________________________________84 5 g:100% 2 16.8 143.25 7.33 106.71 Syn85 2 g:100% 0 18.2 146.31 8.31 116.40 Syn86 1 g:100% 0 20.5 157.68 10.43 127.62 Syn__________________________________________________________________________
Examples 87-89
Examples 87-89 demonstrated the results of direct ammonolysis of polyvinyl trifluoroacetate after the binder precursor solutions was coated on the nonwoven substrate. The absorbency and strength of these articles (Tables 26 and 27) were superior to those of 30% syndiotactic polyvinyl alcohol coated from water described in the preceding examples. One explanation of the benefits observed is that acid catalyzed loss of syndiotacticity was minimized by use of this method which probably provided greater surface area for ammonolysis.
TABLE 26______________________________________ Tensile Tensile Strength Strength % Machine Cross Weight Loss Direction Direction DuringEx. # Description (KPa) (KPa) Conditioning______________________________________87 16 g 3744 3041 0 PVTFA/ ammonolyzed (5 g PVA)88 6.5 g 2544 2082 0 PVTFA/ ammonolyzed (2 g PVA)89 3.2 g 1551 1165 0 PVTFA/ ammonolyzed (1 g PVA)______________________________________
TABLE 27__________________________________________________________________________ Water Total Absorption/ Effective Water Dry wt. WaterEx. Descrip- Wet Out % Water Absorption of Sample Absorption# tion (sec) Loss (g/ft.sup.2) (g/g) (g/ft.sup.2)__________________________________________________________________________87 16 g 0 22.5 114.4 5.86 81.5 PVTFA/ ammono- lyzed (5 g PVA)88 6.5 g 0 23.0 143.2 7.90 107.6 PVTFA/ ammono- lyzed (2 g PVA)89 3.2 g 0 30.1 166.2 9.82 134.1 PVTFA/ ammono- lyzed (1 g PVA)__________________________________________________________________________
Example 90
This example demonstrated the preparation of a bactericidal wipe based on iodine and the polyvinyl alcohol/polyiodide complex utilizing General Procedure IV. A solution of 1.2 g potassium iodide, 0.64 g iodine crystals, and 50 g water was prepared. This solution was coated onto a sample of a wipe as prepared in Examples 84-86. Initially, a brown color was observed where the sample had been treated. The brown color gradually changed to blue characteristic of the polyvinyl alcohol/polyiodide complex. When rinsed with water iodine color and odor were plainly evident.
Example 91
A sample containing 5 g 30% syndiotactic PVA as the only binder Component in 200 g total solution was prepared and coated as in Examples 84-86 containing 0.1 g "Orcobrite Blue 2GN" pigment (Organic Dyestuffs Corp., Concord, N.C.). The sample was cured at 250° F. (121° C.) for 2 hours. The sample discolored slightly and had a strong odor, but was colorfast after conditioning in luke-warm water for 2 hours.
Various modifications and alterations of this invention will become apparent to those skilled in the art without departing from the scope of the invention, and it should be understood that this invention is not to be unduly limited to the illustrated embodiments set forth herein.
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Nonwoven articles having high durability and absorbent characteristics, and their methods of manufacture, are presented. One preferred article is characterized by
(a) a nonwoven web comprised of organic fibers comprised of polymers having a plurality of pendant hydroxyl groups; and
(b) a binder comprising an at least partially crosslinked and at least partially hydrolyzed polymeric resin having a plurality of pendant resin hydroxyl groups, the resin crosslinked by a crosslinking agent, the crosslinking agent selected from the group consisting of organic titanates and amorphous metal oxides, the polymeric resin derived from monomers selected from the group consisting of monomers within the general formula ##STR1## wherein: X is selected from the group consisting of Si(OR 4 OR 5 OR 6 ) and O(CO)R 7 ; and
R 1 -R 7 inclusive are independently selected from the group consisting of hydrogen and organic radicals having from 1 to about 10 carbon atoms, inclusive, and combinations thereof.
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This is a division, of application Ser. No. 07/920,407, filed Jul. 27,1992, now U.S. Pat. No. 5,277,746.
TECHNICAL FIELD OF THE INVENTION
The present invention relates to reactor chambers and methods and, more particularly, to a high pressure liquid phase epitaxial reactor chamber and method with direct see through capability.
BACKGROUND OF THE INVENTION
A technique used in semiconductor materials manufacturing is thin film growth in a liquid phase epitaxial (LPE) reactor with a mercury-rich melt. By a process well known in the art, a cadmium zinc telluride substrate is exposed to a solution comprising tellurium, mercury and cadmium. This process requires a system capable of withstanding the high mercury vapor pressures that occur at growth temperatures in the approximate range of 500° C., which are required to maintain the crystal growth solution in a molten form. To contain these pressures, the growth chamber of a conventional reactor is normally built from stainless steel, instead of the quartz growth chambers that can be used for low pressure reactors. These steel designs of conventional reactors provide little or no visibility of the film growth process.
Because it would be desirable to view and monitor the film growth in process, the steel chambers currently available may offer ports to view the film growth operations from the top of the chamber or from a side port using a mirror located at the top of a chamber. However, these techniques do not offer optimal visibility in that the distance from the melt to the viewing device is relatively large and the vertical vapor activity from the melt makes it difficult to see the melt across the vertical distance without interference. A quartz washer may be suspended above the melt to reduce the vertical vapor activity; but the presence of the washer may distort the viewing. Additionally, using a mirror to view the melt is awkward and leads to difficulty and complexity in the design and operation of a high pressure reactor. Finally, little external lighting is provided in current reactors, thereby making viewing of the film growth process difficult.
It has therefore become desirable to devise a reactor to allow for direct observation of film growth operations in a high pressure liquid phase epitaxy reactor. A technique for directly viewing growth operations from the side of the reactor chamber, previously not possible, will be discussed in this disclosure.
SUMMARY OF THE INVENTION
According to the invention, a high pressure liquid phase epitaxial (LPE) reactor chamber and method is provided having an opening which provides direct observation of the crystal growth process.
According to one aspect of the invention, a high pressure reactor chamber includes an enclosed reactor tube formed of inert material capable of withstanding high pressures, a transparent growth tube disposed within the reactor tube, and a crucible having transparent sidewalls capable of holding molten melt, disposed within the growth tube. The reactor tube has a first opening in a sidewall that includes a transparent sealed plate, such that the molten melt may be viewed through the opening. The reactor tube may also have second window located approximately radially adjacent the first window for projecting light to illuminate the visible surface of the melt. Preferably, the first and second windows are welded to the chamber at an angle. The reactor tube and growth tube include structure for gaining entry, such as for introducing a substrate, to the melt.
According to another aspect of the invention, the growth tube may include a reservoir, typically of mercury, located in its lower sealed end. The reactor tube may then include a lower set of windows located radially adjacent to each other, and lateral to the reservoir. One or more openings having windows may be provided, the first being used for viewing the reservoir level and the second for illuminating the surface of the reservoir. In this instance, these windows will also be capable of withstanding high pressures.
According to yet another aspect of the invention, a molten melt may be held directly in the lower sealed end of the growth tube. According to this aspect, no crucible is used. As described above, one or more openings having windows capable of withstanding high pressures may be provided for illuminating and viewing the melt.
The present invention confers several technical advantages over high pressure reactor chambers presently available in the art. The distance from the melt to the viewing device is relatively small. The invention provides the opportunity for direct observation of the crystal growth process. Any vertical vapor activity from the melt has little effect on the viewing capability. Direct illumination makes viewing the crystal growth easy. Direct observation of the growth provides consistently better quality LPE melts that are easier to use because the growth setup and operation is easier.
BRIEF DESCRIPTION OF THE DRAWINGS
Other aspects of the invention and their advantages will be discerned when one refers to the following detailed description as taken in conjunction with the drawings, in which:
FIG. 1 is a cross-sectional, foreshortened view of the high pressure reactor tube assembly according to one aspect of the invention;
FIG. 2 is a cross-sectional, foreshortened view of the high pressure reactor tube assembly according to another aspect of the invention;
FIG. 3 is a cross-sectional view of a viewport assembly as shown in FIG. 1; and
FIG. 4 is a highly magnified cross-sectional view of a reflux assembly as shown in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiment of the present invention is best understood by referring to FIGS. 1-4 of the drawings, like numerals being used for like and corresponding parts of the various drawings.
FIG. 1 is a foreshortened, cross-sectional view of a vertically oriented high pressure reactor tube assembly according to one embodiment of the invention, indicated generally at 10. The assembly 10 includes an enclosed reactor tube 12, capable of withstanding high pressures. Transparent growth tube 14 is disposed within reactor tube 12. Growth tube 14 has an open first end 16 and a sealed second end 18. Transparent crucible 20 is disposed within growth tube 14. Crucible 20 is capable of holding a molten melt 22 having a visible surface 24. A first viewport assembly 26, having a transparent sealed plate 28, is located in a sidewall of reactor tube 12, such that the molten melt may be viewed through the viewport assembly. The inside diameter of reactor tube 12 is larger than the outside diameter of growth tube 14, forming a cavity 30. Multi-zone furnace 32, described infra, is vertically oriented within cavity 30 and surrounds growth tube 14.
A reservoir 34, preferably of mercury, may be located in sealed end 18 of growth tube 14. A viewport assembly 36, having a transparent sealed plate 38, may be located in the sidewall of reactor tube 12 to enable viewing of reservoir 34. Reflux assembly 40, described infra, is located near the open end 16 of growth tube 14. Reflux assembly 40 aids in cooling the upper portion of assembly 10, above furnace 32.
FIG. 2 is a foreshortened, cross-sectional view of a vertically oriented high pressure reactor tube assembly according to a second embodiment of the invention, indicated generally at 10. The assembly 10 includes reactor tube 12 having a growth tube 14 disposed within, as described in connection with FIG. 1, supra. However, unlike FIG. 1, a molten melt 42 having a visible surface 44 is located in sealed end 18 of growth tube 14, and no crucible 20 is used. Viewport assembly 36, having a transparent sealed plate 38, may then be used to observe the surface 44 of melt 42.
FIG. 3 illustrates a representative viewport assembly 26 located in the mid-portion of assembly 10. Viewport assembly 26, having sealed transparent plate 28, is formed in a sidewall of reactor tube 12 to enable viewing of the crucible 20, which contains the molten melt 22. Melt 22, in the preferred embodiment, includes predominately mercury, i.e., greater than 33.33 mole percent. The composition of the melt 22 is predetermined to provide the desired composition of the mercury cadmium telluride layer to be formed, described infra. Crucible 20 is supported by pedestal 46 within growth tube 14. Pedestal 46 can be of any design such that it holds crucible 20. Pedestal 46 is typically made of inert material and, preferably, is made of quartz rod.
A second viewport assembly 48 also having a transparent sealed plate 50 may be located approximately radially adjacent viewport assembly 26. In the process of the operation, a camera 52 may be located adjacent viewport 26 directed toward surface 22. Contemporaneously, a light source 54 may be located adjacent viewport 48 and directed to illuminate surface 22. As shown in FIG. 1, viewports 26 and 48 may be attached to reactor tube 12 at angles 56 and 58, respectively. Angles 56 and 58 may be determined such that optimal viewing and illumination of melt surface 44 is achieved.
A vertically-oriented furnace 32, located in cavity 30, surrounds the lower and middle portion of growth tube 14. Furnace 32 is a multi-zone furnace, preferably made of quartz, such as is well-known in the art of reactor chambers. A gold film 60 is deposited on the inside of the outermost wall 62 of furnace 32 such that much of the heat in growth tube 14 is reflected back into the tube 14. Gold film 60 does not interfere with viewing surface 24 if enough external lighting is provided via source 54.
The furnace 32 is heated by passing a controlled current through heating elements 64, which surround the outside circumference of quartz tube 14, to create the desired plurality of heating zones. Multi-zone furnace 32 allows for accurate control of the temperature of melt 22 and reservoir 34, critical to the crystal growth process and the melt composition. Temperatures of the melt 22 and reservoir 34 may range from approximately 200° C. to 520° C. Additionally, this control system provides the capability of dynamically changing the temperature of the system as desired and provides flexibility in profiling the system.
The presence of reservoir 34 provides a source of pure mercury that can be used to adjust the mercury composition of melt 22, described herein. When crucible 20 is used along with mercury reservoir 34, viewport assembly 36 may be used to monitor the level of mercury in reservoir 34. Viewport assembly 37 (as shown in FIG. 1) located approximately radially adjacent viewport 36, may be provided to allow illumination of reservoir 34.
If increasing the concentration of mercury in melt 22 is desired, reservoir 34 may be heated, causing vapors to rise into the upper portion of growth tube 14. This process may be referred to as "driving the mercury". As the lower section of furnace 32 is heated, mercury from reservoir 34 converts from liquid to vapor and rises through tube 14. By not heating the furnace elements 64 located in the upper portion of tube 14 as much as those adjacent reservoir 34, in combination with the cooling effects of the reflux assembly 40, the vapor condenses and mercury droplets fall into melt 22, thereby increasing the concentration of mercury of the melt 22. The mercury can be driven from the reservoir 34 to the melt 22, as described, or vice versa, to adjust the melt composition.
When "driving" the mercury from the reservoir 34 to the melt 22, a quartz washer 66 may be placed between the outside of crucible 20 and the inside of tube 14. Optional washer 66 has holes large enough through which vapors may pass, but as the vapors cool, the condensed droplets will fall, hit the washer 66 and eventually fall into the melt 22.
The sealed end 18 of tube 14 is supported by stand 67. Stand 67 provides adjustment of the melt surface relative to the furnace elements (specifically, their transition points). This adjustment can only be made with the reactor shut down and partially disassembled. The stand's main purpose is to provide a structure to support the weight of the growth tube 14 and its contents, which can be substantial, along with the weight of the furnace assembly. Stand 67 can be made of any suitable inert material.
FIG. 4 is a highly magnified cross-sectional view of reflux assembly 40. Reflux assembly 40 uses a water mixture to cool the upper portion of growth tube 14, above furnace 32. The coolant, preferably at an approximate temperature of 0° C., enters the reflux assembly 40 through an inlet 70, circulates through a cavity 72 and exits through an outlet 74. A tube 76 diverts the coolant to the bottom of reflux assembly 40. Tube 76 ensures that the coolant chills the complete interior surface of reflux assembly 40. Collar 78, preferably made of quartz, has a beveled surface 80, which helps to prevent condensed mercury from collecting between tubes 12 and 14 and above reflux assembly 40.
Flange 82 is shown located above reflux assembly 40. Inlet port 84 is located in flange 82, through which hydrogen gas (H 2 ) is introduced into the growth tube 14. Hydrogen is passed continuously through growth tube 14 during the entire crystal growth process. The hydrogen assists in keeping the composition from being degraded or contaminated. An outlet port 86 is provided through which the H 2 may exit.
The present invention recognizes that unique structure must be provided to allow the growth chamber 14 to be made from quartz. In particular, the cavity 30 between the growth tube 14 and the reactor tube 12 must be pressurized to a pressure approximately equivalent to the pressure inside the growth chamber. Transducers located near the reactor monitor the differential pressure across the quartz growth chamber. Pressure control is automatically done to keep the differential pressure small, thereby avoiding burst. To assist, in keeping the reactor tube 12 cool, nitrogen enters the lower portion of assembly 10 through port 68 and circulates throughout open areas. Nitrogen exits through port 69.
Viewport assemblies 26, 36, 37 and 48 are all formed in substantially the same manner. Each viewport is attached to an opening in tube 12 in any conventional manner. A sealed transparent plate is connected to the assembly to provide for viewing or for illuminating the melt or reservoir located within tube 14, as the case may be.
In practicing the process of the present invention using the apparatus described in FIGS. 1-4, a mercury-rich melt of predetermined composition is placed in transparent crucible 20, which is disposed within growth tube 14. Both crucible 20 and tube 14 are preferably made of quartz. Multi-zone furnace 32 is heated by passing a controlled current through the plurality of separately wound heating elements 64. A coolant, such as a water and anti-freeze mixture, is circulated through the reflux assembly 40 via the inlet 70 and the outlet 74.
Referring now back to FIG. 1, gate valve 88 is available for receiving a vertical rod 90. Rod 90 includes a wafer (not shown), which is lowered into the crucible 20.
The desired mercury cadmium telluride layer may be grown by any known process including lowering the wafer below surface 22, holding the wafer in a vertical position, or floating the wafer on surface 22 for a predetermined period of time. The melt is cooled below its liquidus temperature, discussed infra, at a predetermined rate sufficient to cause crystal growth of a layer of mercury cadmium telluride on the wafer. Cooling of the melt 22 is achieved by proper control of the current provided to the multi-zone furnace 62, with reduced current input providing reduced heating (i.e., cooling) of the melt 22. The transition from liquid to solid is approximately in the 400° C. range. The transition temperature may vary ±100° C. depending on the composition.
Direct viewing of the melt is most important during the pre-growth setup, i.e., the liquidus temperature determination. Liquidus determination is very much operator dependant, and requires the visual access to the melt surface that this invention provides. Liquidus determination is critical to LPE growth. The liquidus temperature must be accurately determined in order to (1) grow a good quality film on the wafer and (2) prevent etching back too much of the wafer material, thus shifting the melt composition. During setup, the melt is heated several degrees above the liquidus temperature of the previous run, and then cooled at small temperature increments. During cooling, the formation of crystal growth on the melt surface is monitored, which then determines the liquidus temperature. When the layer of mercury cadmium telluride has been deposited to the desired thickness, the wafer is removed from melt 22, and the crystal growth process is concluded.
By the process of the preferred embodiment of the present invention the high pressure viewport assemblies allow illumination and direct observation of the film growth and/or the reservoir bath. The transparent sealed plates, preferably made of quartz, are capable of withstanding the high pressures associated with this process. The distance from the viewport assembly 26 to the melt surface 24 is relatively short, thereby providing minimal interference from any vertical vapor activity associated with the melt.
The apparatus and process of the present invention provide a crystal growth melt such that its composition is more easily maintained, which enables the formation of more uniform and reproducible layers of mercury cadmium telluride. This composition is achieved by maintaining the volatile mercury within the crystal growth system. The condensed mercury can be driven from the reservoir to the melt, or vice versa, between growths to adjust the melt composition.
This invention was designed for a particular thin film growth reactor, but the concept could be applied to any application where it is desirable to observe any high pressure process.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.
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An apparatus (10) and method are provided for directly viewing, through a viewport assembly (26), the process for forming a layer of mercury cadmium telluride of a predetermined composition on a surface of a wafer (not shown). According to the invention, a molten melt (20) comprising mercury, cadmium and tellurium is provided in a vertically oriented crystal growth chamber (14), which, in turn, is housed in a reactor tube (12). A wafer (not shown) is contacted with the crystal growth melt while cooling the melt below its liquidus temperature at a predetermined rate sufficient to cause a crystal growth layer of mercury cadmium telluride to form on the wafer (not shown). Viewports (26, 48) located approximately radially adjacent to the melt (22) provide direct see through capability to visually monitor the crystal growth process. The present invention is advantageous because the apparatus and method disclosed provide for ease of the growth set-up and operation, yielding mercury cadmium telluride layers of uniform composition and of high purity.
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BACKGROUND OF THE INVENTION
Construction projects typically include the demolition, transportation and reconstruction of materials. In a typical home construction or renovation, materials may be passed into or out of the house through a window frame or doorway. Materials that hit the window frame or doorway can cause damage, requiring repair or replacement. Even if workers use great care to avoid any damage, passing materials through windows or doors is likely to cause some damage eventually. Such damage results in lost time and money devoted to cleanup and repair.
To minimize the potential for damage, workers may place cloth or plastic material over window sills or flooring to protect them from minor damage. However, cloth and plastic material do not protect from moderate or severe impacts, and provide little protection against significant damage such as breaks or indentations in the window sill, door frame, molding, flooring or other exposed surface. Thus, there exists a need to protect spaces such as window frames and door frames while materials are passed through.
Construction projects also produce debris such as dust and small pieces of work materials. For example, a worker sawing wood inside a building produces sawdust, splinters, wood shavings, small pieces of unused wood and similar debris. Further, debris may fall or scatter while transporting materials inside a building. Without a means to contain the debris at the work site, the fallen and scattered debris must be cleaned up. This requires in additional time and effort, increasing the overall cost of the construction project.
To combat this problem, one approach is to cover flooring, doorways or holes with cloth or plastic material. For example, a tarp may be placed on the floor to catch materials dropped during the construction process. While this method prevents materials from coming into direct contact with the floor, a tarp does not prevent the dispersion of debris throughout the surrounding areas. For example, sawdust may blow into adjacent rooms, or paint may splatter onto ceilings or walls. Despite the use of a tarp, the sawdust and paint still must be cleaned up. Thus, there exists a need to contain debris while working on or transporting materials inside a building or structure.
The present invention reduces or eliminates the risk of damage to spaces while transporting materials into, out of, or within a building or structure. The present invention also reduces or eliminates the effort required to clean up after working on or transporting materials inside a building or structure. These and other advantages and features will become apparent in view of the following description.
SUMMARY OF THE INVENTION
Various embodiments of the present invention include a framework through which materials may be transported. Two or more vertical poles are secured between two surfaces and support a center frame. For example, the poles may be secured between a floor and a ceiling within a building.
Optionally, an ankle may also be used with a vertical pole, and functions as a jack to alter the height of the vertical pole. In one embodiment, after the vertical pole has been placed between the floor and ceiling, the ankle is engaged and used to expand the pole until the pole is securely pressing against the floor and ceiling.
In some embodiments, a center frame is mounted on the two vertical poles. The center frame is a structure through which materials may be passed, and provides protection to window frames and other passages and openings. The center frame generally consists of two horizontal bars mounted to the vertical poles. These may be described as upper and lower horizontal bars. Two vertical bars are mounted on the horizontal bars, forming a square or rectangular opening. The mounting of the upper and lower horizontal bars on the vertical poles and the mounting of the vertical bars on the upper and lower horizontal bars are adjustable to accommodate various widths of window sills. Two diagonal bars extend downward and outward from the upper horizontal bar. In an embodiment wherein the vertical bars are mounted inside a building, the diagonal bars extend outward through a window frame. A third horizontal bar is connected between the ends of the diagonal bars. Two horizontal bars, perpendicular to the lower horizontal bar described earlier, connect the ends of the diagonal bars to the lower horizontal bar. Below the two perpendicular horizontal bars are two sill clamp rails that run along the length of the two perpendicular horizontal bars. Together these bars and rails form the center frame.
The center frame is mounted to the vertical poles by any suitable means. The center frame may be attached to a window sill via two sill clamps that slide onto either end of a sill clamp rail.
Preferably, the center frame comprises a rotating segment on the lower horizontal bar. The rotating segment supports materials and rolls as the materials are passed through the window. By rolling, the rotating segment enables the materials to pass freely above it. Because materials passing through the center frame are kept away from the window sill, the potential for damage is minimized or eliminated.
The center frame, including the elements described above, may be expanded or contracted to fit the dimensions of a window frame, doorframe or other passageway. The elements of the apparatus may be attached by use of fittings, T-joints, T-L joints, T-U joints, T-V joints, cotter pins, any other suitable means or any combination thereof.
In another embodiment, four or more vertical poles are positioned in a building and supported by the floor and ceiling, as described above. One or more sheets may be connected to each pole in such a way that the sheet or sheets essentially form a tunnel. Materials may be transported through the tunnel with minimal or no exposure to the surrounding environment. This configuration prevents debris from dispersing throughout the room. Once the materials have been transported, the sheet and structure may be removed without exposing any remaining debris to the surrounding environment.
The present invention is not limited to the field of construction. For example, the apparatus may be used in healthcare applications to provide quarantined transportation of items. In this example, a tunnel of sheet material, as described above, may be used to prevent the spread of contaminants. The present invention may also be used in delivery applications. The rotating segment of the center frame may be used to increase efficiency when transporting items across flat surfaces or through passages or openings without damaging the surrounding area.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A illustrates a front view of one embodiment of the protective apparatus.
FIG. 1B illustrates a side view of one embodiment of the protective apparatus.
FIG. 2 illustrates a perspective view of one embodiment of the center frame.
FIG. 3 illustrates a perspective view of one embodiment of the protective apparatus.
FIG. 4A illustrates an embodiment of the feet in an interlocked position.
FIG. 4B illustrates an interlocking device of the feet.
FIG. 5 illustrates an embodiment of the feet functioning independent of each other.
FIG. 6 illustrates a front view of a sill clamp rail.
FIG. 7A illustrates two sill clamps on a sill clamp rail.
FIG. 7B illustrates a magnified view of a sill clamp and sill clamp rail.
FIGS. 8A and 8B illustrate an ankle jack.
FIG. 9 illustrates a cotter pin attaching a vertical pole and a cross beam through a T joint.
FIG. 10 illustrates a side view of an embodiment of the protective apparatus.
FIG. 11 illustrates a perspective view of an embodiment of the protective apparatus.
FIG. 12 illustrates a perspective view of another embodiment of the protective apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A detailed illustrative embodiment of the present invention is disclosed herein. However, techniques, systems and operating structures in accordance with the present invention may be embodied in a wide variety of forms and modes, some of which may be quite different from those in the disclosed embodiment. Consequently, the specific structural and functional details disclosed herein are merely representative, yet in that regard, they are deemed to afford the best embodiment for purposes of disclosure and to provide a basis for the claims herein which define the scope of the present invention.
None of the terms used herein, including “floor”, “ceiling”, “wall”, “vertical”, “horizontal” and “diagonal” are meant to limit the application of the invention. The terms are used to illustrate the preferred embodiment and are not intended to limit the scope of the invention. Similarly, the use of these terms is not meant to limit the application of the invention, as the invention is versatile and can be utilized in many applications, as will be apparent. The following presents a detailed description of the preferred embodiment of the present invention with reference to the figures.
Referring to FIGS. 1A and 1B , vertical poles 101 a and 101 b support the center frame of the device comprising cross beams 102 a and 102 b , support beams 110 a , 110 b , 111 a (not shown) and 111 b , lateral beams 114 a (not shown) and lib, T-joints 106 a - d , T-V joints 107 a and 107 b , T-L joints 108 a and 108 b , and L-U joints 109 a (not shown) and 109 b . At the ends of vertical poles 101 a and 101 b are feet 103 a , 103 b , 104 a and 104 b . After setting up vertical poles 101 a and 101 b , or while vertical poles 101 a and 101 b are being set up, the center frame is placed into a window frame. The center frame either rests on, or is suspended above, the window sill. Once in place, materials may be transported through the window via the center frame, minimizing or preventing contact with the window sill or surrounding area. Accordingly, damage to the window sill and surrounding area is minimized or prevented.
Preferably, vertical poles 101 a and 101 b each comprise two sections, one of which may be inserted into the other and used to adjust the length of the pole. By sliding the sections together or apart, a vertical pole can be contracted and expanded incrementally to fit between two end surfaces such as a floor and a ceiling. Alternatively, three or more sections may be used in the same manner. The sections are not required to be inserted into one another. For example, in another alternative embodiment, the two or more sections may be placed side-by-side and secured together. The vertical poles may be made of plastic, metal, wood or any combination thereof and may be hollow, solid, semi-perforated or any combination thereof.
Vertical poles 101 a and 101 b are set to the desired height and preferably exert sufficient pressure on the floor and ceiling to remain stationary and stable. Once vertical poles 101 a and 101 b are set to the desired height, the poles are locked securely in place. The vertical poles may be locked in place using any suitable means. For example, the locking mechanism may be a pin inserted through aligned holes in the vertical poles. As seen in FIG. 4A , vertical pole 401 b has holes 421 . These holes provide the increments which allow vertical pole 401 b to be locked in place after being expanded or contracted. The holes may serve as part of a locking mechanism incorporating a pin such as a cotter pin.
Referring to FIGS. 1A and 1B , vertical poles 101 a and 101 b each have top foot 103 a and 103 b , respectively, and bottom foot 104 a and 104 b , respectively. Attachment of feet 103 a - b and 104 a - b to vertical poles 101 a - b may be accomplished by cotter pin 920 , shown in FIG. 9 . Top and bottom feet 103 a - b and 104 a - b may rotate and lock independently of each other, as illustrated in FIGS. 4A , 4 B, and 5 . Each foot has a pad which, when pressed against a surface such as a floor or ceiling, will remain securely fixed to the surface. The feet may be rounded, square, rectangular or any other shape suitable to securely hold the vertical poles. The feet are preferably made of soft yet durable material to prevent damage to surfaces while minimizing wear and the need for replacement. The feet may optionally have gripped surfaces to improve the stability of the vertical pole.
Vertical poles 101 a and 101 b preferably comprise ankle jacks 105 a and 105 b , respectively. As depicted in FIGS. 1A and 1B , ankle jacks 105 a - b are located at the bottom of vertical poles 101 a - b , and above bottom foot 104 a - b . The ankle is preferably located between the end of the vertical pole and the foot at the base of the pole, but may optionally be placed anywhere along the length of the vertical pole. A more detailed description of ankle jacks is provided below with reference to FIGS. 8A and 8B . Vertical poles 101 a and 101 b may be attached to the center frame through T-joints 106 a and 106 b and T-joints 106 c and 106 d , respectively. Attachments between T-joints 106 a - d and vertical poles 101 a and 101 b may be temporary or permanent.
The triangular shape of the center frame can be seen more clearly in FIG. 2 . Attachment pieces for the center frame may slide along the vertical poles, and may be fixed in place by inserting a pin through aligned holes in each vertical pole and attachment piece. For example, in FIG. 2 , cross beams 202 a and 202 b are mounted to vertical poles and (not pictured) using T-joints 206 a - d . Support beams 210 a and 210 b and support beams 211 a and 211 b are connected to cross beam 202 a using T-V joints 207 a and 207 b . Support beams 210 a and 210 b and lateral beams 214 a and 214 b are connected to lower cross beam 202 b using T-V joints 208 a and 208 b . Support beams 211 a and 211 b and lateral beams 214 a and 214 b are connected to cross beam 213 via L-U joints 209 a and 209 b . Sill clamp rails 212 a and 212 b are mounted below lower cross beam 202 b and cross beam 213 . The beams and joints making up the center frame may be permanently attached to each other or may be detachable.
When the center frame is placed in a window, sill clamp rails 212 a and 212 b may rest upon the window sill. Materials may be transported through the center frame, and may pass over cross beams 202 b and 213 . Thus, the center frame provides a supported and protected space between the window sill and the materials being transported through the window.
Preferably, cross beam 213 is capable of rotation. A casing capable of rotation may be placed around cross beam 213 . In one embodiment, a casing capable of rotation is also placed around cross beam 202 b . Cross beam 213 is intended to rotate as it supports materials being passed over it. However, it is not necessary that cross beam 213 rotate in order to provide protection.
Cross beams 202 a and 202 b may be expandable and contractible to better fit the width of various window spaces. Likewise, support beams 210 a and 210 b may be expandable and contractible to better fit the height of various window spaces.
FIG. 3 illustrates a perspective view of the described embodiment.
FIGS. 4A , 4 B, and 5 illustrate possible embodiments of top feet. Although not illustrated, these embodiments may equally apply to bottom feet as well. FIG. 4A illustrates top feet 403 a and 403 b in an interlocking position. In this position, top feet 403 a and 403 b provide added support in certain situations. For example, the interlocking position provides added support when top feet 403 a and 403 b are placed against vertically aligned ceiling beams or other surfaces. To put the top feet in the interlocking position, top feet 403 a and 403 b are rotated inwardly with respect to vertical poles 401 a and 401 b . Each top foot may have a portion of lock slide 413 incorporated onto the bottom side of the foot. One foot, either 403 a or 403 b , may contain locking piece 414 , which slides through lock slide 413 , creating a secure lock between top feet 403 a and 403 b.
Referring to FIG. 5 , top feet 503 a and 503 b may function independently of each other, without a locking mechanism. For example, top feet 503 a and 503 b are connected to vertical poles 501 a and 501 b , and may be rotated to a parallel position. The parallel position may be advantageous when positioning the top feet against horizontal ceiling beams or other surfaces.
The two feet on a vertical pole may either interlock or function independently of each other. In one embodiment, the feet are interlocked via a connection and only move in unison. In another embodiment, the feet are not interlocked and may rotate independently of each other. The feet are preferably interchangeable and may be removed and reattached to the vertical poles. For example, feet may be attached to a vertical pole using one or more pins with aligned holes in the pole.
Sill clamps are optional and not necessary for the operation of the invention. In one embodiment, sill clamps are attached to the center frame and adjusted to securely fit the center frame above and around the window sill. The sill clamps may be attached to the sill clamp rails in any suitable manner. For example, a sill clamp may run along teeth on a sill clamp rail until it is tightly aligned with one side of a window sill. The teeth on the sill clamp rail allow sill clamps to be easily maneuvered along the rail and held securely in place using a sill clamp button. Alternative mechanisms may be used to affix and position window sill clamps on the sill clamp rails and secure the clamps in place.
FIGS. 6 , 7 A, and 7 B illustrate a sill clamp rail and sill clamps. FIG. 6 depicts a front view of sill clamp rail 612 beneath a T-V joint 608 . As depicted in FIG. 7A , sill clamp rail 712 is mounted on lateral beam 714 . Sill clamps 716 a and 716 b may slide onto sill clamp rail 712 . Sill clamps 716 a and 716 b are positioned and held secure on sill clamp rail 712 using teeth 717 a and 717 b . Preferably, sill clamps 716 a and 716 b are maneuvered to fit snuggly against a window sill, as shown.
Preferably, a sill clamp button is used to secure the sill clamp in place. FIG. 7B illustrates sill clamp button 718 which functions to interact with sill clamp teeth 717 a . Sill clamp button 718 can be used to lock sill clamp 716 a in place along sill clamp rail 712 . Preferably, sill clamp button 718 allows forward motion of sill clamp 716 a along sill clamp rail 712 to provide a tighter fit to the window sill. Preferably, sill clamp button 718 must be pressed to release sill clamp 716 a . The sill clamp locking mechanism is optional and not required. The preferred sill clamp locking mechanism is embodied here in teeth 717 a and sill clamp button 718 , but any suitable mechanism may be used.
FIGS. 8A and 8B illustrate the lowered and raised position of ankle jack 805 , respectively. The ankle jack resides between vertical pole 801 and bottom foot 804 . Ankle jack 805 may be used to adjust the height of vertical pole 801 . The use of an ankle jack allows a precise height adjustment and allows a user to increase the pressure between a vertical pole and surfaces such as ceilings and floors. Engaging the ankle in this manner allows for easier placement of the vertical pole between two surfaces and allows a user to increase the pressure between the pole and the surfaces. Lever 819 may be used to exert pressure and expand vertical pole 801 , thereby securing the position of vertical pole 801 between two surfaces. Lever 819 may be repeatedly raised and lowered to expand vertical pole 801 . After each cycle, ankle jack 805 holds the position of vertical pole 801 . Ankle jack 805 may be attached to bottom foot 804 through bottom foot hole 821 using a pin. Ankle jack 805 may be attached to vertical pole 801 . Ankle jack may be attached to the top or bottom of a vertical pole, or ankle joints may be attached at both ends.
FIG. 9 depicts one embodiment of a locking mechanism using cotter pin 920 , vertical pole hole 921 and T-joint hole 922 . When holes on both vertical pole 901 and T-joint 906 are aligned, cotter pin 920 may be inserted to lock vertical pole 901 and T-joint 906 together in place. The rounded portion of cotter pin 920 ensures the locking mechanism is secure.
FIGS. 10 and 11 illustrate an embodiment requiring at least two sets of vertical poles, ankles and feet. FIG. 10 depicts a side view of a frame comprising vertical poles 1001 a - c , with top feet 1003 a - c , bottom feet 1004 a - c , and ankle jacks 1005 a - c , respectively. Sheet material 1023 is securely attached to vertical poles 1001 a - c using any suitable means. For example, circular clasps mounted on the vertical poles may be used to clasp into a hole in the sheet material. The sheet material may be removable or permanently attached to the vertical poles. Preferably, sheet material 1023 comprises one or more sheets of plastic, but may comprise cloth or any other suitable material in any suitable shape. Vertical poles 1001 a - c may be used in tandem with at least one other set of vertical poles to support materials.
Preferably, vertical poles and sheet materials are used to form two walls, as depicted in FIG. 11 . Specifically, sheet materials 1123 a and 1123 b are attached to vertical poles 1101 a - f . Preferably, sheet materials 1123 a and 1123 b each have four sides having holes on each end, such that the sheet materials may be supported by at least two sets of vertical poles, as depicted in FIG. 11 . Alternatively, one or more sheets may be used to create a tunnel, as depicted in FIG. 12 . It should be appreciated that the formation of a complete tunnel is not necessary. For example, sheet material 1223 may be attached to vertical poles to form one or more walls, a ceiling, a floor, or any combination thereof. Additionally, sheet material 1223 may be used to form an incomplete wall, ceiling or floor.
Once a tunnel is formed, work materials may be transported through the tunnel. Any debris will be retained by the sheet materials, preventing the debris from dispersing throughout the surrounding area. With reference to FIG. 11 , when construction is completed, sheet material 1123 may be removed from vertical poles 1101 a - f . Debris captured by the sheet material may be taken to a disposal area, preventing dispersion of debris or damage to the area surrounding construction.
While the present invention has been described with reference to the preferred embodiment, which has been set forth in considerable detail for the purposes of making a complete disclosure of the invention, the preferred embodiment is merely exemplary and is not intended to be limiting or represent an exhaustive enumeration of all aspects of the invention. The scope of the invention, therefore, shall be defined solely by the following claims. Further, it will be apparent to those of skill in the art that numerous changes may be made in such details without departing from the spirit and the principles of the invention. It should be appreciated that the present invention is capable of being embodied in other forms without departing from its essential characteristics.
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The invention relates to the general field of construction, and more specifically, the protection of construction work sites. At least two vertical poles are positioned between two surfaces such as ceilings and floors. A center frame with one or more rotatable segments may be mounted between the vertical poles and secured to a window sill. Construction materials may be passed over the rotatable segment and through the center frame with minimal or no damage to the window sill or surrounding structure. The vertical poles may be used with a sheet material to form a protective tunnel. Construction materials may be passed through the tunnel with minimal or no damage to the surrounding environment. Debris left by the construction materials is captured within the tunnel and can be safely and conveniently removed.
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CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of U.S. application Ser. No. 08/866,192, filed May 30, 1997, now abandoned.
BACKGROUND OF THE INVENTION
The invention relates to hydrogen storage alloys for use in rechargeable batteries.
A battery typically includes one or more galvanic cells (i.e., cells that produce a direct current of electricity) in a finished package. In each cell, two electrodes are separated by an electron insulator, but are joined by an ion-carrying path. The electron-carrying path of the battery is external; the path proceeds, via a conductor, through a device where work is done. The ion-carrying path of the battery is internal and proceeds via an electrolyte.
The electrodes are usually composed of dissimilar metals. For discharge of a cell, the electrode where the electrolyte is broken down upon the receipt of electrons is the positive electrode, also referred to as the cathode. The electrode where the metal goes into solution, releasing electrons, is called the negative electrode, or anode. The electrolyte generally is composed mainly of an ionizable salt dissolved in a solvent.
Batteries may be rechargeable; such batteries are called “storage” or “secondary” batteries. Storage batteries can be recharged by passing current through the cells in the opposite direction of current flow on discharge. The chemical conditions of the battery are restored, and the cells are ready to be discharged again. Primary batteries, on the other hand, are meant to be discharged to exhaustion once, and then discarded.
An example of a rechargeable battery is a metallic oxide-hydrogen storage battery. The positive electrode of this battery includes a metal oxide, such as nickel oxide; the negative electrode includes a hydrogen storage alloy; and the electrolyte includes an alkaline solution.
An example of an electrode reaction in a nickel oxide-hydrogen storage battery is as follows. Postive electrode:
Native electrode:
In the reaction equation (2), M represents a hydrogen storage alloy. Hydrogen storage alloys are capable of electrochemically absorbing and discharging large quantities of hydrogen. One type of hydrogen storage alloy is the AB 5 -type, which has a crystal structure of the CaCu 5 type. The A and B components of the AB 5 -type alloy are present in a mole ratio of about 1:5. The A component is generally composed of a mischmetal (a mixture of rare earth elements, generally cerium (Ce), lanthanum (La), neodymium (Nd), and praseodymium (Pr), as well as zirconium (Zr)), and the B component is generally composed of nickel (Ni), along with two or more elements selected from cobalt (co), manganese (Mn), aluminum (Al), copper (Cu), iron (Fe), or germanium (Ge). The subscripts, which indicate mole fraction, of the elements forming the A component generally have a sum of 1, while the subscripts of the elements forming the B component generally have a sum of 4.75 to 5.50.
It is desirable for metallic oxide-hydrogen storage batteries to have characteristics such as high energy density, relatively high charge retentions, relatively long cycle lives, and good discharge capacities over a range of temperatures. The hydrogen discharge reaction at the negative electrode, however, tends to slow down with decreasing temperature; discharge capacities may therefore deteriorate at low temperatures. The low temperature performance of batteries can be improved, but improved low temperature performance is often accompanied by the loss of other desirable properties such as high temperature performance, capacity (the ability to reversibly store hydrogen) or cycle life.
SUMMARY OF THE INVENTION
In general, the invention features a hydrogen storage alloy with a relatively high content of praseodymium (Pr). The preferred hydrogen storage alloy is of the AB 5 -type; the A component of this alloy includes at least 0.4 mole fraction Pr. The alloy also includes lanthanum (La) and/or neodymium (Nd). The alloy can be used to make batteries with good low temperature discharge capacities, good ambient temperature properties, good charge retention, good cycle life, and uniform discharge capacities over a range of discharge rates.
The invention also features an alkaline storage battery that includes a positive electrode, a negative electrode including a hydrogen storage alloy having a relatively high Pr content and including La and/or Nd, and an alkaline electrolyte.
Other features and advantages of the invention will be apparent from the description of the preferred embodiments thereof, and from the claims.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a sectional view of a cylindrical storage cell;
FIG. 2 a is a perspective view of a rectangular storage cell;
FIGS. 2 b and 2 c are sectional views of a rectangular storage cell;
FIG. 3 is a perspective view of the electrode assembly of a rectangular storage cell; and
FIG. 4 is a graph showing the capacity for various discharge rates for a hydrogen storage alloy.
FIGS. 5 a - 5 e are graphs showing cell capacities after conditioning for cells containing a hydrogen storage alloy at 20° C. (FIG. 5 a ), 45° C. (FIG. 5 b ), 0° C. (FIG. 5 c ), −10° C. (FIG. 5 d ), and −20° C. (FIG. 5 e ).
FIG. 6 is a graph showing cell cycle life for cells containing a hydrogen storage alloy at 20° C.
FIG. 7 is a graph showing cell cycle life for cells containing a hydrogen storage alloy at 45° C.
FIGS. 8 a - 8 e are graphs showing cell capacities after conditioning for a cell containing a hydrogen storage alloy at 20° C. (FIG. 8 a ), 45° C. (FIG. 8 b ), 0° C. (FIG. 8 c), −10° C. (FIG. 8 d ), and −20° C. (FIG. 8 e ).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a cylindrical battery 10 includes a negative electrode 1 , a positive electrode 2 , and a separator 3 . The electrodes and the separator are contained within a case 4 . The top end of the case 4 is closed with a sealing plate 5 and an annular insulating gasket 6 that provide a gas-tight and fluid-tight seal. A positive lead 7 connects the positive electrode 2 to the sealing plate 5 . The sealing plate 5 is provided with a safety valve 8 disposed in the inner side of a positive terminal 9 . The valve 8 is configured to actuate when the pressure inside the battery exceeds a predetermined value.
The main component of negative electrode 1 is an AB 5 -type hydrogen absorbing alloy, which is formed by fusing the appropriate elements. The mixture of elements is melted in an induction furnace under vacuum, under an inert atmosphere such as argon, helium, or other non-reactive gas, under a protective atmosphere, such as an argon/hydrogen mixture, or combinations thereof. The melt is then allowed to cool. The resulting alloy is pulverized by hydrogen absorption and desorption, mechanical pulverization, jet-milling, or other methods known in the art to form a powder, which is sieved to remove particles larger than 75 microns. The alloy can be used in an as-cast and pulverized condition.
Alternatively, the alloy can be heat treated, and then pulverized. The heat treatment includes heating the alloy at 900° C. to 1100° C. for 1 to 12 hours, under vacuum, under an inert atmosphere, or under a protective atmosphere. The heat treatment helps to homogenize the elements.
Negative electrode 1 may contain other ingredients as well. For example, the electrode may include a high surface area carbon. The carbon catalyzes the conversion of O 2 , formed at the positive electrode, into H 2 0, thus promoting pressure reduction in the battery. The electrode may also include a binder such as polytetrafluoroethylene (PTFE), and thickeners, such as a polyvinyl alcohol/sodium polyacrylate copolymer, and carboxymethyl cellulose (CMC).
Negative electrode 1 may be prepared as follows. The alloy is combined with the carbon, the binder, the thickeners, and water to form a paste. The paste is applied to a conductive core substrate, such as perforated nickel-plated cold rolled steel foil, or expanded metal. The material then is dried, rolled, and die cut into pieces of the appropriate size.
Positive electrode 2 may include any of a number of materials known in the electrochemical arts. For example, the positive electrode may include spherical nickel hydroxide, which may contain zinc and cobalt; cobalt monoxide; a binder, such as PTFE; thickeners such as CMC and sodium polyacrylate (SPA); and a paste stabilizer such as sodium borate.
Positive electrode 2 may be prepared as follows. The ingredients are combined with water to produce a paste, which is then applied to a highly porous sintered, felt, or foam substrate. The filled substrate is compacted, then pieces of the appropriate size are cut from the substrate. A nickel tab, which serves as a current collector, is then applied by ultrasonic welding.
Separator 3 is a porous insulator film or thin sheet; the film or sheet can be composed of a polyamide (such as nylon), polypropylene, polyethylene, polysulfone, or polyvinyl chloride (PVC). A preferred material is polypropylene. The separator is cut into pieces of a similar size as the electrodes, and is placed between the negative and positive electrodes to separate them electrically.
Negative electrode 1 , positive electrode 2 , and separator 3 are wound into a Swiss roll and placed in a case 4 made of a metal such as nickel or nickel plated steel, or a plastic material such as PVC, polypropylene, polysulfone, ABS, or polyamide.
The case 4 is then filled with an electrolyte. The electrolyte may be any electrolyte known in the art. An ample of an electrolyte is potassium hydroxide (KOH) with a concentration of 20 to 40 weight %, plus lithium hydroxide (LIOH) with a concentration of 0 to 10 weight %.
The case 4 is then sealed with the sealing plate 5 and the annular insulating gasket 6 .
Examples of cylindrical batteries that may be prepared according to the present invention include A, AA, AAA, 4 / 5 A, 4 / 3 A, sub-C, and half-C batteries.
Alternatively, the battery may be rectangular in form; an example of a rectangular battery is the prismatic cell described in U.S. Pat. No. 4,977,043, which is incorporated by reference in its entirety herein.
Referring to FIGS. 2 a - 2 c , a rectangular battery 11 includes a case 12 , a lid body 13 , a positive electrode terminal 14 , a positive electrode 15 , a separator 16 which surrounds the positive electrode 15 , a U-shaped negative electrode 17 , a negative electrode lead 18 , a positive electrode lead 19 , and a frame body 20 .
FIG. 3 shows an expanded view of the electrode assembly. As shown there, the positive electrodes 15 are sandwiched between the U-shaped negative electrodes 17 . The bottom part of the U includes a negative electrode lead 18 .
The negative and positive electrodes may be prepared as described above, or as described in U.S. Pat. No. 4,977,043.
An example of a rectangular battery that may be prepared according to the present invention is a battery used to power electric vehicles.
Alternatively, a bobbin-type battery can be formed. To form this type of battery, the material forming the positive electrode is pressed into pellets. One or more of these pellets, surrounded by a separator, are placed into a case. The negative electrode material, in the form of a powder, and an electrolyte are added to the case. The case is then sealed.
Other types of batteries known in the art can be prepared as well.
EXAMPLES
Example 1
An alloy having the formula La 0.15 Ce 0.15 Pr 0.7 Ni 3.7 Co 0.7 Mn 0.1 Al 0.5 was made by fusing lanthanum, cerium, praseodymium, nickel, cobalt, manganese, and aluminum in the required proportions to achieve approximately 2 kg of the desired composition. The melt charge was loaded into a magnesia crucible installed in an induction furnace. The atmosphere inside the furnace chamber was evacuated to obtain a vacuum state of ≦0.02 torr. Immediately before melting, the furnace chamber was filled with argon to a pressure of 780 to 790 torr, which was maintained during the melting operation. The molten charge was maintained at 1400° C.-1415° C. for one minute, and then poured onto a copper block and allowed to cool to <50° C. The resulting alloy was pulverized by hydrogen absorption and desorption. The resulting powder was sieved to remove particles larger than 75 microns.
Test cells were prepared as follows. A pellet comprising 1 gram of Ni powder and 0.35 g of the alloy was compacted under a load of 3.5 tons in a die of 12.7 mm diameter. The compacted pellet was wrapped in 60 micron thick perforated nickel-plated cold rolled steel foil to which a tab of nickel was attached. The wrapped pellet and a positive, or counter, sintered Ni(OH) 2 electrode were immersed in 25 cc of de-aerated aqueous electrolyte of 5.5N KOH+2.0N NaOH+0.5N LiOH.
The cells were conditioned at room temperature with six charge/discharge cycles consisting of a 50 mA charge for 2.7 hours, followed by a discharge of 45 mA. The cells were discharged, after the sample temperature and electrolyte temperature stabilized, to −0.6V vs. a Hg/HgO reference electrode. The capacity was then determined at 25° C., 0° C., −10° C., and −20° C. at discharge rates of C/2 (45 mA), C/3 (30 mA), and C/5 (20 mA). The results are presented in Table 1.
TABLE 1
Discharge capacities in mA · hr/g to a cut-off
of −0.6 V vs. Hg/HgO
Temperature
C/2
C/3
C/5
22° C.
302
298
290
0° C.
289
288
—
−10° C.
261
282
286
−20° C.
162
248
275
As Table 1 illustrates, the cells showed high discharge capacities over a broad range of temperatures.
The test cells were then connected to cell cycling equipment and charged with 50 mA for 2.7 hours. The charging cycle was followed by a rest cycle of 10 minutes, with no current flowing. The cells were then discharged at the rates of C/2, C/3, and C/5. Instead of measuring the discharge potential against a reference electrode, the discharge was terminated when the cell voltage reached 1.0V.
The results are shown in FIG. 4, which illustrates that the cells exhibited relatively uniform discharge capacities over a range of discharge rates. The alloy described above showed a capacity decrease of 16 mA·hr/g at C/2 compared to C/5.
Example 2
An alloy having the formula La 0.3 Ce 0.15 Pr 0.55 Ni 3.7 Co 0.7 Mn 0.1 Al 0.5 was prepared. Test cells containing this alloy were prepared and tested as described above. A test cell including this alloy had a discharge capacity of 273 mA·hr/g at a temperature of −20° C. and a discharge rate of C/3.
Example 3
An alloy having the formula Lao 0.15 Ce 0.15 Pr 0.63 Nd 0.07 Zr 0.006 Ni 3.7 Co 0.7 Mn 0.1 Al 0.5 was prepared. Test cells containing this alloy were prepared and tested as described above. A test cell including this alloy had a discharge capacity of 262 mA·hr/g at a temperature of −20° C. and a discharge rate of C/3.
Example 4
An alloy having the formula La 0.15 Ce 0.3 Pr 0.55 Ni 3.7 Co 0.7 Mn 0.1 Al 0.5 was prepared. Test cells containing this alloy were prepared and tested as described above. A test cell including this alloy had a discharge capacity of 231 mA·hr/g at a temperature of −20° C. and a discharge rate of C/3.
Example 5
An alloy having the formula La 0.15 Pr 0.85 Ni 3.7 Co 0.7 Mn 0.1 Al 0.5 was prepared. Test cells containing this alloy were prepared and tested as described above. A test cell including this alloy had a discharge capacity of 245 mA·hr/g at a temperature of −20° C. and a discharge rate of C/3.
Example 6
An alloy having the formula La 0.3 Pr 0.7 Ni 3.7 Co0.7Mn 0.1 Al 0.5 was prepared. Test cells containing this alloy were prepared and tested as described above. A test cell including this alloy had a discharge capacity of 263 mA·hr/g at a temperature of −20° C. and a discharge rate of C/3.
Example 7
An alloy having the formula La 0.3 Ce 0.3 Pr 0.4 Ni 3.7 Co 0.7 Mn 0.1 Al 0.5 was prepared. Test cells containing this alloy were prepared and tested as described above. A test cell including this alloy had a discharge capacity of 232 mA·hr/g at a temperature of −20° C. and a discharge rate of C/3.
Example 8
An alloy having the formula La 0.1 Ce 0.01 Pr 0.8 Ni 3.7 Co 0.7 Mn 0.1 Al 0.5 was prepared. Test cells containing this alloy were prepared and tested as described above. A test cell including this alloy had a discharge capacity of 258 mA·hr/g at a temperature of −20° C. and a discharge rate of C/3.
Example 9
An alloy having the formula La 0.48 Ce 0.03 Pr 0.4 Nd 0.9 Zr 0.006 Ni 4.08 Co 0.4 Mn 0.44 Al 0.34 was prepared the procedure described above. A test cell, including this alloy had a discharge capacity of 254 mA·hr/g at a temperature of −20° C. and a discharge rate of C/3.
Example 10
A 4/5A battery of the type shown in FIG. 1 was prepared using the general procedure described above.
The main component of the negative electrode 1 was a hydrogen storage alloy having the formula La 0.5 Ce 0.15 Pr 0.7 Ni 3.7 Co 0.7 Mn 0.1 Al 0.5 . The alloy was pulverized by hydrogen absorption and desorption, and then sieved. The electrode also included (relative to the amount of hydrogen storage alloy, by weight): 0.7% high surface area carbon; 2.0% PTFE; 0.29% polyvinyl alcohol/sodium polyacrylate copolymer; and 0.12% CMC. The substrate used was perforated nickel plated cold rolled steel foil.
The main component of positive electrode 2 was nickel hydroxide, which included 5.0% zinc and 0.75% cobalt. The electrode also included (relative to the amount of nickel hydroxide, by weight): 0.5% PTFE; 0.13% CMC; 0.18% SPA; 5.0% cobalt oxide; and 0.1% sodium borate. The substrate used was a porous nickel material.
The electrolyte included 5.5N KOH+2.0N NaOH+0.5N LiOH, and the separator 3 was polypropylene.
Example 11
A 4/5A battery of the type shown in FIG. 1 was prepared using the general procedure described above.
The main component of the negative electrode 1 was a hydrogen storage alloy having the formula La 0.3 Ce 0.15 Pr 0.55 Ni 3.7 Co 0.7 Mn 0.1 Al 0.5 . The alloy was pulverized by hydrogen absorption and desorption, and then sieved. The electrode also included (relative to the amount of hydrogen storage alloy, by weight): 0.7% high surface area carbon; 2.0% PTFE; 0.29% polyvinyl alcohol/sodium polyacrylate copolymer; and 0.12% CMC. The substrate used was perforated nickel plated cold rolled steel foil.
The main component of positive electrode 2 was nickel hydroxide, which included 5.0% zinc and 0.75% cobalt. The electrode also included (relative to the amount of nickel hydroxide, by weight): 0.5% PTFE; 0.13% CMC; 0.18% SPA; 5.0% cobalt oxide; and 0.1% sodium borate. The substrate used was a porous nickel material.
The electrolyte included 5.5N KOH+2.0N NaOH+0.5N LiOH, and the separator 3 was polypropylene.
Example 12
A 4/5A battery of the type shown in FIG. 1 was prepared using the general procedure described above.
The main component of the negative electrode 1 was a hydrogen storage alloy having the formula La 0.48 Ce 0.03 Pr 0.4 Nd 0.09 Ni 4.08 Co 0.4 Mn 0.44 Al 0.34 . The alloy was pulverized by hydrogen absorption and desorption, and then sieved. The electrode also included (relative to the amount of hydrogen storage alloy, by weight): 0.7% high surface area carbon; 2.0% PTFE; 0.29% polyvinyl alcohol/sodium polyacrylate copolymer; and 0.12% CMC. The substrate used was perforated nickel plated cold rolled steel foil.
The main component of positive electrode 2 was nickel hydroxide, which included 5.0% zinc and 0.75% cobalt. The electrode also included (relative to the amount of nickel hydroxide, by weight): 0.5% PTFE; 0.13% CMC; 0.18% SPA; 5.0% cobalt oxide; and 0.1% sodium borate. The substrate used was a porous nickel material.
The electrolyte included 5.5N KOH+2.0N NaOH+0.5N LiOH, and the separator 3 was polypropylene.
Testing of Examples 10, 11, and 12
The nominal designed capacity of the cells of Examples 10, 11, and 12 was 1800 mA·hr. Cells were charged for four hours at 90 mA then for 18 hours at 180 mA. The cells were allowed to rest for 30 minutes with no current flowing. The cells were then discharged at a current of 360 mA until the cell voltage fell to 1.0V. After resting for 30 minutes, the cells were given five conditioning cycles according to the following schedule: charge at C/5 (a charge current of 360 mA) with a charge termination of 10 mV −ΔV; rest for 30 minutes with no current flowing; discharge at C/5 (360 mA) to 1.0V; and rest 30 minutes rest with no current flow.
After conditioning, five cells of each of Examples 30 10, 11, and 12 were tested for dependency on discharge rate (0.2C to 2.8C) and discharge temperature (−20° C. to 45° C.). The cells were given a three-hour rest at 20° C. prior to being charged at 600 mA for 3.75 hours at 20° C. The cells were then allowed to rest for three hours at the test temperature prior to discharge at a rate between 0.2C (or 0.36 Amp) and 2.8C (5.0 Amp). In FIGS. 5 a - 5 e , each datum is the average of 5 measurements. The results shown in FIGS. 5 a - 5 e indicate that cells from Examples 10, 11, and 12 have high discharge capacity over a wide range of temperatures and discharge rates. For example, the discharge capacity can be greater than 260 mA·hr/g, preferably greater than 280 mA·hr/g, at room temperature or greater than 230 mA·hr/g, preferably greater than 250 mA·hr/g, at −20° C. and a discharge rate of C/3. The data in FIG. 5 a were collected at 20° C. The data in FIG. 5 b were collected at 45° C. The data in FIG. 5 c were collected at 0° C. The data in FIG. 5 d were collected at −10° C. The data in FIG. 5 e were collected at −20° C.
After conditioning, four cells from each of Examples 10 and 11 were also tested for cycle life at 20° C. The cells were cycled according to the following procedure: charge at 20° C. at 1.8 A with a charge termination of 10 mV −ΔV, rest for 30 minutes at 20° C. with no current flow, discharge at 20° C. at 1.8 A to 1.0V, and rest for 30 minutes with no current flow. Both groups of cells show good cycle life. Cycle life of a battery is the number of charging cycles that the battery can withstand during which the capacity of the battery remains above a threshold level (e.g., 80% of the original capacity). Good cycle life can be greater than 200 cycles, preferably greater than 300 cycles, at room temperature or greater than 150 cycles, preferably greater than 200 cycles at 45° C. Results of the cycling experiments are shown in FIG. 6 . The curves in FIG. 6 are for the average capacities for each of the four cells from Example 10 and 11.
Another set of cells from Examples 10 and 11 were tested for cycle life at 45° C. The cells were cycled according to the following procedure: charge at 45° C. at 1.8 A with a charge termination of 10 mV −ΔV, rest for 30 minutes at 45° C. with no current flow, discharge at 45° C. at 1.8 A to 1.0V, and rest for 30 minutes with no current flow. Both groups of cells show good cycle life. Results are shown in FIG. 7 .
Example 13
The alloy used in Example 13 was that shown in Example 3. The nominal designed capacity of the cells was 1800 mA·hr. Cells were charged for four hours at 90 mA then for 18 hours at 180 mA. The cells were then allowed to rest for 30 minutes with no current flowing; the cells were then discharged at a current of 360 mA until the cell voltage fell to 1.0V. After a rest of 30 minutes, the cells were given five conditioning cycles according to the following regime: charge at C/5 (a charge of 360 mA) with a charge termination of 10 mV −ΔV, rest for 30 minutes with no current flow, discharge at C/5 (360 mA) to 1.0V, and rest for 30 minutes with no current.
After conditioning, three cells were tested for dependency on discharge rate (0.2C to 2.8C) and discharge temperature (−20° C. to 45° C.). The cells were given a three-hour rest at 20° C. prior to being charged at 600 mA for 3.75 hours at 20° C. The cells were then allowed to rest for three hours at the test temperature prior to discharge at the rate and temperature indicated. The results shown in FIGS. 8 a to 8 e indicate that both groups of cell have high discharge capacity over a wide range of temperatures and discharge rates. In FIGS. 8 a to 8 e each datum is the average of 5 values. FIG. 8 a shows the discharge capacities at 20° C. at rates from 0.2C (or 0.36A) to 2.8C (5.0A). FIG. 8 b shows the discharge capacities at 45° C. FIG. 8 c shows the discharge capacities at 0° C. FIG. 8 d shows the discharge capacities at −10° C. FIG. 8 e shows the discharge capacities at −20° C. Other embodiments are within the claims.
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A hydrogen storage alloy of the AB 5 -type, where the A component includes La and/or Nd and at least 0.4 mole fraction Pr, as well as batteries including the alloy, are disclosed.
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CROSS-REFERENCES TO RELATED APPLICATIONS
None
BACKGROUND
1. Field of the Invention
This invention relates to the field of saw systems used to cut I-Joists to size, specifically to a method and an improvement to saw systems, such as but not limited to the Sawtek saw system used by Boise Cascade that is configured to convert raw I-joists from inventory to pre-cut sizes and/or cut routed patterns in I-joists for utility pass-through applications prior to their shipment to a construction site, whereby the prior art saw system is enhanced by the addition of equipment configured for applying a controlled amount of adhesive and a protective liner automatically and successively to the top flange of each I-joist, and wherein such application preferably takes place before the I-joists are cut. The present invention preferably comprises coordinated mechanical, electrical, and pneumatic components to achieve the adhesive and protective liner applications.
2. Description of the Related Art
In today's construction, most local building codes require adhesive bonding in floor construction, which has led to the common practice of manually applying liquid adhesives on site. However, there are at least two important disadvantages to the on-site manual application of liquid adhesives during floor construction. One such disadvantage is that it is labor intensive and can significantly increase construction cost. The second such disadvantage is that there is the potential for inconsistent application, whereby, if too little adhesive is used, maximum sheer and strength in the finished construction project is not achieved. In the alternative, if too much adhesive is applied, material cost is unnecessarily increased. In addition, weather conditions also can adversely affect the bonding of adhesives applied on site by interfering with its application or curing, or both. To overcome these disadvantages, the present invention comprises a method and equipment for improving the saw systems used for cutting and/or routing raw I-joists prior to their shipment to a construction site or return to inventory. It has many advantages over the prior art method of on-the-job manual adhesive application now in use. One of the main advantages of automated adhesive application using the present invention is that it is manufactured in a controlled environment that achieves a more consistent and stronger bond of the adhesive layer to the I-joist than can be achieved with on-the-job adhesive applications. The controlled manufacturing environment for the present invention also creates a good bond between the release liner and the protected adhesive layer beneath it so that the release liner is not easily dislodged by casual contact prior to I-joist installation on a construction jobsite, allowing the adhesive to remain in its optimum condition for easy, rapid, strongly bonded, and secure I-joist installation. Also, as a result of the controlled manufacturing environment at the time the release liner is applied over the present invention adhesive layer, the adhesive layer stays covered and dry prior to I-joist installation, whereby I-joist installation during adverse weather conditions does not interfere with or diminish the bonding capability of the pre-applied adhesive. Further, as no curing time is required for the present invention adhesive layer after on-site I-joist installation, its bonding is prompt and immediately strong. Another advantage of the present invention is that the protective release liner over the adhesive layer is configured and positioned to prevent adhesive degradation prior to I-joist installation, either from casual contact with other objects during transport and handling that could lead to the removal of indiscriminate portions of the adhesive layer via nicking or gouging, as well as various potentially degrading contact of the adhesive layer with airborne particles, other debris, moisture, and direct solar radiation during the transport of the I-joists enhanced with the present invention, their storage, and/or while they are present on a construction site waiting for installation. Further, the cost of the automated application of the present invention adhesive layer and protective release liner to I-joists prior to their delivery to a construction jobsite is very low when compared to the on-site labor cost needed to achieve the enhanced strength in a finished floor that is mandated by most local codes. A further advantage of the low cost present invention' in areas subject to severe weather conditions, such as but not limited to areas frequently experiencing hurricanes, typhoons, and tornados, the present invention can provide a means for strengthening the connection between I-joists and adjacent sheer panels in roof construction for a very low material and labor cost when compared to on-site manual adhesive application, which is not currently required by building codes or routinely done in today's residential and commercial construction. No method or improvement to I-joist cutting saw systems is known that provides the valued-enhanced product or other advantages of the present invention.
BRIEF SUMMARY OF THE INVENTION
The primary object of this invention to provide a method and improvement to saw systems used to cut raw I-joists prior to their delivery to a construction jobsite, whereby I-joists are enhanced by the automated application of an adhesive layer and a protective liner configured and dimensioned to achieve a stronger and more consistent bond between the I-joists and adjacent sheer panels commonly used in today's residential and commercial construction industry. Another object of this invention is to provide a method and improvement to saw systems used to cut raw I-joists prior to their delivery to a construction jobsite that produces adhesive-enhanced I-joists that meet local building codes for floor construction which require the use of adhesives, and does so with a very low cost when compared to the labor cost of manual adhesive application. It is a further object of this invention to provide a method and improvement to saw systems used to cut raw I-joists prior to their delivery to a construction jobsite that produces adhesive-enhanced I-joists that promptly bond with adjacent sheer panels, achieve a more consistent bond between I-joists and adjacent sheer panels in finished construction than manually applied adhesives, and are not compromised by I-joist installation during inclement weather.
The present invention method and saw system improvement, when properly implemented, will provide I-joists enhanced with an adhesive layer and a protective liner that are able to achieve a more consistent bond with adjacent sheer panels to achieve maximum overall strength in finished construction for a very low cost when compared to the cost of on-site manual adhesive application. Such enhanced I-joists can be used in various parts of a building under construction, such as but not limited to floors, walls, decks, and/or roofs. It is contemplated for the adhesive layer and overlaying protective liner to be applied to at least one side of an I-joist flange by coordinated mechanical, electrical, and pneumatic components added to a saw system that convert raw I-joists from inventory to pre-cut sizes prior to shipment to a construction site or return to inventory, and/or a saw system that cuts routed patterns in I-joists for utility pass-through applications. Preferably, the present invention controller first accepts the cut patterns from the associated saw system controller. The associated saw system drive mechanism then begins transfer of the raw I-joist across the present invention improvement. In the alternative the present invention improvement can include an I-joist drive. An air-activated side pressure wheel in the present invention then pushes the I-joist to be enhanced against the opposing straight edge of the saw system's in-feed table assembly. Preferably, a low friction backing material is incorporated into or applied to the opposing straight edge, and/or one or more guide wheels are employed to reduce friction created by contact of the I-joist against the opposing straight edge. At least one present invention adhesive/glue head then extrudes glue/adhesive onto the exposed (top) edge of the I-joist. Once the glue/adhesive is applied, a present invention liner applicator then places a protective liner upon the applied adhesive. A present invention applicator roller bearing and a pressure roller bearing then press the adhesive and the protective liner to the mil thickness desired for the adhesive, after which the present invention liner applicator cuts the protective liner at pre-determined points according to the cut pattern instructions received from the saw system's controller. If needed, a cooler can be used to cool the glue/adhesive before the application of the release liner. An angled wheel in the present invention improvement then holds the enhanced I-joist in a fixed orientation so as to guide the I-joist to the saw system's routing and/or cutting stations and for optimum and expedient travel through the out-feed assembly of the present invention. In the alternative, the present invention improvement can be positioned after the saw system's routing and/or cutting stations, or between them if they are separate. It is contemplated for the combined saw system and present invention improvement to be located in an area where both are readily accessible for inspection, routine maintenance, and repair. The saw system used with the present invention improvement typically exceeds 130 feet in length and maintains a working height of approximately three feet, and further has a controller, a saw and/or router, an inkjet system for applying markings to the flange end web, an in-feed table assembly, an out-feed table assembly, an air compressor, and a dust collector.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a saw system that includes the most preferred embodiment of the present invention improvement.
FIG. 2 is an enlarged side view of saw system in FIG. 1 having a support table, a straight edge, an angled wheel to maintain the opposed end of an I-joist against the straight edge, a liner applicator, at least one glue head, and an alignment/pressure wheel.
FIG. 3 is a top view of the saw system in FIG. 1 having a remotely located drum melter and saw system CPU station.
FIG. 4 is an enlarged front view of the angled wheel used in the most preferred embodiment of the present invention used to maintain the opposed end of the I-joist against the straight edge of the saw system.
FIG. 5 is a further enlarged side view of combined saw system and present invention improvement in FIG. 1 that provides additional visual detail about present invention components.
FIG. 6 is an enlarged top view of the adhesive layer and release liner application system in the most preferred embodiment of the present invention.
FIG. 7 is a perspective view of a protective cover applied by the present invention across the top end of an I-joist.
FIG. 8 is a not-to-scale side view of an I-joist with an adhesive layer and protective cover applied by the present invention.
FIG. 9 is an enlarged top view of the most preferred embodiment of the present invention with alternative positioning of the release liner unwinder, low friction backing material secured to the opposing straight edge in place of guide wheel/roller bearings, a cooler, and I-joist sensors.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention provides value-added construction materials and a method that achieves a more consistent bond between structural framing components, such as but not limited to smaller I-joist 44 and larger I-joist 42 in FIG. 3 , and adjacent sheer panels (not shown) to achieve maximum overall strength in finished construction. Typically in the present invention, but not limited thereto, framing components, such as roof trusses, floor trusses, floor and ceiling joists, walls studs, roof and wall sheathing, and floor panels, will have adhesive (shown in FIG. 8 by the number 58 ) applied during manufacture to at least one surface, with the adhesive being configured and dimensioned to meet up with the intended contact area of the opposing component to which it will be joined after adhesive 58 has been pressed into its final thickness dimension. For example, but not limited thereto, in today's construction when roof trusses are laid out two foot on center, there is no adhesive between each truss and the sheathing above it, and thus no strength is provided in such a bond other than that which is derived via the nails or other fasteners used. When product made by the present invention is used (such as that shown in FIGS. 7 and 8 ), the bonding provided by its adhesive 58 enhances the overall strength of the roof in which it is used to protect roof integrity against strong winds and other harsh weather conditions. This bond can be provided by adhesive 58 applied during manufacture to the truss, the sheathing above it, or both. Similar application is anticipated for floor construction, wall construction, deck construction, and the construction of other areas needing added strength for enduring use. The present invention adhesive 58 can also completely cover a surface, or be applied to the construction materials in strips, such as two foot on center. When it completely covers the surface of a panel, the additional pre-applied adhesive of the present invention not in direct contact with an adjacent structural framing component can be used for interim or permanent bonding of vapor barriers and insulating materials. It is contemplated for the type of adhesive/glue used in the present invention to be unaffected by and/or protected from inclement weather so that a uniform and consistent bond is always achieved between adjacent framing components, even when installation occurs during adverse/inclement weather conditions that would otherwise cause construction delay. It is also contemplated for the product made according to the present invention to be used in all areas of a building, not just its floors, although it may be limited to one part of a structure that according to the intended application is in particular need of added strength. A covering, protective liner (such as liner 56 in FIGS. 7 and 8 ), or removable film is used over the adhesive 58 for pre-installation protection of adhesive 58 , with the intent that the covering/liner/film be removed immediately prior to enhanced framing component use. If the adhesive 58 used as a part of the present invention enhanced framing component is thickly applied during manufacture, the adhesive 58 would also provide a noise buffer in the finished structure, particularly when present invention enhanced framing components are used throughout the structure in its roof and walls, as well as its floor systems. FIG. 7 shows a perspective view section of I-joist 42 having opposed flanges 46 and 48 , with a release liner secured to flange 46 over an adhesive layer 58 that is hidden from view. In contrast, FIG. 8 shows an enlarged side view of the same flange 46 of I-joist 42 having an adhesive layer 58 in contact with flange 46 and a release liner 56 above adhesive layer 58 in a protective position over it.
FIGS. 1-6 and 9 show the most preferred embodiment of the present invention improvement 4 to a saw system 2 which allows the addition of adhesive layer 58 and a protective liner 56 to the flange 46 of various sizes of I-joist (such as but not limited to those shown by the numbers 42 and 44 ), while FIGS. 7 and 8 show an example of a product made by the present invention. As shown in FIG. 3 , a drum melter 52 and CPU station/controller 50 for saw system 2 are typically located remotely from the present invention support table 32 over which the I-joists 42 , 44 , or other travel for cutting/routing, as well as adhesive layer 58 and protective release liner 56 application. When needed, a cooler (such as but not limited to the cooler shown by the number 96 in FIG. 9 ) can be used to lower the temperature of glue/adhesive 58 before release liner 56 is applied. FIG. 1 is a side view of an entire saw system 2 with in-feed table assembly 8 and out-feed table assembly 12 , incorporating the most preferred embodiment of the present invention 4 therebetween for the addition of an adhesive layer 58 and a protective liner 56 to an I-joist 42 or 44 . Unless otherwise specifically excluded herein, it should be understood that any use of the designation I-joist 42 or 44 is not limited to the size and configuration of the I-joists 42 and 44 shown in FIG. 3 . FIGS. 2 and 5 are enlarged side views of a portion of the saw system 2 shown in FIG. 1 , with the present invention 4 having a support table 32 , an angled wheel 34 adapted to maintain the opposed end of the I-joist 42 or 44 against the straight edge 54 of saw system 2 , a liner unwinder 36 , liner applicator/cutter means 60 - 62 , at least one glue head 24 , and an alignment/pressure wheel 38 . Means to permit smoother transfer of an I-joist 42 or 44 across support table 32 during adhesive layer 58 application is also desired, which preferably comprises a low friction backing material (such as but not limited to that shown in FIG. 9 by the number 72 ), one or more guide wheel/roller bearings (such as but not limited to that shown in FIGS. 3 and 6 by the numbers 26 and 28 ), or a combination of the two. FIGS. 2 and 6 are top views of the most preferred embodiment of the present invention improvement 4 . As shown by the horizontally-extending left-pointed arrow in FIGS. 1-3 and 5 - 6 , the travel direction of I-joists 42 or 44 over saw system 2 is from right to left, although repositioning of components could also allow for left to right I-joist 42 or 44 travel. In addition, FIG. 3 shows the in-feed assembly 8 and present invention improvement 4 with the CPU station/controller 50 of saw system 2 being remotely positioned from the saw/router cabinet 6 , with the drum melter 52 for supplying adhesives 58 to glue heads 24 being remotely located from saw/router cabinet 6 . Although shown together in FIG. 3 , it is not critical for CPU station/controller 50 and drum melter 52 to be positioned adjacent to one another. FIGS. 4 and 9 shows an enlarged view of the angled wheel 34 used in the most preferred embodiment of the present invention 4 to maintain the opposed end of the I-joist 42 or 44 against the straight edge 54 of saw system 2 . Further, FIG. 9 is an enlarged top view of the most preferred embodiment of the present invention with alternative positioning of the release liner unwinder 36 and the use of low friction backing material 72 upon the entire face of straight edge 54 in place of guide wheel/roller bearings 26 and 28 .
The present invention improvement 4 is preferably integrated into a saw system 2 between its in-feed table assembly 8 and its sawing and routing station/cabinet 6 . However, although not shown, it is also contemplated for present invention 4 to be positioned between sawing and routing station/cabinet 6 and the out-feed table assembly 12 , or between sawing and routing equipment if not positioned in a combined sawing and routing station/cabinet 6 , as indicated in FIG. 2 . Typically, the raw I-joist product 42 , 44 , or other that needs to be cut to size and/or routed for a special purpose, is transferred through the present invention 4 by the saw system 2 drive. If the saw system 2 used with the present invention 4 does not have drive means, although not shown, it is contemplated that the present invention would include one. In either case, it is preferred for the drive means used to be controlled by electric or hydraulic power. The orientation of I-joist 42 or 44 for transfer along the saw system 2 in-feed table assembly 8 , sawing and routing station/cabinet 6 , and the present invention improvement 4 , is such that the opposed bottom flange 48 of the I-joist 42 or 44 not targeted for adhesive 58 and release liner 56 application is positioned against the straight edge 54 of saw system 2 , while the top flange 46 of the I-joist 42 or 44 targeted for enhancement is in a position remote from the straight edge 54 of saw system 2 . Two important purposes are served by this arrangement. The specified I-joist 42 or 44 orientation permits the operator 20 to visually observe the application of adhesive 58 in progress. Also, the protective release liner 56 will not be in a position to rub against the straight edge 54 of the out-feed table assembly 12 while transferring across the portion of saw system 2 beyond sawing and routing station/cabinet 6 . Rubbing on straight edge 54 could scratch the finish of protective liner 56 and degrade the quality of any ink jet markings applied thereto by printer 18 . Before running the I-joist 42 or 44 product through the combined saw system 2 and present invention improvement 4 , the present invention 4 will be adjusted according to the height and flange width of the I-joist 42 or 44 targeted for adhesive 58 and release liner 56 application. Such adjustment in present invention 4 can be via manual means, by automated operation, or both.
As shown in FIGS. 1-3 , the present invention improvement 4 to a saw system (such as but not limited to the saw system 2 in FIG. 1 ) is supported by a floor-mounted base frame in the form of a support table 32 , preferably made from steel and capable of adjusting to the height of I-joists, including but not limited to the I-joists 42 and 44 shown in FIG. 3 . Support table 32 includes a top surface configured for guiding the I-joist 42 , 44 , or other from the in-feed table assembly 8 of saw system 2 , across present invention 4 , and on to the sawing and routing station/cabinet 6 of saw system 2 . FIG. 2 also shows a dust collector 68 in association with sawing and routing station/cabinet 6 . The saw blade that cuts I-joists 42 or 44 to length is located adjacent to sawing and routing station/cabinet 6 and shown in FIGS. 1-3 and 5 by the number 66 . The present invention improvement 4 includes but is not limited to a top flange face guide/pressure wheel 38 , a length of low friction backing material (identified in FIG. 9 by the number 72 ) and/or series of straight edge guide wheels or roller bearings (identified by the numbers 26 and 28 in FIGS. 3 and 6 ), a cleaning brush assembly 64 , at least one adhesive application head 24 (also identified herein as glue head 24 ) connected via glue hoses 22 to a drum melter 52 with pump and controls, a liner unwinder 36 , a liner applicator 60 , at least one liner cutter 62 , and an adhesive system controller 70 , which is preferably located under and attached to main support table 32 . Mechanical components include a top flange face guide wheel 38 that is configured to push the I-joist 42 , 44 , or other to be enhanced against the straight edge 54 of saw system 2 . Pneumatic operation is contemplated for the opening and closing of guide wheel 38 to accommodate the size of I-joist targeted for enhancement ( 42 , 44 or other). A low friction backing material 72 and/or a series of guide wheels or roller bearings (such as but not limited to guide wheels or roller bearings 26 and 28 shown in FIGS. 3 and 6 ), are integrated into the straight edge 54 that is in an opposed position to the top face guide wheel 38 , whereby they to reduce friction and torque requirements of the saw system 2 drive and thereby permit smoother transfer of the I-joists, such as 42 and 44 , through the present invention improvement 4 . Low friction backing material 72 may comprise ultra high molecular weight (UHMW) polyethylene, but is not limited thereto. The brush assembly 64 sweeps the surface of the I-joist 42 or 44 free of dust immediately prior to the application of adhesive 58 . Preferred glue application components include a bulk hot melt tank 52 (also referred to herein as melter 52 ) with integral temperature controller, a variable speed-controlled pump (not separately identified with a number in the illustrations), at least one heated glue hose 22 , and at least one glue head assembly 24 . Each glue head 24 is independently adjustable according to I-joist 42 or 44 height and flange width. Further, each glue head 24 extrudes adhesive 58 at desired intervals according to patterns cut in response to the instructions given by the CPU station/controller 50 of saw system 2 . When needed, a cooler 96 can be used between glue head 24 and liner applicator 60 to lower the temperature of adhesive 58 before liner 56 is placed over adhesive 58 .
The present invention further has protective release liner 56 application components that include a liner unwinder 36 , as well as a liner applicator 60 with integral liner cutter 62 . As shown in FIGS. 6 and 9 , liner unwinder 36 is positioned above support table 32 and may be in varying positions and orientations relative to support table 32 . Preferably, the cutting knife or blade in liner cutter 62 is located at a distance of less than one inch from the positioning of liner applicator 60 . The liner unwinder 36 can be powered or non-powered, and maintains even tension according to variable saw system 2 speeds. The liner applicator 60 covers the already applied adhesive 58 on the top of the I-joist 42 or 44 with an easily-releasable protective liner 56 , and includes an integral applicator roll and an integral post pressure roll (not separately shown) that together form and maintain the desired mil thickness of adhesive 58 on the targeted top end of I-joist 42 or 44 . Pressure may be applied either mechanically or pneumatically. The liner cutter 62 severs the protective liner 56 at desired intervals according to the I-Joist 42 or 44 cut patterns determined by saw system 2 . Although not critical, it is preferred that the controller 70 in the most preferred embodiment of the present invention 4 have web-based support so that diagnosis and troubleshooting can be performed over an Internet connection. Further, it is contemplated that the most preferred controller 70 of the present invention improvement 4 will provide position verification for its components, it will accept signals from the CPU station/controller 50 of saw system 2 that provide I-joist 42 or 44 dimensions and cut patterns, and it will control the liner unwind, application, and cutting equipment 36 , 60 , and 62 . In addition, although not shown, it is contemplated for the most preferred controller of the present invention to have sensor and push button panel inputs; have mechanical, pneumatic, and alarming outputs; integrate the adhesive control system; monitor I-joist travel speed, and provide a signal for variable control of the adhesive pump associated with glue melter 52 . FIG. 9 also shows a floating sub-base 80 that preferably supports a guide wheel 76 , glue head or heads 24 , liner applicator/cutter 60 - 62 , and an adjustable base 78 . Sub-base 80 is guided by precision V-wheels 82 and V-rail 84 . The in and out motion of sub-base 80 is by air cylinder (not shown). Adjustable base 78 is adjusted manually to go up and down by a hand wheel 86 to position the components supported by sub-base 80 according to the flange width of the I-joist 42 , 44 , or other receiving adhesive/glue 58 and a protective liner 56 during travel across support table 32 . In addition, it is contemplated for liner applicator 60 to have a configuration and positioning that allows temporary rotation ninety degrees to simplify the threading of liner applicator 60 and for maintenance work. The position of liner applicator 60 is secured by a hand knob 94 . The pivot point for liner applicator 60 is shown by the number 92 . FIG. 9 also shows a leading edge control sensor 74 that detects the lead edge of an I-joist 42 , 44 , or other, which sends a signal to controller 70 , which then causes pressure wheel 38 to extend an I-joist 42 , 44 , or other against straight edge 54 . Upon command from controller 70 , sub-base 80 also extends toward I-joist 42 , 44 , or other, and makes contact with the top surface of the adjacent flange 46 of I-joist 42 , 44 , or other. Sub-base 80 will remain under air pressure to keep sub-base guide wheel 76 against I-joist 42 , 44 , or other. Guide wheel 76 and the floating capability of sub-base 80 will maintain a pre-determined desired distance between top surface 46 and glue head or heads 24 , as well as between top surface 46 and liner applicator/cutter 60 - 62 , so as to achieve consistent adhesive application. FIG. 9 also shows a trailing edge sensor 90 that instructs controller 70 that there is no longer an I-joist 42 , 44 , or other moving across support table 32 , whereby controller 70 then releases pressure wheel 38 , sub-base 80 , and angle wheel 34 so that they move away from straight edge 54 to an outermost position ready for the in-feed of another I-joist 42 , 44 , or other.
During its operation, the most preferred embodiment of the present invention 4 undergoes the following sequence of events. The controller 70 of the present invention 4 first accepts the cut patterns from the CPU station/controller 50 of saw system 2 . The trolley track drive assembly (designated by the number 10 in FIG. 1 ) of saw system 2 then begins transfer of the raw I-joist 42 or 44 across present invention improvement 4 . Although not shown, in the alternative the present invention 4 can include a drive for I-joist 42 or 44 travel during adhesive 58 and release liner 56 application. Upon instruction from controller 70 , the side pressure wheel 38 then pneumatically activates to push the I-joist 42 or 44 against the opposing straight edge 54 associated with the trolley track drive assembly 10 . Guide wheel 38 serves two functions. First, it protects the downstream equipment from damage in the event an I-joist 42 or 44 is bowed away from straight edge 54 and thus would strike the adhesive application equipment. Second, it also maintains the desired gap between the I-joist 42 or 44 surface receiving the adhesive 58 and the release liner 56 . If the I-joist 42 or 44 surface were to bow out toward the orifices of the glue head 24 , the adhesive pattern would be adversely affected. Because guide wheel 38 forces the I-joist 42 or 44 against straight edge 54 , friction is produced that can adversely affect the performance of the Sawtek drive mechanism (an AC Servo controlled “Trolley”). Low friction backing material 72 and/or roller 26 opposes guide wheel 38 in order to reduce friction at the straight edge 54 across from guide wheel 38 . Low friction backing material 72 and/or roller 28 serves the same function only it is located opposite of angled wheel 34 . The glue head or heads 24 then extrude glue/adhesive 58 onto the targeted top edge 46 of the I-joist 42 or 44 according to saw system 2 speed. The liner applicator 60 then places the protective release liner 56 on top of the already applied adhesive 58 on the top edge 46 of I-joist 42 or 44 . The applicator roll and post pressure roll integral to liner applicator 60 , and not separately shown, press the adhesive 58 and the protective liner 56 to the desired mil thickness of adhesive 58 that is dictated by the construction application in which it will be used. Further, the liner cutter 62 cuts the protective liner 56 at pre-determined points according to the cut pattern instructions received from the CPU station/controller 50 of saw system 2 . Angled wheel 34 holds the I-joist 42 or 44 against the straight edge 54 as it leaves present invention improvement 4 and travels toward the saw/routing station/cabinet 6 , after which controller 70 releases pressure wheel 38 , sub-base 80 , and angle wheel 34 so that they move away from straight edge 54 to an outermost position ready for the in-feed of another I-joist 42 , 44 , or other. In the alternative, although not shown, it is contemplated that adhesive 58 could be applied first to the release liner 56 , and the combined adhesive 58 and release liner 56 pressed against the top 46 of an I-joist 42 , 44 , or other so that the adhesive 58 is protected between release liner 56 and the top 46 of the I-joist 42 , 44 , or other.
The combined saw system 2 and present invention improvement 4 must be located in an area where they are readily accessible for inspection, routine maintenance, and repair. At a minimum, the saw system 2 used with the present invention improvement 4 has a CPU station/controller 50 , a saw/router cabinet 6 , an air compressor 40 , a dust collector 68 , an in-feed table assembly 8 , an out-feed table assembly 12 , and a trolley track drive assembly 10 and associated straight edge 54 . Although not limited thereto, it is preferred for the combined saw system 2 and present invention improvement 4 to exceed 130 feet in length and maintain a working height of approximately three feet.
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A method and an improvement to saw systems configured to convert raw I-joists from inventory to pre-cut sizes and/or cut routed patterns in I-joists for utility pass-through applications prior to their shipment to a construction site or return to inventory, whereby a controlled amount of adhesive and a protective liner are automatically and successively applied to the top flange of each I-joist. The saw system improvement comprises coordinated mechanical, electrical, and pneumatic components.
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BACKGROUND AND SUMMARY OF THE INVENTION
This invention pertains to devices for shredding stumps of trees and more particularly to such a device which can be maneuvered into small spaces, close to buildings or other trees or the like.
Most stump cutters are trailer-mounted, adapted to be pulled by a pickup truck, or an automobile. Such devices are customarily quite large, having carrier wheels spaced at a distance about equal to or greater than those of the pulling device. This is needed because the cutting wheel normally travels between the carrier wheel spacing and that travel needs to be sufficient to traverse the stump to be removed.
By my invention I provide a small device adapted to be transported on a trailer. However, it is a self-propelled device and when unloaded can be driven precisely to almost any stump and because of its extension, it can be extremely flexible so far as location of the stump is concerned. It is very compact so as to be easily transported and very maneuverable to reach into difficult locations.
A special arrangement of teeth on the cutting wheel also enhances the shredding ability and quick operation of the device.
FIGURES
FIG. 1 is a top plan view of the device of my invention,
FIG. 2 is a side elevational view of the device of FIG. 1,
FIG. 3 is a detailed plan view, to an enlarged scale, of the structure at the swivel joint for the cutter carrier structure,
FIG. 4 is an end view of the structure of FIG. 3,
FIG. 5 is a sectional view from line 5--5 of FIG. 3,
FIG. 6 is a view to an enlarged scale of the edge of the cutter wheel,
FIG. 7 is a view similar to FIG. 6 of an alternate wheel using a different mounting means for the teeth, and
FIG. 8 is a side view of the wheel of FIG. 7.
DESCRIPTION
Briefly my invention comprises a stump cutter having the capability of self-propulsion and using a swinging cutter designed so that the cutter may be relatively narrow while retaining the ability to cut a relatively large stump. I also provide a novel cutting wheel to increase the speed of shredding the stump.
More specifically, and referring to the drawings, my device is mounted on a frame composed of two legs 10 arranged in V-shape and held in that position by a gusset plate 11 attached to the legs 10 by a web 12 (FIG. 5). This web extends from each leg 10 to the edge of the plate 11, but is omitted on both sides for a distance to form a slot on each side. Thus a support plate 13 having ears 14 can be pivotally moved relative to the plate 11. A further description of this function is provided later in this description part of the specification.
The end of the legs 10 opposite the plate 11 carry carrier wheels 15. These wheels are mounted on brackets 16 pivoted to the leg by pins 17. The bracket includes extensions 18 and 18' extending from the pivot point in directions diametrically opposite to each other. A holding pin 19 engaged between the leg 10 and one of the extensions is adapted to hold the wheel supporting bracket in position either outside of the frame as shown on one of the legs 10 in FIG. 1 or on the inside of the frame as shown by the other leg 10 of FIG. 1. Thus, the wheels 15 can be spread wide with both outside the frame for stability while cutting a stump or can both be retracted for compactness while being maneuvered into place in a narrow spot. For transportation, the wheels may be in either position, although I prefer to spread them apart for stability.
At the juncture of the legs 10 the frame includes a yoke member 20 fixed to the legs. This member extends diagonally upward for a small distance and then horizontally. At the end of the horizontal part 22 I provide a socket 23 in which a post 25 on an axle 24 is journalled for pivotal motion. This axle then can be turned to steer the device. Wheels 26 are journalled on the axle 24. Thus the axle 24 becomes a steerable axle. It is envisioned that a single wheel could be used at this point, but for stability I prefer to use a longer axle with wheels at each end.
Steering may be accomplished by use of hydraulic cylinder and piston means. This is illustrated in FIGS. 1 and 2 by the hydraulic assembly 28 connected between the axle 24 and the frame near the end of the leg 10. Control may be from a central control panel 29 mounted on the yoke 20.
Drive means for at least one wheel 26 is also provided. I prefer to use a driven axle with the wheels fixed to the axle and the axle journalled in a tubular journal. However, the drive could be to a single wheel or to both wheels. In the embodiment shown I use a hydraulic motor 30 to drive a belt or chain 31 which, in turn, drives the axle. Where two wheels are driven, they may be linked by what is known as "Positraction" for better traction where necessary. It will also be obvious that other types of drive could be used. Control of the motor 30 is also from the control panel 29.
The cutting mechanism and its motion control is mounted on the frame. In essence, the mounting is the pivotally mounted plate 13. As best shown in FIGS. 3, 4 and 5, this plate is pivoted on the frame at the gusset plate 11 by a pin 35. The elevating mechanism is pivotally mounted on the support plate 13 by means of a yoke having two upstanding ears 36 in which a horizontal pivot pin 37 is mounted.
The cutting mechanism is mounted on a V-shaped member which includes a carrying arm 39 and a raising lever 40. These members are formed into a rigid single member having separate functions. The vertical position of the carrying arm 39 is controlled by the position of the lever 40. That position, in turn, is controlled by a hydraulic piston and cylinder assembly 41 (FIG. 2). That assembly 41 is attached pivotally to the lever 40 and to the frame horizontal member 22. Both of those connections are somewhat loose in order to allow some moderate lateral movement of the arm 39 without binding.
In order to provide added flexibility in positioning the cutter, I prefer that the arm 39 be a telescoping device having a telescoping member 43 slidably engaged with the arm 39. The relative positions of these two members may be controlled by use of another hydraulic assembly 44. Both this mechanism 44 and the assembly 41 may also be controlled from the panel 29.
The cutting mechanism is mounted on the extended telescoping member 43. It includes a cutter wheel 45 rotatably mounted on a depending branch 46 of the member 43. The motor 47 which drives the wheel is also mounted on the member 43 so that there is always a fixed space between the two units. Preferably I use a belt drive 48 from the motor 47. This type of drive absorbs some of the cutting shock from the wheel 45 so that the motor does not have the direct shock, but that those intermittent forces will be somewhat damped. I illustrate, and prefer to use an idler 50 between the motor 47 and the final drive to the wheel 46. This allows for a change in the direction of the drive, as well as allowing for some additional speed modification. Controls for the motor 47 may also be mounted on the control panel 29 so that all controls are located at the same place on the machine. This motor also includes the hydraulic pump which provides pressure to all the hydraulic units shown.
I show the final drive as a chain 51 driving a sprocket 52 on the same axle as the cutting wheel 46. A tension idler 53 may also be used to keep proper tension in the chain.
My cutter wheel is also novel. I have discovered that by using a relatively heavy wheel so that the fly wheel effect is augmented, and by using alternately staggered teeth, I can provide for cutting a much wider kerf across the stump and can therefor chip the stump away considerably faster than with previous types of cutters. As shown in FIG. 6, I provide a disk 55 of steel or the like, thus providing for the flywheel effect. On the periphery of the disk, I use cutting teeth which may cut on either side of the disk as the teeth 56 and 56'. Another set of teeth 57 is mounted on the disk 55 to cut the material between the places cut by the teeth 56 and 56'. Flanges 58 may be used to hold the teeth to the disk, and all of the teeth are variably mounted on the flanges. The exterior teeth 56 and 56' are mounted to one side of the flanges so that these flanges will not cause interference with the portion of the stump not cut away, and thus I provide an easily removable and replaceable tooth as well as a more efficient cutting wheel. It will be obvious that although I have illustrated the teeth 56 and 56' to be mounted together at a single location on the periphery of the wheel, that they, too, could be located in staggered positions around the periphery.
The alternate wheel shown in FIGS. 7 and 8 is very similar to that shown in FIG. 6 except for the mounting of the staggered teeth. In this embodiment, the teeth 61 are all formed the same, and are mounted in sets of four. One tooth of each set is mounted in a socket formed across about half the thickness of the disk 55 on one side. A second tooth is mounted similarly in a socket across about the half of the thickness opposite to the first. The third and fourth teeth are mounted similarly on the exterior faces of the disk 55 on opposite sides. Thus, the coverage of the cutter is similar to that first described.
In use, I prefer to carry my device on a trailer for transportation from one site to another. For that purpose, I pivot both wheels 15 to the outer position in which each wheel is outside the leg 10 to which it is attached. This provides for a stable and easily transported device. If necessary to keep the machine within a given width of trailer, either or both wheels could be turned inward for transport.
On getting to the site where stumps are to be removed, the machine is unloaded and if necessary to get into a tight place the position of the wheels 15 may be reversed to provide a narrow machine capable of getting into narrow areas. Otherwise, the wheels are left spread to provide a broad stable base from which to operate. The motor 47 may then be started to provide motive power through the hydraulic motor 30 and steering through operation of the hydraulic piston-cylinder assembly 28. The operator, walking alongside the machine may handle the controls on the panel 29 to position the cutting wheel properly over the stump. That positioning may also be made easier by being able to extend the telescoping arms 39 and 43. In order to prevent tipping when that arm is extended I may also provide a counterweight 60 to be attached to the end of the device opposite the cutter.
When the device is properly positioned, a clutch (not shown) on the motor may be engaged to cause the wheel 45 to be driven. The controls may then lower the wheel 45 through operation of the hydraulic device 41 until it starts cutting into the stump. Lateral movement is provided by pivoting the plate 13 through operation of hydraulic devices 61 (FIGS. 1 and 2) connected between the ears 14 on the plate 13 and the legs 10 of the frame. Motion of these hydraulic devices is controlled similarly to all other systems from the panel 29, and if two piston and cylinder assemblies are used, as shown, the systems may be interlocked so that only a single control is necessary.
The lateral motion, resulting from the swinging back and forth of the carrying arm 39 and its attachments, causes the cutting wheel 45 to sweep back and forth across the stump. The teeth on the wheel 45 chip the stump into small pieces in a manner common to all cutter devices of this type. Because of the offset location of the teeth 56, 56' and 57, the chipping speed is enhanced and each pass across the stump may be done quickly. At each successive pass, the cutting wheel may be lowered by use of the hydraulic device 41 until the stump is completely destroyed.
Thus, I have provided a device easy to transport; a mobile and compact device easy to position in a working position; and an efficient device, easy to operate and quick to dispose of the stump to be cut up.
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A self-propelled stump cutter adapted to move under its own power to maneuver into small spaces where stumps might be located close to buildings or to other trees. The device includes a frame with a plurality of hydraulic means to steer the cutting wheel over the stump and to raise and lower the wheel. Hydraulic motors are also used to propel the device.
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BACKGROUND OF THE INVENTION
This application is related to copending patent application Ser. No. 07/314,747, filed on Feb. 24, 1989, and assigned to the same assignee.
1. Field of the Invention
The present invention relates generally to floating structures and, more particularly, to oil-and-gas drilling and production platforms using onboard tensioners for tensioning production risers, which extend offshore wells to wellheads on the platforms.
2. Description of the Prior Art
A platform is effectively a spring mass system and as such has a resonant (natural) frequency F n or period T n =l/F n and is subject to resonant oscillatory motion in response to wave action in the seaway. Resonant motion occurs when the natural period of heave is substantially equal to the period of the wave which induces such heave in the platform.
The patent literature describes various structures and arrangements for dynamically and passively damping a floating platform, but these usually require design changes to the platform itself, and/or the use of special devices for achieving the desired damping.
For example, Bergman's U.S. Pat. No. 4,167,147 describes a floating structure having a variety of arrangements for producing velocity damping, i.e., anti-heave forces that are proportional to the heave velocity of the structure.
Bergman's damping system is intended to exert anti-heave forces as the vessel heaves up and also as the vessel heave down. These anti-heave forces are exerted on the structure in a direction opposite to its vertical motion; they are much smaller than the actual wave forces which produce the heave; and they provide a most effective decrease in heave amplitude, especially when the platform is about to approach resonance.
Bergman illustrates in FIG. 14 a passive, damping system which requires a tensioned flexible cable the lower end of which is anchored to a weight on the sea floor, and its upper end passes over a sheave and is fixedly secured to the platform's upper deck. Also on the upper deck is a hydraulic cylinder whose piston rod supports the sheave. The cylinder is filled with pressurized oil below the piston. A restrictive orifice is interposed in the pipe between an oil reservoir and the cylinder to restrict the oil flow between the cylinder and the reservoir.
A deep-floating production platform, which produces oil through wellheads suspended above the waterline, must make use of one production riser for each suspended wellhead. Each riser tensioner system comprises at least one hydraulic cylinder, and a pneumatic-hydraulic source for supplying pressurized fluid to the cylinder. The cylinder is extensibly coupled between a deck and a guide ring which is pivotably anchored to the upper end of the production riser.
This tensioner system is designed to maintain a predetermined minimum, nearly constant tension in the production riser despite relative vertical movement between the floating platform and the guide ring in response to oscillatory wave action on the platform.
It is an object of the present invention to prevent excessive platform resonant heave by modifying the already existing riser tensioner system so that it can generate and apply a downward-acting, anti-heave force to the platform, without interfering with the tensioner's ability to maintain the predetermined minimum tension sufficient to prevent buckling in the production riser, while continuous fluid production takes place from the well through the riser and its associated wellhead tree.
These downward-acting, anti-heave forces can be generated using hydraulic, mechanical, and/or electrical damping means, which maintain, within acceptable limits, the resonant heave response of the platform to wave energy exceeding the expected maximum wave period.
SUMMARY OF THE INVENTION
The damped floating structure has a deck and is free to have limited heave oscillations. A long member has a lower end coupled to the seabed. Coupling means are pivotably secured to the upper end of the long member. An extensible damper-tensioner means is coupled between the deck and the coupling means.
The damper-tensioner suspends the coupling means and applies a predetermined tension thereto. The damper-tensioner includes anti-heave damping means for exerting damping forces on the floating structure, preferably only when the structure heaves up, thereby exerting downward-acting damping forces on the floating structure. The damping means becomes inactive when the structure heaves down.
The floating structure is typically a hydrocarbon production platform, the long member is a production riser, and the coupling means is a guide ring. The extensible damper-tensioner includes a hydraulic cylinder, which has a reciprocating piston rod, and a pneumatic-hydraulic source for feeding and receiving pressurized fluid to and from the cylinder depending on the platform heave oscillations.
A first conduit is coupled between the source and the cylinder. A throttling orifice is in the first conduit. The orifice throttles the fluid flow therethrough as a function of a parameter of the platform heave oscillation.
A second conduit is in parallel with the first conduit. A normally-closed, one-way-acting check valve is in the second conduit. The check valve is closed during a portion of the stroke of the piston rod, and it is open during another portion of the stroke to permit unrestricted fluid outflow from the source to the cylinder, thereby by-passing the orifice. The check valve opens only when the cylinder retracts, i.e., when the platform heaves down.
In some of the embodiments, the damping forces have amplitudes which vary with a parameter of the motion of the cylinder. The parameter is the velocity of the cylinder.
In an alternate embodiment, instead of an orifice, a hydraulic motor is in the first conduit and is operable by the fluid flow through the first conduit. The hydraulic motor drives a suitable load, such as a water pump, etc.
A second conduit with a check valve is in parallel with the first conduit. The check valve opens as in the orifice embodiment.
A third conduit can be provided in parallel with the first and second conduits. A normally-closed control valve is in the third conduit.
When the control valve is opened, the orifice (or the hydraulic motor) together with the check valve become inactive.
In yet another embodiment, at least one rail on the platform is movable therewith relative to the guide ring. The rail preferably has an I-shape in section. A carriage extends radially outwardly from the guide ring. The carriage carries sets of wheels which ride on the web and the flanges of the rail, thereby restricting the tendency of guide ring to rotate and/or to displace laterally.
Motion slowing down means, operatively associated between the guide ring and the rail, are designed to impede the vertical displacements of the rail relative to the guide ring.
The motion slowing down means can be hydraulic brakes, preferably linear friction brakes, for slowing down by friction the upward rail motion.
The motion slowing down means can be linear eddy current brakes.
The linear hydraulic or eddy current brakes are under the control of sensors and instrumentation control modules.
Preferably, only when the platform heaves-up, will the braking action of the linear brakes produce, by friction or electro-magnetically, downward-acting damping forces on the platform.
When the platform heaves-down, the braking action of the brakes is deactivated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side elevation view illustrating applicants' prior semi-submersible floating platform in position for operation and in which the damper-tensioner system of the present invention can be employed;
FIG. 2 is a schematic side elevation view, partly in section, of the novel embodiments of the damper-tensioner system which use linear brakes and guide rails for producing anti-heave damping forces;
FIGS. 3 and 3a are schematic side elevation views of the novel embodiments of the damper-tensioner system in which the pneumatic-hydraulic circuit, coupling the reservoir and the hydraulic cylinder, includes various combinations of flow control elements for generating the anti-heave damping forces;
FIG. 4 is a sectional view taken on line 4--4 of FIG. 2;
FIGS. 5-6 are partly sectional views, respectively taken on lines 5--5 and 6--6 of FIG. 4;
FIGS. 7-8 are partly sectional views, respectively taken on lines 7--7 and 8--8 of FIG. 6;
FIG. 9 is a sectional view taken on line 9--9 of FIG. 5 of the embodiment using hydraulic brakes;
FIG. 10 is a partly sectional view taken on line 10--10 of FIG. 9;
FIG. 11 is a view similar view to FIG. 9 but of the embodiment using eddy current brakes;
FIG. 12 is a partly sectional view of the eddy current braking system taken on line 12--12 of FIG. 11;
FIG. 13 is a graph depicting the variation in tension applied to the production riser as a function of piston-rod stroke for a damper-tensioner using a reservoir of finite volume; and
FIG. 14 is a graph similar to FIG. 13 depicting the tension regime of a damper-tensioner for different constant heave velocities only for upward heave.
DESCRIPTION OF PREFERRED EMBODIMENTS
Many different types of semi-submersible structures are known and presently employed for hydrocarbon drilling and/or production, and principles of the present invention are applicable to many of these, and also to floating structures of other types. Such structures are subject to resonant heave in a seaway.
The invention will be better understood after a brief description of applicant's prior platform and tensioner.
Applicant's Prior Low-Heave Platform
The low-heave, column-stabilized, deep-drafted, floating, production platform 10 (FIG. 1) is described in copending application Ser. No. 07/239,813, filed Sept. 3, 1988, and now U.S. Pat. No. 4,850,744. Platform 10 has a fully-submersible lower hull 11, and an above-water, upper hull 12, which has an upper wellhead deck 13. Lower hull 11 together with large cross-section, hollow, buoyant, stabilizing, vertical columns 14 support, at an elevation above the maximum expected wave crests, the entire weight of upper hull 12 and its maximum deck load.
In use, platform 10 is moored on the production location by a spread-type mooring system (not shown), which is adapted to resist primarily horizontal motion of the platform.
Platform 10 is especially useful in a design seaway for conducting hydrocarbon production operations in relatively deep waters over a seabed site 16 which contains submerged oil and/or gas producing wells 17.
By virtue of the platform's relatively low-heave response in the design seaway, risers 20 and surface-type, production wellhead trees 18 (FIG. 2) can be suspended from wellhead deck 13 above waterline 19. Each wellhead tree 18 is coupled to an individual well 17 through the stiff metal pipe, or production riser 20.
The lower end of riser 20 is tied to a submerged well 17 in seabed 16. Wellhead trees 18 include valves for controlling the fluid flow through risers 20.
Applicant's Prior Tensioner
Each individual riser 20 (FIGS. 1-3) is suspended above water line 19 from a riser tensioner system 21, which comprises one or more, usually four, individual riser tensioners 22.
Pneumatic-hydraulic tensioners are the most commonly used, for example, Model PT400-60, sold by Paul Monroe Co., of Orange Calif. 92668. Also, such tensioners are well described in U.S. Pat. Nos. 4,733,991, 4,379,657 and 4,215,950.
Each tensioner 22 comprises a pneumatic-hydraulic source or reservoir 23 for supplying through a pipe 24 pressurized hydraulic fluid to a hydraulically-operated movable member, typically a hydraulic cylinder 25, having a power piston 26 and a movable piston rod 27. Pipe 24 connects the bottom of hydraulic reservoir 23 with the bottom of cylinder 25 at the rod side thereof.
Each cylinder 25 is pivotably coupled to wellhead deck 13 by a pivot 28. Piston rod 27 extends downwardly and inwardly and is pivotably connected by a pivot 28' to a coupling member, such as a guide ring 30, which is pivotably secured to the upper end 31 of riser 20 by a spherical anchor pivot 29. In use, there should be no relative axial motion between riser 20, wellhead 18, and guide ring 30.
As platform 10 cyclically heaves up and down during each oscillatory cycle, hydraulic fluid is alternately pushed through pipe 24 in and out of cylinder 25, and out of and into reservoir 23. In so doing, the air pressure above the hydraulic fluid in reservoir 23 remains nearly constant due to the large volume of reservoir 23, which allows cylinder 25 to continually support the weight of riser 20 and its wellhead tree 18.
Conventionally, two pairs of such tensioners 22 are located on diametrically-opposite sides of guide ring 30, and each pair operates at identical fluid pressures to prevent uneven riser loading.
For any position of piston 26 along its stroke, piston-rod 27 will apply, through guide ring 30, a continuous, predetermined, large, substantially-constant, upward-acting force F (FIG. 3) for tensioning riser 20.
This force induces a predetermined tension T o at the top of riser 20, regardless of the displacements and velocity of piston-rod 27. The amplitude of tension T o should be sufficient to maintain positive tension along the entire length of riser 20, thereby to protect riser 20 against buckling in the design seaway.
When platform 10 sustains oscillatory heave motion in response to wave actions, piston 26 reciprocates in cylinder 25. Each piston 26 has a fixed stroke range calculated to compensate for the maximum expected heave of platform 10 in the design seaway, i.e., the maximum relative vertical displacement between platform 10 and guide ring 30.
Damper-Tensioner of the Invention
To facilitate the understanding of the damper-tensioner of the present invention and to avoid repetitive description, the same numerals will be used, whenever possible, as in tensioner system 21, to designate the same parts. Similar parts may be designated with the same reference characters followed by a letter or prime () to indicate similarity of construction and/or function.
The novel damper-tensioner will be shown in four embodiments 22A-22D, which vary in their ability to produce the desired downward-acting, damping forces on platform 10.
No upward-acting damping forces are produced and therefore none are applied to platform 10.
First Embodiment 22A
Damper-tensioner 22A (FIG. 2) comprises a damping means 32 within first pipe 24, such as throttling orifice 32A.
When platform 10 heaves up during each cycle of platform oscillation, piston 26 strokes out, thereby pushing hydraulic fluid out of cylinder 25 and into reservoir 23 through pipe 24 wherein it will be throttled by its orifice 32A.
Accordingly, orifice 32A will generate a downward-acting damping force on platform 10 when it heaves up.
If damping means 32 had only an orifice 32A, then it would also generate an upward-acting damping force on platform 10 when it heaves down, thereby permitting the risers tension to decrease. In this case, T o must always have a value at least large enough to prevent riser buckling despite the reduction in tension accompanying the upward-acting damping force.
Accordingly, damper-tensioner 22A also includes a one-way acting check valve 33 in a second pipe 34, and preferably also a normally-closed control valve 35 in a third pipe 36. The second and third pipes 34, 36 are in parallel with first pipe 24.
As before, when platform 10 heaves up, piston rod 27 strokes out, and check valve 33 is closed, thereby pushing the hydraulic fluid out of cylinder 25 and into reservoir 23 through orifice 32A, which will generate and apply only a downward-acting damping force on the platform.
But now, when platform 10 heaves down, piston rod 27 retracts and check valve 33 opens to permit unrestricted hydraulic fluid flow from reservoir 23 to cylinder 25 through the check valve, which by-passes orifice 32A and no upward-acting damping force will be produced.
With proper design of orifice 32A, the generated damping force will increase the predetermined tension T o in riser 20 by an amount which is proportional to the velocity of the upward heave of platform 10. This increase in tension is such that the total tension will not exceed the safe axial tension strength of riser 20.
Control valve 35 can selectively deactivate orifice 32A together with check valve 33, when no damping is desired. When normally-closed valve 35 is opened, unrestricted fluid will flow therethrough, and no hydraulic fluid will flow through first and second pipes 24 and 34.
Second Embodiment 22B
Embodiment 22B (FIG. 2) differs from embodiment 22A primarily in that a hydraulic motor 32B replaces throttling orifice 32A. This can be accomplished by opening certain normally-closed valves and by closing certain normally-open valves in pipe 24 and in a parallel pipe 24'. Hydraulic motor 32B FIG. 3A drives a suitable load, such as a water pump (not shown).
As before, when platform 10 heaves up, piston rod 27 strokes out, check valve 33 is closed, thereby pushing the hydraulic fluid out of cylinder 25 and into reservoir 23 through hydraulic motor 32B, which will generate and apply only a downward-acting damping force on the platform.
Conversely, when platform 10 heaves down, piston rod 27 retracts and check valve 33 opens to permit unrestricted hydraulic fluid flow from reservoir 23 to cylinder 25 through the check valve, which by-passes motor 32B and no upward-acting damping force will be produced.
When control valve 35 is opened, unrestricted fluid will flow therethrough, thereby by-passing check valve 33 and hydraulic motor 32B, and no hydraulic fluid will flow through first and second pipes 24 and 34.
Valve 35 can remain open most of the time and closed only when a storm is anticipated, as a precautionary measure against wave energy approaching the platform's resonant period T n
Third Embodiment 22C
In another embodiment 22C, at least one but preferably four vertical rails 40 (FIGS. 2-10) are secured to the solid frame of platform 10. Each rail 40 preferably has an I-shape in section, which provides a web 41 and inner and outer flanges 42, 43, respectively. A flat bar or fin 44 of suitable metal has a polished surface on both sides and is welded to the inner flange 42 of rail 40.
Carriages 46 are secured to and extend radially outwardly from guide ring 30. Each carriage has sets of guide wheels 48 which ride on the web and the flanges of rail 40.
Rails 40 are movable with production platform 10 relative to guide ring 30, and they restrict the tendency of guide ring 30 to rotate and/or to displace laterally.
Guide ring 30 carries motion slowing down means, generally designated as 50, which are operatively associated between guide ring 30 and rail 40, and are designed to impede the vertical displacements of rail 40 relative to the guide ring.
Guide ring 30 can carry arrays of linear friction brakes, such as mechanical caliper brakes 51, which are adapted to bear against the polished surfaces of fins 44.
Linear brakes 51 are operated by hydraulic power means (not shown) under the control of an instrumentation control module 52 (FIG. 3). Module 52 is responsive to sensors, including motion and load sensors (not shown), for the purpose of controlling the braking actions of the linear caliper brakes 51.
Brakes 51 are applied against fins 44 only when platform 10 heaves up, thereby slowing down by friction the upward motion of platform 10. The brakes 51 are deactivated when platform 10 heaves-down.
In embodiment 22C, the caliper brakes 51 develop frictional forces that are independent of the platform's displacements relative to the riser. Accordingly, brakes 51 will generate downward-acting, anti-heave forces which are substantially constant and also independent of the heave velocity of platform 10.
Fourth Embodiment 22D
In yet another embodiment 22D (FIGS. 11-12), the motion slowing down means 50 are linear eddy current brakes 60, which are comprised of a long, flat conductive armature 61 that is fastened to the face of inner flange 42 of rail 40.
Linear brakes 60 are operated by current means (not shown) under the control of instrumentation control module 52 (FIG. 3) and its motion and load sensors.
A multiple-winding iron core 62 has an array of eddy current coils 63 and serves as the pole piece which rides vertically up and down on armature 61. As such, brakes 61 depend on a change of magnetic flux, and they develop forces that are dependent on the velocity of the platform's displacements. Accordingly, brakes 60 will generate downward-acting, anti-heave forces which are dependent on the heave velocity of platform 10.
Brakes 60 are applied only when platform 10 heaves up, thereby slowing down electro-magnetically the upward rail motion, and producing downward-acting damping forces on platform 10. The brakes 60 are deactivated when platform 10 heaves-down.
In some of the foregoing embodiments, there is a need to remove heat from the damper-tensioner system 21, which can be conventionally absorbed by platform 10, by heat exchangers, etc.
FIG. 13 shows the variation in tension applied to the production riser 20 as a function of stroke of piston for a tensioner system using a reservoir 23 of finite volume. The stroke units on the X-axis are in feet and the tension units on the Y-axis are in kips.
FIG. 14 is similar to FIG. 7 and shows the tension regime of a modified damper-tensioner for different constant upward heave velocities.
THEORETICAL CONSIDERATIONS
Platform 10 may be designed so as to experience a low resultant vertical force or heave response to all waves with substantial energy in the design seaway, and to have a natural heave period T n , which is greater than the longest period of the wave with substantial energy in the design seaway.
However, because determination of the worst expected or design seaway is based on historical records and statistics, a certain degree of uncertainty can be expected. Therefore, designers are always faced with a remote but real probability that the longest design wave period may be exceeded during the expected life of the floating platform.
The platform's heave displacement is a particularly serious problem for the rigid production risers 20 which are suspended by tensioners 22 whose hydraulic cylinders have a fixed stroke range. From a mathematical point of view, the tension generated by a hydraulic-pneumatic, damper-tensioner system (assumed to be frictionless) can be expressed as:
T(S,ds/dt)=T.sub.o +ΔT (1)
ΔT=kS+c(ds/dt) (2)
where:
T(S,ds/dt) = tension versus stroke and stroke velocity
ds/dt = stroke velocity
c(ds/dt) = damping force component of change in tension
S = stroke of the piston in cylinder
kS = stiffness force component of change in tension
ΔT = change in tension
k = spring constant of the tensioner system
c = damping coefficient of the tensioner
T o = tension needed to prevent riser buckling
In a conventional tensioner, the mechanical arrangement including piping is purposely designed and sized to provide an unrestricted flow of fluid between cylinder 25 and reservoir 23, thereby reducing to zero the component of change in tension c(ds/dt), which is the damping force of the tensioner system that causes a change in tension proportional to the stroke velocity of piston 26.
The magnitude of the variation in tension due to stroke (i.e., stiffness component Ks) depends on the volume of reservoir 23. For a reservoir 23 of infinite volume, ks would be zero. This volume of reservoir 23 is usually selected to keep the change in tension due to stiffness kS within + (5-15% of the tension T o , which is the predetermined-tension that is needed to suspend and prevent buckling of production risers 20.
The component of change in tension kS is related to the compression-expansion of the gas in reservoir 23 as the hydraulic fluid is pushed out of and into cylinder 25 and into and out of the reservoir.
The platform's largest expected heave must be within the defined stroke range in order to ensure structural integrity of the stiff production risers 20.
With proper design of hydraulic motor 32B, orifice 32A, or linear eddy current brakes, the generated damping force will increase the tension T o in riser 20 by a velocity dependent change in tension c(ds/dt).
In all embodiments, the downward-acting forces generated by damper-tensioners 22 are preferably downward-acting, thereby only increasing the tension T 0 . When platform 10 heaves down, the increased tension in risers 20 returns to its predetermined value T o .
It will be apparent that variations are possible without departing from the scope of the invention.
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The floating structure has limited heave oscillations. A long member has a lower end coupled to the seabed. An extensible tensioner is coupled between a platform deck and the upper end of the long member. The tensioner suspends the upper end of said long member and applies a predetermined tension thereto. The tensioner includes anti-heave force-exerting means for exerting downward-acting forces on the floating structure.
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BACKGROUND OF THE INVENTION
This invention relates to tufting machines and more particularly to a method and apparatus for selectively forming cut pile and loop pile having substantially the same pile height as the cut pile in the same row of stitching in a backing material.
In Jolley, et al., U.S. Pat. No. 4,134,347 and Inman, U.S. Pat. No. 4,185,569, a method and apparatus for forming cut pile and loop pile are substantially the same pile height in the same row of stitching is disclosed. These patents represent improvement over Card, U.S. Pat. No. 3,084,645 wherein the cut pile projects substantially further from the backing than the loop pile and thus the pile height differs substantially. In McCutchen, U.S. Pat. Nos. 2,879,728 and 2,879,729, prior attempts to provide level cut and loop pile were made without success. The inventions in the aforesaid Jolley, et al., and Inman patents have been and remain very successful. This is especially true of variations of the sliding gate structure of the second embodiment illustrated in FIGS. 7-11 in the Inman patent wherein the gate slides and cooperates with the bill of the hook to open or close passage of a seized loop from the bill to the blade selectively. Those loops released from the bill remain uncut of those loops which pass to the closed end of the hook are cut.
One of the problems with the sliding gate structure which does not occur with a pivoted gate as in Jolley, et al., and the first embodiment in Inman wherein the gate pivots on the hook is that since there is lateral movement, vertical support must be provided to the gate driving mechanism. In the second embodiment of Inman and variations of this in the prior art, there must be an extension connected to the sliding gate or to the equivalent such as a sliding cut/loop clip. In Inman, which for practical reasons was not reduced to practice, this comprised a slide block supported on a fixed member of the tufting machine but in apparatus constructed in the prior art, this comprised of an extension member between the gate and the driving air cylinders which move with the hook bar as the hook rocks or oscillates. These extension members had to be supported on a member fastened to and movable with the hook backing bar and the cylinder support.
The additional linkages between the gate or clip and the air cylinder results in lost motion inefficiencies and wear problems. Moreover, the extra weight associated with the linkage, its supports, and the air cylinders moving with the hooks obviously creates undesirable momentum and inertia forces. Another problem with the prior art structure is that assembly of each separate cylinder to its link and to the gate is time consuming. This also results in additional maintenance costs due to replacement of cylinders or gates that fail or break during normal operation.
SUMMARY OF THE INVENTION
Consequently, it is a primary object of the present invention to provide a sliding gate structure for a tufting machine which is relatively light in weight and which has substantially no lost motion between the gate and the output rod of a driving cylinder.
It is another object of the present invention to provide a mounting of the hooks and cylinders of a sliding gate tufting machine performing cut pile and loop pile in the same row of stitching at substantially the same height, the hooks and cylinders which drive the gate being mounted on the same backing bar of the tufting machine, the mounting having no linkages between the cylinder output rods and the gates.
It is a further object of the present invention to provide mounting apparatus for mounting the gated hooks of a level cut and loop tufting machine and the driving cylinders which provide ease of assembly and maintenance.
It is a yet still further object of the present invention to provide a cylinder module having a plurality of output drive rods for driving an equal number of gates for a substantially level cut and loop pile tufting machine.
Accordingly, the present invention provides a module comprising a common block carrying a plurality of pneumatic cylinders and having securing members for connecting to the common backing bar to which the hook module of a level cut and loop tufting machine is mounted, the output rods of the cylinders having respective coupling members to which the gates of the hooks are coupled. The modules permit elimination of the linkages required in the prior art and permit the cylinders and hooks to be carried by a single backing bar thereby eliminating the need for a bar for mounting the hooks, a separate bar for mounting the cylinders and a separate bar for mounting the linkages which must be connected together and forms a relatively heavy oscillating structure. Moreover, when assembling the structure of the present invention the plurality of cylinders are mounted as a unit thereby reducing assembly time and cost and minimizing down-time during maintenance. The elimination of the intermediate linkages required in the prior art also substantially eliminates the lost motion inefficiencies associated therewith.
BRIEF DESCRIPTION OF THE DRAWINGS
The particular features and advantages of the invention as well as other objects will become apparent from the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a vertical sectional view taken transversely through a multiple needle tufting machine to incorporating apparatus constructed in accordance with the principles of the present invention and illustrating certain features in diagrammatic form;
FIG. 2 is a fragmentary vertical sectional view of a portion of a tufting machine illustrating the prior art hook and gate mounting structure;
FIG. 3 is a fragmentary vertical sectional view of a portion of the tufting machine illustrated in FIG. 1, but enlarged to show the hook and gate mounting structure constructed in accordance with the present invention; and
FIG. 4 is a perspective view of a cylinder module partly broken away constructed in accordance with the principles of the present invention and illustrating one coupling member exploded out from the module.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing, FIG. 1 illustrates apparatus constructed in accordance with the present invention incorporated in a tufting machine 10 having a frame comprising a bed 12 and a head 14 disposed above the bed. The bed 12 includes a bed plate 16 having a support finger plate 17 across which fabric F is adapted to be fed in the direction illustrated by a pair of input feed rolls 18 and output or take-off rolls 20.
Mounted in the head for vertical reciprocation is one of a plurality of push rods 22 to the lower end of which a needle bar 24 is carried and which in turn carries a plurality of needles 26 which are adapted to penetrate the fabric F through fingers in the support finger plate 17 upon reciprocation of the needle bar 24 to project loops of yarn therethrough. Endwise reciprocation is imparted to the push rods 22 and thus the needle bar 24 and needles 26 by a connecting rod 28 which is pivotally connected at its lower end to the push rods 22 and at its upper end to an eccentric 30 on a driven rotary main shaft 32 that is journaled longitudinally in the head 14. A pressure foot assembly 34 may be supported on the head 14 to hold down the fabric F during needle retraction. A yarn-jerker 36 is carried by the needle bar 24 and operates to engage the yarn between a stationary yarn guide 38 on frame of the machine and the needles 26.
Yarn Y is supplied to each needle 26 by a conventional type of yarn feed mechanism including a pair of feed rolls 40, 42 may be mounted on the head 14 adapted to be continuously rotated by any convenient means preferably synchronized with the main shaft 32 to continuously feed lengths of yarn to the needles. For reasons which should be apparent, the amount of yarn fed to the needles is less than that demanded by the system so that yarn is pulled back from each loop after it has been formed as each stitch is tightened and set into the fabric F.
Mounted within the bed for cooperation with the needles to seize loops of yarn presented thereto are a plurality of loopers or gated hooks generally indicated at 44 and as hereinafter described in conjunction with FIG. 3. The hooks as hereinafter made clear are of the cut pile type which point in the direction opposite to that which the fabric is fed, and additionally carry a sliding gate as hereinafter described. The hooks preferably are mounted in modules 48 similar to those modules disclosed in Bardsley, U.S. Pat. No. 4,739,717 which are connected to a mounting bar 49 secured to the upper end of a rocker arm 50. Any conventional means to oscillate the arm 50 may be provided. It is preferred that the lower end of the rocker arm 50 is clamped to a laterally extending rocker shaft 52 journaled in the bed. Pivotally connected to the upper portion of the rocker arm 50 is one end of the connecting link 54 having its other end pivotally connected between forked arms of a jack shaft rocker arm 56. The arm 56 is clamped to a jack shaft 58 which has oscillating motion imparted thereto by a conventional drive means such as a cam and lever means (not shown) from the main shaft 32 in timed relationship with the reciprocation of the needles.
The tufting machine incorporates a plurality of knives 60 which may cooperate with the hooks that cut the selected loops thereon to form cut pile as hereinafter described. The knives may be mounted in knife blocks 62 secured to a knife bar 64 which in turn is secured to a knife shaft rocker arm 66 clamped to a knife shaft 68 to conventionally drive the knives into engagement with one side of the respective hooks as known in the art to provide a scissors-like cutting action.
As illustrated in FIG. 2, in the prior art the gated hooks 44 and the associated modules 48 within which a plurality of hooks are mounted have the gate 46 slidably mounted within a slot formed in the hook to open and close the bill of the hook, the tail of the gate being connected through a linkage 70 including a link 71 and a block fastened to the output rod of the respective pneumatic cylinder 74. Due to space limitations, the cylinders were mounted in a vertical stack with the cylinder 74 supported in a frame 76 and the blocks 72 of adjacent cylinders offset vertically so that a coupling pin 78 on each block may cooperate with a slot 80 in the cooperating end of a respective link 71, the links of alternate hooks 44 differing so that the block connecting portions of alternate links are spaced not only laterally but vertically as illustrated.
The hook mounting bar 49 must be connected to a support member 82 by means of a spacer member 84 therebetween and is in turn connected to the cylinder support frame 76 by another spacer member 86. A cover member 88, which is required to protect the apparatus from lint due to the environment in which it operates is connected to the support member 82 and to the frame 76. Although the elements illustrated in FIG. 2 oscillate with the hook mounting bar drive as aforesaid. Thus, it may be readily understood that since all of these elements are constructed from steel, a very heavy mass must be oscillated, and also the multitude of elements require substantial assembly time during manufacture and both disassembly and assembly time during maintenance.
To overcome these disadvantages of the prior art, the present invention provides a cylinder module 90 illustrated in FIGS. 3 and 4, the module comprising a housing constructed from two body members 91, 93 formed from aluminum alloy so as to be light in weight and carrying a plurality of pneumatic cylinders (not illustrated) fed with air from respective nipples 92 and having piston driven output rods 94. The body member 91 has cylindrical chambers formed therein and receives the pistons 95 with the rods extending out the end remote from the body member 93, the latter having the input nipples 92. A spring 97 biases the rods inwardly. The cylinders and thus the output rods 94 are arranged in two vertical spaced apart rows with the cylinders in one row staggered relative to those in the other row so that coupling members 96 may be attached to each rod and provide clearance for extending freely. In a preferred forms of the module there are twenty cylinders in an 1/8 gauge machine and twenty four cylinders in a 1/10 gauge machine and half of the cylinders are in each row. Disposed at each lateral end integral with the lower surface of the module is a respective tube 99 (only one of which is shown) within which a screw 101 extends for securing the module to the mounting bar 49.
Each of the coupling members 96 includes a slot 98 with an internal nub 100, the coupling being formed from two members, one of which being a small member 102 having the nub 100 formed thereon and fitted laterally into the main body of the member 96 in jigsaw fashion. The nub 100 is adapted to be received within and coupled with a complimentary recess formed in the tail end 104 of the gate 46 so that the gate may move with the cylinder rod of the respective cylinder. In the preferred embodiment, the cylinder rod extends when pressurized air is supplied to the corresponding cylinder and retracts into the cylinder by virtue of a spring internal to the cylinder when the pressure is released. A cover 106 preferably may overlie the module, the rods and the tail end of the gate for the same purpose as in the prior art.
As in known in the prior art when the gate is extended the hook is closed and the loop which has been seized is released to form loop pile, but when the gate is retracted the loop may enter the blade of the hook and move toward the throat at the closed end where it is cut by the knife 60 to form cut pile.
The control of the air cylinders and thus the gates may be via a programmed computer 108 supplying signals to valves 110, the number of valves; preferably corresponding to the cylinders so that each hook in the tufting machine is controlled individually, the valves opening and closing communication between a compressor 112 and air conduits 114 communicating the valves with the cylinders in the module. As understood by those skilled in the art, there will be a plurality of such modules across the tufting machine which may have some 1000 or more hooks cooperating with an equal number of needles.
Accordingly, a module and the mounting thereof is disclosed which is light weight and may be mounted on the hook backing bar without the need for additional linkages.
Numerous alternations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to the preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invent-ion. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.
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A multi-cylinder module has a common block within which the cylinders are formed and having a piston disposed within each cylinder and an output rod connected to each piston. Pressurized air acts on the piston against the bias of a corresponding spring to drive the respective rod outwardly from the module. Each rod has a coupling member which is coupled to the gate of a hook of a tufting machine having gated hooks for forming both loop and cut pile. The modules are mounted directly to the hook bar of the tufting machine and require no additional linkages between the coupling and the gate with the inherent lost motion and other inefficiencies associated with such additional linkages.
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BACKGROUND OF THE INVENTION
The invention relates to a process for the detachable attachment of a tubular strut to a column to a connecting element for performing the process and to a connection of a tubular strut with a column by means of a connection device.
A connection device for connecting a column to a tubular strut has been known from U.S. Pat. No. 4,365,907. In the conventional connection device, a rectangular tubular strut is connected to a rectangular tubular column with the aid of a central wedge element provided with a threaded through bore as well as two lateral wedge elements pressed by the central element against the inner wall of the strut. The three wedge elements are joined by a deformable strip. On the outer wall of the column, a base plate is arranged on which rests, in turn, the end face of one end of the strut. The base plate is pinned to the column. At the mounting site of the strut, the column is equipped diametrically with two bores. A screw can be passed with its head through the bore lying in opposition to the mounting site, the head then being in contact with the rim of the bore of the other bore. For establishing the connection of strut and column, the screw is passed into the column, the base plate is placed on the screw on the outside of the column, and the screw is threaded into the central wedge element. Subsequently, the strut is pushed over the wedge elements, and the screw is tightened; during this step, the central wedge element is pulled against the column and thereby the two lateral wedge elements are urged against the inner wall of the strut. There is no possibility for mounting two opposed struts at the same level.
In a connection of a column with a strut of a different type, as disclosed in Swiss Patent 429,317, the connecting element in each case consists of respectively one wedge element pair which can be inserted in the tube ends of the column as well as of the strut to be joined together, and of a head with threaded bores. The wedge elements are pulled against the head by means of a screw threadable into the thread in the head whereby the wedge elements are pressed against the inner wall of the strut and, respectively, of the column. In the connection, which is not of the type under consideration herein, only tube ends can be joined. If it is intended to attach two opposed struts to a column, then the column must be cut to the length corresponding to the level of mounting of the two struts.
SUMMARY OF THE INVENTION
It is an object of the invention to avoid the drawbacks of the conventional connection devices, and also to provide a connection between column and strut which can be established in a simple way and which transmits high flexural and shear forces.
The attainment of this object with respect to the process for the detachable connection of a tubular strut to a column with respect to the connection device for performing the process and with respect to the connection is set forth hereinafter following in greater detail.
Examples of the connection device according to this invention and of the connection in accordance with the invention will be described in greater detail below with reference to drawings wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective sectional view of a connection of four struts to a column by means of a connection device consisting of a core inserted in the column and four wedge element pairs, the wedge elements of which are axially displaceable with respect to one another by means of a screw,
FIG. 2 shows a perspective view of a wedge element of the wedge element pair utilized in FIG. 1,
FIG. 3 shows a perspective view of the other wedge element of the wedge element pair utilized in FIG. 1,
FIG. 4 is a top view of the wedge element illustrated in FIG. 3,
FIG. 5 is a perspective view of a modification of a connection of a strut to the column,
FIG. 6 is a longitudinal cross-section perspective view illustrating a mandrel positioned for releasing the wedge-elements from a strut, and
FIG. 7 is a view similar to FIG. 5 and showing the screw for holding the core in position inside the column during assembly and dismantling.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the connection of a column 1 with four tubular struts 3a-3d of oval cross section, shown in FIG. 1, the connecting element has four wedge element pairs 5a-5d as wedge element sets, a core 7 within the column 1 as the force-exerting member, and a long cylindrical screw 13 with a hexagon socket head and a nut 14. The cylindrical screw 13 extends through a through bore 9 in the core 7, through respectively one through bore 11b and 11d in the opposite wedge element pairs 5b and 5d in the struts 3b and 3d, and through two opposite holes 12b and 12d in the column wall. Respectively two short cylinder screws 17a and 17c, likewise with a hexagon socket head, extend through respectively one through bore 11a and 11c of the wedge element pairs 5a and 5c and a hole 12a and, respectively, 12c in the column wall, and are threaded into respectively one threaded bore 15a (visible in FIG. 1) and 15c (not visible in FIG. 1). The core 7 has a cross section which is adapted to the interior of the column 1 except for a clearance tolerance. From its topside 19, as a coupling means for a holding element, a central threaded bore 21 emanates; a screw 57, FIG. 7 can be threaded into this bore and functions as a holding element in order to insert and hold the bores 9, 15 and 15c in the core 7 in alignment with the holes 12b, 12d, 12a and 12c in the column wall during the connection assembly at the site of connection in the column 1. The axes of the two threaded bores 15a and 15c are disposed in the core 7 perpendicularly to and at the same level as the through bore 9. The holes 12a-12d in the column 1 are designed to align with the through bore 9 as well as to the threaded bores 15a and 15c. The oval inner cross section of the struts 3a-3d and the diameter of the nut 14, measured between two parallel lateral surfaces as well as between two radially opposite lateral corners, are dimensioned so that although the respective strut 3a, 3b, 3c, or 3d can be placed over the nut 14 seated on the screw 13 the nut 14 cannot be turned within the inner space of the respective strut 3a, 3b, 3c, or 3d (here 3d).
Each of the four wedge element pairs 5a-5d consists of respectively two wedge elements 23 and 24 wherein the screw head 27a and 27c, respectively, adjoins the screw 17a and 17c, respectively, the screw head 27b adjoins the screw 13, and the nut 14 adjoins the end face 25 of the wedge element 23. The wedge element 23 illustrated in FIG. 2 has a through bore 29 extending perpendicularly to the end face 25, this bore being part of the through bores 11a, 11b, 11c, or 11d of the wedge element pairs 5a, 5b, 5c, or 5d and having a diameter that is larger by a tolerance than the shank diameter of the screws 13, 17a and 17c. An annular extension 31 machined to be planar is arranged around the outlet of the through bore 29 on the end face 25, this extension affording a perfect contacting of the respective screw heads 27a, 27b, 27c and, respectively, the nut 14. The extension 31 is provided to avoid machining of the entire end face 25. A curved lateral surface 33 extends at a right angle to the end face 25, the curvature of this lateral surface being adapted to the inner curvature of the strut 3 in the intended supporting zone. On the side located oppositely to the lateral surface 33, the wedge surface 34 extends at an acute angle with respect to the end face 25 and to the line of symmetry of the curved lateral surface 33. The intersecting edge between the end face 25 and the wedge surface 34 is a straight line. The wedge element 23 is truncated at its tip with a frontal surface 35 in parallel to the end face 25.
The wedge element 24, illustrated in FIG. 3 in a perspective view and in FIG. 4 in a top view, exhibits, in contrast to the wedge element 23, a curved end face 39, the curvature of which, as shown in FIG. 4, is adapted to the curvature of the wall of column 1. A through bore 41 extends from the center of the end face 39 and has the median perpendicular of the end face 39 as the axis. The through bore 41 is part of the through bore 11a, 11b, 11c, or 11d of the wedge element pair 5a, 5b, 5c, or 5d, and has a diameter larger than the diameter of the through bore 29 of the wedge element 23. The forward portion of the wedge element 24 carrying the end face 39 is broadened with respect to the remaining portion carrying the wedge surface 42 in such a way that an extension 43 is formed on which rests the front side of the end of the respective strut 3a, 3b, 3c, or 3d facing the column 1. The broadened region forming a shoulder, as visible in FIG. 1, is, for esthetic reasons, smaller by one tolerance than the cross section of the strut 3a, 3b, 3c, or 3d. A curved lateral surface 46 adjoins, at a right angle, the supporting surface for the strut 5a, 5b, 5c, or 5d of the extension 43; the curvature of this curved lateral surface is adapted to the internal curvature of the strut 3a, 3b, 3c, or 3d in the intended supporting zone. On the side in opposition to the lateral surface 46, the wedge surface 42 extends at an acute wedge angle with respect to the center line of the curved supporting surface. The wedge element 24 is truncated at its tip with a frontal surface 49 wherein a depression 50 is provided on the side of the entering wedge surface 42. The depression 50 prevents contact of the nut 14 at the frontal surface 49 when the connection device is assembled.
In order to establish the connection, shown in FIG. 1, of the four struts 3a, 3b, 3c, and 3d with the column 1, the wedge element pair 5b is placed on the cylindrical screw 13 in such a way that the extension 31 of the wedge element 23 is in contact with the screw head 27b of the screw 13. Subsequently, a screw 57, carrying a nut, not illustrated, threaded onto its shank, is partially threaded into the threaded bore 21 of the core 7 and tightened with the nut, the core 7 is held by the screw and is placed into the interior of the column 1 in such a way that the through bore 9 of the core 7 is in alignment with the holes 12b and 12d in the column wall. The screw 13 is passed through the hole 12b, the through bore 9, and the hole 12d, the wedge element pair 5d is pushed first with the wedge element 23 onto the screw 13, and the nut 14 is threaded in place. The wedge element 23 can be disposed at the top, as shown in FIG. 1, but it can also lie at the bottom without impairing its functioning ability. Thereafter the two struts 3b and 3d are pushed over the wedge element pairs 5b and 5d, and the screw 13 is slightly tightened by means of a long hexagon socket wrench through the strut 3b. The nut 14 cannot rotate within the strut 3d, in accordance with the above remarks.
The screws 17a and 17c are passed through the respective wedge element pairs 5a and 5c in such a way that the extension 31 of the wedge element 23 is in contact with the screw head 27a and 27c, respectively. Then the screws 17a and 17c are passed through the holes 12a and 12c in the column 1 and threaded into the threaded bores 15a and 15c in the core 7. The struts 3a and 3c are pushed over the wedge element pairs 5a and 5c until they abut, with the front side of their ends, against the supporting surface of the respective extension 43. By means of the long hexagon socket wrench mentioned above, the screws 17a and 17c are tightened through the struts 3a and 3c, and the screw 13 is retightened. The screw 57 in the threaded bore 21 in the core 7 is again unthreaded. Due to the firm tightening, the wedge elements 23 and 24 slide axially toward each other on their wedge surfaces 34 and 42 whereby they are urged apart with their curved lateral surfaces 33 and 46 against the inner wall of the struts 3a-3d. At the same time, the struts 3a-3d are pulled against the supporting surfaces of the extensions 43 of the wedge elements 24, and thereby their end faces 39 are urged flush against the wall of the column 1 whereby an excellent connection is established between the struts 3a-3 d and the column 1. The core 7 inserted in column 1 and the end face 39 of the wedge element 24, in flush contact with the outer wall of column 1, permit an extensive transmission of flexural and shear forces from the struts 3a, 3b, 3c, and 3d to the column 1, on account of the large force-transmitting surfaces and the rigidification and force distribution over a large column area by the core 7. The connection described here furthermore permits, in contrast to the connection known from U.S. Pat. No. 4,365,907, the mounting of two opposed, or pairs of respectively two opposed struts to the column 1. As contrasted to the known connection wherein the screw for the central wedge can drop into the column during the course of the connection assembly, a dropping of connecting elements into the column 1 is precluded in the connection according to this invention.
In order to release the connection, the procedure is performed in a chronologically reversed mode of operation from that discussed above. Due to the acute wedge angle of the wedge surfaces 34 and 42 with respect to the center line of the curved surfaces 33 and 46, the wedge elements 23 and 24 frequently jam in the struts 3a, 3b, 3c and 3d, respectively, even after release of the screws 13, 17a and 17c. Here, a cylindrical mandrel 56, FIG. 6, the diameter of which is smaller by a clearance tolerance than the diameter of the through bore 41 but larger than the diameter of the through bore 29, is introduced into the through bore 41 of the wedge element 24 from the curved end face 39 until the mandrel 56 abuts against the rim of the through bore 29. With a vigorous hammer strike on the end of the mandrel 56, both wedge elements 23 and 24 in the respective strut 3a, 3b, 3c, and 3d can be detached from each other.
Instead of the depression 50 in the frontal surface 50 of the wedge element 24, the latter can also be shortened by the depth of the depression 49.
Instead of connecting four struts 3a, 3b, 3c, and 3d to the column 1, it is possible to mount only three, two, or merely one strut or struts. A connection with only one strut 3d is illustrated in FIG. 5. In this arrangement, a cylindrical screw 53 is employed which has approximately half the shank length of the cylindrical screw 13. The core 7 is introduced into the column 1, and the through bore 9 is aligned with respect to the holes 12b and 12d in column 1. A shim 54 is pushed onto the screw 53, and the screw 53 is passed through the hole 12b in the column wall, through the through bore 9 of the core 7, through the hole 12d in the column wall, and through the through bore 11d of the wedge element pair 5d analogously to the above description, and also the nut 14 is threaded onto the end of the screw 53. Subsequently, the strut 3d is pushed over the wedge element pair 5d, and the screw 53 is tightened by means of a hexagon socket wrench.
Instead of arranging the threaded bores 15a and 15c perpendicularly to the through bore 9, these bores can also be arranged at a different angle; analogous remarks apply with regard to the fitting holes 12a through 12d in the column wall. Depending on the thickness of column 1 and the dimensions of the struts 3a, 3b, 3c, or 3d, it is also possible to arrange more than three bores 9, 15a, 15c.
In place of a core 7 insertable in the column 1, a solid column can likewise be used, although machining of the latter is expensive.
Instead of using screws 13, 17a and 17c as the force-exerting member for displacing the wedge elements 23 and 24 axially with respect to each other and for pressing these wedge elements, on account of the force-reinforcing action by the inclined plane of the wedge surfaces 34 and 42, with great force against the inner wall of the struts 3a, 3b, 3c, or 3d, it is also possible to utilize a spring-loaded bolt, not shown, in each case, this bolt engaging into a bayonet catch in the column which is not illustrated. The force of the spring in this arrangement urges the wedge element 23 against the wedge element 24. This connection can be established quickly, it is true, but does not result in the high force transmission from the strut to the column, as in the aforedescribed arrangement.
In place of the threaded hole 21 in the core 7 for insertion of the screw 57, a hook or a retaining pin can also be firmly mounted to the top-side 19 of the core 7 as a coupling means for a holding element. Also, in place of the threaded hole 21, a through hole can be provided in which a hook is inserted for holding the core 7 during assembly.
Instead of retaining the core 7 during the connection assembly, for example, at the screw threaded into the threaded bore 21, it is also possible to recess a shoulder 55 in the inner space of the column 1, as illustrated in FIG. 1, the core 7 resting on this shoulder. This shoulder 55 makes it impossible for the core 7 to slide inwards, but represents a higher production expense as compared with the screw threaded into the threaded bore. From the column 1, the core 7 can be removed again when the connection is released, by threading a screw 57 into the threaded bore 21 or by means of a hook engaging into the threaded bore 21.
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In the process proposed, tubular struts (3a to 3d) are detachably connected to a column (1) using a connection device, wedge element pairs (5a to 5d) on the connection device being inserted in the struts (3a to 3d) and the wedge elements (23, 24) of the wedge element pairs (5a to 5d) being displaced longitudinally with respect to each other by screws (13, 17a, 17c) which pass through holes (12a to 12d) in the column wall and through a throughbore (11a to 11d) in each wedge element pair (5a to 5d). The wedge elements (23, 24) of each wedge element pair (5a to 5d) are thus pressed against the inside walls of the struts (3a to 3d). The heads (27a to 27d) of the screws are located outside the column (1). The column (1) is reinforced by an internal core (7) and the shape of the end (39) of one (24) of the wedge elements in each pair matches that of the outside wall of the column (1). The core (7) in the column (1) and the end (39) of the wedge element (24) lying flush against the outside wall of the column (1) permit high flexural and shear forces to be transmitted by the struts (3a, 3b, 3c, 3d) to the column (1) owing to the large force-transmission surfaces and the reinforcing action of the core, as well as the distribution of the forces over a large area of the column by the core (7). Two struts or two pairs of struts can be attached to the column (1) opposite each other at the same height.
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RELATED APPLICATIONS
The present application claims the benefit of U.S. Provisional Patent Application Nos. 61/479,540, filed Apr. 27, 2011, 61/479,537, filed Apr. 27, 2011, and 61/479,543, filed Apr. 27, 2011, the contents of all are hereby incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates generally to agricultural devices and, more particularly, to down force adjustment of a row unit of an agricultural device.
BACKGROUND
Implements for planting row crops, such as corn and soybeans, (planters) typically include row units laterally spaced along a frame, or toolbar. The row units generally include a seed channel opener that creates a channel or furrow in the soil for seed placement. Each row unit is mounted to the toolbar by means of a four-bar linkage or its equivalent which allows each row unit to move vertically to adjust to the contour of the soil independently of the other row units on the same toolbar. Some planters have springs in the four-bar linkage which work to transfer weight from the planter's frame to the row unit creating down force to help the seed channel opener penetrate the soil and to minimize row unit bounce in rough soil conditions. Insufficient down force can result in a seed furrow of inadequate depth or a seed furrow simply not formed, which in turn results in shallow seed placement or seed placement on the soil surface. However, too much down force could overly compact the seed bed or form the seed furrow too deep, which could negatively affect early plant development. Furthermore, excessive down force could accelerate wear on the row units' soil-engaging components. The springs can be adjusted to adjust the down force of the row unit. This adjustment usually is made by manually changing the position of the springs in the four-bar linkage.
In other planters, airbags are employed in the four-bar linkage which are similarly adapted to transfer weight from the planter's frame to the row unit creating down force to help the seed channel opener penetrate the soil and to minimize row unit bounce. In both of these conventional biasing means—springs and airbags—the system lacks accuracy and predictability. For instance, when the biasing means is an airbag, it can be difficult to precisely determine the volume of air in the airbag at a given time and, subsequently, determine needed supplemental down force.
It is desirable to be able to adjust down force on a row unit quickly and accurately so that a consistent seed depth is maintained. It is also desirable to be able to lift the row unit if its own weight is applying too much down force to the soil.
SUMMARY
Accordingly, it is an object of the present invention to provide for a quick and accurate adjustment of the down force on a row unit during planting.
It is another object of the present invention to provide the capability to put both positive and negative pressure on the row unit.
These and other objects are achieved by the present invention. In some exemplary aspects of the present invention, a row unit of a planter is provided. The row unit is mounted to a toolbar of a planter by means of a four-bar linkage having a set of top and bottom parallel arms. At least one spring is provided between the top and bottom arms and connected at one end to the bottom arm in a fixed manner at a connection point. The other end of the spring is connected to a spring mount that is disposed on the top arm and coupled to an electric actuator. The spring mount is longitudinally movable in both directions of the top arm. The electric actuator moves the spring mount forward and backward along the top arm, which adjusts the down or up force placed on the row unit, which in turn can increase or decrease the soil penetration of a seed channel opener component of the row unit, and keep the row unit from bouncing in rough soil conditions.
In other exemplary aspects, an agricultural device is provided and includes a toolbar, a row unit, a linkage coupling the row unit to the toolbar, wherein the linkage includes a first arm and a second arm, and wherein each of the first arm and the second arm includes a first end coupled to the toolbar and a second end coupled to the row unit, an actuator coupled to the toolbar, and a biasing member coupled to the linkage and the actuator, wherein the actuator is adapted to move the biasing member to vary an amount of force applied to the row unit.
In further exemplary aspects, a row unit adjustment system for use in an agricultural planter for planting seeds is provided. The agricultural planter includes a toolbar and a row unit coupled to the toolbar by a linkage. The row unit adjustment system includes an actuator including an adjustment member, a biasing member coupled to the linkage and the adjustment member, a sensor adapted to sense a characteristic associated with planting seeds and generate a signal associated with the sensed characteristic, and a processing unit receiving the signal associated with the sensed characteristic and determining whether adjustment of the biasing member is necessary based on the signal.
In still other exemplary aspects, a method for adjusting a force applied to a row unit of an agricultural planter is provided. The agricultural planter includes a toolbar and the row unit includes a linkage coupling the row unit to the agricultural planter. The method includes providing an actuator including an adjustment member, coupling a biasing member at a first end to the linkage and at a second end to the adjustment member, sensing a characteristic associated with planting with a sensor, generating a signal associated with the characteristic with the sensor, communicating the signal to a processing unit, and adjusting a position of the biasing member with the actuator based on the signal received by the processing unit in order to adjust a force applied to the row unit.
BRIEF DESCRIPTION OF THE DRAWINGS
The appended claims set forth those novel features which characterize the invention. However, the invention itself, as well as further objects and advantages thereof, will best be understood by reference to the following detailed description of an exemplary embodiment, taken in conjunction with the accompanying drawings, where like reference characters identify the elements throughout the various figures in which:
FIG. 1 is a side elevation view of a portion of an exemplary planter row unit, the exemplary row unit including an exemplary down force adjustment system;
FIG. 2 is a side elevation view similar to FIG. 1 showing a down force spring of an exemplary down force adjustment system adjusted to provide a negative down force on the row unit;
FIG. 3 is a side elevation view similar to FIGS. 1 and 2 showing a down force spring of an exemplary down force adjustment system adjusted to provide a positive down force on the row unit;
FIG. 4 is an exemplary system diagram of the present invention; and
FIG. 5 is a side elevation view of a portion of an exemplary planter row unit including an exemplary soil characteristic sensor.
Before any independent features and embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of the construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
DETAILED DESCRIPTION
The contents of U.S. patent application Ser. No. 13/458,012, filed Apr. 27, 2012, entitled “AGRICULTURAL DEVICES, SYSTEMS, AND METHODS FOR DETERMINING SOIL AND SEED CHARACTERISTICS AND ANALYZING THE SAME”, and U.S. patent application Ser. No. 13/457,577, filed Apr. 27, 2012, entitled “REMOTE ADJUSTMENT OF A ROW UNIT OF AN AGRICULTURAL DEVICE”, are both incorporated herein by reference.
Referring to FIG. 1 , there is shown a side elevation view of an exemplary planter row unit 10 in accordance with the principles of the present invention. A single row unit 10 is depicted in the figures and described herein for simplicity, but it is understood that a typical planter 36 (see FIG. 4 ) includes multiple row units 10 . Row unit 10 includes a frame 12 . Mounted to the lower section of frame 12 are a pair of furrow-opening discs 14 (one of which is seen in FIGS. 1-3 ), a pair of depth gauge wheels 16 (one of which is seen in FIGS. 1-3 ) and a pair of furrow closing wheels (not shown). As is known, seed is stored in a hopper (not shown), fed to and “singulated” by a meter (not shown) and deposited at desired spacing in the furrow formed by the furrow-opening discs 14 . The furrow is then closed and soil is packed about the seed by the closing wheels.
The row unit 10 is mounted to a toolbar (not shown) by a conventional four-bar linkage 18 . Four-bar linkage 18 includes parallel top arms 20 (one of which is seen in FIGS. 1-3 ) and parallel bottom arms 22 (one of which is seen in FIGS. 1-3 ) on each side of the row unit 10 . The forward ends of the top arms 20 are pivotally connected to an upper portion of a mounting plate 24 . Likewise, the forward ends of the bottom arms 22 are pivotally connected to a lower portion of the mounting plate 24 . Mounting plate 24 is in turn coupled to the toolbar. A conventional mounting arrangement for attaching the mounting plate 24 to the toolbar would typically include threaded U-shaped bolts and mounting nuts which are not shown in the drawing for simplicity. The rear ends of top and bottom arms 20 and 22 are pivotally connected to row unit frame 12 .
The top and bottom arms 20 and 22 are connected to both the mounting plate 24 and row unit frame 12 by means of a nut and bolt combination which allows the top and bottom arms 20 and 22 to pivot at both ends. The four-bar linkage 18 permits the row unit 10 to move vertically, independently of adjacent row units, while remaining laterally in place on the toolbar.
At least one linear actuator 26 is mounted to the mounting plate 24 above a top arm 20 of the linkage 18 . In other exemplary embodiments, a linear actuator 26 may be provided above each top arm 20 of the linkage 18 . Linear actuator 26 can be of an electric, hydraulic or air type, having a shaft 28 that extends longitudinally parallel to the top arm 20 . A mounting bracket 30 is provided on top arm 20 and coupled to the shaft 28 . The mounting bracket 30 engages and is supported by a top surface of top arm 20 and may slide, roll, or otherwise move along the top surface of the top arm 20 . During up and down movement of the row unit 10 , shaft 28 pivots about pin or pivot 29 to maintain the shaft 28 substantially parallel to the top arm 20 . At least one biasing member 32 under tension is provided between top and bottom arms 20 , 22 . In the illustrated exemplary embodiment, the biasing member 32 is a spring or coil spring. However, it should be understood that the biasing member 32 may be any type of biasing member and other types of springs and still be within the intended spirit and scope of the present invention. In exemplary embodiments including an actuator 26 above each top arm 20 , two tension springs 32 may be included in the linkage 18 with one spring 32 coupled to each actuator 26 . In other exemplary embodiments, one actuator 26 and two springs 32 may be included in the linkage 18 with one spring 32 coupled to the actuator 26 and the second spring 32 coupled to and between the top and bottom arms 20 , 22 . In the illustrated exemplary embodiment, the spring 32 is connected at a lower end to the bottom arm 22 at a fixed point and at an upper end to the mounting bracket 30 on the top arm 20 . The tension applied across the tension spring 20 may be varied to adjust the tension on spring 32 and thus the amount of weight transferred from the toolbar to the row unit 10 by extending or retracting the shaft 28 of the actuator 26 , which in turn will move the mounting bracket 30 forward or rearward along the top arm 20 . Alternatively, the actuator 26 may be a screw-drive type actuator 26 , and the shaft 28 and the mounting bracket 30 may have a screw or threaded engagement between the two components, thereby causing the mounting bracket to translate along the shaft 28 as the shaft 28 rotates. The shaft 28 may rotate either direction to enable the mounting bracket 30 to translate in either direction.
With continued reference to FIG. 1 , dt denotes the distance between the proximal pivot point of the top arm 20 and the mounting bracket 30 , which is the connection point of the upper end of the spring 32 , and db denotes the distance between the proximal pivot point of the bottom arm 22 and the fixed connection point of the lower end of the spring 32 . As shown in FIG. 1 , when dt and db are the same, the spring 32 is in a neutral position where the net effect on the force applied to the soil F g is zero. As shown in FIG. 2 , when the actuator 26 retracts the shaft 28 , the mounting bracket 30 is moved to a position closer to the proximal pivot point of top arm 20 . In this position the spring 32 is in a negative, or up force position in which dt is less than db, and where a net negative force will be put on the row unit 10 which decreases the force applied to the soil by the furrow-opening discs 14 .
As shown in FIG. 3 , when the actuator 26 extends the shaft 28 , the mounting bracket 30 is moved to a position further from the proximal pivot point of top arm 20 . In this position, the spring 32 is in a positive, or down force position in which dt is greater than db, and where a net positive force will be applied to the row unit 10 . This increases the force that is applied to the soil by the furrow-opening discs 14 .
With continued reference to FIGS. 1-3 , an exemplary sensor 34 is provided to sense or determine a position of the biasing member 32 . In the illustrated exemplary embodiment, the sensor 34 is coupled to the mounting plate 24 . In other exemplary embodiments, the sensor 34 may be coupled to any portion of the toolbar, linkage 18 , row unit 10 , etc. and still be within the intended spirit and scope of the present invention. The sensor 34 may be any type of sensor for determining a position of the biasing member 32 . For example, the sensor 34 may be an ultrasonic sensor, a laser sensor, a potentiometer, a hall effect sensor, or any other type of sensor. In other exemplary embodiments, the sensor 34 may be coupled to or included within the actuator 26 and may be a wide variety of types of sensors such as, for example, a potentiometer, a hall effect sensor, etc.
The actuator 26 is controlled by conventional means via a user interface 40 , which can be in the cab of a tractor 38 that pulls the planter 36 and row units 10 through a field. In this way, a farmer can adjust down force on the row unit 10 quickly and accurately so that furrow-opening discs 14 can maintain a consistent furrow depth, or the farmer can lift the row unit 10 if its own weight is applying too much down force to the soil.
Referring now to FIG. 4 , an exemplary system of the present invention is illustrated and includes a tractor 38 and a planter 36 . The tractor 38 includes a control system 39 including a user interface 40 with an optional touch screen 42 and associated touch screen capabilities, a processing unit 44 , an optional mechanical control panel 46 , and a memory 48 . The tractor 38 also includes a tractor electrical power source 50 . The planter 36 includes multiple row units 10 , however, since the row units 10 are substantially identical, only one row unit 10 is illustrated with further detail and described herein. Each row unit 10 includes a down force adjustment assembly including the actuator 26 , the biasing member position sensor 34 , a down force sensor 52 , and a soil characteristic sensor 54 (see FIGS. 4 and 5 ). Each row unit 10 may include an optional row unit electrical power source 56 and the planter 36 further includes a planter electrical power source 58 . In other exemplary embodiments, the planter 36 may include a processing unit and/or the row units 10 may each include a processing unit and the processing unit(s) of the planter 36 and/or the row units 10 may communicate with the processing unit 44 of the tractor 38 via a communication bus.
The down force sensor 52 may be, for example, a force transducer that is coupled to a depth-adjusting lever mechanism 60 (see FIG. 5 ) or the gauge wheels 16 for monitoring and/or measuring a down force occurring in the depth-adjusting mechanism 60 or the gauge wheels 16 and applied to the row unit 10 to force the row unit 10 downward toward the soil. The down force sensor 52 may be any type of sensor such as, for example, a load cell, a pressure sensor, a potentiometer, etc., and may be coupled to any portion of the row unit 10 as long as it can operate appropriately to sense a down force. Such a force sensor 52 may be electronically coupled to the processing unit 44 to enable the processing unit 44 to take readings of the down force and display related information to a user via the user interface 40 or to enable the processing unit 44 to communicate with the necessary components to adjust the down force.
With further reference to FIG. 5 , an exemplary soil characteristic sensor 54 is illustrated and may be coupled to the row unit 10 in any manner and at any location as long as the sensor 54 can sense desired soil characteristic(s). The soil characteristic sensor 54 may sense any soil characteristic and operate in any of the manners described in U.S. Provisional Patent Application Nos. 61/479,537 and 61/479,543, both of which were filed Apr. 27, 2011 and both of which are incorporated herein by reference.
All of the sensors may generate a signal associated with the characteristic they are sensing and communicate with the processing unit so the processing unit may receive the signals, interpret the signals, and react accordingly to perform the desired functions of the system.
It should be understood that the sensors described and illustrated herein may be any type of sensor and be within the intended spirit and scope of the present invention. Exemplary sensors include, but are not limited to, ultrasonic sensors, laser sensors, video cameras, infra-red sensors, infra-red cameras, infra-red scanners, microwave sensors, potentiometers, hall effect sensors, force transducers, etc.
The foregoing description has been presented for purposes of illustration and description, and is not intended to be exhaustive or to limit the invention to the precise form disclosed. The descriptions were selected to explain the principles of the invention and their practical application to enable others skilled in the art to utilize the invention in various embodiments and various modifications as are suited to the particular use contemplated. Although particular constructions of the present invention have been shown and described, other alternative constructions will be apparent to those skilled in the art and are within the intended scope of the present invention.
While particular embodiments of the present invention have been illustrated and described, it will be obvious to those skilled in the relevant arts that changes and modifications may be made without departing from the invention in its broader aspects. Therefore, the aim in the appended claims is to cover all such changes and modifications that fall within the true spirit and scope of the invention. The matters set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.
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An agricultural device includes a number of row units that each includes a seed furrow opener that creates a furrow in the soil for seed placement. Each row unit is mounted to a toolbar of the device by a four-bar linkage which allows each row unit to move vertically to adjust to the contour of the soil independently of the other row units on the same toolbar. The four-bar linkages include one or more springs which work to transfer weight from the toolbar to the row unit. An actuator varies the tension in the spring thereby adjusting the down or up force applied to the row unit.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to flood damage control and, more specifically, to a doorway mounted flood barrier.
2. Description of the Related Art
Flooding is a common problem in low lying areas. When flooding occurs, extensive damage to homes and businesses occurs when flood water enters doorways between the door frame and the door itself. This is because doors are not designed as water barriers. Typically, water seeps through the periphery of the door between the door itself and the door frame. Most flooding situations involve rising water which does not exceed more than a couple of inches to a couple of feet; however, any entrance of water into the house or business will result in substantial property damage.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a doorway mounted flood barrier which is capable of preventing water from seeping between the door and the door frame.
Another object of the present invention is to provide a doorway mounted flood barrier which can be placed in a doorway quickly and easily.
Another object of the present invention is to provide a doorway mounted flood barrier which is relatively simple in construction and cost effective to produce.
These and other objects of the invention are met by providing a doorway mounted flood barrier which includes a barrier wall having two opposite vertical side edges and a horizontal bottom edge, and retainer means disposed between the barrier wall and the doorway for holding the barrier wall sealingly in a lower portion of the doorway.
These and other objects and features of the invention will become more apparent with reference to the following detailed description and drawings.
The seal segments can be attached to the peripheral edges of the barrier wall 18 by any conventional means. In the illustrated embodiment, the peripheral edges are formed as rims with curled ends which grip a base portion 18a of the seal segments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, a doorway mounted flood barrier is generally referred to by the numeral 10 and is designed to fit in a doorway on the outside of a door 12. The door closes in a door frame having a bottom 14 and opposite sides 16 and 17. To the word "doorway" refers to an opening in which a door is mounted. This usually involves a door frame as illustrated.
In a flooding situation, water normally enters the house by seeping between the peripheral edges of the door 12 and the doorway, particularly at the lower one to six inches of the doorway. In other words, most flooding occurs when water one to six inches deep rises on the door 12 and seepage occurs at the bottom of the door and at the sides contiguous with the bottom.
According to the present invention, a doorway mounted flood barrier 10 is mounted in the doorway in front of the door 12 so as to provide a sealed barrier to flood water. The barrier 10 includes a barrier wall 18 which is preferably integrally formed of cast aluminum. As a means of providing strength and reduced weight, the barrier wall 18 can be formed with longitudinally disposed stiffening ribs 20 and 22 which extend from the top 24 to the bottom 26 of the barrier wall.
The barrier wall 18 has a height sufficient to block most flooding situations and is preferably only about one to two feet in total height. The width is selected to stand the doorway horizontally and thus the barrier can be cast to fit standard door dimensions.
The peripheral edges of the barrier wall 18 are provided with an inflatable seal, collectively referred to by the numeral 28 and being composed of three contiguous segments 30, 32, and 34. In a preferred embodiment, the contiguous segments 30, 32 and 34 are separately inflatable through valve stems 30a, 32a and 34a. Inflation can be performed by using a standard bicycle tire pump, for example. Each seal segment has an integrally formed gripping member 36 formed medially on each segment so as to grip the corresponding doorway structure. Inflatable seals suitable for this purpose are commercially available from the SEAL MASTER Corporation of Kent, Ohio.
When flooding conditions are eminent, the barrier 10 is positioned in the doorway with the seals uninflated. A handle 36 can be formed in the barrier wall as a recess so as to aid lifting and placement of the barrier wall. Once positioned at a lower portion of the doorway, with the bottom of the barrier 10 resting on the bottom of the door frame, the two side segments of the seal are inflated so that a water tight barrier is created and held in place. Then, the bottom seal segment is inflated, the barrier wall is retained in its position by the enlargement of the seals due to their inflated condition.
In order to install the device according to the present invention, the device is placed in a doorway and the two side segments 30 and 34 are inflated through their separate inflation valves 30a and 34a. Once these are inflated, the panel is held in place so that the bottom segment 32 can then be inflated through the inflation valve 32a. This arrangement has advantages over a continuous inflatable seal because with a continuous inflatable seal (meaning only a single valve stem inflates a single U-shaped chamber), the bottom portion of the seal would tend not to properly inflate. The bottom is essential for maintaining a water-tight seal and thus, the device would fail without having separately inflatable segments. Moreover, with a continuous inflatable seal, the corners would be difficult to seal because of the creation of a radius, which would allow water to seep in at each corner. In the present invention, the two side segments 30 and 34 are adhesively bonded with epoxy to the bottom segment 32 to form substantially right-angled forms which snugly fit in the corners. Also, the barrier wall is provided with a slot 24c along the sides and bottom, and the seal segments are provided with a correspondingly shaped mounting portion 24d which tightly fits with the slot 24c. Also, adhesive, such as epoxy, is used to secure the segments at their mounted positions so that a water-tight seal is ensured.
Numerous modifications and adaptations of the present invention will be apparent to those so skilled in the art and thus, it is intended by the following claims to cover all such modifications and adaptations which fall within the true spirit and scope of the invention.
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A doorway mounted flood barrier including a barrier wall having two opposite vertical side edges and a horizontal bottom edge, and retainer means disposed between the barrier wall and a lower portion of the doorway for holding the barrier wall sealingly in the lower portion of the doorway.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention generally relates to integrated circuit (IC) fabrication and, more particularly, to a system and method for forming thin films of silicon over a silicon barrier layer by sequential sputter deposition processes.
[0003] 2. Description of the Related Art
[0004] In the manufacture of thin film transistor (TFT) liquid crystal displays (LCDs), the active region of the display consists of an array of pixels, built on a transparent (glass) substrate. The TFTs are in essence optical switches that control the amount of light that is allowed to pass through each pixel before reaching the eye of the viewer(s). TFTs are made using a plurality of typical semiconductor processes, such as deposition, lithography, etching, etc., directly on the glass substrate. Before the TFT fabrication commences, the glass substrate needs to be coated with an appropriate base coat layer, to prevent outdiffusion of impurities, typically present in the glass material, into the TFT layers. The most conventional base coat material is silicon dioxide (SiO2) film. The base coat deposition is usually followed by an annealing (densification) process, to improve the quality of the base coat layer before it comes in contact with subsequently deposited TFT layers.
[0005] The need for the annealing step, to improve the material quality, stems from the fact that the water in the barrier base coat layer tends to promote Si—OH bonds. These Si—OH groups lead to the formation of spatially localized (fixed) electrical charges in the base coat that can, in turn, modulate the transistor characteristics, such as threshold voltage and subthreshold slope, when adjacent silicon films are used as transistor active areas. Furthermore impurities on the interface between the base coat layer and the adjoining silicon film may lead to development of interface trap states that will similarly affect the transistor performance. These phenomena are more likely to occur when the adjacent silicon films are thin, such as the silicon films used to form a TFT.
[0006] Annealing reduces the amount of water that is trapped in the base coat film. Water in SiO2 films is manifested in two main ways: (1) the number of Si—OH bonds in the film, and (2) the amount of absorbed water in the film upon exposure to ambient. The first source is attributed to the deposition chemistry. That is, the interaction of H, O and Si as the film is formed from precursors such as SiH4 or TEOS. This source can be controlled, to a certain extent, by process optimization, so that the amount of Si—OH bonding configurations is minimized. However, an undesirable amount of Si—OH bonding still occurs. The second source depends upon the physical characteristics of the film, such as porosity, and is difficult to eliminate. Even the densest films will tend to absorb some water upon exposure to the ambient environment after the deposition process.
[0007] Another conventional approach used to address the problem of water in the silicon base coat is the formation of a dual base coat layer. When optimized, this process alleviates the need for post-deposition annealing. In this approach, a SiNx/SiO2 stack is deposited. The SiNx layer demonstrates good barrier properties, whereas the SiO2 layer is used to mainly improve the interface quality between the base coat stack and the next TFT layer. This approach, however, requires extra process steps, as two layers must now be deposited. Further, the —OH radicals are not eliminated, merely trapped in the SiO2 film, and the potential still exists for these radicals to create fixed charge groups in the base coat.
[0008] It would be advantageous if a TFT, overlying a glass substrate, could be formed with a minimal number of —OH radicals in the silicon dioxide base coat.
[0009] It would be advantageous if a TFT silicon dioxide base coat could be formed without the necessity of an annealing step. It would be advantageous if the annealing step could be eliminated without the necessity of a nitride layer interposed between the silicon dioxide layer and a silicon thin film.
[0010] It would be advantageous if a TFT silicon dioxide base coat could be deposited with a minimum of hydrogen. It would be advantageous if a thin silicon film could be deposited over the base coat without an intervening process that permits water to be absorbed into the base coat.
SUMMARY OF THE INVENTION
[0011] The present invention describes processes for the deposition of thin-film materials used in the fabrication of amorphous silicon (a-Si) or polysilicon (polycrystalline silicon) TFTs. The invention involves the sputtering, or physical vapor deposition (PVD) of active amorphous silicon and polysilicon layers, and adjacent insulating base coat layers of silicon dioxide. These adjacent film layers are used in the fabrication of TFTs, which in turn are key elements of different types of LCDs.
[0012] The present invention minimizes the formation of Si—OH groups in the oxide barrier layer, significantly improving the quality of the barrier layer. This improvement is accomplished by sputtering the base coat layer and overlying thin silicon film sequentially, to inhibit water absorption. In this manner, the annealing steps, currently employed in conventional TFT fabrication processes to improve the electrical characteristics of the base coat layer, can be eliminated.
[0013] Accordingly, in the fabrication of TFTs, a method is provided for forming a thin film of silicon overlying a base coat in a continuous process. The method generally comprises: forming a vacuum seal; sputter depositing a silicon dioxide barrier layer; and, without breaking the vacuum seal, sputter depositing a thin film of amorphous or polycrystalline silicon overlying the barrier layer. More specifically, in the context of forming a TFT for use in an LCD, the method further comprises introducing a glass substrate. Then, sputter depositing a barrier layer includes sputter depositing a silicon dioxide base coat overlying the glass substrate.
[0014] The base coat is deposited using either a direct current (DC) magnetron sputtering or a radio frequency (RF) sputtering process. When the DC magnetron process is used, an atmosphere is established that includes argon and oxygen. In some aspects of the invention Ar can be replaced by another inert gas such as Ne and Kr. In some other aspects of the invention additional gases such as He and hydrogen can be also used. The target is either a single-crystal silicon, polycrystalline silicon, or doped silicon material. When an RF sputtering process in used, an atmosphere is established that includes Ar and oxygen, and sometimes helium. A silicon target or a silicon dioxide compound target is used.
[0015] The silicon thin film is deposited with a DC magnetron process in an atmosphere of Ar, using a target material of single-crystal silicon, polycrystalline silicon, or doped silicon. In other aspects of the invention a mixture of He and Ar can be used for the deposition of the thin silicon film.
[0016] Additional details of the above-described sputtering deposition process and a system for forming a TFT base coat layer and silicon thin film in a continuous sputtering process are provided below.
BRIEF DESCRIPTION OF THE DRAWING
[0017] [0017]FIG. 1 is a block diagram of the present invention system for forming a barrier layer and a thin film of silicon in a continuous process, such as used in the fabrication of TFTs.
[0018] [0018]FIG. 2 is a partial cross-sectional view of the film layers formed in the present invention system.
[0019] [0019]FIG. 3 is a flowchart illustrating the present invention method for forming a thin film of silicon overlying a barrier layer in a continuous process.
[0020] [0020]FIG. 4 is a flowchart illustrating the present invention method for forming a barrier layer overlying a thin film of silicon in a continuous process.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] [0021]FIG. 1 is a block diagram of the present invention system for forming a barrier layer and a thin film of silicon in a continuous process, such as used in the fabrication of TFTs. The system 100 comprises a first chamber 102 for sputter depositing a barrier layer. Although a direct current (DC) magnetron is shown, a radio frequency (RF) sputtering device provides equivalent results. The first chamber 102 has an atmosphere maintained at a first base pressure, and a load/unload port 104 . A second chamber 106 is used for the deposition of a thin film of silicon. Typically, the second chamber uses a DC magnetron device. The second chamber 106 has an atmosphere maintained at the first base pressure and a load/unload port 108 connected to the first chamber load/unload port 104 , to permit communication between the first chamber 104 and the second chamber 106 without breaking the seal of the first base pressure vacuum. That is, the base pressure need not necessarily be equal in the two chambers, but rather the processes in the two chambers must be conducted without breaking the vacuum seal, giving no opportunity for water to be absorbed into the deposited barrier layer.
[0022] Generally, the system has applications for forming a barrier layer adjacent a thin film of silicon, and the film layers are not limited to any particular film order. Typically, however, the second chamber 106 sputter deposits a thin film of silicon overlying the barrier layer formed in the first chamber 102 . When an LCD is the ultimate object of manufacture, the TFT is formed on a glass substrate. Then, a glass substrate is provided, and the first chamber deposits a base coat barrier layer overlying the glass substrate. Typically, the second chamber 106 deposits a thin film of either amorphous silicon (a-Si) or polysilicon (p-Si).
[0023] [0023]FIG. 2 is a partial cross-sectional view of the film layers formed in the present invention system. As shown, the film layers are supported by a glass substrate 200 . Overlying the glass substrate 200 is the base coat barrier layer 202 , hereafter referred to the base coat. Typically, the base coat is silicon dioxide. Overlying the base coat 202 is the thin film of silicon 204 . The first chamber deposits a base coat of silicon dioxide having a thickness 206 in the range of 100 to 1000 nanometers (nm). Preferably, the thickness 206 is in the range of 100 to 500 nanometers nm. Even more preferably, the thickness 206 is in the range of 100 to 300 nanometers nm.
[0024] Returning to FIG. 1, the load/unload ports 104 / 108 of the first and second chambers 102 / 106 can be connected through a connecting chamber able to maintain the vacuum seal. Alternately, the chambers are more directly connected, such as in an “in-line” system where substrates are transferred from one deposition module (chamber) to the next without passing through an intermediate deposition station. The connection means is not critical, as long as a transfer can be made between chambers without breaking the vacuum seal. The substrate can be moved by conveyers, robotic arms, or the equivalence, the conveyance means is not critical to the invention.
[0025] In some aspects of the invention, the base coat 202 and thin film silicon layer 204 (see FIG. 2) are formed in the same chamber (not shown). However, a single chamber system would require cleaning, after the silicon dioxide barrier layer deposition, and before the silicon film deposition.
[0026] One of the key aspects of the silicon-sputtering process is the target component. The first chamber 102 has a target 210 , and the second chamber 106 has a target 212 . The targets 210 / 212 are blocks of the material to be deposited. Each of the targets 210 / 212 is mounted on an appropriate metal backing plate (not shown), and placed opposite to the substrate 200 (see FIG. 2) where the film is to be deposited. Describing the first chamber process, although an analogous description applies to the second chamber 106 , plasma strikes in the gap between the target 210 and the substrate 200 . First chamber magnet 214 (the second chamber 106 has a magnet 216 ) scans above the target backing plate, and is used to intensify the plasma and confine it in the region defined by the magnetic field. By scanning the magnet 214 , the plasma is swept across the surface of the target 210 , resulting in deposition of the base coat 202 on the substrate 200 opposite to the target 214 . The plasma is generated by applying high voltage to an inert gas that flows in the region between the target 214 and the substrate 200 . For certain applications, other gases may be mixed to the inert gas to alter the composition and/or the properties of the sputtered film.
[0027] The first chamber also includes a gas introduction port 220 and gas exhaust port 222 . When a DC magnetron device is used in the first chamber 102 , the gas ports 220 / 222 are used to supply a first chamber atmosphere including argon and oxygen. In some aspects of the invention Ar can be replaced by another inert gas such as Ne and Kr. In some other aspects of the invention, the first chamber gas introduction port 220 and gas exhaust port 222 supply an atmosphere additionally including helium to reduce the plasma voltage and alleviate the plasma damage to the sputtered dielectric film. In yet other aspects of the invention, the atmosphere optionally includes the addition of hydrogen to passivate dangling bonds that are generated within the sputtered dielectric film during deposition.
[0028] With sputtering, plasma strikes between the substrate and the block of target material to be deposited. The plasma typically consists of ionized Ar (or equivalent) gas. However, He/Ar mixtures are also very effective. Under the influence of the electric field between the target and the substrate, the ionized species are accelerated towards the target and impart part of their energy to atoms of the target material. As a result of this interaction, some of the host atoms are ejected from the target body and are deposited onto the substrate.
[0029] The first chamber DC magnetron device target 214 is a material selected from the group of materials including single-crystal silicon, polycrystalline silicon, and doped silicon. Typically, the doped silicon is a p-doped material having a resistivity in the range of 1 to 500 ohms per centimeter.
[0030] When the first chamber tool is an RF sputtering device, the gas introduction port 220 and gas exhaust port 222 supply a first chamber atmosphere including Ar and oxygen. In some aspects of the invention, the atmosphere optionally includes the addition of helium. The first chamber RF sputtering device target is made from a silicon or silicon dioxide material.
[0031] Likewise, the second chamber 106 has a gas introduction port 230 and gas exhaust port 232 to supply an atmosphere including either argon (Ar), or helium and Ar, for use in conjunction with the second chamber DC magnetron device. The second chamber DC magnetron device target 212 is either a single-crystal silicon, polycrystalline silicon, or doped silicon material. When a doped silicon is used, it is typically a p-doped material having a resistivity in the range of 1 to 500 ohms per centimeter.
[0032] The percentage of Ar varies in response to the optimization objectives for each layer. The reduced plasma voltage, afforded by the He sputtering gas, is beneficial in the deposition of dielectric films. Plasma damage is typically responsible for the introduction of fixed charges in the insulating films. Therefore, lower plasma voltages reduce the plasma damage and, hence, increase the quality of the dielectric layer. The He/Ar ratios used to deposit a base coat in the first chamber 102 may vary from the ratio used to form the silicon film layer in the second chamber 106 .
[0033] As described above, the present invention system 100 uses a sputtering, or PVD process to deposit a SiO 2 film for the base coat layer. Since sputtering is a physical deposition process, no chemistry is used in the deposition. Hence, no H-bearing species are formed that, when combined with O atoms, can produce —OH groups.
[0034] Sputtering is a well-suited method for the formation of the various Si-based TFT layers because:
[0035] 1. it is a safe and environmentally benign technique;
[0036] 2. it can be used even at room temperature and is, thus, compatible with any kind of substrate;
[0037] 3. silicon films with very low H2 content can be typically deposited. Hence, there is no need for dehydrogenation to release excessive hydrogen. Alternatively, hydrogen can be incorporated into the film if, and when necessary;
[0038] 4. it is a simpler and more easily scaled method than comparable methods that rely on chemistry; and,
[0039] 5. it is already used for all metal depositions in TFT-LCD production.
[0040] Given the significant reduction of OH groups in sputtered SiO2 films, the present invention system is very suitable for improving the bulk electronic properties (quality) of the formed layers. Furthermore, by utilizing a continuous (sequential) deposition mode, a silicon film can be deposited on top of the base coat film without breaking vacuum. Maintaining the vacuum eliminates a potential source of water. No water is absorbed in the base coat, as the film is not exposed to ambient conditions between deposition steps. Hence, no separate annealing step is required to remove water absorbed in the base coat between deposition processes. Further, as a result of sputtering the base coat and sequentially sputtering the thin film of silicon, the step of dehydrogenation is also eliminated, as PVD-Si has very low H2 content.
[0041] [0041]FIG. 3 is a flowchart illustrating the present invention method for forming a thin film of silicon overlying a barrier layer in a continuous process. Although the method is depicted as a sequence of numbered steps for clarity, no order should be inferred from the numbering unless explicitly stated. The method starts at Step 300 . Step 302 forms a vacuum seal. Step 304 sputter deposits a barrier layer. Step 306 , without breaking the vacuum seal, sputter deposits a thin film of silicon overlying the barrier layer. Typically, the method includes a further step, Step 301 of introducing a glass substrate. Then, sputter depositing a barrier layer in Step 304 includes sputter depositing a base coat overlying the glass substrate.
[0042] Sputter depositing a thin film of silicon overlying the barrier layer in Step 306 includes forming a thin film from the group including amorphous silicon (a-Si) and polysilicon (p-Si). Sputter depositing a barrier layer in Step 304 includes sputter depositing a base coat of silicon dioxide. Sputter depositing a base coat in Step 304 includes sputter depositing a base coat of silicon dioxide having a thickness in the range of 100 to 1000 nanometers (nm). Preferably, the thickness is in the range of 100 to 500 nm. Even more preferably, the thickness is in the range of 100 to 300 nm.
[0043] Sputter depositing a base coat in Step 304 includes sputter depositing silicon dioxide with a process selected from the group including direct current (DC) magnetron sputtering and radio frequency (RF) sputtering. When the base coat is deposited with a DC magnetron process, the atmosphere includes argon and oxygen. In some aspects of the invention Ar can be replaced by another inert gas selected from the group including Ne and Kr. In some other aspects of the invention, the atmosphere additionally includes helium gas. In other aspects, the atmosphere additionally includes hydrogen.
[0044] Sputter depositing a base coat in Step 304 includes sputter depositing a base coat using a target material selected from the group including single-crystal silicon, polycrystalline silicon, and doped silicon. Typically, the doped silicon target material is a p-doped material having a resistivity in the range of 1 to 500 ohms per centimeter.
[0045] When the base coat is deposited in Step 304 with an RF sputtering process, the atmosphere includes Ar and oxygen. In some aspects of the invention, the atmosphere additionally includes helium. The base coat layer is sputter deposited using a target material of silicon dioxide or silicon.
[0046] Sputter depositing a thin film of silicon overlying the base coat in Step 306 includes sputter depositing with a DC magnetron process in an atmosphere of Ar. In another aspect of the invention the sputtering atmosphere consists of a mixture of He and Ar. Sputter depositing a thin film of silicon overlying the base coat includes sputter depositing using a target material selected from the group including single-crystal silicon, polycrystalline silicon, and doped silicon. Typically, the doped silicon target material is a p-doped material having a resistivity in the range of 1 to 500 ohms per centimeter.
[0047] In some aspects of the invention, the method includes further steps. Step 308 forms a TFT active area from the thin film of silicon formed in Step 306 . Step 310 forms a liquid crystal display (LCD) from the TFT of Step 308 .
[0048] [0048]FIG. 4 is a flowchart illustrating the present invention method for forming a barrier layer overlying a thin film of silicon in a continuous process. The method of FIG. 3 generally describes a process that could be used for the formation of a bottom gate TFT. The present method is intended to cover either more general processes, or processes where the barrier layer is formed over the thin silicon film. The method begins at Step 400 . Step 402 forms a vacuum seal. Step 404 sputter deposits a thin film of silicon. Step 406 , without breaking the vacuum seal, sputter deposits a barrier layer overlying the thin film of silicon.
[0049] Sputter depositing a thin film of silicon in Step 404 includes forming a thin film of amorphous silicon (a-Si) or polysilicon (p-Si). Sputter depositing a barrier layer in Step 406 includes sputter depositing a barrier layer of silicon dioxide.
[0050] A system and method have been presented for sequentially sputter depositing a thin film of silicon over a base coat barrier layer, so that the vacuum seal is not broken between the two deposition processes. A specific example of a glass substrate/base coat/silicon film structure has been given, but the present invention is applicable to the formation of more complex, yet related structures. Other variations and embodiments will occur to those skilled in the art.
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A system and method are provided to sequentially deposit a silicon dioxide base coat barrier layer adjacent a thin silicon films, to minimize the formation of water and —OH radicals. Both the base coat and thin silicon films are sputter deposited to eliminate hydrogen chemistries. Further, the sputter processes are conducted sequentially, with breaking the vacuum seal, to minimize the absorption of water in the base coat layer that conventionally occurs between deposition steps. This process eliminates the total number of process steps required, as there is no longer a need for furnace annealing the base coat before the deposition of the thin silicon film, and no longer a need for a dehydrogenation annealing step after the deposition of the thin silicon film.
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REFERENCE TO RELATED APPLICATIONS
This application is a divisional of application Ser. No. 10/961,352, filed Oct. 8, 2004, now U.S. Pat. No. 7,569,126, which claims the benefit of U.S. Provisional Application No. 60/581,002, filed Jun. 18, 2004, and which are incorporated herein by reference in their entirety. This application is also related to application Ser. No. 10/871,937, filed Jun. 18, 2004, and which is incorporated herein by reference in its entirety.
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an apparatus for use in measuring signals such as those related to concentrations of an analyte (such as blood glucose) in a biological fluid as well as those related to interferants (such as hematocrit and temperature in the case of blood glucose) to analyte concentration signals. The invention relates more particularly to a system and method for quality assurance of a biosensor test strip.
BACKGROUND OF THE INVENTION
Measuring the concentration of substances in biological fluids is an important tool for the diagnosis and treatment of many medical conditions. For example, the measurement of glucose in body fluids, such as blood, is crucial to the effective treatment of diabetes.
Diabetic therapy typically involves two types of insulin treatment: basal, and meal-time. Basal insulin refers to continuous, e.g. time-released insulin, often taken before bed. Meal-time insulin treatment provides additional doses of faster acting insulin to regulate fluctuations in blood glucose caused by a variety of factors, including the metabolization of sugars and carbohydrates. Proper regulation of blood glucose fluctuations requires accurate measurement of the concentration of glucose in the blood. Failure to do so can produce extreme complications, including blindness and loss of circulation in the extremities, which can ultimately deprive the diabetic of use of his or her fingers, hands, feet, etc.
Multiple methods are known for determining the concentration of analytes in a blood sample, such as, for example, glucose. Such methods typically fall into one of two categories: optical methods and electrochemical methods. Optical methods generally involve spectroscopy to observe the spectrum shift in the fluid caused by concentration of the analyte, typically in conjunction with a reagent that produces a known color when combined with the analyte. Electrochemical methods generally rely upon the correlation between a current (Amperometry), a potential (Potentiometry) or accumulated charge (Coulometry) and the concentration of the analyte, typically in conjunction with a reagent that produces charge-carriers when combined with the analyte. See, for example, U.S. Pat. No. 4,233,029 to Columbus, U.S. Pat. No. 4,225,410 to Pace, U.S. Pat. No. 4,323,536 to Columbus, U.S. Pat. No. 4,008,448 to Muggli, U.S. Pat. No. 4,654,197 to Lilja et al., U.S. Pat. No. 5,108,564 to Szuminsky et al., U.S. Pat. No. 5,120,420 to Nankai et al., U.S. Pat. No. 5,128,015 to Szuminsky et al., U.S. Pat. No. 5,243,516 to White, U.S. Pat. No. 5,437,999 to Diebold et al., U.S. Pat. No. 5,288,636 to Pollmann et al., U.S. Pat. No. 5,628,890 to Carter et al., U.S. Pat. No. 5,682,884 to Hill et al., U.S. Pat. No. 5,727,548 to Hill et al., U.S. Pat. No. 5,997,817 to Crismore et al., U.S. Pat. No. 6,004,441 to Fujiwara et al., U.S. Pat. No. 4,919,770 to Priedel, et al., and U.S. Pat. No. 6,054,039 to Shieh, which are hereby incorporated in their entireties. The biosensor for conducting the tests is typically a disposable test strip having a reagent thereon that chemically reacts with the analyte of interest in the biological fluid. The test strip is mated to a nondisposable test meter such that the test meter can measure the reaction between the analyte and the reagent in order to determine and display the concentration of the analyte to the user.
FIG. 1 schematically illustrates a typical prior art disposable biosensor test strip, indicated generally at 10 (see, for example, U.S. Pat. Nos. 4,999,582 and 5,438,271, assigned to the same assignee as the present application, and incorporated herein by reference). The test strip 10 is formed on a nonconductive substrate 12 , onto which are formed conductive areas 14 , 16 . A chemical reagent 18 is applied over the conductive areas 14 , 16 at one end of the test strip 10 . The reagent 18 will react with the analyte of interest in the biological sample in a way that can be detected when a voltage potential is applied between the measurement electrodes 14 a and 16 a.
The test strip 10 therefore has a reaction zone 20 containing the measurement electrodes 14 a , 16 a that comes into direct contact with a sample that contains an analyte for which the concentration in the sample is to be determined. In an amperometric or coulometric electrochemical measurement system, the measurement electrodes 14 a , 16 a in the reaction zone 20 are coupled to electronic circuitry (typically in a test meter (not shown) into which the test strip 10 is inserted, as is well known in the art) that supplies an electrical potential to the measurement electrodes and measures the response of the electrochemical sensor to this potential (e.g. current, impedance, charge, etc.). This response is proportional to the analyte concentration.
The test meter contacts the test strip 10 at contact pads 14 b , 16 b in a contact zone 22 of the test strip 10 . Contact zone 22 is located somewhat remotely from measurement zone 20 , usually (but not always) at an opposite end of the test strip 10 . Conductive traces 14 c , 16 c couple the contact pads 14 b , 16 b in the contact zone 22 to the respective measurement electrodes 14 a , 16 a in the reaction zone 20 .
Especially for biosensors 10 in which the electrodes, traces and contact pads are comprised of electrically conductive thin films (for instance, noble metals, carbon ink, and silver paste, as non-limiting examples), the resistivity of the conductive traces 14 c , 16 c that connect the contact zone 22 to the reaction zone 20 can amount to several hundred Ohms or more. This parasitic resistance causes a potential drop along the length of the traces 14 c , 16 c , such that the potential presented to the measurement electrodes 14 a , 16 a in the reaction zone 20 is considerably less than the potential applied by the test meter to the contact pads 14 b , 16 b of the test strip 10 in the contact zone 22 . Because the impedance of the reaction taking place within the reaction zone 20 can be within an order of magnitude of the parasitic resistance of the traces 14 c , 16 c , the signal being measured can have a significant offset due to the I-R (current x resistance) drop induced by the traces. If this offset varies from test strip to test strip, then noise is added to the measurement result. Furthermore, physical damage to the test strip 10 , such as abrasion, cracks, scratches, chemical degradation, etc. can occur during manufacturing, shipping, storage and/or user mishandling. These defects can damage the conductive areas 14 , 16 to the point that they present an extremely high resistance or even an open circuit. Such increases in the trace resistance can prevent the test meter from performing an accurate test.
Thus, a system and method are needed that will allow for confirmation of the integrity of test strip traces, for measurement of the parasitic resistance of test strip traces, and for controlling the potential level actually applied to the test strip measurement electrodes in the reaction zone. The present invention is directed toward meeting these needs.
SUMMARY OF THE INVENTION
The present invention provides a test strip for measuring a signal of interest in a biological fluid when the test strip is mated to an appropriate test meter, wherein the test strip and the test meter include structures to verify the integrity of the test strip traces, to measure the parasitic resistance of the test strip traces, and to provide compensation in the voltage applied to the test strip to account for parasitic resistive losses in the test strip traces.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be further described, by way of example only, with reference to the accompanying drawings, in which:
FIG. 1 is schematic plan view of a typical prior art test strip for use in measuring the concentration of an analyte of interest in a biological fluid.
FIG. 2 is a schematic plan view of a first embodiment test strip according to the present invention.
FIG. 3 is a schematic diagram of a first embodiment electronic test circuit for use with the first embodiment test strip of FIG. 2 .
FIG. 4 is an exploded assembly view of a second typical test strip for use in measuring the concentration of an analyte of interest in a biological fluid.
FIG. 5 illustrates a view of an ablation apparatus suitable for use with the present invention.
FIG. 6 is a view of the laser ablation apparatus of FIG. 5 showing a second mask.
FIG. 7 is a view of an ablation apparatus suitable for use with the present invention.
FIG. 8 is a schematic plan view of a second embodiment test strip according to the present invention.
FIG. 9 is a schematic diagram of a second embodiment electronic test circuit for use with the second embodiment test strip of FIG. 8 .
FIG. 10 is a schematic diagram of a third embodiment electronic test circuit for use with the second embodiment test strip of FIG. 8 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings, and specific language will be used to describe that embodiment. It will nevertheless be understood that no limitation of the scope of the invention is intended. Alterations and modifications in the illustrated device, and further applications of the principles of the invention as illustrated therein, as would normally occur to one skilled in the art to which the invention relates are contemplated, are desired to be protected. In particular, although the invention is discussed in terms of a blood glucose meter, it is contemplated that the invention can be used with devices for measuring other analytes and other sample types. Such alternative embodiments require certain adaptations to the embodiments discussed herein that would be obvious to those skilled in the art.
Although the system and method of the present invention may be used with test strips having a wide variety of designs and made with a wide variety of construction techniques and processes, a first embodiment electrochemical test strip of the present invention is illustrated schematically in FIG. 2 , and indicated generally at 200 . Portions of test strip 200 which are substantially identical to those of test strip 10 are marked with like reference designators. Referring to FIG. 2 , the test strip 200 comprises a bottom substrate 12 formed from an opaque piece of 350 μm thick polyester (such as Melinex 329 available from DuPont) coated on its top surface with a 50 nm conductive gold layer (for instance by sputtering or vapor deposition, by way of non-limiting example). Electrodes, connecting traces and contact pads therefor are then patterned in the conductive layer by a laser ablation process. The laser ablation process is performed by means of an excimer laser which passes through a chrome-on-quartz mask. The mask pattern causes parts of the laser field to be reflected while allowing other parts of the field to pass through, creating a pattern on the gold which is evaporated where contacted by the laser light. The laser ablation process is described in greater detail hereinbelow. For example, working 214 a , counter 216 a , and counter sense 224 a electrodes may be formed as shown and coupled to respective measurement contact pads 214 b , 216 b and 224 b by means of respective traces 214 c , 216 c and 224 c . These contact pads 214 b , 216 b and 224 b provide a conductive area upon the test strip 200 to be contacted by a connector contact of the test meter (not shown) once the test strip 200 is inserted into the test meter, as is well known in the art.
FIGS. 2 and 3 illustrate an embodiment of the present invention that improves upon the prior art test strip designs by allowing for compensation of parasitic I-R drop in the counter electrode line of the test strip. It will be appreciated that the test strip 200 of FIG. 2 is substantially identical to the prior art test strip 10 of FIG. 1 , except for the addition of the counter sense electrode 224 a , contact pad 224 b , and trace 224 c . Provision of the counter sense line 224 allows the test meter (as described hereinbelow) to compensate for parasitic resistance between the contact pads 216 b , 224 b . Note that the embodiment of FIG. 2 when used with the circuit of FIG. 3 only compensates for the I-R drop on the counter electrode side of the test strip 200 . Parasitic resistance on the working electrode side of the test strip 200 cannot be detected using this circuitry, although it could be replicated on the working electrode side if desired, as will be apparent to those skilled in the art with reference to the present disclosure. Further methods for compensating for parasitic resistance on both the working and counter sides of the test strip are presented hereinbelow. The counter sense line of FIG. 2 therefore allows the test meter to compensate for any parasitic resistance potential drop in the counter line 216 , as explained in greater detail with respect to FIG. 3 .
Referring now to FIG. 3 , there is shown a schematic electrical circuit diagram of a first embodiment electrode compensation circuit (indicated generally at 300 ) housed within the test meter. As indicated, the circuit couples to contact pads 214 b , 216 b and 224 b when the test strip 200 is inserted into the test meter. As will be appreciated by those skilled in the art, a voltage potential is applied to the counter electrode contact pad 216 b , which will produce a current between the counter electrode 216 a and the working electrode 214 a that is proportional to the amount of analyte present in the biological sample applied to the reagent 18 . The current from working electrode 214 a is transmitted to working electrode contact pad 214 b by means of working electrode trace 214 c and provided to a current-to-voltage amplifier 310 . The analog output voltage of amplifier 310 is converted to a digital signal by analog-to-digital converter (A/D) 312 . This digital signal is then processed by microprocessor 314 according to a previously stored program in order to determine the concentration of analyte within the biological sample applied to the test strip 200 . This concentration is displayed to the user by means of an appropriate output device 316 , such as a liquid crystal display (LCD) screen.
Microprocessor 314 also outputs a digital signal indicative of the voltage potential to be applied to the counter electrode contact pad 216 b . This digital signal is converted to an analog voltage signal by digital-to-analog converter (D/A) 318 . The analog output of D/A 318 is applied to a first input of an operational amplifier 320 . A second input of the operational amplifier 320 is coupled to counter sense electrode contact pad 224 b . The output of operational amplifier 320 is coupled to the counter electrode contact pad 216 b.
Operational amplifier 320 is connected in a voltage follower configuration, in which the amplifier will adjust its output (within its physical limits of operation) until the voltage appearing at its second input is equal to the commanded voltage appearing at its first input. The second input of operational amplifier 320 is a high impedance input, therefore substantially no current flows in counter sense line 224 . Since substantially no current flows, any parasitic resistance in counter sense line 224 will not cause a potential drop, and the voltage appearing at the second input of operational amplifier 320 is substantially the same as the voltage at counter sense electrode 224 a , which is in turn substantially the same as the voltage appearing at counter electrode 216 a due to their close physical proximity. Operational amplifier 320 therefore acts to vary the voltage potential applied to the counter electrode contact pad 216 b until the actual voltage potential appearing at the counter electrode 216 a (as fed back over counter sense line 224 ) is equal to the voltage potential commanded by the microprocessor 314 . Operational amplifier 320 therefore automatically compensates for any potential drop caused by the parasitic resistance in the counter electrode trace 216 c , and the potential appearing at the counter electrode 216 a is the desired potential. The calculation of the analyte concentration in the biological sample from the current produced by the working electrode is therefore made more accurate, since the voltage that produced the current is indeed the same voltage commanded by the microprocessor 314 . Without the compensation for parasitic resistance voltage drops provided by the circuit 300 , the microprocessor 314 would analyze the resulting current under the mistaken presumption that the commanded voltage was actually applied to the counter electrode 216 a.
Many methods are available for preparing test strips having multiple electrodes, such as carbon ink printing, silver paste silk-screening, scribing metalized plastic, electroplating, chemical plating, and photo-chemical etching, by way of non-limiting example. One preferred method of preparing a test strip having additional electrode sense lines as described herein is by the use of laser ablation techniques. Examples of the use of these techniques in preparing electrodes for biosensors are described in U.S. patent application Ser. No. 09/866,030, “Biosensors with Laser Ablation Electrodes with a Continuous Coverlay Channel” filed May 25, 2001, and in U.S. patent application Ser. No. 09/411,940, entitled “Laser Defined Features for Patterned Laminates and Electrode,” filed Oct. 4, 1999, both disclosures incorporated herein by reference. Laser ablation is particularly useful in preparing test strips according to the present invention because it allows conductive areas having extremely small feature sizes to be accurately manufactured in a repeatable manner. Laser ablation provides a means for adding the extra sense lines of the present invention to a test strip without increasing the size of the test strip.
It is desirable in the present invention to provide for the accurate placement of the electrical components relative to one another and to the overall biosensor. In a preferred embodiment, the relative placement of components is achieved, at least in part, by the use of broad field laser ablation that is performed through a mask or other device that has a precise pattern for the electrical components. This allows accurate positioning of adjacent edges, which is further enhanced by the close tolerances for the smoothness of the edges.
FIG. 4 illustrates a simple biosensor 401 useful for illustrating the laser ablation process of the present invention, including a substrate 402 having formed thereon conductive material 403 defining electrode systems comprising a first electrode set 404 and a second electrode set 405 , and corresponding traces 406 , 407 and contact pads 408 , 409 , respectively. Note that the biosensor 401 is used herein for purposes of illustrating the laser ablation process, and that it is not shown as incorporating the sense lines of the present invention. The conductive material 403 may contain pure metals or alloys, or other materials, which are metallic conductors. Preferably, the conductive material is absorptive at the wavelength of the laser used to form the electrodes and of a thickness amenable to rapid and precise processing. Non-limiting examples include aluminum, carbon, copper, chromium, gold, indium tin oxide (ITO), palladium, platinum, silver, tin oxide/gold, titanium, mixtures thereof, and alloys or metallic compounds of these elements. Preferably, the conductive material includes noble metals or alloys or their oxides. Most preferably, the conductive material includes gold, palladium, aluminum, titanium, platinum, ITO and chromium. The conductive material ranges in thickness from about 10 nm to 80 nm, more preferably, 30 nm to 70 nm, and most preferably 50 nm. It is appreciated that the thickness of the conductive material depends upon the transmissive property of the material and other factors relating to use of the biosensor.
While not illustrated, it is appreciated that the resulting patterned conductive material can be coated or plated with additional metal layers. For example, the conductive material may be copper, which is then ablated with a laser into an electrode pattern; subsequently, the copper may be plated with a titanium/tungsten layer, and then a gold layer, to form the desired electrodes. Preferably, a single layer of conductive material is used, which lies on the base 402 . Although not generally necessary, it is possible to enhance adhesion of the conductive material to the base, as is well known in the art, by using seed or ancillary layers such as chromium nickel or titanium. In preferred embodiments, biosensor 401 has a single layer of gold, palladium, platinum or ITO.
Biosensor 401 is illustratively manufactured using two apparatuses 10 , 10 ′, shown in FIGS. 4 , 6 and 7 , respectively. It is appreciated that unless otherwise described, the apparatuses 410 , 410 ′ operate in a similar manner. Referring first to FIG. 5 , biosensor 401 is manufactured by feeding a roll of ribbon 420 having an 80 nm gold laminate, which is about 40 mm in width, into a custom fit broad field laser ablation apparatus 410 . The apparatus 410 comprises a laser source 411 producing a beam of laser light 412 , a chromium-plated quartz mask 414 , and optics 416 . It is appreciated that while the illustrated optics 416 is a single lens, optics 416 is preferably a variety of lenses that cooperate to make the light 412 in a pre-determined shape.
A non-limiting example of a suitable ablation apparatus 410 ( FIGS. 5-6 ) is a customized MicrolineLaser 200-4 laser system commercially available from LPKF Laser Electronic GmbH, of Garbsen, Germany, which incorporates an LPX-400, LPX-300 or LPX-200 laser system commercially available from Lambda Physik AG, Göttingen, Germany and a chromium-plated quartz mask commercially available from International Phototool Company, Colorado Springs, Co.
For the MicrolineLaser 200-4 laser system ( FIGS. 5-6 ), the laser source 411 is a LPX-200 KrF-UV-laser. It is appreciated, however, that higher wavelength UV lasers can be used in accordance with this disclosure. The laser source 411 works at 248 nm, with a pulse energy of 600 mJ, and a pulse repeat frequency of 50 Hz. The intensity of the laser beam 412 can be infinitely adjusted between 3% and 92% by a dielectric beam attenuator (not shown). The beam profile is 27×15 mm 2 (0.62 sq. inch) and the pulse duration 25 ns. The layout on the mask 414 is homogeneously projected by an optical elements beam expander, homogenizer, and field lens (not shown). The performance of the homogenizer has been determined by measuring the energy profile. The imaging optics 416 transfer the structures of the mask 414 onto the ribbon 420 . The imaging ratio is 2:1 to allow a large area to be removed on the one hand, but to keep the energy density below the ablation point of the applied chromium mask on the other hand. While an imaging of 2:1 is illustrated, it is appreciated that the any number of alternative ratios are possible in accordance with this disclosure depending upon the desired design requirements. The ribbon 420 moves as shown by arrow 425 to allow a number of layout segments to be ablated in succession.
The positioning of the mask 414 , movement of the ribbon 420 , and laser energy are computer controlled. As shown in FIG. 5 , the laser beam 412 is projected onto the ribbon 420 to be ablated. Light 412 passing through the clear areas or windows 418 of the mask 414 ablates the metal from the ribbon 420 . Chromium coated areas 424 of the mask 414 blocks the laser light 412 and prevent ablation in those areas, resulting in a metallized structure on the ribbon 420 surface. Referring now to FIG. 6 , a complete structure of electrical components may require additional ablation steps through a second mask 414 ′. It is appreciated that depending upon the optics and the size of the electrical component to be ablated, that only a single ablation step or greater than two ablation steps may be necessary in accordance with this disclosure. Further, it is appreciated that instead of multiple masks, that multiple fields may be formed on the same mask in accordance with this disclosure.
Specifically, a second non-limiting example of a suitable ablation apparatus 410 ′ ( FIG. 7 ) is a customized laser system commercially available from LPKF Laser Electronic GmbH, of Garbsen, Germany, which incorporates a Lambda STEEL (Stable energy eximer laser) laser system commercially available from Lambda Physik AG, Göttingen, Germany and a chromium-plated quartz mask commercially available from International Phototool Company, Colorado Springs, Co. The laser system features up to 1000 mJ pulse energy at a wavelength of 308 nm. Further, the laser system has a frequency of 100 Hz. The apparatus 410 ′ may be formed to produce biosensors with two passes as shown in FIGS. 5 and 6 , but preferably its optics permit the formation of a 10×40 mm pattern in a 25 ns single pass.
While not wishing to be bound to a specific theory, it is believed that the laser pulse or beam 412 that passes through the mask 414 , 414 ′, 414 ″ is absorbed within less than 1 μm of the surface 402 on the ribbon 420 . The photons of the beam 412 have an energy sufficient to cause photo-dissociation and the rapid breaking of chemical bonds at the metal/polymer interface. It is believed that this rapid chemical bond breaking causes a sudden pressure increase within the absorption region and forces material (metal film 403 ) to be ejected from the polymer base surface. Since typical pulse durations are around 20-25 nanoseconds, the interaction with the material occurs very rapidly and thermal damage to edges of the conductive material 403 and surrounding structures is minimized. The resulting edges of the electrical components have high edge quality and accurate placement as contemplated by the present invention.
Fluence energies used to remove or ablate metals from the ribbon 420 are dependent upon the material from which the ribbon 420 is formed, adhesion of the metal film to the base material, the thickness of the metal film, and possibly the process used to place the film on the base material, i.e. supporting and vapor deposition. Fluence levels for gold on KALADEX® range from about 50 to about 90 mJ/cm 2 , on polyimide about 100 to about 120 mJ/cm 2 , and on MELINEX® about 60 to about 120 mJ/cm 2 . It is understood that fluence levels less than or greater than the above mentioned can be appropriate for other base materials in accordance with the disclosure.
Patterning of areas of the ribbon 420 is achieved by using the masks 414 , 414 ′. Each mask 414 , 414 ′ illustratively includes a mask field 422 containing a precise two-dimensional illustration of a pre-determined portion of the electrode component patterns to be formed. FIG. 5 illustrates the mask field 422 including contact pads and a portion of traces. As shown in FIG. 6 , the second mask 414 ′ contains a second corresponding portion of the traces and the electrode patterns containing fingers. As previously described, it is appreciated that depending upon the size of the area to be ablated, the mask 414 can contain a complete illustration of the electrode patterns ( FIG. 7 ), or portions of patterns different from those illustrated in FIGS. 5 and 6 in accordance with this disclosure. Preferably, it is contemplated that in one aspect of the present invention, the entire pattern of the electrical components on the test strip are laser ablated at one time, i.e., the broad field encompasses the entire size of the test strip ( FIG. 7 ). In the alternative, and as illustrated in FIGS. 5 and 6 , portions of the entire biosensor are done successively.
While mask 414 will be discussed hereafter, it is appreciated that unless indicated otherwise, the discussion will apply to masks 414 ′, 414 ″ as well. Referring to FIG. 5 , areas 424 of the mask field 422 protected by the chrome will block the projection of the laser beam 412 to the ribbon 420 . Clear areas or windows 418 in the mask field 422 allow the laser beam 412 to pass through the mask 414 and to impact predetermined areas of the ribbon 420 . As shown in FIG. 5 , the clear area 418 of the mask field 422 corresponds to the areas of the ribbon 420 from which the conductive material 403 is to be removed.
Further, the mask field 422 has a length shown by line 430 and a width as shown by line 432 . Given the imaging ratio of 2:1 of the LPX-200, it is appreciated that the length 30 of the mask is two times the length of a length 434 of the resulting pattern and the width 432 of the mask is two times the width of a width 436 of the resulting pattern on ribbon 420 . The optics 416 reduces the size of laser beam 412 that strikes the ribbon 420 . It is appreciated that the relative dimensions of the mask field 422 and the resulting pattern can vary in accordance with this disclosure. Mask 414 ′ ( FIG. 6 ) is used to complete the two-dimensional illustration of the electrical components.
Continuing to refer to FIG. 5 , in the laser ablation apparatus 410 the excimer laser source 411 emits beam 412 , which passes through the chrome-on-quartz mask 414 . The mask field 422 causes parts of the laser beam 412 to be reflected while allowing other parts of the beam to pass through, creating a pattern on the gold film where impacted by the laser beam 412 . It is appreciated that ribbon 420 can be stationary relative to apparatus 410 or move continuously on a roll through apparatus 410 . Accordingly, non-limiting rates of movement of the ribbon 420 can be from about 0 m/min to about 100 m/min, more preferably about 30 m/min to about 60 m/min. It is appreciated that the rate of movement of the ribbon 420 is limited only by the apparatus 410 selected and may well exceed 100 m/min depending upon the pulse duration of the laser source 411 in accordance with the present disclosure.
Once the pattern of the mask 414 is created on the ribbon 420 , the ribbon is rewound and fed through the apparatus 410 again, with mask 414 ′ ( FIG. 6 ). It is appreciated, that alternatively, laser apparatus 410 could be positioned in series in accordance with this disclosure. Thus, by using masks 414 , 414 ′, large areas of the ribbon 420 can be patterned using step-and-repeat processes involving multiple mask fields 422 in the same mask area to enable the economical creation of intricate electrode patterns and other electrical components on a substrate of the base, the precise edges of the electrode components, and the removal of greater amounts of the metallic film from the base material.
The second embodiment of the present invention illustrated in FIGS. 8 and 9 improve upon the prior art by providing for I-R drop compensation of both the working and counter electrode leads on the test strip. Referring now to FIG. 8 , there is schematically illustrated a second embodiment test strip configuration of the present invention, indicated generally at 800 . The test strip 800 comprises a bottom substrate 12 coated on its top surface with a 50 nm conductive gold layer (for instance by sputtering or vapor deposition, by way of non-limiting example). Electrodes, connecting traces and contact pads therefor are then patterned in the conductive layer by a laser ablation process as described hereinabove. For example, working 814 a , working sense 826 a , counter 216 a , and counter sense 224 a electrodes may be formed as shown and coupled to respective measurement contact pads 814 b , 826 b , 216 b and 224 b by means of respective traces 814 c , 826 c , 216 c and 224 c . These contact pads 814 b , 826 b , 216 b and 224 b provide a conductive area upon the test strip 800 to be contacted by a connector contact of the test meter (not shown) once the test strip 800 is inserted into the test meter.
It will be appreciated that the test strip 800 of FIG. 8 is substantially identical to the first embodiment test strip 200 of FIG. 2 , except for the addition of the working sense electrode 826 a , contact pad 826 b , and trace 826 c . Provision of the working sense line 826 allows the test meter to compensate for any I-R drop caused by the contact resistance of the connections to the contact pads 814 b and 216 b , and to compensate for the trace resistance of traces 814 c and 216 c.
Referring now to FIG. 9 , there is shown a schematic electrical circuit diagram of a second embodiment electrode compensation circuit (indicated generally at 900 ) housed within the test meter. As indicated, the circuit couples to contact pads 826 b , 814 b , 216 b and 224 b when the test strip 800 is inserted into the test meter. As will be appreciated by those skilled in the art, a voltage potential is applied to the counter electrode contact pad 216 b , which will produce a current between the counter electrode 216 a and the working electrode 814 a that is proportional to the amount of analyte present in the biological sample applied to the reagent 18 . The current from working electrode 814 a is transmitted by working electrode trace 814 c to working electrode contact pad 814 b and provided to current-to-voltage amplifier 310 . The analog output voltage of amplifier 310 is converted to a digital signal by A/D 312 . This digital signal is then processed by microprocessor 314 according to a previously stored program in order to determine the concentration of the analyte of interest within the biological sample applied to the test strip 800 . This concentration is displayed to the user by means of LCD output device 316 .
Microprocessor 314 also outputs a digital signal indicative of the voltage potential to be applied to the counter electrode contact pad 216 b . This digital signal is converted to an analog voltage signal by D/A 318 . The analog output of D/A 318 is applied to a first input of an operational amplifier 320 . A second input of the operational amplifier 320 is coupled to an output of operational amplifier 910 . Operational amplifier 910 is connected in a difference amplifier configuration using an instrumentation amplifier. A first input of operational amplifier 910 is coupled to working sense electrode contact pad 826 b , while a second input of operational amplifier 910 is coupled to counter sense electrode contact pad 224 b . The output of operational amplifier 320 is coupled to the counter electrode contact pad 216 b.
Operational amplifier 320 is connected in a voltage follower configuration, in which the amplifier will adjust its output (within its physical limits of operation) until the voltage appearing at its second input is equal to the commanded voltage appearing at its first input. Both inputs of operational amplifier 910 are high impedance inputs, therefore substantially no current flows in counter sense line 224 or working sense line 826 . Since substantially no current flows, any parasitic resistance in counter sense line 224 or working sense line 826 will not cause a potential drop, and the voltage appearing across the inputs of operational amplifier 910 is substantially the same as the voltage across the measurement cell (i.e. across counter electrode 216 a and working electrode 814 a ). Because operational amplifier 910 is connected in a difference amplifier configuration, its output represents the voltage across the measurement cell.
Operational amplifier 320 will therefore act to vary its output (i.e. the voltage potential applied to the counter electrode contact pad 216 b ) until the actual voltage potential appearing across the measurement cell is equal to the voltage potential commanded by the microprocessor 314 . Operational amplifier 320 therefore automatically compensates for any potential drop caused by the parasitic resistance in the counter electrode trace 216 c , counter electrode contact 216 b , working electrode trace 814 c , and working electrode contact 814 b , and therefore the potential appearing across the measurement cell is the desired potential. The calculation of the analyte concentration in the biological sample from the current produced by the working electrode is therefore made more accurate.
FIG. 10 , in conjunction with FIG. 8 , illustrates a third embodiment of the present invention that improves over the prior art by providing I-R drop compensation for both the working and counter electrode lines, as well as providing verification that the resistance of both the working and counter electrode lines is not above a predetermined threshold in order to assure that the test meter is able to compensate for the I-R drops. Referring now to FIG. 10 , there is shown a schematic electrical circuit diagram of a third embodiment electrode compensation circuit (indicated generally at 1000 ) housed within the test meter. The electrode compensation circuit 1000 works with the test strip 800 of FIG. 8 . As indicated, the circuit couples to contact pads 826 b , 814 b , 216 b and 224 b when the test strip 800 is inserted into the test meter. As will be appreciated by those skilled in the art, a voltage potential is applied to the counter electrode contact pad 216 b , which will produce a current between the counter electrode 216 a and the working electrode 814 a that is proportional to the amount of analyte present in the biological sample applied to the reagent 18 . The current from working electrode 814 a is transmitted to working electrode contact pad 814 b by working electrode trace 814 c and provided to current-to-voltage amplifier 310 . The output of current-to-voltage amplifier 310 is applied to the input of instrumentation amplifier 1002 which is configured as a buffer having unity gain when switch 1004 in the closed position. The analog output voltage of amplifier 1002 is converted to a digital signal by A/D 312 . This digital signal is then processed by microprocessor 314 according to a previously stored program in order to determine the concentration of analyte within the biological sample applied to the test strip 800 . This concentration is displayed to the user by means of LCD output device 316 .
Microprocessor 314 also outputs a digital signal indicative of the voltage potential to be applied to the counter electrode contact pad 216 b . This digital signal is converted to an analog voltage signal by D/A 318 . The analog output of D/A 318 is applied to the input of an operational amplifier 320 that is configured as a voltage follower when switch 1006 is in the position shown. The output of operational amplifier 320 is coupled to the counter electrode contact pad 216 b , which will allow measurement of a biological fluid sample applied to the reagent 18 . Furthermore, with switches 1006 , 1008 and 1010 positioned as illustrated in FIG. 10 , the circuit is configured as shown in FIG. 9 and may be used to automatically compensate for parasitic and contact resistance as described hereinabove with respect to FIG. 9 .
In order to measure the amount of parasitic resistance in the counter electrode line 216 , switch 1008 is placed in the position shown in FIG. 10 , switch 1006 is placed in the position opposite that shown in FIG. 10 , while switch 1010 is closed. The operational amplifier 320 therefore acts as a buffer with unity gain and applies a voltage potential to counter electrode contact pad 216 b through a known resistance R nom . This resistance causes a current to flow in the counter electrode line 216 and the counter sense line 224 that is sensed by current-to-voltage amplifier 310 , which is now coupled to the current sense line through switch 1010 . The output of current-to-voltage amplifier 310 is provided to the microprocessor 314 through A/D 312 . Because the value of R nom is known, the microprocessor 314 can calculate the value of any parasitic resistance in the counter sense line 224 and the counter electrode line 216 . This parasitic resistance value can be compared to a predetermined threshold stored in the test meter to determine if physical damage has occurred to the test strip 800 or if nonconductive buildup is present on the contact pads to such an extent that the test strip 800 cannot be reliably used to perform a test. In such situations, the test meter may be programmed to inform the user that an alternate test strip should be inserted into the test meter before proceeding with the test.
In order to measure the amount of parasitic resistance in the working electrode line 814 , switches 1006 and 1008 are placed in the position opposite that shown in FIG. 10 , while switch 1010 is opened. The operational amplifier 320 therefore acts as a buffer with unity gain and applies a voltage potential to working sense contact pad 826 b through a known resistance R nom . This resistance causes a current to flow in the working sense line 826 and the working electrode line 814 that is sensed by current-to-voltage amplifier 310 . The output of current-to-voltage amplifier 310 is provided to the microprocessor 314 through A/D 312 . Because the value of R nom is known, the microprocessor 314 can calculate the value of any parasitic resistance in the working sense line 826 and the working electrode line 814 . This parasitic resistance value can be compared to a predetermined threshold stored in the test meter to determine if physical damage has occurred to the test strip 800 or if nonconductive buildup is present on the contact pads to such an extent that the test strip 800 cannot be reliably used to perform a test. In such situations, the test meter may be programmed to inform the user that an alternate test strip should be inserted into the test meter before proceeding with the test.
All publications, prior applications, and other documents cited herein are hereby incorporated by reference in their entirety as if each had been individually incorporated by reference and fully set forth.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the description is to be considered as illustrative and not restrictive in character. Only the preferred embodiment, and certain other embodiments deemed helpful in further explaining how to make or use the preferred embodiment, have been shown. All changes and modifications that come within the spirit of the invention are desired to be protected.
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The present invention provides a test strip for measuring a signal of interest in a biological fluid when the test strip is mated to an appropriate test meter, wherein the test strip and the test meter include structures to verify the integrity of the test strip traces, to measure the parasitic resistance of the test strip traces, and to provide compensation in the voltage applied to the test strip to account for parasitic resistive losses in the test strip traces.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to the art of gas appliances and, more particularly, to a switching device, incorporated in an overall gas flow control valve assembly, for activating an igniter for the flow of gas.
2. Discussion of the Prior Art
In a gas appliance, such as a range, it is common to provide a plurality of gas burner elements to which gas is supplied through respective flow control valves. Typically, each valve is provided with a knob which is exposed at the front of the appliance and can be rotated to regulate the flow of gas to a respective burner. In years past, a pilot light was provided to ignite the regulated flow of gas. In order to avoid the need to maintain a constantly lit pilot light, it has now become commonplace to provide an electric ignition system for the gas, with the ignition system including an electrode provided at the burner element and an electric switch controlled by movement of the knob to develop a series of sparks at the electrode. In general, when the knob is rotated, an initial high gas flow/ignition position is reached wherein a cam inside the switch causes contacts to become electrically engaged. Once the gas is ignited, the user can rotate the knob further to terminate the sparking operation and to establish a desired flame setting.
With this arrangement, it is possible for the user of the appliance to release the knob while still in the initial position such that the igniter continues to unnecessarily spark. This circumstance is considered disadvantageous from various standpoints, including operational and economic inefficiencies. In addition, it would be advantageous to be able to initiate a sparking operation with the control knob in various rotational locations instead of only at an initial, rotational position.
Based on the above, there exists a need in the art for a valve and igniter switch assembly which is designed to automatically cease a sparking operation whenever an associated control knob is released. In addition, there exists a need for a valve and igniter switch assembly which will enable a user to initiate a sparking operation without requiring the knob to be in a specific operational position.
SUMMARY OF THE INVENTION
The present invention is directed to a gas flow control and igniter switching assembly for a gas appliance including a rotary valve body from which projects a control stem along an axially extending axis, with the stem being both rotatable about the axis to control a flow rate of gas through the valve and, preferably, shiftable in the axial direction relative to the valve body. In accordance with the most preferred embodiment of the invention, the switch portion of the assembly includes first and second contacts which become electrically engaged with each other upon shifting of the stem in the axial direction, substantially independent of the rotary angular position of the stem relative to the valve body.
In accordance with a preferred embodiment of the invention, the switch portion of the assembly includes an outer casing formed from first and second pieces which are snap-fittingly interconnected. The first and second contacts are seated in respective portions of the first casing piece. Interposed between the casing pieces is an activation member which is generally in the form of a disk. Attached to the activation member is an electrical connector which, in the most preferred form of the invention, is constituted by a spring member that abuts the first casing piece and biases the activation member towards the second casing piece. The first and second casing pieces, as well as the activation member, are provided with respective holes through which the stem passes. The hole in the first casing piece actually extends about a sleeve projecting from the valve body in order to non-rotatably mount the first casing piece to the valve body, while the stem is frictionally held in the bore of the activation member. A control knob is attached to the end of the stem for selectively rotating and axially shifting the stem.
With this arrangement, the activation member shifts axially in unison with the stem and relative to the contact members. Depressing the knob causes the activation member to electrically interconnect the contacts to initiate a sparking operation for igniting a supply of gas flowing through the valve. Since the activation member is biased away from the first casing piece and the contacts, releasing the control knob will automatically cause the electrical connector to become spaced from the contacts to terminate the sparking operation. The particular configuration of the contacts and the electrical connector establishes a wide range of angular positions for the knob in which the sparking will occur upon depression of the stem. In the most preferred form of the invention, the sparking can be activated throughout substantially the entire range of rotation of the stem.
Additional objects, features and advantages of the invention will become more fully apparent from the following detailed description of a preferred embodiment when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is perspective view of a gas range incorporating the valve and igniter switch assembly of the invention;
FIG. 2 is an exploded view of the valve and switch assembly constructed in accordance with the present invention;
FIG. 3 is a side view of the valve and switch assembly shown in an off state;
FIG. 4 is a side view, similar to that of FIG. 3, depicting a control knob and actuating stem of the valve and switch assembly in a partially depressed, igniter activating position;
FIG. 5 is a side view, similar to that of FIG. 4, but depicting the control knob and actuating stem in a fully depressed and partially rotated position;
FIG. 6 is a side view, similar to FIG. 5, but depicting the valve and switch assembly in a normal operating position;
FIG. 7 is an enlarged perspective view of the switching device incorporated in the valve and switch assembly of FIG. 2;
FIG. 8 is an exploded view of the switching device of FIG. 6; and
FIG. 9 is a cross-sectional view of the switching device of FIG. 7 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With initial reference to FIG. 1, a gas range 2 is depicted incorporating the valve and igniter switch assembly 5 of the present invention. As shown, gas range 2 includes a cabinet 8 and a cooktop 11 . Cooktop 11 is formed with various recessed wells 12 within which are mounted gas burner elements. Extending over gas burner elements 15 , 16 and 17 , 18 are respective grates 20 and 21 . In general, each of the gas burner elements 15 - 18 are preferably of the sealed type and is adapted to receive a gas/air mixture which flows through circumferentially spaced ports and which is ignited through the use of a spark electrode. As this structure is widely known in the art and not considered part of the present invention, it will not be discussed in further detail here. Instead, reference is made to U.S. Pat. No. 5,152,276 directed to such a known type of seal gas burner assembly, with the disclosure in this patent being incorporated herein by reference.
Gas range 2 is also shown to include a control panel 28 that includes a display 30 , a row of function buttons 33 which are used to select a desired cooking operation within an oven located behind door 37 of gas range 2 . For instance, the first row of buttons 33 could be used to select between baked, broiled, clean and keep warm modes of operation. Control panel 28 is also shown to include a light button 39 , a cancel button 40 , an auto-set button 42 used in programming gas range 2 , a timer button 43 , cook and stop time buttons 45 and 46 , a numeric array 48 and a clock setting button 50 . In general, the arrangement and operation of control panel 28 is merely presented here for the sake of completeness and is not an aspect of the present invention. Also for the sake of completeness, gas range 2 is shown to include a lower drawer 52 which can be used to hold pans and the like in a manner known in the art.
In general, gas range 2 is depicted to illustrate an exemplary cooking device to which the valve and igniter switch assembly 5 of the invention can be applied. As will become more fully evident below, the valve and igniter switch assembly 5 of the invention can be used in connection with various different types of appliances and in other environments wherein it is desired for a user to control a flow of gas and the ignition of that gas. Reference will now be made to FIG. 2 in describing the main components of the valve and igniter switch assembly of the invention.
As shown in FIG. 2, valve and igniter switch assembly 5 includes a valve unit 65 having a body 67 provided with a gas inlet 69 , about which is provided a seal 70 , and a gas outlet 71 . Although not shown, valve body 67 houses a rotary valve that is interconnected to a stem 78 of valve unit 65 . Actually, this basic structure and operation of valve unit 65 is known in the art wherein stem 78 can be rotated to cause movement of an internal valve element in order to adjust the flow rate of gas supplied to inlet 69 , through body 67 and gas outlet 71 . As shown, stem 78 preferably includes an elongated cut-out portion 80 . Stem 78 is preferably supported on body 67 through the use of a plate 83 that is attached with threaded fasteners 85 and 86 to body 67 . Plate 83 includes a central sleeve portion 88 , through which stem 78 projects, and a hole 90 . Again, aside from the incorporation of valve unit 65 in the overall valve and igniter switch assembly 5 of the invention, the actual construction and operation of valve unit 65 is known in the art and, in fact, is utilized in various gas ranges currently available on the market today.
FIG. 2 also shows a switch assembly 92 constructed in accordance with the present invention. In accordance with the most preferred embodiment, switch assembly 92 includes an outer casing 94 which is defined by a first piece 96 and a second piece 98 . Details of switch assembly 92 will be discussed more fully below with particular reference to FIGS. 7-9. Valve and igniter switch assembly 5 also includes an indicator cover 104 including first, second and third diametric portions 106 - 108 . Third diametric portion 108 includes a face portion 111 that is preferably provided with various indicia used to aid a user in establishing a desired flow of gas through valve unit 65 . As shown, face portion 111 includes off, high and low positions, as well as representations of reduced flame sizes between the high and low positions. Third diametric portion 108 is interconnected with second diametric portion 107 through a side wall 112 such that indicator cover 104 defines a recessed area 113 . Indicator cover 104 is also preferably provided with a pair of diametrically opposed projections, one of which is indicated at 114 , which are adapted to be received in respective alignment holes 117 and 118 formed in second piece 98 of outer casing 94 of switch assembly 92 . Indicator cover 104 also includes a central bore 120 .
Finally, valve and igniter switch assembly 5 includes a knob 122 . Although knob 122 can take various forms, the preferred embodiment shown illustrates the presence of a sleeve portion 124 , a disk portion 127 and a handle portion 129 . Disk and handle portions 127 and 129 are provided with alignment markings 132 and 133 which are adapted to cooperate with the indicia provided on indicator cover 104 .
FIG. 3 illustrates an assembled state for valve and igniter switch assembly 5 . In this figure, indicator cover 104 has not been included for clarity purposes. The actual mounting of the various components of valve and igniter switch assembly 5 will become more fully apparent below after detailing the preferred construction of switch assembly 92 . However, at this point, it should be noted that interconnecting a valve unit, switch assembly, indicator cover and control knob for use in regulating a flow of gas and controlling the activation of a spark igniter is known in the art. Therefore, it is the particular construction and operation of switch assembly 92 in this overall arrangement which distinguishes the present invention from the known prior art.
Based on the above, reference will now be made to FIGS. 7-9 in describing the preferred construction and operation of switch assembly 92 . As shown, first piece 96 of outer casing 94 includes a first outer diametric portion 145 which is connected to a second outer diametric portion 146 through a radial portion 147 . First diametric portion 145 includes a central opening 148 and a pair of peripherally spaced slots 149 and 150 . At second diametric portion 146 , first piece 96 is provided with a plurality of radial protrusions 152 - 154 , each of which is provided with a respective axial opening 156 . Switch assembly 92 also includes first and second contacts 160 and 161 . More specifically, first contact 160 preferably includes an arcuate segment 163 and a linear segment 164 which defines a first electrical terminal. First contact is also formed with a tab 166 that is provided with an aperture 167 . The second contact 161 is defined by an arcuate segment 169 and a linear segment 170 that defines a second electrical terminal. The second contact 161 is also provided with a pair of spaced tabs 172 and 173 each of which includes a respective aperture 174 and 175 . As perhaps best shown in FIG. 8, first piece 96 of outer casing 94 is provided with an annular groove 177 along with various spaced posts, one of which is indicated at 178 . First and second contacts 160 and 161 are positioned within respective portions of annular groove 177 , with apertures 167 , 174 and 175 each receiving a respective post 178 , and with linear segment 164 of first contact 160 projecting through slot 149 , while linear segment 170 of second contact 161 projects through slot 150 . In this manner, first and second contacts 160 and 161 are seated within first piece 96 of outer casing 94 . When seated, first and second contacts 160 and 161 do not engage each other. Linear segments 164 and 170 are adapted to be respectively interconnected to an incoming electrical source and to an, electrode of a respective gas burner element 115 - 118 . Therefore, with this arrangement, power to the electrode for initiating a sparking operation can be performed by electrically interconnecting first and second contacts 160 and 161 .
Switch assembly 92 further includes an electrical connector 181 which, in the most preferred embodiment, takes the form of a metal spring having an annular body 183 . Stamped from annular body 183 are a plurality of angled, resilient biasing legs 185 - 187 . Annular body 183 also includes a plurality of contact legs 190 - 192 which are generally L-shaped in side-view. As shown, biasing legs 185 - 187 are preferably arranged at an outer peripheral portion of annular body 183 , while contact legs 190 - 192 are arranged at an inner peripheral portion. Arranged preferably radially inwardly of each of the various biasing legs 185 - 187 is a respective protrusion 195 that is provided with a through hole 196 .
Switch assembly 92 also includes an activating member 201 having a first diametric portion 204 and a second diametric portion 205 interconnected by a radial section 207 . Projecting axially from radial section 207 , within the confines of first diametric portion 204 , are various bosses 210 - 212 , each of which includes a respective projecting post 214 - 216 . Each post 214 - 216 is adapted to be frictionally received within a through hole 196 of a respective protrusion 195 such that electrical connector 181 is seated upon bosses 210 - 212 and frictionally retained within the confines of first diametric portion 204 of activating member 201 . First diametric portion 204 of activating member 201 is actually received within the confines of second diametric portion 146 of first casing piece 96 as clearly shown in FIG. 9 . In this position, biasing legs 185 - 187 rest upon a ledge 219 defined by radial portion 147 . With this arrangement, biasing legs 185 - 187 tend to maintain the terminal ends of contact legs 190 - 192 at a position spaced from arcuate segments 163 and 169 of first and second contacts 160 and 161 as shown in FIG. 9 . However, depression of activating member 201 relative to first and second pieces 96 and 98 of outer casing 94 through second diametric portion 205 will cause biasing legs 185 - 187 to deflect which, in turn, will enable contact legs 190 - 192 to abut a respective one of arcuate segments 163 and 169 . When in this position, an electrical circuit between first and second contacts 160 and 161 is completed.
Second casing piece 98 of switch assembly 92 is provided with various outer peripheral tabs 222 - 224 which, upon seating of first and second contacts 160 and 161 and the positioning of both electrical connector 181 and activating member 201 within first casing piece 96 , can each be aligned with the opening 156 providing in a respective protrusion 152 - 154 in order to snap-fittingly interconnect first and second pieces 96 and 98 while containing first and second contacts 160 and 161 , electrical connector 181 and activating member 201 therebetween. FIGS. 2, 7 and 9 therefore show the fully assembled condition for switch assembly 92 , the components of which, in the preferred embodiment, are formed of molded plastic, with the exception of metallic contacts 160 , 161 and electrical connector 181 .
As perhaps best evidenced with reference to FIGS. 2 and 3, when switch assembly 92 is positioned upon stem 78 , a portion of stem 78 projects from second cover piece 98 in order to enable the mounting of knob 122 upon stem 78 . Second piece 98 is provided with a non-circular hole 229 (see FIGS. 2 and 7) which cooperates with the shape of stem 78 given the presence of elongated cut-out portion 80 wherein activating member 201 is frictionally retained by stem 78 for concurrent rotational and axial movement. A similar interconnection is made between sleeve 124 of knob 122 and stem 78 . On the other hand, stem 78 extends freely through central opening 148 of first casing piece 96 . More particularly, central opening 148 is defined, at least in part, by a resilient extension 233 (see FIG. 9) which has formed thereabout various radially inwardly projecting and circumferentially spaced mounting segments 235 . With this construction, when switch assembly 92 is placed over stem 78 , first casing piece 96 is tightly mounted about sleeve 88 . Although not shown, first casing piece 96 could be formed with an indentation to receive the head of one or more of fasteners 85 and 86 to further aid in locating switch assembly 92 for non-rotational movement relative to valve body 67 . In any event, outer casing 94 is fixed against rotation relative to valve unit 65 , along with indicator cover 104 and first and second contacts 160 and 161 . On the other hand, activating member 201 and electrical connector 181 rotate in unison with stem 78 as controlled by the manual manipulation of knob 122 .
FIGS. 3-6 show various operational positions of the valve and igniter switch assembly 5 of the present invention. As indicated above, FIG. 3 simply illustrates an assembled condition wherein the valve unit 65 is closed to prevent the flow of gas from inlet 69 towards outlet 71 . Again, it should also be noted that indicator cover 104 is not shown in these figures for clarity purposes. In a manner known in the art, stem 78 actually terminates within valve body 67 in a plate 252 which is connected by a spring 254 to the actual rotary valve element within body 67 . Again, this particular operation for valve unit 65 is known in the art. However, this arrangement enables a detent configuration to exist which requires a depression of knob 122 and a corresponding axial shifting of stem 78 to the position shown in FIG. 5 in order for knob 122 to be rotated out of the “off” position. That is, plate 252 is formed with a tab 258 which is received within hole 90 in the position of FIG. 3 and stem 78 must be depressed a distance to clear tab 258 from hole 90 . In general, stem 78 can shift in the order of {fraction (3/32)}″ from the FIG. 3 position to the FIG. 5 position. Prior to reaching the FIG. 5 position, contact legs 190 - 192 will engage arcuate segments 163 or 169 such that electrical current is supplied to the electrode at a respective gas burner element 15 - 18 . For instance, contacts 160 and 161 are electrically connected at the position shown in FIG. 4, e.g., upon a {fraction (2/32)}″ (0.16 cm) shifting of stem 78 . Therefore, whenever knob 122 is axially depressed to at least the position shown in FIG. 4, activating member 201 will be shifted relative to outer casing 94 of switch assembly 92 by the deflection of biasing legs 185 - 187 to enable contact legs 190 - 192 to engage a respective arcuate segment 163 , 169 of first and second contacts 160 and 161 . In this position, first and second contacts 160 and 161 will be electrically interconnected to initiate a sparking operation at the respective gas burner element 15 - 18 . Once the user releases knob 122 such that the knob 122 again shifts to the axial position shown in FIG. 6 wherein stem 78 remains deflected only a slight amount, such as {fraction (1/32)}″ (0.08 cm), electrical connector 181 will no longer complete a circuit with first and second contacts 160 and 161 . Although knob 122 and stem 78 can be continually rotated, such as through approximately 270°, in order to select a desired gas flow rate and corresponding flame size for cooking purposes, the ignition circuit will not be closed unless stem 78 is further depressed through knob 122 . In the FIG. 6 position, tab. 258 preferably extends in a groove (not shown) formed in a rear portion of plate 83 , with the groove leading from hole 90 to define the permissible extent of travel for knob 122 .
It should be readily apparent that, unlike the prior art which established a predetermined igniter position between “off” and “high” settings, the igniter circuit associated with the present invention can be closed at a wide range of positions by simply depressing of knob 122 a predetermined extent. The axial deflection of activating member 201 occurs, in the most preferred embodiment, since non-circular hole 229 receives stem 78 in a generally press-fit manner such that any axial shifting of stem 78 will result in a corresponding axial shifting of activating member 201 . In any event, it should also be noted that it is not possible for a user of gas range 2 to inadvertently leave valve and igniter switch assembly 5 in a continued sparking position. In the most preferred form of the invention, the use of three contact legs 190 - 192 enables the igniter to be activated regardless of the angular position of knob 122 . Of course, it would be possible to limit the particular angular range (approximately 270° in the preferred embodiment), such as by simply limiting the length of arcuate segments 163 and 169 , the number of contact legs 190 - 192 or the like. The manner in which switch assembly 92 can be pre-assembled through the snap-fit interconnection of first and second pieces 96 and 98 of outer casing 94 advantageously enables pre-assembling of switch assembly 92 for subsequent interconnection with the various other components of valve and igniter switch assembly 5 . Any maintenance of switch assembly 92 is also enhanced versus the prior art wherein switch housings are typically riveted or otherwise sealed in a manner which would require the entire switching unit to be replaced following a detected malfunction.
Based on the above, it should be recognized that the valve and igniter switch assembly of the present invention provides an advantageous igniter control arrangement in a simple and effective manner. However, although described with respect to a preferred embodiment of the invention, it should be readily understood that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For instance, although first and second contacts 160 and 161 are fixed relative to first casing piece 94 and are adapted to electrically linked by connector 181 , other electrical arrangements including providing one of the contacts on activating member 201 would also be possible. Furthermore, although it is preferred to have activating member 201 both rotate and axially shift in unison with stem 78 and knob 122 , it would be possible to simply have activating member 201 axially shift with knob 122 , such as by having sleeve 124 of knob 122 directly abut a portion of activating member 201 to cause the desired axial shifting. In any event, the invention is only intended to be limited by the scope of the following claims.
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A gas flow control and igniter switch assembly for a gas appliance includes a valve body having a stem, an igniter activating switch and a knob, wherein the igniter is activated upon depressing of the knob a predetermined distance. The igniter switch is preferably constituted by a multi-piece outer casing within which is mounted multiple igniter contacts, an electrical connector, and an activating member. The activating member carries the electrical connector and is biased to a position which maintains an electric circuit to the igniter open. The multi-piece outer casing is adapted to be snap-fittingly secured together and mounted about the stem of the valve. Preferably, the stem extends freely through the outer casing but press-fittingly receives the activating member such that the activating member moves in axial unison with the stem. A knob is employed for rotating the stem to regulate the flow of gas from an inlet to an outlet of the valve, while also permitting the valve stem to be depressed in order to initiate a sparking operation at an electrode for a respective gas burner of the appliance.
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FIELD OF THE INVENTION
[0001] The invention relates to a transdermal reservoir patch according to claim 1 .
BACKGROUND OF THE INVENTION
[0002] The invention relates to a transdermal reservoir patch and in particular to a transdermal nicotine patch. The nicotine patches are generally intended to be applied for a regular and relatively constant maintenance of nicotine or a corresponding tobacco alkaloid in the blood of a user in order to avoid craving.
[0003] Transdermal devices for the delivery of a wide variety of physiologically active substances have been known for some time and transdermal devices in the form of reservoir patches are disclosed in e.g. U.S. Pat. No. 5,254,346 and in the form of matrix patches in e.g. U.S. Pat. No. 6,165,497. Such devices generally comprise an impermeable backing, a drug or physiologically active substance reservoir, a rate controlling membrane and an adhesive layer which by some means are sealed together to produce a transdermal delivery device.
[0004] Matrix designs, where drug provided as a semisolid with no membrane and drug-in-adhesive (DIA) are the dominant products on the market presently. The development of such technologies is relatively complex and costly. These designs require long-term compatibility among the drug, adhesive and excipients. Thus, the demands made on the adhesive may be somewhat stricter than those on reservoir systems. On the other hand, reservoir patches have certain disadvantages when applied as a tobacco alkaloid releasing patch compared to matrix or drug-in adhesive patches.
[0005] A general problem of matrix patches is that the area must be quite significant in order to deliver a desired amount of nicotine. Thus, some matrix patches has areas around 30 cm 2 in order to deliver 10 to 20 mg during a period of 16 hours.
[0006] Especially for matrix patches, the combination of the large dimensions of the patch and the stiffness might cause a higher risk of a corner of the patch releasing from the skin of the user and thereby causing nicotine to escape the skin of the user by evaporating into the air.
[0007] In order to overcome the problem of insufficient attachment of the patch the producers of matrix patches have added a larger amount of adhesive with a following extra irritation to the user.
[0008] A problem of e.g. applying a reservoir patch for nicotine delivery is that reservoir patches may have an even lower comfort level than matrix design, as the design would tend to be stiffer and less comfortable than corresponding matrix designs.
[0009] This problem is believed to be one of the reasons why nicotine reservoir patches have not found their way to market yet.
[0010] A further significant problem related to patches of the reservoir type is a higher risk of having a leakage from the patch; and in case of a leakage naturally more nicotine will be wasted in comparison to matrix and drug-in adhesive transdermal patches where the nicotine is bound e.g. in gels or other flux controlling substance.
[0011] In particular, this problem have proved significant when dealing with e.g. nicotine or nicotine derivates which are highly volatile and escape from the reservoir through even very small leakages even though such leakages are under very low pressure.
[0012] It is an object of the present invention to establish a patch suitable for release of a high dose of nicotine or corresponding tobacco alkaloid, which is secure and at the same time comfortable to the user.
SUMMARY OF THE INVENTION
[0013] Reservoir patches are especially suitable for tobacco alkaloids and in particular for nicotine due to the possibility of delivering a high concentration of nicotine to the user.
[0014] The invention relates to a tobacco alkaloid patch ( 10 ; 41 ; 42 ; 43 ; 51 ; 52 ; 53 ; 54 ) for transdermal administration of a tobacco alkaloid, said patch comprising an impermeable backing ( 11 ) and a membrane ( 14 ) which defines a cavity ( 12 ) there between, said membrane being permeable to and in contact with said tobacco alkaloid, said impermeable backing and said membrane being at least partly joined by a sealing and wherein the amount of tobacco alkaloid is above 10 mg.
[0015] Said viscous flowable gel may work to immobilize said tobacco alkaloid between said impermeable backing and said membrane within said reservoir.
[0016] According to an embodiment of the invention, the amount of said tobacco alkaloid is above 20 mg.
[0017] According to an embodiment of the invention, the amount of said tobacco alkaloid is above 40 mg.
[0018] According to an embodiment of the invention, the amount of said tobacco alkaloid is above 60 mg, preferably above 80 mg, most preferably above 100 mg.
[0019] According to an embodiment of the invention, the initial flux of said tobacco alkaloid through the membrane is above 10 μg/cm 2 h.
[0020] According to an embodiment of the invention, the initial flux of said tobacco alkaloid through the membrane is above 50 μg/cm 2 h.
[0021] According to an embodiment of the invention, it is now possible to obtain patches with a tobacco alkaloid flux higher than the prior art patches. Two patches presently on the market both have fluxes of approximately 30 μg/cm 2 h. These two are a drug in adhesive and a matrix patch respectively and with the use of a reservoir patch according to embodiments of the present invention it is possible to reach a higher flux.
[0022] Throughout the description the initial flux should be understood as the flux immediately after releasing the liner and applying the patch on the body. For all practical purposes it is easier to calculate an average flux of the patch, i.e. a flux that may be calculated as the nicotine amount to be released divided by the delivering area and the amount of time during which the amount is to be released. However, due to the structure of the reservoir patch, the tobacco alkaloid release profile is usually smooth and the flux over an effective period, starting with the initial flux, will be reasonably constant and close to the average flux.
[0023] According to an embodiment of the invention, the initial flux of said tobacco alkaloid through the membrane is above 100 μg/cm 2 h.
[0024] According to an embodiment of the invention, the initial flux of said tobacco alkaloid through the membrane is above 1000 μg/cm 2 h.
[0025] According to an embodiment of the invention, the initial flux of said tobacco alkaloid through the membrane is above 2500 μg/cm 2 h.
[0026] According to an embodiment of the invention, the ratio between said tobacco alkaloid in the patch and the patch delivering area is above 1 mg/cm 2 .
[0027] The term “tobacco alkaloid in the patch” covers the tobacco alkaloid present in the patch as a whole, i.e. all that is in the reservoir, the membrane and adhesive. For a tobacco alkaloid reservoir patch it is to be expected that at any time the most of the tobacco alkaloid is present in the reservoir.
The term “patch delivering area” is to be interpreted as the area of skin above which tobacco alkaloid is present, i.e. the total patch area minus the area of sealing.
[0029] According to an embodiment of the invention, the ratio between said tobacco alkaloid in the patch and the patch delivering area is above 2.5 mg/cm 2 .
[0030] According to an embodiment of the invention, the ratio between the delivered tobacco alkaloid and the patch delivering area is above 0.5 mg/cm 2 .
[0031] According to an embodiment of the invention, the ratio between the delivered tobacco alkaloid and the patch delivering area is above 1 mg/cm 2 .
[0032] According to an embodiment of the invention, a higher delivered amount of tobacco alkaloid per delivering area is possible. Two patches presently on the market have delivered tobacco alkaloid per delivering area of 0.5 mg/cm 2 and 0.9 mg/cm 2 respectively. These two are a drug in adhesive and a matrix patch respectively and with the use of a reservoir patch according to embodiments of the present invention it is possible to have a higher amount of tobacco alkaloid delivered per delivering area.
[0033] According to an embodiment of the invention, the ratio between the delivered tobacco alkaloid and the patch delivering area is above 1.5 mg/cm 2 .
[0034] According to an embodiment of the invention, the ratio between the delivered tobacco alkaloid and the patch delivering area is above 2.5 mg/cm 2 .
[0035] According to an embodiment of the invention, the nicotine permeability of said membrane is above 20 μg·100 μm/cm 2 ·hr.
[0036] According to an embodiment of the invention, the nicotine permeability of said membrane is above 50 μg·100 μm/cm 2 ·hr.
[0037] According to an embodiment of the invention, the nicotine permeability of said membrane is above 220 μg·100 μm/cm 2 ·hr.
[0038] According to embodiments of the invention, an improved low-area tobacco alkaloid patch has been obtained. The patch according to embodiments of the invention benefits from high dose, low leakage and high user comfort.
[0039] According to an embodiment of the invention, said sealing comprises a glue sealing.
[0040] According to an embodiment of the invention, said sealing comprises a heat sealing.
[0041] According to an embodiment of the invention, the width of said sealing is at least 1.5 mm.
[0042] It is advantageous to keep the width of the sealing above a certain value in order to avoid leakage of reservoir content through the adhesive or through holes in the patch caused by a separation of the layers due to a too low seal width.
[0043] According to an embodiment of the invention, the width of said sealing is at least 2.0 mm.
[0044] According to an embodiment of the invention, the width of said sealing is at most 10.0 mm.
[0045] It has been realized that an increased sealing width induces very few benefits, if any, as an increased sealing width causes the reservoir patch to be less comfortable to wear for the user due to the higher stiffness all around the reservoir patch. A higher stiffness like this will also increase the risk of a corner or a side of the patch releasing from the skin of the user when placed on a curving surface as for instance an arm or a leg.
[0046] Therefore, a sealing width will be problematic both when it is produced either too big or too small.
[0047] According to an embodiment of the invention, said membrane and said backing is joined at the circumference of the patch.
[0048] According to an embodiment of the invention, said sealing comprises circumferential sealing plus one or more sealing dots therein between.
[0049] A number of dot-formed sealings within the center of the patch will stabilize the patch and ensure a more equal distribution of gel and tobacco alkaloid.
[0050] According to an embodiment of the invention, said sealing comprises a circumferential sealing plus a pattern of any kind.
[0051] According to an embodiment of the invention, said patch comprises a detachable release liner ( 16 ).
[0052] In an embodiment of the invention, a detachable release liner is provided in order to protect the adhesive layer and retain said tobacco alkaloid prior to use.
[0053] According to an embodiment of the invention, said detachable release liner comprises one or more peelable corners.
[0054] According to an embodiment of the invention, the detachable release liner is attached to the membrane of the patch by an adhesive force which is weaker than the adhesive force obtained by said sealing between said membrane and said backing.
[0055] According to an embodiment of the invention, said tobacco alkaloid comprises nicotine.
[0056] The term “tobacco alkaloid” as used herein and in the claims, is taken to mean nicotine or nicotine-like alkaloid such as nor-nicotine, lobeline, and the like, in the free base or pharmacologically acceptable acid addition salt form. Plant alkaloids of this type are obtainable from species of Nicotiana, which is a source for nicotine and nor-nicotine, as well as species of Lobelia and Lobeliaceae (Indian tobacco) which are sources for lobeline.
[0057] According to an embodiment of the invention, said patch delivers more than about 50% of the total content of tobacco alkaloid to the user within 24 hours from releasing the liner and placing the patch on the skin of the user.
[0058] According to an embodiment of the invention, said patch delivers more than about 60% of the total content of tobacco alkaloid to the user within 24 hours from releasing the liner and placing the patch on the skin of the user.
[0059] According to an embodiment of the invention, said patch delivers more than about 70% of the total content of tobacco alkaloid to the user within 24 hours from releasing the liner and placing the patch on the skin of the user.
[0060] According to an embodiment of the invention, said impermeable backing further comprises permeable layers, said layers may be placed on the inner side and/or on the outer side of the impermeable backing.
[0061] According to an embodiment of the invention, said impermeable backing is made of a multilayer film.
[0062] According to an embodiment of the invention, said impermeable backing is made of a multilayer polyester film.
[0063] According to an embodiment of the invention, said impermeable backing is made of combinations of one or more of the following: pigmented polyolefin, aluminized polyester, metal foil and heat-sealable polyolefinic layers.
[0064] According to an embodiment of the invention, said impermeable backing has a thickness between 1 μm and 500 μm.
[0065] According to an embodiment of the invention, said impermeable backing has a thickness between 5 μm and 200 μm.
[0066] According to an embodiment of the invention, said impermeable backing has a thickness between 10 μm and 100 μm.
[0067] According to an embodiment of the invention, said membrane comprises a polyethylene membrane.
[0068] According to an embodiment of the invention, said membrane comprises polyamides, such as nylon 6,6, or some grades of ethylene vinyl acetate copolymers or functional equivalents of these.
[0069] According to an embodiment of the invention, said membrane has a thickness between 1 μm and 500 μm.
[0070] According to an embodiment of the invention, said membrane has a thickness between 5 μm and 200 μm.
[0071] According to an embodiment of the invention, said membrane has a thickness between 10 μm and 100 μm.
[0072] According to an embodiment of the invention, said membrane is non-porous.
[0073] According to an embodiment of the invention, said patch comprises an adhesive.
[0074] In an embodiment of the invention, said membrane of said patch is faced with an adhesive, e.g. a tape, which may be applied to mount the patch fixedly on the skin of a user.
[0075] According to an embodiment of the invention, said patch comprises an adhesive substantially equally distributed all over the lower part of the patch.
[0076] According to an embodiment of the invention, said patch comprises an adhesive pattern.
[0077] An adhesive pattern may be any possible pattern. Examples of adhesive distribution beneath the patch to be mentioned here are; a circumferential rim around the patch, a circumferential rim plus a central point, a circumferential rim and one or more crossing lines, a circumferential rim and one or more circular rims therein between.
[0078] According to an embodiment of the invention, said adhesive has a thickness of below 3 mm.
[0079] According to an embodiment of the invention, said adhesive has a thickness of below 1 mm.
[0080] According to an embodiment of the invention, said adhesive has a thickness of above 0.01 μm.
[0081] According to an embodiment of the invention, said adhesive has a thickness of above 0.1 μm.
[0082] According to an embodiment of the invention, an adhesive layer is attached to said membrane in order to attach the patch to the skin of a user.
[0083] According to an embodiment of the invention, said cavity forms a reservoir for said tobacco alkaloid.
[0084] According to an embodiment of the invention, said tobacco alkaloid is contained within said reservoir in liquid form.
[0085] According to an embodiment of the invention, said tobacco alkaloid is confined between said impermeable backing and said membrane within said reservoir substantially immobilized by a viscous flowable gel.
[0086] The gel comprises e.g. purified water and a gelling agent in a suitable distribution in order to obtain an appropriate viscosity.
[0087] In an embodiment of the invention, an added dose may be provided when the user activates the patch. In this way the user receives a normal “low” dose of nicotine throughout the day and can activate the patch to give an extra dose if craving symptoms arise. The activation can be performed by e.g. pressing the patch or in any manual or automatic way.
[0088] In an embodiment of the invention, a patch is provided comprising a combination of a matrix patch and a reservoir patch in order to utilize advantages from both.
[0089] According to an embodiment of the invention, said reservoir contains tobacco alkaloid in an amount of more than 0.5 mg.
[0090] According to an embodiment of the invention, said reservoir contains a gelling agent in an amount of less than 20 mg.
[0091] According to an embodiment of the invention, said reservoir contains a gelling agent in an amount of less than 10 mg.
[0092] According to an embodiment of the invention, said reservoir contains purified water in an amount of less than 1000 mg.
[0093] According to an embodiment of the invention, said reservoir contains purified water in an amount of less than 800 mg.
[0094] According to an embodiment of the invention, said reservoir contains tobacco alkaloid, gelling agent and purified water in a total amount of less than 1000 mg.
[0095] According to an embodiment of the invention, said reservoir contains tobacco alkaloid, gelling agent and purified water in a total amount of less than 800 mg.
[0096] According to an embodiment of the invention, said reservoir is shaped in a rectangular, circular or oval form.
[0097] According to an embodiment of the invention, said reservoir is made up of several minor reservoirs separated by sealing.
[0098] According to an embodiment of the invention, said reservoir is shaped in the form of a donut.
[0099] According to an embodiment of the invention, said reservoir is shaped in an essentially rectangular form with rounded corners.
[0100] According to an embodiment of the invention, said reservoir has a volume of less than 4000 mm 3 , preferably less than 3000 mm 3 .
[0101] According to an embodiment of the invention, said reservoir has a volume of less than 2000 mm 3 , preferably less than 1500 mm 3 .
[0102] According to an embodiment of the invention, said reservoir has a volume of more than 50 mm 3 , preferably more than 75 mm 3 .
[0103] According to an embodiment of the invention, said patch can be separated into two or more separate reservoir patches.
[0104] By tearing the patch along the peel line, two or more patches that can work individually are provided. The main patch alone or each patch may be provided with a peel corner.
[0105] According to an embodiment of the invention, the border region(s) between said two or more reservoir patches comprises predefined peel-lines.
[0106] According to an embodiment of the invention, the corners of said two or more separate reservoir patches are pre-rounded.
[0107] The patches may be pre-rounded by shaping of the reservoir patch(es) during manufacturing in such way that at least one of the patches are substantially free of sharp corners when peeled of and positioned on the skin of a user.
[0108] According to an embodiment of the invention, said patch can be separated into two or more separate patches with rounded corners.
[0109] According to an embodiment of the invention, said reservoir comprise a flux controlling gel.
[0110] According to an embodiment of the invention, said gel is constituted by purified water and a gelling agent selected from the group of hyroxyethyl starch, dextran, hydroxyethylcellulose (HEC), hydroxypropylmethylcellulose (HPMC), hydroxypropycellulose (HPC), methylcellulose (MC), hydroxyethyl-methylcellulose (HEMC), ethylhydroxyethylcellulose (EHEC), carboxymethyl cellulose (CMC), poly(vinyl alcohol), poly(ethylene oxide), poly(2-hydroxyethylmethacrylate), pyrolidone), and pluronics.
[0111] According to an embodiment of the invention, said gelling agent is hydroxypropyl methyl cellulose.
[0112] According to an embodiment of the invention, said gelling agent is methyl cellulose.
[0113] According to an embodiment of the invention, said patch is colored in order to match the skin of a user.
[0114] According to an embodiment of the invention, said patch is essentially transparent.
[0115] According to an embodiment of the invention, said patch is produced with a pattern or a picture on the backing.
[0116] According to an embodiment of the invention, the total size of said patch is less than 40 cm 2 .
[0117] It is an advantage of the reservoir patch according to embodiments of the invention that it is possible to increase the amount of tobacco alkaloid without having to drastically increase the size of the patch with a following decreased flexibility. Hence, the reservoir patch is particularly suitable for high-dose patches, compared to matrix patches and drug-in-adhesive patches where a high-dose patch is equivalent to a large-sized patch.
Due to the better utilization of nicotine in the reservoir patches compared to drug-in-adhesive patches and matrix patches, it is possible with reservoir patches to make a high-dose patch capable of delivering a large amount of nicotine.
[0119] The reservoir patch according to an embodiment of the invention is capable of containing very high amounts of nicotine or tobacco alkaloid as compared to e.g. drug-in-adhesive patches, where high amounts of e.g. nicotine in the adhesive may destroy the adhesive or make a reaction therewith due to the fact that all nicotine must be effectively contained in the adhesive. Destruction of the adhesive naturally results in loosening of the patch and a reaction between the adhesive and the tobacco alkaloid may both loosen the patch and/or cause that the amount of tobacco alkaloid released is not as high as intended.
[0120] According to an embodiment of the invention, the total size of said patch is less than 25 cm 2 .
[0121] According to an embodiment of the invention, the total size of said patch is above 1 cm 2 .
[0122] According to an embodiment of the invention, the total size of said patch is above 2 cm 2 .
[0123] According to an embodiment of the invention, said patch is rectangular, circular or oval.
[0124] Any patch shape suitable for defining a cavity between an inner and an outer surface is according to the invention.
[0125] According to an embodiment of the invention, the flexural strength of said patch is below 50 mN/mm.
[0126] According to an embodiment of the invention, said reservoir further contains another active ingredient.
[0127] According to an embodiment of the invention, one or more enhancers are added to enhance the uptake of said other active ingredient.
[0128] According to an embodiment of the invention, said enhancers are present in an amount of less than 2000 mg.
[0129] Different physiologically active substances show very varying ability to penetrate the skin. Nicotine easily permeates the skin, whereas other physiologically active substances, typically larger in molecule size, must be assisted in order to get a noticeable amount of ingredient through the skin. For this purpose enhancers are used in an embodiment of the invention.
[0130] Suitable penetration enhancers (flux enhancers are preferably monovalent, saturated or unsaturated aliphatic, cycloaliphatic or aromatic alcohols having from 4 to 12 carbon atoms, e.g. n-hexanol or cyclohexanol, aliphatic, cycloaliphatic or aromatic hydrocarbons having from 5 to 12 carbon atoms, e.g. hexane, cyclohexane, isopropylbenzene and the like, cyclo-aliphatic or aromatic aldehydes and ketones having from 4 to 10 carbon atoms, such as cyclohexanone, acetamide, N,N-di-lower alkylacetamides such as N,N-dimethylacetamide or N,N-diethyl-acetamide, c.sub.10-c.sub.20-alkanoylamides, e.g. N,N-dimethyllauroylamide, 1-n-C.sub.10-c.sub.20-alkylazcycloheptan-2-one, e.g. 1-n-dodeclyazacycloheptan-2-one(Azone.RTM. laurocapram), or N-2-hydroxyethylacetamide, and known vehicles and/or penetration enhancers such as aliphatic, cycloaliphatic and aromatic esters N,N-di-lower alkylsulphoxides, unsaturated oils, halogenated or nitrated aliphatic or cyclo-aliphatic hydrocarbons, salicylates, polyalkylene glycol silicates, and mixtures thereof.
[0131] The patches according to embodiments of the invention have elasticity suitable to follow the skin of the user. As the seal width will be limiting for the elasticity of the patch, the ability to lower the seal width, increases the elasticity and hence the comfort for the user.
[0132] In an embodiment of the invention, the Young Modulus of the patches is below 50 GPa irrespective of seal width.
[0133] According to an embodiment of the invention, said patch comprising an impermeable backing ( 17 ) and a membrane ( 14 ) which defines a reservoir ( 12 ) there between, said membrane ( 14 ) being permeable to and in contact with said tobacco alkaloid, said impermeable backing ( 17 ) and said membrane ( 14 ) being at least partly joined by a sealing ( 11 ), wherein said patch has a flexural strength of less than about 250 mN/mm.
[0134] According to an advantageous embodiment of the invention, high-dose nicotine patches may be obtained having acceptable membrane areas and featuring acceptable user comfort.
[0135] According to an advantageous embodiment of the invention, a high degree of flexibility, low flexural strength, is advantageous. This is in particular the case for people moving around a lot, e.g. craftsmen or during sports or generally relevant to people who desire freedom to move unrestricted.
[0136] In an embodiment of the invention, said patch has a flexural strength of less than 150 mN/mm.
[0137] In an embodiment of the invention, said patch has a flexural strength of less than 100 mN/mm.
[0138] In an embodiment of the invention, said patch has a flexural strength of less than 70 mN/mm.
[0139] In an embodiment of the invention, said patch comprising an impermeable backing ( 17 ) and a membrane ( 14 ) which defines a reservoir ( 12 ) there between, said membrane ( 14 ) being permeable to and in contact with said tobacco alkaloid, said impermeable backing ( 17 ) and said membrane ( 14 ) being at least partly joined by a sealing ( 11 ), wherein said patch has a flexural strength of less than about 50 mN/mm.
[0140] According to embodiments of the invention, it has been established that the flexural strength comparable and superior to matrix patches may be obtained through a proper design by basic design parameters, and it has moreover been established that bending rigidity may be relatively easily adjusted e.g. by the choice of sealing pattern without compromising the choice of materials.
[0141] Specifically, it has been obtained according to embodiments of the invention that secure and comfortable high-dose nicotine patches may be obtained by applying a reservoir type patch as delivery system.
[0142] Thus, it has been established that the critical backing layer may e.g. be increased in thickness or modified in structure in order to strengthen the resulting protection from the backing if at the same time the sealing pattern is designed to keep the overall flexural strength low.
[0143] A further advantage in keeping the flexural strength low is that the leakage of nicotine from the reservoir is minimized due to a reduced risk of breaking the patch during bending and/or a reduced risk of leakage due to partial release of the patch along the edge or corners when mounted on the skin of a user.
[0144] A further and important advantage of the invention is that high dosage nicotine may be obtained even when increasing the size of the patch as long as the flexural strength is kept below about 50 mN/mm, preferably below 40 mN/mm without compromising user comfort and especially the strict non-leakage requirements related to encapsulation of nicotine or corresponding alkaloids.
[0145] In particular, it has been established that leakage both from and into the patch via a membrane, i.e. leakages due to insufficient mounting on the skin of a user, has been minimized when minimizing the flexural strength of the complete patch.
[0146] According to a preferred embodiment of the invention, flexural strength refers to the ability of the patch to “bend” when mounted on the skin of a user.
[0147] In particular, the obtained tobacco alkaloid releasing patch has demonstrated high-dose application and high protection against intruding air or humidity in the interface between patch and the skin of a user. Moreover, a minimum of leakages in the backing or in the sealing has been obtained due to the flexible construction.
[0148] In an embodiment of the invention, said impermeable backing ( 17 ) has a flexural strength which is greater than the flexural strength of the membrane ( 14 ).
[0149] In an embodiment of the invention, said impermeable backing has a flexural strength of at least 0.5 mN/mm.
[0150] In an embodiment of the invention, said impermeable backing has a flexural strength of at least 1 mN/mm.
[0151] According to a preferred embodiment of the invention, the flexural strength must be at least 1 mN/mm in order to ensure proper protection of the membrane during use. Thus, the backing should be designed to a minimum of flexural strength in order to avoid leakage and damaging of the membrane.
[0152] In an embodiment of the invention, the flexural strength of the impermeable backing is at least 0.5 mN/mm and said patch has a flexural strength of less than about 50 mN/mm.
[0153] In an embodiment of the invention, the flexural strength of the impermeable backing is at least 0.5 mN/mm and said patch has a flexural strength of less than about 40 mN/mm.
[0154] In an embodiment of the invention, the impermeable backing of said patch has a flexural strength of at least less than about 30 mN/mm.
[0155] In an embodiment of the invention, said patch has a flexural strength of less than about 25 mN/mm.
[0156] In an embodiment of the invention, said patch has a flexural strength of about 1 to 30 mN/mm.
[0157] According to a preferred embodiment of the invention, the flexural strength of the nicotine releasing patch should be within a certain desired range in order to obtain an advantageous combination of patch strength, secure patch attachment and user comfort.
[0158] In an embodiment of the invention, the backing ( 17 ) comprises a multilayer structure.
[0159] In an embodiment of the invention, said tobacco alkaloid patch is a nicotine reservoir patch.
[0160] In an embodiment of the invention, said patch has a flexural strength greater than about 2 mN/mm.
[0161] According to a preferred embodiment of the invention, certain rigidity is required in order to facilitate a proper distribution of (an) active substance(s), specifically the tobacco alkaloid. When having certain rigidity, the reservoir may maintain a constant or at least reasonable stable form.
[0162] Moreover, handling requires a minimum of rigidity when positioning the patch on the user.
[0163] According to an advantageous embodiment of the invention, it has been shown that a sealing width too low will cause a risk of leakage of nicotine between the backing layer and the membrane through the sealing. When the width of the sealing is lowered, the sealing will decrease in quality. On the other hand it has also been realized that the width of a sealing may actually be produced lower than expected still featuring a secure sealing. This is partly believed to reside in the fact that a decreased sealing width invokes a higher flexibility in the overall path, which in turn results in a strengthened sealing.
[0164] In an embodiment of the invention, the amount of said tobacco alkaloid is above 110 mg, preferably above 160 mg, most preferably above 210 mg.
[0165] In an embodiment of the invention, said patch has a (reservoir volume)/(delivering area) ratio of more than 1 mm 3 /cm 2 .
[0166] In an embodiment of the invention, said tobacco alkaloid patch is packed in a controlled atmosphere.
[0167] With the tobacco alkaloid patch packed in a controlled atmosphere improved properties may be obtained with regard to ensuring storage life of the patches. Preferably the patch is held in a controlled atmosphere from manufacturing till mounting on the user. Preferred gasses to be used as controlled atmosphere are inert gasses in order to prevent reactions with the tobacco alkaloid.
When e.g. oxygen is present in amounts similar to oxygen in the atmosphere the nicotine may degrade or react with oxygen to reduce the effect of the patch.
[0169] In an embodiment of the invention, said controlled atmosphere is nitrogen.
THE DRAWINGS
[0170] The invention will now be described with reference to the drawings of which
[0171] FIG. 1 illustrates a top view of an embodiment of the invention,
[0172] FIG. 2 a illustrates a side view of said embodiment of the invention, with
[0173] FIG. 2 b illustrating a magnification of FIG. 2 a in order to indicate the different elements,
[0174] FIG. 2 c illustrating the patch of FIG. 2 b after releasing the liner and being placed on a surface,
[0175] FIGS. 3 a , 3 b , 3 c , 4 a , 4 b , 4 c , 5 a , 5 b , 5 c , 5 d , 5 e and 5 f illustrate further embodiments according to embodiments of the invention, and
[0176] FIGS. 6 a and 6 b illustrate how a measurement of the flexural strength of a patch or an element of the patch is performed.
DETAILED DESCRIPTION
[0177] A top view of a transdermal reservoir patch 10 according to an embodiment of the invention is shown in FIG. 1 . The backing layer covers the entire upper side of the patch 10 , and is thus not shown; see e.g. backing layer 17 on FIG. 2 b , which prevents the reservoir content from escaping the reservoir patch through the rear. Moreover, the backing protects the active ingredients of the reservoir against UV radiation and moisture. Moreover, the backing serves as a shield against mechanical impacts on the membrane. The patch 10 comprises a reservoir 12 below the backing layer, a peel strip 13 and a sealing 11 . The parts of the patch 10 will be explained further in the following.
[0178] The peel strip 13 facilitates removal of the liner 16 from the adhesive 15 prior to mounting on the skin of a user and can be seen in FIG. 2 b.
[0179] FIG. 2 a illustrates a cross sectional view along the line I-I in FIG. 1 of the above-illustrated transdermal reservoir patch 10 . In order to distinguish the different layers, a magnification is shown in FIG. 2 b from which the layers will be explained. The transdermal reservoir patch 10 comprises an impermeable backing layer 17 which provides an occlusive layer that prevents the content of the reservoir 12 to escape into the environment and to protect the content of the reservoir from being exposed to e.g. humidity or sunlight. The intended path for the content of the reservoir 12 is through the membrane layer 14 and further through the adhesive layer 15 to finally reach through the skin of the user.
[0180] The different layers are sealed together giving a sealing 11 with a seal width w.
[0181] The impermeable backing layer 17 defines the nonskin facing, or skin distal, side of the patch in use. The material chosen should therefore be nicotine resistant, and should exhibit minimal nicotine permeability. The backing layer should be opaque, because nicotine degrades when exposed to ultraviolet light.
[0182] A preferred material is combinations of pigmented polyolefin, aluminized polyester and heat-sealable polyolefinic layers. Polyester has a nicotine permeability less than 0.2 μg.100 μm/cm2.h. Preferred backings are multilayer polyester films, available for example from 3M Corporation as Scotchpak™ 9730.
[0183] As relatively few materials are actually really sufficiently impermeable to nicotine to retain the nicotine load adequately during storage or use, other low permeability materials that might be tried include, for example, metal foil, metallized polyfoils, composite foils or films containing polyester, Teflon (polytetrafluoroethylene) type materials, or equivalents thereof that could perform the same function.
[0184] The reservoir layer 12 may take various forms, for example, pure nicotine, nicotine diluted with a liquid or immobilized by a gel. The gel can be made from different materials preferably methyl cellulose. The reservoir layer 12 is to be a depot for the nicotine and to keep it in good contact with the membrane layer 14 . The reservoir layer 12 does not contribute to any measurable extent to the rate-controlling mechanism.
[0185] The content of the reservoir may be any tobacco alkaloid, preferably nicotine.
[0186] The term tobacco alkaloid as used herein and in the claims, is taken to mean nicotine or nicotine-like alkaloid such as nor-nicotine, lobeline, and the like, e.g. in the free base or pharmacologically acceptable acid addition salt form. Plant alkaloids of this type are e.g. obtainable from species of Nicotiana which is a source for nicotine and nor-nicotine, as well as species of Lobelia and Lobeliaceae (Indian tobacco) which are a source for lobeline.
[0187] The tobacco alkaloid may furthermore be combined with further physiologically active substances which either compensates the physically induced effect of the tobacco alkaloid of the patch or simply adds a further functionality to the patch.
[0188] The term “physiologically active substance” as used to describe the principal active ingredient of the device intends a biologically active compound or mixture of compounds that has a therapeutic, prophylactic or other beneficial pharmacological and/or physiological effect on the wearer of the device. Examples of types of drugs that may be used in the inventive device are anti-inflammatory drugs, analgesics, antiarthritic drugs, antispasmodics, antidepressants, antipsychotic drugs, tranquilizers, antianxiety drugs, narcotic antagonists, antiparkinsonism agents, cholinergic agonists, anticancer drugs, immunosuppression agents, antiviral agents, antibiotic agents, appetite suppressants, antiemetics, anticholinergics, antihistamines, antimigraine agents, coronary, cerebral or peripheral vasodilators, hormonal agents, contraceptive agents, antithrombotic agents, diuretics, antihypertensive agents, cardiovascular drugs, nitroglycerine or any other nitrites and or nitrates, scopolamine or combination, oestradiol, progesterone, testosterone, diclofenac, oxibutunin, melatonin, clonodine, lidocaine/lignocaine, ibuprofen, lofexidine, nifedipine, morphine, naloxone, apomorphine, diazepam, 5-flourouracil, buprenorphine, betahistitine, metoclopromide, taxol, cannabis, and the like. The appropriate drugs of such types are capable of permeating through the skin either inherently or by virtue of treatment of the skin with a percutaneous absorption enhancer. Because the size of the device is limited for user-acceptance reasons, the preferred drugs are those that are effective at low concentration in the blood stream. Examples of specific drugs are steroids such as estradiol, progesterone, norgestrel, levonorgestrel, norethindrone, medroxyprogesterone acetate, 3-ketodesogestrel, testosterone and their esters, nitro-compounds such as nitroglycerine and isosorbide nitrates, nicotine, chlorpheniramine, terfenadine, triprolidine, hydrocortisone, oxicam derivatives such as piroxicam, ketoprofen, mucopolysaccharidases such as thiomucase, buprenorphine, fentanyl, naloxone, codeine, dihydroergotamine, pizotiline, salbutamol, terbutaline, prostaglandins such as misoprostol and enprostil, omeprazole, imipramine, benzamides such as metoclopamine, scopolamine, peptides such as growth releasing factor and somatostatin, clonidine, dihydropyridines such as nifedipine, verapamil, ephedrine, pindolol, metoprolol, spironolactone, nicardipine hydrochloride, calcitriol, thiazides such as hydrochlorothiazide, flunarizine, sydononimines such as molsidomine, sulfated polysaccharides such as heparin fractions and the salts of such compounds with pharmaceutically acceptable acids or bases. It should be noted that reservoir patches according to embodiments of the present invention are indeed suitable for delivering one or more active substances chosen from the list above alone or in combination with a tobacco alkaloid.
[0189] The membrane layer 14 forms part of the rate-controlling means that regulates the flux of nicotine from the patch to the skin. A suitable material is chosen by considering resistance to attack by nicotine and possession of an appropriate permeability for nicotine. The polymer chosen for the membrane layer 14 should also be compatible with the other components, and workable by standard techniques that are used in fabrication of the patch, such as casting or heat sealing. Dense non-porous membranes have a substantial advantage over micro-porous materials. Micro-porous membranes release the content of the patch by pore flow. Thus, in areas of the pores, the skin is exposed to raw nicotine.
[0190] Also, in the case of a volatile liquid such as nicotine, flow through the pores occurs rapidly so that the system is quickly exhausted and the skin is flooded with excess nicotine for the life of the patch. In contrast, diffusion of nicotine through a non-porous film takes place by dissolution of the nicotine in the film, followed by diffusion under a concentration gradient. By selecting materials with suitable permeabilities, and making a membrane of appropriate thickness, it is possible to tailor systems that can release their nicotine load gradually over 12 or 24 hours in a safe, controlled fashion. Furthermore, the solution/diffusion mechanism protects the user's skin from exposure to excess amounts of raw nicotine.
[0191] Preferred membrane polymers are low-, medium-, or high-density commercial polyethylenes. Particularly suitable is the membrane obtainable under the trade name CoTran™ 9728 EVA from 3M but other polyethylene membranes faced with adhesive tapes from the 3M Corporation might be very suitable. Other possible membrane materials are polyamides, such as nylon 6,6, or some grades of ethylene vinyl acetate copolymers. Functional equivalents of these are intended to be within the scope of the invention. The membrane layer may be formed by preparing a solution of the chosen polymer in an organic solvent, casting on a glass plate or in a mold, and drying to evaporate the solvent. The thickness of the finished film is tailored to give the desired nicotine flux. A typical thickness of membranes used in transdermal patches range from about 5 μm to about 200 μm. Alternatively, it may be possible to purchase the membrane already in film form. This type of transdermal patch may be prepared by heat-sealing the backing to the membrane layer around the perimeter of the patch.
[0192] The nicotine formulation may be added either before or after heat sealing. If the formulation is added before heat sealing, it is convenient to shape the backing so as to form a cavity for retention of the nicotine, or to gel the nicotine. If the formulation is incorporated after heat sealing, the nicotine may be injected into the pouch formed by the heat-sealing process, and the injection hole sealed.
[0193] The adhesive layer 15 should be nicotine compatible and permit a useful nicotine flux. In addition, the adhesive should satisfy the general criteria for adhesives used for transdermal patches in terms of biocompatibility, ease of application and removal, etc. Suitable adhesives for use in the practice of the invention include pressure-sensitive adhesives approved for medical use. Amine-resistant types are preferred, so that the adhesive will not be attacked by the nicotine. A range of useful adhesives are offered by Advanced Medical Solutions Ltd. Particularly suitable is the AMS Pressure Sensitive Adhesive No. 10001875. Alternatively, acrylate-type adhesives with amine resistance can be used. The adhesive layer can be cast directly onto the skin-facing side of the membrane or monolith as a thin film. Alternatively, medical adhesive tape, with or without nicotine-flux controlling properties, may be used.
[0194] The release liner 16 may be composed of a single layer or a multiplicity of layers. Suitable release liners may be made from materials such as polyester, low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene, polystyrene, polyamide, nylon, polyvinyl chloride and specialty papers, and include Akrosil Biorelease liners, Scotchpak 1022 release liners, Adhesives Research AR5MS, Custom Coating and Laminating 7000 on HDPE or 6020 on polyethylene terephthalase (PET). A treatment of the release liner by e.g. a layer of silicon can advantageously be carried out to prevent an undesired sticking between the adhesive layer 15 and the release liner 16 . Generally, the liner should be attached to the membrane with an adhesive force which is less than the adhesive force keeping the membrane to the backing in order to avoid damaging the sealing or the membrane when releasing the liner.
[0195] The sealing 11 can be performed by gluing the layers together or preferably by heat sealing the layers. In any case the sealing will have a certain sealing width w as indicated in FIG. 2 b . Said sealing width w will have a crucial influence on the functionality of the reservoir patch. In case of a too small sealing width there will be a risk of leakage of the reservoir content sideways through the sealing and into the surroundings. On the other hand, a too big sealing width will cause the reservoir patch to be less comfortable to wear for the user due to the higher stiffness all around the reservoir patch. A higher stiffness like this will also increase the risk of release of a corner or a side of the patch from the skin of the user when placed on a curved surface as for instance an arm or a leg. If a corner or a side of the reservoir patch is released from the skin there will immediately be a risk of the reservoir content to escape to the surroundings. This risk will be higher over time as a released part of a patch will have a tendency to spread and cause an even bigger part of the patch to be released.
[0196] FIG. 2 c illustrates the patch 10 after release of the liner 16 and placement on a surface 20 . This surface may be any surface but is most likely to be the skin of a user of the reservoir patch. The patch is to be placed on the skin, preferably on a skin spot with a small amount of hair and preferably on a place with thin skin. The patch 10 is attached to the skin with the help of the adhesive layer 15 .
[0197] FIGS. 3 a , 3 b , 3 c , 4 a , 4 b , 5 a , 5 b , 5 c , 5 d and 5 e illustrate further embodiments according to embodiments of the present invention. FIGS. 3 a , 3 b and 3 c illustrate different sizes 31 , 32 and 33 of the reservoir patch as a whole. FIG. 4 a illustrates an embodiment of the invention 41 . The illustrated patch 41 comprises a sealing 11 which serves to establish a reservoir between a backing and a membrane (not shown). The illustrated patch comprises a peel corner 13 . The further patch components may e.g. correspond to the patch components already described in FIGS. 1 to 2 c . For reasons of explanation, the patch 41 is referred to as a starting point when explaining further embodiments. It should be noted that numerous variations in size, shape and so on may be applied within the scope of the invention.
FIG. 4 b illustrates a patch 42 provided with an extra peel corner 13 a . The further patch components may e.g. correspond to the patch components already described in FIGS. 1 to 2 c . This variant facilitates easier release of the liner. Further numbers of peel corners, sizes of peel corners or peel areas may be applied within the scope of the invention. Generally, according to embodiments of the invention, peel corners are preferred but optional. FIG. 4 c illustrates a further embodiment of the invention 43 where a seal width w of the sealing 11 is decreased in order to increase the flexibility and/or decrease the flexural strength of the patch 43 structure.
[0199] FIGS. 5 a - 5 f illustrate further embodiments according to embodiments of the invention concerning variations in the seal structure. FIG. 5 a shows a patch 51 with a sealing 11 and a peel corner 13 . The further patch components of the patches in FIGS. 5 a to 5 f may e.g. correspond to the patch components already described in FIGS. 1 to 2 c . The patch 51 is provided with an extra seal spot 520 within the middle of the reservoir in order to stabilize the backing and the reservoir. Stabilization here will keep the shape of the reservoir and maintain the distribution of gel. A further variant is illustrated for the patch 52 in FIG. 5 b where two seal spots 521 and 522 are provided. Any number of spots can in this way be provided in order to stabilize the patch according to embodiments of the present invention.
[0200] FIG. 5 c shows a patch 53 provided with an extra sealing between the membrane and the backing crossing the patch, thereby splitting the patch into two separate patches with separate reservoirs 12 a and 12 b . The extra sealing is split by a peel line 523 with which the two patches can easily by separated. In this way the patch can be used as normal if just placed on the skin as whole. In addition to that it is possible to split the patch into two separate patches, each of which giving e.g. half the dose, by tearing along the peel line 523 . A further embodiment is shown in FIG. 5 d illustrating a patch 54 provided with two extra sealings separating the patch into four separate patches each with e.g. one fourth of the total dose. Generally for the patches illustrated in FIGS. 5 a to 5 e , it should be noted that numerous variations in size, shape and so on may be applied within the scope of the invention.
[0201] FIG. 5 e shows a further embodiment of the embodiments shown in FIGS. 5 c and 5 d . A patch 55 where all corners, subject to be exposed when separating the patches, are rounded beforehand in order for the user to avoid sharp corners when separating the patches through the peel line 524 . This rounding may preferably be established during manufacturing of the patch.
[0202] FIG. 5 f shows a cross-sectional view along the line II-II of the patch 55 in FIG. 5 e and might as well have been of any the patches in FIGS. 5 c and 5 d . The widths of the reservoir defining seals are marked w.
[0203] Different physiologically active substances show very varying ability to penetrate the skin. Nicotine easily permeates the skin, whereas other physiologically active substances, typically larger in molecule size, must be assisted in order to get a noticeable amount of ingredient through the skin. For this purpose enhancers are used in an embodiment of the invention.
[0204] Suitable penetration enhancers, flux enhancers, are preferably monovalent, saturated or unsaturated aliphatic, cycloaliphatic or aromatic alcohols having from 4 to 12 carbon atoms. e.g. n-hexanol or cyclohexanol, aliphatic, cycloaliphatic or aromatic hydrocarbons having from 5 to 12 carbon atoms, e.g. hexane, cyclohexane, isopropylbenzene and the like, cyclo-aliphatic or aromatic aldehydes and ketones having from 4 to 10 carbon atoms, such as cyclohexanone, acetamide, N,N-di-lower alkylacetamides such as N,N-dimethylacetamide or N,N-diethyl-acetamide, c.sub.10-c.sub.20-alkanoylamides, e.g. N,N-dimethyllauroylamide, 1-n-C.sub.10-c.sub.20-alkylazcycloheptan-2-one, e.g. 1-n-dodeclyazacycloheptan-2-one(Azone.RTM. laurocapram), or N-2-hydroxyethylacetamide, and known vehicles and/or penetration enhancers such as aliphatic, cycloaliphatic and aromatic esters N,N-di-lower alkylsulphoxides, unsaturated oils, halogenated or nitrated aliphatic or cyclo-aliphatic hydrocarbons, salicylates, polyalkylene glycol silicates, and mixtures thereof.
[0205] The following examples will further illustrate embodiments of the present invention. It is to be understood that the examples set forth are illustrative and not limiting for the present invention.
EXAMPLE 1
[0206] A reservoir patch, with backing layer, membrane and adhesive according to the description, with patch delivering area of 3.2 cm 2 was manufactured comprising 20 mg of nicotine mixed in 170 mg of gelling agent in the reservoir. In this sense the resulting patch had a ratio between the tobacco alkaloid content and the patch delivering area of 6.25 mg/cm 2 .
[0207] The patch with this ratio between nicotine present in the reservoir and patch delivering area proved to be acceptable.
EXAMPLE 2
[0208] A series of reservoir patches with identical patch delivering area of 9.52 cm 2 was manufactured, the data of which are shown in table 1.
[0000]
TABLE 1
Gel content
Nicotine
Area
Flux
Patch
(mg)
content (mg)
Type
(cm 2 )
(mg/h * cm 2 )
A
190
19
15 mg/16 h
9.52
0.10
B
260
26
21 mg/24 h
9.52
0.09
C
190
26.6
21 mg/24 h
9.52
0.09
D
285
39.9
31.5 mg/24 h
9.52
0.14
E
500
50
40 mg/24 h
9.52
0.18
F
1000
100
80 mg/24 h
9.52
0.35
G
1500
150
120 mg/24 h
9.52
0.53
H
1500
210
165 mg/24 h
9.52
0.72
I
1500
300
237 mg/24 h
9.52
1.04
[0209] All patches A-I proved to be acceptable for containing a deliverance of nicotine and for an effective fastening on the human body. In table 1 flux is calculated as delivered nicotine per time per patch delivering area instead of total nicotine content per time per patch delivering area. Thereby this indicates the actual amount delivered, i.e. for patch A the flux is 15 mg/16 h*cm 2 =0.10 mg/h*cm 2 .
EXAMPLE 3
[0210] A series of reservoir patches as in example 1 with higher ratios were manufactured. The series consisted of ratios of app. 10, 20, 40, 60, 80, 100 mg/cm 2 . The patches proved to be acceptable for ratios as high as 100 mg/cm 2 .
EXAMPLE 4
[0211] A series of reservoir patches as in example 1 with increased patch area were manufactured with patch delivering areas of 3.2 cm 2 , 6.3 cm 2 , 9.52 cm 2 , 14.3 cm 2 , 20.1 cm 2 , 27.6 cm 2 and 35.7 cm 2 . A larger size of patch made it possible to contain and deliver a larger amount of nicotine and reducing the risk that the nicotine caused burning of the skin of the user.
EXAMPLE 5
[0212] The tests for flexural strength referred to in the description are based on the ISO 178 standard unless otherwise stated. The test measures the force required to bend a material under 3 point loading conditions as illustrated in FIGS. 6 a and 6 b . A material 62 for which the flexural strength is to be measured is placed on a support span provided by support structures 60 and 61 . In the middle of the material 62 a roll 63 presses down on the material and the necessary force to move the material d mm down is measured within a certain range.
The separation between the support structures 60 and 61 was 30 mm. The velocity of the roll 63 to bend the material 62 was 5 mm/min. The values were found by measuring the necessary force to move the material downwards from d=1 mm to d=5 mm. References to flexural strength of patches according to embodiments of the
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The invention relates to a tobacco alkaloid patch ( 10; 41; 42; 43; 51; 52; 53; 54 ) for transdermal administration of a tobacco alkaloid, said patch comprising an impermeable backing ( 11 ) and a membrane ( 14 ) which defines a reservoir ( 12 ) there between, said membrane being permeable to and in contact with said tobacco alkaloid, said tobacco alkaloid being mixed with a viscous flowable gel, said impermeable backing and said membrane being at least partly joined by a sealing and wherein the amount of said tobacco alkaloid is above 10 mg.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a technique of easily and quickly determining the optimum value of feedback gain used for calculating correction amount in feedback control.
2. Description of the Prior Art
Feedback control is frequently adopted for, for instance, moving an automatic guidance vehicle along a predetermined course. The control comprises a step of detecting a deviation or error ΔE from the course, a step of calculating correction amount according to the detected error ΔE, and a step of correcting the steering angle of the vehicle according to the calculated correction amount, these steps being executed repeatedly.
Generally, in the feedback control, the correction amount is calculated in any of the following ways:
P system: A value (P×ΔE) which is proportional to the error is used as the correction amount.
PI system: The sum of a value proportional to the error and a value proportional to an integral of the error (P×ΔE+I×integral of ΔE) is used as the correction amount.
PD system: The sum of a value proportional to the error and a value proportional to a differential of the error (P×ΔE+D×differential of ΔE) is used as the correction amount.
PID system: The sum of a value proportional to the error, a value proportional to an integral of the error and a value proportional to a differential of the error (P×ΔE+I×integral of ΔE+D×differential of ΔE) is used as the correction amount.
The factors P, I and D as used in the above formula are feedback gains. Specifically, the P gain is a proportional gain, the I gain is an integral gain, and the D gain is a differential gain. The values of the feedback gains such as the P, I and D gains have great influence on the feedback control characteristics. For example, if the P or proportional gain is too small in value, the correction of the running course of the automatic guidance vehicle is delayed. If the gain is too large, on the other hand, the running course meanders greatly.
Accordingly, on-site processes have heretofore been contemplated, which permit the optimum value of feedback gain to be found out easily and in a short period of time. A typical one of such processes is a limit sensitivity process which is disclosed in ASME trans., vol. 64, (1942. 11.), J. G. Ziegler, N. B. Nichols, pp. 759-768.
In this limit sensitivity process, the magnitude of the P gain with which the error is undergoing self-sustaining vibration is obtained by carrying out actual feedback control on the subject of control, and the optimum value of each gain is determined from the value of the P gain at this time in accordance with experiment rules.
Specifically, the I and D gains are set to zero, that is, the sole P gain is made variable in a trial feedback control, and the P gain is increased gradually. When the self-sustaining vibration of the error is obtained, the P, I and D gains are set to be, for instance:
P gain=0.6×P c
I gain=0.5×τ c
D gain=0.125×τ c
where P c is the value of the P gain at this time and τ c is the period of the self-sustaining vibration.
In these formulas, the individual coefficients are obtained experimentally, and their adequacy empirically verified. In this way, the values of the P, I and D gains are determined.
In the limit sensitivity process, however, problems are encountered in the practical way of detecting the self-sustaining vibration. Besides, depending on the subject of control, there may be cases when it is difficult to detect the reaching of the state of the self-sustaining vibration.
As an example, in the feedback control for moving an automatic guidance vehicle (hereinafter referred to as AGV) along a course, it is not easy to accurately determine the instant of reaching of the self-sustaining vibration because of very slow changes in the course of the AGV.
SUMMARY OF THE INVENTION
An object of the invention is to provide a method of determining feedback gain which permits determining the proper value of feedback gain both easily and accurately, in a short period of time and irrespective of the kind of the subject of control.
The method of determining feedback gain according to the invention, as schematically shown in FIG. 1, comprises a first step of provisionally determining a predetermined value of a feedback gain, a second step of executing feedback control by using the provisionally determined feedback gain, a third step of detecting an error between a designated value and an actual value of the subject of control during the execution of the second step, a fourth step of calculating an evaluation value indicative of the character of feedback control according to the error detected in the third step, a fifth step of executing the second to fourth steps repeatedly a plurality of times after provisionally determining a new feedback gain value different from the previous value, and a sixth step of calculating a feedback gain value which can provide for a suitable evaluation value according to the relation between the feedback gain value and the evaluation value obtained through the execution of the fifth step.
This method permits a feedback gain providing for a suitable evaluation value to be calculated on the basis of the relation between feedback gain value and evaluation value, and it is thus possible to determine a feedback gain which can realize a suitable feedback control characteristic quickly and reliably.
Particularly, in case of determining the proportional gain, in the fourth step, the ratio between the length of a curve obtained by plotting the error against time axis and the length of the time axis is calculated as the evaluation value, and in the sixth step, a feedback gain value providing for the minimum evaluation value is calculated.
The proportional gain is a factor which influences the stability of control. The stability of control can be evaluated from the extent of variations of the error, and thus the length of the curve obtained by plotting the error against time axis is suited for evaluating the proportional gain. Thus, by using the length of the curve obtained by plotting the error against time axis as the evaluation value, it is possible to obtain quickly and accurately a value of the proportional gain that provides for the optimum stability.
In case of determining the integral gain, in the fourth step, the evaluation value is calculated by integrating the error, and in the sixth step, a value of feedback gain that provides for an evaluation value closest to zero is calculated.
The integral gain is a factor influencing the accuracy of control. The integral of the error reflects the accuracy of control, and is thus suited for evaluating the integral gain. Thus, by using the integral of the error, it is possible to obtain quickly and accurately a value of integral gain which provides for satisfactory accuracy.
In case of determining the differential gain, in the fourth step, the evaluation value is calculated by integrating the absolute value of the error, and in the sixth step, a value of feedback gain providing for the evaluation value which is closest to zero is calculated.
The differential gain is a factor influencing the response of control. The response of control can be evaluated to the fineness of error variations, and thus the integral of the absolute value of the error is suited for evaluating the differential gain. Thus, by using the integral of the absolute value of the error, it is possible to obtain quickly and accurately a value of differential gain providing for the optimum stability and response.
The present invention will be more fully understood from the following detailed description and appended claims when taken with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view illustrating the method of determining feedback gain according to the invention;
FIG. 2 is a schematic representation of an automatic guidance vehicle used in the method of determining feedback gain according to a first and a second embodiment of the invention;
FIG. 3 is a block diagram showing controllers of the automatic guidance vehicle used in the method of determining feedback gain according to the first and the second embodiments;
FIG. 4 is a view showing the amount of control and evaluation functions in the method of determining feedback gain according to the first and the second embodiments;
FIG. 5 is a graph showing a proportional gain evaluation function in the method of determining feedback gain according to the first and the second embodiments;
FIG. 6 is a graph showing an integral gain evaluation function in the method of determining feedback gain according to the first and the second embodiments;
FIG. 7 is a graph showing a differential gain evaluation function in the method of determining feedback gain according to the first and the second embodiments;
FIG. 8 is a plan view showing an automatic guidance vehicle running course in the method of determining feedback gain according to the first and the second embodiments;
FIG. 9 is a flow chart showing a gain determination routine in the method of determining feedback gain according to the first embodiment;
FIG. 10 is a flow chart showing part of the gain determination routine in the method of determining feedback gain according to the first embodiment;
FIGS. 11(A) and 11(B) are graphs showing examples of gain determination process in the method of determining feedback gain according to the first embodiment; and
FIG. 12 is a flow chart showing a gain determination routine in the method of determining feedback gain according to the second embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
Now, a first embodiment of the invention will be described with reference to FIGS. 2 to 11. In this embodiment, the method of feedback gain determination is applied to the running control of an AGV.
First, the construction of the AGV in this embodiment will be described with reference to FIG. 2. FIG. 2 is a view showing the construction of an AGV 2 in this embodiment. As shown in FIG. 2, the AGV 2 runs along a running surface 8 with front wheels 4 as steering wheels and rear wheels 6 as drive wheels. A steering module 24 is provided for the steering wheels 4. The drive wheels 6 have brakes 32, and a drive module 28 and a brake module 30 are provided for the drive wheels 6. The steering module 24 is controlled by a steering angle controller 22, and the drive module 28 and brake module 30 are controlled by a vehicle speed controller 26. The steering angle controller 22 and the vehicle speed controller 26 are controlled by a central processor 10. The central processor 10 is a computer system including a central processing unit (CPU) 12, and a memory section having a ROM 14 and a RAM 16. The CPU 12, RAM 14 and ROM 16 are interconnected by data buses 18 for mutual data transfer.
The underside of a central portion of the front end of the AGV 2 is provided with a lateral deviation detector 20. The lateral deviation detector 20 includes a sensor having a pick-up coil, and it detects by electromagnetic induction an induction wire which is laid on a running surface 8 along the running course of the AGV 2. The distance between the induction wire and the lateral deviation detector 20, i.e., the lateral deviation of the AGV 2, is detected from the magnitude of a detection signal output from the detector 20. The direction or sense of deviation, i.e., whether the AGV 2 is deviated to the left or right, is detected from the sign (either positive or negative) of the detection signal. The detection signal from the lateral deviation detector 20 is inputted to the central processor 10. The drive module 28 includes a vehicle speed detector 34, and a vehicle speed signal therefrom is inputted to the central processor 10. The central processor 10 executes a predetermined calculation process according to the inputted signals noted above. According to the result of the calculation process, the central processor 10 outputs a control signal to the steering angle controller 22 and the vehicle speed controller 26. The flow of a signal in the running control system for the AGV 2 will now be described in detail with reference to FIG. 3. FIG. 3 is a block diagram showing the running control system for the AGV 2.
Referring to FIG. 3, designated at 34 is the vehicle speed detector which is provided in the AGV 2. A vehicle speed calculator 42 calculates the actual vehicle speed VA according to a signal from the vehicle speed detector 34. Designated at 36 is a vehicle speed designator, and at 38 an error calculator for calculating the error ΔV between a designated vehicle speed VT and the actual vehicle speed VA. Designated at 44 is a feedback gain storage in which feedback gains P V , I V and D V are stored. Designated at 40 is a correction amount calculator for calculating the vehicle speed correction amount from the error ΔV and feedback gains P V , I V and D V . The correction amount thus calculated is fed to the vehicle speed controller 26, which in turn controls the drive module 28 and the brake module 30. Thus, the actual vehicle speed VA is feedback controlled to be equal to the designated vehicle speed VT. Designated at 46 is a feedback gain controller for controlling the feedback gain to a proper value in the manner as will be described later.
Designated at 48 is an error calculator for calculating the deviation or error a ΔE according to a signal from the lateral deviation detector 20. Designated at 54 is a feedback gain storage in which feedback gains P E , I E and D E are stored. Designated at 50 is a correction amount calculator for calculating the steering angle correction amount from the error ΔE and the feedback gains P E , I E and D E . The correction amount thus calculated is fed to the steering angle controller 22, which thus controls the steering module 24. Thus, the steering module 24 is feedback controlled such as to reduce the lateral deviation ΔE to zero. Designated at 52 is a feedback gain controller for controlling the feedback gain to a proper value in the manner as will be described later.
In the running control system having the above constitution for controlling the running of the AGV 2, feedback control (or PID control) is carried out, which involves processes concerning the P (proportional), I (Integral) and D (differential) gains. In this PID control, the methods of determining the optimum values of the P, I and D gains will now be described with reference to FIGS. 4 to 7.
As noted before, during the running of the AGV 2, a detection signal is outputted, which corresponds to the extent and direction of the deviation of the lateral deviation detector 20 from the induction wire which is laid along the running course. FIG. 4 shows an example of the detection signal. In FIG. 4, the ordinate is taken for the voltage value V of the detection signal from the lateral deviation detector 20, and the abscissa is taken for the running time of the AGV 2. The sign of the voltage value V indicates the direction (i.e., to the left or right) in which the lateral deviation detector 20 is deviated with respect to the induction wire. The voltage value V thus corresponds to the error.
When the AGV 2 is running accurately along the induction wire, the voltage value of the detection signal is zero. In the running control of the AGV 2, it is thus necessary the curve ε(t) which represents the voltage value V plotted along the running time to be in as accord as the abscissa axis as possible. In addition, it is necessary to determine the optimum values of the P, I and D gains such that the result of control obtained satisfies all of the stability, accuracy and response.
The P gain governs the stability of control, the I gain is a factor which influences the magnitude of off-set, i.e., the accuracy of control, and the D gain governs the response of control. Thus, in this embodiment, evaluation values are introduced about the individual P, I and D gains having the above characters for accurately evaluating the influence of the value of each gain on the voltage curve ε(t).
Functions LR, Svv and Asv shown by formulas (1) to (3) in FIG. 4 give the evaluation values. In other words, the functions LR, Svv and Asv are evaluation functions for the P, I and D gains, respectively. The meaning of these functions will now be described with reference to FIG. 4.
The function LR, as shown by the formula (1) in FIG. 4, represents the ratio between the length of the voltage curve ε(t) drawn in a measurement time (from instant C S till instant C E ) and the measurement time (C E -C S ). Thus, LR=1 is obtained in the ideal state of control. The stability of the running control can be evaluated from the extent of lateral deviations of the AGV 2. Thus, the evaluation function LR is suited for evaluating the relation between the stability of control and the P gain. The optimum value of the P gain can be obtained by controlling the P gain such that the function LR approaches the ideal value of unity.
The function Svv, as shown by the formula (2) in FIG. 4, represents the product per 30 seconds of the summation of the measured voltage Vi in the measured time (C S -C E ) and constant C. The magnitude and sign of the integral of the measured voltage Vi directly reflect the magnitude and sign of the off-set of the error, and it is thus suited for evaluating the I gain. The ideal value of the function Svv is zero, and the optimum value of the I gain is obtained by controlling the I gain such that Svv approaches zero.
The function Asv, as shown by the formula (3) in FIG. 4, represents the product per 30 seconds of the summation of the absolute value of the measured voltage Vi in the measured time (C E -C S ) and constant C. Its magnitude corresponds to the area enclosed by the voltage curve ε(t) and the abscissa shown in FIG. 4. The response of the running control can be evaluated from the fineness of the lateral deviations of the AVG, i.e., the fineness of the waveform of the curve ε(t) in FIG. 4. Thus, the function Asv is suited for evaluating the D gain which concerns the response of the running control. The response of control is the better the closer the value of Asv is to zero, and the optimum value of the D gain can be obtained by controlling the D gain such that Asv approaches zero.
As shown, the evaluation functions are suited for evaluating the optimum values of the P, I and D gains. Besides, the evaluation functions have an advantage that by using them, the optimum value, of each gain can be obtained accurately irrespective of the settings of the other two gains. It is thus possible to very readily determine the optimum values of the P, I and D gains without using any of very complicated multiple variable analytic processes such as a linear plan process which have been required for obtaining optimum values of a plurality of mutually related functions.
Now, how the evaluation functions change with gain changes will be described with reference to FIGS. 5 to 7. FIG. 5 shows the function LR plotted against the P gain, FIG. 6 shows the function Svv plotted against the I gain, and FIG. 7 shows the function Asv plotted against the D gain.
The function LR, as shown in FIG. 5, draws a downward convex curve with changes in the P gain and is closest to the ideal value of unity at its minimum point. Thus, the value P opt of the P gain corresponding to the minimum point of the curve in FIG. 5 is the optimum value of the P gain.
The function Svv, as shown in FIG. 6, is reduced uniformly as the I gain is increased and is zero at a certain point. Thus, the value I opt of the I gain corresponding to Svv=0 in the curve shown in FIG. 6 is the maximum value of the I gain.
The function Asv, as shown in FIG. 7, draws a downward convex curve with changes in the D gain and is closest to the ideal value of zero at its minimum point. Thus, the value D opt of the D gain corresponding to the minimum point of the curve shown in FIG. 7 is the optimum value of the D gain.
There are two different conceivable methods of obtaining the ideal values of gains from evaluation function data. In one of these methods, as shown in FIGS. 5 to 7, a fixed range with respect to the ideal value of each evaluation function is set as an optimum value range, and the value of gain when the value of the evaluation function enters this optimum value range is selected as the optimum value.
In the other method, the optimum values P opt , I opt and D opt are calculated by function interpolation. More specifically, a plurality of evaluation function values are obtained such that they sandwich the optimum values P opt , I opt and D opt , and using these values, the curves shown in FIGS. 5 to 7 are plotted, thereby calculating the optimum values P opt , I opt and D opt . This function interpolation process has an advantage over the above method based on the optimum range that it is possible to obtain more optimum values.
A specific example of obtaining the optimum values of the P, I and D gains in the AGV running control by using the above evaluation functions will now be described with reference to FIG. 8. FIG. 8 is a plan view showing the running course of the AGV in this embodiment.
As shown in FIG. 8, the running course 70 of the AGV 2 in this embodiment is an oval closed loop consisting of four sections of different running conditions. In a section 72 of the course 70 from a point at a point b, the AGV 2 runs along a curve at low speeds. In a section 74 from the point b to a point c, it runs along a straight line at high speeds. In a section 76 from the point c to a point d, it runs along a curve at high speeds. In a section 78 from the point d to the point a, it runs along a straight line at low speeds.
In the running control for driving the AGV 2 along such running course 70, the procedure for determining the optimum values of the P, I and D gains will be described with reference to FIGS. 9 and 10. FIGS. 9 and 10 are flow charts illustrating the procedure of determining the P, I and D gains in this embodiment. The routine shown in these flow charts is executed in the central processor 10.
In this embodiment, data take-in and gain determination are done for each section of the running course shown in FIG. 8. For example, the AGV 2 is first driven repeatedly only in the section 72 for the data take-in, and first the P, I and D gains are determined for the section 72. Then, the AGV 2 is driven repeatedly only in the section 74 for the data take-in. Likewise, the AGV 2 is driven in the other sections. When the routine is started in Step S2, course conditions are set for either section (among the sections 72, 74, 76 and 78 in FIG. 8), for which the optimum values of the P, I and D gains are to be obtained (Step S4). Then, the values of the P, I and D gains are initialized (Step S6). That is, the individual gains are set to initial values which are preliminarily stored in the ROM 16 of the central processor 10 shown in FIG. 2. As each initial value, a sufficiently small value is set.
Subsequently, a process of obtaining the optimum value of the P gain is first executed (Step S8). The contents of the process or routine in Step S8 will now be described with reference to FIG. 10.
The routine is started in Step S20, and the AGV 2 is driven to run along the course 70 under feedback control using the initial values of the P, I and D gains that have been set in Step S6 in FIG. 9 (Step S22). Then, output voltage data from the lateral deviation detector 20 is taken into the central processor 10 (Step S24). The output voltage data is, for instance, ε(t) in FIG. 4, and by using this data, the value of the evaluation function LR for the P gain is calculated with the formula (1) in FIG. 4 (Step S26). Then, a check is made as to whether end conditions have been met by the value of LR (Step S28).
If the end conditions have been met, that is, if the value of LR is in the optimum value range shown in FIG. 5, the value of the P gain at this time is determined as the optimum value (Step S30). As a result, the routine goes back to the routine shown in FIG. 9 (Step S32). If the end conditions have not been met by the value of LR, the value of the P gain is increased by a predetermined amount (Step S34), and then Step S22 seq. are repeatedly executed.
When the routine shown in FIG. 9 is restored, Steps S10 and S12, i.e., a process of obtaining the optimum value of the I gain and a process of obtaining the optimum value of the D gain, are executed successively. These processes are similar to the process of obtaining the optimum value of the P gain shown in FIG. 10. Specifically, as for the I gain in Step S26 in FIG. 10, the value of the evaluation function Svv for the I gain is calculated with the formula (2) in FIG. 4. As for the D gain, in Step S26 in FIG. 10, the value of the evaluation function Asv for the D gain is calculated with the formula (3) in FIG. 4. If the values of Svv and Asv thus calculated are in the respective optimum value ranges shown in FIGS. 6 and 7, the values of the I and D gains at this time are determined as the optimum values.
The optimum value data of the three different gains are stored together with the course condition data set in Step S4 as a set of data in the RAM 14 of the central processor 10 in FIG. 2. Then, a check is made as to whether the processes have been ended for all the sections of the running course 70 (Step S14 in FIG. 9). If "YES", the data for all the course sections are registered (Step S16), and the routine is ended (Step S18). If the result of the check in Step S14 is "NO", the routine goes back to Step S4 to execute similar operations for the next course section. In this way, the optimum values of the P, I and D gains are determined.
In the routine of the flow charts of FIGS. 9 and 10, the value of each gain at the instant when the optimum value range shown in each of FIGS. 5 to 7 is entered is determined as the optimum value. However, as noted before, it is possible to obtain the individual gain optimum values (P opt , I opt and D opt in FIGS. 5 to 7) by the function interpolation.
FIGS. 11(A) and 11(B) show specific examples of the P, I and D gains obtained in the above procedure.
FIG. 11(A) shows the process contents until the P gain is determined in the procedure shown in FIG. 10, and FIG. 11(B) shows the process contents until determination of each of the P, I and D gains by function interpolation. In the example of FIG. 11(A), the P gain is increased from initial value P1 and up to P5, at which the evaluation value enters the optimum value range. More specifically, the value of the P gain is increased progressively from its value in a first calculation section for data take-in and calculation, and its value when the evaluation value LR is calculated in a fifth calculation section is in the optimum value range shown in FIG. 5. The P gain value at this time is thus determined as the optimum value.
FIG. 11(B) shows the process of determining each of the P, I and D gains by function interpolation. First, the I and D gains are set to forecast optimum values I0 and D0, and in this state, the P gain is increased from initial value P1 in steps of a predetermined amount for taking output voltage data with actual running of the AGV and calculating the value of the evaluation function. When the minimum value is passed by the value of LR, the data take-in is stopped, and the optimum value Popt of the P gain is calculated by function interpolation with the values of LR that have been obtained. In the case of FIG. 11(A), the passage of the minimum value by the value of LR can be known at the instant when P gain value P6 is substituted, and the function interpolation is thus executed using the values of LR corresponding to the gain values P1 to P6, thus determining P opt , Then, using the calculated value P opt and the value DO the I gain is likewise increased from the initial value I1 in steps of a predetermined amount for calculating I opt . Further, using the values P opt and I opt , the value D opt is calculated likewise.
In either of the examples of FIGS. 11(A) and 11(B), the value of each gain is increased in steps of an equal amount. However, it is possible to change the amount of increase not only for each gain but also for each step.
Second Embodiment
A second embodiment of the invention will now be described with reference to FIGS. 2, 8, 10 and 12.
This embodiment, unlike the first embodiment, features that the P, I and D gains are determined by causing the AGV to run continuously along the running course. That is, the optimum P, I and D gains are determined for each of the sections 72, 74, 76 and 78 of the running course 70 shown in FIG. 8 while the AGV makes an excursion of the course.
The construction of the AGV, the constitution of the running control system and the running course are the same as in the first embodiment.
The procedure in this embodiment will now be described with reference to FIG. 12. FIG. 12 is a flow chart illustrating the gain determination procedure in the feedback gain determination method of the second embodiment. The process illustrated in the flow chart is executed in the central processor 10 shown in FIG. 2.
When the routine is started in Step S52 in FIG. 12, the values of the P, I and D are initialized (Step S54). That is, the values of the individual gains are set to initial values which are preliminarily stored in the ROM16 of the central processor 10 in FIG. 2. Then, the AGV 2 is caused to run along the course 70 (Step S56). At each of the boundary points a to d between adjacent course sections, a marker is provided for transmitting a trigger signal, and a check is made as to whether a trigger signal from a marker has been inputted (Step S58). If the result of the check is "NO", the AGV is continually caused to run. Upon inputting of a trigger signal, the routine goes to Step S60, a process of obtaining the optimum value of the P gain. The process has the same contents as those in the first embodiment, and it is executed in the same way as the procedure shown in FIG. 10. Then, a process of obtaining the optimum value of the I gain (Step S62) and a process of obtaining the optimum value of the D gain (Step S64) are executed in succession.
Optimum value data which are thus obtained for the three different gains are registered together with data indicative of the course sections as a set of data in the RAM 14 of the central processor 10 shown in FIG. 2 (Step S66). The data indicative of the source sections are read in accordance with the previously inputted trigger signals. Then, a check is made as to whether the optimum values of all the P, I and D gains have been registered for all the sections of the running course 70 (Step S68). If the result of the check is "YES", the routine is ended (Step S70). Now, data which are necessary for the automatic running of the AGV 2 along the running course 70 are at hand, and it is possible for the AGV 2 to perform predetermined operations. If the result of the check in Step S68 is "NO", the routine returns to Step S56 for executing similar operations for the next course section.
As for the trigger signal inputting, instead of using the markers provided at the boundary points a to d, it is possible that the operator transmits a trigger signal by manual operation by watching the running AGV 2, or it is possible to adopt a system in which a trigger signal is outputted in the AGV 2 in accordance with the accumulated running distance.
There may be a case when the next trigger signal is inputted (for the next course section) before the routine concerning the three different gains have not yet been ended due to such causes as short time necessary for the AGV 2 to cover the present course section and stringent end conditions shown in Step S28 in FIG. 10. In such case, the end conditions shown in Step S28 in FIG. 10 may be made less stringent to obtain the optimum values of the three gains. If the next trigger signal has not yet been inputted in this stage, the end conditions in Step S28 in FIG. 10 may be made more stringent, and the routine may go back to Step S60 as shown by dashed line in FIG. 12 to obtain more suitable optimum value for each gain. As a further alternative, a gain which could have not been calculated until the reaching of the next course section by the AGV, may be calculated concurrently with the data take-in for the next course section.
In the flow chart shown in FIG. 12, the initial value of each gain set in Step S54 is used commonly for all the sections of the course as the initial value for the operation in Step S60 seq. By providing, between Steps S58 and S60, a step for inputting the initial value of each gain suited for each course section afresh in correspondence to the inputted trigger signal, it is possible to reduce the time necessary for the processing.
Each of the above embodiments has concerned with an example in which the P (proportional control), I (integral control) and D (differential control) gains are obtained as feedback gains. However, the invention is also applicable to cases of obtaining the optimum values of feedback gains other than the P, I and D gains. Further, while in the first embodiment, the optimum values are obtained in the order of that for the P gain, that for the I gain and that for the D gain, it is possible to obtain the optimum values in any order. Further, the evaluation functions for the gains in the above embodiments are by no means limitative, and it is possible to use other functions so long as they are suited for the gain evaluation. Furthermore, the construction of the AGV, other steps of the feedback gain determination method etc. in the above embodiments are by no means limitative.
While the invention has been described with reference to preferred embodiments thereof, it is to be understood that modifications or variations may be easily made without departing from the scope of the present invention which is defined by the appended claims.
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A feedback gain determination method permits optimum values of such feedback gains as P, I and D gains to be determined easily, quickly, reliably, and irrespective of the kind of the subject of control. The method comprises a first step of provisionally determining a predetermined value of a feedback gain, a second step of executing feedback control by using the provisionally determined feedback gain, a third step of determining an error between a designated value and an actual value of the subject of control during the execution of the second step, a fourth step of calculating an evaluation value indicative of the character of feedback control according to the error detected in the third step, a fifth step of executing the second to fourth steps repeatedly a plurality of times after provisionally determining a new feedback value different from the previous value, and a sixth step of calculating a feedback gain value which provides for a suitable evaluation value according to the relation between the feedback gain value and the evaluation value obtained through the execution of the fifth step. The method permits easy and quick determination of the proper value of the gain.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a wireless communication data recording medium such as a wireless communication IC card supplied with power in a wireless manner using a radio wave for transmitting and receiving data, and a method of data transmission.
2. Description of the Related Art
In recent years, in order to improve the reliability of the IC cards as a data storing medium, a wireless communication IC card has been proposed for transmitting and receiving data and power in a wireless manner using a radio wave. Such a wireless communication IC card (hereinafter referred to simply as "the IC card") has two antennas built therein for receiving two different carriers transmitted using two radio waves of different frequencies, one for supplying power and the other for transmitting data modulated by the PSK (Phase Shift Keying) modulation scheme, for example. In the process, in order to prevent the power carrier from having an effect on the data transmission, the frequencies of the two carrier waves are sufficiently separated from each other or a filter of a large attenuation is inserted for removing the power carrier from the data carrier.
As described above, the conventional IC card is required to have two antennas, one for receiving a power carrier and one for a data transmission carrier. Also, a filter is required for removing the effect of the power carrier on the data carrier. The result is a number of components having a time constant of an analog circuit, so that it is difficult to configure the circuit on semiconductor integrated circuits (introduction of LSI). This in turn makes it difficult to reduce the circuit size on the one hand and to realize a small package on the other hand.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a wireless communication data storing medium in which a carrier for supplying power and a carrier for transmitting data are received, and data can be transmitted and received stably without any filter, even in the case where the two carriers are proximate to each other, and a method of wireless communication power-data transmission method.
According to one aspect of the present invention, there is provided a wireless communication data storing medium comprising means for receiving a composite wave of a first carrier for supplying a source voltage and of a second carrier for transferring data, means for generating the source voltage by rectifying the composite wave and supplying the rectified source voltage to the internal circuits of the wireless communication data storing medium, means for detecting an amplitude change corresponding to the data transferred by the second carrier on the basis of the composite wave, and means for extracting the data on the basis of the amplitude change detected by the detection means.
In this aspect of the invention configured as described above, the power-supplying carrier and the data-transfer carrier oscillated from a card reader-writer can be received by the same receiving system. In other words, the circuit size can be reduced for a lower cost without using any two independent antennas or any filter for removing the effect of the power carrier on the data transfer carrier as required in the prior art.
According to another aspect of the invention, there is provided a wireless communication data storing medium in which the detection means includes means for comparing the amplitude of a subcarrier based on the envelope of the composite wave with the average amplitude of the subcarrier in synchronism with the first carrier thereby to detect the amplitude change corresponding to the data.
With the above-mentioned configuration of the invention, even in the case where the frequencies of the first and second carriers are proximate to each other, the data of the second carrier can be demodulated stably without being affected by the first carrier. More specifically, in the case where the frequencies of the first and second carriers are proximate to each other, the subcarrier B based on the envelope of the composite wave A assumes a waveform proximate to the received wave A under the effect of the composite wave A. As a result, in the case where the subcarrier B is compared with the average E to detect the amplitude change C corresponding to the transferred data G, the result is undesirably different partially from the transfer data G (operating error) (See x and y in FIG. 3). This is by reason of the fact that when the frequencies of the first and second carriers come to approach each other, the subcarrier B assumes a waveform infinitely approaching the received wave.
The comparison between the subcarrier B and the average E at a timing free of the effect of the first carrier on the envelope, however, is possible if the subcarrier B is compared with the average E in synchronism with the first carrier f1 (See z in FIG. 3). More specifically, the comparison between the subcarrier B and the received wave A is not made at time point x or y shown in FIG. 3, but only at the rise time of a clock signal D at point z. As a result, even when the first carrier f1 and the second carrier f2 are set at frequencies considerably proximate to each other, no operating error is caused when the two radio waves are received as a composite wave A by the same antenna without any filter. Consequently, a wireless communication data storing medium with a simple configuration is realized in which a plurality of carriers having frequencies proximate to each other can be transmitted and received stably without any filter.
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.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate presently preferred embodiments of the invention and, together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.
FIG. 1 is a block diagram schematically showing a configuration of a wireless communication IC card constituting a wireless communication data storing medium according to an embodiment of the present invention.
FIG. 2 is a diagram showing a specific example of a circuit configuration of the essential parts of the IC card shown in FIG. 1.
FIG. 3 shows a waveform for explaining the operation of the circuit configured as shown in FIG. 2.
FIG. 4 shows a waveform for explaining the operation of the essential parts of the IC card for transmitting data to a card reader-writer from the IC card.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the invention will be described below with reference to the accompanying drawings.
FIG. 1 schematically shows a configuration of a wireless communication IC card constituting a wireless communication data storing medium according to the present invention.
In FIG. 1, a non-modulated power-supplying carrier f1 (power carrier) emitted from a power carrier transmission antenna la installed in a card reader-writer 1 and a PSK-modulated data signal carrier f1 (data carrier), for example, emitted from a data transmit-receive antenna 1b are transmitted to a wireless communication IC card (hereinafter referred to simply as "the IC card") P.
The card reader-writer 1 is connected with a host computer 3 through a communication line 2 and adapted to operate under the control of the host computer 3. More specifically, when the card reader-writer 1 receives a data signal from the IC card P, the data signal is demodulated and the resulting data is transmitted through the communication line 2 to the host computer 3. Then, the host computer 3 processes the data variously. Also, the transmission data from the host computer 3 is transmitted to the card reader-writer 1 through the communication line 2. The card reader-writer 1 receives the transmission data, which is PSK-modulated, for example, and the carrier is transmitted to the IC card P. The power carrier has a great energy for supplying power F consumed in the IC card. The data carrier, on the other hand, is for supplying a smaller energy than the power carrier.
When the high-frequency electromagnetic field of the two carriers fl, f2 generated from the antennas 1a, 1b of the card reader-writer 1 is applied to an antenna coil 4 in the IC card P, a resonator circuit including the antenna coil 4 and a capacitor 5 develops an AC induction voltage and an AC induction current of a composite wave of the data carrier and the power carrier due to the electromagnetic induction.
This resonator circuit is connected to a rectifier circuit 6, in which the AC voltage is rectified into a DC voltage. Further, the DC voltage is regulated to a constant level thereby to supply a source voltage F for the IC card P.
The composite wave A (hereinafter referred to as "the received wave") of the data carrier and the power carrier received by the antenna coil 4 is applied to an amplitude demodulator circuit 7 and a clock extraction circuit 8.
The amplitude demodulator circuit 7 detects the subcarrier B constituting the amplitude variations of the power carrier extracted at a frequency equal to the sum or difference between the two carriers f1, f2 contained in the composite wave A, and thus outputs a received modulation data on the basis of the subcarrier B.
The received modulation data C output from the amplitude demodulator circuit 7 is applied to a demodulator circuit 9, where the PSK-modulated received data G, for example, is demodulated and output.
The clock extraction circuit 8 extracts a clock signal D of the same frequency as that of a power carrier synchronous with the power carrier f1 contained in the composite wave, and outputs the same signal as a system clock used in the IC card.
A CPU 10 reads the received data G from the demodulator circuit 9 in accordance with the timing of the system clock signal D supplied by the clock extraction circuit 8, and processes the data stored in a data memory 11 as predetermined. The CPU 10 also is adapted to output transmission data H to the card reader-writer 1 as required. In the case where data is transmitted from the IC card P to the card reader-writer 1, the transmission data H is sent to the modulation circuit 12 under the control of a CPU 10.
The modulation circuit 12 subjects the transmission data to PSK-modulation, for example, at a frequency (the same frequency as the subcarrier) obtained by dividing the system clock signal by a frequency divider 13 at a predetermined frequency-dividing ratio, and modulates the frequency signal in phase with the power carrier in accordance with the modulated data. In this way, the load current of the resonator circuit, including the antenna coil 4 and the capacitor 5, is changed thereby to generate a radio wave of the same frequency component as the data carrier f2 from the antenna coil 4.
This radio wave is received by the data transmission antenna 1b arranged in a manner not to be coupled with the power carrier transmission antenna 1a in the card reader-writer 1, and is output in the form of the power carrier amplitude-modulated by the subcarrier. The subcarrier is extracted by the same process as in the amplitude modulation circuit 7 of the IC card P. The data from the subcarrier is demodulated, and in this way, the transmission data H from the IC card P can be easily received.
The foregoing description concerns the case in which the phase relation between the data carrier and the power carrier is moved for PSK (phase shift keying) modulation. The invention, however, is not limited to such a case, but the amplitude shift keying (ASK) modulation can be carried out on the subcarrier by turning on and off the data carrier, or the frequency shift keying (FSK) modulation can be performed by changing the frequency relation between the data carrier and the power carrier. In the description that follows, the PSK (phase shift keying) modulation is taken as an example.
Now, a specific example of the circuit configuration of the essential parts of the IC card P will be explained with reference to FIGS. 2 and 3. FIG. 3 shows a signal waveform for explaining the operation of the circuit configured as shown in FIG. 2.
The rectifier circuit 6, which is the one most extensively used at present, is a bridge rectifier circuit including four diodes 6a, 6b, 6c, 6d configured in a bridge. More specifically, an end of a coupling coil 4 is connected to the junction point 01 between the cathode of the diode 6a and the anode of the diode 6b, and the other end of the coupling coil 4 is connected to the junction point 02 between the cathode of the diode 6c and the anode of the diode 6d. When a high-frequency radio wave is applied to the antenna coil 4, the AC voltage output thereof is rectified by the bridge rectifier circuit 6. A DC voltage thus is obtained from the junction point 03 between the cathode of the diode 6b and the cathode of the diode 6d. The junction point between the anode of the diode 6a and the anode of the diode 6c is grounded. The DC voltage obtained from the junction point 03 is stabilized by the capacitor 6c thereby to supply a predetermined source voltage F.
Assume that the power carrier f1 ((a) of FIG. 3) and the data carrier f2 ((b) of FIG. 3) are emitted from the antennas 1a and 1b of the card reader-writer 1. FIG. 3 shows the case in which the frequency of the data carrier f2 is three-fourths that of the power carrier f1 and the data carrier is phase-modulated at 180° according to the changes of the data.
When the electromagnetic field of the two carriers f1, f2 having these waveforms is applied to the antenna coil 4 in the IC card P, an AC induction voltage and an AC induction current of a composite signal of the data carrier f1 and the power carrier f2 are generated due to the electromagnetic induction in the resonator circuit including the antenna coil 4 and the capacitor 5. This composite wave, i.e., the composite wave A in FIG. 2 assumes a waveform as shown in FIG. 3c, for example.
The received wave A as shown in (c) of FIG. 3, when applied to the amplitude demodulator circuit 7, is supplied first to an envelope detection circuit including a diode 7a, a resistor 7b and a capacitor 7c, where upon detection of the envelope from the received wave A, the subcarrier B is detected. The frequency of the subcarrier B (the subcarrier observed at the junction point between the cathode of the diode 7a, the terminal of the resistor 7b not grounded and the terminal of the capacitor 7c not grounded) output from the envelope detector circuit is the difference between the frequency of the power carrier f1 and the frequency of the data carrier f2, i.e., one-fourth the frequency of the power carrier. The subcarrier B thus assumes a waveform as shown in (c) of FIG. 3, for example.
In the case of PSK modulation, the phase of the data carrier f2 changes with the data. Since the power carrier f1 is not modulated, the phase of the subcarrier B changes with the phase of the data carrier f2. This indicates that the subcarrier B is said to be a PSK-modulated wave obtained by extracting the amplitude change of the power carrier f1.
The subcarrier B output from the envelope detector circuit is applied through a resistor 7e to a non-inverted input terminal of an operational amplifier. 7d on the one hand and also to an inverted input terminal of the operational amplifier 7d through a low-pass filter including a resistor 7f and a capacitor g. The output of the operational amplifier 7d, on the other hand, is positively fed back through a resistor 7h.
The low-pass filter is for determining an average E of the amplitude of the subcarrier B.
In the comparator circuit of this configuration, the amplitude of the frequency component of the difference between the power carrier f1 and the data carrier f2, i.e., the amplitude of the subcarrier B of a frequency one-fourth that of the power carrier f1, is compared with the amplitude average value E thereby to detect the amplitude change of the power carrier f1.
The clock extraction circuit 8 is supplied with the received wave A as shown in (c) of FIG. 3, which is applied to the gate terminal of a transistor 8a. The source terminal of the transistor 8a is grounded, and the drain terminal thereof is connected to a predetermined voltage. The output from the drain terminal of the transistor 8a is connected to the input terminal of an inverter circuit 8c. As a result, a system clock signal D ((e) of FIG. 3) equal to the frequency of the power carrier f1 is output from the output terminal of the inverter circuit 8c.
Now, the amplitude of the received wave A considerably changes with the frequency of the power carrier f1, and so does the amplitude of the subcarrier B with the frequency of the power carrier f1. This sometimes makes it difficult to retrieve the subcarrier B unless the frequencies of the subcarrier B and the power carrier f1 are a sufficient distance from each other. In other words, in (c) of FIG. 3, the subcarrier B assumes a value smaller than the average E under the effect of the power carrier f1 in spite of the fact that it assumes a normal data value at point x or y. At point x and y, therefore, the demodulation operation leads to an operating error. On the other hand, no operating error occurs at point z, etc. where the adverse effect of the power carrier f1 is small.
In order to remove the effect of the power carrier f1, a flip-flop circuit 20 detects an amplitude change point of the power carrier f1 by comparing the amplitude of the subcarrier B with the average thereof at a timing of the system clock signal D in phase with the frequency of the power carrier f1, i.e., at a period in phase with the power carrier. In this way, the data can be demodulated by the comparison process at a timing free of the effect of the power carrier f1.
As a consequence, the flip-flop circuit 20 (C on FIG. 2) can produce a received data C (received modulated data) PSK-modulated which turns on and off with the change of the data, as shown in (e) of FIG. 3. The intensity of the subcarrier B is determined from the ratio between the amplitude of the power carrier f1 and the amplitude of the data carrier f2. In the case where the amplitude demodulator circuit 7 is configured as shown in FIG. 2, however, the amplitude change of the power carrier with the data change can be easily detected even when the intensity of the data carrier f2 is 1/10 or less the intensity of the power carrier f1, for example.
The received modulated data C output from the amplitude demodulator circuit 7 is applied to the demodulator circuit 9.
Now, the operation of the essential parts of the IC card P at the time of transmitting data from the IC card P to the card reader-writer 1 will be explained with reference to the waveform diagram of FIG. 4.
The data H ((b) of FIG. 4) transmitted from the IC card P to the card reader-writer 1 is applied to the modulator circuit 12 under the control of the CPU 10.
The modulator circuit 12 is supplied with a frequency signal obtained by dividing the system clock signal D at a predetermined dividing ratio (1/4) in the frequency divider 13 in such a manner that the system clock signal D has the same frequency as the period of the subcarrier B. The transmission data H is phase-modulated at 180° with this frequency. As a result, a modulated transmission data as shown in (c) of FIG. 4 is obtained. On the basis of this modulated transmission data, the load current of the resonator circuit including the antenna coil 4 and the capacitor 5 is controlled ((d) of FIG. 4) in such a manner as to change at a period of the subcarrier one fourth that of the power carrier ((a) of FIG. 4). Then, the radio wave of the same frequency component as the data carrier f2 is generated from the antenna coil 4.
When this radio wave is received by the data transmission-receiving antenna 1B of the card reader-writer 1, the power carrier f1 is output in the form amplitude-modulated by the subcarrier B of the transmission data H. In the case where the subcarrier B is extracted by the same process as in the amplitude demodulator circuit 7 of the IC card P and the data is demodulated from the subcarrier B, on the other hand, the transmission data from the IC card can easily be received as in the preceding case.
As explained above, according to this embodiment, the power carrier f1 and the data carrier f2 having different frequencies are received by a single antenna coil 4 at the same time, and the received wave A is rectified by the rectifier circuit 6 thereby to supply the DC voltage F. At the same time, the amplitude demodulator circuit 7 detects the subcarrier B representing the amplitude variations of the power carrier extracted at the period of a frequency equal to the difference between the two carriers from the received wave. The amplitude of the subcarrier B is compared with the average amplitude E of the subcarrier at a period D (timing of the system clock signal) in phase with the power carrier. The amplitude change point of the power carrier thus is detected thereby to output the received modulated data C. This modulated data C is demodulated to produce the received data. As a result, the data can be transmitted and received in stable fashion by the data carrier without any filter large in attenuation for removing the effect of the power carrier from the data carrier even in the case where the frequencies of the two carrier waves are proximate to each other.
Also, when detecting the amplitude change point of the power carrier, the result of comparison made between the amplitude of the subcarrier B and the average amplitude E thereof at a timing synchronous with the power carrier f1 is output as a received modulated data. In this way, the effect of the power carrier is reduced, so that stable data transmission and reception become possible even in the case where the data change is sufficiently small as compared with the intensity of the power carrier or even in the case where the frequencies of the two carrier waves are proximate to each other.
Although the embodiment described above refers to the case in which the envelope of the received wave is detected to detect the subcarrier and the subcarrier frequency is equal to the frequency difference between the power carrier and the data carrier, the invention is not limited to such a case, but the sum frequency of the two carrier waves may be used instead. In this case, a different circuit is used for detecting the subcarrier in the amplitude demodulator circuit 7. The amplitude change of the power carrier is detected from the detected subcarrier, however, on the same principle as in the above-mentioned embodiment.
The embodiment described above refers to the case of PSK-modulation. Instead, the principle is the same for the ASK or FSK modulation, except for the modulation-demodulation operation.
It will thus be understood from the foregoing description that according to the present invention, there is provided a wireless communication data storing medium and a wireless communication data transmission method, in which the data C can be transmitted and received in stable fashion even when the power carrier f1 and the data carrier f2 are received at the same time.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative devices, and illustrated examples 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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A wireless communication data storing medium capable of effectively receiving carrier waves of different frequencies proximate to each other. A composite wave of a first carrier for supplying a source voltage and a second carrier for transferring data is received by a circuit. The composite wave is rectified to generate the source voltage, which is supplied to the internal circuits of the medium from a circuit. On the basis of the composite wave, an amplitude change corresponding to the data transferred by the second carrier is detected by a circuit. The data is extracted by a circuit on the basis of the amplitude change.
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FIELD OF THE INVENTION
[0001] The invention relates to a coating powder based on chemically modified suboxides of titanium of the general formula: Ti n-2 Me 2 O 2n-1 for use in various coating methods including thermal spray technologies such as plasma spraying, high velocity oxy-fuel spraying (HVOF) and detonation spraying, as well as other coating methods using lasers and hybrid coating methods. By means of such coating methods the inventive coating powder can be applied to different components. The resulting coatings excel in providing high resistance to wear, oxidation and corrosion, high electroconductivity and good solid lubricating properties. Parts coated with the inventive powder are useful as functional components of fuel cells, in electrochemical installations, in the motor vehicle industry, mechanical engineering and other industries.
BACKGROUND OF THE INVENTION
[0002] Coating powders based on titanium suboxides have been described, together with a detailed description of the prior art, in DE 100 00 979 (to avoid repetitions, in this passage reference will be had only to said description). Such powders are characterized by the fact that in the formula Ti n O 2n-1 , “n” has a narrow range of n±2 or narrower and the coating powder particles have a particle size in the range of 10-90 μm. But it has been found in experiments with coatings sprayed from such powder, despite having an oxygen deficit compared to TiO 2 , a disturbing partial oxidation is unavoidable in the coating process. In addition the planar defects typical of the titanium suboxides of the formula Ti n O 2n-1 (Magneli phases) could not be transmitted to the thermally sprayed coatings (Berger L.-M., Thiele S., Nebelung M., Storz O., Gasthuber H., Spray Powders and Coatings on the Basis of Titanium Suboxides; in: Thermal Spray 2001; New Surfaces for a New Millennium, Proceedings of the International Thermal Spray Conference, 28-30 May 2001, Singapore, Ed.: C. C. Berndt, K. A. Khor, E. F. Lugscheider; Materials Park/Ohio; ASM International, 2001, p. 291-300).
[0003] One object of this invention is to provide coating powders based on suboxides of titanium having the structure of Magneli phases and which excel in resistance to oxidation and in which the planar defect structure of the Magneli phases can be transmitted to the coatings independently of the coating technique.
[0004] Another object of this invention is to provide a coating powder of the kind mentioned from which can be prepared coatings which excel in superior electroconductivity, solid lubricating properties and resistance to wear.
SUMMARY OF THE INVENTION
[0005] The foregoing and other objects of the invention are provided by the coating powder 15, based on chemically modified titanium suboxides having a defined defect structure, wherein the powder is modified by at least one metallic alloying element and described by the general formula: Ti n-2 Me 2 O 2n-1 .
[0006] Independently of their preparation it is common to all inventive coating powders that they are modified by at least one metallic alloying element and can be described by the general formula: Ti n-2 Me 2 O 2n-1 . The coating powders advantageously contain one or more other alloying elements which stabilize separate phases of the general formula: Ti n-2 Me 2 O 2n-1 or are inert.
DETAILED DESCRIPTION OF THE INVENTION
[0007] Titanium suboxides with planar defect structures (Magneli phases with the general formula Ti n O 2n-1 ) can also be described as homologous series by the formula: x TiO 2 *Ti 2 O 3 . They easily can be synthesized, in addition to the methods mentioned in DE 100 00 979, by a solid state reaction starting from mixtures of different molar ratios of TiO 2 and Ti 2 O 3 . Ti 2 O 3 can be replaced in this reaction by a multiplicity of other trivalent metal oxides. But in the present state of the art there exist only a few trivalent metal oxides in which the reaction products have the structure of Magneli phases. This particularly refers to Cr 2 O 3 and V 2 O 3
[0008] Modified titanium suboxides with the structure of Magneli phases which are described by the general formula: Ti n-2 Cr 2 O 2n-1 with n>4 can easily be prepared by solid state reaction of starting mixtures of different molar ratios of TiO 2 and Cr 2 O 3 . Pure titanium suboxides with the structure of Magneli phases are formed by reaction of TiO 2 and Ti 2 O 3 only when the reaction is carried out in an inert atmosphere such as in argon. Prior to the present invention, Magneli phases of the structure Ti n-2 Cr 2 O 2n-1 with n≧4 prepared formed in air. This means that such phases are oxidation resistant and thus do not have the serious disadvantages of the pure titanium suboxides with the structure of Magneli phases. The phase Ti n-2 Cr 2 O 2n-1 with n=3 (TiCr 2 O 5 ) forms only when stabilized by other alloying elements such as aluminum. Other alloying elements can have a stabilizing effect upon all phases of Ti n-2 Cr 2 O 2n-1 .
[0009] Modified titanium suboxides with the structure of Magneli phases which can be described by the general formula: Ti n-2 V 2 O 2n-1 where n≧3, can also easily be prepared by using vanadium, for example, by the method mentioned in U.S. Pat. No. 5,049,537. But the toxicity of V 2 O 3 and vanadium oxides of different valence of the vanadium requires increased cautionary steps in the synthesis of the Magneli phases during the preparation of the coating powders and in the processing thereof by thermal spraying.
[0010] It is also advantageous if “n” comprises in the formula Ti n-2 Me 2 O 2n-1 a range of n±2. In case of strict requirements regarding the material it is possible, observing narrower technological parameter limits in the preparation, to implement a narrower range of n±1. In case of n<5 it is possible that in the coating powder there exist only phases which correspond to a discrete value for “n”. This means that the coating powder is monophasic when for “n” is known only one phase. When several phases are known for a discrete “n”, they can exist side-by-side. Due to the continuously smaller differences in the oxygen contents with increasing “n”, the coating powders with n≧5 can be prepared in a manner that there exist together with the desired phase with “n” a second phase n+1 or n−1.
[0011] It is advantageous that the coating powder has a particle size in the range of 10-90 μm. In case of special requirements the coating powder also can have a particle size in the range of 10-45 μm.
[0012] The inventive coating powders can have different properties relative to their porosity and their morphology and can be prepared in different ways. A preferred variant consists in a synthesis carried out via a solid state reaction of homogeneous starting mixtures of finely dispersed titanium dioxide powder and trivalent metal oxide powder, preferably Cr 2 O 3 and V 2 O 3 , of different molar ratios. The homogeneous starting mixtures can contain the other alloying elements, for example, in the form of oxides. But there are still multiple other possibilities of doping, metal powders or compounds of the alloying element which dissociate to form oxides can also be used. After the solid state reaction, an additional reduction with a solid or gaseous reduction agent can follow. Based on the different synthesis processes, there can be prepared finely disperse powders according to the formula Ti n-2 Me 2 O 2n-1 , preferably Ti n-2 Cr 2 O 2n-1 and Ti n-2 V 2 O 2n-1 which advantageously have a grain size <5 μm. After the synthesis, the suboxide Ti n-2 Me 2 O 2n-1 optionally can be ground and the grain size can be reduced.
[0013] The coating powder from the synthesized powders of the composition Ti n-2 Me 2 O 2n-1 preferably is produced by agglomeration, sintering and fractionizing according to the process steps described in DE 100 00 979 without changing its phase composition. Spray drying is the preferred method for agglomeration. In one process variant the starting oxides TiO 2 and Cr 2 O 3 are sprayed together in the necessary ratio and by reaction sintering the corresponding Magneli phases are obtained in the sintered coating powder. Another possibility of preparation consists of preserving, during the sintering of the coating powder, the phase composition of the previously synthesized powders. This is done, for example, by changing the sintering temperature in relation to the synthesis temperature. During sintering the grain size of the primary individual grains does not change or changes only slightly. The grain size of the individual grains sintered together in the coating powder particles preferably amounts to <5 μm. Usually no more than about 15% of the sintered coating powder particles are below the particle size range sought, and such value can be sharply reduced when needed by repeated fractionizing. Together with the existence of only one phase or of a narrow range of “n” in Ti n-2 Me 2 O 2n-1 in the phase composition, these coating powders advantageously excel in spheric morphology and have a porosity above about 3%, preferably above about 10%, among other properties.
[0014] The porosity of the coating powders is determined by mercury porosimetry. In the calculation of the porosity the intruded volume at a pressure corresponding to a pore diameter of >1 μm is not taken into account, since the mercury is pressed into the cavities between the individual particles of coating powder. Due to the porosity and the fine individual particles these coating powders are also characterized by specific surface areas >1 m 2 /g .
[0015] Another possible process for preparation of the inventive coating powders consists in the synthesis of Ti n-2 Me 2 O 2n-1 directly during the preparation of the coating powder by other methods such as fusing and crushing or sintering and crushing. Such coating powders easily can be further reduced with a gaseous reduction agent. At the same time the morphology, particle size and particle size distribution of the starting powder is substantially retained. These coating powders also can have a different morphology such as angular morphology and a porosity of <10%, preferably <5%.
[0016] The inventive coating powders can be processed to form coatings with different surface technologies. They are especially suitable for thermal spray processes, such as, for example, plasma spraying, high velocity oxy-fuel spraying (HVOF) and detonation spraying, as well as other coating methods using lasers and hybrid coating methods. In the coatings no changes or only few are detectable in the chemical and phase composition in comparison with the coating powder. Specially when using Ti n-2 Cr 2 O 2n-1 there are no oxidation processes and thus no changes in the chemical and phase composition. The structure of the Magneli phases can be transmitted from the coating powder to the coating.
[0017] The coatings preferably are used as electrically conductive ceramic coatings which at the same time exhibit great mechanical resistance to wear and corrosion. They also can be used as solid lubricants and wear protection coatings. When the coatings are formed porous by selecting suitable coating parameters, they also are suitable for use as electrode coatings.
[0018] The inventive coating powder will now be described in detail in the following non-limiting example.
EXAMPLE
[0019] 2 moles of a finely dispersed titanium dioxide powder and 1 mole of a finely dispersed chromium oxide powder Cr 2 O 3 are intimately intermixed by grinding in a ball mill, compacted by pressing and brought to complete reaction (holding time 4 hours) in a furnace under air at 1380° C. A single-phase Ti 2 Cr 2 O 7 or in other words 2TiO 2 *Cr 2 O 3 is formed. The powder is ground in a planetary ball mill into a finely dispersed state to a average grain size of 3.9 μm. The powder is then dispersed in water and ground in a ball mill for 16 hours, during which process the suspension is simultaneously mixed with 1.5 mass % of a binder consisting of polyvinyl alcohol and polyethylene glycol. Then granulated material of spherical shape was produced by spray drying. The release of the binder and sintering of the granulated material to form the coating powder takes place in a one-step annealing in flat graphite crucibles under argon at a heating rate of 5 K/min up to 600° C. K/min and a rate of 10 K/min until the sintering temperature of 130° C. with an isothermal holding period of 30 min. The sintered powders then were subjected to a careful grinding. The >45 μm fraction was separated by sieves, the <10 μm fraction by air sieving. The fine portion of the powder smaller than <10 m amounted to 4% after fractionizing.
[0020] It was detected by X-ray phase analysis that the phase composition of the coating powder had not changed in comparison with the finely dispersed starting powder. The particle size distribution of the coating particles was measured by aid of a laser diffraction measuring apparatus by means of dry dispersion. The measurement resulted in the characteristic granulometric values d 10 of 15 μm, d 50 of 28 μm and d 90 of 43 μm. The inner open porosity of the coating powder was determined at 11% by means of mercury porosimetry. In the calculation of the porosity the intruded volume at a pressure corresponding to a pore diameter of >1 μm was not taken into account, since the mercury is pressed into the cavities between the individual particles of coating powder. The specific surface area of the powder amounted to 1.5 m 2 /g.
[0021] The coating powder was subsequently applied to a steel substrate roughened by sand blasting immediately before the spraying by atmospheric plasma spraying (APS), using argon/hydrogen plasma with a power of 42 kW under gaseous flows of Ar 45 μ/min and H 2 10 1/min (each under standard conditions). The spraying distance was 110 mm and the powder feed rate was 35 g/min. A coating thickness of about 330 μm was obtained. In the sprayed coating Ti 2 Cr 2 O 7 was detected by X-ray phase analysis.
[0022] Various changes may be made in the above described invention without departing from the spirit and scope thereof.
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A coating powder based on chemically modified titanium suboxides is described. Coatings produced by using the inventive coating powder exhibit high electroconductivity, good solid lubricating properties and resistance to wear. For these reasons, there are possibilities of use for components with such coatings, especially as functional components in fuel cells, in electrochemical installations, in the motor vehicle industry, in mechanical engineering and in other industries. The inventive coating powder based on titanium suboxides having a defined defect structure is characterized in that it is modified by at least one metallic alloying element and described by general formula: Ti n-2 Me 2 O 2n-1 .
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BACKGROUND OF THE INVENTION
The field of this invention is display signs and in particular, signs having a channel mount that conceals a substantial portion of cooperating removable information panels.
DESCRIPTION OF THE PRIOR ART
Signs having changeable elements, eg. panels, tags, etc. that cooperate with a mounting member by engaging the periphery of the element with flanges that define the channel are well known. For example, see U.S. Pat. Nos. 3,081,568; 4,179,138. Such devices are particularly useful for displaying information that is subject to periodic change, eg. prices and the like.
A long standing problem with such signs is that a separate element for each piece of information must be provided and separately stored when not in use.
SUMMARY OF THE INVENTION
The present invention provides a display device having a self-storing changeable message which comprises a mounting member having two opposing flanges defining a channel therebetween and a cooperating display element having information thereon. The display element is adapted to engagement with said flanges and at least one said flange covers a selected portion of the information on said display element. In one embodiment the display element is a foldable resilient sheet preferably having three segments each segment having two sides provided with information thereon. When this element is inserted in the channel member only about one half of the information on one side of a segment is visible and the remaining information on that segment is concealed by an extended portion of a flange.
It is an object of the present invention to provide a display device having easily changeable self-storing information elements.
It is a further object of the present invention to provide an inexpensive, easily manufactured display device.
It is a further object of the present invention to provide a display device which at all times is entirely self-contained eliminating need for separate indexed or compartmented box of extra display elements, eg. numerals and tabs, to make up price changes.
BRIEF DESCRIPTION OF THE DRAWING
With the above and other incidental objects in view as will more fully appear in the specification, the invention intended to be protected by Letters Patent consists of the features of construction, the parts and combinations thereof and mode of operation as hereafter described or illustrated by the accompanying drawings, or their equivalents.
Referring to the drawings wherein some but not necessarily the only forms of the present invention are illustrated.
FIG. 1, is an isometric view of a foldable display element having three segments.
FIG. 2, is an isometric view of the display element of FIG. 1 folded.
FIG. 3, is an isometric view of a channel member having a folded display element inserted therein.
FIG. 4, is an isometric view of a alternate embodiment of the present invention having cooperating channel elements.
FIG. 5, is an isometric view of the reverse side of the display element of FIGS. 1 and 2.
Like parts are indicated by the same reference numerals throughout the drawings.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The element of the present invention illustrated in FIGS. 1,2,3 and 5 comprises a display element 10 formed from a sheet, preferably resilient sheet, having three foldable segments 12, 14, and 16 each provided with information, ie. numerals, printed on both sides thereof. The two creases 18 and 20 that divide segments 12, 14, and 16 bend when the resilient sheet 10 is folded as shown in FIG. 2 and openings 22 and 24 are optionally provided along the creases 18 and 20 to add flexibility to the hinge formed by bending and render a flatter folded form 28. Many modern plastic materials may be bent or folded, as contemplated, many thousands of times without cracking or breaking. It will be appreciated that the number of segments per display element can be varied from one up to several depending on the thickness of the resilient sheet 10 and dimensions of the mounting member 30. The mounting member 30 defines a channel 31 boarded by first and second flanges 32 and 34, respectively. The flange members 32 and 34 engage portions of the periphery of folded display element 28 when it is seated in the channel 31. The outer extended portion 36 of first flange 32 extends downwardly covering approximately one-half of the exposed surface 17 of segment 16 so that only the single numeral six of the seated display element 10 is visible. If the display element 10 is inverted only the numeral five will be seen; if reversed, either the numerals seven or eight appear on the reverse side, shown in FIG. 5, and so on so that each numeral may be individually displayed. It will be appreciated that other information including any symbol or pictorial, eg. letters of the alphabet, words, dollar & cents signs etc. may be substituted for the numerals, in the above example, and that a plurality of display elements in a single mounting member may cooperate to display any desired message. It will be appreciated that the entire alphabet and the numerals zero thru nine can be put on three reversible strips having three segments each. Moreover, a blank portion of one or more segments may be provided so that the display element may be stored in channel 31 without displaying any information. It will be appreciated that the display elements may be easily modified to fit in a cooperating channel with its creases orientated vertically rather than the horizontal orientation shown in the drawings.
Preferably, each of the exterior surfaces of the flanges 32 and 34 are provided with a pair of cooperating flanges 40 40' and 42, 42' defining a simple channel that is adapted to accommodate in any known manner, conventional type display elements 41 and 43 having a message or portion thereof on at least one side.
The embodiment illustrated in FIG. 4 utilizes the same type display elements described above and the structure of the mounting element 50 is modified so that two or more such modified elements 50 cooperate with each other to form a structure that otherwise functions in the same manner as the previously described embodiment. Mounting element 50 is provided with a flange 52 on its forward surface for receiving the periphery 29 of the display element 64 seated therein. The opposite or rearward side of the modified mounting element 50 is provided with a specially adapted shoulder 54 the lower portion of which defines a seat for the upper rearwardly inclined portion 58 of a second element 50'. The rearwardly inclined upper portion 58 of first element 50 and the lower portion 60 of a second cooperating element 50' define a flange-like pocket 62 that functions in substantially the same manner as the extended portion 36 of flange 32, described above. That is, it secures portions of the periphery of the folded display element 64 and conceals approximately half of its exposed surface so that only a selected portion of the information thereon is visible.
From the above description, it will be apparent that there is thus provided a device of the character described possessing the particular features and advantages described herein, but which obviously is susceptible of modification in its form, proportions, details of construction and arrangement of parts without departing from the principle involved or sacrificing any of its advantages.
While in order to comply with the statute the invention has been described in language more or less specific as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein disclosed comprise but a few of several modes of putting the invention into effect and the invention is therefore claimed in any of its forms or modifications within the legitimate and valid scope of the appended claims.
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This invention relates to a display device having a self storing changeable message appearing on a display element that may be folded for insertion into a mounting member having two opposing flanges defining a channel and when the display element is engaged with the channel a selected portion of message printed thereon is displayed.
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BACKGROUND OF INVENTION
This invention pertains to new alkylbenzoylbenzofurans and more particularly to new 2-alkyl-3-[4-(omega-N,N-dialkylaminoacylamino)-3,5-dialkylbenzoyl]benzofurans useful for treating cardiac arrhythmia, as well as pharmaceutical compositions containing these benzofurans and the method of treating cardiac arrhythmia therewith.
Cardiac arrhythmia is an important cause of death following myocardial infarction or from other cardiac pathology. Heretofore, drugs used to control this disorder such as quinidine, lidocaine and procainamide have manifested significant drawbacks. According to Goodman and Gilman, The Pharmacologic Basis of Therapeutics, 7th edition, pp.761-770, "About one third of the patients who receive quinidine will have immediate adverse effects that necessitate discontinuation of therapy . . . Procainamide is useful for the treatment of a variety of arrhythmias, and it can be administered by several routes. Unfortunately its potency and versatility are marred by its short duration of action and high incidence of adverse reactions when it is used chronically . . . Lidocaine has a narrow antiarrhythmic spectrum . . . The main adverse effects are on the central nervous system . . . Higher concentrations may cause decreased hearing, disorientation, muscle twitching, convulsions or respiratory arrest."
The great need for improved antiarrhythmics is evident.
SUMMARY OF THE INVENTION
An object of this invention is the provision of new compounds which have improved antiarrhythmic activity.
A particular object of this invention is the provision of new 2-alkyl-3-benzoylbenzofurans which have improved antiarrhythmic activity.
A further object of this invention is the provision of new pharmaceutical compositions useful for treating arrhythmia.
Another object of this invention is the provision of a new and improved method for treating arrhythmia.
These objects and others which will become evident from the description below are accomplished by our discovery of new 2-alkyl3-benzoylbenzofurans of the following formula (I) ##STR1## wherein R is an alkyl group containing 2 to 4 carbon atoms,
R 1 is an alkyl group containing 1 to 4 carbon atom,
R 2 and R 3 are each an alkyl group containing 1 to 3 carbon atoms and
n is an integer of 1 or 2 and
pharmaceutically acceptable salts thereof.
We have found that compounds of formula (I) display highly significant antiarrhythmic activity and thus provide an improved method for the treatment of arrhythmia.
DESCRIPTION OF THE INVENTION
Compounds of formula (I) wherein R is C 2 H 5 , n-C 3 H 7 , and n-C 4 H 9 are preferred, as are compounds of formula (I) wherein R 1 is CH 3 , C 2 H 5 , i-C 3 H 7 and t-C 4 H 9 . Another group of preferred compounds are those wherein R 2 and R 3 are both C 2 H 5 .
The preparation of compounds of formula (I) of the invention can be accomplished according to the following series of reactions. ##STR2## wherein R, R 1 , R 2 , R 3 and n are as defined above.
To prepare 2,6-dialkyl-alpha-chloroacetylanilide (II) where n=1 or 2,6-dialkyl-beta-chloropropionylanilide (II) where n=2 shown in step A, chloroacetyl chloride or beta-chloropropionyl chloride is reacted with a 2,6-dialkylaniline in an inert solvent such as a lower fatty acid or lower fatty acid ester, as described for example in U.S. Pat. No. 2,441,498.
The dialkyl-chloroacylanilide (II) is then reacted with a secamine in a refluxing hydrocarbon solvent as shown is step B. This reaction has also been described in the above-noted U.S. Patent. After separation and purification, the 2,6-dialkyl-omega-N,N-dialkylaminoacylanilide product (III) is obtained.
As shown in step C, compound (I) of the invention is obtained by reacting 2-alkylbenzofuran-3-carboxylic acid chloride (IV) with 2,6-dialkyl-omega-N,N-dialkylaminoacylanilide (III). This reaction is carried out in an inert solvent by means of a Friedel-Crafts system with a Lewis acid catalyst.
Compounds of the invention have improved antiarrhythmic activity. For example, 2-ethyl-3-[4-(N,N-diethylaminoacetylamino)-3,5-dimethylbenzoyl]benzofuran, (the compound of formula (I) wherein R=C 2 H 5 , R 1 =CH 3 , R 2 and R 3 =C 2 H 5 and n=1), when compared with lidocaine in a rat coronary ligation model, displayed superior activity in suppressing both ventricular fibrillation and ventricular tachycardia, and was comparable in promoting survival of challenged animals. Thus, compounds of formula (I) can provide an improved level of antiarrhythmic activity together with diminished side effects.
The antiarrhythmic compounds of formula (I) can be formulated for use by the oral or parenteral routes. Acute emergency treatment would normally employ an intravenous form containing as an active agent, a pharmaceutically acceptable salt such as the hydrochloride, sulfate, phosphate, etc. in an aqueous vehicle compatible with body fluids. The sterile, isotonic solution for such use is comprised of the soluble salt of the active drug in citrate, phosphate or other physiological acceptable buffer in the pH range of 4.0-7.0. Preservatives such as benzyl alcohol, methyl "Parabens" or propyl "Parabens", esters of p-hydroxybenzoic acid sold by Napp Chemicals, may be used, particularly in multiple dose formulations, to maintain sterility. Typical intravenous or intramuscular preparations may contain from 10-100 mg. of active compound, calculated as base, per ml. of solution. Administration of 0.5-10 mg. of active compound per kg. of patient body weight by the I.V. or I.M. route every 6-8 hours is continued until a satisfactory cardiac rhythm is established.
Chronic therapy is customarily maintained by means of oral tablets or capsules containing 10-200 mg. of a compound of formula (I) per dose. As is usual in this art, the active compound is admixed with excipients such as lactose, starch, "Avicel" or the like, together with lubricants and dispersants such as stearic acid, magnesium stearate, silica, etc. in amounts necessary to confer appropriate disintegration and dissolution properties to the dosage form.
The usual antiarrhythmic maintenance dose will be in the range of 1-100 mg. of active compound per kg. of patient body weight daily, delivered in 3 to 4 divided doses or in a single sustainedrelease dose.
The following examples further illustrate the invention but must not be construed to limit the invention in any manner.
EXAMPLE 1
Step A. Preparation of N-Acylaminoanilide (II) by Reaction of 2.6-Dialkylaniline with omega-Chloroacyl Chloride
One mole of 2,6-dimethylaniline is dissolved in 800 ml. of glacial acetic acid. The mixture is cooled to 10° C., after which 1.1 mole of alpha-chloroacetyl chloride is added rapidly. The mixture is agitated vigorously for two minutes, whereupon 1000 ml. of aqueous sodium acetate (250 g. of sodium acetate per liter of water) is added rapidly with continuous agitation. Agitation is continued for one-half hour; the precipitate which has formed is separated by filtration, washed with water and dried carefully in vacuo at 50° C. The yield of 2,6-dimethyl-alpha-chloroacetanilide is 70-80% of the theoretical.
Following the same procedure, 2,6-diethylaniline, 2,6-diisopropylaniline or 2,6-di-tert-butylaniline is caused to react with alpha-chloroacetyl chloride to yield the corresponding alphachloro-2,6-dialkylacetanilide of formula (II).
Likewise any aniline identified above is caused to react with beta-chloropropionyl chloride to provide the corresponding betachloro-2,6-dialkyl-propionanilide of formula (II).
EXAMPLE 2
Step B. Preparation of N,N-Dialkylaminoacyl-2,6-dialkylanilide (III) by Reaction of omega-Chloroacyl-2,6-dialkylanilide (II) with a sec-Amine.
One mole of alpha-chloroacetyl-2,6-dimethylanilide and 3 moles of diethylamine are dissolved in 1000 ml. of dry benzene. The mixture is heated at reflux for 4 hours. The precipitated diethylamine hydrochloride is separated by filtration and the benzene solution is washed with 3 N hydrochloric acid twice (600 ml. each time). The aqueous acid extracts are made strongly basic by the addition of 30% aqueous sodium hydroxide. The resulting oily precipitate which separates is taken up in diethyl ether (1 liter), the ether phase is dried over anhydrous potassium carbonate, and the resulting dry, filtered ether solution is distilled. Following distillation of the ether at atmospheric pressure, the remainder of the fractionation is carried out in vacuo at about 2 mm. Hg. pressure. The product, alpha-diethylamino-2,6-dimethyl-acetanilide boils at about 159° 160° C. at 2 mm. Hg. It crystallizes in the receiver and the crystalline product melts at 68°-69° C. The yield is 95% of theoretical.
Using the same procedure, each of the three other alpha-chloro-2,6-dialkylacetanilides prepared as in Example 1 is caused to react with diethylamine to yield the corresponding alpha-diethyl-amino-2,6-dialkylacetanilide of formula (III).
Using the the same procedure, each of the four beta-chloropropionyl-2,6-dialkylanilides prepared according to Example 1 is caused to react with diethylamine to provide the corresponding beta-diethylaminopropionyl-2,6-dialkylanilide of formula (III).
When dimethylamine or dipropylamine is employed in this example, in place of diethylamine, the corresponding dimethylamino or dipropylamino product of formula (III), wherein both R 2 and R 3 are either CH 3 or C 3 H 7 , respectively, results.
EXAMPLE 3
Step C. Preparation of 2-Alkyl-3-[4-(omega-N,N-dialkylaminoacylamino)-3,5-dialkylbenzoyl]benzofuran (I) by Friedel-Crafts Acylation of the Anilide (III) with 2-Alkyl-3-benzofuroyl Chloride (IV)
2-Ethylbenzofuran-3-carboxylic acid chloride (0.45 g.;2.1 m.moles) and alpha-diethylamino-2,6-dimethyl-acetanilide (0.5 g.;2.1 m.moles)are dissolved in 1,2-dichloroethane (10 ml.) and cooled to 0° C. Anhydrous aluminum chloride (0.43 g.;3.2 m.moles) is added all at once and the reaction mixture is agitated for 16 hours at room temperature. The 1,2-dichloroethane solvent is then distilled off in vacuo and 10 ml. of 5 N aqueous hydrochloric acid is added to the residue. The resulting mixture is agitated for 30 minutes, made basic with aqueous sodium hydroxide and then extracted three times with 20 ml. portions of ethyl acetate. The ethyl acetate extracts are dried over anhydrous potassium carbonate and concentrated to a residue. The residue is taken up in a small volume of ethyl acetate and column chromatographed over 100 g. of anhydrous magnesium silicate. The column is eluted with hexane and mixtures of hexane and ethyl acetate, progressively enriched with ethyl acetate in the manner of gradient elution. Homogeneous product fractions, determined by TLC, are combined and crystallized from acetonehexane, affording 53 mg. of 2-ethyl-3-[4-(N,N-diethylaminoacetylamino)-3,5-dimethylbenzoyl]benzofuran (I), wherein R=C 2 H 5 , R 1 =CH 3 , R 2 and R 3 =C 2 H 5 and n=1, which has a melting point of 82°-85° C.
Reacting 2-n-propylbenzofuran-3-carboxylic acid chloride or 2-n-butylbenzofuran-3-carboxylic acid chloride with alpha-diethylamino-2,6-dimethyl-acetanilide (IV) in the same Friedel-Crafts procedure provides the corresponding 2-n-propyl- and 2-n-butylbenzofurans (I).
By reacting 2-ethylbenzofuran-3-carboxylic acid chloride with the dialkylanilide (III), wherein: R 1 =C 2 H 5 , i-C 3 H 7 or t-C 4 H 9 ; R 2 =CH 3 or n-C 3 H 7 and n=1, the corresponding compounds of formula (I) are obtained wherein R 1 and R 2 are as follows:
______________________________________ R.sub.1 R.sub.2 and R.sub.3______________________________________ C.sub.2 H.sub.5 CH.sub.3 C.sub.2 H.sub.5 n-C.sub.3 H.sub.7 i-C.sub.3 H.sub.7 CH.sub.3 i-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7 t-C.sub.4 H.sub.9 CH.sub.3 t-C.sub.4 H.sub.9 n-C.sub.3 H.sub.7______________________________________
Reaction of the corresponding 2-n-propylbenzofuran-3-carboxylic acid chloride or 2-n-butylbenzofuran-3-carboxylic acid chloride (IV) affords corresponding compounds of formula (I) according to the choice of R 1 R 2 and R 3 . Likewise compounds of formula (I) are provided wherein n=2, by reacting in the same manner a 2-alkylbenzofuran-3-carboxylic acid chloride (IV) with a beta-diethylaminopropionyl-2,6-dialkylanilide of formula (III).
EXAMPLE 4
Pharmaceutical Compositions
Injectable Composition for I.V. or I.M. Use
Compound (I)*: 50 mg.
Sodium citrate: 2 mg.
Sodium chloride: 14 mg.
Sterile water: 1 ml.
Tablets, 100 mg.
Compound (I)*: 100.0 mg.
"Avicel" ph 102: 83.35 mg.
Lactose, spray dried: 141.65 mg.
Magnesium stearate: 6.65 mg.
"Cab-O-Sil": 0.50 mg.
Tablets of the above formulation are prepared by blending all ingredients, except magnesium stearate, for 25 minutes, then adding the magnesium stearate and blending until homogeneous. The mixture is compressed into tablets using B/32 in standard concave molding. "Avicel" is a microcrystalline cellulose sold by FMC Corporation, Food & Pharmaceutical Products Division, while "Cab-O-Sil" is colloidal silica produced by the Cabot Corporation.
Tablets, 200 mg.
Compound (I)*: 200.0 mg.
"Avicel" ph 102: 144.0 mg.
Stearic acid powder: 9.0 mg.
Magnesium stearate: 3.2 mg.
Tablets are prepared from the above formulation by blending compound (I) with "Avicel" for 25 minutes, screening in the stearic acid and magnesium stearate and blending for 5 minutes more. The resultant mixture is compressed into tablets using 3/8 inch standard concave tooling.
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New 2-alkyl-3-[4-(omega-N,N-dialkylaminoacylamino)-3,5-dialkylbenzoyl]benzofurans useful for treating cardiac arrhythmia, as well as pharmaceutical compositions containing these benzofurans and the method of treating cardiac arrhythmia therewith are disclosed.
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[0001] This application is a CIP of U.S. application Ser. No. 10/762,743 filed 22 Jan. 2004 entitled Intelligent LED Traffic Signal Modules that claimed the benefit of U.S. Provisional Application No. 60/442,082 filed 23 Jan. 2003.
BACKGROUND OF THE INVENTION
[0002] The present invention related to LED traffic signals. More particularly, it relates to an intelligent self-diagnosing traffic signal that identifies the end of the useful life of the signal.
[0003] 1. Field of the Invention
[0004] 2. Description of Related Art
[0005] Light Emitting Diodes (LEDs) traffic signals usage is wide spread. LEDs offer interesting advantages over incandescent lights. Those advantages include, for example, low power consumption and long life.
[0006] While LEDs last for a very long time (typical meantime between failure or MTBF is in the millions of hours), their light output intensity degrades over time. Manufacturers generally warranty their LED products for a certain period of time (typically 5 years). Depending on the operating conditions, including ambient temperature and signal duty cycle, the signal light output might be satisfactory for a period exceeding the warranty period. Users would like to use the LED signal until it reaches the end of its useful life; however because faulty traffic signals can result in an unsafe road condition, signals are required to have sufficient light output. One approach is to replace all signals upon warranty expiration. However, this results in signals being replaced while there is still significant useful life left in them. Another approach is to have the lamp measured in a lab at and/or after warranty expiration to assess the signal's condition. This only provides information at a particular moment in time and does not provide on-going data about the condition of the lamp. There is a need for an intellig3ent self-diagnosing traffic signal that allows users to make use of the long life of the LEDs without compromising safety.
[0007] U.S. application Ser. No. 10/762,743 is herein incorporated in its entirety. The LED signal has a communication link with a traffic controller. It receives commands and provides feedback information to the traffic controller. In the present invention, the signal is a stand-alone system. The traffic controller feeds voltage, but the signal does not have any additional interface with it.
[0008] U.S. Pat. No. 6,667,623 is also incorporated in its entirety. A system to monitor light output degradation is disclosed. The invention in U.S. Pat. No. 6,667,623 uses a light sensor to detect end of life. The proposed invention compiles a database of the various parameters (temperature, hours of operation, light output etc) in order to more accurately assess the signal's end of life and adjust the LED current to extend the signal's life.
[0009] A prior art method to change the LED current in response to a sensor's output uses a variable load in parallel with the LEDs. In the present invention, there is no variable load; current is directly adjusted by the power supply. One prior art signal utilizes a compensation circuit based on light output feedback from a photosensor. The present invention uses the photosensor feedback primarily in order to detect end of life of the signal and to compensate light output by increasing LED current as long as it is in the permissible range in order to extend the signal's life. The present invention also has communication capabilities.
[0010] An alternative prior art method senses the light output of an extra LED and adjusting the power supply according to the light output generated by the extra LED. The present invention measures the light output for the complete array, calculates the number of hours of operation and determine end of life.
[0011] A prior art system predicts when light output will fall under predetermined threshold. The present invention does not predict but actually shuts down the signals or send an EOL signal when the signal has reached the end of its useful life.
SUMMARY OF THE INVENTION
[0012] The inventive signal addresses the problem of users being unable to fully take advantage of the longer LED life. The inventive signal comprises an intelligent diagnosis system inside the LED signal. The signal can self-extinguish or send a signal through its communication port at the end of its useful life when the LEDs are no longer providing the required light output. The inventive signal also utilizes the fact that LEDs put out more light and need less current at the beginning of their life than they do as they degrade over time. Over time, the LEDs need more current to maintain a given light output as they age. The control module in the LED signal provides a signal that increases the current so that the LED signal can continue to provide sufficient light output.
[0013] In the present invention, the LED signal is a stand-alone system. Voltage is still fed by the traffic controller, but the signal does not have any further interface with it. The inventive signal compiles a database of various parameters, such as temperature, hours of operation, light output etc. in order to accurately assess the signal's end of life and adjust the LED current to extend the signal's life.
[0014] The inventive signal uses a photosensor feedback primarily in order to detect end of life of the signal and to compensate for light output degradation by increasing LED current in order to extend the signal's life. The present invention preferably also has communication capabilities. The inventive signal measures the light output for the complete array, calculates the number of hours of operation and uses the measured data to determine end of life for the signal. The present invention does not predict the end of life, but actually shuts down the signals or send an EOL signal when the signal has reached the end of its useful life.
[0015] The inventive signal addresses the need to utilize the LED signal for its full useful life without sacrificing safety by incorporating intelligent diagnosis system inside the LED signal. The signal can self-extinguish or send a signal through its communication port at the end of its useful life when the LEDs are no longer providing the required light output. This invention will also take advantage of the fact that LEDs put out more light at the beginning of their lifer and need less current. They will need more current to maintain a given light output as they age.
BRIEF DESCRIPTION OF THE FIGURES
[0016] FIG. 1 is a block diagram of the inventive signal.
[0017] FIG. 2 is a schematic of the inventive control module.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The inventive signal is an LED signal, preferably an LED traffic signal, with a control module to measure traffic signal data and using that data determine the useful life of the Led signal.
[0019] FIG. 1 is a block diagram of the LED traffic signal module 10 . LED traffic signal module 10 comprises a power supply 12 regulating current through an LED array 14 . The module further comprises a control module 20 inside the LED signal 10 . Control module 20 performs all the checks, diagnosis and communication functions. An optional portable receiver 16 is to be used by authorized personnel in order to check the lamp status. Control module 20 has a communication link 18 allowing it to communicate with receiver 16 . Receiver 16 preferably has a display. Optionally, receiver 16 can have a speaker or other broadcast capabilities. Receiver 16 can be provided with memory allowing data to be stored and later downloaded in a central location. Display can display one or more pieces of data. Preferably, the display shows Lamp ID 42 , light output status 52 and number of hours of operation 48 .
[0020] Control module 20 is shown in FIG. 2 . Microcontroller 30 samples at a first predetermined rate input voltage 32 and ambient temperature 34 and will compile average input voltage 44 , average ambient temperature 46 and number of hours of operation 48 . Microcontroller 30 also samples at a second predetermined rate output current 36 and light output 38 . Light output 38 is measured by photo sensor or photo diode receiving light from the LED array 14 either directly or indirectly through some other light-collecting device.
[0021] Lamp data 32 , 34 , 36 , 38 will be compiled in a table. Light output status 52 is determined using the lamp data 32 , 34 , 36 and 38 . If light output cannot be maintained any more, the LED signal 10 either self-terminates 66 or sends an end-of-life signal 62 . An example is given in Table 1.
[0022] Lamp ID 42 is an identification given to the lamp 14 for communication purposes. Average input voltage 44 is the average line voltage 32 supplied to the lamp. The input voltage 32 is sampled and average input voltage 44 is calculated and stored in the database or flash memory 40 . Average ambient temperature 46 is the temperature seen by the LEDs 14 inside the signal module 10 . A thermal sensor is fitted on the power supply PCB or on the LEDs PCB and an average temperature 46 is calculated throughout the signal's life. The number of hours of operation 48 is the number of hours of service for the LED array 14 . A counter is incremented to keep track of the signal's life. Output current 36 and light output 38 are compiled over time. Output current 36 is obtained by sampling the LED current and storing the data at a fixed interval. Light output 38 is obtained by sampling the light output with a photo sensor receiving light from the LEDs either directly or indirectly through some other light-collecting device.
[0023] The end of life (EOL) signal 62 is derived by comparing the measured light output 38 sensor with a reference level. The reference level may be set by government regulation, the signals environment or be based on other factors. If light output 36 is lower than the reference level and if output current 36 cannot be adjusted anymore to and if number of hours of operation 48 at the average temperature 46 is higher than the minimum number of hours for a given average temperature, then EOL 62 is enabled. The EOL signal 62 activates an EOL circuit that shuts the signal or sends an EOL signal to receiver 16 , traffic controller or other location or device.
[0024] If the light output 38 has fallen below the reference level and output current 36 is below a maximum current, output current adjust 64 provides a signal that increases output current 36 to maintain a sufficient light output. The turn off signal 66 turns the signal off if input voltage is under 35V.
[0025] Table 1 lists exemplary sampling and refresh rates and operational parameters for the inventive self-diagnosing signal. The sampling rates, refresh rates, and other operational parameters may be selected based on lamp color and/or application. The measured and calculated data is stored in the memory 40 of control module 20 . Lamp ID 42 is preferably assigned at the factory. Input voltage 32 is measured more frequently than every 1 ms and average input voltage 44 is calculated. Ambient temperature 34 is measured more frequently than every 100 ms. Average ambient temperature 46 is calculated. An incremental timer keeps track of the number of hours of operation of the signal, the hours of operation is refreshed more frequently than every 1 ms. Output current 36 and light output 38 are measured after every 168 hours of operation. This LED signal data is used to determine whether to send and EOL signal 62 , output current adjust 64, and/or to send turn-off signal 66 . If the input voltage 32 is less than 35 V turn-off signal 66 is generated. If light output 38 is less than a minimum light output and output current 36 is less than a maximum current, an output current adjust signal 64 is generated. If the hours of operation 48 is greater than a calculated maximum number of hours and/or light output 38 is less than a minimum light output and current exceeds the maximum current, end of life signal 62 is generated. LED signal data including average temperature 46 are used to calculate the maximum number of hours.
TABLE 1 Sampling Variable Rate Method of Determination Lamp ID n/a Factory assigned Average Input <1 ms Average of samples of Input Voltage Voltage Average Ambiant <100 ms Average of samples of Ambient Temperature Temperature Number of hours of <1 ms Increment timer operation Output Current 168 hours Each sample of output current stored in a Table Light Output 168 hours Each sample of light sensor stored in a Table Refresh Control variables Rate Method of Determination End of Life signal 168 hours If (nb of h > (Max h = f(Avg T))) (EOL) AND (Light Output < Min) THEN EOL Output Current 168 hours If (Light Output < Min) AND Adjust (I < Imax) THEN (Increment I) Turn-off n/a If Vin < 35 V
[0026] As the LEDs degrade, the control module in the LED signal provides an output current adjust signal 64 to increase the current so that the LED signal can continue to provide sufficient light output. Once the current no longer be increased, the inventive signal self-extinguishes or sends a EOL signal 62 through its communication port at the end of its useful life when the LEDs are no longer providing the required light output.
[0027] In the present invention, the LED signal is preferably a stand-alone system. Voltage is fed by the traffic controller, but the signal does not have any further interface with it. The inventive signal stores the various measured and calculated parameters preferably in a database to accurately assess the signal's end of life and adjust the LED current to extend the signal's life.
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The inventive signal incorporates an intelligent diagnosis module inside a light emitting diode (LED) signal, such as an LED traffic signal. The inventive signal can self-extinguish or send a signal through its communication port at the end of its useful life when the LEDs are no longer providing the required light output. Additionally, the inventive signal sends a signal to increase the current as the LEDs degrade to ensure the light output is above a threshold minimum.
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CLAIM TO PRIORITY
This application is a National entry application of Indian Application No. 5366/CHE/2012, filed on Dec. 24, 2012, the entire contents of which is incorporated herein by reference.
FIELD OF THE INVENTION
Embodiments of the present disclosure relates to a pneumatic feedback system. More particularly, related to unclamp sensing feedback system for sensing fully unclamped condition of link clamp cylinder used in automatic production lines.
BACKGROUND OF THE INVENTION
In production or manufacturing industries, integration of automatic flow lines or automation to the processes involved in production manufacturing is gaining importance due to improved product quality, high repeatability, high positioning accuracy and operating time reduction. Automation also greatly decreases the need for continuous human intervention while increasing load capacity, speed and safety. Machine safety logic, governs the automation to perform specific operations including clamping and unclamping of the work pieces.
One way of clamping and unclamping the work pieces, is carried out using clamping devices such as link clamp cylinders because the link clamp cylinders takes minimum space requirements as there is no swiveling motion of the clamp lever during clamping and unclamping operations. These link clamp cylinders are operated by displacement of hydraulically or pneumatically actuated piston appropriately linked to the link clamp assembly to facilitate clamping and unclamping operations. The link clamp cylinders are placed in required position in an automation system which can hold work pieces, so that the other components of the automation can carry out their pre-set functions on the work piece. After completion of operations, the work piece is unclamped by the link clamp cylinder. Thus, unclamp sensing becomes important in automation because if the work piece is not properly unclamped, the automation system will move the work piece, which is neither clamped nor unclamped rigidly and may cause serious accident in the shop floor and the operators. Hence automation system without feedback unit has disadvantages, predominant one being vulnerability, which makes the automation more prone to errors or mistakes which will have serious consequences or accidents while operating.
For example, in a gantry system used to pick and place heavy work pieces in a shop floor of an industry. The gantry consists of fixture appropriately mounted on a guide way, to hold the work piece that is to be picked and placed, and machine safety logic to govern the movement of the fixture. The machine safety logic first sends signals appropriately so that the fixture clamps the work piece. After clamping the work piece, the work piece is then transferred to a predetermined location at a predetermined speed. A controller in the gantry system sends signals appropriately to machine safety logic, so that the fixture unclamps the work piece. If the unclamping is not carried out properly, the gantry moves the work piece and may cause serious accident in the work space. Hence, safety in automation system becomes a predominant aspect to be considered while constructing any automation system and hence there exist a need of a mechanism for unclamp sensing in the link clamp cylinders used in automation. The safety in automation refers to safety of operators, fixtures and robot/gantry loader.
Further, in the existing link clamp cylinder the unclamp feedback unit is generally provided from the bottom of the link clamp cylinder. In base types of fixture applications use of this bottom pneumatic feedback unit is not feasible because of height and weight constraints. Unclamp sensing feedback unit at the bottom of the link clamp cylinder will increase the height of the cylinder, this increase in height will obstruct the movement of cutting tools during operation. To compensate for the increase in height of link clamp cylinder, the cutting tool length has to be increased which is not desirable. Also, installing the unclamp feedback unit at the bottom of the link clamp cylinder will be expensive. And because of the additional feedback unit, weight of the whole component will increase which is not desirable.
In light of the foregoing discussion, it is necessary to develop unclamp sensing feedback unit which is economical and at the same time overcome the limitations stated above.
SUMMARY OF THE INVENTION
The limitations of the prior art are overcome and additional advantages are provided through the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.
In an embodiment of the present disclosure, a link clamp assembly for detecting the unclamping of the link clamp cylinder is disclosed. The link clamp assembly consists of a piston at the vicinity of centre of the link clamp cylinder. A clamp lever, pivoted by a pivot pin is connected to the piston of the link clamp cylinder. The pivot pin connected to the clamp lever of the link clamp cylinder is fixed to a feedback unit. Further, at least one bracket is mounted on the link clamp cylinder. A plate is mounted below the at least one bracket such that the plate is in between the at least one bracket and the surface of the link clamp cylinder. Further, a feedback unit is configured in the link clamp assembly which comprises of a pivot pin, a spring loaded piston and a pneumatic input unit. A sensor is configured in the machine safety logic, to send a feedback signal upon detecting state of air flow in the pneumatic check line of the link clamp cylinder to indicate the fully unclamped condition.
In one embodiment, the at least one bracket is configured with a substantially flat base, orientation elements and mounting elements. The orientation elements of the at least one bracket extend vertically from the flat base of the at least one bracket. The mounting elements of the at least one bracket extends below the base for mounting the at least one bracket onto the link clamp cylinder. Further, a plate is fixed to the at least one bracket and the plate is configured with a substantial flat surface with at least one side face of the plate is perpendicular to the substantial flat surface.
A method of assembly of the link clamp assembly, to detect unclamping of a link clamp cylinder is disclosed as an embodiment of the present disclosure. The method comprising acts of connecting a clamp lever to a piston located at the vicinity of the centre of a link clamp cylinder and mounting at least one bracket on the link clamp cylinder. Further, mounting a plate below the at least one bracket such that the plate is in between the surface of the link clamp cylinder and the at least one bracket. Further, a feedback unit comprising of a pivot pin, a spring loaded piston and a pneumatic input unit, is connected to the clamp lever of the link clamp cylinder. The feedback unit is connected to the clamp lever by pivoting the pivot pin of the feedback unit to the clamp lever. Upon actuation of the piston of the link clamp cylinder, the clamp lever lowers thereby lowering the feedback unit until the spring loaded piston of the feedback unit contacts the plate mounted below the bracket. The spring loaded piston and the pneumatic input unit of the feedback unit are arranged such that upon actuation of the spring loaded piston, there is a blockage of pneumatic check line of the pneumatic input unit.
In one embodiment, the sensor sends a feedback signal upon detecting change in pressure of air flow into the pneumatic check line to indicate fully unclamped condition of the link clamp cylinder.
The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features and characteristic of the disclosure are set forth in the appended claims. The embodiments of the disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of the illustrative embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings.
FIG. 1 shows a perspective view of the link clamp assembly according to the present disclosure;
FIG. 2 shows a front view of the link clamp assembly according to the present disclosure;
FIG. 3 shows another perspective view of the link clamp assembly according to the present disclosure;
FIG. 4 shows a side view of the assembled link clamp assembly with link clamp cylinder in a clamped condition according to the present disclosure;
FIG. 5 shows a side view of the assembled link clamp assembly with link clamp cylinder in an unclamped condition according to the present disclosure;
FIG. 6 shows a perspective view of the link clamp assembly with link clamp cylinder in the unclamped condition according to the present disclosure; and
FIG. 7 shows another perspective view of the link clamp assembly with link clamp cylinder in the unclamped condition according to the present disclosure.
The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION OF THE INVENTION
In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.
FIG. 1 illustrates a perspective view of the link clamp assembly ( 1 ) according to one embodiment of the present disclosure. The link clamp assembly ( 1 ) comprises at least one bracket ( 5 ), a plate ( 9 ) mounted below the at least one bracket ( 5 ) and a feedback unit ( 3 ). The at least one bracket ( 5 ) is configured with a substantially flat base ( 5 b ), along with orientation elements ( 5 a ) extending substantially vertically from the flat base ( 5 b ). The base ( 5 b ) of at least one bracket ( 5 ) is configured with mounting elements ( 5 c ) to facilitate the mounting of the at least one bracket ( 5 ) on the link clamp cylinder ( 6 ) (best shown in FIG. 2 ). The feedback unit ( 3 ) comprises a pivot pin ( 8 ), a spring loaded piston ( 7 ) and a pneumatic input unit which is at 2 bar pressure connected to air catch sensor unit ( 4 ) (more clearly shown in FIG. 3 ). The pivot pin ( 8 ) is arranged horizontally or substantially horizontally to the top surface of the link clamp cylinder ( 6 ). The spring loaded piston ( 7 ) is substantially vertically aligned with the pivot pin ( 8 ). The spring loaded piston ( 7 ) is configured in such a way that one end of the spring loaded piston ( 7 ) contracts with the plate ( 9 ) during unclamping of a clamp lever ( 2 ) of the link clamp cylinder ( 6 ) (shown in FIG. 5 ) and blocks pneumatic check line of the pneumatic input unit ( 4 ).
FIG. 2 illustrates a front view of the link clamp assembly ( 1 ) according to one embodiment of the present disclosure. The spring loaded piston ( 7 ), pivot pin ( 8 ) and the pneumatic input unit ( 4 ) are configured in the feedback unit ( 3 ) such that, when the feedback unit ( 3 ) is actuated by the clamp lever ( 2 ) (shown in FIG. 5 ), the spring loaded piston ( 7 ) contacts the plate ( 9 ) and compresses or presses inwards, thereby blocking pneumatic check line of the pneumatic input unit ( 4 ). The plate ( 9 ) is placed below the flat base of the bracket ( 5 b ) at predetermined distance, above the top surface of the link clamp cylinder ( 6 ). The pivot pin ( 8 ) with one of its ends fixed to the feedback unit ( 3 ) extends horizontally with the top surface of the link clamp cylinder ( 6 ) to enable pivoting of the clamp lever ( 2 ). The orientation elements ( 5 a ) of the at least one bracket ( 5 ) are placed at a predetermined distance to facilitate the clamp lever ( 2 ) to oscillate freely in between the gap of the orientation elements ( 5 a ) of the at least one bracket ( 5 ).
FIG. 3 illustrates perspective view of the link clamp cylinder ( 6 ) according to one embodiment of the present disclosure. The plate ( 9 ) is fixed to the substantially flat base ( 5 b ) of the at least one bracket ( 5 ). The pneumatic input unit ( 4 ) is placed onto the feedback unit ( 3 ) such that, the spring loaded piston ( 7 ) when compressed, blocks the pneumatic check line of the pneumatic input unit ( 4 ), thereby changing the pressure builds in the line followed by air catch sensor sending the same into the pneumatic input unit ( 4 ).
FIG. 4 illustrates a side view of the link clamp assembly ( 1 ) assembled on the link clamp cylinder ( 6 ) in clamped condition according to one embodiment of the present disclosure. The link clamp assembly ( 1 ) consists of a clamp lever ( 2 ) connected to a piston ( 10 ) at the pivoted end of the clamp lever ( 2 ). At least one bracket ( 5 ) is mounted on the link clamp cylinder ( 6 ) by mounting the mounting elements ( 5 b ) of the at least one bracket ( 5 ) and a plate ( 9 ) is mounted on the substantially flat base ( 5 b ) of the at least one bracket ( 5 ). The clamp lever ( 2 ) is pivoted to the pivot pin ( 8 ), wherein the pivot pin ( 8 ) is configured in the feedback unit ( 3 ).
Further, the clamped condition of the link clamp assembly is defined as top most position or top dead centre position in the stroke length of the piston ( 10 ) of the link clamp cylinder ( 6 ). In clamped condition, there will be no movement of the piston ( 10 ), and the piston ( 10 ) will be at the top dead centre position, thereby the clamp lever ( 2 ) being connected to the piston ( 10 ) will be at the top most position or clamped position. As the pivot pin ( 8 ) fixed to the feedback unit ( 3 ) is pivoted to the clamp lever ( 2 ), the feedback unit ( 3 ) will also be at the top most position and the spring loaded piston ( 7 ) will not be compressed. Hence the clamped condition is also called no load condition as there is no compression of the spring loaded piston ( 7 ) of the feedback unit ( 3 ).
FIG. 5 illustrates side view of the link clamp assembly ( 1 ) assembled on a link clamp cylinder ( 6 ) in fully unclamped condition according to one embodiment of the present disclosure. FIGS. 6 and 7 show perspective views of the link clamp assembly ( 1 ) assembled on the link clamp cylinder ( 6 ) in the fully unclamped condition according to one embodiment of the present disclosure. The fully unclamped condition of the link clamp cylinder ( 6 ) is defined as lowest position or bottom dead centre position in the stroke length of the piston ( 10 ) of the link clamp cylinder ( 6 ). During unclamping, the piston ( 10 ) is actuated hydraulically or pneumatically and thereby the piston ( 10 ) descends from the top dead centre position. The clamp lever ( 2 ) with the pivot end being connected to the piston ( 10 ) also descends, thereby oscillating the clamp lever ( 2 ) at the pivot. The pivot pin ( 8 ) configured in the feedback unit ( 3 ) and pivoted to the clamp lever ( 2 ) also descends, thereby actuating the feedback unit ( 3 ). When the piston ( 10 ) reaches the end stroke, the spring loaded piston ( 7 ) of the feedback unit ( 3 ) contacts the plate ( 9 ) and gets compressed. The compressed spring loaded piston ( 7 ) retracts and blocks the pneumatic check line of the pneumatic input unit ( 4 ), this causes change in the pressure of air flow into the pneumatic check line. The change in pressure of air flow will be detected by a sensor placed at the vicinity of the link clamp assembly, sends a feedback signal to the machine safety logic to indicate the fully unclamped condition of the link clamp cylinder ( 6 ). The feedback signal sent by the sensor to the machine safety logic can be a positive feedback signal or a negative feedback signal. The sensor used to detect the change in pressure of air flow into the pneumatic check line is an air or pneumatic sensor.
While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
REFERRAL NUMERALS
1 : Link clamp assembly
2 : Clamp lever
3 : Feedback unit
4 : Pneumatic input unit
5 : Bracket
5 a : Flat base of bracket
5 b : Orientation element of bracket
6 : Link clamp cylinder
7 : Spring loaded piston
8 : Pivot pin for lever
9 : Plate
10 : Piston
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The disclosure generally relates to unclamp sensing feedback devices for clamping or holding devices in automatic production lines more specifically to a link clamp assembly. Further, the disclosure also provides the method of achieving feedback to sense fully unclamped condition of the link clamp cylinder.
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FIELD OF THE INVENTION
The invention relates to coextruded sheets and containers made from them.
BACKGROUND OF THE INVENTION
Polyolefins with moisture barrier properties such as polypropylene and polyethylene have been used to form containers; however, thermoforming of polyolefins is very slow, and therefore expensive, and it is difficult to achieve a glossy appearance after thermoforming polyolefins. Polyester, on the other hand, has no barrier properties, can be easily thermoformed, and can be heated by microwaves, and polyester surfaces can have gloss after thermoforming.
SUMMARY OF THE INVENTION
It has been discovered that by coextruding polyester with a polyolefin having moisture barrier properties, a useful multilayered sheet results. In addition to a moisture barrier, the sheet can have a glossy surface, chemical resistance, and microwave heatability, and can be easily thermoformed. By coextrusion of the materials, a multilayered sheet with high quality bonds between the layers in terms of consistency and reliability is simply and expeditiously provided in a single process step without having to laminate a plurality of different layers together.
In preferred embodiments, the polyester layer and the polyolefin layer are bonded to each other by an adhesive tie layer; and additional adhesive tie and polyester layers are on the other side of the polyolefin layer to result in a five-layer structure that has resistance to curling owing to the symmetrical structure, and has a glossy appearance on both of the outer surfaces. In some preferred embodiments the polyolefin and polyester are transparent and clear; in other preferred embodiments at least one one of the layers is colored.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The structure and manufacture of the presently preferred embodiment of the invention will now be described after first briefly describing the drawings.
DRAWINGS
FIG. 1 is an elevation, partially broken away, of a container according to the invention.
FIG. 2 is a cross-sectional view, taken at 2--2 of FIG. 1, showing the multilayered structure of the container.
FIG. 3 is a diagrammatical view of the manufacturing process for forming the FIG. 1 container.
STRUCTURE
Turning to the figures, there is shown container 10 in which food (e.g., a ready-prepared stew) has been packed. The container consists of bowl 14 and lid 16.
Both the lid and bowl are made from multilayered sheets that are formed by coextrusion. Bowl 14 is thermoformed from such a sheet, as depicted in FIG. 3. Lid 16 is cut from a similar sheet and sealed to rim 20 of the bowl.
As shown in FIG. 2, the finished bowl and lid have five layers.
Referring to FIG. 2 there is shown a portion of the wall of bowl 14. It has central layer 22 made of crystalline polypropylene (available from Rexene Company, Paramus, N.J. and having an H 2 O permeability at 100° F., 90% humidity of less than about 1.0 gm/mil/100 in 2 -24 hr, a specific gravity greater than 0.9, and a melt flow index of 4 decigrams/min), outer layers 24 of polyester (available from Eastman Kodak Company under the trade designation Kodar), and two intermediate tie layers 26 made of suitable adhesive (ethylene vinyl acetate containing adhesive material available from DuPont under the trade designation CXA 1123). In thermoformed container 10, polypropylene layer 22 is 10 mils thick, outer polyester layers 24 are each 3 mils thick, and intermediate adhesive tie layers 26 are each 1/2 mil thick, resulting in a 17 mil thick wall.
Container 10 is transparent and has a moisture barrier provided by polypropylene layer 22 and, glossy surfaces, chemical resistance, and microwave heatability provided by outer polyester layers 24. The symmetrical nature of the five-layer wall structure provides resistance to curling.
Manufacture
Referring to FIG. 3, the coextrusion process for forming the five-layer sheet for container 10 is shown. Three heated containers 30, 32, and 34, serve as sources of polypropylene, adhesive tie layer, and polyester, respectively. Five conduits 36, 37, 38, 39, 40, supply the heated materials to coextrusion block 42. There the materials merge together to form under pressure a unitary, five-layer thick stream 44 of generally circular cross-section. The middle layer is made of the polypropylene, the outer layers are made of polyester, and the intermediate layers are made of the adhesive tie layer material. Stream 44 passes into extrusion die 46 (e.g., Welex standard 54" flex-lip) and is extruded into continuous sheet 48, about 34 mils thick. Sheet 48 then passes through a series of chill rolls 49. The sheet may then be processed into containers, or wound into spools (not shown) for storage.
To process sheet 48 into containers, the sheet is passed through conventional thermoforming apparatus 50 (the vacuum forming type well-known in the art), which impresses the container shape and in so doing reduces the wall thickness by about 50% on the average, making the finished container wall about 17 mils thick. The thicknesses of individual layers are also reduced by about 50% during thermoforming. It has been found that thermoforming of sheet 48 proceeds easily and faster than the slow, and therefore expensive, thermoforming of polypropylene alone.
After thermoforming, the shaped sheet 52 passes through trim press 54, in which the individual bowls 14 for the containers are separated. Thereafter, each bowl is given curled rim 20 (FIG. 1) by a conventional curling machine (not shown).
Lids 16 are separately cut from sheet 48.
By this method of manufacture, a complex multilayered sheet is simply and expeditiously prepared from three sources of material by a single coextrusion process, and there is no need for laminating a large number of different layers or multilayered sheets together.
Other Embodiments
Other embodiments of the invention are within the scope of the appended claims. The word "polyester" as used in the claims includes polyethylene terephthalate and also includes copolyesters such as glycol modified polyethylene terephthalate. Other polyolefins with moisture barrier properties such as crystalline polyethylene can be used in place of polypropylene. Also, one of the layers could have color concentrate added to it to provide a transparent tint or an opaque color to the structure.
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A multilayered thermoplastic sheet suitable for thermoforming into containers, the sheet being simply and expeditiously prepared and provided with consistent and reliable bonds between layers in a single process step by coextruding a layer of a polyolefin having moisture barrier properties and a specific gravity greater than 0.9 with a polyester layer, to provide chemical resistance, microwave heatability, and quick and inexpensive thermoforming for the multilayered sheet.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of and claims priority to co-pending U.S. Utility patent application Ser. No. 13/335,833, filed Dec. 22, 2011, which is a continuation-in-part of and claims priority to co-pending U.S. Design Patent Application Ser. No. 29/396,206, filed Jun. 27, 2011, and co-pending U.S. Nonprovisional patent application Ser. No. 12/619,670 filed Nov. 16, 2009, the disclosures of each of which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to beverage cup lids for beverages which include foam, whipped cream, or similar top layers.
BACKGROUND
[0003] Its all about the foam. Espresso-based drinks topped with foam and/or whipped cream have become ubiquitous of late. Espresso drinkers enjoy the foam topping which results from steaming milk prior to adding it to the espresso coffee. The resulting top layer of foam adds texture and richness for the consumer. The foam also filters the steam rising from the coffee, enhancing the coffee aroma—which also enhances the beverage flavor, as olfactory stimulation has significant impact on taste. Oftentimes, espresso drinks are topped with a dollop of whipped cream as well, which also enhances the experience by turning a simple espresso or mocha into a full-fledged dessert.
[0004] Baristas take pride in their ability to lay over just the right amount of foam to enhance the drink experience and frequently manipulate the foam layer to create visual artistry. For some baristas, their visual foam designs have become akin to their signatures on consumable works of art. Making and drinking espresso has become almost a ritual for many espresso aficionados, and the foam is an important element of the overall experience.
[0005] Traditionally, espresso drinks are served in an open-topped cup which allows the drinker to take in foam and/or whipped cream with the liquid coffee portion to regulate the temperature and richness as she wishes, and which also stimulates the olfactory senses as she sips, because her nose is right over the drink. Frequently, however, beverages are purchased “to go” such that the vendor is obligated to place a disposable beverage lid onto the beverage cup to prevent spillage.
[0006] Unfortunately, conventional beverage lids tend to prevent the espresso drinker from drawing both coffee and foam (or whipped cream) at the same time. The placement and shape of the drink holes allow the liquid coffee portion through, but block the foam and/or whipped cream. The drinker ends up ingesting a solid stream of hot liquid into their mouth, denied the relative cooling effect of drinking a mixture of liquid and foam. In addition The espresso drinker, denied the rich texture of the foam and/or whipped cream during consumption, removes the lid when finished to find substantial quantities of rich foam remaining and wonders what it was all for.
[0007] Conventional beverage lids also tend to block the nose from getting a proper whiff of the wonderful coffee aroma, although that rich aroma is often what drew people to start drinking coffee in the first place. Again, the espresso drinker's experience is limited and she may wonder why she has paid so dearly for a halfway experience.
[0008] Thus, there is a need for a beverage lid designed for use with foam-topped beverages which permits a drinker to consume the foam topping concurrently with the liquid portion of the beverage, and which links the olfactory senses to the drinking experience.
SUMMARY AND ADVANTAGES
[0009] A lid for a beverage cup includes an annular mounting portion to removably, sealingly, engage the open lip of a round beverage clip; a raised annular ridge inset from the mounting portion, the annual ridge extending circumferentially from a first end to a second end; a central portion spanning the annulus defined by the raised annular ridge, the central portion including an aroma aperture disposed at the center of the central portion; a dispensing portion spanning between the annular ridge first end and second end, the dispensing portion including a front flat portion extending from a bottom edge to a top edge, a sloped dispensing aperture surface extending from the top edge to an intersection edge intersecting central portion, and a dispensing aperture disposed on the sloped surface, the dispensing aperture comprising a triangle with rounded corners having a base proximate and parallel to the intersection edge and an apex proximate the top edge; and, the raised annular ridge and dispensing portion defining a continuous containment surrounding the central portion.
[0010] A beverage cup lid may include wherein the dispensing aperture defines a wide end breadth and a narrow end breadth, and the wide end breadth is approximately twice the magnitude of the narrow end breadth.
[0011] A beverage cup lid may include wherein the containment deck is substantially planar, and further wherein the containment deck is approximately coplanar to the top edge of the beverage cup.
[0012] A beverage cup lid may include wherein the aroma aperture diameter is approximately equal to the drink hole aperture radial axis length.
[0013] A beverage cup lid may include wherein the drink hole aperture radial axis length is approximately 0.4 inches (10 mm)
[0014] A beverage cup lid may include wherein the radiused corners have radii of approximately 0.08 inches (2 mm).
[0015] A beverage cup lid may include wherein the dispensing portion top edge is a radiused edge, the radius being at least 0.03 inches (0.75 mm).
[0016] A beverage cup lid may include wherein the dispensing portion upper edge is coplanar with the top wall of the raised annular ridge.
[0017] The beverage cup lid of the present invention presents numerous advantages.
[0018] Foam Problem—With an espresso drink, the small drink hole in a conventional lid makes it difficult to get foam at the same time with the steamed milk and espresso. Also, if you look at the underside of a conventional lid you'll see that the depression in the lid for the upper lip restricts access for the foam to get to the drink hole.
[0019] Applicant's invention provides a uniquely shaped and oriented drink hole on an angled surface. The angled surface gives the drink hole access to the foam at all tilt angles of the cup. The drink hole is tall enough to allow the consumer to get foam at the same time with the steamed milk and espresso. With the inverted triangular shape there is more room for the foam to get through the top of the hole thus increasing the foam to liquid ratio. The consumer can easily control the amount of foam and coffee by varying the position of the lips and the amount of cup tilt. Side-by-side tests show that with the present invention, there is very little foam left in the cup after finishing the drink. With the conventional lid a lot of the foam is left in the cup.
[0020] Aroma Problem—It is difficult to smell the coffee aroma with conventional lids. As with wine tasting, a major contribution to the overall sensory experience is from the sense of smell.
[0021] Applicant's invention incorporates an air vent hole positioned under the nose to allow the coffee or tea aroma to be enjoyed by the consumer. The consumer may exhale into the cup just prior to drinking to provide a gentle blast of coffee aroma right at the nostrils.
[0022] Temperature Problem—Most conventional lids have a small hole forcing the consumer to ingest 100% hot liquid. Also, with the conventional lid it is difficult to slurp air with the hot liquid to cool it down while maintaining a good lip seal to the lid. For lattes and cappuccinos, foam is mostly air and is much cooler than the hot milk.
[0023] Applicant's invention provides an inverted trapezoidal drinking hole design, allowing the consumer to vary the amounts of foam and liquid thus controlling the temperature of the drink, thus reducing the chance of a burned tongue. Also, with a regular coffee or tea one is able to slurp air through the drink hole because the vent hole is appropriately sized. When hot liquid is aerated it rapidly cools, permitting the consumer to drink the beverage immediately with lowered risk of mouth burns.
[0024] Nose Fit Problem—Conventional lids have a top surface where the drinker's nose hits, forcing the drinker to tilt their head back.
[0025] However, the depression in Applicant's invention provides space for the nose allowing the consumer to fully tilt the cup with less tilting of the head, which may permit the consumer to more conveniently drink espresso while driving or walking.
[0026] Spillage Control Problem—Baristas often complain that if the cup is filled with the level of foam above the top of the cup and a conventional lid is put on foam may ooze out of the hole down the outside of the cup causing a mess and wasting time for cleanup, or requiring a new cup and lid. Consumers sometimes complain that with conventional lids the spillage squirts out of the lid drink hole. This is caused by water hammer effect, as the liquid mass hits the drink hole across its entire cross section nearly simultaneously with contacting the adjacent lid surface, creating a high pressure spike which ejects liquid through the drink hole.
[0027] If foam comes out of the hole while putting on lid embodying Applicant's invention, the foam is contained in the center of the lid. (The first sip is actually quite enjoyable with the foam contained in the lid.) Additionally, the contours of Applicant's lid act as a darn to reduce any spillage and typically it actually takes a vigorous shake of the cup on purpose to create any spillage. If there is spillage, the liquid does not “hammer” the drink hole region, but rises along the length of the drink hole relieving pressure by dribbling into the containment area.
[0028] Straw Problem—The drinking hole in the conventional lid is so small you have to pinch big straws to fit it through. Sometimes the straw stays pinched making it difficult to drink. However, with Applicant's lid, drink and aroma holes are large enough to easily accommodate two large straws.
[0029] Flavor Enhancement—Applicant's invention provides holes appropriately sized to allow the consumer to slurp air with the coffee, thereby atomizing the liquid into small droplets. This atomization process coats the tongue and inside of the mouth with the droplets which enhances the flavor. Like in wine tasting and cupping (coffee tasting) one draw some air into one's mouth with the drink and exhales through the nose. This liberates the coffee aromas and allows them to reach the olfactory senses where they can be detected. This improves regular coffee and tea, as well.
[0030] No Pucker—Many conventional lids require the consumer to pucker his mouth to seal against the raised area around the drink hole. The drink hole shape and orientation of Applicant's invention. enables the consumer to create a good seal around the drink hole with a relaxed mouth, similar to the feeling using an open top cup.
[0031] Drink Hole Alignment Aid—The drink hole in Applicant's invention is centered in an area between the annular ridges. A fiat spot is provided along the front of the drink hole, which can be felt with the bottom lip. Both of these design shapes help the consumer to align their mouth to the drink hole without looking.
[0032] Visual Indication of Liquid Level—With Applicant's invention, the liquid level can be seen through the drink and aroma holes. This allows the consumer to gauge how far the cup needs to be tilted to reach the liquid which helps to alleviate the anxiety around guessing when the hot liquid will get to the drink hole.
[0033] The dispensing aperture is aimed away from the consumer towards the center of the lid. In case of spillage the liquid will be contained within the containment reservoir and has the opportunity to drain back into the cup through the aroma hole or the consumer can drink it.
[0034] The dispensing aperture is on a slanted surface designed to be parallel and even with the top of the liquid when the cup is full and tilted for drinking. This allows the foam floating on the top of the hot milk to easily flow unobstructed to and out of the dispensing aperture from the first to the last sip.
[0035] The dispensing aperture is twice as wide at the top as at the bottom to allow a higher volume ratio of foam to hot coffee/milk. This improves the enjoyment of the foam. Also, the air bubbles in the foam are at a lower temperature than the hot liquid, so provide cooling when taken in together with the hot liquid. The hot coffee/milk thus allowing the consumer to cool the drink by taking more foam.
[0036] The dispensing aperture and aroma hole have enough cross-section area to facilitate air flow for the consumer to slurp air through the aroma hole and out the dispensing aperture while drinking. This simulates the in-shop coffee mug experience allowing the consumer to cool a non-foam drink (plain coffee or tea) and to aspirate the liquid in the mouth for enhanced flavor.
[0037] The dispensing aperture has large radius corners as not to catch the lip in the bottom corner and provide more efficient flow. With a tight radius corner the upper lip sometimes becomes wedged into the bottom corner as the consumer finishes the sip and slides away from the lid.
[0038] The leading edge of the straight dispensing aperture surface has a large radius corner to make it feel more like a thick ceramic mug to the tongue and lips.
[0039] The front surface is flat in front of the dispensing aperture. This combined with the gap in the annular ridge aids the consumer in finding the dispensing aperture without looking.
[0040] The annular ridge height is maintained, for the entire circumference to create a spillage containment area.
[0041] The aroma hole is positioned directly under the drinker's nose.
[0042] The containment reservoir is recessed allowing more room for the drinker's nose.
[0043] The perimeter seal that snaps around the cup rim roll is compatible with standard cup dimensions for the 12-24 oz sizes.
[0044] Additional advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. Further benefits and advantages of the embodiments of the invention will become apparent from consideration of the following detailed description given with reference to the accompanying drawings, which specify and show preferred embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate one or more embodiments of the present invention and, together with the detailed description, serve to explain the principles and implementations of the invention.
[0046] FIG. 1 shows a top plan view of a first embodiment.
[0047] FIG. 2 shows a bottom plan view of a first embodiment.
[0048] FIG. 3 shows a front (drinking side) edge view of a first embodiment.
[0049] FIG. 4 shows a back edge view of a first embodiment.
[0050] FIG. 5 shows a right edge view of a first embodiment.
[0051] FIG. 6 shows a left edge view of a first embodiment.
[0052] FIG. 7 shows a top perspective view of a first embodiment.
[0053] FIG. 8 shows a bottom perspective view of a first embodiment.
[0054] FIG. 9 shows a front perspective view of a first embodiment.
[0055] FIG. 10 shows a beverage cup drink hole of conventional prior art design, for illustration.
[0056] FIG. 11 shows an isolation view of the drink hole geometry of a first embodiment of the invention.
[0057] FIG. 12 shows a cup side view of a first conventional prior art design beverage lid with the conventional drink hole design of FIG. 10 , demonstrating operation, for illustration.
[0058] FIG. 12 a shows a lid top view corresponding to FIG. 12 .
[0059] FIG. 13 shows a cup side view of a second conventional prior art design beverage lid with. the conventional drink hole design of FIG. 10 , demonstrating operation, for illustration.
[0060] FIG. 13 a shows a lid top view corresponding to FIG. 13 .
[0061] FIG. 14 shows a cup side view of a first embodiment of the invention, with the inventive drink hole design of FIG. 11 , demonstrating operation.
[0062] FIG. 14 a shows a lid top view corresponding to FIG. 14 .
DETAILED DESCRIPTION
[0063] Before beginning a detailed description of the subject invention, mention of the following is in order. When appropriate, like reference materials and characters are used to designate identical, corresponding, or similar components in differing figure drawings. The figure drawings associated with this disclosure typically are not drawn with dimensional accuracy to scale, i.e., such drawings have been drafted with a focus on clarity of viewing and understanding rather than dimensional accuracy.
[0064] In the interest of clarity, not all of the routine features of the implementations described herein are shown and described. It will, of course, be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions must be made in order to achieve the developer's specific goals, such as compliance with application- and business-related constraints, and that these specific goals will vary from one implementation to another and from one developer to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of engineering for those of ordinary skill in the art having the benefit of this disclosure.
[0065] Directional descriptors in the Description and Claims are referenced to the normal installed orientation of a beverage lid on a cup. Thus, the “top” or “upper” surface of a drink lid corresponds to the outer or exposed surface of the lid when correctly installed on a cup, and the “bottom” or “lower” surface corresponds to the interior surface of the lid when correctly installed. The “front” or “forward” part of a beverage lid refers to the portion proximate the drink hole which will also be proximate the consumer when in use, and the “back” or “rearward” part of a beverage lid refers to the portion opposing the “front” portion, despite the conventionally circular shape of a beverage cup lid.
[0066] Referring to FIGS. 1-9 , 11 , 14 and 14 a , an embodiment 10 of a disposable beverage cup lid for foamed beverages is shown, sized for a standard 12 oz. (355 ml) hot beverage cup. As shown in FIGS. 1-9 , a beverage cup lid 10 comprises an annular mounting portion 12 , a raised annular ridge portion 14 inset, from the mounting portion and projecting upward therefrom, the ridge portion 14 extending circumferentially from a first end 16 to a second end 18 , a dispensing portion 20 spanning from a first end 22 adjoining ridge first end 16 to a second end 24 adjoining ridge second end 18 , and a center portion 26 spanning the region enclosed by ridge portion 14 and dispensing portion 20 . Center portion 26 includes an aroma aperture 58 disposed at the center of center portion 26 and concentric with annular mounting portion 12 .
[0067] Annular mounting portion 12 includes an underside groove 28 for removably engaging the top rim of a beverage cup to form a liquid-tight seal. Annular mounting portion 12 is circular, to engage the circular rim of a beverage cup.
[0068] Annular ridge portion 14 includes an outer wall 30 , a concentric inner wall. 32 , and a connecting top wall 34 spanning between. In the embodiment, annular ridge portion 14 extends approximately 0.4 inches (10 mm) above the plane of a beverage cup top lip L when lid 10 is mounted on a cup C. In the embodiment, annular ridge outer and inner walls 30 and 32 slope slightly away from vertical toward each other so as to be farther apart at their bases than at their top edges meeting at top wall 34 .
[0069] Dispensing portion 20 includes a substantially vertical front flat 36 spanning from dispensing portion first end 22 to second end 24 , and extending from base 38 to dispensing portion upper edge 40 . Dispensing portion 20 further includes a substantially planar sloped surface 42 extending from upper edge 40 downward to intersect along a lower edge 44 intersecting with central portion 26 , and spanning between dispensing portion first end 22 to second end 24 . In the embodiment, central portion 26 is a flat surface, approximately coplanar with the top lip L of a cup C when lid 10 is mounted to a cup C.
[0070] Dispensing aperture 46 is disposed on sloped surface 42 centered between dispensing portion first and second ends 22 and 24 . Dispensing aperture 46 generally forms a triangle having first, second and third sides 48 , 50 and 52 , respectively. Dispensing aperture 46 is symmetric about a first radial axis 54 which is aligned radially outward, and a second transverse axis 56 is perpendicular to first axis 54 . Dispensing aperture 46 includes first, second and third large radius corners 60 , 62 and 64 .
[0071] Dispensing aperture 46 is oriented with its apex (first radiused corner 60 ) oriented toward dispensing portion upper edge 40 , and third side 52 proximate and parallel to sloped surface lower intersecting edge 44 . Having the wider portion of dispensing aperture 46 oriented downslope permits floating foam to more easily pass through dispensing aperture 46 when the cup is tilted up by the user. Referring to FIG. 11 , dispensing aperture 46 has a narrow end breadth 70 measured across the region where the radiused curvature of radiused corner 60 begins, and a wide end breadth 72 measured. across the widest portion of dispensing aperture 46 at radiused corners 62 and 64 . In the embodiment, wide end breadth 72 is approximately twice the magnitude of narrow end breadth 70 . This proportion provides for reliable flow ratio of foam to liquid. Sloped surface 42 is sloped in the range 20° to 45° from horizontal for efficiency and comfort. In the embodiment, sloped surface 42 is approximately 30°, which provides for efficient dispensing of liquid and foam through most cup tilt angles.
[0072] In the embodiment, aroma aperture 58 is circular, having a diameter 66 approximately equal to dispensing aperture first radial axis 54 . In the embodiment, dispensing aperture first, second and third radius corners 60 , 62 , 64 have radii of approximately 0.08 inches (2 mm), and the diameter 66 of aroma aperture 58 is approximately 0.4 inches (10 mm). The large radius corners provide smoother combined flow of liquid and foam through dispensing aperture 46 , and prevent injury to the user's lips.
[0073] Referring to FIGS. 10-14 a, comparison to conventional designs is shown. FIGS. 10 , 12 & 12 a, and 13 & 13 a show the shape of a conventional hot beverage cup lid drink hole H—basically oval, with the long axis oriented transversely—as used with conventional lid profiles, and how they function at various tilt angles. Various cup tilt angles are indicated by lines a′, b′, c′, d′ and e′, with a′ being the shallowest in each case (i.e. a full cup) and e′ being the greatest tilt (i.e. a nearly empty cup). The dark shaded regions indicate tilt regions where surface foam is blocked from the dispensing hole—in other words, no foam will pass through the drink hole at all. FIGS. 12 , 12 a and 13 , 13 a show that essentially no foam. will pass through the drink holes of conventional beverage cup lids until the cup is at least half empty, and even then the narrow transverse orientation of the drink holes H.
[0074] By contrast, FIGS. 14 , 14 a show that in Applicant's design, foam reaches the drink hole 46 at virtually every angle, including when the cup is full. Additionally, if anything spills out through aroma hole 58 , it either drains back into the cup, or is contained by ridge portion 14 and dispensing portion 20 , to drain into users mouth when he takes a sip of espresso. Additionally, when drinking from the cup, aroma hole 58 is aligns approximately with the user's nostrils to provide olfactory stimulation, while the displacement depth provided by central portion 26 prevents actual contact with the nose except at relatively extreme angles.
[0075] Those skilled in the art will recognize that numerous modifications and changes may be made to the preferred embodiment without departing from the scope of the claimed invention. It will, of course, be understood that modifications of the invention, in its various aspects, will be apparent to those skilled in the art, sonic being apparent only after study, others being matters of routine mechanical, chemical and electronic design. No single feature, function or property of the preferred embodiment is essential. Other embodiments are possible, their specific designs depending upon the particular application. As such, the scope of the invention should not be limited by the particular embodiments herein described but should be defined only by the appended claims and equivalents thereof.
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A lid for a beverage cup includes an annular mounting portion to removably, sealingly, engage the open lip of a round beverage cup; a raised annular ridge inset from the mounting portion extending from a first end to a second end; a central portion spanning the annulus and including an aroma aperture at the center; a dispensing portion spanning between the annular ridge first end and second end including a front flat portion, a sloped dispensing aperture surface, and a dispensing aperture disposed on the sloped surface, the dispensing aperture comprising a triangle with rounded corners having a base proximate and parallel to the intersection edge and an apex proximate the upper edge; and, the raised annular ridge and dispensing portion defining a continuous containment surrounding the central portion.
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RELATED DOCUMENTS
Disclosure Documents deposited with USPTO as follows:
No. 604278 on 2 Aug. 2006
No. 604409 on 7 Aug. 2006
No. 605820 on 6 Sep. 2006
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of Provisional Patent Application Ser. No. 60/854,926 filed 27 Oct. 2006.
FIELD OF INVENTION
This invention relates to structures which can be mounted on highway vehicles. In particular it relates to tent-type structures which can be detachably mounted on open trucks.
BACKGROUND OF THE INVENTION
A number of designs exist for tent structures which can be mounted on pickup trucks and related vehicles. A search was conducted in the U.S. patent literature which resulted in the following patents and patent publications:
U.S. Pat. No. 3,773,379 (Nov. 1973) to Loiseau
U.S. Pat. No. 4,310,194 (Jan. 1982) to Biller
U.S. Pat. No. 4,332,265 (Jun. 1982) to Baker
U.S. Pat. No. 5,238,288 (Aug. 1993) to Chandler
U.S. Pat. No. 6,000,745 (Dec. 1999) to Alexa
U.S. Pat. No. 6,481,784 (Nov. 2002) to Cargill
2003/0146646 (Aug. 2003) to Cervenka
D484,942 (Jan. 2004) to Rapaport et al
U.S. Pat. No. 6,799,787 (Oct. 2004) to Angelos
U.S. Pat. No. 6,932,418 (Aug. 2005) to Connell
U.S. Pat. No. 7,021,694 (Apr. 2006) to Roberts et al.
None of these patents provide the configurations, convenience and facility of erection and removal of the present invention as described in the Summary of the Invention and Detailed Description which follow.
SUMMARY OF THE INVENTION
The Camper. Truck Tent of this invention comprises two horizontal mounting support assemblies, a tent assembly, tent poles, and two beds. The mounting support assemblies are mounted in parallel across the tops of the left and right walls of the truck cargo box, near the front and near the rear, and fastened securely to the truck hooks. The mounting support assemblies contain studs to fasten the beds, and loops to hold the tent poles.
The tent assembly is initially in the collapsed state and placed over the mounting support assemblies such that holes in the tent floor are penetrated by the studs of the mounting support assemblies.
Three top poles are inserted into the sleeves located on the top front, center, and aft portions of the tent. The angled ends of the six side poles are fitted to the top poles in the left and right sleeves, while their other ends are attached to the loops at the tip of the mounting support assemblies, which form three rectangles (forward, center and aft) placed flat on top of the truck cargo box.
To fold out the tent, its front and aft straps are pulled. The front strap is hooked to the front of the truck, lifting the forward top pole and erecting the forward side poles in a pivoting motion around their loop attachment. The aft straps are pulled by tilting down the tailgate, causing the aft wall to lift the center and aft top poles. The length of the front strap is adjusted to maintain the top and aft tent walls properly stretched. Lastly, the two beds are brought in through the aft door and mounted on the studs of the mounting support assemblies.
Various user-friendly features are provided, such as: adjustable lateral position of mounting supports to fit variable width cargo boxes; permanent attachment of properly oriented tent pouch to tent floor for convenient correct tent storage and deployment; concave beds for greater stability; laterally extended attachment points in the mounting support assemblies for more tent space and volume; a tent collapsing system allowing a free rear view for the driver; and storing all the poles in one bed envelope, while the two mounting support assemblies are stored in the other bed envelope, which avoids additional storage bags.
BRIEF DESCRIPTION OF THE FIGURES
A better understanding of the Camper Truck Tent of the present invention may be gained by reference to the following Detailed Description of the Invention, in conjunction with Figures showing the details of the invention.
In the Figures,
FIG. 1 is a pictorial view of front and rear mounting support assemblies mounted on a truck;
FIG. 2 is a pictorial view showing details of the mounting attachment of FIG. 1 ;
FIG. 3 is a pictorial view of mounting attachment details, alternative to FIG. 2 ;
FIG. 4 is a pictorial view of a tent pouch assembly;
FIG. 5 is a pictorial view of a folded tent;
FIG. 6 is a pictorial view of a tent assembly mounted on a truck;
FIG. 7 is a pictorial view showing details of a front pole attachment to a front support;
FIG. 8 is a pictorial view of a rear pole attachment to a rear support;
FIG. 9 is a pictorial view of a tent assembly mounted on a truck, with cramping side pole replacing front hook strap;
FIG. 10 is a pictorial view of connection details of cramping side pole, forward side pole and front support;
FIG. 11 is a pictorial view of connection details of cramping side pole, aft side pole assembly and rear support;
FIG. 12 is a pictorial view showing the interior of a tent;
FIG. 13 is a pictorial view of a right side bed assembly, tent floor and side walls;
FIG. 14 is a side view of a tent assembly installed in a truck;
FIG. 15 is a top view of a tent assembly installed in a truck;
FIG. 16 is a cross-sectional rear view of a tent assembly installed in a truck;
FIG. 17 is a cross-sectional side view of a tent assembly installed in a truck;
FIG. 18 is a pictorial view of a collapsed tent assembly installed in a truck;
FIG. 19 is a pictorial view of Alternative No. 1 tent assembly mounted on a truck, (compare with FIG. 6 );
FIG. 20 is a pictorial view of Alternative No. 2 tent assembly mounted on a truck (compare with FIG. 6 );
FIG. 21 is a side view of Alternative No. 2 tent assembly mounted on a truck (as in FIG. 20 );
FIG. 22 is a top view of Alternative No. 2 tent assembly mounted on a truck (as in FIG. 20 );
FIG. 23 is a pictorial view of Alternative No. 3 tent assembly mounted on a truck (compare with FIG. 6 );
FIG. 24 is a pictorial view of Alternative No. 3 tent assembly, showing details of detachable attachment of rear pole to center pole.
DETAILED DESCRIPTION OF THE INVENTION
The Camper Truck Tent of this invention is shown in several configurations, apparent from the pictorial assembly drawings with the tent assembly fully folded out on a truck, as follows:
Main Configuration in two versions, FIG. 6 and FIG. 9 ;
Alternative No. 1 , FIG. 19 ;
Alternative No. 2 , FIG. 20 , and
Alternative No. 3 , FIG. 23 .
Referring now to FIG. 1 , there is shown the lateral attachment of mounting support assemblies ( 50 , 52 ) to side walls ( 28 , 30 ) of truck cargo box 24 of pickup truck 20 . Frontassembly 50 is located close to cargo box forward wall 32 just below rear window 44 of truck cab 22 . Rear assembly 52 is located just forward of tailgate 34 . Cargo hooks 36 and 40 are attached to the interior of left sidewall 28 , while cargo hooks 38 and 42 are attached to the interior of right sidewall 30 . Cargo box floor 26 supports tent pouch assembly 380 , with details shown in FIG. 4 and FIG. 5 . Mounting attachment subassembly 11 details are shown in two versions, in FIG. 2 and FIG. 3 .
Referring now to FIG. 2 , subassembly 11 shows the attachment of the left side rear mounting support assembly 52 with studs 54 and 56 , and holes 68 , to cargo box left sidewall 28 . Rear support 58 is secured to brackets 60 which are integral with flanged base 62 , via bolt 64 , where brackets 60 rest on rubber sheet 66 placed on flange 29 of sidewall 28 . Stud 56 and hole 71 anchor flexible loop 70 , used for pole support. The attachment of rear support 58 is via buckle cord 72 to hook 36 in sidewall 28 .
Referring now to FIG. 3 , an alternate subassembly 11 is shown. All components are the same, except that the attachment of rear support 58 is via wing bolt 372 through base 362 and hole 363 to nut plate 365 secured to flange 29 (rather than via buckle cord 72 ).
Referring now to FIG. 4 , details of closed tent pouch assembly 380 are shown. Orientation markings “Front” ( 386 ) and “Rear” ( 384 ) are placed on pouch 382 which houses folded tent 390 and is closed by zipper 388 .
Referring now to FIG. 5 , opened tent pouch assembly 380 with thread 392 is shown, with folded tent 390 removed from pouch 382 . The other callouts are the same as in FIG. 4 . The center portion of the tent floor is sewn to the pouch bottom as shown in FIG. 16 and FIG. 17 .
Referring now to FIG. 6 , a pictorial view of the Main Configuration tent assembly 74 mounted on a truck is shown.
First, the six faces of the tent:
Forward wall 96 with screen 98 and cab access panel 100 ;
Top face 76 of inverse U-shape (shown in FIG. 16 );
Left wall 78 with screen 80 , vent panel 82 and two holes 84 ;
Right wall 86
Aft wall 88 with screen door 90 , door panel 92 and envelope 94 , shaped to cover the tail gate of the truck; and
U-shaped floor 102 (details in FIG. 13 ).
The tent is kept erect by means of hooking straps and a pole structure. A front strap 110 is secured to the front of the truck, while aft straps ( 112 left and 114 right) are secured to the tailgate.
The pole structure contains lateral poles and side poles. Three lateral poles engage corresponding sleeves in the tent fabric:
Forward top pole 122 in forward sleeve 104
Center top pole 132 in center sleeve 106 , and
Aft top pole 134 in aft sleeve 108 .
The side poles are as follows
Two forward side poles 116 (left and right) connected at the top to forward top pole 122 and at the bottom to front support 59 , indicated by numeral 12 (details in FIG. 7 );
Two center side poles 126 (left and right) connected at the top to center top pole 132 and at the bottom to rear support 58 , indicated by numeral 13 (details in FIG. 8 );
Two aft side poles 128 (left and right) connected at the top to aft top pole 134 and at the bottom to rear support 58 (details in FIG. 8 ).
Referring now to FIG. 7 , details are shown of the bottom connection of a forward left side pole 116 to front support 59 by means of loop 70 (see FIG. 2 ) together with ring 118 and screw 120 through holes 84 .
Referring now to FIG. 8 , details are shown of the bottom connection of center left side pole 126 to left rear support 58 , which is identical to the bottom connection of forward left side pole 116 to left front support 59 , with identical callouts 70 , 84 , 118 and 120 . In addition, left aft side pole 128 is secured to center left side pole 126 by means of pivotal rivet pin 130 .
Referring now to FIG. 9 , a pictorial view of an alternate version of the Main Configuration is shown in which cramping side pole 416 , acting as a compressive member, replaces front hook strap 110 ( FIG. 6 ) to perform the function of folding out the front of the tent structure.
The front and upper end of cramping side pole 416 is connected to the upper end of forward side pole 412 which at its lower end is connected to front support 59 . These connections are denoted by numeral 15 .
The rear and lower end of cramping side pole 416 is connected to rear mounting support 430 , as shown in FIG. 11 .
Tent structure and pole structure are otherwise identical to those in FIG. 6 and are not reproduced in FIG. 9 for the sake of clarity.
Referring now to FIG. 10 , details of connections 15 are shown. The upper end of cramping pole 416 is attached by pivotal pin 414 to forward side pole 412 through suitable holes in both poles. The lower end of forward side pole 412 is attached to front support 59 by means of flexible cord loop 70 in combination with ring 118 , screw 120 and holes 84 .
Referring now to FIG. 11 , details of connections 16 are shown. The compressed rear end flat 418 of cramping pole 416 holds pin 420 which is inserted into upward facing hole 432 in rear mounting support 430 . Also, string 422 , secured to cramping pole 416 by wide flat 418 , ties cramping pole 416 to rear mounting support 430 . Aft side pole 128 is attached to center side pole 126 by pivotal pin 130 through suitable holes in both poles. Center side pole 126 is attached to rear mounting support 430 by means of flexible cord loop 70 in combination with ring 118 , screw 120 and holes 84 .
Referring now to FIG. 12 , a pictorial view of the interior of a tent is shown, as a breakaway of the exterior view of FIG. 6 . Left bed 140 and right bed 142 abut forward wall 96 and are supported on front mounting support assembly 50 and rear mounting support assembly 52 . Also shown is U-shaped floor 102 .
Referring now to FIG. 13 , details of a bed 144 are shown. Two rigid longitudinal frames ( 146 , 148 ) are clad top and bottom, using threads 150 and 152 , with flexible envelope 145 to accommodate the body shape of the sleeper. Each frame and each bed accommodate two holes 154 (4 holes total each per bed) which engage studs 54 , 56 etc. anchored in front and rear mounting assemblies ( 50 , 52 ) to firmly secure bed 144 to the truck. Being on the right side, bed 144 abuts forward wall 96 with flanged portion 96 a and right tent sidewall 86 with inboard portion 86 a . Also shown are components of floor 102 , such as stud holes 87 and 101 , and zipper 103 .
Referring now to FIG. 14 , this is an external side view of a tent installed in a truck (Main Configuration as in FIG. 6 ). Shown are front hook strap 110 and aft (left) strap 112 secured over tailgate covered with envelope shaped, portion 94 of tent aft wall 88 . Section 16 - 16 is shown in FIG. 16 .
Referring now to FIG. 15 , this is a top view corresponding to views in FIG. 6 and FIG. 14 . Shown are forward sleeve 104 , forward side pole 116 , center sleeve 106 , aft sleeve 108 , aft side pole 128 and tent top face 76 . Section 17 - 17 is shown in FIG. 17 .
Referring now to FIG. 16 , this is a cross-sectional rear view along Section 16 - 16 in FIG. 14 . The tent surfaces are shown: top face 76 , left wall 78 , right wall 86 , screen 80 , vent panel 82 . Then the left bed assembly 140 and right bed assembly 142 . The tent is completed with tent floor 102 and anchored to left sidewall 28 and right sidewall 30 . Cargo box floor 26 supports tent pouch 382 with tent and pouch sewn threads 392 and zippers 388 .
Referring now to FIG. 17 , this is a cross-sectional side view along Section 17 - 17 in FIG. 15 . Shown are the tent components: top face 76 , center sleeve 106 , forward sleeve 104 , aft sleeve, 108 , front hook strap 110 , aft wall 88 , forward wall 96 , tent floor 102 and floor zipper 103 which allows temporary access to support 58 . Other components are cab access panel 100 , aft screen door 90 , door panel 92 , screen 98 , front mounting support assembly 50 and rear mounting support assembly 52 . Truck components are cab rear window 44 , cargo box forward wall 32 , cargo box tailgate 34 , and cargo box floor 26 on which rest tent pouch 382 with tent and pouch sewn threads 392 and zippers 388 . Also shown is the aft wall envelope shaped portion 94 covering tailgate 34 .
Referring now to FIG. 18 , this is a pictorial view of a collapsed tent assembly installed in a truck. It is seen that the driver has a free view through rear window 44 of cab 22 , with all tent components collapsed below window 44 . In the collapsed state, the topmost tent layer is tent forward wall 96 with forward sleeve 104 , rearward rotated forward pole 116 and exposed loose front strap 110 . Immediately adjacent and also laid flat is aft tent wall 88 with rearward facing aft side pole 128 , with aft straps 112 and 114 in place attached to tail gate 34 .
Referring now to FIG. 19 this is a pictorial view of Alternative No. 1 tent assembly mounted on a truck. Compared to the Main Configuration in similar view of FIG. 6 , the number of poles has been reduced. Tent assembly 160 now has these six surfaces:
Top face 162 of inverse U-shape;
Forward wall 157 ;
Left wall 164 with screen 165 and vent panel 161 ;
Right wall 166 ;
Aft wall 167 with aft screen door 159 , door panel 163 and (as before) envelope shaped aft wall portion 94 to cover the tailgate; and
Tent floor 102 .
As before, front strap 110 and rear straps 112 and 114 fulfil the same functions of erecting the tent. Side poles are now: Forward side poles 171 , left and right, at their top attached via forward sleeve 169 to forward top pole 172 , and
Aft side poles 168 , left and right, at their top attached via aft sleeve 170 to aft top pole 173 .
Both the forward and aft side poles are attached at their lower ends to, respectively, front and rear supports by the structure shown in FIG. 7 and indicated on FIG. 19 by numeral 12 in both places.
Referring now to FIG. 20 , this is a pictorial view of Alternative No. 2 tent assembly mounted on a truck. Compared to the Main Configuration of FIG. 6 , additional roof poles are used. Tent assembly 174 now has these six surfaces:
Top face 176 of inverse U-shape;
Forward wall 196 (see FIG. 22 )
Left wall 178 with screen 180 , vent panel 182 and holes 184 ;
Right wall 186 ;
Aft wall 188 with aft screen 190 , door panel 192 and (as before) envelope-shaped aft wall portion 94 to cover the tailgate; and
Tent floor 202 .
Aft straps 112 (left) and 114 (right) are in place. The side poles are now:
1. Forward side poles (left and right) 216 , at their top ends connected via forward sleeves 204 to short forward top poles 222 which terminate in X-shaped central joint 218 . At their bottom ends poles 216 are connected to front support 59 by the structure shown in FIG. 7 and indicated by the numeral 12 on FIG. 20 .
2. Two center side poles 226 and two aft side poles 228 . Center side poles 226 at their top ends connect via center sleeves 206 to short forward top poles 222 which terminate in X-shaped central joint 218 .
Aft side poles 228 at their top end connect via aft sleeves 208 to aft top pole 234 . At their bottoms aft side poles 228 attach to the bottom of center side poles 226 which connect to rear support 58 by the structure shown in FIG. 8 which is indicated by numeral 13 on FIG. 20 . Unlike the Main Configuration ( FIG. 6 ) and Alternative No. 1 ( FIG. 19 ) both of which are collapsible, Alternative No. 2 ( FIG. 20 ) is not collapsible.
Referring now to FIG. 21 , this is an external left side view of Alternative No. 2 Tent Assembly mounted on a truck as in pictorial view of FIG. 20 . All side poles are visible, forward 216 , center 226 and aft 228 , as well as left wall 178 and aft left strap 112 .
Referring now to FIG. 22 , this is a top view of Alternative No. 2 Tent Assembly mounted on a truck as in pictorial view of FIG. 20 . Visible is the X-shaped configuration on the roof of the tent, formed by forward sleeves 204 and center sleeves 206 , all of them attached to short forward top poles 222 leading to central X-shaped joint 218 . Also shown are the tent top face 176 , right wall 186 , left wall 178 , and forward wall 196 .
Referring now to FIG. 23 , this is a pictorial view of Alternative No. 3 tent assembly 274 mounted on a truck. Compared to Alternative No. 2 as shown in FIG. 20 , straight rigid forward, center and aft poles have been replaced by one-piece flexible poles 316 , 326 and 328 , all formed into curved parabolic shapes. Due to the crossing of poles 316 and 326 at top center, pole 316 is forward on the right but center on the left, and pole 326 is center on the right, but forward on the left. Like Alternative No. 2 , Alternative No. 3 is not collapsible.
Pole 316 over its curved portion engages forward sleeves 304 ; pole 326 over its curved portion engages center sleeves 306 ; and aft pole 328 over its curved portion engages one-piece aft sleeve 308 .
The four tent faces are:
forward wall 296 ;
aft wall 288 with aft screen 290 , door panel 292 and envelope shaped portion 94 ;
U-shaped floor 302 and
inverse U-shape top surface 276 with screens 280 , vent panels 282 , and four holes 284 which engage front and rear supports 59 and 58 at their connection with the bottom extremities of poles 316 and 326 . The details of connection of pole 316 with front support 59 are shown in FIG. 7 and indicated by numeral 12 on FIG. 23 .
When left and right hook straps 112 and 114 are secured to the truck tailgate, the tent structure is erected by stretching the contiguous top surface 276 and aft wall 288 over parabolic aft pole 328 .
Referring now to FIG. 24 , details are shown of the connection of aft pole 328 to pole 326 by means of snap pin 330 which links suitable holes in poles 326 and 328 . A mechanism of rings 70 and 118 and screw 120 attaches the bottoms of pole 326 to extremities of rear support 58 , as detailed in FIG. 8 and indicated by numeral 14 on FIG. 23 .
Advantages
The Camper Truck Tent of this invention offers many advantages for use in the outdoors where ease, efficiency and speed of tent deployment and removal are important. Advantages include:
No tools required for tent installation in and removal from a truck;
Ease of attaching and detaching all tent components from a truck;
Tent storage, availability and deployment is foolproof, with tent sewn to storage pouch, and folded and protected in storage pouch in proper orientation for installation in truck;
Mounting support assemblies utilize existing truck cargo hooks or flanges, avoiding need for external equipment;
Tent side poles are attached and detached by a loop-and-ring system which is easily manipulated by unskilled labor without tools;
Tent floor contains a zipper for temporary access to mounting support assemblies;
Tent collapses easily though the pole attachment is outside the truck cargo box;
Mounting support assemblies are located on top of cargo box sidewalls and so make the entire cargo box volume available for camping items and personal belongings;
Mounting support assemblies accommodate different cargo box dimensions and can extend laterally beyond cargo box sidewalls for increased tent volume and tent user comfort;
Raised flexible canvas beds attached to mounting support assemblies provide increased sleeping comfort compared to sleeping on hard cargo box floor; and
Beds are provided with fabric envelopes which serve to store poles and mounting support assemblies when placed in storage.
Comparison of Camper Truck Tent Configurations
This invention provides the Advantages listed above in the configurations which have been described in the Detailed Description. A short comparison of configurations follows:
Main Configuration Collapsible
a. with front hook strap ( FIG. 6 ) b. with cramping side pole instead of front hook strap ( FIG. 9 )
Alternative No. 1 ( FIG. 19 ): Collapsible
With front hook strap—fewer components—no center side and top poles.
Alternative No. 2 ( FIG. 20 ): Not collapsible
No front hook strap, but more poles.
Alternative No. 3 ( FIG. 23 ): Not collapsible
No front hook strap—decreased tent volume.
Operation
As shown in the preceding Comparison, the Main Configuration and Alternative No. 1 are of the collapsible type, whereas Alternative No. 2 and Alternative No. 3 are of the non-collapsible type. However, certain operational procedures are common to both types.
Both types are stored identically, in three items:
a. the tent in a tent pouch ( FIG. 4 , FIG. 5 ) b. all poles in one bed envelope, and c. the front and rear mounting support assemblies ( FIG. 1 ) in the other bed envelope.
The installation in the truck may be divided into an initial and a final installation. The initial installation is the same for both types:
The front and rear mounting support assemblies are removed from their envelope and securely mounted on the truck cargo box side walls ( FIG. 2 , FIG. 3 ). The tent pouch, marked “Front” and “Rear” is properly placed on the truck cargo box floor, the pouch zipper ( FIG. 4 , FIG. 5 ) is opened and the tent is spread out in proper orientation, after which the ten hales in the tent are fitted to the ten studs in the front and rear mounting support assemblies and support ends.
The subsequent final installation is different for all configurations and described in the following four listings:
Final Installation for Main Configuration:
1. Insert three top poles into the sleeves of the tent;
2. Attach the angled ends of four side poles, two left and two right, to the center and aft top poles. Then attach the other ends of the two center side poles to the loops of the rear mounting support assembly ( FIG. 8 ). The left and right side poles, center top and aft top poles and rear mounting support assembly form two horizontal rectangles on the truck cargo box
3. Attach the angled ends of the left and right forward side poles to the forward top pole. Then attach the other ends of the forward side poles to the front mounting support assembly to form a horizontal rectangle placed over the two rectangles formed with the rear mounting support assembly.
4a. For Configuration (a)( FIG. 6 ): Attach the front strap to the front of the vehicle to lift the forward top pole;
4b. For Configuration (b)( FIG. 9 , 10 , 11 ): Rotate forward side pole counterclockwise and lift forward top pole. Insert pin 420 of cramping side pole 416 into hole 432 of rear mounting support 430 . Tie string 422 to rear mounting support 430 to prevent pin 420 from sliding out and to pole 416 until tailgate is tilted down to give compression to pole 416 .
5. Attach the aft straps to the tail gate, then tilt down the tailgate to lift the center top and aft top poles ( FIG. 6 );
6. Close the tent floor zipper;
7. Install left and right beds on the studs of the mounting support assemblies.
Final Installation for Alternative No. 1 (FIG. 19 )
1. Insert the two top poles into the sleeves of the tent;
2. Attach the angled ends of right and left aft side poles to the aft top pole. Then attach the other ends of the side poles to the loops of the rear support as shown in FIG. 7 . The left and right side poles and rear mounting assembly form a horizontal rectangle on the truck cargo box.
3. 4a. 5. 6. 7. of the Main Configuration above.
Final Installation for Alternative No. 2 (FIG. 20 )
1. Insert four forward top poles into tent sleeves and attach to the bare X-shaped joint;
2. Insert aft top pole into aft sleeve;
3. Attach left and right forward side poles to two forward top poles. Attach left and right center side poles to the two top poles. Then attach left and right aft side poles to the aft top pole.
4. Lift the side poles and attach lower ends of side poles to loops of mounting support assemblies at four locations;
5. Attach aft straps to tailgate, then tilt down tailgate to stretch the top and aft tent walls;
6. Close the tent floor zipper;
7. Install left and right beds on studs of mounting support assemblies.
Final Installation of Alternative No. 3 (FIG. 23 )
1. Insert the three poles into the tent sleeves;
2. Attach two forward poles to loops of front and rear mounting support assemblies at four locations;
3-Attach aft poles to forward poles with snap pins 330 at two locations;
4. Attach aft straps to tailgate; then tilt down tailgate to stretch top and aft tent walls;
5. Close the tent floor zipper;
6. Install left and right beds on studs of mounting support assemblies.
Collapsing Main and Alternative No. 1 Configurations
As shown in FIG. 18 , the tent can assume a flat collapsed state in the truck cargo box, giving the driver rear window visibility to drive, if desired, to another camp site and speedily re-deploy the tent.
This is achieved with FIG. 6 and FIG. 19 by lifting the tailgate to vertical and unhooking the front strap from the truck: these actions cause the aft pole and tent aft portion to fall forward on the cargo box; and the forward top pole and tent forward portion to fall rearward on top of the collapsed aft poles and tent.
For FIG. 9 , the pin securing the cramping side pole to the mounting support is removed, causing the forward top pole and tent forward portion to fall rearward.
With both the front strap and cramping pole arrangements, a reversal of the collapsing actions will easily set up the tent again.
Removal of Tent Equipment—all Configurations
1. Dismantle all pole structures and collect poles;
2. Ready the two bed envelopes;
3. Fold up tent assembly and pack into pouch attached underneath tent floor, properly oriented along “Front” and “Rear” markings, and close pouch zipper.
4. Remove front and rear mounting support assemblies;
5. Store mounting support assemblies in one envelope, and all poles in the other bed envelope.
The Camper Truck Tent is now again stored in the three items described at the beginning of the Operation section.
It is to be understood that the invention may be realized with embodiments differing from the specific devices and procedures disclosed herein without departing from the scope of the present invention as delineated in the following claims.
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A Camper Truck Tent for detachably mounting on a pickup truck, consisting of front and rear mounting supports attached to the truck cargo box sidewalls, various tent poles attaching the folded out tent to the mounting supports, erecting means for folding out the tent and two beds placed inside the erected tent. When dismantled, all these components occupy minimum space. The tent itself is stored in a self-contained pouch on the cargo box floor, the mounting supports in an envelope integral with one bed and the tent poles in an envelope integral with the second bed. The stored components are close to the cargo box floor and out of sight of the truck driver. Several tent pole configurations are available: two main configurations and three alternative configurations. Front and aft erecting means keep the tent folded out. The front means is a front strap secured to the front of the truck or a cramping tent pole. The aft means are aft straps secured to the downed tailgate.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The invention relates generally to the field of floating petroleum drilling and production systems. More specifically, the invention relates to methods for retrieving part of a riser connecting a wellbore to a floating platform such that the platform can be moved in preparation for adverse weather conditions.
[0005] 2. Background Art
[0006] Floating structures are known in the art for drilling wellbores in Earth formations located below the ocean floor, and for producing petroleum from such wellbores. The wellbores are typically drilled using fluid pressure control equipment, called a “blowout preventer” (BOP) affixed to the top of a casing cemented into a relatively shallow portion of the wellbore. A “riser”, which is a pipe formed from segments coupled end to end, is affixed to the top of the BOP and extends therefrom to the floating platform. The riser provides a conduit for fluids to move from the wellbore upwardly to the floating platform. Therefore a riser as used in wellbore drilling forms a conduit for drilling fluid and drill cuttings to be returned to the floating platform for processing and recirculation into the wellbore.
[0007] A riser is assembled to the wellbore from the floating platform by coupling together segments, called “joints” of riser, and moving the assembled “string” of joints of riser downward from the floating platform as successive riser joints are coupled to the string on the platform. The foregoing procedure continues until the riser is long enough to reach the wellbore from the floating platform, whereupon the lowermost end of the riser is coupled to the BOP.
[0008] During the approach of severely adverse weather conditions, such as a tropical cyclone (hurricane or typhoon), safety considerations require preparing the well for the possibility that the floating structure will be moved from its location, either by, or intentionally to avoid, the force of such weather conditions. In preparation for such weather conditions, it is necessary to retrieve the riser from the wellbore. Retrieving the riser includes lifting the riser and consecutively disassembling joints from the remaining riser string as it is suspended from the floating platform in the water. The disassembly continued until all the riser is disassembled and is retrieved from the water. Retrieving the riser is a time consuming and therefore costly procedure, the time and cost of which is related to the depth of water in which the well is being operated. Further, because of the amount of time needed to retrieve the riser, it is necessary to begin retrieval thereof at such a time prior to the expected arrival of such weather conditions as to make it more likely that the adverse weather conditions do not in fact approach the location of the floating platform. Thus, in a number of instances, retrieving the riser proves to be unnecessary.
[0009] A riser disconnect system and method disclosed in U S. Patent Application Publication No. 2004/0173356 A1 filed by Dore et al. provides a way to move a floating drilling structure from a well location by enabling disconnecting the riser from the well. Such system and method have particular application for wells drilled from floating drilling structures where the BOP is located at the top of the riser on the floating drilling structure. However, the method and system disclosed in the Dore et al. publication requires that a disconnect device for the riser be located proximate the water bottom in order to prevent the riser from collapsing under its own weight when tensile force from the floating drilling structure is thus removed. Therefore, the method and system disclosed in the Dore et al. publication still require retrieval of a substantial length of riser below the floating drilling structure, which is time consuming as explained above.
[0010] A riser system having a BOP near the water bottom and including a riser disconnect is shown in U.S. Pat. No. 5,657,823 issued to Kogure et al. The system shown in the '823 patent provides a way to disconnect the riser at a relatively shallow depth in the water, described as 50 to 500 feet, to enable relatively quickly moving the floating structure away from the well area if a storm approaches. The system shown in the '823 patent includes buoyancy devices such as canisters that are affixed to the lower portion of the riser in the event the upper portion riser is to be disconnected from the floating platform. When the upper portion of the riser is disconnected from the lower portion, the buoyancy devices support the lower portion of the riser in tension. It can be time consuming and difficult to affix buoyancy devices to a riser when it is deployed in the water.
[0011] What is needed is an improved method and system to reduce the amount of time needed to make adverse weather preparations for a floating drilling or production platform.
SUMMARY OF THE INVENTION
[0012] One aspect of the invention is a method for preparing to move a floating structure away from a wellbore drilled below the bottom of a body of water. A method according to this aspect of the invention includes filling a riser extending from the bottom of the body of water to the floating structure with water. The water in the riser is displaced with gas to a selected first depth below the water surface. The riser is sealed at a second selected depth shallower than the first selected depth. The portion of the riser above the second selected depth is withdrawn onto the floating structure.
[0013] Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows a floating drilling platform drilling a wellbore in the Earth's subsurface below the bottom of a body of water including a riser disconnect disposed at a selected depth below the water line.
[0015] FIG. 2 shows a more detailed view of the riser disconnect, and a special tool for sealing the riser to fluid pressure.
DETAILED DESCRIPTION
[0016] Various embodiments of the invention are explained herein in the context of drilling operations from a floating drilling platform. However, it should be clearly understood that methods and systems according to the invention are also applicable to floating production systems, and thus, application of the method according to the present invention to drilling is not a limitation on the scope thereof. FIG. 1 shows a floating drilling platform 10 , such as a semisubmersible drilling rig or a drill ship, on the surface of a body of water 11 such as the ocean as the platform is used for drilling a wellbore 16 in subsurface Earth formations 17 below the bottom 11 A of the body of water 11 . The wellbore 16 is drilled by a drill string 14 that includes (none of which shown separately) segments of drill pipe threadedly coupled end to end, various stabilizers, drill collars, heavy weight drill pipe, and other tools, all of which may be used to turn a drill bit 15 disposed at the bottom end of the drill string 14 . As is known in the art, drilling fluid is pumped down the interior of the drill string 14 , exits through the drill bit 15 , and is returned to the platform 10 for processing. A riser 18 connects the upper part of the wellbore 16 to the floating platform 10 and forms a conduit for return of the drilling fluid. Wellbore fluid pressure control equipment, collectively referred to as a blowout preventer (BOP) and shown generally at 20 includes sealing elements (not shown separately) to close the wellbore 16 below the BOP 20 in the event closing the wellbore 16 becomes necessary. The BOP 20 is controlled from the platform 10 by suitable control lines 20 A known in the art.
[0017] In the present embodiment, the riser 18 may include a booster line 22 coupled near the BOP end thereof or to the BOP 20 selectively opened and closed by a booster line valve 22 A. The booster line 22 forms another fluid path from the platform 10 to the wellbore 16 at a depth proximate the BOP 20 . The purpose for the booster line 22 and valve 22 A as related to the invention will be further explained below. The riser 18 also includes therein a riser disconnect 24 of any type well known in the art, such as may be obtained from Cooper Cameron, Inc., Houston Tex. The disconnect 24 is disposed in the riser 18 at a selected depth below the water surface. The riser disconnect 24 is preferably located at the shallowest depth in the water that is substantially unaffected by action of storms on the water surface. Such depth is presently believed to be about 500 feet. As will be further explained below, when storm preparations are made, the riser 18 may be uncoupled at the riser disconnect 24 , hydraulically sealed, and the upper section of the riser 18 , from the disconnect 24 to the surface may be retrieved onto the floating platform 10 , whereupon the platform 10 may be moved from the location for safety.
[0018] In a method according to the invention, the riser 18 can be partially filled with gas to a selected depth. Such depth is preferably selected such that the gas in the riser 18 will reduce the weight of the riser 18 in the water 11 so as to provide the portion of the riser 18 below the disconnect 24 with sufficient buoyancy to support the weight of the riser 18 below the disconnect 24 . Such support may require additional buoyancy, such as can be provided by air cans (not shown) or other buoyancy device known in the art, however the principle is that the additional buoyancy provided by gas displacement within the riser 18 will enable disconnection from the riser 18 of the tensile force otherwise provided by the platform 10 to the riser 18 . Where the riser disconnect 24 is located about 500 feet below the water surface, it is contemplated that the displacement of the liquid in the riser 18 with gas should take place to a depth of about 2,500 feet from the water surface. If the riser disconnect 24 is placed about 500 feet below the water surface, the displacement depth would thus be about 2,000 feet below the riser disconnect 24 . The particular depth to which gas should displace liquid in the riser 18 will depend on the weigh in water of the particular riser and the length of the riser below the disconnect 24 .
[0019] In one embodiment of a method according to the invention, to prepare the wellbore 16 and the riser 18 for moving the platform 10 from the location, first the drill string 14 is lifted out of the wellbore 16 such that it is above the BOP 20 . The BOP 20 is then closed to seal the wellbore 16 below the BOP 20 . When the BOP 20 is closed, the control line 20 A may be retrieved therefrom and withdrawn to the platform 10 . Then, the drilling fluid in the riser 18 is displaced with sea water. In one implementation, the sea water is pumped into the interior of the drill string 14 so as to displace all the drilling fluid in the riser 18 up the annular space between the drill string 14 and the riser 18 . By displacing all the drilling fluid, which may have a specific gravity of as much as 2.2 or more, the weight of the riser 18 in the water 11 is reduced. After the drilling fluid in the riser 18 is displaced, the drill string 14 is withdrawn from the riser 18 and a riser fluid displacement and riser sealing tool can be coupled to the drill string. A more detailed view of the riser 18 near the position of the disconnect 24 , and the disconnect 24 , itself are shown in FIG. 2 along with one embodiment of a riser fluid displacement and sealing tool that may be used with a method according to the invention.
[0020] Referring to FIG. 2 , the displacement and riser sealing tool in one embodiment may include a running tool, shown generally at 30 , that may be threadedly coupled to the lower end of the drill string ( 14 in FIG. 1 ). A sealing element, shown generally at 32 , may be itself threadedly coupled to the running tool 30 . The sealing element 32 may include external threads 32 A thereon to mate with corresponding internal threads 24 B in a lower portion 24 A of the riser disconnect 24 . The sealing element 32 includes an opening 39 in the bottom thereof to enable passage of fluids therethrough. The opening 39 is sealed by a flapper valve 38 or the like that closes automatically when the running tool 30 is withdrawn from the sealing element 32 . The running tool 30 may include a J-slot engagement device for coupling to the sealing element 32 to the running tool 30 during the procedure of inserting the sealing element 32 into the riser 18 . The J-slot engagement device is formed from two components, one shown on the running tool at 36 A and the other shown on the sealing element 32 at 36 B. During insertion of the sealing element 32 , the sealing element 32 is affixed to the running tool 30 by the J-slot device 36 A, 36 B. The running tool 30 and sealing element 32 are lowered into the lower portion 24 A of the riser disconnect 24 at the end of the drill string ( 14 in FIG. 1 ) and the sealing element 32 is threadedly engaged to the lower portion 24 A using the corresponding threads 32 A, 24 B by rotating the drill string ( 14 in FIG. 1 ). In the present embodiment, the corresponding threads 32 A, 24 B are left handed, the reason for which will be explained below.
[0021] The interior of the drill string ( 14 in FIG. 1 ) may then be charged with gas, such as nitrogen, under pressure contemporaneously with opening the booster line valve ( 22 A in FIG. 1 ). The gas flows through the drill string ( 14 in FIG. 1 ), outward from the opening 39 , and by action of the gas pressure displaces the water in the riser 18 (which upon displacement travels upwardly through the booster line 22 ) downwardly to a selected depth, which as previously explained may be about 2,000 feet below the riser disconnect 24 . The water leaves the riser 18 through the booster line ( 22 in FIG. 1 ) and moves back toward the platform ( 10 in FIG. 1 ). The booster line valve ( 22 A in FIG. 1 ) is then closed, and the drill string ( 14 in FIG. 1 ) can be withdrawn from the riser 18 by disengaging the running tool 30 from the sealing element 30 . Such disengagement may be performed by suitable axial and rotational movement thereof to disengage the J-slot device 36 A, 36 B. When the running tool 30 is withdrawn from the sealing element 32 , the flapper valve 38 closes, thus hydraulically sealing the riser 18 . The riser disconnect 24 may then be operated in the manner known in the art, and the portion of the riser 18 above the riser disconnect 24 can be withdrawn from the water and placed on the platform ( 10 in FIG. 1 ).
[0022] After any storm danger has passed, the upper portion of the riser 18 may be reengaged with the lower portion thereof by engaging the components of the riser disconnect 24 in the manner known in the art. The sealing element 32 may be removed from the riser disconnect 24 by again affixing the running tool 30 to the drill string ( 14 in FIG. 1 ), and moving the running tool 30 such that it engages the sealing element 32 . In removing the sealing element 32 , the J-slot devices are not used, but instead, corresponding threads 34 A, 34 B on the running tool 30 and the sealing element 32 , respectively, are engaged by rotating the drill string ( 14 in FIG. 1 ) clockwise. The corresponding threads 34 A, 34 B are right-handed, and thus opposite-handed to the threads 24 B on the lower portion 24 A of the riser disconnect 24 and the corresponding threads 32 A on the sealing element 32 . Therefore, continuing drill string rotation in the direction (clockwise in the present embodiment) that engages the threads 34 A, 34 B between the running tool 30 and sealing element 32 disengages the corresponding threads 32 A, 24 B between the sealing element 32 and the riser disconnect 24 . The drill string ( 14 in FIG. 1 ) may then be withdrawn from the riser 18 , with the running tool 30 and sealing element 32 attached at the bottom end thereto, and normal drilling operations may resume.
[0023] In water depths of several thousand feet or more, it is therefore only necessary to remove the length of riser 18 to a depth just below that to which storm effects descend. As an example, only the topmost 500 feet of riser is expected to be withdrawn to the platform ( 10 in FIG. 1 ), leaving the entire lower portion of the riser self-suspended by enough buoyancy to avoid collapse thereof. Such procedure is expected to take only a few hours, as contrasted with the several days it may take to withdraw the entire riser from the water.
[0024] The embodiment explained above with reference to FIG. 2 in which the riser is displaced by pumping gas therein is only one method for displacement. In other embodiments, suitable “swab” devices may be affixed to the lower end of the drill string such that the water in the riser may be lifted out of the riser by motion of the drill string.
[0025] Methods according to the invention can substantially reduce the time necessary to prepare a floating platform for storm evacuation, and can reduce the number of times the preparations are made unnecessarily by shortening such preparation time.
[0026] While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
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A method for preparing to move a floating structure away from a wellbore drilled below the bottom of a body of water includes filling a riser extending from the bottom of the body of water to the floating structure with water. The water in the riser is displaced to a selected first depth below the water surface. The riser is sealed at a second selected depth shallower than the first selected depth. The portion of the riser above the second selected depth is withdrawn onto the floating structure.
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FIELD OF THE INVENTION
This invention relates to an article of clothing worn about the neck. In particular, the invention relates to neckwear with weighted ornamental or interactive toys attached to the neckwear.
PRIOR ART
U.S. Pat. No. 5,720,049 to Clutton discloses a scarf having two ends that are releasably held together by weighted attachment means to secure the scarf by making a loop about an individual. As illustratively shown in FIGS. 1A and 1B , Clutton teaches cup members 101 and 102 attached to each end of a scarf, and barrel members 107 and 108 made of relatively weighty material attached to the cup members 101 and 102 , respectively. Further, the barrel members are screwed onto each other so that the scarf is formed into a closed loop around a wearer's neck when in use. Clutton, however, fails to teach or suggest a means to keep the scarf in place without either a cup and barrel apparatus or without attaching one end of the scarf to the other. Further, Clutton also fails to teach or suggest a decorative ornament that is an amusement toy.
In another example, U.S. Pat. No. 5,713,080 to Tate teaches a clothing ornamentation device 210 that includes weighty ornaments 236 and 238 and a secure element 212 for attaching the ornamentation device 210 to an upper portion of a wearer's garment 214 . FIGS. 2A , 2 B, and 2 C are exemplary illustrations of the clothing ornamentation device of Tate. The ornamentation device 210 is draped over a garment for decorative purposes. The device of Tate is a clothing decorative accessory that is secured to a clothing at the neck area by the secure element 212 . The ornamentation device of Tate can be used to drape over various types of clothing articles; however, the ornamentation device does not provide any warmth, and it is not a toy or a toy carrier.
SUMMARY OF THE INVENTION
Therefore there is a need for a clothing article, which provides warmth and decoration as that of a conventional scarf but in addition has functional devices having decorative value attached to each end of a scarf.
An object of the instant invention is to provide a new and improved scarf with a hands-free means for conveying toys.
Another object of the instant invention is to provide, at each end of the scarf, an interactive toy and/or an ornamental toy for either children or adults to play.
Still another object of the instant invention is to provide an object at each end of a scarf, wherein the objects at each end are approximately evenly weighted so as to hold the scarf in place on a wearer's body and to keep it from falling off without having to tie or otherwise attach the ends together.
Yet another object of the instant invention is to provide an improved scarf that requires no fastener to secure the scarf to a wearer's body.
It is still another object of the instant invention to provide a scarf with a multi-purpose weighted objects attached that serve a interactive or ornamental toys and means for securing a scarf to a body.
It is still another object of the invention to provide a scarf with weight attachments that effectively hold the scarf on a wearer's body, wherein the total weight of the objects attached to the scarf that effectively holds the scarf in place preferably is in the range of about half an ounce to 32 ounces, more preferably in the range of about 1 ounce to 12 ounces, and even more preferably in the range of about 2 ounces to 8 ounces.
As described below, the present invention provides advantages over prior art scarves. For example, the present invention allows the toys to be carried about in a more secured fashion. It also alleviates the need for children or adults to carry bags, backpacks, or purses to secure the toys while moving about.
Another advantage of the present invention is that the objects attached, which are specifically intended to entertain or to be interactive with the wearer, can encourage children to wear scarves for warmth and protection against the elements. The unique entertainment value of the toy attached in the present invention makes wearing a scarf more desirable and thus serves as a parental aid to keep children warm.
Yet another advantage of the present invention is that the weighted object on each end holds the scarf in place. Thus, clips, tying, or other fastening devices are not needed.
Additional advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein only the preferred embodiment of the invention is shown and described, simply by way of illustration of the best mode contemplated for carrying out the present invention. As will be realized, the present invention is capable of other and different embodiments, and its several details are capable of modification in various obvious respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative nature, and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference is made to the attached drawings, wherein elements having the same reference numeral designations represent like elements throughout, and wherein:
FIG. 1A illustrates a prior art article of clothing.
FIG. 1B illustrates a prior art scarf securing means.
FIG. 2A illustrates a prior art clothing ornamentation device.
FIG. 2B illustrates a prior art fastening element.
FIG. 2C illustrates in further details of the clothing ornamentation device shown in FIG. 2A with weighted ornaments.
FIG. 3 illustrates an embodiment of a scarf with ornamental toys of the present invention.
FIG. 4 illustrates another exemplary embodiment of the present invention.
FIG. 5 illustrates an exemplary means for affixing an interactive toy to a scarf.
FIG. 6A illustrates yet another exemplary embodiment of the present invention.
FIG. 6B illustrates another exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention addresses and solves problems related to neckwear falling off a wearer's body, being indistinguishable from other neckwear, being unattractive or uninteresting to a wearer, and carrying toys hands-free.
Referring now to the drawings, FIG. 3 illustrates an embodiment of the present invention including a scarf 1 . The scarf 1 is preferably rectangular or elongated in shape. The scarf can be made up of a material including wool, silk, cashmere, fleece, cotton, polyester, or the like. With a scarf having an elongated shape like that of scarf 1 , objects 4 and 5 may be fixed or removably attached to the ends of 2 and 3 of scarf 1 .
The ornamental objects attached to the scarf preferably are weighted. That is, the objects have higher density, i.e. ratio of mass, to bulk or volume, than that of the material of the scarf so as to provide a means to minimize the scarf from being blown by wind and to secure the scarf to a wearer's body.
The objects attached to the scarf are preferably ornamental toys or interactive toys, and the term objects shall be used interchangeably with toys or devices disclosed herein. The types of objects will become more apparent as the invention is being described.
Further, the objects attached to the scarf preferably have a total weight in the range of 0.5 ounce to 32 ounces, more preferably between about 1 ounce and 12 ounces, and even more preferably between about 2 ounces and 8 ounces.
The scarf may be of a square shape having ornamental and or interactive toys attached to opposite corners 2 and 3 as shown in FIG. 6A . The scarf may have other shapes, such as oblong or polygonal shapes.
The square-shaped scarf 1 of FIG. 6A may be folded as shown in FIG. 6B so that it can be wrapped around the wearer's body more easily.
The toy 6 shown in FIG. 6A may be an interactive learning device. For example, the toy 6 can be a speaking alphabet. The toy 7 in FIG. 6A can be a soft miniature soccer ball.
The objects attached to the scarf are preferably of approximately equal weight so that the scarf could be balanced on the wearer's body. Exact equal weight of each object is not essential as the scarf's fabric material provides some friction against the wearers' clothing or body to further help any unbalance in weight. Further the weighted objects are of sufficient weight so that the scarf cannot easily be blown by gusty winds but are also not overly weighty so that prolonged wearing of the scarf would not overly burden the wearer.
The objects may be affixed permanently or removably against the scarf, partly against the scarf, or partly dangling below the scarf. The weighted objects can be affixed at a location anywhere from the edge of each end of the scarf to a position that is one-fourth the total distance up from the edge of the ends of the scarf.
FIG. 4 illustrates an example of a scarf with ornamental toys 4 and 8 attached fully against the scarf. If the toys are dangling fully below the scarf, such as shown in FIG. 3 , the toy may be attached to the scarf by a string, thread, ribbon, hooks and loops, or similar connector pieces.
Further, the objects may be affixed permanently by sewing, gluing, or other attachment means. The objects may be detachably affixed to scarf 1 by hooks and loops means (i.e., Velcro™), buttons, snaps, hooks, or any other removable means. An example of an interactive electronic toy removably attached to scarf 1 can be seen in FIG. 5 .
FIG. 5 illustrates scarf 1 having hooks and loops attaching means 10 sewn to scarf 1 , and attached to the hooks and loops attachments means is an interactive electronic gadget or toy 9 . The electronic toy 9 can be easily removed from the scarf 1 so that the scarf can be washed and cleaned without damaging the electronic gadget 9 .
An interactive toy can be mechanical, electro-mechanical, or electronic devices. Example of preferred devices are whistles, electronic action figures, Personal Digital Assistant (PDA), wireless communication devices, electronic pets, voice recorder, and the like.
The ornamental toys may include small soft toys, plush stuffed animals, dolls, or other objects that are safe for children. Further, the toys may include teaching aids, miniature storybooks, numbers, letters, shapes, with various colors and designs to stimulate the mind of the wearers.
Not being limited to the scarf shown in FIG. 3 , FIG. 4 , and FIG. 6 , the ends of the scarf to which the toys are affixed may be squared-off, pointed, gathered, rolled, fringed, or finished in any other fashionable manner.
As can be seen in the illustrated embodiments, there are no means provided for attaching one end of the scarf to another. The scarf of the present invention may be worn lying flat with each end hanging separately on either side of the wearer's neck. No fastening implements would be needed as the weight of the objects functionally keep the scarf balanced and secured to the wearer's body.
In the present invention the scarf is advantageously held in place without resorting to means of a cup and barrel apparatus, a ring, a clip, or the like and without attaching the ends to one another. The scarf of the present invention provides a safe method for securing a scarf in place without any fastening means that would be impractical for children or people with insufficient dexterity to secure the scarf by a mechanical fastening means.
Further by way of the present invention children can wear a scarf with the risk of strangulation minimized by the absence of mechanical fastening devices.
In the embodiment shown, the scarf of the present invention becomes more than just a piece of apparel, rather it also serves as a mobile entertainment center. The scarf of the present invention is fundamentally different from all the scarves that have come before, which had fringe or tassels attached to the ends which were solely intended for decoration. The objects combined with the scarf in a strategic location are specifically intended to entertain and be interactive with the wearer. Because of this unique entertainment feature, the present invention makes wearing a scarf more desirable, and, thus, serves as a parental aid to keep the children warm. The ornamental toys or interactive toys are also specifically intended as means to prevent a scarf from flying or slipping off the wearer's body.
The scarf of the present invention is not limited to having a single weighted object attached to each end. Instead, the scarf can have more than one weighted object attached to each end of the scarf.
As various possible embodiments may be made in the above invention for use for different purposes and as various changes might be made in the embodiments and method set forth above, it is understood that all of the above matters here set forth or shown in the accompanying drawings are to be interpreted as illustrative and not in a limiting sense.
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An improved scarf having weighted objects fixedly or removably attached to the ends thereof to provide a means for securing the scarf to a wearer's body without the need for means for securing the ends of the scarf together. The improved scarf also provides a hand-free means for carrying toys and an attractive means for encouraging people to wear a scarf. Further, the improved scarf provides a means to make a scarf more distinguishable so as to make it easier to identify.
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RELATED APPLICATIONS
[0001] This non-provisional patent application is related to, and claims the benefit of U.S. Provisional App. No. 60/508,000, filed on Oct. 2, 2003, which is also hereby incorporated by reference.
BACKGROUND
[0002] This application relates to data transport arrangements that allow a provider to support any client data protocol, as well as provide quality of service monitoring that is ascertainable without delving into the client's signal. More particularly, this application relates to an arrangement that, for example, allows a subwavelength SONET client signal to be transported transparently and with sufficiently high fidelity so that inherent timing information of the signal is maintained.
[0003] A transport provider that wishes to offer high capacity facilities to customers can implement the offer by simply providing so-called “dark fiber,” allowing the customers to place whatever signals they wish on the fiber.
[0004] One value proposition is for the provider to offer a fiber and a “service,” whereby a channel is provided for transmission of information, with a guarantee that the transmitted information will arrive at its destination with an agreed-to quality of service. To provide the agreed-to quality of service, the provider sends the information over the fiber in a particular protocol that is chosen by the provider, monitors the quality of the service, and performs appropriate maintenance activities, as needed. That means that the provider carries on the fiber various signals that do not belong to the customer for the purpose of monitoring the quality of service. Dark fiber clearly cannot meet this value proposition.
[0005] An advanced value proposition is for the provider to offer a fiber, and to also offer a plurality of channels, concurrently, using a particular protocol, with the channels adapted to carry client signals. SONET is an example of such a value proposition. SONET encapsulates a client-provided signal into successive Synchronous Payload Envelope (SPE) blocks of data, injects these blocks into successive SONET frames, modulates numerous SONET frames onto different wavelengths, and places them onto a fiber. The reverse process takes place when data needs to be extracted.
[0006] One aspect of SONET is that it offers clients a variety of bandwidths. The lowest SONET bandwidth (OC-1) is capable of carrying a DS3 signal, having a 44,736 Mb/s rate, and the SONET standard contemplates higher bandwidths in multiples of OC-1. However, commercial equipment that carries SONET signals over fiber handles only OC-3, OC-12, OC-48, and OC-192 signals. Intermediate rates are generally multiplexed into one of these four signal rates.
[0007] Another aspect of SONET is that it can be add/drop multiplexed, meaning that a given channel can be extracted from, or added to, the information signal that is contained in a given wavelength without having to extract all of the other channels that are contained in the information signal, or to reconstitute the information signal.
[0008] Still another aspect of SONET is that it carries it's own maintenance information, permitting the provider to offer a guaranteed level of service quality without having to delve into the client's signal per se.
[0009] What would be desirable that SONET cannot provide is the ability to transmit client signals that themselves are SONET frames, transparently, and in a bandwidth efficient manner while maintaining the timing integrity of the client SONET signals themselves. By “transparently” what is meant is that
the offered client's signal (e.g., an OC-3 SONET signal) can be communicated through the network, from an ingress node to an egress node, in a manner that allows the client's signal to be multiplexed onto a fiber with one or more other signals, where the other signals possibly have different bandwidths, or different protocols, and where the other signals may be time-division-multiplexed onto the same wavelength, or onto different wavelengths, the client's signal can have any desired protocol (i.e., including SONET), the client's signal can be add/drop multiplexed at any point in the network without requiring add/drop operations on other signals and, correspondingly, add/drop operations need not be undertaken relative to the client's signals when add/drop multiplexing is performed on some other signal on the fiber, and the provider is able to ascertain quality of service provided to the client without having to look into the client's signal per se.
[0014] As indicated above, SONET fulfills the above transparency requirements, except that it does not allow the client to send a signal that itself follows the SONET protocol while maintaining the timing integrity of the SONET client signal. Clearly, for example, one cannot send an OC-3 SONET client data frame as a unit over an OC-3 SONET frame, because the payload bandwidth of the provider's OC-3 frames is simply not large enough to carry both the payload and the overhead of the client's signal. One possibility that has been studied by Lucent Technologies is to stuff an OC-3 frame into an OC-4 signal. After extensive efforts it was concluded that this proposal was not able to meet the SONET timing standards for the client SONET signal. This is clearly evident in FIG. 5 - 18 ( a ) of T1X1.3/2002-036 contribution to the T1 Standard Project-T1X1.3. This contribution, titled “Jitter and Wander Accumulation for SONET/SDH over SONET/SDJ (SoS) Transport” by Geoffrey Garner, dated Sep. 30, 2002, which is hereby incorporated by reference. Note that all simulation depicted in the aforementioned FIG. 5 - 18 ( a ) are above the OCN Reference Mask; where the need is to be below this mask.
[0015] Separately, the Digital Wrapper standard exists (G.709) that contemplates signals flowing in frames having one of three line rates. The lowest rate (OTU1) carries 20,420 frames/s, and each frame consists of 16,320 bytes that structurally can be viewed as 4 rows and 4080 columns. Sixteen columns are devoted to overhead, 3808 columns are devoted to client payload, and 256 columns are devoted to forward error correction, which results in a payload rate of approximately 2.666 Gb/s. The OTU1 rate can be used to communicate a 2.48832 Gb/s OC-48 SONET signal, as the payload area was sized for that capacity. Equipment exists to terminate a number of SONET signals and, after removing their payload information (SPE), multiplex the individual payloads to form an OC-48 signal, to encapsulate it in an OTU1 digital wrapper, and to modulate the resulting signal onto a chosen wavelength. To date, however, no design exists for channelizing the Digital Wrapper for the many lower rate data services that a telecommunications carrier is called upon to transport, such as the above-mentioned OC-3 signal, i.e., a design that allows one to carry sub-multiples of the OTU1 signal (also termed sub-wavelength channels) using the Digital Wrapper standard.
SUMMARY
[0016] An advance in the art is realized by extending the Digital Wrapper standard G.709 to create a tributary group from OTU1 16 frames forming a tributary group. This group this group is mapped onto a grouping of 64 OTN tributary frames that are di-byte interleaved. Each tributary frame thus can be viewed as a block of 15240 columns and 4 rows, where the first 4-column section is devoted to overhead. The remaining columns are devoted to payload data, with the fourth row of the overhead section assigned to negative pointer justification opportunities, and the following four bytes (in columns 5th through 8th) are assigned to positive pointer justification opportunities. The payload data section is able to hold OPVC1 frames, each of which has an overhead section, and preassigned negative and positive justification byte positions.
[0017] With the extended Digital Wrapper protocol, which seamlessly dovetails with the G.709 standard, data that entered an ingress node is synchronized to the local clock and a phases offset measure is developed and included in the transmitted signal. This measure is evaluated repeatedly, for example, every OPVC1 frame. At an egress node, the phase-offset measure that is received with the signal is employed to derive a more accurate client signal clock, and this enables the network to support client signals that need to be communicated with high clock fidelity, such as SONET signals.
[0018] Additionally, in order to minimize jitter and wander, pointer processing that is performed in each intermediary node through which a signal travels between the ingress and egress nodes is modified to introduce positive and negative justification bytes in excess of what is minimally necessary so as to shift energy into higher frequencies that can be filtered out by the phase lock loop at the egress node.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIGS. 1A and 1B depict a tributary frame in accord with the principles disclosed, and an OPVC1 frame that is injected payload of the tributary frame;
[0020] FIG. 2 is a block diagram showing selected aspects of an ingress node in accordance with the principles disclosed herein
[0021] FIG. 3 is a block diagram showing selected aspects of an egress node that complements the ingress node of FIG. 2 ;
[0022] FIG. 4 is a block diagram of a node through which a signal traverses between the ingress node and the egress node; and
[0023] FIG. 5 shows the circuit arrangement that performs modified pointer processing.
DETAILED DESCRIPTION
[0024] To gain an appreciation for the disclosed advance, it is beneficial to review the timing problems that arise in the SONET network in spite of the fact that all nodes in a SONET network nominally operate off a common clock. There are two specific timing problems of interest: timing impairments as a result of mapping the client signal into the SONET frame, and timing impairments resulting from SONET pointer processing. Each of these will be discussed separately.
[0025] SONET employs a layered structure, with one layer concerning itself with framing, and another with the payload being carried. As for the framing layer, a SONET STS-1 signal consists of a sequence of frames each containing 810 bytes that can be viewed as a 90 column by a 9 row arrangement, where the first three columns contain transport overhead byes. Of the 27 available header bytes, 9 bytes (the three transport overhead bytes of the first three rows) are devoted for Section Overhead, and 18 bytes are devoted for Line Overhead. The remaining 87 columns make up the STS-1 envelope capacity, which contains the synchronous payload envelope (SPE). The first column of the SPE is devoted to Path Overhead, and two columns (columns 30 and 59) are devoted to “fixed stuff”. This leaves 756 bytes in the SPE for client data, which is sufficient for mapping a DS3 client data signal.
[0026] The SPE can be placed into the STS-1 envelope capacity beginning at any byte position within the STS-1 envelope capacity. The location of the first byte of the SPE (which is called the J1 byte) is identified by a pointer that is contained in the first two bytes of the Line Overhead (H1 and H2 bytes) of the STS-1 frame.
[0027] A SONET client's input data that enters a SONET ingress node (e.g., node A) is mapped into the SPE using conventional buffering techniques. That is, client's data is written into a buffer memory at the client's clock frequency, and is outputted from the buffer memory at the ingress node's clock frequency. The read-out clock frequency, on the average, ought to be the same as the write-in clock, so as not to cause an overflow or underflow. In order to prevent a possible underflow of the buffer when the read-in clock is consistently slower, the read-out operation is stalled (no data is read) at prespecified points of the SPE, as necessary. In order to prevent overflow when the clock situation is reversed, data is read out at times within the SPE that normally are not used for reading out data. A SONET frame is then created (having a fixed number of data bytes) by inserting the SPEs into the SONET frames as indicated above, using the pointer to identify where the SPE begins, and once the SONET frame is created, it can be sent out, for example, to node B.
[0028] It is important to note that these operations (stalling the reading out process and/or reading out extra data) introduce phase jumps in the mapped data stream, which cause timing impairments in a recovered client signal. We refer to this as mapping impairments.
[0029] Considering what happens at node B, it is possible that the frequency of the node B clock might be slightly different from that of the node A clock even though the intent of the SONET network is for all nodes to operate off a common clock (this can occur during timing reference failures or due to the introduction of noise into the timing signals). Because of this possibility and because of normal propagation delays in the signal flows throughout the network, node B must perform at least the following steps:
1. derive an approximation of the node A clock, ŷ A , from the incoming signal, 2. using clock ŷ A , extract the header information that is within the incoming frame, 3. using clock ŷ A , extract the payload information that is within the incoming frame, 4. process the extracted header information and react to it, 5. using clock ŷ A , create new header information for an outgoing frame, 6. using clock ŷ A , inject the extracted payload, into the outgoing frame, and 7. send out the newly created frame (at clock rate y B ).
[0037] Of the above steps, step 6 is the most challenging, because of the asynchrony between the clocks ŷ A , and y B . The task is to create an SPE that is to be inserted into a node B SONET frame, which operates at rate y B , and to do so from data that is received from node A at frequency ŷ A . If y B >ŷ A (even a little) the data arrives more slowly than it leaves, and a consequence of this is that every so often the outputting of actual data must be arrested because there is no data to output. Since the node's output is at a constant clock rate (y B ), during a clock period when there is no data, the system must simply wait and, effectively output a dummy data byte. In order to avoid having to output dummy bytes whenever a no-data condition exists, a buffer is included that, though it introduces delay, affords the flexibility to place dummy bytes in pre-specified overhead positions (the byte position immediately following the H3 byte of the Line Overhead). Since the SONET frames that are created by node B are outputted at a fixed rate, the insertion of a dummy byte in an SPE shifts the positioning of the following SPE forward within each SONET frame. To remain aware of the positioning of the SPE starting point, the pointer in the SONET frame's overhead is adjusted (incremented) to specify where the starting point of the SPE is.
[0038] Correspondingly, if y B <ŷ A , the data arrives more quickly than it leaves, and a consequence of this is that, though the arriving data can be buffered, eventually all of it must be placed within an outgoing SPE, in some otherwise unused byte position, or else an overflow condition would occur. That means that an SPE, or at least the SONET frame, must have such an unused byte position. Indeed, the SONET design includes a byte in the header (the H3 byte) that can be so used. Thus, when y B <ŷ A , every so often (depending on the size of the difference between y B and ŷ A ) a data byte must be stuffed into the available byte position that does not normally carry client data (H3 byte). Consequently, the SPE ends at one position sooner than it would otherwise, and the next SPE's J1 byte is stored one position sooner as well. Correspondingly, the pointer is decremented to correctly specify the SPE's starting point.
[0039] All of this shifting of SPE's, inserting dummy bytes, and/or inserting extra data bytes is carried out with what is typically referred to as “pointer processing.” A side effect of the pointer processing, or more specifically of the addition of dummy bytes or extra data bytes, that results from the asynchrony between clock y A and y B is that the number of actual client bytes in an SPE differs from frame to frame creating phase jumps, and client signal timing impairments are thus introduced. In addition, as each node performs its own pointer processing functions, asynchronously of all other nodes, pointer adjustment decisions may be made at the same time in successive nodes, causing an accumulation of error.
[0040] If the client's data were to be extracted at node B, i.e., if node B were the egress node, it would be quite simple to extract the SPEs based on knowledge of their starting points (provided by the pointer), extract the overhead bytes of the SPEs, identify the dummy bytes and stuffed bytes from apriori information about the nature of the input signal (i.e., number and location of the “fixed stuff” columns) and from the pointer, and output the extracted client data as it is unmapped from the SPE. This unmapping yields the client's signals, but at an irregular rate. There is a hiatus during the 27 transport overhead bytes (that, on occasion, may include a data bye in H3), a hiatus during the 9 path overhead bytes, a hiatus during (at least some of) the 18 fixed stuff bytes (from columns 30 and 59), and a hiatus during the inserted dummy bytes. The client, however, desires its data to be provided by the egress node at a constant rate, and desirably, at the rate at which the data was offered to the ingress node. In addition, the client signal could conceivably traverse multiple SONET networks (due, for example, to the fact that a service may need to be carried via multiple service providers in order to be transmitted end-to-end, i.e., from a local exchange carrier (LEC) to an inter-exchange carrier (IXC) to another LEC). Thus, multiple segments that each have pointer processing, and possibly mapping and unmapping, may be cascaded and the timing impairments introduced by each segment would accumulate, giving rise to a client signal whose clock is impaired. The timing impairments produced by these operations make it impossible to use a received client signal (i.e., that signal derived from the SPE) that is a SONET signal which is used as a source of timing for another SONET network.
[0041] Refocusing on the objective of offering a facility to transport client data of any protocol transparently, including SONET, in order to compensate for the above effects in the SONET network, in accord with the principles disclosed herein a different transport protocol is used, to wit, the Digital Wrapper standard G.709, which happens to be very similar to SONET, but is flexible enough to permit including a number of unique and novel features in the network's nodes that are not defined for current or next generation SONET equipment. These functions, which do not exist in current generation equipment, and are not defined for next generation Digital Wrapper or SONET equipment, are compensation for the timing impairments introduced end-to-end by the client signal mapping and unmapping process, and node-to-node compensation for the timing impairments introduced by the pointer adjustments received from the previous node.
[0042] The compensation for end-to-end timing impairments introduced due to client signal mapping and unmapping functions is addressed through the use of phase-offset information that is derived from the phase difference between the ingress client clock and the ingress node system clock. The phase-offset information is transported end-to-end with the data signal and is used to compensate the egress client clock derived from the outgoing client data stream. This eliminates most of the client egress clock timing error due to mapping/unmapping functions.
[0043] The compensation for node-to-node timing impairments introduced due to pointer processing is addressed through the use of a pointer filter in conjunction with an adaptive pointer generator that filters upstream pointers generated by previous nodes and adaptively generates its own pointers in a manner that allows downstream filters to remove their effects in succeeding nodes. This advanced pointer processor is described in more detail later.
[0044] In accord with an embodiment disclosed herein, the low rate of the Digital Wrapper standard G.709, i.e., OTU1, is used as the underlying network transport mechanism, which carries data in frames running at the rate of approximately 20,420 frames/sec. To provide for the sub-wavelength channels, i.e., for the transporting of signals lower than the SONET OC-48 signals, in accord with the principles disclosed herein an extension to the G.709 Digital Wrapper standard is provided. The extension takes 64 consecutive OTU1 frames, where each frame having 14 columns of overhead at the beginning of each frame, and combines the payload (3808 columns) and payload overhead (2 columns) areas into a very large frame (243,840 columns). Within that very large frame the columns are divided to create 16 frames (also referred to herein as OPTU1 frames, or communication layer frames), that are time division multiplexed and di-byte interleaved timeslots, by assigning the first two columns of the large frame assigned to timeslot #1, the second two columns to timeslot #2, etc. through to the 16 th timeslot, and then repeating the assignments until all columns of the large frame are assigned, thereby attaining effectively communication layer frames having 15,240 columns each. This frame is illustrated in FIG. 1A . Each OPTU1 frame has four columns of overhead and 15,236 columns of timeslot envelope capacity (similar to STS-1 envelope capacity). The four columns of overhead (OVHD) contain pointer information (which controls the operation of an advanced pointer processor to be described later) in the first three rows of the frame and 4 stuff byte positions (negative justification opportunity bytes (NJO)) in the fourth row of the frame. The remaining 15,236 columns constitute the envelope capacity, which includes 4 potential dummy byte positions (positive justification opportunity bytes (PJO)) next to the 4 stuff byte positions in the fourth row of the frame. In such an arrangement, the payload envelope is a frame (herein referred to as an OPVC1 frame, or framing layer frame) that is not unlike the SONET's SPE, which frame contains four columns of timeslot path overhead and 15,232 columns of payload data (into which the client signal is mapped). This is illustrated in FIG. 1B . The overhead bytes of the fourth row are reserved for negative justification bytes, and the four bytes in the fourth row that follow the negative justification bytes are reserved for positive justification bytes. The path overhead includes 10 bits reserved for phase-offset information, and two mapping justification bits (JC). A JC value of 00 means that no dummy bytes were inserted and no extra bytes were stuffed, a JC value of 01 means that four data bytes were inserted, and a JC value of 11 means that four dummy bytes were stuffed.
[0045] The 15232 columns of payload data can exactly contain an OC-3 signal as long as the OPVC1 and OC-3 clock are running at their nominal rates.
[0046] As the above-described structure suggests, one of the similarities between the Digital Wrapper standard, as extended, and SONET is that both employ the layered structure, where one layer concerns itself with framing (placing the client's data into frames) and another layer concerns itself with the payload being carried. One significant difference between SONET and the Digital Wrapper standard is that the former is synchronous, whereas the latter is asynchronous. That is, although all of the nodes' clocks of a network employing the Digital Wrapper standard are close to each other (within ± 40 ppm of each other), there is no requirement that they must be the same.
[0047] Thus, in accord with the principles disclosed herein, a client's signal at an ingress node (node A) has to be mapped into the payload area of an OPVC1 frame, with dummy bytes (positive justification), or extra data bytes stuffed (negative justification), as appropriate (as described above), as well as any residual phase-offset information that exists between the client signal clock and the node A clock, and the OPVC1 frame has to be placed into an OPTU1 time slot segment, with an appropriate pointer included in a header portion that points to the beginning of the OPVC1 frame.
[0048] FIG. 2 shows is a block diagram showing selected aspects of an ingress node in accordance with the principles disclosed above. Client data is applied to buffer 10 , and the client clock is applied to write address counter 11 . Under control of the client clock and address counter 11 client data is stored in buffer 10 (which is sometimes referred to as an elastic store). The line from counter 11 to buffer 10 includes both the address bits and the write command. The node's clock y A is applied to processor 14 , which gates the clock as necessary and applies the gated clock to read counter 12 . The output of counter 12 , which includes both the address bits and a read command, is applied to buffer I 0 and, under influence of counter 12 , data is read out from butter 10 and applied to processor 14 .
[0049] The clock gating performed by processor 14 accounts for the header bytes that need to be included in order to create OPVC1 frames, and the justification that needs to be undertaken because of the difference in clock rates between the client's clock and the node's clock. Negative justification is required when the client's clock is higher than nominal and, therefore, bytes need to be stuffed; positive justification is required when the client's clock is lower than nominal and, therefore, dummy bytes need to be inserted; or no justification is undertaken when neither stuffed bytes nor dummy bytes are called for.
[0050] Information about the need to justify comes from the read and write counters. Specifically, it is recognized that the difference between the read and write addresses should be bounded if no underflow or overflow should occur in buffer 10 , and it is beneficial to have that difference remain as constant as possible. Therefore, the addresses of write counter 11 and read counter 12 are applied to subtractor 13 , and the difference is applied to processor 14 . Based on that difference, processor 14 determines whether bytes need to be stuffed, dummy bytes need to be inserted, or neither task needs to be undertaken, and behaves appropriately, including creating the appropriate justification control (JC) bits.
[0051] The difference produced by subtractor 13 is also applied to sampler 16 . Illustratively, once per frame, just after a justification opportunity, the sampler samples the value of the difference that exists between the write counter 11 and the read counter 12 . This represents the residual phase-offset between the client clock and the gated system clock, and this difference is applied to processor 14 . The phase-offset information is written in to the frame overhead area and transported to the client egress de-mapper at the other end of the network, to be used to regenerate an accurate representation of a clock for the client's signal at the egress node.
[0052] The bytes received by processor 14 from buffer 10 based on the gated clock are then augmented with the appropriate JC bits, phase-offset information, and other overhead information, and formatted to create OPVC1 frames at the output of element 20 . These frames are applied to processor 15 , which creates OPTU1 frames.
[0053] Processor 15 injects OPTU1 overhead bytes into the created OPTU1 frames, determines where within the OPTU1 frame the created OPVC1 frames are to be inserted, generates and inserts an appropriate pointer that points to the beginning of the OPVC1 frame in the OPTU1 payload envelope, inserts the OPVC1 frame, and thus creates the OPTU1 frames at the output of processor 15 .
[0054] At the egress node, for example, node Z, the reverse of this process must be performed, that is, de-mapping of the client signal from the OPVC1 frame. An embodiment of this process is illustrated in FIG. 3 . In FIG. 3 , data originating from an upstream node is applied to clock recovery circuit 31 and to processor 32 . Circuit 31 recovers the clock of the previous node, and applies it to processor 32 . Processor 32 identifies the beginning of the OPTU1 frame, handles the OPTU1 overhead bytes, identifies the pointer, identifies the beginning of the OPVC1 frame, identifies and processes the justification control bits and the phase-offset information and creates a gapped clock that is applied to write counter 33 . This gapped clock is an approximation of the gapped clock generated by node A, the gated y A clock, during the mapping process. Under control of address and write commands that are applied by counter 33 to buffer 34 , the incoming client data is stored in buffer 34 .
[0055] Separately, address counter 35 that is advanced by variable control oscillator (VCO) 37 reads data out of buffer 34 . The address of counter 35 is subtracted from the address of counter 33 in element 38 , and the resulting difference is applied to low pass filter 36 . The output of low pass filter 36 controls VCO 37 .
[0056] The arrangement comprising elements 35 , 38 , 36 and 37 is a phase lock loop (PLL) arrangement that keeps the difference between counter 33 (which is advanced by the estimate of the gated y A clock) and counter 35 fairly stable. This is a mirror image of the feedback arrangement found in FIG. 2 , which keeps the difference between counters 11 and 12 fairly stable, where counter 12 is advanced by clock y A . Consequently, the data read out of buffer 34 is fairly close in frequency to the client's data arriving at node A.
[0057] If not dealt with, the two impairments discussed earlier, end-to-end mapping impairments and node-to-node pointer processing impairments, will corrupt the quality of the client timing information so as to make it unusable as a timing reference. The amelioration of the node-to-node pointer processing impairments will be discussed below, however the end-to-end mapping will be discussed here. The justification operations performed by the mapping function in node A are essentially controlled by the difference in frequency between the incoming client clock and the OPVC1 clock derived from the node A system clock. If the derived OPVC1 clock is running at a rate that allows the client signal to be almost exactly matched to the OPVC1 payload rate then justification operations will be very infrequent. This creates phase jumps in the client signal data that occur at a very slow rate producing significant low frequency components. The de-mapper at node Z contains the low pass filter 36 that can filter some of this noise, however the cutoff frequency cannot be made arbitrarily low. Therefore, whatever cutoff frequency is specified, a difference between OPVC1 clock and client clock can be determined that will produce low frequency components below the cutoff frequency of the de-mapper filter thus corrupting the client timing. The phase-offset information is added to address this issue.
[0058] The phase-offset information extracted by processor 32 is applied to filter 36 via summer 17 . The phase-offset information, being updated once per frame, provides a sampled data representation of the frequency components of the client and OPVC1 clock differences, which when summed with the recovered phase difference produced by subtractor 38 , nulls out the low frequency error, essentially eliminating the impairment.
[0059] Node-to-node pointer processing impairments are introduced by intermediate nodes; i.e., nodes between the ingress node of a signal, and the egress node of a signal. More particularly, the ingress node participates in pointer generation, the egress node participates in pointer interpretation, and the intermediate node participate in pointer interpretation and generation—which we call pointer processing. As a signal arrives at an intermediate node (with respect to the client ingress node, node A), for example, node B, the clock of the arriving signal is extracted, and the OPVC1 frame is extracted from the payload of the OPTU1 frame in a manner similar to that described above in connection with SONET frames (i.e., with the aid of the pointer within the OPTU1 frame's header). At this point the extracted OPVC1 frame is operating on timing that was derived from node A, however, to transmit the OPVC1 frame to the next downstream node it must be operating on local, node B, timing. This is accomplished by adjusting the pointer value (pointer processing) inserted into the outgoing OPTU1 frame in a manner that is also similar to that described in connection with SONET frames. The pointer processing shifts the entire OPVC1 frame within the associated OPTU1 frame, and when the clocks of nodes A and B are relatively close to each other, the negative and positive justifications create low frequency timing components associated with the OPVC1 frame that are embedded in the OPTU1 frame. These low frequency components propagate through the network and ultimately appear at the egress client de-mapper (the operation of this is described above). As was discussed, arbitrary low frequency components cannot be eliminated by the de-mapper low pass filter, and the resulting wander, which can accumulate as the signal passes through network nodes constitutes a problem for communicating client signals that are SONET signals.
[0060] Borrowing from a proposal by Michael Klein et al for advanced pointer processing in SDH/SONET networks, in an article entitled “Network Synchronization—A Challenge for SDH/SONET?”, IEEE Communication Magazine, September 1993, pp 42-50, al advanced pointer processor would operate as described below.
[0061] The general concept behind the advanced pointer processor is to generate pointers such that they contain predominantly high frequency energy which is filtered out at succeeding nodes before generating new pointer values. Specifically, an OPTU1 frame and its timing are recovered from the incoming data stream. Through interpretation of incoming pointer information, an OPVC1 clock is generated from the incoming OPVC1 data stream contained within the OPTU1 frame and any incoming pointers generated by upstream nodes are filtered out (the pointers are responsible for node-to-node timing impairments). The extracted data can then be injected into an OPTU1 frame outgoing from the node under control of an adaptive pointer generator and then be transmitted out of the node. The adaptive nature of the pointer generator provides spectral shaping of the impairments caused by pointer generation, that is, the frequency content of of the noise created by the generated pointers is shifted to higher frequencies. This spectral shaping, which is derived from concepts based on sigma-delta modulation, creates a noise spectrum that allows downstream pointer filters (discussed above) to easily remove the pointer generated timing impairments. The combination of incoming pointer filtering and adaptive outgoing pointer generation makes up an advanced pointer processor.
[0062] In accord with the principles disclosed herein, each node undertakes pointer processing that aims to minimize the low frequency components by performing spectral shaping of pointer impairments. It does so by adaptively undertaking negative justifications and compensating positive justifications (or vice versa) where, otherwise, no justification is necessary. In other words, each node injects voluntary positive and compensating negative justifications. This is effected with a circuit like the one shown in FIG. 4 . It is similar to the FIG. 3 circuit, except that VCO 37 is replaced by ATM circuit 42 , and includes an additional feedback loop, through compensation filter 40 having a transfer function X(z) and summing node 41 . The output of buffer 34 in FIG. 4 delivers OPVC1 frames that are processed via processor 43 , which adds outgoing pointer information and generates outgoing OPTU1 frames.
[0063] In this implementation the compensation filter 40 is required because the incoming pointer filter 36 is located such that it not only filters the incoming write clock (processor 32 produces the write clock which drives write counter 33 which in turn is processed by subtractor 38 , thereby producing a write clock component which would then be filtered by filter 36 ), but also filters the outgoing pointers (processor 39 produces the pointer adjustment signal that controls the read counter 35 which in turn drives the subtractor 38 , thereby producing a read clock component that contains pointer adjustment phase information which would then be filtered by filter 36 ). Since the outgoing pointers must not be filtered (that would essentially nullify the pointer operation which is required in order to compensate for the input and output clock differences), a compensation circuit, compensation filter 40 , must be provided to nullify the effects of incoming pointer filter 36 on any adaptive outgoing pointer generation functions performed by adaptive threshold modulator 42 .
[0064] To determine the transfer function of filter 36 , it is noted that the address of read counter 35 , which can be represented by a cumulative phase signal, φ r (z), is effectively equal to the sum of the phase of the node's clock (gated to account for the overhead bytes), φ n (z), and any phase shift due to pointer adjustments, φ p (z); i.e., φ r (z)=φ n (z)+φ p (z). The pointer adjustment signal is the cumulative phase shift resulting from pointer justification operations, either no pointer justification, positive justification of four bytes, or negative justification of four bytes. It is also noted that the address of write counter 33 can be represented by a cumulative phase signal, φ w (z).
[0065] The output signal produced by the phase detector 38 that is applied to summing node 41 , which is a number that changes each time the read or the write counters ( 35 and 33 , respectively) are incremented, and also represents a phase signal, is the difference between the read and write addresses D o (z)=φ n (z)+φ p (z)−φ w (z). The output of filter 40 is X(z)φ p (z), and therefore the input to filter 36 is D o (z)+φ p (z)X(z), or φ n (z)−φ w (z)+φ p (z)(1+X(z)). The output of filter 36 , therefore, is
[φ n (z)−φ w (z)+φ p (z)(1+ X ( z ))] F ( z ). (1)
[0066] We observe that for proper operation, the input to adaptive threshold modulator 42 must equal the phase difference between the read clock (which includes pointer adjustments) and the filtered write clock, that is, the outgoing pointer adjustments that appear as part of the read clock must not be filtered. Therefore, for proper operation the input to adaptive threshold modulator 42 must correspond to
(φ n (z)−φ w (z))F(z)+φ p (z) (2)
[0067] Setting equation (1) equal to equation (2) yields
X ( z )=( 1 − F ( z ))/ F ( z ). (3)
[0068] We found that the transfer functions pair
X ( z ) = ( 1 - z - 1 ) ( 1 - az - 1 ) K ( 1 - bz - 1 ) and ( 4 ) F ( z ) = ( K K + 1 ) ( 1 - bz - 1 ) 1 - ( 1 + a + Kb K + 1 ) z - 1 + ( a K + 1 ) z - 2 ( 5 )
with X(z) representing a differentiated first order high pass function and F(z) representing a second order low pass filter function, work well.
[0070] The implementation suggested by equation (4) for X(z) includes a (1−z −1 ) term, which represents a differentiator function, followed by a high pass filter. The input to the X(z) function is the cumulative phase output of the adaptive threshold modulator 42 , which is represented by a stairstep function that jumps up or down by four bytes of phase magnitude whenever a positive or negative pointer justification occurs. Differentiation of this type of signal produces a series of unit impulses at each positive or negative pointer justification. By including this differentiation function as part of the ATM functionality and having processor 39 operate on simple positive or negative justification indications instead of cumulative phase, the differentiation term in X(z) can be eliminated.
[0071] The resulting implementation of FIG. 5 shows the physical implementation of these filters, including the implementation of the ATM circuit 42 . It should be noted that the quantizer block simply makes the pointer adjustment decisions instead of outputting cumulative phase information.
[0072] This processing performed at node B is performed at each succeeding downstream node until the client signal egress node is reached. As a signal arrives at the egress node, for example, node Z, the clock of the arriving signal is extracted, and the OPVC1 frame is extracted from the payload portion of the OPTU1 frame in the same manner as described for node B. Also, as for node B, an OPVC1 clock is generated from the incoming OPVC1 data stream and any incoming pointers generated by upstream nodes are filtered. The signal is then processed as described above for the egress node de-mapping function.
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An arrangement that allows transmission of client signals with higher clock fidelity is achieved by developing a phase offset measure at an ingress node, communicating it to the egress node, and recovering the client's clock from the received data and from the received phase-offset information. The ability to recover the client's clock with high fidelity is enhanced by adaptive pointer processing in intermediate nodes and the egress node of the network that the client's signal traverses. The adaptive pointer processing filters incoming pointers from upstream nodes and injects new positive and negative pointer justifications in excess of what is minimally necessary to allow them to be filtered by successive nodes and insure proper transmission over a network that employs a protocol involving framing layer frames embedded in communication layer frames. Illustratively, the network protocol is an extended ITU Recommendation G.709 Digital Wrapper protocol, arranged to employ frames of 15240 columns by four rows.
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CROSS REFERENCES TO RELATED APPLICATIONS
This application claims priority on U.S. Provisional Application 61/705,659, filed on Sep. 26, 2012; and is a continuation-in-part of U.S. application Ser. No. 13/942,920, filed on Jul. 16, 2013, which claims priority on U.S. Provisional Application Ser. No. 61/674,121, filed on Jul. 20, 2012; and is a continuation-in-part of U.S. application Ser. No. 14/033,031, filed on Sep. 20, 2013, which claims priority on U.S. Provisional Application Ser. No. 61/703,838, titled “Multi-Functional Osteotome and Method of Use for Sinus Lift Procedure,” filed on Sep. 21, 2012, and claims priority on U.S. Provisional Application Ser. No. 61/714,345, filed on Oct. 16, 2012. The disclosures of each these applications are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to improvements in the Osteotomes used in the crestal approach for the sinus lift procedure, and more particularly to a series of Osteotome tips that cause less stress and a correspondingly reduced tendency toward fracturing of the crestal area.
BACKGROUND OF THE INVENTION
There are many conditions which may result in a person becoming partially or completely edentulous (periodontal disease, an injury, etc.), which is commonly remedied today by dental implants. Dental implants are endosseous, being a “root” device that is usually made of titanium, where the implants are inserted into the jaw through the bone at the alveolar ridges, after which a healing period on the order of months is necessary for osseointegration. During this healing period the bone will grow in and around the implant to provide support.
The alveolar ridges are columns of bone, found on both the maxilla and the mandible, that surround and anchor the teeth within sockets known as alveoli. However, the alveolar bone quickly becomes atrophic in the absence of teeth, typically resulting in lack of sufficient bone mass for successful implantation. In the Maxilla, when sinus pneumatization decreases available bone after tooth loss, a sinus elevation procedure prior to implant placement is required to increase the amount of bone therein. The sinus lift procedure may be performed either through a lateral approach or a crestal approach.
In the crestal approach for a sinus lift procedure of the posterior maxilla (upper jaw), to which the improvements of the present invention is directed, a pilot drill may initially be used to create a small hole in the crestal cortex to reach the cancellous layer, and to form an implant insertion axis. The anatomical characteristics of the posterior maxilla, particularly the existence of its more spongy (cancellous) bone, enable it to successfully lend itself to undergo the ridge expansion osteotomy technique developed by R. B. Summers (see e.g., Summers, DMD, Robert B, “A New Concept in Maxillary Implant Surgery: The Osteotome Technique;” 1994; Summers, DMD, Robert B, “The Osteotome Technique: Part 2—The Ridge Expansion Osteotomy (REO) Procedure;” 1994; and Summers, DMD, Robert B, “The Osteotome Technique: Part 3-Less Invasive Methods of Elevating the Sinus Floor;” 1994).
The technique causes expansion of the pilot hole without further elimination of bone material, and generally compresses the bone and increases bone density, in the surgeon's favor. The technique uses a succession of conical expansion Osteotome tools having a gradual diameter escalation. The smallest caliber expansion Osteotome tool is inserted manually into the pilot hole, with pressing and rotating of the tool occurring until the desired depth is reached, or until further penetration is resisted, at which time gentle tapping using a surgical mallet on the Osteotome may cause it to reach the proper depth. Further use of successively larger Osteotome tools causes lateral compression that increases bone density and the size of the opening. The procedure is typically carried out by an oral surgeon using different calibers of Osteotomes that are constructed such that the initial diameter of a successively larger Osteotome is the same as the largest penetrating diameter of the previous conical Osteotome that was used, thereby providing a constant progression of increasing separation.
The procedure exhibits high success rates if the sinus membrane was not breached during the procedure, as discussed in the by Hernandez-Alfaro F, Torradeflot MM, and Marti C., title “Prevalence and Management of Schneiderian Membrane Perforations during Sinus-lift Procedures.” But a further consideration for the success of the implant concerns the impact of the Summers' diameter escalation on the crest of the alveolar ridge, when the ridge has undergone resorption producing a knife-edged shape, rather than its tall, rounded shape. The present invention offers various improvements to aid the oral surgeon, including Osteotome configurations and a method of use that reduce fracturing of the crest of the alveolar ridges—the most vulnerable area of the ridge during the osteotomy.
OBJECTS OF THE INVENTION
It is an object of the invention to provide a series of Osteotomes that are constructed to perform a ridge expansion osteotomy.
It is another object of the invention to provide a series of ridge expansion Osteotomes that are particularly adapted to reduce stress on the crestal cortex to reduce the possibility of fracture.
It is a further object of the invention to provide a series of ridge expansion Osteotomes that are particularly adapted to cause more expansion apically and less expansion crestally while proceeding deeper into the osteotomy to working depth.
It is another object of the invention to provide a mathematical formula for the definition of the Osteotome diameter escalation that serves to reduce/eliminate excessive stress at the crestal cortex.
Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings.
SUMMARY OF THE INVENTION
The Osteotomes commonly used for a ridge expansion osteotomy include tips that follow the escalation that was prescribed by Robert Summers, DMD, as documented in his articles that were noted above. This prescribed diameter escalation is such that the initial diameter of a successively larger Osteotome instrument is the same as the largest penetrating diameter of the conical tip of the previous Osteotome that was used. This conventional diameter escalation is suitable for the osteotomy on a patient where there has not been any significant local bone resorption at the implant site, and the alveolar ridge remains tall, and possesses a rounded crest. However, where bone resorption has progressed so as to noticeably reduce the height of the ridge locally and produce a knife-edged shape, this traditional osteotome diameter escalation will tend to result in excessive stress within the reduced bone mass at the pointed crest, with the increased possibility of fracturing off a piece of bone at that location, which is crucial for successfully implanting a platform.
The Osteotomes of the present invention have been developed to address this problem with the prior art. The tips of the Osteotomes of the present invention are also conical, but utilize a diameter escalation that may not be in accord with the escalation prescribed by Summers (the initial diameter of a successively larger Osteotome instrument is the same as the largest penetrating diameter of the conical tip of the previously used Osteotome), and may furthermore use a different scheme for escalation of the diameters at the apex of the tips, than for the escalation of the diameters at the base of the tips.
The scheme for escalating the apex of the conical tips of successive Osteotomes, consists of a linear incremental increase in the diameters thereat. The scheme for escalating the base of the conical tips of successive Osteotomes, consists of a step-wise increase in those diameters, so that only every other incremental increase in the diameter of the tip is accompanied by an increase in the diameter at the base of the cone shape. This assures that a requisite amount of work towards compaction and expansion of the bone at a position slightly below the crest, has been accomplished prior to such compaction at the crest itself, to decrease the possibility of a fracture. Other mathematical relationships also exist with regard to the apex and base of the tips at respective stages of those incremental increases, which are discussed further hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a series of Osteotomes of the prior art, which exhibit conventional escalation of the conical diameters for successive Osteotomes.
FIG. 2 is an enlarged detail view of the tips of the Osteotomes of FIG. 1 , illustrating the Summers' diameter escalation, whereby the initial diameter of a successively larger Osteotome is the same as the largest penetrating diameter of the previous conical Osteotome that was used.
FIG. 3A illustrates a cross-section through an alveolar ridge, showing a tall rounded crest that has not been subjected to resorption.
FIG. 3B illustrates a cross-section through an alveolar ridge, showing an alveolar ridge that has undergone resorption, resulting in a shallower and pointed crest.
FIG. 3C is a cross-sectional view illustrating use of an Osteotome of the present invention on an implant socket of an alveolar ridge that has undergone significant resorption.
FIG. 4 illustrates the series of Osteotome tips of the current invention that are constructed in accordance with a diameter escalation specific for the base and for the free end of the tip, to ensure reduced crestal alveolar stress during the osteotomy.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a series of prior art Osteotomes that are usable for providing the necessary expansion and compaction of bone surrounding an implant pilot hole formed in an alveolar ridge during a sinus lift procedure. The tips for each of the Osteotomes, shown enlarged within FIG. 2 , may be tapered so as to be formed with a conical shape, as seen for tip 10 T of Osteotome 10 . The base of the conical tip may have a first diametrical value, and the free end of the tip may have a second diametrical value, being less that the diametrical value of the base. A typical set of expansion Osteotomes usable for the sinus lift procedure may thus include, for example, a handle with a tip tapering from 2.2 mm to 2.7 mm, another handle with a tip tapering from 2.7 mm to 3.2 mm, a handle with a tip tapering from 3.2 min to 3.7 mm, a handle with a tip tapering from 3.7 mm to 4.2 mm, and a handle with a tip tapering from 4.2 mm to 5.0 mm.
It may thus be seen that typical Summers' expansion Osteotome instruments have been constructed “with gradual diameter escalation from one instrument to the next, whereby the base of each instrument corresponded to the active portion of the next instrument . . . ,” as recounted by Javier Rambla Ferrer, Miguel Peñarrocha Diago, Juan Guarinos Carbó, in the paper titled, “Analysis of the Use of Expansion Osteotomes for the Creation of Implant Beds . . . Technical Contributions and Review of the Literature.”
This typical Summers' diameter escalation has shown good success, generally speaking, but suffers a serious drawback for many dental implant patients. The progression for bone resorption following loss of a tooth is rapid. The alveolar ridge changes from a high well-rounded ridge, as seen in FIG. 3A , to a knife-edged ridge shape, as seen in FIG. 3B . The resorption results in loss in the width at the crest. Although use of the typical diameter escalation is acceptable in the case where no significant resorption has occurred, because there is still sufficient bone mass at the crestal region to support the forces imposed by insertion of the larger diameter of the successive instruments, the same is not true after resorption has progressed. Where bone resorption has caused the ridge to be lowered and to develop a sharp edge, there often is insufficient bone mass at the crestal portion to support the expansion forces and the ridge bone would tend to pivot closer to the crest, which may result in the fracturing off of precious bone material, further reducing the height of the ridge.
FIG. 4 shows a series of Osteotome tips of the present invention that may be constructed to have a unique diameter escalation that is different for the base of the tip than for the free end of the tip, and which is susceptible to definition by a mathematical formula. This unique escalation creates an improved Osteotome tip that is better adapted to providing less stress to the crestal region for the patient where bone resorption is a considerable factor. The progression for size increases in the diameter of the conical tip at its apex (free end) occurs in a linear fashion, while the progression for size increases in the diameter of the conical tip at its working base occurs as a step function (also termed a “stair” function).
The diameter of the conical tip for the first instrument 21 at its free end—apex 21 A, may have an initial value “Y” that may be, for example, the 2.2 mm diameter of the above-mentioned Osteotome set. Thereafter, the initial diameter “Y” of the conical tip at the apex 21 A of the first instrument 21 may be incrementally increased by a value “k” to create the diameter (φ=Y+k) at the apex 22 A of the second instrument 22 . The diameters at the apex of the third, fourth, and fifth instruments ( 23 , 24 , 25 ), etc., may thereafter be similarly incremented, with those diameters being, Y+2k, Y+3k, Y+4k, etc.
The diameter of the conical tip for the first instrument 21 at its base 21 B may have an initial value “X” that may be, for example, the 2.7 mm diameter of the above-mentioned Osteotome set. Thereafter, the initial diameter “X” of the conical tip at its base 21 B of the first instrument 21 may remain unchanged and still be the value “X” for the base 22 B of the second instrument 22 , forming the level portion of the first “step.” Next, the diameter “X” of the conical tip at its base 23 B of the third instrument 23 may be the “stair riser” as it may be incrementally increased above the diametrical value of the base 22 B of the second instrument 22 by a value “C” to create the diameter=X+C). The diameter at the base of the fifth and seventh instruments ( 25 , 27 ), etc., may also be the “stair riser” and may be similarly incremented, with those diameters being, X+2C, X+3C, etc., while the diameters at the base of the fourth and sixth instruments ( 24 , 26 ), etc, may be the “stair step” and may not be incrementally changed.
To be useful in accordance with the Osteotome technique of the present invention, and while nonetheless being in accord with the Summers' technique, the diameter of the tip for the first instrument herein at its base must be larger than the value for the diameter of the tip at its apex, to form the conical shape (i.e., X>Y). It also follows that thereafter, X+C>Y+3k; and similarly, X+2C>Y+5k, and at least that X+3C>Y+6k, etc. The incremental value used for the increase of the diameter at the apex could be the same as the incremental value used for the increase of the diameter at the base (i.e., it may be that k=C). However, from a practical standpoint, to maintain the conical shape during escalation, whereby the tip possesses the smaller diameter, and to satisfy other requirements, the values will not be the same (i.e., k≠C).
In order to protect the knife-edged crest of the ridge, the osteotomes of the present invention may be constructed such that the diameter of the free end, φ FE , of the successive osteotome to be used (see FIG. 3C ), is smaller than the diameter of the base, φ b , of the osteotome that was just previous utilized in the implant socket. This may be expressed mathematically, in that Y+k≦X (the appropriate conical relationship), and it must also be true that Y+2k≦X. Similarly, it also follows that: Y+4k≦X+C; and that: Y+6k≦X+2C. Note that in FIG. 3C , the working base of the tip may be identified on the Osteotome by a marking thereon, rather that utilizing a protruding rigid stop, as the stop could potentially impact the fragile ridge crest when the Osteotome is being driven by a mallet to the proper working depth. Also, depending upon the amount of difference between the diameter of the free end (φ FE ) of the successive osteotome to be used and the diameter of the base (φ b ) of the previous Osteotome, there may be some acceptable range in the depth of usage for particular Osteotomes.
This is shown by the hatching in FIG. 3C , where φ D3 is the osteotome diameter at a greater depth (D 3 ) than a standard depth, D T . Since φ D3 is larger than φ b on that Osteotome, the constraint that the diameter of the free end (φ FE ) of the successive osteotome to be used be smaller than the diameter of the working base (φ b ) of the previously used osteotome will always be true for a greater depth socket (i.e., in this case, because of the depth of the socket is at depth D 3 instead of D T , the effective base will be at φ D3 ); however, the effectiveness of the successive tools will be decreased substantially if the cross-hatched range for φ D3 is not limited, and would require a very large number of Osteotomes in the set to complete socket formation.
The reverse cross-hatched region between φ b and φ D2 may also be indicated on the Osteotome, because it may show the extent to which a shallower depth socket may be accommodated, at which φ D2 becomes the effective base, and where this would nonetheless fulfill the requirement that the diameter of the free end (φ FE ) of the next osteotome to be used will be smaller than φ D2 of the Osteotome of FIG. 3C .
In addition to the above cited requirements, the set of Osteotomes constructed according to the present invention may be even more effective at preventing damage to the crest of the ridge where the diameter of the free end of the successive osteotome (φ FE ) preferably begins to engage the socket at a depth D 1 (i.e., φ FE =φ D1 ). The engagement depth D 1 may preferably be at least 5% of the total depth D T , and may preferably not be more that 40% of the total depth D T . It is more preferable that the ratio of the engagement depth D 1 to the socket depth D T fall within the following range:
0.1≦ D 1 /D T ≦0.25.
If engagement were to occur at a depth of less than 5% of the total depth (i.e., close to the sharp crest of the ridge), excess stress will be introduced at that location, risking failure (fracturing) due to the greater strength of the ridge immediately below. Also, if the engagement depth were to occur at a substantial portion of the total depth, very little work towards compaction of the socket would occur for each osteotome, which would again necessitate the use of numerous Osteotomes in the set to complete the process.
The equation to describe the linear increase in the diameter at the apex for each of the Osteotome instruments may be given by the equation:
φ An =Y +( n− 1)( k )
where n is the numbered Osteotome instrument in the set, and may range from the first Osteotome instrument to be used (i.e., n=1) to the last Osteotome instrument in the set (i.e., where there are seven Osteotome instruments in the set, for the seventh, n=7).
The equation to describe the step-wise increase in the diameter at the base for each of the Osteotome instruments is related to the step equation for f, where:
f
(
x
)
=
∑
i
=
0
n
α
i
χ
A
i
(
x
)
for
all
real
numbers
x
where n≧0, α i are real numbers, A i are intervals, and χ A is the indicator function of A. (see e.g., Bachman, Narici, Beckenstein, “Example 7.2.2 ”, Fourier and Wavelet Analysis . Springer, New York, 2000; and http://en.wikipedia.org/wiki/Step_function, with the disclosures of each being incorporated herein by reference). The difference with the step function as utilized herein is that each step for the incremental increase in the diameter of the base of the tip occurs only for every other Osteotome instrument, rather than for each instrument.
Construction of the tip of the set of Osteotome instruments in accordance with this linear function for the increasing diameter at the apex and the step function for the increasing diameter at the base of the tips, and the disclosed restriction, serves to reduce the stress on the crestal portion of the alveolar ridges during the osteotomy. This reduced stress will often help preserve critical bone mass at the crest of the ridge, and help improve the implant survival rate, by reducing or eliminating the tendency towards fracturing a portion of the crest.
The examples and descriptions provided merely illustrate a preferred embodiment of the present invention. Those skilled in the art and having the benefit of the present disclosure will appreciate that further embodiments may be implemented with various changes within the scope of the present invention. Other modifications, substitutions, omissions and changes may be made in the design, size, materials used or proportions, operating conditions, assembly sequence, or arrangement or positioning of elements and members of the preferred embodiment without departing from the spirit of this invention.
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A set of Osteotomes used for forming an implant socket during a ridge expansion osteotomy may be specially constructed to reduce crestal alveolar stress and to reduce likelihood of a crestal fracture. Each osteotome includes a conical working tip having a free end and a working base. A first osteotome of the set has a working tip formed with a first diameter, Y, at the free end, and a second diameter, X, at the working base, with the second diameter being larger than the first diameter, X>Y; and wherein for each successive osteotome of the set, the diameter at the free end increases linearly by a constant increment, k, and the diameter at the working base alternately increases by a constant increment, C, as a step function. Other interrelationships between the free end and the working base of the previous and successive osteotomes operate to maintain crestal integrity.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to and the benefit of Korean Patent Application No. 2003-91016, filed on Dec. 13, 2003, the disclosure of which is incorporated herein by reference in its entirety.
BACKGROUND
1. Field of the Invention
The present invention relates to a driver agent device and a operation method thereof and, more specifically, to a driver agent device for supporting remote device driver development environment in an embedded system and an operation method thereof, in which a developer can process various services such as retrieving hardware information needed for device development, authenticating resources and applying a device driver to a target system, without expert knowledge on an embedded system in a Linux-operated embedded system.
2. Discussion of Related Art
Recently, an embedded system that had been used in a restricted field such as industry and military has widely used in medicals and consumer electronics. Therefore, much attention is paid to the rapid development of the embedded system by embedded system development industries to acquire a more market share.
A development process of the embedded system can be divided into a hardware development process and a software development process. The device driver development, which may be positioned between these two development processes, is widely known as a time-consuming process as a bottleneck point of the embedded system development process.
In particular, the device driver development environment for the embedded system having inevitably complicated remote development causes much more difficulty in the device driver development. In addition, there are various and unique functions of the embedded systems for each individual embedded system compared with a general computer system so that the used devices are also diversified and unique. Therefore, the costs spent for developing device drivers for these devices are inevitably high.
In addition, conventional technologies for supporting the device driver development have focused on the Window-based device driver development for a desktop system. In the conventional technologies, simple hardware authentication processing, device driver installation, and test processing are provided to support the development of the device driver operating in a given operating system in a negative development environment where a host system and a target system are not separated.
FIG. 1 is a schematic block diagram illustrating a device driver development environment using a device driver development support program according to the prior art.
As shown in FIG. 1 , in the prior art, a device driver development support program 3 supporting a device driver development environment or a development tool 1 is provided to develop a device driver that operates in an operating system of a non-embedded system, where a host system and a target system are not separated, i.e., a development system 4 .
However, the prior art arranged as described above has problems in that it requires version-dependent processing that depends on various kernel versions, and it is impossible to be used in the development of the device driver for a Linux embedded system in which a remote development environment is inevitable.
SUMMARY OF THE INVENTION
The present invention is directed to a driver agent device for supporting a remote device driver development environment in an embedded system, in which a developer can process various services such as retrieving hardware information needed for the development of the device driver, authenticating resources and applying a device driver to a target system, without expert knowledge on the embedded system in a Linux-operated embedded system.
The present invention is also directed to an operation method of a driver agent device for supporting a remote device driver development environment in an embedded system, which transmits various serves requested from a device driver development tool of a host system to a target system, determines types of the various services transmitted to the target system, processes the corresponding service depending on the type of the services, and then, transmits the processed service result to the host system.
One aspect of the present invention is to a driver agent device for supporting a remote device driver development environment in an embedded system, in which a host system having a device driver development tool and a target system having a device driver are separated from each other and interconnected with a communication network, the driver agent device comprising: communication processing means interconnected with the target system to receive and process various service requests from the device driver development tool of the host system, and to transmit the processed services to the host system through the communication network; core means for determining types of the services requested from the device driver development tool of the host system; and service processing means for performing corresponding services based on the types of the services determined by the core means.
In the above aspect, the service processing means includes: a device detection unit for detecting device catalog and information by scanning buses of the target system, in the case that the service determined by the core means is directed to detecting devices mounted on the target system; a device resource authentication unit for providing a read/write access function to the device resources, in the case that the service determined by the core means is directed to authenticating the device resources of the target system; a kernel device information extraction unit for extracting information retained in a device related data structure of the kernel, in the case that the service determined by the core means is directed to requesting kernel information on the devices of the target system, a kernel message detection unit for detecting and collecting the kernel message, in the case that the service determined by the core means is directed to requesting kernel message generated by the kernel of the target system; and a device driver module management unit for installing a device driver transmitted from the host system on a file system of the target system and inserting or deleting the device driver into and from the kernel through a kernel system command, in the case that the service determined by the core means is directed to installation in the target system, start, and end of the device driver module provided on the host system.
Another aspect of the present invention is to a method of operating a driver agent device for supporting a remote device driver development environment in an embedded system, in which a host system having a device driver development tool and a target system having a device driver are separated from each other and interconnected with a communication network, the method including: (a) transferring various services requested from the device driver development tool of the host system to the target system; (b) determining types of the various services transferred to the target system; (c) processing corresponding services based on the types of the various services transferred to the target system; and (d) transmitting results of the services processed in the step (c) to the host system.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features of the present invention will be described in reference to certain exemplary embodiments thereof with reference to the attached drawings in which:
FIG. 1 is a schematic block diagram showing a device driver development environment for a device driver development support program according to the prior art;
FIG. 2 is a schematic block diagram showing a remote device driver development environment for an embedding system using a driver agent device according to an embodiment of the present invention;
FIG. 3 is a detailed block digram showing the driver agent device of FIG. 2 ;
FIG. 4 is a detailed block diagram showing the service processing module of FIG. 3 ;
FIG. 5 is a flowchart illustrating an overall operation method for a service request from a host system by a driver agent device according to an embodiment of the present invention; and
FIG. 6 is a detailed flowchart illustrating the service processing of FIG. 5 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.
FIG. 2 is a schematic block diagram showing a remote device driver development environment for an embedding system using a driver agent device according to an embodiment of the present invention; FIG. 3 is a detailed block digram showing the driver agent device of FIG. 2 ; and FIG. 4 is a detailed block diagram showing the service processing module of FIG. 3 .
As shown in FIGS. 2 to 4 , in a remote device driver development environment for an embedded system using a driver agent device according to an embodiment of the present invention, a host system 100 having a device driver development tool 150 and a target system 200 having a device driver 250 are separated and interconnected with a communication network 400 .
Here, the communication network 400 is preferably implemented with Ethernet, but the present invention is not limited thereto, and thus it can be implemented with typical various wired/wireless communication networks (e.g., PSTN, ADSL, wireless LAN, BLUETOOTH, CMDA, etc.)
Further, a driver agent device 300 arranged to support the remote device driver development environment in the aforementioned embedded system is interconnected with the target system 200 .
The driver agent device 300 includes a communication processing module 310 for receiving and processing various service requests from the device driver development tool 150 of the host system 100 and transmitting the processed services to the host system 100 ; a core module 320 for determining types of the services requested from the device driver development tool 150 of the host system 100 ; and a service processing module 330 for performing corresponding services based on the types of the services determined by the core module 320 .
In the above configuration, the core module 320 serves to call the corresponding service by processing start and end of the driver agent and determining the type of the host request service transmitted from the communication processing module 310 .
In addition, the service processing module 330 includes a device detection unit 331 , a device resource authentication unit 332 , a kernel device information extraction unit 333 , a kernel message detection unit 334 , and a device driver module management unit 335 .
Here, in the case that the service determined by the core module 320 is directed to detecting the devices mounted on the target system 200 , the device detection unit 331 serves to detect device catalog and information by scanning buses of the target system 200 .
In the case that the service determined by the core module 320 is directed to authenticating the device resources of the target system 200 , the device resource authentication unit 332 serves to provide a read/write access function for the device resources.
In the case that the service determined by the core module 320 is directed to requesting kernel information for the devices of the target system 200 , the kernel device information extraction unit 333 serves to extract and collect information retained in a device-related data structure of the kernel.
In the case that the service determined by the core module 320 is directed to requesting a kernel message generated by the kernel of the target system 200 , the kernel message detection unit 334 serves to extract and collect the kernel message.
In the case that the service determined by the core module 320 is directed to installation of the device driver module 250 provided by the host system 100 onto the target system 200 , and start and end thereof, the device driver module management unit 335 serves to install the device driver 250 transmitted from the host system 100 on a file system (not shown) of the target system 200 , and insert or delete the device driver 250 into or from the kernel through a kernel system command.
Next, a method of operating a driver agent device for supporting a remote device driver development environment in an embedded system of the present invention having the aforementioned configuration will be described in detail.
FIG. 5 is a flowchart illustrating an overall operation method for a service request from a host system by a driver agent device according to an embodiment of the present invention; and FIG. 6 is a detailed flowchart illustrating the service processing of FIG. 5 . Here, note that the process is mainly operated in the driver agent device 300 , unless stated otherwise.
As shown in FIGS. 5 and 6 , first, in step 100 , the core module 320 performs an initialization operation, and then waits for a service request from a host system 100 . Next, in step S 110 , the communication processing module 310 determines whether or not the service request is generated from the host system 100 .
As a result of the determination in step S 100 , when the service request is not generated from the host system 100 , the process returns to step 100 , and continues to wait for the service request.
Further, as a result of the determination in step S 110 , when the service request is generated from the host system 100 , in step S 120 , the communication processing module 310 transfers various services requested from the host system 100 to the core module 320 , and the core module 320 determines which service types various services belong to, i.e., the types of the requested various services, and then calls the corresponding service of the service processing module 330 .
Next, in step S 130 , it is determined whether the requested service is an end service of the driver agent. If so, the driver agent is ended.
Further, as a result of the determination in step S 130 , when the requested service is not the end service of the driver agent, in step S 140 , the service processing module 330 processes the corresponding service. Next, in step S 150 , the communication processing module 310 transfers the result of the corresponding service to the host system 100 , and the process returns to step S 100 .
Here, the service processing in step S 140 includes: detecting device catalog and information by scanning buses of the target system 200 , in the case that the service determined by the core module 320 is directed to detecting the device (step S 141 ); providing a read/write access function for device resources, in the case that the service determined by the core module 320 is directed to authenticating the device resources (step S 142 ); extracting information retained in a related data structure from a kernel, in the case that the service determined by the core module 320 is directed to requesting kernel information on the devices (step S 143 ); detecting a kernel message, in the case that the service determined by the core module 320 is directed to requesting the kernel message (step S 144 ); and transmitting and storing a device driver 250 to the target system 200 , and then inserting or deleting the device driver into or from the kernel, in the case that the service determined by the core module 320 is directed to installing and managing the device driver module in the target system (step S 145 ).
The driver agent device for supporting the remote device driver development environment in the embedded system and the operation method thereof as described above are preferably recorded into a recording medium readable with a computer, and processed by the computer.
As described above, according to a driver agent device for supporting a remote device driver development environment in an embedded system of the present invention and an operation method thereof, a driver agents device supports the target system in the development process of a device driver, which is a control program of the device mounted on the embedded system, in the remote host system. Therefore, a device driver developer can effectively process various services such as detecting hardware information needed for the device driver development, resource authentication, and application of the device driver to the target system without expert knowledge on the embedded system. In addition, the device driver developer can also develop the device driver more rapidly and easily and test the device driver by applying it to the target system without a complex procedure. Accordingly, time and manpower required in the device driver development can be effectively reduced.
Although a driver agent device for supporting a remote device driver development environment in an embedded system according to the present invention and an operation method thereof have been described in preferred embodiments of the present invention, the present invention is not limited thereto. However, a variety of modification can be made within the scope of the claims, the detailed description of the invention, and the accompanying drawings, which are also included in the present invention.
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A host system having a device driver development tool and a target system having a device driver agent, the tool and the target system separated from each other and interconnected with a communication network. The driver agent device communicates with the target system, receiving and processing various service requests from the device driver development tool, and transmits the processed services to the host system through the communication network. Thr driver agent determines types of the services requested from the device driver development tool and performs services based on the types of the services determined. Accordingly, the device driver can be adapted to the target system and tested without complex procedures to effectively reduce time and manpower needed for the device driver development.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to thermally-coated wall anchors and associated veneer ties and anchoring systems for cavity walls. More particularly, the invention relates to anchoring systems with thermally-isolating coated wall anchors and associated components made largely of thermally conductive metals. The system has application to seismic-resistant structures and to cavity walls requiring thermal isolation.
2. Description of the Prior Art
The move toward more energy-efficient insulated cavity wall structures has led to the need to create a thermally isolated building envelope which separates the interior environment and the exterior environment of a cavity wall structure. The building envelope is designed to control temperature, thermal transfer between the wythes and moisture development, while maintaining structural integrity. Thermal insulation is used within the building envelope to maintain temperature and therefore restrict the formation of condensation within the cavity. The integrity of the thermal insulation is compromised when used in conjunction with the prior art metal anchoring systems, which are constructed from thermally conductive metals that facilitate thermal transfer between and through the wythes. The use of the specially designed and thermally-protected wall anchors of the present invention lowers the underlying metal thermal conductivities and thereby reducing thermal transfer.
When a cavity wall is constructed and a thermal envelope created, hundreds, if not thousands, of wall anchors and associated ties are inserted throughout the cavity wall. Each anchor and tie combination form a thermal bridge perforating the insulation and moisture barriers within the cavity wall structure. While seals at the insertion locations deter water and vapor entry, thermal transfer and loss still result. Further, when each individual anchoring system is interconnected veneer-tie-to-wall-anchor, a thermal thread results stretching across the cavity and extending between the inner wythe to the outer wythe. Failure to isolate the steel components and break the thermal transfer, results in heating and cooling losses and potentially damaging condensation buildup within the cavity wall structure. Such buildups provide a medium for corrosion and mold growth. The use of thermally-isolating coated wall anchors removes the thermal bridges and breaks the thermal thread causing a thermally isolated anchoring system with a resulting lower heat loss within the building envelope.
The present invention provides a thermally-isolating coated wall anchor specially-suited for use within a cavity wall. Anchoring systems within cavity walls are subject to varied outside forces such as earthquakes and wind shear that cause abrupt movement within the cavity wall, requiring high-strength anchoring materials. Additionally, any materials placed within the cavity wall require the characteristics of low flammability and, upon combustion, the release of combustion products with low toxicity. The present invention provides a coating suited to such requirements, which, besides meeting the flammability/toxicity standards, includes characteristics such as shock resistance, non-frangibility, low thermal conductivity and transmissivity, and a non-porous resilient finish. This unique combination of characteristics provides a wall anchor well-suited for installation within a cavity wall anchoring system.
In the past, anchoring systems have taken a variety of configurations. Where the applications included masonry backup walls, wall anchors were commonly incorporated into ladder- or truss-type reinforcements and provided wire-to-wire connections with box-ties or pintle-receiving designs on the veneer side.
In the late 1980's, surface-mounted wall anchors were developed by Hohmann & Barnard, Inc., now a MiTek-Berkshire Hathaway Company, and patented under U.S. Pat. No. 4,598,518. The invention was commercialized under trademarks DW-10®, DW-10-X®, and DW-10-HS®. These widely accepted building specialty products were designed primarily for dry-wall construction, but were also used with masonry backup walls. For seismic applications, it was common practice to use these wall anchors as part of the DW-10® Seismiclip® interlock system which added a Byna-Tie® wire formative, a Seismiclip® snap-in device—described in U.S. Pat. No. 4,875,319 (319), and a continuous wire reinforcement.
In an insulated dry wall application, the surface-mounted wall anchor of the above-described system has pronged legs that pierce the insulation and the wallboard and rest against the metal stud to provide mechanical stability in a four-point landing arrangement. The vertical slot of the wall anchor enables the mason to have the wire tie adjustably positioned along a pathway of up to 3.625-inch (max.). The interlock system served well and received high scores in testing and engineering evaluations which examined effects of various forces, particularly lateral forces, upon brick veneer masonry construction. However, under certain conditions, the system did not sufficiently maintain the integrity of the insulation. Also, upon the promulgation of more rigorous specifications by which tension and compression characteristics were raised, a different structure—such as one of those described in detail below—became necessary.
The engineering evaluations further described the advantages of having a continuous wire embedded in the mortar joint of anchored veneer wythes. The seismic aspects of these investigations were reported in the inventor's '319 patent. Besides earthquake protection, the failure of several high-rise buildings to withstand wind and other lateral forces resulted in the incorporation of a continuous wire reinforcement requirement in the Uniform Building Code provisions. The use of a continuous wire in masonry veneer walls has also been found to provide protection against problems arising from thermal expansion and contraction and to improve the uniformity of the distribution of lateral forces in the structure.
Shortly after the introduction of the pronged wall anchor, a seismic veneer anchor, which incorporated an L-shaped backplate, was introduced. This was formed from either 12- or 14-gauge sheetmetal and provided horizontally disposed openings in the arms thereof for pintle legs of the veneer anchor. In general, the pintle-receiving sheetmetal version of the Seismiclip interlock system served well, but in addition to the insulation integrity problem, installations were hampered by mortar buildup interfering with pintle leg insertion.
In the 1980's, an anchor for masonry veneer walls was developed and described in U.S. Pat. No. 4,764,069 by Reinwall et al. which patent is an improvement of the masonry veneer anchor of Lopez, U.S. Pat. No. 4,473,984. Here the anchors are keyed to elements that are installed using power-rotated drivers to deposit a mounting stud in a cementitious or masonry backup wall. Fittings are then attached to the stud which include an elongated eye and a wire tie therethrough for deposition in a bed joint of the outer wythe. It is instructive to note that pin-point loading—that is forces concentrated at substantially a single point—developed from this design configuration. This resulted, upon experiencing lateral forces over time, in the loosening of the stud.
There have been significant shifts in public sector building specifications, such as the Energy Code Requirement, Boston, Mass. (see Chapter 13 of 780 CMR, Seventh Edition). This Code sets forth insulation R-values well in excess of prior editions and evokes an engineering response opting for thicker insulation and correspondingly larger cavities. Here, the emphasis is upon creating a building envelope that is designed and constructed with a continuous air barrier to control air leakage into or out of conditioned space adjacent the inner wythe, which have resulted in architects and architectural engineers requiring larger and larger cavities in the exterior cavity walls of public buildings. These requirements are imposed without corresponding decreases in wind shear and seismic resistance levels or increases in mortar bed joint height. Thus, wall anchors are needed to occupy the same ⅜ inch high space in the inner wythe and tie down a veneer facing material of an outer wythe at a span of two or more times that which had previously been experienced.
As insulation became thicker, the tearing of insulation during installation of the pronged DW-10X® wall anchor, see infra, became more prevalent. This occurred as the installer would fully insert one side of the wall anchor before seating the other side. The tearing would occur at two times, namely, during the arcuate path of the insertion of the second leg and separately upon installation of the attaching hardware. The gapping caused in the insulation permitted air and moisture to infiltrate through the insulation along the pathway formed by the tear. While the gapping was largely resolved by placing a self-sealing, dual-barrier polymeric membrane at the site of the legs and the mounting hardware, with increasing thickness in insulation, this patchwork became less desirable. The improvements hereinbelow in surface mounted wall anchors look toward greater insulation integrity and less reliance on a patch.
As concerns for thermal transfer and resulting heat loss/gain and the buildup of condensation within the cavity wall grew, focus turned to thermal isolation and breaks. Another prior art development occurred in an attempt to address thermal transfer shortly after that of Reinwall/Lopez when Hatzinikolas and Pacholok of Fero Holding Ltd. introduced their sheetmetal masonry connector for a cavity wall. This device is described in U.S. Pat. Nos. 5,392,581 and 4,869,043. Here a sheetmetal plate connects to the side of a dry wall column and protrudes through the insulation into the cavity. A wire tie is threaded through a slot in the leading edge of the plate capturing an insulative plate thereunder and extending into a bed joint of the veneer. The underlying sheetmetal plate is highly thermally conductive, and the '581 patent describes lowering the thermal conductivity by foraminously structuring the plate. However, as there is no thermal break, a concomitant loss of the insulative integrity results. Further reductions in thermal transfer were accomplished through the Byna-Tie® system ('319) which provides a bail handle with pointed legs and a dual sealing arrangement as described, U.S. Pat. No. 8,037,653. While each prior art invention reduced thermal transfer, neither development provided more complete thermal protection through the use of a specialized thermally-isolating coated wall anchor, which removes thermal bridging and improves thermal insulation through the use of a thermal barrier.
Focus on the thermal characteristics of cavity wall construction is important to ensuring minimized heat transfer through the walls, both for comfort and for energy efficiency of heating and air conditioning. When the exterior is cold relative to the interior of a heated structure, heat from the interior should be prevented from passing through the outside. Similarly, when the exterior is hot relative to the interior of an air conditioned structure, heat from the exterior should be prevented from passing through to the interior. The main cause of thermal transfer is the use of anchoring systems made largely of metal, either steel, wire formatives, or metal plate components, that are thermally conductive. While providing the required high-strength within the cavity wall system, the use of steel components results in heat transfer.
Another application for anchoring systems is in the evolving technology of self-cooling buildings. Here, the cavity wall serves additionally as a plenum for delivering air from one area to another. The ability to size cavities to match air moving requirements for naturally ventilated buildings enable the architectural engineer to now consider cavity walls when designing structures in this environmentally favorable form.
Building thermal stability within a cavity wall system requires the ability to hold the internal temperature of the cavity wall within a certain interval. This ability helps to prevent the development of cold spots, which act as gathering points for condensation. Through the use of a thermally-isolating coating, the underlying steel wall anchor obtains a lower transmission (U-value) and thermal conductive value (K-value) and provides non-corrosive benefits. The present invention maintains the strength of the steel and further provides the benefits of a thermal break in the cavity.
In the past, the use of wire formatives have been limited by the mortar layer thicknesses which, in turn are dictated either by the new building specifications or by pre-existing conditions, e.g., matching during renovations or additions the existing mortar layer thickness. While arguments have been made for increasing the number of the fine-wire anchors per unit area of the facing layer, architects and architectural engineers have favored wire formative anchors of sturdier wire. On the other hand, contractors find that heavy wire anchors, with diameters approaching the mortar layer height specification, frequently result in misalignment. This led to the low-profile wall anchors of the inventors hereof as described in U.S. Pat. No. 6,279,283. However, the above-described technology did not address the adaption thereof to surface mounted devices. The combination of each individual wall anchor and tie combination linked together in a cavity wall setting creates a thermal thread throughout the structure thereby raising thermal conductivity and reducing the effectiveness of the insulation. The present invention provides a thermal break which interrupts and restricts thermal transfer.
In the course of preparing this Application, several patents, became known to the inventors hereof and are acknowledged hereby:
Pat. No.
Inventor
Issue Date
2,058,148
Hard
October, 1936
2,966,705
Massey
January, 1961
3,377,764
Storch
April, 1968
4,021,990
Schwalberg
May, 1977
4,305,239
Geraghty
December, 1981
4,373,314
Allan
February, 1983
4,438,611
Bryant
March, 1984
4,473,984
Lopez
October, 1984
4,598,518
Hohmann
July, 1986
4,869,038
Catani
September, 1989
4,875,319
Hohmann
October, 1989
5,063,722
Hohmann
November, 1991
5,392,581
Hatzinikolas et al.
February, 1995
5,408,798
Hohmann
April, 1995
5,456,052
Anderson et al.
October, 1995
5,816,008
Hohmann
October, 1998
6,125,608
Charlson
October, 2000
6,209,281
Rice
April, 2001
6,279,283
Hohmann et al.
August, 2001
8,109,706
Richards
February, 2012
Foreign Patent Documents
279,209
CH
March, 1952
2,069,024
GB
August, 1981
It is noted that with some exceptions these devices are generally descriptive of wire-to-wire anchors and wall ties and have various cooperative functional relationships with straight wire runs embedded in the inner and/or outer wythe.
U.S. Pat. No. 3,377,764—Storch—Issued Apr. 16, 1968 Discloses a bent wire, tie-type anchor for embedment in a facing exterior wythe engaging with a loop attached to a straight wire run in a backup interior wythe.
U.S. Pat. No. 4,021,990—Schwalberg—Issued May 10, 1977 Discloses a dry wall construction system for anchoring a facing veneer to wallboard/metal stud construction with a pronged sheetmetal anchor. Like Storch '764, the wall tie is embedded in the exterior wythe and is not attached to a straight wire run.
U.S. Pat. No. 4,373,314—Allan—Issued Feb. 15, 1983 Discloses a vertical angle iron with one leg adapted for attachment to a stud; and the other having elongated slots to accommodate wall ties. Insulation is applied between projecting vertical legs of adjacent angle irons with slots being spaced away from the stud to avoid the insulation.
U.S. Pat. No. 4,473,984—Lopez—Issued Oct. 2, 1984 Discloses a curtain-wall masonry anchor system wherein a wall tie is attached to the inner wythe by a self-tapping screw to a metal stud and to the outer wythe by embedment in a corresponding bed joint. The stud is applied through a hole cut into the insulation.
U.S. Pat. No. 4,869,038—Catani—Issued Sep. 26, 1989 Discloses a veneer wall anchor system having in the interior wythe a truss-type anchor, similar to Hala et al. '226, supra, but with horizontal sheetmetal extensions. The extensions are interlocked with bent wire pintle-type wall ties that are embedded within the exterior wythe.
U.S. Pat. No. 4,875,319—Hohmann—Issued Oct. 24, 1989 Discloses a seismic construction system for anchoring a facing veneer to wallboard/metal stud construction with a pronged sheetmetal anchor. The wall tie is distinguished over that of Schwalberg '990 and is clipped onto a straight wire run.
U.S. Pat. No. 5,392,581—Hatzinikolas et al.—Issued Feb. 28, 1995 Discloses a cavity-wall anchor having a conventional tie wire for mounting in the brick veneer and an L-shaped sheetmetal bracket for mounting vertically between side-by-side blocks and horizontally on atop a course of blocks. The bracket has a slit which is vertically disposed and protrudes into the cavity. The slit provides for a vertically adjustable anchor.
U.S. Pat. No. 5,408,798—Hohmann—Issued Apr. 25, 1995 Discloses a seismic construction system for a cavity wall having a masonry anchor, a wall tie, and a facing anchor. Sealed eye wires extend into the cavity and wire wall ties are threaded therethrough with the open ends thereof embedded with a Hohmann '319 (see supra) clip in the mortar layer of the brick veneer.
U.S. Pat. No. 5,456,052—Anderson et al.—Issued Oct. 10, 1995 Discloses a two-part masonry brick tie, the first part being designed to be installed in the inner wythe and then, later when the brick veneer is erected to be interconnected by the second part. Both parts are constructed from sheetmetal and are arranged on substantially the same horizontal plane.
U.S. Pat. No. 5,816,008—Hohmann—Issued Oct. 6, 1998 Discloses a brick veneer anchor primarily for use with a cavity wall with a drywall inner wythe. The device combines an L-shaped plate for mounting on the metal stud of the drywall and extending into the cavity with a T-head bent stay. After interengagement with the L-shaped plate the free end of the bent stay is embedded in the corresponding bed joint of the veneer.
U.S. Pat. No. 6,125,608—Charlson—Issued Oct. 3, 2000 Discloses a composite insulated framing system within a structural building system. The Charlson system includes an insulator adhered to the structural support through the use of adhesives, frictional forces or mechanical fasteners to disrupt thermal activity.
U.S. Pat. No. 6,209,281—Rice—Issued Apr. 3, 2001 Discloses a masonry anchor having a conventional tie wire for mounting in the brick veneer and sheetmetal bracket for mounting on the metal-stud-supported drywall. The bracket has a slit which is vertically disposed when the bracket is mounted on the metal stud and, in application, protrudes through the drywall into the cavity. The slit provides for a vertically adjustable anchor.
U.S. Pat. No. 6,279,283—Hohmann et al.—Issued Aug. 28, 2001 Discloses a low-profile wall tie primarily for use in renovation construction where in order to match existing mortar height in the facing wythe a compressed wall tie is embedded in the bed joint of the brick veneer.
U.S. Pat. No. 8,109,706—Richards—Issued Feb. 7, 2012 Discloses a composite fastener, belly nut and tie system for use in a building envelope. The composite fastener includes a fiber reinforced polymer. The fastener has a low thermal conductive value and non-corrosive properties.
None of the above provide a thermally-isolating coated anchoring system that maintains the thermal isolation of a building envelope. As will become clear in reviewing the disclosure which follows, the cavity wall structures benefit from the recent developments described herein that lead to solving the problems of thermal insulation and heat transfer within the cavity wall. The wall anchor assembly is modifiable for use on various style wall anchors allowing for interconnection with veneer ties in varied cavity wall structures. The prior art does not provide the present novel cavity wall construction system as described herein below.
SUMMARY
In general terms, the invention disclosed hereby is a high-strength thermally-isolating surface-mounted anchoring system for use in a cavity wall structure. The wall anchor is thermally-coated and interconnected with varied veneer ties. The veneer ties are wire formatives configured for insertion within the wall anchor and the bed joints of the outer wythe. The veneer ties are optionally compressed forming a low profile construct and swaged for interconnection with a reinforcement wire to form a seismic construct.
The first embodiment of the thermally-isolated wall anchor is a sheetmetal device with a bail type receptor for interconnection with a veneer tie. The wall anchor provides a sealing effect precluding the penetration of air, moisture, and water vapor into the inner wythe structure. The cavity portion and aperture receptor portion and optionally, the attachment portion, the wall anchor mounting surface, the outer surface and the pair of legs receive a thermally-isolating coating. The thermally-isolating coating is selected from a distinct grouping of materials, which are applied using a specific variety of methods, in one or more layers which are cured and cross-linked to provide high-strength adhesion. A matte finish is provided to form a high-strength interconnection. The thermally-coated wall anchors provide an in-cavity thermal break that interrupts the thermal conduction in the anchoring system threads running throughout the cavity wall structure. The thermal coating reduces the U- and K-values of the anchoring system by thermally-isolating the metal components.
The second embodiment of the thermally-isolated anchoring system includes a sheetmetal wall anchor with an L-shaped design having an attachment portion, at least one cavity portion with a receptor portion and a receiving aperture in the receptor portion. A pintle-type veneer tie is interconnected with the wall anchor. The receiving aperture and optionally, the attachment portion and the cavity portion receive a thermally-isolating coating.
It is an object of the present invention to provide new and novel anchoring systems for cavity walls, which systems are thermally isolating.
It is another object of the present invention to provide a new and novel high-strength metal wall anchor which is thermally coated with a thermally-isolating compound that reduces the U- and K-values of the anchoring system.
It is yet another object of the present invention to provide in an anchoring system having an inner wythe and an outer wythe, a high-strength wall anchor that interengages a veneer tie.
It is still yet another object of the present invention to provide an anchoring system which is constructed to maintain insulation integrity within the building envelope by providing a thermal break.
It is a feature of the present invention that the wall anchor hereof provides thermal isolation of the anchoring system.
It is another feature of the present invention that the wall anchor is utilizable with a dry wall construct that secures to a metal stud and is interconnected with a veneer tie.
It is another feature of the present invention that the thermally-coated wall anchor provides an in cavity thermal break.
It is a further feature of the present invention that the wall anchor coating is shock resistant, resilient and noncombustible.
Other objects and features of the invention will become apparent upon review of the drawings and the detailed description which follows.
BRIEF DESCRIPTION OF THE DRAWING
In the following drawing, the same parts in the various views are afforded the same reference designators.
FIG. 1 shows a first embodiment of this invention and is a perspective view of a surface-mounted anchoring system with a thermally isolating wall anchor, as applied to a cavity wall with an inner wythe of dry wall construction with insulation disposed on the cavity-side thereof and an outer wythe of brick interconnected with a veneer tie;
FIG. 2 is a perspective view of the surface-mounted anchoring system of FIG. 1 shown with a thermally-isolating folded wall anchor and a veneer tie threaded therethrough;
FIG. 3 is a perspective view of an alternative design thermally-isolating wall anchor and a veneer tie threaded therethrough;
FIG. 4 is a perspective view of an alternative design thermally-isolating wall anchor with notched tubular legs and a veneer tie threaded therethrough with an interconnected reinforcement wire;
FIG. 5 is a perspective view of a second embodiment of this invention showing a surface-mounted anchoring system with a thermally isolating wall anchor, as applied to a cavity wall with an inner wythe of dry wall construction with insulation disposed on the cavity-side thereof and an outer wythe of brick interconnected with a pintle veneer tie;
FIG. 6 is a perspective view of the anchoring system of FIG. 5 with a low profile pintle veneer tie interconnected therewith; and,
FIG. 7 is a perspective view of an alternative design thermally-isolating wall anchor interconnected with a veneer tie and reinforcement wire, forming a seismic system.
DETAILED DESCRIPTION
Before entering into the Detailed Description, several terms which will be revisited later are defined. These terms are relevant to discussions of innovations introduced by the improvements of this disclosure that overcome the technical shortcoming of the prior art devices.
In the embodiments described hereinbelow, the inner wythe is optionally provided with insulation and/or a waterproofing membrane. In the cavity wall construction shown in the embodiments hereof, this takes the form of exterior insulation disposed on the outer surface of the inner wythe. Recently, building codes have required that after the anchoring system is installed and, prior to the inner wythe being closed up, that an inspection be made for insulation integrity to ensure that the insulation prevents infiltration of air and moisture. Here the term insulation integrity is used in the same sense as the building code in that, after the installation of the anchoring system, there is no change or interference with the insulative properties and concomitantly substantially no change in the air and moisture infiltration characteristics.
In a related sense, prior art sheetmetal anchors and anchoring systems have formed a conductive bridge between the wall cavity and the interior of the building. Here the terms thermal conductivity and thermal conductivity analysis are used to examine this phenomenon and the metal-to-metal contacts across the inner wythe. The present anchoring system serves to sever the conductive bridge and interrupt the thermal pathway created throughout the cavity wall by the metal components, including a reinforcement wire which provides a seismic structure. Failure to isolate the metal components of the anchoring system and break the thermal transfer, results in heating and cooling losses and in potentially damaging condensation buildup within the cavity wall structure.
In addition to that which occurs at the outer or facing wythe, attention is further drawn to the construction at the exterior surface of the inner or backup wythe. Here there are two concerns. namely, maximizing the strength of the securement of the surface-mounted wall anchor to the backup wall and, as previously discussed minimizing the interference of the anchoring system with the insulation and the waterproofing. The first concern is addressed using appropriate fasteners such as, for mounting to metal, dry-wall studs, self-tapping screws. The latter concern is addressed by the flatness of the base of the surface-mounted wall anchor and its thermally-isolating characteristics.
In the detailed description, the veneer reinforcements and the veneer ties are wire formatives. The wire used in the fabrication of veneer joint reinforcement conforms to the requirements of ASTM Standard Specification A951-00, Table 1. For the purpose of this application tensile strength tests and yield tests of veneer joint reinforcements are, where applicable, those denominated in ASTM A-951-00 Standard Specification for Masonry Joint Reinforcement.
The thermal stability within the cavity wall maintains the internal temperature of the cavity wall within a certain interval. Through the use of the presently described thermal-isolating coating, the underlying metal wall anchor, obtains a lower transmission (U-value) and thermal conductive value (K-value) providing a high strength anchor with the benefits of thermal isolation. The term K-value is used to describe the measure of heat conductivity of a particular material, i.e., the measure of the amount of heat, in BTUs per hour, that will be transmitted through one square foot of material that is one inch thick to cause a temperature change of one degree Fahrenheit from one side of the material to the other. The lower the K-value, the better the performance of the material as an insulator. The metal comprising the components of the anchoring systems generally have a K-value range of 16 to 116 W/m K. The thermal coating disposed on the wall anchor of this invention greatly reduces such K-values to a low thermal conductive (K-value) not to exceed 1 W/m K. Similar to the K-value, a low thermal transmission value (U-value) is important to the thermal integrity of the cavity wall. The term U-value is used to describe a measure of heat loss in a building component. It can also be referred to as an overall heat transfer co-efficient and measures how well parts of a building transfer heat. The higher the U-value, the worse the thermal performance of the building envelope. Low thermal transmission or U-value is defined as not to exceed 0.35 W/m 2 K for walls. The U-value is calculated from the reciprocal of the combined thermal resistances of the materials in the cavity wall, taking into account the effect of thermal bridges, air gaps and fixings.
Referring now to FIGS. 1 through 4 , the first embodiment shows an anchoring system with a thermally isolating wall anchor that provides an in-cavity thermal break. This system is suitable for recently promulgated standards and, in addition, has lower thermal transmission and conductivity values than the prior art anchoring systems. The system discussed in detail hereinbelow, has a thermally-isolating wall anchor with a bail opening for interengagement with a veneer tie. The wall anchor is surface mounted onto an externally insulated dry wall structure with an optional waterproofing membrane (not shown) between the wallboard and the insulation. For the first embodiment, a cavity wall having an insulative layer of 2.5 inches (approx.) and a total span of 3.5 inches (approx.) is chosen as exemplary.
The surface-mounted anchoring system for cavity walls is referred to generally by the numeral 10 . A cavity wall structure 12 is shown having an inner wythe or dry wall backup 14 . Sheetrock or wallboard 16 is mounted on metal studs or columns 17 , and an outer wythe or facing wall 18 of brick 20 construction. Between the inner wythe 14 and the outer wythe 18 , a cavity 22 is formed. The wallboard 16 has attached insulation 26 .
Successive bed joints 30 and 32 in the outer wythe 14 are substantially planar and horizontally disposed and in accord with building standards are a predetermined 0.375-inch (approx.) in height. Selective ones of bed joints 30 and 32 , which are formed between courses of bricks 20 , are constructed to receive therewithin the insertion portion 68 of the veneer tie 44 of the anchoring system hereof. Being surface mounted onto the inner wythe 14 , the anchoring system 10 is constructed cooperatively therewith and is configured to minimize air and moisture penetration around the wall anchor system/inner wythe juncture.
For purposes of discussion, the cavity surface 24 of the inner wythe 14 contains a horizontal line or x-axis 34 and an intersecting vertical line or y-axis 36 . A horizontal line or z-axis 38 , normal to the xy-plane, passes through the coordinate origin formed by the intersecting x- and y-axes. A folded wall anchor 40 as shown in FIGS. 1 and 2 , is constructed from a sheetmetal plate-like body. Alternative design wall anchors 40 are shown in FIGS. 3 and 4 . The wall anchor 40 has an attachment portion 39 for surface mounting on the inner wythe 14 . The attachment portion 39 is comprised of a mounting face or surface 41 and an outer face or surface 43 . A cavity portion 67 having a receptor or apertured receptor portion 63 is contiguous with the attachment portion 39 . The wall anchor 40 is affixed (as shown in FIGS. 1 , 2 , and 4 ) with a pair of legs 42 extending from the mounting surface 41 which penetrate the inner wythe 14 . The pair of legs 42 have longitudinal axes 45 that are substantially normal to the mounting surface 41 and outer surface 43 . Optionally, as shown in FIG. 3 , the wall anchor 40 is constructed without the pair of legs 42 . The wall anchor 40 is a stamped metal construct which is constructed for surface mounting on inner wythe 14 and for interconnection with veneer tie 44 and affixed to the inner wythe 14 with a pair of fasteners 48 . The receptor 63 is adjacent the outer surface 43 and dimensioned to interlock with the veneer tie 44 .
The veneer tie 44 is a wire formative and shown in FIG. 1 as being emplaced on a course of bricks 20 in preparation for embedment in the mortar of bed joint 30 . In this embodiment, the system includes a wall anchor 40 , a veneer tie 44 , and optionally a reinforcement wire 71 .
At intervals along a horizontal line on the outer surface of insulation 26 , the wall anchors 40 are surface mounted. In this structure, where applicable, the pair of legs 42 sheathe the pair of fasteners or mounting hardware 48 . The wall anchors 40 are positioned on the outer surface of insulation 26 so that the longitudinal axis of a column 17 lies within the yz-plane formed by the longitudinal axes 45 of the pair of legs 42 . Upon insertion in the inner wythe 14 , the mounting surface 41 rests snugly against the opening formed thereby and serves to cover the opening, precluding the passage of air and moisture therethrough. This construct maintains the insulation integrity. In FIGS. 1 , 2 , and 4 , the pair of legs 42 have the lower portion removed thereby forming notches which draw off moisture, condensate or water from the associated leg or hardware which serves to relieve any pressure which would drive toward wallboard 16 . This construct maintains the waterproofing integrity.
Optional strengthening ribs 84 are impressed in the wall anchor 40 . The ribs 84 are substantially parallel to the receptor 63 and, when mounting hardware 48 is fully seated so that the wall anchor 40 rests against the insulation 26 , the ribs 84 are then pressed into the surface of the insulation 26 . This provides additional sealing. While the ribs 84 are shown as protruding toward the insulation, it is within the contemplation of this invention that ribs 84 could be raised in the opposite direction. The alternative structure would be used in applications wherein the outer layer of the inner wythe is noncompressible and does not conform to the rib contour. The ribs 84 strengthen the wall anchor 40 and achieve an anchor with a tension and compression rating of 100 lbf.
A thermally-isolating coating or thermal coating 85 is applied to the receptor 63 to provide a thermal break in the cavity. The thermal coating 85 is optionally applied to the cavity portion 67 , the mounting surface 41 , the outer surface 43 and/or the pair of legs 42 to provide ease of coating and additional thermal protection. The thermal coating 85 is selected from thermoplastics, thermosets, natural fibers, rubbers, resins, asphalts, ethylene propylene diene monomers, and admixtures thereof and applied in layers. The thermal coating 85 optionally contains an isotropic polymer which includes, but is not limited to, acrylics, nylons, epoxies, silicones, polyesters, polyvinyl chlorides, and chlorosulfonated polyethelenes. The initial layer of the thermal coating 85 is cured to provide a precoat and the layers of the thermal coating 85 are cross-linked to provide high-strength adhesion to the veneer tie to resist chipping or wearing of the thermal coating 85 .
The thermal coating 85 reduces the K-value and the U-value of the underlying metal components which include, but are not limited to, mill galvanized, hot galvanized, and stainless steel. Such components have K-values that range from 16 to 116 W/m K. The thermal coating 85 reduces the K-value of the veneer tie 44 to not exceed 1.0 W/m K and the associated U-value to not exceed 0.35 W/m 2 K. The thermal coating 85 is not combustible and gives off no toxic smoke in the event of a fire. Additionally, the thermal coating 85 provides corrosion protection which protects against deterioration of the anchoring system 10 over time.
The thermal coating 85 is applied through any number of methods including fluidized bed production, thermal spraying, hot dip processing, heat-assisted fluid coating, or extrusion, and includes both powder and fluid coating to form a reasonably uniform coating. A coating 85 having a thickness of at least about 5 micrometers is optimally applied. The thermal coating 85 is applied in layers in a manner that provides strong adhesion to the veneer tie 44 . The thermal coating 85 is cured to achieve good cross-linking of the layers. Appropriate examples of the nature of the coating and application process are set forth in U.S. Pat. Nos. 6,284,311 and 6,612,343.
The dimensional relationship between wall anchor 40 and veneer tie 44 limits the axial movement of the construct. The veneer tie 44 is a wire formative. Each veneer tie 44 has an attachment portion 64 that interlocks with the receptor 63 . The receptor 63 is constructed, in accordance with the building code requirements, to be within the predetermined dimensions to limit the z-axis 38 movement and permit y-axis 36 adjustment of the veneer tie 44 . The dimensional relationship of the attachment portion 64 to the receptor 63 limits the x-axis movement of the construct. Contiguous with the attachment portion 64 of the veneer tie 44 are two cavity portions 66 . An insertion portion 68 is contiguous with the cavity portions 66 and opposite the attachment portion 64 .
The insertion portion 68 is optionally ( FIG. 4 ) compressively reduced in height to a combined height substantially less than the predetermined height of the bed joint 30 ensuring a secure hold in the bed joint 30 and an increase in the strength and pullout resistance of the veneer tie 44 . Further to provide for a seismic construct, an optional compression or swaged indentation 69 is provided in the insertion portion 68 to interlock in a snap-fit relationship with a reinforcement wire 71 (as shown in FIG. 4 ).
The description which follows is a second embodiment of the thermally-isolating wall anchor and anchoring system that provides an in-cavity thermal break in cavity walls. For ease of comprehension, wherever possible similar parts use reference designators 100 units higher than those above. Thus, the veneer tie 144 of the second embodiment is analogous to the veneer tie 44 of the first embodiment. Referring now to FIGS. 5 through 7 , the second embodiment of the surface-mounted anchoring system is shown and is referred to generally by the numeral 110 . As in the first embodiment, a wall structure 112 is shown. The second embodiment has an inner wythe or backup wall 114 of a dry wall construction with an optional waterproofing membrane (not shown) disposed thereon. Wallboard 116 is attached to columns or studs 117 and an outer wythe or veneer 118 of facing brick 120 . The inner wythe 114 and the outer wythe 118 have a cavity 122 therebetween. Here, the anchoring system has a surface-mounted wall anchor 140 for interconnection with varied veneer ties 144 .
The anchoring system 110 is surface mounted to the inner wythe 114 . In this embodiment like the previous one, insulation 126 is disposed on the wallboard 116 . Successive bed joints 130 and 132 are substantially planar and horizontally disposed and in accord with building standards set at a predetermined 0.375-inch (approx.) in height. Selective ones of bed joints 130 and 132 , which are formed between courses of bricks 120 , are constructed to receive therewithin the insertion portion 168 of the veneer tie 144 of the anchoring system 110 construct hereof. Being surface mounted onto the inner wythe, the anchoring system 110 is constructed cooperatively therewith.
For purposes of discussion, the insulation surface 124 of the inner wythe 114 contains a horizontal line or x-axis 134 and an intersecting vertical line or y-axis 136 . A horizontal line or z-axis 138 , normal to the xy-plane, passes through the coordinate origin formed by the intersecting x- and y-axes. A wall anchor 140 constructed from a metal plate-like body is shown which has an attachment portion 143 that is substantially planar in form and surface mounted on the inner wythe 114 . A cavity portion 145 is contiguous with the attachment portion 143 and extends from the inner wythe 114 into the cavity 122 . The cavity portion 145 contains a receptor portion 163 with a receiving aperture 165 therewithin disposed horizontally in the cavity 122 for interconnection with a veneer tie 144 . A pair of fasteners 148 secures the wall anchor 140 to the inner wythe 114 . In FIGS. 5 and 6 , the wall anchor 140 contains a single receiving aperture 165 for interconnection with a veneer tie 144 . FIG. 7 provides a variation of the wall anchor 140 having a split cavity portion 145 with two receptor portions 163 for interconnection with a veneer tie.
At intervals along the inner wythe 114 , wall anchors 140 are surface mounted. The wall anchors 140 rest snugly against the inner wythe 114 . Optional strengthening ribs 184 are impressed in wall anchor 140 . The ribs 184 are substantially normal to the apertured receptor portion 163 and when mounting hardware 148 is fully seated, so that the wall anchor 140 rests against the insulation 126 , the ribs 184 strengthen the wall anchor 140 and achieve an anchor with a tension and compression rating of 100 lbf.
The veneer tie 144 is shown in FIG. 5 as being emplaced on a course of bricks 120 in preparation for embedment in the mortar of bed joint 130 . In this embodiment, the system includes a wall anchor 140 and a veneer tie 144 with an optional reinforcement wire 171 to form a seismic construct.
The dimensional relationship between wall anchor 140 and veneer tie 144 limits the axial movement of the construct. The veneer tie 144 is a wire formative. Each veneer tie 144 has an attachment portion 164 that interengages with the apertured receptor portion 163 . As shown in FIGS. 5 through 7 , the attachment portion 164 of the veneer tie 144 is a pintle construct. To further protect against veneer tie 144 pullout, securement portions 181 are formed from the pintle. The apertured receptor portion 163 is constructed, in accordance with the building code requirements, to be within the predetermined dimensions to limit the z-axis 138 movement and permit y-axis 136 adjustment of the veneer tie 144 . The dimensional relationship of the attachment portion 164 to the apertured receptor portion 163 limits the x-axis movement of the construct and prevents disengagement from the anchoring system. Contiguous with the attachment portion 164 of the veneer tie 144 are cavity portions 166 . An insertion portion 168 is contiguous with the cavity portions 166 and opposite the attachment portion 164 .
The insertion portion 168 is (as shown in FIGS. 5 and 6 ) optionally compressively reduced in height to a combined height substantially less than the predetermined height of the bed joint 130 ensuring a secure hold in the bed joint 130 and an increase in the strength and pullout resistance of the veneer tie 144 . Further to provide for a seismic construct, a compression or swaged indentation 169 is provided in the insertion portion 168 (as shown in FIG. 7 ) to interlock in a snap-fit relationship with a reinforcement wire 171 .
A thermally-isolating coating or thermal coating 185 is applied to the receiving aperture 165 to provide a thermal break in the cavity 122 . The thermal coating 185 is optionally applied to the attachment portion 143 , the cavity portion 145 and the receptor portion 163 to provide ease of coating and additional thermal protection. The thermal coating 185 is selected from thermoplastics, thermosets, natural fibers, rubbers, resins, asphalts, ethylene propylene diene monomers, and admixtures thereof and applied in layers. The thermal coating 185 optionally contains an isotropic polymer which includes, but is not limited to, acrylics, nylons, epoxies, silicones, polyesters, polyvinyl chlorides, and chlorosulfonated polyethelenes. The initial layer of the thermal coating 185 is cured to provide a precoat and the layers of the thermal coating 185 are cross-linked to provide high-strength adhesion to the veneer tie to resist chipping or wearing of the thermal coating 185 .
The thermal coating 185 reduces the K-value and the U-value of the underlying metal components which include, but are not limited to, mill galvanized, hot galvanized, and stainless steel. Such components have K-values that range from 16 to 116 W/m K. The thermal coating 185 reduces the K-value of the veneer tie 144 to not exceed 1.0 W/m K and the associated U-value to not exceed 0.35 W/m 2 K. The thermal coating 185 is not combustible and gives off no toxic smoke in the event of a fire. Additionally, the thermal coating 185 provides corrosion protection which protects against deterioration of the anchoring system 110 over time.
The thermal coating 185 is applied through any number of methods including fluidized bed production, thermal spraying, hot dip processing, heat-assisted fluid coating, or extrusion, and includes both powder and fluid coating to form a reasonably uniform coating. A coating 185 having a thickness of at least about 5 micrometers is optimally applied. The thermal coating 185 is applied in layers in a manner that provides strong adhesion to the veneer tie 144 . The thermal coating 185 is cured to achieve good cross-linking of the layers. Appropriate examples of the nature of the coating and application process are set forth in U.S. Pat. Nos. 6,284,311 and 6,612,343.
As shown in the description and drawings, the present invention serves to thermally isolate the components of the anchoring system reducing the thermal transmission and conductivity values of the anchoring system to low levels. The novel coating provides an insulating effect that is high-strength and provides an in cavity thermal break, severing the thermal threads created from the interlocking anchoring system components.
In the above description of the anchoring systems of this invention various configurations are described and applications thereof in corresponding anchoring systems are provided. Because many varying and different embodiments may be made within the scope of the inventive concept herein taught, and because many modifications may be made in the embodiments herein detailed in accordance with the descriptive requirement of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense.
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Thermally-isolating wall anchors and anchoring systems employing the same are disclosed. A thermally-isolating coating is applied to the wall anchor, which is interconnected with a wire formative veneer tie. The thermally-isolating coating is selected from a distinct grouping of materials, that are applied using a specific variety of methods, in one or more layers and cured and cross-linked to provide high-strength adhesion. The thermally-coated wall anchors provide an in-cavity thermal break that severs the thermal threads running throughout the cavity wall structure, reducing the U- and K-values of the anchoring system by thermally-isolating the metal components.
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[0001] This application claims priority of PCT application PCT/CH2006/000489 having a priority date of Oct. 6, 2005, the disclosure of which is incorporated herein by reference.
TECHNICAL FIELD
[0002] The invention relates to a method for weaving a ribbon on a needle ribbon weaving machine and to a needle ribbon weaving machine.
BACKGROUND OF THE INVENTION
[0003] A method and a needle ribbon weaving machine for weaving a ribbon of the type initially mentioned are known from DE 40 09 455A. The method described there for producing a ribbon on a needle ribbon weaving machine takes place by means of two closed weft needles operating contradirectionally, the ribbon being woven by both weft needles as a result of insertion into a common shed. The heads of the contradirectionally inserted weft thread loops are secured on each ribbon side by means of wales which are formed in each case from an auxiliary thread and which are located at the two edges of the ribbon. The disadvantage, then, is that always two weft thread loops have to be inserted into a common shed, so that, in the event of a shed change, two weft thread loops, that is to say four weft thread portions, have to be tied in simultaneously. The stability of the ribbon to be produced is impaired as a result. There are also no variations of any kind possible, since closed weft needles having guide loops on which a weft thread is always arranged are used.
SUMMARY OF THE INVENTION
[0004] The object of the invention is to improve the method for weaving a ribbon on a needle ribbon machine having two simultaneously and contradirectionally operating weft needles.
[0005] Since only that weft which is presented to one of the two weft needles is inserted, any desired weft sequence is possible. Not just two weft threads may be introduced simultaneously into the shed, as is afforded in the prior art, but, in particular, the weft threads may be inserted alternately from ribbon sides to ribbon sides, so that, in the event of each shed change, only one weft thread loop is inserted. Furthermore, it is possible, moreover, to present weft threads even of changing color and quality to the weft needles. This not only affords a mechanically improved quality of the ribbon produced, but the pattern possibility is also increased.
[0006] On each ribbon side, the weft thread loops may be knitted together with themselves, or, they may be knitted by means of an interlaced auxiliary thread.
[0007] For the needle ribbon weaving machine serving for carrying out the method, it is essential that an individually operating thread lifter for presenting a weft thread to a weft needle designed to be open is present on each ribbon side.
[0008] A preferred design of the weft needle which has a fork, arranged on the needle shank, for receiving the weft thread, and also a guide slot for the weft thread, said guide slot running along the needle shank to just short of the fork.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Exemplary embodiments of the invention are described in more detail below by means of the drawings showing the weaving region of a needle ribbon weaving machine in various weaving phases, specifically the tie-off of an inserted weft thread loop by means of an auxiliary thread in FIGS. 1 to 4 and the tie-off of inserted weft thread loops without an auxiliary thread in FIGS. 5 to 7 . In the drawings:
[0010] FIG. 1 shows the weaving region during the beating-up of a weft thread loop inserted by the left weft needle in a diagrammatic illustration;
[0011] FIG. 2 shows the weaving region of FIG. 1 during the insertion of a weft thread loop by means of the right weft needle;
[0012] FIG. 3 shows the weaving region of FIG. 2 with an inserted weft thread loop and before the tie-off of the latter;
[0013] FIG. 4 shows the weaving region of FIG. 3 during the beating-up of the weft thread loop inserted by the right weft needle and during the presentation of the weft thread to the left weft needle;
[0014] FIG. 5 shows the weaving region during the beating-up of a weft thread loop inserted by the right weft needle;
[0015] FIG. 6 shows the weaving region of FIG. 5 during the insertion of a weft thread loop inserted by the left weft needle;
[0016] FIG. 7 shows the weaving region of FIG. 6 during the interlacing of the inserted weft thread loop.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] FIGS. 1 to 4 show the weaving region of a needle ribbon weaving machine with two contradirectionally driven weft needles 2 a, 2 b which insert weft threads 4 a, 4 b into a shed 6 . In the shed 6 formed from warp threads 8 , the weft threads are beaten up at the beating-up edge 10 by means of a reed 9 , thus giving rise to the ribbon 12 .
[0018] The weft needles 2 a, 2 b are in each case open needles, i.e. they have at the front end of a needle shank 14 a, 14 b a fork 16 a, 16 b, into which the respective weft thread 4 a, 4 b is introduced by means of a thread lifter 18 a, 18 b movable up and down. The weft needles 2 a, 2 b contain in each case guide slots 20 a, 20 b which run along the needle shank 14 a, 14 b and which reach beyond the forks 16 a, 16 b . The guide slots 20 a, 20 b serve for guiding the weft thread 4 a, 4 b when the weft thread is not inserted into the shed 6 , and for making it easier to introduce into the fork 16 a, 16 b with the aid of the respective thread lifter 18 a, 18 b. The web thread loop 22 a, 22 b inserted in each case is secured by means of an auxiliary thread 24 a, 24 b which is in each case presented to knitting needles 28 a, 28 b by means of a thread guide 26 a, 26 b such that said auxiliary thread is interlaced with the weft thread loops 22 a, 22 b.
[0019] In the position shown in FIG. 1 , the left weft needle 2 a has just inserted a weft thread loop 22 a into the shed 6 and has been beaten up at the beating-up edge 10 by means of the reed 11 . By means of the left thread lifter 18 a, the left weft thread 4 a is raised on the fork 16 a of the weft needle 2 a as a result of the raising of the thread lifter 18 a, to an extent such that said left weft thread cannot be grasped by the fork 16 a of the weft needle 2 a. On the right side of the shed, the thread lifter 18 b is lowered and brings the weft thread 4 b into engagement on the fork 16 b of the weft needle 2 b, so that, the latter can insert the weft thread loop 22 b into the open shed 6 , as shown in FIG. 2 . The left weft needle 2 a runs, empty, into the shed, the weft thread 4 a being guided in the guide slot 20 a . When the weft thread loop 22 b has been inserted completely into the shed, as is evident from FIG. 3 , the left knitting needle 28 a grasps the auxiliary thread 24 a and draws the latter through the inserted weft thread loop 22 b and further on through the last loop 30 a of the auxiliary thread 24 a . On the right side, the auxiliary thread 24 b is interlaced with itself, that is to say with its last loop 30 b , without being drawn through a weft thread loop. After this securing of the inserted weft thread loop 22 b by means of the auxiliary thread 24 a, the weft needles 2 a, 2 b leave the shed, and the reed 11 beats up the weft thread loop thus inserted at the beating-up edge 10 . The thread lifter 18 b is then raised again and prevents an engagement of the weft thread 4 b on the fork 16 b of the weft needle 2 b . Instead, by means of the thread lifter 18 a, the weft thread 4 a is brought into engagement on the fork 16 a of the weft needle 2 a, in order, during the next shed opening, to insert a further weft thread loop 22 a from the left ribbon side in a similar way.
[0020] FIGS. 5 to 7 show a needle ribbon weaving machine which is constructed similarly to the needle ribbon weaving machine of FIGS. 1 to 4 , and therefore parts identical to the first exemplary embodiment are given the same reference symbols. Reference is made to the relevant statements with regard to FIGS. 1 to 4 . In the exemplary embodiment of FIGS. 5 to 7 , however, no auxiliary threads are used, but, instead, the weft threads 40 a, 40 b are interlaced with themselves. FIG. 6 shows how the weft thread loop 42 a from the weft thread 40 a is inserted into the shed by means of the left weft needle 2 a. After complete insertion, the right knitting needle 28 b grasps the inserted weft thread loop 42 a and draws the latter through the already knocked-over weft thread loop 42 a . During the insertion of the weft thread loop 42 a by means of the weft needle 2 a from the left side of the ribbon, the right weft needle 2 b moves, empty, through the shed. The weft thread 40 b is in this case guided in the guide slot 20 b of the right weft needle 2 b, as may be gathered from FIG. 7 . As soon as the weft needles 2 a, 2 b are drawn back out of the shed, the beating-up of the inserted weft thread loop 42 a by means of the reed 11 at the beating-up edge 10 takes place, as illustrated in FIG. 5 . The shed change is followed by the insertion of the weft thread loop on the right side of the ribbon, the operation taking place in a similar way to the insertion of the weft thread on the left ribbon side.
LIST OF REFERENCE SYMBOLS
[0021] 2 a Weft needle
[0022] 2 b Weft needle
[0023] 4 a Weft thread
[0024] 4 b Weft thread
[0025] 6 Shed
[0026] 8 Warp thread
[0027] 10 Beating-up edge
[0028] 11 Reed
[0029] 12 Ribbon
[0030] 14 a Needle shank
[0031] 14 b Needle shank
[0032] 16 a Fork
[0033] 16 b Fork
[0034] 18 a Thread lifter
[0035] 18 b Thread lifter
[0036] 20 a Guide slot
[0037] 20 b Guide slot
[0038] 22 a Weft thread loop
[0039] 22 b Weft thread loop
[0040] 24 a Auxiliary thread
[0041] 24 b Auxiliary thread
[0042] 26 a Thread guide
[0043] 26 b Thread guide
[0044] 28 a Knitting needle
[0045] 28 b Knitting needle
[0046] 40 a Weft thread
[0047] 40 b Weft thread
[0048] 42 a Weft thread loop
[0049] 42 b Weft thread loop
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The invention relates to a needle webbing machine which comprises two weft needles ( 2 a, 2 b ) which work simultaneously and in opposite directions on both ribbon sides, in addition to knitting needles ( 28 a, 28 b ) which are arranged on both ribbon sides. A yarn lifter ( 18 a, 18 b ) which works individually and which is used to advance a weft thread ( 4 a, 4 b ) to a weft needle ( 2 a, 2 b ), which is open, is provided on each side of the ribbon in order to improve the production thereof.
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This application is a divisional application of U.S. Ser. No. 09/327,065, filed Jun. 7, 1999 now, 6,172,222 which claims benefit of prior U.S. Provisional application No. 60/099,348, filed Jun. 8, 1998.
FIELD OF INVENTION
This invention concerns 4,5-diamino derivatives of (1H)-pyrazoles and their use in the treatment of disorders associated with smooth muscle contraction. Such disorders include, but are not limited to, urinary incontinence, hypertension, asthma, premature labor, irritable bowel syndrome, congestive heart failure, angina, and cerebral vascular disease.
BACKGROUND OF THE INVENTION
Urge urinary incontinence, the abnormal spontaneous contraction of the bladder detrusor muscle leading to a sense of urinary urgency and involuntary urine loss is currently a condition where there exists an unmet medical need (Primeau et al., Current Pharmaceutical Design, 1995, 1, 391). The current treatments for this condition are the use of anticholinergics and anticholinergic/antispasmodics which have the limitations of CNS related side effects and low efficacy which leads to poor patient compliance. Hyperpolarization of bladder smooth muscle leading to the relaxation of detrusor muscle contractions may represent a novel therapeutic approach to urge urinary incontinence.
Few examples of simple 4,5-diaminopyrazoles have appeared in the chemical or patent literature. Moderhack describes the synthesis of several 4,5-diaminopyrazoles as intermediates towards the synthesis of 1,2,4-triazoles ( Liebigs Ann. 1996, 777-9). Lewis et al. describe the synthesis of various 4,5-diaminopyrazoles ( J. Heterocyclic Chem. 1983, 20, 1501-3).
The synthetic procedure used to make the diamninopyrazoles reported in this invention record is based on the procedure of Vicentini et al. ( Tetrahedron 1990, 46, 5777-88 and Tetrahedron Lett. 1988, 29, 6171-2) which outlines the synthesis of 4-nitroso-5-aminopyrazoles as intermediates in the synthesis of imnidazole[4,5-c]pyrazoles.
SUMMARY OF THE INVENTION
The present invention discloses compounds represented by the formula (I):
wherein:
R 1 and R 2 are independently straight chain alkyl of 1 to 6 carbon atoms, branched alkyl of 3 to 6 carbons atoms, or cycloalkyl of 3 to 6 carbons atoms where R 1 R 2 may be optionally substituted by F, Cl, Br, I, OH, NH 2 , cyano, C 1 -C 6 alkoxy, C 1 -C 6 alkylthio, COOH or COOC 1 -C 6 alkyl;
R 3 is an aryl or heteroaryl, optionally substituted with 1 to 4 groups selected independently from straight chain C 1 -C 6 alkyl, branched alkyl of 3 to 6 carbons, or a cycloalkyl of 3 to 10 carbons; C 1 -C 6 alkoxy, cyano, F, Cl, Br, C 1 -C 6 alkylthio, CO 2 R 1 , CONH 2 , OH, NH 2 , and NO 2 ; wherein aryl is phenyl, naphthalene, anthracene or phenanthrene and heteroaryl is furan, thiophene, pyrrole, irnidazole, oxazole, thiazole, isoxazole, pyrazole, isothiazole, oxadiazole, triazole, thiadiazole, quinolizine, quinoline, isoquinoline, cinnoline, phthalazine, quinazoline, quinoxaline, naphthyridine, pterine, pyridine, pyrazine, pyrimidine, pyridazine, pyran and triazine;
n is 0 or 1;
R 4 is a straight chain alkyl group of 1 to 10 carbons atoms, a branched alkyl of 3 to 10 carbons, a cycloalkyl of 3 to 10 carbons, all of which may be optionally substituted by one or more F or Cl atoms; and all crystalline forms, enantiomers, diastereomers, and the pharmaceutically acceptable salts thereof.
It is understood that the definition of the compounds of formula (I), when R 1 , R 2 , R 3 , or R 4 , contain asymmetric carbons, encompass all possible stereoisomers and mixtures thereof which possess the activity discussed below. In particular, it encompasses racemic modifications and any optical isomers which possess the indicated activity. Optical isomers may be obtained in pure form by standard separation techniques. It is also understood that solid invention compounds or pharmaceutically acceptable salts thereof may exist in more than one crystalline form. The form obtained may be dependent upon the crystallization or recyrstallization solvent or solvent mixture, the rate of heating and/or cooling, drying conditions, and other variables. The pharmaceutically acceptable salts are those derived from such organic and inorganic acids as: lactic, citric, acetic, tartaric, succinic, maleic, malonic, hydrochloric, hydrobromic, phosphoric, nitric, sulfuric, methanesulfonic, and similarly known acceptable acids. Where R 2 or R 3 contains a carboxyl group, salts of the compounds of this invention may be formed with bases such as alkali metals (Na, K, Li) or the alkaline earth metals (Ca or Mg).
The compounds of formula (I) have been found to relax smooth muscle. They are therefore useful in the treatment of disorders associated with smooth muscle contraction, disorders involving excessive smooth muscle contraction of the urinary tract (such as incontinence), or of the gastro-intestinal tract (such as irritable bowel syndrome), asthma, and hair loss. Furthermore, the compounds of formula (I) relax bladder smooth muscle precontracted with KCl and thus are active as potassium channel activators which render them useful for treatment of peripheral vascular disease, hypertension, congestive heart failure, stroke, anxiety, cerebral anoxia and other neurodegenerative disorders (J. R. Empfield and Keith Russell, “Potassium Channel Openers,” Annual Reports in Medicinal Chemistry (1995).
DETAILED DESCRIPTION OF THE INVENTION
The present invention also provides a process for the preparation of a compound of formula (I). More particularly, the compounds of formula (I) where n is 1 may be prepared by reacting a compound of formula (II):
with a compound of formula (III):
where R 3 is an aryl or a heteroaryl moiety optionally substituted with 1 to 4 groups as defined previously, in a solvent such as benzene or toluene in the presence of molecular sieves at room temperature, followed by treatment with hydrogen under a pressure of 1 atmosphere in the presence of Pd/BaSO 4 at room temperature, in a polar solvent such as ethyl acetate.
Reaction of compound of formula (II) with a compound of formula (IV):
where R 3 is an aryl or heteroaryl moiety as defined previously, in a solvent such as benzene or toluene in the presence of Pd 2 dba 3 , P(o-tolyl) 3 , and NaOt-Bu at 100° C. gives a formula (I) compound where n is 0. The compounds of formula II are prepared by procedures based on the procedure reported by Vicentini et al., Tetrahedron 1990, 46, 5777-5788 and Tetrahedron Lett. 1988, 29, 6171-6172 as given in steps 1-4 in Example 1.
The following examples are included for illustrative purposes only and are not to be construed as limiting to this disclosure in any way. The chemicals and intermediates are either commercially available or readily prepared according to standard literature procedures. Still other methods of preparation of invention compounds may be apparent to those skilled in the art of organic synthesis.
EXAMPLE 1
N(3)-(2,2-Dimethyl-propyl)-2,5-dimethyl-N(4)-pyridin-4-ylmethyl-2H-pyrazole-3,4-diamine
Step 1
N-(2,5-Dimethyl-2H-pyrazol-3-yl)-2,2-dimethyl-propionamide
To 15.0 g (131 mmol) N-(2,5-dimethyl-2H-pyrazol-3-yl)-amine in 150 mL pyridine at 0° C. was added 19.3 mL (18.9 g, 158 mmol) of pivaloyl chloride. After stirring at 23° C. for 3.5 hours, the reaction solvent was evaporated, and the residue was evaporated with 2×200 mL toluene. The remaining solid was dissolved in 500 mL EtOAc/200 mL H 2 O and extracted. The aqueous layer was extracted with 2×100 mL EtOAc, and the combined organics were washed with 1×200 mL brine, dried over MgSO 4 , filtered and evaporated to an orange solid. Recrystallization from hot hexanes/EtOAc gave 24.45 g (125 mmol, a 96% yield) of the title compound as an off-white, crystalline solid: mp: 86-88° C.; 1 H NMR (300 MHz, CDCl 3 ): δ1.32 (s, 9H), 2.22 (s, 3H), 3.63 (s, 3H), 5.98 (s, 1H), 7.12 (brs, 1H); IR (KBr, cm −1 ): 3316s, 3274s, 2967m, 2935m, 1673s, 1655m, 1570s, 1514m, 1492m, 1457m; MS (ES) m/z (relative intensity): (196, M + , 100).
Anal. Calcd. for C 10 H 17 N 3 O: C, 61.51; H, 8.77; N, 21.52.
Found: C, 61.33; H, 8.80; N, 21.23.
Step 2
(2,2-Dimethyl-propyl)-(2,5-dimethyl-2H-pyrazol-3-yl)-amine
To 4.7 g (123 mmol) of LiAlH 4 in 150 mL of THF at 0° C. was added a solution of 12.0 g (61.45 mmol) of N-(2,5-dimethyl-2H-pyrazol-3-yl)-2,2-dimethyl-propionamide and 100 mL THF in drops over 60 min. After addition is complete, the reaction mixture was heated to 67° C. for 42 h. After cooling to 23° C., 5 mL H 2 O was carefully added, followed by 5 mL 5N NaOH and 5 mL H 2 O. The resulting mixture was filtered through Celite, evaporated to a yellow oil, dissolved in 300 mL EtOAc, washed with 1×100 mL brine, 1×100 mL H 2 O, 1×100 mL brine, dried over MgSO 4 , filtered and evaporated to give 9.45 g (52.1 mmol, an 85% yield) of the title compound as a light yellow oil. 1 H NMR (300 MHz, CDCl 3 ): δ0.98 (s, 9H), 2.17 (s, 3H), 2.81 (m, 2H), 3.56 (s, 3H), 5.24 (s, 1H); IR (KBr, cm− 1 ): 3261m, 2956m, 2866m, 1568s, 1476m, 1367m, 1362m, 1267m, 1200m, 729m; MS (ES) m/z (relative intensity): 182 (M + +H, 100).
Anal. Calcd. for C 10 H 19 N 3 : C, 66.26; H, 10.56; N, 23.18.
Found: C, 64.75; H, 10.23; N, 24.67.
Step 3
(2,5-Dimethyl-4-nitroso-2H-pyrazol-3-yl)-(2,2-dimethyl-propyl)-amine
To a 0° C. solution of 8.43 g (46.5 mmol) of (2,2-dimethyl-propyl)-(2,5-dimethyl-2H-pyrazol-3-yl)-amine and 150 mL EtOH was added 20 mL of 10-20% EtONO/EtOH. After stirring at 23° C. for 17 h, and 21 h, 20 mL portions of 10-20% EtONO/EtOH were added. After a total of 42 h, the reaction mixture was evaporated to a purple oil. Flash chromatography on silica gel, eluting with CH 2 Cl 2 /EtOAc (8/1 to 4/1 to 2/1), gave a purple solid. Recrystallization from hot hexanes/EtOAc gave 4.04 g (19.2 mmol, a 41% yield) of the title compound as a violet crystalline solid. mp: 83-84° C.; 1 H NMR (300 MHz, CDCl 3 ): δ1.02 (s, 9H), 2.61 (s, 3H), 3.24 (d, J=6.0 Hz, 2H), 3.76 (s, 3H), 10.23 (brs, 1H); IR (KBr, cm −1 ): 3428w, 3058w, 2963m, 2872w, 1633s, 1550m, 1479w, 1428w, 1222brm, 1134m, 971m; MS (ES) m/z (relative intensity): 211 (M + +H, 100).
Anal. Calcd. for C 10 H 18 N 4 O: C, 57.12; H, 8.63; N, 26.64.
Found: C, 57.18; H, 8.83; N, 26.69.
Step 4
N(3)-(2,2-Dimethyl-propyl)-2,5-dimethyl-2H-pyrazole-3,4-diamine
(2,5-Dimethyl-4-nitroso-2H-pyrazol-3-yl)-(2,2-dimethyl-propyl)-amine (3.44 g, 16.36 mmol), 400 mg of 10% Pd/C and 60 mL EtOAc were placed under a balloon of H 2 and stirred at 23° C. After 4 h, the reaction mixture was filtered through Celite and evaporated to an orange oil. Flash chromatography on silica gel, eluting with CHCl 3 /MeOH (20/1), gave a yellow solid. Recrystallization from hot hexanes/EtOAc gave 2.86 g (14.57 mmol, an 89% yield) of the title compound as an off-white crystalline solid. mp: 65-69° C.; 1 H NMR (300 MHz, CDCl 3 ): δ1.00 (s, 9H), 1.65 (brs, 2H), 2.13 (s, 3H), 2.77 (brs, 2H), 2.89 (brs, 1H), 3.62 (s, 3H); IR (KBr, cm −1 ): 3347-3204brs, 2952s, 2903w, 1599m, 1528m, 1495m, 1477m, 1378m, 1316m; MS (ES) m/z (relative intensity): 197 (M + +H, 100).
Anal. Calcd. for C 10 H 20 N 4 : C, 61.19; H, 10.27; N, 28.54.
Found: C, 56.19; H, 10.56; N, 26.37
Step 5
N(3)-(2,2-Dimethyl-propyl)-2,5-dimethyl-N(4)-pyridin-4-ylmethyl-2H- pyrazole-3,4-diamine
To 400 mg (2.03 mmol) of N(3)-(2,2-dimethyl-propyl)-2,5-dimethyl-2H-pyrazole-3,4-diamine and 15 mL toluene was added 0.23 mL (261 mg, 2.44 mmol) of 4-pyridinecarboxaldehyde, 500 mg of powdered 4Å molecular sieves and 1 crystal of p-TsOH·H 2 O. After stirring at room temperature for 14 h, TLC indicated that the starting amine (R f =0.40 (10/1 CHCl 3 /MeOH)) had been converted to the imine (R f =0.50 (10/1 CHCl 3 /MeOH). The mixture was filtered through Celite and evaporated to give a yellow oil.
To this oil was added 20 mL EtOAc, 300 mg 5% Pd/BaSO 4 and 1 drop of quinoline. This mixture was placed under a balloon of H 2 , and stirred at room temperature. After 24 h, 200 mg of 5% Pd/BaSO 4 was added and the reaction mixture was again stirred under a balloon of H 2 at room temperature. After a total of 30 h, TLC indicated that practically all of the starting imine (R f =0.50 (10/1 CHCl 3 /MeOH) had been converted to the corresponding amine (R f =0.35 (10/1 CHCl 3 /MeOH). The reaction mixture was filtered through Celite and evaporated to an orange oil. Flash chromatography on silica gel, eluting with CHCl 3 /MeOH (40/1 to 20/1 to 10/1), gave a yellow solid. Recrystallization from hot hexanes/Et 2 O gave 315 mg (1.10 mmol, a 54% yield) of the title compound as a yellow crystalline solid. mp: 88-90° C., 1 H NMR (300 MHz, CDCl 3 ): δ0.94 (s, 9H), 1.70 (brs, 1H), 2.13 (s, 3H), 2.61 (brd, 2H), 2.81-2.90 (brm, 1H), 3.59 (s, 3H), 4.00 (s, 2H), 7.26-7.33 (m, 2H), 8.53-8.60 (m, 2H), IR (KBr, cm −1 ): 3254s, 3047w, 2954m, 2865w, 1604w, 1567m, 1417m, 1389w, MS (ES) m/z (relative intensity): 288 (M + +H, 70).
Anal. Calcd. for C 16 H 25 N 5 : C, 66.87; H, 8.77; N, 24.37.
Found: C, 66.74; H, 8.73; N, 24.20.
EXAMPLE 2
4-{[5-(2,2-Dimethyl-propylamino)-1,3-dimethyl- 1H-pyrazol-4-ylamino]-methyl}-benzonitrile
The title compound was prepared according to the procedure for Example 1, Step 5 except that 4-cyanobenzaldehyde was used in place of 4-pyridinecarboxaldehyde and the final product was isolated as the tosylate salt, prepared by stirring the product with 1 equiv. of p-TsOH·H 2 O in 15 mL Et 2 O and removing the solvent via rotary evaporation. Off-white solid, yield: 85%, mp: 102-104° C., 1 H NMR (300 MHz, CDCl 3 ): δ0.78 (s, 9H), 2.00 (s, 3H), 2.20-2.40 (brm, 1H), 3.64 (s, 3H), 4.20-4.50 (brm, 1H), 4.37 (s, 2H), 7.21 (d, J=8.1 Hz, 2H), 7.39 (d, J=8.1 Hz, 2H), 7.50-7.55 (m, 2H), 7.74 (d, J=8.1 Hz 2H), IR (KBr, cm −1 ): 3500-2300brm, 3333m, 2957m, 2865m, 2230m, 1606m, 1592m, 1497w, 1477m, 1216s, 1158s, 1124s, 1032s, 1009s, 819s, 683s, MS (ES) m/z (relative intensity): 312 (M + -p-TsOH+H, 100).
Anal. Calcd. for C 25 H 33 N 5 O 3 S: C, 62.09; H, 6.88; N, 14.48.
Found: C, 59.00; H, 6.30; N, 13.18.
EXAMPLE 3
N(3)-(2,2-Dimethyl-propyl)-N(4)-(4-fluoro-benzyl)-2,5-dimethyl-2H-pyrazole-3,4-diamine
The title compound was prepared according to the procedure for Example 1, Step 5 except that 4-fluorobenzaldehyde was used in place of 4-pyridinecarboxaldehyde. Yellow solid, yield: 78%, mp: 32-39° C., 1 H NMR (300 MHz, CDCl 3 ): δ0.93 (s, 9H), 2.11 (s, 3H), 2.55 (s, 2H), 3.59 (s, 3H), 3.93 (s, 2H), 7.01 (m, 2H), 7.27 (m, 2H), IR (KBr, cm −1 ): 3334m, 3272s, 2960m, 2918m, 2869m, 1891w, 1592m, 1508s, 1479s, 1462s, 1364s, 1303s, 1283s, 1224m, 1140m, 993m, 819s, 725s, MS (ES) m/z (relative intensity): 305 (M+H + , 100).
Anal. Calcd. for C 17 H 25 FN 4 : C, 67.08; H, 8.28; N, 18.40.
Found: C, 66.58; H, 8.54; N, 18.07.
EXAMPLE 4
N(4)-(2,4-Dichloro-benzyl)-N(3)-(2,2-dimethyl-propyl)-2,5-dimethyl-2H-pyrazole-3,4-diamine
The title compound was prepared according to the procedure of Example 1, Step 5 except that 2,4-dichlorobenzaldehyde was used in place of 4-pyridinecarboxaldehyde and the final product was isolated as the tosylate salt by dissolving in 20 mL Et 2 O and stirring with 1 equiv. of p-TsOH·H 2 O for 1 h, and removing the solvent via rotary evaporation. Off-white solid, yield: 50%, 1 H NMR (300 MHz, CDCl 3 ): δ0.84 (s, 9H), 1.25 (s, 1H), 2.02 (s, 3H), 2.38 (s, 3H), 2.56 (brs, 1H), 3.71 (s, 3H), 4.26 (s, 2H), 4.29 (s, 2H), 7.10-7.50 (m, 5H), 7.77 (s, J=8.2 Hz, 2H), IR, MS (ES) m/z (relative intensity): 355 (M + -p-TsOH, 100).
Anal. Calcd. for C 24 H 32 Cl 2 N 4 O 3 S: C, 54.65; H, 6.11; N, 10.62.
Found: C, 56.95; H, 6.78; N, 9.02.
EXAMPLE 5
4-{[5-(2,2-Dimethyl-butylamino)-1,3-dimethyl-1H-pyrazol-4-ylamino]-methyl}-benzonitrile
Step 1
N-(1,3-Dimethyl-1H-pyrazol-5-yl)-2,2-dimethyl-butyramide
The title compound was prepared according to the procedure of Example 1, Step 1 except that 2,2-dimethylbutyroyl chloride was used in place of pivaloyl chloride. Brown oil, yield: 81%, 1 H NMR (300 MHz, CDCl 3 ): δ0.91 (t, J=7.4 Hz, 3H), 1.25 (s, 6H), 1.63 (q, J=7.4 Hz, 2H), 2.20 (s, 3H), 3.61 (s, 3H), 7.34 (brs, 1H), IR (KBr, cm −1 ): 3293m, 2968s, 2938s, 2879w, 1667s, 1565s, 1511-1447brs, 1381m, 1285w, 1161w, 774m., MS (ES) m/z (relative intensity): 210 (M + +H, 100).
Anal. Calcd. for C 11 H 19 N 3 O: C, 63.13; H, 9.15; N, 20.08.
Found: C, 61.83; H, 9.15; N, 18.54.
Step 2
(2,2-Dimethyl-pentyl)-(2,5-dimethyl-2H-pyrazol-3-yl)-amine
The title compound was prepared according to the procedure of Example 1, Step 2. Yellow oil, yield: 91%, 1 H NMR (300 MHz, CDCl 3 ): δ0.89 (t, 3H), 0.95 (s, 6H), 1.33 (q, 2H), 2.15 (s, 3H), 2.82 (d, 2H), 3.55 (s, 3H), δ5.25 (s, 1H).
Step 3
(2,2-Dimethyl-butyl)-(2,5-dimethyl-4-nitroso-2H-pyrazol-3-yl)-amine
The title compound was prepared according to the procedure of Example 1, step 3. Purple solid, yield: 50%, mp: 45-50° C., 1 H NMR (300 MHz, CDCl 3 ): δ0.89 (t, 3H), 0.97 (s, 6H), 1.37 (q, 2H), 2.61 (s, 3H), 3.25 (d, 2H), 3.76 (s, 3H), IR (KBr, cm −1 ): 2963s, 2878m, 1632s, 1550s, 1528w, 1477m, 1370m, 1356w, 1285w, 1228m, 1134m, 1080w, 967m, 655w, MS (ES) m/z (relative intensity): 225 (M+H +, 100).
Anal. Calcd. for C 11 H 20 N 4 O: C, 58.90; H, 8.99; N, 24.98.
Found: C, 58.14; H, 8.75; N, 25.56.
Step 4
N(3)-(2,2-Di methyl-pentyl)-2,5-dimethyl-2H-pyrazole-3,4-diamine
The title compound was prepared according to the procedure of Example 1, step 4. Yellow oil, yield: 82%, 1 H NMR (300 MHz, CDCl 3 ): δ0.89 (t, 3H), 0.95 (s, 6H), 1.33 (q, 2H), 2.15 (s, 3H), 2.78 (s, 2H), 3.65 (s, 3H).
Step 5
4-{[5-(2,2-Dimethyl-butylamino)-1,3-dimethyl-1H-pyrazol-4-ylamino]-methyl}-benzonitrile
The title compound was prepared according to the procedure of Example 1, Step 5 except that 4-cyanobenzaldehyde was used in place of 4-pyridinecarboxaldehyde and N(3)-(2,2-dimethyl-pentyl)-2,5-dimethyl-2H-pyrazole-3,4-diamine was used in place of N(3)-(2,2-dimethyl-propyl)-2,5-dimethyl-2H-pyrazole-3,4-diamine. Yellow oil, yield: 19%, 1 H NMR (300 MHz, CDCl 3 ): δ0.83 (t, 3H), 0.89 (s, 6H), 1.28 (q, 2H), 2.10 (s, 3H), 2.61 (s, 2H), 3.59 (s, 3H), 4.04 (s, 2H), 7.42 (d, 2H), 7.61 (d, 2H), IR (KBr, cm −1 ): 3340m, 2961s, 2877m, 2226s, 1588m, 1565m, 1537m, 1462m, 1378m, 1365m, 1296w, 821w, MS (ES) m/z (relative intensity): 326 (M+H + , 100).
Anal. Calcd. for C 19 H 27 N 5 : C, 70.12; H, 8.36; N, 21.52.
Found: C, 68.87; H, 8.49; N, 20.92.
EXAMPLE 6
N(4)-(2,4-Difluoro-benzyl)-N(3)-(2,2-dimethyl-propyl)-2,5-dimethyl-2H-pyrazole-3,4-diamine
The title compound was prepared according to the procedure of Example 1, Step 5 except that 2,4-difluorobenzaldehyde was used in place of 4-pyridinecarboxaldehyde. Yellow gum, yield: 61%, 1 H NMR (300 MHz, CDCl 3 ): δ0.96 (s, 9H), 2.07 (s, 3H), 2.62 (s, 2H), 3.59 (s, 3H), 3.97 (s, 2H), 6.77-6.86 (m, 2H), 7.13-7.24 (m, 1H), IR (KBr, cm −1 ): 3300 m, 2960s, 2870m, 1588m, 1531m, l500s, 1433m, 1230m, 1176m, 1125m, MS (ES) m/z (relative intensity): 323 (M+H + , +100).
Anal. Calcd. for C 17 H 24 F 2 N 4 : C, 63.33; H, 7.50; N, 17.38.
Found: C, 62.61; H, 7.59; N, 17.14.
EXAMPLE 7
N(3)-(2,2-Dimethyl-propyl)-2,5-dimethyl-N(4)-pyridin-3-ylmethyl-2H-pyrazole-3,4-diamine
The title compound was prepared according to the procedure of Example 1, Step 5 except that 3-pyridinecarboxaldehyde was used in place of 4-pyridinecarboxaldehyde. Yellow gum, yield: 39%, 1 H NMR (300 MHz, CDCl 3 ): δ0.94 (s, 9H), 2.12 (s, 3H), 2.58 (s, 2H), 3.59 (s, 3H), 4.00 (s, 2H), 7.23(m, 1H), 7.60(m, 1H), 8.55(m, 2H), IR (KBr, cm 1 ): 3289m, 3029w, 2953s, 2867m, 1589m, 1532w, 1478s, 1424m, 1394m, 1296m, 1138m, 1079m, 714m, MS (ES) m/z (relative intensity): 288 (M+H + , 100).
Anal. Calcd. for C 16 H 25 N 5 : C, 66.87; H, 8.77; N, 24.37.
Found: C, 65.20; H, 8.98; N, 23.69.
EXAMPLE 8
N(3)-(2,2-Dimethyl-propyl)-2,5-dimethyl-N(4)-(2,4,6-trimethyl-benzyl)-2H-pyrazole-3,4-diamine
The title compound was prepared according to the procedure of Example 1, Step 5 except that 2,4,6-trimethylbenzaldehyde was used in place of 4-pyridinecarboxaldehyde. Tan solid, yield: 47%, mp: 114-120° C., 1 H NMR (300 MHz, CDCl 3 ): δ0.91 (s, 9H), 2.19 (s, 3H), 2.25 (s, 3H), 2.32 (s, 6H), 2.46 (s, 2H), 3.59 (s, 3H), 3.96 (s, 2H), 6.84(s, 2H), IR (KBr, cm −1 ): 3322 m, 3283s, 2951s, 2922m, 2878m, 2823w, 1583m, 1476s, 1452m, 1285s, 1196m, 851w, 757w, MS (ES) m/z (relative intensity): 329 (M+H + , 100).
Anal. Calcd. for C 20 H 32 N 4 : C, 73.13; H, 9.82; N, 17.06.
Found: C, 73.12; H, 9.97; N, 17.05.
EXAMPLE 9
N( 3)-( 2,2-Dimethyl-butyl)-2,5-dimethyl-N(4)-pyridin-4-ylmethyl-2H-pyrazole-3,4-diamine
The title compound was prepared according to the procedure of Example 5, Step 5 except that 4-pyridinecarboxaldehyde was used in place of 4-cya nobenza ldehyde. Purple oil, yield: 49%, 1 H NMR (300 MHz, CDCl 3 ): δ0.83 (t, 3H), 0.89 (s, 6H), 1.29 (q, 2H), 2.13 (s, 3H), 2.61 (s, 2H), 2.81(br, 2H), 3.60 (s, 3H), 4.01 (s, 2H), 7.27 (d, 2H), 8.55(d, 2H), IR (KBr, cm −1 ): 3296m, 2970s, 2877m, 1601s, 1462m, 1418m, 1378m, 1296m, 1138w, 993w, 799w, 405w, MS (ES) m/z (relative intensity): 302 (M+H + , 100).
Anal. for C 17 H 27 N 5 : C, 67.74; H, 9.03; N, 23.23.
Found: C, 66.82; H, 9.05; N, 23.53.
EXAMPLE 10
N(4)-Benzyl-N(3)-(2,2-dimethyl-butyl)-2,5-dimethyliNl-2H-pyrazole-3,4-diamine
The title compound was prepared according to the procedure of Example 5, Step 5 except that benzaldehyde was used in place of 4icyanobenzaldehyde. Yellow oil, yield: 66%, 1 H NMR (300 MHz, CDCl 3 ): δ0.82 (t, 3H), 0.87 (s, 6H), 1.27 (q, 2H), 2.12 (s, 3H), 2.59 (s, 2H), 2.61(br, 2H), 3.59 (s, 3H), 3.96 (s, 2H), 7.30 (m, 5H), IR (KBr, cm −1 ): 3297m, 3207w, 2970s, 2877m, 1587m, 1461s, 1377m, 1294m, 1136w, 1081w, 746m, 699s, MS (ES) m/z (relative intensity): 301 (M+H + , 100).
Anal. Calcd. for C 18 H 28 N 4 : C, 71.96; H, 9.39; N, 18.65.
Found: C, 71.02; H, 9.33; N, 17.96.
EXAMPLE 11
N(3)-(2,2-Dimethyl-propyl)-2,5-dimethyl-N(4)-phenyl-2H-pyrazole-3,4-diamine
To 300 mg (2.55 mmol) of N(3)-(2,2-dimethyl-propyl)-2,5-dimethyl-2H-pyrazole-3,4-diamine and 20 mL toluene was added 155 mg (0.51 mmol) P(o-tolyl) 3 , 343 mg (3.57 mmol) NaOt-Bu, 0.27 mL (400 mg, 2.55 mmol) of bromobenzene and 116 mg (0.128 mmol) of Pd 2 dba 3 , and the resulting purple mixture was heated to 100° C. After 5 h, the black reaction mixture was filtered through Celite and the filtrate was poured into 50 mL brine. This aqueous mixture was washed with 3×50 mL EtOAc, and the combined organics were dried over MgSO 4 , filtered and evaporated to a brown oil. Flash chromatography on silica gel, eluting with CH 2 Cl 2 /EtOAc (20/1 to 8/1 to 4/1) gave 402 mg (1.48 mmol, a 58% yield) of the title compound as a light yellow gum. 1 H NMR (300 MHz, CDCl 3 ): δ0.88 (s, 9H), 2.02 (s, 3H), 2.78 (brs, 2H), 2.90-3.12 (brs, 1H), 3.67 (s, 3H), 4.71 (brm, 1H), 6.55-6.60 (m, 2H), 6.72 (t, J=6.4 Hz, 1H), 7.15 (t, J=7.3 Hz, 2H), IR (KBr, cm −1 ): 3390m, 3262w, 3174w, 3058w, 2955m, 1602s, 1544m, 1516m, 1497s, 1476m, 1394m, 1316s, 991w, 749m, MS (ES) m/z (relative intensity): 273 (M + +H, 100).
Anal. Calcd. for C 16 H 24 N 4 : C, 70.55; H, 8.88; N, 20.57.
Found: C, 70.00; H, 9.20; N, 19.31.
EXAMPLE 12
N(4)-(4-Chloro-2-methyl-phenyl)-N(3)-(2,2-dimethyl-propyl)-2,5-dimethyl-2H-pyrazole-3,4-diamine
The title compound was prepared according to the procedure of Example 11 except that bromobenzene was replaced with 2-chloro-5-bromotoluene. Orange gum, yield: 56%, 1 H NMR (300 MHz, CDCl 3 ): δ0.87 (s, 9H), 1.99 (s, 3H), 2.77 (s, 2H), 3.02 (brs, 1H), 3.67 (s, 3H), 4.52 (s, 1H), 6.32 (d, J=8.4 Hz, 1H), 6.96 (dd, J=2.1, 8.4 Hz, 1H), 7.05 (d, J=2.2 Hz, 1H), IR (KBr, cm −1 ): 3344w, 3282s, 2952s, 2868m, 1580m, 1503s, 1479s, 1460m, 1432m, 1308s, 1137m, 814w, MS (ES) m/z (relative intensity): 321 (M+, 100).
Anal. Calcd. for C 17 H 25 ClN 4 : C, 63.64; H, 7.85; N, 17.46.
Found: C, 63.95; H, 7.81; N, 16.47.
EXAMPLE 13
4-[5-(2,2-Dimethyl-propylamino)-1,3-dimethyl-1H-pyrazol-4-ylamino]-benzonitrile
The title compound was prepared according to the procedure of Example 11 except that bromobenzene was replaced with 4-cyanobenzaldehye. Light-yellow solid, Yield 54%, mp: 131-134, 1 H NMR (300 MHz, CDCl 3 ): δ0.87 (s, 9H), 2.01 (s, 3H), 2.79 (brs, 2H), 3.02 (brs, 1H), 3.66 (s, 3H), 5.21 (s, 1H), 6.58 (d, J=8.7 Hz, 2H), 7.42 (d, J=8.7 Hz, 2H), IR (KBr, cm −1 ): 3360w, 2961m, 2222m, 1609s, 1515m, 1327w, 1169w, 828w, MS (ES) m/z(relative intensity): 296 (M + −H, 50).
EXAMPLE 14
N(4)-(4-Chloro-phenyl)-N(3)-(2,2-dimethyl-propyl)-2,5-dimethyl-2H-pyrazole-3,4-diamine
The title compound was prepared according to the procedure of Example 11 except that bromobenzene was replaced with 4-bromochlorobenzene. Yellow gum, yield: 56%, 1 H NMR (300 MHz, CDCl 3 ): δ0.88 (s, 9H),1.80-2.15 (brs, 1H), 2.00 (s, 3H), 2.78 (s, 2H), 3.65 (s, 3H), 4.72 (brs, 1H), 6.49 (d, J=8.8 Hz, 2H), 7.09 (d, J=8.8 Hz, 2H), IR (KBr, cm −1 ): 3262m, 3087w, 2955s, 2867m, 1597s, 1491brs, 1394m, 1365m, 1312s, 1253m, 1207w, 1089w, 821m, MS (ES) m/z (relative intensity): 307 (M + +H, 100).
Pharmacology
The smooth muscle relaxing activity of the compounds of this invention was established in accordance with standard pharmaceutically accepted test procedures with representative compounds as follows:
Sprague-Dawley rats (150-200 g) are rendered unconscious by CO 2 asphyxiation and then euthanized by cervical dislocation. The bladder is removed into warm (37° C.) physiological salt solution (PSS) of the following composition (mM): NaCl, 118.4; KCl, 4.7; CaCl 2 , 2.5; MgSO 4 , 4.7; H 2 O, 1.2; NaHCO 3 , 24.9; KH 2 PO 4 , 1.2; glucose, 11.1; EDTA, 0.023; gassed with 95% O 2 ; 2/5% CO 2 ; pH 7.4. The bladder is opened and then cut into strips 1-2 mm in width and 7-10 mm in length. The strips are subsequently suspended in a 10 mL tissue bath under an initial resting tension of 1.5 g. The strips are held in place by two surgical clips one of which is attached to a fixed hook while the other is attached to an isometric force transducer. The preparations, which usually exhibit small spontaneous contractions, are allowed to recover for a period of 1 hour prior to a challenge with 0.1 μM carbachol. The carbachol is then washed out and the tissue allowed to relax to its resting level of activity. Following a further 30 min period of recovery an additional 15 mM KCl are introduced into the tissue bath. This increase in KCl concentration results in a large increase in the amplitude of spontaneous contractions (and initiation of contractions in previously quiescent strips) superimposed upon a small increase in basal tone. Following stabilization of this enhanced level of contractile activity, incremental increases in the concentration of test compound or vehicle are introduced into the tissue bath. Contractile activity is measured for each compound or vehicle concentration during the last minute of a 30 minute challenge.
The isometric force developed by the bladder strips is measured using a concentration required to elicit 50% inhibition of pre-drug contractile activity (IC 50 concentration) and is calculated from this concentration-response curve. The maximum percentage inhibition of contractile activity evoked by a test compound is also recorded for concentrations of test compound less than or equal to 30 μM.
The results of this study are shown in Table I.
TABLE I
Inhibition of Contractions in Isolated Rat Bladder Strips
Compound
n
IC 50 (μM)
Example 1
2
4.9
Example 2
2
8.26
Example 3
2
11.45
Example 4
2
11.8
Example 5
1
12.6
Example 6
2
13.5
Example 7
1
15.4
Example 8
1
17.8
Example 9
2
19.2
Example 10
2
19.9
Example 11
4
4.3
Example 12
2
12.5
Example 13
2
17.9
Example 14
1
22.9
Example 15
2
10.7
In addition, we tested the ability of compounds to inhibit the hyperactivity of hypertrophied bladder (detrusor) smooth muscle in conscious female rats with hypertrophied bladders and thereby alleviate urinary incontinence in rats according to the following protocol described by Malmgren et al. ( J. Urol. 1989, 142, 1134.):
Female Sprague-Dawley rats, ranging in weight from 190-210 g are used. Up to 25 animals are prepared each time. After development of bladder hypertrophy 4-8 animals are used per test.
Compounds are dissolved in PEG-200 and administered by gastric gavage or intravenously in a volume of 5 mL/kg. For primary screening all drugs are administered at the arbitrary dose of 10 mg/kg p.o. to groups of 4 rats.
The animals are anesthetized with halothane. Through a midline incision the bladder and urethra are exposed and a ligature of 4-0 silk is tied around the proximal urethra in the presence of a stainless steel rod (1 mm diameter) to produce a partial occlusion. The rod is then removed. The abdominal region is closed using surgical staples and each rat receives 150,000 units of bicillin C-R. The animals are allowed six weeks to develop sufficient bladder hypertrophy. After six weeks, the ligature is removed under halothane anesthesia and a catheter (PE 60) with a cuff is placed in the dome of the bladder and secured with a purse string suture. The catheter is tunneled under the skin and exteriorized through an opening in the back of the neck. The abdominal incision is sutured and the free end of the catheter sealed. In order to prevent infections the rats receive an injection of bicillin C-R (150000 units/rat). Two days later the animals are used in cystometrical evaluations, The animals are placed in the metabolic cages and the catheter is attached (using a “T” connector) to a Statham pressure transducer (Model P23Db) and to a Harvard infusion pump. A plastic beaker attached to a force displacement transducer (Grass FTO3) is placed under the rat's cage to collect and record urine volume. Animals are allowed 15-30 min to rest before the saline infusion (20 mL/hr for 20 minutes) is started for the first cystometry period. Two hours after the first cystometry period, the rats are dosed with the vehicle or the test compound and one hour later a second cystometry is performed. The following urodynamic variables are recorded:
Basal bladder pressure=the lowest bladder pressure during cystometry
Threshold pressure=bladder pressure immediately prior to micturition
Micturition volume=volume expelled
Micturition pressure=peak pressure during voiding
Basal bladder pressure =
the lowest bladder pressure during cystometry
Threshold pressure =
bladder pressure immediately prior to
micturition
Micturition volume =
volume expelled
Micturition pressure =
peak pressure during voiding
Spontaneous activity =
mean amplitude of bladder pressure
fluctuations during filling
Presentation of Results
The mean value of each variable is calculated before and after compound administration. For each compound the changes in the variables measured are compared to the values obtained before treatment and expressed as percent inhibition. The data are also subjected to 2-way analysis of variance to determine significant (p<0.05) changes in the variable measured.
Criteria for Activity
The most characteristic finding in this rat model is spontaneous bladder contractions which develop during filling. The compounds which inhibit spontaneous contractions by at least 50% at 10 mg/kg p.o. or i.v. (arbitrary chosen dose) are considered active. The results of this study are shown in Table II.
TABLE II
Inhibition of Spontaneous Contractions In Vivo
Compound
# of animals
dose mg/kg (p.o.)
% Red (F) c
Example 1
4
10 mg/kg
−36 ± 7
c Percent reduction in the total number of spontaneous contractions in the hypertrophied rat bladder model
Hence, the compounds of this invention have a pronounced effect on smooth muscle contractility and are useful in the treatment of urinary incontinence, irritable bladder and bowel disease, asthma, hypertension, stroke, and similar diseases as mentioned above, which are amenable to treatment with potassium channel activating compounds by administration, orally parenterally, or by aspiration to a patient in need thereof.
Pharmaceutical Composition
Compounds of this invention may be administered neat or with a pharmaceutical carrier to a patient in need thereof. The present invention accordingly provides a pharmaceutical composition which comprises a compound of this invention in combination or association with a pharmaceutically acceptable carrier. In particular, the present invention provides a pharmaceutical composition which comprises an effective amount of a compound of this invention and a pharmaceutically acceptable carrier. The pharmaceutical carrier may be solid or liquid.
Applicable solid carriers can include one or more substances which may also act as flavoring agents, lubricants, solubilizers, suspending agents, fillers, glidants, compression aids, binders or tablet-disintegrating agents or an encapsulating material. In powders, the carrier is a finely divided solid which is in admixture with the finely divided active ingredient. In tablets, the active ingredient is mixed with a carrier having the necessary compression properties n suitable proportions and compacted in the shape and size desired. The powders and tablets preferably contain up to 99% of the active ingredient. Suitable solid carriers include, for example, calcium phosphate, magnesium stearate, talc, sugars, lactose, dextrin, starch, gelatin, cellulose, methyl cellulose, sodium carboxymethyl cellulose, polyvinylpyrrolidine, low melting waxes and ion exchange resins.
Liquid carriers may be used in preparing solutions, suspensions, emulsions, syrups and elixirs. The active ingredient of this invention can be dissolved or suspended in a pharmaceutically acceptable liquid carrier such as water, an organic solvent, a mixture of both or pharmaceutically acceptable oils or fat. The liquid carrier can contain other suitable pharmaceutical additives such a solubilizers, emulsifiers, buffers, preservatives, sweeteners, flavoring agents, suspending agents, thickening agents, colors, viscosity regulators, stabilizers or osmo-regulators. Suitable examples of liquid carriers for oral and parenteral administration include water (particularly containing additives as above, e.g., cellulose derivatives, preferable sodium carboxymethyl cellulose solution), alcohols (including monohydric alcohols and polyhydric alcohols, e.g., glycols) and their derivatives, and oils (e.g., fractionated coconut oil and arachis oil). For parenteral administration the carrier can also be an oily ester such as ethyl oleate and isopropyl myristate. Sterile liquid carriers are used in sterile liquid form compositions for parenteral administration.
Liquid pharmaceutical compositions which are sterile solutions or suspensions can be utilized by, for example, intramuscular, intraperitoneal or subcutaneous injection. Sterile solutions can also be administered intravenously. For oral administration, either a liquid or solid composition form may be used.
The compositions are preferably adapted for oral administration. However, they may be adapted for other modes of administration, for example, parenteral administration for patient suffering from heart failure.
In order to obtain consistency of administration, it is preferred that a composition of the invention is in the form of a unit dose. Suitable unit dose forms include tablets, capsules and powders in sachets or vials. Such unit dose forms may contain from 0.1 to 100 mg of a compound of the invention and preferably from 2 to 50 mg. Still further preferred unit dosage forms contain 5 to 25 mg of a compound of the present invention. The compounds of the present invention can be administered orally at a dose range of about 0.01 to 100 mg/kg or preferably at a dose range of 0.1 to 10 mg/kg. Such compositions may be administered from 1 to 6 times a day, more usually from 1 to 4 times a day.
The present invention further provides a compound of the invention for use as an active therapeutic substance. Compounds of formula (I) are of particular use in the induction of smooth muscle relaxation. The present invention further provides a method of treating smooth muscle disorders in mammals including man, which comprises administering to the afflicted mammal an effective amount of a compound or a pharmaceutical composition of the invention.
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This invention concerns the treatment of smooth muscle spasticity or excess muscle contraction such as urge urinary incontinence with a compound of the formula
wherein:
R 1 and R 2 are independently straight chain alkyl of 1 to 6 carbon atoms, branched alkyl of 3 to 6 carbons atoms, or cycloalkyl of 3 to 6 carbons atoms where R 1 R 2 may be substituted by F, Cl, Br, I, OH, NH 2 , cyano, C 1 -C 6 alkoxy, C 1 -C 6 alkylthio, COOH or COOC 1 -C 6 alkyl;
R 3 is an aryl or heteroaryl as defined herein, optionally substituted with 0 to 4 groups selected independently from C 1 -C 6 alkyl, C 1 -C 6 alkoxy, cyano, F, Cl, Br, C 1 -C 6 alkylthio, CO 2 R 1 , CONH 2 , OH, NH 2 , and NO 2 ;
n is 0 or 1;
R 4 is a straight chain alkyl group of 1 to 10 carbons atoms, a branched alkyl of 3 to 10 carbons, or a cycloalkyl of 3 to 10 carbons;
and all crystalline forms and the pharmaceutically acceptable salts thereof
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This application is a continuation-in-part of copending application Ser. No. 08/888,149, filed on Jul. 3, 1997.
FIELD OF THE INVENTION
The field of this invention relates to streamlined techniques for removal of an anchor seal assembly from a packer/PBR and/or releasing a packer through tubing to facilitate further downhole operations.
BACKGROUND OF THE INVENTION
The traditional methods of attaching the tubing string to a production packer or other completion equipment rely on devices known as seal assemblies. These assemblies allow the production tubing to maintain a continuous sealing conduit for the purpose of oil and gas production up the inside of the tubing and further allow the ability to disconnect the tubing when desired. The seal assemblies are normally connected to the packer in one of two ways, floating or anchored.
The floating seal assembly, also known as a locator seal assembly, is designed to allow for thermal expansion and contraction of the tubing without adding high stress to the tubing string. The seal assembly simply floats in a polished-bore receptacle (PBR) during the production life of the well.
It is more often desirable to anchor the tubing to the packer completion to ensure tubing stability. This is particularly true in the case of some deepwater completions where a tension leg platform is used. For safety reasons, if a surface failure occurs, such as the platform floats off location and pulls an extreme tension load on the well, the desire is to have the tubing resist this tension by staying anchored to the completion packer. Therefore, the anchor seal assembly is attached to the packer via a threaded connection. Typically, the anchor seal assembly is removed from the packer by means of rotation at the surface or shear release. However, most deepwater completion designs have a significant number of control lines strapped to the outside of the tubing string. Some of these wells are highly deviated, making rotation difficult.
The current method of releasing an anchor in this type of completion is to run through the tubing with an internal tubing cutting assembly to a location just above the anchor seal assembly and cut the tubing completely through. The tubing is then removed. A second trip is then made with a work string to grapple and rotate the anchor out of the completion packer. Once the anchor is removed, a packer retrieving tool can be run to depth to recover the packer. This procedure requires a minimum of three round trips and is very expensive. Rig time in deep-water completions can run over $150,000 per day. Often, several days may be needed to recover the packer in this traditional manner.
In other situations, there arises a need to pull the tubing with the packer to facilitate further downhole operations. This is to be contrasted with dealing with a situation such as a leak in the tubing above the packer, which would not require the removal of the packer. In situations where not only the tubing needs to come out but the packer as well, the prior technique involved going thru-tubing with a tubing cutter to cut the tubing and retrieve the portion of the tubing above the cut. A second trip was required to remove the anchor for the tubing in the packer, and then a third trip was required back into the hole with a retrieving tool so that the packer could be retrieved. The retrieving tool had to be a specific length and have a defined latch to mate up with the packer receptacle assembly which is in the hole. The third trip would involve moving a support ring out from under a collet assembly on the packer, which unlocks the slips and sealing element of the packer and enables the tool to be retrieved with a pulling force.
Thus, in both situations the objective is to be able to accomplish the removal of the tubing only or of the tubing and the packer in fewer trips in the wellbore, thus saving rig time.
Hydraulic release mechanisms, as between the packer and the tubing, have been used in the past. However, the disadvantage of such designs is that they created leak paths between the tubing and the annulus if any of the various O-rings that are required in such designs malfunction. Thus, what is needed is a design which does not have the limitations of hydraulic release techniques as between the tubing and the packer; one such design provides for metal-to-metal sealing components. Thus, one of the objectives of the present invention is to provide a design which does not have the potential leak paths yet at the same time allows for simple separation of the tubing from the PBR without any need for twisting or turning. The objective is met with a design that allows, in a single trip in the hole, the actuation of the release mechanism to separate the anchor seal assembly from the PBR via an internal punch tool. Alternatively, the packer can be released thru-tubing with a retrieving tool which can go thru-tubing to the packer and act on its release assembly and following the operation, be readily removed. With the packer released, it can then be retrieved as the tubing is pulled out of the hole, thus eliminating the time required to pull the tubing to retrieve the packer.
SUMMARY OF THE INVENTION
A configuration is provided to anchor the tubing string into a polished-bore receptacle while providing the ability to disconnect the tubing string from the polished-bore receptacle in a single trip in the wellbore. The configuration of the anchor provides for metal-to-metal sealing, and the disconnection is accomplished by a penetrating tool which accesses an annular cavity to unsupport locking dogs which facilitate removal of the tubing string from the polished-bore receptacle with applied pressure. If the packer needs to come out for any reason, a retrieving tool is described which, in a single trip, allows the retrieving tool to be advanced thru-tubing into the packer itself to unlock it. The retrieving tool is pulled out of the tubing and a pick-up force is applied to the tubing string to extend the packer to allow for its ultimate removal with the tubing. The retrieving tool preferably employs jarring forces to release the packer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of an assembly showing a downhole packer, a polished-bore receptacle, and a tubing string with various control lines schematically attached to it.
FIGS. 2a-2b illustrate the anchor seal assembly in the polished-bore receptacle, showing how the tubing string is anchored to the polished-bore receptacle.
FIGS. 3a-3b are the view shown in FIGS. 2a-2b, with the penetrating tool in position prior to penetration.
FIGS. 4a-4b illustrate the penetrating tool penetrating through the wall of the tubing and hydraulic pressure applied within the tubing to stroke a piston to unsupport the locking dogs.
FIGS. 5a-5b illustrate the connection previously shown in the figures, with the penetrating tool removed and a shear ring about to shear.
FIGS. 6a-6b illustrate the shear ring in a broken position and the tubing movable out of the polished-bore receptacle.
FIGS. 7a-7c illustrate the thru-tubing release tool for the packer mounted below the polished-bore receptacle in the run-in position just prior to a packer release.
FIGS. 8a-8c illustrate the packer in a released position, with the release tool in a position for withdrawal from inside the tubing.
FIGS. 9a-9c illustrate the thru-tubing release tool which operates with a jarring technique.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a tubing string 10 extends form the surface into a polished-bore receptacle (PBR) 12, which is a part of the structure of the packer 14. The packer 14 seals off the wellbore 16. The tubing string 10 has a seal 18 which is in contact with a seal bore inside the PBR 12. An anchor assembly 20 secures the tubing string 10 to the PBR 12. Typically, the tubing string 10 has a series of control lines 22 which are secured by guides 24 at intervals along the tubing string 10. The presence of the control lines 22 with guides 24 precludes a twisting motion as the means to release the anchoring assembly 20. Thus, in the past, cutting tools have been lowered through the tubing string 10 and a cut 26 was made with that tool. The portion of the tubing string above the cut 26 is then removed from the wellbore after the cutting tool is removed. Thereafter, a fishing operation with an overshot or a grappling device is required to latch onto the remainder of the tubing string 10 at cut 26 to provide the requisite rotation to release the remainder of the tubing string 10 from the PBR 12. It should be noted that once the upper portion of the tubing string 10 with the control lines 22 has been removed, a twisting motion is possible on the balance of the tubing string 10 still secured by the anchor assembly 20. If thereafter in the past the packer needed to come out, a separate trip was made after pulling out the balance of the tubing string 10 with a release tool for the packer 14 so that it could then be pulled out. These techniques previously used to either disconnect the tubing string 10 from the packer 14, or to pull out both the tubing string 10 and the packer 14, necessitated numerous trips into the wellbore and, consequently, consumed considerable time which results in expense to the operator who pays for the rig by the day. The cutting technique has created problems because of difficulties in making the cut or presentation of a rough edge which at time was difficult to grapple.
The apparatus and methods of the present invention are designed to streamline the process of either removing the tubing 10 from the PBR 12 and leaving the packer 14 intact, or alternatively, releasing the packer 14 without cutting the tubing 10. In either event, the operations are accomplished with a single trip in the wellbore. Additionally, the configuration as described in FIGS. 1-6 has the additional advantage over hydraulic release techniques in that metal-to-metal seals are used, as will be described below. Thus, the leak paths that exist through the tubing into the annulus in typical hydraulically operated devices are not present in the apparatus and method of the present invention.
Referring to FIGS. 2a-2b, the PBR 12 is illustrated, as is the lower end of the tubing string 10. The tubing string 10, at a lower end 28, has a metallic sealing surface 30 which engages the sealing surface 32 of the PBR 12. Additionally, a backup seal ring 34 backs up the metal-to-metal seal between surfaces 30 and 32. Seal ring 34 can be a composite structure made of a plurality of elastomeric seals. The assembly 34 is retained between the ring 98 and the shoulder 36 on tubing string 10.
Also located on tubing string 10 is a series of serrations 38 which are designed to receive teeth 40 of dog or dogs 42. Dogs 42 extend through an opening 44 in sleeve 46. In the run-in position shown in FIG. 2b, the piston 48 has a surface 50 which contacts the dogs 42 to support them in the position where the teeth 40 extend into the serrations 38. The sleeve 46 is also secured to the tubing string 10 at shear ring 52. A cavity 54 is defined between the tubing string 10 and the piston 48 and is sealed by seals 56, 58, and 60.
Mounted above sleeve 46 is ring 62. Ring 62 ultimately contacts locking collets 64 which have a serrated surface 66 to interact with a similar surface 68 on the PBR 12. The collets 64 are retained within recess 70 of the tubing string 10. A top ring 72 engages the PBR 12, and seal 74 seals off the connection. The nature of the surfaces 66 and 68 permits insertion of the lower end 28 into the PBR 12 but does not permit removal because a support 76 allows assembly by a latching action but does not permit release. Ultimately, the support 76 is translated due to relative movement between the tubing string 10 and the collets 64, as shown by a comparison of FIGS. 5a and 6a so that a release is possible. The release is made possible by a breakage of the shear ring 52, which allows the tubing string 10, when picked up, to bring shoulder 78 against surface 80 of top ring 72. When that position is attained, as shown in FIG. 6a, the support 76 is moved over sufficiently so as to allow flexing of collets 64 sufficiently to allow relative movement of serrated surfaces 66 and 68.
Those skilled in the art will appreciate by looking at FIGS. 2a and 2b that surfaces 30 and 32 form a metal-to-metal seal, backed up by seal ring 34. Accordingly, there are no elastomeric seals which can be leak paths from the tubing 10 into the annulus 82. This provides a distinct advantage over hydraulically releasable systems which generally have hydraulically actuated pistons and flowpaths sealed off by a variety of elastomeric O-ring seals. Here, until penetrated, the cavity 54, with its various seals 56, 58, and 60, are all isolated from the flowpath inside of the tubing string 10. All those elastomeric and other types of seals are behind the metal-to-metal seal formed by surfaces 30 and 32.
The tubing string 10 in FIGS. 2a and 2b is retained to the PBR 12 by virtue of the dogs 42 extending partially out of opening 44, thus locking the sleeve 46 to the tubing string 10. The sleeve 46 is also retained to the tubing string 10 by shear ring 52. Until the dogs 42 retract, there is no way to shear the shear ring 52. The collets 64 keep the entire assembly from coming out so long as they are supported by support 76. Thus, the release sequence cannot be initiated until the tubing string 10 has been penetrated into the cavity 54, as shown in FIGS. 3b and 4b. In FIGS. 3a and 3b, the puncture tool 84 is inserted into the tubing string 10 and landed on shoulder 86. When this occurs, seal 88 comes into contact with surface 90 on the PBR 12, effectively closing off the tubing string 10 internally to permit pressure build-up therein for actuation of the puncture tool 84. The puncture tool 84 is a tool of the type that is well-known in the art. Upon an application of a downward force, the punch 92 moves radially due to a wedging action until it creates an opening 94 into cavity 54, as shown in FIG. 4b. Application of pressure moves the piston 48. At this time, the sleeve 46 is still locked to the tubing string 10 at shear ring 52. Movement of the piston 48 presents recess 96 opposite the dogs 42 to allow them to retract within sleeve 46, thus retracting teeth 40 from the serrations 38 in the tubing string 10. This condition is shown in FIG. 4b, with the piston 48 fully stroked.
The puncture tool 84 is removed, as shown in FIGS. 5a and 5b, and the pickup force is applied to the tubing string 10. Eventually, ring 62 contacts collets 64 and a further upward pull on the tubing string 10 breaks shear ring 52. The tubing string 10 can then move up further as shoulder 78 approaches surface 80 on top ring 72. A continuing upward pull on the tubing string 10 releases the serrated surfaces 66 and 68 due to movement of the support 76 out from under the collets 64. The entire assembly can then be removed, as shown in FIGS. 6a and 6b, as the shoulder 78 carries with it the collets 64 while the assembly of piston 48 and sleeve 46 rides down to the seal ring 34. Seal ring 34, and the assembly that rests on top of it during the movement of FIG. 6, are caught by ring 98, which supports the seal ring 34.
Those skilled in the art can appreciate that, with a single trip downhole with the puncture tool, access is provided into cavity 54, and a subsequent pressurization strokes the piston 48 to unlatch the dogs 42 which have been holding the sleeve 46 to the tubing string 10. With the dogs 42 engaged, there is no way to break the shear ring 52. However, with the dogs 42 disengaged after a puncture operation, a pickup force can then shear ring 52 to allow a release of the collets 64 and removal of the tubing string 10 from the PBR 12. In the meantime, until a puncture opening 94 is made, the tubing string 10 is held to the PBR 12 with a metal-to-metal seal of surfaces 30 and 32.
Situations in a well can arise where it is necessary to not only remove the tubing string but also the packer. In the assembly shown in FIG. 1, as previously described, prior techniques precluded twisting of the tubing string 10 due to the presence of the control lines 22. Accordingly, a multi-step process was necessary in order to first gain sufficient access with a known release tool to go into the packer 14 to release it. The lower end of a known packer 14 is illustrated in FIGS. 7a-7c and 8a--8c. The set of such a packer 14 is held by a series of collets 100 which are retained by a ring 102, held to the collets 100 by shear pin or pins 104. In the past, the tubing string 10 had to be fully removed so that the release tool could go through the PBR 12 into the packer 14 and latch onto ring 102 to break shear pin 104, thus allowing the packer 14 to be withdrawn by an applied pickup force which would in turn stretch out the sealing elements (not shown) and the slips (not shown) which hold the packer 14 in the wellbore 16.
One of the aspects of the invention is to be able to run through the tubing string 10 without disconnecting it from the PBR 12 and reach the release components in the packer 14. The release components, as previously described, are the collets 100 held in position by ring 102. When ring 102 is moved to break shear pin 104, allowing the collets 100 to flex radially inwardly, an upward pull on the packer 14 results in stretching out of the packer 14 so as to release the sealing elements and slips (not shown) on the packer 14.
The invention comprises using a tool that can create relative motion, such as an E-4 setting tool made by Baker Oil Tools. This setting tool 106 is modified from the known design by the inclusion of a cone or cones 108 on which ride slips 110. The setting tool 106 is run in on electric line and when actuated, creates relative movement between a body 112 and an outer sleeve 114. The tool can be run in on coiled tubing or other means. Any tool that can engage the ring 102 and force it to move in a single trip is within the scope of the invention. Via an electric signal communicated from the surface, the tool 106 builds pressure so as to create initial downward movement of outer sleeve 114. That movement pushes the slips 110 against the cone 108 and anchors the outer sleeve 114 to the body 116 of the packer 14. With further downward movement of the outer sleeve 114 being arrested by the slips 110, then the body 112 of the tool 106 moves upwardly. The upward movement of body 112 causes shoulder 118 to engage collets 120. As the collets 120 move up, they pick up ring 102 and break shear pin 104, thus allowing the packer 14 to be withdrawn. On further upward movement of the body 112, ring 122, which had previously provided support for collets 120 to allow them to bear on ring 102 to break shear pins 104, becomes detached for slidable movement on body 112 as the shear ring 124 is broken. This can be seen by looking at FIG. 8c. The breaking of shear ring 124 allows ring 122 to slide downwardly so as to avoid any future reengagement of collets 120 against ring 102 after shear pin 104 has broken. Ring 102, as shown in FIG. 8c, cannot snag surface 126 of the collets 120. At the same time, with shear screw 104 broken, the collets 100 are free to move radially inwardly, as shown in the position of FIG. 8c. At this time an upward pull on the tool 106 brings the cone 108 up, which pulls back slips 110, allowing the tool 106 to be removed from the packer 14. After the tool 106 is removed, the tubing string 10, which is still connected at the PBR 12, is given an upward pull to stretch out packer 14, thus relaxing its sealing elements and slips (not shown). At this time, the tubing string 10 can be disassembled from the surface to bring the packer 14 up to the surface.
As shown in FIGS. 7a-7c and 8a-8c, if further operations in the wellbore require the packer 14 to be removed in a situation where the tubing string 10 is anchored to the PBR 12 and a rotational release is not possible for the tubing string 10, numerous trips into the wellbore are eliminated as, in a single trip, a tool enters the packer 14, actuates its release mechanism, and permits its subsequent removal so as to allow a pickup force at the surface applied thereafter to stretch out the packer and allow the removal of the string with the packer. Considerable rig time is saved from this one-trip procedure, resulting in substantial savings to the operator in rig time.
A preferred embodiment of releasing the packer 14, illustrated in detail in FIG. 9c, is to use the assembly illustrated in FIGS. 9a and 9b. The details of the packer 14 shown in FIG. 9c are identical to those shown in FIG. 7c and, thus, the descriptions of all the components will not be repeated. As previously described for FIG. 7c, the release of the packer occurs as the ring 102 is pulled upwardly, breaking shear pin 104. In order to accomplish the breaking of shear pin 104 and, hence, the release of the slips and sealing element of the packer 14, the assembly illustrated in FIGS. 9a and 9b is secured to the body 112. Releasably connected to body 112 is run/pull tool 128. The run/pull tool 128 is connected to body 112 at thread 130. The tool 128 has a shear rod 132 which, upon application of a predetermined force, will release the tool 128 from the body 112 and leave exposed a fishing neck 134. Connected to the tool 128 is one or more mechanical jars 136 which are intended to function as a back-up to power jars 138. Connected to power jars 138 is roller stem 140, which serves as a centralizer due to its plurality of rollers 142 and also adds mass to the accelerating weight from the power jars 138. Finally, the accelerator 144 keeps the entire assembly in tension until the power jar begins to apply a force when a predetermined applied force has caused it to actuate. The assembly attached to the body 112 is known as a "quick-lock system string" and is offered by Petroline Corporation. The tool 128 and mechanical jars 136 are optional equipment which can also be eliminated as desired. The assembly of the power jars 138, the roller stem 140, and the accelerator 144 collectively apply the necessary jarring force to body 112 to break shear pin 104, thus allowing ring 102 to move so as to release the packer 14 thru-tubing. Again, those skilled in the art will appreciate that no rotation is required for release of the packer. The assembly as illustrated in FIGS. 9a and 9b can be run downhole on wireline or core coiled tubing. It is preferred to release the packer 14 first by breaking shear pin 104 prior to releasing the retrieval tool, which includes body 112, from the body of the packer 14 by breaking shear ring 124. The assembly shown in FIGS. 9a and 9b can be recocked by allowing it to set down on the packer 14. The jar can be applied numerous times so as to release the packer 14 thru-tubing, as well as to release the tool itself from the packer. The pulling force applied by the jar 138 can be adjusted. Thus, in situations where the packer must be released and removed and rotational release is not possible, a single trip is possible to release the packer so that it can then be stretched out by an upward pull on the tubing string. Thereafter, the tubing string, with the packer, can be removed from the wellbore.
The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made without departing from the spirit of the invention.
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A configuration is provided to anchor the tubing string into a polished-bore receptacle while providing the ability to disconnect the tubing string from the polished-bore receptacle in a single trip in the wellbore. The configuration of the anchor provides for metal-to-metal sealing, and the disconnection is accomplished by a penetrating tool which accesses an annular cavity to unsupport locking dogs which facilitate removal of the tubing string from the polished-bore receptacle with applied pressure. If the packer needs to come out for any reason, a retrieving tool is described which, in a single trip, allows the retrieving tool to be advanced thru-tubing into the packer itself to unlock it. The retrieving tool is pulled out of the tubing and a pick-up force is applied to the tubing string to extend the packer to allow for its ultimate removal with the tubing. The retrieving tool preferably employs jarring forces to release the packer.
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BACKGROUND OF THE INVENTION
For interrupting and making electrical circuits, use is made both of mechanical contacts, sliding contacts such as in the case of current collectors on rail vehicles or commutators in electric motors, fusible links, and of semiconductor switches such as transistors, thyristors and semiconductor relays.
During interruption of the electrical circuits, all these switching elements are exposed to a high self-induced voltage as a result of the rapid reduction of the energy stored inductively in the entire electrical circuit.
Said self-induced voltage heats and destroys semiconductor switching elements and protective circuits, causes material migration and welding at contact areas and can prevent the breaking of the electrical circuit as a result of arcing between contact areas.
During making of an electrical circuit, the capacitance present in the circuit has to be charged rapidly, which momentarily leads to a large switch-on current.
Said switch-on current brings about material migrations at contact areas that have not yet completely closed, and can destroy semiconductor switches through local thermal overloading.
During the transition of the switching elements from the conducting to the blocking state and from the blocking to the conducting state, a power loss is produced at the switching elements due to the simultaneous presence of current and voltage, said power loss being referred to as switching power.
In the case of frequent switching operations, this switching power leads to the heating of the switching elements and of adjacent components, and thereby jeopardizes the reliable operation of entire apparatuses and installation.
In order to protect the switching elements from the harmful effects of the self-induced voltage, use is made of RC circuits, but the latter are heated greatly in the event of high switching frequency.
Diode circuits, also known as freewheeling diodes, protect the switching elements from self-induced voltage only after a response time, but cannot be used with AC voltage, and cause a power loss during each switching operation, which limits the efficiency of frequently switching circuit arrangements such as voltage converters or switched-mode power supplies and leads to the heating and damage thereof.
Furthermore, varistor circuits are known, which protect the switch from particularly high self-induced voltages. However, said varistors are rapidly heated and are therefore unsuitable in the event of high switching frequency and high voltage and also for precise limiting of the overvoltages to low values, for the protection of semiconductor components.
It is also known that the self-induced voltage and heating of the switching element during interruption of the electrical circuit can be effectively limited by means of capacitor connected in parallel with the load or else in parallel with the switching element. However, this circuit has the disadvantage that, during the closing of the switching element, the capacitor would have to be short-circuited or abruptly charged, which causes very high switch-on currents, high switching losses and severe wear of the switching elements, so that the capacitance of the capacitor remains limited to a very small value and the effectiveness thereof is thus greatly restricted.
Taking this as a departure point, it is an object of the invention to specify a circuit arrangement which enables the reliable switching of electrical circuits.
SUMMARY OF THE INVENTION
The circuit arrangement according to the invention prevents the occurrence of high self-induced voltage by means of a capacitor which momentarily accepts the current from the electrical load circuit to be broken and, by means of its discharge operation, prevents a rapid rise of the voltage across the windings of the transformer and the opening switching elements connected in series therewith.
The—according to the invention—reliable switch-off operation of current-carrying switching elements is in this case achieved by avoiding voltage spikes, power loss and heating.
Avoiding power loss during the switch-off operation according to the invention also prevents the production of arcs in the case of electromechanical switching elements and fusible links and thus enables the latter to be reliably switched off according to the invention.
If large quantities of energy are present in the electrical load circuit, the circuit arrangement according to the invention may be configured such that the load is short-circuited after disconnection from the voltage source and the energy is held in the electrical load circuit.
During making of an electrical circuit, the load is connected to the voltage source by the circuit arrangement according to the invention via a transformer winding acting as an inductance, which brings about a slow controlled current rise and a slow controlled charging of the capacitance in the electrical load circuit. The slow controlled current rise and the small power loss in the switching element when the load current is switched on via an inductance enables an—according to the invention—reliable closing operation of the switching elements.
The voltage at the transformer winding is transformed to a second winding, which, when the capacitance in the electrical load circuit is charged to the voltage of the voltage source, brings a second switching element into a voltageless state in which it can be reliably closed according to the invention, with little power loss.
Since the circuit arrangement according to the invention enables the reliable switching operations substantially by avoiding power loss, the invention can make a significant contribution to miniaturization and reduction of costs for frequently switching apparatuses such as DC voltage converters, switched-mode power supplies, motor drives, since it permits significantly higher switching frequencies.
Reducing the power loss during switching operations also makes an important contribution to environmental protection.
Since the circuit arrangement according to the invention uses only one transformer and a usually very small capacitor for limiting damaging voltages and damaging rapid current rises, the circuit arrangement can be used for DC voltages and sinusoidal or rectangular AC voltages.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the invention are illustrated in the drawing and are described in more detail below.
In the figures:
FIG. 1 shows a first exemplary embodiment of the circuit arrangement according to the invention,
FIG. 2 shows an example of alternating current direction in the load,
FIG. 3 shows an example with transistors and control device 33 ,
FIG. 4 shows an example of the operation of the circuit arrangement according to the invention from two voltage sources,
FIG. 5 shows an example of the operation of the circuit arrangement according to the invention from one AC voltage source formed from a transformer winding with a center tap, and
FIG. 6 shows an exemplary application of the circuit arrangement according to the invention.
DETAILED DESCRIPTION
The circuit arrangement according to the invention has two series paths 1 and 2 , which are located in the lead to the load 3 and contain two connecting points 4 and 5 for the connection of the voltage source, and also two connecting points 6 and 7 for the connection of the load 3 .
The series path 1 is subdivided into two further series paths containing in each case a winding 8 and 9 of the transformer 10 and also in each case a switching element 11 and 12 , respectively.
Downstream of the transformer 10 , the two windings 8 and 9 are connected to one another and to the connecting point 6 .
A capacitor 13 is connected in parallel with the load between the series paths 1 and 2 . The capacitor 13 may be chosen to be very large in the case of slowly switching circuit arrangements or high load currents, and, in the case of rapidly switching circuit arrangements, be so small that the line capacitance between 1 and 2 suffices for obtaining the desired protective effect.
The load current 14 from series path 1 is divided into the component currents 15 and 16 such that the magnetic field strengths 17 and 18 thereof in the core of the transformer 10 act oppositely to one another and mutually compensate for one another.
If the two component currents 15 and 16 in the windings 8 and 9 are of the same magnitude, the load current 14 cannot store energy in the transformer core.
If the component current 15 is interrupted by the switching element 11 , then its compensating field strength 17 is omitted, as a result of which the remaining current-carrying winding 9 takes effect as an inductance and momentarily interrupts the remaining component current 16 since the transformer core is not yet magnetized. Therefore, immediately after the interruption of the component current 15 , the load current 14 is drawn completely from the capacitor 13 , so that the remaining, second switching element 12 , according to the invention, can be reliably opened in a virtually currentless and voltageless state with little power loss.
The capacitor 13 is discharged by the load current 14 after the opening of switching element 11 , as a result of which the capacitor voltage falls, and a voltage is produced across the transformer winding 9 , which is transformed to the transformer winding 8 . The voltage in transformer winding 8 , together with the voltage across capacitor 13 , has the effect that the switching element 11 , according to the invention, can open reliably in a virtually voltageless state, with very little power loss.
In the simplest case, the switching elements 11 and 12 may comprise a switching contact, a fusible link or a transistor, which undergo transition to the nonconducting state simultaneously, or with a short delay, when the electrical circuit is interrupted. The switching elements 11 and 12 may also be formed as changeover contacts, push-pull or CMOS transistor stages which, after the disconnection of the series path 1 from the connecting point of the voltage source 4 , establish a connection to the series path 2 in order to conduct away the load current 14 and to hold the energy stored in the load 3 in the electrical load circuit.
In order to conduct away the energy stored in the electrical circuit, the switching elements 11 and 12 may also be provided with diodes which conduct away the load current 14 after the disconnection from the voltage source to the series path 2 .
A further possibility is to measure the voltage across the switching elements by means of a voltage measuring device and to establish the connection to the series path 2 with a controllable switching element when the measured voltage has become zero, thereby achieving an—according to the invention—reliable, low-loss closing operation in a voltageless state.
The load can be connected to the voltage source again by only one or both switching elements 11 and 12 interrupting the connection to the series path 2 , and then only one switching element connecting the corresponding transformer winding to the series path 1 , so that the capacitor 13 is charged via the winding inductance of the transformer 10 . In this case, according to the invention, the winding inductance prevents a rapid rise of the charging current and thus enables, according to the invention, the reliable, low-loss closing of the switching element in a virtually currentless state. If the capacitor 13 is completely charged, the second switching element may likewise establish the connection to the voltage source in low-loss fashion in a virtually voltageless state reliably, according to the invention, whereupon the component currents 15 and 16 in the windings of the transformer match one another.
A further embodiment of the circuit according to the invention consists in the fact that the load 3 is connected to the series path 1 or 2 via a capacitor 19 connected in series. This results in an alternating current direction in the load, which permits the capacitor 13 to be charged to the voltage of the voltage source by the load current in the event of switch-on. The two switching elements 11 and 12 can then establish the connection to the voltage source in a currentless and voltageless state without energy being fed into the transformer 10 .
The circuit according to the invention may likewise be used on voltage sources of alternating polarity for rectifying the current and for regulating the power drawn from the voltage source. In this case, at the beginning of the positive half-cycle, the transformer 10 is connected to the voltage source by the switching elements 11 and 12 via the series path 1 and, during the positive half-cycle, after a time period determined by a suitable regulating device, is again connected to the neutral conductor of the voltage source, series path 2 , in order to generate a positive rectified current for the load. At the beginning of the negative half-cycle, the transformer 10 is connected to the voltage source by the switching elements 11 and 12 via the series path 1 and, during the negative half-cycle, after a time period determined by a suitable regulating device, is again connected to the neutral conductor of the voltage source, series path 2 , in order to generate a negative rectified current for the load.
The circuit according to the invention may furthermore be used on voltage sources of alternating polarity with a neutral conductor, such as, for example, the secondary winding of a transformer with a center tap, for rectifying the current and for regulating the power drawn from the voltage source. In this case, at the beginning of the positive half-cycle, the transformer 10 remains connected by the switching elements 11 and 12 to the—at this point in time—positive terminal of the voltage source, and, during the positive half-cycle, at a switching instant determined by a suitable regulating device, is connected via the switching elements 11 and 12 to the—at this point in time—negative terminal of the voltage source. This connection persists to the end of this half-cycle, and through the polarity reversal of the voltage source right into the next half-cycle. In this way, by defining the switching instant, it is possible for the load to be fed a positive current if the switching instant lies in the second half of the half-cycle, a negative current if the switching instant lies in the first half of the half-cycle, and no current if the switching instant lies in the center of the half-cycle.
FIG. 6 shows the possibility of how the circuit described in the application can be used as an active impedance. It can thereby be used very simply as a replacement for an ohmic resistor for current limiting. In this case, the circuit is completely encapsulated and, like a simple impedance, provided only with two terminals. One path is thus not connected.
The circuit may acquire an ohmic characteristic, be embodied as a voltage source or current source, or operate with an additional control input as a potentiometer or power controller, an extremely low power loss occurring in each case.
In the case of the circuit illustrated in FIG. 6 b , the power loss amounts to only approximately 0.05*U*I, that is to say approximately 5 percent of the power loss which would occur at the ohmic resistor of FIG. 6 a . The value of the impedance is dependent on the value of the inductance L 10 and the capacitance C 13 .
Subclaims relate to further refinements of the invention. In this case, such feature combinations for which no express example has been specified are also to be regarded as claimed.
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A circuit arrangement for the reliable switching of electrical circuits contains two series paths, two switching elements being arranged in parallel with one another in one of the series paths, the switching inputs of said switching elements being connected to the input point of the series path and the switching outputs of said switching elements being connected to the input side of a respective winding of a transformer.
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INTRODUCTION
This invention concerns novel pharmaceutical compositions and a method of treating hypertension. Related compositions and methods are described in U.S. Pat. Nos. 4,954,526 and 5,039,705.
BACKGROUND OF THE INVENTION
Endothelium-derived relaxing factor (EDRF) is a labile humoral agent which is part of a cascade of interacting agents involved in the relaxation of vascular smooth muscle. EDRF is thus important in the control of vascular resistance to blood flow and in the control of blood pressure. Some vasodilators act by causing EDRF to be released from endothelial cells. (See Furchgott, Ann. Rev. Pharmacol. Toxicol. 24, 175-197, 1984.) Recently, Palmer et al., have shown that EDRF is identical to the simple molecule, nitric oxide, NO. (Nature 317, 524-526, 1987.) It has been hypothesized for years that many nitrovasodilators, which mimic the effect of EDRF, like glyceryl trinitrate, amyl nitrite, NaNO 2 and sodium nitroprusside (SNP), do so by virtue of their conversion to a common moiety, namely NO, which is also a vasodilator. (See Kruszyna et al., Tox. & Appl. Pharmacol.,91, 429-438, 1987; Ignarro, FASEB J. 3, 31-36, 1989, and Ignarro et al., J. Pharmacol. Exper. Theraputics 218(3), 739-749, 1981.) It has now been discovered that compounds containing the N-oxy-N-nitrosoamine group, N 2 O 2 - (also known as the N-nitrosohydroxylamine group) of the structure: ##STR2## and wherein the compound decomposes under physiological conditions to release NO, are potent anti-hypertensives. The compounds are useful for treating cardiovascular disorders in which lowering the blood pressure has a beneficial result. It is believed that these compounds function by releasing NO in the blood after injection. Alston et al. have shown that NO is generated by in vitro enzymatic oxidation of N-hydroxy-N-nitrosoamines (J. Biol. Chem. 260(7), 4069-4074, 1985) and Kubrina et al. have shown in vivo formation of nitrogen oxide upon injection with ammonium N-oxy-N-nitrosoaminobenzene (cupferron) into experimental animals( Izvestiia Akademii Nauk SSSR Seriia Biologicheskaia 6, 844-850, 1988).
While these compounds are, for the most part, known, there is no suggestion in the prior art that they are anti-hypertensive, indeed, there is no suggestion in the prior art that this general class of compounds has any pharmaceutical use (except for alanosine and dopastin, see below). They are described by Drago in "Free Radicals in Inorganic Chemistry" Advances in Chemistry Series, Number 36, American Chemical Society, Wash. DC, 1962, pages 143-149, which is incorporated by reference in its entirety. The reference is of a theoretical nature and mentions no utility whatsoever. Danzig et al., U.S. Pat. No. 3,309,373, discloses many of the compounds of formula I. Danzig teaches many possible utilities of his compounds, including their use as curing agents in rubber manufacture, antiknock additives for gasoline, indicator dyes, explosives, corrosion inhibitors and as fungicides for agriculture. Danzig et al. is incorporated by reference in its entirety. Wiersdorff et al (Chemical Abstracts 77:48034f, 1972) discloses that compounds of formula I, wherein J is a substituted phenyl, are useful as complexing agents and as fungicides. Fujitsuka et al. (Chemical Abstracts 82:31108p, 1975) discloses that compounds wherein J is phenyl, p-hydroxyphenyl and cyclohexyl are useful as polymerization inhibitors. Japanese patent JP 87017561 B, 4/18/87, discloses that the compounds wherein J is an aromatic hydrocarbon radical or sulfite ( - O 3 S--) are antibiotics for nitrifying bacteria and are added to industrial waters to control the bacteria. This patent does not teach the in vivo use of the compounds. Massengale, U.S. Pat. No. 2,635,978, discloses that compounds wherein J is optionally substituted phenyl are useful as fungicides for treating seeds, plants and fruits. Metzger et al., U.S. Pat. No. 2,954,314, discloses that compounds wherein J is an aliphatic, arylaliphatic or cycloaliphatic group are useful as fungicides for the external treatment of plants, leather, paper etc. Both Massengale and Metzger et al. are incorporated by reference in their entirety. None of the references cited above teach that compounds of formula I are antihypertensives, indeed none of these references teach any in vivo pharmaceutical utility of these compounds. There are two compounds that have in vivo pharmaceutical utility and contain the N-oxy-N-nitrosoamine moiety. These are alanosine, a potential anticancer drug with the structure ##STR3## and dopastin, a dopamine beta-hydroxylase inhibitor of structure ##STR4## These compounds were not known to be antihypertensive previously. The applicant has disclosed the antihypertensive utility of the compounds wherein J is a primary or secondary amine in U.S. Pat. Nos. 4,954,526 and 5,039,705 respectively.
SUMMARY OF THE INVENTION
The present invention provides pharmaceutical compositions comprising: a compound of the following formula ##STR5## wherein J is an organic or inorganic moiety, M +x is a pharmaceutically acceptable cation, wherein x is the valence of the cation, a is 1 or 2, b and c are the smallest integers that result in a neutral compound, and wherein the compound decomposes under physiological conditions to release nitric oxide (NO); and a pharmaceutically acceptable carrier; with the proviso that the compound of formula I not be a salt of alanosine or dopastin. Another object of the invention is a method of treating cardiovascular disorders by lowering the blood pressure by administering a compound of formula I.
DETAILED DESCRIPTION OF THE INVENTION
By J being an organic or inorganic moiety is meant that J is any moiety that results in a compound of formula I that will decompose under physiological conditions to release nitric oxide. This decomposition product is the active agent. By physiological conditions is meant the chemical, physical and biological conditions found in the body at the point of administration or after distribution of the compound by the blood system. Since injection into the bloodstream is the preferred method of administration, those compounds that decompose in the blood system to release NO are preferred. Some of the compounds, such as the diethylamine-nitric oxide adduct (U.S. Pat. No. 5,034,705) spontaneously decompose in water (however not too fast to limit its usefulness), others such as cupferron appear to be enzymatically decomposed (see Alston et al. supra). There are both physico-chemical and biological limitations on the compounds of formula I. Since the compounds are mostly used intraveneously, they should be at least somewhat soluble in aqueous solution, with the help of solubilizing agents or organic solvents. Thus compounds where J is a large hydrophobic moiety, such as a C 20 paraffin or an anthracyl moiety are excluded, since such a compound would not be soluble enough in aqueous solution to be useful. The other limitation on J is that the compound or its decomposition products should not be so acutely toxic at the doses administered that the subject is endangered.
Preferred J moieties are: A) a =1, and J is - O 3 S--(sulfite), - O--(oxide), C 1 -C 12 aliphatic, C 3 -C 8 cycloalkyl, benzyl, phenyl, substituted benzyl, substituted phenyl, benzylcarbonyl, phenylcarbonyl, substituted benzylcarbonyl, substituted phenylcarbonyl, C 1-C 12 acyl, and ##STR6## wherein R is C 1 -C 12 aliphatic, C 3 -C 8 cycloalkyl, benzyl, phenyl, substituted benzyl or substituted phenyl, and said substituted benzyl or substituted phenyl being substituted with one or two substituents selected from the group consisting of halogen, hydroxy, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, amino, mono-C 1 -C 4 alkylamino, di-C 1 -C 4 alkylamino, phenyl and phenoxy; B) 1a=2 and J is para-phenylene; ##STR7## C 2 -C 12 alkylene, --CHR 1 --, wherein R 1 is H or C 1 -C 12 aliphatic, and ##STR8## wherein R" is C 1-C 6 alkylene.
By aliphatic is meant a straight chain or branched chain, saturated or unsaturated, acyclic hydrocarbon moiety. By acyl is meant an aliphaticcarbonyl moiety. By alkyl and alkoxy is meant both straight and branched chain. By alkylene is meant a divalent straight or branched chain saturated acyclic hydrocarbon bridging group such as --CH 2 CH 2 -- or --CH 2 CH(CH 3 )--. By halogen is meant F, Cl, Br, and I, preferably F, Cl, and Br. For aliphatic and alkyl moieties the preferred number of carbon atoms is 1-4. For cycloalkyl the preferred ring size is 5 and 6. For acyl moieties the preferred number of carbon atoms is 2-6.
More preferred J moieties are: A) a=1, and J is - O 3 S--, - O--, C 1 -C 12 alkyl, C 5 -C 6 cycloalkyl, benzyl, phenyl or ##STR9## wherein R is C 1 -C 12 alkyl, C 5 -C 6 cycloalkyl, benzyl or phenyl; B) a=2, and J is para-phenylene, C 2 14 C 4 alkylene or --CHR 1 --, wherein R 1 is H or C 1-C 6 alkyl.
The most preferred J moieties are - O 3 S--, - O-- or phenyl when a=1, and para-phenylene when a=2.
By pharmaceutically acceptable cation is meant any cation that does not render the compound unstable or insoluble in water or toxic at the doses contemplated; these cations are well known to one of ordinary skill in the pharmaceutical arts. Generally the cation will be a group 1 or group 2 ion, such as sodium, potassium, calcium or magnesium ions, or NR 2 R 3 R 4 R 5 30 , wherein R 2 , R 3 , R 4 and R 5 are independently selected from the group consisting of H, C 1 -C 4 alkyl, C 5 -C 6 cycloalkyl, benzyl or phenyl. The most preferred cations are Na + , K 30 , Ca +2 , Mg +2 and NH 4 30 .
The subscripts b and c in formula I mean the number of the particular ion to be found in the empirical formula of the salt. The smallest whole number that results in an electrically neutral compound is used. Thus, if the anion is ON 2 O 2 -2 and the cation is Na + then b is 1 and c is 2.
SYNTHESIS
The methods used to make the compounds of formula I are all known or easily derivable from known methods. Massengale, U.S. Pat. No. 2,635,978, teaches how to make the compounds where J is phenyl or substituted phenyl in examples 1-8. Danzig, U.S. Pat. No. 3,309,373, teaches how to make the compounds wherein J is paraphenylene in examples I-III, V, VII and IX. He teaches how to make the compounds where J is ##STR10## and R is phenyl or alkyl in examples XII, XIII, XV, XVII and XVIII. Danzig teaches how to make the compounds where J is a divalent alkylene moiety and a=2 in the paragraph bridging columns 16 and 17. Metzger et al., U.S. Pat. No. 2,954,314, discusses the compounds where J is aliphatic, arylaliphatic or cycloaliphatic. Drago(supra) discusses the Traube reaction which produces the compound containing the structure (CH 2 (N 2 O 2 ) 2 ) -2 . The Traube reaction can be generalized to produce the compounds containing the structure ##STR11## by starting with the alcohol of structure R 1 --CH 2 CH 2 OH, wherein R 1 is defined above.
The compounds wherein J is an aliphatic, aryl or arylaliphatic moiety and a=1 are generally made by reducing the appropriate aliphatic, aryl or arylaliphatic nitro compound to the corresponding aliphatic, aryl or arylaliphatic hydroxylamine and nitrosating this compound to produce the corresponding aliphatic, aryl or arylaliphatic N-nitrosohydroxylamine (also known as N-hydroxy-N-nitrosoamine)(see Massengale, supra and Alston et al., page 4070). This reaction sequence is shown below: ##STR12## The same reaction scheme can be used to make the compounds wherein a is 2 and J is alkylene by starting with a dinitroalkyl compound, ie, NO 2 --CH 2 CH 2 --NO 2 produces ##STR13## Cupferron, the compound of formula I wherein J is phenyl and M +x is NH 4 + , is commercially available from Aldrich Chemical Company, Milwaukee, Wi.
The compounds wherein a=1 and J is ##STR14## are made by starting with the corresponding aldoxime ##STR15## and reacting it with base (M(OH) x ) and nitric oxide in a non-hydroxylic solvent as shown by the following reaction (see Danzig supra): ##STR16## The following examples show the synthesis details for three of the compounds.
EXAMPLE 1
Angeli's salt, the disodium salt of hyponitric acid, Na 2 (ON 2 O 2 ) was synthesized as follows. A concentrated solution of sodium ethoxide (18 g) in ethanol was added to a saturated solution of hydroxylamine hydrochloride (6 g) in ethanol. The sodium chloride precipitate was filtered off, and 8 g of ethyl nitrate was added to the filtrate at room temperature. A finely divided suspension of Angeli's salt was formed, the yield increasing as the liquid cooled. After several hours, the crystals were filtered and washed with ethanol. They were then recrystallized twice by dissolving them in 4 ml of water and adding a large excess of ethanol. The crystals (5 g) were finally dried by washing them with ether. The ether was removed under reduced pressure.
EXAMPLE 2
The potassium salt of the sulfite addition product of NO, K 2 (O 3 SN 2 O 2 ), was synthesized as follows. KOH (50 g) was dissolved in water (100 ml). The mixture was saturated with SO 2 at room temperature. The reaction mixture became warm. Additional KOH (60 g) was added. Nitric oxide was bubbled through the solution at room temperature. The mixture was stirred for 3 hours and the resultant crystals were suction filtered. The crystals were washed with water (20 ml), followed by washing with 95% ethanol and ether.
EXAMPLE 3
The disodium salt of p-phenylene-N-N'-dinitrosodihydroxylamine, ##STR17## was prepared as follows. To a solution of sodium methoxide (3.9 g) in excess methanol was added 1,4-benzoquinone dioxime (5 g). The solution was cooled to -78° C. and placed in a Parr low pressure hydrogenator modified by having a stainless steel tank, gauge, valves and tubing. The apparatus was subjected to three nitrogen flush/evacuation cycles to remove as much oxygen as possible. Nitric oxide, commercial grade, was bubbled through 10M NaOH and dried by passing it through a column containing NaOH pellets. This nitric oxide was admitted to the Parr apparatus continuously until absorption was complete (about 5 hr). The apparatus was shaken continuously during the addition of the nitric oxide. The nitric oxide was removed by flushing with nitrogen. The resultant product was isolated by filtration, washed and dried.
The cation, M 30 x, can be changed by several well known methods. Most of the synthesis methods described above involve the use of a base as part of the reaction scheme, i.e., NaOH or NaOEt; the resultant salt contains the cation from the base used. By running the reaction with a different base, i.e., KOH, NH 4 OH or KOEt, a different cation is obtained. Alternatively, the cation in an already formed compound can be replaced by another cation by methods, such as a metathesis reaction, that are well known in the art; see, for example, Massengale, examples 3-8.
PHARMACOLOGICAL PROPERTIES
The effect on the mean arterial blood pressure and heart rate of male Sprague-Dawley rats of the compositions of the invention was measured using a standard technique. A pressure transducer (Bell and Howell, type 4-327-I) was connected to the right carotid artery via a catheter containing heparinized saline. The mean arterial pressure and heart rate were recorded on a Gould (Model 2800) 8-channel recorder. The rats were anesthetized with nembutal at an initial dose of 35 mg/kg body weight and recurrent smaller injections as needed. The compounds were dissolved in a pharmaceutical carrier and injected into the rats via a catheter in the right femoral vein. Table 1 shows the results.
TABLE 1______________________________________ Mean Arterial Pressure Heart RateDose Initial Post Change Initial PostCompound (μmole/kg) (mm Hg) (beats/min)______________________________________A 3.4 114 91 -23 420 440A 39.0 126 42 -84 420 480B 3.4 117 109 -8 420 420B 39.0 96 57 -39 540 420C 3.4 114 104 -10 480 420C 42.0 96 75 -21 420 420D 6.8 132 118 -14 420 360D 39.0 108 90 -18 420 420SNP 0.34 113 56 -57 403 454NaNO.sub.2 4.00 126 48 -78 360 420NaNO.sub.3 42.00 117 120 3 420 420______________________________________
In Table 1, the pharmaceutical carrier was Abbott's 5% dextrose USP. Compound A is Angeli's salt, B is K 2 (O 3 SN 2 O 2 ), C is the disodium salt of p-phenylene-N,N'-dinitrosodihydroxylamine and D is cupferron. SNP(sodium nitroprusside), NaNO 2 , and NaNO 3 were used as controls. SNP and NaNO 2 are known vasodilators. NaNO 3 is the oxidative breakdown product of NaNO 2 and has little vasodilatory effect. The results show that the compounds of formula I are potent anti-hypertensives, decreasing the blood pressure significantly. The peak value of the blood pressure decrease, shown in Table 1, takes only about 30 sec to 1 min to occur, after injection, and the blood pressure starts to rise again soon after and has totally recovered within 10-15 min.
The compositions of this invention are useful for treating any cardiovascular disorder that will respond favorably to a decrease in blood pressure. These disorders include chronic hypertension, hypertensive crisis (an acute hypertensive emergency), acute congestive heart failure, angina, acute myocardial infarction, left ventricular failure, cerebrovascular insufficiency and intracranial haemorrhage. Because of the fast response upon intravenous injection the compositions are particularly advantageous for treating acute disorders such as hypertensive crisis, toxemia of pregnancy and acute congestive heart failure. The preferred method of administration is by injection into the blood system, most preferably by intravenous injection. The chronic disorders can be treated by continuous intravenous infusion. A suitable dosage for intravenous administration is about 0.01 to 10.0 mg/kg per day.
The pharmaceutical compositions of the invention comprise the compounds of formula I and a pharmaceutical carrier. The carrier can be any of those conventionally used and is limited only by chemico-physical considerations such as solubility and lack of reactivity with the compound and by the route of administration. For intravenous administration, the carrier will be aqueous and may contain solubilizing agents, buffers, preservatives, antioxidants, chelating agents, and agents to control the tonicity , such as dextrose or sodium chloride. The requirements for effective pharmaceutical carriers for injectable compositions are well known to one of ordinary skill in this art. (See "Pharmaceutics and Pharmacy Practice", J. B. Lippincott Company, Philadelphia, 1982,edited by Banker and Chalmers, pages 238-250, which are incorporated by reference, also see ASHP "Handbook on Injectable Drugs" 4the edition by Trissel, pages 622-630, which lists commercially available intravenous infusion solutions, these pages are incorporated by reference.) The compounds may also be formulated as inclusion complexes, such as, for example, cyclodextrin inclusion complexes; or the compounds may be carried within liposomes. Preferred pharmaceutical carriers for injection are PBS (phosphate buffered saline), 5% dextrose and sterile water. Since the compounds of formula I are subject to being oxidized by oxygen, an antioxidant, such as ascorbate, can be added to the carrier to increase the shelf-life.
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This invention concerns antihypertensive compositions and a method of lowering blood pressure in mammals. The active component of the compositions is a compound of the formula: ##STR1## wherein J is an organic or inorganic moiety, M +x is a pharmaceutically acceptable cation and the compound decomposes under physiological conditions to release nitric oxide (NO).
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 12/323,823, filed Nov. 26, 2008, now U.S. Pat. No. 7,638,647, which claims priority to Japanese Patent Application No. 2007-309892, filed Nov. 30, 2007, which is hereby incorporated herein in its entirety by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for preparing (E3,Z5)-3,5-dodecadienyl acetate, a sex pheromone component of Brazilian apple leafminer ( Bonagota cranaodes ) which is an apple pest in South American countries such as Brazil and Uruguay.
2. Description of the Related Art
Brazilian apple leafminer is one of major apple pests in South American countries such as Brazil and Uruguay and damage caused thereby has become a problem in recent years. Pesticides are used for control of Brazilian apple leafminer but their effect is not sufficient. There is accordingly a demand for the development of a new control method satisfactory from the viewpoint of the global environment and human health.
It has been elucidated (C. R. Unelius, et al., Tettrahedron Lett., 37, 1505(1996)) by C. Ricard Unelius, et al., in 1996 that the sex pheromone of Brazilian apple leafminer has (E3,Z5)-3,5-dodecadienyl acetate as a main component thereof. In addition, M. D. A. Coracini, et al., has reported that (E3,Z5)-3,5-tetradecadienyl acetate is one of subsidiary components of the sex pheromone of the insect and it is therefore known that (E3,Z5)-3,5-alkadienyl acetates having conjugated double bonds which are a double bond with E configuration at the 3-position and a double bond with Z configuration at the 5-position, each counted from the terminal acetoxyl group, are effective as a sex pheromone of Brazilian apple leafminer (M. D. A. Coracini, J. Appl. Ent., 127, 427(2003)).
Protecting groups of an alcohol industrially used in a large amount typically include an acetyl group (Protecting Groups., P. J. Kocienski, Georg Thieme Verlag Stuttgart: New York, P22(1994)), a 1-ethoxyethyl group (Protecting Groups., P. J. Kocienski, Georg Thieme Verlag Stuttgart: New York, P84(1994)), and a tetrahydropyranyl group (Protecting Groups., P. J. Kocienski, Georg Thieme Verlag Stuttgart: New York, P84(1994)).
SUMMARY OF THE INVENTION
The present invention provides a method for preparing (E3,Z5)-3,5-alkadienyl acetate and (E3,Z5)-3,5-dodecadienyl acetate, a sex pheromone of Brazilian apple leafminer.
In the preparation of (E3,Z5)-3,5-alkadienyl acetate having conjugated double bonds which are a double bond with an E configuration at the 3-position and a double bond with a Z configuration at the 5-position, each counted from the terminal acetoxyl group, use of 3-butyn-1-ol having a triple bond at the 3-position from the terminal alcohol group as a starting substance may be considered. Since the method for preparing (E3,Z5)-3,5-alkadienyl acetate by using this 3-butyn-1-ol as a starting substance requires a step of using a carboanion or the like which is adversely affected by an alcohol group, the terminal alcohol group of 3-butyn-1-ol must be protected.
It has been found by the present inventors that an acetal portion of 5,5-diethoxy-(Z3)-3-pentenyl methoxymethyl ether, which can be produced by using 3-butyn-1-ol as a starting substance and protecting the alcohol portion thereof with a methoxymethyl group by using dimethoxymethane which is inexpensive and available in a large amount, can be selectively hydrolyzed with an acid without elimination of the alcohol protecting group and even the Wittig reaction between the resulting 4-formyl-(E3)-3-butenyl methoxymethyl ether and alkylidene phosphorane scarcely generates the corresponding 1,3,5-alkatriene which will otherwise be formed by the elimination reaction. It has also been found that the subsequent deprotection reaction proceeds in a markedly good yield and an intended (E3,Z5)-3,5-alkadienyl acetate can be prepared efficiently, leading to the completion of the present invention.
In the present invention, there is provided a method for preparing (E3,Z5)-3,5-alkadienyl acetate, comprising steps of:
hydrolyzing 5,5-diethoxy-(Z3)-3-pentenyl methoxymethyl ether in the presence of an acid to obtain 4-formyl-(E3)-3-butenyl methoxymethyl ether;
reacting the 4-formyl-(E3)-3-butenyl methoxymethyl ether with alkylidene triphenyiphosphorane in accordance with the Wittig reaction to obtain (E3,Z5)-3,5-alkadienyl methoxymethyl ether; and
obtaining (E3,Z5)-3,5-alkadienyl acetate from the E3,Z5)-3,5-alkadienyl methoxymethyl ether.
The alkylidene triphenylphosphorane may be represented as a preferable example by
RCH═PPh 3
wherein R represents a group having from 4 to 12 carbon atoms, especially from 6 or 8 carbon atoms and Ph represents a phenyl group, and
(E3,Z5)-3,5-alkadienyl methoxymethyl ether may be represented as a preferable example by
RCH═CH—CH═CH—CH 2 —CH 2 —OCH 2 OCH 3 .
According to the present invention, (E3,Z5)-3,5-alkadienyl acetate and (E3,Z5)-3,5-dodecadienyl acetate, which is a sex pheromone of Brazilian apple leafminer, can be prepared efficiently under industrially mild conditions.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preparation method of the present invention will hereinafter be described in detail.
First, 5,5-diethoxy-(Z3)-3-pentenyl methoxymethyl ether to be used as a starting substance can be obtained, for example, by reacting 3-butyn-1-ol with dimethoxymethane to obtain 3-butynyl methoxymethyl ether, reacting the 3-butynyl methoxymethyl ether with methylmagnesium chloride and then, with ethyl orthoformate to obtain 5,5-diethoxy-3-pentynyl methoxymethyl ether, and then subjecting the 5,5-diethoxy-3-pentynyl methoxymethyl ether to catalytic hydrogenation.
More specifically, 3-butyn-1-ol can be prepared readily, for example, in accordance with the following known method:
wherein THF represents tetrahydrofuran and EO represents ethylene oxide.
3-Butyn-1-ol (1) can be reacted with dimethoxymethane in the presence of, for example, para-toluenesulfonic acid and lithium bromide, to produce 3-butynyl methoxymethyl ether (2), protecting the alcohol group. In this reaction, it is preferable to use 0.1 to 1.0 mol of para-toluenesulfonic acid, 0.1 to 0.5 mol of lithium bromide and 3.5 to 5.0 mol of dimethoxymethane per mol of 3-butyn-1-ol (1). The reaction temperature may be desirably from 30 to 45° C.
wherein p-TsOH.H 2 O represents p-toluenesulfonic acid monohydrate.
3-butynyl-methoxymethyl ether (2) can be reacted with methylmagnesium chloride and then with ethyl orthoformate to produce 5,5-Diethoxy-3-pentynyl-methoxymethyl ether (3). The following method may be included by a preferable example.
First, a tetrahydrofuran solution of methylmagnesium chloride is prepared using methyl chloride and metal magnesium in tetrahydrofuran in a known manner. Then, 3-butynyl methoxymethyl ether (2) is added dropwise to the resulting solution and reacted at preferably from 60 to 80° C. Ethyl orthoformate and toluene are then added. The resulting mixture has tetrahydrofuran distilled off by heating, and then reacted at preferably 80 to 95° C. to obtain 5,5-diethoxy-3-pentynyl methoxymethyl ether (3). In these reactions, amounts of methylmagnesium chloride and ethyl orthoformate are preferably 1.1 to 1.3 mol and 1.2 to 1.4 mol, respectively, and those of tetrahydrofuran and toluene are preferably 300 to 500 g and 250 to 300 g, respectively, per mol of 3-butynyl methoxymethyl ether (2).
wherein Et represents an ethyl group and THF represents tetrahydrofuran.
Catalytic hydrogenation of the triple bond of 5,5-diethoxy-3-pentynyl methoxymethyl ether (3) can be reduced into a (Z)-double bond to produce 5,5-Diethoxy-(Z3)-3-pentenyl methoxymethyl ether (4).
Examples of the catalyst used for the reaction may include palladium-carbon, palladium-alumina, Lindlar catalyst, Raney nickel and P2-nickel. Of these, P2-nickel is especially preferred. In order to prevent excessive hydrogenation, amine such as pyridine, quinoline or ethylenediamine may be added for the reaction. The hydrogen pressure may be preferably from normal pressure to 0.5 MPa, while the reaction temperature may be preferably from 30 to 50° C.
wherein Et represents an ethyl group.
Addition of an acid (preferably, an aqueous solution of hydrogen chloride) to 5,5-dimethoxy-(Z3)-3-pentenyl methoxymethyl ether (4), for example, preferably in toluene or n-hexane, can have a diethylacetal portion of the compound hydrolyzed into an aldehyde, more specifically, an α,β-unsaturated aldehyde, thereby isomerizing the double bond into a more stable E configuration to produce 4-formyl-(E3)-3-butenyl methoxymethyl ether (5). In this reaction, the aqueous solution of hydrogen chloride may have a concentration of preferably from 5 to 10% by weight and be added in an amount of preferably from 100 to 130 g per mol of 5,5-dimethoxy-(Z3)-3-pentenyl-methoxymethyl ether (4). The reaction temperature may be preferably from 10 to 20° C.
wherein Et represents an ethyl group.
4-Formyl-(E3)-3-butenyl methoxymethyl ether (5) can be reacted with alkylidene triphenylphosphorane (7) in accordance with the Wittig reaction to produce (E3,Z5)-3,5-alkadienyl methoxymethyl ether (8).
For example, the alkylidene triphenylphosphorane (7) may be synthesized by reacting alkyl bromide with triphenylphosphine in dimethylformamide in a known manner to prepare a dimethylformamide solution of alkyltriphenylphosphonium bromide (6), adding tetrahydrofuran thereto, and then adding potassium t-butoxide to the resulting mixture. Then, the (E3,Z5)-3,5-alkadienyl methoxymethyl ether (8) may be obtained by adding 4-formyl-(E3)-3-butenyl methoxymethyl ether (5) dropwise to the alkylidene triphenylphosphorane (7) for forming a (Z)-double bond in accordance with the Wittig reaction. An amount of 1,3,5-alkatriene produced as a by-product of an elimination reaction is as low as 2.0% or less.
wherein Ph represents a phenyl group, DMF represents N,N-dimethylformamide, and THF represents tetrahydrofuran.
In the above reaction, 1.1 to 1.2 mol of alkyl bromide, 1.0 to 1.1 mol of triphenylphosphine and 100 to 150 g of dimethylformamide may be preferably used per mol of 4-formyl-(E3)-3-butenyl methoxymethyl ether (5). In the phosphorane synthesis reaction, 1.00 to 1.03 mol of potassium t-butoxide may be preferably used per mol of 4-formyl-(E3)-3-butenyl methoxymethyl ether (5). The reaction temperature may be preferably from 15 to 20° C. The Wittig reaction can be preformed at the reaction temperature of −70 to 30° C., particularly preferably −15 to −10° C.
The (E3,Z5)-3,5-alkadienyl methoxymethyl ether (8) can be treated with an acid to produce (E3,Z5)-3,5-alkadienol (9).
For example, the (E3,Z5)-3,5-alkadienol (9) can be obtained by reacting the (E3,Z5)-3,5-alkadienyl methoxymethyl ether (8) with an aqueous solution of hydrogen chloride in methanol to deprotect the methoxymethyl group. The reaction can proceed smoothly by distilling off dimethoxymethane, a by-product of the reaction, in a distillation tower attached to the reactor and no isomerization of the EZ mixture can be confirmed during the reaction.
In the above reaction, the concentration of hydrogen chloride in the aqueous solution may be preferably from 10 to 37% by weight. The aqueous solution of hydrogen chloride may be used preferably in an amount of 300 to 400 g per mol of the (E3,Z5)-3,5-alkadienyl methoxymethyl ether (8). Methanol may be used preferably in an amount of 500 to 1200 g per mol of the (E3,Z5)-3,5-alkadienyl methoxymethyl ether (8). The reaction may be performed at the boiling point of dimethoxymethane, that is, from 42 to 44° C. or greater. It may be especially preferably from 60 to 65° C.
The (E3,Z5)-3,5-alkadienol (9) thus obtained can be then acetylated into (E3,Z5)-3,5-dodecadienyl acetate (10).
For example, intended (E3,Z5)-3,5-alkadienyl acetate (10) can be obtained by reacting the (E3,Z5)-3,5-alkadienol (9) with acetic anhydride in toluene in the presence of a catalyst.
wherein Ac represents an acetyl group.
In the above reaction, 0 to 200 g of toluene and 1.1 to 1.3 mol of acetic anhydride may be preferably used per mol of the (E3,Z5)-3,5-alkadienol (9). The catalyst may be an ordinarily used one such as pyridine, triethylamine or dimethylaminopyridine. The reaction temperature may be desirably from 6 to 70° C.
Example 1
<Preparation of 4-formyl-(E3)-3-butenyl methoxymethyl ether>
A concentrated solution of 5,5-dimethoxy-(Z)-3-pentenyl methoxymethyl ether was dissolved in toluene (80.0 g). The resulting solution was placed in a reactor and stirred at from 10 to 15° C. An 8% by weight aqueous solution of hydrogen chloride was added dropwise thereto at 15 to 20° C., and the mixture was stirred for one hour. After stirring, the reaction mixture was extracted with toluene (200 g). The water phase was removed, while the organic phase was washed with brine and an aqueous solution of sodium bicarbonate.
The organic phase thus obtained was concentrated under reduced pressure by removing the solvent. The residue was distilled under reduced pressure to yield 4-formyl-(E3)-3-butenyl methoxymethyl ether (bp: 65 to 66° C. [2 mmHg], 152.16 g, 1.06 mol) in a yield of 84.0%.
[Nuclear magnetic resonance spetrum] 1 H-NMR (300 MHz, CDCl 3 ): δ 2.60(2H, dt), 3.32(3H, s), 3.67(2H, t), 4.60(2H, s), 6.16(12H, dd), 6.85(1H, dt), 9.49(1H, d); 13 C-NMR (75.6 MHz, CDCl 3 ): δ 32.94, 55.27, 65.42, 96.41, 134.20, 154.81, 193.71
[Mass spectrum] EI-mass spectrum (70 eV): m/z 114(M + ), 83, 75, 55, 45; CI mass spectrum (isobutane): 115 (M+H)
<Preparation of (E3,Z5)-3,5-dodecadienyl methoxymethyl ether>
Triphenylphosphine (105.02 g, 0.40 mol), n-heptyl bromide (76.93 g, 0.43 mol) and N,N-dimethylformamide (82.0 g) were placed in a reactor and stirred at 105 to 110° C. for 26 to 30 hours. After stirring, the reaction mixture was cooled to 20° C. and tetrahydrofuran (370.0 g) and potassium t-butoxide (42.10 g, 0.375 mol) were added thereto successively at 10 to 15° C. The resulting mixture was stirred at 20° C. for one hour. After stirring, the reaction mixture was cooled to −20° C. and 4-formyl-(E3)-3-butenyl methoxymethyl ether (52.47 g, 0.364 mol) was added dropwise thereto at −15 to −5° C.
After dropwise addition was over, the temperature of the mixture was raised to the range of 20 to 25° C. over one hour and then the mixture was stirred as it was for one hour. Then water (200 g) was added thereto to terminate the reaction. The reaction mixture was extracted with toluene (200 g). The organic phase was washed with water and then concentrated under reduced pressure by removing toluene.
After concentration, n-hexane (250 g) was added and triphenylphosphine oxide thus precipitated was separated by filtration. The filtrate was concentrated under reduced pressure again and the concentrate was distilled under reduced pressure to yield intended (E3,Z5)-3,5-dodecadienyl methoxymethyl ether (bp: from 82 to 86° C. [1 mmHg], 52.98 g, 0.23 mol) in a yield of 65.2%.
Gas chromatography (DB-5: 30 m×0.25 mmΦ, temperature elevation from 150° C. to 280° C. at a rate of 10° C./min) revealed that as a result of the Wittig reaction, a 1,3,5-alkatriene content was 1.32% and an EZ:EE isomer ratio was 89.33:10.67.
[Mass spectrum] EI-mass spectrum (70 eV): m/z 226 (M + ), 164, 138, 110, 95, 81, 67, 55
<Preparation of (E3,Z5)-3,5-dodecadienol>
(E3,Z5)-3,5-Dodecadienyl methoxymethyl ether (54.55 g, 0.241 mol) and methanol (300.84 g) were placed in a reactor equipped with a distillation tower and stirred at 22 to 25° C. A 20% by weight aqueous solution (135 g) of hydrogen chloride was added dropwise thereto at 25 to 30° C. over one hour.
After dropwise addition, the temperature of the reaction mixture was raised to 60° C. and stirred for one hour. By gradually reducing the pressure to 450 mmHg, a mixture of dimethoxymethane and methanol produced as a by-product was distilled off from the distillation tower. The residue was stirred for 5 hours. After stirring, the reaction mixture was cooled to 25° C. and extracted with toluene (200 g). The organic phase was washed with brine and an aqueous solution of sodium bicarbonate. The solvent was removed under reduced pressure to yield a concenetrated solution (62.82 g, 73.16%) of (E3,Z5)-3,5-dodecadienol. The resulting concentrated solution was provided for the subsequent reaction without purification:
It was revealed by gas chromatography (DB-5: 30 m×0.25 mmΦ, temperature elevation from 150° C. to 280° C. at a rate of 10° C./min) that an EZ:EE isomer ratio was 91.24:8.75.
[mass spectrum] EI-mass spectrum (70 eV): m/z 182 (M + ), 109, 95, 79, 67; CI mass spectrum (isobutane): 183 (M+H)
<Preparation of (E3,Z5)-3,5-dodecadienyl acetate>
A concentrated solution (62.82 g, 73.16%) of (E3,Z5)-3,5-dodecadienol, toluene (150 g), acetic anhydride (10 g, 0.098 mol) and dimethylaminopyridine (1.0 g) were placed in a reactor and stirred at 50 to 60° C. Acetic anhydride (23.45 g, 0.23 mol) was added dropwise thereto at 65 to 70° C. over 30 minutes, followed by stirring at 75° C. for one hour.
After stirring, the reaction mixture was cooled to 30° C. and water (100 g) was added to terminate the reaction. After separation of the reaction mixture into phases, the organic phase was washed with brine and an aqueous solution of sodium bicarbonate, and then concentrated under reduced pressure by removing the solvent. The residue was distilled under reduced pressure to yield (E3,Z5)-3,5-dodecadienyl acetate (bp: 92 to 96° C. [1 mmHg], 51.43 g, 0.23 mol) in a yield of 95.1%.
It was revealed by gas chromatography (DB-5: 30 m×0.25 mmΦ, temperature elevation from 150° C. to 280° C. at a rate of 10° C./min) that an EZ:EE isomer ratio was 89.65:10.35.
[Nuclear magnetic resonance spectrum] 1 H-NMR (300 MHz, CDCl 3 ):
δ 0.88(3H, t), 1.27-1.43(8H, m), 2.05(3H, s), 2.14(2H, dt), 2.43(2H, dt), 4.11(2H, t), 5.37(1H, dt), 5.60(1H, dt), 5.95(1H, dd), 6.39(1H, dd); 13 C-NMR (75.6 MHz, CDCl 3 ): δ 14.10, 20.97, 22.64, 27.70, 28.94, 29.66, 31.76, 32.17, 63.80, 128.09, 128.24, 128.65, 131.56, 171.07
[Mass spectrum] EI-mass spectrum (70 eV): m/z 165(M + −59), 138, 110, 93, 80, 67; CI mass spectrum (isobutane): 225 (M+H)
[Infrared absorption spectrum] [NaCl]: νmax 3020, 2956, 2927, 2856, 1743, 1457, 1382, 1363, 1236, 1035, 983, 948
Comparative Example 1
<Reaction between 4-formyl-(E3)-3-butenyl acetate and alkylidene phosphorane (in the case where an alcohol is protected with an acetyl group)>
Triphenylphosphine (52.51 g, 0.20 mol), n-heptane bromide (3847 g, 0.215 mol) and N,N-dimethylformamide (41.0 g) were placed in a reactor and stirred at 105 to 110° C. for 26 to 30 hours. After stirring, the reaction mixture was cooled to 20° C. and tetrahydrofuran (185.0 g) was added thereto. Then, potassium t-butoxide (21.1 g, 0.188 mol) was added at 10 to 15° C. and the resulting mixture was stirred at 20° C. for one hour. After stirring, the reaction mixture was cooled to −20° C. and 4-formyl-(E3)-3-butenyl acetate (25.87 g, 0.182 mol) was added dropwise thereto at −15 to −5° C.
After dropwise addition, the temperature of the mixture was raised to the range of 20 to 25° C. over one hour and the mixture was stirred as it was for one hour. Then, water (100 g) was added to terminate the reaction. The reaction mixture was extracted with toluene (100 g). The organic phase was washed with water and then concentrated under reduced pressure by removing toluene.
After concentration, n-hexane (120 g) was added and triphenylphosphine oxide thus precipitated was separated by filtration. The filtrate was concentrated under reduced pressure again and the concentrated solution was distilled under reduced pressure to yield intended (E3,Z5)-3,5-dodecadienyl acetate (9.80 g, 0.04 mol) in a yield of 24.0% and 1,3,5-decatriene (9.87 g, 0.06 mol) in a yield of 33.0%.
Comparative Example 2
<Preparation of 4-formyl-(E3)-3-butenyl 1-ethoxyethyl ether (in the case where an alcohol is protected with a 1-ethoxyethyl group)>
A toluene (80.0 g) solution of 5,5-dimethoxy-(Z3)-3-pentenyl 1-ethoxyethyl ether (30.0 g, 0.122 mol) was placed in a reactor and stirred at 5 to 10° C. A 5% by weight aqueous solution of acetic acid was added dropwise thereto at 10 to 15° C. and the mixture was stirred for two hours. After stirring, toluene (100 g) was added thereto to separate the mixture into phases. The water phase was removed, while the orgnanic phase was washed with brine and an aqueous solution of sodium bicarbonate.
The organic layer thus obtained was concentrated under reduced pressure by removing the solvent, and then the residue was distilled under reduced pressure to yield 2-hydroxy-5,6-dihydropyrane (8.64 g, 0.09 mol) in a yield of 70.7%. Formation of intended 4-formyl-3-butenyl 1-ethoxyethyl ether was not observed.
Comparative Example 3
<Preparation of 4-formyl-(E3)-3-butenyl tetrahydropyranyl ether (in the case where an alcohol is protected with a tetrahydropyranyl group)>
A n-hexane (50.0 g) solution of 5,5-dimethoxy-(Z3)-3-pentenyl 1-tetrahydropyranyl ether (51.7 g, 0.20 mol) was placed in a reactor and stirred at 10 to 15° C. A 15% by weight aqueous solution (30.0 g) of acetic acid was added dropwise thereto at 15 to 20° C. and the mixture was stirred for one hour. After stirring, n-hexane (80 g) was added thereto to separate the reaction mixture into phases. The water phase was removed, while the organic phase was washed with brine and an aqueous solution of sodium bicarbonate.
The organic phase thus obtained was concentrated under reduced pressure by removing the solvent and the residue was analyzed by gas chromatography (DB-WAX: 30 m×0.25 mmΦ, temperature elevation from 150° C. to 280° C. at a rate of 10° C./min). As a result, it was found that the residue contained 9.8 GC % of 4-formyl-(E3)-3-butenyl tetrahydropyranyl ether.
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Provided is a method for preparing (E3,Z5)-3,5-alkadienyl acetate and (E3,Z5)-3,5-dodecadienyl acetate which is a sex pheromone of Brazilian apple leafminer. Specifically, provided is a method for preparing (E3,Z5)-3,5-alkadienyl acetate, comprising steps of hydrolyzing 5,5-diethoxy-(Z3)-3-pentenyl methoxymethyl ether in the presence of an acid to obtain 4-formyl-(E3)-butenyl methoxymethyl ether; reacting the 4-formyl-(E3)-butenyl methoxymethyl ether with alkylidene triphenylphosphorane in accordance with the Wittig reaction to obtain (E3,Z5)-3,5-alkadienyl methoxymethyl ether; and obtaining (E3,Z5)-3,5-alkadienyl acetate using the (E3,Z5)-3,5-alkadienyl methoxymethyl ether as a starting substance.
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TECHNICAL FIELD
[0001] The present invention relates generally to methods of making nonwoven fabrics, and more particularly, to a method of manufacturing a nonwoven fabric exhibiting improved physical characteristics while exhibiting improved three-dimensional image, permitting use of the fabric in a wide variety of consumer applications.
BACKGROUND OF THE INVENTION
[0002] The production of conventional textile fabrics is known to be a complex, multi-step process. The production of fabrics from staple fibers begins with the carding process whereby the fibers are opened and aligned into a feedstock referred to in the art as “sliver”. Several strands of sliver are then drawn multiple times on a drawing frames to; further align the fibers, blend, improve uniformity and reduce the sliver's diameter. The drawn sliver is then fed into a roving frame to produce roving by further reducing its diameter as well as imparting a slight false twist. The roving is then fed into the spinning frame where it is spun into yarn. The yarns are next placed onto a winder where they are transferred into larger packages. The yarn is then ready to be used to create a fabric.
[0003] For a woven fabric, the yarns are designated for specific use as warp or fill yarns. The fill yarns (which run on the y-axis and are known as picks) are taken straight to the loom for weaving. The warp yarns (which run on the x-axis and are known as ends) must be further processed. The large packages of yarns are placed onto a warper frame and are wound onto a section beam were they are aligned parallel to each other. The section beam is then fed into a slasher where a size is applied to the yarns to make them stiffer and more abrasion resistant, which is required to withstand the weaving process. The yarns are wound onto a loom beam as they exit the slasher, which is then mounted onto the back of the loom. The warp yarns are threaded through the needles of the loom, which raises and lowers the individual yarns as the filling yarns are interested perpendicular in an interlacing pattern thus weaving the yarns into a fabric. Once the fabric has been woven, it is necessary for it to go through a scouring process to remove the size from the warp yarns before it can be dyed or finished. Currently, commercial high-speed looms operate at a speed of 1000 to 1500 picks per minute, where a pick is the insertion of the filling yarn across the entire width of the fabric. Sheeting and bedding fabrics are typically counts of 80×80 to 200×200, being the ends per inch and picks per inch, respectively. The speed of weaving is determined by how quickly the filling yarns are interlaced into the warp yarns, therefore looms creating bedding fabrics are generally capable of production speeds of 5 inches to 18.75 inches per minute.
[0004] In contrast, the production of nonwoven fabrics from staple fibers is known to be more efficient than traditional textile processes, as the fabrics are produced directly from the carding process.
[0005] Nonwoven fabrics are suitable for use in a wide variety of applications where the efficiency with which the fabrics can be manufactured provides a significant economic advantage for these fabrics versus traditional textiles. However, nonwoven fabrics have commonly been disadvantaged when fabric properties are compared to conventional textiles, particularly in terms of resistance to elongation, in applications where both transverse and co-linear stresses are encountered. Hydroentangled fabrics have been developed with improved properties, by the formation of complex composite structures in order to provide a necessary level of fabric integrity. Subsequent to entanglement, fabric durability has been further enhanced by the application of binder compositions and/or by thermal stabilization of the entangled fibrous matrix.
[0006] Nonwoven composite structures typically improve physical properties, such as elongation, by way of incorporation of a support layer or scrim. The support layer material can comprise an array of polymers, such as polyolefins, polyesters, polyurethanes, polyamides, and combinations thereof, and take the form of a film, fibrous sheeting, or grid-like meshes. Metal screens, fiberglass, and vegetable fibers are also utilized as support layers. The support layer is commonly incorporated either by mechanical or chemical means to provide reinforcement to the composite fabric. Reinforcement layers, also referred to as a “scrim” material, are described in detail in U.S. Pat. No. 4,636,419, which is hereby incorporated by reference. The use of scrim material, more particularly, a spunbond scrim material is known to those skilled in the art.
[0007] Spunbond material comprises continuous filaments typically formed by extrusion of thermoplastic resins through a spinneret assembly, creating a plurality of continuous thermoplastic filaments. The filaments are then quenched and drawn, and collected to form a nonwoven web. Spunbond materials have relatively high resistance to elongation and perform well as a reinforcing layer or scrim. U.S. Pat. No. 3,485,706 to Evans, et al., which is hereby incorporated by reference, discloses a continuous filament web with an initial random staple fiber batt mechanically attached via hydroentanglement, then a second random staple fiber batt is attached to the continuous filament web, again, by hydroentanglement. A continuous filament web is also utilized in U.S. Pat. Nos. 5,144,729; 5,187,005; and 4,190,695. These patents include a continuous filament web for reinforcement purposes or to reduce elongation properties of the composite. More recently, hydroentanglement techniques have been developed which impart images or patterns to the entangled fabric by effecting hydroentanglement on three-dimensional image transfer devices. Such three-dimensional image transfer devices are disclosed in U.S. Pat. No. 5,098,764, which is hereby incorporated by reference; with the use of such image transfer devices being desirable for providing a fabric with enhanced physical properties as well as an aesthetically pleasing appearance.
[0008] For specific applications, a three-dimensionally imaged nonwoven fabric must exhibit a combination of specific physical characteristics. For example, when such fabrics are used in the formation of cleansing or dusting wipes, the fabric must exhibit sufficient durability to withstand application upon abrasive surfaces and yet exhibit a pronounced three-dimensional pattern so as to capture and retain particulates (application filed separately). Further, three-dimensionally imaged nonwoven fabrics used in home, medical and hygiene applications require sufficient resistance to elongation so as to resist deformation of the image when the fabric is converted into a final end-use article and when used in the final application.
[0009] Notwithstanding various attempts in the prior art to develop a three-dimensionally imaged nonwoven fabric acceptable for home, medical and hygiene applications, a need continues to exist for a nonwoven fabric which provides a pronounced image, as well as the requisite mechanical characteristics.
SUMMARY OF THE INVENTION
[0010] The present invention is directed to a method of forming a nonwoven fabric, which exhibits a pronounced three-dimensional image that is durable to both converting and end-use application. In particular, the present invention contemplates that a fabric is formed from a precursor web comprising at least one support layer or scrim, which when subjected to hydroentanglement on a moveable imaging surface of a three-dimensional image transfer device, an enhanced product is achieved. By formation in this fashion, hydroentanglement of the precursor web results in a more pronounced three-dimensional image; an image that is durable to abrasion and distortion due to elongation.
[0011] In accordance with the present invention, a method of making a nonwoven fabric embodying the present invention includes the steps of providing a precursor web comprising a fibrous matrix. While use of staple length fibers is typical, the fibrous matrix may comprise substantially continuous filaments. In a particularly preferred form, the fibrous matrix comprises staple length fibers, which are carded and cross-lapped to form a precursor web. In one embodiment of the present invention, the precursor web is subjected to pre-entangling on a foraminous-forming surface prior to juxtaposition of a support layer or scrim and subsequent three-dimensional imaging. Alternately, one or more layers of fibrous matrix are juxtaposed with one or more support layers or scrims, then the layered construct is pre-entangled to form a precursor web which is imaged directly, or subjected to further fiber, filament, support layers, or scrim layers prior to imaging.
[0012] The present method further contemplates the provision of a three-dimensional image transfer device having a movable imaging surface. In a typical configuration, the image transfer device may comprise a drum-like apparatus, which is rotatable with respect to one or more hydroentangling manifolds.
[0013] The precursor web is advanced onto the imaging surface of the image transfer device. Hydroentanglement of the precursor web is effected to form a three-dimensionally imaged fabric. Significantly, the incorporation of at least one support layer or scrim acts to focus the fabric tension therein, allowing for improved imaging of the staple fiber layer or layers, and resulting in a more pronounced three-dimensional image.
[0014] Subsequent to hydroentanglement, the three-dimensionally imaged fabric may be subjected to one or more variety of post-entanglement treatments. Such treatments may include application of a polymeric binder composition, mechanical compacting, application of surfactant or electrostatic compositions, and like processes.
[0015] A further aspect of the present invention is directed to a method of forming a durable nonwoven fabric, which exhibits a pronounced three-dimensionality, while providing the necessary resistance to abrasion and elongation, to facilitate use in a wide variety of applications. The fabric exhibits a high degree of fiber retention, thus permitting its use in those applications in which the fabric is used as a home cleaning substrate or medical fabric. Further, the support layer or scrim aids in preventing the distortion of the imprinted image upon the application of tension to the composite fabric during routine processing and use.
[0016] A method of making the present durable nonwoven fabric comprises the steps of providing a precursor web, which is subjected to hydroentangling. The precursor web is formed into a three-dimensionally imaged nonwoven fabric by hydroentanglement on a three-dimensional image transfer device. The image transfer device defines three-dimensional elements against which the precursor web is forced during hydroentanglement, whereby the fibrous constituents of the web are imaged by movement into regions between the three-dimensional elements and surface asperities of the image transfer device.
[0017] In the preferred form, the precursor web is hydroentangled on a foraminous surface prior to hydroentangling on the image transfer device. This pre-entangling of the precursor web acts to integrate the fibrous components of the web, but does not impart a three-dimensional image as can be achieved through the use of the three-dimensional image transfer device.
[0018] Optionally, subsequent to three-dimensional imaging, the imaged nonwoven fabric can be treated with a performance or aesthetic modifying composition to further alter the fabric structure or to meet end-use article requirements. A polymeric binder composition can be selected to enhance durability characteristics of the fabric, while maintaining the desired softness and drapeability of the three-dimensionally imaged fabric. A surfactant can be applied so as to impart hydrophilic properties. In addition, electrostatic modifying compound can be used to aid in cleaning or dusting applications.
[0019] Other features and advantages of the present invention will become readily apparent from the following detailed description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] [0020]FIG. 1 is a diagrammatic view of an apparatus for manufacturing a durable nonwoven fabric, embodying the principles of the present invention;
[0021] [0021]FIG. 2 is a plan view of a three-dimensional image transfer device of the type, referred to as “node”, used for practicing the present invention, with approximate dimension shown in millimeters;
[0022] [0022]FIG. 3 is a top plan photomicrograph of an nonwoven fabric having been imaged using the “node” image transfer device of FIG. 2, produced from a fibrous matrix alone utilizing a backlit light source, the magnification is approximately 10×;
[0023] [0023]FIG. 4 is a top plan photomicrograph of a nonwoven fabric having been imaged using the “node” image transfer device of FIG. 2, produced in accordance with the present invention, the magnification is approximately 10×;
[0024] [0024]FIG. 5 is top plan photomicrograph of the same fabric as in FIG. 3, wherein a top-lit light source at an incident angle of 45 degrees was used, the magnification is approximately 10×;
[0025] [0025]FIG. 6 is a top plan photomicrograph of the same fabric as in FIG. 4, wherein a top-lit light source at an incident angle of 45 degrees was used, the magnification is approximately 10×;
[0026] [0026]FIG. 7 is a side photomicrograph of the same fabric as in FIG. 3, wherein a top-lit light source at an incident angle of about 90 degrees was used, the magnification is approximately 10×;
[0027] [0027]FIG. 8 is a side photomicrograph of the same fabric as in FIG. 4, wherein a top-lit light source at an incident angle of about 90 degrees was used, the magnification is approximately 10×;
[0028] [0028]FIG. 9 is a top plan photomicrograph of a nonwoven fabric having been imaged using an alternate “pique” image transfer device, produced from a fibrous matrix alone, wherein a top-lit light source at an incident angle of 45 degrees was used, the magnification is approximately 10×; and
[0029] [0029]FIG. 10 is a top plan photomicrograph of a nonwoven fabric having been imaged using an alternate “pique” image transfer device, produced in accordance with the present invention, wherein a top-lit light source at an incident angle of 45 degrees was used, the magnification is approximately 10×.
DETAILED DESCRIPTION
[0030] While the present invention is susceptible of embodiment in various forms, there is shown in the drawings, and will hereinafter be described, a presently preferred embodiment of the invention, with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiment illustrated.
[0031] The present invention is directed to a method of forming nonwoven fabrics by hydroentanglement, wherein three-dimensional imaging of the fabrics is enhanced by the incorporation of at least one support layer or scrim. Enhanced imaging is achieved by substantially minimizing and eliminating tension in the overall precursor web as the web is advanced onto a moveable imaging surface of the image transfer device. By use of a support layer or scrim, enhanced fiber entanglement is achieved, with the physical properties, both aesthetic and mechanical, of the resultant fabric being desirably enhanced. It is reasonably believed that the internal support of the precursor web provided by the support layer or scrim, as the precursor web is advanced onto the image transfer device, desirably acts to focus tension to the support layer or scrim. Without tension, the fibers or filaments of the fibrous matrix, from which the precursor web is formed, can more easily move and shift during hydroentanglement, thus resulting in improved three-dimensional imaging on the image transfer device. A more clearly defined and durable image is achieved.
[0032] With reference to FIG. 1, therein is illustrated an apparatus for practicing the present method for forming a nonwoven fabric. The fabric is formed from a fibrous matrix, which typically comprises staple length fibers, but may comprise substantially continuous filaments. The fibrous matrix is preferably carded and cross-lapped to form a fibrous batt, designated F. In a current embodiment, the fibrous batt comprises 100% cross-lap fibers, that is, all of the fibers of the web have been formed by cross-lapping a carded web so that the fibers are oriented at an angle relative to the machine direction of the resultant web. U.S. Pat. No. 5,475,903, hereby incorporated by reference, illustrates a web drafting apparatus.
[0033] A support layer or scrim is then placed in face to face to face juxtaposition with the fibrous web and hydroentangled to form precursor web P. Alternately, the fibrous web can be hydroentangled first to form precursor web P, and subsequently, at least one support layer or scrim is applied to the precursor web, and the composite construct optionally further entangled with non-imaging hydraulic manifolds, then imparted a three-dimensional image on an image transfer device.
[0034] [0034]FIG. 1 illustrates a hydroentangling apparatus for forming nonwoven fabrics in accordance with the present invention. The apparatus includes a foraminous-forming surface in the form of belt 10 upon which the precursor web P is positioned for pre-entangling by entangling manifold 12 . Pre-entangling of the precursor web, prior to three-dimensional imaging, is subsequently effected by movement of the web P sequentially over a drum 14 having a foraminous-forming surface, with entangling manifold 16 effecting entanglement of the web. Further entanglement of the web is effected on the foraminous forming surface of a drum 18 by entanglement manifold 20 , with the web subsequently passed over successive foraminous drums 20 , for successive entangling treatment by entangling manifolds 24 , 24 ′.
[0035] The entangling apparatus of FIG. 1 further includes a three-dimensional imaging drum 24 comprising a three-dimensional image transfer device for effecting imaging of the now-entangled precursor web. The image transfer device includes a moveable imaging surface which moves relative to a plurality of entangling manifolds 26 which act in cooperation with three-dimensional elements defined by the imaging surface of the image transfer device to effect imaging and patterning of the fabric being formed.
[0036] The present invention contemplates that the support layer or scrim be any such suitable material, including, but not limited to, wovens, knits, open mesh scrims, and/or nonwoven fabrics, which exhibit low elongation performance. Two particular nonwoven fabrics of particular benefit are spunbond fabrics, as represented by U.S. Pat. Nos. 3,338,992; 3,341,394; 3,276,944; 3,502,538; 3,502,763; 3,509,009; 3,542,615; and Canadian Pat. No. 803,714, these patents are incorporated by reference, and nanofiber fabrics as represented by U.S. Pat. Nos. 5,678,379 and 6,114,017, both incorporated herein by reference. A particularly preferred embodiment of support layer or scrim is a thermoplastic spunbond nonwoven fabric. The support layer may be maintained in a wound roll form, which is then continuously fed into the formation of the precursor web, and/or supplied by a direct spinning beam located in advance of the three-dimensional imaging drum 24 .
[0037] Manufacture of a durable nonwoven fabric embodying the principles of the present invention is initiated by providing the fibrous matrix, which can include the use of staple length fibers, continuous filaments, and the blends of fibers and/or filaments having the same or different composition. Fibers and/or filaments are selected from natural or synthetic composition, of homogeneous or mixed fiber length. Suitable natural fibers include, but are not limited to, cotton, wood pulp and viscose rayon. Synthetic fibers, which may be blended in whole or part, include thermoplastic and thermoset polymers. Thermoplastic polymers suitable for blending with dispersant thermoplastic resins include polyolefins, polyamides and polyesters. The thermoplastic polymers may be further selected from homopolymers; copolymers, conjugates and other derivatives including those thermoplastic polymers having incorporated melt additives or surface-active agents. Staple lengths are selected in the range of 0.25 inch to 10 inches, the range of 1 to 3 inches being preferred and the fiber denier selected in the range of 1 to 22, the range of 1.2 to 6 denier being preferred for general applications. The profile of the fiber and/or filament is not a limitation to the applicability of the present invention.
EXAMPLES
Comparative Example 1
[0038] Using a forming apparatus as illustrated in FIG. 1, a nonwoven fabric was made by providing a precursor web comprising 100 weight percent polyester fibers. The web had a basis weight of 3 ounces per square yard (plus or minus 7%). The precursor web was 100% carded and cross-lapped, with a draft ratio of 2.5 to 1.
[0039] Prior to three-dimensional imaging of the precursor web, the web was entangled by a series of entangling manifolds such as diagrammatically illustrated in FIG. 1. FIG. 1 illustrates disposition of precursor web P on a foraminous forming surface in the form of belt 10 , with the web acted upon by an entangling manifold 12 . The web then passes sequentially over a drum 14 having a foraminous forming surface, for entangling by entangling manifold 16 , with the web thereafter directed about the foraminous forming surface of a drum 18 for entangling by entanglement manifold 20 . The web is thereafter passed over successive foraminous drums 22 , with successive entangling treatment by entangling manifolds 24 , 24 ′. In the present examples, each of the entangling manifolds included 120 micron orifices spaced at 42.3 per inch, with the manifolds successively operated at 100, 300, 700, and 1300 pounds per square inch, with a line speed of 45 yards per minute. A web having a width of 72 inches was employed.
[0040] The entangling apparatus of FIG. 1 further includes a three-dimensional imaging drum 24 comprising a three-dimensional image transfer device for effecting imaging and patterning of the now-entangled precursor web. The entangling apparatus includes a plurality of entangling manifolds 26 , which act in cooperation with the three-dimensional image transfer device of drum 24 to effect patterning of the fabric. In the present example, the imaging manifolds 26 were successively operated at 2800, 2800, and 2800 pounds per square inch, at a line speed which was the same as that used during pre-entanglement.
[0041] The three-dimensional image transfer device of drum 24 was configured as a so-called “node” image, as illustrated in FIG. 2.
[0042] Images of the comparative material are presented in FIGS. 3, 5, and 7 .
Example 1
[0043] A three-dimensionally imaged nonwoven fabric was manufactured by a process as described in Comparative Example 1, wherein in the alternative, and in accordance with the present invention, a lighter 1.5 ounce per square yard polyester staple fiber web was juxtaposed with a 1.5 ounce polyester spunbond web of approximately 2.0 denier. The staple fiber web/spunbond web layered matrix was then subjected to equivalent hydraulic pressures as described in Comparative Example 1.
[0044] Images of the improved material of the present invention are presented in FIGS. 4, 6 and 8 .
[0045] With reference to FIGS. 3 through 8, it is apparent that the imaged nonwoven fabrics made in accordance with the present invention exhibit greater three-dimensional image clarity and are more pronounced than the image imparted to equivalent basis weight materials without the support layer or scrim. The more pronounced three-dimensional images further result in increased bulk, as is depicted in the comparison of FIG. 7 and FIG. 8. Imaged nonwoven fabrics, such as Example 1, further exhibit a significantly reduced elongation performance, resulting in improved image retention during mechanical processing and use.
[0046] The material of the present invention may be utilized in the construction of a numerous home cleaning, personal hygiene, medical, and other end use products where a three-dimensionally imaged nonwoven fabric can be employed. Disposable absorbent hygiene articles, such as a sanitary napkins, incontinence pads, diapers, and the like, wherein the term “diaper” refers to an absorbent article generally worn by infants and incontinent persons that is worn about the lower torso of the wearer can benefit from the improved resiliency of the imaged nonwoven in the absorbent layer construction. An imaged nonwoven fabric may also be utilized as a landing zone affixed to the disposable absorbent article whereby the distal end of a fastening strip may attach; the imaged nonwoven fabric exhibiting improved “loop” durability and fuzz resistance to repeated, or finite, “hook” attachment cycles. In addition, the material may be utilized as medical gauze, or similar absorbent surgical materials, for absorbing wound exudates and assisting in the removal of seepage from surgical sites. Other end uses include; fabrication into wet or dry facial or hard surface wipes, which can be readily hand-held for cleaning and the like, protective wear for medical and industrial uses, such as gowns, shirts, bottom weights, lab coats, face masks, and the like, and protective covers, including covers for vehicles such as cars, trucks, boats, airplanes, motorcycles, bicycles, golf carts, as well as covers for equipment often left outdoors like grills, yard and garden equipment, such as mowers and roto-tillers, lawn furniture, floor coverings, table cloths and picnic area covers. The material may also be used in apparel construction, such as for bottom weights of every day wear, which includes pants and shorts.
[0047] From the foregoing, it will be observed that numerous modifications and variations can be affected without departing from the true spirit and scope of the novel concept of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated herein is intended or should be inferred. The disclosure is intended to cover, by the appended claims, all such modifications as fall within the scope of the claims.
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The present invention is directed to a method of forming a nonwoven fabric, which exhibits a pronounced three-dimensional image that is durable to both converting and end-use application. In particular, the present invention contemplates that a fabric is formed from a precursor web comprising at least one support layer or scrim, which when subjected to hydroentanglement on a moveable imaging surface of a three-dimensional image transfer device, an enhanced product is achieved. By formation in this fashion, hydroentanglement of the precursor web results in a more pronounced three-dimensional image; an image that is durable to abrasion and distortion due to elongation.
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BACKGROUND OF THE INVENTION
This invention relates to archery equipment and particularly to apparatus and methods for attaching arrow points and nocks to arrow shafts and for balancing arrow shafts.
The end adaptor apparatus and balance pin apparatus of the present invention are an improvement over prior art. For example, as known in the prior art, arrow points have a large externally threaded end and are screwed into an arrow shaft having an internal thread. Shortcomings of the prior art are that the shaft's internal threads cause stress to be exerted on the wall of the shaft. Hollow tubes made primarily of unidirectional fibers running the length direction and bonded together with a plastic resin or matrix are prone to split if stressed from the inside and, in particular, if stressed at the end of a tube. A further shortcoming is that when the arrow point is removed, dirt may easily enter the shaft of internal threads through the unsealed end. This affects the weight and balance of the arrow, making it less desirable to use.
The present invention solves these and other problems associated with the prior art.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide a small lightweight point cap system that may be adjustable in weight so that perfect balance is easily obtained. In one embodiment, the point cap system comprises a point cap and a balance pin which can be varied in size so as to be of adjustable weight.
The present invention provides a point cap system which is small and lightweight and greatly reduces the material and weight of the point or broadhead that may be attached. Light and slim graphite arrows perform and look best with smaller and lighter points than the industry standards.
The present invention also relates to a balance pin whose weight can be adjusted to balance an arrow shaft.
Further, the present invention provides a point cap and balance pin design which works together. When the balance pin is used (and trimmed to the desired length), the exact point weight may be obtained giving the arrow perfect balance.
Also, the present invention relates to means to attach points to arrow shafts without allowing dirt to be able to enter the shaft when the arrow points are not attached.
This invention further attempts to have the threads receiving the arrow point placed on a point cap member such that if the threads are damaged, the point cap member may be replaced with a new threaded point cap member. Thus, the more expensive arrow shaft is not rendered useless.
The invention also relates to a means of attachment that is suited to the use of unidirectional fiber reinforced shafts. This invention utilizes the strength of the reinforcing fibers by reducing the cross fiber stress at the end of the shaft.
The present invention also relates to means for uniformly encapsulating or capping the end of an arrow shaft with a material that has nearly the same strength properties in all directions like steel or aluminum.
One embodiment of the present invention also relates to a point adaptor adhesively attached to the arrow shaft and having internal threads for threaded receipt of various types of arrow points having external threads.
The present invention also relates to a nock cap adaptor for attaching nocks to the end of an arrow shaft.
These and various other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and its objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying description matter, in which there is illustrated and described a preferred embodiment of the invention.
BRIEF DISCUSSION OF THE DRAWINGS
In the drawings, wherein like reference numerals indicate corresponding parts throughout;
FIG. 1 is an enlarged sectional view of one embodiment of a point cap in accordance with the principles of the present invention;
FIG. 2 is a sectional view illustrating attachment of a field point to an arrow shaft by use of the point cap in accordance with the principles of the present invention;
FIG. 3 is an enlarged sectional view of one embodiment of a point adaptor in accordance with the principles of the present invention;
FIG. 4 is a sectional view illustrating attachment of a broadhead to an arrow shaft by use of the point adaptor shown in FIG. 3;
FIG. 5 is an enlarged sectional view of one embodiment of a nock cap in accordance with the principles of the present invention;
FIG. 6 is a sectional view of one embodiment of a balance pin attached to an arrow point and inserted into an arrow shaft in accordance with the principles of the present invention; and
FIG. 7 is a sectional view illustrating an embodiment of an arrow shaft including the point cap and the balance pin.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, where like numerals apply to like parts, and more particularly to FIG. 1, an embodiment of an end adaptor, herein referred to as a point cap, 100 may be seen. The point cap 100 is an integral, one-piece unit which includes an externally threaded end 101, to which an arrow point, such as a target point, a field point, or a broadhead point, with cooperating internal threads may be secured as generally indicated in FIG. 2, wherein a field point 110 is shown attached to an arrow shaft 104 via the point cap 100. In the preferred embodiment, the point cap 100 is made from a hardened steel.
An opposite end portion 103, also referred to as a ferrule end, of the point cap 100 forms a cylinder with a hollow interior 102. Hollow interior 102 has a diameter such that the point cap slides over and is suitably affixed to the arrow shaft 104. The arrow shaft 104 shown in FIG. 2 is hollow and has a bore 105. In the preferred embodiment, the arrow shaft is made of graphite, glass or similar unidirectional reinforcing fibers. The point cap 100 may be affixed to the arrow shaft using an epoxy. The point cap 100 might include identification grooves 106 for identifying varying configurations of point cap as may be used with varied sizes and configurations of arrow points, shafts, etc. The use of an externally attached point cap provides additional support to the end of the arrow shaft. The terminology ferrule, as used herein, refers to a bore with surrounding cylindrical wall portion providing additional support to the shaft it cooperates with.
As opposed to internal threads for arrow point attachment, the use of external threads at the end of a cap is ideal for graphite shafts because stress is reduced at the end of the shaft.
Preferably, the point cap is permanently attached to the arrow shaft; however, in some embodiments the point cap might be attached with a less permanent adhesive such that if the threads are damaged, the point cap may be replaced with a relatively inexpensive new point cap, thereby preventing the loss of the more expensive arrow. In the preferred embodiment, the threaded end 101 has a lesser outside diameter than the outside diameter of the end portion 103 and the outside diameter of the arrow shaft 104. At the junction of the threaded end 101 and the end portion 103, the end portion 103 is circumferentially surrounded by an inclined surface 109 for cooperating with a similarly inclined surface of an arrow point.
Illustrated in FIG. 3 is an embodiment of an internally threaded point adaptor 120 in accordance with the principles of the present invention. The point adaptor 120 is an integral, one-piece unit which includes a first end 122 including an internally threaded portion 124 and a hollow cylindrical bore portion 126. A second end 128 has an externally tapered surface and a bore configured for receipt of the arrow shaft 104, as generally illustrated in FIG. 4. The first and second ends 122,128 are interconnected by a passageway 130 to allow the escape of air upon insertion of the arrow shaft 104 into the bore of the second end 128. In FIG. 4, a broadhead arrow point 111 is illustrated as being threaded into the threaded portion 124, a threaded portion 132 of the broadhead arrow point cooperating with the threaded portion 124 of the point adaptor 120. The broadhead arrow point 111 is shown further including a cylindrical portion 134 slidably received in the bore portion 126 of the point adaptor 120. The point adaptor 120 is preferably made of a light material such as aluminum. As illustrated in FIG. 4, the point adaptor 120 is preferably attached to the arrow shaft 104 by an adhesive 136 such as epoxy. In FIG. 4, the arrow shaft 104 is illustrated as being hollow, although it will be appreciated that the arrow shaft might also be solid. The point adaptor 120 might further include identifying grooves 138 for identifying differing configurations and sizes of the point adaptor 120.
Illustrated in FIG. 5 is an embodiment of a nock cap 140 in accordance with the principles of the present invention. The nock cap 140 includes a first hollow cylindrical end 142 for slidable receipt on the arrow shaft 104 and a hollow tapered end 144 for insertion into a bore of a nock 145, as generally illustrated in FIG. 4. The nock cap 140 provides fluid communication between its ends such that upon insertion of the nock cap 140 onto an end of the arrow shaft 104, air can escape from the nock cap 140. The nock cap 140 is preferably made of a light material such as aluminum and is attached to the arrow shaft by an adhesive 146. The nock cap 140 might further include identifying grooves 148 as in the case of the point adaptor 120. The nock 145 is preferably made of a light material such as plastic and is attached to the nock cap 140 by an adhesive 150.
FIG. 6 refers to a balance pin 207 which may be used with an arrow point such as a target point 201. The balance pin 207 is affixed to the arrow shaft 104 by insertion into the arrow shaft 104 without necessitating the use of a threaded arrow shaft. A head portion 202 of the balance pin 207 is bonded to the interior of the arrow point 201 by adhesive 206. A shaft portion 203 of the balance pin 207 is inserted into the bore 105, of the arrow shaft 104. Preferably, the balance pin 207 is made of a heavy, soft metal such as brass, such that the balance pin shaft 203 may be cut off or trimmed to obtain a desired point weight. In the preferred embodiment, the balance pin 207 is an integral, one-piece unit. The balance pin 207 may also be used with a point cap by binding the balance pin to the interior of the point cap 100. In this way, it is possible to adjust the point weight.
The point cap 100 is used with an arrow shaft by suitably affixing the ferrule end 103 of the point cap 100 to the arrow shaft 104. An arrow point, such as a target point or broad head may be then threadedly attached to the point cap.
The balance pin 207 may be used with an arrow point having a hollow interior by affixing the head portion 202 of the balance pin 207 to the hollow interior of field point 201 by placement of an adhesive between the head portion of the balance pin and the arrow point or point cap. The shaft 203 of the balance pin is then inserted into the arrow shaft bore 105. To prevent movement or vibration of the end cap in the arrow shaft, a small amount of adhesive might be placed on the shaft of the balance pin.
As illustrated in FIG. 7, the balance pin 207 may be used with the point cap 100 by suitably affixing the head portion 202 of balance pin 207 in the bore 102 of the ferrule end 103 of the point cap 100. The point cap 100 is then attached to the arrow shaft 104 such that the balance pin shaft 203 is in the interior of the arrow shaft 104.
It is to be understood, however, that 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, and 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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An arrow end adaptor and a balance pin for an arrow and a method for making the same. The arrow comprising a ferrule having a large enough inner diameter to be placed over the arrow shaft, and further having an exterior threaded end whose diameter is smaller than the diameter of the arrow shaft. The point cap is designed such that an arrow point having interior threads may be attached to the exterior threaded end of the point cap. The balance pin is designed to have a head at one end that may be affixed to either a target point or a point cap and a shaft end that may be inserted into the arrow shaft.
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The present invention relates to an ammonia sensor and particularly to an ammonia sensor comprising a polyaniline as an ammonia-sensing portion.
As the sensor for ammonia gas detection, there were proposed, for example, (1) an ammonia gas electrode using an ammonia-permeable membrane, (2) a semiconductor sensor utilizing the change of resistance of an inorganic oxide semiconductor and (3) an ammonia detector using conductive polypyrrole. However, the ammonia gas electrode (1) is big in size, inconvenient to handle, impossible to use in a small space and troublesome in maintenance works such as make-up or exchange of electrolytic solution; the semiconductor sensor (2) generally has low selectivity for ammonia gas and must be used in a heated condition, and accordingly may cause explosion when used in an atmosphere wherein a flammable gas or a dust is present; the detector (3) using polypyrrole gives large property change with the lapse of a time. Thus, the conventional ammonia sensors have drawbacks.
Present inventors conducted a study in order to provide an ammonia sensor which is free from the above-mentioned drawbacks, is operable at room temperature, is small and lightweight, and has high reliability and high sensitivity. As a result, it was found that polyaniline changes its electric resistance in proportion to the ammonia concentration in a gas atmosphere such as air or other gas, that the utilization of this change in electric resistance enables the detection of ammonia concentration at a high sensitivity, and that polyaniline can be used very effectively as the sensing portion of an ammonia sensor. The finding has completed the present invention.
According to the present invention, there is provided as ammonia sensor consisting of at least one pair of electrodes and an ammonia-sensing material comprising a polyaniline filling the space between the electrodes.
The polyaniline used as an ammonia-sensing component in the ammonia-sensing material of the sensor of the present invention is a conductive organic polymer and can be produced by, for example, chemical or electrochemical polymerization of aniline [reference is made to, for example, A. G. MacDiarmid, J. C. Chiang and M. Halpern, Polym. Prepr. (1984) 248; B. Wang, J. Tang and F. Wang, J. Tang and F. Wang, Synthetic Metals, 13 (1986) 329-3341].
For example, the polyaniline can be produced by electrolytic polymerization of aniline wherein a polymerization solution containing aniline and an appropriate electrolyte is subjected to electrolysis in an ordinary electrolytic cell, using platinum as an anode and palladium as a cathode. In this case, the electrolytic voltage can be ordinarily 0.3-2 V (relative to a standard calomel-alumel electrode), and the current density is suitably 1-100 mA/cm 2 . As the electrolyte usable in the polymerization solution, there can be mentioned, for example, mineral acids such as hydrochloric acid, sulfuric acid and the like; perchloric acids and their salts such as HClO 4 , NAClO 4 , KClO 4 and the like; phosphoric acid buffer tetraethylammonium fluoroborate; and organic sulfonic acids such as toluenesulfonic acid, naphthalenesulfonic acid and the like. The electrolyte can be used generally in a concentration of 0.01-5 M, preferably 0.03-4 M in the polymerization solution.
Aniline can be used in the polymerization solution generally in a concentration of 0.01-5 M, preferably 0.03-4 M. As the solvent usable in the polymerization solution, there can be mentioned, for example, water, ethanol, acetonitrile, propylene carbonate, nitrobenzene and their mixture.
The polyaniline formed by electrolysis can be separated from the polymerization solution, washed with water thoroughly until the washings become almost neutral, and dried until the residual water in polyaniline becomes 5% by weight or less, preferably 2% by weight or less.
The thus formed polyaniline is preferably soluble in ordinary polar organic solvents such as N,N'-dimethylformamide, N,N'-dimethylacetamide, dimethylsulfoxide, N-methylpyrrolidone, acetonitrile and the like.
The present inventors found that the polyaniline obtained by electrolytic polymerization as above changes its electric resistance in proportion to the ammonia concentration in an atmosphere such as air or other gas and accordingly the measurement of the electric resistance enables the detection of the ammonia concentration at a very high sensitivity and that the polyaniline is very effective as an element for ammonia sensor.
In using the thus obtained polyaniline as an ammonia sensor, the polyaniline can be dissolved in a polar organic solvent such as N,N'-dimethylformamide, N,N'-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone or the like, and the resulting solution can be coated on an insulating substrate having at least one pair of electrodes thereon, so as to fill the space between the electrodes. In a specific example, the polyaniline solution can be coated on an insulating substrate having a pair of interdigitated electrodes thereon as shown in FIG. 1, so as to fill the space between the electrodes and further cover the electrodes. The shape of electrodes has no particular restriction and can be not only a interdigitated-type Shape but also various other shapes such as whirl shape and sandwich shape in which a rectangular sensor membrane is sandwiched betwen electrode.
It is not necessary to add additives to the polymerization solution; however, as necessary, it is possible to add, for example, a polymer having film formability such as polyacrylonitrile, poly(vinyl chloride), poly(vinylidene chloride) or polystyrene, or a cellulose derivative, in such an amount as to give substantially no adverse effect on the ammonia-sensing ability of polyaniline.
The concentration of polyaniline in the polymerization solution is not particularly restricted but can be ordinarily 1-30%, preferably 3-20%. The electrodes is preferably made of a conductive metal with excellent corrosion resistance, such as platinum, gold, palladium or the like. As the insulating substrate, there is ordinarily used a ceramic such as glass, alumina or the like.
As the method for coating the polyaniline solution, there can be mentioned, for example, ordinary coating methods such as spin coating, dipping and the like. After the coating, the solvent is removed, whereby an ammonia sensor of the present invention can be obtained. The suitable film thickness after the solvent removal is generally 0.01-100 microns, preferably 0.1-10 microns.
It was found that in another process for producing an ammonia sensor according to the present invention, a thin film of a conductive high-molecular substance is formed on an insulating substrate having at least one pair of electrodes thereon, and then electrolytic polymerization of aniline is effected in the thin film with the thin film used as an anode, whereby an ammonia sensor comprising a polyaniline as an ammonia-sensing element can be produced very easily.
Therefore, according to another embodiment of the present invention, there is provided an ammonia sensor comprising at least one pair of electrodes and an ammonia-sensing material comprising a matrix of a conductive high polymer filling the space between the electrodes and a polyaniline dispersed in the matrix.
The conductive high polymer constituting the matrix of the ammonia-sensing material of the ammonia sensor can be any as long as it is a film-formable high polymer showing a conductivity of certain degree or higher (e.g. 10 -5 mho or higher) when exposed to an electric field. The substance can have conductivity by itself, or can be a mixture with an electrolyte. Specific examples of such a conductive high polymer are as follows.
(a) High polymers having, as a side chain, an ionic group such as sulfonic acid group, carboxylic acid group, phosphoric acid group, secondary, tertiary or quaternary amino group or the like. For example, (co)polymers or graft polymers of an ionic group-containing monomer such as styrenesulfonic acid, acrylamide, methylpropanesulfonic acid, vinylsulfonic acid, acrylic acid, methacrylic acid, ethyleneimine, vinylpyridine or the like; carbamoyl cellulose, sulfated cellulose, etc.; high-molecular electrolytes obtained by chemically introducing an ionic group as mentioned above into an appropriate high-molecular substrate; and their crosslinked products.
(b) High polymers having conductivity by containing an electrolyte. For example, mixtures of a poly(alkelene oxide) [e.g. poly(ethylene oxide), poly(propylene oxide)] and an alkali metal salt; mixtures of an acrylonitrile type high polymer, a rhodanate and zinc chloride; salts between cellulose or its derivative and an alkali metal or an alkaline earth metal; high polymers each containing an anionic or cationic surfactant; mixtures of a water-soluble high polymer [e.g. polyvinylpyrrolidone, poly(vinyl alcohol)] and an alkali metal salt or an alkaline earth metal salt; high-moleculr substances each containing a dispersed amine. It is desirable that these high polymers, particularly those soluble in water be crosslinked by chemical or physical means after having been made into a thin film.
Of these conductive high polymers, there are preferably used in the present invention a high polymer having a sulfonic group or a carboxylic acid group as a side chain, its crosslinked product, a mixture of a poly(alkylene oxide) with an alkali metal salt, a mixture of an acrylonitrile type high polymer with a rhodanate and zinc chloride, and the like.
The ammonia sensor of the present invention can be formed, for example, by dissolving a conductive high polymer as mentioned above and a polyaniline produced as above, in a solvent capable of dissolving both of them and then coating the resulting solution on an insulating substrate having at least one pair of electrodes thereon, so as to fill at least the space between the electrodes. However, the ammonia sensor of the present invention can preferably be produced by forming a thin film of a conductive high polymer as mentioned above, on an insulating substrate having at least one pair of electrodes thereon, so as to cover at least the portion of the insulating substrate not covered by the electrodes and then effecting electrolysis of a polymerization solution containing aniline and an appropriate supporting electrolyte, in an electrolytic cell using the above-formed thin film of a conductive high polymer as an anode and platinum, palladium or the like as a cathode. As the insulating substance having at least one pair of electrodes thereon, there can be illustrated those mentioned above.
The formation of a thin film of a conductive high polymer on an insulating substrate having at least one pair of electrodes thereon can be effected by a per se known method, for example, a method wherein a solution of a conductive high polymer is prepared and then coated by, for example, spin coating, dipping, knife coating, roll coating or the like, a vapor deposition method (e.g. vacuum deposition), a plasma polymerization method or the like.
The suitable thickness of thin film of conductive high polymer can differ depending upon the type of the substance, etc. but is generally 0.1-100 microns, preferably 1-20 microns. The solution of the conductive high polymer can contain, as necessary, a film-formable polymer, etc.
The insulating substrate on which a thin film of a conductive high polymer has been formed, is placed in an electrolytic cell filled with a polymerization solution containing aniline and an appropriate supporting electrolyte; electrolytic polymerization of aniline is effected in the thin film of a conductive high polymer, using the thin film as an anode and palladium or the like as a cathode, in the same manner as mentioned above; thereby, an ammonia sensor of the present invention can be obtained.
In the ammonia sensor of this type, the ratio of the conductive high polymer matrix and the polyaniline in the ammonia-sensor material is not strictly restricted and can vary over a wide range depending upon the requirements for the ammonia sensor, its application, etc. However, the weight ratio of the polyaniline/the conductive high polymer can be generally 10/90 to 90/10, preferably 20/80 to 85/15, more preferably 30/70 to 80/20.
In the ammonia sensor provided by the present invention, the electric resistance of the polyaniline in the ammonia-sensing material changes in proportion of the concentration of ammonia gas, and the change is sharp even at room temperature and accordingly the sensing portion can function at room temperature. Further, the ammonia sensor of the present invention can be easily produced simply by, for example, coating an ammonia-sensing material on a substrate having electrodes thereon, as shown in FIG. 1, can be made small, thin and lightweight, causes no trouble such as separation from electrodes, and is easy to handle and maintain. Furthermore, the ammonia sensor of the present invention shows excellent linear change of electric resistance to the change of ammonia gas concentration, has a high sensitivity, and allows easy designing of electronic circuit containing it.
Thus, the ammonia sensor of the present invention can be used effectively for automation of ammonia concentration control, leakage detection, warning signal, and operation stop in various plants; detection of protein and amino acid by using in combination with an enzyme or microbe producing ammonia gas in the form of metabolism of protein or amino acid; and detection of ammonia gas generated in various reactions, or control of reaction based on the detection.
The present invention is described more specifically by way of Examples and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a plan view of the ammonia sensor.
FIG. 1B is a sectional view taken along line a--a shown in FIG. 1A.
FIG. 2-7 are graphs showing the electric resistance of the ammonia sensor and ammonia concentration according to the present invention.
DETAILED DESCRIPTION
In the drawings, FIG. 1A and 1B are a schematic illustrations of an example of the ammonia sensor of the present invention, wherein the numeral 1 is a polyaniline membrane, the numeral 2 is an insulating substrate, the numeral 3 is interdigitated electrodes, and the numeral 4 is lead wires; FIGS. 2 to 7 are graphs each showing the relationship between the electric resistance of the ammonia sensor of the present invention and ammonia concentration.
EXAMPLE 1
40 g of ethanol, 30 g of propylene carbonate, 12 g of perchloric acid and 8 g of aniline were fed into an electrolytic cell (size=2 cm×2 cm), electrode-to-electrode distance=2 cm) wherein both the anode and the cathode are made of platinum. Then, electrolytic polymerization was effected for 10 minutes at a voltage of 0.7 V (relative to a standard calomel-alumel electrode), whereby a bluish black precipitate was formed. The precipitate was separated, washed with water until the pH of the washings became about 7, and vacuum dried at room temperature.
The resulting dry polyaniline was dissolved in N,N'-dimethylformamide to prepare a 10 weight % solution. The solution was spray coated on an alumina substrate having thereon a pair of interdigitated platinum electrodes (electrode width=100 μm, electrode-to-electrode distance=150 μm) as shown in FIG. 1, followed by drying to form a polyaniline film having a thickness of 10 μm.
The resulting ammonia sensor was set in a glass tube of 24 mm in diameter. Air was passed,through the glass tube from its one end at a rate of 1 g/min; a given amount of ammonia was intermittently injected into the air current; and the electric resistance of the sensor was measured. The results of the measurement are shown in FIG. 2.
EXAMPLE 2
An ammonia sensor was produced according to the same procedure as in EXAMPLE 1 except that the propylene carbonate (30 g) used in EXAMPLE 1 was replaced by 10 g of water.
The ammonia sensor was set in a closed vessel; 10 ppm of ammonia gas was injected to the vessel at intervals of 4 minutes; and the electric resistance of the sensor was measured. The results of the measurement are shown in FIG. 3.
EXAMPLE 3
An ammonia sensor was produced in the same procedure as in EXAMPLE 1 except that the pechloric acid (12 g) was replaced by 15 g of tetraethylammonium fluoroborate, was propylene carbonate (30 g) was replaced by 10 g of water and the platinum cathode was replaced by a palladium cathode.
The ammonia sensor was set in a closed vessel; the vessel was filled with air alone or air containing 10,000 ppm of H 2 , CO, NO or O 2 ; 10 ppm of ammonia was injected into the vessel at intervals of 4 minutes; the electric resistance of the sensor was measured; and there was prepared a graph showing the relationship between ammonia concentration (ppm) and electric resistance difference (R-R.). R is the measured value of electric resistance when ammonia was injected into air alone or air containing H 2 , CO, NO or O 2 ; and R. is the measured value of electric resistance when only air was used and no ammonia was present. The results are shown in FIG. 4. As is clear from FIG. 4, the electric resistance of the ammonia sensor of the present invention is not affected by the co-presence of gas other than ammonia.
EXAMPLE 4
A solution consisting of 10 parts by weight of a polyaniline, 10 parts by weight of sodium thiocyanate and 80 parts by weight of N,N'-dimethylformamide was spin coated on a 96% alumina substrate (1 cm×1.5 cm) having thereon a-pair of interdegitated electrodes (electrode width=150 μm electrode-to-electrode distance=150 m) as shown in FIG. 1, followed by drying to form a thin film of a conductive high-molecular substrate having a thickness of 5 μm.
Then, electrolytic polymerization of aniline was effected in an electrolytic cell using the above-mentioned substrate having a thin film as an anode and a platinum plate as a cathode (electrode-to-electrode distance=2.0 cm), under the following conditions.
Composition of polymerization solution: 1.8 moles of acetonitrile, 1 mole of
propylene carbonate, 0.5 mole of HClO 4 and 0.25 mole of aniline.
Voltage: 0.8 V (relative to a standard calomel-alumel electrode)
Current density: Constant current electrolysis at 20 mA/cm 2
Time: 10 minutes
After the completion of the electrolysis, the anode was taken out, washed with water until the pH of the washings became about 7, and dried at 50° C.
The resulting ammonia sensor was set in a glass tube having a diameter of 24 mm; air was passed through the tube from its one end at a rate of 1 l/min; a given amount of ammonia was intermittently injected into the air current; and the electric resistance of the sensor was measured. The results are shown in FIG. 5.
EXAMPLE 5
An ammonia sensor was produced in the same procedure as in EXAMPLE 4 except that the solution for forming a thin film of a conductive high polymer was changed to the following composition, i.e. a composition consisting of 7 parts by weight of a poly(ethylene oxide) (molecular weight=10,000), 3 parts by weight of lithium perchlorate and 90 parts by weight of water. The properties of the sensor were measured in the same manner as in EXAMPLE 4. The results are shown in FIG. 6.
EXAMPLE 6
An ammonia sensor was produced in the same procedure as in EXAMPLE 5 except that the acetonitrile (1.8 moles) used in the polymerization solution was changed to 2.0 moles of water. This ammonia sensor had about the same properties as the ammonia sensor produced in EXAMPLE 5.
EXAMPLE 7
A solution consisting of 6 parts by weight of an acrylamide-methylpropanesulfonic acid copolymer, 2 parts by weight of a poly(vinyl alcohol) and 92 parts by weight of water was dip coated on the same alumina substrate having a pair of electrodes thereon, as used in EXAMPLE 4, followed by drying at 130° C. to form a think film of a conductive high polymer having a thickness of 10 μm. A Using this substrate having a thin film, as an anode, electrolytic polymerization was effected in the same manner as in EXAMPLE 4 to obtain an ammonia sensor. The properties of this ammonia sensor were measured in the same manner as in EXAMPLE 4. The results are shown in FIG. 7.
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An ammonia sensor consisting of at least one pair of electrodes and an ammonia-sensing material comprising a polyaniline filling the space between the electrodes.
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GOVERNMENT SUPPORT
This invention was made with government support under Contract Number MDA-972-92-J-1083 awarded by the Advanced Research Projects Administration. The government has certain rights in the invention.
FIELD OF THE INVENTION
The invention relates generally to the field of optical storage and optical pulse pattern generation. In particular, the invention relates to optical memories, buffers, and signal generating devices which are useful for optical processing and optical switching systems, and to methods of optical data storage and pattern generation.
BACKGROUND OF THE INVENTION
Optical memories and optical random and pseudo-random pattern generators are important components for optical communication and computing systems such as ultra-high-speed, time-domain, multiplexing, multi-access optical networks. Such devices are useful for performing a variety of functions, including storing data packets during dock recovery, processing of headers, and data rate conversions. Also, optical memory is required for bandwidth-on-demand systems while users wait for access to the network.
Short-term optical data storage has been demonstrated in optical memories. For example, U.S. Pat. No. 4,473,270 discloses an optical circulating loop useful for a short-term optical memory. Data is loaded into the circulating loop and is preserved during multiple circulations in the loop. The data signals are readable until they are attenuated. Because there is no amplification in the loop to compensate for loss, the data signals rapidly attenuate.
U.S. Pat. Nos. 4,738,503 and 4,923,267 disclose an optical circulating loop which includes an amplifier to partially compensate for losses in the loop. The amplifier, however, must operate with a net round trip loss, otherwise noise can build to a large steady-state value. In addition, laser oscillation will occur and destroy the data pattern.
Researchers have discovered that lossless circulation in an optical circulating loop can be achieved by incorporating bistability in the circulating path. J. D. Moores, "On the Ginzburg-Landau Laser Modelocking Model with Fifth Order Saturable Absorber Term," Opt. Comm., vol. 96, pp 65-70, February 1993, H. A. Haus, E. P. Ippen, and K. Tamura, "Additive Pulse Modelocking In Fiber Lasers," IEEE J. Quant. Elec., vol 30 pp. 200-208, January 1994. Bistability introduces different round trip losses for high intensity and low intensity signals. Thus, the bistability amplifies and maintains optical pulses with higher energy and attenuates optical pulses with lower energy.
Storage time in circulating loops having lossless circulation is restricted by propagation limitations. Mechanisms which contribute to propagation imitations include the Gordon-Haus effect, Raman self-frequency shift, and third-order fiber dispersion. J. D. Moores, W. S. Wong, and H. A. Haus, "Stability and Timing Maintenance in Soliton Transmission and Storage Rings", Opt. Comm., 113, p. 153, (1994).
The Gordon-Haus effect is a noise-imparted propagation limitation which occurs when spontaneous emission noise from amplifiers shifts the frequency and thus, the velocity of an optical pulse through group velocity dispersion. These random velocity shifts result in timing errors. The timing errors limit the achievable bandwidth-transmission distance product. In optical memories, the Gordon practical storage time of the memory.
Raman self-frequency shift is another propagation imitation which occurs with short-pulse transmissions and is due to the fad that the pulse frequency shifts with propagation distance at a rate proportional to the squared pulse bandwidth and the intensity. Noise-imparted fluctuations in pulse photon number and pulse width alter the rate of Raman sell-frequency shift of a pulse, or equivalently, alter the rate at which the inverse group velocity changes with distance and result in additional timing errors. This Raman effect is a serious limitation for high-speed long-distance transmissions and long-term storage.
Third order dispersion also limits propagation and storage time. Classically, it leads to distortion of pulses, including solitons. Furthermore, noise-imparted fluctuations in pulse bandwidth result in timing jitter. Other effects which may limit propagation and storage time include electrostriction and inter-pulse interactions. P Researchers have discovered that these propagation limitations can be overcome by incorporating a stabilizing element in the circulating loop. This allows long-term storage without pulse degradation, timing jitter or photon number fluctuations. C. R. Doerr, W. S. Wong, H. A. Haus and E. P. Ippen, "Additive-Pulse Mode-locking/Limiting Storage Ring"; Opt. Lett., 19, p. 1747, (1994). Prior art stabilizing elements utilize electronic or electro-optic devices modulated by an electrical signal to control optical transmission within the circulating loop. The data rate in the circulating loop is limited by the bandwidth of the electronic or electro-optic devices. Unfortunately, the bandwidth of these devices limits the data rate in the circulating loop to around 10-20 GHz.
It is therefore a principal object of this invention to provide a circulating loop memory in which the stabilizing element is all-optical and, therefore, is not limited by the bandwidth of electronic or electro optic devices. It is another object of this invention to provide an all-optical stabilizing element that utilizes known ultrafast optical transmission nonlinearities of semiconductor amplifier devices. Such a stabilizing element allows the storage of a high-speed optical data pattern for long periods of time. It is another object of this invention to provide a monolithically integrated all-optical memory suitable for a compact optical communication system. It is another object of this invention to provide an optical pattern generator for producing high-speed optical random and pseudo-random signals.
SUMMARY OF THE INVENTION
A principle discovery of the present invention is that an optical memory and an optical random and pseudo-random pattern generator can be constructed with an all-optical stabilizing element that utilizes known ultrafast optical transmission nonlinearities of semiconductors. These nonlinearities include carrier-density-induced absorption saturation, carrier-density-induced gain saturation, spectral hole burning, carrier heating, and two-photon absorption.
Because the memory is all-optical, the data rate is not limited to the bandwidth of electronic or electro-optic devices. Data rates in an optical loop with all-optical stabilization can exceed 100 GHz. Such a memory element is advantageous for optical communications, where optical control signals are already present or easily generated and where electrical control signals may require additional hardware.
Accordingly, the present invention features an optical memory and an optical random and pseudo-random pattern generator which incorporates optical amplitude modulation for timing stability and nonlinear polarization rotation for bistability. In one embodiment, an optical memory includes an optical ring resonator having a circulating optical path for sustaining a data stream comprising high and low intensity optical signals. The resonator may include at least three reflecting members, a length of optical fiber that closes back onto itself to form a loop, or a monolithically integrated optical waveguide that closes back onto itself to form a loop.
An optical alter may be disposed within the optical path for optical stability and wavelength selection. A dispersion element may be disposed within the optical path for controlling total dispersion in the optical path in the ring resonator. A unidirectional element may be disposed within the optical path for restricting the direction of propagation of the optical signals.
An optical amplifier is disposed in the optical path of the ring resonator for amplifying the optical signals. The optical amplifier may be a semiconductor amplifier or a fiber amplifier disposed in the optical path. The fiber amplifier may be any rare-earth doped fiber amplifier.
A bistability generator is also disposed in the optical path of the ring resonator. The bistability generator simultaneously provides lossless circulation in the optical path for the high intensity optical signals and net loss circulation for both the low intensity optical signals and any amplified spontaneous emission signals. The bistability generator may be an intensity-dependent loss element. The intensity-dependent loss element may include a polarization rotation generator for providing rotation proportional to intensity and a polarization selective element for selecting only a certain polarization. The polarization rotation generator may be an optical fiber, a bulk optic Kerr medium, or a semiconductor. In addition, the intensity-dependent loss element may include one or more polarization state controllers. The polarization selective element and the polarization state controllers are configured to control the intensity dependent loss.
An optically-controlled stabilizing element is also disposed in the optical path of the ring resonator for providing signal timing stability. The optically controlled stabilizing element also may determine the repetition rate for the data stream in the optical ring resonator and may compensate for timing jitter. Further, the optically-controlled stabilizing element may provide pulse width stability and signal amplitude stability. The optically controlled stabilizing element may be an amplitude-modulated, a phase-modulated, or a frequency-modulated transmission element. The transmission element may be a modulated semiconductor amplifier. The semiconductor amplifier may be modulated by cross-gain saturation, cross-phase modulation, or by four-wave mixing. Optical control for the stabilizing element may be provided by an optical signal generator, an optical pulse source, or an input data source.
The optical memory also includes a coupling element which communicates with the optical path for coupling signals out of the ring resonator. The coupling element may be an optical coupler or switch, which couples the optical signals out of the resonator. In addition, the coupling element may be an optical coupler or switch, which couples the optical signals into and out of the resonator. The coupling element may input optical signals from an optical data source into the ring resonator.
In another embodiment, an optical pattern generator includes an optical ring resonator, having a circulating optical path for sustaining a data stream comprising high and low intensity optical signals. The resonator may be constructed from at least three reflecting members, a length of optical fiber that doses back onto itself to form a loop, or a monolithically integrated optical waveguide that closes back onto itself to form a loop. An optical filter may be disposed within the optical path for optical stability and wavelength selection. A dispersion element may be disposed within the optical path for controlling total dispersion in the optical path in the ring resonator. A unidirectional element may be disposed within the optical path for restricting the direction of propagation of the optical signals.
An optical amplifier having spontaneous emission noise is disposed in the optical path of the ring resonator for amplifying the spontaneous emission noise to generate and sustain a data pattern. The optical amplifier may be a fiber amplifier disposed in the optical path. The fiber amplifier may be any rare-earth doped fiber amplifier. The amplifier may also be a semiconductor amplifier.
A bistability generator is also disposed in the optical path of the ring resonator, which simultaneously provides lossless circulation in the optical path for the high intensity optical signals and net loss circulation for both the low intensity optical signals and any amplified spontaneous emission signals. The bistability generator may be an intensity-dependent loss element. The intensity-dependent loss element may include a polarization rotation generator for providing rotation proportional to intensity and a polarization selective element for allowing only a certain polarization in the optical path. The polarization rotation generator may be an optical fiber, a bulk optic Kerr medium, or a semiconductor. In addition, the intensity-dependent loss element may include one or more polarization state controllers. The polarization selective element and the polarization state controllers are configured to control the intensity dependent loss.
An optically-controlled stabilizing element may be disposed in the optical path of the ring resonator for providing amplitude and pulse width signal timing stability. The optically-controlled stabilizing element also may determine the repetition rate for the data stream in the optical ring resonator and may compensate for timing jitter. Further, the optically-controlled stabilizing element may provide pulse width stability and signal amplitude stability. The optically-controlled stabilizing element may be an amplitude-modulated, a phase-modulated, or a frequency-modulated transmission element. The transmission element may be a semiconductor amplifier. The semiconductor amplifier may be modulated by cross-gain saturation, cross-phase modulation, or by four-wave mixing. Optical control for the stabilizing element may be provided by an optical signal generator, an optical pulse source, or an input data source.
The optical random pattern generator also includes a coupling element, which communicates with the optical path for coupling signals out of the ring resonator. The coupling element may be an optical coupler or a switch, which couples the optical signals out of the resonator. In addition, the coupling element may be an optical coupler or a switch, which couples the optical signals into and out of the resonator. The coupling element may input optical signals from an optical data source into the ring resonator.
In another embodiment, the optical pattern generator also includes a coupling element which communicates with the optical path and couples a predetermined data pattern into the ring resonator in order to seed the optical pattern generator. In this embodiment, the optical pattern generator includes an optical switch disposed in the optical path of the ring resonator for altering the data pattern.
In another embodiment, a monolithically integrated optical memory includes a ring resonator that is formed from an optical waveguide which is monolithically integrated into a substrate. The substrate may be a semiconductor or a lithium niobate substrate. The waveguide forms a circulating optical path for sustaining a data stream comprising high and low intensity optical signals. A unidirectional element may be monolithically integrated into the substrate so that it is disposed in the optical path of the ring resonator. The unidirectional element restricts the direction of the optical signals.
An optical amplifier for amplifying the optical signals is monolithically integrated into the substrate so that it is disposed in the optical path of the ring resonator. A bistability generator is monolithically integrated into the substrate so that it is disposed in the optical path of the ring resonator. The bistability generator simultaneously provides lossless circulation in the optical path for the high intensity optical signals and net loss circulation for both the low intensity optical signals and any amplified spontaneous emission signals. An optically-controlled stabilizing element is monolithically integrated into the substrate so that it is disposed in the optical path of the ring resonator. The stabilizing element provides timing signal stability.
A coupling element is monolithically integrated into the substrate so that it communicates with the optical path and couples the optical signals in and out of the ring resonator. The coupling element may be an optical coupler or a switch.
In another embodiment, an optical memory utilizes a single nonlinear element for generating optical amplification, bistability, and timing signal stability. The nonlinear element is disposed in the optical path of the ring resonator. The nonlinear element includes an amplifier for amplifying the optical signals, a bistability generator, and an optically controlled stabilizing element for providing timing signal stability.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages of the invention will become apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings. The drawings are not necessarily to scale, emphasis instead being placed on illustrating the principles of the present invention.
FIG. 1 is one embodiment of an optical memory which incorporates an optically-controlled stabilizing element.
FIG. 2 is another embodiment of an optical memory which incorporates an all-optical stabilizing element wherein the ring resonator comprises an optical fiber that closes back onto itself to form a loop.
FIG. 3 is another embodiment of the present invention which is a monolithically integrated optical memory.
FIG. 4 is one embodiment of an optical random pattern generator which generates random or pseudo-random optical signals from noise.
FIG. 5 illustrates storage of a data pattern generated from noise in a ring resonator similar to FIG. 4.
FIG. 6 illustrates a portion of the measured R.F. spectrum for a stored pseudo-random word generated by a ring resonator similar to FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is one embodiment of an optical memory which incorporates an optically-controlled stabilizing element in accordance with the principles of the invention. An optical memory 10 is constructed from an optical ring resonator 12 having a circulating optical path 14 for sustaining a data stream comprising high and low intensity optical signals. The ring resonator 12 may be constructed from at least three reflecting members, a length of optical fiber that doses back onto itself to form a loop, or a monolithically integrated optical waveguide that closes back onto itself to form a loop. A unidirectional element 16 is disposed within the optical path 14 for restricting the direction of propagation of the optical signals. The unidirectional element 16 need not be a separate element it may be part of another element disposed in the optical path 14. An optical filter 18 may be disposed in the optical path for providing optical stability and wavelength selection. A dispersion element 19 may be disposed within the optical path 14 for controlling total dispersion in the ring resonator 12.
An optical amplifier 20 is disposed in the optical path 14 of the ring resonator 12 for amplifying the optical signals. The optical amplifier 20 may be a fiber amplifier or semiconductor amplifier. Any rare-earth doped fiber amplifier such as an erbium, praseodymium, ytterbium-erbium or thulium doped fiber amplifier may be used.
A bistability generator 22 is disposed in the optical path 14 of the ring resonator 12. The bistability generator 22 maintains the intensity of the pulses and reduces timing jitter. More specifically, the bistability generator 22 simultaneously provides lossless circulation in the optical path 14 for high intensity optical signals and net loss circulation for both low intensity optical signals and any amplified spontaneous emission signals. That is, low intensity optical signals are suppressed while high intensity signals see unity round-trip gain thus, forcing the high intensity signals to a fixed amplitude.
In one embodiment, the bistability generator 22 is an intensity-dependent loss element which comprises a polarization selective element 24 and a polarization rotation generator 26. The polarization selective element 24 passes only a certain polarization. The polarization rotation generator 26 provides nonlinear polarization rotation proportional to the intensity of the optical signals. The polarization rotation generator 26 may comprise materials such as optical fibers, bulk optic Kerr media, or semiconductors. In one embodiment, the polarization rotation generator 26 is an optical fiber comprising the optical ring resonator 12.
In addition, the bistability generator 22 may include one or more polarization state controllers 28 to adjust the polarization of the optical signal to an optimum polarization. The polarization selective element 24 together with the polarization state controllers 28 control the intensity dependent loss.
An optically-controlled stabilizing element 30 is disposed in the optical path 14 of the ring resonator 12. The optically controlled stabilizing element 30 may determine the repetition rate for the data stream in the optical ring resonator 12 and may compensate for timing jitter. Further, the optically controlled stabilizing element may provide pulse width stability and signal amplitude stability.
The optically controlled stabilizing element 30 may be an amplitude-modulated, a phase-modulated, or a frequency-modulated transmission element. The transmission element may be a modulated semiconductor amplifier. Semiconductor transmission elements are advantageous because semiconductors exhibit known ultrafast optical transmission nonlinearities. These nonlinearities cause transmission changes due to optical control signals in the amplifier. For example, carrier-density-induced absorption saturation occurs in semiconductors when a semiconductor amplifier is biased in the absorption regime. Carrier-density-induced gain saturation occurs in semiconductors when a semiconductor amplifier is biased in the gain regime. Spectral hole burning may also occur in semiconductors which increases transmission during absorption and decreases transmission during gain. Carrier heating occurs in semiconductors and reduces the transmission during both absorption and gain. Also, two-photon absorption occurs in semiconductors and reduces transmission.
An optical signal generator 32 modulates the stabilizing element 30. Modulation of the optically-controlled stabilizing element 30 can be achieved by numerous mechanisms including cross-gain saturation, cross-phase modulation, and four-wave mixing. The optical signal generator 32 may be an optical signal generator, an optical pulse source, or an input data source.
The optical memory includes a coupling element 34 which communicates with the optical path 14 for coupling signals out of the ring resonator 12. The coupling element may be a coupler or a switch which couples the optical signals out of the ring resonator 12. The coupling element may be an optical coupler or a 1×2 switch. In addition, the coupling element 34 may be a coupler or a switch which couples the optical signals into and out of the resonator. The coupling element may be an optical coupler or a 2×2 switch. In addition, the coupling element 34 may input optical signals from an optical data source 36 into the ring resonator 12.
In another embodiment of the present invention, a single nonlinear element 38 is utilized to generate optical amplification, bistability, and timing signal stability. The nonlinear element 38 is disposed in the optical path 14 of the ring resonator 12. The nonlinear element 38 includes the optical amplifier 20 for amplifying the optical signals, a bistability generator 22, and an optically controlled stabilizing element 30 for providing timing signal stability.
FIG. 2 is another embodiment of an optical memory, featuring an all-optical stabilizing element. A ring resonator comprises an optical fiber 50 configured to form a closed fiber loop 52 of a fixed length which defines a fundamental cavity frequency. The fiber 50 may be single mode fiber such as SMF-28 fiber. A polarization-sensitive isolator 53 disposed in the loop 52 restricts propagation of optical signals in the fiber 50 to one direction. A coupler 54 communicating with the loop 52 is utilized to couple a portion of the optical signals propagating in the fiber out of the fiber 50. The coupler 54 may also be utilized to couple optical signals into the fiber 50.
A fiber amplifier 56 disposed in the loop 52 is used to amplify optical signals propagating in the loop 52. The fiber amplifier 56 may comprise a highly-doped rare-earth fiber and a pump laser coupled to the doped rare-earth fiber by a wavelength division multiplying coupler (not shown). Examples of rare-earth doped fibers are erbium, praseodymium, ytterbium-erbium or thulium doped fiber. For example, an erbium-doped fiber amplifier may be pumped by a master oscillator power amplifier (MOPA) at 980 nm.
The optical memory includes a bistability generator 58 disposed in the loop 52 for providing intensity-dependent loss. The bistability generator 58 comprises a polarization selective element 60 and a polarization rotation generator 62 disposed in the loop 52. The polarization selective element 60 allows only a certain polarization in the fiber 50. The polarization rotation generator 62 utilizes a portion of the optical fiber 64 to achieve polarization rotation proportional to intensity. Alternatively, the entire optical fiber 50 may be used to achieve polarization rotation proportional to intensity. In addition, the bistability generator 58 includes one or more polarization controllers 65 which control the polarization states of the optical signals in the fiber 50. Waveplates 66 disposed in the loop 52 may also be used to control the polarization states of the optical signals in the fiber 50.
An optically-controlled stabilizing element 68 is disposed in the loop 52. The stabilizing element 68 is a semiconductor amplifier. The semiconductor amplifier may be a commercially available high-power laser diode with antireflection coating on both facets 70,72. Coupling into and out of the laser amplifier may be achieved by fiber microlenses (not shown).
A control laser 74 and a modulator 76 are utilized to control the stabilizing element 68. The control laser 74 generates an optical control beam 78 and the modulator 76 amplitude modulates the optical beam 78 to create a modulated control beam. The control laser 74 may be a semiconductor diode laser. The modulator may be a LiNbO 3 amplitude modulator.
The optical control beam 78 may be coupled to the fiber 50 by a polarization beamsplitting cube 80 and lenses 82. A fiber coupler (not shown) may be used instead of the beamsplitting cube 80 and lenses 82. A typical optical power for achieving cross-saturation in the semiconductor amplifier is approximately 1 mW. The control beam 78 may be coupled out of the fiber 50 by a wavelength division multiplexing coupler 84 or may be absorbed in the fiber amplifier 56.
The use of the control laser 74 and the amplitude modulator 76 to cross-saturate the gain of the semiconductor amplifier is advantageous because it allows high data rates without the use of a short pulse laser source. Optical signals that are modulated are potentially easier to generate, and more widely tunable in rate and in frequency, than are signals generated by modelocked sources. In addition, optical signals may simplify the access node design because the incoming optical clock or data stream could be used to synchronize the optical memory to the network data rate.
An all-optical memory incorporating the the control laser 74 and the amplitude modulator 6 to cross-saturate the gain of the semiconductor amplifier for timing stability has achieved storage of a 1.25 kbit packet at 10 Gb/s with a data pattern spontaneously generated from noise. The gain was modulated optically at rates exceeding 10 GHz. Modulation rates may be extended to the 100 GHz range by using soliton optical modulation sources, and by taking advantage of enhanced recovery rates and high-speed nonlinearities, such as carrier heating in the diode amplifiers.
Another embodiment of the present invention is a monolithically integrated optical memory shown in FIG. 3. Such a device is advantageous because it is potentially much smaller in size and is directly compatible with other integrated optical devices. The monolithically integrated optical memory 100 has a ring resonator 102 formed from an optical wave guide 104 and mirrors 105 which are monolithically integrated into a substrate 106. The substrate 106 may be a semiconductor or a lithium niobate substrate. The waveguide 104 forms a circulating optical path 108 for sustaining a data stream comprising high and low intensity optical signals. A unidirectional element 110 is monolithically integrated into the substrate 106 so that it is disposed in the optical path 108 of the ring resonator 102. The unidirectional element 110 restricts the direction of the optical signals.
An optical amplifier 112 for amplifying the optical signals is monolithically integrated into the substrate 106 so that it is disposed in the optical path 108 of the ring resonator 102. A bistability generator 114 is monolithically integrated into the substrate 106 so that it is disposed in the optical path 108 of the ring resonator 102. The bistability generator 114 simultaneously provides lossless circulation in the optical path 108 for the high intensity optical signals and net loss circulation for both the low intensity optical signals and any amplified spontaneous emission signals.
An optically controlled stabilizing element 116 is monolithically integrated into the substrate 106 so that it is disposed in the optical path 108 of the ring resonator 102. The stabilizing element 116 provides timing signal stability. The stabilizing element 116 may be a semiconductor amplifier. An optical signal generator (not shown) for modulating the stabilizing element 116 is coupled to the stabilizing element 116 by a coupler 120. Modulation of the optically-controlled stabilizing element 116 can be achieved by numerous mechanisms including cross-gain saturation, cross-phase modulation, and four-wave mixing. The optical signal generator may be an optical signal generator, an optical pulse source, or an input data source
A coupling element 118 is monolithically integrated into the substrate 106 50 that it communicates with the optical path 108 and couples the optical signals in and out of the ring resonator 102. The coupling element may be an optical coupler or a switch that is monolithically integrated into the substrate 106.
FIG. 4 is one embodiment of an optical pattern generator which generates random optical signals from noise. An optical pattern generator 150 is constructed from an optical ring resonator 152 having a circulating optical path 154 for sustaining a data stream comprising high and low intensity optical signals. The ring resonator 152 may be constructed from at least three reflecting members, a length of optical fiber that closes back onto itself to form a loop, or a monolithically integrated optical waveguide that closes back onto itself to form a loop. A unidirectional element 156 is disposed within the optical path 154 for restricting the direction of propagation of the optical signals. An optical filter 158 is disposed within the optical path for optical stability and wavelength selection. A dispersion element 160 is disposed within the optical path 154 for controlling total dispersion in the ring resonator 152.
An optical amplifier 162 having spontaneous emission noise is disposed in the optical path 154 of the ring resonator 152 for amplifying the spontaneous emission noise to generate the data pattern. The optical amplifier 162 may be a fiber amplifier (not shown) disposed in the optical path 154. The fiber amplifier may be any rare-earth doped fiber amplifier such as an erbium, praseodymium, ytterbium-erbium or thulium doped fiber amplifier. The optical amplifier 162 may also be a semiconductor amplifier.
A bistability generator 164 is also disposed in the optical path 154 of the ring resonator 152. As described in connection with FIG. 1, the bistability generator maintains the intensity of optical pulses circulating in the ring resonator 152 and reduces timing jitter. The bistability generator 164 simultaneously provides lossless circulation in the optical path 154 for high intensity optical signals and net loss circulation for both low intensity optical signals and any amplified spontaneous emission signals.
In one embodiment, the bistability generator 164 is an intensity-dependent loss element which comprises a polarization selective element 166 and a polarization rotation generator 168. The polarization selective element 166 allows only a certain polarization in the optical path 154. The polarization rotation generator 168 provides nonlinear polarization rotation proportional to the intensity of the optical signals. The polarization rotation generator 168 may comprise materials such as optical fibers, bulk optic Kerr media, or semiconductors.
In addition, the bistability generator 164 may include one or more polarization state controllers 170 to adjust the polarization of the optical signal to an optimum polarization. The polarization selective element 166 together with the polarization state controllers 170 control the intensity-dependent loss.
An optically controlled stabilizing element 172 may be disposed in the optical path 154 of the ring resonator 152. The optically-controlled stabilizing element 172 may determine the repetition rate for the data stream in the optical ring resonator 152 and may compensate for timing jitter. Further, the optically controlled stabilizing element may provide pulse width stability and signal amplitude stability.
The optically-controlled stabilizing element 172 may be an amplitude-modulated, a phase-modulated, or a frequency-modulated transmission element. The transmission element may be a modulated semiconductor amplifier. As described in connection with FIG. 1, semiconductor transmission elements are advantageous because semiconductors exhibit known ultrafast optical transmission nonlinearities.
Modulation of the optically-controlled stabilizing element 172 can be achieved by numerous techniques including cross-gain saturation, cross-phase modulation and four-wave mixing. An optical signal generator 174 provides optical control for the stabilizing element 172. The optical signal generator 174 may be an optical signal generator, an optical pulse source, or an input data source.
The optical memory includes a coupling element 176 which communicates with the optical path 154 for coupling generated optical patterns into and out of the ring resonator 152. The coupling element 176 may be a coupler or a switch which couples the optical signals out of the ring resonator 152. The coupling element 176 may be an optical coupler, a 1×2 switch or a 2×2 switch.
The present invention also features an optical pattern generator for generating pseudo-random optical signals from noise. The pattern generator includes an optical ring resonator, an optical amplifier, and a bistability generator which corresponds to the pattern generator described in connection with FIG. 4. In addition, the coupling element 176 couples a predetermined data pattern into the ring resonator 152 in order to seed the pattern generator. The pattern generator may also include an optical switch 178 disposed in the optical path of the ring resonator for altering the data pattern.
The coupling element 176 be a coupler or a switch which couples the optical signals into and out of the ring resonator 152. The coupling element 176 may be an optical coupler or a 2×2 switch. In addition, the coupling element 176 may input optical signals from an optical data source 180 into the ring resonator 152.
In another embodiment of the present invention, a single nonlinear element 190 is utilized to generated optical amplification, bistability, and timing signal stability. The nonlinear element 190 is disposed in the optical path 154 of the ring resonator 152. The nonlinear element 190 includes the optical amplifier 162 for amplifying the optical signals, a bistability generator 164, and an optically-controlled stabilizing element 172 for providing timing signal stability.
FIG. 5 illustrates storage of data pattern generated from noise in a ring resonator similar to the configuration shown in FIG. 2 and FIG. 4. The displayed dab pattern is 21 bits long which corresponds to a 2 ns time window. The data rate is 10.6 GHz. The data were detected by a 45 GHz bandwidth photodiode and were displayed on a digital sampling oscilloscope with a 50 GHz bandwidth. The oscilloscope was triggered at the fundamental cavity frequency of the ring resonator. The density of ONE bits in the data pattern is a function of the average gain in the closed fiber loop and the polarization bias of the fiber. The data patterns were stored for several minutes. Unlike prior art optical memories, the storage time is not limited.
FIG.6 shows a portion of the measured R.F. spectrum for a stored pseudo-random word. The portion is centered at 10.6 GHz and has a total span of 100 MHz. The observed sidebands are spaced by the period of the cavity round-trip and are constant while the data pattern is stored. Storage of higher data rates can be achieved by optimizing the loop parameters such as, total dispersion in the loop given the optical data rate and the average power and the optical amplifier bias points and recovery rates.
EQUIVALENTS
While the invention has been particularly shown and described with reference to specific preferred embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. For example, although a particular placement of components in the optical path is illustrated in FIGS. 1-4, it is noted that other placements of components may be used without departing from the spirit and scope of the invention.
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An optical memory and an optical random and pseudo-random pattern generator for ultra-high-speed time-domain multiplexing multi-access networks are described. The optical memory and pattern generators include an optical ring resonator, an optical amplifier, a bistability generator, an optically-controlled stabilizing element, and a coupling element. Such devices are capable of storing high data rates for long periods of time.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of priority from the prior Taiwan Patent Application No. 97120430, filed on Jun. 02, 2008, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to an amphiphilic copolymer and method for fabricating the same, and an amphiphilic copolymer serving as a solubilizing agent and method for fabricating the same.
[0004] 2. Description of the Related Art
[0005] Thermoplastic elastomers are used extensively as the polymeric component of hot melt and pressure sensitive adhesives. In general, the elastomers are multicomponent polymers, and are molten above the glass transition temperature or melt temperature of the hard polymeric phase, and aggregated below the temperatures into domains that behave like physical crosslinks.
[0006] Polylactide (PLA) is a thermoplastic polyester serving as a regenerative biomass polymer material, and can be prepared from polymerization of lactic acid yielded from cornstarch by homofermentation. Due to superior transparency, rigidity, and UV-resistance, polylactide is the only one competitive biodegradable polymer for conventional petrochemical plastics. In comparison with polystyrene, the mechanical attributes of polylactide is equal to that of polystyrene. However, the impact resistance and toughness attributes of polylactide is worse than that of polystyrene.
[0007] In order to improve the impact resistance and toughness of polylactide and facilitate applications thereof, a conventional method comprises performing a blending of thermoplastic polyolefin elastomer (TPO) and polylactide, resulting in the introduction of soft bonds of thermoplastic polyolefin elastomer.
[0008] As used herein, the term “blending” refers to physically mixing at least two polymers to conveniently prepare a novel polymer material. The performance of the obtained novel polymer material depends on the compatibility between the at least two polymers. However, the majority of blended materials, result in phase separation. Please refer to FIG. 1 , the sample bottle (a) shows that thermoplastic polyolefin elastomer (TPO) and polylactide dissolved in ethyl acetate are non-miscible resulting from phase separation, since thermoplastic polyolefin elastomer (TPO) is a non-polar polymer and polylactide is a polar polymer. Therefore, the mechanical characteristics of the obtained novel polymer are degraded.
[0009] Accordingly, it is necessary to develop a novel method to improve the intersolubility between polymers, enhancing physical and mechanical properties, to facilitate applications and mass production.
BRIEF SUMMARY OF THE INVENTION
[0010] An exemplary embodiment of an amphiphilic copolymer comprises: a polar block derived from polylactide; and a nonpolar block derived from thermoplastic polyolefin elastomer, wherein the polar block is connected to the nonpolar block via a moiety derived from maleic anhydride. The amphiphilic copolymer can serve as a solubilizing agent for improving the intersolubility during polymer blending. The polylactide has the structure represented by formula (I).
[0000]
[0011] wherein, R 1 is H, CH 3 , or CH 2 CH 3 .
[0012] The thermoplastic polyolefin elastomer comprises styrene-butadiene copolymer, ethylene-octene copolymer, ethylene-butene copolymer, ethylene-butadiene copolymer, or ethylene propylene diene monomer rubber, and the maleic anhydride has the structure represented by formula (II).
[0000]
[0013] Another exemplary embodiment a method for fabricating an amphiphilic copolymer comprises: bonding a maleic anhydride to a nonpolar polymer via an initiator to prepare a nonpolar polymer with maleic anhydride branches; and reacting a polar polymer and the nonpolar polymer with maleic anhydride branches undergoing esterification in the presence of a catalyst, wherein the nonpolar polymer comprises polylactide and a nonpolar block is derived from thermoplastic polyolefin elastomer. The initiator can comprise a free-radical initiator, such as benzoyl peroxide, azobisisobutyronitrile, acetyl peroxide, t-Butyl peracetate, cumyl peroxide, t-Butyl peroxide, or t-Butyl hydroperoxide. The catalyst comprises 4-dimethylaminopyridine, triethylamine, or pyridine.
[0014] Further, in some exemplary embodiments of the invention, a composition of blended polymers is provided. The composition comprises a polar polymer; a nopolar polymer; and a solubilizing agent, wherein the solubilizing agent comprises the aforementioned amphiphilic copolymer. Particularly, the polar polymer comprises polylactide, polyglycolide, or polycaprolactone, and the polar polymer comprises thermoplastic polyolefin elastomer, polyethylene, polypropylene, or polybutadiene. The weight ratio of the solubilizing agent is 0.1-20 wt %, based on the weight of the polar and nopolar polymers.
[0015] A detailed description is given in the following embodiments with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
[0017] The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
[0018] FIG. 1 is a photograph showing the intersolubility of sample bottle (a) and sample bottle (b).
[0019] FIG. 2 is a FT-IR spectrum of the amphiphilic copolymer prepared from Example 1.
[0020] FIG. 3 a is a TEM spectrum showing the cryo-fracture surface observation of the polymer formed from composition A of Example 2.
[0021] FIG. 3 b is a TEM spectrum showing the cryo-fracture surface observation of the polymer formed from composition A of Example 2.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
[0023] Preparation of Amphiphilic Copolymer
EXAMPLE 1
[0024] 15 g ethylene-octene copolymer (serving as TPO) was dissolved in 175 ml toluene (serving as solvent). After stirring completely, 0.438 g benzoyl peroxide (BPO, serving as initiator) and 0.765 maleic anhydride (MAH) were added into the above solution, thereby obtaining TPO with maleic anhydride branches (TPO-MAH).
[0025] Next, 9.7 g 4-dimethylaminopyridine (DMAP, serving as catalyst), 15 g poly(D,L-lactide), and 7.5 g the obtained TPO-MAH were mixed in 100 ml toluene, and TPO-g-PLA was yielded. FIG. 2 shown a FT-IR spectrum of TPO-g-PLA prepared from Example 1. The FT-IR spectrum has a strong peak at 1764 cm-1 meaning that poly(D,L-lactide) was bonded on the ethylene-octene copolymer via maleic anhydride.
[0026] Preparation of Composition Comprising Polylactide and Thermoplastic Polyolefin Elastomer
EXAMPLE 2
[0027] 16 g poly(D,L-lactide), 4 g ethylene-octene copolymer, and 1 g TPO-g-PLA (prepared from Example 1) were dissolved in 5 ml ethyl acetate (the weight ratio of the PLA, TPO, and amphiphilic copolymer was 80:20:5), obtaining a composition A. Please refer to FIG. 1 , the composition A in the sample bottle (b) formed a homogeneous phase (thermoplastic polyolefin elastomer (TPO) and polylactide were mutually soluble) since the TPO-g-PLA served as a solubilizing agent.
EXAMPLE 3
[0028] Example 3 was performed as Example I to obtain composition (B) except for substitution of 16 g poly(D,L-lactide), and 4 g ethylene-octene copolymer for 32 g poly(D,L-lactide), and 8 g ethylene-octene copolymer. Particularly, the weight ratio between the PLA, TPO, and amphiphilic copolymer was 80:20:2.5.
EXAMPLE 4
[0029] Example 4 was performed as Example 1 to obtain composition (B) except for substitution of 16 g poly(D,L-lactide), and 4 g ethylene-octene copolymer for 80 g poly(D,L-lactide), and 20 g ethylene-octene copolymer. Particularly, the weight ratio between the PLA, TPO, and amphiphilic copolymer was 80:20:1.
COMPARATIVE EXAMPLE 1
[0030] 8g poly(D,L-lactide) and 2 g ethylene-octene copolymer were dissolved in 5 ml ethyl acetate, obtaining composition D.
[0031] Cryo-Fracture Surface Observation
EXAMPLE 5
[0032] The polymers formed from composition A and composition D were respectively subjected to cryo-fracture surface observation by transmission electron microscopy (TEM), and the results were respectively shown in FIGS. 3 a and 3 b . As shown in FIG. 3 b , the polymer formed by composition D (without TPO-g-PLA) had a dispersed particular size of 5 μm. To the contrary, as shown in FIG. 3 a , the polymer formed by composition A (with TPO-g-PLA as a solubilizing agent) had a dispersed particular size of 2 μm.
[0033] Tests of Elongation at Break and Impact Resistance
EXAMPLE 6
[0034] The polymer samples formed from poly(D,L-lactide), composition D, and composition A were respectively subjected to tests of elongation at break and impact resistance, and the results are shown in Table 1.
[0000]
TABLE 1
elongation at break (%)
impact resistance (J/m)
PLA
6.05 ± 0.58
73
PLA/TPO(80/20)
18.1 ± 2.78
137.6
PLA/TPO/TPO-g-PLA
41.9 ± 11.9
No break
(80/20/5)
[0035] As shown in Table. 1, the polymer formed from composition A exhibited superior impact resistance and had seven times the elongation performance of poly(D,L-lactide).
EXAMPLE 7
[0036] The polymer samples formed from composition A, composition B, and composition C were respectively subjected to tests of elongation at break, and the results are shown in Table 2.
[0000]
TABLE 2
elongation at break (%)
PLA/TPO/TPO-g-PLA (80/20/5)
41.9 ± 11.9
PLA/TPO/TPO-g-PLA (80/20/2.5)
140.83 ± 17.99
PLA/TPO/TPO-g-PLA (80/20/1)
68.22 ± 20.94
[0037] As shown in Table. 2, the elongation of polymer formed from the composition of the invention can be modified by means of the amount of the amphiphilic copolymer. When the weight ratio of the amphiphilic copolymer was 2.5 wt %, the polymer formed from the composition comprising the amphiphilic copolymer exhibited superior elongation performance.
[0038] Accordingly, the amphiphilic copolymer serving as a solubilizing agent can be simply prepared from commercial TPO and PLA, rather than from the conventional solubilizing agent (block/branch copolymer) prepared under rigorous reaction conditions, thereby reducing cost. The intersolubility between polymers of the composition of the invention is improved and the polymer formed from the composition exhibits superior physical and mechanical properties.
[0039] While the invention has been described by way of example and in terms of embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
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An amphiphilic copolymer and method for fabricating the same are provided. Further, a polymer composition employing the amphiphilic copolymer is also provided. The amphiphilic copolymer includes a polar block connected to a nonpolar block via a moiety derived from maleic anhydride, wherein the polar block is derived from polylactide, and the nonpolar block is derived from thermoplastic polyolefin elastomer.
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BACKGROUND OF THE INVENTION
The bracket for holding flag or banner poles has been the stepchild of the flag standard field. After a flag or banner is designed, it needs some form of support. An attractive pole is selected of suitable size and strength and to many, the project is completed. The mount or support for the pole is considered incidental, particularly if the flag or banner is small, e.g. under six feet in length.
The result has been that most supports for flag or banner poles are merely weighted bases or pipes with central holes for ground use or pipe sections welded to base plates. Sometimes wall brackets are cast of aluminum, bronze or iron. Brackets of this type usually mount the flag or banner pole at a fixed angle and are notable in their functional effectiveness if not beauty. Some brackets are adjustable but these often lack sufficient strength or are unduly complicated.
BRIEF DESCRIPTION OF THE INVENTION
Faced with this state of the art and particularly the lack of attention to the design of pole brackets, I undertook to carefully analyze the true needs and objectives of pole brackets. I also studied the available materials to determine the most effective and attractive material to use for a pole bracket.
It was apparent to me that the person wanting to display a flag or banner does not want to be limited to one and one only way of displaying said flag or banner which is bracket mounted. Likewise, the surface and orientation of the structure upon which the bracket is to be mounted may not give itself to the available brackets. I therefore sought to design a bracket which may be mounted on horizontal, vertical or inclined flat surfaces. I also sought a bracket which could be mounted on curved or cylindrical surfaces by either mounting screws or straps. I moreover wanted a bracket which itself is attractive, easy to mount and use, flexible as to the mode of displaying the flag or banner and low in cost.
Each of these objectives have been met by my new design of a pole bracket which comprises, generally, an inverted T shaped elongated member, preferably of extruded aluminum. The head of the T which acts as the mounting base includes mounting holes for attachment to flat surfaces regardless of their orientation.
The upstanding part of the leg of the T includes a longitudinal hole which extends through the body from one end to the other. A second hole extends normal to the first hole from the bottom of the base of the T to but not through the head of the T or mounting surface of the bracket. A third hole extends from the base of the T at an angle with respect to the mounting surface, e.g. 45 degrees. The three holes intersect in the body of the T but sufficient material remains in the bracket to support a pole in any of the openings.
Three locking means, for example, set screws, threadably engage the body and are drivable into at least one of the holes to secure poles in place. The locking means are located so that they are hardly noticable and do not detract from the appearance of the bracket.
The mounting surface of the bracket, namely the head of the T, includes a recess which allows the bracket to conform to a curved cylindrical support structure such as a city light standard.
Opposite ends of the bracket each include local grooves between the head and the base of the T extending trasverse to the length of the bracket. These grooves allow a strap to encircle the mounting portion of the bracket for strap mounting without interfering with the display of flags or banner on the bracket.
BRIEF DESCRIPTION OF THE DRAWING
This invention may be more clearly understood from the following detailed description and by reference to the drawing in which:
FIG. 1 is a perspective view of a pole mounting bracket in accordance with this invention;
FIG. 2 is a longitudinal vertical sectional view thereof taken along line 2--2 of FIG. 1;
FIG. 3 is a side elevational view of a mounting bracket in accordance with this invention mounted on a vertical wall with a horizontal pole;
FIG. 4 is a side elevational view of the bracket of FIG. 3 mounting a pole at an inclined angle;
FIG. 5 is a side elevational view of the bracket of FIG. 3 mounting a pole vertically;
FIG. 6 is a side elevational view of the mounting bracket of FIG. 3 mounting two poles, one horizontally and one vertically;
FIG. 7 is a side elevational view of a mounting bracket of this invention mounted on a horizontal surface mounting a vertical pole;
FIG. 8 is a side elevational view of the mounting bracket of FIG. 7 mounting a pole at an inclined angle;
FIG. 9 is a side elevational view of the mounting bracket of FIG. 7 mounting a pair of poles, one vertically and one horizontally;
FIG. 10 is a side elevational view of a pair of brackets in accordance with this invention mounted on opposite sides of a pole by straps;
FIG. 11 is an enlarged fragmentary elevational view of one of the brackets of FIG. 10;
FIG. 12 is a horizontal sectional view of the pole and brackets of FIG. 10, taken along line 12--12 of FIG. 10;
FIG. 13 is a vertical sectional view of the bracket of FIG. 1 taken along line 13--13 of FIG. 1;
FIG. 14 is an end view of an alternate embodiment of this invention; and
FIG. 15 is a side elevational view of another alternate application of this invention mounting a pair of banners side by side.
DETAILED DESCRIPTION OF THE INVENTION
Now referring to FIGS. 1 and 2, the basic form of this invention may be seen. It comprises a bracket, generally designated 10 in the shape of an inverted T with the head 11 of the T constituting the mounting surface for the bracket 10. Extending upward from the base 11 is the body 12 of the bracket 10 being, in one illustrative embodiment, in the order of 11/4" in thickness and approximately 2" high. The overall height of the bracket being in the order of 2 3/8" high. The base 11 includes an undercut 13, the purpose of which will be described below. The bracket 10 may be of any length as desired, and the longer the bracket 10, the more poles it will support.
For purposes of explanation of this invention, the bracket 10 is illustrated as approximately 3" long and includes three openings 14, 15 and 16 for holding flag or banner poles. The opening 14 is longitudinal and extends totally through the body portion 12. The opening 15 is at an inclined angle with respect to the base, the preferred angle being 45 degrees. The opening 16 extends into the body 12 normal (90 degrees) with respect to the base 11 and the hole 14. These three holes 14, 15 and 16 allow the mounting of a pole in four ways,
1. extending out of the left end of opening 14;
2. extending out of the right end of opening 14;
3. extending at an angle out of opening 15; and
4. extending vertically, in FIG. 1, out of opening 16.
A plurality of mounting holes 20 are located at the four corners of the base 11 to secure the bracket 10 to a support structure. One of three set screws 22 appears in FIG. 1, positioned to lock a pole in the angular opening 15. A pair of additional set screws, 21 and 23, appearing in FIG. 2, secure poles in openings 16 and 14, respectively.
FIG. 2 illustrates that the body 11 is solid metal except for the openings 14, 15 and 16. Although the openings 14, 15 and 16 intersect with at least one other opening, sufficient material remains in the bracket 10 to provide adequate strength for holding a pole of as long as eight feet in length and a flag or banner of up to twenty feet in length.
The basic use of this invention is illustrated in FIG. 3 in which bracket 10 is secured as by screws 30 to a wall or other supporting surface 31. A single pole 32 supporting a flag 33 is in slip fit relationship in opening 16 and secured in place by setscrew 21 (of FIG. 2). The mounting of FIG. 3 may be either permanent or temporary. In most cases the bracket 10 is mounted permanently and the pole 32 is either permanently or temporarily in place. The pole 32 may be moved to opening 15, of FIGS. 1 and 2 presenting the appearance of FIG. 4, in this case, supporting a banner 34. The same bracket 10 of FIGS. 1 through 4, without change, supports pole 32 vertically in opening 14 as illustrated in FIG. 5.
The bracket 10 of this invention may be mounted on a horizontal surface such as the cornice of a building 40 as illustrated in FIG. 6. In this case, the bracket 10 is located near the corner of the cornice and supports two poles 32 and 32a with pole 32 extending vertically in opening 16 and pole 32a extending horizontally in opening 14 of FIGS. 1 and 2. The mounting of two or more flags or banners from a single mounting bracket changes the appearance of the area dramatically and all done without any change in mounting brackets. The contrast of double mounting of poles as illustrated in FIG. 6 is more apparent when compared to FIGS. 7 and 8 showing horizontally mounted bracket 10 each carrying one flag or banner.
Dual mounting of a pair of poles 32 and 32a on a vertically mounted bracket 10 is illustrated in FIG. 9.
In each of these cases, the bracket 10 may be left permanently in place and the pole or poles and flags or banners removed. The bracket 10 to the extent that it is visible presents an attractive anodized aluminum surface in any of a number of colors, if desired. It therefore does not detract from the appearance of the support structure when not is use.
A common requirement for municipal flag or banner poles is that they be mounted from street lighting standards and often more than one flag or banner from a single standard. The standards are often tapered and of various diameters.
The bracket of this invention is easily adapted to mounting on round or tapered standards as is illustrated in FIG. 10 through 12. In that figure, a pair of identical brackets 10 are mounted on standard 50 by a pair of straps 51 and 52 which encircle the standard 50 and extend through the slots 17 of FIG. 1. The straps 51 and 52, one at the top region of the brackets 10 and the second at the bottom, when tensioned, as by a screw tensioner 53, for example, better seen in FIG. 12, securely holds both brackets 10 on the standard 50. This form of attachment is accomplished merely by the presence of the slots 17. Of course, self-tapping or other screws may be used as well to mount the brackets on larger cylindrical standards but the strap mounting is preferred because of its simplicity, low cost, rapidity of installation and since it does not mar the standard. Using the straps 51 and 52, as illustrated in FIGS. 11 and 12, the straps need only encircle the standard 50 loosely, the bases 11 of the brackets 10 slipped within the straps and the straps 51 and 52 each slipped into their respective slot 17. Friction of the strap within the slots 17 is sufficient to hold the brackets loosely until properly positioned. Then, tightening the screw fastener 53 securely attaches the brackets 10, two or more at once, to the standard 50. Although two brackets 10 are illustrated as mounted on standard 50 of FIG. 10, it is apparent that four or more brackets may be positioned about the standard 50 depending upon its diameter, all with a single pair of mounting straps 51 and 52.
The slot 13 on the underside of the head portion 11 of brackets 10 allows the standard 50 to engage the bracket at two spaced points rather than a single tangency as would be the case if the head 11 were totally flat. This feature provides a reliable mounting upon cylindrical or tapered standards. In case even more surface contact with the standard is desired, the modified form of head 11a is illustrated in FIG. 14. There, the recess 13 has in fact, not one but two radii of curvature 13a and 13b which match the shape of cylindrical or tapered standards of various diameters.
Alternate side positioning of the setscrews 21 used to secure the poles in the respective openings is best illustrated in FIG. 13. These setscrews are located in relatively thick portions of the body 12 of the bracket 10 and each engage the sidewall of the pole in its receiving hole. In a typical example the poles are aluminum of 1 1/8" diameter.
Now referring to FIG. 15, an alternate form of mounting is illustrated. In this case, bracket 10 is mounted horizontally on a rectangular column 60 by mounting screws. Extending out of both ends of opening 14 are a pair, or preferably, a single longer pole 32b on opposite sides of the vertical standard 60. A pair of banners 61 and 62 are supported on the pole 32b on opposite sides of the standard 60 and are drawn together at the bottom in an attractive pull down heraldic configuration. This figure again illustrates that the bracket of this invention has additional applications while maintaining its attractive yet unobtrusive presence.
One of the great advantages of this invention to the manufacturer is the fact that even with the broad variety of ways this bracket may be used, as illustrated in the drawings, it basically is a single extrusion of a material such as aluminum. In the form here illustrated, the aluminum body has great strength and may be given attractive surface treatments by anodizing. It is still low in cost since it is basically extruded in continuous lengths, cut to whatever length is desired. Three pole mounting holes are drilled in the extrusion (or opening 14 may be formed in the extrusion step if desired). The drilling of mounting holes, drilling and tapping of setscrew holes and milling of slots 17 complete the manufacturing operation save for deburring and surface treatment. The net result is that a far superior, more versatile and yet inexpensive flag or banner pole mounting bracket has been produced.
The foregoing embodiments of this invention are merely illustrative thereof and are not to be considered as limiting. Rather, this invention is defined by the following claims including their equivalents.
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A flag pole bracket is disclosed for attachment to a flat surface or a cylindrical pole. The bracket includes a body with a plurality of openings therein to support flag poles at different angles relative to each other. The bracket also includes screw holes for mounting to a flat surface, and transverse strap receiving openings to receive straps mounted around a cylindrical pole.
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DESCRIPTION
1. Technical Field
The present invention relates to methods and devices for holding down an infusion catheter to prevent unwanted motion of such catheter when attached to the body of a patient, and more particularly to such a device which allows detachment of the catheter from the body of the patient without requiring prior removal of the device.
2. Background Art
It is common hospital practice to administer medicines or other fluids to a patient via an infusion tube attached to an intravenous needle or catheter attached to a patient's limb. The needle or catheter must be manually inserted to a precise location, which may be intravenous, intramuscular or subcutaneous, and thereafter this location must be maintained as appropriate for the particular infusion fluid, despite the possible twisting and turning of the patient or the motion of the appended infusion tubing. In practice, the catheter tube or needle extends from a more substantial catheter hub body to which the infusion tubing is attached; the body has a pair of laterally extending flanges which are generally taped to the patient to prevent extraneous motion of the assembly. Because even minor motions of the body could lead to movement of, or pressure on, a needle assembly, it is common to employ a hollow plastic catheter tube as the element which penetrates the skin to deliver the medication. This tube is initially installed by inserting a conventional needle therethrough and puncturing the skin of the patient for insertion, thereafter withdrawing the needle and leaving the infusion tube as a flexible attachment to the patient. This allows a slight amount of bending of the tube itself, or motion of the catheter hub body, without breaking or kinking of the flow path, or local trauma caused by wobbling of the needle due to lateral pressure being transmitted. However the taping of a catheter body to the skin of the patient is cumbersome, and the catheter may not be removed from the patient thereafter without removing the tape. It can be traumatic for a patient to have adhesive tape painfully pulled from his skin prior to removal of the catheter.
Several devices have been patented for holding such an assembly in a stable position. Thus the device of U.S. Pat. No. 4,129,128 shows a hold-down device with a pair of wings and a central housing, wherein the wings may be taped securely to the body of a patient and the central housing has end walls adapted to receive the laterally extending "ears" of a catheter hub. U.S. Pat. No. 3,900,026 shows a rigid rectangular box-like structure, with a flexible neck which engages the catheter hub, the whole rectangular housing forming a protective shield for the needle and being secured to the body of a patient by an adhesive flange extending around the perimeter. Neither of these devices appears to permit removal of the catheter from the patient's body without prior removal of the hold-down device. There is thus a need for a simple catheter stabilization device capable of securely holding a catheter against unwanted movement yet allowing release of the catheter and removal thereof from the patient without requiring prior removal of the stabilization device.
BRIEF DESCRIPTION OF THE INVENTION
The present invention is a flexible catheter stabilization device formed of sheet material having a pair of laterally protruding flaps on either side of the axis defined by the catheter, and connected by a central portion having a contour for receiving the body of the catheter hub. In a preferred embodiment, the contour is tapered and a hole or detent in the central portion engages a corresponding element of the catheter hub to prevent motion of the catheter assembly along the axis defined by the catheter tube. In a further preferred embodiment the tapered central portion is of conical shape, and pinching the flaps together releases the hub so it may be withdrawn without removing the stabilization pad from the body of the patient. An adhesive band around the perimeter of the flaps on the lower side thereof permits easy application of the pad to the patient, in an adhesive tape-like fashion, after the catheter has been inserted. A non-adhesive tab on one flap aids in gripping the pad for removal after use. A beveled edge portion provides greater flexibility and compliance of the adhesive perimeter of the flaps, for more secure attachment to contoured surfaces. These and other features of the invention will be more readily understood by reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a top view of the catheter stabilization pad according to the present invention;
FIG. 2 shows a side view thereof;
FIG. 3 shows a front view from the catheter end of the present invention;
FIG. 4 shows a perspective view of the pad adhered to the limb of a patient;
FIG. 5 shows a catheter and hub with detent adapted to the pad of FIG. 1; and
FIG. 6 shows a bottom view of the catheter and hub of FIG. 5.
DESCRIPTION OF SPECIFIC EMBODIMENTS
Referring to FIG. 1 there is shown a basic embodiment of the stabilization pad 1 of the present invention, having flaps 3 disposed on either side of a central portion 4. The unit may be made of a molded polyethylene, or vacu-formed from sheet stock of any appropriate flexible plastic. As shown, central portion 4 is adapted to receive the hub 4 of a catheter (shown in phantom) having a catheter tube 6 extending therefrom. Also shown in FIG. 1 is an aperture 8 in the central portion 4 for receiving a corresponding detent or protrusion from the catheter hub and holding the hub secure against axial motion. The perimeter portion 9 of the stabilization pad is preferably treated with an adhesive on the underside thereof so that the pad may be applied like a self-adhesive bandage without requiring external taping or straps to hold it securely on the body of the patient. A tab 5, not having adhesive thereon, but protruding from one wing, serves as a grip to aid in removal of the stabilization pad. As may be seen, the two flaps 3 extend on either side of the catheter body and are approximately symmetrically disposed in relation to the axis defined by the catheter tube 6.
Turning now to FIG. 2, it may be seen that the axis 20 defined by the tube 6 is a central axis of the catheter hub 2. It is conventional for a catheter hub to have a central bore, into which a needle is inserted to stiffen and stabilize the flexible plastic tube 6 to permit insertion thereof through the skin of a patient. Also conventional catheter hubs generally have the external profile of a slightly tapered cone. Such a profile allows the hub body to rest in a position approximately tangential to the skin of the patient when the needle has been inserted, at an angle, to an appropriate depth. In the present device, advantage is taken of this conical profile by providing a contoured tapered sheet surface as the central portion 4, which conformably fits against the profile of the catheter hub. As shown, the central portion 4 narrows as it gets closer to the catheter tube end of the hub. Also shown in FIG. 2 is a nub 21 projecting upward from the body of the catheter hub and through the aperture 8 of FIG. 1. The stabilization pad itself is formed of a flexible but relatively thick sheet. The top surface thereof, around the edges 9 of FIG. 1, is beveled as shown at 23 in FIG. 2, thus effectively thinning the edge portion and permitting a greater pliability in that area. The underside of beveled surface 23 bears an adhesive layer 22 for attaching to the body of a patient. The adhesive need not extend entirely around the perimeter, and indeed, where it is desired to remove the catheter without first removing the pad, it is advisable to omit the adhesive near the central regions of the pad so that the "ears" appearing on a normal catheter may easily slide under the perimeter portion thereof for removal.
Turning now to FIG. 3, there is shown an end view of the stabilization pad according to the present device in which the flaps 3 at each side attach to the center portion 4 which conformally wraps around the catheter hub 2. The protruding nub 21 may be seen projecting up through the sheet of the center portion 4.
FIG. 4 shows a catheter stabilization pad according to the present invention in use, with infusion tubing or inlet connection tubing 41 leading into the hub and catheter tube 6 extending from the front of the hub through the skin of the patient. It will be appreciated that the taper of the central portion permits the catheter to slide into a secure position and subsequently be retained there as the protruding nub 21 reaches the retaining aperture 8 thereby locking the hub into position. As the catheter is inserted there becomes progressively less looseness for maneuvering the hub and upon full insertion the hub is firmly held on all sides against motion. The laterally projecting hub "ears" shown in phantom prevent any twisting of the hub which could cause kinking of the inlet tube or of the catheter tube 6. The conformable contour of the central portion prevents any lateral motion whatsoever; and the detent system comprising the aperture 8 and nub 21 prevents any axial motion. In this manner, the catheter stabilization pad provides an unprecedented degree of stability of the catheter itself. Nonetheless, in the event it is desired to remove the catheter from the body of the patient, as for instance upon discharge, or simply to employ a different vein for the infusion, the catheter hub may be released from the stabilization pad by simply pinching together the skin of the patient in the area of the two wings, thus causing the central portion to rise up releasing the nub 21 and allowing the withdrawal of the hub from the central portion along axis 20. The stabilization pad itself is not situated over the actual site of needle insertion, and therefore may be left in place without worry of infection or other consequences until such time as it may be removed without trauma to the patient. In this manner the association of physical pain with the insertion or removal of needles or catheters is entirely avoided, thus eliminating one of the common negative experiences of modern hospital practice.
Turning now to FIG. 5, there is shown a detailed view of the catheter employed with the present stabilization pad. As noted above, the pad itself is generally adapted or adaptable to common catheters currently used, requiring in addition only a detent or projection, like nub 21, to provide the axial stability of the invention. Such a catheter is shown having flexible catheter tube 6 extending from a tapered hub 52. Hub 52 has a pair of laterally extending wings 51 of relatively small dimension which define a plane at the bottom thereof which rests against the skin of the patent and serves to prevent rotation of the hub 52 in use. Extending from the top of hub 52 is a nub 21 in the form of a straight tab. It is clear that nub 21 may be of virtually any shape so long as it mates with the corresponding aperture 8 of FIG. 1 so as to prevent motion along the catheter axis 20. Similarly wings 51 may be quite small. Unlike the "ears" of a conventional catheter, they need not be taped to the body but serve only the residual purpose of providing a flat orientation against the skin. Similarly, tapered hub 52 may be of virtually any cross-sectional shape, such as a long thin pyramidal shape and need not be conical. The purpose of the taper, in addition to the conventional function of defining a guide for the needle used in inserting tube 6 through the skin, is largely to allow progressively more secure insertion of the body within the stabilizing central portion 4 of the stabilization pad. At the rearmost edge of the catheter hub is flange 42, which extends a slight distance radially outward so as to butt against the edge of the stabilization pad and provide a well-defined stop to limit insertion. While the use of nub 21 and aperture 8 suffices to axially secure the device, the flange 42 adds further restraint against wobble.
Turning now to FIG. 6, there is shown a bottom view of the catheter of FIG. 5. As may be seen, the lower portion 63 of body 52 is flat and forms a common plane with wings 51 so as to rest on the skin of the patient without twisting. Lower edge of flange 42, which would only bear against the skin of the patient, is removed.
It will be appreciated that the precise shape of wings 51 is of little importance, as long as they project somewhat laterally to prevent twisting of the device, and the invention may be practiced altogether without such wings, if lower surface 63 of the catheter body is of sufficient size to assure that the hub 4 does not rotate. However, in the event wings 51 are used, it will be appreciated that a portion of the stabilization pad 1 located adjacent to the central portion should not have any adhesive in a location which would interfere with withdrawal of the catheter from the stabilization pad.
In one embodiment of the invention, wings 51 measure 1/2 inch (13 mm), tip to tip, and the catheter hub is approximately 3/16 (5 mm) of an inch in diameter at its large end. The stabilization pad itself measures 21/4 inches (56 mm), side to side, with a maximum front to back dimension of 11/2 inches (38 mm) and has a beveled peripheral region 1/16 of an inch (11/2 mm) wide. The catheter hub is 3/4 inches (19 mm), tip to tip, and both the rear flange 42 and the nub 21 extend approximately 1/32 (0.75 mm) of an inch and have a thickness of approximately 0.040 inches (1 mm). The stabilization pad provides a high degree of stability and comfort, isolating the catheter tube from the incidental motions of the infusion tube 41.
It will be appreciated that the present invention requires no rigid housing and presents an elastic structure which can removably engage a catheter hub so as to permit sanitary and simple maintenance of the hub in position yet allow convenient removal as needed, without any trauma upon removal. It will be appreciated that the invention may readily be practice with a wide variety of flexible plastic or rubber-like material; it may be practiced with adhesive or non-adhesive flaps, in which case the flaps may be attached with adhesive tape as in a conventional catheter hub. The taper of the central portion may conveniently be of any shape adapted to fit the catheter hub so long as the pad and hub together have a detent means for preventing axial motion after insertion. Similarly the detent may include any means of mating protruding elements, preferably of an aperture and nub variety, which may be released by squeezing together the wings of the pad in such a way as to cause the central portion to flex away from the catheter hub. Accordingly, the invention is limited only by the following claims.
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A unitary sheet device for removably securing a catheter to the skin of a patient includes a pair of flaps for being affixed to the skin and a central portion performed in a contour conforming to the catheter hub. When affixed, the central portion and the patient's skin together form a receptacle for securely holding the catheter against movement. The central portion may be a tapered conical sheet and the flaps may have adhesive for ease of attachment. A detent is provided, which may include a hole through the central portion of the sheet for engaging a protrusion from the catheter hub. Flexing of the sheet disengages the detent. A non-adhesive tab on one flap aids in removing the device.
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FIELD OF THE INVENTION
[0001] The present invention relates to the detection of stress in human beings, and more particularly to using hyperspectral methods to detect physiological stress in human beings.
BACKGROUND OF THE INVENTION
[0002] Sep. 11, 2001 vastly increased the need to unobtrusively detect stress in human beings, particularly in individuals about to commit an atrocity. If the individuals responsible for the destruction that occurred on Sep. 11, 2001 could have been detected based on observable signs of stress without the individuals noticing the surveillance, events of that day may have been far different.
[0003] More mundane needs to detect human stress also exist. For instance, heavy equipment operators who are becoming fatigued experience stress before they subjectively notice their fatigue. Likewise pilots, truck drivers, air traffic controllers, and mass transit and public transportation drivers are similarly situated. Generally, any worker who might endanger others may become tired and therefore pose a hazard to others and also to property. Automatic, objective means to detect the stress associated with their fatigue could save innumerable lives and untold sums otherwise expended in repairing and replacing damaged property.
[0004] In particular, unobtrusive means to detect stress would also be highly desirable. In the related applications of stress detection in anti terror and law enforcement efforts, knowledge of the stress detection system would likely cause the subject to alter his/her behavior to avoid stress detection and subsequent identification as a target or suspect. In fatigue detection applications, typical subjects might find the presence of monitoring equipment offensive or insulting. Moreover, in all of these situations innocent third parties possess civil rights which shield them from intrusive violations of their privacy. Thus, a long felt need exists to unobtrusively detect stress.
[0005] Human subjects react to transient physiological stress in a variety of ways including increased pulse rate, muscle tremor, perspiration, and sub-dermal blow. By monitoring the subject for these stress symptoms the presence of the stress may be detected. Polygraph machines monitor pulse, respiration, and galvanic skin response while the subject is interrogated. His/her responses as measured allow, to an extent, an observer to evaluate the truthfulness of his/her responses to an extent. Unfortunately, polygraph machines remain difficult to use, stressful for the subjects, require a highly trained operator, and are difficult to miniaturize sufficiently to become portable. The fatal flaw possessed by polygraph machines, though, lies in their untrustworthiness.
[0006] In the alternative, fMRI (functional magnetic resonance imaging) machines have been used to detect stress. However fMRI machines also remain large and expensive. These disadvantages prohibit use of fMRI machines to detect stress in many situations including detecting terrorists at airports and other locations, interrogation of witnesses, and many other applications.
[0007] Hyper-spectral image processing has been used for long range unobtrusive reconnaissance but not for detecting stress. Hyper-spectral imaging involves the monitoring of a scene of interest at one or more selected wavelengths of electromagnetic radiation. The selected wavelengths are chosen because the scene is likely to contain a subject of interest which is clearly visible at those wavelengths. Clarity may occur because of the intensity of the particular subject, or because of the contrast of the subject with the background, at the selected wavelength. Additionally, the wavelength selected may be chosen because the background is unlikely to contain other objects which emit or reflect radiation at that wavelength. In the alternative, it may be that the subject is camouflaged, usually imperfectly. If the imperfections allow radiation of a particular wavelength to escape, then that wavelength can be advantageously monitored.
[0008] Because hyper-spectral image processors only monitor select wavelengths, the processing power required may be greatly reduced over devices monitoring large bands of the entire spectrum. Accordingly, a less powerful (and less expensive) processor may be used. In the alternative, a greater number of targets may be monitored or the monitored scene may be expanded. Moreover, because hyper-spectral imaging may be accomplished with machine vision systems, no human intervention is necessary. Though human participation may be desirable to supplement the unobtrusive hyper-spectral processor.
[0009] While observers of a stressed person can readily detect the presence of that stress, a need exists for an apparatus which automatically detects observable symptoms of stress and which triggers an alarm. Additionally, because human sensory perceptions possess limited abilities to discern subtle changes, a need exists for a more sensitive detection system for such stress. Moreover, because observers can err, tire, or be distracted, a need exists for an automated method to accomplish stress detection.
[0010] Such unobtrusive stress detection could be advantageously employed in numerous other applications. For instance, law enforcement personnel investigating crimes could benefit from knowing when a witness or target of an investigation is under stress due to attempting to tell a lie. Retail store owners could benefit from detecting suspected shoppers who are experiencing stress due to their attempt to steal merchandise. Even children with behavioral or learning disorders could benefit from early, reliable detection of stress whereby their care givers can intervene early. Thus a long felt need exists to unobtrusively detect stress.
SUMMARY OF THE INVENTION
[0011] The present invention uses techniques from hyper-spectral processing to detect transient changes of sub-dermal blood flow and dermal hydration (i.e. a stress induced blush causing reddened sweaty skin). Hyper-spectral imaging is a technology in which a given scene is viewed generally in a large number of selected wavelengths and the images recorded for later processing. Immediate, real-time processing may also be used. In some wavelength ranges, features of an observed scene will appear which are easily detectable and obvious, whereas these same features might exhibit low contrast and visibility at other wavelengths. Thus, wavelengths are selected for use in hyper-spectral systems according to whether they convey information in which the observer is interested.
[0012] Usually the subject will be observed against a complex background that tends to mask the presence of the subject. For instance, the background may reflect or emit a spectrum including a variety of ranges which over lap the selected wavelengths. For instance, marijuana growing in a forest may be masked from law enforcement surveillance by the various shades of green of the forest, unless the surveillance occurs at a “green” wavelength unique to marijuana. More particularly, some targets will employ techniques to mask their presence by using aids to alter their reflected spectrum. An example of such a situation would be the use of camouflage netting to conceal a command post or artillery battery.
[0013] An underlying principle of the present invention is that the “color,” or reflectance spectrum, of the skin of a person is modified as a result of transient changes in dermal hydration and sub-dermal hemoglobin flow associated with the emergence of a blush. The blush may be induced by stress or other physiological arousal. In accordance with the present invention, these changes may be passively and unobtrusively detected.
[0014] While observers of the blushing person can readily detect the blush once it progresses far enough, a need exists for an apparatus which can automatically detect the emergence of a blush and trigger an alarm. Additionally, because the human eye is limited in its ability to discern subtle changes in coloration (the reflection spectrum) a need exists for automated detection of physiological stress. Moreover, because observers can err, tire, or be distracted, a need exists for a machine to accomplish stress detection.
[0015] In addition to satisfying those needs, the present invention accounts for intervening reasons which may alter the reflectance spectrum of a person's skin. A database which characterizes typical skin types (i.e. colors) under controlled conditions and subject to a variety of factors (such as age, sex, cultural background and ethnicity) may be consulted to improve the accuracy of the hyper-spectral processing system. Accordingly, the database enables the identification of a hyper-spectral signature for stress despite the presence of these intervening factors.
[0016] The present invention also provides a hyper-spectral system which monitors wavelengths selected based on the considerations discussed herein. Image processing software, decision making software, and display and communication interfaces are also included in accordance with preferred embodiments of the present invention. A spectral instrument, in accordance with a preferred embodiment of the present invention, may be implemented in a portable configuration which operates passively and unobtrusively without physical contact with the subject or his/her awareness of surveillance.
[0017] In accordance with a preferred embodiment of the present invention a circuit for detecting physiological stress in a specimen is provided which includes an input and a processor. The input receives an image from a camera and provides it to the processor. The processor identifies two characteristics of a subject who is within the image. The first characteristic indicates that the subject is not experiencing stress and the second characteristic indicates the subject is experiencing stress. A comparator compares the image of the subject and the two characteristics. If the subject appears to be stressed an alarm is signaled.
[0018] In accordance with a second preferred embodiment of the present invention a method of detecting physiological stress of a subject is provided. The method includes observing the subject who includes a first spectral characteristic when unstressed and a second spectral characteristic when stressed. The image is compared to the first and the second characteristics to determine whether the subject is stressed.
[0019] In accordance with a third preferred embodiment of the present invention a circuit for detecting physiological stress in a subject is provided. The circuit includes a processor which receives an image of the subject. Two areas of the subject's skin are identified by the processor. One area of skin is unlikely to blush and the other area is likely to blush. By comparing the two areas of skin, the processor identifies attenuation of one of the areas of skin which is indicative of a blush.
[0020] 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 are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0022] FIG. 1 is a block diagram of a stress detection system in accordance with a preferred embodiment of the present invention;
[0023] FIG. 2 is a graph of typical reflectance spectra from a variety of human skin types;
[0024] FIG. 3 is a graph of a typical reflectance spectrum of human skin;
[0025] FIG. 4 is a graph of the absorption spectrum of human hemoglobin;
[0026] FIG. 5 is a graph of the extinction coefficient of water; and
[0027] FIG. 6 is a flowchart of a method in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
[0029] Normally ambient light reflected from a person's skin determines the spectrum of light which an observer sees and interprets as color. It should be noted that light, herein, refers to more than visible light. For the term light encompasses electromagnetic radiation, in particular visible and near infrared radiation in the ranges of approximately 350 to 700 nanometers and 700 to 1500 nanometers respectively.
[0030] Those experiencing physiological stress exhibit a number of conditions observable via such radiation. Colloquially, they tend to blush and perspire. The red, sweaty face of a blushing person belies his/her stress. In more scientific terms a blush is an increase in the sub-dermal hemoglobin (blood) flow. More particularly, the hemoglobin visible seen during a blush is generally oxygenated hemoglobin (i.e. red blood).
[0031] Dermal hydration, or an increase in perspiration, also typically accompanies a blush. That perspiration, or sweat, contains mostly water with sodium chloride (disassociated sodium and chlorine ions), potassium, magnesium, skin oils, and other trace chemicals in solution. Thus, during a blush a thin film of water tends to cover the skin.
[0032] To understand the present invention it is useful to review how light reflects off of skin. Instead of merely reflecting off of skin, ambient light penetrates the epidermis, the upper layer of skin, and is reflected back to the surface. During a blush, incident light approaches the epidermis through the film of perspiration. The film may be infinitesimally thin to about a tenth of an inch deep (where a drop or rivulet has formed). Because water blocks certain wavelengths of electromagnetic radiation, the film of perspiration alters the spectrum of the incident radiation. Notably the perspiration attenuates the intensity of the radiation at those wavelengths at which it absorbs the radiation.
[0033] Once the incident radiation enters the epidermis, the epidermis scatters and absorbs some radiation. The remainder it reflects back toward the surface of the skin. It should be noted that normal ambient light only penetrates the epidermis to a depth of about 0.08 inches. Within that region it begins encountering hemoglobin filled capillaries within about the first 0.001 inches. For neonates, as opposed to adults, the amount of blood content ranged from about 4 to about 12 milligram of hemoglobin per gram of tissue (equivalent to about 0.8 to about 2.4% by volume) and the average depth of blood ranged from about 250 to about 425 micrometers as reported by S. L. Jacques, I. S. Saidi, and F. K. Tittel, Average Depth of Blood Vessels in Skin and Lesions Deduced By Optical Fiber Spectroscopy, Society of Photo-Optical Instrumentation Engineers Proceedings of Laser Surgery: Advanced Characterization. Therapeutics, and Systems IV, edited by R. R. Anderson, 2128, 231-237 (1994).
[0034] Because of the capillaries, hemoglobin also absorbs a portion of the incident radiation proportional to the amount of hemoglobin which the radiation encounters. Once reflected out of the epidermis, the reflected radiation again encounters the perspiration which absorbs still more of the incident (now reflected) radiation. Thus, the reflected radiation carries, within its altered spectrum, information indicative of the amount of perspiration and sub-dermal hemoglobin present. In particular, the reflected radiation shows a proportional decrease in intensity at the wavelengths absorbed by water and by hemoglobin. Accordingly, the reflected spectrum indicates the degree to which the person is blushing. Since a blush indicates stress, the reflected spectrum indicates the extent to which the person is under stress.
[0035] Referring in general to the figures and in particular to FIG. 1 , a hyper-spectral system 10 in accordance with a preferred embodiment of the present invention for detecting physiological stress may be seen. The system 10 views, observes, or surveys a scene 12 of interest. Within the scene 12 a subject 14 may be surveyed. Also, as part of a background 18 , other non suspect persons 16 may be present as well as vegetation, equipment, and other objects. The subject 14 (or specimen suspect, or target) may be experiencing stress and accordingly may be blushing to some degree. In particular, the subject 14 may be attempting to suppress his/her blush. Yet, because blushing is a partially involuntary reaction to stress, the subject 14 will not be entirely successful in suppressing his/her blush. To aid in the detection of full, and even partial blushes, a data base of numerous varied subjects may be collected which would include data defining their normal, non blushing, skin reflectance spectra and their skin reflectance spectra as altered by the presence of a full blush. Moreover, the data may reflect the subjects as seen in various environments to enable statistical analysis of the spectra in the data base and also that of the spectra captured from images of the subject(s) 14 .
[0036] To illuminate the scene 12 a visible light source 20 may be included or augmented to illuminate the scene 12 . While the light source 20 may be a conventional light source, it may also contain an infrared radiation source. In the alternative, the source 20 could be natural or even diffuse light. Electromagnetic radiation from the source 20 , including visible light and preferentially near infrared radiation, illuminates the subject 14 . Subject 14 in turn reflects the radiation while altering the spectrum of the incident radiation because of inherent and transient characteristics of his/her skin. More particularly, dermal hydration and oxygenated hemoglobin, indicative of a blush, may attenuate certain wavelengths of radiation in the reflected spectrum.
[0037] To receive an image 22 of the scene 12 , including the subject 14 , the system 10 has a lens or other optical device 24 which focuses the image 22 on a receptor within a hyper-spectral imaging camera 26 . Camera 26 may be any type of electronic camera readily available such as a charge coupled device (CCD) or a complementary metal oxide system (CMOS) device capable of sensing either, or both, visible and infrared radiation. The camera 26 captures the image 22 as an array of pixels 27 . Note should be made that the camera 26 may operate with ambient, indoor radiation alone. In particular, no laser or other high intensity radiation source need be employed to capture the image 22 . Though such high intensity sources, or additional conventional sources, may be employed if it is desired to increase the signal to noise ration of the image, particularly at the selected wavelengths.
[0038] From the camera 26 , the pixel array 27 is sent to a signal processor 28 as shown in FIG. 1 . Note that the camera 26 or the signal processor 28 may filter the image so that only those frequencies of interest may be selectively examined. More particularly, the selected frequencies may be only those at which a blush changes the skin reflectance spectra or just one of these frequencies. Though, other frequencies could be examined also, or ignored, without departing from the spirit or scope of the present invention.
[0039] Within the image processor 28 a machine vision application may recognize the shape of human beings. Once the processor 28 recognizes one or more humans it may then prioritize them for further scrutiny. In one embodiment, the system allows a user to select the prioritization scheme. These schemes include prioritization factors such as proximity to the camera 26 , proximity to a security station (e.g. checkpoint), similarity to a pre selected photograph, or the presence of indicia of membership in some group (e.g. military insignia), particularly terrorist groups.
[0040] Once a target or subject 14 has been selected, the image processor 28 searches for exposed areas of the skin of the subject 14 . Such a search may be based upon identifying areas of the image 22 with spectrum similar to those shown in FIG. 2 . In the alternative a user with a computer mouse, joystick, light pen or other pointing device may direct the image processor 28 to an area to scrutinize.
[0041] Returning now to FIG. 1 , once the image processor 28 has identified an area of exposed skin, the image processor 28 may attempt to determine which inherent skin type (i.e. color) the subject 14 possesses. The determination of the skin type may be based on the overall albedo of the subject 14 and a look up table of different skin types according to albedo. In the alternative, the skin type determination may be by way of a hyper-spectral analysis of the reflected ambient light from the subject 14 and comparison to the skin types of, for example, FIG. 2 which may be stored in a database. Either way, the processor 28 obtains a skin reflectance spectrum (such as spectrum 34 ) against which to compare a spectrum which might exhibit a blush.
[0042] The former alternative (albedo based approach) allows for a quicker, less computationally intensive examination while the latter alternative improves the accuracy of the system. In one preferred alternative the albedo based approach executes first to provide a quick assessment. The hyper-spectral analysis approach then executes (or executes in parallel with the albedo based approach) to confirm the results of the quicker approach.
[0043] After, or in parallel with, determining the inherent skin type, the image processor 28 then performs a hyper-spectral examination of another area of the skin of the subject 14 . With the knowledge of the two partial spectra gained from the examinations the processor compares the two partial spectra searching for difference between the two areas of skin indicative of a blush.
[0044] Having completed the comparison, the image processor 28 may then forward the results of the comparison (including the associated images) to a display and alarm device 30 for the user to view or may forward the results to a computer network 31 . If the results prove negative (no blush) security personnel may allow the prior subject 14 to pass since his/her classification may now change to that of a non suspect person 16 . However, if the results prove positive (the subject 14 is blushing) the image processor 28 may alert security personnel via the display 30 or an alarm.
[0045] Moreover, the image 22 may be sent to the network 31 of FIG. 1 for filing and subsequent data processing. In particular, time, date, and location information may be associated with the image 22 to allow subsequent intelligence analysis of the image 22 and subject 14 . Thus, the network 31 may connect to intelligence, law enforcement, and other appropriate computers via the internet and other connection schemes.
[0046] Since it may be advantageous to allow even a blushing subject 14 to proceed on his/her way (e.g. to expose the remainder of his/her support network or accomplices), the system 10 may be concealed in, or near, the scene 12 . In this manner the subject 14 proceeds unaware of the surveillance and his/her potential identification as an individual under stress. Such an unobtrusive surveillance system allows security personnel to check the target's appearance and take further action as may be required. In the alternative, security personnel may choose to allow a stressed person they deem to be innocent to proceed with out complication.
[0047] While the present invention has heretofore been described as operating with electromagnetic radiation, the present invention is not so restricted. Any energy which radiates in waves, such as sound, may be utilized to detect signs of stress in the subject in accordance with the present invention. Notably, hyper-spectral analysis of sound may be used to detect an increased pulse of the subject as discussed in U.S. Pat. No. 5,867,257 issued to Rice et al and incorporated herein by reference in its entirety.
[0048] Turning now to the image 22 in more detail, reference is made to FIG. 2 . FIG. 2 appeared in Elli Angelopoulou, The Reflectance Spectrum of Human Skin, Technical Report MS-CIS-99-29 (December 1999) (unpublished manuscript on file with the Technical Reports Librarian, Department of Computer and Information Science, University of Pennsylvania, 200 S. 33rd Street, Philadelphia, Pa. 19104-6389). FIG. 2 shows the reflectance spectra for the back of the hand for various types of skin. Because the extremities tend to not participate in blushes the back of the hand is of particular use in the present invention. By a spectral examination of the back of the subject's hand, the image processor 28 may observe, identify, and characterize a typical base line, non blushing, skin reflectance spectrum 34 ( FIG. 3 ) for the particular subject 14 .
[0049] In particular, because the back of the hand and the face of the subject 14 are likely to be exposed to approximately equal amounts of ultraviolet radiation (e.g. the sun or tanning booths), the amount of melatonin, which dominates which type of skin the subject 14 has, will be approximately equal between the hand and the face. That is to say, the face and the back of the hand will be tanned approximately equally, thereby avoiding one intervening factor, tanning, which may cause the system 10 to detect false positive or negative blushes.
[0050] For subjects 14 with skin containing high amounts of melatonin obtaining a real-time non blushing spectrum is of particular importance in suppressing false alarms. That result follows from the tendency of high melatonin skin to have a flatter reflectance spectrum than other skins. Accordingly, these skins attenuate the incident radiation to a greater degree with or without a blush present. As an aside, because people tend to swing their hands slightly as they walk, a machine vision application associated with the image processor 28 may be easily programmed to detect the hand by the swinging motion.
[0051] Note should be made of several characteristics of human skin shown in FIG. 2 . First the skin reflectance intensity 36 generally tends to increase with increasing wavelength. Though a local maximum 38 tends to occur near 500 nanometers with corresponding local minimums 29 and 40 near 375 and 575 nanometers respectively. A plateau 42 also tends to occur at and above 600 nanometers with a high derivative area 44 connecting the local minimum with the plateau 42 . By searching for these features of the image 22 of the subject 14 , the image processor 28 may determine areas of skin visible on the subject 14 . From these areas, the image processor may then extract at least one base line, skin reflectance spectrum 34 (see FIG. 3 ). Extracting more than one base line, skin reflectance spectrum 34 may be useful in mitigating the presence of scars, skin grafts, tattoos, port wine stains, and deliberate skin alterations to camouflage the subject 14 .
[0052] While the features 29 , 38 , 40 , 42 , and 44 tend to appear in all skin types shown in FIG. 2 , darker skin types exhibit a flatter, less intense spectrum than other skins. Thus, the image processor 28 may contain or access a database of other features of the spectra 32 (shown in FIG. 2 ) to aid in distinguishing skin from other objects in the image 22 and to enable the selection of a base line reflectance spectrum 34 . With regard to the spectrum, it will be understood by those skilled in the art that the mention of specific wavelengths herein will be understood to include a sufficient tolerance to accommodate measurement inaccuracy, variations between skin types, variations between individuals, and variations between different areas of the subject's body, and variations of the subject's skin over time.
[0053] As mentioned previously, the processor 28 could measure the overall albedo of the subject 14 and then look up a skin type with a corresponding albedo to improve the speed of the system. However, one albedo may correspond closely with several skin types 32 having different spectrum. To account for such a possibility, an algorithm to choose between the alternatives may be executed by the processor 28 . However, a full spectral analysis of a non blushing area of the subject 14 allows the processor 28 to make the blush determination using the subject's current skin type. Thus tanning, skin bleaching, and other attempts to camouflage the subject 14 may be more easily defeated.
[0054] It should be noted, prior to discussing the comparison between a blushing and non blushing area of skin, that the typical base line, skin reflectance spectrum 34 (of FIG. 3 ) may exhibit some hemoglobin caused attenuation. The reason for the attenuation is that even when the subject 14 is nominally unstressed, his/her skin contains some oxygenated hemoglobin. Thus, three local minimums occur on the base line, skin reflectance spectrum 34 : minimums 35 , 37 , and 40 . These minimums correspond to the peaks 49 , 50 , and 53 which appear on the hemoglobin absorption spectrum 46 of FIG. 4 . Whereas, if the subject 14 had little or no oxygenated hemoglobin in his/her skin (i.e. the subject is cold or dead) his/her base line, skin reflectance spectrum 3 would resemble a line sloping up to the left.
[0055] Nonetheless, once a base line, skin reflectance spectrum 34 (e.g. see FIG. 3 ) has been identified by the signal processor 28 , comparisons between the base line, skin, reflectance spectrum 34 and other areas of the target's skin may be performed. Though only one other area need be examined. These other areas should be selected for their vulnerability to full participation in a blush.
[0056] For instance, in adults, the ears tend to blush relatively easily with the face and neck also susceptible to blushing. Additionally, because of the crenulated or ribbed structure of the ear, machine vision systems may require less processing to identify the ear than other blushing areas might require. Furthermore, the ears will likely contain about the same amount of melatonin as the face and hands. Accordingly, the image processor 28 may select the ears of the subject 14 for further scrutiny.
[0057] As previously noted a blush consists of an increase in dermal hydration and sub-dermal hemoglobin flow indicating that the subject 14 is experiencing physiological stress. The oxygenated hemoglobin tends to absorb incident radiation as shown by the oxygenated hemoglobin absorption spectrum 46 shown in FIG. 4 . In particular, a low wavelength maximum 49 in the absorption spectrum causes a relatively large attenuation in a corresponding range of the skin reflectance during a blush. Local maxima 50 and 53 also cause similar attenuations in the ranges corresponding to the local maxima 50 and 53 .
[0058] Thus, the typical blushing reflectance spectrum will include a low wavelength, low intensity range (corresponding to maximum 49 ) and a pair of mid wavelength, low reflectance ranges (corresponding to maxima 50 and 53 ). These attenuated areas of the blushing skin reflectance spectrum are caused by the increased hemoglobin absorbing radiation according to FIG. 4 . Thus, it is the increased attenuation, over that of non blushing skin, exhibited at the attenuated regions (corresponding to maxima 49 , 50 , and 53 ) upon which the processor 28 bases the determination that a blush is present.
[0059] To aid in detecting the increased attenuation caused by a blush, a data base (not shown) may be accessed by the processor 28 . From the data base the processor may extract normal, non blushing, and blushing skin reflectance data from one or more subjects similar in skin type to that of the subject 14 . From the data, the processor may more precisely determine the range of wavelengths at which blush caused attenuation would occur and further characterize the amount of increased attenuation likely to be observed during a full blush. Accordingly, the system 10 may make a highly accurate determination of the presence of even a partial blush.
[0060] It should also be noted too that the palms have a more reddish tint than other areas of the body. Thus, per the present invention, if the image 22 contains an image of the palm, the palm spectrum can be used to verify that a blush has been positively identified. If the increased attenuation of the identified blushing spectrum resembles, or exceeds, the increased attenuation of the palm spectrum a high likelihood exists that the blush determination was successful. Note that the data base discussed above may also include data for the skin reflectance data for numerous, varied skin types thereby further enabling the system 10 to make a highly accurate blush determination.
[0061] In addition, or in the alternative, the effect dermal hydration has on the reflected skin spectrum may be used to determine if a subject 14 is blushing. In particular, FIG. 5 shows a graph of the extinction coefficient of water. Since perspiration largely consists of water, the properties of perspiration will largely resemble the properties of water.
[0062] Also, of note, FIG. 5 shows the extinction coefficient of water 60 as opposed to a graph of the absorption coefficient (as shown for hemoglobin in FIG. 4 ). However, because the extinction coefficient is the sum of the absorption coefficient and the scattering coefficient, similar reasoning applies to the attenuation caused by hemoglobin and the attenuation caused by thermal hydration. It will be understood also that the extinction coefficient is usually given in terms of the fraction of light lost over a given distance.
[0063] Thus, as indicated in FIG. 5 , dermal hydration will cause attenuation in the skin reflectance spectrum in ranges of high absorption 62 and 64 . The effects, including those of a high derivative range associated with areas 62 and 64 , may be used by the image processor 28 to determine or confirm that a blush has been identified.
[0064] One notable difference between the light absorption by hemoglobin and dermal hydration is that hemoglobin absorbs strongly in ranges of the visible spectrum. In contrast, perspiration is largely transparent to visible radiation. Instead perspiration absorbs strongly in ranges of the near infrared spectrum.
[0065] Accordingly, the presence of perspiration on the selected area of the subject 14 will cause attenuation of the skin reflectance spectrum 34 (shown in FIG. 3 ) in a range 62 near 1400 nanometer and especially in a range 64 above about 1700 nanometers. Thus, image processor 28 may determine, or confirm, the presence of a blush and stress by examining the intensity of the reflected spectrum for a selected area near 1400 nanometers and above 1700 nanometers for attenuation in a manner similar to that set forth herein with reference to hemoglobin. If dermal hydration is found, then the image processor 28 may determine or confirm that a blush is occurring.
[0066] At least one advantage of the present invention arises because of the examination of visible radiation for hemoglobin attenuation and infrared radiation for dermal hydration. Some unsophisticated subjects 14 may be aware enough of the possibility of surveillance to attempt masking their skin with material (e.g. makeup) effective in the visible spectrum yet totally ineffective in the infrared spectrum or visa versa. Thus, the present invention which may examine wavelengths in both ranges provides a mechanism to penetrate attempted camouflage.
[0067] In a preferred embodiment of the present invention, a method 66 may be seen depicted in FIG. 6 . The method 66 consists of identifying a human subject 14 for subsequent examination in step 68 . An area indicative of a blush and an area indicative of the subject's inherent skin type may then be selected in parallel, or series, in steps 70 and 72 respectively. Statistical comparisons of the spectrum from the two areas of skin may then be made to determine by how much one may vary from the other due to factors other than a blush as in step 74 . Of course these statistical comparisons should be made outside of the ranges of interest (e.g. ranges near 542, 560, 576, 1400, and above 1700 nanometers) where large changes are to be expected due to blushing. Such a statistical comparison may suppress false alarms due to variations between the two areas of skin on the same subject. For instance, if the area subject to blushing happens to be in shade, the lessened intensity might otherwise be construed as blushed induced attenuation.
[0068] In step 76 , the spectrum from the two areas may then be compared. In particular comparisons may be made near at least one of 542, 560, 576, 1400, and above 1700 nanometers to determine if a blush is present. If desired, in step 80 , the result may be confirmed by more detailed analysis (e.g. high derivative areas 55 , 56 , and 57 may be examined) or the palm reflectance spectrum may be used. Based on the comparisons, if the blush susceptible area shows attenuation in one or more of the selected ranges a blush may be declared in step 82 . If no attenuation, not enough attenuation, or attenuation in too few of the selected wavelengths is observed then a target is declared to be non-stressed.
[0069] As will be appreciated by those skilled in the art, the present invention provides a reliable system with which to detect physiological stress in human beings. Moreover, because of the image processing software according to the present invention, subtle changes in skin reflectance spectra indicative of an emerging blush may be detected before the human eye would notice the change. Additionally, methods to defeat camouflage or masking of a subject's skin have been presented.
[0070] While various preferred embodiments have been described, those skilled in the art will recognize modifications or variations which might be made without departing from the inventive concept. The examples illustrate the invention and are not intended to limit it. Therefore, the description and claims should be interpreted liberally with only such limitation as is necessary in view of the pertinent prior art.
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A system and method for detecting physiological stress in a person is provided which includes an imagining device and a processor. The processor receives an output from the imagining device representative of the. The processor identifies a characteristic of the person in the image which indicates that the person is not experiencing stress and a second characteristic which indicates the person is experiencing stress. A comparator compares the image of the subject and the two characteristics and the processor extrapolates from the comparison whether or not the person is experiencing a heightened state of stress or nervousness. If so the processor provides an output to activate an alarm or otherwise signal this condition to other individuals involved in monitoring a given area.
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The present application is a continuation and improvement of Canadian patent application No. 2,859,258 filed Aug. 11, 2014.
This invention relates generally to aircraft and watercraft propulsion, more particularly to an apparatus and method for generating fluid-dynamic forces, for augmenting propulsion, creating moments providing directional control to said craft, generating increased thrust at reduced speed, ensuring reduced drag at increased speed.
BACKGROUND
There are a lot of devices that enhance lift generated by a wing at reduced speed, as slats, slots, flaps, but generally they do not provide any lift at zero aircraft speed. There are also well known vertical or short take off and landing (V/STOL) craft that adopts several methods for generating lift during VTOL operation, but each of them has certain disadvantages.
The most known hovering craft is the helicopter; to create lift it employs a rotor, that in order to achieve high efficiency in hover mode, it has a low disc loading, invariably leading to a large rotor, creating difficulties as the helicopter speed increases, such as retreating blade stall, high drag and loss of efficiency, making the helicopters unsuitable to operate at higher speed. A method to combat these deficiencies are employed by tilted rotor and tilted wing aircraft, such as Bell Boeing V-22 Osprey and Canadair CL-84. Their design is a compromise between hovering configuration efficiency, having higher disk loading than helicopters, and horizontal configuration efficiency, having more propeller disk that they need for generating forward thrust, resulting in more drag, compared to fixed wing aircraft. Another approach to eliminate retreating blade stall and to increase speed of a helicopter is employed by the compound helicopter, such as Piasecki X-49 and Eurocopter X3. This approach involves unloading the rotor disk at high speed, lift being provided partially by small wings, and having forward thrust provided by an auxiliary propulsion system. Although this method increases maximum speed of the compound helicopter, efficiencies, both in hovering and in forward flight, are reduced, because in each mode, there is an extra system, contributing little to the operation, leading to increased weight and drag.
Static lift generated by a propeller or fan is increased, if the propeller is enclosed into a shroud or a duct, tip losses are reduced, the shroud intake provides itself thrust, but although a shrouded propeller creates more static thrust, the drag created by the shroud becomes prohibitive as speed increases, and above a certain breakeven speed, the efficiency drops below of that provided by an open air propeller. A shroud optimized for high static thrust have a large bell shaped inlet, creating increased amount of drag, inherently inefficient at increased speed. An VTOL craft employing shrouded propellers to achieve VTOL flight is the experimental Bell X-22, but unable to achieve it's goal, the required maximum speed. Aircraft having shrouds optimized for high static trust are the Hiller VZ-1 Pawnee and the SoloTrek XFV. They were designed to operate exclusively in hover mode, inherently having a reduced transport efficiency.
Channel (Custer) wing type aircraft, as the CCW-5, have wings able to create lift at reduced speed, some test have shown they create an amount of lift even at zero speed. NACA tests of a channel winged aircraft shows less than 10% total thrust increase and lack of control at slow speed. It also suffers from vibration problems because the propeller blades have different loading in the proximity of the channel versus the open air.
In marine application, there are also devices augmenting propulsion system, but each of them are having certain disadvantages. Devices for increasing propeller thrust, as Kurt nozzles or accelerating ducts, are functioning optimum in certain conditions and designed speed. Major disadvantages are increased drag and cavitation as boat speed increases, and decreased efficiency. Debris and ice can be jammed between the propeller and the nozzle, and are much more difficult to clear than open propellers. Another type of devices used for augmenting propulsion are the decelerating ducts, used for reducing cavitation and noise, for high speed applications. They have certain disadvantages as well, the biggest disadvantage is efficient operation around a limited speed range, reduced thrust, increased drag and decreased efficiency. Debris and ice can be jammed between the propeller and the nozzle as well, the same as for Kurt nozzles.
There is a definite need for improvement, a need for a system that augments thrust and provides control at reduced speed, yet ensuring low drag at increased speed.
SUMMARY
It is an object of one or more aspects of the invention to provide craft directional control and propulsion augmentation arrangement and method which is effective at low and zero speed, and ensure low drag at increased speed.
It is a further object of one or more aspects of the invention to provide such an arrangement and method specifically for attitude control and thrust augmentation, in order to provide V/STOL operation capability and aircraft manoeuvrability without affecting high speed performance of the aircraft.
Another object of one or more aspects of the invention is to provide such an arrangement and method specifically for efficiently augmenting thrust, to improve control and acceleration, at slow or zero speed, and improving high speed performance of the craft, used for watercraft and aircraft.
These objects are accomplished by providing a wing, located in a propulsion system fluid intake region. The relative position between the wing and the propulsion system intake can be varied, determining how the intake fluid stream is perturbed and consequently varying direction and magnitude of a fluid-dynamic force generated by the wing, determining craft moments variation, providing directional control, and augmenting propulsion.
The wing is having a slanted trailing edge coinciding with a fraction of the propulsion system intake, so the propulsion system intake can be placed at a predetermined angle, designed so to optimize certain parameters.
The wing and the propulsion system are connected using a joint, allowing adjustment in their relative position. For varying the relative position of the lip wing and the propulsion system, a mechanical linkage or an actuator is employed, controlled manually or by a computerized system, configured to vary the relative position as function of data received from input devices, to control the craft attitude, and control the augmentation of the propulsion system.
At zero or slow speed, the wing and the propulsion system intake are placed adjacently, the intake fluid stream is accelerated creating a low pressure area, influencing the wing so it generates the fluid-dynamic force augmenting thrust and creating control moments for adjusting craft attitude.
As speed increases, the wing and the propulsion system position is varied such as the wing and the propulsion system are disturbing less the fluid stream, the wing follows the fluid stream convergence, maintaining such an angle of attack to ensure increased lift per drag ratio, varying the wing's generated fluid-dynamic force and determining changes in control moments for adjusting craft attitude.
At high speed, the wing and the propulsion system are positioned approximately parallel to the fluid stream, so as to reduce their effect on the drag of the craft. The wing as described is further referred as the lip wing.
Accordingly several advantages of one or more aspects of the invention are as follows: capability to provide efficiently high thrust, to improve acceleration, to provide increased static thrust for watercraft and aircraft, and to improve hovering efficiency for V/STOL aircraft in vertical flight regime. Other objects and advantages are to also ensure low drag at increased speed, improve transport efficiency, reduce fuel consumption and allow a smaller installed power for the craft. Other objects and advantages are the ability to provide directional and attitude craft control, reducing or eliminating need for dedicated control surfaces, and to augment and control the propulsion system generated thrust.
Other objects and advantages are: reduced cavitation and noise; the wings can act as a pair of rudders; total drag is comparable to a standard propeller and rudder combination; ability of the system to be adjustable, at slow speed creating more thrust, improving acceleration or pull, at high speed having reduced drag and cavitation; the propeller is protected and prevented to hit bottom or foreign objects; ensured ability to easily clean debris from a fouled propeller.
Further objects and advantages will become apparent from a consideration of the drawings and ensuing description.
Drawings Reference Numerals
10 - lip wing;
10′ - blended wing
11 - propeller;
13 - intake region;
14 - articulation;
14′ - bracket;
15 - fluid stream;
16 - slanted trailing edge;
17 - inlet;
18 - propeller perimeter;
19 - wing curvature;
20 - shroud;
21 - control angle;
22 - streamlined surface;
23 - control moment;
24 - actuator;
25 - computerized system;
26 - input device;
27 - main pilot control device;
28 - fluid speed sensor;
29 - slant angle;
30 - canopy;
31 - struts;
32 - pivoting direction;
33 - reduced drag position;
34 - main assembly;
35 - conventional wing;
36 - control surfaces;
37 - fuselage;
38 - auxiliary propeller;
39 - canard wings;
40 - control slats;
41 - vertical stabilizer;
42 - engine nacelle;
43 - wing-let;
44 - fluid dynamic force;
45 - thrust;
46 - vertical axis;
47 - axial component;
48 - transversal component;
49 - yaw control moment;
50 - stabilizer;
51 - vertical component;
52 - pitch control moment;
53 - roll control moment;
56 - wing hub;
LIST AND DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of the lip wing apparatus configured for high thrust operation;
FIG. 2 is a sectional side view of the lip wing apparatus configured for high thrust operation;
FIG. 3 is a sectional side view of the lip wing apparatus, low drag configuration;
FIG. 4 is a perspective view of a system having two lip wings, configured for high thrust operation;
FIG. 5 is a perspective sectional front view of the system having two lip wings;
FIG. 6 is a perspective view of a single lip wing system aircraft configured for V/STOL operation;
FIG. 7 is a perspective top view of the single lip wing system aircraft configured for horizontal operation;
FIG. 8 is a perspective front view of the single lip wing system aircraft configured for horizontal operation;
FIG. 9 is a block view of a system for controlling the position of an actuator;
FIG. 10 is a perspective view of an aircraft, having three lip wings, configured for V/STOL operation;
FIG. 11 is a perspective top view of the aircraft, having three lip wings, configured for horizontal operation;
FIG. 12 is a perspective side view of the aircraft, having three lip wings, configured for horizontal operation;
THEORY OF OPERATION
The phenomenon of fluid-dynamic force generation by a wing placed in the intake stream of a propulsion system, such as a propeller or fan, and the effect of the wing exerted on the propulsion thrust have several views or explanations.
A particular view regards pressure distribution around the system formed by the propeller and the wing. A propeller producing thrust can be viewed as an infinitely thin disk creating a pressure difference between it's sides. The amount of thrust created is equal to the area of the disk, multiplied by the average pressure difference. At the edge of the disk the fluid passes from the high pressure side to the low pressure side, reducing pressure difference and efficiency. The addition of the wing creates a separation between the high and low pressure areas, impeding some of the fluid passage, increasing the average pressure difference and resulting in more thrust being produced. Some of the pressure difference act on the wing as well, so it is generating a fluid-dynamic force. Modifying the relative position of the wing and the propeller, is determining changes in the direction and magnitude of the generated force, enabling directional and thrust control. The total system thrust is a resultant of vector addition between the already increased propeller thrust and the wing generated force.
Another view involves Newton's third principle; by accelerating a mass of fluid in one direction, thrust is created in the opposite direction. The amount of generated thrust is equal to fluid mass multiplied by acceleration. Although same thrust magnitude can be produced by a small acceleration of a large mass of air, or a large acceleration of a small mass of air, a small acceleration of a large mass of air is much more efficient, requiring less power, as the kinetic energy transmitted to the air is proportional to the squared speed. Most of the accelerating fluid molecules are in front of the propeller, in the intake region. Because molecules in a fluid are interacting with each other, the acceleration vector also have a side-wise component, more pregnant on molecules situated further from the propeller axis, receiving kinetic energy, but contributing less to the thrust. The molecules situated outside the propeller perimeter are even accelerated forward, diminishing produced thrust. Addition of the wing in the intake region, in certain conditions, impedes side-wise and forward acceleration of some molecules, and forcing more molecules, a larger mass of fluid, to be accelerated in the same general direction, increasing efficiency and contributing to the thrust.
Another particular view, well-known to the art, extensively used to predict and calculate fluid-dynamic forces generated by wings, is given by the mathematical model of circulation or Kutta-Joukowski theorem: generated wing lift is proportional to wing circulation multiplied by free-stream velocity. Unfortunately the Kutta-Joukowski theorem is ill suited to model the lift generated by an airfoil placed in the intake stream of a propulsion system. As defined, the theorem is valid for uniform stream condition, and needs to be amended to correctly predict the lift generated by a wing subjected to a convergent intake stream of a propulsion system.
DETAILED DESCRIPTION
A first embodiment is presented in FIG. 1 , FIG. 2 and FIG. 3 . A perspective view of the apparatus for providing craft control and augmenting propulsion, configured for providing high thrust is shown in FIG. 1 . It shows a propeller or fan 11 , mounted inside a shroud or duct 20 creating what is known in the art as a shrouded or ducted propeller or fan. The shroud 20 is having an intake region or region of disturbed aspirated fluid 13 . Awing or an airfoil shaped body 10 is located in the intake region 13 . An engine, not shown, rotates and provides power to the propeller 11 , housed in an engine nacelle 42 . Struts 31 provide support structure to the shroud 20 .
The shroud 20 is exhibiting an inlet or a leading edge 17 . The wing 10 is having a trailing edge 16 coinciding, matching a fraction of the inlet 17 . The trailing edge 16 is slanted, to allow adjacent placement of the shroud 20 , forming a certain angle. The wing 10 placed adjacently to the inlet 17 , creates a lip or a bell shaped, smooth and aerodynamic streamlined surface 22 , enlarges the surface area, and changes the geometry of the inlet 17 so to accelerate more of the fluid flow. The surface 22 is exposed to low pressure, high speed stream of fluid, the same as the top surface of any regular wing, so it have the same properties. The lip wing 10 exhibits a curvature 19 , to geometrically account for the shape of the slanted trailing edge 16 , to provide a lower front profile for the wing 10 , reducing drag at high speed, and also to form a fore and aft channel, to contain and direct, and to better capture the effect of the fluid stream accelerating towards the inlet 17 . The wing 10 as described, is further referred as the lip wing 10 .
The shroud 20 , the propeller 11 , struts 31 and engine nacelle 42 are connected together, forming a main assembly 34 . The lip wing 10 and the main assembly 34 are connected using aerodynamically shaped pivoting articulations or joints, 14 , to allow adjustment in their relative position. A mechanism for controlling the rotation of the articulations 14 , such as a mechanical linkage or an actuator, is not shown, such devices are well known to the art. Sectioning plane and viewing direction 2 is also shown.
FIG. 2 shows a sectional side view of the first embodiment, configured for high thrust. The support struts, engine and engine nacelle are not shown. At the intake region 13 , aspirated by the propeller 11 , a fluid stream or flow 15 enters the shroud 20 . The streamlined surface 22 , created by adjacently placing the slanted trailing edge 16 of the lip wing 10 to the inlet 17 fraction, is visible. The lip wing 10 and shroud 20 chords are forming a slant angle 29 . The wing 10 disturbs the fluid flow 15 and creates a fluid-dynamic force 44 .
A thrust or propulsive force 45 is generated by the propeller 11 . The fluid-dynamic force 44 is vectorially decomposed into two components, one along the thrust 45 direction, resulting in an axial component or vector 47 , and the other along a transverse direction, resulting in a transversal component or vector 48 . The axial component 47 augments the thrust 45 , the transversal component 48 could in certain conditions to create or augment a control moment 23 .
An arrow 32 shows the pivoting direction of the shroud 20 to reduce the disturbance of fluid stream 15 by the lip wing 10 , consequently reducing drag.
FIG. 3 shows a side sectional view of the first embodiment, configured for low drag. The support struts and engine are not represented. The lip wing 10 and the shroud 20 are positioned approximately parallel to the fluid stream 15 , to ensure low drag. Pivoting the shroud 20 in the direction shown by the arrow 32 modifies a control angle 21 and the direction of the thrust 45 , created by the propeller 11 , consequently modifying the control moment 23 .
Operation
FIG. 2 shows the system configured for generating high thrust, configuration obtained by controlling the control angle 21 , and pivoting the shroud 20 , and placing the inlet fraction 17 adjacently to the slanted trailing edge 16 of the lip wing 10 . This configuration is highly efficient at slow or zero speed, as the lip wing affects highly the fluid stream 15 acceleration, as explained in the theory of operation.
As speed increases, beside creating an increased drag force, not shown, it determine a reduction of thrust 45 augmentation, caused by the fluid stream 15 speed increase for which the position of the shroud 20 is no longer adequate. The shroud 20 is pivoted, by controlling the control angle 21 , in the direction shown by the arrow 32 , to maintain an adequate position, correlated to the increased fluid speed, increasing thrust augmentation, and reducing drag.
As speed is increased further, the shroud 20 is pivoted more, as previously described, until reaching the position depicted in FIG. 3 . In this position the lip wing 10 and the shroud 20 , have less influence on fluid stream 15 , having reduced angles of attack, and are generating reduced drag. By controlling the control angle 21 , and pivoting the shroud 20 , the control moment 23 is modified, capable of providing attitude control to the craft.
System Design
During design, an aircraft could be provided with one or more lip wings, either located and sharing the intake of one propulsion system, or located at the intake of separate propulsion systems. Lip wing thrust augmentation experiments are showing 65% thrust increase of a lip wing system versus a similar dimension open propeller, and 20% thrust increase of a lip wing system versus a similar dimension shrouded propeller. Depending on the location of the lip wings, in respect to the centre of gravity, or the craft's centre of dynamic pressure, the generated fluid-dynamic forces could be varied differentially, to create or augment one or more control moments, consequently to control the attitude of the craft. Further details of control dynamics are well known to the art.
Lip Wing Geometry
Increasing the chord of the lip wing is effectively increasing it's surface area, and cause it to generate an increased amount of force. Increasing the lip wing's chord is effective up to a point because the leading edge of the wing is subjected less and less to the effect of the intake fluid stream. Aircraft weight, wing loading, induced and skin drag, and other considerations could affect the lip wing dimensioning decision.
The lip wing trailing edge slant angle determines also the force generated by the lip wing. The slant angle is calculated as function of fluid convergence, fluid speed, fluid density and temperature, propeller dimensions, geometry and power applied, shroud and lip wing dimensions and airfoil geometry. The geometry of the whole assembly is calculated to increase some goal parameters, as efficiency of the craft at cruise speed correlated to hovering efficiency, or lift per drag ratio in a certain speed range.
The control angle relationship to fluid speed. The intake fluid stream have a high convergence at slow speed, in other words, the side-wise speed of fluid particles located further from axis is high, converging towards the intake. The lip wing lift per drag ratio, L/D, is dependant on the angle of attack, and has an increased value for a specific angle of attack depending on the airfoil geometry. As the intake stream speed increases, the fluid stream convergence becomes lower, decreasing the angle of attack of the wing and decreasing the L/D of the wing. The control angle is changed, pivoting the wing to follow the fluid stream convergence change, to maintain an adequate angle of attack to ensure increased L/D.
Description of a System for Augmenting Propulsion and Providing Yaw Control for a Watercraft
Another particular embodiment is a system for augmenting propulsion and providing yaw control for a watercraft, air-boat, hovercraft or ship. The system can be designed for conventional boats, having water immersed propellers, the working fluid being water, or it can be designed for air-boats and hovercrafts, having air propellers. The system is presented in FIG. 4 and FIG. 5 .
FIG. 4 presents a perspective view of the system. The system is having two lip wings 10 , located in an intake region 13 of a propeller 11 . The lip wings 10 are having similar parts and properties, as defined in the first embodiment. The system have two vertical pivoting articulations or joints 14 for independently pivoting the lip wings 10 on vertical axis 46 . A bracket or similar support structure 14 ′ provide rigidity and support for connected elements. The powering method of the propeller 11 , as an engine or a shaft, is not shown. Also not shown are mechanisms for controlling the rotation of the articulations 14 , such as mechanical linkages or actuators, those devices are well known to the art.
The propeller 11 is having an outside circular perimeter or circumference 18 , delimiting the intake region 13 . Each of the lip wings are having a slanted trailing edge 16 substantially coinciding with a fraction of the perimeter 18 , and consequently having a circular arc shape. Each of the lip wings 10 are exhibiting a curvature 19 , to geometrically account for the circular arc shape of the slanted trailing edge 16 , and consequently forming a fore and aft channel.
FIG. 5 is a front perspective sectional view of the system presented in FIG. 4 . At slow speed, each of the lip wings 10 are pivoted, using articulation 14 , and positioned with the slanted trailing edge 16 adjacently to the perimeter 18 of the propeller 11 . Each of the lip wings 10 is disturbing fluid flow and generating fluid-dynamic forces 44 . The propeller 11 is generating a thrust force 45 . Each of the force generated by the lip wings 10 , is vectorially decomposed into two components, one along the thrust 45 direction, resulting in axial components 47 , and another one along a transverse direction, resulting in transversal components 48 . By asymmetrically pivoting the lip wings 10 in respect to propeller 11 , the direction and magnitude of the forces 44 are varied, so the transversal components 48 , having different magnitudes, are creating a yaw control moment 49 . When the speed is increased, the wings are pivoted as indicated by arrows 32 , until reaching a reduced drag position 33 .
Operation of the System for Augmenting Propulsion and Providing Yaw Control for a Watercraft
At zero or slow speed, the lip wings are pivoted so their slanted trailing edge 16 is positioned adjacently to the perimeter 18 of the propeller 11 , to enhance the effect of the fluid flow and increase augmentation of the thrust 45 by the fluid-dynamic forces 44 . Pivoting and positioning symmetrically each lip wing 10 , relative to the propeller 11 , determine the transversal components 48 to have the same magnitude, but opposite direction, so they cancel each other. Each of the axial components 47 are adding to the thrust 45 , augmenting it.
Steering or yaw control is accomplished by pivoting differentially the lip wings 10 in respect to the propeller 11 , differentially modifying transversal components 48 , consequently modifying the yaw control moment 49 .
As speed increases, the lip wings 10 are pivoted towards a more adequate position, increasing lift per drag ratio, as presented in the first embodiment. Reduced drag is achieved by pivoting the lip wings into positions 33 , as presented in the first embodiment. Yaw control is ensured by using lip wings 10 as rudders, modifying yaw control moment 49 .
Description of a Single Lip Wing V/STOL Aircraft
Another particular embodiment is a V/STOL aircraft, presented in FIG. 6 and FIG. 7 . FIG. 6 is showing a perspective view of the aircraft, configured for V/STOL operation.
The aircraft is having a fuselage 37 , a bow located auxiliary propeller 38 , a stern located lip wing 10 , having same parts and properties as described in the first embodiment. The lip wing is blended with the fuselage 37 , creating a lifting body, and also having a pair of conventional wings 35 , extending the wingspan of the aircraft. The conventional wings 35 are connected to the lip wing 10 , using hubs or hinges or rotary joints 56 , to allow folding for easier storage or road-ability. The conventional wings 35 extremities are ending in wing-let or wing tip devices 43 .
The aircraft is having, at the stern, a main assembly 34 , similar to the assembly described in the first embodiment, having a shroud 20 , a propeller 11 , struts 31 and an engine nacelle 42 . The main assembly 34 also includes a plurality of control surfaces 36 , rotatable on radial axes, placed in the propeller's 11 slip stream.
The main assembly 34 is connected to the lip wing 10 , using a pair of articulations 14 . Blended with the fuselage 37 , a vertical stabilizer 41 houses an actuator 24 , for controlling the pivoting of the main assembly 34 .
The auxiliary propeller 38 is covered top and bottom by a plurality of control slats 40 , exposing the auxiliary propeller 38 , and providing vectored thrust. A pair of canard wings 39 are located on front of the fuselage 37 . A canopy 30 provides visibility and access to a cockpit, not shown.
FIG. 7 shows a top view, and FIG. 8 shows a front view of the V/STOL aircraft configured for horizontal flight.
The main assembly 34 is pivoted, using articulations 14 , in a horizontal position, to generate mainly horizontal thrust, for horizontal flight. Visible components, parts of the main assembly 34 , are: the shroud 20 , the engine nacelle 42 , struts 31 , on FIG. 7 are visible control surfaces 36 , and visible on FIG. 8 is the propeller 11 .
The lip wing 10 is generating lift, as well as the conventional wings 35 , the left conventional wing, partially shown, is symmetrical to the right conventional wing 35 . The hub 56 connects the conventional wings 35 to the lip wing 10 , and during horizontal flight, keeping them in the deployed, extended position. The wing-lets 43 , visible in FIG. 8 , are reducing wing tip loses.
The control slats 40 are covering the auxiliary propeller, not shown, reducing drag. The canard wings 39 provide lift, and are augmenting pitch and roll control. Visible on the fuselage 37 are also the canopy 30 and in FIG. 7 , the blended vertical stabilizer 41 .
FIG. 9 shows a system for controlling the position of the actuator 24 , for pivoting the main assembly, not shown, to a control angle, not shown. A computerized system 25 controls the position of the actuator 24 , and is programmed to calculate the control angle, as function of data provided by input devices 26 . A fluid speed sensor 28 provides speed information, a main pilot control device 27 provides pilot control input information. Other input devices as gyro-sensors and accelerometers, are not shown.
Operation of the Single Lip Wing V/STOL Aircraft
The aircraft configured for VTOL operation, as shown in FIG. 6 , is generating vertical aerodynamic forces or lift, using the main assembly 34 , the lip wing 10 and the auxiliary propeller 38 . The main assembly 34 is pivoted to a position bringing the shroud 20 adjacently to the lip wing 10 , augmenting thrust, as described in the first embodiment. The pitch control is provided by differentially controlling the propellers 38 and 11 , and by pivoting the main assembly 34 , as described in the first embodiment. Roll and yaw control is provided by control surfaces 36 , placed in the propeller's 11 slip stream, providing control even at slow or zero speed, and the bottom control slats 40 which are vectoring auxiliary propeller thrust.
As the aircraft speed increases, the conventional wings 35 are starting to provide lift, unloading the main assembly 34 , which can be pivoted, as described in the first embodiment, and increasing horizontal thrust, that could be used to more speed increase.
Above a certain speed, the canard wings 39 , the lip wing 10 and conventional wings 35 are providing enough lift to balance the weight of the aircraft, the auxiliary propeller 38 is stopped and covered top and bottom by the control slats 40 , and the main assembly 34 is placed in a position as shown in FIG. 7 and FIG. 8 , generating mainly horizontal thrust, position ensuring reduced drag, as described in the first embodiment.
Pitch and roll control is determined by the canard wings 39 and control surfaces 36 . Yaw control is determined by the control surfaces 36 . Pivoting the main assembly 34 also could contribute to pitch control, as described in the first embodiment.
Description of a Three Lip Wing V/STOL Aircraft
Another particular embodiment is a V/STOL aircraft, having a system for augmenting thrust and providing yaw, roll, pitch and thrust control, by using three lip wings arranged around the inlet of a shrouded propeller. The aircraft is presented in FIG. 10 , FIG. 11 and FIG. 12 .
FIG. 10 shows a perspective view of the aircraft configured for VTOL operation. The aircraft is having an extended wingspan, blended wing 10 ′, a central section of the wing forming a lip wing as described in the first embodiment. At extremities, the blended wing 10 ′ is curved, forming wing tip devices or wing-lets 43 . The aircraft is having another two regular lip wings 10 . All three wings, each of the lip wing 10 and the blended wing 10 ′, are having the same elements, and having the same properties and behaviour as described in the first embodiment. They are independently pivoting on three articulations 14 , are arranged around an inlet 17 of a shroud 20 .
Each of the lip wing 10 and the blended wing 10 , are pivoted adjacent to the inlet 17 , forming a VTOL or high thrust position. Attached to the shroud 20 are control surfaces 36 , rotatable on radial axes, located in front of a propeller 11 . The control surfaces 36 also act as support elements, and are providing support structure to fuselage 37 , eliminating the need for separate struts, contributing to reduced drag. Each of the lip wing 10 and the blended wing 10 ′ are having stabilizers 50 , housing actuators 24 , for controlling independently the position of each of the lip wing 10 and blended wing 10 ′.
Each of the lip wing 10 and the blended wing 10 ′ are generating aerodynamic forces, not shown, augmenting and increasing thrust, not shown, provided by the propeller 11 , as described in the first embodiment. The vector addition of wings 10 and 10 ′ generated aerodynamic forces, and the propeller 11 generated thrust, is a resultant force, not shown, that is vectorialy decomposed on an axial component 47 , transversal component 48 , and vertical component 51 . Varying the lip wings 10 , the blended wing 10 ′, and the control surfaces 36 , in different combinations, yaw control moment 49 , pitch control moment 52 , and roll control moment 53 are created.
FIG. 11 shows a top view, and FIG. 12 shows a side view of the V/STOL aircraft configured for horizontal flight. The lip wings 10 and the blended wing 10 ′ are pivoted, using the articulations 14 , in the horizontal position, approximately parallel to the fuselage 37 , reducing drag. The duct 20 and control surfaces 36 provide attitude control and stability to the aircraft. The wing-lets 43 are reducing the blended wing 10 ′ tip loses and are increasing efficiency. The blended wing 10 ′ is swept forward to increase stability provided by the duct 20 .
Operation of the Three Lip Wing V/STOL Aircraft
FIG. 10 is presenting the aircraft configured for high thrust and VTOL operation, the lip wings 10 , and the lip wing section of the blended wing 10 ′, are pivoted adjacently to the inlet 17 of the shroud 20 , increasing the magnitude of the axial component 47 , similar as described in the first embodiment. The force components generated by the lip wings 10 , and the lip wing section of the blended wing 10 ′, along the direction of the transversal component 48 and the vertical component 51 , are cancelling each other.
By pivoting independently each of the lip wing 10 and blended wing 10 ′, the axial component 47 , transversal component 48 and the vertical component 51 are modified, generating yaw control moments 49 , pitch control moment 52 , roll control moment 53 , and thrust augmentation control. Roll control moment 53 is augmented, and propeller 11 anti-torque moment, not depicted, is generated by differentially pivoting the control surfaces 36 .
As speed increases, the blended wing 10 ′ outer region, the conventional wing section, is generating lift, and allowing the lip wings 10 and the blended wing 10 ′ to be pivoted, to improve lift per drag ratio, as described in the first embodiment. As speed increases more, the process described can be repeated, until the lip wings 10 and the blended wing 10 ′ are in a horizontal position, approximately parallel to the fuselage, as shown in FIG. 11 and FIG. 12 , ensuring reduced drag.
Attitude control is provided the same as in VTOL configuration, by pivoting independently each of the lip wing 10 and blended wing 10 ′, by differentially pivoting the control surfaces 36 , determining variation in yaw control moment 49 , pitch control moment 52 and roll control moment 53 .
CONCLUSION, RAMIFICATIONS, AND SCOPE
It will be apparent to those skilled in the art that the invention is applicable to a wide variety of craft design configurations, providing several advantages as: capability to provide efficiently high thrust, to improve acceleration, to provide increased static thrust for watercraft and aircraft, and to improve hovering efficiency for V/STOL aircraft in vertical flight regime. Other objects and advantages are to ensure low drag at increased speed, improve transport efficiency, reduce fuel consumption and allow a smaller installed power for the craft. Other objects and advantages are the ability to provide directional and attitude craft control, reducing or eliminating need for dedicated control surfaces, and to augment and control the propulsion system generated thrust. Other objects and advantages are: reduced cavitation and noise; the wings can act as a pair of rudders; total drag is comparable to a standard propeller and rudder combination; ability of the system to be adjustable, at slow speed creating more thrust, improving acceleration or pull, at high speed having reduced drag and cavitation; the propeller is protected and prevented to hit bottom or foreign objects; ensured ability to easily clean debris from a fouled propeller.
While my above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of embodiments thereof. Many other variations are possible. For example an aircraft could be designed with two or more apparatus as described in the first embodiment, enhancing thrust and control, and having increased stability. A particular embodiment example could have the wing and the propulsion system connected using a sliding joint. The lip wing could enhance a variety of propulsion systems, as gas turbines, turbofans, turbojets or any other jet engines or propulsion systems designed to create propulsion force by accelerating fluid.
Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.
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The invention provides a fluid propulsion augmentation arrangement and method, capable of also generating control moments ( 23 ), providing increased thrust ( 45 ) at reduced speed, reduced drag at increased speed, under conditions in which traditional approach cannot provide sufficient performance. It consists of a wing ( 10 ) located in a propulsion system ( 11 ) fluid intake region ( 13 ), having a slanted trailing edge ( 16 ) coinciding with a fraction of the propulsion intake ( 17 ), pivotally connected ( 14 ), allowing position adjustments. At reduced speed, the wing ( 10 ) and the propulsion system intake ( 17 ) are placed adjacently, the intake low pressure determines wing ( 10 ) fluid-dynamic force ( 44 ) generation. Increasing speed, wing ( 10 ) position varies, following fluid stream ( 15 ) convergence change, maintaining an angle of attack for increased L/D, ensuring increased performance, and also varying control moments ( 23 ).
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This application is a divisional of Ser. No. 013,254, filed Feb. 3, 1993, now U.S. Pat. No. 5,450,564, which is a continuation of Ser. No. 518,911, filed May 4, 1990, abandoned.
BACKGROUND OF THE INVENTION
This invention relates to cache memory systems for use in a parallel-pipelined computer system and in particular to such a cache memory having an efficient interface with main memory.
A conventional computer system includes a central processing unit (CPU) a memory subsystem and an input/output (I/O) subsystem. In some computer systems, the principle connection among these three entities is a single bidirectional bus. In other systems, the CPU and memory are connected by one bus while the I/O subsystem is connected to the memory by another bus. It is well known that, in either configuration, the performance of the system is at least partly dependent on the speed at which data can be transferred between the CPU and the memory.
In general terms, this problem has been addressed by increasing the "bandwidth" of the bus. As used herein, the bandwidth of a bus is a measure of the amount of data which can be transferred over the bus in a unit time interval.
There are, however, many ways in which the apparent bandwidth of the memory bus may be increased. One method is to provide a wider bus, that is to say one which conveys a greater number of bits in parallel between the CPU and the memory. Another method is to provide faster memory. This may be done either by using higher performance memory components or by partitioning the memory so that multiple memory fetch operations may proceed in parallel.
Interleaving is a particular type of memory partitioning. In an interleaved memory subsystem, memory cells having successive addresses are assigned to respectively different partitions. This partitioning allows the fetch operations for consecutively addressed words to be overlapped. In a four-way interleaved memory subsystem, for example, data for any four memory cells having consecutive addresses may be fetched or stored in parallel. Thus, the apparent memory cycle time of an interleaved memory is a fraction of the memory cycle time of the actual memory devices as long as a significant portion of memory operations access consecutive memory cells.
Partitioning does not speed up all memory accesses, however, since successive memory access requests which map onto the same memory partition will occur at the memory cycle time of the actual memory devices.
Another way in which the bandwidth of data transfers between the CPU and memory may be increased is to use high-performance devices in the memory subsystem. This method tends to be of limited utility since both the devices themselves and the hardware used to support them tend to increase the cost of the computer system without producing a proportional increase in performance.
High-performance memory devices of this type, however, are widely used in cache memory systems which interface between the CPU and the main memory subsystem. A cache memory attempts to take advantage of any tendencies toward temporal or spatial locality of reference in computer programs by fetching data from cells surrounding each memory cell accessed by the program. Data in these surrounding cells is held in a relatively small, high-speed memory local to the CPU until it is overwritten by data from other memory access requests. While this data is in the cache, it may be accessed by the CPU-without substantial delay.
While cache memories may tend to increase system performance for programs that frequently access data in relatively small data sets, they present problems when large volumes of data are accessed by the program controlling the CPU. For these programs, data values in the cache memory are continually being replaced to satisfy the requests issued by the CPU. Due to the operation of the cache, each of these requests produces multiple memory access requests which may delay subsequent requests. In addition, when new data to be added to the cache must replace some of the existing data, a data replacement algorithm is invoked to determine which of the existing data entries in the cache is to be replaced by the new data. This replacement algorithm may significantly delay memory accesses by the CPU or it may entail the use of relatively costly dedicated electronic devices.
SUMMARY OF THE INVENTION
The present invention is embodied in a computer system having a cache memory which provides an interface between a CPU and a main memory. The cache memory is coupled to the main memory by two queues, one for data to be fetched from the memory and one for data to be stored into the memory. The interface between the cache and main memories includes circuitry which selects between the next fetch request and the next store request for the next memory access to be performed.
According to one aspect of the invention, the selection circuitry is conditioned to prefer fetch requests to store requests.
According to another aspect of the invention, the main memory is partitioned and the selection circuitry compares the requested partitions of both the store and fetch requests to the partitions accessed by each of the last N memory requests, where N is an integer. The selection circuitry favors access requests to other partitions over requests to the partitions of these last N memory requests.
According to yet another aspect of the invention, the cache memory is organized as a two-way set associative memory and the data replacement algorithm takes into account such factors as impending replacement requests for either set of data values at the requested location.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a computer system which includes an embodiment of the present invention.
FIG. 2 is a block diagram which shows details of the memory access unit (MAU) of the computer system shown in FIG. 1.
FIG. 3 is a block diagram which shows details of the server availability priority control (SAPC) circuitry used in the MAU circuitry shown in FIG. 2.
FIG. 4 is a block diagram which shows details of the cache memory circuitry of the computer system shown in FIG. 1.
FIG. 5 is a flow chart diagram which is useful for explaining the operation of the cache memory circuitry shown in FIG. 4.
FIGS. 6A and 6B are flow chart diagrams which are useful for explaining the operation of the circuitry shown in FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
Overview
FIG. 1 is a block diagram of a parallel-pipelined computer system in which multiple central processing units (CPU's) may be coupled to a main memory 130. Only one CPU 110 is shown in FIG. 1. The CPU 110 includes a code unit (CU) 112, an execution unit (EU) 114, a reference unit (RU) 116 and a cache memory 118. The code unit retrieves instructions from a main memory 130 and partially decodes them. Any memory references in the code processed by the code unit are handled by the RU 116. The data cache memory 118 of the CPU 110 is coupled to main memory 130 via a memory access unit (MAU) 120.
When the RU 116 attempts to resolve a memory reference from an instruction, it passes a virtual memory address to an address conversion unit (ACU) 117 which translates the virtual address into an absolute address. The ACU 117 then passes the absolute address to the cache memory 118. If the referenced address is found, the cache memory 118 either returns the referenced data item to the EU 114 or performs the store operation into the cache using data provided by the EU.
If, however, the referenced address is not found, the cache memory 118 conditions the MAU 120 to make an access request to the main memory 130. As shown in FIG. 1, the cache 118 may simultaneously make two types of access request, a memory fetch request via the bus FR and a memory store request via the bus SR. These parallel requests are analyzed by the MAU 120 to determine if either one would make better use of the memory resources. To this end, two tests are made by the MAU 120. First, the memory access unit 120 determines if either one of the access requests would use a memory partition that may be still busy handling a previous access request. If so, the non-interfering request is preferred over the potentially interfering request. The second test prefers memory fetch requests to memory store requests, that is to say, fetch requests are given a higher priority than store requests. This second test is only performed if the first test does not establish a preferred request.
The cache memory 118, used in this embodiment of the invention, is a two-way set associative memory. Consequently, each addressed location in the memory includes two four-word data sets. Whenever a new data request is made and both of its corresponding data sets are occupied, the cache memory 118 chooses one set to be replaced by the new data. The algorithm for choosing the set to be replaced avoids choosing a set for which a pending request already exists. If, however, both sets have pending requests, one of the sets is selected at random.
The exemplary cache memory 118 is a purgeless cache. Data values are stored in the cache memory 118 in four-word sets and the status of any four-word set is held in the main memory 130. Thus, if processor A fetches a four-word set from memory and intends to modify the data in the set, the cache status entry for the data in the main memory 130 will indicate that the data in the set is held by processor A exclusively. Any attempt by, for example, processor B to access the data in main memory will be unsuccessful until the modified data has been written back into the main memory 130 by processor A.
Alternatively, processor A may request data from memory which will not be modified. In this instance, the cache-status entry for the four-word set will indicate that processor A has the data in a shared state. Processor B may also access shared data but may not gain exclusive access to the data until the set has been invalidated in processor A's cache.
Access to data in the memory 130 is controlled by a demand scheme. A processor which needs to access data can cause the processor which currently holds the data in its associated cache to give it up. Thus, if a task running on processor A requests exclusive access to data which is held with share status by processor B, The memory 130 will send the data to processor A and simultaneously send a purge command for the addressed location to processor B. This command will cause processor B to mark the data set invalid in its cache. It is noted that the memory 130 issues purge commands which invalidate copies of data held in the various cache memories 118 coupled to the memory 130. This system has a reduced processing overhead relative to a system in which the cache 118 or the MAU 120 would be assigned the task of invalidating copies held by other cache memories.
When processor A requests share access to data which is held exclusively by processor B, the memory 130 cannot send the addressed data to the MAU 120 of processor A but, instead, sends a return code to processor B which causes processor B to write the data set back into memory. Once the data has been returned to memory and its cache status has been updated, the data may be sent to processor A.
DETAILED DESCRIPTION
FIG. 2 is a block diagram of the MAU 120 which couples the cache memory 118 to the main memory 130. As shown in FIG. 2, the main memory 130 is divided into two memory banks (BANK 0 and BANK 1). Each bank, in turn, is divided into six slots (M00 through M05 and M10 through M15, respectively) and each slot is divided into two partitions which are controlled by respective servers S0 and S1.
On the occurrence of a cache miss or when a data set in the cache is to be replaced, the cache 119 issues, respectively, a fetch request, through the cache fill list/memory reference table (CFL/MRT) 212, or a store request, through the replace queue (RQ) 210. As described below, in reference to FIG. 4, the CFL/MRT 212 and the RQ 210 are circular queues. The cache memory 118 places memory requests into each of these queues and the MAU 120 removes requests from the queues.
The next entries to be taken from the queues RQ and CFL/MRT are applied to the forward address translation (FAT) circuitry 214 and 216 respectively. The FAT circuitry 214 and 216 are coupled to a forward address map (FMAP) 218 which provides the translation from the absolute memory address held in the queue entry to the physical address of the data in the main memory 130. The translated addresses provided by the FATs 214 and 216 and data values to be stored into the main memory 130, provided by the RQ 210 are applied to respectively different data input ports of a multiplexer 220.
The operation of the MAU 120 is described with reference to FIGS. 2, 6A and 6B. As shown in FIG. 2, the multiplexer 220 and the RQ 210 and CFL/MRT 212 are controlled by signals provided by the server availability priority control (SAPC) circuitry 230. As set forth below in reference to FIG. 3, the SAPC 230, at step 252 of FIG. 6A, conditions the multiplexer 220 to select either the next store request from the RQ 210 or the next fetch request from the memory reference table 212 as the next memory operation to be performed. In addition, when a memory operation has been selected, the SAPC updates the read pointer in the appropriate one of RQ 210 or CFL/MRT 212 via a control bus CONT.
The output port of the multiplexer 220 is coupled to three registers, two memory operation control registers (MOCA 222 and MOCB 224) and an MAU output register (MO) 226. The registers 222, 226 and 224 are controlled by signals (not shown) provided by the SAPC circuitry 230. In response to these control signals, the address values provided by the FATs 214 and 216 is selectively loaded into the MO register 226 and the appropriate control bits are set in either MOCA 222 or MOCB 224, depending on which memory bank is to receive the request. The data values provided by the replace queue 210 are always loaded into the MAU output register 226. The output port of the register MOCA 222 is coupled to the address input port of each slot of BANK 0 while the output port of the register MOCB 224 is coupled to the address input port of each slot of BANK 1. The MO register 226 has two output ports, one coupled to the data bus of BANK 0 and one coupled to the data bus of BANK 1.
In response to a store request from the replace queue 210, the server availability priority control circuitry, at step 254 of FIG. 6A, first conditions the multiplexer 220 to pass the store address value provided by the FAT 214. Based on memory bank information contained in the store address value, the SAPC 230 then enables the appropriate one of the registers MOCA 222 or MOCB 224. The address value defines a slot and a server within the slot which is to receive the data. In step 256, as this address value is stabilized in the slots of the selected memory bank, the SAPC 230, at step 260, conditions the multiplexer 220 to apply the data value from the replace queue 210 to the MO register 226 and indicates to the memory 130, via the MOCA 222 or MOCB 224 that there is valid data in the MO register. The main memory 130 acknowledges receipt of the store command by sending a signal to the SAPC 230 via the signal path A/N. The SAPC 230 waits for this acknowledgement at step 266 and then branches to step 252 to choose the next memory request to be processed.
The signal provided by the SAPC 230 to the selected server conditions the server to transfer the data from the MO register 226 into the addressed memory cell. All memory control signals (e.g. write enable) are generated by logic in the server. In this embodiment of the invention, while there is an acknowledgement that the server has received the store command, there is no acknowledgement from the server that the memory write operation has occurred.
Store requests from the replace queue 210 may involve a zero word (i.e. unmodified data) or a four word (i.e. modified data) group. In the case of a four word group, the SAPC 230 applies successive data values from the replace queue 210 to the MO register 226 and asserts the appropriate control signals (e.g. DATA VALID) in MOCA 222 or MOCB 224 to condition the main memory 130 to store the data values.
If a fetch request from the CFL/MRT 212 is selected at step 252, the SAPC 230, at step 254, conditions the multiplexer 220 to pass the address value provided by the FAT 216 to the MO register 226 and sets the appropriate control signals (e.g. REQUEST VALID) in MOCA 222 or MOCB 224. At step 256, the control signals and the fetch request are sent to the selected memory bank. Upon receiving the fetch request, the main memory 130 sends an acknowledgement to the SAPC 230 via the control line A/N. When, at step 266, this acknowledgement is received, the SAPC 266 branches to step 252 to select the next memory operation.
When the fetch operation is complete, and data is ready to be sent to the cache 118, the server, at step 270 of FIG. 6B, sends a control signal (e.g. REQUEST VALID) back to the SAPC 230 via the control line A/N. In response to this control signal from the selected server, the SAPC 230 emits an input control signal IC to a MAU input controller (MIC) 234. When the MIC 234 receives this signal, it conditions the hardware elements on the right side of FIG. 2 to pass the data from the main memory 130 to the CPU 110. The first step in this process is to condition a multiplexer 232 to pass a value from the Selected memory bank to an MAU input (Mi) register 236 and to a multiplexer 246.
The value provided by the memory 130 includes either one word of data or one word which includes a cache status entry and an address in the memory 130 of a data word. The cache status portion of this value is monitored by the MAU input controller 234 which determines whether the data, a return code, or a purge command should be sent to the requesting processor.
If, at step 272, it is determined that data is to be sent to the cache 118, it is passed, at step 274, directly through the multiplexer 246 to the cache 118. In this instance, the other three words of the four word data set are provided in sequence by the memory 130. In this embodiment of the invention, the address to be used for these data words is retained by the cache and is associated with the data via a job number that is assigned to the fetch request, by the cache 118, and is transferred through the memory 130 with the data.
A return command or a purge command is not the result of a fetch operation from the CPU to which it is directed and, so has no corresponding entry in the cache 118 of that CPU. Consequently, at step 276, the address values to be sent to CPU are translated from physical addresses in the memory to absolute addresses, that is to say to address values used by the CPU. To perform this translation, the MIC 234 loads the cache status value and the address into the MI register 236. The address value is applied to reverse address translation (RAT) circuitry 238 which translates the physical address into its corresponding absolute address according to the reverse address map RMAP 240.
If, at step 278, the cache status value indicates that a purge command is to be sent to the CPU 110, the cache status word and the address are applied, at step 280, directly from the output port of the RAT 238 to the cache 118 through the multiplexer 246. Alternatively, if a return command is indicated, the cache status word and the virtual address are placed, at step 286, into a MAU return queue (MRQ) 242, the output port of which is coupled to an input port of the multiplexer 246.
A fourth input port of the multiplexer 246 is coupled to receive an error code provided by an error detector (ED) 244. The ED 244 detects errors in the data being returned from the main memory (e.g. parity errors, invalid addresses or the results from fetch instructions that have been superseded by a branch instruction that redirected the flow of the program). The MAU input control circuitry 234, at step 282 detects the presence of an error condition and, at step 284, conditions the multiplexer 246 to pass the error code to the cache 118. If an error has occurred in a transfer from memory, the step 282 will detect the error and pass the error code value to the cache 118. In this instance, the value provided by the memory 130 will not be treated as data, a purge command or a return command.
When the SAPC 230 has processed a command from the replace queue 210 or from the memory reference table 212, and the main memory 130 has acknowledged receiving the command, the SAPC 230 sends a signal to the RQ 210 or CFL/MRT 212, respectively, via the bus CONT. This signal conditions the respective RQ 210 and CFL/MRT 212 to advance the appropriate queue pointer to point to the next entry. As set forth below, in reference to FIG. 3, the SAPC 230 retains the addresses of the last four commands from the RQ and CFL/MRT, these addresses are applied to the SAPC 230 from the output of the multiplexer 220 and are used to determine which of the two requests provided by the RQ 210 and CFL/MRT 212, respectively, should be handled next.
To perform this command selection, the SAPC 230 records the physical addresses used for the last four memory operations. These addresses indicate which memory banks, which slots and which servers were used by the respective memory operations. At any time, the physical addresses to be used by the memory requests at the top of the replace queue 210 and memory reference table 212 are available at the output ports of the respective forward address translation circuits 214 and 216. These physical addresses are simultaneously compared with the last four physical addresses by the SAPC circuitry 230.
FIG. 3 is a block diagram which illustrates the structure of the SAPC circuitry 230. Information on the last four processed memory operations are stored in the four registers 310, 312, 314 and 316. Each of these registers is temporarily associated with a particular server in the main memory 130. For each of the registers 310, 312, 314 and 316, there is a corresponding server busy counter 320, 322, 324 and 326, respectively. The server busy counter is a timer which indicates the length of time that a server is busy with a memory request. This counter is loaded with a predetermined time value when the SAPC circuitry 230 sends the operation to the main memory 130 and is decremented each system clock period afterward until its value equals zero.
As each memory operation is scheduled, the physical address of the most recently initiated memory operation and its counter value are loaded into the next available register pair. The contents of the registers 310, 312, 314 and 316 and the contents of the respective busy counters 320, 322, 324 and 326 are applied to respective comparator circuits 330, 332, 334 and 336. Each of these comparators is also coupled to receive the physical memory addresses of the next store and fetch commands from the FAT circuitry 214 and 216, respectively.
Each of the comparators 330, 332, 334 and 336 compares the stored address from its associated register with each of the addresses from the FAT circuits 214 and 216. If the address of the server to be used either by the next store or the next fetch operation matches that of the stored server address, and if the server busy count is not equal to zero then the server is presumed to be busy. The comparators 330, 332, 334 and 336 each have two output terminals, one indicating the result of the fetch comparison and the other indicating the result of the store comparison. The respective output terminals of each of the comparators are tied together in a wired-OR configuration. The coupled fetch terminals form a fetch server busy (FSB) signal and the coupled store terminals form a store server busy (SSB) signal.
In this configuration, if the signal FSB has a logic-one value then the address from the FAT circuitry 216 matches at least one of the addresses stored in the registers 310, 312, 314 and 316 and the corresponding server is still busy. Similarly, if the signal SSB has a logic-one value, the address from the FAT circuitry 214 matches one of the stored addresses and its corresponding server is still busy.
The signals FSB and SSB are applied to the SAPC controller 340. Based on these signals, the controller 340 selects whether the next entry in the replace queue 210 or the next entry in the memory reference table 212 is the next memory operation to be performed. If FSB is logic-one and SSB is logic-zero then the store is preferred over the fetch. Otherwise the fetch is preferred over the store. Fetch operations are preferred over store operations when the decision parameters are equal because the CPU waits for the results of a fetch operation while it does not wait for a store operation. By preferring fetch operations when all else is equal, the MAU 120 helps to increase the perceived performance of the CPU.
FIG. 4 is a block diagram which illustrates the structure of the cache memory 118 of the CPU 110. As set forth above, the exemplary cache memory 118 is a two-way set associative memory. In this configuration, 4096 words are arranged in two pages, each page containing 512 four-word data sets. If the address bits are numbered from 0 to 28 with bit 28 being the most significant bit (MSB) and bit 0 being the least significant bit (LSB) the address of a set in the cache memory is denoted by bits 2 through 10. Bits 11 through 28 are stored in an address area (AA) 416 of the cache memory to fully identify the set and the corresponding data words are stored in four corresponding word locations of a data area (DA) 426.
In the exemplary embodiment of the invention, the cache memory 118 has an input interface which is coupled both to the EU 114 (or RU 116) and to the MAU 120. Via this interface, the cache 118 receives a cache command, a cache input address (CIA) and, optionally, a cache input data value (CID). These are stored in the cache input controller (CIC) and the registers 412 and 414, respectively.
The CIC 410 used in this embodiment of the invention includes a sequencer which is responsive to the various cache commands to control the other components of the cache memory 118. For the sake of simplicity, these control lines are not shown in FIG. 4. The operation of the cache 118 is described below for five commands: fetch and store commands originating in the EU 114 or RU 116 and store, purge and return commands originating in the MAU 120.
On any access to the cache memory 118, the first step is to determine if the value addressed by CIA has been captured in the cache. To this end, the CIC 410 applies bits 2 through 10 of the address value stored in register 212 to both the address area 416 and the data area 426. Simultaneously, bits 11 through 28 are applied to first input ports of respective comparators 418 and 420. The second input ports of these comparators are coupled to receive the data stored in the respective pages, P1 and P2 at the addressed locations of the address area 416. If the addressed set has been captured by the cache memory 118, then one of the comparators 418 or 420 will signal a match. The output signals of the comparators 418 and 420 are logically ORed together by an OR gate 422. The output signal, HIT, provided by this gate indicates whether the data set has been captured by the cache memory 118.
For a fetch operation from the RU 116, the CIC 410 applies the two parts of the cache input address to the address area 416, as described above, and simultaneously applies bits 2 through 10 of the address value to the data area 426. The output signal of the comparator 420 is applied to a multiplexer 424 which selectively passes the addressed data value from either page P1 or page P2 of the data area 426. The signal HIT is applied to an output controller (OC) 425 which develops control signals for a multiplexer 429 and a cache output data register (COD) 430. The OC 425 conditions the multiplexer to pass either the data value from the addressed location of the data area 426 or the cache input data value from the register 414. The OC 425 conditions the COD 430 to load the output value of the multiplexer 429 only if the signal HIT is logic-true.
Otherwise, the signal HIT conditions the CIC 410 to reserve a four-word data set in either page P1 or page P2 of the cache at the address indicated by bits 2 through 10 of the CIA register. The algorithm for selecting which page is to hold the data fetched from memory is described below in reference to FIG. 5. The logic-false signal HIT also conditions a fetch controller 440 to create a fetch queue entry in the CFL/MRT 212 for the addressed location. It also conditions a store controller 442 to place a 0, 3, or 4 word store request into the replace queue 210. This entry is handled in due course by the MAU 120 as set forth above. When the data values are returned by the MAU 120 they are written into the reserved data set. When the store request is placed into the replace queue 210, one word of the four word data set is entered during the fetch operation that caused the data set to be entered into the replace queue. The remaining words are copied into the replace queue 210 sequentially after the first word. This technique saves time in the fetch operation by reducing the amount of time used to store the data in the data set being replaced by the fetch operation.
As set forth above, the fetch and store operations are handled by separate queues and operations from the fetch queue are preferred over operations from the store queue. This scheme results in a time saving for bringing new data into the cache 118 since the fetched data may be stored in the cache 118 before the cache status for the data being replaced is updated.
For a store command from the EU, the cache input address and data values are applied to the address and data areas 416 and 426 as described above. The CIC 410 conditions the appropriate page of the data area 426 to store the cache input data value, from the register 414, into the addressed word of the addressed data set.
A store request from the MAU 120 adds a data set to the cache memory 118. As set forth above, the data provided by the MAU 120 is the result of a fetch command issued by the cache 118 through the CFL/MRT 212. The data returning from the MAU 120 is keyed to an address held by the CFL/MRT by a job number that is associated with the data. In response to this job number, the CIC 410 conditions the register 412 to load this address value as the cache input address value. Bits 2 through 10 of this value and a page indication value are used to address the address area 416 and the data area 426. As the data values are stored into the data area 426, bits 11 through 28 of the address value are stored into the address area 416.
The data set to be used to hold this data will have been preselected during the handling of the fetch command that generated the store command from the MAU 120. The data set selection algorithm is described below in reference to FIG. 5.
Since the RU 116 had originally requested this data, the requested data value is loaded into the COD register 430 at the same time it is written into the data area 426 of the cache 118. The cache input controller 410 and the logic-zero signal HIT condition the multiplexer 429 to pass the cache input data value from the register 414 to the COD register 430 and condition the register 430 to load the value. As set forth above, this value is applied to the RU 116.
In response to a purge command from the MAU 120, the address value provided by the MAU 120 is loaded into the CIA 412 and, if the signal HIT is logic-true, the addressed entry in the appropriate page of the cache 118 is marked invalid. If HIT is logic-false, no action is taken.
In response to a return command from the MAU 120, the provided address value is loaded into the CIA 412 and, if the signal HIT is logic-true, the addressed entry in the appropriate page is written back into main memory using the replace queue 210. If HIT is logic-false, no action is taken.
The algorithm for determining which of a pair of page locations in the cache 118 is to be replaced by a new data set is set forth in FIG. 5. At step 510, a memory fetch request for the new data set is received at the cache memory 118. The first step in the algorithm is to determine if either of the two pages, having the same cache address as the new set, is marked as having a deferred replace request scheduled. If so, then the set which is not marked for a deferred replace request is selected at step 514.
A page is marked for a deferred replace request only when, upon attempting to select one of the pages for a new data set, the CIC 410 finds both pages already reserved for outstanding data fetch operations. In this instance, the CIC 410 enters a deferred replace request for one of the two pages. No action is taken by the MAU 120 on a deferred request until the outstanding fetch request for the specified page at the addressed cache location returns. At this time, the newly returned set is immediately scheduled to be replaced, the page containing the set is marked as being reserved and a fetch request is entered into the CFL/MRT 212.
As set forth below, only one of the two pages at any given address may be marked for a deferred replace when a replace request is to be processed. The processing of that request, however, may cause the other page at the given address to be marked for a deferred replace.
If neither of the addressed pages is found to be marked for a deferred request at step 512, the algorithm, at step 516, checks for pending store requests. If one of the two pages is found to have a pending store request, that is to say a pending modification of a data word by the EU 114, step 518 is executed which selects the page that does not have an outstanding store request.
If neither page or both pages are found to have an outstanding store request then, step 524 is executed to determine if either of the pages or the selected page has an active fetch request, that is to say, a fetch request that is marked as active in the CFL/MRT 212. If so, the step 526 is executed which selects the page opposite to the one having the pending fetch request.
If neither page or both pages are found to have a pending fetch request, then step 532 is executed. This step determines if either page (but not both pages) is empty. If only one page is found to be empty, it is selected at step 534. If both pages are in use or if both pages are empty, one of the pages is selected at random at step 536.
If, at step 538, the selected page which was chosen to be replaced at one of the steps 514, 518, 526, 534 or 536, is marked as active in the CFL/MRT 212, then, at step 540, this fetch is marked as requiring a deferred replace. When marked in this way, the fetch cannot be issued to the MAU 120. This action blocks other units (e.g. the EU 114 and RU 116) from sending requests to the cache memory 118. These units remain locked out of the cache memory 118 until the active fetch request for the page is completed. At step 542, the fetch request is loaded into the CFL/MRT 212.
If a loaded request is marked as requiring a deferred replace, then, when the active request for this page is completed, the deferred fetch becomes active and may be issued to the MAU 120. Due to the pipelined operation of the cache memory 118, however, it is possible that a second access request for a particular addressed cache location is already being processed when the suspension occurs. If the cache address of this current request is the same as that of the deferred request, then a deferred replace request for the other page at the addressed cache location is entered into the CFL/MRT 212 for the current request.
An improved cache memory system has been described in which separate store and fetch queues are maintained to make memory access operations more efficient and to improve the apparent performance of the processing elements coupled to the cache memory system. While this invention has been described in terms of an exemplary embodiment, it is contemplated that it may be practiced as outlined above with modifications within the spirit and scope of the appended claims.
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A two-way set associative cache memory system for a parallel-pipelined computer system uses separate queue structures to hold main memory fetch and store requests generated by the central processing unit (CPU). A memory access unit, coupled between the cache memory system and the CPU selects the next request to be processed by the main memory from between the requests at the heads of the fetch and store queues. The request at the head of the fetch queue is preferred over the request at the head of the store queue unless the memory partition to be used by the fetch request is still busy with a previous request while the partition to be used by the store request is idle. Data retrieved from the main memory replaces data in the cache according to an algorithm that prefers empty pages within a set to pages that contain data and prefers pages that do not have pending update requests scheduled to pages that do have pending update requests scheduled. In the event that only pages having pending update requests are found, input requests to the cache are inhibited until at least one fetch request for a page in the set is completed and the page is no longer marked as having a pending update request.
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RELATED APPLICATION
[0001] This application is based upon U.S. provisional patent application serial No. 60/293,707.
FIELD OF THE INVENTION
[0002] The present invention relates to a system and device for low power consumption of on/off control of a single or a plurality of electronic ballasts that can be used for a variety of lighting functions.
BACKGROUND
[0003] Electronic ballasting of gas discharge lighting has become the leading option over passive reactive ballasting. Gas discharging lighting includes fluorescent and high intensity discharge (HID) lamps. Electronic ballasts are constructed with active electronic components such as transistors that allow functional electrical control. The normal operation of the ballasted lights requires them to be energized or de-energized corresponding to “on and off” operation. This is usually accomplished by an external mechanical switch, which applies or interrupts electrical power to the ballast and corresponding causes the lamp(s) to go on or off.
[0004] The ballast operating current and voltage that powers the ballast must be experienced by this power switch which for safety reasons is under restrictions governed by building code wiring requirements for safety. Because of the special knowledge associated with such power wiring a costly professional electrician is normally required to alter any switching control within a given building space.
[0005] There are a number of limitations associated with this common means for on/off control. First the control switch must support the current requirements of all the lighting in a given area, so for large areas, the current carrying capacity of the switch must be raised to accommodate the greater load currents of the lighting. When this happens the power switching arrangement becomes complex with power switching implemented through a combination of mechanical and electric relays (contactors) that increase to hardware needs, increase expense and reduced reliability of the system.
[0006] Another limitation occurs if the switch is very remote and distant for the lights, requiring the lighting load current to pass to and from the remote switch causing an undesirable electrical loss corresponding to resistive voltage drops. Additionally, such a system is inflexible to alterations and modifications, essentially requiring the special training and experience of higher cost electric contract service assistance, to alter a switching arrangement, or to add automated remote functions to the lights.
OBJECTS OF THE INVENTION
[0007] It is therefore an object of this invention to cause a ballast to be energized in satisfaction of the “on/off” control, by an ultra low power controller that may be essentially isolated for primary power circuit or derive its very low switch power from the ballast itself. With this invention it is possible to effect on/off control with the lowest voltage and current for an essentially near lossless control means. The invention can be used with lighting ballasts, but also for any devices with on/off switches, such as motors, appliances, heaters and the like.
[0008] It is also an object of this invention to use its on/off control means to effect other desirable functions in the electric ballast. Such functions include but are not limited to electronic action that would cause the electronic ballast to operate at fractional power levels corresponding to different lighting intensities and/or with conventional occupancy sensors.
[0009] It is a further object of this invention to utilize wiring components in the on/off control that correspond to the domain of signal or control wiring and which are characterized by very low power requirements and do not have the restrictions associated with power wiring. Such wiring is common in the telecommunications industry and may be applied to external programmed control.
SUMMARY OF THE INVENTION
[0010] In keeping with these objects and others which may become apparent, the present invention is a ballast or power electronics module which is controlled by a remotely located switch function with a low amount of control current and little power loss. This is effected by means of a photo-isolator interfacing circuit within the ballast or within the power electronics module that provides high electrical isolation between an external control signal current and the power electronics of the ballast. The photo-isolator is the switch interface from signal level to power level control.
[0011] The on/off switching system can be used for one or more electronic ballasts for one or more lamps, of one or more lighting fixtures. The system includes the one or more ballasts having power electronics, wherein the system further includes a remote switch function in each ballast, which remote switch function is remotely located apart from each ballast. The remote switch function operates with a low amount of control current and little power loss. This on/off switching system further includes one or more connections connecting the remotely located switch to a ballast resident opto-isolator circuit, with associated interfacing electronics within each ballast. Therefore, each ballast provides high electrical isolation between the external switch function and the ballast power electronics to each lamp.
[0012] Besides its use with lighting ballasts, the remote on/off switching function system can also be used for one or more electronically interfaceable end-use appliance devices which function through on/off control. For example, the devices can include motors, heaters, appliances, industrial electrical equipment or other appliances which benefit from proportional on/off control as a means for power modulations. In these embodiments for other devices, each device has an on/off switch function, as well as power electronics, wherein the remote switch function is remotely located apart from the device's resident power electronics, wherein further the remote switch function operates with a low amount of control current and little power loss. This on/off switching system further includes one or more connections connecting the remotely located switch function to an opto-isolator circuit with high electrical isolation to the power electronics. The power electronics provides electrical computability between the switch function and the operation of the device.
[0013] The remote on/off switching system can be applied for proportional light dimming control having as its interface an optically isolated on/off function interfacing with remote circuitry, providing pulse width modulation to the optically isolated interface control, to cause proportional light dimming. The remote circuitry includes a fixed frequency oscillator influenced by a pulse-width modulator controlled by a voltage setting, wherein proportional pulses cause constant current to flow remotely through a light emitting diode in an optical isolator in the electronic ballast, wherein a constant current driver insures a predetermined proper current to the light emitting diode in compensation for variable cable lengths. A phototransistor/switch of the optical isolator complies with the periodic “on” duty cycle set remotely and causes the power in the ballast circuitry to be applied to the lamp with variable intensity.
[0014] A similar on/off switching system can be applied to one or more electrical end-use appliances compatible with electronic on/off control in which a similar optically isolating interface utilizing circuitry influences very low power remote control of power levied in the various end-use appliances such as motor driven devices, electrical heaters, industrial equipment and any other device that might benefit from proportional on/off control as a means for power modulation.
[0015] The singular switch can also control a plurality of ballasts including but not limited to ballasts applied to a plurality of HID or fluorescent lamps. This switching function can also be applied to programed interruption such as in controlled blinking functions which are used as an attraction in lighted advertising signs.
[0016] Optionally, an external repetitive control may be applied that causes the “on” periods to be different from the “off” period such that power to the lamp is proportional to the on period. The said interface thus becomes a means for dimming with external singular functional control eliminating costly internal dimming control circuitry.
[0017] Furthermore, the external remote switch function may be provided through active electronic, such as, in part, a transistor. In addition, the remote switching function can be provided by a programmable electronic system, with or without feedback.
[0018] A plurality of lead wires connects the remote switch function, a low current power source, and the light emitting diode (LED) is available at the input of the opto-isolator. The low current power source can be derived from the ballast, or it can be supplied externally.
[0019] Although the connectors for the control of the ballast may be any signal type connector, a modular phone jack and plug and the use of the flat 4-conductor cable, common to telephone systems, as the plurality of lead wires facilitates installation.
[0020] Through the use of a common four wire 3-way RJ11 telephone coupler at each ballast and a length of flat 4-conductor telephone cable with reversed RJ11 plugs at each end (i.e. a reversed cable net) any number of ballasts can be connected in daisy-chain fashion to be controlled by a single remote switch. Adding, rerouting, or reconfiguring switches to control a network of light fixtures can be accomplished without the need of an electrician.
[0021] The electrically isolated photo-transistor portion of the opto-isolator is controlled by light emitted by the LED within the opto-isolator. The state of conduction of its collector-emitter junction is used to electronically control the operation (in an on/off fashion) of any standard high frequency electronic inverter circuitry used to derive AC power of any frequency to the fluorescent or HID lamps.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The present invention can best be understood in connection with the accompanying drawings, in which:
[0023] [0023]FIG. 1 is a Prior art block diagram of the common method for switching a lighting ballast;
[0024] [0024]FIG. 2 is a Schematic diagram of an electronic ballast of this invention with optically isolated power control;
[0025] [0025]FIG. 3 is a Top plan schematic view of a common type RJ11 four wire 3-way coupler;
[0026] [0026]FIG. 4 is a Schematic Contact representation of a reversed 4-wire reversed cable set common to the telephone industry;
[0027] [0027]FIG. 5 is a Side elevation view of a reversed cable set;
[0028] [0028]FIG. 6 is a Block diagram of multiple ballast network controlled by one switch;
[0029] [0029]FIG. 7 is a physical layout of a electronic ballast with electrical connection for this invention;
[0030] [0030]FIG. 8 is a block diagram of an alternate embodiment offering remote proportional dimming of a simple low cost electronic ballast using the on/off optically isolated interface embodied in the invention.
[0031] [0031]FIG. 9 is a block diagram showing use of low power external ballast control for on/off control and bi-level HID dimming functions, showing the control cabling with RJ11 connectors; and,
[0032] [0032]FIG. 10 shows a block diagram of a fully isolated remote switch.
DETAILED DESCRIPTION OF THE INVENTION
[0033] A block diagram of a prior art lighting circuit 1 is shown in FIG. 1. A power source 2 is used to power ballast 4 which operates two gas discharge (fluorescent) lamps 5 . On/off control of the lamps is influenced by mechanical switch 3 which must be rated for the full supply voltage and current requirements of the lamp load, when multiple ballasts are used in parallel. A long distance from switch 3 to ballast 4 requires evaluation of the effects of the consequent voltage drop. In most jurisdictions, the initial switch wiring as well as any alterations is legally performed only by a licensed electrician.
[0034] [0034]FIG. 2 is a schematic diagram of an electronic ballast 9 of this invention. A control switch 10 is wired to connector 11 . A cable (not shown) connects connector 11 to connector 12 ; this could be a long distance. A length of flat 4-conductor telephone or any corresponding signal type cable 13 goes from connector 12 to connections within ballast 9 . Terminals 14 and 15 supply input power to ballast 9 . Output terminals 16 and 17 connect to each of two lamps (not shown.) while connector 18 is common to each of the lamps.
[0035] [0035]FIG. 2 also shows that the key element that distinguishes this ballast from, other electronic ballasts is the use of an electronic optical isolator component 19 which includes a matched pair of light emitting diode (LED) 20 and photo transistor 21 . A internal low voltage and low current supply source for energizing LED 20 may be optionally derived from resistors R 5 and R 6 which are connected in the ballast internally to the power input supply terminals 14 and 15 . When using the internal power source LED 20 is energized when remote switch 10 is closed causing limited power supply current to flow through supply terminals 14 and 15 , resistor R 1 and LED 20 , causing LED 20 to forward bias transistor 21 into conduction. Conducting transistor 21 causes transistor Q 3 to stop conducting which reverses biases diodes D 1 and D 2 conduct, allowing the gates of the transistors in the power oscillator portion of the circuitry 23 in ballast 9 to function in an un-impeded or power “on” mode.
[0036] Schematic section 23 (indicated by a dashed line box) serves to typify a standard high frequency inverter circuit used to energize a fluorescent lamp. A similar circuit may be applied to the operation of a HID lamp with emphasis applied to the essential functions of this invention.
[0037] Schematic section 22 (indicated also by a dashed line box) is new circuitry related to remote on/off switching, control of one or more ballasts, except for subcircuit 19 , which is depicted within the confines of schematic section 22 , which is a reverse polarity protector.
[0038] Ballast 9 is designed for use with DC power input at terminals 14 and 15 .
[0039] Reference numeral 19 is a commercial photo-isolator integrated circuit that is capable of providing high electrical isolation between an external control signal and the power electronics in ballast 9 .
[0040] To turn on ballast 9 , a voltage which is either internally generated (as shown) or externally supplied (shown in drawing FIG. 8 herein) is applied to isolator 19 LED 20 and current limited by resistor (R 1 ); light is emitted by LED 20 which excites photo transistor 21 to conduct (i.e.—reduce resistance). This causes current to flow in resistor R 2 . With resistor R 2 and isolator transistor 21 forming a voltage divider, the conducting opto-isolator 19 transistor 21 causes the base-emitter voltage on transistor Q 3 to go below conduction, causing the collector-emitter junction on transistor Q 3 to become highly resistive (non-conducting). With transistor Q 3 non-conducting, there is no current path for diodes D 4 and D 5 to the power supply return allowing the gates of transistors Q 1 and Q 2 to remain in a high impedance state and thus unencumbered to function as part of the self-excited power oscillation inverter servicing the gas discharge lamps. A typical example of a transistor, such as transistor Q 1 and transistor Q 2 , is a field effect transistor.
[0041] Alternatively, no voltage on the input of opto-isolator 19 reverses the process described above and causes the gates of transistors Q 1 and Q 2 to be clamped to the potential of the power supply return.
[0042] This effectively causes transistors Q 1 and Q 2 to be placed in a non-conductive state. This action interrupts the power oscillator/inverter causing the lamps to go off.
[0043] Thus it can be seen that a low voltage, low current interface controlled by a remotely located wall-mounted switch 10 can be used to control the operation of an electronic ballast to turn lamps on or off. Since each LED 20 just draws a few milliamperes of current, long distance to a remote switch are irrelevant since any voltage drops is insignificant.
[0044] While any low voltage connector wire can be used, for convenience and low cost, the use of modular connectors and light weight 4-conductor cable from the telephone industry is part of the preferred embodiment of this invention. For example, FIG. 3 shows a standard telephone RJ11 four wire 3-way coupler 30 . This has an input port 31 and two identical output ports 32 and 33 internally wired to maintain terminal correspondence for each of the four terminals in each port.
[0045] Cable 13 spans between cable end connectors 45 and 46 , forming together reversed cable 47 of FIG. 5. Reversed cable 47 includes flat four wire cable 13 with opposing end connectors 45 and 46 , wired as shown in FIG. 4, such that reference numerals 40 and 41 refer to the physical order of the respective colored wire connections 40 in cable end connector 45 , and to the reversed order of colored wire connections 41 in cable end connector 46 , of reversed cable 47 of FIG. 5. For example, FIG. 4 shows the configurations of opposite end contact wire connections 40 and 41 of the four colored wires of reversed cable 47 , labeled “Black”, “Red”, “Green” and “Yellow”, such that the physical order shown at contact connections 40 is used in cable end connector 45 , whereas the reversed order shown at contact connections 41 , labeled “Yellow”, “Green”, “Red” and “Black”, is used in cable end connector 46 . Other wire patterns can be used.
[0046] The reversed cable 47 is shown in FIG. 5 (a reversing telephone cable is common and used here, but is not required to effect this invention) while the terminal wiring is shown schematically in FIG. 4. The RJ11 cable end connectors 45 and 46 are attached to four wire cable 13 in opposite orientation (see FIG. 5) to maintain the conductor/terminal integrity shown in FIG. 4.
[0047] [0047]FIG. 6 shows a wiring diagram of multiple ballasts 9 controlled by a single remote switch 10 . A modular phone plate 50 is locally wired to wall switch 10 which attaches to the red and green wires. A long cable 52 with RJ11 cable end connectors attaches phone plate 50 to the first 3-way coupler 30 . Short single-ended cable 13 plugs into either output port of coupler 30 while the other end is hard wired to ballast 9 as shown in FIG. 2. The other output port of coupler 30 is used to connect to a second ballast through reversed cable 47 and a second coupler 30 as shown.
[0048] Additional ballasts are similarly added in “daisy-chain” fashion as shown in FIG. 6. The network is extendable to a large number of individual ballasts since the only load experienced by switch 10 and long cable 52 is that of the parallel load of the LED's 20 in each of the opto-isolators 19 in each ballast 9 . In this manner, 3-way couplers 30 in the vicinity of each ballast are used as extension elements to create an easy connection to the next ballast in the chain.
[0049] [0049]FIG. 7 shows a physical layout of a lighting fixture using ballast 9 powering lamps 5 . Short single-ended cable 13 with RJ-11 connector 60 extends from the housing of ballast 9 ; red and black power input leads 61 also extend from ballast 9 . As shown in FIG. 6, cable 13 is plugged into 3-way coupler 30 via RJ-11 connector 60 .
[0050] The block diagram of FIG. 8 is an alternate embodiment utilizing the enhanced electronic ballast 9 of FIG. 2 with the optically isolated ON/OFF control interfacing with remote circuitry providing pulse width modulation to the optically isolated ballast interface for proportional dimming control. FIG. 8 also shows a device 75 controlled by circuitry of FIG. 10.
[0051] A fixed frequency oscillator 103 feeds pulse-width modulator 102 which is controlled by a voltage setting provided by the wiper 101 on potentiometer 100 .
[0052] By varying the setting, duty cycles from close to 0% to almost 100% can be derived. These pulses are fed to constant current driver 104 which interfaces remotely with the light emitting diode in optical isolator 19 which is part of electronic ballast 9 . This is the same optical isolator that is used for the remote ON/OFF control described previously.
[0053] Constant current driver 104 for a series connected control system insures the proper current to the remote ballast interface 19 and any voltage drops in the long control cable. The phototransistor output of optical isolator 19 then complies with the duty cycle set remotely and varies the average power to the ballast circuitry resulting in proportional changes in light intensity.
[0054] [0054]FIG. 9 shows the wiring of a network of ballasts 66 . In this case, switch 68 is used for dimming and switch 69 is used for on/off control while utilizing the same 4-wire signal cable system.
[0055] [0055]FIG. 10 shows a block diagram of a fully isolated remote switch 78 with remote battery 77 and remote current limiting resistor 76 selectively supplying power to control a device 75 with function 84 therein. Long low power/voltage cables 85 and 86 operate light emitting diode (LED) 81 through further current limiting resistor 79 . Resistor 76 maybe substituted with any electronic current limiting means. Phototransistor 82 is controlled by light from LED 81 into either a conducting or non-conducting state to control function 84 . Device 75 is supplied with DC power by positive (+) terminal 87 and negative (−) terminal 88 . Current limiting resistors 80 and 83 may be used to support any low power remote equipment (not shown) which may not require totally isolated power.
[0056] It is further noted that other modifications may be made to the present invention, without departing from the scope of the invention, as noted in the appended claims.
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An electronic ballast system controls one or more ballasts of HID or fluorescent lamps, which are controlled in an “on/off” manner by a ultra low power controller that is isolated for a primary power circuit or derives its very low switch power from the ballast itself. The on/off control provides a near lossless control system. This system may be applied to electronic ballast for operates at fractional power levels corresponding to different lighting intensities and with conventional occupancy sensors. The system may also be applied to other electronically compatible end-use devices and applications.
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This application claims the benefit of U.S. provisional application no. 60/045,365, filed May 2, 1997, which application is incorporated herein by reference.
FIELD OF THE INVENTION
The invention relates generally to coiled tubing injectors for handling a continuous length of tubing or pipe for insertion into or removal from a well bore, and for drilling well bores. More particularly, it concerns gripping elements used by such injectors.
BACKGROUND OF THE INVENTION
Continuous, reeled pipe is generally known within the industry as coiled tubing and has been used for many years. It is much faster to run into and out of a well bore than conventional jointed, straight pipe.
Coiled tubing is run into and out of well bores using what are known in the industry as coiled tubing injectors. The name derives from the fact that, in preexisting well bores, the tubing must be literally forced or “injected” into the well through a sliding seal to overcome the well pressure until the weight of the tubing exceeds the force produced by the pressure acting against the cross-sectional area of the tubing. However, once the weight of the tubing overcomes the pressure, it must be supported by the injector. The process is reversed as the tubing is removed from the well.
The only method by which a continuous length of tubing can be either forced against pressure into the well, or supported while hanging in the well bore or being lowered or raised is by continuously gripping a length of the tubing just before it enters the well bore. This is achieved by arranging continuous chain loops on opposite sides of the tubing. The continuous chains carry a series of grippers which are pressed against opposite sides of the tubing and grip the tubing.
Coiled tubing has traditionally been used primarily for circulating fluids into the well and other work over operations, rather than drilling, because of its relatively small diameter and because it was not strong enough, especially for deep drilling. However, in recent years, coiled tubing has been increasingly used to drill well bores. For drilling, a turbine motor suspended at the end of the tubing and is driven by mud or drilling fluid pumped down the tubing. Coiled tubing has also been used as permanent tubing in production wells. These new uses of coiled tubing have been made possible by larger, stronger coiled tubing.
SUMMARY OF THE INVENTION
A coiled tubing injector according to the present invention includes a quick-release carrier for mounting gripping shoes to chains of the injector. The carrier enables removal and replacement of grippers in the field without tools, even when the injector is operating. An injector thus may be quickly adapted to run coiled tubing within a wide range of diameters, for purposes of a well work over to drilling. Furthermore, an injector having grippers according to the present invention may be used to run conventional jointed, straight pipe, or a tool string on the end of coiled tubing. The diameter of joints are larger than the diameter of the pipe. Tool strings have various diameters. The quick-release carrier enables gripping shoes to be easily removed to accommodate a joint or a tool as it passes through the injector during operations. Gripping shoes can be easily replaced with gripping shoes that have the appropriate size and shape for gripping the tool. All shoes are sized so that, when attached to the injector, they have same centerline or axis as the other shoes. Thus, gripping shoes of differing sizes can be used on the injector to grip a downhole tool or irregularly sized object in the pipe string as it is passing through the injector.
These and other aspects and advantages of the invention are discussed below in connection with a preferred embodiment illustrated by the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a coiled tubing injector intended to be representative of coiled tubing injectors generally, but with grippers according to the present invention.
FIG. 2 is a front elevational view of the coiled tubing injector shown in FIG. 1 .
FIG. 3 is a left side elevational view of the coiled tubing injector shown in FIGS. 1 and 2 .
FIG. 4 is an plan view of a drive chain of a coiled tubing injector having gripper carriers according to the present invention.
FIG. 5 is a side, elevational view, partially sectioned, of a gripper with a first shoe type mounted on one of the gripper carriers on the drive chain of FIG. 4 .
FIG. 6 is a side, elevational view, partially sectioned, of a gripper with a second shoe type mounted on one of the gripper carriers on the drive chain of FIG. 4 .
FIG. 7 is a side, elevational view, partially sectioned, of a gripper with a third shoe type mounted on one of the gripper carriers on the drive chain of FIG. 4 .
FIG. 8 is a perspective view of the gripper carrier and the gripper shoe of FIG. 6 before as one is being mounted to the other.
FIG. 9 is a side, elevational view of the gripper shoe mounted on the gripper carrier of FIG. 8 .
FIG. 10 is a top, plan view of the gripper shoe of FIG. 6 .
FIG. 11 is a partially sectioned, end view of the gripper shoe of FIG. 10 .
FIG. 12 is a partially sectioned, side view of the gripper shoe of FIG. 10 .
FIG. 13 is a bottom, plan view of the gripper shoe of FIG. 10 .
FIG. 14 , is a top, plan view of the gripper carrier shown in FIGS. 4-9 .
FIG. 15 is a side view of the gripper carrier of FIG. 14 .
FIG. 16 is a cross-section of the gripper carrier taken along section line 16 - 16 in FIG. 15 .
FIG. 17 illustrates flexing of a leaf spring of the gripper carrier.
DESCRIPTION
In the following description, like numbers refer to like elements.
FIGS. 1 , 2 and 3 illustrate an example of a coiled tubing injector 101 . It is intended to be representative of coiled tubing injectors generally for purposes of describing the invention, even though it may differ from other prior art coiled tubing injectors in several important aspects.
Referring first to FIG. 1 , coiled tubing is transported into the top of coiled tubing injector 101 from a reel (not shown) on a “goose-neck” support 103 . The goose-neck support includes a frame 105 supporting a plurality of rollers 107 . Bracing 108 extending from cage 109 positions the goose-neck support 103 in proper relation to the injector 101 . The cage also supports the injector 101 for transportation. Legs (not shown) may also be attached to the corners of the bottom of the cage 101 to stand the injector above a well head (not shown).
Referring now to FIGS. 1 , 2 and 3 together, injector 101 includes two, continuous loop drive chains generally designated by reference numbers 111 and 113 . The drive chains revolve generally within a common plane defined by axes 114 and 116 , which plane is normal to axis 118 . Connected to each drive chain is a plurality of grippers 115 . The drive chains 111 and 113 are arranged in a conventional, opposing relationship. Each drive chain 111 and 113 is mounted on an upper drive sprocket (not shown) and a lower drive sprocket 119 and 121 , respectively. The upper drive sprockets are mounted within drive housing 117 and are not visible in these views. One set of bearings for the shafts of upper drive sprockets are mounted within bearing housings 118 and 120 , respectively. The other set of bearings on which the shafts of upper drive sprockets are journalled are mounted to the opposite side of the drive housing 117 .
A box-shaped frame is formed from two, parallel front plates 123 and 125 , separated by side plate 127 and a second side plate parallel to side plate 127 but not visible in these views. This frame supports the drive housing 117 and transmission gear box 131 at its upper end, and the lower drive sprockets at its lower end.
The lower drive sprockets 119 and 121 are connected to shafts 133 and 135 , respectively. The ends of each shaft is journalled on opposite sides of the injector frame within a movable carrier 137 . Each carrier is mounted so that it may slide vertically within an elongated slot 139 defined in either the front plate 123 or rear plate 125 . A hydraulic cylinder 141 is inserted between the top of each carrier 137 and a block 143 connected to the frame at the top of each elongated slot 139 . Each cylinder 141 applies a spreading force between the stationary block and the moving carrier 137 to push down on the lower drive sprockets 119 and 121 and thus tension the drive chains.
Although not visible, coiled tubing injector 101 includes two skates, one for each drive chain, for forcing the grippers 115 toward each other as they enter the area between the two drive chains through which the coiled tubing passes. Examples of such skates are shown in U.S. Pat. No. 5,309,990 and are well known in the art. A plurality of hydraulic cylinders 145 are used to pull together the skates and maintain uniform gripping pressure against coiled tubing (not shown) along the length of the skates. Each cylinder 145 is connected at each end through a clevis and pin to an eyelet 147 of a bar extending behind one of the skate and terminating in another eyelet connected to another piston on the opposite side of the injector.
At the bottom of the injector, a stripper 149 carried by a stripper adapter 151 , connects the injector to a well head. Power for driving the injector is provided by a high speed, low torque hydraulic motor 153 coupled with the transmission gear box 131 through brake 155 . The hydraulic motor is supplied with a pressurized hydraulic fluid in a conventional manner.
Referring now to FIGS. 4-7 , drive chain 111 includes a roller chain having two strands, 157 and 159 , on either side of the row of grippers 115 . (Note that in FIG. 4 , the grippers have their shoes removed, revealing gripper carriers 161 .) The roller chain is of well-known construction. Rollers 163 are mounted on pins 165 which extend from an exterior side of strand 157 , through gripper carrier 161 , to the exterior side of strand 159 . Roller links 167 are disposed on opposite sides of each pair of rollers 163 . Pin link plates 169 are outboard of each roller plate and connect pairs of pins.
Mounted to an underside of gripper carriers 161 are a pair of roller bearings 171 and 173 which ride upon the skates of the injector. The roller bearings are rotatably mounted on pin 175 .
As illustrated by FIGS. 5 , 6 and 7 , a plurality of different shoes may be attached to the same gripper carrier 161 . For example, in FIG. 5 , “V”-shaped gripper shoe 179 can support large diameter tubing or pipe, the outer diameter of which is indicated in phantom by dashed circle 181 . In FIG. 6 , it is round-shaped gripper shoe adaptor 183 which may hold various sizes of rounded gripper shoes disposed therein (not shown) for gripping smaller diameter pipes and tubing. In FIG. 7 , a comparatively small gripper shoe 185 is shown mounted to gripper carrier 161 . When installed in an injector, the position of the center line of the pipe to be gripped by gripper shoe 185 will be the same as the center line of the larger diameter pipe to be gripped by gripper shoe 179 . This allows different shoes to be installed on the same injector in order to accommodate gripping of irregularly shaped tools or joints being passed through the injector without changing the relative position of the skates on which the gripper carriers roll.
Each of the gripper shoes may be quickly inserted and removed from the gripper carrier 161 without the use of tools. This is especially useful when running conventional, jointed pipe rather than coiled tubing, or when running a tool string corrected to one end of the coiled tubing. One or more gripper shoes are removed from each drive chain to pass the pipe joint or tool. In FIG. 5 , for example, the diameter of a joint is illustrated by dashed circle 187 and the outer diameter of the pipe by dashed circle 181 .
Referring now to FIGS. 8-17 , to mount a gripper shoe to the carrier 161 , a universal base 189 is integrally formed on the bottom of the gripper shoe. The base mounts to the gripper shoe carrier using a tongue and groove type of mounting that allows the gripper shoe to be slid onto and out of the mounting in directions that, when the injector is in an operational position, are generally parallel to the ground, which directions are generally oriented along axis 118 , and perpendicular to the directions in which the chain moves, which directions are generally oriented along axis 114 . Thus, forces exerted by the pipe string on the gripping elements, which forces are primarily along axis 114 , tend to act in a direction along axis 114 . along which the grippers shoe is slid into and out of the gripper shoe carriers. For purposes of explanation only, the gripper shoe adaptor 183 is chosen to illustrate this base. The same base is found on each of the gripper shoes 179 and 185 . The universal base 189 includes four mounting lugs, 191 a, 191 b, 191 c and 191 d which function as tongues that slide into grooves in the form of slots defined by ledges 195 and rails 197 around the periphery of the carrier. When the gripper shoe is lowered toward the carrier, lug 191 a fits into slot 193 a defined between ledges 195 a and 195 c extending from left side rail 197 a. Lug 191 b fits in slot 193 b defined between ledges 195 b and 195 c extending from right side rail 197 b. Lugs 191 c and 191 d fit over the end of the side rails 197 a and 197 b, respectively. The base of the gripper shoe presses against a flat, metal leaf spring 199 , forcing it down to allow the gripper shoe base 189 to be slid into the base, toward end rail 201 . When base is pushed back to the end rail, the lugs 191 a- 191 d pass under ledges 195 a- 195 d, respectively and cooperate with the ledges to retain the gripper shoe on the carrier. Leaf spring 199 then pops up, as best shown in FIG. 9 , and retain the gripper show on the carrier. During normal operation of the injector, lateral forces which would push the gripping shoe against the leaf spring are not substantial. Nevertheless, the leaf spring does possess substantial lateral strength. To reduce the effect of forces acting as the gripper shoes in lateral direction, the orientation of the carriers may be alternated on the chain, thus preventing the springs from carrying the lateral load.
The flat, metal leaf spring 199 is formed of an arched body section 199 a and feet 199 b and 199 c. The feet of the spring are trapped within open-ended slots 203 a and 203 b formed in the carrier 161 . Depressing the leaf spring flattens it and causes the feet to slide outward, as illustrated in phantom by FIG. 17 . When the feet slide outward, any dirt or other debris which may have accumulated in the slots 203 a and 203 b is pushed out through their open ends. The spring force of the spring is such that it may easily be manually depressed to release the gripper shoe, or pulled to remove the spring to clean a shallow channel 205 formed in the carrier between the open slots 203 a and 203 b for accommodating the body of the leaf when it is depressed.
Sandwiched between the gripper shoe base 189 and the carrier 161 is an elastomeric pad 206 of high spring rate which allows the gripper shoe to float on the carrier 161 . Slightly floating the gripper shoe allows the gripper shoe to automatically make small adjustments in its alignment with the coil tubing or pipe as it engages the tubing or pipe, thus providing a more even distribution of gripping forces across the shoe. The elastomeric pad also accommodates manufacturing tolerances that result in slight variations in the distances between the skate on which the roller bearings of the gripper carriers ride and the centerline of the pipe or other object being gripped. Thus, more of the gripping shoes will make good gripping contact with the pipe, improving overall grip. Preferably, only gripping shoes are used that have fixed shapes conforming to the normal shape of the pipe, and that surround substantially half of the circumference of the pipe. The fixed shape shoes cause the pipe to maintain its normal shape as strong forces are applied to the pipe, thus preventing deformation. By forcing the pipe to retain its normal shape and floating the gripper shoe for better alignment of the shoe with the pipe, contact area between the gripping shoe and pipe is increased. Furthermore, greater force may be applied to the pipe without concern of deformation. Thus, with greater contact area and force, gripping is improved.
Each shoe carrier 161 is mounted to one of the two drive chains by inserting one of the chain pins 165 ( FIG. 5 ) through each of the bores 207 a and 207 b. Rollers 171 and 173 ( FIGS. 5-7 ) are mounted between flanges 209 a, 209 b and 209 c. Roller 175 extends though openings 211 a and 211 b in flanges 209 a and 209 b, and in a similar opening in flange 209 c which is not visible in these views.
Gripping shoe adaptor 183 includes rims 213 a and 213 b located at opposite ends for retaining removable gripping elements (not shown). Gripping elements may thus be replaced when worn or changed in size or shape, or to accommodate passing of downhole tools or other downhole assemblies having different diameters than the pipe.
The forgoing embodiments are but examples of the invention. Modifications, omissions, substitutions and rearrangements may be made to the forgoing embodiments without departing from the invention as set forth in the appended claims.
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The gripping element of a coiled tubing injector has a carrier and a removable gripping shoe mounted to the carrier. The removable shoe slides onto slots formed on the carrier and is floated on the carrier by inserting an elastomeric pad sandwiched between the carrier and shoe. A manually depressible spring along ones side of the carrier prevents the shoe from sliding out of the slots during operation of the injector.
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BACKGROUND OF THE INVENTION
The present invention relates in general to centrifugal pumps of the pitot tube type, and, more in particular, to an improvement in such pumps that reduces the net positive suction head required to prevent cavitation.
Centrifugal pumps of the pitot type are well known. In general, these pumps include a drive that drives a rotor in rotation within a casing. A pitot pickup in a chamber of the rotor and stationary relative to the rotor intercepts fluid within the chamber and draws that fluid from the chamber. The exiting fluid has a head larger than its inlet fluid head because of energy imparted to the fluid by the rotor. Typically, fluid enters the rotor chamber along a path that includes an annulus surrounding the pitot tube mount and inside the rotor. From this annulus the fluid passes through a plurality of generally radial passages in the rotor to exit near the outer radial limit of the rotor chamber. The pitot inlet in the chamber may be comparatively close to the outer radial limits of the chamber or comparatively close to the axis of rotation of the rotor, depending on the application.
Typically, the pitot tube mount is in the form of a duct or tube extending along the axis of rotation of the rotor and through a wall of the rotor, usually a rotor cover. The duct is attached to the casing, or some other stationary support.
Pitot pumps are noted for their ability to impact large increase in head in the fluid being pumped. Adaptations of these pumps into separators and cleaners are possible because of the opportunity to stratify fluids within the rotor chamber and sort materials according to their density. Stratification, of course, comes from the large centrifugal force field present within the rotor chamber. An example of this application is a separator for separating solids from a liquid. In petroleum applications it is not uncommon to use production fluid from a petroleum well to power downhole machinery. This fluid must be free of solids. A pitot separator separates solids from the power fluid by centrifugal action and removes the solids either through a pitot pickup or nozzles in the wall of the rotor. A second, clean pitot tube pickup draws solid-free material from the chamber. Thus, in this application, it is possible to have more than one pitot pickup within the chamber. Separators, too, can use multiple head pitot pickups, as well as weir-like take-offs from the chamber in the walls of the rotor.
Known pitot pumps include those described in the following U.S. Pat. Nos.: 3,384,024; 3,776,658; 3,795,459; 3,817,659; 3,838,939; 3,926,534; 3,960,319; 3,977,810; and 3,994,618.
In these pitot-type pumps and separators, the duct mounting the pitot tube extends through a wall of the rotor. The duct is stationary while the wall rotates. Fluid inside of the rotor has a considerably higher head than incoming fluid in the annulus on the outside of the duct. Fluid leaking from the rotor chamber into the annulus has a deleterious effect on the net positive suction head of the pump. The net positive suction head (NPSH) is that pressure over and above the vapor pressure of the fluid being pumped within the inlet of the pump required to prevent cavitation in the pump inlet. Cavitation is localized vaporization of fluid. Cavitation adversely affects pump performance by reducing flow rate and discharge head. Cavitation also physically degrades the pump, often quite quickly. In previous designs, the interface between the rotor and the duct provided a labyrinth path for fluid through a plurality of axially spaced, circular grooves on the outside of the duct. Nonetheless, line-of-sight communication between the rotor chamber and the duct above the lands of the grooves and within the bore of the rotor receiving the duct permitted fluid from within the rotor to enter the duct resulting in a high velocity head, even jet-like, with the harmful impact on net positive suction head.
SUMMARY OF THE INVENTION
The present invention provides in a pitot type pump means for improving the net positive suction head by blocking a direct leak path of fluid from a rotor chamber of the pump into a fluid inlet passage to the chamber but outside that chamber and along an interface between the pitot tube and the rotor.
One form of the present invention provides a pitot pump with a rotor having a chamber in which a pitot tube pickup is disposed. A duct passing through an end wall of the chamber and the rotor supports the pitot tube. An interface between the duct and wall provides a leak path between the rotor and an inlet passage into the rotor chamber. A barrier in this leak path prevents line-of-sight communication between the inlet and the rotor chamber.
It has been found that despite the presence of a leak path between the rotor chamber and the inlet, interrupting line-of-sight communication between the two results in an improvement in the net positive suction head for the pitot pump. It is thought that the problem has been with the line-of-sight communication, permitting the fluid from the rotor chamber to jet into the entrance with adverse consequences on net positive suction head. By interrupting line-of-sight communication, the jet dissipates and the suction head improves.
To further enhance net positive suction head, radial passages of the rotor communicating with the entrance passage have large openings in the direction of fluid flow in the entrance, almost invariably axial.
In a detailed form, the present invention contemplates a centrifugal pump of the pitot tube type that employs a rotor havng a rotor chamber within it. The rotor is adapted to be driven in rotation by some prime mover, such as an electric motor. A casing houses the rotor and provides a shroud. The pitot tube pickup within the chamber mounts on a duct that extends coaxially with the rotor through an end wall of the rotor and anchors to a stationary part of the pump. The pitot tube and duct form a pitot tube assembly. The duct has an axial passage in communication with the entrance of the pitot tube for the discharge of fluid from the pump. An annulus around the duct provides the entrance into the rotor chamber, and it is this annulus that receives discharge through the leak path between the rotor chamber and the inlet. A circular lip received in a groove prevents line-of-sight communication through the leak path from the rotor chamber to the inlet. Generally, radial passages extend from the annulus to outlets proximate the outer radial limit of the chamber. These radial passages at their entrances are wider in cross section than in their medial portions in order to further improve net positive suction head.
These and other features, aspects and advantages of the present invention will become more apparent from the following description, appended claims and drawings.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a side elevation, predominantly in half section, of the preferred construction of a centrifugal pitot pump with the improved pitot assembly-to-rotor interface of the present invention;
FIG. 2 illustrates the preferred pitot tube assembly and rotor interface illustrated in FIG. 1 in the area bounded generally by lines 2--2;
FIG. 3 illustrates in end elevation and partly fragmented the generally radial passages in a cover of the rotor taken generally along lines 3--3 of FIG. 1; and
FIG. 4 is a plot of net positive suction head versus flow rate illustrating the improvement in that pump characteristic because of the construction of the pitot assembly rotor interface.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference in general to FIG. 1, pitot pump 10 is shown in side elevation. The general organization of the pump includes a rotor assembly 12 disposed within a casing 14 for rotation. A drive shaft 16 drives the rotor in rotation. The drive shaft is adapted to be coupled to a prime mover, such as a motor. A pitot tube assembly 18 is stationary relative to the rotor, the assembly extending from outside the rotor into a rotor chamber 20 within the rotor. Outside the rotor, the pitot tube anchors to a stationary part of the pump by attachment to manifold 22.
Rotor 12 includes a rotor cover 24. A plurality of generally radial passages 26 in the cover open at their outer ends into chamber 20 and open at their inner ends into an annulus 28. Annulus 28 feeds fluid to passages 26. Pitot tube assembly 18 includes a tube or duct 30 that defines the inner wall of annulus 28. A pitot tube arm 32 extends from an interior end of duct 30 (with respect to the rotor) radially within chamber 20. A scoop 34 caps the arm and provides the entrance for fluid to enter the pitot tube assembly. Duct 30 has a passage 36 extending through it to a discharge chamber 38.
Manifold 22 receives inlet fluid from a source and passes that fluid into annulus 28. Fluid passes through annulus 28 and into radial passages 26 for discharge into rotor chamber 20. Rotor 12, rotated by the prime mover, increases the head of the fluid as it passes up passages 26. Fluid within chamber 20 will have a higher head than fluid within annulus 28. This fluid will eventually be taken off by scoop 34, passed through arm 32 and through duct 30, and into discharge chamber 38.
With reference to FIG. 2, a leak path exists along the interface between rotor 12 and pitot tube assembly 18 communicating rotor chamber 20 and inlet annulus 28. This leak path is indicated in general by reference character 40. Fluid passes from chamber 20 into annulus 28 through path 40. An annular, circular ring 42 in the wall of cover 24 prevents therefore line-of-sight communication between chamber 20 and annulus 28. An annular, circular channel 44 radially inside of ring 42 but on pitot tube assembly 18 receives the ring. The axial width of channel 44 exceeds the axial width of ring 42 to provide tolerance clearance between the radial walls of the channel and the ring. Fluid will then flow from chamber 20 into annulus 28 about ring 42 but will be intercepted by the ring. It has been found that with the provision of the ring, this fluid flow is considerably less energetic and velocity head is dissipated. The ring interrupts the jet-like flow that would otherwise exist. With the interruption, an adverse effect of net positive suction head is attenuated.
A further improvement in the net positive suction head results from increasing the axial reach of the mouth of passages 26. A widened mouth 46 for these passages parallel to an axis 50 of the pump reduces corner losses of fluid passing from entrance 28 into passages 26 by reducing the sharpness of the corner. As will be developed subsequently, this increase in the axial span of the mouth for passages 26 is accompanied by a decrease in the rotary or circumferential span of the mouth. See FIG. 3.
In greater detail and with reference to both FIGS. 1 and 2, pitot tube assembly 18 is an integral assembly of arm 32 and duct 30. This assembly must pass through rotor cover 24. Thus the diameter of the duct cannot exceed the inside diameter of ring 42. Pitot tube assembly 18 in the vicinity of leak path 40 includes a hub or an elbow 52 at the base of arm 32. The elbow ends in a radial shoulder 54 that steps the diameter of the pitot tube assembly down to about the same as the inside diameter of ring 42. An annular, axially extending land 56 extends from shoulder 54 to channel 44. A shoulder 58 of channel 44 extends from the base of the channel to land 56. On the opposite end of channel 44, a flange 60 extends radially from duct 30 to a diameter about the same as the inside diameter of ring 42. A shoulder 62 of channel 44 and a flange 60 extends radially of axis 50. Flange 60 thus forms a land for channel 44. A tapered shoulder 64 extends from the major diameter portion of flange 60 to a reduced diameter section of duct 30 that exists away from leak path 40. Thus, flange 60 also acts as a dam in reducing the effect of the fluid from chamber 20 entering annulus 28.
With reference again to FIG. 1, duct 30 extends along axis 50 away from the zone of leak path 40 towards chamber 38. A flange 66 extends radially away from the adjacent portion of duct 30 to provide an anchor for the duct in manifold 22. This anchor is effected through a plurality of fasteners 68 that secure the duct to an interiorly extending radial flange 70 of the manifold. An O-ring 72 between the manifold and the duct seals the outgoing fluid in the duct from escaping into incoming fluid in annulus 28. A stub passage section 74 in the manifold extends between a chamber 76 of the manifold and passage 36 of the duct. Chamber 76 opens into an exit passage 78.
Annulus 28 within cover 24 opens into a plurality of passages 26, as can be seen in FIG. 3. Considered generally radially of axis 50, mouths 46 for passages 26 are narrow at their entrances and widen in the direction of rotor rotation as the radial distance from axis 50 increases to a fully developed passage section 80. With this increase in width of passages 26 in the direction of rotor rotation, passages 26 narrow in the direction along axis 50 in an amount corresponding to the widening in rotational direction so as to present substantially the same cross-sectional area to the flow of fluid through the passage. Passages 26 turn axial at their ends to exit through exit ports 82 into chamber 20. Passages 26 are slightly off radii from axis 50 to compensate for rotation of the passages with respect to annulus 28. The direction of rotation is indicated by the arrow in FIG. 3.
With reference to FIG. 1, pitot tube arm 32 extends from elbow 52 radially within chamber 20. The outside of the arm progressively narrows with increases in radius in a known fashion. Initially, the arm reaches a minimum thickness facing the rotary motion of fluid within chamber 20 so as to reduce drag. Scoop 34 that caps the arm intercepts the fluid and directs it down through the arm and into passage 36 for discharge.
With continued reference to FIG. 1, rotor 12 is formed of a deeply dished drum 84 that forms the radial boundaries of chamber 20 and one end boundary. Cover 24 attaches to drum 84 as through a plurality of fasteners 86 between the two and provides the other end boundary. Drum 84 has a hub 88 that secures the rotor to a mounting flange 90 at the end of drive shaft 16. Attachment is through fasteners 92.
Drive shaft 16 extends from a prime mover to mounting flange 90 and steps up before meeting the flange at a shoulder 93 of an axially extending section 94.
Casing 14 has a cylindrical section 100 that spans the axial extent of rotor 12. An end plate 102 attaches to cylindrical section 100 through fasteners 104. A second end plate 106 attaches to cylindrical section 100 through fasteners 108. End plate 106 has a large diameter hole 110 that receives a bearing retainer plate 112. This plate extends radially of section 94 of drive shaft 16. The retainer plate nests within a hub 118 of a lubricant reservoir and journal assembly for the drive shaft. This reservoir assembly has been largely omitted because it is of standard configuration. A bearing 120 for the interior end of drive shaft 16 is received on the drive shaft. An oil slinger 122 directs oil at the bearing. A second oil slinger 124 on the opposite side of bearing 120 does the same thing. A bearing retainer 126 receives bearing 120. A bearing mount spring ring 128 in turn receives the bearing retainer. A sleeve 130 receives this entire assembly. Sleeve 130 is received within hub 118. Hub 118 has a radially extending flange 140 that secures to plate 106 through fasteners 142. A breather passage 144 in end plate 106 communicates the volume outside of rotor 12 and within casing 14 to atmosphere. A lubricant bleed passage 146 through plate 112 and hub 118 drains lubricant to outside the pump.
At the other end of the pump, a seal 150 is disposed radially within a seal adapter 152 that is in turn received in a bore manifold 22. An O-ring between seal adapter 152 and this bore prevents leakage along the interface between the two. A second O-ring between the seal adapter and the seal prevents leakage along the interface between these two items. A seal clamp ring 156 on the inside of adapter 152 bears on one axial end of the seal and the adapter bears on the other axial end of the seal. These three elements are stationary. A ring 158 within a retainer 160 seals against seal 150. A spacer 162 positions ring 160 relative to seal 150. O-rings between the interfaces of this spacer and the rotor cover and the ring seal these interfaces.
Manifold 22 secures to end plate 102 as through fasteners 166. Chamber 76 of manifold 22 is capped by a plug 168 which is secured to the manifold as by fasteners 170. An O-ring may be provided between the plug and the walls of chamber 76 to effect a seal.
FIG. 4 illustrates the improvement in the net positive suction head attendant with the present invention. The ordinate shows net positive suction head required to operate the pump without cavitation. The abscissa shows the flow rate of the pump. The upper, dashed line shows the net positive suction head of the pump without the lip and channel of the present invention. The lower, solid line shows the net positive suction head requirements with the lip and channel of the present invention. It is clear from the plot that the improvement in net positive suction head obtains for a large range of flow rates.
The operation of the present invention has been described earlier in connection with specific structural functions but an overall description will be presented here.
Rotor 12 is caused to rotate within casing 14 and this causes fluid to enter chamber 20 of the rotor through the following path. The fluid enters manifold 22 and from there flows into annulus 28. There, the fluid flows axially of the pump outside duct 30. Then the fluid enters generally radial passages 26. Within these passages, the fluid picks up head. The fluid discharges out outlets 82 and into chamber 20. There, the head can be further increased. The net positive suction head required to maintain satisfactory fluid flow through the pump varies considerably with the fluid losses into the chamber. With large losses due to fluid head losses in the inlet path, the net positive suction head requirement for the pump increases.
Assuming an adequate net positive suction head to operate the pump, fluid is drawn off from chamber 20 through scoop 34 and flows down through arm 32, out passage 36, into chamber 76, and out exit passage 78. During operation, a substantial pressure differential exists between chamber 20 and annulus 28.
Production tolerance requirements require that a fairly substantial leak path exist between chamber 20 and inlet annulus 28 along path 40. With the substantial driving pressure differential between chamber 20 and annulus 28, fluid flows along a leak path 40 at a high velocity. If this leaking fluid is allowed to enter annulus 28 with its velocity unabated, the net positive suction head requirements for the pump increase substantially. The presence of the lip and channel arrangement of lip 42 and channel 44 substantially attenuates the adverse effect of leakage on the net positive suction head. The lip and channel reduce the jet-like flow of the escaping head, and an effective restriction in the mouth of passages 26 and annulus 28 is removed. It is noted that a head loss exists with or without the lip from the loss of the velocity head of the fluid flowing from the chamber to the annular passage. This loss with the invention, however, takes place away from the mouth and annulus.
The present invention has been described with reference to a preferred embodiment. The spirit and scope of the appended claims should not, however, necessarily be limited to the foregoing description.
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A centrifugal pitot pump has a rotor driven in rotation within a casing. A pitot tube pickup in a rotor chamber within the rotor intercepts rotating fluid and withdraws the fluid through a duct. The duct mounts the pitot tube and passes through the rotor casing. Fluid to be pumped passes through the annulus between the rotor and the duct and up through generally radial passages in the rotor into the rotor chamber. A leakage path from the rotor chamber to the inlet annulus between a hub of the pitot tube pickup and the rotor permits fluid to pass from the chamber into the annulus. A ring interrupts line-of-sight communication between the chamber and the annulus along the leak path and dissipates considerable of the leaking fluid velocity head to thereby improve the net positive suction head of the pump. The entrances of the radial passages in the rotor are large in the axial direction to reduce the sharpness of the turn from the annulus into these passages, to thereby reduce the net positive suction head required to operate the pump without cavitation.
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This application is a continuation of U.S. application Ser. No. 9/350,894, filed Jul. 7, 1999, now U.S. Pat. No. 6,687,814.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to application specific attachments allowing communication and control between a portable universal controller and a controlled application device.
2. Background of the Invention
Processes and machines routinely incorporate electronics for control and monitoring. The electronics for such processes and machines is typically localized and application specific. Often related local processes or machines are networked for the purposes of central control or monitoring of the larger system, process or machine of which they are a part.
A characteristic of all of the aforementioned processes, machines and systems is that specific equipment is controlled by electronic circuits, which may be formed as circuit boards, circuit modules, integrated circuits, chips or dies, etc. These electronic circuits are manufactured to suit specific needs and perform application specific functions and consequently have different circuitry and mounting systems. Consequently, each electronic circuit requires an associated application specific controller for the purposes of operating, monitoring, controlling, testing, debugging, programming, registering, initialization, identification, etc.
In many situations, it is inefficient to maintain all the different controllers that are required to control a broad range of electronic circuits. Therefore, there is a need for a portable, universal controller. A practical portable, universal controller must overcome several problems. Because electronic circuits have different functions, are from different manufacturers, and are installed at different periods, the nature of the electronics, software, and electronic interface may be very different.
The controller will also have to accommodate many different types of connectors depending on the nature of the electronic communication with respect to both types and number of contacts and the physical shape of the connectors used in peripheral equipment. It can be seen that any portable controller that is burdened with all of the software, communication electronics and connectors required to effectively operate a useful range of electronic circuits, or all of the localized equipment in a given system, will be complex and expensive. Moreover, it would be inflexible and unable to easily accommodate new localized equipment. What is required is a portable controller that practically and effectively will operate diverse electronic circuits.
SUMMARY OF THE INVENTION
The present invention meets the need for a single, practical, flexible and universal portable controller for controlling different electronic circuits, such as circuit boards, circuit modules, integrated circuits, chips, dies, etc. The invention includes a processor based portable controller which includes a reconfigurable programmable logic device. An application specific attachment is connected to both the universal controller and an electronic circuit. The attachment has a connector compatible with the I/O terminal of the electronic circuit and a memory which contains configuration data for electronically accessing the electronic circuit and operational software for operating the electronic circuit. The universal controller reads the configuration data of the electronic circuit from the memory of the application attachment and configures the programmable logic device giving the controller access to the electronic circuit. The universal controller also reads the operational software from the application attachment's memory and implements the operational software in order to control the electronic circuit. The universal controller may be used to operate, debug, control, program, initialize, identify, monitor, test, or register an electronic circuit. Those skilled in the art with appreciate the many, varied uses for the universal controller.
The advantages and features of the invention will be more readily understood from the following detailed description of the invention, which is provided in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram of a controller with an interface attachment.
FIG. 2 is a flow chart of the operation of an electronic circuit by a controller with an interface attachment.
FIG. 3 is a schematic block diagram of the testing of an electronic circuit by a controller with an interface attachment.
FIG. 3A is a schematic block diagram of the control of an electronic circuit by a controller with an interface attachment.
FIG. 4 is a schematic block diagram of the operation of an electronic circuit in the form of an integrated circuit by a controller with an interface attachment.
FIG. 4A is a schematic block diagram of the testing of an integrated circuit by a controller with an interface attachment.
FIG. 5 is a schematic block diagram of a controller with application attachments used in series.
FIG. 6 is a schematic block diagram of a controller for operating an electronic circuit in the form of an integrated circuit with application attachments used in series.
FIG. 7 is a flow chart of the programming of a custom application attachment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1 , a universal controller system is illustrated which includes a portable, universal controller 10 and an application attachment 20 . Also illustrated is an electronic circuit 30 which is to be controlled.
The universal controller 10 includes a housing 100 , a CPU 101 , a display 102 , such as an LCD, a keypad 104 , random access memory 106 , read only memory 108 , a reconfigurable programmable logic device 110 , an internal communication bus system 112 , a multi-pin socket connector 114 , an application input/output connector 116 , and a second input/output connector 118 . All of the elements of the universal controller 10 are connected to, and operate through, the internal communications bus system 112 , except the multi-pin connector 114 , which is connected to the reconfigurable programmable logic device 110 .
Each application attachment 20 includes a housing 200 , a multi-pin plug connector 202 , an input/output connector 204 , a non-volatile memory 206 , for example, a flash memory, and an application connector 208 . The flash memory 206 stores the operational software and application configuration data necessary for the electronic circuit 30 . The multi-pin plug connector 202 of the application attachment 20 is internally connected with the application connector 208 . The application connector 208 may be mounted on housing 200 or attached to the application attachment 20 by a cable, depending on the characteristics of the electronic circuit 30 . The multi-pin socket connector 114 of the universal controller 10 and the multi-pin plug connector 202 of the application attachment 20 must each have enough terminals to conform to the electronic circuit 30 with the largest number of terminals expected. Often, other electronic circuits 30 expected to the used with the universal controller 10 will require a smaller number of terminals. Thus, the application connector 208 will often have less terminals than the multi-pin plug connector 202 .
The application connector 208 is connected to the multi-pin connector on a terminal-to-terminal basis until all the terminals of the application specific connector 208 are exhausted, sometimes leaving some of the pins of the multi-pin plug connector 202 unconnected. In the example shown, the electronic circuit 30 requires less than all of the terminals of multi-pin socket connector 202 .
The flash memory 206 is connected to the input/output connector 204 . The multi-pin connector 202 and input/output connector 204 are located on the housing 200 of the application specific attachment 20 , and the multi-pin connector 114 and application input/output connector 116 are located on the housing 100 of the universal controller 10 , in a manner that they engage together when the application specific attachment is attached to the universal controller 10 . The application attachment 20 may also mechanically attach to the universal controller 10 in any one of many ways known in the art.
In an alternative embodiment of the invention, input/output connector 116 of the universal controller 10 , and input/output connector 204 of the application attachment 20 may be part of multi-pin socket connector 114 and multi-pin plug connector 202 , respectively. In this embodiment, a signal connector pair is used to provide the required signal paths for the invention.
The electronic circuit 30 may be a circuit board, circuit module, integrated circuit, chip, die, etc. That is, the electronic circuit 30 can be any type of electronic circuit, in any form, which can be operated on in any way, for example, programmed, monitored, tested, debugged, registered, initialized, identified, controlled, etc. The electronic circuit has a connector 302 electronically connected to it.
In practice, when it is desired to operate an electronic circuit 30 , an application attachment 20 matching the electronic circuit 30 is attached to the universal controller 10 and to the electronic circuit 30 . Connections between the controller and the attachment which are not needed for accessing configuration or operational software are kept in a passive state until a valid configuration is established. Data and one or more programs relating to the electronic circuit 30 prestored in flash memory 206 are loaded into RAM 106 for use by CPU 101 . CPU 101 runs the programs transferred from flash memory 206 using the transferred data to configure PLD 110 and conduct the predetermined operations on electronic circuit 30 . Since all control software and data for an electronic circuit are stored in application attachment 20 , an operator need merely choose a new application attachment 20 when the operator desires to use the universal controller 10 with a different electronic circuit 30 .
Referring to FIG. 2 , the overall control program executed by CPU 101 is shown. Upon powering on, the universal controller implements at step 401 the universal controller's operations software, which causes a menu of operations to appear on display 102 at step 402 . One of the entries on the menu is “Application Operation.” Other entries will be for other operations of the universal controller 10 , such as self diagnostic routines and the like. An operator then responds at step 404 with the appropriate keystroke to select application operation. In response, CPU 101 accesses at step 406 the flash memory 206 through the universal bus 112 , reads the configuration data and operational software for the electronic circuit 30 stored in the flash memory 206 at step 408 , and loads the configuration data and operational software in random access memory 106 at step 410 . CPU 101 then configures PLD 110 according to the application's configuration data at step 412 . With this configuration, data and address signals will be properly routed between various source pins of connector 302 and the address and data lines of the internal communication bus system 112 . CPU 101 then runs the application software at step 414 causing operation of the electronic circuit 30 . With appropriate software, memory and processing capacity, the universal controller can be used for any type of operation which can be performed on any electronic circuit. Once operation of the electronic circuit 30 is completed, the universal controller 10 can be turned off and disconnected, or left connected for another operation.
An example of a specific application with which the invention can be used is to test the erase time of an electronic circuit in the form of a memory device 304 , as shown in FIG. 3 . In this example, a particular electronic circuit 30 A has, among other things, a four terminal connector 302 A, an internal bus 303 A, and a memory device 304 A.
The operator selects the appropriate application attachment. The application specific connector 208 of the application attachment 20 is a four terminal connector that matches the application connector 302 A. Contained in the flash memory 206 of the application attachment 20 are the configuration data for the application connector 302 A, internal bus 303 A, and a program for testing the erase time of the memory device 304 A of the electronic circuit 30 A. The operator attaches the application attachment 20 to the universal controller 10 and attaches the application connector 208 of the application attachment 20 to the application connector 302 A of the electronic circuit 30 A. When the operator initiates the test routine, CPU 101 of the controller 10 accesses and reads the flash memory for the configuration data and operational software for the electronic circuit 30 A. Based on the configuration data, CPU 101 configures PLD 110 to route signals from the appropriate address and data lines of internal communication bus system 112 through to the appropriate terminals of multi-pin socket connector 114 of the universal controller 10 and multi-pin plug connector 202 of the application attachment 20 , through to application connector 208 of the application attachment 20 , through to application connector 302 A of the electronic circuit 30 A. The universal controller 10 then initiates the erase time test program contained in the operational software. Under the test program, the time required to completely access the memory device 304 A and erase it is recorded and compared to a standard, and a pass/fail indication appears on the display 102 . The operational software could also include other memory-related routines, such as a check for bad memory locations. With changes in software, the universal controller 10 could also be used to program, debug, identify, monitor, initialize, register, test or otherwise control the memory device 304 A.
In another embodiment of the invention illustrated in FIG. 3A , the direct connections between multi-pin plug connector 202 of the application attachment 20 and application connector 208 of the application attachment 20 are replaced by logic circuitry 210 . The logic circuitry 210 may afford direct connections, logic connections or a combination of both direct and logic connections, as will be understood by those skilled in the art.
In another embodiment of the invention illustrated in FIG. 4 , the universal controller 10 is used to operate electronic circuits in the form of integrated circuits, or similar electronic circuits. These integrated circuits could be newly manufactured or removed from an existing electronic environment. In this embodiment, the application connector 208 is an integrated circuit socket appropriate for the integrated circuits in question. The integrated circuit socket is situated on the housing 200 of the application attachment 20 and connects directly to the application connector 208 .
In another embodiment of the invention illustrated in FIG. 4A , the direct connections between multi-pin plug connector 202 of the application attachment 20 and application connector 208 of the application attachment 20 is replaced by IC testing electronics 212 , which incorporate direct and/or logic connections and testing hardware suitable for testing integrated circuit application 30 B, as will be understood by those skilled in the art.
In another embodiment of the invention illustrated in FIG. 5 , attachments may be used in series to accommodate families of applications. This approach will be most useful when certain electronic circuits share basic characteristics but have minor software or hardware differences. In this embodiment, a primary application attachment 20 P will include a multi-pin plug connector 202 P for connection with the universal controller 10 and a multi-pin sub-connector 208 P of adequate capacity for the designated family of electronic circuits. Also included will be a flash memory 206 P holding at least the configuration data for the sub-connector 208 P, and possibly configuration data for the ultimate electronic circuit 30 . The flash memory 206 P may also hold operational programming for the ultimate electronic circuit 30 . The primary application attachment 20 P may also have a second input/output connector 210 P internally connected to the first input/output connector 204 P.
The secondary application attachment 20 S has a multi-pin connector 202 S that matches the multi-pin sub-connector 208 P of the primary application attachment 20 P. An application connector 208 S is provided and is electrically connected to the multi-pin connector 202 S, terminal for terminal until the terminals of the application connector 208 S are exhausted. The secondary application attachment 20 S may also have a flash memory 206 S containing configuration data and operational programs for the particular electronic circuit 30 .
As an example, a series attachment system would be useful when dealing with families of electronic circuits 30 , such as integrated circuits, with identical electronics but different sockets, as shown in FIG. 6 . In this example, the flash memory 206 P of the primary application attachment 20 P would hold the operation programming for a family of electronic circuits 30 (here integrated circuits). The flash memory 206 S of the secondary application attachment would hold the configuration data for the specific electronic circuit 30 . For example, the configuration data for a particular 16 pin integrated circuit 30 C would route the address and data lines of the internal communication bus system 112 to the appropriate power pin 1 , input pins 2 through 8 , and output pins 9 through 16 .
In another example, series attachments can be used for monitoring electronic circuits having analog sensors. In this example, an analog/digital converter, required for each electronic circuit, would be included in the primary application attachment 20 P. The memory 206 S of the secondary application attachment 20 S would contain the configuration data and operations software specific to each electronic circuit.
Electronic circuits requiring supervoltages to operate may also be efficiently operated through series attachments. For example, a supervoltage is required to access test modes of certain dynamic random access memories (DRAMs). For these type of applications, the primary application attachment could include a voltage pump for multiplexing a supervoltage with logic signals, and any software necessary for this operation would be included in the flash memory of the primary application attachment. In this example, the secondary application attachments would have the appropriate connector, configuration data, and operation software for the particular electronic circuit, e.g. a memory device.
Those skilled in the art will appreciate that the examples used to illustrate series attachment could also be implemented with a single attachment. Such choices will depend on the particular economies of scale for each type of application.
A useful feature of the invention is its adaptability to custom applications, including one-time applications. For custom applications, attachments could be produced with unprogrammed flash memory and a specific connector that is likely to be used. An alternative would be to produce these unprogrammed attachments with several widely used connectors. Another alternative would be to produce the attachments with screw or similar terminals to allow any connector required to be connected to the multi-pin connector of the attachment.
A personal computer or similar device can be used to program the flash memory of the attachment with the appropriate software and configuration data. Referring to FIG. 7 , the operator would first load at step 500 and implement at step 502 the custom application software in the personal computer. When running, the program first will inquire at step 504 on the availability of a record of the configuration data for the application. If no record is available, the program will prompt the operator at step 506 to enter manually at step 508 the configuration data, which will be stored in the computer's memory at step 514 . If a record is available, the program will prompt to operator at step 510 to identify its location (which drive) at step 512 , and the configuration data will be stored in the computer's memory at step 514 .
The program then will inquire at step 516 on the availability of operational software for the application. If no software is available, the program will prompt at step 518 the operator to enter manually at step 520 the operational software which will be stored at step 526 in the computer's memory. If a record is available, the program will prompt at step 522 the operator to identify at step 524 its location, and the operational software will be stored at step 526 in the computer's memory.
The program then will inquire at step 528 whether the configuration data and operational software should be transferred to the application attachment. If no, the program will end. If yes, the program will transfer at step 530 the configuration data and operational software to the flash memory 206 of the attachment 20 via a connection to the input-output port 204 of the attachment 20 , or through terminals of connector 202 , if a separate input-output port 204 is not used.
The present invention provides a portable universal controller which can operate different types of electronic circuits using an application attachment for each different type of electronic circuit that provides the specific connection, configuration data and operational software required to control a specific electronic circuit. By providing the application specific data in an attachment, the present invention constitutes a flexible, truly universal controller for electronic circuits.
Variations of the embodiments will be readily apparent to those skilled in the art. Accordingly, it is to be understood that although the present invention has been described with references to preferred embodiments, various modifications, known to those skilled in the art, may be made to the structures and steps presented herein without departing from the invention, which is defined in the claims appended hereto.
The detailed workings of the processor and circuits, etc., set forth herein will also be readily apparent to those skilled in the art. In addition, those skilled in the art will recognize that the circuits and functions set forth may be realized by microprocessors, catalog and custom integrated circuits, etc., or combinations thereof as a matter of engineering choice.
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A controller with attachments for controlling specific electronic circuits is disclosed. Each attachment has a connector connectable to the electronic circuit to be controlled, and a memory accessible by the controller that contains configuration data for accessing the electronic circuit, and operational software for operating the electronic circuit.
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BACKGROUND OF THE INVENTION
This invention relates to d.c. motors fed by controlled converters in general and more particularly to a phase monitoring arrangement for a three phase network from which such motor is supplied which insures that operation that can be damaging to the motor or converter will not take place in the case of improper phase sequence or phase failure.
D.C. motors which are controlled by controlled converters in a three phase bridge circuit and which have their field circuits supplied by a rectifier bridge with a regulator providing inputs to a control circuit for generating firing pulses for the converter are known. In such devices, there is also provided a d.c. power supply to supply the necessary d.c. current to the regulator control circuit and the converter.
In drives of this nature, there is a danger to the converter, and particularly to their controlled switching elements, e.g., thyristors, which are sensitive to overloads if they are connected to the motor with the rotating field reversed because of an incorrect phase sequence. Similar problems occur in the event of a phase failure in the a.c. supply network. In particular, if a phase of the network fails there is a great danger, particularly if the failure occurs during the "standstill" control of the d.c. motor. The reason for this is that in the event of a failure of a phase of the network, the three phase bridge circuit of the converter operates like a single phase bridge circuit and the current regulator draws the required bridge current for the d.c. motor from the network through correspondingly fewer switching elements. This leads to larger a.c. currents in the inverter input and larger currents through the switching elements. Furthermore, the current ripple becomes larger and is accompanied by a degradation of the commutating properties resulting in brush arcing. Furthermore, with the smoothing of the actual current value input being the same, too low an actual current value is provided as an input to the current regulator. This causes the current limitation to be raised. Since the current transformer in the network feed line which is provided for measuring the actual current value is connected only to two phases, the actual current value provided as an input through the current regulator is reduced to less than one half if one of these phases fails. As a result, the current limitation assumes more than twice the value of the set magnitude and thus becomes practically ineffective as far as the switching elements are concerned. The greatest danger exists if a phase fails during standstill since the firing pulses are close to the inverter control limit of the three phase bridge circuit and a considerable residual voltage of √2U sine 30° is present on the d.c. side where a control angle of α = 150° is set for the effective a.c. bridge. This residual voltage drives a large motor current, limited only by the ohmic resistance of the armature and therefor drives a large current through the switching elements.
In view of these problems, the need for a phase monitor which is capable of monitoring phase failures and phase sequence and of shuting down the d.c. motors where conditions which are not compatible with proper operation occur in order to protect the converter against overload becomes evident.
SUMMARY OF THE INVENTION
The present invention solves this problem through the use of a discriminator which is supplied from the power line transformer. The discriminator forms a smoothed, rectified monitoring voltage which depends on the phase sequence and phase failure utilizing R-C members. It also supplies a supplementary rectified and smoothed monitoring voltage which depends only on phase failure. The monitoring voltage and supplementary monitoring voltage from the discriminator are compared in an evaluating circuit with a constant reference voltage. The output signals obtained from the comparision are utilized to control switching means connected in parallel along with a current regulator for the control permitting a blocking signal for suppressing the firing pulses to be delivered through the switching means of the control circuit and a blocking control signal to be delivered from the current regulator for controlling the inverter control limit of the converter in the case of an incorrect phase sequence when the motor is switched on or in the case of a phase failure.
Disclosed is a particularly simple circuit for the discriminator. In this circuit, two phases of a secondary winding of the power line transformer are connected to each other in a V connection and two equal R-C members connected to this V connection. Connected to the two R-C members is a first rectifier bridge and a parallel storage capacitor. A second rectifier bridge is provided along with a parallel storage capacitor and this bridge separately connected to the third phase of the secondary winding. The first rectifier bridge supplies the monitoring voltage and second rectifier bridge the supplementary monitoring voltage.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1, 1a and 1b are a circuit-block diagram of an inverter controlled d.c. motor illustrating the phase monitoring arrangement of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
For completeness, the whole inverter control system for the d.c. motor has been shown on FIGS. 1, 1a and 1b. However, since the majority of this circuitry is conventional, only those portions which are necessary for an understanding of the phase monitoring arrangement of the present invention will be explained in detail. Shown on FIG. 1 is a motor 11 which can be regulated and controlled in a well known manner utilizing a converter 13 coupled through chokes 15 to a.c. network 17. The field winding 19 of the motor 11 is supplied from an uncontrolled rectifier bridge 21 which is coupled to the a.c. network 17 through fuses 23. The current and speed of the d.c. motor 11 are controlled by means of a known control system illustrated on FIG. 1a. This control system receives as inputs the actual speed value n act developed in a tachometer generator 25 shown on FIG. 1. This voltage representing the actual speed is supplied to a terminal 27 shown both on FIG. 1 and FIG. 1a. The tachometer generator 25 is coupled to the shaft of motor 11 as illustrated. The second input to the control system 24 is an actual current value I act obtained from a current transformer 29 shown on FIG. 1. As illustrated, the current transformer is disposed in the supply to the inverter 13. Desired value inputs for the controller are set at resistors R n and R I which are used to set respectively, the desired speed n d and the desired current I d . In conventional fashion, the desired values are compared with the actual values to develop a necessary control voltage U st shown at terminal 31 for the inverter 13. This output is supplied to the inverter control circuit 32 illustrated on FIG. 1b, this circuit also being of conventional design.
The present invention provides for this known control arrangement a phase monitoring system which permits monitoring of the individual phases for failures as well as monitoring all three phases for phase sequence over a wide range of variation in the network voltage. As will become evident below, the outputs developed by the phase monitoring arrangement are used to influence both the control system 24 of FIG. 1a and the firing control circuit 32 of FIG. 1b. In accordance with the present invention, a transformer 33 is coupled to the three phases of the network 17 through the fuses 23. Transformer 33 has a primary winding W and secondary windings W1, W2, W3 and W4. The secondary windings W1 and W2 along with the primary winding W are all delta connected. The two secondary windings W1 and W2 feed a three phase rectifier bridge in a regulated power supply 35. The rectifier bridge itself develops voltages +U v and -U v referenced to a common point designated M. The regulated portion of the power supply 35 develops voltages +U k and -U k also referenced to the reference point M. The voltage +U v is supplied as an input to the control system of FIG. 1a and is also used for supplying the firing current to the thyristors in converter 13 through conventional protection circuits 37. (These circuits, of course, also receive the firing inputs developed in the firing control circuit of FIG. 1b as indicated by +R, +S, +T, -R, -S and -T.) The voltage -U V is provided as an input to an indicating circuit 30 to be described in more detail below.
The regulated voltage +U k and -U k because of the regulation are independent of disturbances and remain unchanged even in the case of a failure of a network phase. This is accomplished by using capacitors in the circuit which are of sufficiently large size. These voltages are used as the d.c. power supply for the control circuit 24 of FIG. 1a and the firing control circuit 32 of FIG. 1b. The winding W4 of the transformer 33 is also coupled to the circuit of FIG. 1b so as to synchronize it with the line voltage 17 in known fashion.
The phase monitoring arrangement of the present invention includes a discriminator 41, an evaluating circuit 43 and the indicating circuit 39. In addition to having a terminal for the reference point M, evaluating circuit 43 has two input terminals 45 and 47. These are coupled to respective output terminals 48 and 49 of the discriminator circuit 41. The monitoring voltage is present at the terminal 47 and the supplementary monitoring voltage at 45. These monitoring voltages are developed in the discriminator 41. Inputs thereto are obtained from the winding W3 of the transformer 33. As illustrated, two of the phase windings of this secondary winding are connected in a V connection. The two free ends of the V connected windings are coupled across two R-C members in series. The one R-C member is made up of a capacitor C1 and resistor R1 and the second of a capacitor C2 and resistor R2. Across the R-C member made up of capacitor C1 and resistor R1 the voltage U RS is developed and across the other R-C member, the voltage U ST . The junction points of the two R-C members are taken off and provide the inputs to a rectifier bridge 51. The input to this bridge is designated U U . The third winding is separately coupled as the input to a second bridge 52 at which input point the voltage U z appears.
The R-C members have equal resistors as well equal capacitors and are designed so that
R1 = R2 = |1/jωC1| = |1/jωC2|
the secondary voltages U RS and U ST are equal to U during undisturbed operation. As a result, at the series circuit made up of capacitor C1 and resistor R2, where the voltage U U is taken off and fed to the rectifier bridge 51, there will be a voltage which is dependent on the phase sequence. If the phase sequence is incorrect (rotating to the left) the voltage appearing will be as follows:
U.sub.U1 = U · √2 · sin 15° = 0.366 U.
for the correct sequence (rotating to the right) the voltage will be
U.sub.U2 = U · √2 · cos 15° = 1.336 U.
if one of the phases R or T fail on the primary side then the monitoring voltage which will be taken off at the series circuit of C1 and R2 is as follows: ##EQU1## If the phase S fails, however, the voltage will be
U.sub.U4 = 0.5 U.
thus, the ratio of the monitoring voltage values to the voltage U varies depending on the conditions described above and may take the value 0.366, 0.5, 0.791 and 1.366. These differences which occur in the event of a failure of the phases R, S. or T do not alone permit the circuit to have the same range of operation for all three phases over an extended voltage range of the line voltage and for all network frequencies. In order to have such a capability the separate monitoring voltage U z from the third phase of the secondary winding W3 coupled to the rectifier 52 and providing an output voltage of the same value but rectified is used. The voltage U z during normal operation will be equal to the voltage U T equal to the voltage U independent of phase sequence. If the phase S fails, it will still have the value U. On the other hand, it will have a value equal to 0.5 U if the phase R or T fails. Thus, the following table may be established showing the relationship between the monitoring voltage and supplementary monitoring voltage to the voltage U.
______________________________________U.sub.U /U U.sub.Z /U Operation______________________________________1.366 1.0 Correct phase sequence, undisturbed condition of the phases0.366 1.0 incorrect phase sequence when put into operation, undisturbed condition of the phases0.791 0.5 failure of phase R0.5 1.0 failure of phase S0.791 0.5 failure of phase T.______________________________________
As indicated above, the monitoring voltage U U is rectified in the bridge 51 and the supplementary monitoring voltage U z in the bridge 52 to provide the respective outputs at terminals 49 and 48 which are fed to the terminals 47 and 45 of the evaluation device 43. In the device 43, storage capacitors C21 and C11 are provided between the reference point M and the terminals 45 and 47 respectively. Thus, across these capacitors the rectified monitoring and supplementary monitoring voltages designated U U and U z are present. The magnitudes of these voltages correspond approximately to the peak values of the corresponding variables. As is evident and indicated above, both bridges and the capacitors are referenced to the point M. Across the capacitor C11 is a resistive voltage divider made up of the resistors R11 and R12. Similarly, across the capacitor C21 is a voltage divider made up of the resistors R21 and R22. Voltages U z22 and U U12 with respect to the reference point M are then taken off these voltage dividers. These voltages supply the inputs to differential amplifiers 55 and 57 respectively which are connected as comparators. At the differential amplifiers, they are compared with a voltage U R which is obtained from a voltage regulator network made up of a resistor R3, a diode N2 and a zener diode N1 coupled between the reference point M and the regulated voltage +U k . Thus, appearing at the input of the differential amplifier 55 will be difference voltage U D1 and at the input of the differential amplifier 57 a voltage U D2 . These are respectively the differences between the voltage U R and the voltage U U12 and between U R and U Z22 . The differential amplifiers operate as comparators such that either a positive or negative voltage U A1 or U A2 will appear at their respective outputs. The circuit with the differential amplifiers 55 and 57 is arranged such that the following is satisfied:
U U12 > U R results in U D1 > 0 and yields +U A1
U U12 < U R results in U D1 < 0 and yields -U A1
U Z22 > U R results in U D2 > 0 and yields +U A2
U Z22 < U R results in U D2 < 0 and yields -U A2
The output voltages U A1 and U A2 are fed respectively to the bases of transistors Q3 and Q4. Transistors Q3 and Q4 are coupled in parallel with their collectors coupled to the reference potential M and their emitters tied together and to an output terminal 59 at which their output I sp is supplied. This output is used in a manner to be more fully described below. The voltage U A1 and U A2 are also fed to transistors Q5 and Q6 in the indicating unit 39. These transistors are also connected in parallel with their emitters coupled to the reference point M and their collectors tied together and to one side of a relay coil 61, the other side of which is connected to the voltage -U V . The contact 63 of relay 61 may then be used to drive an indicating device. The amplifier outputs U A1 and U A2 are also coupled through diodes N3 and N4 of FIG. 1 to terminal 65 which is coupled to a terminal 67 also shown on FIG. 1a. It is from that point coupled through a resistor R4 to one input of the current regulating amplifier 69 of the control system 24 of FIG. 1a. The other input of the amplifier 69 is coupled through a resistor to the reference point M. The output of the amplifier 69 is the control signal U st which is the control input to the firing control circuit 32 of FIG. 1b. The signal I sp of FIG. 1 is also an input to this circuit at terminal 71.
In the case of an incorrect phase sequence connection or the failure of phase S, the differential amplifier 55 has a negative output voltage -U A1 . If the phase R or T fails, both differential amplifiers 55 and 57 have negative output voltages -U A1 and -U A2 , respectively. As a result in case of any kind of a failure, either one or both of the transistors Q3 and Q4 will become conductive resulting in the blocking signal I sp appearing at terminal 59. In addition, at the same time in every case, corresponding negative signals will appear at terminal 65 and will be fed through the resistor R4 to the amplifier 69 of FIG. 1a. The signal I sp at the input terminal 71 of FIG. 1b blocks the output of the circuit shown thereon. In other words, the firing pulses which normally appear at the output terminals and which are fed to converter 13 of FIG. 1 are blocked. The signal at the input of the amplifier 69 of FIG. 1a results in a larger current value being simulated. This causes the amplifier 69, which is the current regulator, to deliver a positive output signal U st which is also fed to the circuit 32 of the FIG. 1b. This causes the firing control circuit 32 to control the converter 13 toward the inverter control limit. In other words, it results in a shift of the firing pulses toward that limit. Of course, these firing pulses do not reach the inverter because of a blocking effect of the signal I sp . At the same time, the negative signal or signals U A1 and U A2 will cause the transistors Q5 and Q6 in the indicating circuit 39 to be conductive actuating the relay 61 to close the contacts 63 to give an external indication such as by light or sound. Thus, upon a failure in one of phases or an incorrect phase sequence, the inverter is immediately shut down, the control circuit controlled toward the inverter limit and an output indication given. At this point, the trouble may be investigated and corrected.
Once the trouble is corrected, which may be a reversal of inputs to establish the proper phase sequence or a correction so that all phases are again present, the signal I sp will be removed as will be the input to the amplifier 69 through the resistor R4 on FIG. 1a. However, the amplifier 69 is connected as an integral controller and will not immediately change its output because of the capacitor in its feedback path. This results in a control delay for the current regulator amplifier 69. As a result, the motor 11 will be gradually brought up to the speed determined by the speed control potentiometer R n and to a current determined by the setting of the potentiometer R I . Through the feeding of an additional control voltage through the resistor R4 to the current controller 69 when a disturbance occurs, the firing pulses are automatically shifted to the inverter locking limit and remain in this end position indicating that the rectifier voltage is at zero, so that, when the trouble is eliminated, operation is resumed from this end position with the voltage increasing from zero. Thus, in all cases excessive current peaks which could occur when the trouble is eliminated if the position of the control pulses was not defined, are avoided. Therefore, additional control of the rotating field at the start of operation is unnecessary since the drive will not start if, upon switching on, the phase sequence is incorrect. Thus, if the drive does not start it is only necessary to interchange two of the network phases.
The monitoring of the phases using the arrangement of the present invention is continuously effective, i.e. it also operates when the motor is standing still. This is a particular advantage since it is in such a case that a phase failure can be most damaging. As noted above, under such conditions the large current drain, which overloads the converter, results in a degradation of commutation and brush arcing and a simulation of an actual current value that is too low with an increasing current limitation occur.
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In a phase monitoring arrangement for a three phase network which supplies a controlled d.c. motor through a controlled converter, a power line dependent discriminator along with R-C circuits forms a smoothed, rectified monitoring voltage which depends on the phase sequence and is sensitive thereto and to phase failure along with a supplementary monitoring voltage dependent only on phase failure, the rectified monitoring voltage and supplementary monitoring voltage being supplied to an evaluating circuit comprising differential comparing amplifiers at which the monitoring voltages are compared with constant reference voltages independent of faults and the output thereof used to control switching means and a current regulator so that in the event of incorrect phase sequence or of a phase failure, the switching means feed a blocking signal which suppresses firing pulses to the controlled converter and the current regulator feeds a control signal to control the converter to its operating limit.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a vehicle with a door which is capable of swinging horizontally.
[0003] 2. Description of the Related Art
[0004] Conventionally, a door which swings horizontally to open and close is constructed such that two door hinges are mounted between the door and a vehicle body. The front edge of the door, on which the door hinges are mounted, is substantially vertical, so that the rotation centers of the upper and lower hinges correspond to each other. Also, as disclosed in Japanese Laid-Open Utility Model Publication No. 6-79617, there has been proposed a door which is constructed such that a double hinge is mounted on the front edge of the door to increase the angle at which the door can be swung.
[0005] However, according to the above described arrangement in which two hinges are provided at upper and lower locations, if a vehicle has a door with such a special shape that the front edge thereof is not vertical, but is shaped like e.g., an arc, the rotation centers of the upper and lower hinges cannot be made to correspond to each other. Further, according to the arrangement disclosed in Japanese Laid-Open Utility Model Publication No. 6-79617, the weight of the door must be supported by a lower part thereof, and hence the hinge needs to be large and heavy.
SUMMARY OF THE INVENTION
[0006] It is therefore an object of the present invention to provide a vehicle which is simply constructed, but can considerably increase the degree of freedom in designing a door capable of swinging horizontally.
[0007] To attain the above object, there is provided a vehicle having a door capable of swinging horizontally to open and close via at least two hinges, in which door side hinge mounting parts are out of alignment in a direction of a length of a vehicle body, wherein at least one of the hinges comprises a vehicle body side hinge mounting part, a door side hinge mounting part, and an extension part connecting the vehicle body side hinge mounting part and the door side hinge mounting part to each other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The nature of this invention, as well as other objects and advantages thereof, will be explained in the following with reference to the accompanying drawings, in which like reference character designate the same or similar parts throughout the figures and wherein:
[0009] FIG. 1 is a partial side view showing a vehicle with a door capable of swinging horizontally to open and close according to an embodiment of the present invention;
[0010] FIG. 2 is a perspective view showing a lower hinge of the door in FIG. 1 ; and
[0011] FIG. 3 is a partial plan view showing the lower hinge of the door in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0012] The present invention will now be described in detail with reference to FIGS. 1 to 3 showing an embodiment thereof.
[0013] In FIGS. 1 to 3 , reference numeral 1 denotes a vehicle; 2 , a door (front door); and 3 , a wheel (front wheel).
[0014] As shown in FIG. 1 , the front door 2 of the vehicle 1 is inclined such that a front edge 4 thereof below a side window glass line projects toward the front of a vehicle body, and recedes toward the rear of the vehicle body as it goes downward. An upper hinge mounting part 6 , on which an upper hinge 5 is mounted, is provided in an upper part of the front edge 4 of the door 2 , while a lower hinge mounting part 8 on which an upper hinge 7 is mounted is provided in a lower part of the front edge 4 of the door 2 .
[0015] As shown in FIG. 1 , the front edge 4 of the door 2 is formed to recede toward the rear of the vehicle body as it goes downward, and hence the upper hinge mounting part 6 and the lower hinge mounting part 8 are significantly out of alignment in the direction of the length of vehicle.
[0016] The upper hinge 5 is a gooseneck hinge which is projected and curved toward the inner side of the vehicle body, and prevents interference between the edge of the door 2 and the edge of the vehicle body when the door 2 is opened, and enables the door 2 to be opened at a large angle in such a way that the edge of the door 2 as well as the upper hinge 5 goes around the outer side of the edge of the vehicle body. The upper hinge 5 has one end thereof fixed to part of the vehicle 1 in front of and corresponding to the upper hinge mounting part 6 , and has the other end thereof fixed to part of the vehicle 1 in front of and corresponding to the upper hinge mounting part 6 , so that the door 2 can be pivotally supported on the vehicle 1 such that it may swing horizontally to open and close. It is to be noted that the upper hinge 5 may not necessarily be the gooseneck hinge as above, but may be either a single hinge or a double hinge insofar as it enables the door 2 to be opened and closed at a sufficient angle.
[0017] As shown in FIGS. 2 and 3 , the lower hinge 7 is comprised of a door side hinge mounting part 9 fixed to the lower hinge mounting part 8 of the door 2 , a vehicle body side hinge mounting part 10 fixed to part of the vehicle 1 in front of and corresponding to the lower hinge mounting part 8 , and an extension part 11 which is extended from the door side hinge mounting part 9 to be pivotally supported on the vehicle body side mounting part 10 . The extension part 11 is pivotally supported on the vehicle body side hinge mounting part 10 at the front of the vehicle so that the rotation centers of the extension part 11 and the upper hinge 5 can correspond to each other. The door 2 is pivotally supported on the vehicle 2 by the upper hinge 5 and the lower hinge 7 such that the door 2 may swing horizontally to open and close.
[0018] Further, a cover 12 which covers the extension part 11 of the lower hinge 7 to form a surface substantially flush with the vehicle body with the door 2 being closed as shown in FIG. 1 is provided on the side of the lower part of the vehicle body. In the lower part of the inner side of the vehicle body, the cover 12 is pivotally supported on the vehicle body by a hinge 13 so that the cover 12 can spread out to the outside of the vehicle body. It should be noted that the hinge 13 , which pivotally supports the cover 12 , is forced in such a direction as to be flush with the outer side of the vehicle body.
[0019] When the door 2 is opened, the extension part 11 of the lower hinge 7 pushes the cover 12 to the outside of the vehicle body so that the cover 12 can spread out to the outside of the vehicle body, and hence the extension part 11 never interferes with the vehicle body. When the opened door 2 is closed, the cover 12 which has spread out to the outside of the vehicle body moves in such a direction as to be flush with the external side of the vehicle body, so that the cover 12 can be flush with the outer side of the vehicle body with the door 2 being closed.
[0020] Therefore, even in the door 2 , which is constructed such that the front edge 4 thereof recedes toward the rear of the vehicle body as it goes downward, and the upper hinge mounting part 6 and the lower hinge mounting part 8 as shown in FIG. 1 , are significantly out of alignment, the rotation centers of the upper hinge 5 and the lower hinge 7 can be made to correspond to each other by a simple construction in which the lower hinge 7 is provided with the extension part 11 , so that the door 2 can swing horizontally to open and close. Further, the provision of the cover 12 , which covers the extension part 11 , improves the appearance when the door 2 is closed, and prevents the extension part 11 from interfering with the side of the vehicle body when the door 2 is opened. Further, the provision of the cover 12 considerably increases the degree of freedom in designing the shape of the door 2 .
[0021] Although in the above-described embodiment, the present invention is applied to the door 2 shaped as illustrated in FIG. 1 , but the present invention may be applied to doors with various shapes, such as a door whose front edge is inclined to recede toward the rear of a vehicle body as it goes downward. If the present invention is applied to such a door, an upper hinge provided with an extension part as described above is mounted on the front edge of the door, and a cover for the upper hinge is provided so that the door can be swung horizontally to open and close by a simple construction without degrading the appearance.
[0022] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
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There is provided a vehicle with a door which is capable of swinging horizontally to open and closed via at least two hinges. Two door side hinge mounting parts are out of alignment in the direction of the length of a vehicle body, and at least one of the hinges is comprised of a vehicle body side hinge mounting part, a door side hinge mounting part, and an extension part which connects the vehicle body hinge mounting part and the door side hinge mounting part.
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TECHNICAL FIELD
[0001] The invention pertains to methods of forming materials comprising tungsten and nitrogen, and in an exemplary application pertains to methods of forming capacitors.
BACKGROUND OF THE INVENTION
[0002] Tungsten nitride has properties which render it particularly suitable for utilization in integrated circuitry. For instance, tungsten nitride is found to exhibit better or equivalent electrical properties when compared to such commonly utilized compositions as, for example, TiN. Further, tungsten nitride retains its good electrical properties after being subjected to relatively high temperature processing, such as a polysilicon anneal or borophosphosilicate glass (BPSG) reflow.
[0003] Tungsten nitride materials can be formed by, for example, chemical vapor deposition processes, such as, for example, plasma enhanced chemical vapor deposition (PECVD). The tungsten nitride materials formed by such methods can have good step coverage over an underlying substrate and be continuous, particularly if formed at lower working ends of temperature and plasma power ranges. However, utilization of such tungsten nitride materials has been limited due to difficulties in working with the materials. Specifically, tungsten nitride can peel, and/or bubble, and/or crack when exposed to high temperature processing (such as, for example, the greater than 800° C. processing associated with anneal steps). The peeling, cracking and bubbling lead to a non-continuous film. It would be desirable to develop methods of forming materials comprising tungsten nitride which overcome problems associated with tungsten nitride exposure to high temperature processing conditions.
SUMMARY OF THE INVENTION
[0004] In one aspect, the invention includes a method of forming a material comprising tungsten and nitrogen. A layer comprising tungsten and nitrogen is deposited over a substrate. Subsequently, and in a separate step from the depositing, the layer comprising tungsten and nitrogen is exposed to a nitrogen-containing plasma.
[0005] In another aspect, the invention includes a method of forming a capacitor. A first electrical node is formed and a dielectric layer is formed over the first electrical node. A second electrical node is formed and separated from the first electrical node by the dielectric layer. A layer comprising tungsten and nitrogen is provided between the dielectric layer and one of the electrical nodes. The providing the layer comprising tungsten and nitrogen includes: a) depositing a layer comprising tungsten and nitrogen; and b) in a separate step from the depositing, exposing the layer comprising tungsten and nitrogen to a nitrogen-containing plasma.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Preferred embodiments of the invention are described below with reference to the following accompanying drawings.
[0007] [0007]FIG. 1 is a fragmentary, diagrammatic, cross-sectional view of a semiconductor wafer fragment at a preliminary step of a method of the present invention.
[0008] [0008]FIG. 2 is a view of the FIG. 1 wafer fragment shown at a processing step subsequent to that of FIG. 1.
[0009] [0009]FIG. 3 is a view of the FIG. 1 wafer fragment shown at a processing step subsequent to that of FIG. 2.
[0010] [0010]FIG. 4 is a view of the FIG. 1 wafer fragment shown at a processing step subsequent to that of FIG. 4.
[0011] [0011]FIG. 5 is a fragmentary, diagrammatic, cross-sectional view of a semiconductor wafer fragment at a preliminary step of a second embodiment method of the present invention.
[0012] [0012]FIG. 6 is a view of the FIG. 5 wafer fragment shown at a processing step subsequent to that of FIG. 5.
[0013] [0013]FIG. 7 is a view of the FIG. 5 wafer fragment shown at a processing step subsequent to that of FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] This disclosure of the invention is submitted in furtherance of the constitutional purposes of the U.S. Patent Laws “to promote the progress of science and useful arts” (Article 1, Section 8).
[0015] The invention encompasses methods of forming materials comprising tungsten and nitrogen. An exemplary method of the present invention is described with reference to a semiconductor wafer fragment 10 in FIGS. 1 and 2. Referring to FIG. 1, wafer fragment 10 comprises a substrate 12 and a layer 14 formed over substrate 12 . Substrate 12 includes a step 16 . Substrate 12 can comprise, for example, a conductive material, or an insulative material. Exemplary conductive materials include, for example, conductively doped polysilicon and metals, such as, for example, copper. Conductive materials of substrate 12 can be incorporated into, for example, interconnect lines. Exemplary insulative materials include, for example, silicon dioxide, tantalum pentoxide (Ta 2 O 5 ) and barium strontium titanate (BST). The insulative material can have a dielectric constant or “K” value which is greater than or equal to about 10. For instance, Ta 2 O 5 comprises a “K” value of from about 10 to about 25, and BST comprises a “K” value of from about 80 to about 1,000 or greater.
[0016] Layer 14 comprises tungsten and nitrogen, and can, for example, consist essentially of tungsten nitride. Such tungsten nitride can have the chemical formula WN x , wherein “x” is from 0.05 to 0.5. In one aspect, layer 14 is a tungsten nitride layer. Tungsten nitride layer 14 can be formed by, for example, chemical vapor deposition utilizing WF 6 and N 2 and H 2 as precursors, with either He or Ar as a carrier gas. The deposition can be plasma enhanced, with a plasma power of from about 50 watts to about 700 watts. A temperature of a substrate upon which deposition occurs can be from about 170° C. to about 550° C., and a pressure within the deposition chamber can be from about 500 mTorr to about 8 Torr. The described conditions are for deposition of tungsten nitride over a single semiconductor material wafer.
[0017] Tungsten nitride layer 14 is preferably formed to a thickness of from about 30 Å to about 2000 Å, and more preferably from about 50 Å to about 500 Å. An exemplary thickness of layer 14 is from about 150 Å to about 500 Å. The shown layer 14 has a number of defects. Specifically, voids (or cracks) 20 occur throughout layer 14 . An additional defect is a bubble 22 formed within layer 14 at an interface of layer 14 and substrate 12 . The above-described defects can occur either during deposition of layer 14 , or during high temperature processing subsequent to the deposition.
[0018] Referring to FIG. 2, layer 14 is exposed to a nitrogen-containing plasma in accordance with a method of the present invention. Such exposure removes at least some of defects 20 and 22 . After the exposure, layer 14 forms a stable film over substrate 12 , with the term “stable” indicating that layer 14 is resistant to formation of cracks, voids or bubbles during subsequent processing.
[0019] The plasma to which layer 14 is exposed preferably comprises a nitrogen-containing compound that does not contain oxygen. Suitable compounds are, for example, N 2 and NH 3 .
[0020] Exemplary conditions for treating layer 14 in accordance with the present invention include subjecting layer 14 to a plasma within a reaction chamber at a temperature of from about 170° C. to about 550° C., and a pressure of from about 500 mTorr to about 8 Torr. N 2 gas is flowed into the chamber at a rate of from about 50 standard cubic centimeters per minute (sccm) to about 800 sccm, and a plasma is maintained within the chamber at a plasma power of from about 100 watts to about 800 watts. One or more of H 2 and Ar can be flowed into the chamber in addition to the N 2 . If H 2 is flowed, it is preferably flowed at a rate of from about 50 sccm to about 800 sccm, and if Ar is flowed, it is preferably flowed at a rate of from about 200 sccm to about 2,000 sccm. An exposure time of a substrate to the plasma of from about 10 seconds to about 80 seconds is found to be generally sufficient to cure defects in a tungsten nitride layer having a thickness of less than or equal to about 2000 Å, and to convert such layer to a stable film.
[0021] The treatment discussed above with reference to FIG. 2 is conducted in a discrete step separate from the step of forming layer 14 that is discussed with reference to FIG. 1. The separate step of FIG. 2 can, however, be conducted in the same chamber as the layer-forming step of FIG. 1 by ceasing the forming step while maintaining a plasma utilized for the forming step. For instance, in embodiments wherein WF 6 and either N 2 or NH 3 are utilized as precursors in the layer-forming step of FIG. 1, the layer-forming step can be stopped by ceasing a flow of WF 6 into the reaction chamber. If the nitrogen precursor flow and plasma are maintained within the chamber, the treatment described with reference to FIG. 2 can proceed.
[0022] Another aspect of the invention is described with reference to FIGS. 3 and 4. In this aspect, the layer 14 formed above by the processing of FIGS. 1 and 2 is utilized as a substrate for formation of a second layer 30 comprising tungsten and nitrogen. Second layer 30 can be formed by identical processing as that described above with reference to FIG. 1. Layer 30 can then be treated by processing analogous to that described above with reference to FIG. 2 to eliminate defects and form the construction illustrated in FIG. 4.
[0023] Layers 14 and 30 of FIG. 4 together comprise a mass 32 of tungsten and nitrogen. The tungsten and nitrogen of mass 32 can, for example, be in the form of tungsten nitride.
[0024] It is noted that although the above-described embodiments illustrate a tungsten nitride material being treated with a plasma after formation of defects in the material, the invention also encompasses methods wherein a tungsten nitride material is treated with plasma before defects occur. For instance, in one aspect the invention encompasses treating a tungsten nitride material that is substantially free of defects with a plasma comprising a nitrogen-containing compound (preferably a nitrogen-containing compound that lacks oxygen). Such treatment can densify the tungsten nitride material to render it less susceptible to prior art problems associated with high temperature processing of tungsten nitride materials.
[0025] Another embodiment of the invention is described with reference to a semiconductor wafer fragment 50 in FIGS. 5 - 7 . Referring to FIG. 5, wafer fragment 50 comprises a substrate 52 and an insulative layer 54 formed over substrate 52 . Insulative layer 54 can comprise, for example, BPSG. Substrate 52 can comprise, for example, monocrystalline silicon lightly doped with a p-type background dopant. To aid in interpretation of the claims that follow, the term “semiconductive substrate” is defined to mean any construction comprising semiconductive material, including, but not limited to, bulk semiconductive material such as a semiconductive wafer (either alone or in assemblies comprising other materials thereon), and semiconductive material layers (either alone or in assemblies comprising other materials). The term “substrate” refers to any supporting structure, including, but not limited to, the semiconductive substrates described above.
[0026] An electrical node 56 is provided within substrate 52 . Node 56 can comprise, for example, a conductively doped diffusion region. Such diffusion region can be formed by implanting a conductivity-enhancing impurity into substrate 52 .
[0027] An opening 58 extends through insulative material layer 54 and to node 56 . Opening 58 can be formed by conventional methods, such as, for example, an etch utilizing CF 4 /CHF 3 and a plasma.
[0028] An electrically conductive material 60 is formed within opening 58 , and a dielectric material 62 is formed over conductive material 60 . Conductive material 60 and dielectric material 62 can be formed by conventional methods, such as, for example, chemical vapor deposition and photolithographic processing. Conductive material 60 can comprise, for example, a metal-containing layer, such as, titanium nitride or titanium. Alternatively, conductive material 60 can comprise conductively doped polysilicon. In yet other alternative embodiments, conductive material 60 can comprise tungsten nitride formed in accordance with the methods of the present invention described above. Dielectric material 62 can comprise, for example, a dielectric material having a “K” value greater than or equal to 10.
[0029] A layer 64 comprising tungsten and nitrogen is formed over dielectric material 62 . Layer 64 can be formed by, for example, the processing described above with reference to FIG. 1, and comprises a number of defects. Generally, it is found to be particularly difficult to form tungsten nitride over dielectric materials having “K” values of greater than 10 utilizing prior art methods.
[0030] Referring to FIG. 6, layer 64 is exposed to a nitrogen-containing plasma under conditions such as those described above with reference to FIG. 2. The exposure to the plasma removes the defects from layer 64 and converts layer 64 to a conformal and stable layer over dielectric material 62 . Layers 60 , 62 and 64 now together comprise a capacitor construction 70 , with layers 60 and 64 comprising electrodes of such capacitor construction.
[0031] Capacitor construction 70 can be incorporated as is into integrated circuitry. Alternatively, subsequent processing can be conducted to add a second conductive layer over layer 64 to increase a thickness of the top electrode of capacitor 70 . FIG. 7 illustrates wafer fragment 50 after such subsequent processing, and specifically illustrates an additional conductive layer 72 formed over layer 64 . Layer 72 can comprise, for example, an additional tungsten nitride layer formed in accordance with the processing described above with reference to FIGS. 3 and 4. Alternatively, layer 72 can comprise a conductive material other than tungsten nitride, such as, for example, conductively doped polysilicon, or a metal-containing layer. In alternative methods of describing capacitor structure 70 of FIG. 7, layer 64 can be considered as part of an upper electrode of the capacitor structure, or as being between dielectric layer 62 and an upper electrode consisting of layer 72 .
[0032] In the shown embodiment, capacitor construction 70 is a container-type capacitor. The invention encompasses other embodiments (not shown) wherein the capacitor has a shape other than a container-type structure.
[0033] In the shown embodiment, tungsten nitride layer 64 is formed between dielectric layer 62 and an upper conductive electrode 72 . However, it is to be understood that the invention encompasses other embodiments (not shown) wherein layer 64 is formed between dielectric layer 62 and lower electrode 60 , either in addition to, or alternatively to forming layer 64 between dielectric layer 62 and upper electrode 72 .
[0034] It is noted that an advantage of providing tungsten nitride layer 64 between dielectric layer 62 and a capacitor electrode is that tungsten nitride layer 64 can function as a barrier layer to alleviate or prevent diffusion of materials between dielectric layer 62 and conductive layer 72 .
[0035] In compliance with the statute, the invention has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the invention is not limited to the specific features shown and described, since the means herein disclosed comprise preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents.
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In one aspect, the invention includes a method of forming a material comprising tungsten and nitrogen, comprising: a) providing a substrate; b) depositing a layer comprising tungsten and nitrogen over the substrate; and c) in a separate step from the depositing, exposing the layer comprising tungsten and nitrogen to a nitrogen-containing plasma. In another aspect, the invention includes a method of forming a capacitor, comprising: a) forming a first electrical node; b) forming a dielectric layer over the first electrical node; c) forming a second electrical node; and d) providing a layer comprising tungsten and nitrogen between the dielectric layer and one of the electrical nodes, the providing comprising; i) depositing a layer comprising tungsten and nitrogen; and ii) in a separate step from the depositing, exposing the layer comprising tungsten and nitrogen to a nitrogen-containing plasma.
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