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FIELD OF THE INVENTION
[0001] The present invention relates to an arrangement, device and method for resolving hydrate plugs in oil wells and any pipeline transporting oil and gas, such as tubing, casing, drill pipe, drilling or production risers.
BACKGROUND
[0002] Hydrate plugs are sometimes formed in oil wells and pipelines transporting oil and gas. The plugs are apt to form in pipes where the pressure is high and the temperature low. This may in particular occur in offshore wells.
[0003] In order for hydrate plugs to form in wells, the following conditions must be present:
Access to free water (free water means water in liquid form as a separate phase or dispersed in the hydrocarbon phase). Access to light gas molecules (C 1 , C 2 , C 3 , iC 4 , CO 2 , N 2 , H 2 S). Relatively high pressure. Relatively low temperature.
[0008] Hydrates are mixtures of water (as ice) and methane gas. The methane gas occurs in cavities in the ice and changes the physical properties of the ice. The presence of methane will, inter alia, lower the melting point, but the most important effect is the release of gaseous methane when the hydrate is melting. The melting of the ice will lower the volume, but the released methane gas will increase the pressure (1 m 3 of ice can release up to 180 Sm 3 of gas).
[0009] Several methods exist for inhibiting the formation of hydrate plugs, but nevertheless hydrate plugs sometimes form, as mentioned above. Hydrate can cause problems in wells, process systems and transportation pipelines. Massive hydrates which close the flow cross section can cause serious operating problems. Small amounts of hydrate formation can put valves out of function or hinder well operations. These problems can have serious safety and economic consequences.
[0010] Hydrate plugs can be expected to form in many types of operations, such as cable operations, coiled tubing, hydraulic pipeline pressure operations, pump operations, leak testing, pumping of well fluids, input and/or output of equipment/tools, shut down of flow lines/gas lift lines, perforation of tubing, flow operations, well cleaning and change of christmas trees.
[0011] The standard method for removing a hydrate plug is to inject Methanol (MeOH), mono ethylene glycol (MEG), triethylene glycol (TEG) or brine (KCl, NaCl, CaCl 2 ) and maintain relative high pressure at the top of the well. When injecting the hydrate inhibitor, it is important to note that it may be difficult (time consuming, days, weeks or even months) to get the inhibitor down to the hydrate plug, due to the long distance from the top of the well to where the hydrate plug is located.
[0012] In order to increase the efficiency of the chemicals and to reduce the fluid requirements, the chemicals may be delivered directly at the plug through coil tubing. However, it normally takes a long time to get coil tubing equipment mobilized and heavy coil tubing equipment must be lifted as “Heavy Lift” onto the rig. This means that critical weather limitations exist for heavy lift to be performed on platforms, especially onto semi-submersible rigs and Tension Leg Platforms (TLP). In addition to this, considerable time is needed to rig up the coil tubing equipment on the rig. A relatively large crew is also needed to operate the coil tubing equipment.
[0013] Another method is to drill through the plug by using coil tubing. But again, it normally also takes a long time to mobilize the coil tubing equipment and, again, the heavy coil tubing equipment is susceptible to the critical weather limitations for heavy lift onto similar platforms like semi-submersible rigs and (TLP) Platforms. Considerable time is also needed here to rig up the coil tubing equipment. A relatively large crew is also needed to operate the coil tubing equipment.
[0014] From U.S. Pat. Nos. 5,619,611 and 6,343,652 is known a method for unplugging pipes by lowering an electric heat device down to the plug. The heat device is mounted inside an encapsulation with a blunt end face. The heated end face will rest against the plug and melt it. Due to the small contact area between the tool and the plug, the heat transfer will be slow. The use of wire line tractors to transport the tool in deviated wells is also described. However, the tractors described are well known in the art but are too small to provide any appreciable force between the plug and the tool. There is also the danger of accidental release of the hydrate plug upwards due to high pressure from below. As far as we know, this method is currently not in commercial use.
SUMMARY OF THE INVENTION
[0015] An object of the present invention is to provide a new way of removing hydrate plugs that is more efficient, less costly and also more predictable then the above mentioned methods.
[0016] This is achieved in an invention according to the appended claims.
[0017] According to a first aspect, the invention comprises an arrangement for resolving a hydrate plug in a pipeline, said arrangement comprising a heating device mounted on a stroking device, wherein the heating device is elongate and spear shaped and the stroking device is adapted to provide a traction force of sufficient strength to force the spear-shaped heating device into the hydrate plug. Simultaneously, hydrate inhibitor liquid may be pumped in from the surface.
[0018] The stroking device is provided with anchors that will prevent the tool from being pushed out of the well when/if the hydrate plug releases from the tubing, casing, drill pipe or drilling-production riser due to high pressure from below the plug. Significant pressure may be present below the hydrate plug.
[0019] The arrangement will also be provided with two temperature sensors, one placed in the top of the tool and one placed in the bottom of the tool, that allow us to control the temperature in the heat device area and behind the tool in order to take action before the environment gets back to the critical stage regarding temperature.
[0020] The inventive device may also be provided with one hydrate inhibitor/water (density) sensor to measure the hydrate inhibitor/water concentration, so we can take action before the environment gets back to the critical stage regarding concentration hydrate inhibitor/water.
[0021] According to a second aspect, the invention comprises a heating device for use in an arrangement for resolving hydrate plugs, the device including a first section that is cylindrical and slightly tapered, a middle section that is conical, a cylindrical end section and at least one heating element inside at least one of said sections.
[0022] The heating device may also include centralizers from aft to 1 - 2 cm in front of the pip (heating element). The centralizers will form an angle in front where the edges will be coated with nano-diamonds.
[0023] According to a third aspect, the invention comprises a method for resolving a hydrate plug in a pipeline, wherein a spear-shaped heating device is forced into the hydrate plug and the hydrate plug is heated.
[0024] The method may include an additional step of injecting a hydrate inhibitor near the plug and mixing hydrate inhibitor and freed water from the plug, wherein an agitator is placed in or near the heating device. Freed water means water in liquid form as a separate phase or dispersed in the hydrocarbon phase.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The invention will now be described in detail with reference to the appended drawings, where
[0026] FIG. 1 shows the overall design of the inventive arrangement,
[0027] FIG. 2 shows the heating device in detail,
[0028] FIG. 3 a - e is a sequence showing the invention in operation dissolving a hydrate plug in a pipeline.
DETAILED DESCRIPTION
[0029] FIG. 1 shows an assembly according to the present invention in use in a pipe 2 which is obstructed by a hydrate plug 1 . The assembly comprises a spear-shaped electric heating device 4 that is mounted on a stroking device or stroker. The assembly is connected to the surface through an electric wire-line 5 . The electric wire-line 5 includes an electric cable supplying electric power to the device 4 , as well as signal cables needed for controlling the assembly. The stroker shown in the figure includes first and second sections, 3 a, b , with clamping devices 6 allowing each section to be anchored to the tube. The stroker includes a hydraulic cylinder/piston arrangement 7 . When the first section 3 a has been anchored to the pipe, the cylinder 7 may be expanded forcing the heating device 4 into the hydrate plug. Then, electric power may be applied to the device for melting the plug. As the spear-shaped device is forced into the plug, a large surface for transferring heat is obtained. The device should be arranged to conduct heat over the whole body, not just in the tip as in prior art arrangements.
[0030] The assembly may include an agitator 18 . In the figure, the agitator is placed near the heating element, but it may be mounted anywhere on the tool. The agitator 18 includes a small propeller that may be run in both directions, which means that it may be reversed if the agitator should become clogged from debris present in the pipeline. The agitator may also be run periodically in alternate directions. The agitator serves to mix hydrate inhibitor and free water and to homogenize the temperature in the liquid mixture.
[0031] The assembly may be provided with a hydrate inhibitor/water sensor 15 that measures the hydrate inhibitor/water concentration in order to indicate when the injected hydrate inhibitor has been diluted and must be replenished.
[0032] The assembly may also be provided with two temperature sensors 13 , 14 , one 13 placed in the top of the tool and one 14 placed in the bottom of the tool, that allow us to control the temperature in the heat device area and behind the tool, so we can take action before the environment gets back to the critical stage regarding temperature.
[0033] In particular for deviated wells, the assembly could include a wire-line tractor. The tractor will ease transport along the well pipe.
[0034] It is essential for the invention to provide a large contact area between the heat body and the plug. Thus, the stroker must be able to confer substantial forces to the spear-shaped heating device in order to force it into the plug. A stroking device such as the Well Stroker (OD 21/8″-3⅜″) marketed by the company Welltec A/S can be modified for this purpose, even though a stroker from other suppliers may also be used. The stroker must not necessarily be as shown in FIG. 1 . However, the stroker must be able to deliver a sufficient forward pressure on the heating device, 1-10 tons or more. At the same time it will be anchored to the pipe. A large forward pressure will slightly lower the melting point of the hydrate plug, but more important is that it may allow the device to break through the far end of the plug, and thus provide an even faster removal of the plug. The stroker should be securely anchored at all times to the pipe in case a high pressure has built up behind the plug.
[0035] The cable to the surface must be dimensioned to deliver sufficient electric power to the heating device, preferably in the range of 1.5 kW or more.
[0036] FIG. 2 shows the heating device in detail. The device includes a slightly tapered cylindrical section 8 with a rounded tip 8 a . The heating assembly also includes centralizers 11 from aft to 1-2 cm in front of the pip (heating element). The centralizers will form an angle in front where the edges will be coated with nano-diamonds 19 . When forced into the hydrate plug, this front section with nano diamonds will cut into the plug and make larger contact area for the heating device radically. The front section is connected to a more steeply conical middle section 9 . This again is connected to a cylindrical end section 10 . All sections should be heated. The sections are hollow and one or preferably all sections should contain a heating device. In order to provide good thermal conduction from the element(s) into the hydrate plug, the elements may be filled with a heat conducting fluid. The device could be made from any metal of sufficient strength for the intended application, such as stainless steel, but should preferably be made from a metal that conducts heat well, such as copper. The heating device includes a number of wane shaped stabilizers with nano-diamonds 11 . These will cut into the plug and also conduct heat into the hydrate plug. The end section 10 also includes means 12 for connecting to the stroker, such as a threaded contact.
[0037] FIG. 3 a - e illustrates the sequence of operations when removing a plug.
[0038] The sequence involves an initial step when the area 16 adjacent to the plug 1 is filled with hydrate inhibitor, from the surface or delivered from a so-called retainer 17 , or preferably both, FIG. 3 a . This hydrate inhibitor spot will replace the oil phase above the plug due to the hydrate inhibitor being denser than the oil phase. A retainer is a container with a suitable ejector mechanism, such as a valve, at the outlet and a piston. The retainer may be lowered to the plug on an electric wire-line 18 , and is remotely operated from the surface.
[0039] The method may be described in technical detail as follows:
1. Start injection of hydrate inhibitor while waiting for wire line equipment to arrive at the rig. (Sub-step 1; inject and pressure up the well with hydrate inhibitor to 5-30 bar above wellhead pressure. Sub-step 2; wait for hydrate inhibitor to fall down into the oil phase. Sub-step 3; bleed of oil phase to shut in pressure (5-30 bar) Sub-step 4; repeat step 1 to 3 until rig up is complete.) 2. Rig up wire line and put in a retainer ( FIG. 3 a ) filled with hydrate inhibitor (30-100 litres) to the tool string. 3. Run in hole with retainer down to hydrate plug, spot hydrate inhibitor on top of hydrate plug. 4. Pressure up well with hydrate inhibitor from top of the well, this will help to squeeze the hydrate inhibitor against/into the hydrate plug. Pressure is now kept on the well for the rest of the operation. 5. Pull out of hole and exchange retainer with inventive device. 6. Run inventive device down to hydrate plug. 7. Activate rear anchor on the stroker to the tubing wall, FIG. 3 b. 8. Activate heating device and agitator device, let them work for a number of minutes. Record temperature in the top and bottom of tool area under whole operation. Regulate electric power to heat device if needed. Record hydrate inhibitor/water condition at all times until hydrate plug is melted. 9. Activate and extend stroker, FIG. 3 c , start putting small force to heat device to drive it into hydrate plug. Record temperature. 10. When stroker is extended all the way, activate front anchor to tubing wall, FIG. 3 d. 11. Deactivate then rear anchor. 12. Retract stroker, FIG. 3 e. 13. When stroker is retracted, activate rear anchor to tubing wall. 14. Deactivate front anchor. 15. Go back to step 4, perform steps 9-14 until hydrate plug is removed. 16. If hydrate inhibitor has been diluted and must be replenished, go back to step 2-14.
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An arrangement for resolving a hydrate plug ( 1 ) in a pipeline ( 2 ), such as tubing, drill pipe, casing etc., is described, said arrangement comprising a heating device ( 4 ) run on wire line. The heating device ( 4 ) is elongated and spear shaped and is mounted on a stroking device ( 3 ), the stroking device ( 3 ) being adapted to provide a pushing force of sufficient strength to force the heating device into the hydrate plug ( 1 ). The heating device then has a large surface towards the hydrate plug. When heat is applied to the heating device, the hydrate plug will melt. A hydrate inhibitor may be added to the liquid near the hydrate plug.
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BACKGROUND OF THE INVENTION
This invention relates to a process for improving the bulk oxidation stability and storage stability of lube oil base stocks derived from hydrocracked bright stock.
The term "oxidation stability" refers to the resistance of the oil to oxygen addition, in other words, how rapidly is oxygen picked up by and added to molecular species within the oil. Oxidation stability is indicated by the oxidator BN measured in hours. Oxidator BN is thoroughly described in U.S. Pat. No. 3,852,207 granted Dec. 3, 1974 to B. E. Stangeland et al at column 6, lines 15-30. Basically, the test measures the time required for 100 grams of oil to absorb one liter of oxygen. The term "storage stability" refers to the resistance of the oil to floc formation in the presence of oxygen.
The process comprises two steps. In the first step a hydrocracked bright stock is hydrodenitrified to reduce its heteroatom, particularly nitrogen, content using, for example, a sulfided nickel-tin catalyst having a siliceous matrix or a nickel-molybdenum hydrotreating catalyst having an alumina matrix. In the second step, the hydrocracked bright stock, having a reduced nitrogen content, is hydrofinished using, for example, an unsulfided nickel-tin or palladium hydrotreating catalyst having a siliceous matrix.
Both steps are carried out at an unusually low liquid hourly space velocity (LHSV), about 0.25 Hr -1 . In the first step, a low LHSV permits the desired hydrodenitrification reaction to proceed at relative low temperatures, about 700° F. Under these conditions hydrocracking is minimized. In the second step a low LHSV permits thorough saturation of aromatics which are floc-forming species. Thus, in general, the first step removes nitrogen and sulfur, known catalyst poisons, and improves oxidation stability; and the second step saturates aromatic floc precursors, and improves storage stability. Accordingly, it has been found that the stability of the resultant lube oil base stock is significantly improved.
Lubricant refining is based upon the fact that crude oils, as shown by experience or by assay, contain a quantity of lubricant base stocks having a predetermined set of properties such as, for example, appropriate viscosity, oxidation stability, and maintenance of fluidity at low temperatures. The process of refining to isolate a lubricant base stock consists of a set of unit operations to remove or convert the unwanted components. The most common of these unit operations include, for instance, distillation, hydrocracking, dewaxing, and hydrogenation.
The lubricant base stock, isolated by these refining operations, may be used as such as a lubricant, or it may be blended with another lubricant base stock having somewhat different properties. Or, the base stock, prior to use as a lubricant, may be compounded with one or more additives which function, for example, as antioxidants, extreme pressure additives, and viscosity index improvers. As used herein, the term "stock", regardless whether or not the term is further qualified, refers to a hydrocarbon oil without additives. The term "dewaxed stock" will refer to an oil which has been treated by any method to remove or otherwise convert the wax contained therein and thereby reduce its pour point. The term "base stock" will refer to an oil refined to a point suitable for some particular end use, such as for preparing automotive oils.
In general, refineries do not manufacture a single lube base stock but rather process at least one distillate fraction and one residuum fraction to produce several lube base stocks. Typically, three distillate fractions differing in boiling range and the residuum of a vacuum distillation operation are refined. These four fractions have acquired various names in the refining art, the most volatile distillate fraction often being referred to as the "light neutral" oil. The other distillates are called "medium neutral" and "heavy neutral" oils. The residuum fraction, is commonly referred to as "bright stock". Thus, the manufacture of lubricant base stocks involves a process for producing a slate of base stocks, which slate may include a bright stock.
Processes have been proposed to produce lubricating oil base stocks by refining bright stocks. Most such refining processes require hydrocracking the bright stock to produce a hydrocrackate which is in turn dewaxed to produce a dewaxed bright stock. The problem is that lubricating oil base stocks derived from hydrocracked stocks are unstable in the presence of oxygen and light.
Various stabilizing steps have been proposed. U.S. Pat. Nos. 3,189,540, 3,256,175 granted June 15, 1965 and June 14, 1966, respectively, to Kozlowski et al, describe a typical stabilization. The proposed stabilization uses a series of process steps employing a severe catalytic hydrogenation step to convert the remaining aromatic constituents into desirable lubricating oil constituents.
The goal of hydrogenation is to hydrogenate the unstable species, which are thought to be partially saturated polycyclic compounds. Unfortunately, severe hydrogenation of hydrocracked bright stocks not only hydrogenates the undesirable polycyclic constituents, but also further hydrocracks desirable constituents resulting in the loss of valuable lubricant base stock. Thus, recent processing schemes have suggested several alternatives to severe hydrogenation.
Refiners often now use mild hydrogenation (sometimes referred to as hydrofinishing) to produce more stable lubricating oils. Obviously, mild hydrogenation requires a compromise between the desired stabilization and the undesired hydrocracking. Consequently, thorough stabilization is often not accomplished. As an alternative to hydrofinishing, stabilizing agents, such as olefins, alcohols, esters, or alkylhalides can be added to the hydrocracked base stock in the presence of acidic catalysts having controlled alkylation activity. The resulting alkylation stabilizes the aromatic floc formers. While these and other processing schemes have achieved some success, in the case of highly aromatic stocks, such as bright stock, none of the previously known schemes is entirely satisfactory.
Thus, in general, at the time of the present invention, the literature relating to lube oil stabilization taught the use of severe hydrogenation or, alternatively, mild hydrofinishing and/or alkylation to stabilize a hydrocracked bright stock. However, in spite of the large amount of research into developing lubricant base stocks and stabilizing them, there continues to be intensive research into developing a more efficient and more convenient method for achieving those goals, especially for lubricant base stocks derived from hydrocracked bright stocks. The object of the present invention is to provide such a process.
It has now been discovered that a two-step hydrogenation process comprising a first step to reduce the nitrogen and sulfur content and a second step to thoroughly hydrogenate unstable polycyclics will produce a more stable lubricating oil base stock from hydrocracked bright stock. Thus, rather than employing a single severe hydrogenation step, the present invention employs a relatively milder two-step hydrofinishing stabilization for hydrocracked bright stocks.
SUMMARY OF THE INVENTION
The discovery of the present invention is embodied in an improved process for stabilizing a lube base stock derived from hydrocracked bright stock, comprising:
(a) contacting said hydrocracked bright stock with hydrogen in the presence of a catalyst having hydrodenitrification activity under conditions, including a low LHSV, effective to reduce the nitrogen content of said bright stock to less than about 50 ppm by weight, preferably less than 10 ppm by weight, and most preferably less than 3 ppm; and
(b) contacting the denitrified product of step (a) with hydrogen in the presence of a catalyst having hydrogenation activity under conditions, including a low LHSV, effective to reduce the level of unsaturated polycyclic compounds to produce a lubricant base stock.
DETAILED DESCRIPTION
The hydrocarbonaceous feeds from which the hydrocracked bright stocks used in the process of this invention are obtained usually contain aromatic compounds as well as normal and branched paraffins of very long chain lengths. These feeds usually boil in the gas oil range. Preferred feedstocks are vacuum gas oils with normal boiling ranges above about 350° C. and below about 600° C., and deasphalted residual oils having normal boiling ranges above about 480° C. and below about 650° C. Reduced topped crude oils, shale oils, liquefied coal, coke distillates, flask or thermally cracked oils, atmospheric residua, and other heavy oils can also be used as the feed source.
Typically, the hydrocarbonaceous feed is distilled at atmospheric pressure to produce a reduced crude (residuum) which is then vacuum distilled to produce a distillate fraction and a vacuum residuum fraction. According to the present process the residuum fraction is then hydrocracked using standard reaction conditions and catalysts in one or more reaction zones. The resulting hydrocracked bright stock can be further refined, for instance dewaxed, or used as such as the feed stock to the two-step process of this invention.
In the first step of the present process, the hydrocracked bright stock is hydrodenitrified to reduce its nitrogen level. Conventional hydrodenitrification catalysts and conditions can be used when carrying out this step. However, in order for the second step, detailed below, to achieve complete, or nearly complete aromatic saturation, of the hydrocracked bright stock which is essential to the present process; in the first step a combination of catalysts and hydrogenation conditions which will reduce the nitrogen level of the hydrocracked bright stock to below about 50 ppm by weight without substantially increasing the quantity of aromatic unsaturates by hydrocracking side reactions are essential. In addition, it will be desirable to select catalysts and conditions which inherently result in cleavage of carbon-sulfur bonds with formation of hydrogen sulfide to achieve some level of hydrodesulfurization. Organic sulfur, like nitrogen, is deleterious to the activity of the hydrogenation catalysts used in the second step. It is desirable to reduce the sulfur level to less than about 50 ppm, preferably less than about 10 ppm, and most preferably less than about 3 ppm. Typical first step hydrodenitrification catalysts comprise a Group VIIIA metal, such as nickel or cobalt, and a Group VIA metal, such as molybdenum or tungsten (unless otherwise noted references to the Periodic Table of Elements are based upon the IUPAC notation) with an alumina or siliceous matrix. These and other hydrodenitrification catalysts, such as nickel-tin catalysts, are well known in the art. U.S. Pat. No. 3,227,661 granted Jan. 4, 1966 to Jacobson et al, describes a method which may be used to prepare a suitable hydrodenitrification catalyst.
Typical hydrodenitrification conditions which are useful in the first step of the present process vary over a fairly wide range, but in general temperatures range from about 600° F. to about 850° F., preferably from about 650° F. to 800° F., pressures range from about 500 psig to about 4000 psig, preferably from about 1500 psig to about 3000 psig, contact times expressed as LHSV range from about 0.1 per hour to about 3 per hour, preferably from about 0.1 per hour to about 0.8 per hour, and hydrogen rates range from about 5000 cu. ft. per barrel to about 15,000 cu. ft. per barrel. U.S. Pat. No. 3,227,661 describes those conditions required for various processing schemes using the denitrification catalysts taught in that patent. A general discussion of hydrodenitrification is available in U.S. Pat. No. 3,073,221 granted on Feb. 19, 1963 to Beuther et al. As previously discussed, the overlying consideration, when selecting suitable denitrification conditions from the general conditions taught in these patents and the art generally, is the use of a relatively low LHSV and temperature in order to achieve nearly complete denitrification with minimal hydrocracking.
In the second step of the present process the denitrified, "clean" stock is hydrofinished using a mild hydrogenation catalyst and conditions. Suitable catalysts can be selected from conventional hydrofinishing catalysts having hydrogenation activity. Since this step can also be carried out under relatively mild conditions when a low LHSV is employed, it is preferable to use a hydrogenation catalyst such as, for example, a noble metal from Group VIIIA, such as palladium, on a refractory oxide support, or unsulfided Group VIIIA and Group VI, such as nickel-molybdenum, or nickel-tin catalysts. U.S. Pat. No. 3,852,207 granted on Dec. 3, 1974 to Stangeland et al, describes suitable noble metal catalysts and mild conditions.
As mentioned already, suitable hydrofinishing conditions should be selected to achieve as complete hydrogenation of unsaturated aromatic as possible. Since the first step has removed the common hydrogenation catalyst poisons, the second step run length can be relatively long affording the opportunity to use a relatively low LHSV and mild conditions. Suitable conditions include a temperature ranging from about 300° F. to about 600° F., preferably from about 350° F. to about 550° F., a pressure ranging from about 500 psig to about 4000 psig, preferably from about 1500 psig to about 3000 psig, and an LHSV ranging from about 0.1 to about 2.0 per hour, preferably from about 0.1 per hour to about 0.5 per hour. Thus, in general terms the clear hydrodenitrified effluent of the first step is contacted with hydrogen in the presence of a hydrogenation catalyst under mild hydrogenation conditions. Other suitable catalysts are detailed, for instance in U.S. Pat. No. 4,157,294 granted June 5, 1979 to Iwao et al and U.S. Pat. No. 3,904,513, granted Sept. 9, 1975 to Fischer et al, both incorporated herein by reference.
The product of the process of the present invention is suitable for use as a lubricant base stock. Typically, it is dewaxed, if that has not already been done, prior to final blending.
The present invention is exemplified below. The examples are intended to illustrate representative embodiments of the invention and results which have been obtained in laboratory analysis. Those familiar with the art will appreciate that other embodiments of the invention will provide equivalent results without departing from the essential features of the invention.
Examples
EXAMPLE 1
In a single step stabilization carried out for comparison with the two-step process of the present invention, a solvent dewaxed hydrocracked bright stock (Table I) was hydrofinished over a sulfided nickel-tin on silica-alumina hydrogenation catalyst at 705°-716° F., 0.25 LHSV, 2200 psig, and 8M SCF/bbl H 2 . At 1080 hours onstream and 716° F., conversion below 900° F. was 22 wt. %. Product sulfur was 33 ppm and nitrogen 6.7 ppm. The product was tested for storage stability by placing 40 cc. of oil in an unstoppered cylindrical glass bottle of 13/8 inches diameter and putting the bottle in a forced convection oven controlled at 250° F. The sample was examined once per day for floc. The test was ended when a moderate to heavy floc could be observed. The product formed heavy floc within one day. The oxidator BN was 4.6 hours.
In order to illustrate the two-step process of the present invention and obtain a comparison with the single step process described above, the denitrified product from Example 1 was subjected to a second hydrofinishing over a catalyst composed of 2 wt. % palladium on silica-alumina. Hydrofinishing conditions were 0.25 LHSV, 400° F., 2200 psig, and 8M SCF/bbl H 2 . The 250° F. storage stability of the product from 0-500 hours onstream was 15+ days, and the oxidator BN was 20.0 hours demonstrating the significant benefit of the two-stage process.
EXAMPLE 2
In a second comparison with the single step process of Example 1, the denitrified product from Example 1 was subjected to a second hydrofinishing over the palladium catalyst of Example 1, and at the same conditions except for an LHSV of 1.0. After 48 hours onstream, the product had a 250° F. storage stability of 4 days, demonstrating the importance of low LHSV to successfully stabilize the bright stock.
EXAMPLE 3
In another comparative test, the dewaxed hydrocracked bright stock feed (Table I) was hydrofinished over a sulfided Ni-Mo on alumina hydrogenation catalyst at 0.5 LHSV, 760°-767° F., 2200 psig, and 8M SCF/bbl H 2 for 584 hours. At 584 hours onstream and a catalyst temperature of 767° F., conversion below 900° F. was 26 wt. %. Product sulfur was 4.6 ppm and nitrogen 73 ppm. The product samples were combined and tested for 250° F. storage stability, which was found to be less than one day.
The first stage run with Ni-Mo on alumina described above was continued for another 600 hours, but at an LHSV of 0.25 and a catalyst temperature of 742° F. Conversion below 900° F. was 27 wt. %. Product sulfur was 1.8 ppm and nitrogen 17 ppm, well below that achievable at 0.5 LHSV and the same conversion. The 250° F. storage stability was less than one day. This product was then hydrofinished in a second stage over a fresh charge of the Pd/SiO 2 -Al 2 O 3 catalyst of Example 1 at 0.25 LHSV, 350° F., 2200 psig, and 8M SCF/bbl H 2 . After 182 hours, the 250° F. storage stability was 15+ days.
TABLE I______________________________________Dewaxed Hydrocracked Bright Stock Inspections______________________________________Gravity, °API 21.8Sulfur, ppm 970Nitrogen, ppm 980Pour Point, °F +10Viscosity, cSt, 40°C 1148.0Distillation, LV%, °F.ST/5 990/101910/30 1034/106750 1093Oxidator BN, hr. 2.5______________________________________
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A process for stabilizing a lubricating oil base stock derived from a nitro-aromatic-containing hydrocracked bright stock, comprising a two-step stabilizing process utilizing hydrodenitrification followed by mild hydrofinishing.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority from related Patent Cooperation Treaty application PCT/JP 99/01229 filed Mar. 15, 1999 that claims priority from related Japanese Patent Applications No. 10-324482 filed Oct. 28, 1998; 10-324483 filed Oct. 28 1998; and 10-100141 filed Mar. 26, 1998.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the composition of a novel lead-free solder alloy.
2. Description of the Related Art
In the solder alloy, lead has been conventionally an important metal for diluting tin to improve flow factor and wettability. Obviating the use of lead, a toxic, heavy metal, is preferred in consideration of working environments in which soldering operation is performed, operating environments in which soldered products are used, and the earth friendly to which solder is released. Avoiding the use of lead in solder alloy is thus noticeable practice.
When a lead-free solder alloy is formed, the alloy is required to have wettability to metals to be soldered. Tin having such wettability is an indispensable metal as a base material. In the formation of a lead-free solder alloy, it is important to fully exploit the property of tin and to determine the content of an additive metal for the purpose of imparting, to the lead-free solder alloy, strength and flexibility as good as those of the conventional tin-lead eutectic alloy.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a lead-free solder alloy having tin as a base material with other additive materials that are easily gettable as good as the conventional tin-lead eutectic alloy, and offers a stable and liable solder joint.
To achieve the object of the present invention, the solder alloy is preferably formed of three metals of 0.1-2 weight percent (hereinafter wt %) Cu, 0.002-1 wt % Ni and the remaining wt % Sn. Of these elements, tin has a melting point of about 232° C., and is an indispensable metal to impart wettability of the alloy against the metals to be soldered. A tin-based alloy, without lead of a large specific gravity, is light in its molten state, and cannot offer enough flowability to be appropriate for a nozzle-type soldering operation. The crystalline structure of such solder alloy is too soft and not mechanically strong enough. By additive of copper the alloy reinforces strongly. The addition of approximately 0.7% copper added to tin forms an eutectic alloy having a melting point of approximately 227° C., which is lower than that of tin alone by approximately 5° C. The addition of copper restrains copper leaching in which copper, a typical base material of lead wire, leaches out of the surface of the lead wire in the course of soldering operations. At a soldering temperature of 260° C., for example, the copper leaching rate of the copper-added alloy is half as high as the copper leaching rate in the tin-lead eutectic solder. Restraining the copper leaching reduces a copper density difference present in a soldering area, thereby slowing the growth of a brittle compound layer.
The addition of copper is effective to prevent a rapid change in composition in the alloy itself when using a long period on a dipping method.
The optimum amount of additive copper is within a range of 0.3-0.7 wt %, and if more copper is added, the melting temperature of the solder alloy rises. The higher the melting point, the higher the soldering temperature needs to be. A high soldering temperature is not preferable to thermally weak electronic components. Typical soldering temperature upper limit is considered to be 300° C. or so. With the liquidus temperature of 300° C., the amount of additive copper is about 2 wt %. The preferable value and limits are set as the above.
In the present invention, not only a small amount of copper is added to tin as a base material, but also 0.002-1 wt % nickel is added. Nickel controls intermetallic compounds such as Cu 6 Sn 5 and Cu 3 Sn, which are developed as a result of reaction of tin and copper, and dissolves the developed compounds. As such intermetallic compounds have a high temperature melting point, they hinder flowability of milting solder and make solder function declined. Therefore, if these intermetallic compounds remain on patterns at a soldering operation, these become to be so-called bridge that shorts conductors. Namely, needle-like projections remains when leaving from melting solder. To avoid such problems, nickel is added. Although nickel itself produces intermetallic compound with tin, copper and nickel are always solid soluble at any ratio. Therefore, nickel cooperates with the development of Sn—Cu intermetallic compounds. Since the addition of copper to tin helps the alloy to improve its property as a solder compound in the present invention, a large amount of Sn—Cu intermetallic compounds is not preferable. For this reason, nickel, in an all-ratio solid soluble relationship with copper, is thus employed to control the reaction of copper with tin.
The liquidus temperature rises if nickel is added because a melting point of nickel is high. In consideration of the typical permissible upper temperature limit, the amount of additive nickel is limited to 1 wt %. It was learned for an inventor that the amount of additive nickel as low as or greater than 0.002 wt % held a good flowability and solderability showed a sufficient strength of a soldered joint. According to the present invention, a lower limit of the amount of additive nickel is thus 0.002 wt %.
In the above process, Ni is added to the Sn—Cu alloy. Alternatively, Cu may be added to an Sn—Ni alloy. When nickel alone is slowly added to tin, according to the raising up of a melting point, the flow factor drops in its molten state by reason of producing intermetallic compounds. By adding copper, the alloy has a smooth property with an improved flow factor but some degree of viscosity. In either process, the interaction of copper and nickel helps create a preferable state in the alloy. The same solder alloy is therefore created not only by adding Ni to the Sn—Cu base alloy but also by adding Cu to the Sn—Ni base alloy.
Referring to FIG. 1, a range of 0.002-1 wt % nickel and a range of 0.1-2 wt % copper result in a good solder joint. When the base alloy is Sn—Cu, the content of copper represented by the X axis is limited to a constant value within a range of 0.1-2 wt %. If the content of nickel is varied within a range of 0.002-1 wt % with the copper content limited to within a range of 0.1-2 wt %, a good solder alloy is obtained. When the base alloy is Sn—Ni, the content of nickel represented by the Y axis is limited to a constant value within a range of 0.002-1 wt %. If the content of copper is varied within a range of 0.1-2 wt %, a good solder alloy is obtained. These ranges remain unchanged even if an unavoidable impurity, which obstructs the function of nickel, is mixed in the alloy.
Germanium has a melting point of 936° C., and dissolves in only a trace amount into the Sn—Cu alloy. Germanium makes the crystal finer when the alloy solidifies. Germanium appears on a grain boundary, preventing the crystal from becoming coarse. The addition of germanium prevents oxide compounds from developing during the solution process of the alloy. However, the addition of germanium in excess of 1 wt % not only costs much, but also makes an oversaturation state, hindering the molten alloy from spreading uniformly. Excess germanium above the limit does more harm than good. For this reason, the upper limit of the content of germanium is thus determined.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a graph showing proper ranges of additive metals.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The physical properties of solder alloys having the composition of the present invention are listed in Table. The alloy of 0.6 wt % Cu, 0.1 wt % Ni, and the remaining percent Sn, which the inventors consider one of the proper compositions of solder alloy, was prepared.
Melting point:
Its liquidus temperature was approximately 227° C. and its solidus temperature was approximately 227° C. Tests were conducted using a differential thermal analyzer at a temperature rise rate of 20° C./minute.
Specific gravity:
The specific gravity of the alloy, measured using a specific gravity meter, was approximately 7.4.
Tensile test under a 25° C. room temperature atmosphere:
The tensile strength of the alloy was 3.3 kgf/mm 2 with a stretch of approximately 48%. The conventional Sn—Pb eutectic solder alloy, tested under almost the same conditions, exhibited a strength of 4-5 kgf/mm 2 . The alloy of the present invention has a tensile strength lower than that of the conventional solder alloy. However, considering that the solder alloy of the present invention is chiefly intended to solder relatively light-weight electronic components onto a printed circuit board, the solder alloy of the present invention meets strength requirement as long as the application is limited to this field.
Spreading test:
The alloy, measured under JIS (Japanese Industrial Standards) Z3197 Test Standard, exhibited 77.6% at 240° C., 81.6% at 260° C., and 83.0% at 280° C. Compared with the conventional tin-lead eutectic solder, the solder alloy of the present invention offers a small spreading factor, but is still sufficiently acceptable.
Wettability test:
A copper strip of 7×20×0.3 mm was subjected to acid cleaning using 2% diluted hydrochloric acid and was tested for wettability under the conditions of a dipping rate of 15 mm/second, a dip depth of 4 mm, and a dipping time of 5 seconds, using a wettability test apparatus. The zero crossing time and maximum wetting force of the alloy were 1.51 seconds and 0.27 N/m at 240° C., 0.93 second and 0.3 N/m at 250° C., 0.58 second and 0.33 N/m at 260° C., and 0.43 second and 0.33 N/m at 270° C. From these results, the start of wetting is late at higher melting points, compared with the eutectic solder, but the wetting speed increases as the temperature rises. Since the metals to be soldered have typically low heat capacity in practice, the delay of the start of wetting presents no problem.
Peel test:
QFP lead peel tests showed a peel strength of approximately 0.9 kgf/pin. A visual check to the peeled portion revealed that all peelings took place between a board and a copper land. This showed that the solder joint had a sufficient strength.
Electric resistance test:
A wire solder of 0.8 mm diameter and 1 meter long was measured using the four-terminal measurement method. Its resistance was 0.13 μΩ. The resistance of the wire solder was close to that of tin. A low resistance increases the velocity of propagation of electrons, improving high-frequency characteristics, and changing acoustic characteristics. Measured under the same conditions, a tin-lead eutectic solder alloy had an electric resistances of 0.17 μΩ and a tin-silver-copper solder had an electric resistance of 0.15 μΩ.
Creep strength test:
A tin-plated brass pin having a 0.8×0.8 mm square cross section was flow-soldered onto a land of a 3 mm diameter with a hole of a diameter of 1 mm formed on a paper phenolic board. A weight of 1 kg was hung on the pin using a stainless steel wire in a temperature-controlled bath until the pin dropped out of the solder joint. With the bath temperature at 145° C., the pin remained connected over 300 hours. At 180° C., the pin did not fall even after 300 hours had passed. The pin connected by the tin-lead eutectic solder joint dropped within several minutes to several hours under the same conditions. Different from the Pb including solder, the solder alloy of the present invention has resistance to creep even if its tensile strength is low, and the reliability of the solder alloy of the present invention is particularly excellent under the high-temperature atmosphere.
Heat shock test:
An hour of heat shock at −40° C. and +80° C. was given to the solder alloy. The solder alloy withstood 1000 cycles of shocks. The conventional tin-lead eutectic solder alloy withstood 500-600 cycles of shocks.
Migration test:
A type II comb-like test specimen specified JIS Standard was dip-soldered using RMA flux. Flux residues are cleaned, and resistance was measured with a terminal attached to a lead wire. This measurement result was treated as an initial value. The test specimen was introduced into a thermohygrostat, and rated direct currents were applied for 1000 hours to measure resistance at predetermined time intervals while the test specimen was observed using a magnifier with a magnification of 20 times. No abnormal change was observed both when 100 VDC current was applied at 40° C. and a humidity of 95% and when 50 VDC current was applied at 85° C. and a humidity of 85%. This means that the alloy of the present invention performed as well as the conventional tin-lead eutectic solder.
Leaching test:
A copper wire of 0.18 mm diameter with RA type flux attached thereto was dipped in a solder bath filled with molten solder at 260±2° C. The copper wire was agitated until it disappeared by leaching, and the time to the full leaching was counted using a stopwatch. The full leaching of the copper wire in the solder of the present invention took about 2 minutes while the identical copper wire leached in the tin-lead eutectic solder for about 1 minute. It is apparent that the longer resistance to the leaching was attributed to the addition of an adequate amount of copper. Specifically, the originally added copper that had leached resulted a relatively slow copper leaching rate regardless of a large content of tin. Another likely reason for the slow leaching rate was that the melting point of the solder was higher than the eutectic solder by approximately 40° C.
The melting point and strength of the alloy having another composition is listed in Table.
Studying the above tests results, compared with a comparative example, all examples of the present invention present satisfactory results. The conventional tin-lead eutectic solder alloy, measured under the same conditions, exhibited a strength of 4-5 kgf/mm 2 . All examples exhibited strength values lower than that of the conventional tin-lead eutectic solder alloy. As already described, the solder alloy of the present invention is chiefly intended to solder relatively light-weight electronic components onto a printed circuit board, and the solder alloy of the present invention meets strength requirement as long as the application is limited to this field.
No particular data were taken about the spreading of the samples. The addition of nickel imparted a smooth surface structure to the alloy itself. Since the smooth surface was maintained after solidification, the spreading was considered good.
The melting point are represented by two temperatures, in which a lower one is a solidus temperature while a higher one is a liquidus temperature. The smaller the temperature difference between the two, the less a component to be soldered moves during solder solidification prior to the soldering operation, and the stabler the solder joint. This is also true of the conventional tin-lead solder. However, which solder outperforms which is not generally determined. Depending on the application of solder, a solder alloy having an adequate temperature difference may be employed.
Wettability to the copper, one of the important characteristics of solder, is good with the RMA type flux. A good wettability is thus assured using the RMA type flux.
The three-element Sn—Cu—Ni solder of the present invention may be progressively formed by preparing the Sn—Ni base alloy and mixing a molten Sn—Cu solder with the base alloy for uniform diffusion. As already described, the melting point of nickel is high. When pure nickel is introduced into the Sn—Cu alloy, dissolving and diffusing nickel uniformly is difficult. To prepare the alloy of the present invention, the base alloy is beforehand melted at a relatively high temperature so that nickel is sufficiently mixed with tin, and the base alloy is then introduced into the molten Sn—Cu bath. In this way, the lead-free solder alloy in which nickel is diffused into tin at a relatively low temperature is obtained.
Forming beforehand the Sn—Ni base alloy helps prevent other unwanted metals from being included thereinto. The present invention takes advantage of the fact that nickel is in an all-ratio solid soluble relationship with copper and that the alloy of copper and nickel controls the development of bridges. The presence of any metal in the alloy that hinders the function of nickel is not preferred. In other words, the addition of any metal other than copper, which may easily cooperate with nickel is not preferred in the present invention.
Although the lead-free solder of the present invention suffers a slow start of wetting because of a melting point higher than that of the conventional tin-lead eutectic solder, the lead-free solder of the present invention forms an interfacial alloy layer quickly and reliably in accordance with a variety of surface processes once the wetting starts. The lead-free solder alloy of the present invention has a creep strength high enough to support bulky and heavy components and heat-generating components. Since the copper leaching, which is considered serious in the conventional solder alloy, is alleviated, the durability of lead wires is substantially increased.
Because of its high electric and thermal conductivities, the lead-free solder of the present invention imparts high-speed property and high heat dissipation property to electric components, and improves acoustic characteristics of electric components.
Since the lead-free solder of the present invention does not include, in its composition, bismuth, zinc, and indium, it is free from an abnormal reaction with a coating containing lead that is soluble from a terminal materials, other lead-free solder coating such as Sn—Ag solder, Sn—Bi solder, and Sn—Cu solder. This means that the continuous use of a solder bath is assured and lead-rich wires compatible with lead are used without any problem when the conventional tin-lead solder is switched to the lead-free solder alloy of the present invention.
TABLE
Compounds
Melting point
Strength
Rate of stretch
Sn
Cu
Ni
Ga
Ge
deg. C
kgf/mm2
%
Sample
1
remain
0.5
0.05
227/232
3.4
36
2
remain
0.5
0.1
227/232
3.4
42
3
remain
0.5
1
229/233
3.5
33
4
remain
0.6
0.05
227/231
3.3
48
5
remain
0.7
0.4
227/231
3.4
40
6
remain
2
0.02
227/245
3.4
24
7
remain
0.5
0.05
0.01
0.02
227/235
3.3
46
8
remain
0.5
0.05
0.1
227/236
3.2
38
9
remain
0.5
0.05
0.3
227/236
3.3
35
Comparative
Sample
A
remain
0.5
227/232
3
23
B
remain
0.7
227/231
3.1
20
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A lead-free solder which is comprised of three elements Sn-Cu-Ni. Cu and Ni are 0.1-2 wt % and 0.002-1 wt % respectively. Preferable weight percentage of Cu and Ni are 0.3 to 0.7 percent and 0.04 to 0.1 percent respectively. Both methods of additive Ni to a base alloy of Sn—Cu and additive Cu to a base alloy of Sn—Ni are applicable.
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FIELD OF THE INVENTION
The present invention relates generally to a tag monitoring system network used for tracking object movement. The tags utilized in the system incorporate a bump sensor which detects movement and a transmitter that relays movement information to a central location. The method of the present invention includes several transmitter protocol schemes that broadcast information related to object movement dependent on the type of object being tracked.
BACKGROUND OF THE INVENTION
Methods and systems for electronic surveillance and tracking of articles are generally known. Such systems include passive article attached devices, wherein the attached devices do not include power sources. In such a system determination of the article location relates to the passage of the device through a specific monitored zone. Such systems are limited by the number of zones to be monitored and are generally only useful in confined areas.
Other systems include active devices which have an on board power source and which can transmit information to a receiver. Active article or tagged systems are typical in theft deterrent devices. In such devices, a motion detector and transmitter are set on board an object. When the object is moved in such a manner to be detected by the motion sensor, a transmitter activates a signal broadcast to a receiver. The receiver is typically only capable of broadcasting a single transmitter signal. Such device may be dependent on an event other than motion to activate a signal, such as unauthorized break-in of a vehicle. Further, such devices are only capable of signaling a single type of movement and the device is incapable of discerning the type of movement occurring and transmitting the nature of the movement to the receiver. Further, such systems are typically only capable of monitoring a single event, without tracking and continuous monitoring capabilities.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided a system for monitoring the movement of a tagged object. The system includes at least one overall system receiver which receives radio input signals from the tags used in the system. Each tag in the system is releasably engagable to an object that is desired to be tracked.
The tag which is used in accordance with the present invention incorporates a motion sensor which detects object movement and includes a signal generation circuit adapted to generate a signal when motion is detected. A microcontroller is provided which is in electrical communication with the motion sensor and includes a transmitter activation circuit wherein said microcontroller includes a preprogrammed transmitter sequence which is activated by receipt of a signal from the motion sensor. A radio transmitter is also provided on the tag which is in electrical communication with the microcontroller, and generates radio signals at the direction of the microcontroller.
The transmitted signal is received by a remote receiver where the signal is processed and an appropriate action is taken.
Thus, according to the preferred embodiment of the present invention, each radio tag transmitter comprises an oscillator.
Further, according to the preferred embodiment of the present invention, a timing circuit effects transmission of the normal radio signals at either a random interval or a pseudo-random interval, so as to mitigate communications contention and so as to conserve power. Communications contention is mitigated since the use of such a random or pseudo-random transmission interval substantially reduces the likelihood that two radio tag transmitters will transmit to a single remote receiver at the same instant. Indeed, if two radio tag transmitters were to transmit to the same remote receiver at the same instant, one or both such transmissions would be ignored and it is extremely unlikely that subsequent retransmissions of the two radio tag transmitters would occur at exactly the same instant again, since the time intervals between transmissions are either random or pseudo-random in nature.
The radio tag transmitter preferably, but not necessarily, comprises a circuit for transmitting a direct sequence spread spectrum radio signal. As those skilled in the art will appreciate, it is possible to maximize the effective range of such a transmitter, without requiring FCC licensing, via the use of direct sequence spread spectrum modulation.
The microcontroller preferably includes a series of preprogrammed broadcast schemes which allow the tag to be utilized in a variety of systems. A first scheme provides for a series of frequent bursts that commence upon the start of detected movement and continuously transmits signals until an indication that there is a cessation of movement is received.
A second scheme produces an initial series of transmission bursts for a short time following the detection of initial movement, and a second series of frequent transmission bursts for a short time following detection of cessation of movement of the object.
A third scheme provides an initial series of frequent bursts for a short period of time following an indication of initial movement. A series of periodical bursts are thereafter transmitted until the cessation of movement is detected wherein a final series of bursts are transmitted for a short period of time.
A further scheme provides an initial series of frequent bursts for a short time following a detection of initial movement, a series of random bursts thereafter until detection of cessation of movement wherein a final series of bursts are transmitted for a short time.
A further scheme provides a series of frequent bursts for a short time following detection of initial movement. There are no additional transmissions following in the initial movement.
A further scheme provides transmission of a series of frequent bursts for a short time following the detection of ceasing of object movement. The frequent bursts at the end of the movement is the only transmission completed under such a scheme.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the overall components of the system for monitoring movement of a tagged object of the present invention showing an exemplary tag transmitting to a network receiver;
FIG. 2 is a block diagram of the components of the tag which is utilized in the system for monitoring of a tagged object of the present invention;
FIG. 3a is a graphical representation of broadcast of radio bursts where those bursts are continuous;
FIG. 3b is a graphical representation of broadcast of radio bursts where frequent bursts are only at the start and end of the movement;
FIG. 3c is a graphical representation of broadcast of radio bursts where frequent bursts are at the start and end of the movement and include periodical intermediate bursts;
FIG. 3d is a graphical representation of broadcast of radio bursts where frequent bursts are at the start of movement only; and
FIG. 3e is a graphical representation of broadcast of radio bursts where frequent bursts are at the end of movement only.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The detailed description as set forth below in connection with the appended drawings is intended as a description of the presently preferred embodiments of the present invention, and are not intended to represent the only form in which the present invention may be constructed or utilized. The description sets forth functions and sequence of steps for constructing and operating the invention in connection with the illustrated embodiments. It is understood, however, the same or equivalent functions and sequences may be accomplished by different embodiments and that they are also intended to be encompassed within the spirit and scope of this invention.
Referring particularly to FIG. 1, there is shown the tagged monitoring system network of the present invention used for tracking object movement. In FIG. 1 a tag 10 is shown, and such tag 10 is adapted to be releasably engagable, via mount 11, with an object desired to be tracked. The tag 10 includes a bump sensor or movement detector which operates to create a signal to be broadcast over the tag antenna 12 for receipt by a network antenna 14 to be processed by the network system 16. It is contemplated by the present invention that a series of network antennas would be strategically located about an area in which the objects which are tagged are to be monitored. In the case of a very limited area, a single network antenna may only be required. However, if the monitoring area could be over a large region, a series of network antennas may be required. It is contemplated by the present invention that the tagged monitoring system network would be used in association with asset and inventory tags. Different types of information could be broadcast from the tag antenna 12 depending on the nature and use of the inventory tag system. In application, the inventory tagged system may be used to track cargo moved by truck, ship, rail, air and other means of transportation. The system may also be utilized to determine the occurrence of a seismic event and could be used to trigger emergency alarms or other procedures. Further, the inventory tagging system may be used to determine movement of precious and valuable objects for security and locating purposes. Such tag system may be used in a machine environment to determine when machinery stops operating or begins operating. The system may also be utilized to track people or objects within a certain area. Additional applications such as use in a seismic detector for metering and monitoring applications is also contemplated. In this regard, the system of preferred embodiment may be used in a number of applications when it is important to know when and where an object/individual is moving, and to monitor that movement.
Referring specifically to FIG. 2, there is shown the tag 10 and the component parts thereto. A bump sensor 18 is shown in electrical communication with a microcontroller 20. The bump sensor 18 is essentially a motion detector which, when attached to the object desired to be tracked will be able to generate a signal in response to movement of the object. Examples of suitable bump sensors include mercury tilt switches, accelerometers, velocity sensors, displacement sensors, rotation sensors, etc. Those skilled in the art will appreciate that various other types of bump sensors are likewise suitable. A signal from the bump sensor 18 is received by the microcontroller 20, and based upon the information stored on the microcontroller, in certain situations, the microcontroller will initiate the modulator 22 to generate a signal which is amplified by the amplifier 24 and transmitted over the tag antenna 12. The oscillator 26 regulates the frequency of the tag antenna 12 output.
In operation, the bump sensor 18 detects movement of the object and generates a signal to be received by the microcontroller 20. The microcontroller 20 therefore initiates a transmission sequence to be broadcast over the antenna 12. It is additionally contemplated by the present invention that the microcontroller 20 could additionally serve other functions such as triggering an alarm or other related functions. The microcontroller activates the circuity necessary to transmit signals over the tag antenna 12 namely the modulator 22, amplifier 24 and oscillator 26. The duration and the number of transmission bursts from the antenna 12 is preprogrammed into the microcontroller which initiates the transmission circuity. Also, the bump sensor 18 may be able to send a signal or terminate a signal to the microcontroller 20 when the motion of the object has ceased.
The tag transmitter which comprises the modulator 22, amplifier 24, oscillator 26 and antenna 12 transmits radio signals at a frequency with an unknown center frequency within a known frequency band. Accordingly, each time the tag transmitter transmits a radio signal, it generates the signal at a random frequency which is then received by the system receiver 16. The system receiver 16 identifies the center frequency of the radio signal, tunes to the center frequency of that radio signal and gathers information from the tag based upon the signal. Several types of receiver devices in the system receiver 16 may be utilized such as a scanner or other similar receiver which is capable of receiving a number of different frequencies within a known band.
Referring specifically to FIGS. 3a-3e, there is shown a plurality of possible transmission schemes from the tag in order to transmit information to the tag monitoring system. Referring specifically to FIG. 3a, a timeline is shown indicating start movement detected by the bump sensor 18 and stop movement by the same bump sensor 18. In the scheme pictured in FIG. 3a, the microcontroller 20 receives a start movement signal, and based upon the scheme preprogrammed into the microcontroller 20, initiates the transmitter circuity to transmit continuous frequent bursts from the antenna 12 to be received by the network system 16. At the stop movement signal (or lack of movement signal) the microcontroller ceases further transmission of the frequent bursts. In the transmission sequence of FIG. 3a, such scheme would be appropriate in instances where it is important to always know the state of the tag 10. In the FIG. 3a scheme the continuous bursts require additional power which may decrease battery life. The scheme in FIG. 3a is useful to continuously track the movement of certain objects and is also appropriate when the tracking of the object must be extremely accurate.
Referring specifically to FIG. 3b, there is shown a further scheme which contemplates the use of frequent bursts at the start and end of movement of the object. First, the bump sensor 18 detects movement of the object and sends a signal to the microcontroller 20. The microcontroller, based upon preprogrammed information, initiates the transmission circuit to broadcast a series of frequent bursts for a short period of time at the beginning of the movement to notify the system network 16 that movement has begun. A second series of bursts would not initiate until the bump sensor 18 determines that all movement is stopped. Again, based upon preprogrammed information in the microcontroller 20, a second series of frequent bursts notifies the network 16 that the object has ceased movement. The scheme described in FIG. 3b notifies the system 16 when the object starts and stops moving and is advantageous for power consumption savings. The scheme described in FIG. 3b would be particularly suited when tracking shipments by truck, ship, rail, sea and other modes of transportation where the bump sensor 18 would be tripped continuously for long periods of time.
Referring specifically to FIG. 3c there is shown a further scenario for transmitting signals from the tag 10 to the system network 16. In the scheme of FIG. 3c a series of frequent bursts are made at the start and end of the object's movement. In between the start and end of the object's movement periodical or random bursts are transmitted. In this regard, at the initiation of movement of the object, which is detected by the bump sensor 18, a signal is forwarded to the microcontroller 20. The microcontroller 20, based upon preprogrammed information, initiates the transmitter circuity to transmit a first series of frequent bursts for a short period of time following the initial movement. Thereafter, random or periodical bursts are transmitted until such time as the bump sensor 18 detects cessation of movement of the object. At that time, the microcontroller initiates a final series of frequent bursts for a short period of time immediately following the ceased activity. The scheme as shown in FIG. 3c is similar to the scheme as shown in FIG. 3b, however, the scheme of FIG. 3c includes the periodical or random bursts. This will allow periodic monitoring by the system 16 to determine location of the object. FIG. 3c is advantageous in certain situations over the scheme as shown in FIG. 3a as it reduces power consumption since the intermediate bursts are random or periodical. The random bursts allow continued monitoring during movement. The scheme of FIG. 3c, however, is not as accurate in object tracking as the scheme of 3a.
Referring to FIG. 3d, there is shown another scenario wherein a series of frequent burst occurs only at the start of the movement of the object. In this regard, upon movement of the object, the bump sensor 18 senses the movement, and forwards a signal to the microcontroller 20. The microcontroller 20, based upon preprogrammed information, transmit a series of frequent bursts, short in time duration, following the movement to notify the system 16 that movement has started. No further bursts are required under the scheme of FIG. 3d. The scheme of FIG. 3d is similar to that of 3b except that there is no burst at the termination of movement.
Referring particularly to FIG. 3e, there is shown a further scheme wherein the bump sensor 18 only sends a signal to the microcontroller 20 at cessation of the movement of the object. Upon cessation of movement, the bump sensor 18 forwards a signal to the microcontroller 20, and based upon the preprogrammed information, the microcontroller 20 directs the transmission circuit to transmit a series of bursts short in time duration for receipt by the system 16. Thus, the tag transmits only after the object has stopped moving. The scheme of FIG. 3e is particularly suited in use of monitoring machine operation as it would be a preferred method of monitoring whether machinery has stopped operating.
Additional modifications and improvements of the present invention may also be apparent to those skilled in the art. Thus, a particular combination of parts described and illustrated herein is intended to represent only certain embodiments of the present invention, and is not intended to serve as limitations of alternative devices within the spirit and scope of the invention.
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The present invention relates generally to a tag monitoring system network used for tracking object movement. The tags utilized in the system incorporate a motion sensor which detects object movement and includes a signal generation circuit adapted to generate a signal when motion is detected. A microcontroller is provided which is in electrical communication with the motion sensor and includes a transmitter activation circuit wherein said microcontroller includes a preprogrammed transmitter sequence which is activated by receipt of a signal from the motion sensor. A radio transmitter is also provided on the tag which is in electrical communication with the microcontroller, and generates radio signals at the direction of the microcontroller.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to internal combustion engine oil pans. More specifically, the present invention relates to a demountable, sealable plate for a throughbore in an internal combustion engine oil pan and a method for installing the engine plate.
2. Description of the Prior Art
An internal combustion engine oil pan is located beneath the engine. The oil pan collects the oil that is circulated through the engine. The engine's mechanical pump draws oil from the oil pan for continuous oil circulation in the engine.
Removing the oil pan provides access to the main bearings, crankshaft, throws, connecting rods and seals, and other mechanisms. These items occasionally require maintenance or repairs. Unfortunately, multiple design considerations drive the configuration of the oil pan and the environment in which it is assembled. Typically, the oil pan is trapped behind a web of cross members, steering members and shielding. Removal of the oil pan is typically a substantial undertaking. Maintenance to the vehicle requiring oil pan removal is usually quite costly.
Several types of removable engine plates are described in the literature. For example, U.S. Pat. No. 1,737,466, issued Dec. 12, 1927, to Harry J. Lind, describes a noise eliminator for internal combustion engines. The device includes a lower crank case cover extending the entire length of the crankcase cavity. The cover has a flange that mates with the cavity periphery. The cover has two gaskets disposed on the inner and outer surface of the flange. A protecting plate seats on the outside of the outer gasket. The cover, gaskets and plate are bolted to the oil pan with a plurality of bolts.
U.S. Pat. No. 4,068,646, issued Jan. 17, 1978, to Joseph F. Hnojsky, describes a crank case oil pan. The device includes a plurality of sections. When the sections are sealed and bolted together, they form an oil pan extending the entire length of the crank case cavity.
U.S. Pat. No. 4,457,274, issued Jul. 3, 1984, to Clifford E. Gottlob, describes an oil pan assembly. The device includes an auxiliary oil pan with a four-sided bottom and three walls extending generally perpendicularly from three of the sides, respectively. A throughbore is cut into the back, generally vertical panel of a vehicle's oil pan. Then the device is permanently welded onto the back end of the oil pan. The device increases the oil capacity of the oil pan.
U.S. Pat. No. 4,770,276, issued Sep. 13, 1988, to Hiroichi Takubo, describes an oil pan for automotive engine. The device includes an L-shaped cover plate demountably fixed with threaded fasteners to a clutch housing opening. No sealing means between the plate and housing is described. The opening provides access to a bolt for securing the clutch housing to the cylinder block.
U.S. Pat. No. 5,161,642, issued Nov. 10, 1992, to Tomohiro Murakawa, describes an oil pan construction. The invention includes a skirt surrounding the crank case cavity. A generally horizontal blanking plate mounts with threaded fasteners to the bottom of the skirt defining a crankcase volume. The blanking plate extends almost the entire length of the crank case cavity.
Japanese Patent 59-126052 (A), published Sep. 9, 1982, issued to Masahiro Noda, in the abstract describes an oil pan. The device appears to include a four-sided bowl that is welded to the oil pan over a throughbore therein. The device is purposed at increasing structural rigidity of an extant oil pan.
None of the above references, taken alone or in combination, are seen as teaching or suggesting the presently claimed removable engine plate and installation method therefor.
SUMMARY OF THE INVENTION
The present invention relates to internal combustion engine oil pans. The present device is for an oil pan having a throughbore. The oil pan may also have secured to it a reinforcing member. The oil pan has a plurality of threaded bores peripherally disposed about the throughbore. In practice, the reinforcing member should be installed, if at all, prior to cutting the threaded bores in the oil pan to assure registration of the threaded bores in the oil pan and reinforcing member. A gasket and plate sealingly mount to the oil pan over the throughbore. The plate and gasket each have a plurality of throughbores peripherally disposed and in registration with threaded bores in the oil pan. Conventional bolts fix the plate and gasket to the oil pan.
The present method is for installing the removable engine plate. The method includes cutting a throughbore in the oil pan, cutting threaded bores about the peripheral edge of the throughbore, and mating a gasket and plate to the oil pan. The method also may include securing a reinforcing member to the oil pan. The reinforcing member, if installed prior to cutting the threads in the oil pan, would be taped along with the oil pan. The method further may include cutting a threaded bore into the oil pan for use as an oil drain.
In consideration of the above, an object of the invention is to provide an oil pan having a throughbore for access to engine components covered by the oil pan.
Another object of the invention is to provide an oil pan having an easily removable cover for accessing the contents of the oil pan.
A further object of the invention is to provide an oil drain for use with the present engine cover.
An additional object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE is a bottom side perspective view of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
1. Engine Plate
Referring to the FIGURE, the invention shows a conventional internal combustion engine oil pan 10. The oil pan 10 has a throughbore 12 disposed in the lower, generally horizontal surface 14 of the oil pan 10. The oil pan 10 also has a plurality of threaded bores 16 peripherally disposed about the throughbore 12.
A reinforcing member 13 may be secured to the oil pan 10. The reinforcing member 13 is generally flat, and extends entirely around the throughbore 12, as shown in the FIGURE. The preferred means for securing the reinforcing member 13 is welding. However, any equivalent means for demountably fixing the reinforcing member 13 to the oil pan 10 will suffice. The reinforcing member 13 should be mounted prior to cutting the threaded bores 16 in the oil pan 10. The reinforcing member 13 would then be assured of having threaded bores (not shown) in registration with the threaded bores 16 in the oil pan 10.
A gasket 18 sealingly mates with the peripheral edge 19 of the oil pan 10. The gasket 18 is generally planar, and extends entirely across the throughbore 12, as shown in the FIGURE. The gasket 18 be may be constructed from any conventional material commonly used in similar applications. The gasket 18 has a like number of throughbores 20 as threaded bores 16 in the oil pan 10. The throughbores 20 are in registration with the threaded bores 16. The throughbores 20 are substantially similar or larger than the threaded bores 16 in the oil pan 10.
A plate 22 sealingly mates with the gasket 18. The plate 22 is generally planar, and extends entirely across the throughbore 12, as shown in the FIGURE. The plate 22 may be constructed from any conventional material commonly used in similar applications. The plate 22 has a like number of throughbores 24 as threaded bores 16 in the oil pan 10. The throughbores 24 are in registration with the threaded bores 16. The throughbores 24 are substantially similar or larger than the threaded bores 16 in the oil pan 10.
Conventional bolts 26 are received in throughbores 20 and 24 and threadingly interengage the threaded bores 16 in the oil pan 10. Tightening the bolts 26 clampingly maintains the plate 22 and gasket 18 against the peripheral edge 19 of the throughbore 12 in the oil pan 10.
A user will be able to loosen the bolts 26 and remove the plate 22 and gasket 18 to access the contents of the oil pan 10. This accessibility will usefully permit the user to perform maintenance operations on the engine previously reserved to seasoned professionals having professional equipment.
2. Engine Plate Installation Method
Referring again to the FIGURE, the present method is for installing the removable engine plate. The method includes cutting a throughbore 12 in the oil pan 10. The throughbore 12 is shown having a square shape, however, any shape suited for the intended purposed of the invention will suffice.
The invention includes cutting threaded bores 16 about the peripheral edge 19 of the throughbore 12. The preferred embodiment includes twenty-two threaded bores 16. Twelve threaded bores 16 are shown for clarity only.
The invention provides for mating a gasket 18 to the oil pan 10. The gasket 18 may be constructed from any material suited to the purposes of the invention.
The invention also provides for mating a plate 22 to the gasket 18. Threaded fasteners 26 may provide the means for securing the plate 22 and gasket 18 to the oil pan 10, however any equivalent means will due.
The method may include securing a reinforcing member 13 to the oil pan 10. The reinforcing member 13 should be secured to the oil pan 10 prior to the step of cutting threaded bores 16 in the oil pan 10. The sequence is suggested to assure registration of the threaded bores (not shown) of the reinforcing member 13 with the threaded bores 16 of the oil pan 10.
The invention provides for securing the plate 22 and gasket 18 to the oil pan by inserting threaded fasteners 26 through the throughbores 24 and 20 of the plate 22 and gasket 18, respectively. The invention provides for interengaging the threaded fasteners 26 with the threaded bores 16 of the oil pan 10. Tightening the threaded fasteners 26 against the plate 22 clampingly secures the plate 22 and gasket 18 to the oil pan 10.
The invention also may include an additional step of cutting a threaded throughbore 28 into the oil pan 10. The throughbore 28 may be required to permit drainage of the oil from the oil pan 10.
The present invention is not intended to be limited to the sole embodiment described above, but to encompass any and all embodiments within the scope of the following claims.
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A conventional internal combustion engine oil pan having a throughbore which is sealingly covered by a gasket and plate mounted over the throughbore and fixed thereto with threaded fasteners. A method for installing the engine plate is also provided.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority of U.S. Provisional Patent Application No. 61/170,805 filed Apr. 20, 2009, the contents of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention generally relates to the production of ethanol from biomass and in particular to a process for the pretreatment of lignocellulosic biomass.
BACKGROUND OF THE INVENTION
[0003] World energy consumption is predicted to increase 54% between 2001 and 2025. Considerable research effort is being directed towards the development of sustainable and carbon neutral energy sources to meet future needs.
[0004] Biofuels are an attractive alternative to current petroleum-based fuels, as they can be utilized in transportation with little change to current technologies and have significant potential to improve sustainability and reduce greenhouse gas emissions.
[0005] Biofuels include fuel ethanol. Fuel ethanol is produced from biomass by converting starch or cellulose to sugars, fermenting the sugars to ethanol, and then distilling and dehydrating the ethanol to create a high-octane fuel that can substitute in whole or in part for gasoline.
[0006] In North America, the feedstock for the production of fuel ethanol is primarily corn, while in Brazil sugar cane is used. There are disadvantages to using potential food or feed plants to produce fuel. Moreover, the availability of such feedstocks is limited by the overall available area of suitable agricultural land. Therefore, efforts are being made to generate ethanol from non-food sources, such as cellulose, and from crops that do not require prime agricultural land.
[0007] One such non-food source is lignocellulosic biomass. Lignocellulosic biomass may be classified into four main categories: (1) wood residues (sawdust, bark or other), (2) municipal paper waste, (3) agricultural residues (including corn stover, corncobs and sugarcane bagasse), and (4) dedicated energy crops (which are mostly composed of fast growing tall, woody grasses such as switchgrass and miscanthus).
[0008] Lignocellulosic biomass is composed of three primary polymers that make up plant cell walls: Cellulose, hemicellulose, and lignin. Cellulose fibres are locked into a rigid structure of hemicellulose and lignin. Lignin and hemicelluloses form chemically linked complexes that bind water soluble hemicelluloses into a three dimensional array, cemented together by lignin. Lignin covers the cellulose microfibrils and protects them from enzymatic and chemical degradation. These polymers provide plant cell walls with strength and resistance to degradation, which makes lignocellulosic biomass a challenge to use as substrate for biofuel production.
[0009] There are two main approaches to the production of fuel ethanol from biomass: thermochemical and biochemical. Thermochemical processes convert the biomass to a reactive gas called syngas. Syngas is converted at high temperature and pressure to ethanol by a series of catalyzed processes. Biochemical processes use biocatalysts called enzymes to convert the cellulose and hemicellulose content to sugars, which are then fermented to ethanol and other fuels such as butanol.
[0010] Biochemical conversion of lignocellulosic biomass to ethanol in general involves five basic steps (1) Feed preparation—the target biomass is cleaned and adjusted for size and moisture content; (2) Pretreatment—exposure of the raw biomass to high pressure and temperature for a specified duration; with or without catalyzing additives; (3) Hydrolysis—conversion of the pretreated biomass to simple sugars using special enzyme preparations to hydrolyze pretreated plant cell-wall polysaccharides to a mixture of simple sugars; (4) Fermentation, mediated by bacteria or yeast, to convert these sugars to fuel such as ethanol; and (5) Distillation and Dehydration of the ethanol/fuel.
[0011] Pretreatment processes, such as steam explosion, generally result in extensive hemicellulose breakdown and, to a certain extent, to the degradation of xylose and glucose to unwanted byproducts. Certain pretreatment methods may also employ added acids to catalyze the hydrolysis of hemicellulose. Additives such as sulfuric acid are often used when the biomass has insufficient acetate residues on the hemicellulose sugars to acidify the mixture sufficiently. Alkalis may also be added during pretreatment to remove lignin. However, acids and alkalis are themselves inhibitors of hydrolysis and fermentation. Moreover, lignin and some soluble lignin derivatives are toxic to yeast and also have been found to inhibit hydrolysis. Also, the hemicellulose of some feed stocks is highly acetylated which means that the breakdown and liquefaction of the hemicellulose, which occurs during pretreatment, leads to the formation of acetic acid. Acetic acid is a powerful inhibitor of both hydrolysis and fermentation. Hemicellulose decomposition products such as acetic acid, formic acid, furfural and hydroxyl methyl furfural etc., which are produced during biomass pretreatment, remain in the pretreated biomass and carry through to the hydrolysis and fermentation steps, negatively affecting the enzymatic processes and the fermentation process.
[0012] A key inhibitor of the catalytic activities of cellulolytic enzymes is the soluble forms of hemicellulose, predominantly the soluble xylo-oligosaccharides, the soluble polymeric chains of xylose. Hemicellulose decomposition products which remain in the pretreated biomass and carry through to the hydrolysis and fermentation steps can negatively affect enzymatic conversion of cellulose to glucose, most predominantly the xylo-oligosaccharides which must be removed. The hemicellulose decomposition products reduce the effectiveness of the cellulose hydrolyzing enzymes, requiring increased levels of added enzyme, the cost of which is an important factor in providing a cost effective commercial process. In addition, the pre-treatment and preparation steps also have a significant impact and the recovery of a usable hemicellulose (etc.) stream for value added use is equally important.
[0013] Furthermore, all forms of lignocellulosic biomass have some level of sterols, fatty acids, ethers and other extractives that can also be inhibitory.
[0014] Diverse techniques have been explored and described for the pretreatment of size-reduced biomass material with the aim of producing a substrate that can be more rapidly and efficiently hydrolyzed to yield mixtures of fermentable sugars.
[0000] These approaches have in common the use of conditions and procedures which greatly increase the surface area to which aqueous reactants and enzymes have access. In particular, they increase the percentage of the cellulose that is opened up to enzymatic hydrolysis of cellulose to glucose. Unfortunately, many of the degradation products released in the pretreatment step are also inhibitors, as described previously, that retard the downstream hydrolysis and fermentation processes. This results in increased capital equipment costs and results in an uneconomical process.
[0015] One approach to address the inhibitory effect of all of these substances is the use of harsher pre-treatment conditions, which can for example be tailored to effectively hydrolyze and degrade the hemicellulose to such an extent that very little xylose and xylan oligosaccharides remain to interfere with the cellulose enzymes. However this approach creates another significant disadvantage in that it causes significant cellulose degradation, which then reduces glucose yield and ultimately the ethanol yield, often creating a commercially significant reduction of the overall ethanol process efficiency.
[0016] In another approach xylanases are used to completely hydrolyze the xylan oligomers to xylose and lessen the inhibitory effect of these oligomers. However, although this approach is somewhat effective, it produces high levels of xylose which is itself an inhibitor. Moreover, the other inhibitory compounds generated in the pretreatment step are still present. Thus, although the overall yield is better, in the end this approach is not commercially viable due to the added cost for the xylanases and still higher cellulase cost.
[0017] Yet a further approach to improving the overall yield is to fully wash the pretreated biomass for removal of all inhibitory compounds. Although this results in improved downstream hydrolysis and fermentation yields, washing of the pretreated biomass to remove all of the inhibitory compounds, which of course would theoretically lead to the best hydrolysis and fermentation yields, is as uneconomical as it is capital intensive. Moreover, this approach is very environmentally unfriendly due to the need for vast quantities of washing fluid, generally water. In addition, this complete removal produces a huge volume of eluent stream that needs to be concentrated at great cost if the eluted compounds are to be disposed of or prepared for other purposes and the eluent recovered for reuse. As with other approaches discussed above, the cost for operating the washing process with the aim to completely remove all inhibitors virtually negates or even exceeds the value of the lower enzyme dosages, reduced processing times, or potentially higher ethanol yield achievable.
[0018] In known pretreatment processes in which the inhibitory compounds are not removed prior to hydrolysis the prehydrolysed biomass must be diluted in order to reduce the concentrations of toxic and inhibitory compounds to an acceptable level with respect to cellulolytic enzymes and fermenting organisms. As a result, large amounts of water are required prior to the enzymatic hydrolysis step. This results, not only in increased capital equipment cost (tankage) but also in increased operating cost (fuel) associated with low ethanol yield. High amounts of steam energy are then needed to concentrate the dilute ethanol to the finished product concentration.
[0019] Thus, compared to the prior art processes, a more economical and effective approach for dealing with the inhibitor compounds produced during pretreatment is desirable.
SUMMARY OF THE INVENTION
[0020] It is now an object of the present invention to provide a process which overcomes at least one of the above disadvantages by reducing the inhibition impact on the rate of hydrolysis and fermentation of pretreated biomass by degradation and hydrolysis products and other inhibitory compounds produced during pretreatment of lignocellulosic biomass.
[0021] It is a further object of the invention to provide a lignocellulosic biomass pretreatment process wherein hemicellulose, hemicellulose degradation and hydrolysis products, cellulose degradation products and other inhibitory compounds typically present in biomass such as fatty acids, sterols, esters, ethers etc. are removed in a commercially viable, economical manner prior to the enzymatic hydrolysis step to achieve the most economical maximization of hydrolysis and fermentation yields.
[0022] As is apparent from the above discussion, known approaches to improve the overall ethanol yield by successfully reducing the amount of inhibitory compounds in the pretreated biomass are generally linked to increased cost for operating the respective method. As a result, increased yields are only obtainable at significantly increased costs which are higher overall than the value of the increased ethanol yield or decreased hydrolysis or fermentation times and reduced enzyme costs, rendering existing methods economically unacceptable.
[0023] The inventors of the present application have now surprisingly discovered that complete removal of the inhibitory compounds is neither required nor desirable for the achievement of the most economically viable pretreatment process. The inventors have discovered a narrow range of extraction and inhibitory compounds removal conditions at which hemicelluloses and hemicellulose hydrolysis and degradation products and other inhibitors are still present, but reduced to a level where they have a much reduced inhibitory effect on the enzymes. The extraction is achieved with the use of a lower volume of diluent and level of dilution and at equipment cost which requires sufficiently lower additional extraction and compound removal cost to render the process much more cost effective, practical and commercially viable. In effect, the additional extraction cost is thereby significantly less than the value of any increased ethanol yield, enzyme cost reduction or reduced processing time achieved.
[0024] The removal of inhibitory compounds can be carried out through many different methods, typically a combination of mechanical pressing and draining, aqueous extraction, solvent extraction, filtering, centrifuging, venting, purging, draining, or the like, with or without the addition of eluents. These removal steps can occur during and/or after the pretreatment process. The removal of inhibitory compounds improves the economics of the process by reducing enzyme load and improving enzyme efficiency and fermentation performance. The term washing used throughout this specification defines removal of inhibitory compounds using water as the eluent.
[0025] In another aspect, the inventors have discovered that the xylose oligosaccharide content of the pretreated biomass is the single most determinative factor of hydrolysis inhibition and that operating the process for removing any inhibitory compounds most efficiently can be achieved by simply controlling the xylose content in the treated biomass. The term xylose within this specification includes xylose and xylose-oligosacharides. The term washing used in this specification describes removal of inhibitory compounds using water or other eluents for the inhibitory compounds removal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Other objects and advantages of the invention will become apparent upon reading the detailed description and upon referring to the drawings in which:
[0027] FIG. 1A shows the impact of xylose removal by water washing on pretreated corncobs hydrolysis time, i.e. the time to reach 90% of the maximum theoretical cellulose to glucose conversion (t90%, hours). Similar results were obtained with batch and continuous pretreatment. Xylose and Xylo-oligosaccharides content is expressed as percentage dry matter (dm) of xylose. Hydrolysis experiments were carried out at 10% consistency, a 1% load of enzyme, 50° C., and pH 5.0. The effect of inhibitor removal on hydrolysis time is even more pronounced at 17% consistency, as seen in FIG. 7 .
[0028] FIG. 1B shows the hydrolysis time (t90%) of unwashed and washed pretreated corncobs. Hydrolysis experiments were carried out at 10% consistency, a 1% load of enzyme, 50° C., and pH 5.0.
[0029] FIG. 2A shows the xylo-oligosaccharides content of unwashed and washed pretreated fibres of corncobs on a dry matter basis.
[0030] FIG. 2B shows the acetic acid concentration of 17% consistency corncob slurry produced using unwashed or washed pretreated corncobs.
[0031] FIG. 3 shows the fermentation time of 17% corncob hydrolysates unwashed (dashed line) or washed (plain line) prior to enzymatic hydrolysis. Fermentation experiments were carried out at 17% consistency, 35° C., pH 5.3 using an industrial grade C6-fermenting yeast, following hydrolysis with a 0.5% load of enzyme, at 50° C., a pH 5.0, and at 17% consistency hydrolysis.
[0032] FIG. 4A shows a process diagram of the pilot scale (i.e. one metric tonne per day) pretreatment unit used.
[0033] FIG. 4B shows the process as in FIG. 4 a where a more practical industrial setup is shown with the washing occurring under pressure prior to pressure release.
[0034] FIG. 5 shows hydrolysis and fermentation results of washed pretreated corncobs at pilot scale (2.5 metric tonnes, 17% consistency). Hydrolysis was carried out at 50° C., and pH 5.0, using a 0.5% enzyme load. Fermentation was carried out at 33° C., at a pH of 5.3 using industrial grade C6-fermenting yeast. Hydrolysis and fermentation pH adjustment was carried out using liquid ammonia (30%). Grey circles indicate the glucose concentration. Black squares indicate the ethanol concentration.
[0035] FIG. 6 illustrates the impact of wash-ratio (single stage washing) on corncobs prehydrolysate content of xylo-oligomers and resulting t90% values of 10% consistency hydrolysis. The xylose based sugars content plotted on the x-axis represents xylan and xylan hydrolysis monomers and oligomers (Xylo-oligosaccharides).
[0036] FIG. 7 illustrates the impact of inhibitory compounds removal on corncobs prehydrolysate content of xylose-based sugars (xylose and xylo-oligomers) (light grey columns) and resulting enzyme load (dark grey columns) required to reach 90% of the maximum theoretical cellulose to glucose conversion by 100 hours hydrolysis of 17% consistency corn cobs hydrolysate.
[0037] FIG. 8 shows the relationship between the amount of washing water needed for the achievement of a specific xylose dry matter content in the pretreated biomass when a commercial 2-stage counter current washing process is used.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0038] Before explaining the present invention in detail, it is to be understood that the invention is not limited to the preferred embodiments contained herein. The invention is capable of other embodiments and of being practiced or carried out in a variety of ways. It is to be understood that the phraseology and terminology employed herein are for the purpose of description and not of limitation.
[0039] The abbreviations used in the Figures have the following meaning:
[0000] ° C., temperature in degree Celsius
ms, millisecond
DM, Dry matter
t 90% , time (hours) to reach 90% of the maximum theoretical conversion of cellulose to glucose.
[0040] The invention is directed to lignocellulose pretreatment processes that condition biomass for biochemical conversion into biofuels. These processes produce inhibitors to the downstream biochemical process. The invention reduces these inhibitors by removing them from the biomass, thus improving the process. These inhibitors consist of hemicellulose, hemicellulose hydrolysis and degradation products, cellulose degradation and other inhibitory compounds typically present in biomass such as fatty acids, sterols, esters, ethers etc. These compounds negatively affect the enzymatic hydrolysis and subsequent fermentation processes which are critical to the economics of the process.
[0041] In an exemplary pretreatment process for corn cobs, for example, it was shown that removing 80% to 90% of the hemicellulose and hemi hydrolysis and degradation stream is effective and still commercially viable. As seen in FIG. 1 , a clear correlation exists between xylose (xylose and Xylo-oligosaccharides) content and cellulose to glucose conversion. The Figure also illustrates that the added incremental yield obtained by reducing the xylose content progressively decreases below about 8% of xylose (w/w dry matter) and becomes small at xylose dm contents below 4%. Furthermore, FIG. 6 shows that the diluent amount needed for xylose removal increases exponentially with each additional percent of dry matter extracted below a xylose dry matter content of 10%.
[0042] In general, the removal of inhibitory compounds applies to all lignocellulosic biomass feedstock such as bagasse, grass and wood and can be described as a ratio of cellulose to hemicellulose (as hydrolysis and degradation products) remaining post pre-treatment and extracting steps. Theoretically, one would expect to see an increase in enzymatic activity with an increase in this ratio, with the theoretically highest possible ratio attainable at a hemicellulose content of 0%. However, the inventors of the present invention have now, surprisingly, discovered that the ratio of remaining hemicellulose hydrolysis products to cellulose is of little consequence to the enzymatic activity. The inventors further discovered that it is the actual amount of dry matter (dm) of hemicellulose hydrolysis products, in particular xylose oligosaccharides, in the remaining cellulose prehydrolysate which is determinative of the enzyme activity.
[0043] The inventors have found that a dm content of xylose (xylose and Xylo-oligosaccharides) from 3% to 10% is preferred. This is much higher than the 0% content theoretically expected. The most effective level is between 4% and 9% and, since the benefit below 6% in terms of potentially increased ethanol yield, reduced enzyme costs or processing time is counteracted by the exponentially increasing added cost of extraction, for example, in terms of eluent used and the cost for downstream eluent disposal or recovery, a xylose dry matter content of 6% is preferred.
[0044] The inhibitory compounds are removed through many different methods, for example by mechanical compressing and draining, aqueous extraction and/or solvent extraction, filtering, centrifuging, pressing, venting, draining, or purging and the like with or without the addition of eluents. These removal steps can occur during and/or after the pretreatment process.
[0045] The removed inhibitors are collected and concentrated for value added applications. Efficient collection and cost effective use and value addition of these inhibitors is further beneficial to the economic viability.
[0046] In one embodiment, inhibitors are removed during pretreatment by venting volatiles with strategically placed vents to cyclones installed throughout the pressurized pretreatment apparatus and stages.
[0047] In another embodiment, inhibitors are removed during pressurized pretreatment by draining or purging liquefied inhibitors. This can be accomplished for example with a simple drain at the lower portion of one of the vessels where condensed liquid collects, or with a complex mechanical apparatus called a screw drainer. The inhibitors, containing liquid, drains out of the biomass without the aid of directed or deliberate mechanical compression; it drains on its own via gravity.
[0048] In another embodiment, inhibitors are removed during pressurized pretreatment by draining or purging with the addition of a single or sequential addition of some type of eluent, typically water. The eluent is mixed with the biomass and carries away inhibitors via gravity and is removed to recover eluent consisting of the eluent and soluble solids. This is accomplished in a continuous pretreatment apparatus with a drainer screw. In a screw drainer a mechanical screw transports the biomass upward at a steep angle. Water is added near the top and allowed to filter down through the material and to exit through the screen, pooling at the bottom for collection. The addition of the eluent allows for a greater reduction in the amount of inhibitors extracted. The level of inhibitors can be further reduced by repeating the process in series until desired levels are achieved.
[0049] In yet another embodiment the use of an eluent in the removing step can be executed in a counter current washing method.
[0050] It is understood by those skilled in the art that the use of eluent will enhance the ability of all liquid removing methods to reduce inhibitors. Those skilled in the art will also understand that it is important to have an inhibitor extract that is as concentrated as possible to afford economically effective downstream processing. Thus minimizing the level of eluent is important. If the eluent is water this could be described as aqueous extraction. If the eluent is alcohol this could be described as organic solvent extraction.
[0051] For the purpose of clarity, the liquid extracted from the biomass during and/or just after pretreatment extracted with or without additional eluent can be described in several terms such as “wash water” “inhibitor extract” “xylo-oligosaccharide rich extract”, “hemicellulose rich extract”, “C5 stream” and the like. Although the term “washing” is often used to describe an aqueous eluent aided removal step, other removal methods and eluents are encompassed by this term as discussed herein.
[0052] In another embodiment, inhibitors are removed during pressurized pretreatment with the use of mechanical compression or by squeezing the biomass against a screen or drain of some type that allows the biomass to be pressurized and the inhibitor-rich liquid to be released. These are typically accomplished with powerful finely engineered machines such as modular screw devices. These devices are sealed and can run under the heat and pressure conditions of pretreatment. These mechanical compression steps can be repeated in series to increase removal. These mechanical compression steps can be used with an eluent added to further increase the level of removal.
[0053] In a further embodiment, inhibitors are removed after pressurized pretreatment with the use of mechanical compression or squeezing against a screen or drain of some types that allows the biomass to build pressure against a screen and the inhibitor rich liquid entrained to be released through the screen and removed. This is typically accomplished with machines such as screw presses and belt presses etc. These mechanical compression steps can be repeated in series to increase overall removal. These mechanical compression steps can be used with an eluent added to further increase the level of removal.
[0054] In yet another embodiment, inhibitors are removed after pressurized pretreatment with, for example, the use of batch operated filter presses that pump the treated biomass against a filter, building up a cake that is low in inhibitors. The pumping is then stopped and the cake is collected. This filtering step can be repeated in series to increase removal. These filters can be used with added eluent to further increase the level of removal.
[0055] In still another embodiment, it would be common to see draining of impurities followed by compression, and then draining with or without eluent still under pressure during pretreatment, in turn combined with a post pretreatment extraction step via draining and/or filtering in a filter press depending on the pretreatment process and biomass.
[0056] In a particular embodiment and illustrative example corn cobs are cleaned, sized and adjusted for moisture to 40-60%. They are then pretreated with steam in a steam gun at temperatures of 152° C. to 226° C. (severity index 3.8-4.2) for periods of 3-180 min during which time the volatiles are vented and the liquid drained. The condensate is collected at the bottom of the reaction vessel and removed through a drainage valve. The solids expelled from the reaction vessel upon pressure release, also referred to as pre-hydrolysate, are separated from the gaseous reaction products in a cyclone separator, and collected at the bottom of the separator.
[0057] Water as eluent is added to the biomass which is then fed to a press that removes most of the liquid reducing the hemicellulose content as xylose to about 6% DM at which point the cellulose is described as being adequately cleaned of inhibitor and transported to the enzymatic hydrolysis step. The liquid removed from the eluent and pretreated biomass can be described as the wash liquid stream.
[0058] The remaining cob solids is then reacted with 0.6% enzymes, hydrolyzing greater than 90% of the cellulose to glucose in less than 100 hrs.
[0059] Composition analysis was carried out at the analytical laboratory of Paprican (Montreal, Canada), using the TAPPI methods T249 cm-85 and Dairy one (wet chemistry analysis).
[0060] Quantification of soluble products from pretreatment, post washing and enzymatic hydrolysis was carried out by HPLC analysis. The target molecules were sugar monomers such as glucose, xylose, xylo-oligosacharides (as xylose) as well as toxic compounds such as different carboxylic acids, namely acetic acid, formic acid, succinic acid and lactic acid and degradation products of carbohydrates such as hydroxyl-methyl-furfural (HMF) and furfural.
[0061] The wash liquid stream contained xylo-oligosaccharides, xylose, acetic acid, formic acid, furfural, arabinose, glucose, mannose, galactose and other inhibitory compounds and toxic compounds that affect the hydrolysis and fermentation processes.
[0062] The analytical method used to measure xylan, xylo-oligosaccharide and xylose first hydrolyses the sample fully into xylose. This does not provide the ratio of xylose to xylo-oligosaccharides. A modified method was used to determine the extent to which the xylan has been converted to monomers verses oligomers of xylose. It was found that 40-80% of the xylose was present as xylo-oligosacharides after pretreatment.
[0063] FIG. 1 shows that decreasing the xylo-oligosaccharides (measured as xylose) content by washing decreased the amount of time needed to achieve cellulose to glucose conversion, with the fastest conversion achieved at complete xylose removal. However, the inventors surprisingly found that a complete removal of the xylose is neither required nor desirable for the achievement of the most economically viable pretreatment process.
[0064] Through their diligent investigation, the inventors have discovered a narrow range of conditions for extraction and inhibitory compounds removal at which hemicelluloses and hemicellulose hydrolysis and degradation products and other inhibitors are still present, but reduced to a level where they have a much reduced inhibitory effect on the enzymes. The inventors have discovered, that the most preferable and commercially viable extraction process was achieved with the use of a lower than theoretically required volume of diluent and with termination of the extraction at a higher than theoretically optimal level of xylose content. As a result, the extraction was carried out at a level of dilution and at equipment cost which resulted in sufficiently lowered additional extraction and compound removal cost than the theoretically optimal xylose extraction process, thereby rendering the inventive process much more cost effective, practical and commercially viable. As a result of operating the extraction process at less than theoretically optimal extraction levels, the additional cost for carrying out the xylose extraction step in accordance with the invention over and above regular biomass pretreatment becomes significantly less than the value of any increased ethanol yield, lower enzyme dosages, or reduced processing times achieved. This is surprising and contrary to the cost situation associated with extraction to theoretically optimal levels, the complete removal of all xylose, wherein the additional cost for carrying out the xylose extraction step would exceed the value of any increased ethanol yield, lower enzyme dosages, or reduced processing times, as discussed above.
[0065] Washing of pretreated biomass is intended to remove impurities. These impurities have a severe impact on the hydrolysis time and the degree of conversion of cellulose to glucose ( FIG. 1B ). FIGS. 2A and 2B show the impurities before and after washing of the steam pretreated prehydrolysate.
[0066] Impurities also increase fermentation time and reduce yield ( FIG. 3 ). We have found that xylose (xylose and xylo-oligosaccharides) concentration should be about 6% w/w overall in the wet washed cobs to minimize hydrolysis time. Acetic acid and other fermentation inhibitors must also be removed in order to minimize fermentation time.
[0067] A balance must be maintained between the removal of impurities and the need to minimize the amount of wash water added. Wash water must be concentrated for its eventual re-use. This requires equipment and energy, both of which must be minimized. There are two basic mechanisms for removing impurities by washing—displacement and diffusion. In displacement washing, the impurities are displaced by the washing liquid. In diffusion washing, impurities diffuse from the fibres into the washing liquid. In most practical washing applications both mechanisms play a key role.
[0068] Rydholm et al. (1965) refer to two key parameters in the washing process. In the case where the impurities have value such as in Kraft pulping, the recovery of solids is measured as a percentage of the total impurities. If recovery is 100%, all the solids have been recovered (or all impurities have been removed). The second parameter is the dilution factor. This is usually expressed as tons of water per ton of dry substance. This should be kept as low as possible.
[0069] A simple form of washing was used throughout our examples. Biomass at about 35% DM after pretreatment was diluted with water at to afford a ratio of about 16:1 (water:dm). The diluted biomass was then squeezed in a hydraulic press to bring the consistency up to about 40% (removal step). The solids were then shredded and diluted to the desired consistency for hydrolysis and fermentation. The recovery factor was >99%.
[0070] It should be noted that a more complex commercial system of washing could also be employed as described previously. The washing system could include multiple washers, presses, filters, or other equipment arranged with counter current and recycle streams to minimize the dilution factor while achieving the desired recovery of soluble impurities. A 2 stage counter current washing system, see FIG. 8 , would gives a practical commercial ratio of about 3:1 (water:biomass) for a result of 6% xylose in the biomass solids.
Example
[0071] Batch steam explosion pretreatment of corncob was carried out in a steam gun ( FIGS. 4A and 4B ). The steam gun ( 50 ), was supplied with saturated steam from a steam storage vessel ( 40 ). Pre-steamed ground corncobs of 0.5 to 1 cm 3 particle size were fed through a V shaped hopper and screw auger (from Genemco, not shown). The amount of each batch load was controlled by a weigh hopper. Batch loads of 6 kg corncob were used per steam explosion shot. Corncob weight and production rates are expressed on a dry matter basis. After filling the batch load into the steam gun ( 50 ) from above, a fill gate (not shown) was closed to seal the steam gun. Pressurized saturated steam until the desired cooking pressure was reached. Cooking pressures of 167 to 322 psig were used (12.6 to 23.2 bar). After a residence time of 3 to 10 minutes, at temperatures from 190° C. to 220° C., the pressure in the steam gun was quickly released by opening a flash purge valve (not shown) located at the bottom of the steam gun. Complete pressure relief was achieved in up to 1000 ms. During the residence time and prior to pressure release, condensate and cooking liquids collected at the bottom of the steam gun were purged through a purge discharge control valve ( 55 ) and fed to a condensate collection system (not shown) through a purge conduit. Volatile reaction products generated during steam treatment were removed through the purge valve and directed to an environmental control unit (not shown) through a purge line. The solids collected at the bottom of the cyclone separator ( 60 ) were subjected to further processing in the lab. The gaseous components were collected and condensed ( 70 ) and fed to the condensate collection system. Any gaseous emissions from the steam gun, the cyclone separator and other parts of the setup were collected and treated in an environmental control unit (not shown). Cleaned gases were exhausted to atmosphere from the unit.
[0072] Pre-hydrolyzed cob dry matter was diluted 16:1 with fresh water ( 90 ). The slurry was pressed to 40% solids in a hydraulic cylinder ( 80 ). The solids ( 120 ) were shredded in a garden shredder (not shown) and then diluted with fresh water to the desired consistency for hydrolysis and fermentation. The resulting xylose DM content achieved was 6% and the dilution factor was 6. Wash water containing hydrolyzed soluble hemicellulose products and toxic compounds, the inhibitory compounds ( 100 ), was collected and concentrated to the desired dryness for further applications.
[0073] Composition analysis of the wash water showed that over 80% of the xylo-oligosaccharides present in the wet fraction of pretreated cob fibres were removed by water washing ( FIG. 2 ). Results of the 2.5 tonne pilot scale trial carried out showed that a concentration of 100 g/L glucose was reached at t 90% of 100 hours. An alcohol concentration of 5% was reached in 20 hours.
[0074] The same process of washing of the pre-hydrolyzed dry matter was carried out at various different dilution ratios to determine the impact on downstream enzyme activity on the cellulose illustrated by the time (hrs) to 90% hydrolysis and the observed results are illustrated in FIGS. 1 and 6 .
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A process for the pretreatment of lignocellulosic biomass is disclosed. The process is intended for use in connection with biomass to ethanol processes and is directed in particular to an economical removal of inhibitory compounds generated in biomass pretreatment, which are inhibitory to downstream hydrolysis and fermentation steps. The process includes the steps of heating the lignocellulosic biomass with steam to a preselected temperature, at a preselected pressure and for a preselected time to hydrolyze and solubilize hemicelluloses in the biomass; explosively decomposing the biomass into fibers; and extracting from the resulting reaction mixture a liquefied portion of the lignocellulosic biomass before or after explosive decomposition. The liquefied portion is extracted to remove compounds from the lignocellulosic biomass which are inhibitory to enzymatic cellulose hydrolysis and sugar fermentation to ethanol. For improved efficiency and economy, the inhibitory compounds are not completely removed. Furthermore, xylose has been found to be a good indicator compound for the general level of inhibitory compounds in the reaction mixture and the extraction step is therefore controlled on the basis of the xylose content in the reaction mixture. In particular, the extracting step is discontinued once a dry matter (dm) content of xylose, as monomer or oligomer, in the reaction mixture of 4% to 8% (w/w dm) is achieved. This most economically balances the practical need for inhibitory compound removal with the economical need to control and preferably minimize the costs of the overall ethanol production process.
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CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of U.S. application Ser. No. 08/421,109, filed Apr. 13, 1995 , now U.S. Pat. No. 5,495,231 entitled Metallic Glass Alloys For Mechanically Resonant Marker Surveillance Systems.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to metallic glass alloys; and more particularly to metallic glass alloys suited for use in mechanically resonant markers of article surveillance systems.
2. Description of the Prior Art
Numerous article surveillance systems are available in the market today to help identify and/or secure various animate and inanimate objects. Identification of personnel for controlled access to limited areas, and securing articles of merchandise against pilferage are examples of purposes for which such systems are employed.
An essential component of all surveillance systems is a sensing unit or "marker", that is attached to the object to be detected. Other components of the system include a transmitter and a receiver that are suitably disposed in an "interrogation" zone. When the object carrying the marker enters the interrogation zone, the functional part of the marker responds to a signal from the transmitter, which response is detected in the receiver. The information contained in the response signal is then processed for actions appropriate to the application: denial of access, triggering of an alarm, and the like.
Several different types of markers have been disclosed and are in use. In one type, the functional portion of the marker consists of either an antenna and diode or an antenna and capacitors forming a resonant circuit. When placed in an electromagnetic field transmitted by the interrogation apparatus, the antenna-diode marker generates harmonics of the interrogation frequency in the receiving antenna. The detection of the harmonic or signal level change indicates the presence of the marker. With this type of system, however, reliability of the marker identification is relatively low due to the broad bandwidth of the simple resonant circuit. Moreover, the marker must be removed after identification, which is not desirable in such cases as antipilferage systems.
A second type of marker consists of a first elongated element of high magnetic permeability ferromagnetic material disposed adjacent to at least a second element of ferromagnetic material having higher coercivity than the first element. When subjected to an interrogation frequency of electromagnetic radiation, the marker generates harmonics of the interrogation frequency due to the non-linear characteristics of the marker. The detection of such harmonics in the receiving coil indicates the presence of the marker. Deactivation of the marker is accomplished by changing the state of magnetization of the second element, which can be easily achieved, for example, by passing the marker through a dc magnetic field. Harmonic marker systems are superior to the aforementioned radio-frequency resonant systems due to improved reliability of marker identification and simpler deactivation method. Two major problems, however, exist with this type of system: one is the difficulty of detecting the marker signal at remote distances. The amplitude of the harmonics generated by the marker is much smaller than the amplitude of the interrogation signal, limiting the detection aisle widths to less than about three feet. Another problem is the difficulty of distinguishing the marker signal from pseudo signals generated by other ferromagnetic objects such as belt buckles, pens, clips, etc.
Surveillance systems that employ detection modes incorporating the fundamental mechanical resonance frequency of the marker material are especially advantageous systems, in that they offer a combination of high detection sensitivity, high operating reliability, and low operating costs. Examples of such systems are disclosed in U.S. Pat. Nos. 4,510,489 and 4,510,490 (hereinafter the '489 and '490 patents).
The marker in such systems is a strip, or a plurality of strips, of known length of a ferromagnetic material, packaged with a magnetically harder ferromagnet (material with a higher coercivity) that provides a biasing field to establish peak magneto-mechanical coupling. The ferromagnetic marker material is preferably a metallic glass alloy ribbon, since the efficiency of magneto-mechanical coupling in these alloys is very high. The mechanical resonance frequency of the marker material is dictated essentially by the length of the alloy ribbon and the biasing field strength. When an interrogating signal tuned to this resonance frequency is encountered, the marker material responds with a large signal field which is detected by the receiver. The large signal field is partially attributable to an enhanced magnetic permeability of the marker material at the resonance frequency. Various marker configurations and systems for the interrogation and detection that utilize the above principle have been taught in the '489 and '490 patents.
In one particularly useful system, the marker material is excited into oscillations by pulses, or bursts, of signal at its resonance frequency generated by the transmitter. When the exciting pulse is over, the marker material will undergo damped oscillations at its resonance frequency, i.e., the marker material "rings down" following the termination of the exciting pulse. The receiver "listens" to the response signal during this ring down period. Under this arrangement, the surveillance system is relatively immune to interference from various radiated or power line sources and, therefore, the potential for false alarms is essentially eliminated.
A broad range of alloys have been claimed in the '489 and '490 patents as suitable for marker material, for the various detection systems disclosed. Other metallic glass alloys bearing high permeability are disclosed in U.S. Pat. No. 4,152,144.
A major problem in use of electronic article surveillance systems is the tendency for markers of surveillance systems based on mechanical resonance to accidentally trigger detection systems that are based an alternate technology, such as the harmonic marker systems described above: The non-linear magnetic response of the marker is strong enough to generate harmonics in the alternate system, thereby accidentally creating a pseudo response, or "false" alarm. The importance of avoiding interference among, or "pollution" of, different surveillance systems is readily apparent. Consequently, there exists a need in the art for a resonant marker that can be detected in a highly reliable manner without polluting systems based on alternate technologies, such as harmonic re-radiance.
SUMMARY OF INVENTION
The present invention provides magnetic alloys that are at least 70% glassy and, upon being annealed to enhance magnetic properties, are characterized by relatively linear magnetic responses in a frequency regime wherein harmonic marker systems operate magnetically. Such alloys can be cast into ribbon using rapid solidification, or otherwise formed into markers having magnetic and mechanical characteristics especially suited for use in surveillance systems based on magneto-mechanical actuation of the markers. Generally stated the glassy metal alloys of the present invention have a composition consisting essentially of the formula Co a Fe b Ni c M d B e Si f C g , where M is selected from molybdenum and chromium and "a", "b", "c", "d", "e", "f" and "g" are in atom percent, "a" ranges from about 40 to about 43, "b" ranges from about 35 to about 42 and "c" ranges from about 0 to about 5, "d" ranges from about 0 to about 3, "e" ranges from about 10 to about 25, "f" ranges from about 0 to about 15 and "g" ranges from about 0 to about 2. Ribbons of these alloys, when mechanically resonant at frequencies ranging from about 48 to about 66 kHz, evidence relatively linear magnetization behavior up to an applied field exceeding 8 Oe as well as the slope of resonant frequency versus bias field close to or exceeding the level of about 400 Hz/Oe exhibited by a conventional mechanical-resonant marker. Moreover, voltage amplitudes detected at the receiving coil of a typical resonant-marker system are higher for the markers made from the alloys of the present invention than those of the existing resonant marker. These features assure that interference among systems based on mechanical resonance and harmonic re-radiance is avoided
The metallic glasses of this invention are especially suitable for use as the active elements in markers associated with article surveillance systems that employ excitation and detection of the magneto-mechanical resonance described above. Other uses may be found in sensors utilizing magneto-mechanical actuation and its related effects and in magnetic components requiring high magnetic permeability.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood and further advantages will become apparent when reference is made to the following detailed description of the preferred embodiments of the invention and the accompanying drawings in which:
FIG. 1(a) is a schematic representation of the magnetization curve taken along the length of a existent resonant marker, where B is the magnetic induction and H is the applied magnetic field;
FIG. 1(b) is a schematic representation of the magnetization curve taken along the length of the marker of the present invention, where H a is a field above which B saturates;
FIG. 2 is a schematic representation of signal profile detected at the receiving coil depicting mechanical resonance excitation, termination of excitation at time t=t 0 and subsequent ring-down, where V 0 and V 1 are the signal amplitudes at the receiving coil at t=t 0 and t=t 1 (1 msec after t 0 ), respectively; and
FIG. 3 is a schematic representation of the mechanical resonance frequency, f r , and response signal, V 1 , detected in the receiving coil at 1 msec after the termination of the exciting ac field as a function of the bias magnetic field, where H b1 and H b2 are the bias fields at which V 1 is a maximum and f r is a minimum, respectively.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the present invention, there are provided magnetic metallic glass alloys that are characterized by relatively linear magnetic responses in the frequency region where harmonic marker systems operate magnetically. Such alloys evidence all the features necessary to meet the requirements of markers for surveillance systems based on magneto-mechanical actuation. Generally stated the glassy metal alloys of the present invention have a composition consisting essentially of the formula Co a Fe b Ni c M d B e Si f C g , where M is selected from molybdenum and chromium and "a", "b", "c", "d", "e", "f" and "g" are in atom percent, "a" ranges from about 40 to about 43, "b" ranges from about 35 to about 42 and "c" ranges from about 0 to about 5, "d" ranges from about 0 to about 3, "e" ranges from about 10 to about 25, "f" ranges from about 0 to about 15 and "g" ranges from about 0 to about 2. The purity of the above compositions is that found in normal commercial practice. Ribbons of these alloys are annealed with a magnetic field applied across the width of the ribbons at elevated temperatures for a given period of time. Ribbon temperatures should be below its crystallization temperature and the heat-treated ribbon needs to be ductile enough to be cut up. The field strength during the annealing is such that the ribbons saturate magnetically along the field direction. Annealing time depends on the annealing temperature and typically ranges from about a few minutes to a few hours. For commercial production, a continuous reel-to-reel annealing furnace may be preferred. In such cases, ribbon travelling speeds may be set at between about 0.5 and 12 meter per minute. The annealed ribbons having, for example, a length of about 38 mm, exhibit relatively linear magnetic response for magnetic fields up to or more than 8 Oe applied parallel to the marker length direction and mechanical resonance in a range of frequencies from about 48 kHz to about 66 kHz. The linear magnetic response region extending to the level of more than 8 Oe is sufficient to avoid triggering most of the harmonic marker systems. The annealed ribbons at lengths shorter or longer than 38 mm evidence higher or lower mechanical resonance frequencies than 48-66 kHz range.
Ribbons having mechanical resonance in the range from about 48 to 60 kHz are preferred. Such ribbons are short enough to be used as disposable marker materials. In addition, the resonance signals of such ribbons are well separated from the audio and commercial radio frequency ranges.
Most metallic glass alloys that are outside of the scope of this invention typically exhibit nonlinear magnetic response regions below about 8 Oe level. Resonant markers composed of these alloys accidentally trigger, and thereby pollute, many article detection systems of the harmonic re-radiance variety.
There are a few metallic glass alloys outside of the scope of this invention that do show linear magnetic response for an acceptable field range. These alloys, however, contain high levels of molybdenum or chromium, resulting in increased raw material costs and reduced ribbon castability owing to the higher melting temperatures. The alloys of the present invention are advantageous, in that they afford, in combination, extended linear magnetic response, improved mechanical resonance performance, good ribbon castability and economy in production of usable ribbon.
Apart from the avoidance of the interference among different systems, the markers made from the alloys of the present invention generate larger signal amplitudes at the receiving coil than conventional mechanical resonant markers. This makes it possible to reduce either the size of the marker or increase the detection aisle widths, both of which are desirable features of article surveillance systems.
Examples of metallic glass alloys of the invention include Co 42 Fe 40 B 11 Si 7 , Co 42 Fe 40 B 12 Si 6 , Co 42 Fe 40 B 13 Si 5 , Co 42 Fe 40 B 14 Si 4 , Co 42 Fe 40 B 15 Si 3 , Co 42 Fe 40 B 16 Si 2 , Co 42 Fe 40 B 17 Si 1 , Co 42 Fe 40 B 13 Si 3 C 2 , Co 40 Fe 40 Ni 2 B 13 Si 5 , Co 40 Fe 38 Ni 4 B 13 Si 5 , Co 41 Fe 40 Mo 1 B 13 Si 5 , Co 41 Fe 38 Mo 3 B 13 Si 5 , Co 41 Fe 40 Cr 1 B 13 Si 5 , Co 41 Fe 38 Cr 3 B 13 Si 5 , and Co 43 Fe 35 Ni 3 B 13 Si 4 C 2 , wherein subscripts are in atom percent.
The magnetization behavior characterized by a B-H curve is shown in FIG. 1 (a) for a conventional mechanical resonant marker, where B is the magnetic induction and H is the applied field. The overall B-H curve is sheared with a non-linear hysteresis loop existent in the low field region. This non-linear feature of the marker results in higher harmonics generation, which triggers some of the harmonic marker systems, hence the interference among different article surveillance systems.
The definition of the linear magnetic response is given in FIG. 1 (b). As a marker is magnetized along the length direction by an external magnetic field, H, the magnetic induction, B, results in the marker. The magnetic response is relatively linear up to H a , beyond which the marker saturates magnetically. The quantity H a depends on the physical dimension of the marker and its magnetic anisotropy field. To prevent the resonant marker from accidentally triggering a surveillance system based on harmonic re-radiance, H a should be above the operating field intensity region of the harmonic marker systems.
The marker material is exposed to a burst of exciting signal of constant amplitude, referred to as the exciting pulse, tuned to the frequency of mechanical resonance of the marker material. The marker material responds to the exciting pulse and generates output signal in the receiving coil following the curve leading to V 0 in FIG. 2. At time t 0 , excitation is terminated and the marker starts to ring-down, reflected in the output signal which is reduced from V 0 to zero over a period of time. At time t 1 , which is 1 msec after the termination of excitation, output signal is measured and denoted by the quantity V 1 . Thus V 1 /V 0 is a measure of the ring-down. Although the principle of operation of the surveillance system is not dependent on the shape of the waves comprising the exciting pulse, the wave from of this signal is usually sinusoidal. The marker material resonates under this excitation.
The physical principle governing this resonance may be summarized as follows: When a ferromagnetic material is subjected to a magnetizing magnetic field, it experiences a change in length. The fractional change in length, over the original length, of the material is referred to as magnetostriction and denoted by the symbol λ. A positive signature is assigned to λ if an elongation occurs parallel to the magnetizing magnetic field.
When a ribbon of a material with a positive magnetostriction is subjected to a sinusoidally varying external field, applied along its length, the ribbon will undergo periodic changes in length, i.e., the ribbon will be driven into oscillations. The external field may be generated, for example, by a solenoid carrying a sinusodaily varying current. When the half-wave length of the oscillating wave of the ribbon matches the length of the ribbon, mechanical resonance results. The resonance frequency f r is given by the relation
f.sub.r =(1/2L)(E/D).sup.0.5,
where L is the ribbon length, E is the Young's modulus of the ribbon, and D is the density of the ribbon.
Magnetostrictive effects are observed in a ferromagnetic material only when the magnetization of the material proceeds through magnetization rotation. No magnetostriction is observed when the magnetization process is through magnetic domain wall motion. Since the magnetic anisotropy of the marker of the alloy of the present invention is induced by field-annealing to be across the marker width direction, a dc magnetic field, referred to as bias field, applied along the marker length direction improves the efficiency of magneto-mechanical response from the marker material. It is also well understood in the art that a bias field serves to change the effective value for E, the Young's modulus, in a ferromagnetic material so that the mechanical resonance frequency of the material may be modified by a suitable choice of the bias field strength. The schematic representation of FIG. 3 explains the situation further: The resonance frequency, f r , decreases with the bias field, H b , reaching a minimum, (f r ) min , at H b2 . The signal response, V 1 , detected, say at t=t 1 at the receiving coil, increases with H b , reaching a maximum, V m , at H b1 . The slope, df r /dH b , near the operating bias field is an important quantity, since it related to the sensitivity of the surveillance system.
Summarizing the above, a ribbon of a positively magnetostrictive ferromagnetic material, when exposed to a driving ac magnetic field in the presence of a dc bias field, will oscillate at the frequency of the driving ac field, and when this frequency coincides with the mechanical resonance frequency, f r , of the material, the ribbon will resonate and provide increased response signal amplitudes. In practice, the bias field is provided by a ferromagnet with higher coercivity than the marker material present in the "marker package".
Table I lists typical values for V m , H b1 , (f r ) min and H b2 for a conventional mechanical resonant marker based on glassy Fe 40 Ni 38 Mo 4 B 18 . The low value of H b2 , in conjunction with the existence of the nonlinear B-H behavior below H b2 , tends to cause a marker based on this alloy to accidentally trigger some of the harmonic marker systems, resulting in interference among article surveillance systems based on mechanical resonance and harmonic re-radiance.
TABLE I______________________________________Typical values for V.sub.m, H.sub.b1, (f.sub.r).sub.min andH.sub.b2 for a conventional mechanicalresonant marker based on glassy Fe.sub.40 Ni.sub.38 Mo.sub.4 B.sub.18.This ribbon at a length of 38.1 mm has mechanicalresonance frequencies ranging from about 57 and 60 kHz.V.sub.m (mV) H.sub.b1 (Oe) (f.sub.r).sub.min (kHz) H.sub.b2 (Oe)______________________________________150-250 4-6 57-58 5-7______________________________________
Table II lists typical values for H a , V m , H b1 , (f r ) min , H b2 and df r /dH b H b for the alloys outside the scope of this patent. Field-annealing was performed in a continuous reel-to-reel furnace on 12.7 mm wide ribbon where ribbon speed was from about 0.6 m/min. to about 1.2 m/min.
TABLE II__________________________________________________________________________Values for H.sub.a, V.sub.m, H.sub.b1, (f.sub.r).sub.min, H.sub.b2 anddf.sub.r /dH.sub.btaken at H.sub.b = 6 Oe for thealloys outside the scope of this patent. Field-annealing was performed incontinuous reel-to-reel furnace where ribbon speed was from about 0.6m/min. toabout 1.2 m/min and ribbon temperature was about 380° C. Theannealing fieldwas about 1.4 kOe applied across the ribbon width.Composition (at. %) H.sub.a (Oe) V.sub.m (mV) H.sub.b1 (Oe) (f.sub.r).sub.min (kHz) H.sub.b2 (Oe) df.sub.r /dH.sub.b (Hz/Oe)__________________________________________________________________________A. Co.sub.42 Fe.sub.35 Mo.sub.5 B.sub.13 Si.sub.5 11 70 4.5 59 7.5 900__________________________________________________________________________
Alloy A shows not only an unacceptable magnetomechanical resonance responses, but contains a high level of molybdenum, resulting in increased raw material costs and reduced ribbon castability.
The following examples are presented to provide a more complete understanding of the invention. The specific techniques, conditions, materials, proportions and reported data set forth to illustrate the principles and practice of the invention are exemplary and should not be construed as limiting the scope of the invention.
EXAMPLES
Example 1: Co--Fe--B--Si--C Metallic Glasses
1. Sample Preparation
Glassy metal alloys in the Co--Fe--B--Si--C series, designated as samples No. 1 to 8 in Table III and IV, were rapidly quenched from the melt following the techniques taught by Narasimhan in U.S. Pat. No. 4,142,571, the disclosure of which is hereby incorporated by reference thereto. All casts were made in an inert gas, using 100 g melts. The resulting ribbons, typically 25 μm thick and about 12.7 mm wide, were determined to be free of significant crystallinity by x-ray diffractometry using Cu-Kα radiation and differential scanning calorimetry. Each of the alloys was at least 70% glassy and, in many instances, the alloys were more than 90% glassy. Ribbons of these glassy metal alloys were strong, shiny, hard and ductile.
The ribbons were cut into small pieces for magnetization, magnetostriction, Curie and crystallization temperature and density measurements. The ribbons for magneto-mechanical resonance characterization were cut to a length of about 38.1 mm and were heat treated with a magnetic field applied across the width of the ribbons. The strength of the magnetic field was 1.1 or 1.4 kOe and its direction was varied between 75° and 90° with respect to the ribbon length direction. Some of the ribbons were heat-treated under tension ranging from zero to about 7.2 kg/mm 2 . The speed of the ribbon in the reel-to-reel annealing furnace was changed from about 0.5 meter per minute to about 12 meter per minute.
2. Characterization of Magnetic and Thermal Properties
Table III lists saturation induction (B s ), saturation magnetostriction (λ s ), crystallization temperature (T c )of the alloys. Magnetization was measured by a vibrating sample magnetometer, giving the saturation magnetization value in emu/g which is converted to the saturation induction using density data. Saturation magnetostriction was measured by a strain-gauge method, giving in 10 -6 or in ppm. Curie and crystallization temperatures were measured by an inductance method and a differential scanning calorimetry, respectively.
TABLE III______________________________________Magnetic and thermal properties of Co--Fe--B--Si--Cglassy alloys. Curie temperatures of these alloys are above thecrystallization temperatures and are not listed.Composition (at. %)No. Co Fe B Si C B.sub.s (Tesla) λ.sub.s (ppm) T.sub.c (°C.)______________________________________1 42 40 11 7 -- 1.56 26 4512 42 40 12 6 -- 1.55 26 4563 42 40 13 5 -- 1.55 25 4544 42 40 14 4 -- 1.55 25 4545 42 40 15 3 -- 1.55 25 4546 42 40 16 2 -- 1.55 25 4527 42 40 17 1 -- 1.55 25 4528 42 40 13 3 2 1.57 26 442______________________________________
Each marker material having a dimension of about 38.1 mm×12.7 mm×20 μm was tested by a conventional B-H loop tracer to measure the quantity H a and then was placed in a sensing coil with 221 turns. An ac magnetic field was applied along the longitudinal direction of each alloy marker with a dc bias field changing from 0 to about 20 Oe. The sensing coil detected the magneto-mechanical response of the alloy marker to the ac excitation. These marker materials mechanically resonate between about 48 and 66 kHz. The quantities characterizing the magneto-mechanical response were measured and are listed in Table IV for the alloys listed in Table III.
TABLE IV__________________________________________________________________________Values of H.sub.a, V.sub.m, H.sub.b1, (f.sub.r).sub.min, H.sub.b2 anddf.sub.r /dH.sub.btaken at H.sub.b = 6 Oe for the alloys of Table III heat-treated at375° C.for 15 min in a magnetic field of about 1.4 kOe applied perpendicularto the ribbon length direction (indicated byasterisks). Alloys No. 1, 2 and 8 were field annealed in a reel-to-reelannealing furnace at 380° C. with a ribbon speed of about 0.6m/mimutewith a magnetic field of about 1.4 kOe applied perpendicularto the ribbon direction.Alloy No. H.sub.a (Oe) V.sub.m (mV) H.sub.b1 (Oe) (f.sub.r).sub.min (kHz) H.sub.b2 (Oe) df.sub.r /dH.sub.b (Hz/Oe)__________________________________________________________________________1 20 415 8.0 53.5 17.0 6102 20 350 9.0 52.3 16.2 6203* 21 330 7.5 50.8 18.5 4704* 20 375 9.0 50.5 17.2 5405* 21 320 8.5 51.3 18.7 4206* 21 320 8.8 51.5 18.5 4907* 20 330 8.5 51.0 18.2 5508 20 325 9.0 54.8 17.0 550__________________________________________________________________________
All the alloys listed in Table IV exhibit H a values exceeding 8 Oe, which make them possible to avoid the interference problem mentioned above. Good sensitivity (df r /dH b ) and large response signal (V m ) result in smaller markers for resonant marker systems.
The quantities characterizing the magneto-mechanical resonance of the marker material of Table III heat-treated under different annealing conditions are summarized in Table V.
TABLE V______________________________________Values of V.sub.m, H.sub.b1, (f.sub.r).sub.min, H.sub.b2, df.sub.r/dH.sub.btaken at H.sub.b = 6 Oe for Alloy No. 3of Table III heat-treated under different conditions ina reel-to-reel annealing furnace. The annealing field directionwas perpendicular to the ribbon length direction.RibbonSpeed Tension V.sub.m H.sub.m (f.sub.r).sub.min H.sub.b2 df.sub.r /dH.sub.b(m/minute) (kg/mm.sup.2) (mV) (Oe) (kHz) (Oe) (Hz/Oe)______________________________________Annealing Temperature: 320° C. Applied Field: 1.1 kOe0.6 0 290 7.2 52.6 16.5 6200.6 7.2 410 7.2 52.9 16.0 7402.1 0 290 6.8 52.5 14 8002.1 7.2 355 6.0 51.9 14 820Annealing Temperature: 360° C. Applied Field: 1.4 kOe0.6 0 330 8.0 53.7 16.5 5500.6 2.1 390 7.9 52.5 16.5 6200.6 7.2 410 7.4 52.2 16.3 620Annealing Temperature: 440° C. Applied Field: 1.1 kOe9.1 0 410 6.0 51.5 14.0 9009.1 1.4 440 6.4 51.6 13.0 7806.1 0 340 6.4 51.3 14.8 8306.1 1.4 460 6.3 51.6 13.0 7503.0 0 320 6.0 51.8 14.6 7803.0 1.4 430 6.0 51.9 13.7 840______________________________________
The most noticeable effect is the increase of the signal amplitude when the marker material is heat-treated under tension.
Example 2: Co--Fe--Ni--Mo/Cr/--B--Si--C Metallic Glasses
Glassy metal alloys in the Co--Fe--Ni--Mo/Cr/--B--Si--C system were prepared and characterized as detailed under Example 1. Table VI lists chemical compositions, magnetic and thermal properties and Table VII lists quantities characterizing mechanical resonance responses of the alloys of Table VI.
TABLE VI______________________________________Magnetic and thermal properties of low cobalt containing glassyalloys. T.sub.c is the first crystallization temperature.Al-loy Composition (at. %) B.sub.s λ.sub.s T.sub.cNo. Co Fe Ni Mo Cr B Si C (Tesla) (ppm) (°C.)______________________________________1 41 40 -- 1 -- 13 5 -- 1.51 24 4632 41 38 -- 3 -- 13 5 -- 1.34 20 4673 41 40 -- -- 1 13 5 -- 1.51 24 4604 41 38 -- -- 3 13 5 -- 1.37 20 4635 40 40 2 -- -- 13 5 -- 1.53 27 4566 43 35 3 -- -- 13 4 2 1.50 19 4687 40 38 4 -- -- 13 5 -- 1.50 23 456______________________________________
TABLE VII__________________________________________________________________________Values of H.sub.a, V.sub.m, H.sub.b1, (f.sub.r).sub.min, H.sub.b2 anddf.sub.r /dH.sub.btaken at H.sub.b = 6 Oe for the alloys listed in Table VI heat-treatedat 380° C. in a reel-to-reel annealing furnace with a ribbonspeed of about 0.6 m/minute and an applied field of 1.4 kOeapplied perpendicular to the ribbon length direction.Alloy No. H.sub.a (Oe) V.sub.m (mV) H.sub.b1 (Oe) (f.sub.r).sub.min (kHz) H.sub.b2 (Oe) df.sub.r /dH.sub.b (Hz/Oe)__________________________________________________________________________1 18 400 8.0 52.3 15.3 7302 14 270 6.0 56.3 12.4 9403 18 330 8.5 52.6 16.5 7204 16 320 7.3 53.9 13.8 8605 20 250 8.0 54.7 15.2 5906 19 330 8.2 56.7 16.0 5007 20 420 9.3 53.8 16.4 500__________________________________________________________________________
All the alloys listed in Table VII exhibit H a values exceeding 8 Oe, which make them possible to avoid the interference problems mentioned above. Good sensitivity (df r /dH b ) and large magneto-mechanical resonance response signal (V m ) result in smaller markers for resonant marker systems.
Having thus described the invention in rather full detail, it will be understood that such detail need not be strictly adhered to but that further changes and modifications may suggest themselves to one skilled in the art, all falling within the scope of the invention as defined by the subjoined claims.
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A glassy metal alloy consists essentially of the formula Co a Fe b Ni c M d B e Si f C g , where M is selected from molybdenum and chromium and "a", "b", "c", "d", "e", "f" and "g" are in atom percent, "a" ranges from about 40 to about 43, "b" ranges from about 35 to about 42 and "c" ranges from 0 to about 5, "d" ranges from 0 to about 3, "e" ranges from about 10 to about 25, "f" ranges from 0 to about 15 and "g" ranges from 0 to about 2. The alloy can be cast by rapid solidification into ribbon, annealed to enhance magnetic properties thereof, and formed into a marker that is especially suited for use in magneto-mechanically actuated article surveillance systems. Advantageously, the marker is characterized by relatively linear magnetization response in the frequency regime wherein harmonic marker systems operate magnetically. Voltage amplitudes detected for the marker are high, and interference between surveillance systems based on mechanical resonance and harmonic re-radiance is virtually eliminated.
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This invention relates to composite framing members, more specifically to studs and tracks from metal and wood composites. This invention is a Continuation-In-Part of U.S. Applications: 08/974,898 filed Nov. 20, 1997; now issued as U.S. Pat. No. 5,921,054, 08/975,437 filed Nov. 21, 1997 now issued as U.S. Pat. No. 5,881,529; 08/975,642 filed Nov. 21, 1997 now issued as U.S. Pat. No. 4,875,603; 08/976,107 filed Nov. 21, 1997 now issued as U.S. Pat. No. 5,875,604; 08/976,151 filed Nov. 21, 1997 now issued as U.S. Pat. No. 5,875,605; which are all divisional applications of 08/664,662 filed Jun. 17, 1996, now abandoned,
BACKGROUND AND PRIOR ART
Residential and light commercial construction generally use wood lumber as the primary building material for studs, plates, joists, headers and trusses. However, wood lumber construction has problems. The rapidly rising cost of raw wood supplies has in effect substantially raised the cost of these members. Further, the quality of available framing lumber continues to decline. Finally, wood is flammable and susceptible to insects and rot.
Due to these problems, many builders have been switching to light gauge steel framing. The costs between using wood or steel framing is getting closer. In January 1990, the cost of framing lumber was about $225 per thousand board feet, peaking to highs of $500 in both January, 1993 and January 1994. Since June 1995, the framing lumber composite price has been rising from $300 per thousand board feet. Estimates from the AISI and NAHB Research Center state at a framing lumber cost of $340 to $385, there would be no difference between the cost of framing a house in steel as compared in wood. Thus, the break-even point between wood and steel framing is at about $360 per thousand board feet of framing lumber, and the lumber price has exceeded that point several times in recent years by as much as 40%, giving steel a competitive advantage.
Recycling has additionally helped the cost of steel to remain on a stable or downward trend. Steel costs have varied little in recent years. Traditionally variations can be correlated to steel demand by the automobile industry, when demand is high, steel usually increases slightly in pnce. Consequently, the use of metal framing in residential and light commercial construction is increasing, a trend recognized and encouraged by the American Iron and Steel Institute (AISI).
Steel studs, tracks and trusses are commonly manufactured by industry by companies such as Deitrich, Unimast, Alpine, Tri-Chord, HL Stud, Truswall Systems, Techbuilt, Knudson, John McDonald, and MiTek.
A problem with steel framing is its high thermal conductivity, leading to thermal bridging, “ghosting”, and greater potential for water vapor condensation on interior wall surfaces. “Ghosting” is when an unsightly streak of dust accumulates on the interior wallboard, where the steel studs lie behind, due to an acceleration of dust particles toward the colder surface. Another problem of using steel framing is the increased energy use for space conditioning (heating and cooling). Metal used for exterior framing members allows greater conduction heat transfer between the outside and inside surfaces of a wall, roof or floor. In colder climates, this increased conduction can cause condensation in interior surfaces, contributing to material degradation and mold and mildew growth. Metal framing also decreases the effectiveness of insulation installed in the cavity between the metal framing due to increased three-dimensional thermal short circuiting effects. Higher sound transmission is another disadvantage of metal framing since sound conductivity is greater in metal than in wood. Electricians have more difficulty working with steel framing for running wiring since its more difficult to cut holes in steel than in wood, and grommets or conduits must be used to protect the wire.
U.S. Pat. No. 5,768,849 to Blazevic describes a “composite structural post”, title, having L-shaped metal members on sides of stud members, FIG. 3 . However, L-shaped legs are directly connected to the side edges of the wood stud base, and are not structurally wrapped about side edges of the wood stud bases. The orientation of the L shaped legs would not adequately increase the thermal resistance over single wood material stud members, nor have a greater axial load capability over single wood material stud members, nor substantially reduce interior condensation and ghosting. The embodiments covering using cap shaped metal members in FIGS. 6, 6 A, 7 and 7 A are limited to using only the metal cap shapes in a longitudinal postion as corner posts, and also would not adequately increase the thermal resistance over single wood material stud members, nor substantially reduce interior condensation and ghosting.
U.S. Pat. No. 5,285,615 to Gilmour describes a thermal metallic building stud. However, the Gilmour member is entirely formed from metal. In Gilmour, the thermal conductivity is only partially reduced by having raised dimples on the ends contacting other building materials.
U.S. Pat. No. 4,466,225 to Hovind describes a “stud extenders”, title, that is limited to converting a “2×4 . . . into a 2×6”, abstract. However, Hovind is limited to putting their metal side “extender” on one side of a “2×4”, and thus would not adequately increase the thermal resistance over single wood material stud members, nor have a greater axial load capability over single wood material stud members, nor substantially reduce interior condensation and ghosting.
U.S. Pat. No. 3,960,637 to Ostrow describes impractical metal and wood composites. Ostrow requires each end flange have tapered channels, the end flanges being formed from extruded aluminum, molded plastic and fiberglass. Ends of the vertical wood web must be fit and pressed into a tapered channel. Besides the difficulty of aligning these parts together, other inherent problems exist. Extruding the channel flanges from aluminum or using molds, cuts and rolling to create the channelled plastic and fiberglass end flanges is expensive to manufacture. To stabilize the structures, Ostrow describes additional labor and manufacturing costs of gluing members together and sandwiching mounting blocks on the outsides of each channel.
Other metal and wood framing member patents of related but less significant interest include: U.S. Pat. No. 5,452,556 to Taylor; U.S. Pat. No. 5,440,848 to Deffet; U.S. Pat. No. 5,072,547 to DiFazio; U.S. Pat. No. 5,024,039 to Karhumaki; U.S. Pat. No. 4,875,316 to Johnston; U.S. Pat. No. 4,301,635 to Neufeld; U.S. Pat. No. 4,274,241 to Lindal; U.S. Pat. No. 4,031,686 to Sanford; U.S. Pat. No. 3,566,569 to Coke et al.; U.S. Pat. No. 3,531,901 to Meechan; U.S. Pat. No. 3,310,324 to Boden;
SUMMARY OF THE INVENTION
The first objective of the present invention is to provide metal and wood composite wall stud that increases the total thermal resistance of a typical steel framed insulated wall section by some 43 percent and would eliminate interior condensation and “ghosting” for all but the coldest regions of the United States.
The second object of this invention is to provide metal and wood composite framing combinations that achieve a resource efficient and economic construction framing member. Metal is used for its high strength, and potentially lower cost and resource efficiency through recycling. Wood is used primarily for its lower thermal conductivity and for its availability as a renewable resource, and for its workability.
The third object of this invention is to provide metal and wood composite framing members that allow electricians to be able to route wires through walls in the same way they are accustomed to doing with solid framing lumber.
The fourth object of this invention is to provide metal and wood composite framing members that would be easy to manufacture.
The fifth object of this invention is to provide metal and wood composite framing members that have low sound conductivity compared to prior art steel framing members.
The sixth object of this invention is to provide metal and wood composite framing members that have reduced effects from flammability compared to all wood members.
The invention includes J-shaped, P-shaped, L-shaped, triangular shaped cross-sectional metal forms connected by a wood midsection, whereby the wood is fastened to the metal by machine pressing of the metal to wood, similar to the common truss plate, or by nails, staples, screws, or other mechanical fastening means, or by adhesive glue. The outward faces of the metal members can be pre-formed with longitudinal ridges such that the contact surface area to applied sheathings is reduced by about 90%.
Metal and wood composites are used to create framing members (studs and tracks, joists and bands, headers, rafters, and the like) for light-weight construction. Metal is utilized for its high strength, resistance to rot and insects, cost stability, and potentially lower cost through recycling. Wood is used primarily for its lower thermal conductivity, and availability. The metal components form the primary structure while wood, either solid or other engineered wood, provides some structure and a thermal break.
Metal and wood composite framing members can be used in place of conventional wood framing members such as: 2×4 and 2×6 wall studs, and 2×8, 2×10, 2×12 and other dimensions of roof rafters, floor joists and headers. The novel framing members can be used to replace conventional light-gauge steel framing to reduce thermal transmittance and sound transmission.
Further objects and advantages of this invention will be apparent from the following detailed description of a presently preferred embodiment which is illustrated schematically in the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1A is a perspective isometric view of a first preferred embodiment metal and wood stud.
FIG. 1B is a cross-sectional view of the embodiment of FIG. 1A along arrow AA.
FIG. 2A is a perspective isometric view of a second preferred embodiment metal and wood stud.
FIG. 2B is a cross-sectional view of the embodiment of FIG. 2A along arrow BB.
FIG. 3A is a perspective isometric view of a third preferred embodiment metal and wood stud.
FIG. 3B is a cross-sectional view of the embodiment of FIG. 3A along arrow CC.
FIG. 4A is a perspective isometric view of a fourth preferred embodiment metal and wood joist, rafter and header.
FIG. 4B is a cross-sectional view of the embodiment of FIG. 4A along arrow DD.
FIG. 5A is a top perspective view of a fifth embodiment track for metal and wood stud systems.
FIG. 5B is a bottom perspective view of the embodiment of FIG. 5A along arrow E 1 .
FIG. 5C is a cross-sectional view of the embodiment of FIG. 5B along arrow EE.
FIG. 6A is a perspective view of a sixth preferred embodiment metal and wood band.
FIG. 6B is a cross-sectional view of the embodiment of FIG. 6A along arrow FF.
FIG. 7 is a cross-sectional view a framing system utilizing the embodiments of FIGS. 1A-6B.
FIG. 8A is a perspective view of a seventh preferred embodiment metal-wood stud.
FIG. 8B is a cross-sectional view of the embodiment of FIG. 8A along arrow GG.
FIG. 8C is another cross-sectional view of FIG. 8A along arrow GG with circular ridges.
FIG. 9A is a top view of a eigth preferred embodiment metal-wood top and bottom track.
FIG. 9B is a cross-sectional view of the embodiment of FIG. 9A along arrow HH.
FIG. 9C is a bottom view of the top metal-wood top and bottom track of FIG. 9 A.
FIG. 10A is a perspective view of a ninth preferred embodiment metal-wood stud.
FIG. 10B is a cross-sectional view of the embodiment of FIG. 10A along arrow II.
FIG. 10C is another cross-sectional view of FIG. 10A along arrow II with circular ridges.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Before explaining the disclosed embodiment of the present invention in detail it is to be understood that the invention is not limited in its application to the details of the particular arrangement shown since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.
The preferred method of calculating thermal transmittance for building assemblies with integral steel is the zone method published by the American Society of Heating Refrigeration and Air-Conditioning Engineers (ASHRAE). A recent study by the National Association of Home Builders Research Center and Oak Ridge National Laboratory verified the usefulness of the zone method for calculating thermal transmittance for light gauge steel walls.
Thermal transmittance calculations were completed using the zone method for the metal and wood stud invention embodiments. Table 1 shows a comparison of thermal transmittance (given as total R-value) for nine wall configurations. The first wall listed is a conventional 2×4 wood frame wall with ½″ plywood sheathing and R-11 fiberglass cavity insulation. The total wall R-value is 13.2 hr-F-ft 2 /Btu. the second and third walls listed are conventional metal stud walls, one with ½″ plywood sheathing (R-7.9) and the other with ½″ extruded polystyrene sheathing (R-11.4). With conventional metal studs, high resistivity insulated sheathing is necessary to limit the large loss of total thermal resistance when low resistivity sheathings are used. In some cases, it is not desirable to use the non-structural insulated sheathing, such as when brick ties are needed, or when higher racking resistance is needed.
In comparison, the metal and wood stud walls corresponding to those described in the subject invention has a 43 per cent greater total R-value than the conventional metal stud wall when using plywood sheathing. Thermal performance of the metal and wood stud wall with plywood sheathing is nearly the same as the conventional wall with ½″ extruded polystyrene (XPS insulated sheathing). Where non-structural sheathing is acceptable, fiber board sheathing, which is much less expensive than plywood, further increases the total R-value of the metal and wood stud wall.
TABLE 1
COMPARISON OF THERMAL TRANSMITTANCE FOR CONVENTIONAL
METAL STUD WALL AND NOVEL METAL AND WOOD STUD WALL
Stud Size
Stud Spacing
Cavity
Exterior
Total
Description
Inch
Inch O.C.
Insulation
Sheathing
R-Value
1. Conventional metal stud,*
1.625 × 3.625
24
R-11
½″ plywood
7.9
2. Conventional metal stud,*
1.625 × 3.625
24
R-11
½″ XPS
11.4
3. Novel metal and wood stud,
1.5 × 3.5
24
R-11
½″ plywood
11.3
4. Novel metal and wood stud
1.5 × 3.5
24
R-13
½″ plywood
12.8
5. Novel metal and wood stud
1.5 × 3.5
24
R-15
½″ plywood
14.2
6. Novel metal and wood stud
1.5 × 3.5
24
R-11
½″ fiber board
12.1
7. Novel metal and wood stud
1.5 × 3.5
24
R-13
½″ fiber board
13.6
8. Novel metal and wood stud
1.5 × 3.5
24
R-15
½″ fiber board
15.0
*Conventional metal stud values from “Thermodesign Guide for Exterior Walls, American Iron and Steel Institute, Washington, D.C., Pub. No. RG-9405, Jan. 1995.
Summary calculation results compared the allowable axial load for stud elements subjected to combined loading with axial and bending components. The three elements analyzed were a conventional 2×4 wood, a conventional 20 gauge steel stud, and the present invention metal and wood composite stud. All elements were 8′ tall, and spaced 16″ O.C.. Wind (transverse) load at 110 mph. Table 2 shows that the metal and wood composite section can support 54% more weight than the metal stud, and 250% more weight than the wood stud. This gives the opportunity for further cost optimization by increasing the spacing which would reduce the number of studs required, or for reducing the amount of steel used in the composite section.
TABLE 2
STRUCTURAL CALCULATION RESULTS FOR
NOVEL METAL AND WOOD
3.5″ 20 Gauge
3.5″ Metal and wood
STUD
2 × 4 Wood Stud
Metal Stud
Composite Section
Allowable Axial Load
551 lb
894 lb
1378 lb
8′ tall stud
16″ O.C.
110 mph wind
Comparison of vertical, transverse, and racking load capacities of 2 × 4 wood stud, metal stud, and subject invention wood/metal composite stud. Structural analysis by Kim McLeod, P.E. Of Keymark Enterprises, Boulder, Colorado.
FIG. 1A is a perspective isometric view of a first preferred embodiment metal and wood stud 100 . FIG. 1B is a cross-sectional view of the embodiment 100 of FIG. 1A along arrow AA. Referring to FIGS. 1A-1B, embodiment 100 includes metal forms 110 , 120 such as but not limited to 20 gauge steel has been cold-formed in a roll press into a cross-sectional channel Jshape. Each form 110 , 120 includes steel web portions 112 , 122 that have staggered rows of cutout portions 115 , 125 which are of a pressed tooth type triangular shape. Web portions 112 , 122 are perpendicular to flanges 116 , 126 which include approximately 4 rows of raised V-shaped grooves 117 , 127 running longitudinally along the exterior of the flanges 116 , 126 . Flange returns 118 , 128 are perpendicular to flanges 116 , 126 . Teeth 115 , 125 can be hydraulically pressed adjacent the top and bottom rear side 152 of central web board 150 . Central web board 150 can be solid wood, OSB, (oriented strand board) plywood and the like, having a thickness of approximately ½ an inch. Alternatively, web portions 112 , 122 of forms 110 , 120 can be fastened to the central web board 150 by nails, screws, staples and the like, or adhesively glued. A finished metal and wood s˜d 100 can have a length, L I, of approximately 8 feet or longer, height HI of approximately 3.5 to 5.5 inches, width WI of approximately 1.5 inches. Web portions 112 , 122 can have a height, h I of approximately 1.125 inches, front plate height, h2 of approximately 0.75 inches, raised grooves RI, of approximately 0.125 inches. A spacing, xl of approximately 0.125 inches separates each flange 116 , 126 from the top and bottom of central web board 150 .
FIG. 2A is a perspective view of a second preferred embodiment metal and wood stud 200 . FIG. 2B is a cross-sectional view of the embodiment 200 of FIG. 2A along arrow BB. Referring to FIGS. 2A-2B, embodiment 200 includes metal forms 210 , 220 such as but not limited to 20 gauge steel that has been roll pressed into a cross-sectional channel right-triangular-shape. Each form 210 , 220 includes outer web portions 212 , 222 that have staggered rows of cut-out portions 213 , 223 which are of a pressed tooth type triangular shape. Outer web portions 212 , 222 are perpendicular to flanges 214 , 224 which include approximately 4 rows of raised V-shaped grooves 215 , 225 running longitudinally along their exterior surface. Flange returns 216 , 226 are approximately 45 degrees to flanges 214 , 224 , and are connected to inner web portions 218 , 228 each having staggered rows of cut-out portions 219 , 229 which also are of the pressed tooth type triangular shape. Teeth 213 , 219 and 223 , 229 can be firmly pressed adjacent the top and bottom of central web board 250 . Central web board 250 can be solid wood, OSB, plywood and the like, having a thickness of approximately ½ an inch. Alternatively, web portions 212 , 218 , 222 , 228 can be fastened to the central web board 250 by nails, screws, staples and the like. Outer web portions 212 , 222 can have a height, B 1 of approximately 1.1625 inches, flanges 214 , 224 can have a width, B2 of approximately 1.5 inches, flange returns 216 , 226 can have a height, B3 of approximately 0.925 inches and inner web portions 218 , 228 can have a height, B4 of approximately 1 inch. A finished metal and wood stud 200 can have the remaining dimensions and spacings similar to the embodiment 100 previously described, except height, B5 can be approximately 5.5 to approximately 7.25 inches.
FIG. 3A is a perspective isometric view of a third preferred embodiment metal and wood stud 300 . FIG. 3B is a cross-sectional view of the embodiment 300 of FIG. 3A along arrow CC. Referring to FIGS. 3A-3B, embodiment 300 includes metal forms 310 , 320 such as but not limited to 20 gauge steel has been roll pressed into a cross-sectional channel triangular-shape with parallel plates on the apex of the triangle. Each form 310 , 320 includes metal web portions 312 , 322 , 318 , 328 that have staggered rows of cut-out portions 313 , 323 , 319 , 329 which are of a pressed tooth type triangular shape. Web portions 312 , 322 , 318 , 328 attach to 45 degree flange returns 314 , 324 which are attached to respective flanges 315 , 325 which include approximately 4 rows of raised V-shaped grooves 316 , 326 running longitudinally along their exterior surface. Teeth 313 , 319 and 323 , 329 can be pressed adjacent the top and bottom of central web board 350 . Central web board 350 can be solid wood, OSB, plywood and the like, having a thickness of approximately ½ an inch. Alternatively, metal web portions 312 , 318 , 322 , 328 can be fastened to the central web board 350 by nails, screws, staples and the like. Metal web portions 312 , 318 , 322 , 328 can have a height, C1 of approximately 0.875 inches, flanges 315 , 325 can have a width, C2 of approximately 1.5 inches, flange returns 314 , 317 , 324 , 327 can have a height, C3 of approximately 0.4625 inches. A finished metal and wood stud 300 can have remaining dimensions and spacings similar to the embodiment 200 previously described.
FIG. 4A is a perspective isometric view of a fourth preferred embodiment 400 useful as a metal and wood joist, rafter and header. FIG. 4B is a cross-sectional view of the embodiment 400 of FIG. 4A along arrow DD. Referring to FIGS. 4A-4B, embodiment 400 includes metal forms 410 , 420 such as but not limited to 20 gauge steel has been roll pressed into a cross-sectional channel triangular-shape with parallel plates on the apex of the triangle. Each form 410 , 420 includes metal web portions 412 , 422 , 418 , 428 that have staggered rows of cut-out portions 413 , 423 , 419 , 429 which are of a pressed tooth type triangular shape. Metal web portions 412 , 422 , 418 , 428 attach to 45 degree flange returns 414 , 424 , 417 , 427 which are attached to respective flanges 415 , 425 which include approximately 4 rows of raised V-shaped grooves 416 , 426 running longitudinally along their exterior surface. Teeth 413 , 419 and 423 , 429 can be pressed adjacent the top and bottom portions of central web boards 452 , 454 . A central metal plate 460 has left facing tooth rows 463 and right facing tooth rows 465 for connecting to adjacent respective web boards 452 , 454 . Plate 460 has a spacing above and below to separate such from flanges 415 , 425 . Central web boards 452 , 454 can be solid wood, OSB, plywood and the like, having a thickness of approximately 0.375 inches. Alternatively, metal web portions 412 , 418 , 422 , 428 can be fastened to the central web boards 452 , 454 by nails, screws, staples and the like. Metal web portions 412 , 418 , 422 , 428 can have a height, Dl of approximately 1.0188 inches, flanges 415 , 425 can have a width, D2 of approximately 1.5 inches, flange returns 414 , 417 , 424 , 427 can have a height, D3 of approximately 0.3188 inches. A finished embodiment 400 can have practically any length, L2 to serve as a floor joist, rafter or header, width D2 can be approximately 1.5 inches and height D4, can be approximately 5.5 inches or more.
FIG. 5A is a top perspective view of a fifth embodiment track 500 for metal and wood stud and track systems. FIG. 5B is a bottom perspective view of the embodiment 500 of FIG. 5A along arrow El. FIG. 5C is a cross-sectional view of the embodiment 500 of FIG. 5B along arrow EE. Referring to FIGS. 5A-5C, embodiment 500 includes metal forms 510 , 520 each having a generally L-shaped cross-section. Forms 510 , 520 each include flanges 512 , 522 approximately 1.125 inches in height perpendicular to metal web portions 514 , 524 , which are approximately 1.1625 inches in length. Metal web portions 514 , 524 have tooth shaped triangular cut-outs 515 , 525 , which are pressed into sides of center-web-board 550 . A spacing E2 of approximately 0.125 inches separates the ends of center-web-board 550 from flanges 512 , 522 , respectively. A finished embodiment 500 can have remaining dimensions and spacings similar to the embodiments 100 , 200 , and 300 above.
FIG. 6A is a perspective view of a sixth preferred embodiment metal and wood joists and bands 600 . FIG. 6B is a cross-sectional view of the embodiment 600 of FIG. 6A along arrow FF. Referring to FIGS. 6A-6B, embodiment 600 includes top metal form 610 having a T-cross-sectional shape and lower metal form 620 having a straight line cross-sectional shape. Form 610 includes metal web portion 612 , having a length, F1 of approximately 1.0375 inches having tooth shaped triangular cut-outs 613 which are pressed into upper end sides of wood center web board 650 . Form 610 further includes an upright leg 614 having a length F2 of approximately 1.3 inches, perpendicular to a third leg 616 , having a length, F3 of approximately 1.25 inches, which abuts against and overlaps top end 652 of centerboard 650 . Lower metal form 620 has a metal web portion 622 having tooth shaped triangular cut-outs 623 which are pressed into upper end sides of wood center board 650 , and a continuous extended plate 624 . The continuous width F4, of metal plate 622 , 624 is approximately 1.75 inches, with plate 624 extending a length F5 of approximately 0.75 inches from the lower end 654 of center-web-board 650 having thickness of approximately 0.5 inches. A finished embodiment 600 can have a width F6 and length L3 similar to embodiment 400 .
FIG. 7 is a cross-sectional view a framing system 700 utilizing the embodiments of FIGS. 1A-6B. Embodiment 700 can be a two story building having a metal and wood bottom track 500 attached at floor 702 by conventional fasteners such as nails, screws, bolts and the like. Vertically oriented metal and wood studs 100 / 200 / 300 can be attached to floor and ceiling tracks 500 by steel framing screws 715 and the like. A metal and wood band 600 attaches first floor ceiling track 500 to metal and wood floor joist 400 and subfloor 710 , which has conventional steel framing flathead type screws 716 and the like. The second floor has a similar arrangement with rafters 400 attached at conventional angles to upper metal and wood top track 500 .
A cost of a metal and wood composite stud such as those described in the previous embodiment 100 is estimated to be $4.24. The lowest cost of conventional 20 gauge steel studs is $2.52 each, however, to obtain the same thermal performance, an insulated sheathing is required which raises the cost to $4.55 per stud. The metal and wood framing member's invention is directly cost effective compared to the conventional metal stud. In addition, structural calculations show that the metal and wood stud configuration can support 54% more weight at the same 8′ wall height, 16″ O.C. spacing, and 110 mph wind load. This give opportunity for further cost optimization by increasing the spacing which would reduce the number of studs required. For example, a 2000 square foot house framed 16″ O.C. will have about 168 conventional steel exterior wall studs, the same house framed 24″ O.C. with the stronger metal and wood composite exterior wall studs will use only 107 studs. With 61 fewer exterior wall studs required, the builder can save about $270.
Metal-Wood Stud Adhesive Pocket Configuration
FIG. 8A is a perspective view of a seventh preferred embodiment metal-wood stud 1000 . FIG. 8B is a cross-sectional view of the embodiment 1000 of FIG. 8A along arrow GG. Referring to FIGS. 8A-8C, embodiment 1000 includes metal forms 1010 , 1020 such as but not limited to 20 gauge galvanized steel that has been cold-formed into a cross-sectional channel J-shape with integral U-shape. Each form 1010 , 1020 includes metal web portions 1012 , 1022 . Metal web portions 1012 , 1022 are perpendicular to flanges 1016 , 1026 which may include approximately four rows of V-shaped ridges 1017 , 1027 , or approximately four rows of semi-circular ridges 1038 , 1039 running longitudinally along the exterior of the flanges 1016 , 1026 . Lip portions 1018 , 1028 are perpendicular to flanges 1016 , 1026 . Integral U-shaped adhesive pockets are made up of portions 1030 , 1031 , 1032 , 1033 , 1034 , 1035 . Central web board 1050 can be OSB (oriented strand board), plywood, solid wood, plastic, fiber reinforced plastic, fiber reinforced cementitious material and the like, having thickness of approximately ⅜ to approximately ½ inch. Adhesive pocket portions 1030 , 1031 , 1032 , 1033 , 1034 , 1035 can be adhesively fastened to the central web board 1050 and metal tabs 1036 , 1037 , pressed from metal web portions 1012 , 1022 and adhesive pocket portions 1030 , 1032 , 1033 , 1035 protrude into central web board 1050 in such a way as to keep the central web board from withdrawing from the adhesive pockets. Alternatively, adhesive pocket portions 1030 , 1031 , 1032 , 1033 , 1034 , 1035 can be mechanically fastened to the central web board 1050 by screws, nails, rivets, pins and the like. A finished metal-wood stud 1000 can have a length, L10, of approximately 8 feet or longer, height H10 of approximately 3.5 to approximately 5.5 inches, and width W10 of approximately 1.5 inches. Metal web portions 1012 , 1022 can have a height, h11, of approximately 1.125 inches, lip height, h13, of approximately 0.75 inches, raised grooves height, h12, of approximately 0.0625 inches, raised grooves width, w12, of approximately 0.125 inches. A spacing, h14, of approximately 0.375 inches separates each flange 1016 , 1026 from the adhesive pocket portions 1031 , 1034 . Adhesive pocket portions 1031 , 1034 can have a width, w11, of approximately 0.375 to approximately 0.5 inches to match the thickness of central web board 1050 .
Metal-Wood Top and Bottom Track Adhesive Pocket Configuration
FIG. 9A is a top perspective view of an eigth preferred embodiment metal-wood top and bottom track 2000 . FIG. 9C is a bottom perspective view of metal-wood top and bottom track 2000 . FIG. 9B is a cross-sectional view of the embodiment 2000 of FIG. 9A along arrow HH. Referring to FIGS. 9A-9B, embodiment 2000 includes metal forms 2010 , 2020 such as but not limited to 20 gauge galvanized steel that has been cold-formed into a cross-sectional channel L-shape with integral U-shape. Each form 2010 , 2020 includes metal web portions 2012 , 2022 . Metal web portions 2012 , 1022 are perpendicular to flanges 2016 , 2026 . Integral U-shaped adhesive pockets are made up of portions 2030 , 2031 , 2032 , 2033 , 2034 , 2035 . Central web board 2050 can be OSB (oriented strand board), plywood, solid wood, plastic, fiber reinforced plastic, fiber reinforced cementitious material and the like, having thickness of approximately ⅜ to approximately ½ inch. Adhesive pocket portions 2030 , 2031 , 2032 , 2033 , 2034 , 2035 can be adhesively fastened to the central web board 2050 metal tabs 2036 , 2037 , pressed from metal web portions 2012 , 2022 and adhesive pocket portions 2030 , 2032 , 2033 , 2035 , protrude into central web board 2050 in such a way as to keep the central web board from withdrawing from the adhesive pockets. Alternatively, adhesive pocket portions 2030 , 2031 , 2032 , 2033 , 2034 , 2035 can be mechanically fastened to the central web board 2050 by screws, nails, rivets, pins and the like. A finished metal-wood track 2000 can have a length, L20, of approximately 8 feet or longer, height H20 of approximately 1.25 inches, and width W20 of approximately 3.5 to approximately 5.5 inches. Metal web portions 2012 , 2022 can have a width, w21, of approximately 1.125 inches. Adhesive pocket portions 2031 , 2034 can have a height, h21, of approximately 0.375 to approximately 0.5 inches to match the thickness of central web board 2050 .
Metal-Wood Stud P-shape Configuration
FIG. 10A is a perspective view of a ninth preferred embodiment metal-wood stud 3000 . FIG. 10B is a cross-sectional view of the embodiment 3000 of FIG. 10A along arrow II. Referring to FIGS. 10A-10B, embodiment 3000 includes metal forms 3010 , 3020 such as but not limited to 20 gauge galvanized steel that has been cold-formed into a cross-sectional channel P-shape. Each form 3010 , 3020 includes metal web portions 3012 , 3022 . Metal web portions 3012 , 3022 are perpendicular to flanges 3016 , 3026 which can include approximately four rows of V-shaped ridges 3017 , 3027 , or approximately four rows of semi-circular ridges 3038 , 3039 (as shown in FIG. 10C) running longitudinally along the exterior of the flanges 3016 , 3026 . Lip portions 3018 , 3028 are perpendicular to flanges 3016 , 3026 . Lip returns 3030 , 3031 are perpendicular to lips 3018 , 3028 and parallel to flanges 3016 , 3026 and abut against central web board 3050 inhibiting the central web board 3050 from loosening from the metal web portions 3012 , 3022 . Central web board 3050 can be OSB(oriented strand board), plywood, solid wood, plastic, fiber reinforced plastic, fiber reinforced cementious material and the like, having a thickness of approximately ⅜ to approximately ½ inch. A finished metal-wood stud 3000 can have a length, L30 of approximately 8 feet or longer, height H30 of approximately 3.5 to approximately 5.5 inches, and width W30 of approximately 1.5 inches. Metal web portions 3012 , 3022 can have a height, h31 of approximately 1.125 inches, lip height h2, of approximately 0.5 inches, raised grooves height h33 of approximately 0.0625 inches, raised grooves width, w31, of approximately 0.125 inches. A spacing, h34 of approximately 0.125 inches separates each flange 3016 , 3026 from the central web board 3050 .
While the invention has been described, disclosed, illustrated and shown in various terms of certain embodiments or modifications which it has presumed in practice, the scope of the invention is not intended to be, nor should it be deemed to be, limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended.
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Metal and wood composites are used to create framing members (studs and tracks, joists and bands, rafters, headers and the like), for lightweight construction. Metal is utilized for its high strength, resistance to rot and insects, cost stability, and potentially lower cost through recycling. Metal that can be used includes roll formed steel approximately 18-22 gauge. Wood is used primarily for its lower thermal conductivity, and availability. The metal components form the primary structure while wood, either solid or other engineered wood, provides some structure and a thermal break. A central web board can have a length of approximately 8 feet or longer with metal forms running along each of the longitudinal side edges of the board. A first embodiment metal-wood stud member has adhesive pocket end configurations. A second embodiment is a metal-wood top and bottom track having an adhesive pocket configuration. A third embodiment is a metal-wood stud having P-shape end configurations. The wood is fastened to the metal by machine pressing of the metal to wood. Alternatively the fastening includes nails, staples, screws, and the like, and also by adhesive glue. The outward faces of the metal members can be preformed with four longitudinal v-shaped or rounded edge ridges such that the contact surface area to applied sheathings is reduced by about 90%.
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FIELD OF THE INVENTION
This invention generally relates to hand coverings. More particularly, the present invention relates to an improved hand covering which is well fitting and which may be employed individually, (i.e. as a stand alone hand covering) or in combination with a glove shell as either a liner or insert.
BACKGROUND OF THE INVENTION
Historically, the making of hand coverings, such as gloves, glove liners or glove inserts, has required the use of skilled labor to manufacture and seam together various complicated uneven panels of patterns to provide a comfortable fit. Presently, most glove patterns, and patterns used to make glove liners and glove inserts, do not lend themselves well, if at all, to automatic seaming methods. Additionally, those patterns which can easily be automatically seamed do not provide a comfortable fit in all of the portions of the glove, liner or insert. Among the various glove patterns presently in use are the Clute Cut Pattern, the Gunn Cut Pattern, the Fourchette or Montpelier Pattern and the Flat Pattern.
The Clute Cut Pattern provides roominess in the finger for good fit by wrapping material around the back or dorsal part of the finger. The front, or palmar panel of the ringer, is cut to a width that approximates the width of the finger plus desired clearances. The back, or dorsal panel of the finger, must be cut to a width that approximates the finger width, as well as two thicknesses of the finger plus desired clearances. The discrepancy in the widths of the dorsal ringer panel and the palmar finger panel requires that the edges of the dorsal panel be carefully placed together with the edges of the palmar finger panel when it is sewn to the palmar finger panel. This alignment of the edges precludes automatic seaming of the finger panels and necessitates the use of skilled labor in assembling the hand covering, which of course, increases the attendant manufacturing cost of such a hand covering.
The Gunn Cut Pattern provides roominess in the finger for good fit by wrapping material around the front of the finger, rather than the back of the finger, as is done in the Clute Cut Pattern. The Gunn Cut Pattern suffers from similar problems in assembly as the Clute Cut Pattern. Similarly, the attendant manufacturing costs of a hand covering made from such a pattern are increased.
In the Fourchette or Montpelier Pattern, roominess in the finger for good fit is provided by material being equally divided between the palm, back and sides of the fingers. This pattern has many panels which must be seamed together to form the hand covering. As with the Clute Cut Pattern and the Gunn Pattern, a Fourchette or Montpelier Pattern hand covering is costly to produce and may not be manufactured by seaming in-the-flat.
The Flat Pattern incorporates palmar and dorsal panels which are the same size. Flat Pattern hand coverings are seamed together "in-the-flat". The front and back panels of the Flat Pattern are each single whole pieces and are generally mirror images of one another. The disadvantage of this Flat Pattern is that it compromises the fit of the hand covering. The quality of a fit achievable by the Flat Pattern is limited by the fact that each half finger portion must have a width at its base and throughout its length that approximates half of the circumference of the finger, plus desired clearance and seam widths, in order to properly fit the finger. Thus, the sum of the widths of each panel at the base of each finger approximates half of the sum of the circumference of each finger, plus desired clearances and eight seam widths, whereas the width of material required to cover the palm of the hand at the base of the fingers is only approximately half of the circumference of the palm, plus desired clearances and two seam widths. Therefore, if the Flat Pattern is used, the sum of the widths of each panel at the base of the fingers includes much more material than is required to enclose the palm and back of the hand. This additional material gathers in the palm or back of the hand covering.
From the foregoing, it should be readily apparent that, although a Flat Pattern hand covering may be easily seamed in-the-flat, (i.e. the Flat Pattern allows for automatic seaming, thereby reducing manufacturing costs) the fit of a hand covering made from this pattern must be compromised by either having the palm fit too loosely, if the fingers fit properly, or by having the fingers fit too tightly, if the palm fits properly.
In any of the hand covering constructions described above, it is sometimes desirable to provide a waterproof insert member or liner to protect the wearer's hand against moisture. Also, it may be desirable to provide a liner which is suitable for protecting a wearer from contact with noxious chemical agents, noxious gases or any other foreign irritants to the human body. Generally, very thin materials are used to fabricate such a liner so as to keep the bulk and stiffness of the liner and the overall glove to a minimum. Rubber and polymer-dipped waterproof liners are not generally acceptable, as they are too stiff, or bulky or have pinholes and/or thin spots, and as such, adversely affect the dexterity, mobility and/or durability of the entire glove assembly.
Materials suitable for waterproof liners presently used in glove constructions include relatively inelastic thin, pliable materials such as a breathable microporous expanded polytetrafiuoroethylene and other suitable breathable and non-breathable films. Other microporous and non-microporous films having similar characteristics are also suitable for liners, either alone or as a laminated construction bonded to other materials, for example, thin stretch nylon fabric. In assembling these materials into a liner, they are heat sealed, adhesively bonded, glued, or the seams are sealed with waterproof tapes. Stitching is generally avoided, as it produces holes in the material which requires further sealing.
Waterproof/breathable liners can be used either alone with an outer glove shell, or in combination with additional insulation to make an insulated and waterproof glove. In the latter construction, the liner is disposed between the outer shell and the inner insulation liner. In all situations, it is necessary that the liner have sufficient size so as not to adversely affect the dexterity, mobility and tactility of the total glove system. Bending of the wearer's hand within the glove requires that the liner, as well as the other parts of the glove, have sufficient length so as to accommodate the bending of the fingers at the knuckle joints without binding of the layers during such movement of the hand.
Although glove systems incorporating inserts or liners made from a Flat Pattern are less costly to manufacture, (i.e., the liners can be completely manufactured by utilizing an automated seam sealingly process thereby significantly reducing the amount of process steps and labor required to produce the liner) such glove systems are often difficult to don. More particularly, in glove systems incorporating Flat Pattern liners, often the excess liner material gathers in horizontal folds in the palm and dorsal region in a fashion which occludes the passageways which lead to the finger portions of the glove shell. Therefore, when a wearer attempts to don such a glove, his fingers become jammed, or otherwise become entangled within this excess liner material causing great discomfort and frustration to the wearer.
In the past, various attempts have been made to overcome this shortcoming. These attempts have included the application of an adhesive material between the insert, or liner, and the outer glove shell. The adhesive material is applied in a fashion to prevent the excess liner material from occluding the finger passageways. Although this type of solution has achieved varying degrees of success, it suffers from many shortcomings which detract from its usefulness. For example, the process of applying the adhesive material is difficult to control. An excess application of adhesive renders the hand covering too stiff or rigid. An insufficient application of adhesive does not permanently solve the initial problem.
Another disadvantage of a Flat Pattern hand covering made from relatively inelastic materials, is that generally, such a hand covering cannot be used in a stand alone application (e.g., a clean room glove). A Flat Pattern stand alone hand covering is aesthetically unappealing and is functionally ineffective, i.e., the excess material of the palm or dorsal portions can reduce the wearer's gripping ability.
In the electronics and pharmaceutical industries, requirements for contamination control in clean room environments have become more and more demanding. Contamination can result from air-borne particles of submicron size or from material transfer from one surface to another. One source of contamination is from the clean room personnel and their associated clothing. Therefore, on-going efforts exist in developing clothing articles, including gloves, that enhance contamination control. Contamination control is provided by a glove when:
1. The glove prevents particles, or other undesired materials from the hand, to pass from the hand to the outside of the glove;
2. The glove can be rendered free of contamination before used by the wearer; and
3. The glove does not, during use, abrade or otherwise break down, and subsequently become a source of contamination.
Workers in a clean room perform numerous operations while wearing gloves. Throughout the day, they must be able to perform these operations reliably and with minimum hindrance by their gloves. They must be able to handle objects, and move their hands and fingers, both freely and delicately. Therefore, desirable glove characteristics, from the wearer's consideration, are as follows:
1. Form-fitting--A glove should be form-fitting, and contoured to the shape of the hand, neither having an undesirable excess and/or a bunching of the material, nor intense tightening upon the hand.
2. Touch--Touch is defined as the array of sensations arising from the pressure sensitivity of the skin. Therefore, desirably the glove should not impair touch or tactility (i.e. the sense of touch) while picking up and handling objects.
3. Dexterity--Dexterity is the skill in using one's hands. A clean room glove should allow for great dexterity.
4. Comfort--The glove should be comfortable during use, it is undesirable to have either an accumulation of sweat inside the glove or have the hand in intimate contact with something that feels "plastic or rubbery."
Thus, taken collectively, the desired clean room glove:
1. provides contamination control;
2. provides a functional design (i.e.--form-fitting, with good touch and dexterity characteristics); and
3. provides comfort to a wearer.
Flat Pattern hand coverings made from relatively inelastic materials have not heretofore been employed in stand alone applications, such as a clean room glove, due to the limitations of fit which have been described hereinabove. It would be desirable to make such a Flat Pattern hand covering because such a hand covering would be significantly less costly to manufacture than a clean room glove made from other type patterns.
The foregoing illustrates limitations known to exist in present hand coverings. Thus, it is apparent that it would be advantageous to provide an improved hand covering directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.
SUMMARY OF THE INVENTION
The present invention is a distinct advancement in the art of hand coverings, and the techniques for their manufacture. In one embodiment of the present invention, an improved hand covering is provided which is defined by mating first and second hand shaped portions seamed one to each other to form a complete hand covering. The hand covering defines at least one finger stall, a thumb stall, a palm portion, a dorsal portion, and at least one finger crotch. At least one vertical fold is permanently defined in the hand covering. The at least one vertical fold is oriented parallel to the at least one finger stall. The at least one vertical fold reduces an original palm circumferential dimension of the hand covering in an amount from about 10% to about 50%.
It is, therefore, a purpose of the present invention to provide a relatively inelastic insert for a glove system which may be completely and automatically produced in the fiat.
It is another purpose of the present invention to provide a relatively inelastic Flat Pattern hand covering which is functional and comfortable.
It is another purpose of the present invention to provide a Flat Pattern hand covering, made from a relatively inelastic material, which may be used in various stand alone applications, such as but not limited to a clean room glove, for example.
The foregoing and other aspects will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a glove system comprising a glove shell and an insert.
FIG. 2 is a plan view of a Flat Pattern used to make a hand covering in accordance with the teachings herein.
FIG. 3 is a view of the glove system of FIG. 1 in a flexed or slightly curled position.
FIG. 3A is a sectional view of a glove system of FIG. 3, taken along line A--A, and illustrating a glove system with a conventional Flat Pattern insert, which is disposed such that it occludes the finger passageways of the glove shell.
FIG. 4 is a plan view of a Flat Pattern hand covering having disposed within its interior an orienting assembly. An arrow represents a force applied to the hand covering against the orienting assembly. This force creates at least one vertical fold oriented substantially parallel to at least one finger portion of the hand covering.
FIG. 5A is a plan view (palm side up) of a hand covering made in accordance with the present invention.
FIG. 5B is a plan view (dorsal side up) of the hand covering of FIG. 5A.
FIG. 6 is a sectional view of a glove system of FIG. 3, taken along line A--A, and illustrating a glove system with a Flat Pattern insert of the present invention, which does not occlude the finger passageways of the glove shell.
FIG. 7A is a plan view (palm side up) of an alternate embodiment of the hand covering of the present invention.
FIG. 7B is a plan view (dorsal side up) of the hand covering of FIG. 7A.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, wherein similar reference characters designate corresponding parts throughout the several views, FIG. 1 illustrates generally at 10 a glove system. As used herein, a "glove system" means at least an outer glove shell 12 and an insert or hand covering 14, which is illustrated individually in FIGS. 5A, 5B, 7A, and 7B. The glove system also may optionally include insulation and/or an inner lining, (not shown).
The outer glove shell may be produced from any suitable material, such as but not limited to knit, woven or nonwoven materials, leather, composite fabrics or any other suitable material. The outer glove shell may be patterned in accordance with any suitable pattern, such as but not limited to, the Clute Cut Pattern, Gunn Cut Pattern or the Fourchette Pattern, for example. As best seen by reference to FIGS. 1 and 3, the glove system 10 may include any of the following: a palm portion 16, a dorsal portion 17, finger stalls or passageways 18, 20, 22 and 24, a thumb stall or passageway 26, a gauntlet 28, or an opening 30 facing inwardly of the wearer. Although the glove system 10 is illustrated as a conventional glove system, in the sense that it includes an individual finger stall for each finger of a human hand and a thumb stall, the teachings of the present invention may be applied to other glove systems having less than four finger stalls, but at least one. Additionally, the glove system 10 may be provided with an elastically yielding area (not shown) proximate a wrist portion 32 to provide close contact of the glove system to a wearer's wrist.
FIG. 3 is a view of a glove system 10 in a flexed or slightly curled position. As seen therein, horizontal folds 34 are formed in the palm region 16. These horizontal folds also form in the dorsal portion 17. In glove systems incorporating conventional Flat Pattern inserts made from relatively inelastic materials, excess insert material gathers in the horizontal folds 34 in a fashion which occludes the finger stalls 18, 20, 22 and 24 of the glove shell 12. This is best seen by reference to FIG. 3A. In the conventional glove system of FIG. 3A, frequently, a wearer's fingers become entangled within the excess material, which makes the donning of such a glove system a frustrating and cumbersome experience.
As should be understood, the insert or hand covering 14 may be made from any material which is desirable for a particular application. Also, the insert or hand covering may be incorporated as an integral element of a glove system 10, or may be employed in a stand alone application. When used as an integral element of a glove system, the insert 14 is conformably dimensioned to be insertably received by a respective glove shell 12.
For purposes of example only, and without intending to limit the scope of the present invention, described hereinafter is a waterproof insert material, a material suitable for a stand alone clean room hand covering, and an insert material suitable for use in glove systems for protecting a wearer from noxious gases.
A material suitable for making a waterproof insert for a glove system may be made of a laminate comprising a membrane of an expanded polytetrafluoroethylene (ePTFE) upon which a 1.8 oz./sq. yd. polyester brush knit is bonded to a first membrane side and a 0.5 oz./sq. yd. nylon nonwoven material is bonded to a second membrane side. The ePTFE membrane is comprised of nodes interconnected by fibrils. Such a membrane may be made in accordance with the teachings of U.S. Pat. No. 4,187,390 or U.S. Pat. No. 3,953,566 which are incorporated herein by reference. In general, the ePTFE membrane will be from about 1 to about 4 mils thick. The polyester brush knit will be next to a wearer's skin in an assembled glove system and the nylon nonwoven material will be applied on an exterior insert surface.
An insert material suitable for use in a glove system for protecting a user from noxious gases is described in detail in U.S. Pat. No. 5,391,426, which is incorporated herein by reference. Briefly, such an insert material may comprise at least the following sequence of layers:
(a) a first pliable porous substrate of porous polytetrafluoroethylene (PTFE) having a thickness of from about 1 to about 2 mils,
(b) a gas-blocking water-vapor-permeable polymeric coating (crosslinked polyethyleneimine), and
(c) a second pliable porous substrate of porous PTFE having a thickness of from about 1 to about 2 mils.
Such a composite insert material may be combined with backing fabrics and/or facing fabrics. These backing or facing fabrics may be any material, such as woven or nonwoven textiles, or knits. These fabrics can be treated with water and oil repellents or with the gas-blocking polymer, or with both. Fluoroacrylate water repellents are one preferred class of coating on the fabric. Representative fluoroacrylates are available from companies such as E. I. DuPont de Nemours and Co. (Zonyl® compositions) or ICI Co. (Milease® compositions).
A material which may be suitable for use in producing a stand alone clean room glove, made in accordance with the teachings of the present invention, comprises at least:
(a) a microporous polymeric membrane having a thickness of less than about 4 mils,
(b) a water vapor-permeable polymer, and
(c) an elastomeric thermoplastic fibrous nonwoven web in which the fibers are elastomeric and are less than 50 microns in diameter.
Such a material is described in detail in U.S. Pat. No. 5,036,551, which is incorporated herein by reference.
FIG. 2 is a pattern 36 for sizing blanks to be assembled into a hand covering in accordance with the teachings herein. Pattern 36 is a Flat Pattern type. Pattern 36 defines half-finger portions 38, 39, 40 and 41, and a half thumb portion 42. The half-finger portions and the half thumb portion define a sufficient length to enclose the finger it is designed to fit. The half finger portions are generally symmetrical. A peripheral edge 43 forms three V-shaped finger crotches 45, 46 and 47.
An insert 14 for the glove system 10 is made by initially cutting two pattern pieces, or blanks, from the pattern 36. The blanks are positioned in a flat superimposed relationship, one to each other, and are joined or seamed along the peripheral edge 43. The blanks may be seamed by any suitable method, such as by adhesive bonding, welding, heat sealing, ultrasonic sealing, or RF sealing, for example. After the blanks have been seamed to form a flat pattern insert 14, at least one vertical fold is defined in the insert 14 such that the at least one vertical fold is oriented substantially parallel to at least one finger stall of the insert. Preferably, a plurality of vertical folds are formed in the insert. The vertical folds may be formed by any suitable method. One such method may include "pinching" the insert material at predetermined locations. This method is time consuming.
Another method of forming vertical folds includes pulling an insert or hand covering 14 against a suitable apparatus. Preferably, an orienting assembly 50 may be employed to establish at least one vertical fold in the insert or hand covering. Referring to FIG. 4, the orienting assembly 50 may comprise a flat main body formed of a resilient material which may define a thumb portion and at least one finger portion. The orienting assembly is dimensioned to be insertably received by the insert or hand covering 14. In a preferred embodiment, the orienting assembly defines a thumb portion and four finger portions. The thumb and finger portions are each formed to be insertably received by the thumb stall 26 and a respective finger stall 18, 20, 22 and 24. The orienting assembly is shaped such that it may be compressed or squeezed upon insertion into the insert or hand covering 14. Upon insertion, the resilient orienting assembly is permitted to decompress, and at such time, the orienting assembly fills the interior of the insert 14, in much the same manner as a human hand. When properly inserted, the orienting assembly extends from the finger stalls, through the palm portion 16 and out the opening 30. Thereafter, the insert 14 is pulled against the orienting assembly 50 in a direction generally indicated by the arrow 52. This force creates at least one vertical fold 54. Typically, this force creates a plurality of vertical folds, which each serves to gather excess insert material in the palm portion 16 and the dorsal portion 17. Generally, these vertical folds originate from the finger crotches 45, 46, and 47 and extend through a predetermined length of the insert. The vertical folds 54 generally are oriented parallel to the finger stalls 18, 20, 22 and 24.
After at least one vertical fold has been formed in the insert or hand covering, a means is employed to permanently define the at least one vertical fold. For the purpose of example only, the at least one vertical fold, or the plurality of vertical folds, may be permanently defined by any suitable method, such as by adhesive bonding, welding, heat sealing, ultrasonic sealing, or RF sealing. Alternatively, a length of tape may be employed individually, or in combination with any of the foregoing. As used herein, the term "tape" means a narrow strip of a kit, woven, nonwoven or polymeric material, with or without a bonding substance disposed thereupon. A suitable permanent vertical fold defining means is applied to the insert or hand covering 14 at predetermined locations. Preferably, the permanent vertical defining means is applied to the insert at either the palm portion or the dorsal portion. Most preferably, the means 56 for permanently defining the vertical folds 54 is applied to both the palm portion 16 and the dorsal portion 17.
As should be understood, in a case where a vertical fold defining means is to be applied to both the palm and the dorsal portion of an insert, any combination of the foregoing may be employed. For example, adhesive bonding may be employed to permanently define vertical folds in the palm portion, and a length of tape may be employed to permanently define folds in the dorsal portion. After a desired permanent vertical fold defining means has been applied to the insert, the excess insert material, which previously existed in the palm and dorsal portions, is permanently gathered, such that the insert conformably fits a suitable human hand, unlike a conventional Flat Pattern insert made from relatively inelastic material.
As should be understood, if the insert of the present invention is used as an element of a glove system 10, the insert will not occlude the finger stalls 18, 20, 22 and 24, as best seen by reference to FIG. 6.
In a preferred embodiment of the present invention, the permanent vertical fold defining means is a strip of tape having disposed thereupon a suitable permanent bonding material. Such a strip of tape may include, but is not limited to, heat sealable tapes, heat sealable urethane tapes, heat sealable PVC tapes, or pressure sensitive tapes. The strip of tape may be from about 1/4" to about 1 1/2" wide. As best seen by reference to FIGS. 5A, 5B, 7A and 7B, the strip of tape may extend across the palm and dorsal portions, short of the peripheral edge 43. Typically, a length of about 4 1/2" is a suitable length to perform in accordance with the teachings herein, although the actual length will depend upon the relative size of the insert or hand covering 14. Also, preferably, the strip of tape is positioned in the palm and dorsal portions at a location slightly below the finger crotches 45, 46 and 47 and generally laterally aligned with the thumb crotch.
If the insert 14 is to be used within a glove system 10, the tape 56 may be applied to an exterior insert surface, as best seen by reference to FIGS. 5A and 5B. Alternatively, if the insert is to be used as a hand covering for a stand alone application, the tape is first applied as described hereinabove, and then the insert 14 is reversed, i.e., the insert is pulled inside out such that the tape is disposed interiorly of the insert, as best seen by reference to FIGS. 7A and 7B.
In a most preferred embodiment of the present invention, the permanent vertical fold defining means is a two layer heat sealable urethane tape, which is commercially available from W. L. Gore & Associates, Inc. under the tradename GORE-SEAM™. Such tape is comprised of an expanded polytetrafluoroethylene bonded to a layer of hot-melt urethane adhesive.
Without intending to limit the scope of the present invention, the present invention may be better understood by referring to the following example:
EXAMPLE 1
A breathable waterproof insert material was provided which was defined by a laminate which included a membrane of ePTFE having opposed first and second sides. A 1.8 oz./sq. yd. polyester brush knit was bonded to a first membrane side, and a 0.5 oz./sq. yd. nylon nonwoven material was bonded to a second membrane side. A hand covering was made by cutting suitable blanks and seaming the blanks by adhesively bonding the blanks as described hereinabove. The orienting assembly was then inserted into the hand covering and a plurality of vertical folds were established by pulling the hand covering against orienting assembly. A strip of GORE-SEAM™ tape 7/8" wide by 4 1/2" in length was placed perpendicularly across the vertical folds at a location slightly below the finger crotches on both the palm and dorsal portions of the insert. The hand covering and tapes were then placed under a heated press at a temperature of between 250° F. to about 350° F. A pressing force of about 2 pounds per square inch was applied to the hand covering and tape for a dwell time of from about 2 to about 4 seconds. Thereafter, the hand covering was removed from the press. The resultant hand covering had a palm circumference which was sized relative to a palm circumference of a human hand.
EXAMPLE 2
An insert material was provided which was defined by a laminate which included:
(a) a first pliable substrate of porous polytetrafluoroethylene PTFE,
(b) a gas-blocking water-vapor-permeable polymeric coating (crosslinked polyethyleneimine), and
(c) a second pliable substrate of porous PTFE.
The thickness of this laminate was less than about 4 mils. Bonded to a first laminate side was a 1.8 oz./sq. yd. Nomex® jersey knit. Bonded to a second laminate side was a 0.5 oz./sq. yd. nylon nonwoven material. A hand covering was made by cutting suitable blanks and seaming the blanks by adhesively bonding the blanks as described hereinabove. The orienting assembly was then inserted into the hand covering and a plurality of vertical folds were established by pulling the hand covering against orienting assembly. A strip of GORE-SEAM™ tape 7/8" wide by 4 1/2" in length was placed perpendicularly across the vertical folds at a location slightly below the finger crotches on both the palm and dorsal portions of the insert. The hand covering and tapes were then placed under a heated press at a temperature of between 250° F. to about 350° F. A pressing force of about 2 pounds per square inch was applied to the hand covering and tape for a dwell time of from about 2 to about 4 seconds. Thereafter, the hand covering was removed from the press. The resultant hand covering had a palm circumference which was sized relative to a palm circumference of a human hand.
Resultant hand coverings made in accordance with the teachings herein may have a palm circumference which has been reduced anywhere from 10% to 50% the original dimensions of the palm circumference.
Although a few exemplary embodiments of the present invention have been described in detail above, those skilled in the art readily appreciate that many modifications are possible without materially departing from the novel teachings and advantages which are described herein. Accordingly, all such modifications are intended to be included within the scope of the present invention, as defined by the following claims.
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An improved hand covering is provided which is defined by mating first and second hand shaped portions seamed one to each other to form a complete hand covering. Permanent vertical folds are formed in the hand covering. The vertical folds are oriented parallel to finger stalls of the hand covering. The vertical folds reduce an original palm circumferential dimension of the hand covering in an amount from about 10% to about 50%.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to carts for transporting furniture articles such as chairs, loveseats and sofas and which ca also be used as a display rack.
2. Description of the Prior Art and Objectives of the Invention
Hand trucks and carts have long been used in the wholesale and retail furniture businesses to transport furniture in warehouses and display rooms and throughout furniture stores. Store owners know that by offering customers a greater selection of furniture sales will increase as will profits. One fixed cost for most retail furniture stores is the rental of floor space. Consequently, large items such as sofas and loveseats require extended floor space for adequate displaying thus raising the consumer's cost and reducing the owner's profit per unit of furniture shown. Certain store owners in the past have used racks which are mounted on walls or which are freestanding to provide "stackable" displaying. Because of the permanent nature of conventional furniture racks and their lack of versatility and also due to the somewhat unrealistic presentation of furniture, store owners and potential customers have not been entirely pleased with the results. Thus, with the need of store owners to reduce their overhead cost per unit of furniture shown and with the need for a realistic, natural display or presentation to the customer, the present invention was conceived and one of its objectives is to provide a cart which can be rolled by a single worker to a specific location within a display area, and upon which two or more furniture pieces can be placed and displayed in vertical or "stacked" fashion.
It is another objective of the present invention to provide a display cart which will allow the displayed furniture to substantially hide the cart thus providing a more realistic appearance for the customer.
It is still another objective of the present invention to provide a display cart which can be moved within the display area with furniture thereon and which can be nested for storage purposes.
It is also an objective of the present invention to provide a display rack with adjustable frames which can be moved vertically to accommodate a variety of furniture having different dimensions.
It is yet still another objective of the present invention to provide a display rack which is relatively inexpensive to manufacture and economical to purchase for the store owner yet which will effectively increase the store display area thereby reducing the overhead cost per furniture unit displayed.
SUMMARY OF THE INVENTION
The aforesaid and other objectives are realized by a multi-tiered display cart which can be moved by a single employee as a result of a plurality of casters affixed thereto. The display cart can be used for three separate pieces of furniture and includes a base frame which is somewhat wedge-shaped and is mounted to a pair of rear vertical stanchions. An upper frame is affixed to a pair of stanchion sleeves which are slidably positioned on the stanchions and can be adjustably positioned therealong. Stanchion pins allow the upper frame to be "locked" at a suitable height above for example a chair or sofa which may be displayed on the base frame. A top frame is attached to a pair of stanchion inserts which are slidably received into the top ends of the stanchions and stanchion locking pins also maintain the top frame at a desired height. Top frame is angularly disposed relative to the stanchion inserts so a customer or others may view furniture which is positioned on the top frame fully while standing in front of the cart as said furniture is tilted towards the viewer. The display cart of invention is designed so it can be nested with similar carts for compact storage when not in use.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective view of the display cart of the invention;
FIG. 2 is a front perspective view of the cart as shown in FIG. 1 but with furniture positioned thereon;
FIG. 3 is the side elevational view of the cart as shown in FIG. 1;
FIG. 4 is a rear elevational view of the cart;
FIG. 5 demonstrates a view of several of the carts of the invention in nestled storage; and
FIG. 6 is an enlarged top plan view of a section of the top frame showing the furniture retainers.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred form of the invention is shown in FIG. 1 which demonstrates a three tier furniture display cart and rack having upper and top frames adjustably movable along rear vertical stanchions. The lower or base frame is affixed to the stanchions and includes a plurality of casters for moving the cart with or without furniture thereon. The top frame being angularly disposed relative to the vertical stanchions includes restraints at the forward end thereof which can be rotated upwardly to prevent items positioned on the top frame from sliding. The frames of the preferred embodiment are formed from channel steel for durability. The upper frame is joined to a pair of stanchion sleeves which provides adjustability along the stanchions and stanchion locking pins secure the sleeves at any desired location. The top frame is affixed to a pair of stanchion inserts which are positionable and telescope within the stanchions and stanchion locking pins likewise are employed to hold the top frame at the desired height. The rear width of the display cart is approximately 30 inches and the front width is approximately 13 inches. The depth of the frames are approximately 33 inches with an overall height adjustable from approximately 51/2 feet to 8 feet when the top frame insert is fully extended. As earlier mentioned the display carts of the invention can be nestled for compact and convenient storage when not in use.
DETAILED DESCRIPTION OF THE DRAWINGS AND OPERATION OF THE INVENTION
Turning now to the drawings, FIG. 1 demonstrates a three tier furniture cart 10, which when not in use, may be conveniently stored in a nestled configuration as shown in FIG. 5. Display cart 10 includes base frame 11, upper frame 12 and top frame 13. All three frames are joined to and supported by rear stanchions 14 and are capable of holding relatively large pieces of furniture such as sofas, loveseats, chairs and the like for display purposes as further shown in FIG. 2.
Base frame 11 is affixed to four casters 15 which will allow a single employee to roll cart 10 in a warehouse or display showroom as needed with minimal effort. As seen in FIG. 1 base support 16 is attached to stanchions 14 and is positioned vertically above base frame 11 as shown in FIG. 4 thereby allowing carts 10 to nest as earlier mentioned. Stanchion gussets 17 as shown in FIG. 4 are disposed at a forward angle on rear caster plates 18 as seen in FIG. 3. The angular disposition of gussets 17 provide additional strength and rigidity for stanchions 14 when sofas or other large furniture items are displayed on upper frame 12 and top frame 13. Front caster plate 19 spans base frame 11 and is rigidly joined thereto.
As illustrated in FIG. 2, display cart 10 is practically invisible and provides a substantially realistic furniture presentation for the purchasing public. The overhang of conventional furniture "skirts" substantially conceals frames 11, 12 and 13 upon which the furniture is placed and the back of the furniture substantially conceals stanchions 14 and stanchion inserts 23. In addition, a practical floor display is provided demonstrating a chair with end tables in a pleasing natural setting.
The adjustable features of display cart 10 can be understood from FIG. 3 whereby upper frame 12 is affixed to a pair of stanchion sleeves 20 which are slidable over stanchions 14. Stanchions 14 define a series of lower apertures 21 through which locking pins 22 are positionable. Thus, sleeves 20 are placed over stanchions 14 and are raised or lowered as required. Once the bottoms of sleeves 20 are at a desired height along stanchion 14, pins 22 are inserted in desired apertures 21 and sleeves 20 then rest thereon. Pins 22 can be removed as desired and upper frame 12 can be further raised or lowered as needed.
Top frame 13 is likewise adjustable along stanchions 14 in that stanchion inserts 23 may be for example 36 inches in length and may have an outside diameter of 11/2 inches with insert apertures 24 spaced at 2 inch increments therealong. Apertures 24 may be for example 5/8 inch in diameter as are apertures 21 in stanchions 14. Stanchions 14 may have an outside diameter of approximately 2 inches with stanchion sleeves 20 having an inside diameter slightly larger than 2 inches to slidably move therealong. The inside diameters of stanchions 14 are slightly greater than 11/2 inches whereby stanchion inserts 23 are slidable therein and as would be understood, stanchion inserts 23 can be raised or lowered as required. With stanchion pins 22 inserted into apertures 24, top frame 13 is then "locked" at a suitable height.
As further shown in FIG. 3, top frame 13 is angularly disposed to insert 23 and stanchion 14 in order for a customer to better view furniture which is positioned thereon. As would be understood, top frame 13 may be positioned for example 7 feet from the floor and thus a customer of normal height would have difficulty in seeing the furniture thus displayed at a close range. The angular disposition of top frame 13 which may be for example a 30 degree angle from the horizon will provide a good view of the furniture displayed. Also, top frame 13 includes a pair of pivotal retainers 25 which can be raised as shown in FIG. 3 to prevent heavy furniture items such as sofas from sliding along top frame 13. Pivotal retainers 25 are mounted on rotatable retainer axles 26 as shown in FIG. 6 and may be manually raised by rotation as required. Display cart 10 can be formed rom steel or other suitable materials.
Base support 16 in FIG. 4 is shown above base frame 11 and upper support 27 is seen vertically above upper frame 12 and upper support 27 is mounted on and affixed between stanchion sleeves 20. Top support 28 is also shown in FIG. 4 vertically above top frame 13. As explained earlier this particular configuration of the supports above the relative frames and with the frames being substantially wider at the rear than at the front allows for nesting of the display carts 10 as earlier mentioned.
The illustrations and examples provided herein are for explanatory purposes and the invention can be modified for example by having additional frames attached to stanchions 14 for display of more furniture items. Thus, the particular structures shown are for explanatory purposes and are not intended to limit the invention beyond the scope of the appended claims.
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A furniture display cart is provided which allows vertical placement of furniture and display items to maximize warehouse or showroom capacity. The utilization of carts having vertical adjustable frames for three or more furniture items transforms a relatively small floor space into a much effectively larger space thus utilizing the area to its maximum potential. The cart is movable and can be nestled for storage purposes when not in use.
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BACKGROUND OF THE INVENTION
The present invention relates to an improved thermosensitive recording material, and more particularly to a thermosensitive recording material comprising a support material and a thermosensitive coloring layer formed on the support material, which thermosensitive coloring layer comprises a colorless or light-colored coloring material and a developing material, which developing material contains at least two particular bisphenol derivatives, capable of coloring the coloring material upon application of heat thereto.
Recently, thermosensitive recording materials have been employed in a variety of fields, for instance, for use with printers of computers, recorders of medical analytical instruments, facsimile apparatus, automatic ticket vending apparatus, and thermosensitive copying apparatus, since they have the following advantages over other recording materials: (1) Images can be formed by simple heat application, without any complicated steps for development; (2) the thermosensitive recording materials can be produced by a simple apparatus and the storage of the thermosensitive recording materials is simple and does not involve excessive costs; (3) as the support material of the thermosensitive recording materials, paper is usually used, which is rather inexpensive in comparison with other support materials, such as synthetic resin films; and (4) when paper is used as the support material, the thermosensitive recording material has a pleasing plain-paper-like touch.
A conventional thermosensitive recording material is produced by coating a support material (for instance, a sheet of paper or a synthetic resin film) with a thermosensitive coloring liquid containing a coloring component and a color developing component which can be colored when heated, and then by drying the coloring liquid to form a thermosensitive coloring layer.
Images are formed and recorded in the thus produced thermosensitive recording material by heat application by use of a thermal pen or head.
Thermosensitive recording materials of the above-described type are disclosed, for instance, in Japanese Patent Publications No. 43-4160 and No. 45-14039.
The conventional thermosensitive recording materials have the shortcomings that they are slow in thermal response, not allowing rapid recording with high image density and high image sharpness.
In order to increase the thermal coloring sensitivity of these thermosensitive recording materials, there have been proposed methods in which a particular thermo-fusible material is added to the thermosensitive coloring layer, thereby attaining high thermal coloring sensitivity and allowing rapid recording with high image density and high image sharpness.
Examples of such thermo-fusible materials are disclosed, for instance, in the following Japanese laid-open patent applications: nitrogen-containing compounds, such as acetamide, stearamide, m-nitroaniline, and phthalic acid dinitrile in Japanese Laid-open Patent Application No. 49-38424; acetoacetanilide in Japanese Laid-Open Patent Application No. 52-106746; N,N-diphenylamine derivatives, benzamide derivatives and carbazole derivatives in Japanese Laid-open Patent Application No. 53-11036; alkylated biphenyls and biphenyl alkanes in Japanese Laid-Open Patent Application No. 53-39139. In Japanese Laid-Open Patent Application No. 56-144193, there are disclosed p-hydroxybenzoic acid ester derivatives which serve as thermo-fusible materials and as color developing materials.
Of the above compounds, p-hydroxy benzoic acid ester derivatives have been considered to be the best to be used as color developer in the thermosensitive coloring layer of the thermosensitive recording materials.
However, the method of using p-hydroxybenzoic acid derivatives still has the shortcomings that the recorded images fade and white powder or a crystal-like material appears on the surface of the image portions of the thermosensitive recording materials, so that the image portions are whitened.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an improved thermosensitive recording material from which the above-described shortcomings of the conventional thermosensitive recording materials are eliminated, more specifically, which improved thermosensitive recording material is capable of allowing rapid recording with high image density and high thermal coloring sensitivity, without the recording image areas being faded and the formation of white powder or crystals on the image areas taking place.
According to the present invention, this object is attained by use of at least a first bisphenol derivative of the following formula (I) and a second bisphenol derivative of the following formula (II) in combination in a color developing material in a thermosensitive recording material of the type comprising a support material and a thermosensitive coloring layer formed on the support material, which thermosensitive coloring layer comprises a colorless or light-colored coloring material and a color developing material which colors the coloring material when heated to a predetermined temperature. ##STR4## wherein n is an integer of 1 or 2. ##STR5## wherein X represents halogen, Y represents ##STR6## m is an integer of 1 or 2, and the substitution positions of Xm in the benzene rings are symmetrical with respect to Y.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As mentioned above, a thermosensitive recording material according to the present invention comprises a support material and a thermosensitive coloring layer formed on the support material, which thermosensitive coloring layer comprises a colorless or light-colored coloring material and a color developing material capable of coloring the coloring material upon application of heat thereto, with a key feature thereof being that the color developing material comprises at least the first bisphenol derivative of the formula (I) and the second bisphenol derivative of the formula (II).
Specific examples of the first bisphenol derivatives of the formula (I) are as follows: ##STR7## 1,7-di(4-hydroxyphenylthio)-3,5-dioxaheptane ##STR8## 1,5-di(4-hydroxyphenylthio)-2,4-dioxapentane
Specific examples of the second bisphenol derivatives of the formula (II) are as follows: ##STR9##
The first bisphenol derivatives of the formula (I) have melting points in the range of 100° C. to 150° C., have high coloring performance, and therefore exhibit higher thermal response than the conventional color developing materials, such as 4,4'-isopropylidenediphenol and 4,4'-butylidenediphenol, so that the first bisphenol derivatives are capable of yielding images with high and uniform image density.
The second bisphenol derivatives of the formula (II) have higher melting points than the first bisphenol derivatives of the formula (I). However, when the first and second bisphenol derivatives are used in combination, the two bisphenol derivatives constitute an eutectic mixture, so that recrystallization of the first bisphenol derivative in the developed image areas is prevented, and accordingly the fading and whitening of the developed image areas are prevented.
Generally, when two or more color developing materials are used in combination, it occurs that the water-solubility of the mixture of the color developing materials increases and the eutectic point thereof significantly decreases, resulting in that the fogging of the thermosensitive coating liquid and the background of the thermosensitive recording material considerably takes place during the storage thereof. The second bisphenol derivatives of the formula (II), however, do not have such problems, since the water-solubility thereof is low.
In the present invention, it is preferable that the developing material consisting essentially of a combination of the above described first bisphenol derivatives (at least one) and the second bisphenol derivatives (at least one) be employed in an amount of 1 to 10 parts by weight, more preferably in an amount of 2 to 6 parts by weight, with respect to 1 part by weight of the leuco dye.
Further, it is preferable that the ratio by weight of the first bisphenol derivative of the formula (I) to the second bisphenol derivative of the formula (II) employed in the present invention be in the range of (1:1) to (10:1), more preferably in the range of (2:1) to (5:1).
When necessary, conventional phenolic materials can be added to the above color developing material.
The thermosensitive recording material according to the present invention can be used in various structure including the conventional structures in which the thermal coloring reaction between the leuco dyes and the color developers are employed. For example, the thermosensitive recording material according to the present invention can be formed in the structure in which the leuco dye and the color developer are contained in the same coating layer on a support material. In another example, the thermosensitive coloring layer can be constructed so as to include at least 2 layers, and the leuco dye is contained in one layer and the color developer is contained in the other layer. In a further example, an intermediate layer is interposed between the leuco dye layer and the color developer layer, or a protective layer is formed on the front surface or back surface of the thermosensitive coloring layer.
The thermosensitive recording materials according to the present invention can also be used in the form of an image-transfer type recording material, which consists of, for instance, a transfer sheet with an image-transfer layer thereon containing the above-mentioned leuco dye, and an image receiving sheet with an image receiving layer thereon containing the above-mentioned color developer.
The thermal image transfer by use of the image-transfer type recording material is conducted, for instance, by closely superimposing the image receiving sheet on the image transfer layer, and performing direct thermal printing from the back side of the image transfer sheet by use of a thermal printer, whereby the desired colored images are formed on the image receiving layer of the image receiving sheet.
The leuco dyes for use in the present invention are those employed conventionally in the field of thermosensitive recording materials. They can be used alone or in combination. Examples of such leuco dyes for use in the present invention are triphenylmethane-type leuco compounds, fluoran-type leuco compounds, phenothiazine-type leuco compounds, auramine-type leuco compounds and spiropyran-type leuco compounds. Specific examples of those leuco dyes are as follows:
3,3-bis(p-dimethylaminophenyl)-phthalide,
3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide (or Crystal Violet Lactone),
3,3-bis(p-dimethylaminophenyl)-6-diethylaminophthalide,
3,3-bis(p-dimethylaminophenyl)-6-chlorophthalide,
3,3-bis(p-dibutylaminophenyl)-phthalide,
3-cyclohexylamino-6-chlorofluoran,
3-dimethylamino-5,7-dimethylfluoran,
3-diethylamino-7-chlorofluoran,
3-diethylamino-7-methylfluoran,
3-diethylamino-7,8-benzfluoran,
3-diethylamino-6-methyl-7-chlorofluoran,
3-(N-p-tolyl-N-ethylamino)-6-methyl-7-anilinofluoran,
3-pyrrolidino-6-methyl-7-anilinofluoran,
2-[N(3'-trifluoromethylphenyl)amino]-6-diethylaminofluoran,
2-[3,6-bis(diethylamino)-9-(o-chloroanilino)xanthylbenzoic acid lactam],
3-diethylamino-6-methyl-7-(m-trichloromethylanilino)fluoran,
3-diethylamino-7-(o-chloroanilino)fluoran,
3-dibutylamino-7-(o-chloroanilino)fluoran,
3-N-methyl-N-amylamino-6-methyl-7-anilinofluoran,
3-N-methyl-N-cyclohexylamino-6-methyl-7-anilinofluoran,
3-diethylamino-6-methyl-7-anilinofluoran,
3-(N,N-diethylamino)-5-methyl-7-(N,N-dibenzylamino)fluoran,
benzoyl leuco methylene blue,
6'-chloro-8'-methoxy-benzoindolino-spiropyran,
6'-bromo-3'-methoxy-benzoindolino-spiropyran,
3-(2'-hydroxy-4'-dimethylaminophenyl)-3-(2'-methoxy-5'-chlorophenyl)phthalide,
3-(2'-hydroxy-4'-dimethylaminophenyl)-3-(2'-methoxy-5'-nitrophenyl)phthalide,
3-(2'-hydroxy-4'-diethylaminophenyl)-3-(2'-methoxy-5'-methylphenyl)phthalide,
3-(2'-methoxy-4'-dimethylaminophenyl)-3-(2'-hydroxy-4'-chloro-5'-methylphenyl)phthalide,
3-morpholino-7-(N-propyl-trifluoromethylanilino)fluoran,
3-pyrrolidino-7-trifluoromethylanilinofluoran,
3-diethylamino-5-chloro-7-(N-benzyl-trifluoromethylanilino)fluoran,
3-pyrrolidino-7-(di-p-chlorophenyl)methylaminofluoran,
3-diethylamino-5-chloro-7-(α-phenylethylamino)fluoran,
3-(N-ethyl-p-toluidino)-7-(α-phenylethylamino)fluoran,
3-diethylamino-7-(o-methoxycarbonylphenylamino)fluoran,
3-diethylamino-5-methyl-7-(α-phenylethylamino)fluoran,
3-diethylamino-7-piperidinofluoran,
2-chloro-3-(N-methyltoluidino)-7-(p-n-butylanilino)fluoran,
3-(N-benzyl-cyclohexylamino)-5,6-benzo-7-α-naphthylamino-4'-bromofluoran, and
3-diethylamino-6-methyl-7-methyl-7-mesidino-4',5'-benzofluoran.
As mentioned previously, these leuco dyes can be used alone or in combination.
In the present invention, a wide variety of conventional binder agents can be employed for binding and supporting the above-mentioned leuco dyes and color developing materials. Examples of the binder agents are as follows: polyvinyl alcohol; starch and starch derivatives; cellulose derivatives such as methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose and ethylcellulose; water-soluble polymeric materials such as sodium polyacrylate, polyvinylpyrrolidone, acrylamide/acrylic acid ester copolymer, acrylamide/acrylic acid ester/methacrylic acid copolymer, styrene/maleic anhydride copolymer alkali salt, isobutylene/maleic anhydride copolymer alkali salt, polyacrylamide, sodium alginate, gelatin and casein; and latexes of polyvinyl acetate, polyurethane, styrene/butadiene copolymer, polyacrylic acid, polyacrylic acid ester, vinyl chloride/vinyl acetate copolymer, polybutylmethacrylate, ethylene/vinyl acetate copolymer and styrene/butadiene/acryl-type copolymer.
Further in the present invention, auxiliary additive components which are employed in the conventional thermosensitive recording materials, such as fillers, surface active agents and thermo-fusible materials, can be employed.
As the fillers, for example, the following can be employed: inorganic powder such as powder of calcium carbonate, silica, zinc oxide, titanium oxide, aluminium hydroxide, zinc hydroxide, barium sulfate, clay, talc and surface-treated calcium carbonate and silica; and organic powder such as powder of urea-formaldehyde resin, styrene/metacrylic acid copolymer and polystyrene resin.
As the thermo-fusible materials, for example, the following can be employed: higher fatty acids, esters, amides and metallic salts thereof, waxes, condensation products of aromatic carboxylic acids and amines, benzoic acid phenyl esters, higher straight chain glycols, 3,4-epoxy-dialkyl hexahydrophthalate, higher ketones and other thermo-fusible organic compounds with a melting point ranging from about 50° C. to 200° C.
The thermosensitive recording material according to the present invention can be prepared, for example, by applying a thermosensitive coloring layer formation liquid containing the above-mentioned components to an appropriate support material such as paper, synthetic paper or plastic film, followed by drying the applied thermosensitive coloring layer formation liquid. The thus prepared thermosensitive recording material according to the present invention can be employed for recording in a wide variety of fields.
In comparison with the conventional thermosensitive recording materials, the thermosensitive recording material according to the present invention is significantly improved with respect to the minimizing of the fading of recorded images and whitening thereof by the formation of white powder or crystals in the image areas, thermal sensitivity with high image density and the preservability of the recorded images, because of the use of the color developing material consisting essentially of the first and second bisphenol derivatives which are respectively represented by the previously described formula (I) and (II).
Referring to the following examples, embodiments of a thermosensitive recording material according to the present invention will now be explained in detail.
EXAMPLE 1
Liquid A and liquid B were prepared by grinding the respective following components in a ball mill for 1 day:
______________________________________ Parts by Weight______________________________________Liquid A3-Nmethyl-3-Ncyclohexylamino- 3006-methyl-7-anilinofluoran10% aqueous solution of polyvinyl 300alcoholWater 400Liquid B ##STR10## 150 1,7-di(4-hydroxyphenylthio)-3,5-dioxaheptane)2,2',6,6'-tetrabromo-4,4'-sulfonyl- 50diphenolCalcium carbonate 10010% aqueous solution of polyvinyl 200alcoholWater 500______________________________________
One part by weight of the liquid A and 8 parts by weight of the liquid B were mixed, so that a thermosensitive coloring layer formation liquid was prepared. The thermosensitive coloring layer formation liquid was applied with a deposition of 5 g/m 2 by a wire bar to a sheet of high quality paper with a base weight of 52 g/m 2 , and was then dried, whereby a thermosensitive coloring layer was formed. The thus prepared thermosensitive recording material was subjected to calendering, so that the smoothness of the surface of the thermosensitive coloring layer was caused to be in the range of 700 to 1200 in terms of Bekk's smoothness, whereby a thermosensitive recording material No. 1 according to the present invention was prepared.
EXAMPLE 2
Example 1 was repeated except that the 2,2',6,6'-tetrabromo-4,4'-sulfonyldiphenol in the liquid B was replaced by 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane, whereby a thermosensitive recording material No. 2 according to the present invention was prepared.
EXAMPLE 3
Example 1 was repeated except that the 1,7-di(4-hydroxyphenylthio)-3,5-dioxaheptane in the liquid B was replaced by 1,5-di(4-hydroxyphenylthio)-2,4-dioxapentane, whereby a thermosensitive recording material No. 3 according to the present invention was prepared.
COMPARATIVE EXAMPLE 1
Example 1 was repeated except that 2,2',6,6'-tetrabromo-4,4'-sulfonyldiphenol in the liquid B was replaced by the same amount of 1,7-di(4-hydroxyphenylthio)-3,5-dioxaheptane, whereby a comparative thermosensitive recording material No. 1 was prepared.
COMPARATIVE EXAMPLE 2
Example 1 was repeated except that the 1,7-di(4-hydroxyphenylthio)-3,5-dioxaheptane in the liquid B was replaced by the same amount of 2,2',6,6'-tetrabromo-4,4'-sulfonyldiphenol, whereby a comparative thermosensitive recording material No. 2 was prepared.
COMPARATIVE EXAMPLE 3
Example 1 was repeated except that 1,7-di(4-hydroxyphenylthio)-3,5-dioxaheptane in the liquid B was replaced by the same amount of p-hydroxy benzylbenzoate, and 2,2',6,6'-tetra-bromo-4,4'-sulfonyldiphenol in the liquid B was also replaced by the same amount of 2,2'-methylenebis(3-methyl-6-t-butylphenol), whereby a comparative thermosensitive recording material No. 3 was prepared.
The thermosensitive recording materials No. 1 through No. 3 according to the present invention and the comparative thermosensitive recording materials No. 1 through No. 3 were subjected to dynamic thermal coloring sensitivity tests, image fading tests, and visual inspection of the formation of white powder or crystals in the recorded image areas.
The dynamic thermal coloring sensitivity tests were conducted by performing thermal printing on each of the above thermosensitive recording materials by a thermal printing experiment apparatus having a thin-film thermal head (commercially available by Matsushita Electronic Components Co., Ltd.), with application of electric power of 0.45 W/dot to the thermal head for a recording time of 20 ms per line, and with a scanning line density of 8×3.85 dots/mm, with the pulse width thereof being changed to 1.0, 1.2, 1.4, 1.6, 1.8 and 2.0 msec. The density of each of the printed images was measured by use of a Macbeth densitometer RD-514 with a filter W-106 attached thereto.
The image fading tests were conducted to the thermosensitive recording material samples with printed images having an image density ranging from 1.0 to 1.2, which were obtained in the above dynamic thermal coloring sensitivity tests, by allowing the samples to stand at room temperature for 15 days.
The image fading degree was determined in accordance with the following formula: ##EQU1## where D 0 is the initial density of a printed image and D is the image density after 15 days in the above tests.
The visual inspection of the formation of white powder or crystals in the recorded image areas was performed by allowing each sample obtained in the dynamic thermal coloring sensitivity tests to stand at room temperature for 15 days as in the image fading tests. The formation of white powder or crystals in the recorded image areas was visually inspected. The results of the above-mentioned tests are summarized in the following table.
TABLE 1__________________________________________________________________________ Whitening Image ofDynamic Thermal Coloring Sensitivity Fading Recorded1.0 ms 1.2 ms 1.4 ms 1.6 ms 1.8 ms 2.0 ms Ratio Images__________________________________________________________________________Example 0.55 0.81 1.06 1.18 1.24 1.26 6% oExample 0.52 0.82 1.07 1.17 1.24 1.27 8% o2Example 0.54 0.82 1.08 1.19 1.25 1.27 7% o3Compara- 0.53 0.83 1.08 1.20 1.25 1.28 33% otiveExample1Compara- 0.08 0.08 0.08 0.12 0.20 0.32 12% otiveExample2Compara- 0.48 0.75 1.02 1.14 1.23 1.26 15% ΔtiveExample3__________________________________________________________________________ Note: o: Almost no white powder or crystals were formed in the recorded image areas. Δ: White powder or crystals were slightly formed in the recorded image areas, but there was no problem for practical use.
As can be seen from the results shown in the above table, the thermosensitive recording materials according to the present invention are improved with respect to the dynamic thermal coloring sensitivity, the image fading degree and the whitening of the recorded images, in comparison with the comparative thermosensitive recording materials.
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A thermosensitive recording material comprising a support material and a thermosensitive coloring layer formed on the support material, the thermosensitive coloring layer comprising a colorless or light-colored coloring material and a color developing material capable of coloring the coloring material upon application of heat thereto, is disclosed, in which the color developing material comprises at least one first bisphenol derivative of the formula (I) and at least one second bisphenol derivative of the formula (II), ##STR1## wherein n is an integer of 1 or 2, ##STR2## wherein X represents halogen, Y represents ##STR3## m is an integer of 1 or 2, and the substitution positions of Xm in the benzene rings are symmetrical with respect to Y.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of and priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 61/891,841, filed Oct. 16, 2013, and entitled “Z-axis determination in a 2D gesture system,” which is incorporated herein by reference in its entirety.
BACKGROUND
[0002] I. Field of the Invention
[0003] This disclosure relates generally to systems, apparatus and methods for determining a direction, and more particularly to determining a direction, change in distance and/or distance from a camera to a hand making gestures.
[0004] II. Background
[0005] Many mobile devices today contain a camera to capture images, for example, containing a hand. A standard two-dimensional (2D) camera image provides accurate measurements perpendicular to the camera (referred to here as a plane parallel to the x-axis and y-axis of the camera) but unfortunately little or no information about a perpendicular distance (along the z-axis of the camera) from the camera to the hand. A depth sensor or stereo cameras may provide distance information, thus supplementing a single camera. Other methods estimate an absolute perpendicular distance, usually based upon anatomical models of the hand, but are sensitive to variations in hands between different people, are sensitive to differences in poses and/or require a predefined pose to operate. What is needed is a means to determine a gesture involving a perpendicular distance to a hand using a standard 2D camera image, independently of assumption of a user's hand size and independently of hand pose.
BRIEF SUMMARY
[0006] Disclosed are systems, apparatus and methods for determining a gesture. According to some aspects, disclosed is a method for determining a gesture that compares different images and deduces a direction and/or distance based on a relative and size. After a reference hand size is registered, subsequent hand sizes are compared to the reference to determine if and/or how much the hand is moving. The hand gesture is determined based on changes in the moving hand.
[0007] According to some aspects, disclosed is a method in a mobile device for determining a gesture, the method comprising: capturing a first image containing a hand having a first size; computing a first indication of the first size of the hand in the first image; capturing a second image containing the hand having a second size; computing a second indication of the second size of the hand in the second image; computing a relative change between the first image and the second image; and determining the gesture based on the relative change.
[0008] According to some aspects, disclosed is a mobile device for determining a gesture, the mobile device comprising: a camera configured to: capture a first image containing a hand having a first size; and capture a second image containing the hand having a second size; and a processor coupled to the camera and comprising code to: compute a first indication of the first size of the hand in the first image; compute a second indication of the second size of the hand in the second image; compute a relative change between the first image and the second image; and determine the gesture based on the relative change.
[0009] According to some aspects, disclosed is a mobile device for determining a gesture, the mobile device comprising: means for capturing a first image containing a hand having a first size; means for computing a first indication of the first size of the hand in the first image; means for capturing a second image containing the hand having a second size; means for computing a second indication of the second size of the hand in the second image; means for computing a relative change between the first image and the second image; and means for determining the gesture based on computing the relative change.
[0010] According to some aspects, disclosed is a non-transient computer-readable storage medium including program code stored thereon, comprising program code to: capture a first image containing a hand having a first size; compute the first indication of the first size of the hand in the first image; capture a second image containing the hand having a second size; compute the second indication of the second size of the hand in the second image; compute a relative change between the first image and the second image; and determine the gesture based on computing the relative change.
[0011] It is understood that other aspects will become readily apparent to those skilled in the art from the following detailed description, wherein it is shown and described various aspects by way of illustration. The drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWING
[0012] Embodiments of the invention will be described, by way of example only, with reference to the drawings.
[0013] FIG. 1 shows a mobile device with a nearby gesturing hand.
[0014] FIGS. 2-4 illustrate a change in hand size, in accordance with some embodiments.
[0015] FIG. 5 plots a hand size verses a distance, in accordance with some embodiments.
[0016] FIG. 6 shows a method, in accordance with some embodiments.
[0017] FIGS. 7A-7D illustrate a set of hand contours of common hand poses, and the largest circle that fit within each hand contour, in accordance with some embodiments.
[0018] FIGS. 8 and 9 illustrate a method of computing an approximation of the largest circle that hits within a hand contour, in accordance with some embodiments.
[0019] FIG. 10 shows two thresholds of a hand, in accordance with some embodiments.
[0020] FIG. 11 illustrates a device, in accordance with some embodiments.
DETAILED DESCRIPTION
[0021] The detailed description set forth below in connection with the appended drawings is intended as a description of various aspects of the present disclosure and is not intended to represent the only aspects in which the present disclosure may be practiced. Each aspect described in this disclosure is provided merely as an example or illustration of the present disclosure, and should not necessarily be construed as preferred or advantageous over other aspects. The detailed description includes specific details for the purpose of providing a thorough understanding of the present disclosure. However, it will be apparent to those skilled in the art that the present disclosure may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the present disclosure. Acronyms and other descriptive terminology may be used merely for convenience and clarity and are not intended to limit the scope of the disclosure.
[0022] As used herein, a device, sometimes referred to as a mobile device, a mobile station (MS) or user equipment (UE), such as a cellular phone, mobile phone or other wireless communication device, personal communication system (PCS) device, personal navigation device (PND), Personal Information Manager (PIM), Personal Digital Assistant (PDA), laptop or other suitable device without such a wireless link. The term “mobile device” is intended to include devices which communicate with a personal navigation device (PND), such as by short-range wireless, infrared, wireline connection, or other connection—regardless of whether satellite signal reception, assistance data reception, and/or position-related processing occurs at the device or at the PND. Also, “mobile device” is intended to include all devices, including wireless communication devices, computers, laptops, etc. which are capable of communication with a server, such as via the Internet, WiFi, or other network, and regardless of whether satellite signal reception, assistance data reception, and/or position-related processing occurs at the device, at a server, or at another device associated with the network. Any operable combination of the above are also considered a “mobile device.”
[0023] FIG. 1 shows a mobile device 100 with a nearby gesturing hand 200 . The hand 200 may be pushing towards or pulling away from the mobile device 100 or may be performing a more complex gesture. Usually, a distance between a camera 110 in the mobile device 100 and a hand 200 is unknown without a depth sensor, such as a stereoscopic camera, time-of-flight sensor, or structured light sensor. Some embodiments described herein register a hand size defining a reference size S. The hand size may be determined in various ways. For example, in some embodiments, hand size is estimated by filling the hand with a circle and using the radius, diameter or area of that circle to represent the size of the hand. In some embodiments, hand size is estimated by filling the hand with a square and using a width or area of the square to represent the hand. Other geometric shapes, such as a rectangle or oval, or single dimensions such as hand width, may be used. Alternatively, hand size may be estimated by encompassing a hand in a geometric shape rather than encompassing a geometric shape in a hand. For example, hand size may be estimated by the smallest square that encompasses a hand. For the description below, diameter of a circle that fits within a palm is used as an approximation of hand size.
[0024] In some embodiments, hand size is estimated with a palm size S, where the palm size S is a linear dimension. In other embodiments, the hand size is estimated with a palm area A. A palm is minimally influenced by the hand pose and orientation. As a result, the palm size S and palm area A are advantageous over the hand size, hand area, hand dimensions (such as, width W and length L) because these hand measurements are highly influenced by hand pose. On the other hand, palm size and palm area are advantageously less influenced by hand pose. For example, a hand in an open pose has a hand length and hand area that includes the length of the fingers, while a hand in a closed fist pose has a hand length and hand area that excludes the length of the fingers. Therefore, the hand length and hand area changes significantly depending on whether the hand is open or closed, however, the palm size remains similar throughout a variety of hand poses. Therefore, relative palm sizes are more relavant even if a hand pose changes.
[0025] A first indication of hand size may occur or be set to a first time a hand 200 is in a distinctive pose or other reference pose. A distinctive pose or reference pose may be an engagement pose, indicating to the system impending movement of the hand is to be interpreted as a gesture. For example, a first time a hand 200 provides a silhouette of a hand 200 with four fingers and a thumb, such as with a flat hand 200 perpendicular to a camera with a palm facing directly towards or away the camera. The figure shows a palm of a flat hand 200 facing directly towards a camera 110 of a mobile device 100 . The camera 110 defines Cartesian coordinate with an x-axis and a y-axis in a plane on an image captured by the camera 110 and a z-axis perpendicular axis to the image plane.
[0026] FIGS. 2-4 illustrate a change in hand size, in accordance with some embodiments. In FIG. 2 , a first image contains a reference size 210 of a hand 200 . Here, the reference size 210 is defined by a palm size of hand 200 in an open hand pose. Alternatively, a palm size of a hand 200 , in a closed hand pose such as a fist or the like, may be used as defining the reference size 210 . Still alternatively, a palm size of a hand, where the hand is performing a part of a hand gesture, may define an indication of the reference size 210 . To set a reference size 210 , a user may be prompted to hold a hand position over a mobile device 100 . For example, the user may be requested to hold an open hand over the mobile device 100 . In some embodiments, a user fixes a hand 200 at a variable (unknown) height above the mobile device 100 . In such embodiments, a relative height may be determined. In other embodiments, a user fixes a hand 200 at a particular height above the mobile device 100 . For example, the user may be instructed to fix an open hand 200 at one foot above the mobile device 100 . In such embodiments, the user may be instructed to fix a hand at a particular height above the mobile device 100 that is dependent upon the field of view (FOV), range, and resolution of a particular camera and lens being used, to assure that the hand may be detected within a sufficient range of motion for a user to complete a gesture without unintentionally moving the hand outside the FOV, range, and resolution of the particular camera and lens being used.
[0027] In FIG. 3 , a second image shows the same hand 200 farther away. When the hand 200 is farther away, the camera 110 captures a second image with a smaller size 230 when compared to the reference size 210 . Before comparing the second image to the first image, the mobile device 100 may compensate for a field of view (FOV) of a particular camera and lens being used. Therefore, a hand size from the first (reference) image may be directly compared to a hand size from the second image. As such, a relative difference between lengths may be determined.
[0028] In FIG. 4 , another second image shows the same hand 200 closer to the camera 110 . When the hand 200 is closer, the camera 110 captures a second image with a larger size 220 when compared to the reference size 210 . When compared to an indication of the reference size 210 , an indication of the smaller size 230 or the larger size 220 results in a relative difference to the reference size 210 .
[0029] FIG. 5 plots a hand size verses a distance, in accordance with some embodiments. Neither relative distance nor hand size is shown on a linear scale. Similar, the processor has compensated for effects of a FOV of a particular lens. The non-linear scales show a relationship between relative distance and hand size such that a translation between the two falls on a line. If drawn on a linear scale, the graph would appear having an inverse proportional relationship. That is, relative distance is proportion to an inverse of hand size after accounting for a particular FOV of a camera 110 .
[0030] In FIG. 5 , a relative distance is shown with respect to a hand size. The value of H may be unknown. A reference size 210 is set to 100% for a height H. When an image shows the hand 200 is 50% of the reference size 210 (e.g., a smaller size 230 ), the relative distance is 2*H. When an image shows the hand 200 is 200% of the reference size 210 (e.g., a larger size 220 ), the relative distance is H/2. If H is referred to as a relative height, 2*H and H/2 are determinable relative heights. Therefore, an arbitrary hand size may be translated to a relative distance above the camera 110 , without calculation of the absolute height of the hand, and without knowledge of the absolute hand size or the assumption that the hand matches an anatomical model of a hand size. The graph may be used to determine a direction from a reference height H, wherein the reference height H results in an image of a hand 200 having a relative size 210 . For example, the graph may be used to determine if a hand 200 is moving towards or away from a camera 110 . In addition to direction, the graph may be used to compute a relative height with respect to the reference height H.
[0031] FIG. 6 shows a method 300 , in accordance with some embodiments. At 310 , a camera 110 captures a first image. The first image is a reference image containing a hand 200 having a reference size. At 320 , a processor in a mobile device 100 computes an indication of the first size as a reference size. As previously stated, the indication of a size may be a size S corresponding to a diameter or an area of the palm. At 330 , the camera 110 also captures a second image. Step 330 may occur before or after step 320 . At 340 , the processor computes an indication of the second size of the hand 200 within the second image. At 350 , the processor computes a change between the first image and the second image wherein the change includes a direction and/or a distance based on the first indication of size and the second indication of size. The change may be only a direction, only a relative distance, or both a direction and a relative distance. For example, if the second size is less than the first size, the hand 200 has moved away from the reference height. If the second size is greater than the first size, the hand 200 has moved towards the reference height. Alternatively, two sequential images may be examined to determine whether the hand 200 is currently moving up (away from the camera 110 ) or down (towards the camera 110 ).
[0032] Optionally, at 360 , a determination is made to check if a change is insignificant, for example, if the change is below a threshold size. If the change is insignificant, processing may continue at optional step 370 or again at step 330 . If the change is significant, processing may continue at step 380 .
[0033] At 370 , a time limit T may be checked to see whether one interaction occurs within a single session. For example, processing at step 330 may continue only if a threshold time (e.g., T=5 seconds) has not been exceeded. During the time limit T, the change in palm size or area may be used to identify a push or a pull. In this case, a hand 200 stays within a viewing frame and moves in height. The computed height change may result in a gesture defining zooming in or out operation. Also in this case, a hand 200 may disappear from a viewing frame by being too low or too high along the Z-axis. For example, when a hand 200 is too close it occupies a majority of an image and cannot be detected. When a hand 200 is too far it is smaller than a defined minimum number of pixels for a hand 200 . Alternatively, a hand 200 may disappear because it is outside of the X-Y plane of the camera 110 . That is, the hand 200 exits a view of a camera 110 . For example, a hand 200 may exit at a low height and then reappear at a higher height. Such a gesture includes a close interaction followed by a far interaction. At 380 , the processor determines a gesture based on the change.
[0034] FIGS. 7A-7D illustrate a set of hand contours of common hand poses, and the largest circle that fit within each hand contour, in accordance with some embodiments. For many common hand poses, the largest circle within a silhouette of a hand corresponds closely to the palm, therefore a palm may be detected within a segmented contour of a hand, as the largest circle that fits within the hand contour. FIG. 7A shows an open hand with fingers and thumb spread out. FIG. 7B shows an open hand with fingers and thumb together. FIG. 7C shows partially closed hand with an index finger and a thumb pointing out. FIG. 7D shows closed hand with fingers and thumb together in a fits.
[0035] It should be apparent that the palm size remains fairly constant for these various poses, while other metrics of hand size such as hand length and hand area are more greatly affected by the hand pose.
[0036] FIGS. 8 and 9 illustrate a method of computing an approximation of the largest circle that hits within a hand contour, in accordance with some embodiments. A palm size may be used as an approximation of the hand size by using the largest circle that fits within the hand contour. This approximation requires relatively little computation as compared to determining an area of a hand.
[0037] In FIG. 8 , two axes 810 and 820 are identified. The axes may correspond to the length of the hand and the width of the hand. Alternatively, the axes may correspond to the vertical and horizontal axes of the image. The longest contagious segments (for example, 811 , 812 and 813 ) perpendicular to axis 810 are projected along axis 810 to form a projected contour 814 . It can be seen in this example that segments identified as 811 , 812 , and 813 within projected contour 814 match the length of corresponding segments 811 , 812 , and 814 within hand contour 801 . Similarly, the longest contagious segments (for example 821 , 822 , 822 ) perpendicular to axis 820 , are projected along axis 820 to form a projected contour 824 .
[0038] In FIG. 9 , within projected contour 814 , the largest half-ellipse 815 is found Similarly, within projected contour 824 , the largest half-ellipse 825 is found. Half-ellipses 815 and 825 may be back-projected into hand contour 801 to identify circle 802 . Circle 802 is an approximation of the largest circle within the hand contour. Other shapes may be used instead of half-ellipses. For example, a half-circle, square or rectangle may be used.
[0039] In an alternative embodiment of a method of identifying a palm, the palm position is identified as the point furthest from any point on a hand and the palm radius is identified as the distance of that point to the closest point on the contour. This method may be computed as a series of morphology erosion operations computed on a segmentation of a hand, applied recursively until any further erosion results in a null image. The number of recursions equates to the radius of the palm and the remaining points represent the center of the palm.
[0040] FIG. 10 shows two thresholds of a hand 200 , in accordance with some embodiments. A palm size 240 of a hand 200 is shown with a solid line. A threshold size increase to palm size 250 , corresponding to hand 220 , is shown. A threshold size decrease to palm size 260 , corresponding to hand 230 , is also shown. This threshold size increase or decrease may be used to determine whether a change is insignificant or significant.
[0041] FIG. 11 illustrates a mobile device 100 , in accordance with some embodiments. The mobile device 100 includes a camera 110 and a processor 120 having memory. The camera 110 is configured to capture a first image containing a hand 200 having a first size. The camera 110 also is configured to capture a second image containing the hand 200 having a second size. The processor 120 and memory are coupled to the camera, for example, via a bus 130 . The processor 120 and memory comprise code to: (1) compute a first indication of the first size of the hand in the first image; (2) compute a second indication of the second size of the hand in the second image; (3) compute a change between the first image and the second image; and (4) determine the gesture based on computing the change.
[0042] The camera 110 acts as: (1) a means for capturing a first image containing a hand having a first size; and (2) a means for capturing a second image containing the hand having a second size. The processor 120 and memory act as: (1) a means for computing a first indication of the first size of the hand in the first image; (2) a means for computing a second indication of the second size of the hand in the second image; (3) a means for computing a change between the first image and the second image; and (4) a means for determining the gesture based on computing the change.
[0043] The methodologies described herein may be implemented by various means depending upon the application. For example, these methodologies may be implemented in hardware, firmware, software, or any combination thereof. For a hardware implementation, the processing units may be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, electronic devices, other electronic units designed to perform the functions described herein, or a combination thereof.
[0044] For a firmware and/or software implementation, the methodologies may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. Any machine-readable medium tangibly embodying instructions may be used in implementing the methodologies described herein. For example, software codes may be stored in a memory and executed by a processor unit. Memory may be implemented within the processor unit or external to the processor unit. As used herein the term “memory” refers to any type of long term, short term, volatile, nonvolatile, or other memory and is not to be limited to any particular type of memory or number of memories, or type of media upon which memory is stored.
[0045] If implemented in firmware and/or software, the functions may be stored as one or more instructions or code on a computer-readable medium. Examples include computer-readable media encoded with a data structure and computer-readable media encoded with a computer program. Computer-readable media includes physical computer storage media. A storage medium may be any available medium that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer; disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.
[0046] In addition to storage on computer readable medium, instructions and/or data may be provided as signals on transmission media included in a communication apparatus. For example, a communication apparatus may include a transceiver having signals indicative of instructions and data. The instructions and data are configured to cause one or more processors to implement the functions outlined in the claims. That is, the communication apparatus includes transmission media with signals indicative of information to perform disclosed functions. At a first time, the transmission media included in the communication apparatus may include a first portion of the information to perform the disclosed functions, while at a second time the transmission media included in the communication apparatus may include a second portion of the information to perform the disclosed functions.
[0047] The previous description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the spirit or scope of the disclosure.
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Systems, apparatus and methods for determining a gesture are presented. According to some aspects, disclosed are systems, apparatus and methods for determining a gesture that compares different images and deduces a direction and/or distance based on a relative size change of a palm in the different images. After a reference palm size is registered, subsequent palm sizes are compared to the reference to determine if and/or how much the hand is moving. The hand gesture is determined based on these relative changes in hand movement.
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FIELD OF THE INVENTION
This invention relates to printing stations. Such structures of this type, generally, provide for a printing station to be located in the back of mass transit vehicle seats such that the mass transit rider can be able to view and subsequently print that viewed information.
DESCRIPTION OF THE RELATED ART
Prior to the present invention, as set forth in general terms above and more specifically below, it is known, in the printer art, to employ centralized printers in mass transit vehicles, such as airplanes. Exemplary of such prior art are U.S. Pat. No. 4,774,514 ('514) to F. Hildebrandt et al., entitled “Method and Apparatus for Carrying Out Passenger-Related and Flight Attendant-Related Functions in an Airplane,” U.S. Pat. No. 6,058,288 ('288) to D. P. Reed et al., entitled “Passenger Service and Entertainment System,” and U.S. Pat. No. 6,177,887 ('887) to G. A. Jerome, entitled “Multi-Passenger Vehicle Catering and Entertainment System.” While the '514, '288, and '887 references disclose printers for use in mass transit vehicles, the printers are centralized printers which require that an attendant shuttle printed materials back to the passengers and/or the passengers would be required to get out of their seats in order to retrieve the printed materials which could cause safety concerns. Also, the passenger is not afforded much privacy with respect to who has access to the printed document. Therefore, a more advantageous system, then, would be presented if each passenger had access to his/her own printer located in the seatback in front of the passenger so that the passenger is afforded some privacy without having to get out of his/her seat.
It is also known, the mass transit vehicle seat art, to install a telephone and a display panel in the seat back. While this affords the passenger some convenience in being able to use the telephone without having to leave his/her seat, if the passenger wants to print something, these prior art systems do not allow for such printing. Therefore, a further advantageous system, then, would be provided if the passenger were able to print out the desired information at his/her seat.
It is apparent from the above that there exists a need in the art for a printer system for use in a mass transit vehicle which allows the user to print documents without having to get out of the passenger seat, but which at the same time provides the user with a modicum of privacy with respect to who can view the document to the printed. It is a purpose of this invention to fulfill this and other needs in the art in a manner more apparent to the skilled artisan once given the following disclosure.
SUMMARY OF THE INVENTION
Generally speaking, this invention fulfills these needs by providing a mass transit vehicle seat printing station, wherein the station is comprised of: a mass transit vehicle seat having a seat back; a display means located within the seat back; a printing means located within the seat back and operatively connected to the display means; and a control means located within the seat back and operatively connected to the display means and the printing means in order to control the display means and the printing means.
In certain preferred embodiments, the mass transit vehicle can be, but is not limited to, an airplane, a bus, a train, passenger ship or the like. Also, the display means includes a display monitor for Web based interaction and, possibly, a smaller 2-4 line display. Also, the printing means includes a small inkjet or thermal color printer. Also, the control means can be a control panel that includes alphanumeric keys, print buttons, and scroll buttons. Finally, the printing station may include an IR port or other such types of connectors that will provide access to and power for the user's mobile devices, such as laptop computers, cell phones, personal digital assistants (PDAs) or the like.
In another further preferred embodiment, the user is able to view information on the display located in the mass transit vehicle seat back printing station and, possibly, print that information without having to leave his his/her seat or have to share the information with others.
The preferred mass transit vehicle printing station, according to this invention, offers the following advantages: excellent printing characteristics; excellent document viewing characteristics; excellent document controlling characteristics; increased privacy; increased passenger safety; ability to interact with mobile devices; and excellent economy. In fact, in many of the preferred embodiments, these factors of excellent printing characteristics, excellent document viewing characteristics, excellent document controlling characteristics, increased privacy, increased passenger safety, and ability to interact with minimal devices are optimized to an extent that is considerably higher than heretofore achieved in prior, known mass transit vehicle printing stations.
The above and other features of the present invention, which will become more apparent as description proceeds, are best understood by considering the following detailed description in conjunction with the accompanying drawings, wherein like characters represent like parts throughout the several views and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of a mass transit vehicle printing station, according to one embodiment of the present invention; and
FIG. 2 is a schematic illustration of another mass transit vehicle printing station, according to a second embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
With reference first to FIG. 1, there is illustrated one preferred embodiment for use of the concepts of this invention. FIG. 1 illustrates printing station 2 . Printing station 2 includes, in part, conventional mass transit vehicle seat back 4 , conventional mass transit vehicle seat back tray 5 , display 6 , printer 8 , printed document 10 , control panel buttons 11 and 12 , secondary display 14 , IR port 16 , and power and workstation/Internet access connections 18 .
Display 6 , preferably, is any suitable display monitor that will adequately fit within mass transit vehicle seat back 4 and allow for the display of any Internet based interaction between the user and printing station 2 . Printer 8 , preferably, is any suitable small inkjet or thermal color printer which is capable of printing document 10 and which will adequately fit within mass transit vehicle seat back 4 . Printed document 10 , preferably, is any document that is printed on conventional 4″ by 6″ media or any other suitable media size. Control panel buttons 11 and 12 , preferably, should include a keyboard having alphanumeric keys, scroll keys, print keys or the like which will allow the user to interact with and/or manipulate the information displayed on display 6 and/or any mobile devices (not shown) connected to printing station 2 through power and workstation/Internet access connections 18 . Mobile devices can be, but are not limited to, laptop computers, personal digital assistants (PDA) or the like. As a possible addition, secondary display 14 , preferably, is a smaller 2-4 line display that can be added to allow the user to view various documents at printing station 2 at the same time. IR port 16 , preferably, allows the user to conventionally, electronically transmit machine-readable data from any mobile devices (not shown) to printing station 2 so that the data can be viewed on displays 6 and/or 14 and/or printed by printer 8 . Power and workstation/Internet access connections 18 , preferably, allow the user to connect any mobile device (not shown) to printing station 2 so that the mobile device can be powered by printing station 2 and/or the mobile device can conventionally download information to and receive information from printing station 2 . It is to be understood that printing station 2 is, preferably, conventionally connected to the Internet in order to allow the user to have Web based interaction access.
With reference to FIG. 2, there is illustrated another preferred embodiment for use of the concepts of this invention. FIG. 2 shows printing station 50 . Printing station 50 includes, in part, conventional mass transit vehicle seat back 4 , display 6 , printer 8 , printed document 10 , control panel buttons 11 and 12 , secondary display 14 , IR port 16 , power and workstation/Internet access connections 18 , telephone head set 52 , telephone display 54 , printer 56 , and document 58 . It is to be understood that printer 56 is, preferably, constructed in the same manner as printer 8 (FIG. 1 ).
During the operation of printing station 2 (FIG. 1 ), the user may elect to fold down mass transit vehicle seat back tray 5 and place a mobile device (not shown), such as a laptop computer on tray 5 . The user then would be able to do many things with print station 2 . For example, the user may already have information on the laptop computer that the user wants to be printed. The user conventionally transmits the information from the mobile device to IR port 16 where the information can be subsequently printed by printer 8 . Also, the user may need to utilize the power and workstation/Internet access connections 18 in order to provide power to the mobile device and/or transmit information to printing station 2 so that it can be printed by printer 8 if the mobile device lacks the proper equipment to interact with IR port 16 . Power and workstation/Internet access connections 18 can also be used to transfer information from the Internet to printing station 2 and/or the mobile device. After the user has connected to printing station 2 , the user may use the alphanumeric keyboard located on the mobile device in order to manipulate the information on displays 6 and 14 and/or the display on the mobile device. The user may also elect to manipulate control panel buttons 11 and 12 in order to manipulate the information on displays 6 and 14 and/or the display on the mobile device. Finally, the user may decide to use the telephone (FIG. 2) for variety of personal/business-related reasons. As shown in FIG. 2, printer 56 can be used to print document 58 that is a hard copy of what is displayed on telephone display 54 .
Finally, it is to be understood that printing station 2 can be located adjacent to the seat that the passenger is sitting in, such as a seat compartment beside the seat and/or below the seat, so long as the passenger has easy access to printing station 2 .
Once given the above disclosure, many other features, modifications or improvements will become apparent to the skilled artisan. Such features, modifications or improvements are, therefore, considered to be a part of this invention, the scope of which is to be determined by the following claims.
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This invention relates to printing stations. Such structures of this type, generally, proved for a printing station to be located in the back of mass transit vehicle seats such that the mass transit rider can be able to view and subsequently print that viewed information.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not applicable.
FIELD OF THE INVENTION
[0003] The present invention generally relates to hybrid thermal oxidizer systems and methods. More particularly, the invention relates to a hybrid thermal oxidizer for combusting waste gas and heating utility oil using an efficient transfer of heat from fuel gas.
BACKGROUND OF THE INVENTION
[0004] In facilities that process liquefied natural gas (“LNG”), the natural gas is typically cleaned of impurities and cooled thus, removing a fair amount of energy to bring it to a liquid state. In this state, it is easy to transport in large quantities. Before bringing the gas to a liquid state, the impurities are removed from the raw gas. These impurities are burned in a conventional thermal oxidizer to break them down to CO 2 , H 2 O and nitrogen, for example. Based on the impurities, the thermal oxidizer needs to operate at elevated temperatures to minimize emissions. When a thermal oxidizer operates at a high temperature, the fuel gas leaves the unit at very high temperatures thus, wasting heat.
[0005] Referring now to FIG. 1 , a conventional thermal oxidizer 100 is illustrated for use in an LNG facility. A fuel gas stream 101 enters a burner 102 at the same time a combustion air stream 104 enters the burner 102 . The burner 102 combusts the fuel gas stream 101 and the combustion air stream 104 in a combustion chamber 106 . Impurities from a waste gas 107 enter the combustion chamber 106 through inlet opening 108 at about 122° F. and are burned with the fuel gas stream 101 and the combustion air stream 104 to break them down into an exhaust gas comprising CO2, H2O and nitrogen, for example. Based on the type of impurities in the waste gas 107 , the combustion chamber 106 needs to operate at an elevated temperature to minimize emissions in the exhaust gas. Emission requirements often require operating a conventional thermal oxidizer at much higher temperatures to obtain a 99.99% Destruction and Removal Efficiency (“DRE”). DRE is defined as the percentage of molecules of a compound removed or destroyed in the thermal oxidizer related to the number of molecules that entered the system. The operating temperature of a thermal oxidizer therefore, varies depending upon the impurities in the waste gas. If, for example, benzene, toluene, ethyl-benzene and xylenes (collectively referred to as “BTEX”) are present, then the combustion chamber 106 needs to operate at about 1742° F. with a residence time of 1.5 to 2 seconds for 99.99% DRE. Residence time is defined as the time of exposure of waste gas in the combustion chamber 106 . The combustion air stream 104 entering the burner 102 may be regulated with a valve 112 so that if the temperature in the combustion chamber 106 drops below or goes above a predetermined value such as, for example, about 1742° F. when detected by a temperature sensor 110 , the flow of combustion air stream 104 into the burner 102 may be increased or decreased using the valve 112 . Likewise the fuel gas stream 101 entering the burner 102 may be regulated with a valve 103 so that if the temperature in the combustion chamber 106 drops below or goes above a predetermined value such as, for example, about 1742° F. when detected by the temperature sensor 110 , the flow of fuel gas stream 101 into the burner 102 may be increased or decreased using the valve 103 . In order to maintain the combustion air stream 104 ahead of the fuel gas stream 101 for safety reasons, the combustion air stream 104 entering the burner 102 may be regulated with the valve 112 so that if the oxygen in the combustion chamber 106 drops below a predetermined value such as, for example, about 2% when detected by an oxygen sensor 111 , the flow of the combustion air stream 104 into the burner 102 may be increased using the valve 112 . The exhaust gas from the combustion chamber 106 with impurities enters the fuel gas duct 113 before entering the exhaust stack 114 and exiting the top of exhaust stack 114 through an opening 116 into the atmosphere at about 1742° F. The exhaust gas exiting the conventional thermal oxidizer illustrated in FIG. 1 therefore, wastes a significant amount of heat.
[0006] Referring now to FIG. 2 , a conventional fired heater 200 is illustrated for use in an LNG facility. Utility oil is used in the LNG facility to heat the feed gas, to heat gas turbine fuel and to remove carbon dioxide from the feed gas. The utility oil must be separately heated in a hot oil heater also referred to as a fired heater. A combustion air stream 202 and a fuel gas stream 204 enter a burner 206 at the same time. As a result, the combustion air stream 202 and the fuel gas stream 204 are heated by the burner 206 in a radiant section 208 . The radiant section 208 includes vertical coiled tubing 210 . A convection section 212 includes horizontal tubing (not shown). A utility oil stream 214 may be heated by directing the utility oil stream 214 through an inlet opening 216 , through the horizontal tubing, through the vertical coiled tubing 210 and out an outlet opening 218 as a preheated utility oil stream 220 . The utility oil is thus, heated from about 260° F. to about 475° F. as heat from the combustion of the combustion air stream 202 and the fuel gas stream 204 in the radiant section 208 and in the convection section 212 passes around the vertical coiled tubing 210 and the horizontal tubing as it rises through the fired heater 200 and exits through an exhaust stack 216 into the atmosphere at about 400° F.
[0007] Both a conventional thermal oxidizer and fired heater are significant pollutant emitting equipment in any LNG facility. With EPA regulations becoming more stringent, end users, EPA companies and heater/burner vendors face a constant challenge to improve processes and equipment design to reduce pollutant emissions.
SUMMARY OF THE INVENTION
[0008] The present invention therefore, meets the above needs and overcomes one or more deficiencies in the prior art by providing systems and methods for combusting waste gas and heating utility oil using an efficient transfer of heat from fuel gas in a hybrid thermal oxidizer.
[0009] In one embodiment, the present invention includes a hybrid thermal oxidizer, comprising i) a combustion chamber for burning impurities in a waste gas to produce an exhaust gas; ii) a gas preheater for preheating the waste gas before it enters the combustion chamber; and iii) a quench chamber positioned between the combustion chamber and the gas preheater for controlling a temperature of the exhaust gas before it enters the gas preheater.
[0010] In another embodiment, the present invention includes a method for processing a hazardous waste gas, which comprises: i) burning impurities in the waste gas to produce exhaust gas; ii) controlling a temperature of the exhaust gas before preheating the waste gas; and iii) preheating the waste gas before burning the impurities using heat transferred from the exhaust gas preheater.
[0011] Additional aspects, advantages and embodiments of the invention will become apparent to those skilled in the art from the following description of the various embodiments and related drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present invention is described below with references to the accompanying drawings, in which like elements are referenced with like numerals, wherein:
[0013] FIG. 1 illustrates a conventional thermal oxidizer used in an LNG facility.
[0014] FIG. 2 illustrates a conventional fired heater used in an LNG facility.
[0015] FIG. 3 illustrates one embodiment of a hybrid thermal oxidizer for use in an LNG facility.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] The subject matter of the present invention is described with specificity, however, the description itself is not intended to limit the scope of the invention. The subject matter thus, might also be embodied in other ways, to include different steps or combinations of steps similar to the ones described herein, in conjunction with other present or future technologies. Moreover, although the term “step” may be used herein to describe different elements of methods employed, the term should not be interpreted as implying any particular order among or between various steps herein disclosed unless otherwise expressly limited by the description to a particular order. While the following description refers to the oil and gas industry, the systems and methods of the present invention are not limited thereto and may be applied in other industries to achieve similar results.
[0017] Referring now to FIG. 3 , one embodiment of a hybrid thermal oxidizer is illustrated for use in an LNG facility. A fuel gas stream 301 enters the burner 302 at the same time a combustion air stream 304 enters the burner 302 . The burner 302 combusts the fuel gas stream 301 and the combustion air stream 304 in a combustion chamber 306 . Impurities from a preheated waste gas stream 307 enter the combustion chamber 306 through inlet opening 308 and are burned with the combustion air stream 304 and the fuel gas stream 301 at about 1742° F. to break them down into an exhaust gas in the same manner as described in reference to FIG. 1 . The preheated waste gas stream 307 , however, enters the combustion chamber 306 at a much higher temperature of about 900° F. than the waste gas stream entering a conventional thermal oxidizer. In this manner, less fuel gas stream 301 is required to burn and break down the impurities in the preheated waste gas stream 307 through combustion. The combustion air stream 304 entering the burner 302 may be regulated with a valve 312 so that if the temperature in the combustion chamber 306 drops below or goes above a predetermined value such as, for example, about 1742° F. when detected by a temperature sensor 310 , the flow of combustion air stream 304 into the burner 302 may be increased or decreased using the valve 312 . Likewise, the fuel gas stream 301 entering the burner 302 may be regulated with a valve 303 so that if the temperature in the combustion chamber 306 drops below or goes above a predetermined value such as, for example, about 1742° F. when detected by the temperature sensor 310 , the flow of fuel gas stream 301 into the burner 302 may be increased or decreased using the valve 303 . In order to maintain the combustion air stream 304 ahead of the fuel gas stream 301 for safety reasons, the combustion air stream 304 entering the burner 302 may be regulated with the valve 312 so that if the oxygen in the combustion chamber 306 drops below a predetermined value such as, for example, about 2% when detected by an oxygen sensor 311 , the flow of the combustion air stream 304 into the burner 302 may be increased using the value 312 .
[0018] A waste gas stream 314 enters a gas preheater 318 through inlet opening 316 where it passes through a coiled tubing and exits the gas preheater 318 through outlet opening 320 as the preheated waste gas stream 307 at about 900° F. The waste gas stream 314 may enter the gas preheater 318 at a temperature of about 122° F. The waste gas stream 314 should not be heated above a predetermined auto ignition temperature of the hydrocarbons in the waste gas stream 314 when the hydrocarbons in the waste gas stream 314 are more than 50% of a lower explosion limit. A lower explosion limit is the concentration of a gas or vapor in air capable of producing a flash fire in the presence of an ignition source.
[0019] A quench chamber 322 is positioned between the combustion chamber 306 and the gas preheater 318 to control the temperature of the exhaust gas exiting the combustion chamber 306 before it enters the gas preheater 318 . A quench air stream 324 enters the quench chamber 322 through inlet opening 326 , which is controlled and regulated by a quench air valve 328 and a temperature sensor 321 to maintain a predetermined temperature in the quench chamber 322 of about 1400° F. In this manner, the temperature of the exhaust gas from the combustion chamber 306 can be controlled to about 1400° F. before passing through to the gas preheater 318 . Controlling the temperature of the exhaust gas before it enters the gas preheater 318 is necessary in order to avoid damaging the gas preheater 318 . If, for example, the waste gas stream 314 entering the gas preheater 318 is interrupted for a while due to unexpected reasons, then the exhaust gas from the combustion chamber 306 may be controlled to a temperature of about 1400° F. in the quench chamber 322 before it passes through the gas preheater 318 at about the same temperature without damaging the coiled tubing therein. Otherwise, the exhaust gas exiting the combustion chamber 306 at about 1742° F. would directly enter the gas preheater 318 at about the same temperature and most likely damage the coiled tubing therein because the gas preheater 318 cannot handle such an elevated temperature due to high thermal expansion stresses. If, however, the waste gas stream 314 entering the gas preheater 318 is consistently uninterrupted at about 74,132 lbs/hr, then exhaust gas exiting the combustion chamber 306 at about 1742° F. is cooled in the quench chamber 322 to about 1400° F. and loses some of its heat in the gas preheater 318 , to the waste gas stream 314 passing therethrough. The exhaust gas exits the gas preheater 318 at about 1097° F.
[0020] The exhaust gas exiting the gas preheater 318 enters a waste heat recovery module 330 . A utility oil stream 332 enters an upper portion of the waste heat recovery module 330 through inlet opening 334 , passes through a coiled tubing therein and exits the waste heat recovery module 330 through outlet opening 336 . The utility oil stream 332 is used in a separate process for the LNG facility and, in this manner, is heated to about 475° F. using heat from the exhaust gas exiting the gas preheater 318 at about 1097° F. The heat from the exhaust gas in the waste heat recovery module 330 therefore, passes around the coiled tubing containing the utility oil stream 332 , which exits outlet opening 336 as a preheated utility oil stream 338 .
[0021] Heat from the exhaust gas passing through the hybrid thermal oxidizer 300 is therefore, used to efficiently produce a preheated waste gas stream 307 and a preheated utility oil stream 338 . The exhaust gas exits exhaust stack 340 through an opening 341 into the atmosphere at about 424° F. or less. In order to control the temperature in the waste heat recovery module 330 , a valve 342 and a temperature sensor 331 are used to regulate exhaust gas through outlet opening 344 thus, bypassing the waste heat recovery module 330 and entering exhaust stack 340 through inlet opening 346 at a temperature of about 1097° F. Regulation of the valve 342 therefore, controls the temperature of the preheated utility oil stream 338 to about 475° F. The temperature in the waste heat recovery module 330 may also be indirectly regulated by valve 303 . If, for example, the utility oil temperature falls below about 475° F., even after full closure of valve 342 , the fuel gas stream 301 may be increased through the valve 303 to increase the utility oil temperature to about 475° F.
EXAMPLE
[0022] In the example below, table 1 summarizes the cost of using a regular Thermal Oxidizer (Regular TO x ) and a fired heater. Table 2 summarizes the savings associated with using a Hybrid Thermal Oxidizer (Hybrid TO x ) according to the present invention.
[0000]
TABLE 1
(Regular TO X +
Regular TO X
Fired Heater
Fired Heater)
Equipment Cost
$1,340,000
$985,000
$2,325,000
(+fuel skid) ($)
Fuel Cost ($/yr)
$1,401,600
$1,236,900
$2,638,500
NO X Emissions
25,580
10,820
36,400
(lbs/MM Btu/yr)
[0000]
TABLE 2
(Regular TO X +
Fired Heater)
Hybrid TO X
Savings
Equipment Cost
$2,325,000
$2,200,000
$125,000
(+fuel skid) ($)
Fuel Cost ($/yr)
$2,638,500
$1,401,600
$1,236,900
NO X Emissions
36,400
25,580
10,820
(lbs/MM Btu/yr)
[0023] In table 1, the fired heater fuel cost assumptions are 85% thermal efficiency for a 30 MM Btu/hr heater with a fuel usage of about 35.3 MM Btu/hr. The fuel cost is estimated at $4/MM Btu (no inflation/fluctuation considered), which results in about $1,236,900 per year. The Regular TO x fuel cost assumptions include a 40 MM Btu/hr Thermal Oxidizer with a fuel usage of about 40 MM Btu/hr. The fuel cost is estimated at $4/MM Btu (no inflation/fluctuation considered), which results in about $1,401,600 per year.
[0024] In table 2, the Hybrid TOx fuel cost assumes that no additional fuel consumption is required to heat the hot oil when the Hybrid TO x is operating under normal conditions to burn a waste gas stream.
[0025] In addition to the fuel cost savings, the Hybrid TO x also produces fewer noxious emissions (“NO x Emissions”). In table 1, the NO x Emissions for a conventional fired heater assume:
NO x emitted by a 30 MM Btu/hr heater, lbs/MM Btu/hr 0.035 Efficiency of the heater=85% NO x emissions eliminated, lbs/MM Btu/yr=0.035*35.29*8,760=10,820 In table 1, the NOx Emissions for a Regular TO x assume: NO x emitted by a 40 MM Btu/hr TO x , lbs/MM Btu/hr=0.073 NOx emissions, lbs/MM Btu/yr=0.073*40*8,760=25,580
[0032] In addition to the significant and substantial cost savings and environmental impact by reducing noxious emissions by approximately 10,820 lbs/yr, eliminating the use of a separate fired heater will provide cost savings by eliminating the maintenance and operational costs associated with a fired heater. Moreover, construction costs and space are reduced by eliminating the requirement of a separate fired heater.
[0033] While the present invention has been described in connection with presently preferred embodiments, it will be understood by those skilled in the art that it is not intended to limit the invention to those embodiments. It is therefore, contemplated that various alternative embodiments and modifications may be made to the disclosed embodiments without departing from the spirit and scope of the invention defined by the appended claims and equivalents thereof.
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Hybrid thermal oxidizer systems and methods for combusting waste gas and heating utility oil using an efficient transfer of heat from fuel gas.
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RELATED APPLICATIONS
[0001] This application is continuation of U.S. patent application Ser. No. 13/915,990, filed Jun/. 12, 2013, which is a divisional of U.S. patent application Ser. No. 13/071,997 filed on Mar. 25, 2011, now U.S. Pat. No. 8479492, issued Jul. 9, 2013, the content of which is hereby incorporated by reference.
TECHNICAL FIELD
[0002] The application relates generally to gas turbine engines and, more particularly, to a hybrid system for injecting fuel into a combustor.
BACKGROUND OF THE ART
[0003] Gas turbine engines used for powering aircrafts comprise a combustor in which fuel is mixed with compressed air and ignited to provide combustion gases for the turbine section of the engine. In a slinger combustion system, fuel is delivered and atomized through spraying fuel through a rotary fuel slinger. The rotary fuel slinger is designed for maximum fuel flow and optimized for cruise condition to improve the combustion efficiency and thus reduce smoke and gaseous emission. Thus at low power levels, when the slinger rotates at lower speeds, fuel tends to not atomize properly, thereby resulting in low combustion efficiency, and high emission/smoke/particulates/ unburned hydrocarbons.
[0004] Conventional rotary slingers have to be operated at high speed for properly atomizing the fuel. When, the slinger is rotated at low speeds, such as during starting and altitude relight conditions, the fuel atomization effect of the slinger is relatively poor, thereby requiring a relatively expensive and complex architecture for the ignition system with relatively long igniters to deliver spark energy close to the stinger system. Starting a slinger combustor at low speeds and at high altitudes without relatively complex high pressure fuel injection system has heretofore been challenging.
SUMMARY
[0005] In one aspect, there is provided a hybrid slinger combustor system for an aero gas turbine engine powering an aircraft, the combustor system comprising a combustor shell defining a combustion chamber, the combustion chamber having first and second combustion zones; two distinct fuel injector units for respectively spraying fuel into said first and second combustion zones, said two distinct fuel injector units including a rotary fuel slinger for spraying fuel radially outwardly into the first combustion zone, and a set of circumferentially spaced-apart fuel nozzles for spraying fuel into the second combustion zone; and a control unit controlling the rate of fuel flow to said rotary fuel slinger and said set of fuel nozzles as a function of the power demand of the gas turbine engine.
[0006] In a second aspect, there is provided a method for improving the combustion efficiency of a combustor of a gas turbine engine powering an aircraft, comprising: selectively using two distinct fuel injection units or a combination thereof for spraying fuel in a combustion chamber of the combustor of the gas turbine engine, a first one of the two distinct fuel injection units being selected and optimized for high power demands, whereas a second one of the two distinct fuel injection units being selected and optimized for low power level demands, and controlling a fuel flow ratio between said two distinct injection units as a function of the power level demand.
DESCRIPTION OF THE DRAWINGS
[0007] Reference is now made to the accompanying figures, in which:
[0008] FIG. 1 is a schematic cross-sectional view of a turbofan gas turbine engine;
[0009] FIG. 2 is a schematic cross-sectional view of the combustor section of the gas turbine engine, the combustor section having a hybrid slinger combustion system including a high power combustion zone supplied with fuel by a slinger and a low power combustion zone supplied with fuel by a set of fuel nozzles; and
[0010] FIGS. 3 a to 3 c are graphic representations illustrating the fuel flow distribution between the slinger and the fuel nozzles at different power level conditions.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] FIG. 1 illustrates a turbofan gas turbine engine 10 of a type preferably provided for use in subsonic flight, generally comprising in serial flow communication a fan 12 through which ambient air is propelled, a multistage compressor 14 for pressurizing the air, a combustor 16 in which the compressed air is mixed with fuel and ignited for generating an annular stream of hot combustion gases, and a turbine section 18 for extracting energy from the combustion gases.
[0012] As can be appreciated from FIG. 2 , the combustor 16 is a hybrid slinger combustor combining two distinct fuel injector units, a rotary fuel slinger 20 and a set of spaced-apart fuel nozzles 220 As will be discussed in further details hereinbelow, the rotary fuel slinger 20 may be optimized for high power engine demands, such as a during take-off and climb phases of a flight, while the set of individual fuel nozzles 22 may be optimized for low power engine demands, for example, at ground or flight idle. Under certain flight conditions, such as at cruise power level, the two distinct fuel injector units, the rotary fuel slinger 20 and the set of fuel nozzles 22 , may be both used to co-inject fuel according to a predetermined fuel flow ratio.
[0013] Referring more particularly to FIG. 2 , it can be appreciated that the combustor 16 is housed in a plenum 25 supplied with compressed air from the compressor diffuser 27 of the compressor 14 . The combustor 16 has an annular combustor shell 24 concentrically mounted about the engine centerline 11 in the plenum 25 . The combustor shell 24 may have a front annular liner 26 and a rear annular liner 28 . The front and rear annular liners 26 and 28 are axially spaced-apart to define therebetween a combustion chamber 30 . As schematically depicted by flow arrows 32 , the front and rear liners 26 and 28 each include a plurality of air inlet openings for allowing air to flow from the plenum 25 into the combustion chamber 30 . Cooling holes (not shown) such as effusion cooling holes, may also be defined in the front and rear liners 26 and 28 to provide cooling to the liners 26 and 28 .
[0014] As schematically shown in FIG. 2 , the rotary fuel slinger 20 is mounted for rotation with an engine shaft 34 coupled to the compressor or the turbine rotor. The rotary fuel slinger 20 is axially aligned with a radially inner circumferential opening 36 defined in the combustor shell 24 . The rotary fuel slinger 20 is configured to atomize and spray fuel radially outwardly through the circumferential opening 36 into a first combustion zone 38 of the combustor chamber 30 . A fuel manifold 40 extends into the plenum 25 for directing a flow of fuel from a fuel source (not shown) to the rotary fuel slinger 20 . As the slinger rotates 20 , fuel is centrifuged through outlet holes 42 defined in the slinger 20 , thereby atomizing the fuel into tiny droplets and evenly distributing the fuel into the first combustion zone 38 of the combustor chamber 30 .
[0015] The set of individual fuel nozzles 22 , which may be of any suitable types, are uniformly circumferentially distributed about the combustions chamber 30 and disposed generally downstream of the rotary slinger 20 relative to the flow of combustion gases through the combustions chamber 30 . By way of example, the set of fuel nozzles 22 may be composed of three or four air assisted fuel nozzles (low pressure fuel system). The fuel nozzles 22 extend in respective openings defined in the front liner 26 of the combustor shell 24 and are disposed to spray fuel into a second combustion zone 44 of the combustion chamber 30 . The fuel nozzles are connected to the fuel source via any appropriate fuel manifold structures (not shown). The fuel nozzles manifold can be integrated to the slinger fuel manifold. Valves (not shown) may be provided to control the split of fuel flow between the slinger 20 and the fuel nozzles 22 .
[0016] An appropriate number of igniters (only one being schematically shown in FIG. 2 at 46 ) are provided to ignite the fuel supplied by both the slinger 20 and the fuel nozzles 22 . The igniters 46 may all be disposed to provide spark energy in the second combustion zone 44 only. By using the fuel nozzles 22 in place of the fuel slinger 20 at ground or flight idle, it is possible to eliminate the need for long igniters which are typically required to deliver spark energy very close to conventional slinger systems in order to compensate for the poor atomization provided by the slinger when operated at low rotational speeds. Due to lower number of fuel nozzles, the fuel nozzles internal cavities can be designed to minimize internal carbon formation in addition to the optimized fuel atomization. The fuel nozzle tip orifice and internal passages may be higher than certain size to minimize internal carbon formation on the wall.
[0017] As mentioned above, the rotary fuel slinger 20 is suited for high power conditions (e.g. take-off, climb and cruise power levels). The fuel nozzles 22 are mainly used for improved starting/altitude relight and other low power level conditions. The fuel nozzles 22 provide for better fuel atomization than the fuel stinger 20 when the engine 10 is operated at low power levels. Such a hybrid or dual mode injection system allows optimizing a first one of the dual fuel injectors for low power fuel consumption and a second one of the injectors for high power fuel consumption. This provides for improved combustion efficiency and lower smoke emission as compared to conventional slinger combustors.
[0018] The split of fuel flow between the rotary fuel slinger 20 and the fuel nozzles 22 is controlled by a control unit 50 . The control unit 50 is configured for controlling the flow of fuel to the rotary fuel slinger 20 and the fuel nozzles 22 as a function of the power demand.
[0019] FIGS. 3 a to 3 c graphically illustrate three possible fuel schedules for the hybrid slinger combustions system, each graph illustrating the relative use of the stinger 20 and the set of fuel nozzles 22 in terms of fuel flow during ground operation and various phases of flight, including: ground idle, take-off, climb, cruise and decent.
[0020] According to the first option illustrated in FIG. 3 a , at ground idle, the fuel is solely injected into the combustion chamber 30 by the fuel nozzles 22 . The fuel flow through the fuel nozzles 22 at ground idle is about 20% to about 35% of the maximum fuel flow (Le. the take-off fuel flow). The slinger 20 only starts injecting fuel into the combustion chamber 30 during the ground idle to take-off acceleration phase. At the same time, the nozzle fuel flow is reduced to zero. The flow of fuel through the fuel nozzles 22 remains at zero during the various flight phases, including the climb and cruise phases. During flight all the fuel is atomized through the rotary fuel slinger 20 . The fuel slinger 20 is thus the primary fuel injector during the flight. At the decent approach, the fuel flow is switched hack to the fuel nozzles 22 as during the first ground idle phase of the engine operation.
[0021] FIG. 3 b illustrates a second option in which the fuel nozzles 22 atomise a small portion (e.g. 10%) of the fuel required during flight. According to this scenario, during flight the fuel nozzles 22 will have fuel just enough to maintain a flame. The amount of fuel through the rotary fuel slinger 20 during flight will total the required amount of fuel minus the fuel flowing through the fuel nozzles 22 .
[0022] FIG. 3 c illustrates a third option in which through out the engine running, the fuel nozzles 22 will have the ground idle fuel flow condition (i.e. the fuel flow will remain constant at about 30% to 35% of the maximum fuel flow). Again, the fuel will be supplied to the rotary slinger 20 at the beginning of the ground idle to take-off acceleration phase. During flight, the slinger fuel flow will total the required fuel flow minus the fuel through the fuel nozzles 22 (the ground idle fuel flow).
[0023] As can be appreciated from the description of FIGS. 3 a to 3 c , the fuel flow ratio between the rotary slinger 20 and the fuel nozzles 22 is controlled by the control unit 50 as a function of the variation of the power demand over a full range of engine power settings.
[0024] The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without departing from the scope of the invention disclosed. Modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the appended claims.
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There is provided a method for improving the combustion efficiency of a combustor of a gas turbine engine powering an aircraft. The method comprises selectively using two distinct fuel injection units or a combination thereof for spraying fuel in a combustion chamber of the combustor of the gas turbine engine. A first one of the two distinct fuel injection units is selected and optimized for high power demands, whereas a second one of the two distinct fuel injection units is selected and optimized for low power level demands. In operation, the fuel flow ratio between the two distinct injection units is controlled as a function of the power level demand.
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TECHNICAL FIELD
[0001] The present invention relates to a therapeutic agent for treating cancer whose retention time is appropriate for intraperitoneal administration, comprising a block copolymer containing an anti-cancer agent or a micelle preparation using the block copolymer.
BACKGROUND
[0002] Death rates of cancer have been increasing over the years in Japan. Among cancers, most of the progressed or recurrent cancers that are believed to have no complete cure available therefor, for example, stomach cancer, colorectal cancer, and ovarian cancer, are accompanied with peritoneal disseminated metastasis, which causes ileus or hydronephrosis. Peritoneal disseminated metastasis has thus damaged quality of life (QOL).
[0003] From the viewpoint of a strategy for cancer treatment, it is extremely important to establish a therapeutic method for treating peritoneal disseminated metastasis, but peritoneal disseminated metastasis is difficult to treat. A chemotherapy, an intraperitoneal hyperthermic chemotherapy, and an intraperitoneal immunotherapy have been developed, but none of them is certainly y established as a therapeutic method for peritoneal disseminated metastasis at present. With respect to the chemotherapy used for treating peritoneal disseminated metastasis caused by a cancer, an intravenously-administered anti-cancer agent is not well delivered to abdominal cavity due to a blood peritoneum harrier, and the drug efficacy may not reach the sufficient level. A clinical trial based on an intraperitoneal chemotherapy has also been developed to promote drug efficacy of paclitaxel (cf. Non-Patent Literature 1). An intraperitoneal retention time however depends on each anti-cancer agent, and such effect cannot be fully obtained with an anti-cancer agent which is lost within a short period of time (cf. Non-Patent Literatures 2 and 3). Further, a hydrophobic anti-cancer agent requires a solubilizing agent which may cause a considerable side effect. To solve the issues above, it is essential to have a method of controlling intraperitoneal drug concentration for an extended period of time without using a solubilizing agent.
[0004] It has been known that a block copolymer of polyethylene glycols and polycarboxylic acid derivatives may combine with camptothecin via ester bond to produce a polymer derivative (Patent Literature 1), and a micelle preparation may include encapsulated paclitaxel (Patent Literature 2). They showed a water solubility and a sustained release property for a long period, of time in PBS and may maintain high blood drug concentration.
CITATION LIST
Patent Literature
[0005] Patent. Literature 1: International Publication No. WO/2004/039869
[0006] Patent Literature 2: International Publication No. WO/2006/033296
Non Patent Literature
[0007] Non -Patent Literature 1: Deborah K. Armstrong et al., The New England Journal of Medicine, 2006, Vol. 354, pp. 34-43.
[0008] Non-Patent Literature. 2: Jones A I et al., Annals of Oncology, 1994, Vol. 5, pp. 123-126.
[0009] Non-Patent Literature 3: Atiq O T et al., Journal of Clinical Oncology, 1993, Vol. 11, pp. 425-433.
SUMMARY OF INVENTION
Technical Problem
[0010] The present invention provides a therapeutic agent for treating cancer which is appropriate for intraperitoneal administration of an anti-cancer agent. The agent enables a long term retention of the anti-cancer agent in an abdominal cavity.
[0011] It is preferred to control the intraperitoneal drug concentration for an extended period of time without using a solubilizing agent to avoid an adverse side effect of a solubilizing agent used for dissolving a hydrophobic anti-cancer agent.
Solution to Problem
[0012] The present inventors have made extensive study to solve the problems above, and found that a micelle preparation comprising a block copolymer bonding to or encapsulating 7-ethyl-10-hydroxycamptothecin (SN-38) or paclitaxel as an anti-cancer agent may be intraperitoneally administered such that the anti-cancer agent may be retained in an abdominal cavity for an extended time period. A superior life-prolonging effect has been obtained in a mouse model for peritoneal disseminated metastasis compared to a case in which the anti-cancer agent was intravenously administered. The present invention has been completed accordingly.
[0013] Specifically, the present invention relates to the following items (1) to (9).
(1) An therapeutic agent for treating cancer and being intraperitoneally administered as a micelle preparation, comprising:
[0015] a copolymer having a hydrophilic polymeric moiety and a polycarboxylic acid derivative moiety; and
[0016] an anti-cancer agent bonding to or encapsulated in the copolymer, and
[0017] wherein the micelle preparation exhibits sustained drug release capability, and enables an extension of a retention time period of the anti-cancer agent in an abdominal cavity.
(2) The therapeutic agent according to item (1), wherein the copolymer is a block copolymer having polyethylene glycol as the hydrophilic polymeric moiety and the polycarboxylic acid derivative moiety. (3) The therapeutic agent to according to item (2), wherein the polycarboxylic acid derivative is an acidic polyamino acid. (4) The therapeutic agent according to item (3), wherein the acidic polyamino acid is polyglutamic acid or polyaspartic acid. (5) The therapeutic agent according to item (1), wherein the block copolymer has formula (1):
[0000]
[0000] where
[0022] n is an integer of from 100 to 300,
[0023] x or y is an integer of 1 or more,
[0024] z is an integer of 1 or more,
[0025] (x+y+z) is an integer of from 10 to 80,
[0026] the ratio of x to (x+y+z) is 0 to 90%,
[0027] the ratio of y to (x+y+z) is 0 to 90%,
[0028] the ratio of z to (x+y+z) is 1 to 80%, and
[0029] R is a combination of one or more selected from hydroxy, 4-phenyl-1-butoxy, and isopropylaminocarbonyl-isopropylamino groups, with the proviso that the ratio of the hydroxy group to (x+y+z) is 0 to 10%, the ratio of the 4-phenyl-1-butoxy group to (x+y+z) is 10 to 90%, and the ratio of the isopropylaminocarbonyl-isopropylamino group to (x+y+z) is 5 to 30%.
(6) The therapeutic agent according to item (5), wherein the anti-cancer agent is paclitaxel. (7) The therapeutic agent according to item (1), wherein the micelle preparation includes a polymeric derivative drug derived from camptothecins, represented by formula (2):
[0000]
[0000] where
[0032] t is an integer of from 100 to 300,
[0033] (d+e+f) is an integer of from 6 to 60,
[0034] the ratio of d to (d+e+f) is 0 to 60%,
[0035] the ratio of e to (d+e+f) is 0 to 60%,
[0036] the ratio of f to (d+e+f) is 1 to 100%, and
[0037] R is isopropylaminocarbonyl-isopropylamino group.
(8) The therapeutic agent according to any one of items (1) to (7) for preventing and/or treating peritoneal disseminated metastasis. (9) The therapeutic agent according to any one of items (1) to (7), wherein the micelle preparation is intraperitoneally administered to treat cancers occurring in an organ present in an abdominal cavity, stomach cancer, colorectal cancer, pancreatic cancer, liver cancer, gall bladder cancer, ovarian cancer, uterine cancer, kidney cancer, ureteral cancer, or peritoneal cancer.
Advantageous Effects of Invention
[0040] The present micelle preparation for intraperitoneal administration, which includes a block copolymer bonding to or encapsulating an anti-cancer agent, has an advantageous effect of extending the abdominal retention time of the anti-cancer agent, and therefore may be effectively used for treating cancers occurring in an organ present in an abdominal cavity or accompanying peritoneal disseminated metastasis which is difficult to treat. In addition, the present micelle preparation may exert sustained drug release capability without a solubilizing agent, and therefore it is expected to be used as a therapeutic agent for intraperitoneal administration with less adverse side-effects.
BRIEF DESCRIPTION OF DRAWINGS
[0041] FIG. 1 illustrates an effect of paclitaxel (PTX) and a micelle preparation encapsulating PTX on a nude mouse model for peritoneal disseminated metastasis with human ovarian cancer cell line ES-2. The vertical axis represents the survival rate and the horizontal axis represents the days after transplantation.
[0042] FIG. 2 illustrates an effect of irinotecan hydrochloride (CPT-11) and a micelle preparation bonding to SN-38 which is an active metabolite of CPT-11 on a nude mouse model for peritoneal disseminated metastasis with human ovarian cancer cell line ES-2. The vertical axis represents the survival rate and the horizontal axis represents the days after transplantation.
[0043] FIG. 3 illustrates an effect of paclitaxel (PTX) and a micelle preparation encapsulating PTX on a nude mouse model, for peritoneal disseminated metastasis with human ovarian cancer cell, line SHIN-3. The vertical axis represents the survival rate and the horizontal axis represents she days after transplantation.
[0044] FIG. 4 illustrates an effect of paclitaxel (PTX) and a micelle preparation encapsulating PTX on a nude mouse model for peritoneal disseminated metastasis with human stomach cancer cell line MKN45-P. The vertical axis represents the survival rate and the horizontal axis represents the days after transplantation.
DESCRIPTION OF EMBODIMENTS
[0045] According to the present invention, any copolymers may be used as a copolymer of a hydrophilic polymeric moiety and a polycarboxylic acid derivative moiety as far as the copolymer exhibits the required properties The copolymer may include, but not limited to, a copolymer having polyethylene glycols as a hydrophilic copolymer and polycarboxylic acid derivative. The copolymer may also include a graft polymer and a block polymer, and a block polymer is preferred.
[0046] The polyethylene glycols may include, but not limited to, polyethylene glycol having either or both modified ends. The modified end may be a group including C 1 -C 4 alkyl group. Molecular weight of the polyethylene glycol moiety may generally be 300 to 500,000, and preferably 500 to 100,000.
[0047] The polycarboxylic acid derivative indicates a polymer having a carboxylic acid group as a side chain. The polycarboxylic acid derivative may include, but not limited to, polyacrylic acid, polymethacrylic acid, polymalic acid, and acidic polyamino acid such as polyaspartic acid and polyglutamic acid. Polyaspartic acid and polyglutamic acid may be particularly preferable.
[0048] The block copolymer may include, but not limited to, a copolymer of polyethylene glycols and polycarboxylic acid derivative, and C 1 -C 4 alkoxy polyethylene glycol-polyaspartic and C 1 -C 4 alkoxy polyethylene glycol-polyglutamic acid may particularly be preferable. The copolymer may be prepared by a process described in a conventional article, e.g., Patent Literature 1 or 2, Japanese Patent Application Laid-Open No. 06-206815, Japanese Patent Application Laid-Open No. 2003-504393.
[0049] The anti-cancer agent, which is bound to or encapsulated in the block copolymer, may be any anti-cancer agents generally used for cancer treatment. The anti-cancer agent may include, but not limited to, taxoid-based drug, platinum drug, nitrosourea-based drug, nitrogen mustard-based drug, triazine-based drug, anthracycline-based drug, vinca alkaloid-based drug, epipodophyllotoxin-based drug, camptothecin-based drug, and fluoropyrimidine-based drug. The taxoid-based drug may include taxol, taxotere, paclitaxel, and docetaxel. The platinum-based drug may include cisplatin and carboplatin. The nitrosourea-based drug may include carmustin and lomustin. The nitrogen mustard-based drug may include cyclophosphamide. The triazine-based drug may include dacarbazine. The anthracycline-based drug may include doxorubcin. The vinca alkaloid-based drug may include vincristine and vinblastine. The epipodophyllotoxin-based drug may include etoposide. The camptothecin-based drug may include irinotecan. The fluoropyridine-based drug may include tegafur. A preferred anti-cancer agent may include paclitaxel and 7-ethyl-10-hydroxycamptothecin (SN-38) which is an active metabolite of irinotecan. Irinotecan is a water soluble prodrug, and converts into active metabolite SN-38 to exhibit an anti-tumor activity by a hydrolysis mainly with liver carboxyesterase after administration.
[0050] The method for binding or encapsulating an anti-cancer agent to/in the present block copolymer may be carried out in view of the Patent Literatures above.
[0051] With regard to a micelle preparation including a block copolymer to which an anti-cancer agent is bound, the amount of the agent may appropriately be varied from low concentration to high concentration.
[0052] In the case that a micelle preparation comprising a block copolymer in which an anti-cancer agent is encapsulated, the ratio of the amount of the anti-cancer agent to the total weight of the anti-cancer agent and the block copolymer is 0.1% to 50% by weight. Further, the drug content may be about 0.01 mg or more, and preferably about 0.1 mg or more by 1 ml of an aqueous solution of the micelle preparation.
[0053] A cancer which is an object of the treatment in the present therapeutic agent may include, but not limited to, a cancer occurring in an organ present in an abdominal cavity such as stomach cancer, colorectal cancer, pancreatic cancer, liver cancer, gall bladder cancer, ovarian cancer, uterine cancer, kidney cancer, ureteral cancer, and peritoneal cancer. The present therapeutic agent may be intraperitoneally administered to effectively treat or prevent a recurrence of those cancers and peritoneal disseminated metastasis complicated with the cancers.
[0054] The term “peritoneal disseminated metastasis” indicates that visible particulate nodes or lumps are formed on a peritoneum. The nodes or lumps may be occurred by repeated divisions and proliferations of cancer cells distributed on a peritoneum, that are released from a surface of a cancer in an abdominal organ.
[0055] It is considered that progressed or recurred stomach cancer is often accompanied with peritoneal disseminated metastasis, and it would make the cancer treatment difficult. Further, it is known that peritoneal disseminated metastasis may be also accompanied with colorectal cancer, ovarian cancer, uterine cancer, gall bladder cancer, and ureteral cancer, as well as stomach cancer.
[0056] The present therapeutic agent may be administered intraperitoneally. The term “intraperitoneal administration” means that a drug is administered directly into an abdominal cavity. The intraperitoneal administration of a drug may be carried out by injection or by using a catheter, for example.
[0057] Dosage of an anti-cancer agent may vary depending on the type of an anti-cancer agent used. The dosage may preferably be appropriately chosen and determined in view of the dosage that is used for general treatment. In the case that a micelle preparation containing paclitaxel or SN-38 (an active metabolite of irinotecan) is applied via intraperitoneal administration, its dosage may generally be about 0.1 to 500 mg/m 2 (body surface area) as an active component per day for an adult patient. Dosage may vary depending on age, symptom, or the like of a patient.
[0058] The present therapeutic agent may be prepared with various common additive components. The additive may include, but not limited to, a stabilizing agent, a bactericidal agent, a buffer agent, an isotonizing agent, a chelating agent, a pH controlling agent, a surfactant, and a solubilizing agent.
[0059] The stabilizing agent may include, but not limited to, human serum albumin, common L-amino acids, sugars, and cellulose derivatives. The stabilizing agent may be used either singly or in combination with a surface active agent or the like. According to the use of the combination, the stability of the effective component may be further improved. The L-amino acids are not particularly limited, and examples thereof may include glycine, cysteine, and glutamic acid. The sugars may include, but not limited to, monosaccharides such as glucose, mannose, galactose, and fructose; sugar alcohols such as mannitol, inositol, and xylitol; disaccharides such as sucrose, maltose, and lactose; and polysaccharides such as dextran, hydroxypropyl starch, chondroitin sulfate, and hyaluronic acid; and derivatives thereof. The cellulose derivatives may include, but not limited to, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxylpropylmethyl cellulose, and sodium carboxymethyl cellulose. The surfactant may include, but not limited to, an ionic surface active agent and a non-ionic surface active agent, and may preferably include polyoxyethylene glycol sorbitan alkyl esters, polyoxyethylene alkyl ethers, sorbitan monoacyl esters, and fatty acid glycerides.
[0060] The buffer agent may include, but not limited to, boric acid, phosphoric acid, acetic acid, citric acid, ε-aminocaproic acid, glutamic acid, and/or salts thereof (e.g., an alkali metal salt such as sodium salt, potassium salt, calcium salt, and magnesium salt, and an alkali earth metal salt).
[0061] The isotonizing agent may include, but not limited to, sodium chloride, potassium chloride, sugars, and glycerin.
[0062] The chelating agent may include, but not limited to, edetate sodium and citric acid.
[0063] The solubilizing agent may include, but not limited to, alcohols such as ethanol.
EXAMPLES
[0064] Hereinafter, the present invention is described in greater detail by reference to the Examples, but the present invention is not limited to the following examples.
<Test Summary>
[0065] A micelle preparation, in which paclitaxel or SN-38 (an active metabolite of irinotecan hydrochloride) is encapsulated or bound, was used. An intraperitoneal administration of paclitaxel has been known as a significantly effective method for treating peritoneal disseminated metastasis caused by ovarian cancer compared to an in administration (Non-Patent Literature 1). One of advantages of the intraperitoneal administration of paclitaxel relates to the fact that the intraperitoneal concentration maybe higher than that of intravenous administration. However, although a direct effect of the intraperitoneal administration on peritoneal disseminated metastasis is expected, a drug is quickly lost from an abdominal cavity and therefore the concentration level will be reduced from the level required for exhibiting an anti-tumor effect after a short period of time. In the regard, a micelle preparation was prepared by binding a drug to a block copolymer or encapsulating it therein and administered to provide a sustained release capability. Then consistency of the concentration required for exhibiting an anti-tumor effect and a superior life-prolonging effect obtained therefrom were estimated.
<Test Protocol>
[0066] Therapeutic effects on peritoneal disseminated metastasis were tested by using a mouse model for peritoneal disseminated metastasis. Specifically, the mouse model for peritoneal disseminated metastasis was prepared by intraperitoneal injection of human ovarian cancer cell line ES-2 (1.0×10 6 cells) to an 8-week old BALE/c nude mouse. Note that the present therapeutic agent may apply to any other cancer cell lines other than ES-2.
[0067] A micelle preparation having sustained release capability in which paclitaxel is encapsulated was prepared according to the description of Examples 1 and 4 of Patent Literature 2 (International Publication No. 2006/033296). The micelle preparation was used for present Test Example 1
[0068] A micelle preparation having sustained release capability to which SN-38 is bound was prepared according to the description of the Example 1 of Patent Literature 1 (International Publication No. 2004/039869). The preparation was used for present Test Example 2.
Reference Example 1
Production of Micelle Preparation Having Encapsulated Paclitaxel
[0069] A copolymer of formula (1) was synthesized according to the process disclosed in Example 1 of Patent Literature 2 (International Publication. No. 2006/033296)
[0000]
[0000] where n is about 272; (x+y+z) is 40; the ratio of (x+y) to (x+y+z) is 63%; the ratio of z to (x+y+z) is 37%; and for R, the ratio of the hydroxy group to (x+y+z) is 0%, the ratio of 4-phenyl-1-butoxy group to (x+y+z) is 49%, and the ratio of isopropyl aminocarbonyl-isopropylamino group to (x+y+z) is 14%.
[0070] According to a process described in JP-A No. 06-206815, 42 g of PEG (average molecular weight 12000)-pAsp (polyaspartic acid; average polymerization number 40)-Ac (n is about 272, x is about 10, and y is about 30) was prepared, and DMF (630 ml), N,N-dimethyl aminopyridine (9.9 g), 4-phenyl-1-butanol (10.93 ml), and diisopropylcarbodiimide (15.86 ml) were added and maintained for 24 hours at 25° C. After purification of the reactants, about 48 g of block copolymer 1 was obtained. Block copolymer 1 (47.32 g) was dissolved in DMF (946 ml), added with N,N-dimethyl aminopyridine (7.23 g) and diisopropylcarbodiimide (14.37 ml), and maintained for 20 hours at 35° C. After purification of the reactants, about 44 g of target block copolymer 2 was obtained. The ratio of ester-bonded 4-phenyl-1-butanol was 49% to (x+y+z), and the ratio of hydroxy group was 0% to (x+y+z). The ratio of (x+y) to (x+y+z) was 63% and the ratio of z to (x+y+z) was 37%.
[0071] Block copolymer 2 (300 mg) was added to 30 ml of an aqueous maltose solution (40 mg/ml) to make a dispersion, and then cooled to 4° C. with stirring. 30 mg/ml paclitaxel of 3 ml dichloromethane solution was added, and stirred without sealing for 16 hours in a refrigerator. The mixture was subjected to an ultrasonication treatment at 130 W for 10 min to obtain a micelle preparation. The paclitaxel concentration was 2.2 mg/ml.
Reference Example 2
Production of Micelle Preparation Bound to SN-38
[0072] A copolymer derivative of camptothecins of formula (2) was synthesized according to the process disclosed in Example 1 of Patent Literature 1 (International Publication No. 2004/039869).
[0000]
[0000] where t is about 273; (d+e+f) is about 28; the ratio of d to (d+e+f) is 15.5%; the ratio of e to (d+e+f) is 36.1%; the ratio of f d to (d+e+f) is 48.4%; and R is an isopropylaminocarbonyl-isopropyiamino group).
[0073] A block copolymer (210 mg) of methoxypolyethylene glycol (molecular weight: about 12,000) and polyglutamic acid (polymerization degree: about 28) and 7-ethyl-10-hydroxycamptothecin (80 mg) were dissolved in DMF (14 ml), added with N,N-dimethyl aminopyridine (13.5 mg) and diisopropylcarbodiimide (0.116 ml), and stirred for 20 hours at room temperature. After purification of the reactants, the target compound (270 mg) was obtained. The target compound had 7-ethyl-10-hydroxycamptothecin (25.4 w/w %) conjugate and an isopropylaminocarbonyl-isopropylamino group (3.0 w/w %) bound to the polyglutamic acid moiety. The ratio of d to (d+e+f) was 15.5%, the ratio of e to (d+e+f) was 36.1%, and the ratio of f to (d+e+f) was 48.4%.
Test Example 1
Intraperitoneal Administration of Micelle Preparation Having Encapsulated Paclitaxel
[0074] In order to estimate advantageous life-prolonging effects of the present micelle preparation having encapsulated paclitaxel, the model mice were divided into three groups, i.e., 8 mice per group. 1 ml of saline (Control group); 1 ml of saline containing 70 mg/kg of paclitaxel (70 mg/kg PTX administered group); and 1 ml of 5% glucose solution containing the micelle preparation containing 50 mg/kg of encapsulated paclitaxel (50 mg/kg PTX micelle administered group) were intraperitoneally administered to the mouse of each group, respectively. Intraperitoneal administrations were carried out once after three days of tumor transplantation. In addition, the drug dosage was determined by converting a clinical dosage for intravenous route (paclitaxel: 210 mg/m 2 and paclitaxel micelle preparation: 150 mg/m 2 ) to those for a mouse using an AUC comparison. The mice were observed until 80 days after the cell transplantation. The survival rates were recorded and the survival curves were plotted in FIG. 1 .
[0075] Superior life-prolonging effect of the present micelle preparation having encapsulated paclitaxel was estimated on the mouse model for peritoneal disseminated metastasis. The 50% survival rates of the Control group, the 50 mg/kg PTX micelle administered group, and the 70 mg/kg PTX administered group were on Day 17, Day 69, and Day 44 after the transplantations, respectively. The paclitaxel micelle preparation had a superior effect over paclitaxel
Test Example 2
Intraperitoneal Administration of Micelle Preparation Having Bound SN-38
[0076] In order to determine the superior life-prolonging effect of the micelle preparation having bound SN-38 (an active metabolite of irinotecan hydrochloride), the model mice were divided into three groups, i.e., 6 mice per group. 1 ml of saline (Control group); 1 ml of saline containing 66.7 mg/kg of irinotecan hydrochloride (66.7 mg/kg CPT-11 administered group); and 1 ml of 5% glucose solution containing the micelle preparation containing 30 mg/kg of SN-38 (30 mg/kg SN-38 micelle administered group) were intraperitoneally administered to the mouse of each group, respectively. The intraperitoneal administrations were carried out once after three days of tumor transplantations. In addition, the drug dosage was determined as the one-third of the maximum amount allowed for intravenous route administration for a mouse. The mice were observed until 80 days after the cell transplantation. The survival rates were recorded and the survival curves were plotted in FIG. 2 .
[0077] Superior life-prolonging effect of the micelle preparation having bound SN-38 was estimated on a model for peritoneal disseminated metastasis. The 50% survival rate of the Control group was on Day 21 after the transplantation. The five-sixth of the mice in the 30 mg/kg SN-38 micelle administered group were survived for 80 days after the transplantation. The 50% survival rate of the 66.7 mg/kg CPT-11 administered group was on Day 56 after the transplantation. The SN-38 micelle preparation had a superior effect over irinotecan hydrochloride
Test Example 3
Intraperitoneal Administration of Micelle Preparation Having Encapsulated Paclitaxel
[0078] In order to estimate an effect of intraperitoneal administration of the micelle preparation having encapsulated paclitaxel, a mouse model for peritoneal disseminated metastasis was prepared by intraperitoneal injection of human ovarian cancer cell line SHIN-3 (1.0×10 7 cells) to an 8-week old BALB/c nude mouse. Three groups were created as following: 1 ml of saline (Control group, 18 mice); 1 ml of saline containing 100 mg/ml of paclitaxel (100 mg/kg PTX administered group, 8 mice); and 1 ml of 5% glucose solution. containing the micelle preparation containing 50 mg/ml of encapsulated paclitaxel (50 mg/kg PTX micelle administered group, 8 mice) were intraperitoneally administered to the mouse of each group, respectively. The amounts of the ingredients were of by 20 g mouse body weight. The administrations were carried out once after one week of the tumor transplantations. The mice were observed until 120 days after the cell transplantation. The survival rates were recorded and the survival, curves was plotted in FIG. 3 .
[0079] The effect of the intraperitoneal administration of a micelle preparation having encapsulated paclitaxel Was estimated. According to the intraperitoneal administration, the 50% survival rate of the 50 mg/kg PTX micelle administered group was on Day 95 after transplantation, and those of the 100 mg/kg PTX administered group was on Day 100 after transplantation. Their effects were similar in each group. There were two cases of toxic death recognized in the PTX administered group, while no toxic death was observed in the PTX micelle administered group at the dosage of 100 mg/kg as paclitaxel. The micelle preparation had no adverse effect and the same efficacy as paclitaxel at dosage which was half of those of paclitaxel showing toxicity. The intraperitoneal administration of a micelle preparation was certainly useful for treating peritoneal disseminated metastasis.
Test Example 4
Intraperitoneal Administration of Micelle Preparation Having Encapsulated Paclitaxel
[0080] In order to estimate an effect of intraperitoneal administration of a micelle preparation having encapsulated paclitaxel, a mouse model for peritoneal disseminated metastasis was prepared by intraperitoneal injection of human stomach cancer cell line MKN45-P (1.0×10 6 cells) to an 8-week old BALB/c nude mouse. Three groups were created as following: 1 ml of saline (Control group, 8 mice); 1 ml of saline containing 50 mg/ml of paclitaxel (50 mg/kg PTX administered group, 8 mice); and 1 ml of 5% glucose solution containing the micelle preparation containing 25 mg/ml of encapsulated paclitaxel (25 mg/kg PTX micelle administered group, 8 mice) were intraperitoneally administered to the mouse of each group, respectively. The amounts of the ingredients were of by 25 g mouse body weight. The administrations were carried out once after three days of the tumor transplantation. The mice were observed until 60 days after the cell transplantation. The survival rates was recorded and the survival curves was plotted in FIG. 4 .
[0081] An effect of the intraperitoneal administration of a micelle preparation having encapsulated paclitaxel was estimated. According to the intraperitoneal administration, the 50% survival rates of the 50 mg/kg PTX administered group and the 25 mg/kg PTX micelle administered group were on Day 55 and Day 60 or later after transplantation, respectively. Efficacy shown in the 25 mg/kg PTX micelle administered group was the same or higher than the paclitaxel group, even with half dosage. The intraperitoneal administration of the present micelle preparation having encapsulated paclitaxel was useful not only for human ovarian cancer but also for peritoneal disseminated metastasis associated with human stomach cancer.
INDUSTRIAL APPLICABILITY
[0082] The drug, method, and use according to the present invention has an effect of extending retention time of an intraperitoneally administered anti-cancer agent in an abdominal cavity, and may provide an advantageous effect of the anti-cancer agent. The present invention can effectively treat a cancer which occurs in an abdominal, organ and accompanying peritoneal disseminated metastasis which was difficult to treat. Thus, the applicability of the present invention is extremely high and useful in the field of medicine.
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To provide a therapeutic method using a water soluble, high molecular weight block polymer to enable that an intraperitoneally administered anti-cancer agent may maintain for a long-term retention in the abdominal cavity to enoughly exert the effect of the anti-cancer agent and reduce adverse side-effects thereof.
A therapeutic agent as a micelle preparation, comprising a copolymer having a hydrophilic polymeric moiety and a polycarboxylic acid derivative moiety; and an anti-cancer agent bonding to or encapsulated in the copolymer, wherein the micelle preparation may exhibit sustained drug release capability, and enables an extension of a retention time period of the anti-cancer agent in an abdominal cavity, is provided. A superior life-prolonging effect was found in an intraperitoneal administration mouse model compared with a case in which only an encapsulated drug is administered, and thus the present invention was completed accordingly.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present patent application claims priority under 35 U.S.C. §119 to the provisional patent application identified by U.S. Ser. No. 60/415,259, filed on Sep. 30, 2002, the entire content of which is hereby incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF INVENTION
Today, most stores selling goods or services have both a computer transaction system to record sales activity when employees are present and a store security system to watch the store when employees are not present. Often the computer system is a Point Of Sale (POS) hardware and software system provided to the owner of a franchise such as a McDonalds, Wendy's, Great Clips, Pro Cuts, Texaco, Exxon, Pep Boys, Auto Zone, Jiffy Lube, etc., by the franchiser and is designed to provide the owner with customer and sales information as input by the employees into the POS computer system.
Store security systems are provided by a number of vendors such as ADT and Smith Alarm and are primarily designed to store activity and after hours and thwart attempted burglaries. Since the advent of the video camera, a video camera connected to other sensors such as motion, or door and window, or cash drawer sensors are the primary elements of store security systems.
More recently, video surveillance systems have been employed to help owners catch employee theft. It is well known in all the various industry sectors (especially service industries) that employee theft is the greatest operating loss facing owners due to the discrepancy between the actual customer store transaction versus the data entered (or not entered) into the store POS computer system. The video surveillance systems in recent years have provided more information to help curb this loss, but it still requires a lot of time and effort by the owner to try and correlate information from a store surveillance system depicting customer store activity, for example, with the store POS computer system operated by the employee. Such correlation must show that an employee serviced a customer without inputting the transaction into the store computer system and kept the revenue or input an incorrect amount in order to manipulate the reported amount.
Large corporations such as Dillard's, Macy's, Neiman Marcus, Wal-Mart, Target and many others, including casinos, have developed extensive security monitoring systems to help catch employee theft, but these are primarily systems requiring management personnel and strict employee money handling policies implemented to quickly catch unsophisticated employee theft through a series of daily checks and balances but not through any fully automated system.
Store and business computer systems are well known in the art and recently companies such as BEA, Peoplesoft, IBM, Siebel, Microsoft, Oracle and many others have developed specialized business programs accessible from the Web but not store computer systems where the owner can operate the store computer program from remote locations and none of them have developed store transaction system. Programs such as PC anywhere or services such as www.gotomypc.com can be used to operate a computer remotely but a “disconnected” system that behind the scenes goes and operates the store computer to input changes made by store owners are not available.
The Franchise companies are taking the lead in developing Internet sites where a store owner can view their operational data such as at www.salondata.com but do not offer the ability to operate the store computer system in a connected or disconnected manner from a website.
A typical state of the art web accessible store or home security surveillance system can be seen at www.adt.com. However, store surveillance systems fall way short of the complicated customer activity determination required by a store transaction system and, a store transaction system as described herein has not been developed in the industry until now. Furthermore the integration of a store point of sale computer system with a store transaction system such as described in this invention is not even being discussed in the current business trade journals as a solution to the employee revenue theft problem and the system described herein offers a way for technology to greatly lower employee theft in a cost effective manner.
Problems to be Solved
A primary problem to be solved is that of first providing a store “transaction system” that can be installed in a store to automatically provide information regarding what revenue the store “should” be making if all of the customers being serviced are entered into the stores point of sale “computer system” properly. Such a system will be sensitive to the type of store business (e.g. type service, type product, store and facility layout, etc.) and complicity of the transaction pricing system (e.g. product store may have several thousand possible transaction prices whereas a service store may only have 5 to 20).
Consequently the transaction system for one type store may vary considerable in the way it computes revenue versus a transaction system from that of another type store. However the basic architecture will be virtually the same with the main difference being in the transaction system revenue computational programs of the various type stores.
A second primary problem to be solved is that of combining a store transaction system with a store point of sale computer system in such a manner that the difference between the revenues from these two systems can be determined automatically and when possible associate the difference with the employees responsible for these discrepancies. When possible the solution to this problem should be done completely automatically and the results accessible by the owner from any web access device.
It will be assumed through out these descriptions that the store transaction system captures all of the “actual” revenue transactions each day so that any discrepancy is because one or more employees does not enter into the store point of sale computer, revenue they received from a customer.
Another employee theft problem to be solved, and preferably with the same system, is that of allowing the owner to review and alter the store employee hours accumulated by the store computer from remote locations each day so the employee computer work hours can be maintained in accordance with the actual worked hours as seen by the store transaction system or other employee time control system.
SUMMARY OF THE INVENTION
The current invention disclosed and claimed herein relates to a store transaction system that determines automatically the revenue the store should be making based on the transactions being observed by the system. Several preferred embodiments for different type businesses are described and a more detailed description is provided for a Hair Salon business.
The current invention disclosed and claimed herein also relates to an “Integrated Computer And Store Transaction System” (ICASTS) that compares information accumulated in a store point of sale computer system as input by the store employee and corresponding information accumulated in a store transaction system and notes any differences automatically. In a preferred embodiment information from both computer systems are accumulated at a third party Website and the comparisons are made available to the owner or operator in several ways so as to gain quick insight into when and what employees are involved in causing discrepancies. A preferred embodiment to build the ICASTS utilizes the “Split Personal Computer System” described in U.S. Pat. Nos. 6,243,743 and 6,350,253 developed by Freeny et al at www.mosspc.com along with the “Master Operating Software System” and “Low Entropy Terminal User System” of Pending applications disclosed in U.S. Ser. No. 09/697,557 respectively to provide an easy to use Internet computer available anytime anywhere from virtually any Internet device available to the owner.
The simple Internet Computer solution allows an owner to completely control their stores from anywhere in the world and forbid access to most store information by the store employees. The invention described herein allows stores (or store departments) providing both service and product to have two integrated computer systems one automatically computing transaction revenue plus one computing point of sale revenue and comparing the two revenues.
The various inventions described herein solve the problems listed above.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a block diagram of an integrated computer and store transaction system constructed in accordance with the present invention.
FIG. 2 is a block diagram of a store transaction system constructed in accordance with the present invention.
FIG. 3 is a pictorial representation of a remote store control system constructed in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings and in particular to FIG. 1 , shown therein and designated by a reference numeral 10 is an integrated computer and store transaction system constructed in accordance with the present invention. The system 10 includes a store transaction system 12 , a store computer system 14 (or point of sale system 14 ), an owner computer 16 and a store control unit 18 . Each of the store transaction system 12 , the store computer system 14 , the owner computer 16 and the store control unit 18 typically communicate with each other via a network 20 . The network 20 can be a wide area network or a local area network. In general, The system 10 is designed to monitor activity associated with one or more stores and determine an automated tracking signal indicative of a predetermined activity to be automatically monitored. In one preferred embodiment, the activity to be monitored is customer activity, and the automated tracking signal is indicative of expected revenue based on the customer activity.
The store control unit 18 receives the automated tracking signal and also receives a baseline comparison signal. The store control unit 18 compares the automated tracking signal with the baseline comparison signal so that an owner can be notified of any discrepancy or difference between the automated tracking signal and the baseline comparison signal.
In one preferred embodiment, the automated tracking signal is indicative of expected revenue and the baseline comparison signal is actual revenue received from the store computer system 14 . In this embodiment, the expected revenue is compared with actual revenue so that an owner can determine if any employee theft, bad salesmanship or other problem is occurring. The store control unit 18 outputs an alert signal upon determination of a difference exceeding a predetermined level between the automated tracking signal and the baseline comparison signal.
The term “store” as used herein refers to a location where one or more good and/or service is provided to a customer. The term store can also refer to a department within a store. Common examples of a store is fast food delivery stores, such as McDonalds and Wendy's, a hair salon, such as Great Clips, or Pro Cuts, a gas station, such as Texaco, or Exxon, automobile service stations, such as Pep Boys, or Jiffy Lube, or automobile parts store, such as Auto Zone.
The store transaction system 12 includes one or more sensor 24 ( FIG. 2 ) associated with a store. The sensor 24 receives information indicative of activity, such as customer activity and automatically outputs activity signals via a signal path 26 . The activity signals can be customer activity signals indicative of customer activity sensed by the sensor 24 . The store transaction system 12 also includes an activity computer 30 and a transaction computer 32 . The activity computer 30 collects the activity signals and sends information indicative of such activity signals to the transaction computer 32 for automated tracking determination. The transaction computer 32 automatically receives the activity signals and automatically generates an automated tracking signal, such as an expected revenue signal indicative of expected revenue, to be received by the store based on the activity.
The transaction computer 32 outputs the automated tracking signal, such as the expected revenue signal, via a signal path 40 to the store control unit 18 via a signal path 40 , the network 20 and the signal path 42 . The store computer system 14 generates or has stored therein baseline comparison signals or information. In one preferred embodiment, the baseline comparison signals can be actual revenue signals based on actual revenue derived from transactions actually entered into the store computer system 14 . The store computer system 14 outputs the baseline comparison signals, such as the actual revenue signals to the store control unit 18 via a signal path 46 , the network 20 and the signal path 42 .
The store control unit 42 receives the automated tracking signals and the baseline comparison signals. The store control unit 42 compares the automated tracking signal with the baseline comparison signal. In one preferred embodiment, if a large discrepancy exists between the automated tracking signal and the baseline comparison signal, the store control unit 18 outputs an alert signal. As will be understood by one skilled in the art, the amount of the discrepancy can be tailored based on many factors, such as the expected accuracy of the automated tracking signal, the comfort level of the owner, or the like. In one preferred embodiment, the store control unit 18 is established as a website communicating with the Internet.
The store or department in a multiple department store 5 will generally have the store computer system 14 generally referred to as a “Point Of Sale” (POS) system operated by the store employees. The POS 14 is designed to record all of the store customer sales noted by customers, for example. The customer sales can be for services or store products which are not shown separately.
Typical employee theft occurs when a customer pays an employee for either a product or service and the employee either fails to enter the transaction into the store computer system 14 or enters an incorrect or lesser amount than paid by the customer. In the case of thefts involving products most store computer system 14 track inventory and physical counts versus POS counts and can detect when these numbers are different. However for service businesses such as a hair salon or an automobile oil change service theft is hard to detect with out some means of watching all store customer transactions.
The store transaction system 12 has a means to detect each store customer and their corresponding transactions independent of the store POS system 14 operated by the store employees. Store computer systems 14 are well known in the art and will not be described herein other than noting the type of information normally accumulated in the store computer system 14 . The store transaction system is primarily designed to provide an independent assessment of what revenue the store should be collecting based on the customer and their activity. Note that although the store computer system 14 and the store transaction system 12 are shown separately for purposes of clarity they may in fact share the same physical housing and computer hardware.
In order that both the store computer system 14 and the store transaction system 12 have identical information regarding the store employees and store products or services a connection 50 serves to allow the store transaction system 12 and the store computer system 14 to share such information. The network 20 which can be a WAN or LAN including the Internet connects the various elements together and allows the owner or manager of the store to observe activity in both the store computer system 14 and the store transaction system 12 via an owner computer 16 . The owner computer 16 communicates with the store transaction system 12 , the store computer system 14 , or the store control unit 18 via a signal path 52 and the network 20 .
One preferred embodiment automatically compares the store activity, such as revenue, using the store control unit 18 such as a website or local client server which are well known in the art. The owner can utilize the owner computer 16 to access the store control unit 18 to observe any differences in actual and expected store revenue. Preferred embodiments provide various ways to compare the activity being accumulated in the store computer system 14 and the store transaction system 12 such as by employee, by shift, by product or service and many others.
In FIG. 2 the basic elements of the store transaction system 12 are shown and include the transaction computer 32 connected to the store computer system 14 via the signal path 40 to receive employee and product and service transaction data (automated tracking signals) for use in determining each of the various transactions such as expected revenue, or other activity signals that owners might deem important to want to have automated tracking such as employee time, customer service treatment (i.e. length of time, proper greetings), or other store policies.
The invention will be described hereinafter with reference to the determination of expected revenue based on customer activity signals. However, it should be understood that the present invention is equally applicable to determining other types of automated tracking signals.
The transaction computer 32 receives data from the activity computer 30 via the signal path 34 . The activity computer 30 receives information from the sensors 24 such as video cameras, sound detectors or other sensors such as motion, proximity, and many others well known in the art of surveillance via line the signal paths 26 . In one preferred embodiment, each of the sensors 24 observe each customer and employee. It should be understood that activity, such as customer and/or employee activity does not have to be at a physical location, the activity can be call in, website or any other method of receiving activity, such as customer and/or employee activity. The information observed from activity is collected in the activity computer 30 and sent to the transaction computer 32 via signal path 34 for automated tracking determination.
For example the transaction computer 32 might determine each store customer for one set of data and use an average store sales price to determine how much revenue the store should be collecting. There are many ways to determine the store activity depending on the type of store and a specific method is described below for a hair salon. The more information supplied by the activity computer 30 the more precise the transaction computer 32 can determine the store transaction for each customer and employee. Note that although the transaction computer 32 and the activity computer 30 are shown separately they may share the same housing and computer hardware.
The activity computer 30 may also serve as the store security system and security signals from the activity computer 30 are sent directly to the store security monitor service (not shown) via signal path 60 .
The basic elements of the Store Control Unit 18 is shown in FIG. 3 and includes a computer 70 connected to the other store elements via the network 20 and the signal path 42 . The computer 70 has both input units 72 , such as a keyboard and a mouse and outputs units 74 . A preferred embodiment of the store control unit 18 and/or the owner computer 16 is such that a third party website maintains the computer 70 and the input unit(s) 72 and the output unit(s) 74 are located with or at the store for easy access from any location at any time. Such a system and design are described in U.S. Pat. Nos. 6,343,743 and 6,350,253. Also it should be mentioned that the store control unit 18 , the store transaction system 12 and the store computer system 14 may in fact share the same housing and computer hardware depending on the particular system desired by the store owner. Further, the owner computer 16 and the store control unit 18 can be located at a store or a department within a store, or maintained as a web site.
One embodiment of the system 10 for a hair salon will be described hereinafter. The sensors 24 can be included in a combination of salon cameras with audio and salon sensors located for example at the salon door, stylist chairs, and POS cash register (not shown but well known to those in the surveillance business). For example, one or more of the sensors 24 can be a pressure sensor or photosensor placed in or on the stylist's chair to determine when a person is sifting in the chair. A transaction is determined for each customer from the sensors 24 along with salon product and service data sent to the store transaction system 12 . The salon product and service data can be correlated with each salon stylist or employee if desired.
The store activity information such as revenue and customer count as determined by the store transaction system 12 is sent from the store transaction system 12 to the store control unit 18 , which is implemented as a store website. The store activity information can be transmitted via a predetermined polling or data uploading program stored in either the store control unit 18 or the store transaction system 12 .
For example store revenue can be computed by using a standard average sale value for each customer serviced or using a value based on the type service being provided by the stylist in each case. Depending on the sophistication of the store transaction system 12 , additional activity information such as, time each employee worked, number of time each stylist greets customer according to store policy, plus employee selling activity, and time to service a customer can be recorded. That is, additional information that can be used for employee performance appraisals can also be obtained from the store transaction system 12 . In essence the store transaction system 12 can be made just as effective or more effective as having a store manager actively watching every employee servicing every customer. During the same time period the hair salon store computer system 14 records customer sale transactions based on the hair stylist inputs transactions. The store computer system 14 also computes other hair salon information such as time to cut each customer, number of customers per stylist, product sales and time the employee is clocked in to work based on the employee inputs to the store computer system 14 . The store activity information such as revenue and customer count as determined by the store computer system 14 is sent from the store computer system 14 to the store control unit 18 , which is established as a website according to a predetermined polling or data uploading program.
The store control unit 18 compares the store activity information sent by both the store transaction system 12 and the store computer system 14 and makes available the differences between the data along with the data from each system. The owner computer 16 can access the store activity information from any Internet access device with a proper browser such as Netscape 6.0 or IE 6.0.
The store control unit 18 for the hair salon can be used to determine many types of store activity comparisons such as plotting differences in the two activity systems based on: a) store employee shifts; b) days of the week; c) hours of the day; and many more. Such differences can be used to quickly focus in on camera data for example that also can be made available from the store control unit 18 to observe employees during periods the automated system suggest a large discrepancy between store transaction system 12 activity and store POS computer activity. In addition, in a preferred embodiment using the Split PC system described in U.S. Pat. No. 6,343,743, for example, the owner computer 16 can alter the employee time worked data entered into store POS computer 430 using their access device along with other data the store transaction system 12 suggests should be corrected.
The elements and system to produce an automated store transaction system 12 capturing the store activity independently of the activity as input by employees into the store point of sale computer system 14 and the integrated computer and store transaction system 10 that compares two relative independent automated store or service activity system in order to determine employee theft has been described using specific type stores and services stores. Although 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. Accordingly, it is intended to embrace all such alternatives, modifications, and variations that fall within the spirit and broad scope of the appended claims.
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A store transaction system that can determine what a store should be making each day if all the customer transactions were entered into the stores point of sale computer. The store transaction system combines various sensor outputs activated by customer activity in a logical manner to develop an independent store monitor that can operate 24/7 to reduce employee theft. A preferred embodiment compares the store transaction system revenue with the store point of sale computer system operated by the employees so an owner can determine a shift or the employees that are involved with theft without having to manually view video surveillance information or hire extra managers to watch the store operations. The invention also allows remote reviewing of those that are having exceptional positive impact on store sales. Another preferred embodiment allows an owner to remotely operate their integrated computer and store transaction system from any Internet access device with the proper browser.
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RELATED APPLICATION
[0001] This application claims the benefit of priority from European Patent Application No. 07 291 494.8, filed on Dec. 11, 2007, the entirety of which are incorporated by reference.
FIELD OF THE INVENTION
[0002] The invention relates to a shear screw for fastening an electrical conductor in a metallic terminal designed as a tubular piece, which shear screw has in its wall at least one through-hole, provided with a thread, for receiving the shear screw which in two planes separated axially from one another has predetermined breaking points, a first predetermined breaking point and a second predetermined breaking point, and which has centrally a blind hole extending over a substantial length and having a cross section which is suitable for transmitting a torque to the shear screw by means of a pin-like tool which can be inserted into the blind hole and the cross section of which corresponds to the cross section of the blind hole and the external dimensions of which correspond to the clear dimensions of the latter (EP 0 750 723 B1).
BACKGROUND
[0003] A cross-sectional shape, suitable for the transmission of a torque, of blind hole and tool is to be understood, in particular, as meaning a polygonal cross section, advantageously a hexagon. Likewise suitable cross-sectional shapes are stars, which may also have rounded tips and corners, or else simple slots and cross slots made in the shear screw, with the corresponding tool shaped as flat profiles and cross. The polygonal cross section is considered below as representing all possible cross-sectional shapes.
[0004] A shear screw of this type, referred to briefly below as a “screw”, is used, for example, in electrical power engineering for connecting the conductors of two power cables. To achieve and maintain electrically highly conductive contact, a firm connection is required between the conductors of the two cables and a tubular metallic terminal into which the conductors are inserted. This can be ensured, using what is known as a torque wrench, which, when the screw is tightened, then “spins” when a sufficiently firm fit of the latter is achieved. However, such a torque wrench is often not available on a building site. The screw is therefore, as a rule, screwed tight by means of another tool, for example by means of a simple spanner. In order to ensure, and also make it possible to check, that the screw is tightened sufficiently firmly, the upper part of the screw is then sheared off when the strength of its predetermined breaking point is reached or overshot. The then missing screw head is an indication that the screw is tightened sufficiently firmly. After the screw head has been sheared off, the screw does not project or projects only insignificantly out of the terminal. An insulating element to be mounted above the latter is therefore neither damaged mechanically nor impaired in terms of its insulating properties.
[0005] The known screw according to EP 0 750 723 B1, mentioned in the introduction, has a plurality of predetermined breaking points spaced axially apart. It is sheared off at one of the predetermined breaking points as a function of its depth of penetration into a cable plug designed as a metallic tubular piece, its depth of penetration depending on the dimensions of a conductor to be secured. A tool pin initially inserted completely into a blind hole of the screw is, for this purpose, gradually moved out of the screw in relation to the latter as a result of a screwing operation by means of an outer bell-like supporting means which is part of the tool and which bears against the cable plug. The screw is sheared off at a predetermined breaking point which lies approximately level with the end face of the tool pin, in the position in which the screwing operation is terminated. The tool is, overall, complicated.
OBJECTS AND SUMMARY
[0006] The subject on which the invention is based is to configure the screw outlined in the introduction, such that it can be brought to bear firmly against a conductor in a simpler way.
[0007] This object is achieved, according to the invention,
in that the blind hole extends to about level with the second predetermined breaking point which is arranged in the lower region, facing the end face of the screw, of the latter and which has a greater strength than the first predetermined breaking point, in that the screw has formed in it, concentrically to the blind hole, a recess axially shorter than the latter and having a cross section identical to the cross section of the blind hole, which recess has the same clear width as the blind hole and is displaced with respect to the latter in the circumferential direction at an angle lying preferably between 10° and 40°, and extends to about level with the first predetermined breaking point which is arranged in the upper region, facing the head of the screw, of the latter, and in that the orifice of the blind hole at the head of the screw is deformed in such a way that the tool can be inserted only into the shorter recess.
[0011] This screw is configured such that it can be rotated in the threaded bore of a terminal by means of a simple pin-like tool, until a conductor to be fastened is secured with sufficient pressure in the said terminal.
[0012] Its two predetermined breaking points have different strength, so that the screw is sheared off first or only in a first working position at the first predetermined breaking point having the lower strength. In this first working position, for example, a thinner conductor of a cable is secured in the terminal. After the head of the screw has been sheared off at the first predetermined breaking point, the latter may, if appropriate, be brought by means of the same simple tool as before into a second working position which is provided, for example, for securing a thicker conductor and in which the screw is sheared off at the second predetermined breaking point. This simple operation is made possible, on the one hand, by the blind hole and, on the other hand, by the recess which is rotated with respect to the latter. In this case, the deformation of the blind hole in the region of the head of the screw ensures that the screw is sheared off first at the first predetermined breaking point, because the tool can be inserted only into the recess which reaches only to level with the first predetermined breaking point. Thereafter, the blind hole is accessible to the tool, and therefore the screw can be rotated further with increased force to secure a thicker conductor in the terminal, until the screw is sheared off also at the second predetermined breaking point.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Exemplary embodiments of the subject of the invention are illustrated in the drawings in which:
[0014] FIG. 1 shows a longitudinal section through a screw according to the invention.
[0015] FIG. 2 shows a top view of the head of a screw according to FIG. 1 .
[0016] FIG. 3 shows a detail from FIG. 2 in an enlarged illustration.
[0017] FIG. 4 shows a longitudinal section through an embodiment of the screw, modified with respect to FIG. 1 .
[0018] FIGS. 5 to 13 show different positions of the screw in a terminal.
DETAILED DESCRIPTION
[0019] The shear screw S illustrated in longitudinal section in FIG. 1 , and designated below, further, as “screw S”, has a threaded part 1 and a head 2 which, in the exemplary embodiment illustrated, has smaller radial dimensions than the threaded part 1 and which is designed without an external thread. The threaded part 1 ends on the end face 3 of the screw S. The transition from the head 2 to the threaded part 1 is conically tapered continuously. The point having the smallest diameter forms a first predetermined breaking point 4 of the screw S. Moreover, in the threaded part 1 , a peripheral gap-like depression is made, which forms a second predetermined breaking point 5 of the screw S. The strength of the second predetermined breaking point 5 is greater than that of the first predetermined breaking point. In the embodiment of the screw S according to FIG. 1 , the two predetermined breaking points 4 and 5 run at right angles to the axis of the screw S and parallel to one another.
[0020] Formed centrically in the screw S is a blind hole 6 with a polygonal cross section which extends from the end face of the head 2 to level with the second predetermined breaking point 5 . The blind hole 6 has a preferably hexagonal cross section, as shown in FIGS. 2 and 3 . It may, however, also have a different polygonal cross section. Formed in the screw S concentrically to the blind hole 6 is a recess 7 , likewise of polygonal cross section, which is axially shorter than the blind hole 6 and reaches to level with the first predetermined breaking point 4 . The recess 7 has the same cross section and the same clear dimensions as the blind hole 6 . It is therefore likewise advantageously of hexagonal design. The recess 7 is offset in the circumferential direction with respect to the blind hole 6 , for example by an angle of 30°, as depicted in FIG. 2 . This angle should preferably lie between 10° and 40°, specifically, advantageously, at 20°.
[0021] The blind hole 6 is deformed at its entrance into the screw S, that is to say on the end face of the head 2 , such that a pin-like tool 8 depicted, for example, in FIG. 6 cannot be inserted into the said blind hole. The tool 8 serves for rotating the screw S. It has a polygonal cross section which corresponds to the cross section of blind hole 6 and recess 7 . Its external dimensions correspond to the clear dimensions of blind hole 6 and recess 7 . According to FIG. 2 , the blind hole 6 has as deformation, for example at three points 9 , small projections which project into its profile and serve as stoppers for the tool 8 . Such a stopper basically is sufficient at only one point 9 . The recess 7 has an unchanged cross section in the end face at the head 2 of the screw, so that the tool 8 can be inserted, unimpeded, into the latter.
[0022] The handling of the screw S according to the invention is explained below, by way of example, with reference to FIGS. 5 to 13 :
[0023] An electrical conductor 11 having relatively small dimensions is to be secured with a predetermined pressure in a terminal 10 designed as a metallic tubular piece. For this purpose, the screw S is screwed into a threaded bore of the terminal 10 until, according to FIG. 5 , it bears against the conductor 11 previously inserted into the latter. This may, however, also be carried out by hand, using the tool 8 .
[0024] The tool 8 is inserted, in the position according to FIG. 6 , into the recess 7 . Its end face then lies level with the first predetermined breaking point 4 . By the tool 8 being rotated about the axis of the screw S, the latter is screwed further into the terminal 10 , with the result that the conductor 10 is compressed. In the position of the screw S, as illustrated in FIG. 7 , the conductor 10 is loaded with sufficient pressure. When the tool 8 is further rotated, the head 2 of the screw S is sheared off. According to FIG. 8 , the threaded part 1 remains in the terminal 10 , without any projecting excess.
[0025] The same process also applies initially to securing a thicker conductor 12 in the terminal 10 . According to FIG. 9 , the screw S is first screwed into the terminal 10 again until it comes to bear against the conductor 12 , and is then further rotated by means of the tool 8 ( FIG. 10 ), with the result that the conductor 12 is deformed. The counterforce of the conductor 12 then becomes so high that the head 2 of the screw S is sheared off at the weaker first predetermined breaking point 4 , before a sufficiently high pressure is exerted on the conductor 12 . This position of the remaining threaded part 1 of the screw S is illustrated in FIG. 11 .
[0026] The tool 8 is then inserted into that part of the blind hole 6 which is present in the threaded part 1 . The threaded part 1 of the screw S is then further rotated until the pressure to be exerted on the conductor 12 is reached ( FIG. 12 ). The upper part of the threaded part 1 of the screw S is then sheared off at the second predetermined breaking point 5 . According to FIG. 13 , the lower part of the threaded part 1 remains in the terminal 10 , again without any projecting excess.
[0027] To connect the conductors of two power cables, in the customary technique the stripped conductor of a second cable is secured to the other end of the terminal 10 in a similar way by means of a screw S. Finally, an insulating element can be formed around the terminal 10 .
[0028] The predetermined breaking points 4 and 5 of the screw S, according to the embodiment of the latter shown in FIG. 1 , run at right angles to the axis of the screw S and parallel to one another. According to FIG. 4 , they may also run obliquely to the axis of the screw S, specifically preferably with opposite direction of the slopes. The directions of these then form an acute angle of, for example, 30° with one another. In this embodiment of the screw S, the predetermined breaking point 5 ends nearer to the end face 3 of the latter, so that the blind hole 6 can be lengthened, as compared with the embodiment according to FIG. 1 . The tool 8 can thereby be inserted more deeply into the screw S, and a correspondingly higher torque can be transmitted to the predetermined breaking point 5 .
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A shear screw has predetermined breaking points in two planes, separated axially from one another, and it has centrally a blind hole extending over a substantial length and having a cross section which is suitable for transmitting a torque to the shear screw by means of a pin-like tool of adapted dimensions which can be inserted into the blind hole. The blind hole extends to about level with the predetermined breaking point which is arranged in the lower region, facing the end face of the shear screw, of the latter and has a strength greater than that of the other predetermined breaking point.
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BACKGROUND OF THE INVENTION
This invention relates to a method for cementing a casing in a wellbore in which the casing will subsequently be heated to a high temperature, and more particularly to a method for anchoring the lower end of the casing while upward tension is applied to the casing while cement is allowed to set.
Prior art, which is believed to be relevant to the present invention, includes U.S. Pat. No. 3,976,139, issued to L. B. Wilder on Aug. 24, 1976, and assigned to the assignee of the present invention. Discussed in this patent are the problems encountered in thermal wells in which heating of the casing can cause buckling and joint failure. This is due to the fact that in normal cementing operations the tension applied to the casing is merely that occurring due to its own weight. This tension has been found to be insufficient to prevent the casing from being placed in a condition of compression at high temperatures which are often encountered. As discussed in the patent, such problems can be overcome by anchoring the bottom of the casing during the cementing operation and applying extra tension to the casing while the cement sets. The patent discusses prior art mechanical anchors which have been used and discloses an improved anchor. The disclosed anchor has a number of steel arms which are extended from the casing after cement has been circulated through the annulus and engage the borehole wall to resist upward movement of the casing. As noted at column 4, lines 44-47, of that patent, the anchors tend to plow through soft formations when they are encountered. It has been found in many cases that formations may be in fact so soft or the borehole is so irregular that the anchors will not provide sufficient resistance to movement to allow the desired level of extra tension to be applied. As a result, it has become standard practice to use fast-setting cement at the bottom of the borehole so that it may be used as an additional anchor while slower-setting cement in the upper parts of the borehole is still fluid as tension is placed on the casing.
It can be seen from an inspection of the prior art that these mechanical anchoring devices have been, in general, fairly complex. Even with such complexity, they have been found to not provide the desired anchoring in soft formations or irregular shaped boreholes.
Accordingly, an object of the present invention is to provide an improved and simplified method of extra tensioning a casing string during cementing operations.
Another object of the present invention is to provide a method of extra tensioning a casing string which is particularly effective in soft formations or irregular shaped boreholes.
These and other objects are achieved by using an inflatable casing packer at the bottom of the casing string as an anchor. Cement is pumped behind the casing in the normal manner prior to inflation of the packer. A cement wiper plug is then used to actuate the inflatable packer which is inflated with additional cement pumped in behind the wiper plug. After the packer is inflated with the desired pressure, extra tension is applied to the casing while the cement is allowed to cure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of a lower end of a casing with an external packer in place while cement is circulated down the casing and up the annulus surrounding the casing.
FIG. 2 is an illustration of the lower end of the casing after the annulus has been filled with cement and the packer has been inflated with cement.
FIG. 3 illustrates the final completion after the cement has been drilled out of the casing.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The method of completing the well according to the present invention is shown in the three figures. FIG. 1 illustrates the lower end of a casing 2 with an inflatable packer 4 positioned at essentially the lowest point on the casing. In the preferred embodiments the only elements below packer 4 are a short section of casing 6, a wiper plug seat 8, and a float shoe 10. Also illustrated in FIG. 1 is a wiper plug 12, which is typically used to follow cement 14, which is pumped down the casing to fill the annulus between the casing and the borehole. In the preferred embodiment, additional cement 16 is pumped down the casing behind wiper plug 12. During the pumping of cement into the annulus, the casing 2 is kept in motion relative to the borehole wall, since this has been found to greatly improve the integrity of the cementing job. Either a vertical reciprocation of the casing or a rotation of the casing 2 may be employed, depending upon the equipment available at the wellhead. Packer 4 does not interfere with either type of motion. The preferred packers are more specifically known as external casing packers and are sold by Lynes, Inc. of Houston, Tex., under the designation "Model RTS." These are commercially available in most standard casing sizes.
FIG. 2 illustrates the condition of the casing after the annulus has been filled with cement and motion of the casing has ceased. The wiper plug 12 has sealed into seat 8 to prevent further flow of cement into the annulus. An input seal 18 (FIG. 1) to packer 4 has been broken off by wiper 12 when it passed through packer 4. The pressure inside the casing was then increased to cause cement 16 to flow through a valve 20 and inflate packer 4. An additional wiper plug 22 follows cement 16 to prevent contamination of cement 16 by a displacing fluid 24 which fills the casing above wiper plug 22. Wiper plug 22 is used in the preferred embodiment but is not essential if the displacing fluid is much lighter in specific gravity than the cement slurry so that cement contamination is minimized by gravity segregation. After the packer 4 has thus been pressurized and thereby expanded to grip the borehole wall, extra tension is applied to the casing at the wellhead and maintained during the setting period of the cement. Valve 20 includes a check valve which prevents back flow of inflating cement so that extra pressure does not need to be maintained in the casing while the cement sets.
If additional anchoring power is needed, a fast-setting tack cement may also be used in combination with the packer element as taught herein. But to avoid the complexities of the tack cement operation, it is preferred to simply use a longer inflatable element or a second packer positioned immediately above packer 4 or a packer with grit rings on its outer surface to increase the anchoring capacity.
It can be seen that the inflatable packer 4 has several advantages over a mechanical anchor such as that described in the above-referenced U.S. Pat. No. 3,976,139. As noted in that patent, the steel anchor bars tend to plow into a soft formation to obtain its anchoring effect; but in very soft formations the steel bars will simply continue to plow through the formation, damaging the borehole wall and filling the hole with loose debris. The steel bars do, in fact, act as plows and tend to dislodge the formation wall materials into the borehole. In contrast, the inflatable packer element 4 applies pressure normal to the borehole wall spread over a much larger surface area. Thus, the packer does not tend to pull the borehole wall materials into the hole nor to break up the borehole wall. Thus, it is seen that the inflatable packer is particularly suited for soft borehole materials, since it merely helps pack the borehole wall more tightly and as a result anchors more tightly to the borehole.
The inflatable packer also has advantages in irregular shaped boreholes which often occur in soft formations but may also occur in relatively hard formations. In such boreholes, steel anchor bars will not be loaded equally and some may not contact the borehole at all. In addition to reducing the anchoring effect, some of the bars may be bent or broken due to being overloaded. In contrast, an inflatable packer inflates to whatever shape the borehole has and anchors better when the borehole is irregular.
FIG. 3 illustrates the final completion of the well according to the present invention. The cement which was left in the casing, to set therein, can be drilled out along with wiper plugs 22 and 12 to provide an open conduit to the very bottom of the casing and underlying formations if an open-hole completion is desired. It is apparent that more cement must be drilled out due to the quantity of cement left in the casing behind wiper plug 12, but this is a fairly simple matter. As an alternative, the inflatable packer anchor may be positioned below the objective formation and the casing may be perforated for access to the formation. If the anchor is set deeply enough to place plug 22 below the perforation depth, the drilling operation illustrated in FIG. 3 can be totally eliminated. It is also noted that in the final completion the packer 4 is filled with cement 16 so that it becomes a permanent part of the cement job. This is primarily due to the fact that the packer 4, being made mostly of rubber, could not withstand the normal operating temperatures in thermal wells and can be expected to disintegrate eventually. Since the packer is filled with cement, its disintegration will not leave any substantial void behind the casing.
Although the present invention has been illustrated in terms of particular steps and apparatus, it is apparent that other changes and modifications can be made within the scope of the present invention as defined by the appended claims.
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A simplified method for tensioning casing in thermal wells involving the use of an inflatable packer element. The packer element is positioned at or near the bottom of a casing string and is inflated with cement after the cement annulus has been filled with cement. The packer is used to anchor the bottom of the casing while tension is applied to the top of the casing during the setting of the cement. After the cement has set the packer is a permanently imbedded in the casing cement.
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This is a continuation-in-part of U.S. Ser. No. 08/677,276, filed on Jul. 9, 1996, now U.S. Pat. No. 5,725,732, which is a continuation-in-part of U.S. Ser. No. 08/344,582, filed on Nov. 18, 1994, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a process for treating paper machine stock containing bleached hardwood pulp with an enzyme preparation, prior to refining, to reduce vessel element picking and to improve paper printability.
2. Background Art
Hardwood pulp is used in the paper industry to produce a variety of end products. Some of these products are designed specifically for the printing and book publishing industries. The paper used in these industries has a high content of hardwood pulp which gives the paper good formation, opacity and printability. However, one problem with regard to the use of hardwood pulps results from their basic structure. Hardwoods contain two principle cell types, namely, fiber cells and vessel element cells. The non-fibrous vessel cells transport water throughout the entire tree. Consequently, they do not add strength or quality to the paper and, therefore, are not desirable. The vessel cells remain intact through the pulping, bleaching and refining processes. During the papermaking process, the vessel cells remain on the paper surface and are not bonded to the fibers. While printing, the problem is that the large unbonded vessel elements on the surface of a sheet get picked out by the printing press roll. This results in ink not being applied to all of the parts of the paper to which it was intended to be applied. The vessel cells also can remain on the roll causing voids or spots to form. The net result is that the paper is of unacceptable quality.
In the past, vessel picking problems have been addressed using sizing, coating or refining technologies. The first two approaches have been unsuccessful in fully combating this problem, and the latter approach tends to require significant amounts of capital and energy. Refining tends to be the most successful in reducing vessel picking (although high reductions have not been achieved). However, many mills are reluctant to spend the capital required to reduce this problem. Therefore, combating this problem (both tolerating and preventing it) is not only costly, but also usually goes unaddressed or accepted as normal.
Enzymes have been used in the pulp and paper industry. Xylanase enzymes have been used to improve the bleachability of kraft pulps. These enzymes attack the reprecipitated xylan and, therefore, allow better accessibility to delignify and bleach the pulp. Early work in this technology used xylanase enzyme preparations which had significant cellulase activity. These cellulases supposedly actively broke down the usable pulp fiber and reduced the fiber strength. Therefore, enzyme suppliers were heavily encouraged to remove any cellulase activity and purify the xylanases. These xylanase enzymes effectively improve the bleachability of hardwood pulp.
European Patent No. 0,351,655 discloses the treatment of an unbleached, mechanically-prepared pulp (or an unbleached, chemimechanically-prepared pulp) with a xylanase preparation which is substantially free of cellulases, to improve drainability. Cellulase was said to deteriorate the tear index.
European Patent No. 0,430,915 discloses the treatment of mechanically-prepared, softwood pulp with hydrolytic enzyme, e.g., hemicellulase, cellulase, esterase, pectinase or mixtures thereof, to modify the structure of the hemicellulose and or cellulose in the fibers so that the fibers come apart more easily during mechanical refining.
The brochure "Pulpzyme HA", apparently published in September 1989, of Novo, Enzyme Process Division, discloses Pulpzyme HA, a mixture of xylanase (500 XYU/g) and cellulase (about 300 EGU/g). The enzyme mixture is stated to be intended for use is pulping operations where a partial breakdown of the xylan structure is desirable. Page one of the brochure states: "By proper selection of process conditions (e.g., pH 6.5, 45° C.) undesirable effects of the cellulase activity may be further reduced."
The brochure "On The Use Of Pulpzyme HA For Bleach Boosting", Pedersen, L. S., (September 1989), Novo-Nordisk a/s, discloses the use of Pulpzyme HA as a pretreatment of (oxygen delignified) hardwood kraft pulp to reduce the amount of activated chlorine subsequently needed to bleach the pulp. Loss of pulp yield is said to be probably due to the cellulase content in the enzyme preparation.
U.S. Pat. No. 4,923,565 (Fuentes et al. I) discloses treating refined or recycled papermaking pulp with an enzyme preparation containing cellulases and/or hemicellulases. Xylanases are a type of hemicellulase. The enzyme treatment lowers the Schopper-Riegler (SR) degree of the pulp while maintaining the mechanical characteristics of the papers manufactured from the treated pulp. The method improves the draining of the aqueous pulp suspension. Column 2, lines 49 to 51, states that the pulp can be bleached chemical pulps for providing kraft papers. See also Examples 8 to 10. The cellulase enzyme preparations can contain a xylanase activity (column 2, lines 57 to 59). Fuentes et al. I states that the xylanase activity enables the hydrolysis of the bonding xylanases. The enzyme preparation can be at a concentration of 0.01 to 2 weight percent. The treatment is conducted at a pH of 3 to 7 and a temperature of 20° to 60° C. There is no overt mention of hardwood pulps in Fuentes et al. I, but kraft pulp can be made from hardwoods or softwoods. While column 2, lines 31 to 33, of Fuentes et al. I says that its process is not related to unrefined papermaking pulps, column 2, lines 49 to 51, says that natural or bleached chemical pulps can be used. A review of the examples (e.g., Examples 8 to 10) shows that Fuentes et al. I refines bleached pulps before enzyme treatment. Fuentes et al. I does not disclose reducing the hardwood vessel element picking of bleached hardwood pulp.
The prior art section of Fuentes et al. I refers to French Patent No. 2,557,984, which discloses treating an unrefined pulp, which has a low SR, with an enzyme solution containing xylanases.
U.S. Pat. No. 5,308,449 (Fuentes et al. II) has the same disclosure as Fuentes et al. I and is based on a line of continuing applications based on Fuentes et al. I.
U.S. Pat. No. 5,110,412 (Fuentes et al. III) discloses treating a papermaking composition of recycled fibers with an enzyme preparation to improve the machinability of the composition and the drainability of water through the fibrous layer. The enzyme preparation acts on all or part of the cellulose fiber components. The pulp is all or in part recycled fibers. The prior art section of Fuentes et al. III says that papermaking pulp of recycled fibers generally needs to be refined. Fuenes et al. III uses an enzyme preparation containing cellulases plus other enzymes. Preferably, the enzymes have a C 1 activity, a C x activity and a xylanase. See Examples 13 to 15, for example.
U.S. Pat. No. 5,179,021 (du Manoir et al.) discloses oxygen bleaching lignocellulosic material followed by enzymatic treatment with a substantially cellulase-free xylanase. The lignocellulosic material can be an unbleached kraft pulp. Satisfactory brightness and viscosity of bleached pulps are obtained. Example 6 of du Manoir et al. reversed the sequence with the xylanase treatment first and obtained improved brightness and viscosity.
The prior art section of du Manoir et al. states that French Patent No. 2,557,984 discloses a process for treating a hardwood bleached kraft pulp with an enzyme solution containing xylanase to reduce the amount of refining for papermaking. One xylanase required the addition of mercuric chloride to suppress the present "detrimental cellulose activity".
U.S. Pat. No. 5,395,765 (Dahlberg et al.) discloses a specific xylanase capable of hydrolyzing birchwood, oataspelt and larchwood xylans. Enzymatic treatment with the xylanases of lignocellulosic pulp improves the bleachability of the pulp.
U.S. Pat. No. 5,407,827 (Casimar-Schenkel et al.) discloses bleaching hardwood pulp with an enzyme system containing thermostatic xylanose activity. The enzyme system obtained from I. fusca acts on the hemicellulose/cellulose. The total enzyme system of I. fusca KW3 also contains cellulase. Casimar-Schenkel et al. states that supernatants of I. fusca KW3 only contain small amounts of cellulase activities (provided such does not adversely affect cellulose and the quality of the paper made therefrom.) See the table in Example 2 and column 1, lines 10 to 23. Sometimes the pulp is also chemically bleached after the enzyme treatment. Example 5 treated oxygen-bleached softwood Kraft pulp with the enzyme system and then is further bleached.
International WO 91/02839 (Pedersen et al.) discloses treating a hardwood pulp with an alkaline xylanase followed by treatment with chlorine. The cellulase activity (page 3 gives the preferred upper limit) in the alkaline xylanase preparation should be relatively low.
Noe. P., et al., "Action of Xylanases on Chemical Pulp Fibers", 6 (2), (1986), pp. 167-184, discloses treating chemical-bleached pulps with a crude enzyme mixture (including xylanases), wherein the endo-cellulases had been inhibited by MgCl 2 . The pulp can be a kraft birch pulp. The xylans were, thereby, subjected to selective in-situ hydrolysis. It is stated that the treated pulps can be compared to slightly beaten pulps.
There are two abstracts of a Japanese article that describe the use of a cellulase enzyme to reduce the vessel picking of pulp. The abstracts mention that the treatment was especially effective on eucalyptus, which is a hardwood. The pure cellulase enzyme used in the Japanese article is marketed under the name Vesselex. Vesselex is stated to be used for the suppression of vessel pick formation. The abstracted article is Ishizaki, H., Tappi J., 46, No. 1, (January 1992), pages 149 to 155.
There is an abstract of Uchimoto. I., et al., Jpn. J. Pap. Technol., No. 2, (February 1990), pages 1 to 5, that describes the use of Vesselex (a pure Trichoderma cellulase) to treat pulp to improve vessel picking.
BROAD DESCRIPTION OF THE INVENTION
The main objective of the invention is to provide a method for treating bleached paper machine stock, which contains some percentage of bleached hardwood pulp or a mixture of bleached hardwood and softwood pulps plus any useful or conventional chemical additives, with an enzyme mixture prior to refining which will reduce vessel element picking on the paper machine (without significant pulp degradation). Other objectives and advantages of the invention are set out herein or are obvious herefrom to one skilled in the art.
The objectives and advantages of the invention are achieved by the process of the invention.
The invention treatment reduces the hardwood vessel element picking of bleached hardwood pulps used in the printing or book publishing industry. The invention process uses a mixture of cellulases and xylanases to chemically change the hardwood vessel elements, rendering them susceptible to breaking under normal mill refining. Thus, any additional refining equipment is not required.
It has been found that treating bleached hardwood pulp with an enzyme mixture containing primarily xylanase, but with significant cellulase activity, chemically effects the vessel elements so that they are more susceptible to breaking through normal mill refining.
The invention involves a process for reducing bleached hardwood vessel element picking in prepared paper machine stock containing bleached hardwood pulp, comprising said prepared paper machine stock containing bleached hardwood pulp with an enzyme mixture comprised of cellulases and xylanases in an amount of about 0.05 to about 1.0 weight percent, based on the weight of the wood fiber, dry basis, in said prepared paper machine stock, the mixture having a cellulase activity of at least 200 EGU/g, in a pH range of about 4 to about 10, at a temperature from about 85° to about 145° F. for a reaction time of about 30 to about 240 minutes at a consistency of about 1 to about 15 percent, whereby the hardwood vessel element picking in said prepared paper machine stock containing bleached hardwood pulp, which is used in the printing or book publishing industry, is substantially reduced.
As used herein, the term cellulase includes all varieties of cellulases, endo or exo, and the term xylanase includes all varieties of xylanases, endo or exo. The enzyme mixture may contain other enzymes than cellulases and xylanases. However, cellulase is not the primary component of the mixtures.
The bleached pulp is best produced from the Kraft, Sulfite, or any other commercially feasible process and bleached to a minimum of 80 percent brightness. The hardwood pulp typically is oak, maple, poplar, birch, chestnut, aspen, beech, walnut or eucalyptus or mixtures thereof.
The enzyme treatment preferably corresponds with the activity ranges of the enzymes used. The enzyme treatment is specifically effective at 0.1 percent, dry basis, on the fiber or less but can be from 1.0 percent or less. The bleached pulp is treated with the enzyme prior to refining.
The resulting paper product is any paper that ink is applied to and vessel picking will reduce the quality of the paper, such as, printing and book publishing papers. The enzyme-treated, bleached pulp can be further bleached to a brightness of 80 or greater and refined prior to the paper machine.
Bleached hardwood pulp or bleached hardwood/softwood mixture pulp or paper machine stock containing bleached hardwood pulp, are treated with an enzyme mixture, as mentioned above, in a manner that simulates the paper machine stock preparation (e.g., Valley Beaters, machine chests and storage chests) or any intermediate step following bleaching but prior to refining. The stock is at a consistency between about 1 and about 15 percent. The stock is pH adjusted to a range of about 4 to about 10, with either acid or alkali, that preferably corresponds with the optimum pH range for that specific enzyme mixture. Alkaline papermaking normally has a pH of near 7 and, therefore, an enzyme (mixture) can be used which requires no pH adjustment. The stock is held at a temperature between about 85° and about 145° F., for a reaction time of about 30 to about 240 minutes. The temperature also preferably corresponds to the optimum temperature of the specific enzymes used. When the enzyme mixture is added to the pH adjusted stock, thorough mixing should take place. After enzyme treatment, the stock is further prepared for paper machine use (i.e., dilution) for an end use in the printing and book publishing industry.
The invention enzyme treatment effectively reduces hardwood vessel picking in paper or handsheets produced from the treated stock by up to at least 70 percent. The invention enzyme treatment also improves the surface characteristics of the sheet. Various enzymes can be chosen to reduce the amount of vessel picking reduction, if desired. While the enzyme mixtures effectively reduce vessel picking, the pulp strength properties of tensile (breaking length), tear and burst are not negatively affected.
The prior art generally did not use cellulase-containing enzymes for fear of pulp degradation. The invention has the goal of substantial vessel pick reduction without significant pulp degradation. The invention excludes the use of a pure cellulase enzyme (for example, Vesselex) and the use of a xylanase which is substantially free of cellulase activity. Xylanase are hemicellulases. The concomitant use of cellulases and xylanases in the proper proportions is a core factor of the invention.
As used herein, the term "cellulase/xylanase mixture", or variations thereof, means that the enzyme mixture contains a substantial amount of cellulases, namely, at least a sufficient amount of cellulases to achieve substantial hydrolysis of the glucosidic linkages in the cellulose when the enzyme mixture is applied to aqueous, bleached cellulose pulps. Cellulase-free xylanases and xylanase-free cellulases are not within the scope of the invention process. In the cellulase/xylanase mixture, both the cellulases and the xylanases are active.
Preferably, the cellulase/xylanase mixture is obtained by natural expression from a microorganism, as opposed to a cellulase/xylanase mixture prepared by mixing the individual enzymes.
DETAILED DESCRIPTION OF THE INVENTION
The aqueous, bleached hardwood pulp slurry can, for example, be that of northern or southern hardwood. While it is preferred to employ a kraft pulp, other chemically digested pulps and mechanically-prepared pulps can be used. A bleached pulp is used. The hardwood pulp can be prepared typically in a digester in the presence of chemicals, such as, sodium hydroxide and sodium sulfide (to produce a kraft pulp) or sulfites, usually sodium or magnesium, (to produce a sulphite pulp). (Kraft pulp is often prepared by digestion with a mixture of caustic soda, sodium carbonate and sodium sulfide.) The removal of the lignin content of wood pulps is measured by a permanganate oxidation test, according to a Standard Method of the Technical Association Of The Pulp And Paper Industry (TAPPI), and is reported as a Kappa Number. The chemical pulp from the digester still contains an appreciable amount of residual lignin at this stage, and, in some cases, is suitable for making construction or packaging paper without further purification. For the manufacture of printing and book publishing papers, however, the pulp is too dark in color and must be delignified and brightened by bleaching. After the lignocellulosic material is bleached, the process of the present invention can be employed, said material sometimes referred to herein as bleached (chemical) hardwood brownstock pulp.
There are four different kinds of wood pulp: mechanical or chemimechanical pulp, sulfite pulp, sulfate or Kraft pulp, and soda pulp. The first is prepared by purely mechanical (or semi-mechanical) means, the other three by chemical means. The mechanical pulp contains all of the wood except for the bark. Chemical pulps, however, are essentially pure cellulose, the undesirable lignin and the other noncellulosic components of the wood having been dissolved away by the treatment. Because of this, chemical pulps are much superior to mechanical (or ground-wood pulp) for fine papermaking.
It has been found that treating bleached hardwood brownstock pulp with an enzyme mixture containing primarily xylanase, but with substantial cellulase activity, chemically affects the bleached vessel elements so that they are more susceptible to breaking through normal mill refining.
Prior to enzyme treatment, the pulps are fully bleached to a GE or TAPPI brightness of 80 percent or greater for use in the printing and book publishing industry. The bleached hardwood brownstock is treated with an enzyme mixture in a manner that simulates the brownstock high density storage tower. The bleached brownstock is at a consistency between 1 and 15 percent. The bleached pulp is pH adjusted (if necessary) to a range of 4 to 10, with either acid or alkali, preferably to correspond with the optimum pH range for that specific enzyme mixture. The stock is held at a temperature between 85° to 145° F. for a reaction time of 30 to 240 minutes. The temperature also corresponds to the optimum temperature of the specific enzymes used. The xylanase/cellulase mixture is used in an amount of about 0.05 to about 1.0 percent, preferably about 0.1 percent, based upon the weight of the bleach wood fiber, dry basis. The preferred xylanase/cellulase mixture is preferably Pulpzyme HA. When the enzyme mixture is added to the pH adjusted pulp, thorough mixing takes place as performed by a thick stock pump, for example. The mixture can be agitated at various speeds with the use of various mixing devices which simulate a thick stock pump. The cellulase/xylanase mixture can be applied as it is produced in a fermentation broth, or a concentrated form thereof, or as a composition prepared from either a more concentrated composition of the cellulase/xylanase mixture or a dried preparation of the cellulase/xylanase mixture. Thereafter, preferably no mixing takes place, simulating high density pulp storage and normal mill conditions. High density storage towers normally have poor or no mixing. The bleached hardwood pulp can be enzyme treated in one or more stages.
The invention enzyme treatment effectively reduces hardwood vessel picking in fully bleached hardwood pulp handsheets by up to 70 percent or more. The enzymes can be chosen so as to vary the amount of vessel picking reduction, if desired. While the enzyme mixtures effectively reduce vessel picking, the pulp strength properties of Instron tensile (breaking length), tear (Elmendorf) and burst (Mullen) have not been negatively affected.
The hardwood pulp usually is a pulp of a species of oak, maple, poplar, birch, chestnut, aspen, beech, walnut, eucalyptus or mixtures thereof.
The hardwood pulp is produced from the Kraft process, Sulfite process, or any other commercially feasible process. Preferably, the hardwood pulp is a chemically-digested hardwood pulp, most preferably, (bleached) hardwood Kraft pulp.
The consistency of the hardwood brownstock (bleached) pulp to be treated is usually from about 1 to about 15 weight percent, preferably about 2 to about 13 weight percent, based upon the oven-dry (O.D.) weight of the pulp (bleached wood fiber).
The acid to adjust the pH of the hardwood pulp before the enzyme treatment can be any suitable inorganic or organic acid which does not have an adverse effect on the enzyme treatment of the bleached hardwood pulp. Examples of suitable inorganic acids are sulfuric acid, sulfurous acid, nitric acid, nitrous acid, phosphoric acid, phosphorous acid and mixtures thereof. The preferred inorganic acid is sulfuric acid. Chlorine-containing acids should be avoided when Pulpzyme HA is used. Examples of suitable organic acids are benzoic acid, bromoacetic acid, maleic acid, formic acid, lactic acid, malic acid, acetic acid, butyric acid, propionic acid, citric acid, oxalic acid, succinic acid, picolinic acid and mixtures thereof. The preferred organic acid is acetic acid.
The base used to adjust the pH of the hardwood pulp before the enzyme treatment can be any suitable inorganic or organic base which does not have an adverse effect on the enzyme treatment of the hardwood pulp. Examples of suitable inorganic bases are sodium hydroxide, zinc hydroxide, ammonium hydroxide, aluminum hydroxide, potassium hydroxide and mixtures thereof. The preferred inorganic base is sodium hydroxide. Examples of suitable organic bases are aniline, tripropylamine, ethylamine, propylamine, acetamide, acetanilide, diethylamine, methylamine and mixtures thereof. The preferred organic base is ethylamine.
As used herein, acids are usually defined as being substances whose molecules ionize in water solution to give the hydrogen ion(s) from their constituent elements. As used herein, bases are usually defined as being substances which ionize in water to give the hydroxyl ion(s) from their constituent elements.
Preferably an enzyme mixture is used which has an optimum pH range of 6 to 8, particularly preferred of 7 to 8.
The enzyme mixture used is a mixture of cellulase and xylanase enzymes (there must be a substantial cellulase activity). The term cellulase includes all varieties of cellulases, endo and exo. The term xylanase includes all varieties of xylanases, endo and exo. The enzyme mixture can contain enzymes other than cellulases and xylanases. However, the cellulase is not the primary component. Rather, xylanase is the primary component of the mixtures. The enzyme mixtures can be of bacterial or fungal origin. The cellulase/xylanase mixture should have a cellulase activity of at least 200 EGU/g, preferably at least 300 EGU/g, and a xylanase activity of at least 200 XYU/g, preferably at least 300 XYU/g and best at about 500 XYU/g.
The most preferred cellulase/xylanase enzyme mixture is Pulpzyme HA, which is produced by the microorganism Trichoderma longbrachiatum. It is a product of Novo Nordisk Bioindustrials Inc., Enzyme Process Division, of Connecticut. Pulpzyme HA is a brown liquid preparation. The Pulpzyme HA enzyme mixture contains xylanases, that is, endo-xylanase (endo-1, 4-beta-D, specifically, EC 3.2.1.8) and exo-xylanase (exo-1, 4-beta-D, specifically, EC 3.2.1.37), cellulases, that is, endo-glucanase (possibly 2 or 3 types), cellobiohydrolase (possibly 2 or 3 types) and beta-glucosidase (possibly 2 or 3 types), acetyal esterase and alpha galactosidase. The cellulase/xylanase enzyme mixture has low activity towards crystalline cellulose. One xylanase unit (XYU) is defined as the amount of enzyme which under standard conditions (pH 3.8, 30° C., 20 min. incubation) degrades larchwood xylan to reducing carbohydrates with a reducing power corresponding to 1 μmol xylose. One endo-glucanase unit (EGU) is defined as the amount of enzyme which under standard conditions (pH 6.0, 40° C., 30 min. incubation) lowers the viscosity of a carboxymethyl cellulose solution to the same extent as an enzyme standard defining 1 EGU. The Pulpzyme HA is standardized to a xylanase activity of 500 XYU/g and contains a cellulase activity of about 300 EGU/g. (A trace cellulase activity would be less than 50 EGU/g.)
While theoretically there should be little or no cellulase activity at about pH 7, the invention secured the best results at about pH 7 when using Pulpzyme HA. The preferred pH for Pulpzyme HA is about 7 to 8, although a range of 6 to 8 gives good results.
A preferred cellulase/xylanase enzyme mixture is SP 342. The multi-enzyme complex known by the designation/name SP 342 includes cellulase, glucanase, hemi-cellulase and pentosanase activities. SP 342 is a product of Novo Nordisk Bioindustrials Inc., Enzyme Process Division. SP 342 is usually in the form of a stabilized liquid preparation. A brochure says that SP 342 is active in slightly acidic to mild alkaline conditions and at moderate temperatures. FIG. 1 in the brochure shows about 100 percent relative activity in the pH range of 5 to 7.
The process uses conditions which correspond with the activity ranges of the enzymes used. The enzyme dosage is effective even at 0.5 weight percent, based on the dry bleached fiber.
The bleached hardwood pulp is treated with the enzyme prior to refining. The enzyme can be inhibited after the treatment, by heating the pulp to a sufficient temperature or by adding an acid or base to change the pH to an inhibition value, at the end of the time period for the cellulase/xylanase treatment, the resultant treated material can either be used directly or thickened, and the treated material, then, can be used for further processing.
The pulp is bleached to a GE or TAPPI brightness of 80 or greater prior to the enzyme treatment, the refinement and the paper machine. The pulp is subsequently treated in various ways, depending upon the type of paper desired.
Before the enzyme treatment, the conventional method for further delignifying and bleaching pulp can be to employ a variety of multi-stage bleaching sequences, including anywhere from three to six stages or steps, with or without washing between steps. The objective in bleaching is to provide a pulp, in the case of chemical pulps, of sufficiently high brightness and strength for the manufacture of paper and tissue products. Characteristically, pulps of GE or TAPPI brightness of 80 to 86 percent are produced. The bleaching sequences can be based on the use of chlorine and chlorine-containing compounds, in one form or another. Some of the chlorine-containing compounds that are used are chlorine, chlorine dioxide, and hypochlorites, usually, sodium hypochlorite. Chlorine, with or without admixture of chlorine dioxide, is commonly employed to initiate the bleaching or chemical pulp, followed by extraction of the chlorine-treated pulp in an aqueous alkaline medium. Also, oxygen can be used as the delignifying and bleaching agent. One application is the use of oxygen in conjunction with a conventional alkaline extraction stage.
If chlorine or a chlorine-containing compound is used, it is best to remove, e.g., water washing, as much of the residual chlorine or chlorine-containing compound as possible before using Pulpzyme HA as the enzyme agent because Pulpzyme HA is chlorine sensitive.
The resultant paper product is any paper which ink is applied to and which vessel picking will reduce the quality of the paper, such as, printing and book publishing papers.
Vesselex is a liquid cellulase preparation standardized at 100 U/g FPase which is marketed by Solvay Biosciences Pty. Ltd., Victoria, Australia. When hardwood pulp (Eucalyptus) is used as the raw material for the manufacture of paper, the vessels which remain in the paper cannot properly accept the ink during printing, and the ink at the site of the vessels comes off causing the vessel pick phenomena. Solvay Biosciences asserts that Vesselex is a cellulase enzyme which has been specially developed to reduce the formation of vessel picks in paper manufactured from hardwood pulp. The process of using Vesselex in the paper industry uses pulp thickening and then, before bleaching, enzyme (from an enzyme holding tank at 5° C.) added to white water which is fed to a static mixer and the mixture is then added to a pulp chest which is sent to a refinery. The stated conditions were: pulp concentration, 5 to 6 percent; pH, 5.0 to 5.5; enzyme dose, 0.02 to 0.03 percent (w/w); temperature, 30° to 40° C.; and reaction time, not less than 4 hours. Regarding the prevention of vessel pick formulation by Vesselex cellulase: at an enzyme dosage of zero percent (w/w), the vessel picks were 185 (count per 10 sqr. cms.); at an enzyme dosage of 0.1 percent, the vessel picks were 18; and at an enzyme dosage of 0.2 percent, the vessel picks were 22. It is reported that, as the Vesselex cellulase dosage increases, the pulp degradation increases, but at the ideal dosage of 0.03 to 0.05 percent, there is almost no pulp loss. It is also reported that the Vesselex cellulase is completely inactivated in one minute under normal machine drying conditions at 120° C.
Vesselex is used for the prevention of vessel pick formation before bleaching. However, the invention is different, for example, because of different conditions: pH (5.0 to 5.5, Vesselex vs. pH 4 to 10, invention), temperature (30° to 40° C., Vesselex vs. 85° to 145° F., invention), reaction time (4 hours, Vesselex vs. 0.5 to 4 hours, invention), and pulp concentration (5 to 6 percent, Vesselex vs. 1 to 15 percent, invention). Most importantly, cellulase use can prove detrimental for paper properties other than vessel picking, and, thus, its use should be minimized. The disclosed discovery allows for the beneficial end product of vessel picking by using decreased levels of cellulase activity, and, thus, reducing the detrimental effects of cellulase use. Also, the invention process treats bleached hardwood pulp.
EXAMPLE 1
Laboratory work was conducted on stock collected from a Valley Beater in a mill stock preparation area. The stock contained approximately 78 percent of bleached hardwood pulp by weight. After processing this stock, it will ultimately be used in making paper that will be printed. 80 oven dry (O.D.) grams of stock were used. 0.10 percent of Pulpzyme HA (manufactured by Novo Nordisk, this product is a mixture of xylanase and cellulase enzymes) by weight on hardwood fiber was applied to the stock. The stock/enzyme mixture was mixed on a ball mill for 5 hours at a starting temperature of 115° F. After the reaction, the stock was treated with sulfuric acid to denature the enzyme. Then, the stock was made into TAPPI standard handsheets. This same experiment was repeated with 0.16 percent and 0.08 percent of Pulpzyme HA. A control was also performed using the same conditions without any Pulpzyme HA. The handsheets were analyzed for IGT vessel picking. The following Table 1 sets out the bleached hardwood vessel pick results. The average results are of four IGT vessel pick tests.
TABLE 1______________________________________Pulpzyme HA, percent Vessel Picking/cm.sup.2______________________________________0 40.10 00.16 00.08 0______________________________________
Another observation was made regarding surface appearance. The handsheets were examined for surface appearance and fiber protrusion. Fiber protrusion may indicate a deteriorated fiber or a weakened, poor bonding fiber. Fiber protrusions may ultimately result in fiber picking, and, thus reduced print quality. The enzyme treated sheets had 80 percent fewer fiber protrusions than did the control sheets. The enzyme treated sheets also appeared to have a better bonded surface, appearing to be smoother and more uniform than the control sheets.
EXAMPLE 2
This work was done in a mill trial using Pulpzyme HA addition to a Valley Beater, prior to refining and papermaking. The grade of paper furnish used was a printable grade. The enzyme was added directly to the beater charged with the furnish. The enzyme was added at a dosage of 1 kg/ton of hardwood pulp (0.11% w/w). The retention time in the system was a minimum of 3 hours before the paper machine. The temperature in the beater was 115° F. and the pH was 7.2. There was a control phase, followed by an enzyme phase, followed by another control phase. The level of the machine chest just prior to the paper machine was lowered between phases to ensure a good break. Paper samples were collected from the reel and tested for IGT vessel picking. Six different samples in duplicate were evaluated for IGT vessel picking from the pre-enzyme control period, eight in duplicate from the enzyme period, and eight in duplicate from the post-enzyme control period. The IGT results are as follows:
TABLE 2______________________________________Pre-control: 4, 6, 4, 4, 5, 6, 5, 5, 4, 4, 6, 5/cm.sup.2 Avg = 5/cm.sup.2Enzyme: 1, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 1, 2, 0/cm.sup.2 Avg = 1/cm.sup.2Post-control: 4, 4, 4, 4, 4, 4, 4, 5, 5, 6, 6, 5, 4, 5, 4, Avg = 5/cm.sup.2______________________________________
The same observations in surface appearance which were made in Example 1 were also true in Example 2.
The Pulpzyme HA mill trial reinforced the results of the laboratory vessel pick reduction study.
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The process uses a mixture of cellulases and xylanases to chemically change the hardwood vessel elements, rendering them susceptible to breaking under normal mill refining, thus not requiring any additional refining equipment. The process involves treating bleached hardwood brownstock pulp with the cellulase/xylanase mixture. The use of a pure cellulase enzyme is excluded.
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This is a continuation in part of Ser. No. 06/406,349, filed Aug. 9, 1982 now abandoned.
BACKGROUND OF THE INVENTION
1. Technical Field
Devices of this type are used to remove a disintegrable core from a metal casting by vibration with air and water blasts. These devices have used a combination of treatments to clean a metal casting of the mold material, such as sand mixed with a binder to help hold the desired shape. The core material is disintegrable allowing complex shapes of the metal casting to be thoroughly cleaned by vibration.
2. Description of the Prior Art
Prior art devices of this type have relied on a variety of different structures to clean the castings. See for example U.S. Pat. Nos. 4,206,800, 2,686,991, 2,008,741, U.K. Pat. No. 2,067,938.
In U.S. Pat. No. 4,206,800, a rotating acoustic sand core shake-out device is disclosed using a plurality of shake out stations which are rotated cycling the cleaning time.
In U.S. Pat. No. 1,966,571, a wet blast apparatus is shown wherein a reservoir is formed for collecting the rinsing liquid dispensed within.
U.S. Pat. No. 2,686,991 discloses a blast cleaning apparatus to clean drums within a cabinet. The device rotates the drum within to expose the surface to the abrasive.
U.K. Pat. No. 2,067,938 discloses a casting core knockabout machine having an enclosure of sound proofing material in which the work piece is positioned. A movable carriage having a hammer is engagable on the work surface.
Applicant's device utilizes a sound and dust isolation enclosure. The work piece is secured to a support fixture within and a predetermined time cycle is actuated.
SUMMARY OF THE INVENTION
A casting decoring device having a single station enclosure that isolates both sound and dust emissions usually associated with decoring operations. The device isolates and holds a number of different work pieces on a single fixture within and processes the same through a predetermined time cycle indicated by a controller associated with the device.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the casting decoring device;
FIG. 2 is an enlarged cross sectional view of a portion of the casting decoring device;
FIG. 3 is a front plan view of a mounting fixture within a portion of the device;
FIG. 4 is an enlarged cross sectional view of a fixture supporting guide;
FIG. 5 is a perspective view of the fixture within the casting decoring device;
FIG. 5A is an enlarged view of a portion of a work piece and vibrating mechanism of the fixture;
FIG. 6 is a portion of side elevation with a portion broken away of the casting decoring device; and
FIG. 7 is a schematic diagram of the control circuitry of the device.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A casting decoring device comprising an enclosure 10 having oppositely disposed side walls 11 and 12, a back wall 13, a top 14 and an apertured bottom panel 15. A plurality of tubular legs 16A, 16B, 16C, and 16D extend from within the enclosure 10 outwardly through the bottom panel 15 supporting the same in an elevated manner. The legs 16A and 16B also extend upwardly above the enclosure 10 and each have an axle support bracket 17 secured to their free ends.
The side walls 11 and 12 and the top 14 are all formed with sound absorbing insulation 18 enclosed between an outer surface 19 and an inner surface 20 as best seen in FIG. 2 of the drawings. Each of the side walls 11 and 12 and back wall 13 are secured to the tubular legs 16A, 16B, 16C, and 16D by a plurality of fasteners 21.
A door 22 has a main support frame member 23 with a sound isolation panel 24 secured thereto. The isolation panel 24 is filled with sound absorbent material 25 as best seen in FIG. 2 of the drawings. A secondary panel 26 is secured to the opposite side of said main support frame 23 and may also be filled with sound absorbing material. The main support frame member 23 has right angularly disposed vertical edges 26 which are adapted to receive each, a roller assembly 27 having a roller 27A thereon. A vertically extending L-shaped guide track 28 is secured to each of the tubular support legs 16A and 16B extending from the bottom panel 15 to the free end of said legs 16A and 16B.
A secondary guide track 29 is secured in spaced relation to the guide track 28 on the tubular legs 16A and 16B. The rollers 27A are registrable between the guide tracks 28 and secondary guide tracks 29, the latter of which restricts the lateral movement of the door 22 towards and away from the enclosure 10. A gasket 30 extends around the perimeter of the enclosure adjacent the opening in sealing relation with the door 22 when in closed position as seen in FIG. 6 of the drawings. The door 22 has a counter weight assembly 31 comprising a weight 31A with chains 32 extending therefrom to the door 22 over a pair of spaced sprockets 33 on a shaft 34 rotatably secured to the axle support bracket 17.
A pair of oppositely disposed pneumatic door clamps 35 are secured to the legs 16A and 16B so as to be engageable on the door as seen in FIGS. 2 and 6 of the drawings. A cross support bar 36 extends between the legs 16A and 16B from their free ends and supports a shock absorber 37 therebetween for engagement with the door 22 when in fully opened position. The pneumatic door clamps 35 are comprised of a mounting bracket 38 having an apertured free end 38A and a pivot support brace 39 extending outwardly at right angles therefrom. The pneumatic piston and cylinder assembly 40 is mounted to the apertured free end 38A with a piston 41 pivotally secured to a clamp arm 42 which is in turn pivoted to the pivot support brace 39 at 43. The opposite end of the clamp arm 42 is engagable on the right angular disposed vertical edges 26 upon activation of said piston and cylinder assembly 35 affectively sealing the door 22 against the gasket 30.
Referring now to FIGS. 3, 4, 5, and 5A of the drawings, a support fixture 44 can be seen comprising an apertured flat base member 45 with a variety of vertically upstanding work piece engagement brackets 46 and a pair of pneumatic guns 47 secured thereto. It will be evident to those skilled in the art that the placement of the engagement brackets 46 will vary depending on the work piece to be held and that the positioning of the pneumatic guns 47 will also be a matter of choice suited to the particular requirements of the user. An isolator support plate 48 is positioned directly under said fixture 44 and has a pair of oppositely disposed inverted U-shaped brackets 49 extending longitudinally along each edge.
Base member engagement members 50 extend from said brackets 49 stabilizing the fixture 44 which is supported in spaced relation to said isolation plate 48 by a number of isolation members 51. Each of said isolation members 51 is comprised of a multiple layered configuration having an inflatable isolation bag 51A positioned between two supporting members 51B and 51C. The isolation support plate 48 has a number of widely spaced support feet 52 which in turn are registrable within an equal number of locator wells 53 having an inner diameter greater than that of said support feet 52 and which are located on the bottom panel 15 with a resilient rubberized pad 54 within each of the locator wells as best seen in FIG. 4 of the drawings. The bottom panel 15 has a pair of oppositely disposed U-shaped members 55 registrable with a fork lift (not shown) for transport of the casting decoring device.
Referring now to FIG. 1 of the drawings, a control box 56 can be seen secured to the side wall 12 with a plurality of supply lines 57 extending therefrom and communicating with the door clamps 35, the isolation bags 51A, the pneumatic guns 47 via fittings 47A and an on-off switch 58.
In FIG. 7 of the drawings, a control system 59 can be seen having a supply pressure inlet line 60 with a main system control valve 61, a plurality of in line filters 62, 63 and 64 and regulators 65, 66, and 67 to reduce the line pressure and condition the control fluid as will be well understood by those skilled in the art.
A pilot control switch 68 on the inlet line 60 controls the pneumatic guns 47 via a supply line 69 while a secondary pilot control switch 70 controls the door clamps 35 via supply lines 71 and 72. The on-off switch 58, a system timer 73, a limit valve 74 and a shuttle valve 75 complete the major control components of the pilot control of the system.
In operation, the door 22 is raised by a handle H and the fixture 44 with the work pieces W positioned thereon is set into the enclosure 10. The supply lines 57 are connected as hereinbefore described and the door 22 is closed. The pilot control system acuates the door clamps 35 via the secondary pilot control switch 70 which in turn activates the pneumatic guns 47 via the pilot control switch 68. The timer 73 controls the overall cycle of the system which is predetermined based on the number and type of workpieces W on the fixture 44. The on-off switch 58 gives the operator overall control of the pilot control system as will be evident from the above description.
Referring again to FIG. 1 of the drawings, a disposal chute 76 can be seen in broken lines in which the sand and binder freed from the work piece passes out of the casting decoring device as it falls through the aperture in the base panel 15.
It will thus be seen that a casting and decoring device has been illustrated and described that provides a single station operation that reduces the noise and dust associated with such decoring operations in the past and provides a controlled time cycle for the effective treatment of the work pieces within a removable isolation fixture.
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A casting decoring device to decore metal castings by vibration within an enclosure. The enclosure provides a dust and sound isolation of the casting from the environment with the casting held in an isolation fixture within. A time control circuit is provided to cycle the device according to the size and number of castings within to be treated.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to providing the capability for peer processes in an application server cluster to detect failure of and recover transactions from any application server in the cluster.
2. Description of the Related Art
An application server is a process on a server computer on a computer network dedicated to running certain software applications (as opposed to, for example, a file server or print server). Generally, an application server is a software process that delivers applications to client computers. Moreover, an application server should handle most, if not all, of the business logic and data access of the application. Typically, multiple application servers are grouped into clusters of server computers. A computer cluster is a group of loosely coupled computers that work together closely so that in many respects they can be viewed as though they are a single computer. The components of a cluster are commonly, but not always, connected to each other through fast local area networks. Clusters are usually deployed to improve speed and/or reliability over that provided by a single computer, while typically being much more cost-effective than single computers of comparable speed or reliability.
Given that there are multiple computers in a server cluster, a need arises for high availability of Global/XA transactions. This entails the collaboration of a number of application server processes within the cluster to provide information on and timely recovery of such transactions. Problems that result from lack of such a capability include potential transactional inconsistencies due to lack of correct information as well as the prolonged holding of resource locks (such as databases) which present serious performance repercussions. One specific aspect of this high-availability is the need for enterprise information systems to be able to call any application server in the cluster and request information about or execute actions upon any transaction in the cluster.
Thus, a need arises for a technique that provides improved availability of Global/XA transactions in an application server cluster.
SUMMARY OF THE INVENTION
The present invention provides recovery of inflowed transactions by any instance in the cluster, peer recovery of transactions in a cluster, and administrative functionality related to these aspects.
A method of managing transaction processing comprises performing transaction processing using a first process, wherein the first process logs the transaction processing that it performs, detecting failure of the first process, wherein the transaction logs of the first process are locked, taking ownership of the locked transaction logs of the first process at a second process, unlocking the locked transaction logs of the first process for use by the second process, and recovering at least one transaction using the transaction logs. The transaction may be processed using a two-phase commit protocol. The first process and the second process may be transaction managers. The method may further comprise updating a parent process of the first process to use the second process instead of the first process. The method may further comprise taking ownership of other locked resources of the first process at a second process, unlocking the other locked resources of the first process for use by the second process, and recovering at least one transaction using the other resources.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the invention can be ascertained from the following detailed description that is provided in connection with the drawings described below:
FIG. 1 is an exemplary block diagram of an application server cluster in which the present invention may be implemented.
FIG. 2 is an exemplary flow diagram of a process of High Availability recovery of inflowed transactions.
FIG. 3 is an exemplary flow diagram of an implementation of recovery of inflowed transactions.
FIG. 4 illustrates an example of processing of a complex transaction in the system shown in FIG. 1 .
FIG. 5 illustrates an example of processing in which an Application Server Transaction Manager has crashed in the system shown in FIG. 1 .
FIG. 6 illustrates an example of processing in which an Application Server Transaction Manager has crashed in the system shown in FIG. 1 .
FIG. 7 illustrates an example of processing of a complex transaction in the system shown in FIG. 1 .
FIG. 8 illustrates an example of processing in which network communications crash have crashed in the system shown in FIG. 1 .
FIG. 9 illustrates an example of processing in which an Application Server Transaction Manager has crashed in the system shown in FIG. 1 .
FIG. 10 is an exemplary block diagram of a system in which the present invention may be implemented.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
High-availability clusters are implemented primarily for the purpose of improving the availability of services which the cluster provides. They operate by having redundant nodes, which are then used to provide service when system components fail. The minimum size for an HA cluster is two nodes, which is the minimum requirement to provide redundancy. HA cluster implementations attempt to manage the redundancy inherent in a cluster to eliminate single points of failure.
In computing, Java EE Connector Architecture (JCA) is a Java-based technology solution for connecting application servers and enterprise information systems (EIS) as part of enterprise application integration (EAI) solutions. While JDBC is specifically used to connect Java EE applications to databases, JCA is a more generic architecture for connection to legacy systems (including databases). One common example of an implementation of J2EE containers is called Oracle® Containers for J2EE which is abbreviated as OC4J. OC4J includes the following servers—Web Container, Enterprise Java Beans (EJB) Container, and JMS Server. Although the present invention is described in the context of an OC4J implementation, it is not limited to such an implementation. Rather the present invention contemplates implementation within any application server architecture.
In order to provide a high-availability of Global/XA transactions within a cluster, the collaboration of processes within the cluster to is needed to provide information on and timely recovery of such transactions.
One aspect of the present invention is recovery of inflowed transactions by any OC4J process in a cluster. An OC4J process may act as an interposed Transaction Manager (TM) in a global transaction propagated (and in the common case initiated) from an Enterprise Information System (EIS). A TM manages the transaction processing, which is designed to maintain a database in a known, consistent state, by ensuring that any operations carried out on the database that are interdependent are either all completed successfully or all cancelled successfully. This transaction processing is information processing that is divided into individual, indivisible operations, called transactions. The TM ensures that each transaction must succeed or fail as a complete unit; it cannot remain in an intermediate state. Typically, this is done using the two-phase commit processing protocol. The two-phase commit protocol is a distributed algorithm which lets all nodes in a distributed system agree to commit a transaction. The protocol results in either all nodes committing the transaction or aborting, even in the case of network failures or node failures.
In the event of such a failure during Two-phase commit (2PC) processing (such as a process crash) either on the EIS or OC4J side (network included), it is possible, particularly in the latter case, that recovery may be initiated by this parent EIS upon an OC4J process in the cluster other than the one that was used during the actual runtime. In the case where the EIS has crashed, the Transaction Terminator process (XATerminator) of this recovering process must locate all Xids across the cluster and/or the requested Transaction identifier (Xid) and also be able to resolve this Xid's transaction as instructed by the EIS. The overall concept is that the OC4J cluster (of Transaction Managers/Recovery Managers) should be exposed as one highly available TM.
An exemplary system 100 , in which the present invention may be implemented, is shown in FIG. 1 . System 100 includes Application Server cluster 102 , which includes a plurality of Application Server Transaction Managers 102 - 1 to 102 - 4 , a number of potential transaction participants, such as EIS (inbound 104 , EIS and outbound communication 106 , database 108 , JMS 110 , and ORB Transaction Service (OTS) or Web Transaction Service (WTS) 112 , and shared storage location for transaction logging 114 .
An exemplary flow diagram of a process 200 of High Availability recovery of inflowed transactions by any OC4J process in a cluster 102 is shown in FIG. 2 . Process 200 begins with step 202 , in which a transactional application processes transactions. In step 204 , there is implicit interaction with Two-phase commit protocol processing due to the transactional nature of the application. In step 206 , when an OC4J process fails during 2PC processing and/or it is impossible to start a new OC4J process on the machine it was running in a timely manner in order to recover its transaction logs, this leaves the resources that were being used to process the transaction locked by the now crashed process.
In step 208 , a peer OC4J process in cluster 102 detects the failed process, takes ownership of the crashed process's logs and recover its transactions. In step 210 , when transactional application 202 reattempts the request that failed, the request will be successfully executed because the peer process has recovered the failed process and freed the resource locks.
In the case where the crashed OC4J is an interposed TM/coordinator, this peer must also update any coordinators in the cluster in order to redirect them to the takeover peer, redirect the tree of processes according to this new graph construct, recover, release resources locks, etc.
The peer process can take over in these situations due the requirement that all OC4J processes in the highly-available cluster log their transaction records to a shared location, i.e. shared disk or common database. Additionally, other software (virtual directories, etc.) and hardware (replication, etc.) solutions might be employed to further the reliability.
1. Database Logging: Due to the various transactional locking mechanisms inherit in databases and the nature of the OC4J database store's current use of them, transfer of ownership becomes chiefly a matter of updating the instanceid field of the crashed OC4J process, remapping any parent OC4J instances records accordingly, and recovering the imported transactions.
2. File Logging: The imported transactions/logs should be migrated to the recovering peer rather than simply processed from the logging location of the crashed process in order to prevent conflict should the crashed process subsequently restart successfully. This also allows for a simpler locking process that is set at the logging directory level (the instance id for the file store) in order to be most performant.
In process 200 , a system administrator 212 may control recovery processing by registering for JMX notifications in order to monitor the health of the system. Such registration may be performed, for example, via a JTAResource MBean.
An exemplary flow diagram of a process 300 by which recovery of inflowed transactions may be implemented is shown in FIG. 3 . Process 300 begins with step 302 , in which EIS transactions are imported via the JCA transaction inflow contract. In step 304 , when a failure occurs during two-phase commit processing, such as a process crash, a hardware failure, or a network communications failure, JCA interface (the recover method of the XATerminator.) is called. All of the OC4J processes in the cluster are called to return all of the Xids of interposed TMs across the cluster. Step 304 includes step 306 , in which every OC4J cluster that is logging two-phase commit transactions calls XATerminator.recover to return the Xids. This technique requires querying every node in the cluster and insuring that either all nodes in the cluster are active during/for the request, or, in the case that one or more nodes have crashed and have been unable to restart, that all of the logs/records belonging to the crashed process have been recovered by a peer. Failing this, it is necessary to know that not all logs are available and have the appropriate XAException (with errorcode of XAER_RMFAIL) thrown rather than an incomplete list returned.
Another scenario along these lines involves an OC4J process that does not crash, but is shutdown or restarting and has in-doubt records. In this case, a message must be sent from the OC4J that is shutting down to the rest of the cluster, informing each OC4J in the cluster that, until it is restarted or has received a message that a peer has recovered it, all instances must return a XAER_RMFAIL XAException error code for XATerminator.recover calls as well as a XAER_RMFAIL XAException error code from XATerminator.rollback/commit/forget calls if a XAER_NOTA XAException error code would have been returned otherwise. If this message is not successfully received by the entire cluster, a severe message must be logged to the debug and by natural course, it's unavailability will result in the correct XAER_RMFAIL being returned by the other OC4J members in the cluster that can not contact it. In the case where a message that a peer has recovered the files is received, an OC4J instance can update its server list accordingly thus removing the subscription of and reliance on the OC4J that was shutdown (of course if the previously crashed OC4J is restarted it rejoins the group and therefore server list).
In step 308 , in the case where the Xid is found on an OC4J process in the cluster other than the one which was called upon initially, the method call will be issued upon the process that owns this record, rather than changing the ownership to the OC4J process/XATerminator which has received the initial request before issuing the command which is non-performant in the best case and dangerous in the worst. The XATerminator always looks locally first for the Xid in order to prevent network calls where possible, but even if it is found locally, in a cluster environment it must be determined that the Xid/node found is the root of the OC4J process/transaction tree lest (in the case where there are multiple OC4J nodes of this cluster in the transaction) not all branches be resolved consistently following the symantecs of checked transactions. Included in step 308 is step 310 , in which an OC4J/XATerminator that owns a Xid calls XATerminator.rollback or XATerminator.commit on that Xid.
Alternatively to the log-type agnostic approach just described, an approach to exploit each log type's characteristics may be implemented:
1. Database Logging: If XATerminator.recover is called, in the case where the common database logging store is used, any OC4J process may query the database for all Xids in the cluster (the database store can not be shared across more than one cluster without modifications but this would likely be a very rare requirement) and so it is not required that all OC4J processes in a cluster be alive nor that any be contacted for the recover call. Also, there are no contention issues during this call. In the case where only a particular Xid is necessary (i.e. for recovery commit or rollback), the logging agnostic approach may still be used and may be preferable to a technique whereby ownership of a single record is changed/migrated.
2. File Logging: In this case the ability to know if all OC4J processes in a cluster are alive or have been recovered by a peer may be cheaper to determine due to the existence or non-existence of the appropriate log(dir)s. Due to various performance and resource issues associated with processing the entire cluster of file-based logs, however, the logging agnostic approach may well be the best alternative for file logging both for the XATerminator.recover and termination calls.
An example of processing of a complex transaction is shown in FIG. 4 . The transaction is initiated within Application Server Transaction Manager 102 - 1 , which enlists a number of different resources and spans multiple Application Server Transaction Managers. The procedure call flow and therefore enlistment may occur in a number of combinations and there may be repeated calls between all nodes and resources within the context of the same transaction. For example, Application Server Transaction Manager 102 - 1 may enlist 402 database 108 and Application Server Transaction Manager 102 - 2 , Application Server Transaction Manager 102 - 2 may enlist 402 JMS 110 , OTS or WTS participants 112 , and Application Server Transaction Manager 102 - 3 , and Application Server Transaction Manager 102 - 3 may enlist an 402 EIS 106 . Each Application Server Transaction Manager 102 - 1 to 102 - 4 logs 404 the transactions it has processed in the shared storage location for transaction logging 114 .
Examples of peer recovery are shown in FIGS. 5 and 6 . An example of application processing flow in which an Application Server Transaction Manager has crashed is shown in FIG. 5 . In this example, Application Server Transaction Manager 102 - 2 has crashed during processing of a complex transaction. As shown in FIG. 6 , Application Server Transaction Manager 102 - 4 takes over the transaction logs of the crashed Application Server Transaction Manager 102 - 2 process and notifies any superior Application Server Transaction Manager nodes, such as Application Server Transaction Manager 102 - 1 and Application Server Transaction Manager 102 - 3 , in order for these superior nodes to update their logs to point to the new server, Application Server Transaction Manager 102 - 2 . Bottom-up recovery modeled participants such as OTS or WTS 112 can query 602 against any other live node in the cluster to determine and drive the outcome. Also, OC4J will drive the recovery top-down if appropriate. Each Application Server Transaction Manager 102 - 1 to 102 - 4 logs 204 the transactions it has processed in the shared storage location for transaction logging 114 .
Examples of JCA inflow recovery are shown in FIGS. 7-9 . An example of processing of a complex transaction is shown in FIG. 7 . Complex transaction initiated within EIS enlists 702 Application Server Transaction Manager 102 - 1 via the JCA transaction inflow contract. Application Server Transaction Manager 102 - 1 in turn enlists 704 a number of different resources, such as database 108 and Application Server Transaction Manager 102 - 2 , and spans multiple Application Server Transaction Managers. The call flow and therefore enlistment may occur in a number of combinations and there may be repeated calls between all nodes and resources within the context of the same transaction. For example, Application Server Transaction Manager 102 - 2 may enlist 706 JMS 110 and OTS or WTS 112 . Each Application Server Transaction Manager 102 - 1 to 102 - 4 logs 204 the transactions it has processed in the shared storage location for transaction logging 114 .
A more complex example of processing in which network communications crash is shown in FIG. 8 . In this example, network communications 802 between inbound EIS transactions 104 and Application Server Transaction Manager 102 - 1 crash. In this case, Application Server Transaction Manager 102 - 1 is both a subordinate (to EIS inbound transactions 104 ) and a superior (to Application Server Transaction Manager 102 - 2 ).
An example of High Availability recovery processing in which an Application Server Transaction Manager crashes is shown in FIG. 9 . In this example, Application Server Transaction Manager 102 - 1 crashes. In this case Application Server Transaction Manager 102 - 1 is both a subordinate (to EIS inbound transactions 104 ) and a superior (to Application Server Transaction Manager 102 - 2 ). EIS inbound transactions 104 attempts recovery 902 on a different Application Server Transaction Manager, Application Server Transaction Manager 102 - 3 .
An exemplary block diagram of a application server system 1000 in which the present invention may be implemented, is shown in FIG. 10 . System 1000 is typically a programmed general-purpose computer system, such as a personal computer, workstation, server system, and minicomputer or mainframe computer. System 1000 includes one or more processors (CPUs) 1002 A- 1002 N, input/output circuitry 1004 , network adapter 1006 , and memory 1008 . CPUs 1002 A- 1002 N execute program instructions in order to carry out the functions of the present invention. Typically, CPUs 1002 A- 1002 N are one or more microprocessors, such as an INTEL PENTIUM® processor. FIG. 10 illustrates an embodiment in which DBMS 1000 is implemented as a single multi-processor computer system, in which multiple processors 1002 A- 1002 N share system resources, such as memory 1008 , input/output circuitry 1004 , and network adapter 1006 . However, the present invention also contemplates embodiments in which DBMS 1000 is implemented as a plurality of networked computer systems, which may be single-processor computer systems, multi-processor computer systems, or a mix thereof.
Input/output circuitry 1004 provides the capability to input data to, or output data from, database/DBMS 1000 . For example, input/output circuitry may include input devices, such as keyboards, mice, touchpads, trackballs, scanners, etc., output devices, such as video adapters, monitors, printers, etc., and input/output devices, such as, modems, etc. Network adapter 1006 interfaces system 1000 with Internet/intranet 1010 . Internet/intranet 1010 may include one or more standard local area network (LAN) or wide area network (WAN), such as Ethernet, Token Ring, the Internet, or a private or proprietary LAN/WAN.
Memory 1008 stores program instructions that are executed by, and data that are used and processed by, CPU 1002 to perform the functions of system 1000 . Memory 1008 may include electronic memory devices, such as random-access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), electrically erasable programmable read-only memory (EEPROM), flash memory, etc., and electro-mechanical memory, such as magnetic disk drives, tape drives, optical disk drives, etc., which may use an integrated drive electronics (IDE) interface, or a variation or enhancement thereof, such as enhanced IDE (EIDE) or ultra direct memory access (UDMA), or a small computer system interface (SCSI) based interface, or a variation or enhancement thereof, such as fast-SCSI, wide-SCSI, fast and wide-SCSI, etc, or a fiber channel-arbitrated loop (FC-AL) interface.
The contents of memory 1008 varies depending upon the functions that system 1000 is programmed to perform. One of skill in the art would recognize that these functions, along with the memory contents related to those functions, may be included on one system, or may be distributed among a plurality of systems, based on well-known engineering considerations. The present invention contemplates any and all such arrangements.
In the example shown in FIG. 10 , memory 1008 includes application server transaction managers 1012 A-N, recovery routines 1014 , transaction data 1016 , and operating system 1018 . Application server transaction managers 1012 A-N manage the transaction processing, which is designed to maintain resources such as a database in a known, consistent state, by ensuring that any operations carried out on the database that are interdependent are either all completed successfully or all cancelled successfully. Recovery routines 1014 are software routines that perform recovery of transactions when transaction managers, or other nodes, fail during transaction processing. Transaction data 1016 is data relating to transactions that are being performed, which is typically used by one or more transaction managers 1012 A-N to perform transaction processing. Transaction data 1016 also includes data that may be used by recovery routines 1014 to recover transactions when transaction managers, or other nodes, fail during transaction processing. Operating system 1018 provides overall system functionality.
As shown in FIG. 10 , the present invention contemplates implementation on a system or systems that provide multi-processor, multi-tasking, multi-process, and/or multi-thread computing, as well as implementation on systems that provide only single processor, single thread computing. Multi-processor computing involves performing computing using more than one processor. Multi-tasking computing involves performing computing using more than one operating system task. A task is an operating system concept that refers to the combination of a program being executed and bookkeeping information used by the operating system. Whenever a program is executed, the operating system creates a new task for it. The task is like an envelope for the program in that it identifies the program with a task number and attaches other bookkeeping information to it. Many operating systems, including UNIX®, OS/2®, and Windows®, are capable of running many tasks at the same time and are called multitasking operating systems. Multi-tasking is the ability of an operating system to execute more than one executable at the same time. Each executable is running in its own address space, meaning that the executables have no way to share any of their memory. This has advantages, because it is impossible for any program to damage the execution of any of the other programs running on the system. However, the programs have no way to exchange any information except through the operating system (or by reading files stored on the file system). Multi-process computing is similar to multi-tasking computing, as the terms task and process are often used interchangeably, although some operating systems make a distinction between the two.
Although specific embodiments of the present invention have been described, it will be understood by those of skill in the art that there are other embodiments that are equivalent to the described embodiments. Accordingly, it is to be understood that the invention is not to be limited by the specific illustrated embodiments, but only by the scope of the appended claims.
The present invention further contemplates implementation in the form of computer program instructions, recorded on a computer readable storage medium, and executable by a processor, for performing processing.
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Recovery of inflowed transactions are provided by any instance in a cluster, along with peer recovery of transactions in a cluster, and administrative functionality related to these aspects. A method of managing transaction processing comprises performing transaction processing using a first process, wherein the first process logs the transaction processing that it performs, detecting failure of the first process, wherein the transaction logs of the first process are locked, taking ownership of the locked transaction logs of the first process at a second process, unlocking the locked transaction logs of the first process for use by the second process, and recovering at least one transaction using the transaction logs.
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This is a continuation of application Ser. No. 07/166,556, filed on Mar. 10, 1988, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
On rotary printing presses, particularly on offset rotary printing presses, it is necessary to feed a very thin and uniform ink film to a printing plate wetted by a wetting agent. For the high-viscosity printing inks normally used currently, a complex inking unit equipped with many rollers is generally required to produce this thin and uniform ink film. A result of the high viscosity of the inks currently used and the many rollers employed in the inking unit is that it takes longer to achieve an appropriate ink distribution in the inking unit to ready it for printing.
2. Description of the Prior Art
U.S. Pat. No. 4,660,470, entitled "Inking Unit Pre-Adjustment Method" and issued Apr. 28, 1987, which corresponds to German Laid Open Patent Appln. No. DE-OS 33 38 143, describes a process for presetting the inking unit, wherein the process starts with an empty, washed inking unit. The objective is to produce a defined basic ink layer 4 to 5 microns thick on all the rollers, so that the desired ink profile can be applied to them in a second process step. The second step is thereby either performed when printing has started, or else the printing is delayed until after the definitive achievement of the desired ink profile and ink gradient.
In practice, when there is a job change, the new printing job is set up and run without washing the inking unit. Additionally, in many cases, the inking unit is not washed before long periods of inactivity, e.g., before weekends or holidays. Such practices are made possible by so-called "overnight inks". In actual practice, therefore, regardless of the quantity of ink and the ink distribution of the previous job, the machine is positioned to the new setting, and the zonally existing excess quantities of ink are removed from the inking unit by the printing of a large number of waste sheets, if the new job requires zonally less ink than the previous job.
As noted above, U.S. Pat. No. 4,660,470 (issued Apr. 28, 1987) described as process for establishing a desired ink zone profile in a rotary printing press. This U.S. patent hereby expressly incorporated herein by reference, as if the contents thereof were fully set forth herein.
The published technical papers "Possibilities and Margins of the Computerized Analysis of Offset Inking Units (I)", Prof. Dr.--Ing. Helmut Rech, druck print 8/1984, pp. 522-523; "Possibilities and Margins of the Computerized Analysis of Offset Inking Units (II)", Prof. Dr.--Ing. Helmut Rech, druck print 9/1984, pp. 578-582; "Possibilities and Margins of the Computerized Analysis of Offset Inking Units (III)", Prof. Dr.--Ing. Helmut Rech, druck print 10/1984, pp. 659-660; "Possibilities and Margins of the Computerized Analysis of Offset Inking Units (IV)", Prof. Dr.--Ing. Helmut Rech, druck print 11/1984, pp. 725-726; and "Rechnergestutzte Entwicklung von Farbwerken in Druckmaschinen", Prof. Dr.--Ing. Helmut Rech, Der Polygraph 9, 1981, pp. 699-709 discuss the use of computer assisted iterative simulations, modelings, and empirical or semi-empirical methods for establishing ink transfer characteristics and parameters in rotary printing presses.
Issued U.S. Pat. No. 4,441,819 (issued Apr. 18, 1984) and issued U.S. Pat. No. 3,958,509 (issued May 25, 1976), issued European Patent No. 0 081 739, published European Patent Appln. No. 0 095 606 and the prior published technical documents "Flow of Information in the System", "Description of Commands, Store", "Description of Commands, Zones Identical-Gradual Adjustment", "Description of Commands, Cassette: Read In", and "Heidelberg CPC" (Publication No. HN 2/43.e), all of which have been previously published by Heidelberger Druckmaschinen AG, D-6900 Heidelberg, Federal Republic of Germany, discuss the use of a control stand computer to control the printing process and methods by which appropriate ink zone settings and appropriate ink strip lengths may be chosen, preset into the control stand computer, and/or adjusted during the printing process. The above mentioned U.S. Pat. Nos. 4,441,819 and 3,958,509 are additionally expressly incorporated by reference herein.
OBJECTS OF THE INVENTION
A principal object of the present invention is, therefore, the provision of a process for the production of a defined ink distribution (or new ink profile) in the inking unit appropriate to a new (or subsequent) printing run, in which the new profile is achieved without the need to completely empty and wash the inking unit.
This object may be achieved by adoption of the embodiments set forth below.
SUMMARY OF THE INVENTION
In a first embodiment, the modification of the ink profile takes place before the printing of the subsequent run and includes two steps. First, the ink profile present in the inking unit from the previous printing job is removed (or leveled to a uniform thickness) while the machine is still rotating by: initially, closing the ink dosing (or metering) elements, and transporting the quantities of ink present zonally in the inking unit, as a function of the profile, back into the ink duct by means of a specified number of rotations (which may, according to the invention, be determined by simulative, empirical or semi-empirical methods well known in the art), until a uniformly small and defined thickness of ink, independent of the profile (e.g., a base ink layer), is present on all the rollers. Thereafter, the ink profile required for the subsequent printing job is established in the inking unit by a zonal adjustment of the ink metering elements by adjusting the length of the ink strip which is transferred into the inking unit (hereinafter referred to as the "ink strip length" or, more colloquially, as used by artisans in the printing field, the "ink strip width"), and by means of a defined number of rotations of the inking unit (determined via simulative, empirical or semi-empirical methods), so that an appropriate profile can be established under precisely defined conditions.
A primary advantage of the present invention is that a precisely defined base ink layer can be produced on all rollers directly from the ink profile remaining after the preceding job, starting from any given profile, and that the subsequent establishment of a new profile is accomplished automatically, that is, with very little intervention or judgement required on the part of the printing press operator. The printing press operator is thereby able to set up a new printing job in the shortest possible time and without major effort or expense, eliminating the use of a large number of waste sheets and the major time and expenditures involved in cleaning the inking unit. The ink strip to be transferred into the inking unit by means of a vibrator inking unit, for example, can be the length of the ink strip transferred by the vibrator roller.
An inking unit with a uniformly low and defined ink thickness on all the rollers independent of the profile is achieved by setting the vibrator roller for a specified number of machine rotations with closed ink dosing elements, preferably with a setting to invoke the maximum ink strip length, and according to the ink separation characteristics of the particular ink employed, that ink is transported back into the ink duct (or ink reservoir). Since the zonal ink profile gradually disappears, the closer it gets to the inking rollers, during the return of the ink, in addition to the removal of the ink gradient, the zonal profile is also eliminated. The next process step can either take place immediately afterward, or be delayed in relation to the first. That is, some time interval may be imposed between the achievement of a uniform ink profile in the inking mechanism due to the removal of ink from the inking mechanism and the subsequent process step of setting up a new ink profile appropriate to the subsequent printing job. In the determination of the required number of rotations of the inking unit, as described below, the required ink gradient in the inking unit is taken into consideration, so that the printer operator need only start the job change, and in the shortest possible time, and without manual intervention, he can start to print the new job.
The process according to another embodiment, as a function of the quantitative zonal ink balance between the previous printing job and the subsequent printing job, makes it possible to produce the new ink profile in the ink unit directly, ready for the print run, without the production of an intermediate uniform base ink layer. For this purpose, before beginning to print, first the values stored in the computer for the zonal adjustment of the dosing elements and the length of the ink strip used for the previous print job are compared with the values input into a computer memory for the zonal adjustment of the ink dosing elements and the length of the ink strip used for the subsequent print job, and the zonal differences are determined from the ink zone values. These values, supplemented by the zonal quantities stored by the inking unit, are transported from the rotating inking unit back into the ink reservoir, depending on whether the difference in the quantity of ink is positive or negative. The number of inking unit rotations required for the purpose until the zonal differences are equalized is initially determined first, and only then are the ink dosing elements adjusted and the length of the ink strip transferred into the inking unit for the subsequent printing job. During this adjustment, before the beginning of the print run, no ink is transported out of or into the inking unit when printing has been stopped.
The process steps take place automatically, so that here too, an ink distribution in the inking unit can be achieved which is appropriate to the printing run.
To obtain the correct ink gradient in the inking unit, this process also makes it possible to withdraw somewhat more ink than strictly necessary during the first part of the activation of the inking unit, and during the remainder, to add the same amount of ink back again. The correct ink gradient is thereby adjusted automatically, which fact can be taken into consideration in the determination of the number of rotations or zonal adjustments.
In zones with a satisfactory balance, no change is made. For example, ink can be extracted during the first half of the number of machine rotations to be executed, and the same amount of ink can be added back again in the second half. The correct ink gradient is thereby adjusted automatically, which fact can be taken into consideration in the determination of the number of rotations or zonal adjustments.
The determination of the required number of machine rotations can be based, for example, on a maximum ink strip length, the closing of the zones with positive ink differences and the opening of the zones with negative ink differences to the new position. Naturally, other combinations are also possible, e.g., the determination of an ink strip length which results in the same number of machine rotations for the zones with positive quantitative ink differences as for the zones with negative quantitative ink differences.
The ink profile corresponding to the new printing job and the corresponding ink strip length can be determined, for example, by gauging the printed proof or the printing plate, and inputting the result via a data line or a data medium, or it can be manually input and stored by the printer.
For the characteristics described above, it is to be assumed that the zonal ink differences are used for the calculation of the ink strip length and the zonal adjustments required. Also taken into consideration is the fact that the ink roller unit stores a zonal quantity of ink which is a function of the zonal ink consumption, which is greater than the quantitative ink differences between the two printing jobs. For example, it is possible, in the computation of the ink strip length, to determine an average value of the ink quantities stored in the inking unit between zones with positive and negative differences.
There may also be provided advantageous process steps to remove the current ink profile, whereby the ink dosing elements are moved into closed positions, the ink duct rollers are preferably set to maximum ink strip length, the vibrating roller movement is initiated, a defined number of inking unit rotations are executed, the vibrating roller movement is stopped, and the inking unit continues to rotate a defined number of rotations until the end of the ink profile removal.
During this process, the establishment of the ink profile required for the subsequent print job is accomplished by individual process steps, whereby the ink metering elements are adjusted by zones to the required ink profile, the ink duct rollers are set to the determined ink strip length, the vibrator roller motion is initiated, a defined number of inking unit rotations are executed, and the paper flow and printing begin, or the vibrator roller motion is stopped, or the vibrator roller motion is stopped and the machine is stopped.
The present invention also provides for an accelerated removal of the current ink profile, while the paper flow continues, by means of the following process steps: with simultaneous paper flow, the ink duct rollers are preferably set to maximum ink strip length; the vibrator roller motion is initiated; the paper flow and printing are initiated: a defined number of machine rotations are executed; the vibrator roller movement is stopped; at the end of the ink profile removal, the machine continues to rotate for a determined number of rotations without paper flow; and thereafter the profile is established as described above.
There is also provided an alternative embodiment, wherein the paper flow continues, but without the return of ink to the ink duct, and wherein an accelerated removal of the current ink profile is accomplished by means of the following process steps; the paper flow and printing are started: a defined number of machine rotations are executed; the paper flow and printing are stopped; at the end of the ink profile removal the machine continues to rotate for a determined number of rotations without paper flow; and thereafter the profile is established as described above.
The invention also provides a second embodiment for the execution of an automatic sequence of operation, in which a removal of the current ink profile and a simultaneous establishment of the ink profile required for the subsequent print job are carried out simultaneously by means of the following individual process steps: the ink dosing elements are zonally adjusted according to the differential ink quantities determined; the ink duct rollers are set to a calculated ink strip length: vibrator roller movement is initiated: the mathematically determined number of inking unit rotations for the simultaneous removal of the old profile and establishment of the new profile are executed; the ink metering elements for the subsequent print job are zonally adjusted to the required ink profile: the ink duct rollers are set to the required ink strip length; and the paper flow and printing are initiated; or, alternatively, the vibrator roller movement is stopped and the machine is shut down.
In general, the invention features a controlled process for changing an ink zone profile in at least one printing stand from a previous ink zone profile corresponding to a previous printing job to a subsequent ink zone profile corresponding to a subsequent printing job, the printing press comprising a printing plate cylinder for positioning a printing plate, an ink reservoir for holding a supply of ink and an inking mechanism for transferring the ink between the ink reservoir and the printing plate during operation of the printing stand, the inking mechanism comprising a plurality of inking rollers and a plurality of individually adjustable ink zone metering devices for transferring the ink between the ink reservoir and at least one of the plurality of inking rollers, the process comprising the steps of: (a) calculating at least one previous parameter characterizing the previous ink zone profile; (b) calculating at least one subsequent parameter characterizing the subsequent ink zone profile; and (c) adjusting at least one of the plurality of adjustable ink zone metering devices, in accordance with the calculated previous and the subsequent parameters, and operating the inking mechanism to thereby change the ink zone profile in the printing stand from the previous ink profile to the subsequent ink profile.
In one aspect, the process includes the steps of (A) beginning with the previous ink zone profile; (B) transferring ink from the inking mechanism, through at least one of the plurality of ink zone metering devices and into the ink reservoir so as to establish, on the plurality of inking rollers, a base ink layer, the base ink layer being substantially uniform in thickness across the ink zones; and (C) thereafter, transferring ink from the ink reservoir, through at least one of the plurality of ink zone metering devices and into the inking mechanism so as to establish the subsequent ink zone profile.
In another aspect, the process includes the steps of (A1) beginning with the previous ink zone profile; (B2) determining, for each of the plurality of ink zones, a volumetric difference indicator indicative of the change of ink volume between the ink volume remaining in the inking mechanism from the previous printing job and the ink volume required in the inking mechanism for the subsequent printing job; (C2) adjusting each of the plurality of ink metering devices in accordance with the corresponding ink zone volumetric difference indicator determined in step (B2): and (D2) actuating the inking mechanism until the subsequent ink zone profile is substantially achieved therein.
The invention will now be described by way of particular preferred embodiments, reference being had to the accompanying drawings, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of one printing stand of a rotary offset printing press known in the art and in cooperation with which the present invention provides an improved process for the adjustment of the inking mechanism thereof:
FIG. 2 is a flow chart of a process according to a first embodiment of the present invention for adjusting the inking mechanism of a rotary offset printing press, such as that depicted in FIG. 1;
FIG. 3 is a flow chart of a subprocess for determining certain parameters for the implementation of a process conducted according to FIG. 2;
FIG. 4 is a flow chart of another subprocess for determining an additional parameter for the implementation of a process conducted according to FIG. 2;
FIG. 5 is a flow chart of a process according to a second embodiment of the present invention for adjusting the inking mechanism of an offset rotary printing press, such as that depicted in FIG. 1; and
FIGS. 6a, 6b and 6c constitute a flow chart of a subprocess for determining certain parameters for the implementation of a process conducted according to FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1, a rotary print stand 10, well known in the art, generally includes: a plate cylinder 11 having mounted thereon a printing plate D; an inking unit 12 which includes ink applicator rollers 13 for applying to printing plate D an ink profile of a single color printing ink (for example, black, cyan, magenta or yellow): a dampening (or wetting) unit 18 having dampening applicator rollers 19 for transferring a dampening agent to printing plate D; a blanket cylinder 16 carrying a rubber blanket 17 for receiving an ink impression from printing plate D; and a sheet drum 15 for carrying a printed sheet 14 onto which the ink impression carried by blanket 17 is transferred.
It is particularly important that the ink be applied to printing plate D in a precisely defined and controllable manner. That is, those areas of printing plate D having a high density of printed content will require a greater ink flow during the printing process than those areas having a lower density of printed content. To this end, the printing stand 10 is typically provided with a means for zonally varying the ink application profile across the width of the printing stand 10. For example, as shown in FIG. 1, printing stand 10 may be provided with an ink duct 21 which extends across its width. The zonal adjustment of the ink application profile is provided by a plurality of ink metering ducts 22 which may be controlled or adjusted by a zonal ink metering adjustment mechanism 30 under the control of a computer 31.
A duct roller 23 is typically mounted adjacent to ink duct 21. An ink duct of this type is further described in U.S. Pat. No. 3,978,788, issued Sept. 7, 1976, the contents of which are hereby expressly incorporated by reference as if this patent were set forth in its entirety herein.
Typically, the ink application profile which is set up on duct roller 23 is transferred into the inking unit 12 by means of a vibrator roller 24 which oscillates to successively pick up strips of ink from duct roller 23 and transfer them into inking unit 12, as for example, by contacting one of the rollers 32 thereof. The operation of such a vibrator roller 24 is more fully described in U.S. Pat. No. 3,908,545, issued Sept. 30, 1975, this issued U.S. patent being hereby expressly incorporated by reference as if the contents thereof were set forth fully herein.
Typically, the printing stand 10 will also include auxiliary mechanisms such as, for example, a duct roller drive 28, a vibrator roller drive 29, an applicator roller throw-off 27' for lifting the ink applicator rollers 13 off of the printing plate D, a press drive 25 and a sheet feed 27 for supplying the sheets to be printed 26 to sheet drive drum 15.
U.S. Pat. No. 4,660,470, which has been incorporated herein by reference, describes the difficulties encountered in achieving a desired ink profile equilibrium for a particular printing job. For example, that patent notes that some 300 prints may be required before any adjustment of the ink metering elements reaches the paper and equilibrium is reliably established in the ink transport mechanism. That patent also describes a method for achieving a desired ink profile, which method assumes that the inking unit has been washed and cleaned prior to setting up the desired profile. However, as noted above, such cleaning and washing of the inking mechanism between successive printing jobs is not in accord with present day practice. Rather, most printing press operators would merely run off successive waste sheets during the transition period between the previous and the successive print jobs.
In contrast, the present invention provides a method of transition between a previous and a subsequent desired ink profile without the necessity of cleaning and washing the inking unit or of removing excess ink therefrom by the printing of an excessive number of waste sheets.
In a first embodiment of the invention, the steps of which are schematically indicated in the flow charts of FIGS. 2, 3 and 4, ink is transferred from the inking mechanism back into the ink reservoir until a base ink layer of, for example, 5 microns is established in the inking mechanism. Thereafter, the desired subsequent ink profile may be established in a determined number of print stand revolutions through adjustment of the zonal ink zone settings and the ink strip lengths transferred by the vibrator roller.
In a second embodiment of the invention, the steps of which are schematically set forth in FIGS. 5, 6a, 6b and 6c, a direct transition is made between the preceding and subsequent ink profiles without the necessity of an intervening reduction to a base ink layer.
We turn now to FIG. 2, wherein a first embodiment of the invention is illustrated which presumes that the printing stand would be in a typical condition following the termination of a previous printing job. That is, the inking mechanism would not be cleaned and washed, but would carry the ink profile corresponding to the previous printing job. The printing stand would be in rotation, but the paper feed and printing processes would be temporarily suspended.
Typically, the ink zone settings Si and the ink strip lengths bi entered into (or measured from) the printing stand would be those appropriate for developing the ink profile required for the previous job, namely, Simeas and bimeas. The new (or subsequent) ink zone settings S Yni set and ink strip lengths biset for the new or subsequent job are entered into the control stand computer. Methods by which the ink zone settings S and ink strip lengths b may be varied to thereby attain varying desired ink profiles are well known in the art and are described in documents incorporated by reference herein. Additionally, methods by which the ink zone settings S and ink strip lengths b which will achieve a desired ink application profile may be determined are also well known in the art and are described in documents incorporated by reference herein.
Each ink zone within the printing stand is now closed. That is, S Yni is set to zero. At the same time, the ink strip length bi within the printing stand is set to the maximum bmax.
With the ink zones closed, ink is transferred from the inking mechanism back into the ink reservoir provided in the printing stand. The ink strip lengths bi determine the quantity of ink transferred by the vibrator roller. With the ink strip lengths set to bmax, the maximum amount of ink is transferred back into the ink reservoir.
Hereafter, there are three submethods encompassed by the first embodiment of the present invention.
In Embodiment 1A, the vibrator roll is activated, and the paper feed, printing and wetting mechanisms are temporarily held in abeyance. That is, the primary method for removal of ink from the inking mechanism down to the desired base layer of, for example, 5 microns, is via the vibrator roll and back into the ink reservoir. The printing stand now performs a number of revolutions equal to Zn1i, the determination of which is described more fully below. Following Zn1i revolutions, a desired base ink layer of approximately 5 microns will have been substantially established.
In Embodiment 1B, ink is removed from the inking mechanism both via the vibrator roll transfer back to the ink reservoir and also through an actual printing process. Thus, the vibrator roller, as well as the paper feed, printing and wetting mechanisms are activated. Thereafter, the printing stand performs Zn2i revolutions, the determination of which number is explained more fully below, after which a desired base ink layer will have been substantially established.
In Embodiment 1C, the vibrator roller is not activated, and the removal of ink from the inking mechanism takes place primarily via the printing process. Thus, the paper feed, printing and wetting mechanisms are activated, and the printing stand executes Zn3i revolutions, the determination of which number is explained more fully below, after which a desired base ink layer will have been substantially established.
At this point, the three embodiments 1A, 1B and 1C converge, and the printing stand executes a predetermined number of stabilizing revolutions Z, for example, 10.
Thereafter, as discussed more fully below, the number of printing stand revolutions Zn4 required, with ink zone settings of S Yni set and ink strip lengths biset, to establish the desired ink profile appropriate for the subsequent printing job is determined. The inking mechanism (including the vibrator roller) is now activated to transfer ink from the ink reservoir back into the inking mechanism, and the printing stand executes Zn4 rotations.
Finally, the printing of the subsequent job may be executed immediately or postponed.
FIG. 3 sets forth a subroutine for the determination of the number of printing stand revolutions Zn1, Zn2 and Zn3 required for the removal of ink down to a desired base layer according to the Embodiments 1A, 1B and 1C set forth in FIG. 2.
Initially, the arithmetic average of all ink zone settings S mi meas of all ink zone settings S Yni meas currently existing in the printing stand is calculated. Typically, the existing ink zone settings S Yni meas will be those utilized for the establishment of the desired ink profile of the preceding job.
Thereafter, the desired number of vibrator roller strokes, either Z1i, Z2i or Z3i, is determined, according to which of the three embodiments 1A, 1B or 1C is to be employed in the practice of the invention. In all three cases, as noted in both FIGS. 2 and 3, the ink strip lengths b of each ink zone are set to the maximum bmax. The relationship between the average ink existing zone settings S mi meas and the number of vibrator roller strokes Z required for establishment of the desired base layer may be established, as is well known in the art and described in documents incorporated herein, either empirically or by simulation for the particular printing stand being employed.
Finally, when the required number of vibrator roll strokes Z1i, Z2i or Z3i has been established for each print stand i, the corresponding number of printing stand revolutions may be determined via conversion by the printing stand vibrator roll rate x.
FIG. 4 sets forth schematically a method for the determination of the number of printing stand revolutions Zn4 required to construct a desired ink profile for a subsequent printing job on a predetermined base ink layer of, for example, 5 microns. For each printing stand i, the arithmetic average S mi set of all ink zone settings for the new printing job S Yni set is calculated. Using S mi set, the number of required vibrator roller strokes Z4 is determined. As shown in FIG. 4, Z4 is also a function of the ink strip length biset. The relationship between S mi set and Z4 or various ink strip length settings biset may be established either empirically or by simulation as is well known in the art and described in documents incorporated by reference herein.
The number of vibrator roller strokes Z4i for each printing stand i having thus been determined, the corresponding number of printing stand revolutions Zn4i is then determined by conversion, using the printing stand vibrator roller rate x.
Finally, the arithmetic average Zn4m of all printing stand revolutions Zn4i is determined, and this value is employed in the process according to the first embodiment of the invention described above primarily with reference to FIG. 2.
FIG. 5 shows schematically an overall view of a process according to the second embodiment of the invention, wherein a transition is made directly from the preceding ink profile to the desired subsequent ink profile, without an intervening reduction to a base ink layer. Generally, the process begins with the printing stand configured as it would be at the end of the previous printing job. That is, the inking mechanism has not been cleaned and washed, and the ink zone settings and ink strip lengths stored in the printing stand will typically be those required for the establishment of the ink profile of the previous printing job.
Initially, the existing ink zone settings Simeas and the existing ink strip lengths bimeas are either entered into the control computer, or they may already reside therein due to the execution of the previous printing job.
Thereafter, as explained below with reference to FIGS. 6a, 6b and 6c, the following parameters are determined and/or calculated:
Si*=the required ink zone settings for either the addition of ink to, or the removal of ink from, each ink zone during a number of vibrator roller strokes Zn5i;
bi*=the ink strip lengths which, in conjunction with the ink zone settings Si*, will either remove from, or transfer to, an appropriate volume of ink for each ink zone during a number of vibrator roller strokes Zn5i;
Si**=an equilibrium ink zone setting at which ink will be neither transferred to nor removed from the inking mechanism: and
ΔZn5i=the number of vibrator roller strokes during which a particular ink zone should be set to the equilibrium setting Si**, such that ink is neither transferred to nor removed from that ink zone.
As noted immediately above, there are two separate ink zone settings Si* and Si**, as well as two separate respective numbers of vibrator roller strokes Zn5i and ΔZn5i, employed using a process carried out according to the second embodiment of the present invention. The present inventor has determined that, in general, ink can be fed much more rapidly into the inking mechanism than it can be removed therefrom. That is, for a given quantity of ink, many fewer vibrator roller strokes (and, therefore, many printing stand revolutions) are required to transport the ink from the inking reservoir into the inking mechanism than are required to withdraw the same quantity from the inking mechanism and back into the ink reservoir. In general, and for the average ink thicknesses encountered, the ratio is approximately 1:10, assuming the desired ink profile is being built up on a base ink layer of approximately 5 microns, or assuming that the existing profile is being reduced to a similar base ink layer.
If, according to the second embodiment of the invention, a direct transition is being made between the existing and subsequent ink profiles, then generally, the ink zone in which the maximum amount of ink is to be transported out of the inking mechanism and back into the ink reservoir is the ink zone which will determine the total number of printing stand revolutions required to execute the process. If, on the other hand, in those ink zones in which ink is to be transported from the ink reservoir and into the inking mechanism, the ink zone settings were to be maintained at Si* throughout the entire Zn5i printing stand revolutions, then an excess of ink in these ink zones would result. Accordingly, for a determined number of printing stand revolutions ΔZn5i, the ink zones in which a substantial amount of ink is to be transported into the inking mechanism are set to an equilibrium ink zone setting Si**, such that, during the initial ΔZn5 printing stand revolutions, ink is neither transported into or out of the inking mechanism. Thereafter, from ΔZn5i to Zn5i printing stand revolutions, ink is transported into the inking mechanism at an ink zone setting of Si*.
The value ΔZn5i may be calculated as described more fully below in connection with FIG. 6b, or it may be chosen to be a certain percentage of the total number of printing stand revolutions Zn5i required for accomplishing a direct transition process. For example, ΔZn5i may be determined, assuming that 90 percent of the required printing stand revolutions Zn5i will have been executed prior to the addition of a positive volume difference ΔV Yni . The positive volume difference ΔV may then be determined for each ink zone requiring the addition of ink. Then, during the remaining 10 percent of the required printing stand revolutions Zn5i, each required addition ΔV may be introduced into the inking mechanism at ink zone settings Si* determined as discussed below.
Further, the present invention contemplates that, in those ink zones wherein ink is being transferred out of the inking mechanism and back into the ink reservoir, it may be appropriate to initially transfer an excess amount of ink back into the reservoir and, thereafter, to transfer this excess amount of ink back into the inking mechanism. This variation is a result of the "ink splitting laws" which are clearly described in U.S. Pat. No. 4,660,470. As noted therein, during transport of the ink through the numerous rollers of the inking mechanism, an ink gradient is set up. For example, during transfer from the ink reservoir to the plate cylinder, in each ink zone, the greatest ink thickness exists on the roller closest to the ink reservoir, and this ink thickness decreases on successive rollers as the ink approaches the printing plate.
Conversely, if in a particular ink zone, ink is being transferred back to the ink reservoir, a reverse gradient is eventually established, in which the inking roller closest to the printing plate carries the greatest thickness of ink, with the ink thickness on successive rollers being gradually reduced in the direction of the ink reservoir.
Since one object of the present invention is the establishment of a desired ink profile and an associated appropriate ink gradient, in order that printing may begin as soon as possible, it may therefore be desirable to initially withdraw an additional amount of ink and to thereafter restore the additional ink withdrawn, thereby establishing an appropriate ink addition gradient decreasing the direction of the printing plate, such as would be employed during the subsequent printing process.
Referring back now to FIG. 5, following determination of the parameters Si*, Si**, bi*, Zn5i and ΔZn5i, the ink strip lengths in the printing stand are set to bi*, and a determination is made as to whether any of the ink zones in the printing stand should be set to an intermediate (or equilibrium) setting Si**. If so, the appropriate ink zones are so set, and the printing stand is caused to begin executing successive revolutions.
Following each successive revolution, for each ink zone Yni of the printing stand set to the intermediate (or equilibrium) setting Si**, a determination is made as to whether the number of printing stand revolutions so far executed is equal to the number of intermediate (or equilibrium) revolutions ΔZn5 Yni for that particular ink zone. When such determination yields a positive result, each ink zone Yni is then set to an appropriate ink zone setting Si*, so as to yield a rapid construction of the desired ink profile for the subsequent job.
When each ink zone Yni has had either the appropriate amount of ink added thereto or removed therefrom, as indicated by the fact that the total number of printing stand rotations executed equals the number of revolutions Zn5 Yni appropriate for that ink zone, the ink strip lengths biset and the ink zone settings S Yni set which will maintain a substantially constant and appropriate flow of ink for the subsequent printing job may be entered into the printing stand.
Finally, printing of the subsequent job may begin immediately, or may be held in abeyance for some time.
Referring now to FIGS. 6a, 6b and 6c, the determination of the parameters bi*, Si*, Si**, Zn5i and ΔZn5i is carried out as follows:
For each ink zone Yni in each printing stand i, a number ΔV, which is indicative of the difference in the volume of ink (or ink volume change) required between the previous and subsequent jobs, is calculated. For example, knowing the "ink splitting laws" as described in U.S. Pat. No. 4,660,470, the ink zone setting of the previous job S Yni meas, the ink strip length of the previous job bi*meas and the circumferences of all rollers in the inking mechanism, a stored volume V could be calculated. Additionally, a base layer volume V G corresponding to the base layer thickness of approximately 5 microns on all rollers, could also be calculated. The difference between these two so-calculated volumes V-V G would yield a job-specific storage volume V A . Two such job-specific storage volumes V A1 and V A2 , corresponding to the previous job and the subsequent job, respectively, could also be determined. Their difference ΔV A =V A1 -V A2 would theoretically yield the volume of ink which must be transferred either into or out of the inking mechanism in a direct transition from the previous to the subsequent ink profile.
However, given the specific characteristics of a particular printing stand, it is unnecessary to calculate the actual volume difference ΔV A . Rather, for each ink zone Yni in each printing stand i, a volume difference indicator ΔV Yni is calculated, which is equal to the difference between the products of the ink zone settings S Yni and the ink strip lengths bi* of the previous and subsequent jobs. The volume difference indicator ΔV Yni calculated is thus inherently indicative of the actual volume change ΔV AYni required in each ink zone. A ΔV Yni greater than zero indicates that ink must be removed from the inking mechanism for a particular ink zone, and a ΔV Yni less than zero indicates that ink must be added. Similarly, a ΔV Yni of zero indicates that no ink volume change is necessary for a particular ink zone.
All ink zone volume difference indicators ΔV Yni are checked for greater than and less than zero conditions. If all ink zone volume difference indicators are substantially zero, then adjustment of the ink profile becomes unnecessary. If at least one of the ink zone volume difference indicators is greater than zero, indicating the required removal of ink from that ink zone, then the ink strip length is set to the maximum value bmax of the printing stand. If no ink zone volume difference indicators are greater than zero, but at least one is less than zero, indicating only the addition of ink in at least one ink zone, then the ink strip length is set to a value biset, derived as discussed below.
Referring now to FIG. 6b, for each ink zone Yni, appropriate parameters are determined depending upon whether there is to be an addition to, a reduction from or no change in the ink volume.
If there is to be an ink volume reduction, the appropriate transition ink zone setting Si* is determined using an empirically or simulatively derived relationship between the ink volume difference indicator ΔV Yni and the ink zone setting Si*. To expedite the ink removal, the relationship used is that established for a maximum ink strip length bmax.
Thereafter, the required number of vibrator roller strokes Z5 is similarly determined as a function of the ink volume difference indicator, and using a maximum ink strip length of bmax.
If, on the other hand, ink is to be added to a particular ink zone Yni, the particular transition ink zone setting for that ink zone S Yni * is determined using an empirically or simulatively derived relationship with the ink strip length set to the bi* value selected. Similarly, the required number of vibrator roller strokes Z5 is determined to yield an appropriate ink volume addition at ink strip length bi*.
Having now determined, for each ink zone, an appropriate transition ink zone setting Si* and the required number of printing stand revolutions to effect the desired ink volume change at that transition ink zone setting, the maximum number of printing stand revolutions Z5 Yni max and the corresponding ink zone Ynimax may also be determined. For each ink zone, a difference ΔZ5 Yni is now determined which corresponds to the number of initial revolutions during which an ink zone setting should be maintained at the intermediate (or equilibrium) setting Si**. As noted in FIG. 6b, if ink is neither to be added nor removed from a particular ink zone, that ink zone is maintained at the Si** setting throughout the entire ΔZ5 Yni =Z5 Yni max vibrator roller strokes of the transition process.
Next, actual intermediate (or equilibrium) ink zone settings Si** are calculated for each ink zone which will utilize an equilibrium ink zone setting Si** during the transition process. As illustrated, the appropriate equilibrium ink zone setting may be determined as a function of the existing ink zone setting S Yni meas, normally existing as a result of the previous printing job. Methods of establishing the proper relationship are well known in the art and are described in documents incorporated herein.
The thus determined required vibrator roller strokes Zn5 Yni and ΔZ5 Yni are now translated into required printing stand revolutions through use of a conversion factor x=the printing stand vibrator roller rate.
The above process is repeated iteratively, as required, for each ink zone of each printing stand, and the determined parameters are tabulated and stored in the control stand computer, as noted in FIG. 6c.
The invention as described hereinabove in the context of the preferred embodiments is not to be taken as limited to all of the provided details thereof, since modifications and variations thereof may be made without departing from the spirit and scope of the invention.
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In the inking unit of a rotary printing press stand, a specified zonal adjustment for each print job is made to the ink ducts, which corresponds to the ink consumption required for the printed product in question. To create an ink distribution in the inking unit appropriate to the print run during the conversion of the inking unit from a previous job to a subsequent and new print job, the invention provides an improved method for the removal of the current ink profile so that the new ink profile can be established for the subsequent print job in a short time, without the necessity of emptying, cleaning and washing the inking unit. To change the ink profile before the beginning of printing, two process steps are proposed. First, the ink profile in the inking unit from the previous job is removed while the machine is running, and thereafter the ink profile in the inking unit appropriate to the subsequent print job is established under precisely defined conditions. Alternatively, a direct transition is made between the previous and subsequent required ink profiles.
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CROSS-REFERENCE TO RELATED APPLICATIONS
(Not Applicable)
STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
(Not Applicable)
BACKGROUND OF THE INVENTION
Ligand-receptor assays or immunoassays are well-known in the art. Since their introduction in 1971, such assays have been utilized in a variety of applications to detect minute amounts of hormones, drugs, antibodies, and other substances suspected of being present in a given fluid sample. In this regard, researchers equipped with enzymes, antibodies, gene probes, and other reagents have made it possible to create chemical detection schemes for almost any compound of interest in a great diversity of applications. Among these applications are: commercial production of pharmaceuticals and food stuffs; food safety; diagnosis and treatment of disease in medical, veterinary, and agricultural environs; and detection and eradication of toxins in the environment. Common to all such applications is the requirement that chemical detection be performed in a timely, reliable, and cost effective manner.
Generally, bioassay schemes are developed and commercialized in formats suitable for use in laboratories equipped with general purpose instrumentation. Examples of these formats include immunoassay and DNA hybridization performed in test tubes, cuvettes, microtiter plates, columns, and electrophoretic gels. These formats usually include elaborate operational procedures and require frequent calibration using several calibrants which contain the analyte of interest at different concentrations. As a consequence, the high cost and complexity of operation associated with such formats limits widespread utilization thereof.
To address such drawbacks, developers and end users of immunoassays are increasingly replacing conventional bioassay formats which use test tubes, cuvettes, microtiter plates, columns, and electrophoretic gels with thin film chromatographic devices known as test strips. As is known in the art, the majority of test strips used for immunochemical detection of compounds are so called lateral flow test strips in which sample and reagents flow within the plane of the test strip. Advantageously, assays configured in a test strip format can produce rapid results, are simpler to operate, and are more cost-effective than conventional formats. Additionally, such test strip assays may be utilized by unskilled laborers and can produce results on-site (i.e., outside a laboratory facility).
Generally, such assays rely on the binding of analytes by receptors to determine the concentration of such analytes in a given sample and are typically characterized as either competitive or non-competitive. Non-competitive assays generally utilize receptors in substantial excess over the concentration of analytes to be determined in the assay. Typical of such non-competitive immunoassays include sandwich assays, which detect the presence of an analyte by binding two receptors thereto. In such arrangement, the first receptor, which is typically an antibody is bound to a solid phase such that when the analyte is present, such analyte becomes affixed thereto. A second receptor having a label covalently attached thereto, which may comprise a radioactive, fluorescent, enzymatic, dye or other detectable moiety (collectively referred to as tracers), is introduced to the assay which consequently binds to the bound ligand, to the extent the ligand is present, and thereafter produces a signal consistent with the presence of such ligand. If the sample does not contain the molecules of interest, the labeled receptor is carried past the immobilized receptor without reacting which, as a consequence, will not cause a change in the membrane. Such non-competitive immunoassays are primarily useful for the detection of large molecules such as proteins, large hormones or molecules which have multiple binding sites, such as human chorionic gonadotropin (HCG) and typically will not work with small molecules that have only one binding site.
Competitive assays, in contrast, generally involve competition between a ligand present in a given sample, and a ligand analog having a tracer/label covalently linked thereto to permit detection for a limited number of binding sites provided by the ligand receptor, which typically comprises an antibody bound to a solid phase. Such assays are particularly suited to detect smaller molecules, such as drugs and drug metabolites. In this context, drug analogs are utilized that have been covalently bound to a protein which is then immobilized on a membrane. Antibody specific to the drug is then labeled and immobilized on a porous pad. When a sample is added which is suspected of containing a given analyte, such sample dissolves the labeled antibody and carries it into contact with the immobilized drug-protein region. If there is little or no drug in the sample, a large amount of the labeled antibody is bound to the immobilized drug-protein region which, consequently, produces a detectable signal. If the sample contains a high amount of drug, little or no labeled antibody is bound to the immobilized drug-protein region and thus in turn gives little or no signal.
Today, rapid immunoassays generally consists of an adhesive-covered plastic backing onto which several porous pads and a piece of protein-binding membrane are attached. The membrane typically contains a section that has been impregnated with a binding partner (i.e., a receptor or ligand analog). A second pad is typically provided which contains a labeled target molecule or labeled antibody protein-binding membrane. When a sample suspected of containing a target ligand is contacted with the immunoassay, such sample dissolves the labeled element or tracer and the capillary action of the protein-binding membrane subsequently draws the sample with tracer dissolved therein into contact with the impregnated binding partner. When this reaction occurs, there is a change in the appearance of the binding membrane, with the difference providing a qualitative indication of the presence or absence of the ligand suspected of being present in such sample.
Typical examples of this form of test strip are those which visually display two parallel lines (known as capture lines) on a test membrane. Capture lines consist of immobilized capture reagents or receptors which are preapplied to the test membrane during its manufacture. In this regard, both virtually all prior art assays, whether competitive or non-competitive, typically deploy a receptor immobilized on a membrane, as assessed above. A schematic representation of the construction of a typical lateral flow test strip is as follows:
reagent pad//test membrane/capture line/test membrane/capture line/test membrane//absorbent pad
where:
symbol / designates a phase boundary within a single chromatographic medium; and
symbol // designates a union of two separate mediums (chromatographic or other medium).
One of the two capture lines serves as an indication that the test strip performance has not been compromised. In this regard, such capture line serves an important function by providing quality assurance and integrity of the assay, which is generally considered necessary insofar as individual test strip performance can vary greatly. The second of such capture lines becomes visible only when the sample contains an amount of analyte in excess of a minimum concentration (threshold concentration). Exemplary of such prior art systems and methodologies include the immunoassay systems and test strips disclosed in U.S. Pat. No. 5,658,723, issued on Aug. 19, 1997, to Oberhardt entitled "Immunoassay System Using Forced Convection Currents" and U.S. Pat. No. 5,712,170, issued on Jan. 27, 1998, to Kouvonen, et al. entitled "Test Strip, Its Production and Use", the teachings of each of which are expressly incorporated herein by reference.
Unfortunately, despite their cost-effectiveness and simplicity of use, typical test strip format assays are less accurate, less precise, and less sensitive to analyte presence than conventional formats. As a result of such drawbacks, the application of test strip format assays has been limited to semi-quantitative or qualitative assays. Among the more significant factors that contribute to the inaccuracy and imprecision of test strip format assays include the manufacture and use of capture lines. As is widely recognized, the manufacture of consistently uniform capture lines requires elaborate material control and manufacturing processes with rigid specifications that must operate within narrow tolerances. Moreover, to function properly, most test strip formats require that the analytes to be detected must be uniformly captured in a precise geometry at a precise location on the test strip and that factors such as the ambient humidity present at the time of test strip manufacture, type of membrane utilized in such manufacturing process, and a capture reagent-receptor itself contributing greatly to assay inaccuracies and false readings. A detailed discussion regarding the drawbacks associated with the binding of protein capture reagents in immunochromatographic assays can be found in Jones, Kevin D., "Troubleshooting Protein Binding in Nitrocellulose Membranes", Part I, IVD Technology, Volume V, No. II, March-April 1999, pages 32-41 and Part II, IVD Technology, Volume V, No. III, May-June 1999, pages 26-35, the teachings of which are expressly incorporated herein by reference.
It is therefore desirable to devise an alternative lateral flow device which can capture analyte at a precise location and in a precise geometry without the use of preapplied capture lines. There is further a need for an assay that has greater sensitivity in reproduceability than prior art assays and methods and is likewise inexpensive, relatively easy to manufacture, and capable of being utilized for a wide variety of applications. There is still further a need in the art for such an assay that can identify the presence of two or more suspect ligands in a given sample. It is also desirable to devise an analytical instrument which can provide a quantitative analysis of a captured analyte on a lateral flow assay device.
BRIEF SUMMARY OF THE INVENTION
The present invention specifically addresses and alleviates to the above-identified deficiencies in the art. In this regard, the present invention pertains to several novel bioassay methodologies, chromatographic devices, and an optional multimode photometer/analyzer which together can perform bioassays with accuracy and precision like that of conventional laboratory formats while retaining the operational simplicity, rapid analysis, and cost-effectiveness like that of test strip formats. The chromatographic devices and novel bioassay methodologies of the present invention further minimize problems associated with the manufacture of test strips which incorporate preapplied capture lines. Moreover, multimode photometer, novel test strip devices, and unique chemical analysis methods of the present invention represent a versatile, cost effective, simple, and accurate system which can quantify the amount of a chemical substance present in a sample that has not heretofore been available via prior art bioassay test strips.
According to a first aspect of the present invention, there is provided a novel magnetic chromatography method which consists of the steps of contacting activated magnetic particles suspended in a reaction mixture with a chromatographic medium (e.g., test strip or chromatographic plate), and thereafter applying a magnetic field thereto. As the activated magnetic particles flow laterally within the plane of the medium they encounter the applied magnetic field. The applied magnetic field attracts the magnetic particles forming a magnetic barrier that selectively retains magnetic particles while allowing the reaction mixture to continue to flow laterally there across. As such, there is thus eliminated the conventional capture lines formed by bound receptors that are utilized in prior art immunoassays. In this regard, a capture line is in effect assembled during the assay. Advantageously, the magnetic chromatography assay methods of the present invention allow test strips and the like to be manufactured without preapplied capture lines. However, the methods of the present invention also anticipate a magnetic chromatography test strip having both preapplied capture lines and capture lines formed during the bioassay using magnetic chromatography as may be desired for a specific application.
The novel methods of the present invention may further deploy one or more applied magnetic field source(s) applied to the chromatography test strip assembly to detect multiple spectrophotometric analysis. For example, a common bar magnet or magnetic strip can be attached to the test strip backing with adhesive at one or more locations. Alternately, the magnetic source can be external to the test strip assembly whereby the magnetic source is selectively positioned in close proximity with the test strip while magnetic particles flow laterally therewithin. In preferred embodiments of the present invention, the source of the applied magnetic field may comprise either permanent magnets or electromagnets.
The present invention further includes the use of a novel analyzer comprised of a multimode photometer which can measure front surface fluorescence, luminescence and reflectance at a single focal point on the test strips of the present invention. According to a preferred embodiment, the multimode photometer consists of a base and optical canopy which collectively define an optical tunnel into which at least one test strip may be disposed. The chamber may include a magnetic source or be designed to be placed in close proximity to a magnetic source such that the test strip having activated magnetic particles flowing laterally therewithin may be caused to become substantially bound at a specific site or sites upon the test strip. When so arranged, a light or radiation source may be focused upon the test strip disposed within the optical tunnel such that the light or radiation may be aligned with the magnetic source and the reflected or emitted light from the test strip analyzed for analyte presence. Light and radiation of differing wave lengths may be utilized to determine the presence of appropriate analytes as per conventional spectrophotometric analysis. Optical filters and photodetectors may further be deployed as may be necessary for a particular spectrophotometric applications.
It is therefore an object of the present invention to provide a novel magnetic chromatography assay and method utilizing a test strip format that has greater sensitivity and reproduceability than prior art test strip assays.
Another object of the present invention is to provide a novel magnetic chromatography assay and method that utilizes a test strip format, but dispenses with a need to form a capture line by binding receptors to a test membrane.
Another object of the present invention is to provide a novel magnetic chromatography assay and method that can be arrayed in a test strip format and utilized to provide quantitative analysis.
Another object of the present invention is to provide a novel magnetic chromatography assay and method that may be adapted to provide quantitative and qualitative analysis for multiple analytes.
Another object of the present invention is to provide a novel magnetic chromatography assay and method that is easy to use, of simple construction, and inexpensive to manufacture.
Another object of the present invention is to provide a novel magnetic chromatography assay and method that may be utilized to provide spectrophotometric analysis, including but not limited to, surface reflectance, surface fluorescence, and surface luminescence.
Another object of the present invention is to provide a novel magnetic chromatography assay and method which may be configured to perform individual sample analysis, batch sample analysis, and linear-array analysis.
Another object of the present invention is to provide a novel magnetic chromatography assay and method wherein such assay may be configured to be reusable or disposable.
Another object of the present invention is to provide a novel magnetic chromatography assay and method which will accommodate conventional reagents prepackaged in unit doses.
Another object of the present invention is to provide a novel magnetic chromatography assay and method that can be used for quantitative, semi-quantitative, and qualitative immunoassay of analytes and DNA hybridization assays.
Another object of the present invention is to provide an optical analyzer consisting of a multimode photometer for performing spectrophotometric analysis, including but not limited to, surface reflectance, surface fluorescence, and surface luminescence.
Another object of the present invention is to provide an analyzer consisting of a multimode photometer which is of simple construction, easy to utilize, and may be configured to perform individual sample analysis, batch sample analysis, and linear-array analysis.
Another object of the present invention is to provide an analyzer consisting of a multimode photometer that, when utilized in conjunction with the magnetic chromatography assays of the present invention, may be utilized to quantitate the amount of a given analyte at a fixed location on a test strip assay, irrespective of orientation of such assay and lateral flow of reaction mixture utilized therewith.
FIGURE DESCRIPTIONS
FIG. 1a is a perspective view of an assay test strip for using the practice of the methods of the present invention, said test strip being constructed in accordance to a first preferred embodiment.
FIG. 1b is an exploded view of the components comprising the assay test strip depicted in FIG. a.
FIG. 1c is a side view of the assay depicted in FIG. 1a.
FIG. 2a is an exploded perspective view of an assay test strip constructed in accordance with a second preferred embodiment of the present invention.
FIG. 2b is a side view of the assay test strip depicted in FIG. 2a.
FIG. 3a is a cross-sectional view of a multimode photometer constructed in accordance with a preferred embodiment, as utilized in the practice of the methods of the present invention.
FIG. 3b is a cross-sectional view and block diagram of the multimode photometer depicted in FIG. 3.
FIG. 4a is perspective view of the multimode photometer depicted in FIG. 3.
FIG. 4b is a top view of the multimode photometer depicted in FIG. 3.
FIG. 4c is an exploded cross-sectional view of the components comprising the multimode photometer depicted in FIG. 3.
FIG. 5a is a top view of a multiplicity of test strips arrayed in parallel rows on a common backing for use in detecting the presence and quantity of one or more analytes from a plurality of samples.
FIG. 5b is a top view of a muiplicity of test strips utilizing a single-common absorbent pad having fluid contact with a multiplicity of test membranes, the latter being arranged in a generally linear fashion.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following detailed description and the accompanying drawings are provided for the purpose of describing certain presently preferred embodiments of the invention only, and are not intended to limit the scope of the claimed invention in any way. In this regard, there is disclosed herein a novel assay system and method that, unlike prior art assay systems, and in particular test strip assays, can quantitatively and qualitatively detect the presence of an analyte, control, calibrator, or combination thereof in a given fluid sample with extraordinary precision and reproduceability. Moreover, the novel assays and methods of the present invention provide all of the advantages associated with conventional test strips assays insofar as the same need not undergo remote analysis at a laboratory facility and further, do not require handling by trained professionals. There is further provided a novel analyzer, which comprises a multimode photometer, is useful in conducting spectrophotometric analysis in conjunction with the assays and methods of the present invention.
Referring now to the drawings, initially to FIGS. 1a-1c, there is shown a preferred embodiment of a test strip for use in magnetic chromatography. The test strip is comprised of a test membrane 1 having a reagent zone 2 at its one end and an absorbent pad 3 at its other end. These components are attached to a backing 4 made of plastic or other suitably rigid material. Similar to prior art test strips, the test strip is simple to manufacture by lamination.
Another embodiment of the test strip for use in the practice of the present invention is shown in FIGS. 2A and 2B. In this embodiment of the invention, there is provided a reagent pad 5 at one end and absorbent pad 3 at the respective other end. In this regard, the reagent pad 5 is shown partially overlapping the test membrane 1 to thus produce a greater degree of saturation thereacross, as may be desired for a given application.
In either of the test strip embodiments depicted in FIGS. 1a-1c and FIG. 2a-2b, it will be readily understood and appreciated by those skilled in the art that the same are designed to produce a lateral flow or path of migration that extends from the reagent pad 5 to the absorbent pad 3 at the other end. As per conventional test strip assays, the lateral flow of a reaction mixture across the test membrane 1 provides a basis for conducting chemical analyses over a given surface area (i.e., the test membrane 1).
Unlike prior art test strip assays, however, the assays and methods of the present invention do not utilize a capture barrier formed by bound receptors formed along a portion of the test membrane 1, but rather utilize a novel magnetic approach to generate such capture lines. In this regard, due to the novel methods and systems by which capture lines are generated via the present invention, it will be recognized that although the test strip configurations depicted in FIGS. 1 and 2 may be readily utilized in the practice of the present invention, the only essential element thereof comprises a chromatographic medium, such as a test strip or chromatographic plate, upon which a test sample may flow laterally thereacross. Accordingly, it will be understood that a path of migration need not necessarily be formed, as per conventional test strips and the like, in order to practice the present invention.
Test Membrane
The test membrane 1 can be selected from any available material having appropriate thickness, pore size, lateral flow rate, and color. It is preferred that the test membrane be made from a material which has a low affinity for the analyte and test reagents. This is to minimize or avoid pretreatment of the test membrane to prevent nonspecific binding of analyte and/or reagent. Polyester is an example of a suitable test membrane material.
Reagent Pad
The (optional) reagent pad 5 can contain all or a portion of the reagents necessary to complete the assay. Reagents can include a capture ligand and reporter ligand which specifically bind different regions of the analyte to be detected in a given sample. The capture ligand can be covalently bound or absorbed to the surface of magnetic particles. Capture ligands can also be bound indirectly using binding partners such as anti-IgG antibody, streptavidin/biotin, and others. The reporter ligand is covalently bound to a dye, particle, radioisotope, or enzyme which produce fluorescence or luminescence. The reagent pad 5 can also contain stabilizers, buffers, surfactants and other agents which improve the performance of the assay. The reagent pad 5 receives the sample and all subsequent liquid reagents used to perform the assay.
The reagent pad 5 also can be selected from any available material having appropriate thickness, pore size, and flow rate. It is preferred that the reagent pad be made from a material which has a low affinity for the analyte and test reagents. Again, this is to minimize or avoid pretreatment of the reagent pad 5 to prevent non20 specific binding of analyte and/or reagent. Polyester and porous polyethylene are examples of suitable reagent pad 5 materials. The reagent pad 5 should be of sufficient size and void volume to accept the entire sample volume.
In some embodiments of the invention the reagent pad 5 may not be a physically separate component. Rather, instead the reagents can be stored in a reagent zone 2 formed on the test membrane 1 itself. In other embodiments of the invention, the reagent pad 5 does not contain reagents and instead is used as a liquid reagent receiving pad. As will be appreciated by those skilled in the art, by forming such reagent zones upon the test membrane as a substitute for reagent pads, the cost and complexity of manufacturing is substantially reduced insofar as the reagent pad component may be eliminated altogether. In this regard, the non-binding properties of the test membrane, coupled with the ability to form a capture line magnetically, as discussed more fully below, eliminates the need to design a test strip whereby a fluid sample must necessarily flow sequentially in one direction so that a given fluid sample with reagents thoroughly and precisely comes into contact with a conventional capture zone defined by a multiplicity of bound antibodies.
Absorbent Pad
The (optional) absorbent pad 3 should have absorbent capacity sufficient to contain all liquid volumes used during the test procedure. Cotton fiber and absorbent paper are examples of suitable absorbent pad 3 materials. As discussed above, however, the absorbent pad is optional insofar as the chromatographic medium utilized in the practice of the present invention may merely consist of a test membrane or chromatographic plate and does not necessarily require the use of an absorbent pad to produce or generate a direction of flow or path of migration for a given test sample, as is typically required in prior art assay strips.
Backing
The magnetic chromatography test strip backing 4 can be made of plastic, glass or other suitably rigid material. The backing length can exceed the length required to support the test membrane and pads, as may be desired to serve several functions. For example, such extended backing length can provide a handle or it can display information such as bar codes, fluorescent marks, and colored marks which can aid in the calibration of the individual test strip and multimode photometer, as discussed more fully below.
In order to analyze a multiplicity of samples in a single analysis, there is further disclosed herein certain novel assay strips for performing such function. Referring now to FIG. 5a, there is shown a top view of a multiplicity of test strips arrayed in parallel rows on a common backing 4. The backing 4 has a top side and bottom side and can be in sheet or roll form and is preferably manufactured from an opaque plastic sheet material of appropriate color, thickness, and rigidity. Each respective test membrane 1 is sufficiently spaced to avoid fluid contact between adjoining test membranes 1. An absorbent pad 3 is preferably positioned to be in fluid contact at one end of the test membrane 1. FIG. 5b shows a top view of test strips manufactured using a single common absorbent pad 3 having fluid contact with all test membranes in a given row. Placement of test membranes 1 and absorbent pads 3 are such that multiple parallel rows of test strips are advantageously manufactured on a sheet or continuous web of backing 4. Each row of test strips is positioned with adequate spacing such that individual test strips for different rows are not in fluid contact with each other.
In order to identify the presence of a particular analyte, control, calibrator, or combination thereof, these novel methods of the present invention deploy a magnetic field at a specific site upon the test membrane portion of the test strips of the present invention. Such magnetic field, in which may be generated by any type of magnetic source, such as a permanent magnet or an electromagnet, is selectively positioned such that when applied to a portion of the test membrane, magnetic particles present within a given sample that are flowing laterally across the test membrane will become substantially bound at the specific site where the magnetic field is applied. In this regard, the applied magnetic field attracts the magnetic particles forming a magnetic barrier that selectively retains magnetic particles, with the analyte of interest having complexed thereon with appropriate labels bound thereto, while allowing the remainder of the reaction mixture to continue the flow laterally across such barrier or zone.
With respect to those strips depicted in FIG. 5a and 5b, to generate the desired capture zones of lines, a magnetic barrier is formed using a bar magnet(s) 20 laminated or placed in close proximity to the bottom side of backing 4. The bar magnet(s) or magnetized rail(s) 20 is positioned perpendicular to the test membrane(s) 1 in each row and between said test membrane(s) 1 fluid receiving and absorbent ends. A reagent zone 2 is positioned at the fluid receiving end of each test membrane.
By selectively applying the magnetic field about or upon the test strip, a capture line is magnetically assembled thereon insofar as magnetic particles are substantially immobilized by the magnetic field at a specific site of sites situated across the test membrane. The remaining reaction mixture components which are not magnetically bound thus continue to flow laterally within the test membrane, typically in a path of migration toward an absorbent pad. Advantageously, such method allows more than one analyte, control, calibrant, or combination of these to be quantitatively assayed on a single test strip. Accordingly, it is an object of this invention to provide a useful method for the performance of assays, e.g. biological assays.
While the test strips depicted in FIGS. 1a-1c and 2a-2b depict only one section of test membrane disposed between a reagent pad and an absorbent pad, it will be recognized by those skilled in the art that when more than one analyte, control, calibrator, or combination thereof are to be assayed within a test solution using a single test strip, a cascade of reagent zones or pads can be placed down stream from the first applied magnetic field. Several schematic examples of flow test strip assemblies which can be used with magnetic chromatography are given:
Single Assay
reagent zone 1/test membrane//absorbent pad
reagent pad 1//test membrane//absorbent pad
Multiple Assay
reagent zone 1/test membrane/reagent zone 2/test membrane//absorbent pad
reagent pad 1//test membrane//reagent pad 2//test membrane//absorbent pad
Opposing Multiple Assay
reagent zone 1/test membrane//absorbent pad//test membrane/reagent zone 2
reagent pad 1//test membrane//absorbent pad//test membrane//reagent pad 2
where:
symbol / designates a phase boundary within a single chromatographic medium; and
symbol // designates a union of two separate mediums (chromatographic and other).
As a consequence, the multiple assay examples given causes test solution to encounter two groups of magnetic particles. The flow of test solution is unilateral moving from reagent zone or pad 1 at one end of the test strip to absorbent pad at the opposite end of the test strip. Magnetic barriers are positioned at each test membrane. The first magnetic barrier is positioned across the test membrane prior to reagent zone or pad 2 while the second magnetic barrier is positioned across the test membrane prior to the absorbent pad. Reagents from reagent zone or pad 2 can be used to analyze additional analytes in the test solution or can be used to perform calibration or quality control.
The opposing multiple assay example given will allow assay of identical analytes from separate test solutions. This is advantageous when a calibrator must be assayed simultaneously with a test sample. The flow of test solution is from each reagent pad or zone toward a single common absorbent pad. Magnetic barriers are positioned across each test membrane. It is also anticipated by the invention that magnetic chromatography can be used with other multiple assay test strip configurations including rosettes, parallel arrays, and others.
In order to manipulate the width (i.e., surface area) of the capture line formed by the application of a magnetic field to the test strip, it has been unexpectedly discovered that the width of such capture line may be selectively controlled depending upon the number of magnets and/or degree of magnetic force applied to the test membrane. In this regard, it has been discovered that by stacking multiple magnets upon one another beneath the test membrane where the captures zone is sought to be formed, the increased number of magnets applied thereto correspondingly produces an increase in the width of the capture line. As will be appreciated by those skilled in the art, by utilizing a greater degree of magnetic force, the corresponding capture line produced thereby will have a greater surface area which, as a consequence, can be utilized to determine concentration per unit area. Along these lines, it is contemplated that manipulating the magnetic field to produce a wider or narrower capture line or area may prove extremely beneficial. For example, by manipulating the width or surface area of the capture line, a means may thus be provided to facilitate the inspection of individual particles utilizing a microscope. Likewise, such selective manipulation of the capture zone may be used to isolate target cells from a population of cells, and thereafter perform microscopic inspection thereof as may be necessary for a given application.
With respect to the dimensions of such magnets that are preferably utilized in the practice of the present invention, it is currently believed that bar magnets and/or magnetized rails may be utilized whose width is between 0.003 to 3.0 inches, and whose length is between 0.010 inches to 100 inches. In this regard, it will be understood that such magnets, and in particular magnetized rails, may be sized and configured to generate any degree of magnetic field necessary to form a desired capture line and may be readily determined for a given application by one having ordinary skill in the art. The present invention further includes a novel analyzer having a multimode photometer module included therein which can measure front surface fluorescence (fluorimetry mode), luminescence (luminometry mode), and reflectance (densitometry mode) at a single focal point on a test strip. The use of multiple optical methods at a single focal point provides information regarding the quality and structure of an individual capture line as well as the amount of analyte, control, or calibrator present at the capture line. Thus an object of the invention is to minimize accuracy and precision problems associated with test strips by interrogating important test strip locations using two or more optical methods.
As illustrated in FIG. 3a, the multimode photometer consists of an optical canopy 9a and a base 9b which cooperate to form an optical tunnel 9. The optical tunnel 9 aligns light sources and photodetectors, with magnetic sources and test membranes, chromatographic plates, etc. to form optical paths. In this regard, base 9b includes a channel formed therein for receiving a test strip of the aforementioned variety. The base 9b further preferably includes a magnetic source fixed therein or fixed relative the channel to thus create the desired capture line at a specified location within the optical tunnel 9. For example, a magnetic source, such as a magnet, may be placed beneath the base of the optical tunnel 9b such that the test strip rests in the channel situated thereabove.
The optical canopy 9a is formed to have a ceiling through which a light source may be transmitted, and angled sidewalls through which the resultant reflected light may be emitted. As will be recognized by those skilled in the art, the multimode photometer, and more particularly the optical tunnel defined thereby, may be extruded, machined, or molded from any of a variety of suitable opaque materials, including but not limited to PVC, ABS, or anodized aluminum. As such, the optical tunnel 9 of the present invention may be fabricated inexpensively from inexpensive materials.
Referring now to FIG. 3b, there is schematically illustrated the components utilized for analyzing a test strip with the multimode photometer of the present invention. Initially, an excitation path 6 is formed from the light source 7 to a focal point 8 at the base 9b of the optical tunnel 9. As will be readily appreciated, the magnetic source incorporated into the base 9b for forming the capture line on a given test membrane or chromatographic plate will be precisely aligned with the excitation path 6 such that the path 6 is directly aimed at the capture line produced by such magnetic source. As will be appreciated, light emitting diodes (LEDs), laser diodes, mercury vapor lamps, and xenon lamps are among many suitable light sources which can be used. If necessary, an optical filter 10 can be used to select an excitation wavelength 6. This excitation filter 10 can be placed on either side of the canopy wall 9a provided, however, the same is in the excitation path 6 between the light source and test strip 11. When a test strip 11 is inserted into the optical tunnel 9, such strip is held in position at the base and intersects the excitation path 6 at the focal point 8.
Emission paths 12 are formed from the focal point to one or more photodetectors 13. Apertures are positioned using a radial geometry in the canopy wall 9a at angles which optically align each photodetector 13 with the focal point 8. Light pipes, optical fibers, and other wave guides can be used to transmit emission light to the photodetectors 13. Excitation light 6 excites fluorophores present on the test strip 11 at the focal point 8, which then emit light 12 of a longer wavelength. If luminescence is used excitation light 6 is not required and can be omitted during luminescence measurement. Emission filters 14 are used to specifically select the emission wavelength 12 of the light emitted from the fluorescer or luminescer and to remove traces of excitation light 6. As will be appreciated by those skilled in the art, such emission filter 14 can be placed on either side of the canopy wall 9a providing it is in the emission path 12 between the photodetector 13 and test strip 11.
Reflectance paths 15 are also formed from the focal point 8 to one or more photodetectors 16. Such reflectance path 15 carries both excitation 6 and emission light 12. If necessary, excitation filters 10 can be used to specifically select the excitation wavelength 6 of the light reflected from the test strip and to revoke traces of emission light 12. This excitation filter 10 can be placed on either side of the canopy wall 9a providing it is in the reflectance path 15 between the photodetector 16 and test strip 11.
The filters 10 and 14 can be of the type known in the art as interference filters, due to the way in which the same block out-of-band transmissions. In this respect, interference filters exhibit an extremely low transmission outside of their characteristic bandpass and, as such, are very efficient in selecting the desired excitation and emission wavelengths.
As will further be appreciated by those skilled in the art, an optical tunnel can have multiple focal points at which photometric measurements can be made simultaneously, which advantageously allows multiple points on a test strip to be used for sample analysis and/or calibration. In such applications, optical components, such as LEDs, photodiodes, and interference filters, may be clustered at each focal point along the optical tunnel.
As perspectively illustrated in FIGS. 4a and 4b, there is shown different views of an optical tunnel equipped with two optical clusters as may be utilized for multispectral analysis. A light source 7 (LEDs 7a and 7b are shown) is positioned above an excitation filter 10 (filters lOa and lOb are shown) which in turn covers each excitation aperture (not shown). Two of four photodiodes 13a, 16a with filters 10,14, as shown in the cross-sectional view of FIG. 4C, are mounted on the canopy 9a. A bar magnet 20a, as shown in FIG. 4C, is positioned at the base of the optical tunnel beneath each focal point 8 such that appropriate spectrophotometric analysis may be made at each location.
Although believed to be apparent from the foregoing discussion, there is provided herebelow a variety of examples by which the novel magnetic assays and methods of the present invention may be utilized in a variety of applications. As will be appreciated by those skilled in the art, for the purpose of discussion in the following examples the term "test solution" can mean test sample, test calibrator, or test control material.
EXAMPLE 1
A test strip is manufactured according to the description given in FIG. 1. The backing 4 is extended in length beyond the absorbent pad 3 end to allow application of bar codes, fluorescent markings, and other indicators to the backing 4. Reagent zone 2 contains streptavidin conjugated magnetic particles, buffers, stabilizers, surfactants, and other reagents in dry form.
The test strip 11 is inserted absorbent pad 3 end first into the optical tunnel 9. Indicators on the test strip are interpreted as calibration information by the analyzer. For example, the analyzer verifies that the same bar code was read at both focal points 8a and 8b and stores reflectance and fluorescence values for photodetectors 13 and 16. The calibration information and measured values are used by the analyzer to verify the quality and structure of an individual capture line as well as the amount of analyte, control, or calibrator present at the capture line, and to verify the performance of each optical module.
In a separate container the operator adds a measured volume of sample to a measured volume of test reagents and mixes them to form a reaction mixture. The test reagents include biotin conjugated anti-beta HCG, and fluorescent microsphere conjugated anti-alpha HCG which cooperatively bind HCG molecules present in the sample.
A measured volume of this reaction mixture is applied to the test strip reagent zone 2 it forms a new reaction mixture which contains magnetic particles in suspension as buffers, stabilizers, surfactants, and other reagents previously dried on the reagent zone 2. The magnetic particles bind the biotin conjugate in all of its complexed forms including those which have formed a cooperative complex (sandwich assay) with HCG and the anti-alpha HCG conjugate. Thus, fluorescent microspheres are indirectly bound to magnetic particles in proportion to the amount of analyte present in the reaction mixture.
As the magnetic particles suspended in the reaction mixture flow laterally within the plane of the test strip 11 they encounter a magnetic field applied using a bar magnet 20 attached to the base 9b of the optical tunnel 9. The applied magnetic field attracts the magnetic particles forming a magnetic barrier that selectively retains the magnetic particles at the focal point 8 while allowing reaction mixture to continue to flow laterally across this barrier toward the absorbent pad 3.
A measured volume of wash solution can also be added subsequent to the addition of reaction mixture. This will reduce the amount of fluorescent microspheres retained by the test membrane 1 and magnetic particles due to nonspecific binding.
The analyzer monitors and compares photodetectors 16a and 16b measuring reflectance at the focal point 8a and 8b. The reflected light intensity at the focal point 8a decreases as the magnetic particles are retained by the magnet 20. The reflected light intensity at focal point 8b is a background (blank) measurement used to correct for differences between individual test strips and sample matrix effects. This allows the analyzer to determine whether the magnetic particles have been properly captured at focal point 8a, and to reject samples which are hemolyzed or contain elevated amounts of chromophores such as bilirubin. If the reflected light intensity is not within specification at focal points 8a and 8b during a predefined elapsed time the test is determined invalid and no result is reported.
Alternating with photodetectors 16a and 16b, the analyzer also monitors and compares photodetectors 13a and 13b measuring fluorescence. The emitted light intensity at focal point 8b is a background (blank) measurement used to correct for non-specific binding, differences between individual test strips, and sample matrix effects. The analyzer compares the blank emission measurement at 8b and test emission measurement at 8a and calculates HCG concentration.
EXAMPLE 2
Example 2 mirrors Example 1 but for the following differences:
Reagent zone 2 contains all test reagents prepackaged in unit dose dried form including: streptavidin conjugated magnetic particles, biotin conjugated anti-beta HCG, and fluorescent microsphere conjugated anti-alpha HCG which cooperatively bind HCG molecules present in the sample. Reagent zone 2 also contains buffers, stabilizers, sufactants, and other reagents in dry form.
The operator adds a measured volume of test solution directly to reagent zone 2.
EXAMPLE 3
Example 3 mirrors Example 2 but for the following differences:
Anti-alpha HCG is conjugated using alkaline phosphatase, instead of fluorescent microspheres.
A measured volume of fluorescent substrate is added to the reagent zone 2 subsequent to the addition of a measured volume of wash solution.
EXAMPLE 4
Example 4 mirrors all of the above examples but for the following differences:
Example 4 substitutes a reagent pad 5 for reagent zone 2 in each of the preceding examples.
EXAMPLE 5
A test strip is manufactured according to the prescription given in FIG. 1. The backing 4 is extended in length beyond the absorbent pad 3 end to allow application of bar codes, fluorescent markings, and other indicators to the backing 4. Reagent zone 2 contains streptavidin conjugated magnetic particles, buffers, stabilizers, surfactants, and other reagents in dry form.
In a separate container, the operator adds a measured volume of test solution (containing cells, cell lysate, total RNA) to a measured volume of test reagents and mixes them to form a reaction mixture. The test reagents include biotinylated oligo (dT) probe and a 5' fluorescent dye labeled DNA hybridization probe specific for chlamydia.
A measured volume of this reaction mixture is applied to the test strip reagent zone 2. As the reaction mixture comes in contact with the reagent zone 2 it forms a new reaction mixture which contains magnetic particles in suspension as well as buffers, stabilizers, surfactants, and other reagents previously dried in the reagent zone 2. the biotinylated oligo (dT) probe hybridizes specifically to the 3' poly(A) region of all mRNA present in the test solution. Consequentially, all mRNA is bound to the magnetic particles via a biotin/streptavidin bond. Labeled hybridization probe, in contrast, binds only target mRNA. The magnetic particles bind the biotinylated oligo (dT) probe in all of its complexed forms including those which have formed a cooperative complex (hybrid) with chlamydia mRNA and the fluorescent dye labeled DNA hybridization probe specific for chlamydia. Thus, fluorescent dye is indirectly bound to magnetic particles in proportion to the amount of chlamydia mRNA present in the reaction mixture.
As the magnetic particles suspended in the reaction mixture flow laterally within the plane of the test strip 11 they encounter a magnetic field applied using a bar magnet 20 attached to the base 9b of the optical tunnel 9. The applied magnetic field attracts the magnetic particles forming a magnetic barrier that selectively retains the magnetic particles at the focal point 8 while allowing reaction mixture to continue to flow laterally across this barrier toward the absorbent pad 3.
A measured volume of wash solution can also be added subsequent to the addition of reaction mixture. This will reduce the amount of labeled DNA probe retained by the test membrane 1 and magnetic particles due to non-specific binding.
The analyzer monitors and compares photodetectors 16a and 16b measuring reflectance at the focal point 8a and 8b. The reflected light intensity at the focal point 8a decreases as the magnetic particles are retained by the magnet 20. The reflected light intensity at focal point 8b is a background (blank) measurement used to correct for differences between individual test strips and sample matrix effects. This allows the analyzer to determine whether the magnetic particles have been properly captured at focal point 8a, and to reject samples which are hemolyzed or contain elevated amounts of chromophores such as bilirubin. If the reflected light intensity is not within specification at focal points 8a and 8b during a predefined elapsed time the test is determined invalid and no result is reported. Alternating with photodetectors 16a and 16b, the analyzer also monitors and compares photodetectors 13a and 13b measuring fluorescence. The emitted light intensity at focal point 8b is a background (blank) measurement used to correct for non-specific binding, differences between individual test strips, and sample matrix effects. The analyzer compares the blank emission measurement at 8b and test emission measurement at 8a and calculates chlamydia concentration or determines simply if chlamydia is present in the test solution.
EXAMPLE 6
Other detection methods can be used with magnetic chromatography. In this example, x-ray film is used to detect the presence of target DNA in a population of transfected cells. PCR amplification of cDNA present in each test solution is accomplished using P32 labeled nucleotides. Amplified DNA is hybridized using 5' biotin DNA hybridization probe forming a reaction mixture which is applied to the test strip reagent zone 2 containing streptavidin conjugated magnetic particles.
Utilizing a test strip of the variety depicted in FIG. 5b, a wash solution is applied to reagent zone 2 subsequent to application of the reaction mixture.
A sheet of x-ray film is placed on top of said test strip array and exposed for a suitable length of time.
A visible band is seen on the developed x-ray film whose position corresponds with a sample which has tested positive for the target DNA.
EXAMPLE 7
Example 7 mirrors Example 6 but for the following differences:
Said PCR amplification is accomplished using 5' fluorescent dye labeled primer.
Said test strip array is positioned within a fluorescent scanner.
Said fluorescent scanner detects a fluorescent band whose position corresponds with a sample testing positive for the target DNA.
EXAMPLE 8
Example 8 mirrors Example 1 but for the following differences:
Said backing 4 is a microscope slide.
Said magnet 20 is positioned above said test membrane 1, so that magnet 20 is not in contact with test membrane A fluorescent microscope is used to count individual fluorescent microspheres bound to magnetic particles.
EXAMPLE 9
A test strip is manufactured according to the description given in FIG. 1. The backing 4 is extended in length beyond the absorbent pad 3 end to allow application of bar codes, fluorescent markings, and other indicators to the backing 4. Reagent zone 2 contains streptavidin conjugated 0.86 micron magnetic particles, anti-mouse IgG conjugated 150 nm magnetic particles, buffers, stabilizers, sufactants, and other reagents in dry form.
The test strip 11 is inserted absorbent pad 3 end first into the optical tunnel 9. Indicators on the test strip are interpreted as calibration information by the analyzer. For example, the analyzer verifies that the same bar code was read at both focal points 8a and 8b and stores reflectance and fluorescence values for photodetectors 13 and 16. The calibration information and measured values are used by the analyzer to verify the quality and structure of an individual capture line as well as the amount of analyte, control, or calibrator present at the capture line, and to verify the performance of each optical module.
In a separate container the operator adds a measured volume of sample to a measured volume of test reagents and mixes them to form a reaction mixture. The test reagents include biotin conjugated goat anti-beta FSH, and fluorescent microsphere conjugated goat anti-alpha FSH which cooperatively bind follicle stimulating hormone (FSH) molecules present in the sample. The test reagents also include mouse anti-beta LH, and fluorescent microsphere conjugated goat anti-alpha LH which cooperatively bind FSH molecules present in the sample.
A measured volume of this reaction mixture is applied to the test strip reagent zone 2. As the reaction mixture comes in contact with the reagent zone 2 it forms a new reaction mixture which contains 0.86 micron and 150 nm magnetic particles in suspension as well as buffers, stabilizers, surfactants, and other reagents previously dried on the reagent zone 2. The 0.86 micron magnetic particles bind the biotin conjugate in all of its complexed forms including those which have formed a cooperative complex (sandwich assay) with FSH and the anti-alpha FSH conjugate. Thus fluorescent microspheres are indirectly bound to magnetic particles in proportion to the amount of analyte present in the reaction mixture. The 150 nm magnetic particles bind the mouse anti-beta LH conjugate in all of its complexed forms including those which have formed a cooperative complex (sandwich assay) with LH and the goat anti-alpha LH conjugate. Thus, fluorescent microspheres are indirectly bound to magnetic particles in proportion to the amount of analyte present in the reaction mixture.
As the magnetic particles suspended in the reaction mixture flow laterally within the plane of the test strip 11 they encounter a first magnetic field applied using a bar magnet 20a attached to the base 9b of the optical tunnel 9. The applied magnetic field is of sufficient strength that it provides a magnetic barrier that selectively retains the 0.86 micron magnetic particles at the focal point 8a while allowing reaction mixture including 150 nm magnetic particles in suspension to continue to flow lateral across this barrier toward the absorbent pad 3.
As the 150 nm magnetic particles suspended in the reaction mixture flow laterally within the plane of the test strip 11 they encounter a second magnetic field applied using a second bar magnet 20b (not shown) attached to the base 9b of the optical tunnel 9. The second applied magnetic field is significantly stronger than said first applied magnetic field. This second applied magnetic field provides a magnetic barrier that selectively retains the 150 nm magnetic particles at the focal point 8b while allowing reaction mixture to continue to flow laterally across this second magnetic barrier toward the absorbent pad 3.
A measured volume of wash solution can also be added subsequent to the addition of reaction mixture. This will reduce the amount of fluorescent microspheres retained by the test membrane 1 and magnetic particles due to nonspecific binding.
The analyzer monitors and compares photodetectors 16a and 16b measuring reflectance at the focal point 8a and 8b.
The reflected light intensity at the focal point 8a decreases as the magnetic particles are retained by the first magnet 20a and second magnet (not shown). The reflected light intensity at focal points 8a and 8b are measurements used to determine whether the magnetic particles have been properly captured at focal points 8a and 8b. If the reflected light intensity is not within specification at focal point 8a and 8b during a predefined elapsed time the test is determined invalid and no result is reported.
Alternating with photodetectors 16a and 16b, the analyzer also monitors and compares photodetectors 13a and 13b measuring fluorescence. The emitted light intensity at focal points 8a and 8b are used to calculate FSH and LH concentrations respectively. The analyzer compares these emitted light intensities with those of test solutions containing known concentrations of FSH and LH, based upon such parameters, and calculates FSH and LH concentrations.
It is to be further understood that various additions, deletions, modifications and alterations may be made to the above-described embodiments without departing from the intended spirit and scope of the present invention. In this regard, it should expressly be recognized that in addition to the magnetically-generated capture lines formed herein, additional capture lines may be formed as per conventional test strip assays which incorporate the use of bound receptors formed upon a test membrane. Accordingly, it is intended that all such additions, deletions, modifications and alterations be included within the scope of the following claims.
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Novel magnetic assay methods and systems, as well as systems for conducting spectrophotometric analysis therewith. According to a preferred embodiment, the magnetic assay methods and systems incorporate a chromatographic medium, such as an assay test strip, that is designed to be contacted with a test solution having activated magnetic particles. A magnetic field, generated by a magnet or electromagnet, is additionally provided that if selectively applied to a chromatographic medium which causes the charged particles to become substantially bound at a site all in the chromatographic medium specified by the position of the magnets, to thus form a captured line or zone. To the degree of magnetic force applied to the medium may be selectively adjusted to vary the width or surface area of the capture line or zone. Additionally, in a preferred embodiment, capture lines may be formed while test strips are in motion along a stationary magnetized rail. Spectrophotometric analysis may be made at the captured lines and zones for qualitative and quantitative analysis of unidentifiable analyte. A multimode photometer consisting of an optical canopy and base that defines an optical chamber may be utilized for conducting spectral or multi-spectral analysis.
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BACKGROUND OF THE INVENTION
The present invention relates to a hydraulic brake system comprising an antiskid control apparatus, a master cylinder and at least one wheel cylinder, with the wheel cylinder being adapted to be connected to the master cylinder or a fluid outlet via antiskid control valves.
Brake systems of this type are known, for example, from the magazines "Automobil-Technik" of Oct. 30, 1978, pages 28 to 30, and "Automobiltechnische Zeitschrift" 81 (1979) 5, pages 201 to 208. In these magazines, brake systems are described in which a recirculating pump feeds the fluid returned to the master cylinder pressure chamber under high pressure. As a result of this arrangement, once the wheel cylinder is disconnected from the master cylinder, the fluid volume returned causes a volume increase in the master cylinder pressure chamber. This volume increase in the pressure chamber resets the master cylinder piston, the brake pedal moves in opposition to its actuating direction. Such pulsating brake pedal movements by no means appeal to the vehicle operator, they impair the pedal feeling considerably and affect the application of a dosed brake pressure adversely.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to supply the fluid required during an antiskid control action to the wheel brake cylinder of a conventional brake system such that the volume of the master cylinder pressure chamber remains unchanged.
A feature of the present invention is the provision of a hydraulic brake system having an antiskid control apparatus comprising a master brake cylinder; a fluid return line; at least one wheel brake cylinder; antiskid control valves coupled to the master cylinder, the wheel cylinder and the return line to connect the wheel cylinder to one of the master cylinders and the return line; and a valve device coupled to a fluid source, the master cylinder and the return line to deliver fluid from the fluid source to the wheel brake cylinder through at least one check valve opening in opposition to master cylinder pressure, the valve device being controlled by a piston having a first end surface acted upon by the master cylinder pressure in the sense of opening the valve device and a second end surface acted upon by the pressure of the fluid of the source in the sense of closing the valve device.
Whenever a substantial amount of fluid is required for the purpose of building up pressure again in a wheel cylinder after an antiskid control operation has taken place, the above arrangement causes the required fluid to be supplied through the check valve rather than being withdrawn from the master cylinder. By arranging the valve device to be controlled by a piston acted upon by hydraulic pressure, it is achieved that the fluid pressure present at the check valve is adapted to the pressure in the master cylinder. Therefore, during normal brake application, the fluid pressure present at the check valve approximates the pressure in the master cylinder, conditioned by the piston acted upon by pressure. Only when the pressure in the master cylinder drops can the check valve open, enabling the required fluid volume to be supplied to the master cylinder directly. The decrease in the fluid pressure acting on the check valve is accomplished via the master cylinder.
In order to realize the highest possible energy savings, the fluid source will deliver fluid only on actuation of the master cylinder. Such control elements may shut off the drive for the fluid source by electrical and/or mechanical means.
Because the fluid source is a fluid accumulator whose fluid flow to the valve device is ducted through a valve opening at the beginning of a braking action and closing on termination of a braking action, a constant-pressure fluid volume may be withdrawn by the brake system at all times. With a simple valve function, controlled delivery of fluid to the brake system is possible via a favorably constructed valve in which the piston acts as a valve slide, with the fluid admitted through the inlet located in the housing being deliverable to the outlet of the valve device through a channel system in the piston, or the inlet being adapted to be closed by the piston.
In a particularly favorable embodiment, the pressure chamber bounded by the second end surface of the piston and the housing communicates with the outlet of the valve device through a channel in the piston. This avoids the need for an external pressure pipe. By arranging the pressure chamber as an outlet chamber, the space additionally provided as the outlet chamber is no longer necessary, the valve device becomes simpler per se and thus more economical.
Because with the valve device in the open position the piston closes a fluid connection to an unpressurized compartment which will be opened with the valve device closed, it is possible to adapt the pressure to the master cylinder pressure without appreciable error. It is possible to reduce the residual pressure which remains on a pressure decrease via the master cylinder as a result of the check valves, fully and independently of the master cylinder. This pressure decrease may be accomplished substantially faster than a pressure decrease via the master cylinder.
It will be an advantage to arrange the check valve in the piston, thereby obviating the need for an external fluid line and resulting in a space-saving construction.
Further, it is advisable from the engineering point of view to arrange for limiting the displacement travel of the piston by means of axial stops so that in the event of abrupt pressure changes occurring in extreme situations the valve device is assigned a defined position in which operability is ensured. Still further, it will be advantageous to arrange for the piston to rest against the stop in its open position such that the fluid inlet is only partially open. In this manner, a throttling effect is achieved, permitting a high-pressure accumulator to be utilized because then a smooth pressure adaptation is possible. The use of such a high-pressure accumulator allows relatively long intervals between the individual accumulator charging cycles and, thus, the pump drive need not be actuated so often.
It will also be an advantage to supply the fluid to the valve device through a valve which is controlled electro-magnetically and/or hydraulically. If a valve is provided which is adapted to be driven by an electric pulse and returns to its closed state in the presence of specific hydraulic conditions, this valve may be opened by a control signal of the antiskid control apparatus and closed again with the master cylinder in the unpressurized state. By controlling the fluid flow in such a manner, it is achieved that the valve device is actuated only on demand, thereby precluding fluid losses in the valve device with no fluid flow required. Thus, in the use of such a brake system, it may be indeed possible that the pump system charges the pressure accumulator when the vehicle is started, after which it is only required to compensate for the very minor losses of the pressure accumulator. By this arrangement the pump drive is actuated relatively rarely, resulting in energy savings.
BRIEF DESCRIPTION OF THE DRAWINGS
Above-mentioned and other features and objects of this invention will become more apparent by reference to the following description taken in conjunction with the accompanying drawing, in which:
FIG. 1 is a schematic diagram of a power-assisted hydraulic brake system in accordance with the principles of the present invention; and
FIG. 2 is a longitudinal cross-sectional view of a modified valve device that may be employed in the hydraulic brake system of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, reference number 1 designates a master cylinder and reference number 2 designates a vacuum brake booster inserted upstream from master cylinder 1. Via a port 4, vacuum brake booster 2 is connected to a vacuum source providing the power assistance. The arrangement comprising vacuum brake booster 1 and master cylinder 1 connected downstream therefrom is controlled by a brake pedal 3. Mounted on master cylinder 1 is a fluid reservoir 5 which is connected to pressure chambers 6 and 7 of master cylinder 1 through breather bores not shown.
Fluid reservoir 5 is preferably subdivided into three compartments 8, 9 and 10 which are interconnected by overflow pipes. In this arrangement, compartment 8 is assigned to pressure chamber 6 via a breather bore, compartment 9 to chamber 7 via another breather bore, and compartment 10 serves as a sump which via a pump 12 feeding the fluid into a pressure accumulator 11.
The master cylinder chambers are connected to the brake actuating members 17 to 20 of vehicle wheels 13 to 16. Via a pressure line 21 and a solenoid valve 22 which is open in the de-energized state, pressure chamber 6 supplies pressure to wheel cylinders 19, 20 of rear wheels 15, 16. Via line 23 and solenoid valves 24 and 25 which are open in the de-energized state, pressure chamber 7 supplies pressure to brake-actuating members 17 and 18 of front wheels 13 and 14. Associated with brake-actuating members 19 and 20 of rear wheels 15 and 16 is a solenoid valve 26 which is closed in the de-energized state and connects, in the event of a desired pressure decrease in the brake-actuating members 19 and 20, these actuating members to an unpressurized collector line 27 which connects with a port 29 of fluid reservoir 5 via a return line 28. Similarly, brake-actuating members 17 and 18 of the front wheels 13 and 14 are connected separately to collector line 27 via solenoid valves 30 and 31, respectively, which are closed in the de-energized state. This makes it possible to increase or decrease the pressures in brake-actuating members 17 and 18 of the front wheels to different magnitudes separately from each other whereas the pressures in the brake-actuating members 19 and 20 of the rear wheels can only be changed jointly.
Solenoid valves 22, 24 to 26, 30 and 31 are controlled by an antiskid control apparatus not shown, receiving their information from sensors associated with the wheels. The antiskid control apparatus will detect an imminent locked condition of a wheel in time for it to actuate the relevant solenoid valves in order to withdraw pressurized fluid from the associated brake-actuating member and thus lower the pressure. As a result of the reduced braking torque, the wheel will accelerate again and leave the danger area in which lockup may occur. Then the antiskid control apparatus may undertake another pressure increase in the appropriate brake actuating member.
Because valves 22, 24 and 25 which are open in the de-energized state are conventionally constructed such that in the open state only one direction of flow is allowed, or only one direction of flow should be preferably used, each of them is connected in parallel with an associated check valve 32 opening in opposition to the pressure of pressure chambers 6 and 7. In this manner it is ensured that upon termination of a braking action the pressure in wheel cylinders 17 to 20 is allowed to decrease via the associated check valves 32, pressure chambers 6 and 7 and the breather bores of reservoir 5.
Allocated to the brake system described so far is a pressure accumulator 11 which is charged by pump 12 via check valve 33. Suction port 34 of pump 12 communicates with compartment 10 of fluid reservoir 5. In order to filter out any impurities that may be contained in the pressure fluid, a filter 35 is inserted in suction port 34. Further, it is possible to provide in suction port 34 a check valve 36 opening in the direction of pump 12 in order to prevent fluid from being fed in the direction of fluid reservoir 5.
The fluid flow from pump 12 to pressure accumulator 11 is likewise ducted through a valve device 37 which is a pressure-relief valve and with accumulator 11 fully charged returns any excess of fluid supplied to return line 28 via line 38.
In order to prevent any fluid under pressure from travelling down line 38 to line 27 and possibly affect the valve functions, a check valve 39 opening in the direction of return line 28 is provided between collector line 27 and return line 28.
Drive unit 40 for pump 12, may, for example, be the engine of the automotive vehicle. For this purpose, it will be an advantage to flange pump 12 directly to a rotating part of the engine. Advantageously, drive unit 40 for pump 12 could be an electric motor rather than the vehicle engine which is actuated in response to the pressure prevailing in pressure accumulator 11. To this end, the instantaneous pressure of accumulator 11 is signalled via a control line 42 to a pressure switch 41 which actuates the electric motor of drive unit 40 via an electric control line 43. It should be understood that in this arrangement pressure switch 41 requires a hysteresis permitting pressure fluctuations in accumulator 11 of about 30 bars. Thus, for instance, the minimum accumulator pressure could be fixed at 140 bars and the maximum pressure at 170 bars.
Via a pressure line 44 and a solenoid valve 46 which is closed in the de-energized state, accumulator 11 communicates with the inlet 47 of a valve device 45. Valve 46 which is closed in the de-energized state is connected to outlet 49 of valve device 45 via a hydraulic control line 48. Valve 46 which is closed when de-energized is opened under electrical control and will not close until after outlet 49 is unpressurized and this condition has been signalled to the open valve 46 via hydraulic control line 48.
Valve device 45 includes a piston 50 which acts as a hydraulically operated valve member between inlet 47 and outlet 49 in the sense of a pressure reduction. In the embodiment shown, piston 50 is a stepped piston having its first end surface 51 exposed to the pressure of pressure chamber 7. Since piston 50 is sealed to and slides in the housing of valve device 45, outlet 49 is formed at the step 53 between piston 50 and the housing of valve device 45, this outlet communicating with pressure lines 21 and 23, and thus, with pressure chambers 6 and 7 via check valves 55 and 56, respectively. In this embodiment, check valves 55 and 56 are arranged to be openable in opposition to the pressure of pressure chambers 6 and 7.
Outlet 49 is connected to the pressure chamber 57 bounded by the housing of valve device 45 and piston 50 via an axial channel 67 so that the second end surface 52 of piston 50 is acted upon by the pressure of outlet 49. Via a radial channel 68 which overlaps inlet 47 depending on the position of piston 50, fluid is ducted from inlet 47 to outlet 49 and into pressure chamber 57. Radial bore 68 and inlet 47 will overlap to a greater or lesser extent in accordance with the position of piston 50 so that, dependent on the piston position, a pressure will build up in outlet 49 which, starting from zero pressure, may increase up to the pressure of accumulator 11.
Provided in pressure chamber 57 is a stop 58 which limits the open position of piston 50, and thereby provides a defined open condition of the controlled system. Similarly, it is advisable to provide a stop 60 in pressure chamber 59 which is bounded by end surface 51 of piston 50 in order to be able to limit the closed position of piston 50.
Provided just in front of stop 58 is a pressure outlet 61 which is connected to the unpressurized fluid reservoir 5 via line 62, line 38 and return line 28. In the open position of piston 50, i.e., with piston 50 in abutment with stop 58, pressure outlet 61 is closed by piston 50. Piston 50 acts as a valve slide for pressure outlet 61.
The mode of operation of the arrangement of FIG. 1 is as follows.
Application of brake pedal 3 causes actuation of vacuum brake booster 2, its output force being transmitted to master cylinder 1. In pressure chambers 6 and 7 a pressure will build up which travels down to brake-actuating members 17 to 20 through lines 21 and 23. If the antiskid control apparatus (not shown) detects an imminent locked condition of a wheel during a braking action, it will close the associated pressure inlet valve 22, 24 and 25 (open in the de-energized state) and open the associated pressure outlet valve 26, 30 and 31 (closed in the de-energized state) in accordance with the wheel rotational behavior. The pressure in the associated wheel cylinder will drop, the wheel being allowed to accelerate again and leave the danger zone in which it may become locked.
The pressure built up in pressure chamber 7 at the beginning of the braking operation will propagate into pressure chamber 59 and act on end surface 51 of piston 50, holding it in abutment with stop 58 in the position shown. However, because valve 46, which is closed in the de-energized state, is closed during normal brake application, inlet 47 and outlet 49 will remain unpressurized. Only when the antiskid control apparatus has established an imminent lockup and a relevant pressure outlet valve 26, 30 and 31 opens, will this opening signal cause at the same time opening of valve 46 which is closed when de-energized, and the full pressure of accumulator 11 will be present on inlet 47 of valve device 45 via line 44. Because piston 50 is in the open position, the pressure will immediately be present in pressure chamber 57 and in outlet 49. On attainment of the pressure prevailing in pressure chamber 7, however, piston 50 will assume a pressure-balanced state because the pressure acting on end surface 51 is equal to the pressure acting on annular surface 54 in outlet 49 and on end surface 52. Any further, minor, pressure increase will immediately cause a displacement of piston 50 to the left, thus moving radial channel 68 away from under inlet 47 so that inlet 47 will be closed by piston 50. Should the pressure increase have been greater than the pressure prevailing in pressure chamber 7, piston 50 will be shifted an amount sufficient to enable the excess pressure to escape through pressure outlet 61, i.e., piston 50 will assume a defined position with the pressure in pressure chamber 7 constant. The pressure thus metered into outlet 49 corresponds to the pressure in pressure chamber 7 and acts on the relevant pressure chambers 6 and 7 directly via check valves 55, 56.
The antiskid control apparatus which then establishes that the wheel concerned has largely recovered, will again close the associated one of outlet valves 26, 30 and 31, and open the associated one of inlet valves 22, 24 and 25. As a result, a substantial amount of fluid will be required to flow through the associated pressure line in order to adapt the pressure in the associated brake-actuating member to the pressure in the other brake-actuating members. However, because of the arrangement of check valves 55 and 56, this fluid requirement will not be withdrawn from the relevant one of pressure chambers 6 and 7 of master cylinder 1, but rather will enter the associated brake circuit via check valves 55 and 56. The vehicle operator who depresses brake pedal 3 will hardly, if at all, be able to notice this fluid flow in the relevant brake circuit by a different pedal feeling. It is insured in this manner that master cylinder 1 fluid volume cannot become exhausted, no matter how many control cycles are performed.
Also after termination of an antiskid control cycle, valve 46 which is closed when de-energized will remain open because it is not allowed to return to the closed state until outlet 49 is unpressurized. This, however, will be the case only if the vehicle operator releases brake pedal 3 and the braking action is terminated. In this case, the pressure acting on end surface 51 of piston 50 will drop to zero, and the pressure acting on end surface 52 and annular surface 54 will immediately displace the piston to the left, closing inlet 47 and opening pressure outlet 61 fully. There will thus occur a prompt pressure decrease in outlet 49. This will be signalled to valve 46 via hydraulic control line 48 so that it will return again to its closed rest position.
It is to be understood that the valve operation described so far is presented in a highly simplified form in order to make the arrangement more clearly understood. In reality, on opening of valve 46 which is closed when de-energized, piston 50 will reciprocate continuously in order to compensate for the respective pressure fluctuations to maintain a constant output pressure. In the presence of faulty condition, this valve device will operate in a manner similar to constructions known in the art. The antiskid control apparatus will be disabled, making normal braking of the device possible. However, with the antiskid control apparatus disabled, it will also be ensured that valve 46 which is closed when de-energized cannot open with the operation of the brake system continuing.
FIG. 2 shows a more favorable embodiment of a valve device 45 of FIG. 1. A simple piston 50' slides in a housing of valve device 45', and end surfaces 51 and 52 are again exposed to pressure in accordance with the description given above. In this embodiment, pressure outlet 49 is located in pressure chamber 57 which is adapted to be connected to the inlet through channels 67 and 68. Check valve 56 is preferably inserted in an extended bore 63 provided in end surface 51, with bore 63 communicating with channel 67. In a simple embodiment, a spring 64 bearing against a circlip 65 provided in extended bore 63 holds a ball 66 in sealing engagement with a valve seat formed by the channel orifice in bore 63. In contrast to FIG. 1, this embodiment dispenses with the need for an external check valve so that additional fluid ports are avoided which, as sources of errors, might cause a failure of the valve device. Further, this valve device permits a particularly small and accordingly compact design which makes it advantageously suitable for use in a bulky antiskid control apparatus.
While I have described above the principles of my invention in connection with specific apparatus is it to be clearly understood that this description is made only by way of example and not as a limitation to the scope of my invention as set forth in the objects thereof and in the accompanying claims.
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Brake systems having an antiskid control apparatus are known in which pressure fluid is additionally supplied from a dynamic circuit into the static brake circuit when pressure fluid has been taken therefrom due to an antiskid control operation. In this situation, the known systems were not able to maintain the master cylinder pressure at a constant value. Therefore, according to the present invention a valve device is provided which is acted upon by the static master cylinder pressure in the opening direction and by the dynamic auxiliary pressure in the closing direction.
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FIELD OF THE INVENTION
[0001] The present invention relates to a method for track jumping for optical recording media exhibiting eccentricity, and to an apparatus for reading from and/or writing to optical recording media using such method.
BACKGROUND OF THE INVENTION
[0002] On optical recording media such as, for example, CD and DVD, data is stored in the form of pits following tracks. Recordable media, such as DVD-RAM or DVD-RW, often use land-groove track structures, where data is written either in the grooves or both in the lands and the grooves. The tracks are centered relative to the center of the optical recording medium, either in the form of concentric circles or as a spiral. Favorably, the center of the tracks corresponds to the axis of rotation of the optical recording medium upon playback in an apparatus for reading from and/or writing to optical recording media. However, due to manufacturing tolerances of the optical recording medium and/or the drive of the apparatus, during playback or recording the center of the tracks does generally not coincide exactly with the axis of rotation. In other words, the optical recording medium exhibits eccentricity. The eccentricity affects the accuracy of track counting during a track jump, and, therefore, increases the time needed for accessing a specific track on the optical recording medium. During a track jump, the tracking loop of the servo controller, i.e. the control loop which ensures that the light beam used for reading and/or writing remains centered relative to the track, has to be opened. Once the track jump is finished, the tracking loop is closed again. As long as the tracking loop is opened, the eccentricity causes interfering activity on the tracking error signal, without any indication whether the light beam is moving inwards or outwards. This leads to an erroneous track counting.
[0003] For optical recording media exhibiting a difference in reflectivity between lands and grooves, a solution for this problem is found in using two signals for counting the number of tracks which are being crossed during a track jump. The first signal is the tracking error signal, the second signal is a mirror signal. Both signals are obtained as a combination of photodetector signals. By monitoring the phase relationship between these signals, it is possible to determine whether the light beam is moving inwards or outwards while the tracking loop is opened. This allows to compute the number of tracks which are being crossed during a track jump with sufficient accuracy, even under the influence of eccentricity.
[0004] However, recordable optical recording media such as, for example, DVD+RW do only exhibit a very small or even no difference in reflectivity between lands and grooves in the unrecorded areas. During a track jump the system has to rely solely on the tracking error signal for track counting. This signal, however, does not give any indication on the interfering influence of the eccentricity during the track jump.
[0005] To alleviate the above problem, JP 10-112039 discloses a method to improve the random access stability of an optical disk memory device. The device is provided with an eccentricity detecting circuit, which discriminates the direction of the eccentricity of the disk and the eccentric acceleration from the tracking error signal. Eccentric acceleration here denotes the acceleration of a track relative to its mean position caused by eccentricity. When a track jump is to be performed, a track jump enable signal generating circuit determines the track jump start timing from the obtained eccentricity condition, the track jump direction, the number of tracks crossed during the jump, and the relationship with the current rotation speed of the disk. The track jump is then initiated with an optimum timing against the disk eccentricity.
[0006] It is an object of the invention to improve the methods known from prior art.
SUMMARY OF THE INVENTION
[0007] According to the invention, a method for track jumping for optical recording media exhibiting eccentricity, whereby a sled and/or an actuator are moved from a start track to an end track, comprises the steps of determining the eccentricity of the optical recording medium, initiating the track jump at minimum eccentric acceleration, and completing the track jump at minimum eccentric acceleration. By completing the track jump at minimum eccentric acceleration it is ensured that the influence of the eccentricity of the recording medium on the track counting is minimized, which leads to a more reliable track jump. The condition of minimum eccentric acceleration occurs only two times per revolution, which is approximately every 10 ms. For short jumps these time slots are very challenging. Also for long jumps the sled traverse speed has to be selected carefully to exactly match the optimum landing condition. Acquisition of data on the eccentricity of the recording medium is advantageously performed on the fly, i.e. during normal operation with closed tracking loop. It is, however, also possible to perform data acquisition only at the time when a track jump is to be initiated. The data on the eccentricity is favourably obtained from a tracking error signal or a signal comparable to a tracking error signal, which is not necessarily used as a tracking error signal. Of course, other methods for obtaining the data can also be used.
[0008] Advantageously, the method further comprises the step of setting the rotation of the optical recording medium to constant angular velocity before initiating the track jump. This allows a reduction in the computation power and, consequently, the hardware expenses necessary for a phase control operation. By setting the rotation to constant angular velocity it is ensured that the eccentricity at the destination track is the same as the eccentricity at the start track if the track jump is performed in a period of time corresponding to an integer multiple of the time needed for a complete rotation of the optical recording medium. This allows one to easily calculate the necessary travelling speed of the sled and/or the actuator by simply determining the time needed for a single rotation of the optical recording medium at the current angular velocity and comparing this time with the time needed for accelerating and braking the sled and/or the actuator and the time needed for crossing the tracks when the sled and/or the actuator travel with the calculated speed. Preferably these values are stored in a table within the apparatus for reading from and/or writing to optical recording media.
[0009] The step of initiating the track jump preferably comprises starting the movement of the sled and/or the actuator. This ensures that the sled and/or the actuator arrive at the destination track at the calculated time. The necessary calculations for determining the travelling speed and for setting the rotation to constant angular velocity are advantageously performed before the track jump is initiated. Otherwise a delay in one of the operations could lead to a delayed movement of the sled and/or the actuator, which would then arrive at the destination track at a wrong time. Preferably, a track jump enable signal is emitted when the track jump preparations are finished. It is of course, also possible to initiate the track jump by performing the necessary calculations. However, in this case the time needed for calculating has to be taken into account when the travelling speed of the sled and/or the actuator is determined. In this case a safety margin for the track jump preparation is advantageously provided.
[0010] According to the invention, the method further comprises the step of opening a tracking control loop shortly before starting the movement of the sled and/or the actuator. This has the advantage that the tracking control loop is ready for track counting when the movement of the sled and/or the actuator is started at minimum eccentric acceleration. Though the track counting is preferably done by a separate hardware counter, this hardware counter uses the track zero cross signal as an input signal. Opening the tracking control loop shortly before starting the movement of the sled and/or the actuator further allows one to take into account the inertia of the mechanical components and the processing time of the controller. In practise, however, opening the control loop and starting the movement of the sled occur almost simultaneously since the microcontrollers, which are available today, are very fast.
[0011] Preferably, the step of completing the track jump comprises closing the tracking control loop. In this way the tracking control loop is closed at the time of minimum eccentric acceleration. This helps to make the track jump more reliable, since the risk that the tracking control loop loses the track due to the eccentricity is greatly reduced. Though during normal operation the tracking control loop is not very likely to lose the track, just after closing the loop has to stabilize and is more susceptible to distortions such as eccentricity.
[0012] Advantageously, the method further comprises the step of finishing the movement of the sled and/or the actuator shortly before closing the tracking control loop. This step ensures that the tracking control loop is ready for closing at minimum eccentric acceleration. Otherwise it could occur that the tracking control loop is closed too late and the destination track is lost due to the distortions caused by the eccentric acceleration.
[0013] Preferably, the forced movement of the sled and/or the actuator is finished before arriving at the destination track. This allows one to take into account the time which is needed for braking the sled and/or the actuator. Otherwise the sled and/or the actuator could overshoot the destination track during braking. The necessary offset, which for the track jump is subtracted from the number of tracks between the start track and the destination track, is advantageously determined empirically by the designer of the apparatus for reading from and/or writing to optical recording media. The offset may vary with the length of the track jump and/or the travelling speed of the sled and/or the actuator. Offset values are preferably stored in a table within the apparatus.
[0014] Advantageously, the eccentricity of the optical recording medium is determined from a tracking error signal. Since means for generating a tracking error signal are provided anyway, no additional hardware has to be introduced for this purpose. This helps to reduce the cost for implementing the method according to the invention. Usually a PID controller is used for tracking control. The integral part of the controller tries to compensate for the eccentricity and can, therefore, be used as a measurement tool for the eccentricity. In this case it is not the tracking error signal directly which is used, but the reaction of the controller to this signal. In a standard PID controller design the task of the integral part of the controller is to eliminate the deviation which remains if just a proportional part is present. In a tracking servo control loop the PID controller tries to keep the track actuator in the center position of the track. As every disc is eccentric to a certain extent this results in an actuator movement in radial direction back and forth. If only a proportional part is present this compensation movement is not sufficient, which means that there is a remaining deviation from the mid center position of the track. This deviation is proportional to the elongation of the actuator due to eccentricity. To overcome this problem the integral part of the controller is introduced. This part compensates for the deviation until a mid center position is reached. As the integral part that has to be added is proportional to the elongation of the actuator it can be used as a measure for the eccentricity itself. Of course, it has to be taken into account that depending on the gain and time constant of the integral part there is a phase delay between maximum eccentricity and maximum integral control output. Of course, other methods for determining the eccentricity can also be provided. Preferably, an apparatus for reading from and/or writing to recording media uses a method according to the invention for track jumping. Such an apparatus performs very reliable track jumps, which leads to a reduced random access time. For every track jump which does not arrive at the desired destination track, a further, shorter correction track jump is necessary. By ensuring that the sled and/or the actuator arrive essentially at or very close to the desired destination track, the correction track jumps become obsolete.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] For a better understanding of the invention, an exemplary embodiment is specified in the following description with reference to the figures. It is understood that the invention is not limited to this exemplary embodiment and that specified features can also expediently be combined and/or modified without departing from the scope of the present invention. In the figures:
[0016] [0016]FIG. 1 shows a method for track jumping according to the invention, and
[0017] [0017]FIG. 2 schematically shows an apparatus for reading from and/or writing to optical recording media using the method.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] A method for track jumping according to the invention is shown schematically in FIG. 1. Before a track jump is executed, in a first step 1 data on the eccentricity of the recording medium is acquired and the eccentricity is determined. This is preferably done on the fly, i.e. during normal operation with closed tracking loop, preferably as a part of the general alignments that are done during start up of a new recording medium. It is, of course, also possible to determine the eccentricity only at the time when a track jump is to be performed, e.g. by using the reaction of the PID controller. However, this will significantly increase the time needed for the track jump. Once the eccentricity has been evaluated, the angular position of the disc measured by a dedicated counter is taken into account for determining at which point of the recording medium a jump can be initiated. In order to simplify the phase control operation and to reduce the required computation power, in the next step 2 the system is set to a constant angular velocity. Though in this way the method is simplified considerably, the method can also be performed without setting the system to constant angular velocity. Furthermore, it is likewise possible to increase or decrease the angular velocity to reach the point of minimum eccentric acceleration faster. However, it should be ensured that the time needed for acceleration or deceleration does not vitiate this beneficial effect. In both cases the change of the rotation speed has to be taken into account during a track jump. Shortly before the minimum eccentric acceleration is reached, e.g. 1 ms, which represents 1 cm on the recording medium (at 3000 rotations per minute along a 20 cm track, v=10 m/s), in a step 3 the tracking loop is opened and a track counting is started. Another method for determining the correct point of time is to use a frequency counter which measures the track crossing frequency. If this frequency drops below approximately 1 kHz a good point for starting the track jump has been reached. The track counting is based on the tracking error signal. The track counting allows to determine the number of tracks which have been crossed so far during the track jump. The minimum eccentric acceleration denominates the point in time when the absolute value of the acceleration of the track relative to its mean position is essentially zero. At minimum eccentric acceleration, in a step 4 the movement of the sled and/or the actuator relative to the recording medium, i.e. the track jump is initiated. The sled continues its movement until the track counting indicates that a previously calculated number of tracks, which corresponds to the jump from the start track to the destination track, has been crossed. In a step 5 , shortly before the minimum eccentric acceleration is reached, the forced sled movement is stopped. Advantageously, an empirically determined offset is subtracted from the calculated number of tracks. For precise working controllers this offset can be as low as 0 or 1. This allows to compensate for the distance that the sled continues to travel before it comes to a complete stop. At essentially minimum eccentric acceleration, in a step 6 the tracking loop is closed again and the track counting is stopped. Preferably the tracking loop is closed as soon as the correct track has been reached. If a traverse speed controller is used, which controls the track crossing frequency, at the end of the jump the track crossing frequency has reached a minimum so that the tracking loop is closed again. With step 6 the track jump is completed.
[0019] In FIG. 2 an apparatus for reading from and/or writing to optical recording media 16 using the method according to the invention is shown schematically. The apparatus comprises a sled 10 , which can be moved relative to the surface of the optical recording medium 16 to access different areas of the optical recording medium (coarse tracking). The sled 10 carries a light source 11 emitting a light beam 12 for scanning a recording layer of the optical recording medium 16 . The light beam 12 is collimated by a collimator 13 before it is diverted by means of a beam splitter 14 . An objective lens 15 focuses the light beam 12 onto a track of the optical recording medium 16 , the track carrying information. The objective lens 15 can be moved relative to the track by an actuator (not shown) for ensuring that the light beam 12 is kept as close as possible to the track center (fine tracking). Part of the light beam 12 is reflected from the recording layer. The reflected light is collimated by the objective lens 15 and imaged onto a photodetector 18 by means of a further objective lens 17 . The signals obtained from the photodetector 18 are fed to an evaluation unit 19 , which generates a tracking error signal TE. This tracking error signal TE is on the one hand supplied to a tracking regulator 20 controlling the position of the objective lens 15 , and on the other hand also transmitted to a track jump controller 21 . The track jump controller 21 determines the eccentricity of the optical recording medium 16 , controls the movement of the sled 10 during a track jump, and performs track counting during the track jump. When a track jump is initiated, the track jump controller 21 ensures that the tracking loop controlling the position of the objective lens 15 is opened shortly before the optical recording medium 16 is at the position of minimum eccentric acceleration. It further ensures that the sled 10 starts to move when the optical recording medium 16 has reached the position of minimum eccentric acceleration. At the end of the track jump the track jump controller 21 guarantees that the movement of the sled 10 is stopped shortly before the optical recording medium 16 is at the position of minimum eccentric acceleration, and closes the tracking loop when the optical recording medium 16 has reached the position of minimum eccentric acceleration. During the movement of the sled, the track jump controller 21 performs a track counting operation for determining the number of tracks which have been crossed so far during the track jump. The track counting operation ensures that the movement of the sled is stopped before the destination track is crossed.
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A method for track jumping for optical recording media exhibiting eccentricity, and to an apparatus for reading from and/or writing to optical recording media using such method is disclosed. The method for track jumping for optical recording media exhibiting eccentricity, whereby a sled and/or an actuator are moved from a start track to an end track, includes the steps of: determining the eccentricity of the optical recording medium, initiating the track jump at minimum eccentric acceleration, and completing the track jump at minimum eccentric acceleration.
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This is a continuation-in-part application of Ser. No. 916,469, filed June 19, 1978, now abandoned, which was a continuation of Ser. No. 565,119, filed Apr. 4, 1975, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a system generating pattern information by digitizing patterns being analyzed, for producing Jacquard patterns by a fabric-making, machine such as a weaving-machine or a knitting-machine.
2. Prior Art
Lately, techniques for automatically representing patterns on a fabric have greatly advanced, as exemplified by a Jacquard knitting machine called "SYSTEMNIT", which is a computerized knitting-machine developed by the Fibrous High Molecular Material Laboratory of the Ministry of International Trade and Industry of Japan. To operate the Jacquard knitting-machine, it is necessary to apply pattern information to the machine. The nature of the pattern information varies depending on the type of the knitting-machine, i.e., a machine having a mechanical pattern control device or a machine having an electronic pattern control device, so that signals which are adapted for the specific pattern control device are formulated directly or indirectly by suitable processes. Generally speaking, the pattern information is derived from a design developed by an artist, by using a pattern analyzing device.
With a conventional pattern analyzing device, a paper carrying a pattern (design) to be analyzed is wound on a rotary drum, and the paper is optically and electrically scanned while mechanically rotating the drum, for generating sequential electric signals corresponding to the color (red, green, or blue) of each of the picture elements in the design. The electric signals thus generated are converted into digital signals, for providing pattern information, e.g., in the form of punched tape.
The conventional pattern analyzing device, however, has a shortcoming in that its operation is rather complicated, because rotation of the drum is involved therein, and that it requires a considerably long time and a large amunt of labor to complete the analysis of a pattern due to the need of a long analyzing time.
SUMMARY OF THE INVENTION
It is an object, therefore, of the present invention to overcome said disadvantage and limitation of prior arts by providing a new and improved pattern generating system.
The above and other objects are attained by a pattern generating system having at least an arithmetic unit having at least one digital register and a controller, said operating unit processing digital information through said register under the control of said controller;
a digital memory connected to said arithmetic unit, said digital memory having at least one main canvas area and one sub-canvas area;
a monitor means connected to said arithmetic unit, said monitor means monitoring contents of each of said areas of the digital memory;
an output means connected to said arithmetic unit, said output means reading out the contents of said main canvas area; and
an input means connected to said arithmetic unit, so as to receive input relating to control information for controlling operation of the arithmetic unit and stored pattern information to be applied to said areas;
said controller being adapted to, in response to said control information from the input means, transfer digital information between said main canvas area and said sub-canvas area in a predetermined fashion, process digital information on specified patterns in said areas, and control said monitor means and said output means; said system producing, under the control of said controller, digital information corresponding to colors of individual picture elements of a desired pattern at different cells of said main canvas area; said output means producing an output pattern information consisting of the contents of said main canvas area.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features, and attendant advantages of the present invention will be appreciated as they become better understood by the accompanying drawings wherein;
FIG. 1A is a depiction of a pattern which is to be reproduced by a knitting machine;
FIG. 1B is a diagram of an equivalent digital coding of the colors of the pattern in FIG. 1A;
FIG. 2 is a block diagram of an embodiment of the pattern generating system according to the present invention;
FIG. 3 is a block diagram indicating that it is comprised of FIGS. 3A and 3B;
FIG. 3A is part of an overall block diagram of a practical embodiment of the pattern generating system according to the present invention;
FIG. 3B is the other part of the overall block diagram of said embodiment;
FIGS. 4A through 4G illustrate formation of a pattern by the system according to the present invention;
FIGS. 5A through 5F illustrate formation of another pattern by the system according to the present invention;
FIG. 6 shows a format of output information for a pattern;
FIG. 7 is a block diagram indicating that it is comprised of FIGS. 7A and 7B;
FIG. 7A is one part of a general flow chart of computer software for the pattern generating system according to the present invention;
FIG. 7B is the other part of said general flow chart;
FIGS. 8-32 are respective block diagrams which are break downs of corresponding blocks of FIG. 7 that are identified below;
FIGS. 33-35 are diagrams of check patterns related to the explanation of FIG. 17;
FIG. 36 is a diagram of a pattern related to the explanation of FIGS. 21 and 22; and
FIG. 37 is a diagram of a color pattern related to the explanation of FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates operative principles of a pattern generating system according to the present invention. Let it be assumed that a pattern, as shown in FIG. 1A, is to be produced by knitting, and that the pattern to be knit consists of very small predetermined picture elements and only one color is allowed in one picture element. Each element of the lattice of FIG. 1A represents such picture elements in which, for instance, the element a with hatches from the top right to the bottom left represents a red element; the blank element b represents a blue element; the element c with hatches from the top left to the bottom right represents a yellow element; and the element d with crosshatching represents a black element. Accordingly, when the elements a, b, c and d are designated by digits 00, 01, 10, and 11, respectively, so as to produce an information pattern, as shown in FIG. 1B, then, the information of FIG. 1B is completely equivalent to the pattern of FIG. 1A. Thus, it is possible to obtain an information pattern corresponding to a desired knit pattern by producing such a digital information pattern as shown in FIG. 1B, on the digital memory of the information processing means and suitable processing it. The information pattern can be extracted as an output, for instance, onto a paper tape, which is usable as pattern information for controlling the knitting-machine.
FIG. 2 shows a basic block diagram of the pattern generating system according to the present invention. In the figure, reference numeral 1 is an operational unit, 2 and 2a are digital memories which, for instance, consist of magnetic drums, 3 is a monitor means including a cathode ray tube display means 3a and a line printer 3b, 4 is an output means which, for instance, consists of a paper tape puncher 4a, and 5 is an input means consisting of a paper tape reader means, a card reader means, a typewriter means, or an operating means. The digital memories 2 and 2a correspond to a main canvas area and a sub-canvas area, respectively, which are used in producing a desired pattern thereon. More particularly, the purpose of the main canvas area is to generate a finalized complete information pattern for the desired pattern, and the sub-canvas area 2a generates a pattern which is used in modifying all of part of the overall pattern on the main canvas area 2. The size of the sub-canvas area 2a is the same as or smaller than that of the main canvas area.
The operating unit 1 includes at least a register 1a and a controller 1b. The register 1a has a code portion S and a data portion D, and information processing operations on the digital memories 2 and 2a are all effected through the register 1a. For example, when it is desired to modify the information relating to a specific picture element on the digital memory 2 or 2a, that information is read out onto the register 1a from the digital memory 2 or 2a under the control of the controller 1b, and after completing the desired modification, the modified information is written again at the original position of that picture element.
In more detail, the pattern course number (PCN) is read out in sequence from 1 to 2 in FIG. 8 and the pattern wale number (PWN) is read out in sequence from 2 to "STEP 2". Then an area having the size of PCN×PWN is allotted on the digital memory as the main canvas. Similarly, the sub-canvas pattern course number SPCN and the sub-canvas pattern wale number SPWN are read out in sequence from 2 to the eleventh block at the bottom of FIG. 9. Then an area having a size of SPCN×SPWN is allotted in the digital memory as the sub-canvas.
The monitor means 3 displays an information pattern stored in the digital memory 2 or 2a, e.g., as shown in FIG. 1B, after converting it into a design pattern, e.g., as shown in FIG. 1A, so as to enable operating personnel to monitor the progress of the process of pattern formation.
The purpose of the output means 4 is to produce output information upon completion of the desired pattern, for instance, by punching a paper tape or cards so as to represent the information formed on the main canvas 2.
The input means 5 acts to place a separately prepared pattern on the entire area or a part of the main canvas or the sub-canvas, or to deliver control information into the pattern analyzing system for controlling the formation of a desired pattern on said main canvas area and sub-canvas area. The input means consists of a paper tape reader, a card reader, a keyborad, a character display means, or a special operating means.
The operating unit 1, as shown in FIG. 2, may be formed by using special integrated circuit hardware. Alternately, the operating unit 1 can be a conventional small computer, known as a mini-computer, with a suitable software loaded in its memory.
FIG. 3 is a block diagram of a practical pattern analyzing system corresponding to the diagram of FIG. 2, which system uses an operating unit 1 consisting of a computer of the HIDIC-500 series made by Hitachi, Ltd. in Japan. In the figure, elements encircled in dash-dot lines form the arithmetic unit 1; a magnetic drum provides the digital memories 2 and 2a; a display and a line printer forms the monitor means 3; a paper tape punch is the output means 4; and a paper tape reader and a character display means form the input means 5. The peripheral devices, as designated by the reference numerals 2 through 5, are connected to the computer 1 through suitable control means.
Processing functions, which can be performed by the main canvas area and the sub-canvas area in the system according to the present invention, are as follows.
(a) Ground Color
Information specified as the background color (in case of a four color pattern, one of the codes 00, 01, 10, and 11) is applied to the entire area covering each of the picture elements on the main canvas or the sub-canvas (see FIG. 13).
(b) Points
Any picture element at the specified coordinates on the main canvas or the sub-canvas can be colored, as specified (see FIG. 14).
(c) Straight Line
Straight lines can be drawn at specified locations on the main canvas or the sub-canvas in specified colors (see FIG. 15).
(d) Stripes
Stripes (vertical lines) can be drawn on the main canvas or the sub-canvas in specified colors (see FIG. 16).
(e) Check
Check patterns can be drawn on the main canvas or the sub-canvas in specified colors (see FIG. 17).
(f) Border
Borders (horizontal lines) can be drawn on the main canvas or the sub-canvas in specified colors (see FIG. 18).
(g) Oblique or Bias Patterns
Oblique or bias patterns can be drawin on the main canvas or the sub-canvas in specified colors (see FIG. 19).
(h) Random Input
In addition to the foregoing functions, arbitrary information can be placed on the sub-canvas area through the input means as an input thereto (see FIG. 27).
(i) Simple Transfer
The pattern on the sub-canvas can be transferred onto the main canvas as it is (see FIG. 20).
(j) Horizontal Transfer
The pattern on the sub-canvas can be repeatedly transferred onto the main canvas in a horizontal arrangement (see FIG. 21).
(k) Vertical Transfer
The pattern on the sub-canvas can be repeatedly transferred onto the main canvas in a vertical arrangement (see FIG. 22).
(l) Right Upward Transfer
The pattern on the sub-canvas can be repeatedly transferred onto the main canvas in a right upward direction with an angle of 45° C. relative to the horizontal direction (see FIG. 23).
(m) Left Upward Transfer
The pattern on the sub-canvas can be repeatedly transferred onto the main canvas in a left-upward direction with an angle of 45° C. relative to the horizontal direction (see FIG. 24).
(n) Lattice or Grid Transfer
The pattern on the sub-canvas can be repeatedly transferred onto the main canvas in a lattice or grid disposition (see FIG. 25).
With the functions i through n, it is possible to arbitrarily specify the number of repetition, color modification, expansion or reduction of the pattern size, or reversing rotation.
(o) Others
In addition to the foregoing, the following functions can be fulfilled; namely, to transfer outside information from a tape (FIG. 28) or cards (FIG. 26) to the main canvas or the sub-canvas; to monitor the information on the main canvas or the sub-canvas; and to read out the contents of the main canvas or the sub-canvas onto a paper tape (or magnetic tape) (FIG. 29) or cards as an output (see FIGS. 22 and 24).
In operation of the pattern analyzing system for performing the above functions, the following four operative modes are selectively assumed, namely, (i) design on the main canvas, (ii) design on the sub-canvas, (iii) output, and (iv) monitor.
The actual pattern designing operation using the aforesaid functions of the pattern analyzing system will now be described, with reference to two embodiments.
Embodiment 1
A composite design, as shown in FIG. 4G, was formed through the following steps by the pattern analyzing system according to the present invention, which design was basically a combination of a lattice and stripes with an oblique pattern and a modified zig-zag pattern superposed thereon.
Step 1: As fundamental information, the pattern name, the pattern number, the number of colors (four colors in this embodiment), and the number of wales and the number of courses per repeat (e.g., 32×32), were set.
Step 2: The stripes, as shown in FIG. 4A were produced on the main canvas by selecting the operative mode (i) for main canvas design and using the function (d) for stripes, while specifying the coloring and the widths for both the color 1 and the color 2.
Step 3: The two vertical lines, as shown in FIG. 4B, were produced by using the aforesaid function (c) for straight lines, while specifying the starting and ending addresses of the lines (1 and 32), together with the coloring and the widths thereof.
Step 4: The two vertical lines and the two horizontal lines, as shown in FIG. 4C, were produced by similarly using the function (c) for straight lines.
Step 5: The two horizontal lines of the color 3, as shown in FIG. 4D, were produced by similarly using the function (c) for straight lines.
Step 6: The oblique patterns of the color 2, as shown in FIG. 4E, were produced by using the aforesaid function (g) for oblique patterns. To draw the oblique patterns, the starting and the color and the width of the first oblique pattern and the spacing between adjacent oblique patterns were specified. In this embodiment, oblique patterns of the color 2 and colorless oblique patterns (with background color) were set, so as to maintain the previously produced pattern by using the colorless oblique patterns thereon.
Step 7: The modified zig-zag pattern, as shown in FIG. 4F, was produced on the sub-canvas, by selecting the operative mode (ii) for sub-canvas design while specifying its size at 6×6 and using the aforesaid function (h) for random input.
Step 8: The pattern on the sub-canvas, as shown in FIG. 4F, was transferred to the main canvas, as shown in FIG. 4G, by resuming the operative mode (i) for main canvas design and using the aforesaid function (i) for simple transfer while specifying the main canvas address to which the sub-canvas pattern was to be transferred.
Step 9: The contents, or pattern, of the main canvas was checked by selecting the operative mode (iv) for monitor and using the display or the line printer.
Step 10: The contents of the main canvas were read out by selecting the aforesaid operative mode (iii) for output, so as to produce the output information which could be stored on a paper tape or magnetic tape, or could be directly applied to a knit control system for generating a sample of knit or woven wear.
Embodiment 2
The pattern, as shown in FIG. 5A, was produced by a pattern analyzing system according to the present invention. This pattern consists of fundamental elements, as shown in FIG. 5B a and b, which are disposed at different sections of FIG. 5C after modifying the coloring and the size thereof.
Step 1: The pattern name and the pattern number were registered. The three colors for the pattern were set, and the number of wales and the number of courses were set at 140×140.
Step 2: The background color, as shown in FIG. 5D, was specified by selecting the aforesaid operative mode (i) for main canvas design and using the aforesaid function (a) for background color.
Step 3: The fundamental pattern, as shown in FIG. 5B a, was produced on the sub-canvas by selecting the aforesaid operative mode (ii) for sub-canvas design while specifying the sub-canvas size of 10 wales times 20 courses and using the aforesaid function (h) for random input or using a stored pattern (on a tape or cards). Those portions which have the same coloring as the background color were made colorless.
Step 4: The pattern, as shown in FIG. 5E, was produced on the main canvas by selecting the aforesaid operative mode (i) for main canvas design and using the aforesaid function (i) for simple transfer so as to carry out the transfers of the following table.
______________________________________ Vertical HorizontalNo. magnification magnification Remarks______________________________________1 1 1 --2 1 1 top-bottom reversed, right-left reversed, color changed3 2 2 color changed5 2 2 top-bottom reversed, right-left reversed, color changed7 4 5 --9 4 5 top-bottom reversed, right-left reversed______________________________________
Step 5: The fundamental pattern, as shown in FIG. 5B b, was produced on the sub-canvas, by selecting the aforesaid operative mode (ii) for sub-canvas design while specifying the sub-canvas size of 20 wales times 10 courses and using the aforesaid function (h) for random input or using stored pattern (on a tape or cards). Those portions which have the same coloring as the background color were made colorless.
Step 6: The pattern, as shown in FIG. 5F, was produced on the main canvas by selecting the aforesaid operative mode (i) for the main canvas design and using the aforesaid function (i) for simple transfer so as to carry out the transfers of the following table.
______________________________________ Vertical HorizontalNo. magnification magnification Remarks______________________________________4 2 2 top-bottom reversed, right-left reversed6 2 2 --8 4 5 top-bottom reversed, right-left reversed, color changed10 4 5 color changed______________________________________
Step 7: The contents of the main canvas were monitored for the purpose of checking.
Step 8: The contents of the main canvas were read out as the output information, which could be stored on a tape or cards, or could be directly applied to a knit control system.
FIG. 6 illustrates a paper tape format which is punched for storing the output from the pattern analyzing system. For instance, a paper tape with six units or eight units can be used. When the information for each of the picture elements of FIG. 1B are punched on the paper tape in one row, if the information 00, 01, 10, and 11 are stored by punching the first, second, third and fourth holes of the paper tape, respectively, then each row of the paper tape always has one hole punched, so that erroneous reading of the information on the paper tape can be easily checked. Furthermore, since the information for any of the four colors can be coded in two bits, it is possible to store information relating to a plurality of picture elements in one row of the paper tape. In the format of FIG. 6, the portion M at the beginning of the tape is punched in such a way that it carries reference such as the pattern name and the pattern number. The next portions of the paper tape are punched so as to successively carry a start mark S, a first course information C1, a course end mark CE, a second course information C2, and so on. At the end of the pattern information, end mark E is punched.
Next, an example of the major actual hardware needed to realize the system in FIG. 3 by using an HIDIC-500 computer system, is listed below:
A Magnetic Drum (2, 2a): H-7541-2
A Paper Tape Reader (5): H-7014
A Character Display (5): H-7833-4
A Paper Tape Puncher (4): H-7856
A Line Printer (3): H-7031
These devices are manufactured by HITACHI, Ltd. in Japan.
FIG. 7 shows a general flow chart of software for effecting the aforesaid operative steps by a computer. Since the flow chart can be easily understood by those skilled in the art, its detailed explanation will not be made here. However, a fuller explanation of formation of the main and sub-canvas will now be given.
MAIN CANVAS FORMATION
In FIG. 9, the block "SET FLAG OF MAIN CANVAS MODE (MSFLG)", corresponds to the block "MAIN CANVAS FORMATION" in FIG. 7A. This "FLAG" indicates that the pattern generation has to be performed on the main canvas. Desired patterns are stored in the main canvas.
SUB-CANVAS FORMATION
The SUB-CANVAS MODE FORMATION in FIG. 7 is shown in FIG. 9 beginning with the block "SET FLAG OF SUB-CANVAS MODE". This "FLAG" indicates that the pattern generation has to be performed on the sub-canvas, based on the desired pattern. The size of the pattern is defined by SPCN (sub-canvas pattern course number)×SPWN (sub-canvas pattern wale number).
FIG. 8 is a more detailed, breakdown of the block in FIG. 7 "ADMINISTRATIVE PROGRAM STEP 1 PATTERN DEFINITION". Specified addresses are allotted, in advance, to respective parameters, such as color code, canvas size and so on, in the core memory (not shown). Accordingly, each of the parameters can be directly accessed by programs. For example,
PWN←Address 200
PCN←Address 201
SPWN←Address 202
SPCN←Address 203
FIGS. 9 and 10 are more detailed breakdowns of the block in FIG. 7 "ADMINISTRATIVE PROGRAM STEP 2 MODE SELECTION".
CODE OF COLOR REMOVEMENT
To better understand FIG. 9, reference is made to FIG. 37. In FIG. 37, the ground pattern is created in the main canvas MC. The ground pattern is composed of color 4 and color 2 . Then, the basic pattern BP' in the sub-canvas SC, is transferred to the main canvas MC. The pattern BP' is composed of color 3 and color 1 . If there is no code of color removement, the pattern BP'1 is obtained. If there is a code of color removement, which code specifies, for example color 3 , the pattern BP'2 is obtained.
FIG. 11 is a more detailed breakdown of the block of FIG. 7 "ADMINISTRATIVE PROGRAM STEP 3 PATTERN FORMING FUNCTION SELECTION".
FIG. 12 is a more detailed breakdown of the same block in FIG. 7 but directed to the "PATTERN FORMING FUNCTION SELECTION" part.
FIG. 13 is a more detailed breakdown of the block in FIG. 7 "BACKGROUND COLOR INPUT".
FIG. 14 is a more detailed breakdown of the block in FIG. 7 "POINT INPUT".
FIG. 15 is a more detailed breakdown of the block in FIG. 7 "STRAIGHT LINE INPUT".
FIG. 16 is a more detailed breakdown of the block in FIG. 7 "STRIPE PATTERN INPUT".
FIG. 17 is a more detailed breakdown of the block in FIG. 7 "CHECK PATTERN INPUT". In this figure the instruction shown as "CALCULATE SCANNING PARAMETERS OF CANVAS IN ORDER TO WRITE CHECK PATTERN" is now explained.
A check pattern to be displayed on the monitor is composed of a desired basic pattern BP such as shown in FIG. 33. The basic pattern BP is made of four colors, 1 through 4 . Of course C 1 , color 1 is indicated by W 1 wale, color 2 has W 2 wale. Similarly, on course C 2 , color 3 has W 1 wale, color 4 has W 2 wale. The numbers of (W 1 +W 2 ) to be repeated along both the course direction and wale direction are calculated in advance for the purpose of creating the check pattern shown in FIG. 34. These numbers are scanning parameters. Pattern generation is performed by using the scanning parameters.
In FIG. 17, the instruction "WRITE ONE COURSE OF CHECK PATTERN INTO BUFFER AREA IN ACCORDANCE WITH SCANNING PARAMETERS OF CANVAS" may be explained with reference to FIG. 35. In FIG. 35, color 1 has W 1 wale and color 2 has W 2 wale. The (W 1 +W 2 ) wales comprise one basic pattern. One course C 1 of the check pattern is written in the buffer area in accordance with the scanning parameter, that is PWN/W 1 +W 2 (PWN=pattern wale number).
When the basic pattern (1 and 2 ) is repeated (PWN/W 1 +W 2 ) times along one course, a part of the desired check pattern is created as seen in FIG. 35.
FIG. 18 is a more detailed breakdown of the block in FIG. 7 "BORDER PATTERN INPUT".
FIG. 19 is a more detailed breakdown of the block in FIG. 7 "OBLIQUE PATTERN INPUT".
FIG. 20 is a more detailed breakdown of the block in FIG. 7 "SIMPLE TRANSFER".
FIG. 21 is a more detailed breakdown of the block in FIG. 7 "HORIZONTAL TRANSFER".
FIG. 22 is a more detailed breakdown of the block in FIG. 7 "VERTICAL TRANSFER".
In FIGS. 21 and 22 the instruction "SUPERPOSE OF SUB-CANVAS ONTO REFERENCE COORDINATES OR TRANSFER ON PATTERN MONITOR BY CONVERTING DATA IN ACCORDANCE WITH FIRST (OR SECOND) TRANSFER CONDITION" may be understood by reference to FIG. 36. In FIG. 36, the reference 5 is a basic pattern on the sub-canvas SC. Many basic patterns 5 are arranged in the main canvas MC along the reference (W 1 , C 1 ) of transfer. In the main canvas MC, the patterns referenced by the numeral 5 1 are arranged according to the first transfer condition, and the patterns referenced by the numeral 5 2 are arranged according to the second transfer condition, when the transfers are carried out under the top-bottom reverse mode. These transfers are also carried out under the right-left reverse mode or the color removement-non removement mode.
FIG. 23 is a more detailed breakdown of the block in FIG. 7 "RIGHT UPWARD TRANSFER".
FIG. 24 is a more detailed breakdown of the block in FIG. 7 "LEFT UPWARD TRANSFER".
FIG. 25 is a more detailed breakdown of the block in FIG. 7 "GRID TRANSFER".
FIG. 26 is a more detailed breakdown of the block in FIG. 7 "CARD INPUT".
FIG. 27 is a more detailed breakdown of the block in FIG. 7 "RANDOM INPUT".
FIG. 28 is a more detailed breakdown of the block in FIG. 7 "TAPE INPUT".
FIG. 29 is a more detailed breakdown of the block in FIG. 7 "TAPE OUTPUT".
FIGS. 30, 31, and 32 are more detailed breakdowns of the block in FIG. 7 "CONTROL PREPARING PROGRAM".
As is apparent from the foregoing detailed explanation of the present invention with reference to the preferred embodiments, the present invention enables the formation of a pattern by suitable processing digital information without drawing it on a sheet of paper. With the pattern analyzing system according to the present invention, it is also possible to produce a knit pattern, by using the aforesaid digitally produced pattern or by suitably processing information representing a design drawn on a sheet of paper.
In FIGS. 20B through 25C, there are a number of blocks which include the instruction "SUPERPOSE SUB CANVAS ONTO REFERENCE COORDINATES OF TRANSFER IN PATTERN MONITOR BY CONVERTING DATA ACCORDING TO FIRST (OR SECOND) TRANSFER CONDITION". This instruction can be broken down into the following subroutine:
Step A:
WRITE DATA TO BE TRANSFERRED FROM SUB-CANVAS IN COURSE BUFFER AREA FOR SUB-CANVAS IN ACCORDANCE WITH TOP-BOTTOM REVERSED CONDITION
Step B:
WRITE DATA TO BE TRANSFERRED FROM MAIN CANVAS IN COURSE BUFFER AREA FOR MAIN CANVAS
Step C:
DETERMINE DIRECTION ALONG WHICH DATA OF COURSE BUFFER AREA FOR SUB-CANVAS ARE READ OUT DOT BY DOT, IN ACCORDANCE WITH DISCRIMINATION OF LEFT-RIGHT REVERSE CONDITION
Step D:
TRANSER DATA OF COURSE BUFFER FOR SUB-CANVAS TO COURSE BUFFER FOR MAIN CANVAS DOT BY DOT, IN ACCORDANCE WITH COLOR CHANGE CONDITION
Step E:
DOES OPERATION FOR PROCESSING DATA OF DOTS STORED IN COURSE BUFFER FOR SUB-CANVAS FINISH?
1. If "YES", go on to Step F.
2. If "NO", go back and perform Step D, etc. again.
STEP F:
DOES OPERATION FOR PROCESSING ALL DATA OF SUB-CANVAS FINISH?
1. If "YES", go on to Step G.
2. If "NO", go back and repeat STEPS A-F.
STEP G:
TRANSFER DATA OF COURSE BUFFER FOR MAIN CANVAS TO MAIN CANVAS AND TRANSFER DATA OF MAIN CANVAS TO PATTERN MONITOR
and proceed therefrom to the next program steps, as the case may be, to Step 5.
Regarding the above block A, the course buffer area for sub-canvas is a buffer area which stores all the data concerning each course sequentially supplied from the sub-canvas. The sequence for reading out data, from the sub-canvas, of each course, that is from the top of the course to the bottom thereof or from the bottom thereof to the top thereof, is determined in accordance with the top-bottom reverse condition. Thus, the data of each one of the courses is written into the buffer area along the steps defined by the above recited blocks A through E. When the data process-operation for all the courses finishes, the result of above block F becomes "YES". Regarding the above recited block B, the course buffer area for the main canvas is a buffer area which has a capacity for accommodating all the data stored in the sub-canvas and also has a capacity for accommodating the data of each one course of the main canvas.
The program list for setting up the above block D, which is realized through the assembler language for said HIDIC-500 computer, is shown below. This program concerns the program routine for transferring the color information from the main-canvas to the sub-canvas and changing the colour.
______________________________________ Oper- In-Label ation dex Address Comments______________________________________ LD L1 SCORS A dot of pattern information is loaded in ACC from the course buffer in the sub-canvas. CMP L N2 The color of the pattern infor- mation is tested; N2 means a code of the color number 2. NDX TRA05 If the color is color number 3 or 4, the step jumps to TRA05. MDX TRA04 If the color is color number 1, jump to TRA04. LD CHCL2 If the color is color number 2, MDX TRA07 a desired new color code is loaded into ACC, and jump to TRA07.TRA04 LD CHCL1 A desired new color code for MDX TRA07 the color number 1 is loaded into ACC, and jump to TRA07.TRA05 CMP L N3 Test if the color is color number 3. MDX TRA06 If the color is number 4, jump to TRA06. MDX * If the color is number 3, execute the next instruction. LD CHCL3 A new color code number 3 is MDX TRA07 loaded into ACC, and jump to TRA07.TRA06 LD CHCL4 A new color code number 4 is loaded into ACC.TRA07 STO DOTCL A new color code is stored.TRA08 LD L 2 If the coordinates of the BSC L TRA09, main-canvas are negative, +Z jump to next step. LD DOTCL A new color code is loaded into ACC. BSC L TRA09, If the code is colorless ← code, jump to next step. STO L2 MCORS A new color code is stored in the course buffer of the main canvas______________________________________ Note: The index register 1 holds the address of the course buffer in the subcanvas. The index register 2 holds the address of the course buffer in the maincanvas.
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A computerized pattern generating system for producing a knit or a woven pattern has been found. Any desired pattern can be obtained without drafting a picture. The system has at least a digital memory and an arithmetic unit. On the digital memory, each color of a knit pattern corresponds to binary digital 00, 01, 10 or 11. Said digital information is automatically created by using the arithmetic unit, and is further modified according to the desired pattern. The pattern on the digital memory is applied to a fabric-making machine through a punched paper tape, a direct communication line, or any magnetic storage means.
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FIELD OF THE INVENTION
[0001] The invention relates to a barrier movement or garage door operator, in particular, to a jack shaft operator having a coupling for connecting a power shaft to a jack shaft for operating the barrier or garage door.
BACKGROUND OF THE INVENTION
[0002] In general terms, a barrier such as a garage door is installed on a pair of rails having generally vertical portions positioned proximate the sides of a garage opening and having generally horizontal portions extending away from the opening into the interior of the garage. The garage door is moved along the rails to shift between a generally closed position within the garage opening and between the vertical rail portions, and a generally open position away from the garage opening and between the horizontal rail portions. A garage door operator is used to drive the movement of the garage door between the open and closed positions.
[0003] Currently, jack shaft garage door operators are well-known for driving the movement of a garage door. The door operator includes a generally vertically extending cable having a first end secured to a lower portion or panel of the garage door. The door operator exerts tension on the cable to lift and shift the garage door from the closed position to the open position. The cable has a second end connected to a pulley. In order to exert tension on the cable, the door operator rotationally drives the pulley so that the cable is wound around the pulley, thereby shortening the distance between the pulley and the cable first end, as well as between the pulley and the lower portion of the garage door being raised.
[0004] The pulley is located on and secured with a jack shaft extending parallel to the garage opening. As the cable is attached to a lower portion of the door and within the rails, the pulley and jack shaft are positioned so that movement of the door does not interfere with operation of the pulley. The jack shaft is typically a torsion bar which can include either a coil spring or extension springs to provide a spring bias to the pulley tending to draw the garage door toward the open position. However, the bias is insufficient to overcome the weight of the door without additional power being provided to the pulley.
[0005] The additional power for overcoming the door weight to open the garage door is provided to the pulley by a drive system, typically an electric motor driving an output power shaft extending from a housing of the drive system. The power shaft and pulley are operably coupled with a transmission system which may include a belt or drive chain for driving sprockets respectively fixed on the power shaft and jack shaft or its pulley.
[0006] The drive system is mounted to a wall in a position outside of the opening and rails. The power shaft extends from the housing a short distance toward a first rail with its sprocket located on and end thereof. The drive chain extends vertically, either upwardly or downwardly, between the power shaft sprocket and the jack shaft sprocket. Accordingly, the jack shaft must extend beyond at least one of the rails, and the sprockets are aligned to rotate generally in the same plane.
[0007] Such an arrangement presents a number of issues. Because of the transmission including the sprockets and chain, the system has particular space requirements for installation. A certain precision must be provided in aligning the sprockets to generally rotate in the same plane, and a certain amount of precision must be provided in mounting the drive system to provide the chain with the proper amount of tension between the sprockets.
[0008] Additionally, the sprockets have an annular hub or collar, and securing the sprocket hub to their respective shaft presents further problems. One approach for securing the hub is with set screws which are known to loosen over time, allowing the sprocket to slip. Set screws can also compress a hollow shaft or bar, leading to stress concentrations and failure of the system including twisting or deflection of the shaft.
[0009] Another manner for securing the sprocket to a shaft is with some type of keyed mating such as drilling a hole through the hub and its shaft, and inserting a pin therein. This method is labor intensive, incurring additional costs in machining and milling the surfaces, and stress concentrators may be produced which may lead to damage and failure. Additionally, such mating reduces the flexibility in mounting the components of the system, such as the drive system, as the sprockets are to be aligned to rotate in the same plane.
[0010] Some of the problems with securing the sprockets may be overcome by using a solid shaft. However, a solid shaft significantly increases the cost of the component, as well as significantly increases the weight such that an increase in the operational torque of the motor is needed.
[0011] Accordingly, there has been a need for an improved jack shaft door operator.
SUMMARY
[0012] A jack shaft barrier movement or garage door operator is disclosed herein for opening and closing a movable barrier or garage door. The garage door operator includes an electric motor for rotationally driving a power shaft operably connected to a jack shaft having a pulley thereon. The pulley has a cable secured thereto such that rotation of the jack shaft rotates the pulley and causes the cable to be wound around the pulley. An end of the cable is secured to a lower portion or panel of the garage door so that winding of the cable around the pulley draws the lower portion of the garage door towards the pulley, thereby lifting the door and moving the door along its track or rails from a closed position to an open position.
[0013] The jack shaft and the power shaft are connected by a compression coupling. In this manner, the jack shaft and power shaft are fixed relative to each other. Each shaft has a coupling end that is inserted into a portion of the coupling and is compressed therein. This eliminates the need for the sprocket system and its above-described problems. For instance, the coupling is compressed in a radially inward manner against a entire circumference of the shaft, avoiding the issues of the set screws or keyed mating. The coupling is removable and may be placed on either end of the shaft, facilitating different mounting conditions and not requiring a pre-drilled hole in the shaft for pinning a sprocket thereon. Elimination of the belt or chain drive eliminates tensioning issues with the chain drive, and allows the drive system to be installed by simply aligning the shafts relative to each other. Alignment of the shafts is achieved easily by securing the shafts in the coupling. As the sprockets are not necessary, alignment of the sprockets for co-planar rotation is not necessary.
[0014] The drive system can be placed in a number of positions by securing the shafts directly with the coupling. For instance, when lateral clearance outside of the rails is minimal, the jack shaft can be shortened and the drive system can be located above the door opening without needing to be offset a distance to provide for the sprocket and chain transmission system. In addition, the space requires for the operator are reduced as the drive system can be mounted at the end of the jack shaft and close to the rail.
[0015] In one form, the coupling is a double split-ring, one split-ring for each of the shafts to be connected by the coupling. Both rings are joined to form a base portion and have respective compressive portions. In one form, the rings have different internal diameters sized generally for respective shafts having different external diameters, such as the jack shaft and output power shaft. Accordingly, a shoulder is formed between the rings. In some forms, the larger of the shafts may be inserted in the larger internal diameter ring of the coupling to a depth to contact the shoulder and be secured therein. The other shaft is then inserted in the other ring to an appropriate depth and secured therein. In the event the larger shaft is hollow, the smaller shaft may be received by both the coupling and the larger shaft.
[0016] In some forms, the coupling is a unitary member having a base and a pair of deflectable portions in the form of arms extending from the base. One end of each arm is secured to the coupling base, and the other end is generally free prior to installation. To couple the shafts, the free ends of the arms are secured relative to the base. A shaft is inserted within the base and an arm, and the arm free end is drawn toward the base such that an interior surface of the base and arm compress radially inwardly on the outer, circumferential surface of the shaft.
[0017] In other forms, the coupling has a partial-circular base and two partial-circular arms, each having two free ends that are securable to the base to form a complete circle. Each shaft may be positioned between an arms and the base, and the arm is then secured to the base to compress the circumference of the shaft.
[0018] The coupling generally defines an internal cavity for receiving the ends of the jack shaft and output power shaft such that the coupling provides an overlapping connection with of the shafts. Each shaft may have a predetermined outer diameter, and the internal cavity may have a predetermined inner diameter generally sized with respect to the diameters of the shafts. Once the shafts are received therein, at least a portion of the coupling is compressed against the shaft. In one form, the coupling includes compressing portions that are deflected toward a base to compress the shafts therebetween are moved toward a base to reduce size of the internal cavity. In another form, the coupling includes compressing portions that are moved toward a base to compress the shafts therebetween.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In the drawings, FIG. 1 is fragmentary perspective view of a garage having a garage door in a closed position with a jack shaft garage door operator attached to the garage door for moving the door between the closed position and an open position, the door operator including a drive system and an output shaft connected to a jack shaft by a coupling;
[0020] FIG. 2 is a first fragmentary perspective view of the coupling connected to the jack shaft and to the output shaft, and the door operator having a housing partially cut-away to show the output shaft;
[0021] FIG. 3 is a prior art perspective view of a door operator having an output shaft operably connected to a shaft by a sprocket and chain or belt drive transmission;
[0022] FIG. 4 is a second fragmentary perspective view of the door operator showing the coupling secured on the jack shaft;
[0023] FIG. 5 is a third fragmentary perspective view showing the coupling secured on the jack shaft, the door operator housing and output shaft in phantom, and the jack shaft extending through a hollow center of the output shaft;
[0024] FIG. 6 is a first perspective view of a form of the coupling showing a base portion and a pair of deflectable portions;
[0025] FIG. 7 is a second perspective view of the coupling of FIG. 5 showing clamping bores;
[0026] FIG. 8 is a first side elevational view of the coupling of FIG. 5 showing internal diameters of the coupling;
[0027] FIG. 9 is a second side elevational view of the coupling of FIG. 5 showing a gap between a free end of the deflectable portions and the base; and
[0028] FIG. 10 is a second form of a coupling showing a base and a pair of compression portions securable to the base.
DESCRIPTION
[0029] Referring initially to FIG. 1 , a garage door operator 20 having a shaft coupling 30 embodying aspects of the present invention is depicted. The door operator 20 is secured to an interior wall 3 of a garage 1 proximate a garage opening 2 . The garage opening 2 is covered by a garage door 4 , depicted in a closed position. The door operator 20 functions to move the garage door 4 from the closed position to an open position to allow passage through the garage opening 2 . The garage door 4 is represented as having four panels 5 connected by hinges 6 , and has wheels (not shown) secured to the lateral sides 5 a , 5 b of the panels 5 . The wheels are located within rails 7 a , 7 b having a generally vertical sections 8 secured to the wall 3 and to a garage floor 11 , and having generally horizontal sections 9 secured to a ceiling 12 . When the garage door 4 is moved to the open position, the panels 5 are guided along the rails 7 a , 7 b by the wheels. The rails 7 a , 7 b further have curved transition portions 10 , and the panels 5 pivot relative to each around the hinges 6 to allow the panels 5 to move between the vertical and horizontal sections 8 , 9 .
[0030] The door operator 20 includes a jack shaft 22 positioned above the opening 2 and a drive system 24 positioned lateral to the opening 2 . The drive system 24 includes an output power shaft 26 connected to the jack shaft 22 by the coupling 30 . Thus, when the power shaft 26 is rotated, such as by an electric motor 28 (see FIG. 3 ), the jack shaft 22 is directly rotated to raise the garage door 4 , as will be discussed below.
[0031] As can be seen in FIGS. 2 and 5 , the drive system 24 includes a housing 40 secured to the wall 3 , such as by a bracket 42 ( FIG. 1 ). The drive system 24 includes the electric motor 28 providing a sufficient torque for moving the garage door 4 . As depicted, the motor 28 is operably connected to the power shaft 26 with a belt or chain 46 to a sprocket 48 or the like secured to the power shaft 26 . As is known in the art, the electric motor 28 has a rotor (not shown) rotationally driving a motor axle (not shown) having an output sprocket or pulley (not shown). It should be noted that the motor 28 alternatively may be alternatively a direct drive motor with the power shaft 26 being the motor axle, or the motor 28 may be connected to the power shaft 26 via another transmission system, such as a geared transmission. A desired gear ratio for providing a desired speed and torque from the motor to the power shaft can be produced by proper selection of the size of the sprocket 48 relative to the output sprocket, or by a geared transmission, for instance.
[0032] As shown in FIGS. 1,2 and 5 , the jack shaft 22 and the power shaft 26 are co-axially aligned. More specifically, the coupling 30 receives an end of each of the power shaft 26 and jack shaft 22 to secure the shafts 22 , 26 together in the co-axial arrangement. In this manner, rotation of the power shaft 26 causes equal rotation of the jack shaft 22 , as will be described below.
[0033] In contrast, a prior art operator 50 is shown in FIG. 3 without the coupling 30 . The prior art operator 50 includes a jack shaft 52 , and a drive system 54 for rotating the jack shaft 52 to move the garage door 4 . The operator 50 includes a housing 56 and an electric motor 58 coupled to a power shaft 60 , with or without a chain drive (not shown) within the housing 56 . The power shaft 60 extends from the housing 56 towards the garage opening 2 and includes a sprocket 62 secured thereto. The sprocket 62 drives a chain or belt 64 connected to a sprocket 66 located on the jack shaft 52 . As can be seen, the position of the prior art operator 50 is offset from the jack shaft 52 , requires an increased number of components than the door operator 20 of the present invention, requires alignment of the sprockets 62 , 66 to rotate in a common plane, requires tensioning of the chain 64 , and requires securing the sprockets 62 , 66 to their respective shafts 52 , 60 . The operator 20 of the present invention each of these problems is reduced or eliminated by use of the coupling 30 .
[0034] Referring to FIGS. 2 and 4 , the operator 20 is provided with a pulley 70 and cable 72 to raise or lower the garage door 4 . The pulley 70 is attached to the jack shaft 22 , as can be seen in FIG. 4 , while the cable 72 has a lower end 74 connected at a lower portion 76 of the garage door 4 , such as the bottom panel 5 c. The cable 72 has a portion wound around the pulley 70 and secured thereto. When the jack shaft 22 is rotated, the pulley 70 is also rotated so that the cable 72 is either payed-out from or wound-up on the pulley 70 . That is, when the pulley 70 rotates in a first direction, the cable 72 is wound around the pulley 70 so that the distance from the pulley 70 to the cable lower end 74 is shortened and the door lower portion 76 is drawn toward the pulley 70 . When the pulley 70 is rotated in a second direction opposite from the first, the cable 72 is payed-out from the pulley 72 so that the door 4 is lowered.
[0035] The pulley 70 is positioned close to a support bracket 80 secured to a rail frame 82 , itself secured with the rail 7 a . The support bracket 80 includes a bearing 84 for allowing rotation of the jack shaft 22 within the support bracket 80 . The bracket 80 , frame 82 , and bearing 82 provided support for the jack shaft 22 . With reference to FIG. 1 , a support bracket 80 is provided at preferably both ends of the jack shaft 22 and secured to each rail 7 a , 7 b . The pulley 70 is preferably proximate the support bracket 80 to reduce the moment arm or torque exerted by the tension on the cable during operation. In the prior art operator 50 ( FIG. 3 ), deflection of the jack shaft 22 due to tension on the cable 72 may cause the sprocket 66 to deflect out of its proper plane of rotation, resulting in excessive wear against the chain 64 and possibly cause the chain 64 to jump from the sprocket 66 .
[0036] By eliminating the sprockets 62 , 66 of the prior art operator 50 , any deflection experienced is transmitted directly through to the power shaft 26 where it has minimal effect. The power shaft 26 is relatively short and is secured within the housing 40 by a pair of bearings 90 positioned at each end 92 of the power shaft 26 . In this manner, the power shaft 26 is constrained from shifting or deflecting, thereby serving to constrain the jack shaft 22 from deflection. Significant stresses exerted on the power shaft 26 would, regardless, be transmitted to the wall 3 by the bracket 42 .
[0037] With specific reference to FIG. 5 , the power shaft 26 and housing 40 are shown in phantom. In some forms, one of the shafts 22 , 26 and preferably the power shaft 26 may be hollow to provide a cavity 96 therein. The jack shaft 22 may be inserted through the coupling 30 and further into the cavity 96 . This serves to further join the jack shaft 22 and power shaft 26 for rotation and relative securement, as well as reducing effects of deflection. Additionally, this facilitates different mounting conditions by reducing the need for precisely measured shafts and allows the drive system 24 to be mounted close to the rail 7 a .
[0038] Turning now to FIGS. 6-9 , a form of the coupling 30 for securing the power shaft 26 with the jack shaft 22 is depicted. Generally speaking, the coupling 30 is a split ring having a gap 100 so that the shafts 26 , 22 may be received within the coupling 30 , whereupon the coupling 30 is compressed to reduce or eliminate the gap 100 . This compression applies radial compressive force around an entire circumference of each shaft 22 , 26 located therein. The above-described problems with using set screws and keyed mating are thus eliminated, and the coupling 30 is suitable for use with both solid and hollow shafts without distorting or damaging the shaft and without creating stress concentrations.
[0039] More specifically, the coupling 30 is formed as a double split-ring where the rings are joined together for a base portion 102 . The coupling 30 generally forms a C-shape and with base portion 102 generally formed as a half C-shape. A pair of generally parallel compressing portions or arms 104 a , 104 b are formed integrally with the base 102 and complete the C-shape having the gap 100 . Each arm 104 a , 104 b has a respective width 106 a , 106 b , and the widths may be identical or one may be larger. As shown, arm 104 a has a smaller width 106 a than the width 106 b of the other arm 104 b.
[0040] The coupling 30 has an internal diameter 108 for receiving the shafts 22 , 26 therein. In the preferred embodiment, the coupling 30 has separate internal diameteral portions 108 a , 108 b generally sized for the power shaft 22 and jack shaft 26 , respectively. As can be seen, the diametral portion 108 a is larger than the diametral portion 108 b so that the power shaft 22 may have a larger diameter than the jack shaft 26 . The power shaft 22 , in the form including the cavity 96 , may receive the smaller jack shaft 26 within the cavity 96 , and thus requires the larger diametral portion 108 a within the coupling 30 . Alternatively, the shafts 22 , 26 may simply having different diametral sizes, in which case a coupling designed to compress the shafts 22 , 26 in a generally distributed manner around the shaft circumferences is desirable. A shoulder 110 is formed between the larger and smaller diametral portions 108 a , 108 b . During installation, the larger of the shafts 22 , 26 may be inserted into the coupling 30 while using the shoulder 110 as a stop. The larger shaft may then be secured, and the other shaft then inserted and secured. Thus, the coupling 30 provides an overlapping connection to the ends of each shaft 22 , 26
[0041] In order to secure the coupling 30 , holes are provided for insertion of fasteners 124 (see FIG. 4 ). The arms 104 a , 104 b are each provided with a hole 120 , and the base 102 is provided with a two holes 122 , each aligned with one of the respective holes 120 of the arms 104 a , 104 b . In the preferred embodiment, the fasteners 124 are threaded bolts. Either the holes 120 or holes 122 is an insertion hole having a larger diameter than the other holes and larger than the thread profile of the fasteners 124 so that the fastener 124 simply passes through the insertion hole. The other of the holes 122 , 120 is preferably threaded to receive the fastener therein in threaded engagement. To secure the coupling 30 on the shafts 22 , 26 , the fasteners 124 are received by the insertion hole, either hole 120 or 122 , and threads into the hole aligned with the insertion hole. As the fasteners 124 thread in, the arms 104 a , 104 b are compressed inwardly to compress on the shaft 22 , 26 , and to reduce the gap 100 between the arms 104 a , 104 b and the base 102 .
[0042] A second form of the coupling is depicted as coupling 130 in FIG. 10 . The coupling 130 is similar to the coupling 30 in operation. However, the coupling 130 has a base 132 , generally a half C-shape, and two arms 134 a , 134 b , similar to arms 104 a , 104 b , that are not integrally formed with the base 132 . Instead, the arms 134 a , 134 b are secured to the base 132 at both ends 135 , 137 of each arm 134 . Accordingly, the base 132 is provided with holes 140 , the arms 134 are provided with holes 142 which are aligned with the holes 140 , and the above-described fasteners 124 are received by the holes 140 , 142 to secure the arms 134 to the base 132 to compress the shafts 22 , 26 within the coupling 130 .
[0043] While the invention has been described with respect to specific examples including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described systems and techniques that fall within the spirit and scope of the invention as set forth in the appended claims.
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A barrier movement or garage door operator has a jack shaft connected to an output shaft delivering power to move a barrier or garage door between open and closed positions, the jack shaft and output shaft being connected by a coupling. The coupling, jack shaft, and output shaft are fixed relative to each other. The coupling connects the jack shaft and output shaft for rotation around a common axis. The coupling receives a portion of the jack shaft and output shaft for securing the shafts within the coupling by compressing against an outer surface of each shaft. The shafts may be cylindrical, and the compressive force may be distributed around the cylindrical outer surface of the shafts. The coupling may have a portion sized to correspond to respective predetermined diameters or sizes of the shafts.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an apparatus for measuring a flow velocity of fluid by detecting a time interval of vortexes being generated at the downstream side of a member for generating vortexes (hereinafter referred to "vortex-generating member") placed in a flow of the fluid.
2. Description of the Prior Art
In flow velocity measuring apparatuses of such type as mentioned above, a thermistor has usually been employed as a means for detecting Karman's vortex street or Strouhl vortexes being produced on the downstream side of a vortex-generating member used. To the thermistor utilized as such member for detecting vortexes, constant current is always supplied in order to maintain a temperature thereof to a prescribed constant value. From the thermistor, variation in value of resistance at the time when the thermistor is cooled by means of contact with vortexes is taken out as a detection signal. Since vortexes are produced with such a time interval being in a prescribed functional relationship with respect to the flow velocity of fluid, when frequency of the detection signal taken out of the thermistor is measured, the flow velocity of the fluid can be determined. In a conventional flow velocity measuring apparatus, such detection signal is converted into DC voltage signal by a frequency-voltage converting means, and a thermistor is subjected to feedback controlling in response to the resulting DC voltage. Accordingly, response speed of detection output of the thermistor is restricted by response speed of the frequency-voltage converting circuit, i.e., time constant thereof. Furthermore, such feedback controlling requires correction of detection signal within a considerably wide area of a range of flow velocity being measurable so that the feedback circuit becomes complicated.
Temperature-resistance converting elements other than thermistor may be utilized in such flow velocity measuring apparatuses as mentioned above. However, even though any type of detection element is used, the required condition for avoiding disappearance of detection signal due to vortexes is such that a temperature of the detection element or time constant of variation in the current flowing through the detection element differs from time constant of variation in temperature on the basis of cooling by means of vortexes. However, in the case where a time constant in the feedback circuit is lengthy, the detection output is disordered at sudden change of flow velocity, and further an excess current flows temporarily through the detection element, resulting in danger of damage of the detection element due to overheating thereof.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a flow velocity measuring apparatus which comprises a bridge circuit formed by utilizing a temperature-resistance converting element as a side of the bridge circuit, and an amplifier circuit for amplifying output of the bridge circuit, the temperature-resistance converting element being placed at the downstream side of a vortex-generating member disposed in a flow path of fluid to be measured, an output of the amplifier circuit being used as such output signal having a frequency corresponding to flow velocity of the fluid to be measured, and at the same time, such current to be fed back to the bridge circuit being adapted to be used in such a way that the current is controlled in order to maintain the temperature-resistance converting element at a prescribed temperature. The temperature-resistance converting element is maintained at a low preset temperature which has previously been determined in such a condition where flow velocity of the fluid to be measured is relatively low, but when the flow velocity reaches a value higher than a prescribed one, the temperature-resistance converting element is maintained at a higher preset temperature which has also previously been set, whereby the flow velocity can accurately be measured with high sensitivity in respect of a wide range of flow velocity.
It is an object of the present invention to provide a flow velocity measuring apparatus by which flow velocity can accurately be measured extending over a wide range thereof.
Another object of the present invention is to prolong a service life of a temperature-resistance converting element being in contact with fluid to be measured.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 (a) is a planar view showing an arrangement of a vortex-generating member and two heater wires utilized in a flow velocity measuring apparatus according to an embodiment of the present invention;
FIG. 1 (b) is a perspective view of those shown in FIG. 1 (a);
FIG. 2 is a circuit diagram of the flow velocity measuring apparatus in FIGS. 1 (a) and 1 (b); and
FIG. 3 is a graphical representation indicating change due to flow velocity in characteristics with sensitivity of frequency signal in the circuit of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Next, the explanation will be made hereinbelow by referring to the accompanying drawings. In FIG. 1 (a), reference numeral 1 designates a conduit through the inside of which fluid to be measured flows in the direction indicated by arrow A, and a vortex-generating member 2 consisting of a trigonal prism 2a as well as three plates 2b, 2c and 2d are disposed in the conduit 1. The trigonal prism 2a and the plates 2b, 2c and 2d are arranged in this order from the upstream side to the downstream side of flow of the fluid with a prescribed spacing from one another so that the vortex-generating member 2 generates regular Karman's vortexes on the downstream side of the plate 2d positioned at the most downstream side in the aforesaid plates. Two pairs of supports 3 extending towards the downstream side of flow of the fluid are fitted at both sides of the plate 2d, respectively, as shown in FIG. 1 (b), and heater wires 4 and 5 are stretched between each pair of the supports, respectively. Each of the heater wires 4 and 5 is periodically cooled by means of Karman's vortex street being produced around the heater wires 4 and 5, respectively.
The vortex-generating member shown in FIGS. 1 and 2 is the one having a construction which has already been well known as a member for generating Karman's vortexes. In the present invention, any type of vortex-generating member which has heretofore been utilized for generating Karman's vortexes may be used; besides such a vortex-generating member for generating Strouhl vortexes may also be applied to the apparatus of the present invention as in customary flow velocity measuring apparatuses.
FIG. 2 is a circuit diagram illustrating electrical connection in the flow velocity measuring apparatus according to the present invention in which each one end of the heater wires 4 and 5 is grounded, whilst another end of the heater wire 4 is connected with an inverting input terminal of an operational amplifier 21 and at the same time, the same end is connected to the emitter of a transistor 39 through a resistance 23. A contact point P 1 of this emitter with the resistance 23 is grounded through a series circuit being composed of resistances 25-27, whilst a thermistor 31 is connected in parallel to the resistance 25.
A contact point of the resistance 26 with the resistance 27 is connected to a non-inverting input terminal of the operational amplifier 21, besides this non-inverting input end is grounded through a resistance 61 and a diode 62, and at the same time the same end is connected with an output end of an operational amplifier 78 through a series circuit consisting of a diode 76 and a resistance 67.
A bridge circuit is constructed by means of the aforesaid heater wire 4, the resistance 23, the resistances 25-27, and the thermistor 31. A feedback circuit which comprises the operational amplifier 21 and the transistor 39 as its principal constituents operates together with the bridge circuit so as to control the heater wire 4 in such a manner that the heater wire 4 is maintained at a constant temperature.
An output end of the operational amplifier 21 is connected to the base of the transistor 39 through a resistance 35, and the same end is grounded through a resistance 36. In the circuit, it is constructed in such a way that voltage Vcc is applied to the collector of the transistor 39, whilst output V 1 appears on the emitter thereof as detection output of the heater wire 4 cooled by means of Karman's vortexes.
The emitter of the transistor 39 is connected with an inverting input end of an operational amplifier 48 through a capacitor 41 and a resistance 42. A resistance 43 is connected between the inverting input end and the output end of the operational amplifier 48, and further a non-inverting input end of the operational amplifier 48 is connected with a contact point P 2 . The voltage Vcc is applied to the contact point P 2 through a resistance 46, and further the contact point P 2 is grounded through a resistance 47.
Likewise, another end of the heater wire 5 is connected with the inverting input end of an operational amplifier 22 and further is connected to the emitter of a transistor 40 through a resistance 24. A contact point P 3 of the above emitter with the resistance 24 is grounded through resistances 28-30, and a thermistor 32 is connected in parallel to the resistance 28. A contact point of the resistance 29 with the resistance 30 is connected to a non-inverting input end of the operational amplifier 22. This non-inverting input end is grounded through a series circuit consisting of a resistance 63 and a diode 64, and at the same time, is connected to the output end of operational amplifier 78 through a series circuit consisting of a diode 75 and a resistance 68.
The heater wire 5, the resistances 24 and 28-30 and the thermistor 32 constitute a bridge circuit. A feedback circuit which comprises the operational amplifier 22 and the transistor 40 as its principal constituents operates together with the bridge circuit so as to control the heater wire 5 in such a manner that the heater wire 5 is maintained at a constant temperature.
An output end of the operational amplifier 22 is connected to a base electrode of the transistor 40 through a resistance 37 and is grounded through a resistance 38; besides, voltage Vcc is applied to the collector electrode of the transistor 40. Furthermore, it is arranged such that a detection output V 2 derived from the heater wire 5 cooled by Karman's vortexes appears on the emitter electrode of the transistor 40.
The emitter of the transistor 40 is also connected with a contact point P 4 through a resistance 66. This contact point P 4 is connected to the emitter of the aforesaid transistor 39 through a resistance 65 and is grounded through a resistance 67a so that voltage V 5 proportional to a sum of V 1 and V 2 generates in this contact point P 4 .
Moreover, the emitter of the transistor 40 is also connected with the contact point P 2 through a capacitor 44 and a resistance 45. Thus, the output V 2 is applied to the non-inverting input end of the operational amplifier 48 through the capacitor 44 and the resistance 45, whilst the output V 1 is applied to the inverting input end thereof through the capacitor 41 and the resistance 42 so that difference between the output V 1 and the output V 2 is amplified by the operational amplifier 48. Therefore, detection output V 3 appearing on the output end of the operational amplifier 48 corresponds to the output which is derived only from Karman's vortexes.
The output end of the operational amplifier 48 is connected to the inverting input end of a voltage comparator 49. Voltage Vcc is applied to the non-inverting input end of the voltage comparator 49 through a resistance 50, and the non-inverting input end thereof is grounded through a resistance 51. A resistance 52 is connected between the non-inverting input end and the output end of the voltage comparator 49, and further voltage Vcc is applied to the output end thereof through a resistance 53.
The voltage comparator 49 constitutes together with the resistances 50-53 a waveform shaping circuit converting the output V 3 of the operational amplifier 48 into pulse output V 4 .
On the other hand, a circuit being composed of the resistances 65, 66, 67a is a circuit for outputting a sum signal V 5 of the output V 1 and the output V 2 , and the value V 5 is the one responding to average flow velocity of fluid to be measured. The output V 5 is applied to the non-inverting input end of a voltage comparator 77. Voltage Vcc is impressed to the inverting input end of the voltage comparator 77 through a resistance 69, and further is grounded through a resistance 70.
Voltage Vcc is impressed to the output end of the voltage comparator 77 through a resistance 71, and the same output end is connected with the non-inverting input end of the operational amplifier 78 through a resistance 72. This non-inverting input end is grounded through a capacitor 74. The output end of the operational amplifier 78 is grounded through a resistance 73, and further the same output end is connected to the inverting input end of the operational amplifier 78.
A circuit being composed of the aforesaid resistances 69-71 and the voltage comparator 77 is the one for deciding whether a value of the output V 5 reaches a specified value Vth or not in which when the output V 5 is lower than the specified value, output V 6 of the voltage comparator 77 is in level "L", whilst when the output V 5 is over the specified value, the output V 6 is in level "H".
Furthermore, the resistance 72 and the capacitor 74 construct a delay circuit for the aforesaid output V 6 which is the one for delaying rate of change in respect of level at the time of switching the same. The operational amplifier 78 and the resistance 73 construct a buffer amplifier for amplifying delay signal of the output V 6 , and which puts out output V 7 .
The resistance 67 and a diode 76 are the ones for switching a preset temperature of the heater wire 4. In the case when the output V 7 is in level "L", a temperature of the heater wire 4 is preset at a rather low temperature, whilst the temperature of the heater wire 4 is preset at a rather high temperature in the case when the output V 7 is in level "H".
Moreover, in the intermediate level extending over "H" to "L", any intermediate value spreading from rather high to rather low values may continuously be adopted in respect of the temperature of the heater wire 4.
The resistance 68 and a diode 75 operate for switching a preset temperature of the heater wire 5, and the functions thereof are similar to those in case of the heater wire 4.
Further, the thermistors 31 and 32 are the ones for detecting a temperature of fluid to be measured to correct the preset temperatures of the heater wires 4 and 5, respectively.
Next, operations of the flow velocity measuring apparatus constructed as mentioned above according to the present invention will be described hereinbelow.
First, the bridge circuit being constructed of the heater wire 4, resistances 23 and 25-27, and the thermistor 31 will be observed. If it is assumed that the voltage V 1 impressed across the input ends of the bridge circuit as well as a resistance value of the thermistor 31 are constant, respectively, the output voltage of the bridge circuit is proportional to a resistance value or a temperature of the heater wire 4. As mentioned above, since the heater wire 4 is disposed at a position contacting with either Karman's vortex street produced on the downstream side of the vortex-generating member 2, the heater wire 4 is periodically cooled in response to the interval of the vortexes produced. Thus, the output voltage of the bridge circuit varies with the same period as the interval of the vortexes in either Karman's vortex street. The output voltage of this bridge circuit is amplified by functions of the operational amplifier 21 and the transistor 39 to produce the output voltage V 1 . When the voltage V 1 is fed back to the bridge circuit, the heater wire 4 is maintained substantially at a constant temperature.
Similar operations are performed in respect of the other heater wire 5 so that the output voltage V 2 appears on the emitter side of the transistor 40.
The output signal V 1 is supplied to the inverting input end of the operational amplifier 48 through the capacitor 41 and the resistance 42, whilst the output signal V 2 is supplied to the non-inverting input end of the operational amplifier 48 through the capacitor 44 and a voltage regulating circuit being composed of the resistances 45-47. The operational amplifier 48 has a function of operating a difference between ac signals supplied to the above two input ends and therefore, the output signal V 3 is a signal based on the difference between the signals V 1 and V 2 , i.e., only on the Karman's vortexes. In this embodiment, the signal V 3 is converted into the pulse signal V 4 having the same frequency with that of the signal V 3 by means of a converting circuit involving the voltage comparator 49 in order to make processing of the signal easy in the succeeding stage.
On the other hand, the voltage signals V 1 and V 2 are added in an adder consisting of the resistances 65, 66, 67a to obtain the signal V 5 , and the resulting signal V 5 is compared with the specified value Vth which has previously been set in the comparator 77. Thus, the output signal V 6 of the comparator 77 possesses the level "H" in the case where a level of the signal V 5 is over the specified value Vth, while the level "L" in the case where the level of the signal V 5 is lower than the specified value. The signal V 6 is delayed by means of a delay circuit composed of the resistance 72 and the capacitor 74, and then, the signal delayed is amplified by the buffer amplifier 78. In the case where the output signal V 7 of the buffer amplifier 78 is in the level "H", the diode 76 is non-conductive state so far as the level at the non-inverting input end of the operational amplifier 21 is lower than the level of the signal V 7 , and as a result, the non-inverting input end of the operational amplifier 21 is maintained at a high level preset. In this situation, an output level of the operational amplifier 21, i.e., a quantity fed back to the heater wire 4 is preset at a large value so that the heater wire 4 is maintained at a high temperature preset. In the case when the signal V 7 reaches the level "L", the level at the non-inverting input end of the operational amplifier 21 is preset at the lowest value, while the level at the non-inverting input end of the operational amplifier 21 is at an intermediate value in the case when the level of the signal V 7 is an intermediate value in between the levels "H" and "L". The other diode 75 connected to the output end of the amplifier 78 is useful for presetting a voltage level at the non-inverting input end of the operational amplifier 22 in response to the level of the signal V 5 , whereby a temperature of the heater wire 5 is similarly preset to that of the case of the heater wire 4.
FIG. 3 is a graphical representation showing an example of sensitivity characteristics of the output V 3 with respect to flow velocity of fluid to be measured in which curve 101 indicates characteristics in the case where preset temperatures of the heater wires 4 and 5 are low, respectively, whilst curve 102 indicates characteristics in the case when the preset temperatures of both the heater wires are high, respectively.
In case where a flow velocity of the fluid to be measured is low, level of the output V 5 being the sum of the detection signal V 1 of the heater wire 4 and the detection output V 2 of the heater wire 5 is lower than the specified voltage Vth, as mentioned above, so that the heater wires 4 and 5 are automatically preset at the respective preset temperatures. In this condition, sensitivity of the output V 3 exibits such tendency that with increase of flow velocity of the fluid to be measured, the sensitivity increases until it reaches a certain value along the curve 101, thereafter it shifts at a substantially constant ratio, and when the sensitivity reaches a certain value, it decreases. The specified voltage Vth should be preset at the same value as the level of the output V 5 being obtained at a flow rate immediately before turning the sensitivity of the output V 3 decreasing. If the specified voltage Vth has appropriately been preset, the output V 5 reaches the specified voltage Vth at point B being immediately before turning the sensitivity of the output V 3 decreasing. As the result, the output V 6 of the comparator 77 inverts the level "L" to the level "H" so that input voltage level of the buffer amplifier 78 increases gradually and thus, level of the output V 7 gradually increases up to a prescribed value. The increase in level of the output V 7 brings in rise in temperatures of the heater wires 4 and 5, whereby sensitivity of the output V 3 shifts from the point B on the curve 101 to point C on the curve 102. The curve 102 keeps a high sensitivity level up to a region where the flow velocity is high as compared with that of the curve 101. Accordingly, even if the flow velocity increases up to around point D, the sensitivity of the output V 3 has a value sufficient for practical use.
Next, such a case where the flow velocity decreases gradually from the point D will be observed. When temperatures of the heater wires 4 and 5 belong to the higher preset temperatures, the output voltage V 5 becomes a higher value than that of the case where the temperatures of both the heater wires are preset at the lower preset temperatures. Under the circumstances, even though the flow rate passes through the point C and decreases further, the output V 5 keeps a higher value than the specified value Vth. Such a case where the output V 5 decreases up to the specified value Vth is in the event that the flow velocity reaches point E being lower than the point C, and at this moment, level of the output V 6 turns from the level "H" to the level "L". When the output V 6 turns to the level "L", a level of input signal of the buffer amplifier 78 decreases gradually so that when the level of the output signal V 7 becomes stable at the lower preset value, the temperatures of the heater wires 4 and 5 are stabilized at values of lower ones, respectively.
Although the above explanation has been made in respect of the case where two heater wires are employed, either of the heater wires may be omitted if not so high precision is required. For instance, in the case where the heater wire 5 is omitted in the circuit illustrated in FIG. 2, the emitter of the transistor 39 is connected to the input end of the voltage comparator 49 through the capacitor and the resistance 42, and is connected with the non-inverting input end of the comparator 77 through the resistance 65. In also this case, the preset temperature of the heater wire 4 is switched and thus, the switching of sensitivity as mentioned above is effected.
In addition, the present invention is similarly applicable for the case where the vortex-generating member 2 is a Strouhl vortex-generating member.
Each of the heater wires utilized as a vortex-detecting element in the above-mentioned embodiment possesses such characteristics that its resistance value varies sharply in response to the change in ambient temperature. Therefore, such heater wire is advantageous for the purpose of realizing high sensitivity. However, a temperature-resistance converting element being utilized customarily in the field of this invention such as a thermistor having positive or negative temperature-resistance characteristics may also advantageously be used.
As described above, temperature of the temperature-resistance converting element can automatically be turned over in such manner that the temperature is set at a lower temperature in case of low flow velocity, whilst the temperature is set at the higher temperature in case of high flow velocity in response to the flow velocity of fluid to be measured in the flow velocity measuring apparatus according to the present invention.
Accordingly, the flow velocity measuring apparatus of the present invention has such advantages in that a range for measuring flow velocity becomes broader, and that since the temperature-resistance converting element can be used at a low temperature in such a region where the flow velocity is low, life of the converting element can be prolonged.
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A flow velocity measuring apparatus includes a vortex-generating member disposed in the flow path and a temperature-resistance converting element positioned in contact with vortexes produced at the downstream side. A bridge circuit includes as one side the temperature-resistance converting element, and an amplifier circuit amplifies the output of the bridge circuit to provide a detection signal having a frequency corresponding to the periodic change in temperature of the element due to cooling action of the vortexes. A comparator provides one of a high level or a low level at the input end of the amplifier circuit to keep the temperature-resistance converting element at a first temperature when the level of the detection signal is lower than a prescribed preset value and provides the other of a high level or a low level at the input of the amplifier circuit to maintain the element at a second temperature higher than the first temperature when the level of the detection signal is higher than the prescribed preset value.
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FIELD OF THE INVENTION
This invention relates to improvements in candles and particularly to the fuel and wicks used in candles and to the ability to produce smokeless and coloured flames.
BACKGROUND TO THE INVENTION
Candles generally use paraffin wax and cotton wicks. Parrafin has the disadvantage that combustion is incomplete and fine particulates or soot is produced. The flame is generally yellow and the temperature of the flame is usually not high enough to provide sufficient heat for cooking or food warming. These characteristics make paraffin candles unsuitable for catering applications and for use in producing coloured flames.
For catering, alcohol is usually used but, being a liquid, spillage can cause safety problems. U.S. Pat. No. 5,858,031 discloses water alcohol mixtures that may also be gelled. Isopropanol is included to provide flame visibility as a safety precaution. For camp stove use hexamine has proved to be the heating fuel of choice but is unsuitable for indoor use because of the nitrogen oxides produced in combustion. To produce a coloured flame by the addition of colouring agents it is best to begin with a colourless flame.
Alternate fuels that can produce a colourless flame have been suggested and U.S. Pat. No. 2,551,574 included examples which use mannitol, and mannitan mono stearate and sorbitan monostearate as the main candle body.
U.S. Pat. No. 4,997,547 uses methyl alcohol and ethylene glycol and a cellulose ester to produce a gelled fuel to which colouring agents may be added.
A difficulty with non paraffin fuels is that the higher flame temperature creates a higher burn rate for the cotton wick and thus yellow the flame.
Although there have been suggestions to produce coloured flames none have been widely adopted.
U.S. Pat. No. 3,586,473 suggests that the colourant be incorporated in the rim of the candle so that the rim touches the edge of the flame. This construction would not work with wide candles. It is restrictive, suffers loss of precision if the candle burns unevenly and the support polymers suggested, produce undesirable odours and toxic gases.
U.S. Pat. No. 4,386,904 proposes the use of two wicks. The colouring wick is positioned at a lower edge of the flame and is of a similar material to the combustion wick [cotton]. This candle construction is not suitable for fuels which produce reactants with the colourant, its flame shape is distorted by the presence of the second wick and the relative burn rate is difficult to control.
It is an object of this invention to provide a candle which can support higher flame temperatures and at the same time provide a colourless flame [if desired] and low levels of soot and noxious gases.
BRIEF DESCRIPTIONS OF THE INVENTION
To this end the present invention provides a candle in which the fuel consists of a mixture of components that are mouldable into a solid shape at ambient conditions wherein the components are
a) a major portion of a C-6 polyalcohol or esters thereof b) a minor portion of a C-2 or C-3 diol c) and a minor portion of a plasticizer and all the components are composed only of oxygen, carbon and hydrogen.
This invention is partly predicated on the discovery that flame temperature, flame height, burn rate and flame transparency can be varied by varying the content of the diol and plasticizer. The carbon content of the molecules used in the fuel components should be no higher than 50% to avoid incomplete combustion which results in soot formation and flame luminosity.
The preferred C-6 polyalcohol is sorbitol although mannitol and esters of sorbitol or mannitol such as stearates may be used. Mannitol has the advantage of having lower water absorption than Sorbitol. This provides the bulk of the fuel and is selected for its melting temperature and low flame luminosity and ability to be moulded into shaped products. Further because these compounds are available as food grade products they are non toxic and safe. The polyalcohol forms about 60 to 80% of the candle fuel.
The preferred diol is ethanediol (ethylene glycol) and is used to adjust the flame height, flame temperature and burn rate of the fuel. It increases flame temperature and burns with a transparent flame. The diol may comprise up to 20% of the fuel. The amount of the diol is determined by the proposed use of the fuel. For heating use (eg: catering and camp stove) a higher flame temperature is desired and the diol content is increased. Because of the benign emissions the candle can be used indoors and in enclosed spaces such as tents.
The plasticizer is used to facilitate the blending of the diol and the polyalcohol into a stable mouldable composition. The preferred plasticizer is glycerol. The plasticizer may comprise up to 20% of the fuel. Usually the glycerol content is adjusted to blend the diol content with the polyalcohol.
The fuel may have added to it any of the usual adjuvants or additives that are used for candles including colouring agents to colour the candle body, fragrances, and biologically active molecules such as insecticides. Because the solubility characteristics of the sorbitol/mannitol system is different to paraffin not all adjuvants used with paraffin candles will be suitable. However many adjuvants used with food such as food colourants are suitable for use in the fuel composition of this invention. Paraffin may also be added to provide luminosity to the flame where this is desired. Ethanol and higher alcohols may be added in small amounts to adjust flame height and luminosity. These additives will normally constitute less than 10% by weight of the fuel.
An advantage of the fuel composition of this invention derives from its water solubility. Fuel spillages from burning candles onto table cloths or clothes do not stain and can easily be washed out. Spent candles are environmentally benign as well and can be disposed of in landfill.
In a further aspect this invention provides a candle having a wick composed of a synthetic carbon based material which decomposes above 400° C. and chars without losing structural integrity up to temperatures above 1000° C.
Cotton wicks generally decompose at 250° C. and lose structural integrity below 1000° C. Non carbon based wicks such as fibre glass are not consumed and will extend well above the candle once fuel is consumed.
The preferred wick material is selected from thermally resistant polymers of compounds that meet these requirements. Polyamides which are members of the class of liquid crystalline polymers are the most suitable class of polymers and in particular polyparabenzamineterephthalamide or polymetabenzamineterephthalamide are preferred. These polymers are generally known as polyaramids and one preferred class are marketed under the brand name Kevlar®. These wicks are best used with the fuel of this invention for catering candles and also as decorative candles. Glass fibre and carbon fibre wicks may be used for candles of reasonably fixed dimensions or if wick emissions need to be controlled during combustion.
In another aspect this invention provides a coloured flame candle in which the candle consists of
a) a fuel capable of providing a flame of low luminosity and a flame temperature greater than that provided by paraffin b) a combustion wick c) a colourant delivery wick adapted to deliver the colourant to the portion of the flame that maximises the temperature and the residence time of the colourant in the flame.
This invention is predicated on the realisation that satisfactory flame colour to be most effective, is dependent on flame temperature and the residence time of the colourant in the high temperature portion of the flame. This cannot be satisfactorily achieved by mixing the colourant in the fuel as proposed in prior patents. The delivery wick may be separate from the combustion wick or may be interwoven or formed with the combustion wick to ensure that it extends into the lower edge of the hottest portion of the flame. The colourant wick may be impregnated with a solution of the colourant material or may extend into a reservoir of the colourant solution. Carbonised starch is one material which has performed adequately as a colorant wick. It is preferred to use a fibrous absorbent material as the colourant wick to maximise the amount of colourant that may be absorbed into the wick. The colourant wick also needs to have a high decomposition temperature compared to cotton as well as structural integrity in the charred state. Again polyaramids that are fibrous or are woven or non woven materials are preferred as providing the optimum mix of these properties. Surface treated polyparabenzamineterephthalamide (to improve absorbency) sold under the brand Kevlar® or polymetabenzamineterephthalamide sold under the brand Nomex® are preferred.
In a further aspect this invention provides a candle which burns with a coloured flame which includes
a) a combustion wick b) a colourant delivery wick spirally wound around the combustion wick c) the colourant delivery wick being composed of a material that relaxes in the heat at the base of the flame so that it extends into the portion of the flame that maximises the temperature and the residence time of the colourant in the flame.
In forming the colourant wick the material that can be wound about the combustion wick and relax in the flame need not be a wicking or absorbent material but can be combined with such a material as long as one of the two components also burns at the same rate as the combustion wick and retains its structural integrity. Preferably the material that chars above 400° C. can also be heat set into a spiral and then relaxes in the flame. This material may be tubular so that an absorbent or wicking material can be threaded in the tube to deliver the colourant. Preferably the delivery material and the material capable of relaxing in the flame is the same and an absorbent polyaramid material is preferred.
The polyaramid material used for the colourant wick can be heat set into the spiral shape and then the combustion wick can be threaded through the spiral. The heat setting temperature is within the range of 80° C. to 120° C. and is selected so that the degree of relaxation ensures that the end of the spiral uncurls as far as the outer edge of the lower part of the flame.
The colourant materials may be any known metal salts capable of producing desirable colours although for health and occupational safety reasons lithium, strontium and copper salts are preferred. The salts may be carbonates, nitrates, stearates, acetates, citrates, halides and organometallics with chlorides being preferred.
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the invention are illustrated in the drawings in which
FIG. 1 illustrates a catering candle according to this invention;
FIG. 2 illustrates a first embodiment of a coloured flame candle;
FIG. 3 illustrates a second embodiment of a coloured flame candle;
FIG. 4 illustrates a method of forming the colourant wick of the FIG. 3 embodiment.
As shown in FIG. 1 a catering candle or basic version comprises a candle body 5 formed of the solid fuel of this invention. The combustion wick 7 extends through the body 5 of the candle and projects above the melt pool 6 created in the top surface of the candle body 5 by the radiant heat of the flame 9 which extends above the wick 7 .
In FIG. 2 one or more colorant wicks 8 extend parallel to the combustion wick 7 into the hottest portion 10 of the flame 9 . It is the portion 10 which becomes coloured by the introduction of the colourant. Where the fuel forming the body 5 is hygroscopic a coating 11 of hydrophobic material such as paraffin is used to protect the body 5 .
In FIG. 3 a variation on the design of FIG. 2 is shown where the colourant wick 8 A is spirally wound around the combustion wick 7 . As the wick 7 burns the colourant wick 8 A relaxes and its end lies in the region 10 of the flame 9 .
The colourant wick is formed as shown in FIG. 4 where a strip of wick material 8 A is wound onto a former 15 and heat set into a spiral shape. The former 15 is removed and the combustion wick 7 is threaded through to obtain the combination as shown in FIG. 3 .
Fuel
The candles prepared according to this invention generally have a composition of 75% sorbitol, 12.5% ethane diol and 12.5% glycerol. One particular fuel for heating or coloured flames comprises 75 g Sorbitol, 15.4 g Ethane diol, 12.6 g Glycerol and 0.1 g of polypropylene wax.
The materials are mixed as a melt and then allowed to crystallise in the mold. Vigorous shearing of the mix or seeding to encourage nucleation assists in rapid crystallisation of the fuel. Moulding can be achieved by pouring the melt into moulds, by pressing, or by extrusion.
The fuel is hygroscopic and does absorb water and it has been found necessary to coat the candle body in paraffin or similar water repellant coating to inhibit water absorption. The candles may be dipped brushed or sprayed with paraffin wax melting between 40-200° C. This property means that the candles can be sold for single use as once the candle has been used the fuel is exposed and the water absorption that occurs will make the candle more difficult to reignite. This feature renders the candle less easy to burn in a fire and is safer around children. The candles of this invention can be easily extinguished with water if needed unlike pooled burning of paraffin. If the candles need to be reignited easily paraffin wax melting between 40-100° C. can be added to the melt pool at the end of the burning cycle to saturate the wick with paraffin to control water absorption.
An alternative fuel which is less hygroscopic is to use mannitol or blends of sorbitol and mannitol.
The candle may be coloured by addition of dyes or colouring agents to the fuel and perfumes or fragrances may also be added. The water proof or paraffin coating may also coloured. Most of the coatings conventionally used for paraffin candles may be used. Fragrances, insecticides, odour inhibitors, anti-tobacco odour suppressants may be added. These additives will usually be stable at 100-200° C. and can be added to the fuel.
Combustion Wick
The combustion wick is made from Kevlar® fibres. To improve wicking and to facilitate initial ignition the wicks are impregnated with sorbitol or the actual candle fuel and coated with paraffin to inhibit water absorption. An alternative is to impregnte the wick with a non water absorbent fuel starter, such as polyethylene glycol, that does not inhibit wicking of the fuel. The wick is preferably about 2 mm in diameter.
The Kevlar® wicks char and remain upright and stable in the melt pool which forms from the candle fuel around the base of the wick. The candles are ignitable using conventional matches or gas flames at 600-1000° C.
The burn rates for these candles are about 5-7 grams of fuel per hour and can be controlled by wick design and fuel formulation.
It has been found that candles made in this way burn with a transparent hot flame that can be used in catering without any of the problems of taint from smoking fuels or the safety problems of liquid fuels. The candles comply with international indoor air quality standards. Another important advantage in manufacturing and consumer use is that the fuel is water soluble and biodegradable which allows waste or spillages to be easily washed away or reclaimed for purification and reuse.
These candles are also useful as coloured flame candles because the flame height and temperature allow colourants to have a sufficiently high temperature and residence time in the flame.
Colourant Delivery
The colourant is delivered using a range of meta aramid papers such as Nomex® paper [non woven fabric] strip impregnated with the colourant solution. The colourant wick may be cut as a rectangular strip that is curved and placed adjacent the combustion wick so that the upper edge of the colourant wick extends partly circumferentially around the lower edge of the hottest portion of the flame which is the outer surface of the flame. Alternately the Nomex® paper may be twisted, woven or supported together with the Kevlar® combustion wick so that the end of the colourant wick remains in the outer lower edge of the flame. A preferred structure is to spirally wind the meta polyaramid on a wire mandrel and heat set it at about 100° C. The para polyaramid combustion wick is then threaded through. When the combustion wick is lit the meta polyaramid spiral relaxes adjacent the bottom of the flame to deliver the colourant to the hottest edge of the flame.
It is preferred to coat the colourant wick to prevent leakage of the colourant into the fuel. These metal salts may react with the fuel or absorb water and therefor a coating of polypropylene or ethyl cellulose may be used for copper salts or poly propylene wax may be used for all colourants. The coating may be a preformed film or more preferably a thin walled tube of polypropylene or ethyl cellulose of wall thickness of about 50 microns. The meta polyaramid is
1) soaked in sheet form in the colourant solution 2) slit into wicks of appropriate width and length 3) threaded into a tube of polypropylene or ethylcellulose 4) spirally wound on a mandrel 5) heat set at about 100° C. 6) then the combustion wick is threaded into the spiral.
The strength of the polyaramid dominates the coated colourant wick which behaves much the same as an uncoated wick.
The preferred colourants used are lithium chloride for red, and cuprous or cupric chloride for green/blue. However nitrates, stearates, organometallic and other compounds such as those of calcium, strontium, magnesium, aluminium, iron, or potassium may be used. A preferred red flame is produced with lithium chloride on a poly meta-aramid strip coated with polypropylene.
From the above it can be seen that the present invention provides a unique fuel and wick structure for candles that is safe and has excellent combustion so that particulates and toxic gases are reduced.
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A candle with transparent flame and flame temperature higher than paraffin candles consists of a fuel mix consisting of sorbitol, ethane diol and glycerol with a polyaramid wick. The candle can be used in catering and for the production of colored flames. For colored flames a colorant wick delivers the colorant to the portion of the flame that maximises the temperature and the residence time of the colorant in the flame. The colorant wick may be spirally wound around a former, heat set and then threaded with the combustion wick so that when alight the free end of the colorant wick relaxes to lie in the hottest portion of the flame.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a fluorescent material which is produced after a solid solution comprising gallium nitride and indium nitride have been doped with a doping substance, or to a fluorescent material which emits light by electron beam excitation, has a property to emit light different in color according to what materials are chosen for the constituents, and has an excellently long life.
2. Description of the Related Art
Japanese Unexamined Patent Publication No. 51-41686 discloses a fluorescent material which is produced after Ga 2 O 3 has been nitrified in an atmosphere of ammonia to produce GaN, and then GaN, being made as a substrate, has been doped with Cd a dopant. This fluorescent material is not applied, however, for the purpose of light emission by electron beam excitation, and the said reference does not give any mention of the method how to use the fluorescent material to emit light by electron beam excitation.
When Ga 2 O 3 is nitrified in an atmosphere of nitrogen, nitrification of Ga 2 O 3 starts from the surface. When the system is heated to a high temperature, the nitrified surface is oxidized again. Namely, gallium nitride has a tendency to easily lose nitrogen. This is the reason why Ga 2 O 3 becomes an n type, has a very low resistance and emits light even when not doped.
Emission of light from gallium nitride occurs as a result of the pairing between donors (D) and acceptors (A). Acceptors are formed after Zn, Mg, etc. are added. Donors are nitrogen deficits naturally produced. When a conventional procedure is used for increasing the concentration of donors, it results in the increase of nitrogen deficits of the material, which will degrade the crystal regularity of the material. As seen from this, with gallium nitride produced by a conventional procedure, it is impossible to adjust the number of donors to a desired value.
Further, gallium nitride has a possibility of being oxidized in the presence of oxygen. Accordingly, if Ga 2 O 3 or an oxide is used as a starting material, it is quite difficult to convert it completely into a nitride compound. Even if this is feasible, the resulting gallium nitride will be inferior in quality because residual oxygen therein will have an adverse effect on light emission.
SUMMARY OF THE INVENTION
This invention intends to provide a fluorescent material which remains uninfluenced in the presence of oxygen during fabrication, allows a highly efficient light emission because the concentration of donors can be adjusted as appropriate, and is excellent in giving a bright light and having a long life.
A fluorescent material as described is represented by Ga 1-x In x N:M, X (where 0≦x<0.8, M is at least one element chosen from the group comprising Be, Mg, Ca, Sr, Ba, Zn, Cd and Hg, and X is at least one element chosen from the group comprising C, Si, Ge, Sn and Pb).
A fluorescent material as described is characterized by being derived from a fluorescent material as described above, wherein the concentration ranges (mol %) of the elements M and X are 0.005<M<0.7 and 0.002<X<0.8, respectively.
A fluorescent material as described is characterized by being derived from a fluorescent material as described above, wherein the concentration ranges (mol %) of the elements M and X are 0.01<M<0.3 and 0.005<X<0.3, respectively.
A fluorescent material as described is characterized by being derived from starting materials which are substances devoid of oxygen.
A fluorescent material as described is characterized by being derived from a material including the element Si and is (SiH a N b ) n which is devoid of oxygen (where a=1-3, b=0 or 1 and n=an integer of 1 or more).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the effect of Example 1 of this invention.
FIG. 2 shows the effect of Example 1 of this invention.
FIG. 3 shows the effect of Example 3 of this invention.
FIG. 4 shows the effect of Example 5 of this invention.
FIG. 5 shows the effect of Examples 3 and 5 of this invention.
FIG. 6 shows the effect of Example 6 of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The fluorescent material of this invention improves the efficiency of light emission, because it allows the concentration of donors to be adjusted by controlling the addition of an element to act as donors. Further, it is made from materials which are inherently unresponsive to oxygen. It is represented by the chemical formula of Ga 1-x In x N:M, X (where 0≦x<0.8). The element X which acts as the donor may include preferably C, Si, Ge, Sn, Pb, etc., or elements belonging to the fourth family of the periodic table. The element M to act as an additive element may preferably include Be, Mg, Ca, Sr, Ba, Zn, Cd and Hg. Particularly, when Si is added to the fluorescent material, use of Polysilazane (TM, Tonen Co., Ltd.) is preferred. Polysilazane is perhydropolysilazane represented by the formula (SiH a N b ) n (where a=1-3, b=0 or 1 and n=an integer of 1 or more). When this substance is used, the number of Si atoms to be added to the fluorescent material can be precisely adjusted. Further, as this substance does not contain C and 0, it is useful for production of a nitride. It is worthy of notice here that GeS 2 should be used for addition of Ge and SnCl 2 for addition of Sn. If addition of the donor substance is adjusted properly, it will be possible to produce a fluorescent material which is excellent in emitting bright light with different colors under electron beam excitation, and in having a long life.
(1) EXAMPLE 1
GaN:Mg, Si
A 23.5 g (0.1 mol) of Ga 2 S 3 was weighed, to which was added 0.02 g (0.1 mol %/Ga) of MgCl 2 . Then, 0.05 g of 20% solution of Polysilazane was added so that the concentrations of Si and Mg became equal. The mixture was mixed well, and was transferred, on a quartz board, into a quartz tube. The system was maintained at 1100° C. for 10 hours while ammonia was allowed to flow through the quartz tube at a rate of 10 ml/min, to produce GaN:Mg, Si.
The same procedure was followed except that, although the amount of Mg was kept constant, the amount of 20% solution of Polysilazane was varied so that the amount of Si varied between 0.001 mol % to 10 mol %, to produce a plurality of specimens varying in the Si content. The shape of particles constituting the fluorescent material of this invention produced as above, when examined under SEM, looked like thin flakes, in contrast with needles as is seen for a conventional fluorescent material made of gallium nitride.
A specimen with no Si being added, and another specimen to which SiO 2 had been added instead of Polysilazane were also prepared.
These specimens were bonded with an organic binder onto anode conductors on glass substrates, and baked in the air at 500° C., to remove the binder. Thus, the anode substrate with a fluorescent layer formed thereupon was prepared. On the top surface of the anode substrate were placed a control electrode and a cathode. On the top surface of the anode substrate was bonded a vessel member in the form of a box with frit glass to form an externally sealed enclosure. The interior of the enclosure was evacuated to form a vacuum, and the enclosure was sealed at about 500° C. (B, to form a fluorescence indicator tube. A voltage of about 50V was applied to the anode conductor, to allow the fluorescent material to emit light. The characteristics of the light were compared among different specimens for evaluation.
As shown in FIG. 1, the light from all the specimens looked blue. As shown in FIG. 2, the light intensity varied according to the amount of Si doped: when the doped amount of Si is small, the light intensity becomes low; and when Si is added too much, extra Si crystalizes and the light intensity is reduced, and light emission from the surface of fluorescent material becomes uneven, and spots indicative of charge-up appear here and there on the surface. The sample doped with SiO 2 gave light whose intensity was about 75% that from the sample doped with Polysilazane.
(2) EXAMPLE 2
GaN:Mg, Ge
A 23.5 g (0.1 mol) of Ga 2 S 3 was weighed, to which was added 0.01 g (0.05 mol %/Ga) of MgCl 2 . Then, 0.014 g of GeS 2 was added so that the concentrations of Mg and Si became equal. The mixture was mixed well, and was transferred, on a quartz board, into a quartz tube. The system was maintained at 1100° C. for 10 hours while ammonia was allowed to flow through the quartz tube at a rate of 10 ml/min, to produce GaN:Mg, Ge.
A specimen with no Ge being added, and another specimen to which GeO 2 had been added instead of GeS 2 were also prepared.
These specimens were used to produce the same fluorescence indicator tubes as in Example 1. A voltage of about 50V was applied to the anode conductor, to allow the fluorescent material to emit light. The characteristics of the light were compared among different specimens for evaluation.
The light from all the specimens was blue in color. When the light intensity emitted by the specimen not doped with Ge was taken as 100%, the light from the specimen of this example was 170%, suggesting that doping with Ge is effective in enhancing the intensity of emitted light. The specimen doped with GeO 2 gave light whose intensity was 130%.
(3) EXAMPLE 3
Ga 0 .7 In 0 .3 N:Zn, Ge
A 16.4 g of Ga 2 S 3 and 9.8 g of In 2 S 3 were combined, to which were added 0.02 g of ZnS (0.1 mol %/Ga). Then, 0.027 g of GeS 2 was added so that the concentrations of Zn and Ge became equal. The mixture was mixed well, and was transferred, on a quartz board, into a quartz tube. The system was maintained at 1150° C. for 6 hours while ammonia was allowed to flow through the quartz tube at a rate of 10 ml/min, to produce Ga 0 .7 InN:Zn, Ge.
The same procedure was followed except that, although the amount of Ge was kept constant, the amount of ZnS was adjusted so that the amount of Zn varied between 0.001 mol % to 10 mol %, thereby to produce a plurality of specimens varying in the Zn content. A specimen to which SiO 2 had been added instead of Polysilazane was prepared. Another plurality of specimens of which the amount of Ge was varied from 0.01 to 5 mol %, although the amount of Zn being kept constant, were also prepared.
These specimens were combined with PVA to give slurry solutions. The slurry solution was applied onto an ITO electrode on a substrate. This preparation was baked at 480° C. in the air, to produce an anode substrate with a fluorescent layer formed thereupon. A cathode substrate which had a cathode for discharging electricity formed on its inner surface was prepared. The inner surface of the cathode substrate was placed opposite with a specified distance to the top surface of the anode substrate. The periphery of the two substrates was closely sealed with spacers inserted between the two, to form an externally sealed enclosure. The interior of the enclosure was evacuated to produce a vacuum, and the air-vent was sealed to produce a field emission cathode (FED). A voltage was applied to the anode conductor, to allow electrons to be released from the cathode for discharging electricity, and to hit upon the fluorescent layer on the anode so that the fluorescent layer emits light. The characteristics of the light were compared among different specimens for evaluation.
As shown in FIG. 3, the light intensity varied according to the amount of Ge doped: when the doped amount of Ge is small, the light intensity becomes low; and when Ge is added too much, the light intensity is reduced. The same was observed for Zn: as seen in FIG. 5 the relative light intensity varies according to the doped amount with an optimum value at the center.
(4) EXAMPLE 4
Ga 0 .7 In 0 .3 N:Mg, Zn, Si
A 16.4 g of Ga 2 S 3 and 9.8 g of In 2 S 3 were combined, to which were added 0.01 g of MgCl 2 (0.05 mol %/Ga) and 0.01 g of ZnS (0.05 mol %/Ga). Then, 0.05 g of 20% aqueous solution of Polysilazane was added so that the concentration of Si became equal to the summed concentrations of Zn and Ge. The mixture was mixed well, and was transferred, on a quartz board, into a quartz tube. The system was maintained at 1180° C. for 6 hours while ammonia was allowed to flow through the quartz tube at a rate of 10 ml/min, to produce Ga 0 .7 InN:Mg, Zn, Si. A specimen with no Si added was also prepared.
FEDs were produced using these specimens as in Example 1. A voltage of about 100V was applied to the anode conductor, to allow the fluorescent material to emit light, and the characteristics of the light were compared among the specimens for evaluation.
The specimens of this example emitted light green in color. When the light intensity emitted by the specimen not doped with Si was taken as 100%, the light from the specimen of this example was 180%, suggesting that doping with Si is effective in enhancing the intensity of emitted light.
(5) EXAMPLE 5
GaN:Mg, Sn
A 23.5 g (0.1 mol) of Ga 2 S 3 was weighed, to which was added 0.02 g (0.1 mol %/Ga) of MgCl 2 . Then, 0.04 g of SnCl 2 was added so that the concentration of Si became equal to that of Mg. The mixture was mixed well, and was transferred, on a quartz board, into a quartz tube. The system was maintained at 1200° C. for 10 hours while ammonia was allowed to flow through the quartz tube at a rate of 10 ml/min, to produce GaN:Mg, Sn.
The same procedure was followed except that, although the amount of Sn was kept constant, the amount of Mg was varied from 0.001 mol % to 10 mol %, to produce a plurality of specimens varying in the Mg content. A specimen with no Sn added was also prepared. Another plurality of specimens of which the amount of Sn was varied from 0.001 to 5 mol %, although the amount of Mg being kept constant, were also prepared.
These specimens were used to produce the same fluorescence indicator tubes as in Example 1. A voltage of about 50V was applied to the anode conductor, to allow the fluorescent material to emit light. The characteristics of the light were compared among the specimens for evaluation.
As shown in FIG. 4, the light intensity varied according to the amount of Sn doped: when the doped amount of Sn is small, the light intensity becomes low; and when Sn is added too much, the light intensity is reduced. The same was observed for Mg: the relative light intensity, as shown in FIG. 5, varies according to the doped amount with an optimum value at the center.
(6) EXAMPLE 6
Ga 0 .5 In 0 .5 N:Zn, Sn
A 11.7 g of Ga 2 S 3 and 16.3 g of In 2 S 3 were combined, to which was added 0.004 g of ZnS (0.02 mol %/Ga). Then, 0.008 g of SnCl 2 was added so that the concentration of Sn became equal to that of Zn. The mixture was mixed well, and was transferred, on a quartz board, into a quartz tube. The system was maintained at 1150° C. for 8 hours while ammonia was allowed to flow through the quartz tube at a rate of 10 ml/min, to produce Ga 0 .5 InN:Zn,Sn. A specimen with no Sn added was also prepared.
FEDs were produced using these specimens as in Example 1. Voltages varying in intensity of about 0-100V were applied to the anode conductor, to allow the fluorescent material to emit light, and the characteristics of the light were compared among different voltages for evaluation.
The fluorescent bodies of this example emitted light orange in color. The specimen with Sn doped gave light whose relative intensity was two times as strong as that from the specimen with no Sn doped, suggesting that Sn doping is effective for enhancing emission of light.
For Mg and Zn used in the examples described above, the concentration M preferably has a range of 0.005<M<0.7, more preferably 0.01<M<0.3. Be, Ca, Sr, Ba, Cd and Hg may be used instead of Mg and Zn.
For Si, Ge and Sn used in the examples described above, the concentration X (mol %) preferably has a range of 0.002<X<0.8, more preferably 0.005<X<0.3. C or Pb may be used instead of Si, Ge and Sn.
The fluorescent material of this invention uses, as a substrate, Ga 1-x In x N (0≦x<0.8), and dopes the substrate with an additive element such that the concentration of a donor can be adjusted as appropriate. Accordingly, the fluorescent material of this invention is excellent in the light emitting property and in giving a long life, and is capable, under electron beam excitation, of emitting light different in color according to the kind of additive element applied. In addition, when starting materials devoid of oxygen are used for preparation of the present product, no adverse effects due to the presence of oxygen will be encountered during manufacture.
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A fluorescent material is described which remains uninfluenced in the presence of oxygen during fabrication, allows a highly efficient light emission due to the concentration of donors being adjustable as appropriate, and is excellent in giving a bright light and having a long life. The fluorescent material is represented by the formula Ga 1-x In x N:M,X, wherein 0≦x<0.8, M is at least one element selected from the group of Be, Mg, Ca, Sr, Ba, Zn, Cd and Hg, and X is at least one element selected from the group of C, Si, Ge, Sn and Pb. The fluorescent material preferably has concentration ranges (mol %) of the elements M and X of 0.005<M<0.7 and 0.002<X<0.8. The starting materials utilized for preparing the fluorescent material are substances devoid of oxygen, preferably (SiH a N b ) n where a=1-3, b=0 or 1, and n=an integer of 1 or more.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related to the field of computer systems. More particularly, the present invention is a method and apparatus for aligning a restored parent environment to its child environments with minimal data loss.
2. Art Background
Today, many computer systems offer support for hierarchies of inter-related environments for software development. For example, the Network Software Environment (NSE) supported on the SUN microsystems manufactured by SUN Microsystems, Inc., Mountain View, Calif. An environment 20 or 21 is a named envelope of a collection of objects 24, 26 or 25, 27 (FIG. 1a). Typically, the objects are organized under a directory 22 or 23. An environment 20 or 21 may be created on any machine 12, 14, 16 or 18 in a network of computers 10. An object 24, 25, 26 or 27 is a named data container. An object 24, 25, 26 or 27 may be a simple object 26 or 27 or a compound object 24 or 25. A simple object 26 or 27, is an object that does not contain other objects, for example, a source file. A compound object 24 or 25 is a list of other objects, including other compound objects, for example, a component containing a list of its source files. The objects 24, 25, 26, 27 of an environment 20, 21 may be physically located on any machine 12, 14, 16 or 18 in the network of computers 10.
Typically, environments 31-36 are logically organized into an hierarchy 30 (FIG. 1b). For example, a software development project may comprise a grand-parent release environment 31 for holding the various revisions of the project 40 that have been released to the customers, a plurality of parent integration environments 32, 33, each holding the latest revisions of component 41 or 42 of the project, and a plurality of child development environments 34, 35, 36, each holding the latest editions of various subcomponents 43-46 being modified by the individual developers.
A developer who wish to modify an object acquires a new edition of the object 52 or 53 into the child environment from the latest revision of the object 51 in the parent environment (FIG. 2). After modifying the new edition of the object 52 or 53 in the child environment, the latest revision of the object 51 or 56 in the parent environment is reconciled to the modified edition of the object 54 or 55 in the child environment. If the latest revision of the object 51 in the parent environment is the same revision of the object 51 in the parent environment previously acquired for the modified edition of the object 54 in the child environment, the reconciliation process is successful, resulting in a new latest revision of the object 56 being made in the parent environment.
If the latest revision of the object 56 in the parent environment is not the same revision of the object 51 in the parent environment previously acquired for the modified edition of the object 55 in the child environment, the reconciliation process is unsuccessful, resulting in the initiation of the resynchronization process and acquisition of a new edition of the object 57 into the child environment from the new latest revision of the object 56 in the parent environment. After resolving the differences between the modified edition of the object 55 and the acquired new edition of the object 57, the latest revision of the object 56 in the parent environment is reconciled again to the consolidated edition of the object 58 in the child environment. Since the latest revision of the object 56 in the parent environment has remained unchanged, the reconciliation process is successful, resulting in another new latest revision of the object 59 being made in the parent environment.
For the environments to work cooperatively with each other, each environment contains a plurality of internal files (not shown in FIGS. 1a, 1b and 2) for keeping track of status and attribute information regarding the objects. Thus, consistency between these internal files must be maintained, in order for the environment hierarchy to work properly. The environments are said to be aligned if consistency is maintained.
Ideally, these environments are all backed up at the same time, when they are all quiescent. But, in practice, particularly for large software development projects, it is often impossible to do so. The environments tend to be backed up at different times. Furthermore, other environments tend to be active when a quiescent environment is being backed up. Therefore, when damages occur to one or more of the environments, restoration of the damaged environments, and aligning the restored environments to the other environments, without substantial data loss, becomes a problem.
The problem tends to be more tolerable if the damages are confined to the leaf environments. A leaf environment is a child environment that is not a parent environment to other child environments. Typically, a damaged leaf environment is restored to its last back up. Since after the restoration, all objects in a restored leaf environment would be older in time than their corresponding revisions in the parent environment, the restored leaf environment is automatically in alignment with its parent environment. Changes previously made to objects in the restored leaf environment, from the time the restored leaf environment was last backed up to the time the restored leaf environment was damaged, are lost, unless the prior changes can be recovered from the parent environment. Such changes are recoverable, only if the corresponding revisions in the parent environment were previously reconciled to the objects in the restored leaf environment, between the time the restored leaf environment was last backed up and the time the restored leaf environment was damaged.
The problem is a lot less tolerable when damages are not confined to the leaf environments. After a non-leaf environment is restored, since the objects in the child environments to the restored non-leaf environment would be younger than the corresponding revisions in the restored non-leaf environment, the restored non-leaf environment is most likely no longer in alignment with its child environments. To return the environment hierarchy into alignment, all the child environments to the restored non-leaf environment has to be restored to previous back up times that are older than the back up time of the damaged non-leaf environment being restored to. Similarly, if the restored child environments themselves are parent environments to other child environments (grand-child environment to the damaged non-leaf environment), these other child environments (grand-child environment to the damaged non-leaf environment) also have to be restored to previous back up times that are older than the corresponding back up times of their parent environments (child environments to the damaged environment). Although similar to restoring a leaf environment, for those objects in a child environment whose corresponding revisions in their parent environment have been previously reconciled, between the time the restored child environment was backed up and the time the restored parent environment was backed up, prior changes made to these objects between these times are recoverable; nevertheless, the amount of data loss could be substantial, due to the multiplying effect for each layer of the environment hierarchy that has to be restored.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to a align a restored parent environment to its child environments with minimal data loss.
The method of the present invention comprises the steps of logging all transactions affecting revisions of objects in the parent environment and their corresponding objects in the child environments when the transactions are executed; identifying the transactions logged between a first time t 0 and second time t 1 where time t 0 is the last back up time the parent environment is being restored to, time t 1 is the time the parent environment is damaged, and time t 1 is greater than time t 0 ; sorting the identified transactions into a chronological order in accordance to their time of execution; and performing remedial action for each of the sorted transactions in the chronological order.
The apparatus of the present invention comprises transaction procedures for acquiring a revision of an object from the parent environment into one of the child environments, resynchronizing an object in one of the child environments to a corresponding revision of the object in the parent environment, reconciling a revision of an object in the parent environment to the object in one of the child environments, these transaction procedures being invoked by users of the child environments, and capable of being re-executed in accordance to their original order of execution for aligning the parent and child environments; a logging procedure for logging these transactions when they are executed, the logging procedures invoked by the transactions; an identifying procedure for identifying the transactions occurred between time t 0 and time t 1 , the identifying procedure being invoked by a user of the restored parent environment; and a sorting procedure for sorting the identified transactions into a chronological order in accordance to their time of execution, the sorting procedure invoked by the identifying procedure.
BRIEF DESCRIPTION OF THE DRAWINGS
The object, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiment of the invention with references to the drawings in which:
FIGS. 1a & 1b show block diagrams illustrating a physical view and a logical view of the inter-related development environments of the prior art.
FIG. 2 shows a block diagram illustrating exemplary transactions of the prior art for maintaining consistency across the environments.
FIG. 3 shows a block diagram illustrating a physical view of a network of computer systems employed by the present invention organized by the hardware elements.
FIG. 4 shows a block diagram illustrating a logical view of a typical computer system employed by the present invention organized by the system software.
FIG. 5 shows a block diagram illustrating a logical view of the apparatus of the present invention organized as a class hierarchy.
FIG. 6 shows a block diagram illustrating a logical view of the directories, files and databased used by the present invention.
FIG. 7 shows a block diagram illustrating the method of the present invention.
FIGS. 8a, 8b, 8c-1, 8c-2, 8d, 8e-1, 8e-2 show various diagrams illustrating an exemplary application of the present invention.
NOTATIONS AND NOMENCLATURE
The detailed description which follows is presented largely in terms of program procedures executed on a network of computers. This procedural descriptions and representations are the means used by those skilled in the art to most effectively convey the substance of their work to others skilled in the art.
A procedure is here, and generally, conceived to be a self-consistent sequence of steps leading to a desired result. These steps are those that require physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It proves convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, objects, characters, terms, numbers, or the like. It should be borne in mind, however, that all these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities.
Further, the manipulations performed are often referred to in terms, such as adding or comparing, which are commonly associated with mental operations performed by a human operator. No such capability of a human operator is necessary, or desirable in most cases, in any of the operation described herein which form part of the present invention; the operations are machine operations. Useful machines for performing the operations of the present invention include general purpose digital computers or other similar devices. In all cases, it should be borne in mind that the distinction between the method operations in operating a computer and the method of computation itself. The present invention relates to method steps for operating a computer in processing electrical or other physical signals to generate other desired physical signals.
The present invention also relates to apparatus for performing these operations. This apparatus may be specially constructed for the required purposes or it may comprise a general purpose computer as selectively activated or re-configured by a computer program stored in the computer. The procedures presented herein are not entirely related to any particular computer or other apparatus. In particular, various general purpose machines may be used with procedures written in accordance with the teaching herein, or it may prove more convenient to construct more specialized apparatus to perform the required method steps. The required structure for a variety of these machines will appear from the description given below.
DETAILED DESCRIPTION OF THE INVENTION
A method and apparatus for aligning a restored parent environment and its child environments is disclosed. In the following description for purposes of explanation, specific numbers, materials and configurations are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the present invention may be practiced without the specific details. In other instances, well known systems are shown in diagrammatical or block diagram form in order not to obscure the present invention unnecessarily.
Referring now to FIG. 3, a block diagram illustrating a physical view of a network of computer systems used by the present invention organized by its hardware element is shown. The network of computer systems 60 comprises at least one computer system 61a or 61b. If more than one computer system 61a, 61b are employed, the computer systems 61a, 61b are coupled to each other through a network 62. Each computer system 61a or 61b comprises a central processing unit (CPU) 63a or 63b, a memory unit 65a or 65b, a mass storage unit 67a or 67b and an input/output (I/O) device 69a or 69b. The characteristics of these hardware elements on each of the computer systems 61a or 61b, such as speed, size, may differ from each other. These hardware elements are those typically found in most general purpose computer systems and almost all special purpose computer systems. In fact, the several hardware elements contained within each of the computer system 61 a or 61b are intended to be representative of this broad category of data processing systems. Particular examples of suitable data processing systems to fill the role of these computer systems 61a, 61b include computer systems manufactured by Sun Microsystems, Inc., Mountain View, Calif. Other computer systems having like capabilities may of course be adapted in a straight forward manner to perform the functions described below.
Referring now to FIG. 4, a block diagram illustrating a logical view of a typical computer system used by the present invention organized by its system software is shown. The system software 70 comprises an operating system 71, a file system 72, and at least one language compiler 73. The applications 74 executing on the computer system 70 utilize the underlying system services offered by the system software 71-73. The system software used on each of the computer system may be different provided they offer equivalent functions and capable of communicating with each other. These software elements are those typically found in most general purpose computer systems and almost all special purpose computer systems. In fact, the several software elements contained within each of the computer system are intended to be representative of this broad category of system software. Particular examples of suitable system software to fill the role of these system software 70 of the computer systems used by the present invention include the UNIX operating system, its file system and its Shell command language (UNIX is a registered trademark of AT&T). Other system software having like capabilities may of course be adapted in a straight forward manner to perform the functions described below.
Referring now to FIG. 5, a block diagram illustrating a logical view of the apparatus of the present invention organized as a class hierarchy is shown. In the realm of object oriented programming, an object is an entity comprising data and operations which can be invoked to manipulate the data. Object users manipulate the data by invoking the operations. Objects are organized as class instances and classes. The data are contained in the class variables and/or the class instance variables. The operations that can be invoked to manipulate the data are defined in the methods of the class. Additionally, these classes and a root class are ordered into a hierarchy. Each class, except the root class, is subclassed to at least one of the other classes with the subclass inheriting the class methods, class instance variables and class variables of the other classes. The other classes are also referred as the super classes of the subclass. For further descriptions on object-oriented design and programming techniques, see B. Meyer, Object-oriented Software Construction, (Prentice Hall, 1988), pp. 65-382.
The apparatus of the present invention 80 comprises a plurality of procedures 83 through 88 being executed, and a plurality of directories 82, 92, 102, 112, files 105, 115, and databases 95, 106, 116 being stored, on the network of computer systems comprising the system software described above. The procedures 83 through 88, in conjunction with the directories 82, 92, 102, 112, files 105, 115, and databases 95, 106, 116 allow a restored parent environment to be aligned to its child environments with minimal data lost.
The procedures comprise an acquire procedure 83, a resync procedure 84, a reconcile procedure 85, a log procedure 86, an indentify procedure 87 and a sort procedure 88. These procedures 83 through 88 are logically organized as methods of a root class 81 defining a root environment having at least one subclass 91 defining at least one parent environment. The directories, files, and databases comprise at least one directory 82, 92, 102, or 112, one for each environment, at least one revision database 95, one for each parent environment, at least one command log file 105, 115, one for each child environment, and at least one transaction database 106, 116, one for each child environment. The directories 82, 92, 102, 112 are logically organized as the class directories of the classes 81, 91, 101, 111 defining the environments. The files 105, 115, and databases 95, 106, 116 are logically organized as class instance variables of the classes/subclasses 91, 101, 111 defining the parent and child environments. For further descriptions on implementing a class hierarchy of objects in a hierarchical file system, see U.S. patent application, Ser. No. 07/681,071 filed on Apr. 5, 1991, entitled Method and Apparatus for implementing a class hierarchy of objects in a hierarchical file system, by Owen M. Densmore and David S. H. Rosenthal, assigned to the assignee of the present invention, Sun Microsystems Inc., Mountain View, Calif.
The acquire procedure 83 is for a child environment 101 or 111 to acquire an object 104 or 114 based on the lastest revision of the object 94 in the child's parent environment 91, during normal operation. The acquire procedure 83 is also for a child environment 101 or 111 to re-acquire an object 104 or 114 based on the latest revision of the object 94 in the child's restored parent environment 91, when the restored parent environment 91 is being aligned with its child environments 101, 111. If the child environment 101 or 111 is created after the last backup, the parent environment 91 being restored to the acquire procedure 83 is re-executed for re-acquiring an object 104 or 114, after the previously acquired object 104 or 114 is first deleted from the child environment 101 or 111. The previously acquired object 104 or 114 is deleted from the child environment 101 or 111, even the child environment 101 or 111 is not damaged.
The acquire procedure 83 functions in substantially the same manner as the prior art. Additionally, the acquire procedure 83 invokes the log procedure 86 to update the appropriate files/databases 95, 105, 106, 115, 116 in the parent and child environments 91, 101, 111, regarding the acquire procedure 83 being executed for the parent and child environments 91, 101, 111. Updating the files/databases 95, 105, 106, 115, 116 will be discussed in further detail later. When the acquire procedure 83 is re-executed for re-acquiring a latest revision of an object 94 from a restored parent environment 91, the acquire procedure 83 updates the re-acquiring child environment 101 or 111 handling the latest revision 94 being re-acquired as a normal latest revision being acquired from the restored parent environment 91 during normal operation.
The resync procedure 84 is for resynchronizing an object 104 or 114 in a child environment 101 or 111 to the latest revision of the object 94 in the child's parent environment 91, during normal operation. Similarly, the resync procedure 84 is also for re-synchronizing an object 104 or 114 in a child environment 101 or 111 to the latest revision of the object 94 in the child's restored parent environment 91, when the restored parent environment 91 is being aligned with its child environments 101, 111.
Likewise, the resync procedure 84 functions in substantially the same manner as the prior art. Additionally, the resync procedure 84 also invokes the log procedure 86 to update the appropriate files/database 95, 105, 106, 115, 116 in the parent and child environments 91, 101, 111, regrading the resync procedure 84 being executed for the parent and child environments 91, 101, 111. Using the files/databases 95, 105, 106, 115, 116 will be discussed in further detail later. When the resync procedure 84 is re-executed for re-resynchronizing an object 104 or 114 of a child environment 101 and 111 to the latest revision of the object 94 in the child's restored parent environment 91, the resync procedure 84 updates the re-resynchronizing child environment 101 or 111 handling the object 104 or 114 being resynchronized as a normal object being resynchronized in the re-resynchronizing child environment 101 or 111 during normal operation.
The reconcile procedure 85 is for reconciling a latest revision of an object 94 in a parent environment 91 to the object 104 or 114 in one of the parent's child environment 101 or 111, during normal operation. The reconcile procedure 85 is also for re-reconciling a latest revision of an object 94 in a restored parent environment 91 to the object 104 and 114 in one of the restored parent's child environment 101 or 111, when the restored parent environment is being aligned with its child environments 101 and 111.
Similarly, the reconcile procedure 85 functions in substantially the same manner as the prior art. Additionally, the reconcile procedure 85 invokes the log procedure 86 to update the appropriate files/databases 95, 105, 106, 115, 116 in the parent and child environments 91, 101, 111, regarding the reconcile procedure 85 being executed from the parent and child environments 91, 101, 111. Using the files/databases 95, 105, 106, 115, 116 will be discussed in further detail later. When the reconcile procedure 85 is re-executed for re-reconciling a latest revision of an object 94 of a restore parent environment 91 to the object 104 and 114 in one of the restored parent's child environment 101 or 111, the reconcile procedure 85 handles the object 104 or 114 in the child environment 101 or 111 in accordance to a plurality of timing parameters extracted for the latest revision 94 and the object 104 or 114 being re-reconciled to, from the directories 92, 102, 112, files/databases 95, 105 or 115, 106 or 116 of the parent and child environments 91, 101, 111.
The reconcile procedure 85 extracts the time the object being reconciled to was made from the directory structure 102 or 112 of the child environment 101 or 111, the time the object being reconciled to was last involved in an transaction between the parent and the child environments 91, 101, 111 from the transaction database 106 or 116 of the child environment 101 or 111, and the time the latest revision being reconciled was made from the revision database 95 of the parent environment 91. The directory structure 102 or 112, the transaction database 106, 116 and the revision database 95 will be discussed in further detail later.
If the time the object being reconciled to was made, equals the time the object being reconciled to was last involved in an transaction between the parent and the child environments, and equals a non-zero value, furthermore, the time the latest revision being reconciled was made, equals a value zero, the reconcile procedure 85 resets the object being reconciled to 104 or 114, and updates the restored parent environment 91 handling the object being reconciled to 104 or 114 as a normal new object being reconciled to in the child environment 101 and 111.
If the time the object being reconciled to was made, equals the time the object being reconciled to was last involved in an transaction between the parent and the child environments, and equals a non-zero value, furthermore, the time the latest revision being reconciled was made, equals a lesser non-zero value, the reconcile procedure 85 outputs a flag indicating a conflict and requires the conflict to be resolved before updating the restored parent environment 91 handling the object being reconciled to 104 or 114 as a normal old object being reconciled to in the child environment 101 and 111.
If the time the object reconciled to was made, equals a non-zero value, the time the object being reconciled to was last involved in an transaction between the parent and the child environments, and the time the latest revision being reconciled was made, equal a value zero, the reconcile procedure 85 updates the restored parent environment 91 handling the object being reconciled to 104 and 114 as a normal new object being reconciled to in the child environment 101 or 111.
If the time the object being reconciled to was made, equals the time the object being reconciled to was last involved in an transaction between the parent and the child environments, and the time the latest revision being reconciled was made, and equals a non-zero value, the reconcile procedure 85 takes no action.
The log procedure 86 if for updating the appropriate files/databases 95, 105, 106, 115, 116 regarding all transactions affecting revision of objects 94 in the parent environment 91 and the objects 104, 111 in the child environments 101, 111, when the transactions are executed. As described earlier, the log procedure 86 is invoked by the acquire 83, the resync 84 and the reconcile 85 procedures. Upon invocation, the log procedure 86 logs the information regarding the particular transaction between the parent 91 and the child environment 101 and 111 into the command log file 105 or 115 in the child environment 101 and 111. Additionally, the log procedure 86 updates the transaction database 106 and 116 in the child environment 101 and 111 to reflect the particular transaction as the latest transaction for the object 101 or 114. Furthermore, in the invoking transaction is a reconcile procedure 85, the log procedure 86 also logs the making of the latest revision for the object 84 in the revision database 95 in the parent environment 91. The revision database 95, the command log files 105, 115, and the transaction databases 106, 116 will be discussed in further detail later.
The identify procedure 87 is for identifying the transactions occurred between the parent 91 and its child environments 101, 111 during a particular time period. The relevant time period is the time period between the last back up time the parent environment 91 is being restored to and the time the parent environment 91 was damaged. The identify procedure 87 scans the command log files 105, 115 in all the child environments 101, 111, and extracts the logged transactions that occurred between the parent 91 and child environments 101, 111, during the relevant time period.
The sort procedure 88 is for sorting the identified transaction into a chronological order in accordance to their time of execution. The sort procedure 88 receives the identified transactions as inputs and outputs them in a sorted order. Preferably, the sort procedure 88 is invoked by the identify procedure 87 automatically.
Referring now to FIG. 6, a block diagram illustrating a logical view of the directories, files and databases used by the present invention is shown. As described earlier, the directories 120 are used to described a class or subclass defining an environment. The directories 120 are updated by the file system as members of the directories 120 are created, updated and deleted. Each directory 120 comprises a plurality of records 121 describing the members of the directory defining the class instance variables of the class. Each record 121 comprises a member name field 122 and a time field 123. The member name field 122 identifies the member. The time 123 records the time the member was made.
The revision database 130 are used for recording the time the revisions of objects in the parent environment are made. As described earlier, the revision databases 130 are caused to be updated by the transaction procedures. A revision database 130 is created in each parent environment. A revision database 130 comprises a plurality of revision records 131 describing the makings of revisions of objects. Each revision record 131 comprises an object name field 132, a revision identifier field 133 and a time field 134. The object name field 132 is for recording the name of the object whose latest revision is being made in the parent environment. The revision identifier field 133 is for recording the revision level. The time field 134 is for recording the time the latest revision of the object was made.
The command log files 140 are used for recording the transactions between the parent and child environments. As described earlier, the command log files 140 are caused to be updated by the transaction procedures. Each command log file 140 comprises a plurality of records 141 describing the transactions being logged. Each record 141 comprises a command name field 142, an object name field 143 and a time field 144. The command name field 142 records the procedure involved, i.e. acquire, resync or reconcile. The object name field 143 record the object in the child environment involved in the transaction. The time field 144 records the time the procedure was executed.
The transaction databases 150 are used to record the last transactions of objects in the child environments with their parent environments. As described earlier, the transaction databases 150 are caused to be updated by the transaction procedures. Each transaction databases 150 comprises a plurality of records 151 describing the last transaction for an object in the child environment with its parent environment. Each record 151 comprises a transaction type field 152, a time field 153, an object type field 154, an object name field 155, a parent environment filed 156 and a parent time field 157. The transaction type field 152 records the procedure executed, i.e. acquire, resync or reconcile. The time field 153 records the time the procedure was executed. The object type field 154 identifies the object type of the object involved in the transaction. The object name field 155 identifies the object involved in the transaction. The parent environment field 156 identifies the parent environment involved in the transaction. The parent time field 157 identifies the time of the revision in the parent environment involved in the transaction was made.
Referring now to FIG. 7, a block diagram illustrating the method of the present invention is shown. Initially, the apparatus of the present invention is used to log all the relevant information regarding the transactions between the parent and its child environments 161. When a parent environment is damaged, 162, the parent environment is first restore to its last back up 163. Then, the transactions between the restored parent and its child environments between the time of the parent's last back up and the time the parent was damaged 164 are identified. After sorting the identified transactions into a chronological order according to their time of execution 165, remedial action is performed for each of the identified transactions in the order they were executed 166.
Referring now to FIGS. 8a, 8b, 8c-1, 8c-2, 8d, 8e-1, 8e-2, various diagrams illustrating an exemplary application of the method and apparatus of the present invention are shown. In this exemplary application, an administrator Jacob creates a parent environment named P. Developers Alice, Betty and Charles create three child environments C1, C2, and C3 respectively, and do work in them. Jacob then performs back up of all the environments. Developer Daniel then creates another child environment C4, and the other developers do additional work in the other child environments. The parent environment is then damaged and restored to its last back up time. The exemplary application shows how Jacob aligns the restored parent environment to its child environment, applying the method and apparatus of the present invention.
Referring first to FIG. 8a, Jacob creates the parent environment P 171. He then populates the parent environment P with two compound objects, components ":a", and ":a:b" 172. He then creates two simple objects, files "firstfile" and "secondfile" 173, and places them under the compound object component ":a:b" 174.
Referring now to FIG. 8b, after creating the child environment C1 on her machine "beret", Alice acquires the latest revisions of all objects in the parent environment P 180, thereby, acquiring the compound objects, components ":a", ":a:b", and the simple objects, files "firstfile" and "secondfile". Similarly, after creating the child environment C2 on her machine "bowler", Betty acquires the latest revisions of all objects in the parent environment P 182, thereby, acquiring the compound objects, components ":a", ":a:b", and the simple objects, files "firstfile" and "secondfile". Likewise, after creating the child environment C3 on his machine "fedora", Charles acquires the latest revisions of all objects in the parent environment P 182, thereby, acquiring the compound objects, components ":a", ":a:b", and the simple objects, files "firstfile" and "secondfile". In each of the three acquire cases, the appropriate files and databases are caused to be updated by the acquire procedure as described earlier. Then, Jacob backs up the parent environment P 186.
Referring now to FIG. 8c-1, 8c-2, after making changes to the object, file "firstfile" (not shown), Alice reconcile the latest revision of the object, component ":a:b", in the parent environment P, to the object, component ":a:b", in the child environment C1 188. The reconcile procedure detects the changes in the object, component ":a:b", in the child environment C1, makes a new revision of the object, component ":a:b", in the parent environment P, and causes the appropriate files and databases to be updated as described earlier.
Then, Betty resynchronizes the object, component ":a:b", in the child environment C2, to the latest revision of the object, component ":a:b", in the parent environment P 191, before doing additional work. By resynchronizing, the object, component ":a:b", in the child environment C2, is updated with the changes made and reconciled by Alice into the object, component ":a:b", in the parent environment P. The appropriate files and databases in the parent and child environments are also caused to be updated by the resync procedure as described earlier. After making changes to the object, file "secondfile" (not shown), Betty reconcile the revision of the object, component ":a:b", in the parent environment P, with the object, component ":a:b", in the child environment C2 192. This time, the reconcile procedure detects the changes in the object, component ":a:b", in the child environment C2, makes another new revision of the object, component ":a:b", in the parent environment P, and causes the appropriate files and databases to be updated as described earlier.
Now, Daniel creates the child environment C4 on his machine "stetson", and acquires all the latest revisions of objects in the parent environment P, thereby, acquiring the latest revisions of the compound objects, components ":a:b", ":a:b", and the simple objects, files "firstfile" and "secondfile", which include the changes made and reconciled by Alice and Betty. The appropriate files and databases in the parent and child environments are caused to be updated by the acquire procedure as described earlier. Then, Charles resynchronizes the object, component ":a:b", in the child environment C3, to the latest revision of the object, component ":a:b", in the parent environment P 196, thereby, also acquiring the changes made and reconciled by Alice and Betty. The appropriate files and databases in the parent and child environments are caused to be updated by the resync procedure as described earlier. At this time, the parent environment P is critically damaged by a system crash requiring it to be restored.
Referring now to FIG. 8d, Jacob first restore the parent environment P to its last back up 198. As a result, the parent environment P and the child environments C1 through C4 are no longer in alignment. The parent environment P no longer has the changes made and reconciled by Alice and Betty, but the child environments C1 and C4 think it does. Furthermore, the parent environment P is not aware of the existence of the child environment C4, since it was created after the last back up.
In order to align the restored parent environment P with the child environments C1 through C4 again, Jacob first identifies the transactions occurred between the parent and the child environments 201 between the time of last back up the parent environment P is restored to and the time the parent environment P was damaged. The identify procedure extracts the logged transaction and sorts them into a chronological order according to their order of execution as described earlier 202. Jacob then proceeds to perform the remedial action for each of the transaction in their order of execution.
Referring now to FIGS. 8e-1, 8e-2, Jacob first activates the child environment C1 and re-reconciles the latest revision of the object, component ":a:b", in the parent environment P, to the object, component ":a:b", in the child environment C1 205. As described earlier, the reconcile procedure detects the conflict in the object, file "firstfile", and requires the conflict to be resolved before re-reconciling the latest revision in the parent environment to the object in the child environment. After resolving the conflict 206, Jacob attempts to re-reconcile again 207. This time, the reconcile procedure makes a new revision of the object, component ":a:b", incorporating the changes made by Alice to the object, file "firstfile", and causes the appropriate files and databases to be updated as described earlier. The parent environment P is now in alignment with the child environment C1.
Jacob then activates the child environment C2 and re-resynchronizes the object, component ":a:b", in the child environment C2, to the latest revision of the object, component ":a:b", in the parent environment P. As a result, the object, component ":a:b", in the child environment C2, is resynchronized to include the changes made and re-reconciled by Alice. The appropriate files and databases are caused to be updated by the resync procedure as described earlier. Jacob then has to go through the similar steps he went through for the child environment C1, to re-reconcile the latest revision of the object, component ":a:b", in the parent environment P, to the object, component ":a:b", in the child environment C2 (not shown). Again, the reconcile procedure detects the conflict in the object, file "secondfile", and requires the conflict to be resolved before re-reconciling the latest revision in the parent environment to the object in the child environment, incorporating the changes made to the object, file "secondfile", by Betty. Now, the parent environment P is aligned with the child environments C1 and C2.
Jacob then deletes the child environment C4 (not shown) and reacquires the latest revision of the objects, component ":a", "a:b" and files "firstfile" and "secondfile", in the parent environment P 210. As a result, the appropriate files and databases are caused to be updated by the acquire procedure as described earlier, thereby, causing the child environment C4 to be known to the parent environment P. Now, the parent environment P is aligned with the child environments C1, C2 and C4.
Lastly, Jacob has to go through similar steps he went through to re-resynchronize the object, component ":a:b", in the child environment C2, to the latest revision of the object, component ":a:b", in the parent environment P, for the object, component ":a:b", in the child environment C3 (not shown). As a result, the object, component ":a:b", in the child environment C3, is resynchronized to include the changes made and re-reconciled by Alice and Betty. Now, the parent environment P is aligned with the child environments C1, C2, C3 and C4.
While the invention has been described in terms of a preferred embodiment, those skilled in the art will recognize that the invention is not limited to the embodiment described herein. The method and apparatus of the present invention can be practiced with modification and alteration within the spirit and scope of the appended claims.
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A method and apparatus for aligning a restored parent environment to its child environments with minimal data loss is disclosed. The method and apparatus achieve the alignment by re-executing the transactions affecting the objects in the child environments and the revisions of the objects in the parent environment in their order of execution, thereby, allowing the restored parent to further recover loss data from its child environments. The transactions are enhanced to facilitate collection of information regarding the transactions during normal operation, and to adjust their actions during their re-execution based on the information collected. As a result of further data recovery by the restored parent environment, alignment may be achieved with substantially less data loss.
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RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Non-provisional application Ser. No. 11/333,742 titled “Magnetic damping field armor system and method” filed Jan. 17, 2006, by Fullerton, which claims the benefit under 35 USC 119(a) of U.S. Provisional application 60/644,605 filed Jan. 15, 2005 by Fullerton, all of the above listed patent documents are hereby incorporated herein by reference in their entirety.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention pertains to the field of protection of a resource by dispersion and distribution of threat energy, more particularly by using protective armor.
[0004] 2. Background of the Invention
[0005] There is a class of weapon that uses a shaped charge to form a high-speed molten metal jet to cut through armor as a method of armor piercing. Once through the armor, the molten metal continues to do damage to personnel or items such as explosives stored behind the armor. One typical example of such a weapon is a Russian made RPG-7 (Rocket Propelled Grenade) that is being used extensively in Iraq to inflict casualties to US troops. The RPG-7 has been successful in penetrating many inches of steel armor and is notoriously difficult to develop protection against. One method of protection involves the use of high temperature materials, but the temperature of the shaped charge is effective in penetrating even the highest temperature materials. Alternatively, more and more armor may be used, but the weight becomes prohibitive, especially for mobile assets such as tanks and armored troop carriers. Another type of armor is active armor that explodes on contact or near contact to prematurely set off the shaped charge to disperse the energy and reduce the effectiveness. Active armor, however, when used is spent, providing no protection until replaced.
[0006] Therefore, there is a need for an effective method and system of protection against a shaped charge type of armor piercing round, yet is light enough to be used for mobile equipment including tanks and armored troop carriers and maintains integrity and effectiveness when attacked repeatedly.
BRIEF SUMMARY OF THE INVENTION
[0007] Briefly, a resource is protected by an armor structure comprising a magnetic field such that the magnetic field will interfere with a warhead blast to weaken the blast. In particular, magnetic field will interfere with a molten metal jet from a shaped charge to disperse the jet, allowing subsequent relatively light layers of armor to absorb the jet energy without penetration. In one embodiment, the magnetic field is produced by a layer of magnetic material magnetized with the field lines perpendicular to the primary threat direction and typically parallel to the surface of the area to be protected. The magnetic material layer may include ferromagnetic (iron or steel, or other) layers to strengthen and contain the magnetic field, protect the magnetic material and act as additional armor layers. The magnetic layer is typically used in conjunction with an inner shield armor layer to absorb the diffused jet after passing through the magnetic layer.
BRIEF DESCRIPTION OF THE FIGURES
[0008] The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. Additionally, the left most digit(s) of a reference number identifies the drawing in which the reference number first appears.
[0009] FIG. 1A illustrates an exemplary arrangement of layers of armor utilizing a magnetic layer to disperse a shaped charge in accordance with the present invention.
[0010] FIG. 1B (prior art) illustrates the action of a shaped charge warhead on conventional armor.
[0011] FIG. 2 illustrates a perspective view of the magnetic and cladding layers of FIG. 1A .
[0012] FIG. 3 illustrates an alternate layer stack including two magnetic layers in accordance with the present invention.
[0013] FIG. 4 illustrates an application of the invention and illustrates an angled orientation to the threat direction.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] The present invention is an armor system comprising a magnetic layer that disperses and deflects a molten metal jet from a shaped charge to allow the jet to be stopped or rendered ineffective by a subsequent layer of ordinary armor or other protective material. The magnetic layer may be effective against any molten jet, regardless of temperature, because the principle depends only on the magnetic and conductive properties of the jet. The dispersion of the jet is derived from Lenz's law, a law of physics discovered by the German scientist H. F. E. Lenz in 1834. Lenz's law states that the electromotive force (emf) induced in a conductor moving perpendicular to a magnetic field tends to oppose that motion. Thus, in accordance with the present invention, the molten jet forms a moving conductor in the magnetic field of the magnetic armor. Thus, the magnetic field acts to slow and deflect the conducting molten jet of metal. In the process of slowing the jet, the jet is broken up and dispersed over a wide area, reducing the penetration capability of the jet.
[0015] FIG. 1A illustrates an exemplary arrangement of layers of armor utilizing a magnetic layer to disperse a shaped charge in accordance with the present invention. Referring to FIG. 1A , the armor comprises an outer cladding layer 104 having a hard surface 118 , a magnetic layer 102 , an inner cladding layer 106 and a shield layer 108 spaced from the inner cladding layer 106 by an expansion space 110 . An RPG 104 contacts the outer cladding layer 104 and triggers the shaped charge explosive 112 . The explosive then melts a metal core and propels the molten metal 114 forward to penetrate the armor. The molten metal 114 penetrates the outer hard surface layer 104 and then encounters the magnetic field layer 102 . Upon encountering the magnetic field layer 102 , the metal jet 114 is dispersed 116 . The jet may still be concentrated enough to penetrate the inner cladding 106 , but continues to expand 116 in the space between the inner cladding and the blocking shield 108 . Upon reaching the blocking shield, the blast 116 is dispersed sufficiently to be stopped by the blocking shield 108 .
[0016] The magnetic layer 102 is magnetized parallel to the surface of the area to be protected 124 and perpendicular to the expected direction of the metal jet 114 . This ensures that the incoming projectile 112 will have to cut through the magnetic lines of force contained within the magnetic armor 122 in order to reach the intended target 124 . When such a conducting projectile 114 begins to penetrate the magnetic armor 122 and begins to cut through the magnetic lines of force contained within, the projectile 114 will be subjected to a braking force that is in accordance with Lenz's law:
[0000]
F=Qv×B
[0017] where,
F is the force vector; Q is the charge; v is the velocity vector of the charge; B is the magnetic field vector; and x is the vector cross product operation.
[0023] When a conductor, such as the molten metal jet 114 , penetrates the magnetic field 102 , electric currents are generated within the conductor 114 and are experienced as eddy currents, or shorted current loops. These currents are oriented to generate counter-acting magnetic forces that oppose the field contained within the armor, thus slowing the forward progress of the conductor. Since the conductor is liquid, the slowing of the jet allows portions of the tail to catch up with the leading portion causing the jet to change from a pencil shape to that of a mushroom with the head toward the front. The increased cross section of the jet 114 caused by passage through the magnetic field 102 makes the expanded jet 116 vulnerable to conventional shielding or armor 108 , since the pressure (force per square area) has been greatly reduced. Thus, the benefit of expanding the jet by using the magnetic layer is further enhanced by using a stopping shield 108 spaced from the magnetic layer to stop the expanded jet 116 .
[0024] The outer cladding layer 104 may provide multiple benefits to the armor assembly 122 . The outer layer 104 is a hard protective layer to protect the typically more fragile magnetic material 120 in the magnetic layer 102 . The outer layer 104 may also be a ferromagnetic material to enhance the magnetic field by providing a return path for the field and also may provide a magnetic shielding function to keep the strong magnetic field contained within the armor and minimize the long range effect of the magnetic field. The outer layer also provides a hard surface 118 to trigger warheads 112 just prior to the magnetic layer 102 . Further benefit may be obtained by having an additional outer layer (shown later in FIG. 4 ) spaced from the outer cladding layer to trigger warheads early. In some embodiments, the outer layers 104 and 106 may not be necessary, permitting the magnetic layer 102 to be used alone.
[0025] The magnetic layer 102 may comprise a permanent magnetic material such as Neodymium Iron Boron (NdFeB) magnetic material or other magnetic material. NdFeB is also called Neodymium magnetic material in this disclosure. Neodymium magnetic material is inexpensive, lightweight, and relatively non-toxic. Neodymium magnets may be extremely strong, permitting minim thickness of the magnetic layer 102 . The magnetic layer 102 may be one continuous layer of magnetic material; however, magnetization may be greatly simplified by magnetizing smaller individual magnets 120 and assembling the multiple magnets 120 as shown in the FIG. 1A .
[0026] An inner cladding layer 106 may be provided to hold and protect the magnetic material 102 . The inner cladding 106 may also be ferromagnetic and thus further contain and shield the magnetic field in a similar manner as the first cladding layer 104 . The inner cladding layer 106 may also be a factor in the spreading of the jet 114 and may be optimized in thickness and material for best performance.
[0027] The blocking layer 108 , if used, may also be the inner cladding layer 106 ; however, for best performance, the blocking layer 108 is an additional layer spaced from the magnetic layer 102 and cladding layers 104 and 106 . The spacing 110 allows the jet 114 to further expand 116 before impacting the blocking layer 108 . The blocking layer 108 is preferably high strength, high temperature material such as conventional steel armor. The blocking layer 108 is used to stop the expanded jet 116 of molten metal that emerges from the magnetic layer 102 after being velocity dampened. In the case of an add-on installation of magnetic armor, the magnetic layer assembly 122 may be added to the top of existing armor, using the existing armor for the blocking layer 108 . In some cases, additional material may be added to augment existing armor for the blocking layer 108 .
[0028] FIG. 1B (prior art) illustrates the action of a shaped charge warhead 112 on conventional armor 126 . In contrast with the armor if FIG. 1A , the conventional armor 126 of FIG. 1B does not disperse the shaped charge 114 , which penetrates the armor 126 and invades the protected space 124 .
[0029] FIG. 2 illustrates a perspective view of the magnetic 102 and cladding layers 104 , 106 of FIG. 1A . Referring to FIG. 2 , the magnetic layer 102 comprises a plurality of magnets 120 assembled with the field in the same direction, parallel to the cladding plates 104 , 106 and perpendicular to the direction 202 of the threat warhead as shown. Note that the warhead may come from any direction to penetrate the armor.
[0030] FIG. 3 illustrates an alternate layer stack including two magnetic layers in accordance with the present invention. FIG. 1A illustrates the basic layers that illustrate the principle of the invention; however, the system may be augmented with additional layers as needed for a particular application. FIG. 3 shows an additional magnetic layer assembly 322 including cladding layers along with an outer protective layer 302 . Referring to FIG. 3 , the armor system 300 comprises a first magnetic assembly 122 comprising a magnetic layer 102 and a first cladding layer 104 and a second cladding layer 106 . The armor system 300 further includes a second magnetic assembly 322 , also comprising a second magnetic layer 306 and third 308 and fourth 310 cladding layer. The second magnetic assembly 322 is spaced from the first magnetic assembly 122 with an air space 312 to allow expansion of the jet 114 to further weaken the jet 114 . The armor system 300 also includes a blocking layer 108 spaced from the second magnetic assembly 322 . Also shown is a top plate 302 to trigger the warhead 112 prematurely at a distance 304 from the first magnetic assembly 122 . As many magnetic layers and additional layers may be used as are needed for a particular application.
[0031] FIG. 4 illustrates an application of the invention and illustrates an angled orientation to the threat direction. Referring to FIG. 4 , a tracked vehicle with existing armor 108 is fitted with magnetic armor 122 . The nose of the vehicle is designed to provide a wedge shape to deflect the threat in addition to preventing penetration of the armor. The armor 122 is arranged at an angle (not perpendicular) to the threat direction 202 to cause the threat to impact the armor at an angle. The angle impact will tend to deflect warhead energy and/or cause the threat to take a longer path through the armor 122 , effectively increasing the thickness of the armor 122 . In the angled armor embodiment, the magnetic direction may be preferably in a horizontal plane so that the magnetic vector is most nearly perpendicular to the threat direction.
CONCLUSION
[0032] Thus described is a new protective armor system especially adapted to defending against armor piercing shaped charge weapons, yet is light enough to be used for mobile equipment including tanks and armored troop carriers and maintains integrity and effectiveness when attacked repeatedly.
[0033] While particular embodiments of the invention have been described, it will be understood, however, that the invention is not limited thereto, since modifications may be made by those skilled in the art, particularly in light of the foregoing teachings. It is, therefore contemplated by the appended claims to cover any such modifications that incorporate those features or those improvements which embody the spirit and scope of the present invention.
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A resource is protected by an armor structure comprising a magnetic field such that the magnetic field will interfere with a warhead blast to weaken the blast. In particular, magnetic field will interfere with a molten metal jet from a shaped charge to disperse the jet, allowing subsequent layers of armor to absorb the jet energy without penetration. In one embodiment, the magnetic field is produced by a layer of magnetic material magnetized with the field lines perpendicular to the primary threat direction and typically parallel to the surface of the area to be protected. The magnetic material layer may include ferromagnetic (iron or steel, or other) layers to strengthen and contain the magnetic field, protect the magnetic material and act as additional armor layers. The magnetic layer is typically used in conjunction with an inner shield armor layer to absorb the diffused jet after passing through the magnetic layer.
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BACKGROUND
[0001] 1. Technical Field
[0002] The present disclosure relates to a method of adjustment during the manufacture of a capacitor laid on a substrate and, by way of example, the present disclosure relates to a method of manufacturing that provides for adjusting the frequency of a circuit having a resonant element, for example, a monolithic oscillator using bulk acoustic wave (BAW) resonators.
[0003] 2. Description of the Related Art
[0004] Oscillators are mainly used in electronic devices to provide clock signals at reference frequencies. Currently, an oscillator includes oscillating circuit elements and a quartz resonator that enables accurately setting the oscillation frequency. An alternative to quartz oscillators is the use of oscillators based on
[0005] BAW resonators. The use of BAW resonators enables implementing higher oscillation frequencies, for example, approximately ranging from a few hundreds of MHz to a few tens of GHz. Lower clock frequencies may also be generated by using, at the oscillator output, a frequency-division circuit. Further, BAW resonators have the advantages of having a low bulk and a good quality factor.
[0006] It has also been provided to form a monolithic oscillator using a BAW resonator, that is, an oscillator in which the oscillating circuit elements and the resonator are assembled inside and on top of a same integrated circuit chip. The oscillating circuit elements may be formed inside and on top of a semiconductor substrate, for example, a silicon wafer. The BAW resonator is then deposited above this substrate and connected to the oscillating circuit elements. Such an oscillator has the advantages of being very compact and of providing good performance.
[0007] FIG. 1 is a cross-section view schematically showing a BAW resonator 1 formed on a semiconductor substrate 3 . In this example, the substrate is coated with an insulator 4 . Resonator 1 includes a resonator core or piezoelectric resonator 5 formed of two electrodes 5 a, 5 c between which is arranged a layer 5 b of a piezoelectric material. When an electric field is created in the piezoelectric layer by application of a potential difference between electrodes, this results in a mechanical disturbance in the form of acoustic waves. The waves propagate in the resonator. The fundamental resonance establishes when the acoustic wavelength in the piezoelectric material substantially corresponds to twice the thickness of piezoelectric layer 5 b.
[0008] An acoustic isolation device is provided between the resonator core and the substrate to avoid losing acoustic waves in the substrate. There mainly exist two types of BAW resonators: BAW resonators deposited on a membrane, and BAW resonators mounted on the substrate.
[0009] BAW resonators deposited on a membrane, such as the resonator 1 , such as FBARs (Film Bulk Acoustic Wave Resonators) or TFRs (Thin Film Resonators) form a recess 7 between the resonator core and the substrate. A membrane 8 supports the various layers of the resonator above the recess 7 .
[0010] BAW resonators mounted on the substrate, or SMRs (Solidly Mounted Resonators), are generally isolated from the substrate by an acoustic reflector, currently a Bragg mirror.
[0011] FIG. 2 shows a simplified electric diagram of an oscillator with a BAW resonator 25 . This oscillator has various elements of a circuit 23 , connected between a high voltage power supply terminal V CC and a terminal of low voltage, for example, the ground, and the BAW resonator 25 , connected to circuit elements 23 .
[0012] The circuit 23 especially includes active elements capable of sustaining oscillations and of amplifying an output signal OUT, and passive elements, for example, capacitors. The BAW resonator 25 enables to select the oscillation frequency.
[0013] FIG. 3 shows the circuit of FIG. 2 in a more detailed fashion in which the circuit 23 is a Colpitts oscillator. In this example, the circuit 23 more particularly includes a MOS transistor 31 series-connected with a current source 33 between a high supply voltage terminal V CC and the ground. Two capacitors 35 and 37 are series-connected between the gate of transistor 31 and the ground. A resistor 39 is connected between high voltage power supply terminal V CC and the gate of the transistor 31 . The terminal or node common to the capacitors 35 and 37 is connected to the drain of the transistor 31 . The BAW resonator 25 is connected between the gate of the transistor 31 and the ground. The oscillator output is connected to the source of the transistor 31 .
[0014] The transistor 31 and the current source 33 amplify the output signal and sustain the oscillations. The frequency of output signal OUT is especially dependent on the resonance frequency of the resonator 25 and on the capacitances of the capacitors 35 and 37 .
[0015] In practice, it is difficult in manufacturing to obtain an oscillation frequency with the desired accuracy.
[0016] A first source of inaccuracy is due to the BAW resonator manufacturing dispersions. Indeed, methods of deposition of the different layers of a BAW resonator do not enable obtaining a resonance frequency with the desired accuracy. Substantial variations of the resonance frequency can especially be observed between resonators formed from a same substrate wafer.
[0017] For this reason, as illustrated in FIG. 1 , a frequency adjustment layer 9 , for example made of silicon nitride, is provided at the surface of the resonator 1 . The presence of this layer modifies the behavior of the resonator, and especially its resonance frequency. In a manufacturing step, the layer 9 is thinned down by local etching, for example, by ion etching, to get closer to the aimed resonance frequency.
[0018] Despite this adjustment, the accuracy of the BAW resonators is not ideal.
[0019] A second source of inaccuracy results from manufacturing discrepancies in the elements of circuit 23 . Indeed, despite the attention brought to the forming of these elements, behavior differences can be observed between circuits formed inside and on top of a same substrate wafer.
[0020] To overcome this lack of accuracy, a variable capacitance, for example a network of switched capacitors, is generally used in the circuit 23 , at least for a portion of one of the two capacitors 35 and 37 . The frequency of the output signal of each oscillator can thus be finely corrected in a final calibration step when the BAW resonator is connected to the circuit 23 and the oscillator is powered.
[0021] A disadvantage of this calibration mode is that, to be able to compensate for the above-mentioned significant inaccuracy of the oscillation frequency, a large network of switched capacitors must be provided.
BRIEF SUMMARY
[0022] The present disclosure overcomes all or part of the disadvantages of conventional oscillators using BAW resonators.
[0023] One embodiment of the present disclosure provides a method for forming oscillators with BAW resonators that minimizes the inaccuracy of the oscillation frequency, and minimizing or suppressing the calibration switched capacitor network.
[0024] The present disclosure also provides a method of adjustment in the manufacture of a circuit having a resonant element, and a method of adjustment in the manufacture of the capacitance of a capacitor.
[0025] Thus, the present disclosure provides a method of adjustment in the manufacture of the capacitance of a capacitor supported by a substrate, this method including the steps of: a) forming a first electrode parallel to the surface of the substrate and covering it with a dielectric layer; b) forming, on a first portion of the dielectric layer, a second electrode; c) measuring the capacitance between the first electrode and the second electrode, and deducing therefrom the capacitance to be added to obtain the desired capacitance; d) thinning down a second portion of the dielectric layer that is not covered by the second electrode so that the thickness of this second portion is adapted to the forming of the deduced capacitance; and e) forming a third electrode on the thinned-down portion and connecting it to the second electrode.
[0026] Another embodiment of the present disclosure provides a method of adjustment in the manufacture of an oscillator having circuit elements and a resonator, this oscillator further including a capacitor connected to the circuit elements so that the oscillation frequency depends on the capacitance of the capacitor, this method includes the steps of: forming the circuit elements and the resonator and connecting them; and forming, connecting, and adjusting the capacitor by the above-mentioned method; and step c) of measurement of the capacitance to be added further including an intermediary step of measurement of the output frequency of the circuit.
[0027] According to an embodiment of the present disclosure, thinning-down step d) is performed by ion etching of the second portion of the dielectric layer.
[0028] According to an embodiment of the present disclosure, the resonator is a BAW resonator deposited on a membrane. According to an embodiment of the present disclosure, the resonator is a BAW resonator with a Bragg mirror.
[0029] According to an embodiment of the present disclosure, the electrodes and the dielectric layer of the capacitor are made of the same materials as the BAW resonator.
[0030] According to an embodiment of the present disclosure, the first and second electrodes are made of molybdenum, the third electrode is made of a copper and aluminum alloy, and the dielectric layer is made of silicon oxide.
[0031] According to an embodiment of the present disclosure, the third electrode covers all or part of the second electrode to provide an electric contact between these two electrodes.
[0032] According to an embodiment of the present disclosure, the second and third electrodes are electrically interconnected by a wire.
[0033] According to an embodiment of the present disclosure, the resonator is a MEMS-based resonator.
[0034] An embodiment of the present disclosure provides a capacitor supported by a substrate and including a first electrode parallel to the surface of the substrate; on the first electrode, a dielectric layer having a first region, and a second region against the first region of a smaller thickness than the first region; a second electrode covering the first region; and a third electrode covering the second region and covering all or part of the second electrode so that the second and third electrodes are electrically interconnected.
[0035] In accordance with another aspect of the present disclosure, a method of forming a capacitor with a specified capacitance in conjunction with a BAW resonator on a semiconductor substrate is provided. The method includes forming a first electrode on the substrate; forming a dielectric layer over the first electrode; forming a second electrode over a portion of the dielectric layer that is over a portion of the first electrode to leave a remaining uncovered portion of the dielectric over the first electrode; measuring capacitance between the first and second electrodes and determining a thickness of the uncovered portion of the dielectric layer to obtain the specified capacitance; reducing a thickness of the uncovered portion of the dielectric layer over the first electrode to a thickness that will result in the specified capacitance; and forming a third electrode over the uncovered portion of the dielectric layer and in contact with the second electrode to obtain the capacitor with the specified capacitance.
[0036] In accordance with another aspect of the present disclosure, a capacitor is provided, the capacitor including a first electrode formed on a semiconductor substrate to form a first plate; a dielectric layer formed over the first electrode; a second electrode formed over a first portion of the dielectric layer that is over the first electrode; a third electrode formed over a second portion of the dielectric that is over the first electrode and in contact with the second electrode to form a second plate; and wherein the second portion of the dielectric layer has a thickness that is smaller than a thickness of the first portion of the dielectric layer.
[0037] In accordance with another aspect of the present disclosure, the second portion of the dielectric layer is formed by measuring capacitance between the first and second dielectric layers prior to forming the third electrode and determining a thickness of the second portion of the dielectric layer to obtain a specified capacitance; reducing a thickness of the second portion of the dielectric layer over the first electrode to a thickness that will obtain the specified capacitance; and forming the third electrode over the second portion of the dielectric layer and in contact with the second electrode to obtain the specified capacitance.
[0038] The foregoing features and advantages of the present disclosure will be discussed in detail in the following non-limiting description of specific embodiments in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0039] FIG. 1 , previously described, is a cross-section view schematically showing a BAW resonator;
[0040] FIG. 2 , previously described, shows the simplified electric diagram of an oscillator with a BAW resonator;
[0041] FIG. 3 , previously described, shows the electric diagram of an oscillator with a Colpitts-type BAW resonator; and
[0042] FIGS. 4 to 6 are cross-section views schematically illustrating steps of an example of a method of adjustment in the manufacture of an oscillator with a BAW resonator.
DETAILED DESCRIPTION
[0043] For clarity, the same elements have been designated with the same reference numerals in the different drawings and, further, as usual in the representation of integrated circuits, the various drawings are not to scale.
[0044] FIGS. 4 to 6 are cross-section views schematically illustrating steps of an example of a method of adjustment on manufacturing of an oscillator with a BAW resonator.
[0045] FIGS. 4 to 6 schematically show an embodiment of a monolithic oscillator with a BAW resonator 41 formed inside and on top of a semiconductor substrate 3 coated with an insulator 4 . It should be noted that the presence of insulator 4 is optional. Although each of these drawings shows a single oscillator, in practice, many oscillators are formed simultaneously inside and on top of a same semiconductor wafer.
[0046] Various elements of a circuit 23 , connected between a terminal of high voltage V CC and a terminal of low voltage, for example, the ground, are formed inside and on top of substrate 3 . As an example, elements of a Colpitts-type oscillating circuit, such as described in relation with FIG. 2 , may be formed inside and on top of substrate 3 .
[0047] A BAW resonator 25 is formed above or next to substrate area 3 inside and on top of which are formed the elements of circuit 23 . In this example, BAW resonator 25 is a BAW resonator deposited on a membrane, such as described in relation with FIG. 1 .
[0048] Electrodes 5 a and 5 c of BAW resonator 25 are connected to circuit elements 23 . These connections are schematically shown by lines 43 a and 43 c . As an example, connections 43 a and 43 c have vias.
[0049] An aspect of an embodiment of the present disclosure is to provide to form, next to resonator 25 , an adjustable capacitor 45 , this capacitor being connected to circuit elements 23 so that the oscillation frequency depends on the capacitance of this capacitor.
[0050] FIG. 4 schematically illustrates a first step of an example of a method of adjustment in the manufacture of the oscillator 41 .
[0051] It is provided to form, next to the resonator 25 and above the substrate 3 , a lower electrode 45 a of capacitor 45 , and to cover this electrode with a layer of a dielectric material. It is further provided to form, at the surface of a portion 47 b of this dielectric layer, an upper electrode 47 c. At this stage of the manufacturing, a portion 49 b of the dielectric layer is not covered with the upper electrode 47 c, and the capacitance of capacitor 45 depends on the surface of upper electrode 47 c and on the thickness of the dielectric layer 47 b. Electrodes 45 a and 47 c are connected to circuit elements 23 .
[0052] The oscillator is then powered and the frequency of the output signal OUT is measured. The capacitance to be added in parallel with the current capacitance of the capacitor 45 to accurately obtain the desired oscillating frequency can be deduced therefrom.
[0053] As an example, to power the oscillator and measure its output frequency by means of test probes, contact pads (not shown) connected to the circuit elements 23 may be provided at the surface of the semiconductor wafer. In practice, several oscillators of a same wafer may be powered and tested at the same time, by using a test board having a large number of probes. Should the desired degree of accuracy allow it, the substrate wafer may be tested by areas, that is, an oscillator of a predefined area may be tested, to deduce the capacitance to be added in parallel to capacitor 45 for all the neighboring oscillators formed within this area.
[0054] FIG. 5 schematically illustrates a second step of a method of adjustment in the manufacture of the oscillator 41 . Portion 49 b of the dielectric layer has been thinned down to form, from this portion 49 b, a capacitor precisely having the capacitance previously deduced from the oscillation frequency measurement.
[0055] Indeed, knowing that portions 47 b and 49 b of the dielectric layer have been deposited with the same thickness, and knowing the surfaces of portions 47 b and 49 b, the thinning to be undergone by dielectric portion 49 b so that final capacitor 45 has the desired capacitance can be determined.
[0056] The thinning-down of dielectric portion 49 b may advantageously be performed by ion etching, like the above-described step of adjustment of the resonance frequency of a BAW resonator. As an example, the semiconductor wafer on which the oscillators are formed is scanned by an etching ion beam 51 . The scan speed is controlled so that the beam stays longer on the oscillators for which a greater thickness is desired to be etched. Such a thinning-down technique enables to form capacitors having highly accurate capacitances. As for the above oscillation frequency measurement step, the thinning down of dielectric 49 b may be carried out simultaneously for several neighboring oscillators, for example, by increasing the diameter of the etching ion beam.
[0057] FIG. 6 schematically illustrates a final step of an example of a method of adjustment in the manufacture of the oscillator 41 .
[0058] An upper electrode 49 c, which is connected to the neighboring upper electrode 47 c, is formed above the thinned-down portion 49 b of the dielectric layer. A single capacitor 45 having exactly the desired value is thus formed.
[0059] To interconnect upper electrodes 47 c and 49 b, the electrode 49 c is formed to at least partially cover electrode 47 c. An alternative, not shown, is to provide a wire connection.
[0060] Upper electrodes 47 c and 49 c of the capacitor 45 preferably take up a large surface area. As an example, each of these electrodes may have a surface area approximately ranging from 1,000 μm 2 to 10,000 μm 2 . As a result, the possible inaccuracies linked to the surface delimitation of the two regions of capacitor 45 are negligible.
[0061] To limit the number of manufacturing steps, materials of BAW resonator 25 are used to form capacitance 45 . As an example, electrodes 45 a and 47 c may be formed at the same time as electrodes 5 a and 5 c of the BAW resonator, for example, with molybdenum. Similarly, dielectric layer 47 b, 49 b may be formed at the same time and with the same material as one of the following layers:
[0062] piezoelectric layer 5 b, for example, made of aluminum nitride, a temperature-compensation layer, not shown, for example made of silicon oxide, currently arranged between piezoelectric layer 5 b and upper electrode 5 c, or upper frequency adjustment layer 9 , for example, made of silicon nitride.
[0063] Upper electrode 49 c requires a dedicated manufacturing step. This electrode may, for example, be made of an alloy of copper and aluminum identical to that generally used to form contact pads, not shown.
[0064] To improve the accuracy of the dielectric layer thinning-down step, it is desirable to provide, on deposition of this layer, the approximate capacitance that capacitor 45 must have. For this purpose, after the deposition of layer 47 b , 49 b, there is a measurement by ellipsometry of the thicknesses of the different dielectric layers forming the capacitor 45 .
[0065] According to an advantage of an embodiment of the present disclosure, the provided method enables very accurate adjustment of the frequency of an oscillator in a final manufacturing step. The network of switched capacitors generally used to carry out this adjustment can thus be suppressed or reduced.
[0066] An advantage of the above-described embodiment is that it only implements conventional steps of the manufacturing of an oscillator with a BAW resonator.
[0067] One of the issues of the implementation of the BAW resonator frequency-adjustment step is that the frequency shift linked to the thickness adjustment is not constant at the scale of a wafer. This difference in the frequency sensitivity of resonators is linked to technological dispersions. The provided solution enables to adjust the frequency of the BAW resonator (and by extension, of the oscillator) by means of a capacitor having a sensitivity according to the adjusted thickness which is constant at the scale of the wafer. This property accordingly increases the accuracy that can be achieved to finely correct the oscillation frequency.
[0068] A specific application of an embodiment of the present disclosure has been described hereabove. More generally, the adjustment on manufacturing of any device having its behavior depending on the capacitance of a capacitor is provided. It is then provided, in a final manufacturing step, to test the device, then to correct possible behavior irregularities, by adjusting the capacitance of the capacitor in the way described hereabove.
[0069] As an example, such a method may be implemented to adjust on manufacturing the frequency of an oscillator based on MEMS (“MicroElectroMechanical Systems”).
[0070] Further, the provided method may also be implemented to manufacture capacitors having very accurate capacitances. Errors linked to the inaccuracies of methods for depositing the different layers of a capacitance can indeed thus be corrected.
[0071] According to an alternative embodiment of the provided methods, it is provided, for the adjustment of capacitance 45 , to form a temporary upper electrode covering the entire surface of the dielectric layer, to test the device, to remove the temporary upper electrode, to modify the thickness of the dielectric layer, then to form a final upper electrode. The temporary upper electrode will for example be removed by ion etching, according to the same method as the dielectric layer thinning step.
[0072] Specific embodiments of the present disclosure have been described. Various alterations and modifications will occur to those skilled in the art. In particular, a method of adjustment on manufacturing of an oscillator with a BAW resonator deposited on a membrane has been described hereabove. It will be within the abilities of those skilled in the art to implement the desired operation to adjust an oscillator with a BAW resonator mounted on a substrate.
[0073] Further, the above-described embodiments provide for thinning down, by ion etching, the dielectric layer of the capacitance to be adjusted. The present disclosure is not limited to this specific example. It will be within the abilities of those skilled in the art to use any other method capable of thinning down the dielectric layer.
[0074] Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and the scope of the present disclosure. Accordingly, the foregoing description is by way of example only and is not intended to be limiting. The present disclosure is limited only as defined in the following claims and the equivalents thereto.
[0075] The various embodiments described above can be combined to provide further embodiments. All of the U.S. patents, U.S. patent application publications, U.S. patent application, foreign patents, foreign patent application and non-patent publications referred to in this specification and/or listed in the Application Data Sheet are incorporated herein by reference, in their entirety. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, application and publications to provide yet further embodiments.
[0076] These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.
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A method of adjustment in the manufacture of a capacitance of a capacitor supported by a substrate, the method including the steps of: a) forming a first electrode parallel to the surface of the substrate and covering it with a dielectric layer; b) forming, on a first portion of the dielectric layer, a second electrode; c) measuring the capacitance between the first electrode and the second electrode, and deducing therefrom the capacitance to be added to obtain the desired capacitance; d) thinning down a second portion of the dielectric layer, which is not covered by the second electrode, so that the thickness of this second portion is adapted to the forming of the deduced capacitance; and e) forming a third electrode on the thinned-down portion and connecting it to the second electrode.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a National Stage Application of PCT International Application No. PCT/FR2013/050151 (filed on Jan. 25, 2013), under 35 U.S.C. §371, which claims priority to French Patent Application No. A 12 50833 (filed on Jan. 30, 2012), which are each hereby incorporated by reference in their respective entireties.
TECHNICAL FIELD
This invention relates to an indicator or display that may be in the form of a label that can instantaneously provide confirmation that a product is in a good preservation state by making a simple visual check, and particularly to detect if the product temporarily went outside a determined temperature range and to memorize this event. Strict monitoring of a temperature range is essential to be able to guarantee quality of many products.
In general, the invention is applicable to any product or device for which the temperature has to be monitored between two thresholds.
BACKGROUND
Different types of systems are known that detect if a setpoint temperature is exceeded. In particular, there are indicators described in many documents reporting a failure of the cooling system or indicators showing that a product temperature has been too high.
French Patent Publication No. FR 2 899 684 discloses a product preservation status indicator to detect if the temperature of a product has exceeded a predetermined threshold called the setpoint temperature. This indicator comprises two transparent films hermetically assembled so as to trap two doses of liquid or viscous products, these doses being separated by a glue joint hermetically sealing adjacent faces of the two films. This glue is such that it loses its adhesive properties when a predetermined temperature is exceeded, so that if the setpoint temperature is reached after the indicator has been activated, then the viscous products will be free to mix and the result of this mix will be an irreversible change in the state such as a change in the color. Apart from the complexity of the system, this indicator cannot be used to make a visual check so as to immediately make sure that the state of preservation of the product has been good and maintained between two temperature thresholds. This indicator can only detect a crossing of a temperature threshold, but it is impossible to know if the product was too cold or too hot. Furthermore, the status change of the system is irreversible, and this is not a color memory system. Finally, irreversibility of the system makes it impossible to reuse the indicator once the temperature threshold has been exceeded.
European Patent Publication No. EP 1 410 368 discloses a fuel tank provided with a safety label located on the outside face of a tank, said label containing at least one reversible thermochromic material. This label changes color above a temperature threshold to inform the user about a possible burn on the skin if he does not have any protection. The label simply detects that the temperature has been exceeded (overheating). Therefore this label cannot be used as an indicator for a low temperature crossing (frost), for example for products that must not be frozen under any circumstances.
Indicators according to the state of the art have disadvantages firstly due to their complexity, and secondly because they are limited to a single threshold, in that they can indicate crossing of a temperature only above the setpoint temperature (abnormal overheating) or below the setpoint temperature (frost).
Two temperature thresholds frequently have to be monitored to assure good preservation of a product; there are many products that are sensitive to both cold and heat. Existing indicator systems are not suitable for these products. For example, some pharmaceutical and medical preparations are sensitive to cold and to heat and must not go outside a specific temperature range even for an instant. For example, a blood pouch must be kept at between +8° C. and +32° C., a vaccine must be kept (for example) between +3° C. and +8° C., and even an instantaneous exceedance of either of these two limits may make the product unsuitable for its planned used.
Similarly, most technical dispersions or emulsions (such as paints) suffer irreversible transformations as soon as they go outside a specific temperature range. And finally, many food products in the case of dispersions, emulsions, solutions or other systems, do not resist frost or excessively high temperatures; this is the case for some dairy products and some drinks (wine, beer, spirits, etc.), knowing that these products are not always stored and transported in an isothermal environment.
Thus, the problem that this invention aims to solve is to disclose a simple and reliable system for precisely determining whether or not an object or a product has gone outside a determined temperature range and to memorize this event. It must be possible to manufacture this system so that it can react to different temperature thresholds. It must be inexpensive, resistant to the environment wherein it is used and it must not contaminate the product to which it is affixed.
SUMMARY
The purpose of this invention is an indicator system to monitor that a setpoint temperature range is respected, comprising a thermochromic product (E) such as an ink, paint, or a thermochromic plastic material (E) composed of at least two thermochromic compositions (E 1 ) and (E 2 ), each with a first and a second color state as a function of the temperature, the transition from said first color state to said second color state being reversible, characterized in that said thermochromic compositions (E 1 , E 2 ) have a thermal hysteresis, such that when the temperature of said thermochromic compositions (E 1 , E 2 ) is increased, the transition from said first color state to said second color state takes place at a different temperature threshold than the transition from said second color state to said first color state when said system is cooled. Thus, said thermochromic product (E) has several color states that depend not only on its temperature at a given moment, but also on the temperature history applied to it.
In one embodiment, said system has an adjustable thermal hysteresis. “Adjustable” means that thermal hysteresis is such that the response curve (color density/temperature curve) of one of the two thermochromic compositions, for example (E1), is envelope to the response curve of the second thermochromic composition (E2).
Advantageously, the thermochromic compositions (E1, E2) contained in said system are in micro-encapsulated form. This means that the entire chemistry of the mix can be maintained and the mix can be protected from the outside environment. More particularly, each of the thermochromic compositions (E1, E2) may be micro-encapsulated separately from the other; thus, the thermochromic product (E) comprises at least two different types of microcapsules, namely a first type for the thermochromic composition (E1) and a second type for the thermochromic composition (E2). As will be explained below, each thermochromic composition (E1, E2) has at least two components that will interact optically or visually.
In one particular embodiment, the indicator system is in the form of a support, particularly a flexible, semi-rigid or rigid support such as a plastic film, preferably transparent, whereon a thermochromic ink (E) was applied as a thermochromic product (E) composed of at least two thermochromic compositions (E1, E2). More particularly, after application of said thermochromic product (E), said support may be placed on a packaging or a product or batch of products (P).
In one particular embodiment, the indicator system is in the form of a support, particularly a flexible, semi-rigid or rigid support such as a plastic film, preferably transparent, wherein at least two thermochromic compositions (E1, E2) have been incorporated so as to form a thermochromic support (E) such as a thermochromic plastic film (E). More particularly, after application of said thermochromic compositions (E1, E2), said support may be placed on a packaging or a product.
According to another particular embodiment, the indicator system is in the form of a thermochromic label on a white, colored or transparent background, comprising a transparent, white or colored substrate whereon a thermochromic ink (E) has been applied as a thermochromic product (E) composed of at least two thermochromic compositions (E1, E2).
In another particular embodiment, the indicator system is characterized in that at least one of the color states of at least one of the thermochromic compositions (E1, E2) may be detected outside the visible spectrum, and in one variant of this embodiment only outside the visible spectrum. More particularly, at least one of the color states of at least one of the thermochromic compositions (E1, E2) may be detected in the ultraviolet and/or infrared range, and particularly the near ultraviolet range and/or the near infrared range.
In another particular embodiment, the indicator system comprises a thermochromic product (E) composed of more than two thermochromic compositions (E1, E2, . . . En).
The indicator system according to the invention may be used as a temperature range compliance indicator, particularly as a good preservation indicator for products sensitive to temperature. The indicator system according to the invention may be useful particularly as a good preservation indicator for pharmaceutical products (particularly blood pouches, injectable products, vaccines, pharmaceutical preparations, pharmaceutical emulsions, creams, gels), food products (particularly dairy products, alcoholic drinks, non-alcoholic drinks and particularly wines and spirits), industrial emulsions (particularly varnish, paint, concrete additives, cleaning products) and other products such as flowers and plants.
Another purpose of the invention is a method of using the indicator system according to the invention comprising at least two thermochromic compositions (E1, E2), in which method: (a) said indicator system according to the invention is provided, (b) said system is put into a required initial color state by heating it or cooling it to a temperature causing a color change of at least one of the thermochromic compositions (E1, E2), and (c) said system is affixed to a product or batch of products (P) to be monitored such that it is kept within a temperature range (Ta, Tb) between steps (b) and (c) such that there is no change in the color state of one of the thermochromic compositions (E1, E2) of said system. In particular, the indicator system is a thermochromic label.
In a particular embodiment of the usage method according to the invention, a transparent or translucent indicator system according to the invention is applied in step (c) of said method above a barcode of a product or a batch of products (P) to be monitored, and wherein said thermochromic compositions (E1, E2) are chosen such that: the barcode is legible within the temperature range (Ta, Tb); and the change in the color state caused by one and/or the other of the limits (Ta, Tb) being exceeded makes said barcode illegible.
In another particular embodiment of the usage method according to the invention, the following steps are carried out when the system indicates a change in the color state after having been affixed to said product or batch of products (P) to be monitored: (d) one or several of said products or batches of products (P) to be monitored is (are) analyzed and a decision is made about the state of preservation of said products or batches of products (P) to be monitored; and (e) if the preservation state is considered to be satisfactory, then the expert in the system puts the system back into its initial color state using an appropriate heat treatment.
Another purpose of the invention is a thermochromic ink (E) composed of at least two thermochromic compositions (E1) and (E2), each of said thermochromic compositions (E1, E2) being micro-encapsulated separately from the other, and each having a first and a second color state dependent on the temperature, the transition from said first to said second color state being reversible, characterized in that said thermochromic compositions (E1, E2) have an adjustable thermal hysteresis such that the response curve (color density/temperature curve) of one of the two thermochromic compositions (E1) is envelope to the response curve of the second thermochromic composition (E2), and such that when said thermochromic ink (E) is heated, the transition from said first color state to said second color state takes place at a different temperature threshold than the transition from said second color state to said first color state when said thermochromic ink is cooled (E).
A final purpose of the invention is a writing or drawing instrument, particularly a pen, a felt pen, a wax crayon or chalk, containing thermochromic ink (E) according to the invention.
DRAWINGS
FIG. 1 is a graph illustrating a color density/temperature curve for the thermochromic compositions (E1, E2) contained in a thermochromic ink (E).
DESCRIPTION
The indicator system according to the invention comprises a thermochromic product (E) such as an ink, paint or a thermochromic plastic material (E) composed of at least two thermochromic compositions, for example (E1) and (E2), each having binary color variations (for example colored state/uncolored state) depending on the temperature.
Thermochromy is the capability of some materials to change color depending on the temperature. Thermochromic compositions used may be known thermochromic compositions, for example, like those disclosed in FR 2 591 534 or EP 1 477 320. These compositions typically include: (A) at least one chromatic organic compound called a leuco dye (dye wherein molecules may be in one of two forms, one of the two being colorless), which is an electron donor, (B) an electron acceptor compound that may be chosen particularly from the group formed by phenolic compounds, metallic salts of phenolic compounds, aromatic carboxylic acids, aliphatic carboxylic acids, metal salts of carboxylic acids, acid phosphoric esters, metallic salts of acid phosphoric esters and derivatives of triazole, and (C) a solvent, as the reactional medium that controls the colored reactions between compounds (A) and (B); this is usually a polar solvent. Solvents may be alcohols, esters, amides or acids, particularly with a long aliphatic chain.
In these thermochromic compositions, components (A), (B) and (C) will act on the shading type, the color density and the coloration or discoloration temperature respectively. By combining these components, a variety of reversible thermochromic compositions can be obtained wherein the shading type, the color density, the discoloration temperature and the recording preservation temperature interval can be determined depending on the relative proportions of components in the composition.
In one preferred embodiment, the thermochromic compositions used in a thermochromic product (E) are in the micro-encapsulated form. The advantage of micro-encapsulation is that the chemical integrity of the composition of each thermochromic composition (for example (A)+(B)+(C)) can be maintained and it can be protected from the outside environment. Products necessary to make the micro-encapsulation must not react with the thermochromic composition. The size of micro-capsules depends on several factors such as the concentration and the type of product used for micro-encapsulation. For example, an epoxy or melamine resin may be used for interface polymerization.
Compounds of components (A), (B) and (C) are exemplified in the following, for illustrative purposes. Known compounds such as lactone violet crystal that is an organic electron donor compound can be used as component (A) of the invention. The electron acceptor compound of component (B) may be composed of a group of compounds that have an active proton, a group of pseudo-acid compounds (a group of compounds that are not acid but that cause a change in the color of component (A) by acting like an acid in the composition) and a group of compounds that have electron holes. Finally, the compound for solvent (C) may be a fatty acid ester, for example ethyl palmitate.
The solubilized mix comprising the above-mentioned compounds may form a thermochromic product (E) such as an ink, paint or a thermochromic plastic material with a micro-encapsulated color memory, by inserting the mix in micro-capsules.
In one advantageous embodiment, the average diameter of the micro-capsules is between 0.5 and 50 μm and preferably between 1 and 15 μm. When the micro-capsules are too large, their dispersion in a liquid phase leads to an unstable system. When the micro-capsules are too small, it is difficult to obtain a high density coloring clearly visible to the naked eye.
Examples of the method for a micro-encapsulation system include a known type of interface polymerization of an isocyanate system, in situ polymerization for example of a melamine system, an immersed coating dip, a phase separation starting from an aqueous solution, a phase separation starting from an organic solvent, cooling by dispersion in the molten state, coating in suspension in air and drying by atomization.
In one particular embodiment, the indicator system may be in the form of a thermochromic label with a transparent or translucent white background, comprising a substrate (for example polymer film or paper sheet), that may be transparent or white, whereon a thermochromic ink (E) has been applied as the thermochromic product (E) with at least two thermochromic compositions (E1, E2).
In another particular embodiment, the indicator system may be in the form of a thermochromic label with a colored background comprising a substrate with a colored background whereon a thermochromic ink (E) is applied as the thermochromic product with at least two thermochromic compositions (E1, E2).
In general, the system comprises a thermochromic product (E) composed of at least two thermochromic compositions, for example (E1) and (E2), preferably with thermal hysteresis, each of which is characterized by four critical temperatures Ti,j: a temperature called the “lower color transition start temperature for increasing temperature” T1,2, T2,2; a temperature called the “lower color transition end temperature for increasing temperature” T1,3, T2,3; a temperature called the “upper color transition start temperature for reducing temperature” T1,4, T2,4; and a temperature called the “upper color transition end temperature for reducing temperature” T1,1, T2, 1.
Knowing that the abbreviations Ti,j (where i=1 or 2, j=1, . . . , 4) refer to the example in FIG. 1 . T1,j represents a critical temperature for the thermochromic composition (E1), T2,j represents a critical temperature for the thermochromic composition (E2).
We will now describe a first embodiment of the invention for illustrative purposes, namely an indicator system in the form of a thermochromic label with a white or transparent background comprising a transparent or white substrate (for example a polymer film) whereon a thermochromic ink (E) has been applied as the thermochromic product (E) composed of two thermochromic compositions (E1, E2).
The hysteresis characteristic in a color density/temperature curve for the thermochromic compositions (E1, E2) contained in the thermochromic ink (E) is described below with reference to the graph shown in FIG. 1 .
In FIG. 1 , the color density is shown on the ordinate and the temperature is shown on the abscissa. The variation in the color density due to a change in the temperature varies along the arrows.
Curve 1 shows the variation in the density of the black color of the thermochromic composition (E1) as a function of the temperature. Curve 2 shows the variation in the density of the red color of the thermochromic composition (E2) as a function of the temperature.
In FIG. 1 , T1,1 is the upper color transition end temperature for reducing temperature of the thermochromic composition (E1); T1,2 is the lower color transition start temperature for increasing temperature of the thermochromic composition (E1) (T1,2>T1,1);
T1,3 is the lower color transition end temperature for increasing temperature of the thermochromic composition (E1) (T1,3>T1,2); T1,4 is the upper color transition start temperature for reducing temperature of the thermochromic composition (E1) (T1,4<T1,3); T2,1 is the upper color transition end temperature for reducing temperature of the thermochromic composition (E2) (T2,1>T1,1); T2,2 is the lower color transition start temperature for increasing temperature of the thermochromic composition (E2) (T2,2>T2,1 and T1,2≈T2,2); T2,3 is the lower color transition end temperature for increasing temperature of the thermochromic composition (E2) (T2,3>T2,2 and T1,3≈T2,3); and T2,4 is the upper color transition start temperature for reducing temperature of the thermochromic composition (E2) (T1,4<T2,4<T2,3).
Zone 3 is the “ideal” temperature range for good preservation of the product or the batch of products (P) herein referred to as the “temperature range to be monitored” or the “setpoint temperature range”. Zone 1 is a temperature range lower than the temperature range to be monitored of the product or the batch of products (P). Zone 2 is the indicator activation zone. The user activates the indicator by putting it into very precise temperature conditions: the conditions for the Zone 2 window. Zone 4 represents a temperature range above the temperature range to be monitored for the product or batch of products (P).
We will start by describing a first usage situation wherein a product or a batch of products (P) whereon the thermochromic label (indicator) has been affixed, is overheated. The overheating phenomenon of the product or batch of products (P) can be described in several steps.
Step 1: firstly, the user activates the indicator by bringing it to a temperature T such that T1,4<T<T2,4 (Zone 2) for which only the thermochromic composition (E2) is in its colored state (since the temperature is still too low for the thermochromic composition (E1) to be colored). The indicator is red.
Step 2: the temperature is increased such that T2,4<T<T1,2 (Zone 3), the thermochromic composition (E2) is still in its colored state, the thermochromic composition (E1) is still in its uncolored state. Therefore, the indicator is red, and the product or batch of products (P) is still within the temperature range to be monitored.
Step 3: the temperature is increased once again such that T1,2<T<T1,3 (Zone 3) and then the temperature is increased such that T>T1,3 (Zone 4). The thermochromic composition (E2) is discolored until discoloration is complete for T>T1,3. The indicator becomes white or transparent (depending on the case). This means that the product or the batch of products (P) has been overheated (i.e. the temperature has momentarily exceeded the predetermined setpoint temperature) and the indicator retains this fact in memory even if the temperature returns into the temperature range to be monitored.
Step 4: the temperature is lowered to T2,4<T<T1,3 (Zone 3); due to their hysteresis, neither of the two thermochromic compositions (E1, E2) is recolored; therefore the indicator is white or transparent (depending on the case), since the ink is invisible. This means that the product or the batch of products (P) has been overheated, and the indicator remembers this even if the temperature returned into the temperature range to be monitored.
We will now describe a second usage situation wherein the product or batch of products (P) has been overcooled.
Step 1: firstly, the user activates the indicator by bringing it to a temperature T such that T1,4<T<T2,4 (Zone 2) for which only the thermochromic composition (E2) is in its colored state (since the temperature is still too low for the thermochromic composition (E1) to be colored). The indicator is red.
Step 2: the temperature is reduced to temperature T such that T1,1<T<T1,4 (Zone 1), the thermochromic composition (E1) is colored in turn. Therefore, the indicator turns black while retaining its red shade. The appearance of the black color means that the product or batch of products (P) has been cooled to below the temperature range to be monitored.
Step 3: the temperature is increased to temperature T such that T2,4<T<T1,2 (T1,2≈T2,2 Zone 3). The temperature has returned to the “ideal” range, the two thermochromic compositions (E1, E2) are not discolored. The result is that the indicator remains black with a red shade (the organic color donor compound can be chosen to make this red shade visible or not to the naked eye and/or in the infrared and/or in the near infrared). Therefore the appearance of the black color provides information that the product or the batch of products (P) has been cooled below the critical temperature and that the indicator retains this fact in memory even if the temperature returns into the temperature range to be monitored.
Step 4: the temperature is increased to reach a temperature T such that T>T1,3 and T>T2,3 (T1,3=T2,3, Zone 4). The two thermochromic compositions (E1, E2) are discolored and the indicator becomes white or transparent (depending on the case). This means that the product or batch of products (P) has been overheated and the indicator stores this fact in memory, but this is not sufficient to know if the product or batch of products (P) has been overcooled or if it has been previously overheated.
Consequently, if an indicator is used for example for a vaccine: if the indicator (label) is completely white or transparent on delivery, then the product or batch of products (P) has been overheated, threatening the integrity of the vaccine and notifying a danger. The merchandise can be refused; and if the indicator (label) is black on delivery, then the product or batch of products (P) has been overcooled, threatening the integrity of the vaccine and notifying a danger. The merchandise can be refused.
We will now describe a second embodiment of the invention for illustration purposes, namely a thermochromic label (indicator) with a colored background comprising a substrate with a colored background onto which a thermochromic ink (E) has been applied as the thermochromic product (E) with two thermochromic compositions (E1, E2). This second embodiment is also described with reference to FIG. 1 .
In the case of the second embodiment, FIG. 1 shows the variation of the color density relative to the temperature of a thermochromic ink system (E) comprising two thermochromic compositions (E1, E2), with different colors (e.g. (E1)=blue and (E2)=green). In this embodiment, the indicator has a colored background (e.g. yellow).
Curve 1 shows the variation in density of the blue color of the thermochromic composition (E1) as a function of the temperature. Curve 2 shows the variation in density of the green color of the thermochromic composition (E2) as a function of the temperature.
In FIG. 1 , T1,1 is the upper color transition end temperature for reducing temperature of the thermochromic composition (E1); T1,2 is the lower color transition start temperature for increasing temperature of the thermochromic composition (E1) (T1,2>T1,1); T1,3 is the lower color transition end temperature for increasing temperature of the thermochromic composition (E1) (T1,3>T1,2); T1,4 is the upper color transition start temperature for reducing temperature of the thermochromic composition (E1) (T1,4<T1,3); T2,1 is the upper color transition end temperature for reducing temperature of the thermochromic composition (E2) (T2,1>T1,1); T2,2 is the lower color transition start temperature for increasing temperature of the thermochromic composition (E2) (T2,2>T2,1 and T1,2≈T2,2); T2,3 is the lower color transition end temperature for increasing temperature of the thermochromic composition (E2) (T2,3>T2,2 and T1,3≈T2,3); and T2,4 is the upper color transition start temperature for reducing temperature of the thermochromic composition (E2) (T1,4<T2,4<T2,3).
Zone 3 corresponds to the temperature range to be monitored. Zone 1 corresponds to a temperature range below the temperature range to be monitored. Zone 2 is the indicator activation zone. The user activates the indicator by putting it under very precise temperature conditions: the conditions shown in the window in Zone 2. Zone 4 corresponds to a temperature range above the temperature range to be monitored.
We will now describe a first usage situation wherein a product or batch of products (P) has been overheated. In this example, the indicator has a yellow background.
Step 1: firstly, the user activates the indicator by bringing it to a temperature T such that T1,4<T<T2,4 (Zone 2) for which only the thermochromic composition (E2) is in its colored state (since the temperature is still too low for the thermochromic composition (E1) to be colored). The indicator is therefore green on a yellow background.
Step 2: the temperature is increased such that T2,4<T<T1,2 (Zone 3), the thermochromic composition (E2) is still in its colored state, the thermochromic composition (E1) is still in its uncolored state. Therefore, the indicator is green on a yellow background, and the product or batch of products (P) is still within the setpoint temperature range.
Step 3: the temperature is increased once again such that T1,2<T<T1,3 (Zone 3) and then the temperature is increased such that T>T1,3 (Zone 4). The thermochromic composition (E2) is discolored until discoloration is complete for T>T1,3 (Zone 4) The indicator becomes yellow. This means that the product or the batch of products (P) has been overheated and the indicator retains this fact in memory even if the temperature has since returned into the temperature range to be monitored.
Step 4: the temperature is then lowered such that T2,4<T<T1,3 (Zone 3); due to their hysteresis, neither of the two thermochromic compositions (E1, E2) is recolored; therefore the indicator is yellow. This means that the product or the batch of products (P) has been overheated, and the indicator remembers this even if the temperature has since returned into the temperature range to be monitored.
We will now describe a second usage situation in which case the product or batch of products (P) has been overcooled. In this example, the indicator has a yellow background.
Step 1: firstly, the user activates the indicator by bringing it to a temperature T such that T1,4<T<T2,4 (Zone 2) for which only the thermochromic composition (E2) is in its colored state (since the temperature is still too low for the thermochromic composition (E1) to be colored in turn). The indicator is therefore green on a yellow background.
Step 2: the temperature is reduced to a temperature T such that T1,1<T<T1,4 (Zone 1), the thermochromic composition (E1) is colored in turn. The indicator becomes Blue+Green on yellow background=Blue on yellow background. The appearance of the color blue means that the product or batch of products (P) has been cooled below the setpoint temperature range.
Step 3: the temperature is increased such that T2,4<T<T1,2 (T1,2≈T2,2, Zone 3). The temperature has returned inside the set range, the two thermochromic compositions (E1, E2) are not discolored. The result is that the indicator is Blue+Green on yellow background=Blue on yellow background. The appearance of the color blue means that the product or batch of products (P) has been cooled below the critical temperature and the indicator retains this fact in memory even if the temperature has since returned inside the setpoint temperature range.
Step 4: the temperature is then increased to a temperature T such that T>T1,3 and T>T2,3 (T1,3≈T2,3, Zone 4). The two thermochromic compositions (E1, E2) are discolored and the indicator becomes yellow (background color). The yellow means that the product or the batch of products (P) has been overheated, and the indicator remembers this, although it is impossible to know if the product or batch of products (P) had previously been overcooled or had previously been overheated.
Consequently, if the indicator is used for example for a vaccine: if the indicator has become yellow on delivery, then the product or batch of products (P) has been overheated, threatening the integrity of the vaccine and notifying a danger. The merchandise can be refused. If the indicator (label) has become blue, then the product or batch of products (P) has been overcooled, threatening the integrity of the vaccine and notifying a danger. The merchandise can be refused.
The state of the thermochromic label (indicator) according to the invention can be reset (i.e. the label can be returned to its initial state) by an appropriate heat treatment. The “initial state” according to the invention means the state of the indicator system (label) when it is placed under zone 2 temperature conditions (see FIG. 1 ), i.e. the activation zone of said system. For example, in the first usage situation described above (i.e. a product or batch of products (P) has been overheated), the label can be returned to its initial state by cooling to a temperature between T1,4 and T2,4. In practice, this can be useful when a batch of products (for example a batch of food products) has exceeded the upper setpoint temperature for a short period (for example T1,3), but after analysis of the product (for example by a microbiological and/or taste analysis), it is concluded that said product has not been damaged as a result of this brief passage at an excessive temperature. Therefore this possibility of “resetting” the label eliminates the need to destroy products that can still be sold, while notifying the stock manager about the temperature difference applied to the product. In many cases, a very short period outside the setpoint temperature range will not significantly deteriorate the product (P), knowing also that this temperature will firstly affect the packaging of the product (P) to which the label according to the invention is affixed, and will then propagate inside the product (P): the label according to the invention usually reacts to the effect of temperature more quickly than the product (P) for which it is monitoring good preservation inside the temperature range to be monitored.
The indicator is reset to zero by putting it under Zone 2 temperature conditions ( FIG. 1 ). The narrower the Zone 2 temperature interval, the more difficult it will be to make the reset. The advantage of such a narrow interval is that resetting requires precision and considerable skill and therefore it is very difficult for someone who is not familiar with the system to reset it.
The indicator system according to the invention may be made in the form of a thermochromic label, preferably self-adhesive, that can easily be affixed onto the product (P) or packaging of said product (P). The label advantageously comprises a substrate whereon a thermochromic ink (E) is applied as the thermochromic product; this application may be done by any known inking technique, for example ink jet. Optionally, this thermochromic ink (E) may be protected by a transparent film. Said substrate may be a usual type of polymer film (for example PP, PE, PVC, PET) or a sheet of paper, both cases being transparent, translucent, opaque, colored or not colored. Said substrate may also be a metal sheet, or a sheet of metallized polymer or any other appropriate substrate.
The invention may also be made in the form of a flexible, semi-rigid or rigid support, preferably transparent or translucent, for example a thermochromic plastic film (E) as the thermochromic product (E) wherein at least two thermochromic compositions (E1, E2) have been incorporated in said plastic film. This incorporation may be done during fabrication of said support, for example by a method wherein a plastic raw material is provided (for example pellets or a powder), with at least two thermochromic compositions (E1, E2) according to the invention, or said thermochromic compositions (E1, E2) can be incorporated in said raw material, preferably in the form of a powder, and said support is formed for example in the form of a flexible, semi-rigid or rigid sheet or plate, that can then be cut to the required dimensions. Said support may be flexible, semi-rigid or rigid. The result obtained is a particularly resistant indicator system, possibly reusable, for example in the form of a label or a wafer; this system, label or wafer may be coated with an adhesive glue on one side so that it can be affixed onto a product or packaging.
The thermochromic product (E) according to the invention may be in the form of a thermochromic ink (E) that can be used in a writing or drawing instrument, for example a pen, a ball point pen, a fountain pen, a felt pen, a wax crayon or chalk. Felt pens, ball point pens or fountain pens can use thermochromic ink (E) according to the invention directly in liquid form. A piece of chalk is fabricated by impregnating an appropriate colored mineral powder (typically white) with thermochromic ink (E) according to the invention, and an appropriate shaped block of chalk can then be formed by compression. A wax crayon can be made by incorporating thermochromic ink (E) according to the invention into an appropriate wax, preferably a colorless wax, and an appropriate shaped crayon is formed. These writing or drawing instruments may have many industrial, commercial and games applications.
Example
An example synthesis of a thermochromic product (E) composed of at least two thermochromic compositions (E1, E2) for the indicator system according to the invention is presented below, but the invention is not limited to this example. All the percentages characterizing a composition are given as percentages by mass.
a) Preparation of the Thermochromic Product (E1)
Step 1: 2 g of sodium alginate and 0.7 g of Uramine P-1500 are dispersed in a solution A of 100 grams of water.
Step 2: a solution B containing 5% of Pergascript Green® (CIBA) (CAS No. 34372-72-0), 10% of Bisphenol-A, 10% of Ethyl palminate and 73% of glycerol trilaurate are solubilized by heating to 100° C.
Step 3: solution B is poured into solution A while stirring (5 550 rev/min) for two minutes, and then 25 grams of a 25% solution of melamine formaldehyde in 75% water are poured slowly. The resulting emulsion is transferred while stirring slowly at 700 rev/min and is held in a warming bath for 8 hours.
After the suspension of micro-capsules has cooled, a discoloration temperature of 29° C. and a green re-coloration temperature of 7° C. are measured.
b) Preparation of the Thermochromic Product (E2)
Step 1: 2% of sodium alginate and 0.7% of Uramine P-1500 are dispersed in a solution A of 100 grams of water.
Step 2: a solution B containing 2.3% of Pergascript Blue® (BASF) (CAS No. 1552-42-7), 10.25% of Bisphenol-A, 8.25% of Ethyl palminate and 79% of Glycerol trilaurate.
Step 3: solution B is poured into solution A while stirring (5 550 rev/min) for two minutes, and then 25 grams of a 25% solution of melamine formaldehyde and 75% water are poured slowly. The resulting emulsion is transferred while stirring slowly at 700 rev/min and is held in a warming bath for 8 hours.
After the suspension of micro-capsules has cooled, a discoloration temperature of 32° C. and a blue re-coloration temperature of 6° C. are measured.
The indicator system may be in the form of a thermochromic label whereon a thermochromic ink (E) has been applied as the thermochromic product (E), said label being prepared as follows: 50 grams of type (E1) micro-capsules, 50 grams of type (E2) micro-capsules and 100 grams of silk screen printing resin are incorporated in an aqueous base. The thermochromic ink (E) thus obtained has been printed on a flexible, transparent or colored substrate to form a label.
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An indicator or display that may be in the form of a label that can instantaneously provide confirmation that a product is in a good preservation state by making a simple visual check, and particularly to detect if the product temporarily went outside a determined temperature range and to memorize this event. Strict monitoring of a temperature range is essential to be able to guarantee quality of many products. The indicator or display may be applicable to any product or device for which the temperature has to be monitored between two thresholds.
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BACKGROUND OF THE INVENTION
[0001] The present invention generally relates to apparatus and methods for providing vapor barriers and, more specifically, to apparatus and methods of inhibiting the migration of harmful vapors from the ground.
[0002] Many parcels of land are contaminated with harmful substances. Some sites may be contaminated by naturally occurring substances, such as Radon, or Methane. More commonly, sites are contaminated by industrial or commercial uses. For example, land and groundwater often becomes contaminated by factories, chemical processing plants, dry cleaning facilities, gasoline service stations, landfills and other facilities. When such parcels of land are no longer needed for these operations, they may sit idle because of the high cost of removing the contaminants.
[0003] In some cases, land has been contaminated by such high levels of hazardous waste or pollution that it is considered un-developable. Such sites are sometimes designated as hazardous waste sites or Superfund sites. In other cases, the level of contamination, and the cost to restore the land, may be low enough that the land is a candidate for redevelopment. In the U.S., such sites are often referred to as “Brownfields”. There has been an increase in the number of developments on Brownfields partly because these sites often exist in high-population density areas where there is a great demand for developable land.
[0004] Because of these trends, there has been an increased demand for economical ways to make Brownfields suitable for redevelopment. In some cases the contaminants may be removed. In many cases, however, it is either not possible, or practical, to remove all of the contaminants. In these cases, development may still be possible if ways are found to protect future occupants of the site from exposure to the hazardous substances at the site. One way to do this is to incorporate a barrier beneath newly constructed buildings that will inhibit the upward migration of chemical contaminants into the construction materials and indoor air space of the structure.
[0005] Unfortunately, past techniques for providing effective barriers to hazardous substances to make land safe for redevelopment have had a number of drawbacks, including high cost and difficulties in installation, or they may have not provided an adequate level of isolation from contaminant vapors. For example, various forms of polyolefin sheeting have been used as barriers to contaminant vapor intrusion. These may comprise low and medium density polyethylene, which is laid down in an overlapping pattern. The overlaps are then chemically sealed or heat welded to produce a continuous sheet. Penetrations through the membrane (e.g. sewer piping, electrical conduit, etc.) are sealed by wrapping and mechanically binding the membrane to the penetrating object. The use of these membrane materials for vapor barrier application is very labor intensive as the seam binding/welding and mechanical sealing of penetrations requires significant time by skilled technicians to ensure membrane integrity.
[0006] Latex modified asphalt sprays have also been used as a low cost alternative vapor barrier. Typically, the material is spayed onto the ground surface. In some cases, the asphalt may be applied over a typical geo-textile fabric, which serves to add tensile strength, but is not a barrier to vapor movement. During application, when encountering a penetration (e.g. conduit protruding upward) sealing around the protrusion is easily accomplished by spraying the asphalt-based material from the ground surface up to and contacting the protrusion, thus making a continuous seal. Asphalt-based membranes have been shown to perform well as barriers to water, but have limited ability to inhibit volatile organic vapors (e.g. gasoline, degreasing solvents, etc.) commonly found on previously polluted properties. In fact these membranes will be degraded by many of the chemicals commonly found on polluted sites (benzene, perchloroethene, etc.).
[0007] As can be seen, there is a need for improved ways to provide a barrier to hazardous materials that protects occupants of contaminated land, in a way that is effective, economical and easy to install. There is also a need for a contaminant vapor barrier that is easy to install on buildings which have penetrations through the barrier surface. There is also a need for a contaminant vapor barrier that is not degraded by the chemicals present on polluted sites.
SUMMARY OF THE INVENTION
[0008] In one aspect of the present invention, a composite membrane comprises: a first layer of high-density polyethylene (HDPE); a layer of asphalt applied over the first layer of HDPE; and a second layer of HDPE sheeting applied over the layer of asphalt.
[0009] In another aspect of the present invention, a method of creating a composite barrier to chemical vapors comprises: applying a base layer comprising high density polyethylene (HDPE); applying an asphalt layer over the base layer; and applying a top layer comprising HDPE over the asphalt layer.
[0010] In a further aspect of the invention, a method of constructing a building comprises: applying a base layer comprising polyethylene against a ground surface; applying an asphalt layer against the base layer; applying a top layer comprising polyethylene against the asphalt layer; and pouring a concrete layer against the top layer.
[0011] These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a partial perspective cut-away view of a partially constructed building utilizing the composite contaminant vapor barrier according to an embodiment of the present invention;
[0013] FIG. 2 is cross-sectional view of a below-grade floor of a building having overlapping sections of a composite contaminant vapor barrier according to an embodiment of the present invention;
[0014] FIG. 3 is a cross-sectional view of a composite contaminant vapor barrier according to an embodiment of the present invention; and
[0015] FIG. 4 is a flow chart of a method of preventing contaminant vapors from entering a building.
DETAILED DESCRIPTION OF THE INVENTION
[0016] The following detailed description is of the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.
[0017] The present invention generally provides a composite membrane system that may be placed directly on the ground surface prior to erecting a building on site. The resulting membrane system serves to inhibit vapors from upward migration into the construction materials and indoor air space of the structure. The composite membrane system of the present invention may be employed horizontally, beneath a concrete floor. Alternatively, embodiments may be employed in vertical configurations, such as between a below-grade wall and the adjacent soil. The present invention may also find applications on contaminated sites besides buildings, for example, to provide a contaminant vapor barrier under playgrounds and other recreational developments or under parking lots. The present invention may also provide protection from a range of contaminant vapors including those from petroleum-based products and chlorinated hydrocarbons.
[0018] Embodiments of the invention may provide a composite membrane system comprising various combinations of polyethylene sheeting and latex modified asphalt. The composite membrane system may be placed between the foundation of a building and the soil pad to eliminate vapor exposure pathways and to stop contaminated vapors from permeating through the slab. The present invention is not susceptible to chemically induced materials breakdown, punctures, and seam weakness resulting from poor detail work and/or application installation imperfections around penetrations. In some prior vapor barrier systems, asphaltic layers were susceptible to chemical breakdown. Prior vapor barriers employing polyethylene sheeting were difficult to install and were prone to vapor pathways around penetrations or seams.
[0019] FIG. 1 is a partial perspective cut-away view of a partially constructed building utilizing the composite membrane contaminant vapor barrier system according to an embodiment of the present invention. The vapor barrier 10 is installed directly on the soil 12 of a building pad. A concrete slab floor 14 is installed on top of the vapor barrier 10 . The floor 14 may be part of a building 16 , which includes a wall 18 and a footing 20 .
[0020] The vapor barrier 10 is constructed on-site by laying down a base layer 22 , which may comprise HDPE sheeting, directly onto the building pad soil 12 . HDPE provides chemical resistance, high tensile strength, and stress-crack resistance. The edges of individual sections of the base layer 22 are overlapped and bonded together, as described below.
[0021] A core layer 24 of asphalt in an emulsion form is layered directly over the base layer 22 . The core layer 24 may comprise an elastic co-polymer modified asphaltic membrane that may be spray-applied or applied by hand directly over the base layer 22 . The core layer 24 provides additional protection against vapor transmission and insures proper sealing of potential vapor pathways. The core layer also serves to secure the overlapping edges to the base layer 22 as well as attach the vapor barrier 10 to the building surfaces. The core layer 24 also creates an effective seal around slab penetrations, such as pipes, conduits and building structures that penetrate the vapor barrier 10 . One example of a penetration is pipe 28 which protrudes through an opening 30 in the vapor barrier 10 . As a result, the need for expensive mechanical fastening at termination points is eliminated. Furthermore, the core layer 24 serves to protect the base layer from potential damage during construction on the site.
[0022] A bond layer 26 is applied over the core layer 24 . The bond layer 26 may comprise the same material as the base layer 22 , which in the present embodiment is HDPE. The bond layer 26 helps protect the system from getting punctured after installation and provides a final layer of chemical resistance. The resulting vapor barrier 10 with the combination of the base layer 22 , the core layer 24 and the bond layer 26 is a vapor barrier that is resistant to even very concentrated chemical pollutant vapors, is puncture resistant and is economical to install.
[0023] FIG. 2 shows a cross-sectional view of a below-grade floor of a building having overlapping sections of the vapor barrier according to another embodiment of the present invention. In this embodiment, two overlapping adjacent sections of the vapor barrier are shown. In particular, a vapor barrier 32 is shown overlapping an adjacent vapor barrier 34 . Vapor barriers 32 and 34 may each include a base layer 36 , a core layer 38 and a bond layer 40 that are similar to the corresponding layers shown in FIG. 1 . Vapor barriers 32 and 34 are installed directly on the soil 42 of the building pad. A floor 44 comprises a poured concrete slab installed directly over the vapor barriers 32 and 34 .
[0024] In the region where vapor barriers 32 and 34 overlap, an additional asphaltic layer 50 may be applied between the two layers. This insures that the two layers are firmly and sealingly attached to each other. This asphaltic layer may be identical to the core layer 38 and may be applied in the same manner as the core layer 38 . In other embodiments, other sealing materials may be applied to form a seal between the two vapor barriers 32 and 34 . Also, in additional embodiments, instead of overlapping the vapor barriers 32 and 34 , the edges of the two vapor barriers may be placed adjacent to each other and a sealing material placed across the edges. In other embodiments, one or both of vapor barriers 32 and 34 may be entirely, or partially, disposed in a vertical orientation, for example, against a vertical wall of soil (not shown). In this vertical orientation, a below-grade concrete wall (not shown) may be installed on the side of the vapor barrier opposite the soil.
[0025] FIG. 3 shows a cross-section of a composite vapor barrier 52 in accordance with an alternative embodiment of the invention. Vapor barrier 52 includes base 54 , core 56 and bond 58 layers, as described above. However, in this embodiment, the base 54 and bond 58 layers have an additional layer added to them. In particular, the base layer 54 includes an HDPE layer 60 with a geo-textile layer 62 bonded to its bottom surface. Geo-textile layer 62 provides a friction course between the base layer 54 and the soil. This inhibits movement between the base layer 54 and the soil during installation. The geo-textile layer 62 may comprise a coating of unwoven spun polypropylene fibers. In one embodiment, the base layer 54 comprises the product Geo-Seal Base, core layer 56 comprises the product Ecoline S, and the bond layer 58 comprises the product Geo-Seal Bond, all three products being available from Land Science Technologies Division of Regenesis Corporation of San Clemente, Calif.
[0026] The core layer 56 may be identical to the core layers 24 and 38 described above. The bond layer 58 may comprise a layer of HDPE 64 with a geo-textile layer 66 bonded to its top surface. Like the geo-textile layer 62 , geo-textile layer 66 may comprise a coating of unwoven spun polypropylene fibers. The geo-textile layer 66 provides and effective bond between the vapor barrier 52 and the adjacent concrete slab.
[0027] The bond layer 58 may also have a series of perforations 68 passing through it. These perforations may serve two functions. They allow for water vapors that occur upon the dehydration curing of the latex modified asphalt in the core layer 56 to move upwards. Also, upon laying the concrete structural slab on the bond layer, the perforations 68 allow water penetration and vaporization to aid in the curing of the concrete slab.
[0028] FIG. 4 shows a flow chart of a method of preventing contaminant vapors from entering a building. In step 72 a sheet of the base layer is applied to the soil. This may comprise, for example base layers 22 , 36 or 54 . This step may also include adding openings for penetrations, such as opening 30 . The core layer is then applied on the base layer in step 74 . This may comprise core layer such as core layers 24 , 38 or 56 . In step 76 the base layer is also applied to the penetrations and edge regions of the base layer. This may include penetrations, such as pipe 28 and opening 30 as well as the perimeter edges of the base layer.
[0029] In step 78 , the bond layer, such as bond layers 26 , 40 or 58 , is applied to the core layer. In step 80 an additional core layer may be applied to the top of the bond layer where it will overlap with an adjacent vapor barrier. For example this may comprise the region of bond layer 50 as shown in FIG. 2 . Finally, a concrete slab is installed on top of the bond layer in step 82 . This slab may be, for example, slab 14 , 44 or 49 .
[0030] As can be appreciated by those skilled in the art, the present invention provides a composite contaminant vapor barrier system and method. The vapor barrier may be economically installed on-site directly on contaminated soil. The vapor barrier is effective in inhibiting the upward migration of vapors into a building constructed over the vapor barrier. The vapor barrier is resistant to puncturing. Penetrations, such as pipes, passing through the vapor barrier are easily sealed by the sprayed-on core layer. Also, the materials used in the vapor barrier are not susceptible to chemical breakdown.
[0031] It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.
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A composite membrane comprises: a first layer of high-density polyethylene (HDPE) and a layer of asphalt applied over the first layer of HDPE. A second layer of HDPE sheeting is applied over the layer of asphalt. A method of creating a composite barrier to chemical vapors is also disclosed which comprises applying a base layer comprising high density polyethylene (HDPE); applying an asphalt layer over the base layer; and applying a top layer comprising HDPE over the asphalt layer.
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This is a continuation of application Ser. No. 222,909, filed Apr. 5, 1994, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to locks having key-controlled removable and installable cores and, more particularly, to such locks in which the core must be rotated to a specific position before the removal or installation can be effected.
2. Description of the Prior Art
The use of cylinder locks in connection with various pieces of equipment, such as cabinet drawers and the like, is well known. Various forms of such locks have been constructed for diverse applications, the specific configuration of any particular lock being a function of the particular application. In one such configuration, typically used for locking cabinet drawers and the like, the lock controls a latch member or cam which is engageable with a keeper for locking the drawer. Typically, the latch member or cam is engaged with a shifter which is rotatable within the rear end of the cylindrical housing of the lock and is, in turn, engageable with a key-operated core rotatably disposed in the forward end of the housing. Absent the key, combinating tumblers in the core, which may be disks or pins, are biased into longitudinal grooves or splines in the housing to prevent rotation. When the combinating tumblers read a properly bitted key inserted in a keyway in the core, they are retracted within the core to accommodate rotation of the core between locked and unlocked positions. Each groove may be paired with a companion, diametrically opposed groove, to allow the tumblers to shift about as the key is inserted and withdrawn.
It is often necessary to replace the core. To this end, various constructions of removable lock cores have been developed, wherein the core is usually removable by means of a special release or control key which is intended to operate a special retaining tumbler once the lock core is manipulated into a certain release position by the standard key. Exemplary locks of this type are disclosed, for example, in U.S. Pat. Nos. 5,101,649 and 5,119,654, in each of which locks the core is removable only when disposed in its unlocked position. When such a lock is used in an application utilizing a rotatable latch cam and shifter, the core decouples from the shifter as a result of removal from the housing. While the core can be removed and reinstalled in only a single rotational position relative to the housing, once it is removed the shifter might accidentally be rotated so that, upon reinstallation of a new core, the shifter is no longer in a proper rotational orientation relative to the core. Thus, when the core is rotated to its locked position, the latch cam may not actually be in engagement with the keeper.
SUMMARY OF THE INVENTION
It is a general object of the invention to provide an improved removable-core lock mechanism, which avoids the disadvantages of prior lock mechanisms while affording additional structural and operating advantages.
An important feature of the invention is the provision of a lock mechanism of the type set forth, which includes a latch member shifter which is engageable with the removable core in only a single relative rotational orientation thereof.
Yet another feature of the invention is the provision of a lock mechanism of the type set forth, which inhibits migration of the shifter from the single rotational orientation upon removal of the core.
Still another feature of the invention is the provision of a lock mechanism of the type set forth, which effectively prevents rotation of the shifter beyond positions corresponding to the locked and unlocked conditions of the core.
These and other features of the invention are attained by providing a lock mechanism comprising: a generally cylindrical housing having a bore extending axially therethrough, a key-controlled core rotatable within the bore between locked and unlocked conditions and removable from the bore, a latch shifter adapted to be coupled to the core for rotation therewith within the bore and adapted to be coupled to an associated latch member, first and second coupling structures respectively on the core and the shifter and mateably engageable with each other in only a single rotational orientation thereof relative to each other for rotating the shifter in response to rotation of the core in the bore, and stop structures respectively formed on the housing and the shifter, one of the stop structures including first and second stop surfaces respectively engageable with the other of the stop structures in the locked and unlocked conditions of the core for limiting rotation of the shifter.
The invention consists of certain novel features and a combination of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the details may be made without departing from the spirit, or sacrificing any of the advantages of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
For the purpose of facilitating an understanding of the invention, there is illustrated in the accompanying drawings a preferred embodiment thereof, from an inspection of which, when considered in connection with the following description, the invention, its construction and operation, and many of its advantages should be readily understood and appreciated.
FIG. 1 is a perspective view of a lock in accordance with the present invention illustrated in a locked condition, with a latch member and standard key illustrated in phantom;
FIG. 2 is a view similar to FIG. 1, illustrating the lock in an unlocked position;
FIG. 3 is a partially exploded perspective view of the lock of FIG. 2, illustrating the core of the lock removed with a control key;
FIG. 4 is an enlarged, perspective, exploded view of the cylindrical housing of the lock of FIG. 3;
FIG. 5 is an enlarged, fragmentary, rear perspective view of the core of the lock of FIG. 3;
FIG. 6 is an enlarged, fragmentary, rear perspective view of the cylindrical housing of the lock of FIG. 3;
FIG. 7 is an enlarged top plan view of the latch shifter of the lock of FIG. 4;
FIG. 8 is a view in vertical section taken along the line 8--8 in FIG. 7;
FIG. 9 is an enlarged view in vertical section taken along the line 9--9 in FIG. 2, with the core illustrated in phantom;
FIG. 10 is a view in horizontal section taken along the line 10--10 in FIG. 9, with the latch member removed;
FIG. 11 is an enlarged, fragmentary, sectional view of the rear end of the lock of FIG. 9, illustrating the shifter rotation stop mechanism;
FIG. 12 is a view in vertical section taken along the line 12--12 in FIG. 10;
FIG. 13 is a fragmentary, sectional view illustrating the inter-engagement of the core and the shifter of the lock of FIGS. 1-4; and
FIG. 14 is a rear end elevational view of the lock of FIG. 9, taken generally along the line 14--14 therein, with the latch member removed.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1-4 and 6, there is illustrated a removable-core lock, generally designated by the numeral 10, constructed in accordance with and embodying the features of the present invention. The lock 10 includes a cylindrical housing 11 having an externally threaded body 12 with diametrically opposed flats 13 (FIGS. 4 and 10), and having an enlarged-diameter collar 14 at the forward end thereof. A cylindrical bore 15 extends axially through the cylindrical housing 11 from a front end 16 to a rear end 17 thereof. Referring also to FIGS. 9, 10 and 12, the bore 15 has a substantially cylindrical inner surface 18 with an enlarged-diameter counterbore 19 at the forward end thereof. Formed in the inner surface 18 and extending longitudinally thereof, from the counterbore 19 approximately half the length of the cylindrical housing 11, are a pair of diametrically opposed grooves or splines 20, and a pair of diametrically opposed grooves or splines 21 which are, respectively, spaced substantially 90° from the grooves 20. Also formed in the inner surface 18 a slight distance rearwardly of the rear ends of the grooves 20 and 21 is an annular groove 22. A notch 23 at the rear end of one of the grooves 20 provides communication between that groove 20 and the annular groove 22 (FIGS. 10 and 12). A stop finger 25, longitudinally aligned with the bottom one of the grooves 21, as illustrated in FIG. 9, projects radially into the bore 15 at the rear end of the cylindrical housing 11 (see FIGS. 6, 11 and 14).
Referring in particular to FIGS. 4 and 7-14, a latch shifter 30 is rotatably disposed in the bore 15 at the rear end of the cylindrical housing 11. The shifter 30 has a cylindrical body 31 with a circumferential groove 32 formed in the outer surface thereof in which is disposed an O-ring 33. The outer surface of the cylindrical body 31 has a reduced-diameter portion 35 adjacent to the rear end thereof, from which there extends axially rearwardly a projection 36, which is substantially square in transverse cross section. The cylindrical body 31 has an axial bore 37 therethrough, having an internally threaded portion 38 at the rear end thereof. Also formed in the rear end of the body 31 is a generally rectangular slot 39 which diametrically intersects the threaded bore portion 38. The forward end of the bore 37 is enlarged to define a coupling socket 40, which has a central region 41 substantially square in transverse cross section and a rectangular lobe 42 which projects laterally from one side of the central region 41, as is best illustrated in FIG. 12. The reduced-diameter portion 35 of the body 31 has an arcuate groove 45 formed therein, which has a circumferential extent of approximately 90° and defines radial stop shoulders 46 and 47 at its opposite ends (see FIGS. 7, 8, 11 and 14). The rear end of the reduced diameter portion 35 has a notch 44 therein (FIGS. 7 and 14) which communicates with the groove 45. A latch cam 48 (FIGS. 1, 2 and 9) may be fixedly secured to the rear end of the shifter 30, as by a screw 49 threadedly engaged in the threaded bore portion 38. The latch cam 48 may have a rectangular opening therethrough which fits over the rectangular projection 36 on the shifter 30 to prevent rotation of the latch cam 48 relative to the shifter 30.
Referring in particular to FIGS. 3, 5 and 10, the lock 10 also includes a cylindrical core 50 which is removably receivable in the forward end of the bore 15. The core 50 has an enlarged-diameter, radially outwardly extending flange 51 at the forward end thereof dimensioned to fit in the counterbore 19 of the bore 15. The core 50 has a plurality of tumblers 52 disposed in diametrical slots in the core 50 in a known manner. The tumblers 52, two of which are illustrated in FIG. 5, preferably include a plurality of combinating tumblers to control locking and unlocking of the lock and a retaining tumbler to control removal of the core 50 from the housing 11. The combinating tumblers are dimensioned and arranged to be receivable in the longitudinal splines or grooves 20 and 21 in the cylindrical housing 10, while the retaining tumbler 52 is positioned and dimensioned so as to be receivable in the annular groove 22. Formed axially through the core 50 is a key slot 53 which receives a standard key 58 (FIG. 1) having bittings which are read by the combinating tumblers 52 for retracting the tumblers inside the circumference of the core 50 to permit rotation of the core 50 between its locked and unlocked positions, again all in a known manner. In the preferred embodiment, the locked and unlocked positions are spaced 90° apart, as can be seen in FIGS. 1 and 2. The core 50 also has a retaining lug 54 (FIG. 10) which projects radially outwardly therefrom into the annular groove 22.
In order to remove the core 50 from the housing 11, both the retaining tumbler 52 and the retaining lug 54 must be disengaged from the annular groove 22. The standard key 58 is not long enough to reach the retaining tumbler 52. Thus, for removal of the core 50, a control key 59 is used which is dimensioned to reach the retaining tumbler and retract it into the core 50. However, in the preferred embodiment, the core 50 can be removed only in its unlocked position, in which position the retaining lug 54 aligns with the notch 23 to permit its release from the annular groove 22. Preferably, the control key 59 does not include the standard bittings, so that it cannot be used to rotate the core 50 between its locked and unlocked positions.
Referring in particular to FIGS. 5 and 13, the core 50 includes a coupling plug 55 which projects axially from the rear end thereof and is shaped and dimensioned for mating engagement in the coupling socket 40 of the shifter 30. More specifically, the plug 55 has a central portion 56, which is substantially square in transverse cross section and dimensioned for mating engagement in the central region 41 of the coupling socket 40, and a lug 57 which projects laterally from one side of the central portion 56 and is disposed for mating engagement in the lobe 42 of the coupling socket 40.
It is a significant aspect, of the invention that, because of the lobed arrangement of the coupling socket 40 and the coupling plug 55, the core 50 can be engaged with the shifter 30 only in one relative rotational orientation thereof. Also, as was explained above, because of the retaining lug 54 on the core 50, the core 50 can be removed from and inserted in the housing 11 in only the unlocked position. This will ensure that, when a new core 50 is installed, the latch cam 48 will also be in the unlocked position. Otherwise, it will not be possible to fully insert the core 50 in the housing 11. It will further be appreciated that the frictional engagement of the shifter O-ring 33 with the inner surface 18 of the cylindrical housing 11 inhibits free rotation of the shifter 30 from the unlocked position once the core 50 is removed. Furthermore, the engagement of the stop finger 25 of the housing 11 in the arcuate groove 45 of the shifter 30, and specifically with the stop shoulders 46 and 47, prevents rotational movement of the shifter 30 beyond the locked and unlocked positions. Also, the groove 45 captures the stop finger 25 to prevent axial movement of the shifter 30 except when the stop finger 25 is aligned with the notch 44, which preferably occurs between the locked and unlocked positions. This permits assembly of the shifter 30 in the housing 11. In the event that the shifter 30 should somehow be rotated slightly from the unlocked position after removal of the core 50, an appropriately-sized square drive tool can be inserted in the coupling socket 40 to rotate the shifter 30 back to the unlocked position to permit reinstallation of the core 50.
In the illustrated embodiment, the core 50 carries a male member (55), while the shifter 30 carries a female socket 40, for inter-engagement of the core 50 and the shifter 30. However, it will be appreciated that a reverse arrangement could be utilized. Similarly, while inter-engagement between the shifter 30 and the housing 11 is effected by a male member (25) formed on the housing 11 and a female groove 45 formed on the shifter 30, it will be appreciated that a reverse arrangement could be utilized.
From the foregoing, it can be seen that there has been provided an improved removable-core lock which includes alignment structure to ensure that the core and the shifter can be inter-engaged in only a single relative rotational orientation, and further including means to inhibit and limit free movement of the shifter from that orientation when the core is removed.
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A lock mechanism has a cylindrical housing with an axial bore therethrough, and a key-controlled core rotatable within the bore between locked and unlocked conditions and removable from and installable in the bore in the unlocked condition. The core has a plug at its rear end which is mateably engageable in a socket on the front face of a shifter, for rotating the shifter within the bore in response to rotation of the core, and thereby operating a latch member coupled to the shifter. A radial tab on the housing is receivable in an arcuate groove formed in the outer surface of the shifter for limiting rotation of the shifter to facilitate retention of the shifter in the single rotational orientation upon removal of the core from the housing. An O-ring on the shifter frictionally inhibits rotation thereof.
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RELATED APPLICATION
[0001] This application is a non-provisional application of provisional application 61/968,581, filed Mar. 21, 2014, the disclosure of which is incorporated by reference herein.
TECHNICAL FIELD
[0002] The present disclosure relates generally to turbines, and, more specifically, to a method and system for controlling an amount of fluid in a control cavity using a hydraulically controlled secondary valve.
BACKGROUND
[0003] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
[0004] Turbochargers are used for many applications. A turbocharger includes a pump portion and a turbine portion. Turbochargers are used for recovering energy from a pressurized stream of fluid. Excessive pressure in the turbine portion is used to drive the pump portion. One use for a turbocharger is recovering energy from a brine outlet of a reverse osmosis membrane assembly.
[0005] Reverse osmosis systems operate in a wide range of operating conditions for any given flow while seeking to maintain a high level of performance. Various turbine configurations are known for improving levels of performance for the turbine.
[0006] In one known turbine, single volute nozzle volute systems use a valve stem to allow bypass fluid from the turbine inlet to the impeller. Some improvement in performance is achieved. A valve is used to control the amount of fluid in the bypass. Manually controlled valves require a person to physically move the control wheel using high torque. This is not practical especially in systems with multiple stages. Electrically controlled valves can be automated. However, due to the high torque involved in turning the valves, the systems for rotating the valves are expensive.
SUMMARY
[0007] The present disclosure provides a turbine design that allows for controlling an amount of fluid entering a control volume using a hydraulically controlled valve in a bypass path.
[0008] In one aspect of the disclosure, a turbine includes a housing having an inlet, a volute and an outlet. The inlet is coupled to the volute through a primary fluid path and a secondary fluid path. The turbine further includes an impeller rotatably coupled to the housing, and a hydraulically actuated valve assembly disposed within the secondary fluid path selectively communicating fluid from the inlet to the volute. The turbine includes a hydraulic actuator coupled to the valve assembly moving the valve assembly from a first position communicating fluid from the inlet into the volute to a second position blocking flow from the inlet to the volute.
[0009] In another aspect of the disclosure, method of operating a turbine includes communicating fluid from an inlet of the turbine to a volute through a primary fluid path and selectively communicating fluid from the inlet of the turbine to the volute through a secondary path fluid path through a hydraulically controlled valve assembly. The hydraulically controlled valve assembly comprises a housing and a piston head defining a control cavity and a valve stem having a valve head thereon. The method further comprises communicating fluid to the control cavity, moving the valve head relative to a valve seat, and changing an amount of fluid flowing though the primary fluid path to the volute in response to communicating fluid to the control cavity.
[0010] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
[0011] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
[0012] FIG. 1A is a block diagrammatic view of a reverse osmosis system that includes a turbocharger.
[0013] FIG. 1B is a block diagrammatic view of the turbocharger of FIG. 1A .
[0014] FIG. 1C is a block diagrammatic view of a turbocharger and motor assembly referred to as a HEMI.
[0015] FIG. 2A is a perspective view of the hydraulic valve assembly on a turbocharger according to the present disclosure.
[0016] FIG. 2B is an exploded view of the of the hydraulic valve assembly of the turbocharger according to the present disclosure.
[0017] FIG. 3 is a cutaway perspective view of the turbocharger and valve assembly.
[0018] FIG. 4 is a cutaway view of the hydraulic valve assembly according to the present disclosure.
[0019] FIG. 5A is a schematic view of a control circuit for control of the hydraulically actuated valve assembly in a closed position.
[0020] FIG. 5B is a schematic view of a control circuit for control of the hydraulically actuated valve assembly in an open position.
DETAILED DESCRIPTION
[0021] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical or. It should be understood that steps within a method may be executed in different order without altering the principles of the present disclosure.
[0022] The present disclosure improves the hydraulic range of a turbine by allowing a variable amount of fluid to be communicated to the volute. The turbine has a primary fluid path and a secondary fluid path for communicating fluid from the inlet to the volute. The primary path is always open. As will be described below, a hydraulically actuated valve is attached to the turbine housing and opens and closes (including positions therebetween) a secondary fluid path from the inlet to the volute
[0023] The turbocharger described below may be used for various types of systems, including a reverse osmosis system. Non-hydraulic applications such as natural gas processing are also possible. Further, the valves used in the turbocharger may be controlled based upon various process parameters.
[0024] Referring now to FIG. 1A , a reverse osmosis system 10 that includes a turbocharger 12 is set forth. In this example, feed fluid from an input manifold 14 is communicated through a high pressure pump 16 which in turn is communicated to a membrane housing 18 through the turbocharger 12 . The membrane housing 18 includes a reverse osmosis membrane 20 that is used to generate fresh water from sea water. Fresh water is generated at the permeate output 22 of the membrane housing. A brine stream from the membrane housing is directed to an inlet 24 of the turbocharger 12 through a brine control valve 25 selectively communicates the fluid from the turbocharger 12 to the membrane housing 18 . The turbocharger 12 uses the energy from the high pressure brine stream to increase feed fluid pressure. The pressurized feed fluid from the high pressure pump 16 is received through a pump input 26 . The turbocharger 12 increases the pressure of the feed fluid and increases the pressure of the feed fluid at the pump output 28 . Waste from the turbocharger 12 is discharged at a lower pressure through the turbocharger outlet 30 . Although one specific example of a reverse osmosis system 10 is illustrated, various examples for reverse osmosis systems will be evident to those skilled in the art. By providing the turbocharger 12 , the required pressure from the high pressure pump is reduced and the overall energy consumed by the system is also reduced as compared to a system without the turbocharger 12 .
[0025] Referring now to FIG. 1B , the turbocharger 12 is illustrated in further detail. The turbocharger 12 includes a turbine portion 40 and a pump portion 42 . The turbine portion 40 recovers energy from the high pressure stream by rotating and ultimately rotating the components within the pump portion 42 . The pump is used to increase the pressure of fluid to the input of the membrane housing 18 .
[0026] Referring now to FIG. 1C , the turbocharger 12 may also be incorporated into a system that includes a common shaft 50 that extends not only through the pump and turbine portion illustrated in FIG. 1B but extends to a motor 52 . The motor 52 includes a controller 54 the addition of the motor 52 allows the turbocharger to act as a pump when desired. The controller 54 may be used to drive the motor 52 . The controller 54 may be referred to as a variable frequency device. The motor 52 may also act as a generator to recover the excess power generated.
[0027] Referring now to FIGS. 2A and 2B , an assembled view and an exploded view of a turbocharger 12 is illustrated. In this example, the turbine portion 40 and a pump portion 42 having a common shaft 50 therebetween (as denoted by the dotted line). The turbine portion 40 includes a turbine housing assembly 202 and a hydraulically controlled valve assembly 204 . The turbine housing assembly 202 includes the brine stream the inlet 24 . The turbine outlet 30 is not illustrated in the perspective of FIG. 2A .
[0028] The hydraulically controlled valve assembly 204 has a piston housing 206 coupled to the turbine housing assembly 202 and an end cap 208 . Fasteners 209 may be used to secure the end cap 208 to the piston housing 206 .
[0029] The hydraulically controlled valve assembly 204 has a linear guide 210 that is in physical communication with a position sensor 212 and which extends through the end cap 208 . The linear guide 210 is movable in a direction parallel with the direction of movement of a piston head 216 and valve stem 218 that is coupled thereto. The linear guide 210 may extend into the hydraulically controlled valve assembly 204 a varying amount.
[0030] The position sensor 212 may be coupled to the housing 202 with a holder 214 . The position sensor 212 may be various types of sensors used to determine the relative position of the linear guide 210 . The position sensor 212 generates a position signal corresponding to the linear position. The position sensor 212 may, for example, be formed of a linear potentiometer that changes an output signal or voltage based upon the position of the linear guide 210 . The position sensor 212 may also be a linear encoder that provides the relative position of the linear guide 210 to a controller as described below. The position sensor 212 may also be comprised of a limit switch if exact positions of the system are not required. Details of the movement of the linear guide 210 and the position sensor 212 will be described in more detail below.
[0031] The valve stem 218 is coupled to the piston head 216 and moves together therewith during use. The housing comprises a valve guide 220 . The valve guide 220 may be integrally formed with the piston housing 206 . The valve guide 220 positions the valve stem 218 so that the valve head 222 is positioned in the desired position relative to a valve seat as is described below.
[0032] Referring now to FIG. 3 , an end view of the turbine assembly 200 illustrating the turbine housing assembly 202 , the volute 232 , the hydraulically controlled valve assembly 204 and the inlet 24 are set forth in an assembled manner. The hydraulically controlled valve assembly 204 is set forth without the position sensor 212 , guide 210 and the holder 214 for simplicity.
[0033] The shaft 50 is coupled to and rotates with a turbine impeller 228 . The shaft 50 represents the axis of rotation of the impeller 228 . The shaft 50 may extend out of the turbine housing 202 into the pump portion 42 of the turbocharger as described above. The impeller 228 has impeller vanes 234 that are used to receive pressurized fluid and rotate the shaft 50 .
[0034] The housing 202 has a primary fluid path 240 from the turbine inlet 24 to the volute 232 . The primary fluid path 240 has a fixed width to allow fluid to pass therethrough. The primary fluid path 240 does not change. That is, fluid is always communicating therethrough during operation. A secondary fluid path 242 also communicates fluid from the inlet 24 to the volute 232 . The secondary fluid path 242 has the hydraulic actuated valve assembly 204 disposed therein. The hydraulically controlled valve assembly 204 is used to selectively move between an opened and closed position in the secondary fluid path 242 . Thus, the valve assembly 204 may be partially opened or closed. The hydraulically controlled valve assembly 204 is illustrated in an open position. However, as the valve stem 218 moves, the valve head 222 contacts the valve seat 252 . The valve seat 252 may be formed as part of the housing 202 .
[0035] Referring now to FIG. 4 , details of the hydraulically controlled valve assembly 204 is set forth. In this example, the piston head 216 and the valve stem 218 moves in the direction indicated by the arrows 410 , which corresponds to the longitudinal axis of the valve assembly 204 . The linear guide 210 that moves the position sensor 212 also moves in the direction indicated by the arrows 410 . The linear guide 210 may have seals 412 that seal a control cavity 414 from the external environment to prevent leakage. The piston head 216 may also include seals 416 . The seals 416 may be referred to as piston rings. The seals 416 prevent fluid from within the control cavity 414 from leaking outside of the control cavity 414 .
[0036] The piston head 216 divides the piston housing 206 into the control cavity 414 and a movement area 418 that allows the piston to travel back and forth and expand and contract the control cavity 414 .
[0037] An inlet port 420 is used to provide a control fluid to the control cavity 414 . By providing a high pressure fluid to the control cavity 414 , the control cavity 414 is expanded and the piston head 216 is moved toward the valve seat 252 . When a low pressure fluid is provided to the control cavity 414 , the piston head 216 moves toward the inlet port 420 . This, in turn, moves the valve stem 218 and the valve head 222 away from the valve seat 252 .
[0038] An exit port 422 is in fluid communication with the movement area 418 . The inlet port 420 allows any air to escape the volume between the piston head 216 and the other part of the piston housing 206 .
[0039] In an alternative embodiment, the exit port 422 may be used to provide high pressure into the movement area 418 while the inlet portion 420 is used as an inlet port for the control cavity 414 which is exposed to a low pressure. In this manner, the piston head 216 may be forced toward the inlet 420 .
[0040] A plurality of seals 424 may be used to seal the valve stem 218 within the valve guide 220 . The valve guide 220 may be sealed within the housing 202 with seals 426 .
[0041] A control circuit 440 may be coupled to the inlet port 420 . As mentioned briefly above, the control circuit 440 may also be coupled to the exit port 420 . The control circuit 440 may be combination of valves that are electrically controlled to provide fluid paths to the control cavity 414 to control the movement of the piston head 216 and the valve stem 218 attached thereto. By controlling the movement of the valve stem 218 , the opening and closing of the hydraulically controlled valve assembly 204 is controlled.
[0042] The valve head 222 may include an angular seal surface 426 that is used for engaging the seal seat 252 to form a seal therebetween. The seal prevents fluid flow through the secondary fluid path 242 . An angular surface 428 may couple the valve stem 218 to the seal surface. The valve head 222 may also include a flat surface 430 . In this example, the flat surface 430 is perpendicular to the longitudinal axis of the valve stem 218 .
[0043] Referring now to FIG. 5A , a simplified hydraulic control diagram is illustrated in which the control circuit 440 provides high pressure fluid to the control cavity 414 . In this example, the valve head 222 is shown in a closed position. That is, the fluid from the inlet 24 does not travel through secondary fluid path 242 to the volute 232 . In this example, valve 510 is in an open position to allow high pressure fluid from the high pressure source 508 into the control cavity 414 through the inlet port 420 . The low pressure valve 512 is in a closed position. The high pressure valve or the low pressure valve may be a normally open valve for failsafe operation. When the high pressure valve is a normally open valve, the system will close the valve assembly 204 upon loss of power or control. If the low pressure valve 512 is replaced with a normally open valve, the system will open the secondary fluid path 242 upon loss of system power or shutdown. The choice between which valve is normally open is based on design considerations.
[0044] A controller 514 controls the operation of the valves 510 , 512 . During operation, typically either the high pressure valve 510 or the low pressure valve 512 is open to allow a varying amount of fluid to pass though the valve assembly 204 and through the fluid path 242 . However, during a cleaning process or other type of process, both valves 510 and 512 may be opened. The controller 514 is in communication with a plurality of process sensors 520 . The process sensors 520 may include the position sensor illustrated above. Other types of sensors such as temperature sensors, flow sensors, flow rate sensors, or the like may be used by the controller 514 to determine whether to open or close the high pressure valve 510 or the low pressure valve 512 to change the amount of fluid passing through the fluid path 242 . It should be noted that both valves 510 and 512 may be closed when no change is desired in the position of the valve head 222 relative to the valve seat 252 . From an at-rest position, the piston head 216 , the valve stem 218 and valve head 222 may be moved by introducing high pressure fluid into the inlet port 420 . To move the piston head 216 and valve head 222 toward the valve seat 252 , low pressure may be exposed to the control cavity 414 through the low pressure valve 512 .
[0045] Feedback control is achieved by periodically monitoring the process variables using the process sensors 520 . The controller 514 , in response to the process sensors 520 , open and close the appropriate valves 510 , 512 to change the opening between the valve head 222 and the valve seat 252 . The process variables are described below:
[0000]
Loop Forever
E = (P − S) / S
Calculate error percentage
If E >1 then E = 1
Limit error to range [−1 . . . 1]
If E <−1 then E = −1
TO = K E T
Compute valve open time
TC = T − TO
Compute valve closed time
If E > D
Check for outside of deadband
Open V1 for time TO
Open V1 to close primary fluid path
Close V1 for time TC
If E < −D,
Check for outside of deadband
Open V2 for time TO
Open V2 to open primary fluid path
Close V2 for time TC
P—Process variable, measured value.
S—Set point for process.
E—Current error (percent).
K—Proportional gain (~1, tunable value).
D—Deadband in percent (typically 1%).
T—Update time period (typically 5 seconds).
TO—Valve open time period.
TC—Valve close time period.
[0046] In the above algorithm the error percentage is calculated between a range of −1 and +1. The valve open time and the valve close time may be calculated using a proportional gain, a current error and an update. A deadband D may be compared to the current error. When the current error is outside of the deadband, the valve may be opened or closed. That is, when the error is greater than the deadband, valve 510 is opened to close the amount of the opening of valve assembly 204 . When the error is less than the negative deadband, then the valve 512 is opened so that the piston moves toward the control port.
[0047] Referring now to FIG. 5B , the piston 216 is illustrated toward the inlet port 420 . To move the piston 216 toward the inlet port 420 as compared to that in FIG. 5A , the high pressure valve is 510 is closed and the low pressure valve 512 is opened. This causes the valve head 222 to be in an open position to allow flow through the valve. A plurality of valve head positions may be achievable between the valve head positions illustrated in FIGS. 5A and 5B so that the flow through the fluid path 242 may be varied.
[0048] In both FIGS. 5A and 5B high pressure source 508 and the low pressure source 516 may be hydraulically coupled to the turbine portion. That is, the high pressure source 508 may be in fluidic communication with the turbine inlet 24 which is a high pressure source. The low pressure source 516 may be coupled to the turbine outlet 30 or even to the atmosphere.
[0049] Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification and the following claims.
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A turbine and method of operating a turbine includes a housing having an inlet, a volute and an outlet. The inlet is coupled to the volute through a primary fluid path and a secondary fluid path. The turbine further includes an impeller rotatably coupled to the housing and a hydraulically actuated valve assembly disposed within the secondary fluid path selectively communicating fluid from the inlet to the volute. The turbine includes a hydraulic actuator coupled to the valve assembly moving the valve assembly from a first position communicating fluid from the inlet into the volute to a second position blocking flow from the inlet to the volute.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for injecting fluid into a wellbore and, more particularly, to a method for injecting fluid, such as an accelerator, into a cement slurry in a subterranean wellbore.
2. Description of the Prior Art
Well established methods are employed in oil and gas exploration for cementing-in a wellbore that penetrates subterranean formations. Typically, casing is installed in the wellbore, displacing mud therein. The outside diameter of the casing is smaller than the inside diameter of the wellbore, providing thereby an annular column, or annulus, between the casing and the wellbore. In a primary cementing job, cement is pumped into the annulus to bond the casing to the earth formation of the wellbore, protect the casing against corrosive gases and liquids, and provide zonal isolation which prevents vertical communication of fluids along or within the annulus or otherwise through the column.
In a typical primary cementing job, a bottom, hollow-core, diaphragm plug is pumped (run) down the interior of the casing using a cement slurry. After sufficient cement slurry to fill the annulus has been pumped down the casing, a top, solid-core plug is pumped down the casing using displacement fluid such as mud. The bottom and top plugs protect the cement slurry from contamination by mud which precedes the bottom plug and follows the top plug. The bottom plug moves downwardly until it comes to rest at the casing shoe, at which time pressure builds up in the slurry above the bottom plug and ruptures the diaphragm therein. The cement slurry then passes down through the bottom plug and the bottom of the wellbore and up into the annulus. The top plug continues to move downwardly until it comes to rest on top of the bottom plug, at which time the annulus should be substantially filled with cement slurry, thereby completing the cementing operation. The cement slurry is then allowed to set up or harden in the annulus, forming thereby a rigid annular column between the casing and the earth formation of the wellbore.
Spacer fluids, such as soap-water mixes or weighted polymer fluids compatible with both mud and cement, are often used to perform, in the annulus, the functions performed by the plugs in the casing. That is, the spacer fluids are run before and after the cement to flush the mud out of the annuls before the cement slurry enters the annulus and to keep the mud and the cement separate in the annulus.
The time required for cement to set, which is often referred to as the "waiting-on-cement" (WOC) time, may range from several days up to a week. WOC time is costly because it represents downtime during which drilling equipment is idle. Furthermore, a long WOC time increases the probability that cement may fall back into the casing, or into a "rat hole," or the like, thereunder, and that gaseous or liquid fluids from a reservoir may invade and weaken the cement column while the cement is in transition from a liquid to a solid state (the "transition-to-set" time). To reduce the WOC and transition-to-set times, as well as the cement slurry thickening (hardening) time, common accelerators, such as calcium chloride, sodium chloride, sodium meta-silicate, and others well known to the art, are often blended at the surface of the wellbore with bulk cement or prepared cement blends and mix water. These accelerator-treated cement slurries are then pumped down the well. Because several hours may elapse before such slurries reach the bottom of deep wells, if accelerators are not controlled, they may cause the cement slurry to set prematurely while still in the casing, thereby preventing the slurry from being run into the annulus and, furthermore, requiring the subsequent removal of hardened cement from the interior of the casing. To ensure against such a premature set, a "safety factor" is included in the calculated thickening time, thus further reducing the usefulness of these types of accelerators in deep wells.
Other accelerators, such as amines, amides, and organic acids, all well known in the art, will also accelerate cement slurries and provide the same desired properties mentioned above. However, these accelerators typically have uncontrollable behaviors and, for that reason, may not be pre-blended at the surface with the cement slurry.
One attempt to reduce, or accelerate, the WOC time has been to use an accelerating overwash similar to that used in permafrost applications in which coil tubing is run down the wellbore and cement, followed by a spacer fluid, is pumped therethrough. The cement is partially set or dehydrated and the accelerating overwash is then pushed through the partially set matrix or permeability of the cement resulting in some acceleration of the WOC time. However, in conventional cementing practice, this method is limited due to (1) the high potential for contamination of the treating fluid with displacing fluids such as drilling muds, (2) the volume of additives required to condition a much larger slurry volume and, (3) the inability of the accelerator to control the slurry in the annulus or even to mix sufficiently with the cement slurry at the casing shoe.
In addition to accelerators, it may also be necessary to mix other additives with the cement slurry to effect one or more of the following: retard the cement set, control fluid minimize or stop fluid or gas migration, increase the gel strength or thixotropic behavior of the cement, nullify the contamination and over-retardation effects of mud on the cement, or improve the cement's bonding.
A device developed for injecting chemical additives into subterranean wellbores is shown in U.S. Pat. No. 4,361,187 to Luers which discloses a downhole mixing valve for such applications as cementing or fracturing wells. This valve is generally mounted on tubing which is run into a wellbore casing. A first fluid is pumped down the tubing while a second fluid is pumped down an annulus formed between the tubing and the casing and the two fluids are mixed at the mixing valve. However, there are several disadvantages to such a device. For example, if displacement fluid is used to pump the first and second fluids down the tubing and the annulus, then the fluids will inevitably become contaminated. If displacement fluid is not used, then an exorbitant, very uneconomical, quantity of first and second fluids will be required to fill the tubing and the annulus. Furthermore, Luers requires that the two fluids converge at the mixing valve at the same time, a very difficult task. Such a device would also be impractical for cementing an entire wellbore annulus, and only one such device could be used in a wellbore at a time. Moreover, such a device requires an additional trip mechanism with the tubing which increases the costs and time required for cementing operations.
In view of the foregoing, what is needed is a method for reducing cement slurry thickening, transition-to-set, and WOC times in a manner that can be controlled, even in deep wellbores, without premature setting of the cement.
SUMMARY OF THE INVENTION
The foregoing problems are solved and a technical advance is achieved by a method in which fluids, such as accelerators, are injected downhole into a wellbore. In a departure from the art, the method comprises storing a first fluid, such as an accelerator, in a reservoir or device; disposing of or locating the device or reservoir downhole in a wellbore; and then causing the device or reservoir to inject or transfer the first fluid into a second fluid, such as a cement slurry, at a desired time and location in the wellbore.
In one embodiment of the invention, the reservoir is defined by an annular space surrounding a central passageway in a plug. The reservoir is provided with openings through which the first fluid may flow from the reservoir into the passageway. The plug is then pumped down to the bottom of the casing in a conventional manner. The second fluid is then caused to flow through the passageway so as to create a pressure drop and venturi effect across the openings, thereby inducing the first fluid to flow out from the reservoir through the openings and into the second fluid in the passageway.
In another embodiment of the invention, the reservoir is defined by an annular space enclosed within the wall of a portion of casing. The casing is set in the wellbore. The reservoir is provided with openings through which the first fluid may flow from the reservoir into an annulus defined between the casing and the wellbore. The second fluid is then caused to flow through the annulus so as to create a pressure drop and venturi effect across the openings, thereby inducing the first fluid to flow out from the reservoir through the opening and into the second fluid in the annulus.
Many advantages are achieved with this invention, including control, or a reduction, of cement slurry thickening time, transition-to-set time, and compressive strength development (and consequent WOC) time, without causing the cement to set prematurely in associated casing. Some consequences of controlling or accelerating these slurry properties include the reduction of over-retardation resulting from mud contamination, minimization of gas and fluid migration, control of lost circulation, and elimination of cement fall-back or U-tubing.
Many further advantages are also achieved with the present invention. For example, well testing, logging, drillout, and completion procedures may be safely started earlier. Less time is required to meet Federal, State, and local government regulations governing cement set procedures. Zonal isolation is maximized by promoting cement set before gas encroachment can create channels through the annulus. Extra thickening time can be designed into slurries to relax thickening times for pumping safety and control standards, thereby minimizing the degree of laboratory support required. Wet shoes and damage to primary cement jobs by early shoe tests may be minimized. The compressive strength and ductility of hardened cement is improved. Quicker setting cement squeezes, resulting in better, more cost effective remedial applications, may be performed. Quicker hardening cement plugs may be utilized for whipstocking or well abandonment. Treating fluids may be separately disposed as preflushes or overflushes to the cement in the wellbore, though effective treatment through commingling of two fluid phases is restricted to the fluid interfaces.
Several further advantages result from the second embodiment described above, that is, from storing fluid in a reservoir integrated into a casing wall. For example, fluid may be injected anywhere in the upper or lower region of the wellbore where there may exist, for example, a weak zone, a gas invasion problem, lost circulation, or significant changes in thermal gradients which further affect conventional practices. Furthermore, cement slurry, including lead slurry (i.e., slurry intended for the upper region of the annulus), may be flash-set before it gets contaminated or diluted, and external casing packers may be obviated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional, elevational view of a first preferred embodiment of a downhole injection plug that may be utilized to implement the method of the present invention;
FIG. 2 is a cross-sectional, elevational view of a case cementing system in which the plug of FIG. 1 may be utilized;
FIG. 3 is a cross-sectional, elevational view of the plug of FIG. 1 incorporating a sliding ring;
FIG. 4A and 4B are partial, cross-sectional, elevational views of a casing wall having a reservoir that may be utilized to implement the method of the present invention; and
FIGS. 5A and 5B are is a cross-sectional, elevational views of the casing wall of FIG. 4 engaging a cementing valve.
DESCRIPTION OF PREFERRED EMBODIMENTS
In FIG. 1, the reference numeral 10 designates a first embodiment of a downhole injection plug that may be used to implement the method of the present invention. As shown therein, the plug 10 includes a cylindrical housing 12 having a substantially cylindrical outer wall 14 and an upper end portion 16 extending radially inwardly from the upper end of the wall. An opening 18, concentric with the wall 14, is formed extending through the upper end 16. The opening 18 is sealed off by a diaphragm 20 which may be ruptured upon the application to the diaphragm of a predetermined pressure, as will be described. An additional opening 22 is formed through the upper end portion 16 intermediate the opening 18 and the wall 14. Preferably, a plurality of pliable wiper blades 24 are provided encircling the upper and lower portions of the outside of the wall 14.
A mandrel 26 is secured within the housing 12 and includes a substantially cylindrical inner wall 28 having an upper end portion seated against the periphery of the opening 18, and a lower flanged end portion 30 extending radially outwardly therefrom. The inner wall 28 defines a central cylindrical passageway 32 extending longitudinally through the housing 12. In the lower portion of the passageway 32, a counterbore 34 is formed which is concentric with, and has a slightly larger diameter than, the passageway 32. An annular chamber 36 is defined by the inside of the outer wall 14, the inner wall 28, the upper end 16, and the lower end 30. Four angularly spaced fluid metering orifice ports (or openings) 38 (two of which are shown) extend radially through the lower portion of the wall 28 from the chamber 36 into the counterbore 34. Three spaced counterbore openings 40 are also formed extending radially from the counterbore 34 into the flange 30. A recess 42 is formed on the bottom side of the flange 30, which recess is concentric with, and extends radially and outwardly from, the counterbore 34.
An elastomer bladder 44 is disposed inside, and substantially fills, the annular chamber 36. Four orifice blocks 46, each of which define a plurality of orifices 48, are evenly spaced, and secured to, the lower inner portion of the bladder 44 such that the blocks align with and engage the orifice ports 38, thereby establishing fluid communication between the interior of the bladder 44 and the counterbore 34. The upper portion of the bladder 44 includes a filling stem 50 extending through the opening 22, which stem has a conventional back check valve (not shown) to permit the bladder to be precharged with a fluid, such as a cement slurry accelerator, but to prevent such fluid from discharging therefrom.
A sliding valve sleeve 52 is disposed in the counterbore 34 and includes a cylindrical wall 54 having three sleeve holes 56, four sleeve ports (or openings) 58, and a flange 60 extending radially outwardly from the bottom thereof. The wall 54 and the flange 60 are sized so that the sleeve 52 can slide within the counterbore 34 and so that the flange may be received by the recess 42. The sleeve 52 has a hollow core sized to form substantially an extension of the central passageway 32.
The sleeve 52 is disposed within the counterbore 34 such that the sleeve flange 60 is spaced outwardly from the counterbore, as shown in FIG. 1. The three sleeve holes 56 are arranged on the sleeve 52 to correspond and align with the three counterbore openings 40. Three shear pins 62 are provided which extend through the corresponding aligned sleeve holes 56 and counterbore openings 40 thereby substantially securing the sleeve 52 relative to the counterbore 34. The shear pins 62 are sized so that they will shear when a predetermined longitudinal load is applied to the wall 54 and the sleeve flange 60. Two O-rings 64 are arranged on the circumference of the sleeve 52 for sealing the orifice ports 38 and containing fluid within the bladder 44.
In FIG. 2, the reference numeral 70 designates a case cementing system in which the downhole injection method of the present invention may be implemented utilizing the plug 10. The cementing system 70 is designed to operate in subterranean wellbore 72 and includes a string of casing 74 and a plurality of centralizers 76 for centering the casing in the wellbore. The casing 74 includes a float collar 78 secured to the casing a short distance up from the bottom of the casing. An annulus 80 is defined between the wellbore 72 and the casing 74.
During a primary cementing operation, a conventional bottom cementing plug 82 and top cementing plug 84 are provided in addition to the plug 10. The bottom plug 82 has a hollow core sealed with a rupturable diaphragm (not shown), and the top plug 84 has a solid core. Both plugs 82 and 84 are designed to prevent the mixing of fluids above and below the diaphragm or solid core and to permit a differential pressure to be applied across the plugs so that the plugs may be pumped down the casing 74. To this end, the plugs 82, 84 are further provided with conventional wiper blades similar to the wiper blades 24 on the injection plug 10 (FIG. 1). The wiper blades wipe the inside surface of the well casing 74 free of drilling mud or other fluids present therein and sealingly separate the fluids above and below the respective plugs (e.g., mud below and cement slurry above the bottom plug), thereby minimizing contamination of the cement slurry by mud.
In accordance with the method of the first embodiment of the present invention, the casing 74, including the float collar 78, is set in the wellbore 72 as shown in FIG. 2, and the bottom plug 82 is pumped down the casing 74 using a "lead" cement slurry. After a pre-determined amount of cement slurry has been pumped down the casing 74, the downhole injection plug 10, precharged with fluid and having the sleeve 52 spaced outwardly therefrom as shown in FIG. 1, is pumped down the casing using additional, or "tail," cement slurry. After a pre-determined amount of additional cement slurry has been pumped down the casing 74, the top plug 84 is pumped down the casing using displacement fluid such as mud.
The bottom plug 82 moves downwardly until it comes to rest on the float collar 78, at which time the slurry pressure above the plug is increased momentarily until the diaphragm on the plug is ruptured. The cement slurry then begins to pass downwardly through the hollow core of the bottom plug 82, the float collar 78, the bottom of the casing 74, and upwardly into the annulus 80.
The injection plug 10 moves downwardly until the sleeve 52 and the sleeve flange 60 impact the bottom plug 82, thereby shearing the shear pins 62 and causing the sleeve to slide upwardly into the counterbore 34 until the sleeve flange is seated within the recess 42 and is flush with the bottom of the mandrel flange 30. Slurry pressure is then increased momentarily until the diaphragm 20 on the injection plug 10 is ruptured. The cement slurry then passes downwardly through the central passageway 32 and the sleeve 52 of the injection plug 10, the bottom plug 82, the float collar 78, the bottom portion of the casing 74, and upwardly into the annulus 80.
In addition to the foregoing, with the sleeve 52 fully disposed within the counterbore 34, the orifice ports 38 and the corresponding sleeve ports 58 align with each other, thereby establishing fluid communication between the interior of the bladder 44 and the interior of the sleeve. Furthermore, because the inside diameter of the sleeve 52 is less than that of the casing 74, the velocity of the fluid passing through the sleeve is greater than through the casing. Therefore, as the cement slurry passes through the sleeve 52, a venturi effect is generated across the sleeve ports 58 in a manner commonly understood in the art, thus creating a pressure drop at the sleeve ports. At the same time, pressure on the bladder 44 and fluid therein is equalized, via the stem 50, with the pressure of the cement slurry above the injection plug 10. As a consequence, because pressure above the injection plug 10 is greater than the venturi pressure drop at the sleeve ports 58, a differential pressure is created between the bladder 44 and the sleeve ports, thereby causing fluid to flow outwardly from the bladder through the ports 38 and 58 into the sleeve 52 and to mix with the cement slurry as the slurry flows through the passageway 32.
The top plug 26 continues to move downwardly until it comes to rest on the injection plug 10, thereby terminating the cementing operation (except, of course, for the WOC time).
FIG. 3 depicts a second embodiment of a downhole injection plug 90 for implementing the method of the present invention. Since the plug 90 contains many elements that are identical to those of the first embodiment, these identical elements are referred to by the same reference numerals and will not be described in any further detail.
According to the second embodiment shown in FIG. 3, there is no bladder 44 or stem 50; rather, a sliding ring 92 is provided which can slide vertically within the annular chamber 36, thus dividing the chamber into an upper chamber portion 94 and a lower chamber portion 96. The lower chamber portion 96 stores fluid, such as a cement slurry accelerator. Fluid, such as downhole cement slurry, may enter, via the opening 22, and fill the upper chamber portion 94. The ring 92 is provided with seals 98 which prevent fluids in the upper and lower cavity portions from mixing.
In accordance with the method of the second embodiment, when the injection plug 90 is pumped down the wellbore 72 (FIG. 2), and impacts the bottom plug 82, the sleeve 52 slides upwardly, and the orifice ports 38 and corresponding sleeve ports 58 align. Cement slurry then flows through the central passageway 32 and sleeve 52 creating thereby a venturi effect at the sleeve ports 58 and a differential pressure across the fluid such that fluid is caused to flow outwardly from the lower chamber 96 into the sleeve 52 and to mix with the cement slurry as in the first embodiment.
FIGS. 4A and 4B depict a fluid reservoir integrated into the wall of a casing string according to a third embodiment for implementing the method of the present invention. According to the third embodiment shown in FIGS. 4A and 4B, a casing string 110, shown in a wellbore 112, includes a casing portion 114 having an outer casing wall 116 and an inner mandrel 118 coupled together at an interface 120. The lower end of the mandrel 118 is connected to a conventional casing shoe 122 at a threaded connection 124. The lower end 126 of the casing wall 116 fits closely around the upper end of casing shoe 122. The casing wall 116 and the mandrel 118 define an annular chamber 128 therebetween. A vent tube 130 provides fluid communication between the chamber 128 and a well annulus portion 132a of an annulus 132, which annulus is defined between the casing 110 and the wellbore 112.
A reservoir elastomeric bladder 134 is disposed in the chamber 128 in a manner similar to the disposition of the bladder 44 in the plug 10 of the first embodiment. The lower end of the bladder 134 is connected to a plurality of solenoid-actuated valves 136 which are normally closed. A battery-powered microprocessor 138 is connected to the solenoid-actuated valves 136 by a connector 140. The microprocessor 138 is adapted for controlling the solenoid-actuated valves 136 and opening it in response to the presence of a magnetic field of a predetermined minimum strength. When the solenoid-actuated valves 136 are opened, fluid communication is established between the interior of the bladder 134 and the annulus 132.
In accordance with the method of the third embodiment of the present invention as shown in FIGS. 4A and 4B, during a cementing operation, a first or bottom plug 140, a second or intermediate plug 142, and a solid core top plug (not shown) are provided. The plugs 140, 142 have hollow cores sealed with diaphragms 144, 146, respectively, to prevent mixing of fluids above and below the diaphragm and to permit a differential pressure to be applied across the plug so that the plug may be pumped down the casing 110. The plugs 140, 142 are further provided with conventional wiper blades 148, 150, respectively, for wiping the inside surface of the well casing 110 free of drilling mud or other fluids present therein and sealingly separating the fluids above and below the respective plugs. Additionally, the intermediate plug 142 is also magnetized sufficiently to exude a magnetic field of the predetermined minimum strength required to signal the microprocessor 138 to open the valve 136.
The first, or bottom, plug 140 is pumped downwardly into the casing 110 until it comes to rest on the casing shoe 122 and seats thereon. Slurry pressure is then increased momentarily until the diaphragm 144 is ruptured. The cement slurry then flows downwardly through the bottom plug 140 and through an opening 152 of the casing shoe 122 and upwardly into the well annulus 132 as indicated by the arrow 154.
After a predetermined amount of cement slurry has been pumped down the casing string 110, the second, or intermediate, plug 142 is pumped down the casing. As the plug 142 passes the microprocessor 138, the latter senses the magnetic field exuded by the plug and actuates the solenoid-actuated valves 136 to establish fluid communication between the bladder 134 and the well annulus 140. As the plug 142 comes to rest on the bottom plug 140, the slurry pressure is increased momentarily until the diaphragm 146 is ruptured.
The cross-sectional area of well annulus 132 is smaller than that of the well annulus 132a so that fluid flows at a higher velocity through the well annulus 132 than through the well annulus 132a. As in the first embodiment, this increased fluid flow velocity creates a venturi effect with a consequent pressure differential across the casing portion 114. This collapses the bladder 134 so that the fluid therein is forced outwardly through the orifices of the valve 136 into the cement slurry stream flowing upwardly through the well annulus 132.
After a predetermined additional amount of cement slurry has been pumped down the casing 110, the top plug (not shown) is pumped down the casing using a displacement fluid such as mud in a manner substantially identical to that shown in FIG. 3 for the first embodiment. When the top plug comes to rest on the intermediate plug, the cementing operation is complete.
FIGS. 5A and 5B depict a fourth embodiment of a casing string 110 for implementing the method of the present invention. Since the casing string 110 contains many elements that are identical to those of the third embodiment, the identical elements are referred to by the same reference numerals and will not be described in any further detail. The only difference between the third and the fourth embodiments is the inclusion in the latter embodiment of a cementing valve 160 rather than the casing shoe 122 of the third embodiment. Also, the bottom plug 140, rather than the intermediate plug 142 (which is not used in the fourth embodiment), is magnetized sufficiently to exude a magnetic field of the predetermined minimum strength required to signal the microprocessor 138 to open the valve 136.
The cementing valve 160 is of a conventional design and includes a body 162, a central passageway 164 extending longitudinally through the valve, a plurality of cementing ports (or openings) 166 extending radially from the passageway through the body into the annulus 132, and a longitudinal slot 168 located above the cementing ports 166 and extending through the body. An opening sleeve 170 is slidably disposed within the lower end of the body 162. A closing sleeve 172 is disposed within the body 162 above the opening sleeve 170. The closing sleeve 172 has a seat 174 formed at its upper end for receiving the bottom plug 140 and is secured to the body 162 with a shear pin 176. An outer sleeve 178 is slidably disposed outside the body 162. A coupling pin 180 is provided which extends through the slot 168 and into corresponding holes in the closing sleeve 172 and the outer sleeve 178 so that the closing and outer sleeves move together and close the port 166 when the closing sleeve is resting on top of the opening sleeve 170.
In accordance with the fourth embodiment of the present invention, pressure is applied in a conventional manner to move the opening sleeve 170 downwardly to an open position, as shown in FIG. 5B, thereby facilitating fluid communication between the central passageway 164 and the annulus 132 via the port 166. The casing 110 is closed below the valve 160.
A predetermined amount of cement slurry is then pumped down the casing 110 followed by the bottom plug 140 and additional slurry until the bottom plug comes to rest on the seat 174. Slurry pressure is then increased momentarily until the diaphragm 144 is ruptured. The cement slurry then flows downwardly through the bottom plug 140, the central passageway 164 of the closing sleeve 172, through the port 166, and upwardly into the well annulus 132.
As the bottom plug 140 comes to rest on the seat 174, the microprocessor 138 senses the magnetic field exuded by the bottom plug and opens the valve 136 thereby establishing fluid communication between the fluid in the bladder 134 and the well annulus 132. As in the third embodiment, a venturi effect is created with a consequent pressure differential across the casing portion 114. This pressure collapses the bladder 134, forcing the fluid therein outwardly through the orifices of the valves 136 into the cement slurry stream flowing upwardly through the well annulus 132.
After a predetermined amount of additional cement slurry has been pumped down the casing, a solid core top plug (not shown) is pumped down. As the top plug 142 comes to rest upon the upper end of the bottom plug 140, the slurry pressure is momentarily increased until the top and bottom plugs force the closing sleeve 172 in the cementing valve 160 to move downwardly and shear the shear pin 176. Because the outer sleeve 178 is connected to the closing sleeve 172 by the coupling pin 180, the outer sleeve moves downwardly with the closing sleeve to sealingly close the cementing ports 166 to terminate the cementing operation. It is understood that the method of the present invention may be implemented utilizing many forms and embodiments. The embodiments shown herein are intended to illustrate rather than to limit the invention, it being appreciated that variations may be made without departing from the spirit or the scope of the invention. For example, the venturi effect utilized could be supplemented by pre-charging the fluid reservoir (e.g., a bladder or a chamber above a ring) with gas prior to pumping the reservoir downhole to ensure that the fluid flows outwardly from the reservoir when it should. Furthermore, the bladder may include a pump which may meter fluid into a cement slurry stream, which pump may be, for example, a screw or centrifugal type pump powered either electrically (e.g., by a battery) or hydraulically (e.g., from the flow of slurry).
In further embodiments, a ring could be used in the fluid reservoir of the third or fourth embodiments in place of a bladder in a manner analogous to that described in relation to the second embodiment.
In still further embodiments, one or more of the aforementioned embodiments may be used in various combinations at multiple points in a wellbore. For example, the plug disclosed in the first embodiment may be introduced at any point in the slurry or used to inject fluid at the bottom of the wellbore while at the same time fluid is injected into an upper region of the wellbore using the fourth embodiment described above. Furthermore, the third embodiment described above may be connected at its lower end to other casing rather than a casing shoe, thereby enabling it to be used in an upper region of the wellbore.
In still further embodiments, the method may include injecting a variety of types of fluids at any point in a subterranean wellbore, and, with respect to cement slurries therein, to effect one or more of the following: accelerate or retard the WOC, control fluid loss in the cement, gel the cement, increase or decrease the slurry's weight or density, increase the mechanical strength of the cement when set, reduce the effect of mud on the cement, or improve the cement's bonding. Such fluids used primarily during cementing operations are known in the art and include accelerators, retarders, fluid loss agents, and friction reducers in a variety of forms commercially available to and commonly used in the industry. Such fluids used primarily during stimulation operations are known in the art and include cross-linking polymers, gel breakers, and corrosion inhibitors known to and commonly used in well fracturing and acidizing procedures. Such accelerators include: metal chlorides such as calcium chloride, sodium chloride, potassium chloride; alkali metal silicates such as sodium metasilicate, sodium silicate, potassium silicate; amines such as triethanolamine, diethanolamine, monoethanolamine; amides such as formamide; organic acids such as acetic formic acid; esters of organic acids such as the first four carbon esters of formic acid, methyl formate, ethyl formate, normal-propyl formate, isopropyl formate, normal-butyl formate, iso-butyl formate, and t-butyl formate; sodium fluoride solutions; and salts of formic acid such as mixtures thereof and the like. Retarders include tartaric acid, sodium glucoheptonate, glucono-delta lactone, sodium lignosulfonate, and the like. Fluid loss agents include polyethyleneimine, polyalkaline polyamine, styrene butadiene, polyvinyl alcohol, and the like. Friction reducers include polynapthalene sulfonate, sulfonic acid, calcium lignosulfonate, quebracho, and the like. Cross-linking polymers include borate, zirconium lactate, titanium solutions, and the like. Gel breakers include ammonium persulfate, oxalic acid, hydrochloric solutions, and the like. Corrosion inhibitors include gluteraldehyde, potassium iodide, corban, and the like.
In still further embodiments, the method of the present invention may include mixing slurry and injected fluid by utilizing baffle plates inside the shoe or cementing valve. The method may also include utilizing a greater or lesser number of ports, shear pins, orifice blocks, solenoid valves, or the like than described hereinabove.
In still further embodiments, the method of the present invention may include using a magnetized ball or dart instead of a magnetized plug to effect a signal to a microprocessor. Such signal may also be effected by irradiating a portion of the slurry, as by adding a radioactive tracer thereto, and releasing fluid from the reservoir only into the irradiated portion, or, conversely, only into the nonirradiated slurry. Such signal may further be effected mechanically by a trip hammer or a shear pin protruding into the casing; the port sleeve or valve may be opened when the hammer or pin are tripped or sheared, respectively, as by a plug, ball, or dart moving down the casing. Furthermore, a trip hammer or a shear pin may be used to actuate a pressurized canister of, for example, CO 2 , to open a port sleeve or valve.
Although illustrative embodiments have been shown and described, a wide range of modification, change, and substitution is intended in the foregoing disclosure and in some instances, some steps of the present invention may be employed without a corresponding use of the other steps. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.
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A method for injecting fluid, such as an accelerator, into a wellbore comprises storing the fluid in a reservoir, locating the reservoir downhole in the wellbore, and then transferring the fluid from the reservoir into the wellbore. More particularly, one embodiment of the method comprises storing the fluid in a reservoir in a plug, pumping the plug down casing in a wellbore, and transferring the fluid at the bottom of the wellbore via a venturi effect. Another embodiment of the method comprises storing the fluid in a reservoir integrated into the wall of a portion of casing, setting the casing in the wellbore, and then transferring the fluid via a venturi effect from the reservoir into the annulus defined between the casing and the wellbore.
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BACKGROUND OF THE INVENTION
The present invention concerns a spinning preparatory machine, in particular a card, with a feeder roll including a body supporting the feeder trough coordinated thereto, a loosening roll provided with points or tips, and with a loosening zone for the fibre material, located between the feeder roll and the loosening roll, and with a suction device located in the converging space formed between the incoming or inbound surface of the loosening roll and the surface of the feeder roll.
In staple fibre yarn spinning the open-end spinning method has found increasing acceptance since this method is more economical in certain yarn count ranges in comparison to the older ring spinning method. In processing natural fibres especially, the open-end spinning method, however, shows the disadvantage, that it reacts susceptibly to the trash present in the fibre slivers to be fed. Mainly the contaminations consisting of micro dust and short fibres are accumulated during the spinning process on the inside rotor wall to which they adhere, which results in the formation of an increasingly uneven yarn and finally results in yarn breakages.
There is no lack of attempts to effectively eliminate contamination of the fibre material in opening and cleaning and in carding. These measures, however, are not sufficient to reach the low content of contaminations, required for open-end spinning, in the fibre material.
In a known card (GB-PS No. 791,339) an air supply opening merges, seen in the direction of rotation of the loosening roll (licker-in or taker-in roll), after the trough nose around which the fibre layer is supplied, through which air supply opening air is sucked into the interior of the perforated loosening roll. The air flowing in the direction towards the loosening roll causes the fibre material already taken over by the licker-in or taker-in roll and stored on its clothing to be pressed into the clothing and to be condensed there, in such manner that the contamination is retained therein.
Also known already in this art is a suction device on cards (DE-AS No. 1,685,552), in which immediately above the feeder roll a suction hood with a suction slot facing the licker-in roll is arranged. The hood is provided for sucking off the fibres clinging to the fluted or knurled feeder roll, the feeder roll being subject to an air flow from both sides, flowing into the hood. Furthermore, only the fibres released by the sharp deflection of the fibre layer supplied at the end of the feeder table trough are to be sucked off using the suction slot, which is desirable in view of their reusability or reworkability. On the other hand, however, a suction device of this type does not permit elimination of contaminations and dust freed from the fibre material during passage over the loosening roll, as the fibre layer, deflected sharply at the end of the trough in the direction of rotation, here widens up or enlarges and forms a throttle. This reduces the effectiveness of the suction stream up to the loosening zone too much, as the latter is located considerably below the deflection point.
SUMMARY OF THE INVENTION
It thus is an object of the present invention to eliminate the disadvantages cited and to free the fibre material as effectively as possible from dust, which detrimentally influences subsequent processing, and to prevent it from freely escaping into the atmosphere of the plant room.
This object is achieved in that the feeder trough body extends into the converging space up to the loosening zone and that a suction opening of the suction device opens onto the zone.
In applying these measures, the suction air stream is caused to develop its full effect directly above the loosening zone, and owing to the vacuum prevailing there no build up of static pressure is possible, which could permit lateral escape of contaminated air carried on by the suction air stream.
The suction opening can be formed on one hand, by a nose extending along the feeder trough up to the loosening zone and, on the other hand, by a trough plate extending at a distance and protruding less far.
This embodiment is advantageous in that in this arrangement the suction air stream can enter directly at the nose, which increases its effectiveness, and in that a very simple design is possible.
A further embodiment consists in that the loosening zone which is formed by using a further loosening roll is connected with the suction device via a duct formed between a cover and the surface of the first loosening roll. This makes it possible to take care of a further source of dust without further complications, such as special ducts or cover hoods.
The feeder trough body in advantageous manner can contain air passage openings lined up or extending in a row over the length of the feeder trough, and ending at the suction opening, which air passage openings merge into a common air exhaust housing. This proves advantageous, as it improves the distribution and stabilization of the suction stream within the body in such manner that the suction action is effective at all places evenly.
In a further embodiment of the invention the feeder trough body including the suction device can be removed as a unit from the feeder roll along a rigid pathway or fixed path. This permits freeing of the converging space or room between the rolls in an operationally simple manner for maintenance purposes and for inspecting and cleaning the passage openings in the body.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in greater detail in the following with reference to illustrated design examples. It is shown in:
FIG. 1 a section along line I--I according to FIG. 2 of a card with a contamination suction arrangement; and
FIG. 2 a section along line II--II according to FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A feeder roll 1 (FIG. 1) is fluted or knurled on its outer or sleeve surface or provided with coarse teeth, tips or points 2 or similar elements and can be driven in the direction of arrow A. A feeder trough 3 located above the feeder roll 1 and which is worked into or machined at a trough body 4, and a trough plate 5 mounted thereon extend mutually parallel in axial direction. Between the feeder roll 1 and the trough 3 the fibre material 6 to be transported is placed e.g. in form of a fibre layer from e.g. a picker lap. A loosening roll 7 is provided with fine teeth or points 8 respectively, and can be driven in the direction of arrow B, i.e. opposite to the direction of rotation of the feeder roll 1. In operation the surface or circumferential speed of the roll 7 is much higher than that of roll 1. The trough body 4 comprises a nose 9 extending almost up to the point of the smallest distance E of the two rolls 1 and 7. Between this nose 9 and the trough plate 5 which extends somewhat less far, i.e. in the converging space between the cylindrical surface of the loosening roll 7 rotating towards a loosening zone 10 and the cylindrical surface of the feeder roll 1 also moving towards the loosening zone, there is located an air exhaust duct 11 having the suction opening 12. In the loosening zone 10, which begins somewhat in front of the point E between the loosening roll 7 facing this point directly and the feeder roll 1, the fibre material 6 supplied is taken up and loosened in the process. Immediately upon release by the trough 3 the previously extensively compressed material widens or enlarges to about 10 to 20 times its previous thickness (e.g. to 5 to 10 mm), is combed in this state at high speed in the range of 8 to 18 m/sec, releases dust in the process and is transferred furthermore to the roll 7. Subsequently the loosening roll 7 also co-operates with drum 13, which is provided with still finer teeth or points and acts as a second loosening roll, of e.g. a card, which in FIG. 1 is not shown completely, which rotates in the direction of the arrow C. The increasing lengths of the arrows A, B, C indicate that the circumferential speed of each successive roll exceeds that of the preceding one. Between the rolls 7 and 13 a second loosening zone 14 is formed, in which the fibres are transferred to the drum 13. Also here dust is released.
A suction arrangement comprises, in addition to the air exhaust or suction duct 11 formed by the trough body 4 and the trough plate 5, an air exhaust housing 15 adjacent thereto, which extends along the feeder trough 3, to which housing 15 a suction duct 16 of about the same length is connected, which distributes the vacuum, the duct 16 being connected via a flexible or extendable duct 17 with a vacuum generator or source (not shown). The trough body 4, the air exhaust housing 15 and the suction duct 16 are integrated into a unit and are supported by supporting arms 18 (one of which only is visible in FIG. 1), which are pivotable about a bearing 19 rigidly mounted to the machine frame, i.e. the unit can be moved away on a rigid pathway. During operation the unit of course is fixed and secured (not shown) relative to the machine frame. By pivoting the support arm 18 counterclockwise (arrow D) the trough body 4 together with the elements 15, 16 can be tilted away from the feeder roll 1. This permits easy access to the elements 1, 3, 7 and 11, e.g. for the purpose of inspecting and cleaning them.
Extending from the second loosening zone 14 is a cover 20, which, while closely hugging the loosening roll 7, extends in the direction of rotation over the roll 7 up to the plate 5 on which it is supported sealingly. Together with the roll 7 the cover 20 forms a connecting duct 21 between the suction opening 12 of the air exhaust or suction duct 11 and the second loosening zone 14.
At suitable mutual distances the trough body 4 is provided with holding members 22 (FIG. 2) in rib form. Onto these the trough plate 5 is detachably mounted using screws 23. The air exhaust or suction duct 11 thus is subdivided along the feeder trough 3 into a plurality of individual air passage openings 24, each of which is laterally limited by two neighbouring holding members 22. All air passage openings 24 extend at an angle between the body 4 and the plate 5 to the air exhaust housing 15.
During operation the fibre material 6 is pressed by the feeder roll 1 into the trough 3, from which it is released such that it widens or expands under the influence of its inherent elasticity. In the loosening zone 10 it then is loosened by the roll 7 and is drawn out. During this process a substantial portion of the impurities or contaminations present in the fibre material 6, particularly fine dust (micro dust), clinging thereto, is released. Impurities not yet released are loosened in the fibre material 6 to such an extent that in one of the subsequent loosening zones they can be released. The air carried on by the rapidly rotating cylindrical surface of the loosening roll 7 in the duct 21 at the loosening zone 10 is prevented from passing the narrowest point E between the two rolls, owing to the small distance between the surfaces of the two rolls 1 and 7 and the expanded fibre material placed therebetween. The impurities released thus are caught by the suction air stream from the suction opening 12 and subsequently are eliminated with the air moved through the suction duct 11 and the suction arrangement formed by the elements 15, 16 and after filtering out the impurities are exhausted.
It proves advantageous if the suction action generated at the suction opening 12 is of such strength that the air supplied to the loosening zone 10 between the loosening roll 7 and the cover 20 is sucked off completely, as in this case a build-up of static pressure in front of the loosening zone 10, and thus an axial flow and lateral escape of contaminated air into the plant room can be avoided, and a special seal can be dispensed with, respectively.
During the transfer from the loosening roll 7 to the drum 13 in the loosening zone 14 the fibre material is loosened once more, during which process further impurities possibly preloosened earlier already, are now released. These impurities thus are carried on by the air stream flowing in the connecting duct 21 and after being sucked into the duct 11 also are eliminated by the suction arrangement (elements 15, 16). A separate duct outside the cover 20 thus can be dispensed with.
The inventive apparatus proves advantageous in that the feeder trough 3 used for feeding the fibres extends by means of a trough body 4 in which a duct is provided from above into the converging space or room between the feeder roll 1 and the loosening roll 7, e.g. the licker-in or taker-in roll of a card, and that the suction opening of this duct 11 thus is brought into close vicinity to the point where dust is released. At the same time lateral escape of the contaminated air carried on by the loosening roll is decisively reduced or completely prevented using this arrangement.
The invention provides a spinning preparatory machine comprising a feeder roll, a fibre loosening roll which removes fibre material from the feeder roll and a suction device extending into the convergent space between the rolls, so that the device opens onto a loosening zone between the rolls. The device can be integrated with a feeder member which co-operates with the feeder roll; the suction device can be on the side of the feeder member facing away from the feeder roll.
While there are shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims. Accordingly,
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The converging space between the moving-in or inbound surface of a loosening roll and the surface of a feed roll contains a suction duct, which is brought into close vicinity of the fibre loosening zone located between the two rolls, and which is used for sucking off of dust released in this zone. The suction duct is supported by the body forming the fibre feeder trough. Detrimental deposits of impurities in the subsequent processes, e.g. in the open-end spinning rotors, thus are greatly reduced.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of my U.S. patent application Ser. No. 08/192,018 entitled "Air Gun Gas Piston Device" filed on Feb. 4, 1994, now abandoned.
BACKGROUND OF THE INVENTION
Air guns use compressed air to discharge a pellet. Some air guns use a piston in a compression chamber. A spring is mounted between the piston and a trigger mechanism. The piston is retracted to cock the trigger and to compress the spring. When the trigger is released, the spring biases the piston toward the barrel to compress the air in the compression chamber. The compressed air then propels the pellet through the barrel. One problem with air guns using a mechanical spring is that the spring tends to fatigue or break, and also to produce an excessive amount of spring vibration upon firing.
Some air guns use a gas spring instead of a mechanical spring. The piston is moved toward the trigger to compress a gas or air behind the piston. When the trigger is released, the piston is driven forward by the compressed gas thereby compressing the air in front of the piston to discharge the pellet out of the barrel.
Such guns are illustrated in U.S. Pat. No. 4,709,686 which was issued Dec. 1, 1987 to Hugh F. Taylor and David R. Theobald for "Air Weapon With Gas-Tight Expansion Chamber"; U.S. Pat. No. 4,771,758 which was issued Sep. 20, 1988 to the same inventors for "Air Weapon With Air Compression System Having Grooves For Air Transfer"; and U.S. Pat. No. 4,850,329 which was issued to Jul. 25, 1989 to Hugh F. Taylor, David R. Theobald and Derek J. C. Bernard for "Firing Mechanisms For Air Weapons".
SUMMARY OF THE INVENTION
The broad purpose of the present invention is to provide a kit for converting a mechanical spring-operated air gun to a pneumatic or gas-spring operated air gun.
Another object of the invention is to provide an improved air gun having a primary air-compressing piston with an internal, self-contained power chamber having a gas that is compressed by a smaller piston as the primary piston is retracted toward a cocked position. When the trigger is actuated, the compressed gas expands to bias the primary piston toward the barrel, compressing the air in front of the piston.
Still another object of the invention is to provide an air gun with a self-contained gas piston having a center latch for engaging a center latch carried in the trigger housing.
Still further objects and advantages of the invention will become readily apparent to those skilled in the art to which the invention pertains upon reference to the following detailed description.
DESCRIPTION OF THE DRAWINGS
The description refers to the accompanying drawings in which like reference characters refer to like parts throughout the several views and in which:
FIG. 1 is a fragmentary view of a conventional mechanical spring-operated air gun;
FIG. 2 illustrates the air gun with the mechanical spring and piston removed through an opening at the trigger end of the receiver tube;
FIG. 3 is a view showing the self-contained gas piston mounted in the receiver tube of FIG. 1, in an unlatched position;
FIG. 4 is a view similar to FIG. 3 but showing the gas piston in section;
FIG. 5 is a view similar to FIG. 4 but showing the latch carried by the piston engaged with the trigger-operated latch;
FIG. 6 is a view similar to FIG. 5 but in which the primary piston has been partially actuated in a power stroke by the compressed gas in the piston; and
FIG. 7 is an enlarged sectional view as seen along lines 7--7 of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a conventional barrel-cocking air gun 10 has an elongated cylindrical receiver tube 12 defining a compression chamber 14 at the forward or left end of the receiver tube. A primary piston 16 having a crown 18 and cylindrical wall 20 is slideably mounted in the compression chamber.
A barrel 22 is connected to the receiver tube for pivotal motion around pivot member 25, from a firing position illustrated in solid in FIG. 1 toward a fully cocked position illustrated in phantom at "A".
A trigger housing 24 is threadably mounted at 26 at the rearward end of the receiver tube. A conventional trigger mechanism 28, partially shown, operatively connects a trigger 30 to a hook-shaped latch 32 carried in the trigger housing adjacent latch opening 34.
A helical power spring 36 is mounted in the receiver tube. One end of the power spring is mounted against the trigger housing, and the opposite end engages the crown of the piston. An elongated second trigger latch 38 is carried by the piston inside the spring, and has a hook-shaped element 40 which passes through opening 34 to engage latch 32 when the power spring is fully compressed. The trigger mechanism cocks the trigger as the two latches become engaged.
A lever 42 has one end connected by pivot 44 to the barrel, and its opposite hook-shaped end 46 received through a bottom slot opening 48 in the receiver tube for engaging a recessed portion 50 of the piston. As the barrel is pivoted toward position "A", lever 42 pushes the piston toward the trigger housing thereby compressing the power spring until the two latches are in their latched position. When the trigger is pulled to release the two latches, the power spring then pushes the piston toward the left, compressing the air in the compression chamber forward of the piston. The compressed air then passes through an opening 52 to explosively propel a projectile 54 through barrel 22 in the conventional manner.
FIG. 2 illustrates air gun 10 with the trigger housing unscrewed from the receiver tube to form an opening 56. Piston 16, power spring 36, latch 40 and the related sealing components are removed from compression chamber 14. A replacement, self-contained gas piston assembly 58 is then inserted through the opening into the compression chamber.
Referring to FIGS. 3-7, the replacement gas piston assembly comprises a metal compression piston 60 having a cylindrical wall 62 with a crown 64 blocking one end of the piston. Valve means 66 provide means for introducing a gas into a power chamber 68 entirely contained in the compression piston valve means 66 can be a conventional check valve. A cap-shaped seal 70 is mounted around crown 64 and forms a sliding sealing engagement with the internal wall of the receiver tube.
An inner elongated cylindrical member 72 is carried within piston wall 62. Member 72 has an enlarged annular section 74 which closely fits the inside wall of compression piston wall 62. An annular seal 76 forms an air-tight seal between the inside of the piston wall and member 72. The outer diameter of inner cylindrical member 72 is less than that of the inner diameter of the piston wall to form an elongated annular outer gas power chamber 78. The inner end of the inner cylindrical member is shorter than the length of the piston so that an inner power chamber 88 is formed within member 72. An orifice member 80 is carried on the inner end of member 72. Member 80 has a flow orifice 94 therein connecting chambers 78 and 88.
A transverse pin 82 extends through the wall of the compression piston and through annular section 74 so that the compression piston and cylindrical member reciprocate in the compression chamber together as a unit.
An elongated tubular latch guide member 84 has one end press fitted around the central opening of a nylon washer 86 fixedly mounted adjacent the trigger housing, and its free end received inside cylindrical member 72 to form a wall of the power chamber. The latch guide has an end wall which forms a piston head 90. The piston head carries an annular seal 92 to form a sliding sealing engagement between piston head 90, and the inner wall of cylindrical member 72. Latch guide 84 and piston head 90 are fixed with respect to the receiver tube in such a manner that as the compression piston is moved toward the trigger housing, nitrogen gas, disposed within the piston, is compressed.
The gas is compressed because of the reducing volume of the power chamber in cylindrical member 72. The gas being compressed by piston head 90 in the cylindrical member is in communication through orifice 94 with that portion of the power chamber outside member 72 so that the gas pressure throughout the power chamber is uniformly compressed. The orifice member can be changed to change the orifice opening to change the rate of motion of the compression piston as the gas expands in the power chamber.
The latch guide member has an elongated longitudinal slot 96. Pin 82 extends through both sides of slot 96 thereby permitting the compression piston to move either toward or away from latch 32.
Referring to FIG. 4, a short latch 98 supported along the central longitudinal axis 99 (FIG. 5) of the compression chamber, has one end connected to pin 82 so that latch 98 moves with the pin and the compression piston. Latch 98 is disposed inside latch guide member 84 so that a hooked-shaped latch end 100 approaches the hooked-shaped end 102 of latch 32.
Referring to FIG. 5, as the compression piston is moved toward its fully latched position, latch 98 moves through opening 34 in the trigger housing to engage latch 32. Like the mechanical spring version of the gun, latch 32 is pivoted as it engages latch 98 thereby cocking trigger member 30 in the usual manner.
Referring to FIG. 4, the bottom side of the piston wall has an elongated recess 104 aligned with the longitudinal slot 48 in receiver tube 12 for engaging end 46 of the cocking lever. As barrel 22 is pivoted toward position "A", the lever engages the end of recess 104 and pushes the compression piston rearwardly until the two latches engage and cock the trigger. When the trigger is squeezed by the user in the usual manner, latch 32 is pivoted thereby releasing latch 98. The compressed gas in compression piston 60 then expands thereby moving the compression piston toward the barrel end of the compression chamber, compressing the air in front of the compression piston. The compressed air then passes through port 106 driving the projectile through the barrel in the usual manner.
Thus, it is to be understood that I have described an improved self-contained gas piston assembly that can be mounted in a conventional mechanical spring-operated air gun. The retrofit is accomplished by removing the trigger housing from the end of the receiver tube, removing the mechanical spring, the piston and related components, and then inserting the self-contained gas piston into the receiver tube. The center latch carried by the gas piston lines up with the center latch 32 of the trigger housing along the central longitudinal axis of the receiver tube. The retrofit takes place in a very few minutes thereby providing all the advantages of a gas piston gun over a mechanical spring-operated piston gun.
An air gun can also be made with the gas spring piston and the center latching mechanism as original equipment.
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This invention is related to a kit to retrofit a mechanically spring-powered air gun to a gas spring-powered air gun, and to a self-contained gas piston for an air gun. The gas piston has a center latch which engages the center latch operated by the trigger.
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BACKGROUND OF THE INVENTION
1. Technical Field
The present invention generally relates to alkali metal thermal to electric conversion (AMTEC) cells and more particularly to a return channel for such a cell having a graded capillary structure for supporting the flow of condensed alkali metal in the cell which provides enhanced flow characteristics.
2. Discussion
An AMTEC cell is a thermally regenerative concentration cell typically utilizing sodium or potassium as a working fluid and a beta-alumina type solid electrolyte as an ion selective membrane. While throughout this description sodium is referred to as the working fluid, it is to be understood that other alkali metals are applicable to this invention. The electrolyte permits a nearly isothermal expansion of sodium to generate high-current/low voltage power at high efficiency. Most AMTEC cells employ at least one beta-alumina type solid electrolyte (BASE) element which is exposed to high-pressure sodium on one surface and low-pressure sodium on the opposite surface.
The BASE element's opposed surfaces are overlaid with permeable electrodes which are connected to each other through an external load circuit. Neutral sodium atoms incident on the BASE element's high pressure surface give up their electrons at one electrode (the anode). The resulting sodium ions pass through the element wall under the applied pressure differential, and the emerging sodium ions are neutralized at the other electrode (the cathode) by electrons returning from the external load. Thus, the pressure differential drives the sodium through the BASE element thereby creating an electrical current which passes through the external load resistance. One configuration for such an AMTEC cell utilizes BASE elements in the form of hollow cylindrical tubes in which the tube's inner surface supports the anode and the outer surface supports the cathode.
The neutral sodium atom vapor leaving the cathode flows through the space between the BASE elements and the cell wall until it condenses at the low-temperature condenser at one end of the cell. From there, the sodium condensate flows through an artery containing a fine pore wick commonly consisting of a packed metallic felt. The liquid sodium evaporates at the end of an evaporator wick which is coupled to the artery. The high-pressure sodium vapor is returned to the BASE elements through a common plenum at the opposite "hot" end of the cell.
Some cells employ multiple BASE tubes and are operated under conditions such that the sodium is in the vapor phase on both sides of the BASE elements to prevent shorting of the electrodes. In the cell configuration mentioned above, the inner surface of each BASE tube is exposed to high-pressure sodium vapor and the outer surface is exposed to low-pressure sodium vapor. The high-temperature evaporator near the hot end of the cell produces the high pressure and the low-temperature condenser at the cold end of the cell maintains the low-pressure.
In order to operate at high efficiency, the artery and evaporator, hereinafter referred to collectively as "the return channel", must support the recirculation of the alkali metal at a capillary pressure equal to or greater than the vapor pressure of the alkali metal at the hot end. As the alkali metal migrates along the length of the return channel, the vapor pressure changes in relation to the local cell temperature. That is, at lower temperature regions of the cell, the alkali metal vapor pressure is lower than it is at higher temperature regions of the cell.
To support the vapor pressure of the alkali metal, the capillary structure of the return channel creates a capillary pressure capable of sustaining the alkali metal flow. Conventional AMTEC cells employ a metallic felt or screen wick capillary structure with uniformly sized small pores or openings along the entire length of the return channel. This ensures that the capillary pressure at the hot end of the return channel is sufficient to support the flow of the alkali metal. However, the small pores at the cold end of the return channel typically result in a higher flow resistance which unduly restricts the flow of the alkali metal. This causes an undesirable pressure drop within the cell which adversely affects performance and leads to a corresponding low power output.
Accordingly, it is desirable to provide a return channel having a capillary structure for sustaining the flow of the alkali metal over a broad range of alkali metal vapor pressures. To accomplish this, a graded pore size capillary structure may be employed in the return channel having a small pore size, and corresponding high capillary pressure, at the hot end of the artery, and a larger pore size, and corresponding low capillary pressure and low flow resistance at the cold end of the artery. As such, the varying vapor pressure of the alkali metal is sustainable along the entire length of the return channel while minimizing the pressure drop of the working fluid traveling along the capillary structure. It is also desirable to provide a method of forming the graded capillary structure which is quick, reliable, and cost effective.
SUMMARY OF THE INVENTION
The above and other objects are provided by an alkali metal thermal to electric conversion (AMTEC) cell of the type employing an alkali metal flowing between a high-pressure zone and a low-pressure zone in the cell through a solid electrolyte structure. The cell preferably includes a condenser communicating with the low-pressure zone for condensing alkali metal vapor migrating through the low-pressure zone from the solid electrolyte structure. An artery is coupled to the condenser for directing condensed alkali metal from the condenser toward a hot end of the cell. An evaporator for evaporating the condensed alkali metal is coupled to the artery and communicates with the high-pressure zone. The artery and evaporator combine to form a return channel which preferably includes a graded pore size capillary structure having a small pore size region gradually transitioning to a larger pore size region resulting in a range of capillary pressures within the return channel corresponding to the changing alkali metal vapor pressure within the artery structure.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to appreciate the manner in which the advantages and objects of the invention are obtained, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings only depict preferred embodiments of the present invention and are not therefore to be considered limiting in scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
FIG. 1 is a perspective view in partial cross-section of an AMTEC cell having a return channel incorporating the teachings of the present invention;
FIG. 2 is a more detailed view in cross-section of the return channel including a graded pore size capillary structure;
FIG. 3 is a schematic view of a method of forming the graded pore size capillary structure of the present invention;
FIG. 4 is a schematic view of a second method of forming the graded pore size structure of the present invention;
FIG. 5 is a cross-sectional view of a two-stage permeability return channel;
FIG. 6 is a cross-sectional view of a two-stage permeability return channel having a radially graded pore size capillary structure; and
FIG. 7 is a cross-sectional view of a return channel having a non-uniform cross-sectional shape.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is directed towards a return channel with a graded pore size capillary structure extending between the condenser and evaporator in an alkali metal thermal to electric conversion (AMTEC) cell. As the alkali metal travels along the return channel from a cold cell region adjacent the condenser to a hot cell region proximate the evaporator, the changing alkali metal vapor pressure is sustained by increasing capillary pressure generated by the graded pore size capillary structure. As such, the flow of the alkali metal flows with minimal restriction through regions of relatively low alkali metal vapor pressure and regions of relatively high alkali metal vapor pressure. Thus, the vapor pressure is maintained within the return channel and the output performance of the AMTEC cell is optimized.
Turning now to the figures, an AMTEC cell incorporating the teachings of the present invention is illustrated in FIG. 1 and indicated generally at 10. The AMTEC cell 10 generally includes a cell wall 12 defining a chamber 14 which is closed at a first end 16 by a first end cap 18. The first end 16 is generally known in the art as the hot end of the cell 10. The chamber 14 is also closed at a second end 20 by a second end cap 22. The second end 20 is generally known in the art as the cold end of the cell 10. The chamber 14 is separated into a low-pressure zone 24 and a high pressure zone 26 by a solid electrolyte structure 28. In the illustrated embodiment, the solid electrolyte structure 28 includes a plurality of beta-alumina type solid electrolyte (BASE) tubes 30 electrically connected in series by leads 31. The leads 31 are coupled to a terminal 33 projecting exterior of the cell 10. Although the BASE tubes 30 are shown, it is to be understood that the present invention is also suitable for use in conjunction with solid electrolyte structures of other configurations.
A condenser 32 is disposed in, and therefore communicates with, the low-pressure zone 24. As can be seen, the condenser 32 is coupled to the cell wall 12 about its periphery adjacent the second end cap 22. An artery 35, preferably packed with metallic felt to be described in greater detail below, is coupled to the condenser 32 by a mounting member 36. The artery 35 extends from the condenser 32 through the low-pressure zone 24 towards the hot end 16 of the cell 10.
The artery 35 is connected to an evaporator 38 which communicates with the high-pressure zone 26. A common plenum 40 adjacent the hot end 16 of the cell 10 interconnects the evaporator 38 and the high-pressure side of the solid electrolyte structure 28. An alkali metal working fluid, such as sodium, is disposed within the cell 10. For convenience, the artery 35 and evaporator 38 will be referred to hereinafter collectively as the return channel 34.
In operation, neutral sodium atoms incident on the high pressure side of the electrolyte structure 28 release their electrons to an inner electrode. The resulting sodium ions pass through the solid electrolyte structure 28 under an applied pressure gradient and the emerging sodium ions are neutralized at an outer electrode by electrons returning from the external load. The neutral sodium atom vapor leaving the outer electrode migrates through the low-pressure zone 24 and condenses at the condenser 32. The sodium condensate flows through the artery 35 to the evaporator 38. The liquid sodium evaporates at the evaporator 38 and the high-pressure sodium vapor is returned to the high-pressure side of the solid electrolyte structure 28 through the plenum 40.
Turning now to FIG. 2, the return channel 34 is shown in greater detail. As can be seen, the return channel 34 includes a graded pore size capillary structure 48. The graded pore size structure 48 includes small-sized pores 48a yielding a corresponding high capillary pressure and lower permeability in the higher temperature regions of the return channel 34 near the hot end 16 of the cell 10. The small-sized pores transition to larger-sized pores 48b yielding corresponding lower capillary pressure and higher permeability in the lower temperature regions of the cell 10 at the opposite end of the return channel 34. The graded pore size structure 48 enables the return channel 34 to provide an optimal capillary pressure along the entire length of the return channel without unnecessary flow restrictions. It should be noted that although both the artery 35 and evaporator 38 are illustrated with the graded pore size structure, an artery with a graded pore size structure may also be used with a conventional evaporator. Likewise, an evaporator with a graded pore size structure may be utilized with a conventional artery. In certain instances it may be desirable to vary the pore size gradient such that the pore sizes vary from large to small and back to large, or even from small to large among others. The skilled practitioner will recognize that the gradient of the pore sizes may be selected on a case by case basis to yield the desired permeability, flow conductance and/or capillary pressure along the length of the return channel. Also, the term "pores" as used herein is meant to encompass any "openings" or radii of curvature of features with a definable characteristic dimension within the membrane of the return channel.
Referring now to FIG. 3, a method of forming the return channel 34 is illustrated. The graded pore size structure in the return channel 34 is preferably formed by cutting and pressing small felt discs 50 into a return channel tube 52. Each disc 50 is pressed by a mandrel 54 to a specified force or displacement within the tube 52. This force reduces the individual pore size in each disc 50 to a pre-selected size. The pre-selected pore size is determined so as to produce the capillary forces equal to, or greater than, the vapor pressure of the alkali metal typically found at the disc's location within the tube 52 when it is assembled in the cell 10 as the return channel 34. The vapor pressure of the alkali metal at different locations within the return channel 34 may be determined according to the known temperature gradient within the cell 10.
A second method of forming the graded pore size capillary structure in the return channel 34 is depicted in FIG. 4. According to this method, a tapered sheet of felt 56 is initially rolled about a mandrel 58. The felt 56 and mandrel 58 are then inserted into a hollow ductile metal cylinder 60. The metal cylinder 60 is then swagged to a smaller diameter at 61 followed by drawing through a dye 63. During the swagging and drawing process, the cylinder 60 is compressed to a pre-determined, fixed outer diameter. As such, the felt material at one end 62 of the cylinder 60 is compressed to a greater degree than at an opposite end 64. Additionally, the permeability of the felt at the end 62 is decreased along with its average pore diameter. As can be appreciated, the initial taper of the sheet of felt directly corresponds to the resulting pore size gradient and permeability.
It is presently preferred to use stainless steel or refractory metal felt-type material with a fiber size of one to five microns for forming the graded pore size structure in the return channel 34. However, the material is not limited to these metals so long as the material may be well wetted by the alkali metal under operating conditions. Also, a gradient of 3:1 has been found to serve well for avoiding excessive flow restriction for arteries with a 10/1 length to diameter aspect ratio. Shorter or longer structures call for different compressions considering the expected current capability of the cell and the alkali metal flow required therein.
Turning now to FIG. 5, an alternate embodiment of the return channel 34 is shown. In the illustrated embodiment, an open flow tube 68 is disposed along a longitudinal axis of the return channel 34. The open flow tube 68 is in contact with the artery 35 along its entire length via a plurality of apertures 70. As such, alkali metal flowing through the open flow tube 68 travels towards the hot end of the cell 10 until it reaches a location where the capillary forces generated at the local temperature can no longer sustain the locally generated vapor pressure. At this point, the alkali metal migrates into the artery 35 and continues to the evaporator 38. Porous vapor blocks 72 may be installed within the open flow tube 68 to prevent vapor blowout of the open flow tube 68 and causing undesirable "heat piping."
A variation of the open flow tube embodiment of the return channel 34 is illustrated in FIG. 6. In this embodiment, the pore size structure 48 is graded in a radial direction. In this embodiment, larger-sized pores 48b adjacent the open flow tube 68 gradually transition to small-sized pores 48a radially outwardly towards the boundary of the return channel 34.
In this embodiment, the liquid sodium returning from the condenser 32 flows through the open flow tube 68 and in some of the pores 48a and 48b towards higher temperature regions and the evaporator 38 until it becomes too hot for the sodium to remain in the open flow tube 68 characteristic dimension. At this point, the sodium discontinues its flow in the open flow tube 68 and continues flowing in the larger-sized pores 48b and the small sized pores 48a where it can remain as a liquid at higher temperatures. As the sodium continues to flow into higher temperature regions nearer the evaporator 38, it continues to flow in progressively smaller pore sizes progressively nearer the boundary of the return channel 34 where it can exist as a liquid at successively higher temperatures. In this manner, there is liquid sodium continuously in contact with the wall of the return channel 34 all the way along the return channel 34. This facilitates and enhances the heat transfer into the liquid sodium at the wall of the return channel 34 as it travels towards and near the evaporation zone in the evaporator 38, while simultaneously decreasing sodium flow pressure drop in the artery return channel 34.
Still another embodiment of the present invention is illustrated in FIG. 7. In this embodiment, a return channel 34a having a non-uniformal cross-sectional shape is illustrated. Although other shapes may be utilized, it is presently preferred to design the non-uniform return channel 34a as an elongated cone. According to this embodiment, the pressure drop typically encountered through the use of smaller sized pores is counteracted by the larger diameter flow area which decreases flow resistance. As illustrated, this embodiment employs the graded pore size structure 48 with larger sized pores 48b yielding low capillary pressure in low temperature regions and small-sized pores 48a yielding high capillary pressure in higher temperature regions. However, one skilled in the art will appreciate that the non-uniform cross-sectional shape return channel 34a lends itself to use with a non-graded pore structure within the return channel 34a. One skilled in the art will also appreciate that it is desirable to keep the cross-section of the return channel 34a relatively small to reduce thermal conductance.
Thus, the present invention provides a return channel having a graded pore size capillary structure for providing optimized capillary pressure with minimal flow losses. The large size pores at the cold end of the return channel allow the alkali metal to flow therethrough relatively unrestricted. As the alkali metal moves to hotter regions of the cell along the return channel its vapor pressure increases. The increasing vapor pressure is compensated for by increasing capillary pressure in the return channel generated by the progressively smaller size pores for sustaining alkali metal flow. This enables the alkali metal to flow between the condenser and evaporator without unnecessary restriction over a broad range of changing vapor pressure. As such, the power conversion capability of the AMTEC cell is enhanced particularly at high temperatures.
Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present invention can be implemented in a variety of forms. Therefore, while this invention has been described in connection with particular examples thereof, the true scope of the invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specification, and following claims.
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The present invention provides an alkali metal thermal to electric conversion (AMTEC) cell of the type employing an alkali metal flowing between a high-pressure zone and low-pressure zone in the cell through a solid electrolyte structure. The cell preferably includes a condenser communicating with the low-pressure zone for condensing alkali metal vapor migrating through the low-pressure zone from the solid electrolyte structure. An artery is coupled to the condenser for directing condensed alkali metal from the condenser toward a hot end of the cell. An evaporator for evaporating the condensed alkali metal is coupled to the artery channel and communicates with the high-pressure zone. The artery and evaporator combine to form a return channel which preferably includes a graded pore size capillary structure for creating a region having a large pore size transitioning in any predetermined manner to a region having a relatively smaller pore size. In this way, the capillary pressure provided by the return channel is optimized along its length while minimizing flow restrictions which are presented where the pore sizes are smaller than required to sustain alkali metal flow in portions of the return channel.
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FIELD OF THE INVENTION
The present invention relates generally to exercising accessories, and more particularly to an improved exercise walking stick for hand-held or strap-on use by a walker which simultaneously provides a walker or jogger with an enhanced adjustable muscular and aerobic workout, a means for enhancing the walker's visibility, and a means of protecting the walker against unwanted aggressors such as thieves or animals.
BACKGROUND OF THE INVENTION
The benefits of low-impact aerobic exercises have become well known to exercise enthusiasts over the past several years. Sports such as walking, swimming, and bicycling offer many of the same benefits as high impact forms of exercise, but do not place as much strain on the participant's body. Walking has always been advocated as a beneficial health measure, and is currently the most popular form of exercise. In fact, recent polls show that some 100 million people walk for exercise. Low impact walking exercises provide a means of exercise for nearly everyone, regardless of age or cardiovascular condition. Walking exercises serve to strengthen the heart and lungs, making them work more efficiently. Studies have shown that this easy to perform, natural activity can provide powerful health benefits including reduced anxiety, weight loss, reduced cholesterol levels, controlled hypertension, improved cardiovascular health, and slowed aging. Walking exercises also improve muscle and skeletal strength, particularly in the walker's arms and legs. Walking exercises much of the walker's body to at least some extent, though walkers have found it advantageous to enhance the workout to the walker's upper body and to increase the muscular workout available to the walker's lower body. The recent increase in interest and participation in walking exercises has led to the development of exercising accessories to be used in conjunction with a walker's or light jogger's workout. More particularly, walkers have desired to incorporate into their walking routine some form of enhanced muscular exercise, allowing them to build muscle mass to a greater extent than if they were walking unassisted. To this end, walkers have in the past carried free weights while they walk in order to provide some upper body muscular workout during their walking routine.
One drawback to walking exercises is the fact that it is usually practiced outdoors. Thus, the walker's security is entirely dependent on the security of the walker's neighborhood. Even those who exercise in a health club or gym can place themselves at risk when they walk from the gym to their car or to a bus stop after dark. Likewise, if the walker is walking outdoors after sundown, they always run the risk of a dangerous confrontation with traffic if they are not properly illuminated. To alleviate these problems, walkers will at times carry a simple walking stick which can serve to provide some means of defense against would be attackers, and a flashlight to indicate their presence to traffic.
SUMMARY OF THE INVENTION
The present invention meets the needs of walkers to have a variable weight device for exercising various muscle groups of the body during their walking routine, while offering a safety device to dissuade would be attackers and to show their presence to passing traffic. The present invention provides joggers, exercise walkers, and others with a means of conveniently carrying a variable weight, sectional walking and self defense stick incorporating a means of illumination during their exercise routine. The present invention is used for balance and support, and can be used as a club for personal security against animals and other would be attackers. The sectional stick may either be carried or strapped on to the user's extremities and worn as weights, thus increasing the walker's exercise benefits by providing greater resistance and making the body work harder to move its extremities. The placement of a user defined amount of weight in each of the sections allows the walker the flexibility to vary the dynamic motion of the walking stick to offer greater or lesser resistance to the walker's natural limb movements, in turn providing a wide variety of exercising effects to the various parts of the walker's body. Likewise, reflectors and bright colors are provided on the walking stick in order to illuminate the walker to traffic.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiment and certain modifications thereof when taken together with the accompanying drawings in which:
FIG. 1 is a perspective view of the fully assembled exercise walking stick of the present invention.
FIG. 2 is a fragmentary, sectional view of the exercise walking stick of the present invention.
FIG. 3 is a close up view of a two sided hook and loop fastening material strap of the present invention.
FIG. 4 is a close up side view of the weighted steel balls of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a perspective view of the fully assembled exercise walking stick 30 of the present invention. As shown more particularly in FIG. 2, the exercise walking stick 30 is comprised of numerous sections, including a top cap 10, a top weight receiving section 11, a middle extension section 12, a bottom weight receiving section 14, and a bottom cap 9, each of which are described in detail below.
The top end of the exercise walking stick 30 is an internally threaded top screw cap 10. Top screw cap 10 is provided at its top face with a slot 38 for assisting in the closing and sealing of a ball chamber 34 (discussed below), such as by engagement with a screwdriver. Directly below top cap 10 is a top weight receiving section 11 comprised of a lightweight polyvinyl chloride or plastic, and is approximately 12 inches in length. Top weight receiving section 11 is provided at its top perimeter with external threads which receive top cap 10. The outer surface of top weight receiving section 11 is colored in either a variety of flourescent colors or a reflective material, allowing the stick, and thus the user, to readily be seen in any poorly lit area by oncoming traffic and by other pedestrians, regardless of the weather conditions or the time of day. The top wall of top weight receiving section 11 is provided with an opening allowing access to a cylindrical weighted ball chamber 34 running along the central axis of top weight receiving section 11. Ball chamber 34 extends only partially along the length of top weight receiving section 11, leaving enough room at its base to provide a female threaded channel 18 on the bottom face of top weight receiving section 11 for connecting other sections of the exercise walking stick to the top weight receiving section 11. During use, the walker may place up to four 1 pound steel balls 13 into weighted ball chamber 34 in order to vary the weight of the fully assembled exercise walking stick or alternatively of the individual, strap-on sections of the exercise walking stick, as explained below.
On the cylindrical sidewall of top weight receiving section 11 are provided channels 16 through the sidewall surface which receive straps 17. Straps 17 are configured as elongated straps of a two-sided hook and loop type fastening material. During use, the exercise walking stick may optionally be separated into its above-described sections and attached to the user's limbs using straps 17. For example, if while the user is walking they desire to exercise their upper arms, straps 17 of each of the top weight receiving section 11 and the bottom weight receiving section 14 may be wrapped around the users upper arms and fixed in place by connecting the hook and loop fastening material of the opposing free ends of straps 17. Likewise, should the user desire to increase the work out on their legs, straps 17 of each of the sections may be similarly wrapped around the walker's thighs. Because their is no buckle type structure and the entire strap 17 is composed of hook and loop material, straps 17 may readily be used for any diameter limb up to the length of strap 17, and may be quickly applied and removed as necessary, such as when needed to defend against a would be attacker.
Top weight receiving section 11 is provided on its bottom face with a female threaded channel 18 along the central axis of top weight receiving section 11. Female threaded channel 18 allows top weight receiving section 11 to be threadably attached either to bottom weight receiving section 14 or to a middle extension section 12, as discussed below.
Middle extension section 12 is provided at its top face with a male threaded connector 15 which is optionally threadably received by female threaded channel 18 on top weight receiving section 11. Likewise, middle extension section 12 is provided at its lower face with a second female threaded channel 18, identical to that on the bottom face of top weight receiving section 11, configured to optionally threadably receive a second male threaded connector 15 located on the top face of bottom weight receiving section 14.
Bottom weight receiving section 14 is identical in construction to top weight receiving section 11, with the exception that the bottom weight receiving section 14 is provided with a male threaded connector 15 at its top face for attachment to top weight receiving section 11 or optionally to middle extension section 12. Otherwise, bottom weight receiving section is provided with an identical ball chamber 34 for receiving up to four 1 pound steel balls 13 for varying the weight of the bottom weight receiving section 14, and is provided around its bottom perimeter with external threads for receiving an internally threaded bottom cap 9 for closing off ball chamber 34.
During use, the walker thus has the option of using the exercise walking stick in its disassembled state whereby the top and bottom weight receiving sections are provided with the preferred weights and strapped on the walker's extremities using straps 17. Otherwise, should the walker desire to utilize the exercise walking stick in its assembled form to provide a stronger work out for either of the walker's arms, they may threadably attach the bottom weight receiving section 11 to the top weight receiving section 14, providing an assembled exercise walking stick of approximately 24 inches. Because each of the ball chambers 34 may receive anywhere from zero to four steel balls 13, the fully assembled stick is provided with an overall weight of from 1 to 10 pounds. For taller walkers with a longer arm span, intermediate sections 12 may be provided between the top and bottom weight receiving sections, allowing the overall exercise walking stick to be adjusted to any desired length.
Because the user may freely select the amount of weight to place in either of the weight receiving sections of the stick, the user may readily vary the dynamic motion of the exercise walking stick while in use, and thus the overall exercising effect of the stick. For example, increasing the amount of weight in one portion of the fully assembled stick while decreasing the weight in the other section will provide both a modified rhythm to the natural swinging movement of the stick, as well as a modified force distribution to vary the effects on different parts of the user's limbs, allowing the user to adjust the stick for both their desired workout and desired comfort level.
The exercise walking stick of the present invention thus combines a convertible carried variable weight system with a visibility enhancing means, a walking aid, and a self defense aid in one convenient device which may easily be carried by one hand or alternatively strapped on to the limbs of the user. Thus, the present invention eliminates the need to use a bulky backpack or belt pouch to carry separate gear for performing these functions during walking exercises, allowing the walker greater flexibility in movement and freeing them of the distraction of carrying various articles during their exercises. Likewise, the present invention makes each of these features always available, including an effective means of protecting the walker from unwanted aggressors.
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An improved exercise walking stick for hand-held or strap-on use by a walker which simultaneously provides a walker or jogger with an enhanced adjustable muscular and aerobic workout, a means for enhancing the walker's visibility, and a means of protecting the walker against unwanted aggressors such as thieves or animals.
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BACKGROUND OF THE INVENTION
This invention relates to yellow iron oxide pigments of greatly improved thermal stability and enchanced color quality.
The yellow pigments which are available today include lead chromate, strontium chromate, cadmium sulfide, benzidine yellow, etc. However, since these pigments are invariably noxious or carcinogenic substances, use of these pigments will be increasingly more restricted in the future with a view to preserving human health and reducing environmental pollution. In view of the likelihood of such restriction, industries which produce or use coloring materials anxiously await the development of an excellent innocuous yellow pigment capable of taking the place of such noxious yellow pigments as mentioned above.
The principal drawback associated with yellow iron oxide pigments is a lack of thermal stability. Hydrated iron oxides (α-FeOOH), when heated above approximately 200° C., begin to lose water of hydration and change from the desirable yellow color to red or brown.
This thermal instability of the hydrated iron oxides limits the applications where these very desirable pigments can be used. Thus, hydrated ferric oxide would constitute a very useful alternative for certain applications if it possessed sufficient thermal stability. Others have sought to overcome the problem of lack of thermal stability, and other deficiencies, in iron oxides. For example:
1. A method of surface coating α-FeOOH with aluminum or silica salts at normal pressure. (No. 49-16531 Japan)
2. A method of surface coating αFeOOH with metal oxide, as induced water soluble metal compounds, by using an autoclave. (No. 49-16531 Japan)
3. In an aqueous alkaline solution, a method to convert imperfect crystals to perfect crystals and control of particle distribution by hydrothermal treatment. (Unexamined Pat. No. 50-115698 Japan, published as No. 53-28158 Japan, and now U.S. Pat. No. 3,969,494).
The yellow iron oxide pigments which are treated by these methods, however, don't always have a sufficient heat stability compared with such aforesaid noxious yellow pigments. Therefore, the inventors have been studying how to improve the heat stability of yellow iron oxide. We have formed a heat stable yellow iron oxide by subjecting the colloidal dispersions obtained from an aqueous ferric salt solution, an alkali solution, and an aqueous aluminum solution to a hydrothermal treatment at 100°-250° C. for more than about 30 minutes.
The product of this invention exhibits remarkable thermal stability that is greater than the products from the prior art methods.
Heat stable yellow iron oxide of this invention possesses a film or coating of (FeAl)OOH (solid solution) on the surface of the yellow iron oxide pigment.
This dramatic improvement in thermal stability means that the yellow iron oxide of this invention can be used for melt-type traffic paint and in a majority of plastics requiring elevated heat stability, where commercial yellow iron oxides cannot be used.
SUMMARY OF THE INVENTION
The present invention provides a hydrothermal treatment in which yellow iron oxide is dispersed in a mixture of aqueous ferric sulfate solution, an alkali solution, and an aqueous aluminum solution.
The resultant dispersion is subjected to a hydrothermal treatment at 100°-250° C., such as heating the dispersion in an autoclave under pressure at 180° C. This treatment causes the surface of the yellow oxide to become at least partially covered with a coating or film of (FeAl)OOH (solid solution). By this treatment, the thermal stability temperature is increased by about 50° C., that is, to a range of approximately 200°-250° C.
The modified synthetic yellow iron oxide thus obtained is used as coloring pigment for melt-type traffic paint and in a majority of plastics in the place of prior art pigments. The present invention also comprises a process for the manufacture of the thermally stable yellow iron oxide product described above, wherein an aqueous slurry comprising said yellow iron oxide (α-FeOOH), ferric sulfate, water-soluble or alkali-soluble aluminum salt, and adequate alkali is heated at a temperature of about 100°-250° C. until a film of (FeAl)OOH (solid solution) precipitates on the surface of said oxide, and the resulting coated oxide product is recovered.
The hydrothermal treatment lasts for a period of from about one-half to about 4 hours, depending on the temperature. A preferred treatment is 180° C. for one hour.
Broadly, the invention comprises the aspects of
(a) forming the solid solution (FeAl)OOH,
(b) the compound (FeAl)OOH,
(c) forming a yellow iron oxide having at least a partial coating of (FeAl)OOH, and
(d) the composition of α-FeOOH having at least a partial coating of (FeAl)OOH.
DETAILED DESCRIPTION OF THE INVENTION
Hydrated ferric oxide loses water at about 200° C. and, in the process, changes from yellow to red or brown iron oxide. This thermal decompostion, accompanied by the color change, limits the application for which yellow iron oxide pigment can be used. In the course of studying methods of improving the thermal stability of yellow iron oxide, we found that the thermal stability and, consequently, the color stability of the yellow iron oxide could be dramatically improved by depositing (FeAl)OOH (solid solution) onto at least a portion of the surface of the yellow iron oxide particles. Furthermore, it was found that the greatest improvement would be effected by surface treating with (FeAl)OOH (solid solution), using an autoclave under saturated pressure of steam of the order of about 15 kg/cm 2 .
Now, a description will be given with respect to the construction of the present invention.
T. Ando reported that a certain curing (aging or growth period) at room temperature was required when a sodium hydroxide solution was added to a solution of ferric sulfate or ferric chloride, with pH values maintained above about 10. The precipitate was given the hydrothermal treatment in order to produce a yellow iron oxide. (Powder and Powder Metallurgy, Vol. 13 No. 1, 1966). This curing at room temperature is essential to make a yellow iron oxide, because if a hydrothermal treatment is done without curing, the products exhibit two-phase characterization, such as α-iron oxide (α-Fe 2 O 3 ) (red) and α-iron hydroxide (α-FeOOH) (yellow).
On the other hand, if an aluminum salt is added to the aforementioned solution to make a (FeAl)OOH (solid solution), regardless of sufficient curing, it was found by the present inventors that two phases, not only α-iron yellow hydroxide but also α-iron red oxide, are produced by hydrothermal treatment. It appears that the aluminum salt inhibits the curing effect.
The problem investigated was how to produce a single phase of yellow iron oxide under these conditions. Consequently, it was discovered that the formation of red α-iron oxide was suppressed, reduced, or prevented if, after curing, a water-soluble or alkali-soluble aluminum salt, such as sodium aluminate, together with water-soluble silica salts, tin salts, or zinc salts was added. Typically, the tin and zinc salts can be substituted for the silica salts. The amount of soluble aluminum salt added is more than 20 wt.%, based on the soluble ferric salt used. For example, the amount of aluminum salt can be from 35 to 129 wt.% of the ferric salt. The amount of these added salts is about 0.3-5.0% of the aluminum included in the aluminum salts. The product produced by such a hydrothermal treatment possessed single phase yellow iron oxide.
The pH of the reaction mixture of alkali and ferric salts is over 10, such as from 10 to about 13.
If yellow iron oxide is present in the solution before-hand, to act as seed, it is able to produce a (FeAl)OOH solid solution without curing, or without curing and addition of silica salts, tin salts, or zinc salts.
The following examples are presented to illustrate the present inventions more fully.
EXAMPLE I
Formation of (FeAl)OOH (no yellow iron oxide seed present)
A solution of 50 g/l sodium hydroxide solution was added to 500 ml of ferric sulfate solution having a concentration of 60 g/l as Fe 2 (SO 4 ) 3 until the pH value was about 12. The precipitated material was then cured about 23 hours at room temperature. Then, 19.4 ml of sodium aluminate solution having a concentration of 291 g/l as Al 2 O 3 and 6.7 ml sodium silicate solution having a concentration of 20 g/l as SiO 2 were added. The resultant dispersion was subjected to a hydrothermal treatment carried out at 180° C. for one hour, using a stainless steel autoclave. In this case, the pH of this dispersion, after the addition of the sodium silicate solution, was about 13.
The precipitates of (FeAl)OOH formed as a consequence of this hydrothermal treatment were separated from the mother liquor, washed with water until electroconductivity values of the filtrate were below 100 μψ/cm, filtered, and dried at 120° C. for 4 hours in electric oven. The dried material was pulverized (with a sample mill), giving a final product which was a (FeAl)OOH solid solution.
The results of X-ray diffraction and Differential Thermal Analysis (DTA) on the product are as shown in Table I and Table II. Commercial yellow iron oxide and three kinds of yellow iron oxide were also treated by the aforementioned treatment for comparison. The results also are shown in Table I and Table II. The differential thermal analyses were recorded under the following conditions:
______________________________________INSTRUMENT FACTORS______________________________________Sample weight 300 mgAtmosphere dry airHeating rate 5° C./minStandard sample α-Al.sub.2 O.sub.3______________________________________
In Table I and Table II, mark (1) is commercial yellow iron oxide (Mapico LL-XLO, equivalent to Mapico 1050; Cities Service Co.); mark (2) is yellow iron oxide coated with aluminum hydroxide, as described in Japanese unexamined Pat. No. 51-66320; mark (3) is the yellow iron oxide sample of mark (2), hydrothermally treated at 180° C. for one hour, according to the procedure of Japanese Pat. No. 49-16531; mark (4) is the yellow iron oxide of mark (2) which was hydrothermally treated in sodium hydroxide solution at 180° C. for 5 hours, as described in Japanese unexamined Pat. No. 50-115698; and mark (5) is (FeAl)OOH, as obtained by the present invention.
TABLE I__________________________________________________________________________(X-Ray Data) 2 3 4 Yellow iron Yellow iron oxide Yellow iron oxide 51 oxide coated obtained by hydro- obtained by hydro- (FeAl)OOHCommercial with alumi- thermal treatment thermal treatment obtained by presentiron oxide num hydroxide of sample 1 in NaOH solution inventiond I/Io d I/Io d I/Io d I/Io d I/Io h k l__________________________________________________________________________5.00 15 4.99 16 5.00 13 4.99 16 4.93 16 0 2 04.20 100 4.19 100 4.20 100 4.20 100 4.15 100 1 1 03.39 10 3.39 10 3.39 10 3.39 13 3.35 11 1 2 02.70 38 2.70 38 2.70 38 2.70 43 2.66 30 1 3 02.59 15 2.59 16 2.59 12 2.59 12 2.55 16 0 2 12.52 6 2.53 6 2.53 4 2.53 5 2.50 7 1 0 12.49 15 2.49 14 2.49 14 2.49 14 2.46 16 0 4 02.453 55 2.451 58 2.453 54 2.453 53 2.424 59 1 1 12.255 17 2.255 18 2.256 14 2.255 12 2.228 19 1 2 12.193 23 2.191 24 2.193 22 2.193 25 2.165 21 1 4 01.923 5 1.923 7 1.922 4 1.923 5 1.875 5 0 4 11.803 7 1.802 8 1.803 7 1.803 9 1.785 6 2 1 11.721 23 1.720 25 1.720 24 1.720 26 1.700 18 2 2 11.693 8 1.691 7 1.693 9 1.693 10 1.672 6 2 4 01.604 5 1.605 3 1.605 4 1.607 5 1.587 3 2 3 11.565 15 1.564 17 1.565 14 1.565 15 1.544 11 151 1601.511 8 1.510 10 1.510 8 1.510 7 1.491 9 250 002 a.sub.0 = 4.60 a.sub.o = 4.56 b.sub.o = 10.00 b.sub.o = 9.84 c.sub.o = 3.03 c.sub.o = 2.99__________________________________________________________________________
TABLE II______________________________________Differential Thermal Analysis Data Decomposition Peak temperature temperatureSample (°C.) (°C.)______________________________________1. Commercial yellow 226 331 iron oxide2. Yellow iron oxide coated 238 338 with aluminum hydroxide3. Yellow iron oxide obtained 238 336 by hydrothermal treatment of sample 24. Yellow iron oxide obtained 255 346 by hydrothermal treatment in sodium hydroxide solution5. (FeAl)OOH obtained by 277 398 present invention______________________________________
It is evident from Table I that for the (FeAl)OOH as obtained by the treatment of the present invention, the lattice constant shows a o =4.56 A, b o =9.84 A, c o =2.99 A, which is smaller than those of another yellow iron oxide. The lattice constant of the other yellow iron oxides shows a o =4.60 A, b o =10.00 A, c o =3.03 A.
It is also evident from Table II that, for the (FeAl)OOH obtained by the present invention, the decomposition temperature and peak temperature by DTA at 277° C. and 398° C., respectively, are higher than those of prior art yellow iron oxides.
It is reported that yellow iron oxide (α-FeOOH) and diaspore (α-AlOOH) have a similar crystal structure and that (1) the lattice constant of diaspore is a o =4.40 A, b o =9.39 A, c o =2.80 A, which is smaller than the constant of yellow iron oxide (Palache, L. G. et al., The System of Mineralogy, 7th Ed., Vol. 1, J. Wiley and Sons, New York, 1944), and (2) the decomposition temperature of diaspore (T d of 400°) is higher by about 200° C. than that of yellow iron oxide. (B. Yoshigi, Mineral Technology, Kihodo, Tokyo, Japan, 1959).
From the above observations, we believe that the product obtained by the present invention has a (FeAl)OOH characterization (solid solution), since the heat stability of synthetic yellow iron oxide was improved. In the hydrothermal treatment, pH values of the colloidal solution are preferred at above 12.5, because if the pH is lower than about 12.5, a boehmite (ν-Al00H) is formed with yellow iron oxide in the solution.
EXAMPLE II
Formation of (FeAl)OOH (yellow iron oxide seed present)
Commercial yellow iron oxide (20 g.) was added to 500 ml ferric sulfate solution having a concentration of 45 g/l as Fe 2 (SO 4 ) 3 . The mixture was stirred, and 500 ml sodium hydroxide solution having a concentration of 60 g/l, 29 ml of sodium aluminate solution having a concentration of 291 g/l as Al 2 O 3 , and 5 ml sodium silicate solution having a concentration of 20 g/l as SiO 2 were added. The resultant dispersion was subjected to hydrothermal treatment at 180° C. for one hour. The slurry thus obtained was removed from the autoclave and filtered to separate the precipitate from the mother liquor. The precipitate was washed with water, dried, and pulverized in the same way as example I.
The yellow iron oxide with at least a partial coating of (FeAl)OOH which was obtained in this method showed high heat stability. For example, the product exhibited a decomposition temperature of 283° C., which is higher than that of untreated yellow iron oxide (228° C.).
On the other hand, to compare the heat stability of treated and untreated samples, paint panels were made and tested. The color results are shown in Table III. The paint was formulated as follows:
______________________________________Yellow iron oxide 8 gOil-free alkyd resin (M6401, Japan Reichold 40 gChemicals, Inc.)Xylol 4 gBeads (GB 503, Bridgestone Glassbeads Ltd.) 40 g______________________________________
The above mixture was placed in a 150 ml container placed in a paint conditioner (Red Devil Co.), and shaken for 20 min. Then, the product was coated on an aluminum plate (0.1 m/m thickness), using a barcoater, and baked at various temperatures for 15 min.
Each baked panel was measured using a NIHONDENSYOKU color and color difference meter. The results were expressed as HUNTER L a b units. The total color difference (ΔE) is based on comparing the 150° C. baked panel and the other panels baked at other temperatures. A smaller ΔE indicated less color change and, hence, better thermal stability.
TABLE III__________________________________________________________________________ 150° C. × 30 min 200° C. × 15 min 220° C. × 15 min L a b Δ E L a b Δ E L a b Δ E__________________________________________________________________________Raw material (un- 49.0 15.1 28.7 -- 48.1 15.5 28.2 1.10 47.1 16.0 27.2 2.58treated iron oxide)Yellow iron oxide 46.3 15.1 28.7 -- 46.3 17.7 27.5 0.32 45.5 18.0 27.3 0.96obtained by presentinvention__________________________________________________________________________ 240° C. × 15 min. 260° C. × 15 min. 280° C. × 15 min L a b Δ E L a b Δ E L a b Δ E__________________________________________________________________________ 45.6 16.5 26.1 4.50 37.1 22.6 20.3 16.4 28.7 23.5 13.5 26.7 45.3 18.1 27.1 1.26 44.9 18.7 26.5 1.97 40.8 19.1 19.0 10.5__________________________________________________________________________
It is clear from the preceeding Table III that, as a consequence of the treatment according to the present invention, the temperature at which a change of color occurs (ΔE 1.5) (NBS) was increased by about 50° C., from about 200°-210° C. to about 250°-260° C.
Improved heat stability was shown by (1) the decomposition temperature (by DTA) was higher by about 30° C. than that of hydrothermal treatment of commercial yellow iron oxide and (2) the shape of yellow iron oxide treated by this invention was different from iron oxide having only hydrothermal treatment. Therefore, the reason why the heat stability was improved was thought to be due to the fact that heat stable (FeAl)OOH was coated onto the surface of yellow iron oxide and not due to the hydrothermal treatment. Consequently, since the product obtained by the method of the invention has the following characteristics compared with example I, it is advantageous on a commercial basis:
(1) curing of the colloidal suspension is not necessary.
(2) particle size of the commercial yellow iron oxide is easily controlled.
(3) color control of yellow iron oxide is simplified.
EXAMPLE III
Commercial yellow iron oxide, (Mapico LL-XLO, equivalent to Mapico 1050) (20 g.) was added to 500 ml ferric sulfate solution having a concentration of 27 g/l as Fe 2 (SO 4 ) 3 . Then, with stirring, were added 500 ml sodium hydroxide solution having a concentration of 50 g/l and 29 ml. sodium aluminate solution having a concentration of 291 g/l as Al 2 O 3 . The resultant dispersion was subjected to hydrothermal treatment at 180° C. for one hour. The slurry thus obtained was removed from the autoclave and filtered to separate the precipitate from the mother liquor. The precipitate was washed with water, dried, and pulverized in the same way as in example I, resulting in heat-stable yellow iron oxide. The decomposition temperature of this product, by DTA, was about 30° C. higher, from 227° C. to 261° C., as compared to the starting iron oxide product. Also, examination of results from Table IV are shown, in which the change of color (ΔE=1.5; NBS) was higher by about 40° C., from 200°-210° C. to 240°-250° C.
It is to be noted that Ex. III shows the formation of (FeAl)OOH, with yellow oxide seed present, in a lower concentration of ferric salt solution and in the absence of silicate ions.
TABLE IV__________________________________________________________________________ 150° C. × 30 min 200° C. × 15 min 240° C. × 15 min L a b Δ E L a b Δ E L a b Δ E__________________________________________________________________________Raw material (untreated 48.8 13.0 26.8 -- 48.5 13.9 26.2 1.12 46.2 14.6 25.3 3.32iron oxide)Yellow iron oxide 50.4 15.5 28.6 -- 50.0 15.5 28.5 0.41 49.5 15.6 28.1 1.03obtained by presentinvention__________________________________________________________________________ 260° C. × 15 min 280° C. × 15 min L a b Δ E L a b Δ E 33.9 21.1 17.2 19.4 30.0 17.7 10.4 25.3 47.7 17.4 26.0 4.20 39.6 20.2 17.6 16.1__________________________________________________________________________
The amount of alkali, such as NaOH, added to the mixture is that which is necessary to give a pH of the resultant slurry mixture a pH of between 10 and 13, preferably about 12. The addition of sodium silicate, chosen as the preferred silicate of an alkali metal hydroxide, typically maintains of pH of about 12-13.
Based on the amount of soluble ferric salt used in the slurry, the amount of soluble aluminum salt used varies between about 35 and 120 wt.%.
BRIEF EXPLANATION OF THE DRAWINGS
FIG. 1 is an electron microphotograph of yellow iron oxide treated by the method of the present invention (example I.)
FIG. 2A is an electron microphotograph of the raw material of example III.
FIG. 2B is an electron microphotograph of yellow iron oxide treated by the method of the present invention (example II).
FIG. 3A is an electron microphotograph of untreated yellow iron oxide.
FIG. 3B is an electron microphotograph of yellow iron oxide treated by the method of the present invention (example III).
FIG. 4 is an electron microphotograph of the product obtained by hydrothermal treatment of commercial yellow iron oxide in alkali solution as in U.S. Pat. No. 3,969,494.
The magnification of the electron microphotographs is 50,000.
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Synthetic yellow iron oxide (α-FeOOH) is dispersed in an aqueous ferric solution, and an adequate alkali solution and an aqueous aluminum salt solution are added. The resultant dispersion is subjected to a hydrothermal treatment at 150°-250° C. By this treatment, the surface of the synthetic yellow iron oxide is covered with a (FeAl)OOH (solid solution). Yellow iron oxides treated thus have an elevated resistivity to heat of about 50° C. The modified synthetic yellow iron oxide thus obtained is non-toxic and can be used as a pigment in plastics and melt-type traffic paint.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of Provisional Patent Application Ser. No. 60/875,677 filed on Dec. 19, 2006.
STATEMENT OF GOVERNMENTAL INTEREST
This invention was made with Government support, in whole or in part, under a NASA grant no. NNG04CB08C, NSF grants DMI-0422094 and DMI-0522177. The government has certain rights in this invention.
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to a magnetoelectric heterostructure, which consists of a ferromagnetic layer and a ferroelectric layer with some buffer layers in between. And more particular a magnetoelectric heterostructure with magneto-optic and electro-optic effects. It is also related to a method to fabricate the magnetoelectric heterostructure.
2. Technical Background
Interest in multiferroic materials combining two or more ferroic properties, especially ferroelectric and ferromagnetic properties, has inspired a flurry of research activities in recent years due to a great expectation of potential applications in the microelectronics field. Aside from the applications of both ferroelectric (FE) and ferromagnetic (FM) properties, the magnetoelectrics effect can be used in multiple-state memory elements, in which data is stored both in the electric and the magnetic polarizations, or magnetoelectric signal processing devices, such as an FMR-based phase shifters and filters.
The magnetoelectric (ME) effect is defined as the dielectric polarization of a material in an applied magnetic field or an induced magnetization in an external electric field. The effect, first observed in antiferro-magnetic Cr 2 O 3 , is weak in single-phase compounds. Promising single-phase multiferroic materials, such as BiFeO 3 , TbMnO 3 , and YMnO 3 , have been found, and their modified derivatives been extensively investigated. However, there are still very few applicable magnetic ferroelectric materials discovered so far, and their multiferroic effects are not significant enough to be useful in practical applications.
An alternative is to form multiphase complexes, e.g., composites or multilayer structures, in which each phase exhibits a strong ferroic property. To date, in most research, multilayer or bilayer multiferroic structures are laminated and sintered together, or bonded by silver epoxy. In such circumstances, strains and inhomogeneities at the interfaces, or the existence of a foreign layer, complicate the understanding of the important magnetic-electric coupling phenomenon. In contrast, epitaxial multilayer films are more desirable for both theoretical studies and potential applications since there are many factors such as layer thickness and interfacial roughness that may be accurately controlled.
On the other hand, both magneto-optic (MO) and electro-optic (EO) effects are widely used in optical industry. Current photonic integrated circuits (PICs) are based on either polymer or SiO 2 films that are limited in device functionality. Electro-optic or magneto-optic materials are very attractive in adding functionality and adaptivity to PICs. However, very limited work has been done on PICs with functional materials. In this invention, we have developed a multifunctional thin film structure with MO and EO effects, which would enable the integration of MO isolators with other monolithic optical devices, such as lasers, waveguides, modulators, and detectors.
SUMMARY OF THE INVENTION
One aspect of the invention relates to a multiferroic heterostructure comprising a ferromagnetic layer and a ferroelectric layer, therefore with both ferromagnet and ferroelectric properties.
Another aspect of the invention relates to a multiferroic heterostructure constituted of a ferromagnetic layer which has a magneto-optic effect, and a ferroelectric layer which has a electro-optic effect.
Another aspect of the invention relates to a proper buffer layer for cracking-free heterostructure film fabrication.
Yet another aspect of the invention relates to a solution coating method to fabricate the said multiferroic heterostructure.
Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the detailed description which follows, the claims, as well as the appended drawings.
It is to be understood that both the foregoing general description and the following detailed description present embodiments of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated into and constitute a part of this specification. The drawings are not necessarily to scale. The drawings illustrate one or more embodiment(s) of the invention, and together with the description serve to explain the principles and operations of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram illustrating of the multiferroic heterostructure in accordance with the present invention;
FIG. 2 is a schematic illustration of the solution coating apparatus used for fabricating the multiferroic heterostructure in this invention;
FIG. 3 is a flow chart explaining a process of manufacturing the films;
FIG. 4 is a cross-section SEM image of a multiferroic heterostructure film;
FIG. 5 is showing a typical XRD spectrum of a multiferroic heterostructure film;
FIG. 6 is showing a typical Faraday rotation curves of the multiferroic heterostructure film; and
FIG. 7 is showing a typical EO effect curve of the multiferroic heterostructure film.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Shown in FIG. 1 is a preferred embodiment according to present invention. The heterostructure is consisted of a substrate, a buffer layer on the substrate, a ferromagnetic layer, a complex buffer layer and a ferroelectric layer.
In one of the preferred embodiment, c-sapphire was used as the substrate. The ferromagnetic thin film layer, which is also a magneto-optic layer, is bismuth and aluminum substituted yttrium iron garnet, or BiAl:YIG. One of the preferred compositions is Bi 1.8 Y 1.2 Fe 4.2 Al 0.8 O 12 . Undoped yttrium iron garnet (YIG) or other doping elements, such as, but not limited to, Tb, Ga, Al, Ce, and Ge can also be incorporated into the YIG. The ferroelectric thin film layer, which is also an electro-optic layer, is lanthanum modified Pb(Mg 1/3 Nb 2/3 )O 3 —PbTiO 3 (La:PMNT or PLMNT). Other electro-optic materials, such as La modified PBZNT, lanthanum-doped lead zirconate titanate (PLZT) or BST can also be used as the ferroelectric thin film layer.
Several buffer layers were incorporated into the heterostructure to prevent the cracking problem by reducing the stress between substrates and films. An appropriate buffer layer can also protect the substrate at high deposition temperature and improve the substrate/film interfaces. Magnesium oxide (MgO) is a good candidate for a buffer because it is chemically stable and its lattice constant matches to that of both YIG and PLMNT, as well as to that of the sapphire substrates (a=4.758 Å, c=12.991 Å). MgO has a cubic structure and its lattice constant is 4.216 Å, three times of which would match that of YIG (a=12.38 Å), and very close to that of PLMNT (˜4.12 Å). The coefficient of thermal expansion (CTE) of MgO is 10.8×10 −6 /° C. at 0° C., 8.0×10 −6 /° C. at 100° C. It matches well with sapphire's (7.9 to 8.8×10 −6 /° C.) and YIG's CTE (8.13×10 −6 /° C.). We used MgO as buffer and found it works perfectly to help growing both YIG and PLMNT films.
Indium Tin Oxide (ITO) is another good buffer candidate for growing YIG and PLMNT films on a sapphire substrate, especially when a conductive layer is desired. The CTE of ITO is 8.5×10 −6 /° C., lattice constant is about 10.2 Å.
A complex buffer, which comprises MgO, lanthanum-doped lead titanate (PLT), and lanthanum-doped lead zirconate titanate (PLZT), has been developed in this invention especially for the growth of PLMNT onto BiAl:YIG layer.
The film was fabricated by a solution coating method. The coating apparatus used for coating films in this invention are shown schematically in FIG. 2 . It consists of three major parts: a driving mechanism 21 , a vertical tube furnace 22 , and a computerized controller 23 . This apparatus is capable of multiple cycles that consist of immersing, withdrawing, drying, annealing and cooling stages. The number of cycles, the number of stages in a cycle and the motion and/or duration of each stage can all be programmed into the computer. The system is also equipped with an automated exchanger 24 for solutions of different precursors. A unique advantage of the coating process is that it can be used to grow multilayer (or superlattice) materials conveniently by dipping the substrate into different chemical precursors each time.
In this technique, solutions of individual metal-organic compounds are mixed at the desired cation ratios to form a coating solution. This coating solution is deposited on a substrate by dip-coating to produce a wet film, which is then heated to first remove any solvent that did not evaporate during the deposition step and then to decompose the metal-organic compounds to produce an inorganic film. For most applications, the first consideration for an adequate film forming process is the ability to produce a final crack-free film. Solution-derived films tend to form cracks with increasing thickness owing to the high volume shrinkage as organic materials are removed during the firing process. This is especially true for films requiring a high-temperature treatment for crystallization. Not only is there another volume shrinkage accompanying the amorphous-to-crystalline transformation but factors like thermal expansion mismatch between the film and the substrate also become more severe as the processing temperature increases.
A similar solution coating method is spin-coating.
A typical flow chart for preparing crystalline films from solutions by multiple dipping is shown in FIG. 3 . The temperature cycling nature of the solution coating process (by repeated heating and cooling for each layer) significantly reduces the stress due to thermal expansion mismatch between the substrate and film materials.
Precursors for preparing the garnet FM films were all nitrate compounds (Y(NO 3 ) 3 , Fe (NO 3 ) 3 , Al (NO 3 ) 3 and Bi (NO 3 ) 3 ). Nitrates (˜10 g in total according to the desired cation ratios) were first dissolved into 30 mL acetylacetone (2,4-pentanedione). Ethanol (30-50 mL) was then added to a desired level for the subsequent coating process. The solutions were aged overnight prior to coating. The cracking-free film is up to the thickness of 3 μm.
For PLMNT films and PLT or PLZT buffers, the precursors in the forms of acetates and alkoxides were dissolved in methanol and 2-methoxyethanol after proper dehydration. Magnesium acetate, dissolved in 2-methoxyethanol, was used as the precursor for MgO. Concentrations of the various solutions were between 0.1 and 0.4 M (mol/L). The cracking-free film is up to the thickness of 3 μm.
The on site heating temperature used to crystallize the film is in the range of 500-800° C. The dipping speed is 1-2 mm/second. The firing times are around 2-3 minutes. The firing speed is about 3 mm/second. The precursors for the PLMNT film and PLT and PLZT buffers are made of all acetates (except niobium ethoxide) dissolved in methanol and 2-methoxyethanol. The precursor for MgO solution is magnesium acetate solved in 2-methoxyethanol. Concentrations of the solutions are between 0.2-0.4 M (mol/L).
The heterostructure film exhibits excellent optical qualities with smooth surfaces and high transparency. Scanning electron microscopy (SEM, JEOL 6320, Peabody, Mass.) was used to examine the morphologies of the heterostructure films. FIG. 4 is the SEM image of the cross section. (The film and substrate were cleaved by a diamond knife without further polishing.) It can be seen that the multilayer structure is well formed. The thicknesses of the ferromagnetic layer and the ferroelectric layer are about 800 and 900 nm, respectively. The thicknesses of the individual buffer layers (shown as the white lines) are in the range of 5 to 20 nm.
Crystallinity of the heterostructure was characterized using a Rigaku (Rigaku Americas Corp., The Woodlands, Tex.) x-ray diffractometer (XRD) system. FIG. 5 shows the XRD pattern of the heterostructure. Both garnet (BiAl:YIG) and perovskite (PLMNT) crystalline structures are well formed. The heterostructure exhibits both ferromagnetic and ferroelectric effects as illustrated in FIGS. 6 and 7 . The ferromagnetic and magneto-optic effects of the BiAl:YIG layer were not negatively affected by the existence of the ferroelectric layer. Shown in FIG. 6 is the Faraday rotation curve of a heterostructure film. The heterostructure film has a Verdet constant as high as 4.5°/mm-Oe at the wavelength of 633 nm, which is higher than that of the referenced single BiAl:YIG film at 2.7°/mm-Oe. Shown in FIG. 7 is measured EO coefficient of the heterostructure at 532 nm. The EO coefficient is about 0.3×10 −16 (m/V) 2 , which is significantly higher comparing to that of other EO films.
Although particular embodiments of the invention have been described and illustrated herein, it is recognized that modifications and variations may readily occur to those skilled in the art. For example, other film fabrication technologies can be used to make the structure, or different precursor can be used in a solution coating method. The thickness of any layer can be changed. To enhance the ferromagnetic and ferroelectric effects of the individual layer, periodic multilayer structures can be further incorporated into the heterostructure multiferroic film.
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A heterostructure of multiferroics or magnetoelectrics (ME) was disclosed. The film has both ferromagnetic and ferroelectric properties, as well as magneto-optic (MO) and electro-optic (EO) properties. Oxide buffer layers were employed to allow grown a cracking-free heterostructure a solution coating method.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation in part of U.S. patent application Ser. No. 11/772,669, filed Jul. 2, 2007, said application being based on Provisional Application No. 60/818,424, filed Jul. 2, 2006, both applications being by the same inventor and incorporated herein by reference.
[0002] This invention relates to a biological radiation shield apparatus and more particularly to a track mounted, steam generator, man-way radiation shield apparatus that reduces the radiation exposure to the workers as they perform maintenance or inspection of a steam generator, especially the primary heat transfer system of a pressure water reactor (PWR) nuclear electric generating plant.
BACKGROUND OF THE INVENTION
[0003] Routine maintenance or inspection requires the opening of certain ports in the Steam Generator system of a Pressure Water Reactor Nuclear Electric Generating Plant, thereby exposing the workers to significantly increased radiation levels.
FIELD OF THE INVENTION
[0004] This invention relates to the field of apparatus typically defined as “shielding” against radiation in order to reduce the radiation levels and radiation exposure to the workers that are maintaining and/or inspecting Pressure Water Reactor (hereinafter “PWR”) Steam Generator systems. The invention provides an improved apparatus for and method of shielding (reducing the radiation levels through the physics principle of attenuation) while permitting the required maintenance or inspection. The improved shielding specifically addresses the elevated radiation levels that occur when the access ports, commonly called “man-ways”, are opened in order to perform this maintenance and/or inspection.
[0005] Most reactors of this type have limited usable shielding. The main requirement that causes a limitation on the amount of shielding that can be utilized is due to the fact that the shielding has to be placed in a plane that is customarily offset approximately 25 degrees from vertical.
[0006] Typically, a radiation shield apparatus is heavy so that a radiation shielding panel as a part thereof cannot be easily moved out of the way of the opening. Weight makes it a difficult item to move without having to overcome gravity. Yet, the shield apparatus must be heavy in order to reduce the radiation exposure to nuclear workers. Shield weight or mass in the path of the radiation is directly proportional to the effectiveness of the shielding. The prior art swing door shield system's shielding effectiveness is compromised by the weight that can be safely and easily be manipulated by the workers.
[0007] The radiation shield apparatus must also provide adequate shielding while maintaining the necessary functional qualities to workers that are inspecting or maintaining the steam generator component of a pressure water nuclear electric generating plant. It is very desirable to increase the shielding by placing a significant weight or mass in the path of the radiation, while keeping maintenance or inspection accessible. Shielding must be maintained while accessing the port.
[0008] The shielding must also be movable in a lateral or manipulated so as to remain between the worker and the radiation source while performing much of the work activity. Yet, again gravity limits the amount of shielding that can be utilized due to the shielding having to be placed in a plane that is customarily offset. Openings or radiation paths that occur with any shield that is hinged from one side and must be manipulated or swung open for access, have to be avoided.
[0009] The worker cannot maintain the shield between him and the radiation source(s) and still be able to swing the shield out from in front of the man-way opening in order to have access for lines and hoses leading to robotics equipment for installing repair sleeves to eliminate leaking or failing tubes and other maintenance and inspection equipment.
[0010] The existing shielding apparatus has a hinged shield that requires swinging out and away from the man-way port for access and therefore the workers are not able to “hide” behind the shield as they manipulate the maintenance and inspection equipment. Each opening and closing of the shield further exposes the worker to increased radiation levels due to the physical positions that the worker must assume in order to unlock, lock and manipulate this relatively heavy swinging shield door.
[0011] By reference to FIG. 2 , FIG. 3 , FIG. 4 , and FIG. 5 , a structure of the prior art becomes clear. The man-way 102 has a typical shield 110 mounted thereover. The typical shield 110 includes a heavy hinge 112 supporting a swing door shield 114 . Due to tremendous weight of typical shield 110 , hinge 112 makes it difficult for swing door shield 114 to provide access for maintenance or repair of the reactor.
[0012] In FIG. 5 , it becomes clear that worker 124 must juggle a yellow lead blanket panel 120 and to use hoses 310 in order to perform maintenance on the reactor. Prior to doing anything, white lead blankets 122 must be placed around the man-way 102 . Thus, this cumbersome procedure indicates a great advantage for any system, which simplifies this procedure.
[0013] Another object of the present invention is to address the demands of the Nuclear Regulatory Commission that requires all activities within the Radiological Controlled Area (RCA) be conducted with the goal that the radiation exposure to the nuclear workers be “as low as reasonably achievable” (ALARA).The worker cannot maintain the shield between him and the radiation source(s) and still be able to swing the shield out from in front of the man-way opening in order to have access for lines and hoses leading to robotics equipment for installing repair sleeves to eliminate leaking or failing tubes and other maintenance and inspection equipment.
SUMMARY OF THE INVENTION
[0014] Among the many objectives of the present invention is the provision of a radiation shield apparatus with a track support frame on which at least one shielding assembly can be easily moved out of the way of the opening without having to overcome gravity.
[0015] Another objective of the present invention is the provision of a radiation shield apparatus to reduce the radiation exposure to nuclear workers that will substantially overcome the deficiencies of the prior art devices.
[0016] Yet another objective of the present invention is to provide adequate shielding while maintaining the necessary functional qualities to workers that are inspecting or maintaining the steam generator component of a pressure water nuclear electric generating plant.
[0017] Still another objective of the present invention is to increase the shielding which means placing significant weight or mass in the path of the radiation.
[0018] A further objective of the present invention is to be able to maintain the shielding effectiveness while accessing the man-way port.
[0019] Yet a further objective of the present invention is the provision of an apparatus to permit the shielding to be moved laterally or manipulated so as to remain between the worker and the radiation source while performing much of the work activity.
[0020] A still further objective of the present invention is to eliminate the effects of gravity that limit the amount of shielding that can be utilized due to the shielding having to be placed in a plane that is customarily offset.
[0021] Another objective of the present invention is to eliminate the openings or radiation paths that occur with any shield that is hinged from one side and as a result must be manipulated or swung open for access.
[0022] Yet another objective of the present invention is to permit the worker to maintain the shield between him and the radiation source(s) and still be able to swing the shield out from in front of the man-way opening in order to have access for lines and hoses leading to robotics equipment for installing repair sleeves to eliminate leaking or failing tubes and other maintenance and inspection equipment.
[0023] Still another objective of the present invention is to address the demands of the Nuclear Regulatory Commission that requires all activities within the Radiological Controlled Area (hereinafter “RCA”) be conducted with the goal that the radiation exposure to the nuclear workers be “as low as reasonably achievable” (hereinafter “ALARA”).
[0024] In addition, the actual installation process of the shielding material prior to any work or inspection is to be performed, must be considered as part of the total dose impact for the work to be performed and clearly a concern to the facility management and the Nuclear Regulatory Commission (hereinafter “NRC”).
[0025] Therefore, being able to implement a track support frame by which the shielding is installed in a low dose area and then moved by means of or on a track support frame of this invention to move the shielding material into position for the maximum radiation dose impact for the work or inspection that is to be performed provides a great advantage. However, such a system is not in the prior art.
[0026] It is intended that any other advantages and objects of the present invention that become apparent or obvious from the detailed description or illustrations contained herein are within the scope of the present invention. These and other objectives of the invention (which other objectives become clear by consideration of the specification, claims and drawings as a whole) are met by providing an apparatus for and method of shielding (reducing the radiation levels through the physics principle of attenuation) while permitting the required maintenance or inspection. The improved shielding specifically addresses the elevated radiation levels that occur when the man-ways are opened in order to perform maintenance or inspection.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 depicts a block diagram for the radiation shield apparatus 100 of this invention.
[0028] FIG. 1 a depicts a second block diagram for the radiation shield apparatus 100 of this invention.
[0029] FIG. 2 depicts a perspective view of the man-way 102 of the prior art.
[0030] FIG. 3 depicts a perspective view of the cover plate 104 of the prior art.
[0031] FIG. 4 depicts a front, top perspective view of swing door shield 114 of the prior art.
[0032] FIG. 5 depicts a perspective view of worker 124 protected by yellow lead blanket panels 120 and white lead blankets 122 with the swing door shield 114 of the prior art.
[0033] FIG. 6 depicts a perspective view of the radiation shield apparatus 100 .
[0034] FIG. 7 depicts a perspective view of the track support frame 140 .
[0035] FIG. 8 depicts a perspective view of top stud bolt assembly 148 .
[0036] FIG. 9 depicts a perspective, top view of bottom stud bolt assembly 147 .
[0037] FIG. 10 depicts a front, perspective view of radiation shield apparatus 100 in lock down configuration 179 .
[0038] FIG. 11 depicts a front, perspective view of track roller stop 170 .
[0039] FIG. 12 depicts a perspective view of roller 154 on track member 142 .
[0040] FIG. 13 depicts an exploded view of hinge pin 200 .
[0041] FIG. 14 depicts a perspective view of hinge pin 200 secured by pin clip 204 .
[0042] FIG. 15 depicts a perspective view of right side-panel 212 being mounted in position.
[0043] FIG. 16 depicts a side perspective view of right adjustable secondary lower shield panel 222 .
[0044] FIG. 17 depicts a front, perspective view of radiation shield apparatus 100 .
[0045] FIG. 18 depicts a front, perspective view of radiation shield apparatus 100 .
[0046] FIG. 19 depicts a front, perspective view of the radiation shield apparatus 100 .
[0047] FIG. 20 depicts a front, perspective view of the radiation shield apparatus 100 .
[0048] FIG. 21 depicts a front, perspective view of the radiation shield apparatus 100 .
[0049] FIG. 22 depicts a front, perspective view of the radiation shield apparatus 100 .
[0050] FIG. 23 depicts a front, perspective view of the radiation shield apparatus 100 .
[0051] FIG. 24 depicts a front, phantom view of radiation shield apparatus 100 showing port cover plug 252 , safety bars 251 , and HEPA port shield adapter 256 .
[0052] FIG. 25 depicts a front, phantom view of radiation shield apparatus 100 showing port cover plug 252 , safety bars 251 , and HEPA port shield adapter 256 .
[0053] FIG. 26 depicts a front view of original version 300 of radiation shield apparatus 100 .
[0054] FIG. 27 depicts a profile cut-away view of original version 300 .
[0055] FIG. 28 depicts a profile cut-away view of original version 300 .
[0056] Throughout the figures of the drawings, where the same part appears in more than one figure of the drawings, the same number is applied thereto.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0057] The invention provides an improved apparatus for and method of shielding (reducing the radiation levels through the physics principle of attenuation) while permitting the required maintenance or inspection. The improved shielding specifically addresses the elevated radiation levels that occur when the man-ways are opened in order to perform this maintenance and/or inspection. Moreover, it pertains specifically to an improved shield door system used as a radiation shield apparatus that includes a track system on which a radiation shielding panel or panels can be easily moved out of the way of the opening without having to overcome gravity. The shielding provided by the shield door system has two half shield panels closing the man-way; and that, when moved, can provide partial or full access to the man-way port. Each of the shield panels includes a hinged lower section that can be opened as needed to permit insertion of inspection devices, including robotics and other equipment for the repair and/or inspection of the internals of the Steam Generator. This rolling shield system easily moves (rolls) across the face of the open port on rollers and permits the worker to manipulate the maintenance and/or inspection equipment as needed and still remain completely or partially behind the protective radiation shield.
[0058] In view of the limitations now present in the prior art, the present invention provides a new and useful radiation shielding apparatus which reduces the radiation dose received by the workers that are maintaining or inspecting PWR Steam Generator system. The improved shielding specifically addresses the elevated radiation levels that occur when the man-ways, are opened in order to perform this maintenance and/or inspection.
[0059] The invention significantly decreases the radiation dose that the workers receive during all phases of work performed in the area of the man-way port. In addition, the effective shielding of the prior art system when fully installed is approximately one-third that of the present invention due to the fact that the face of the port is inclined downward by approximately 25 degrees and the existing shielding must overcome gravity in order to swing the door up and into position.
[0060] Even though the invention includes the use of a single door or shield panel assembly that will move laterally on a track member, this description will detail the invention utilizing two doors or shield panel halves, a right half and a left half. The use of a double shield door or panel minimizes the amount of weight of any single component that must be handled by an individual nuclear worker.
[0061] Each shielded door panel half of the shield door system has three parts, an upper primary shield panel that includes the rollers, a secondary lower shield panel that is hinged off of the primary shield panel and a side shield that also is attached to the angle steel on the primary shield panel. The assembled shielded door panel weighs significantly more than what can be easily handled and as described above must be assembled in place from three lighter weight component shield panel pieces. All of the shield panels have at least 2.5 centimeters (one inch) thick lead sheet or shielding equivalent to that of 2.5 centimeters (one inch) of lead and are contained in a metal covering such as stainless steel sheeting.
[0062] The goal is to improve the shielding quality of the shield which requires placing mass in the path of the radiation. The shield panel halves roll on an upper track that supports the weight and a lower track that maintains the shield at an angle from vertical and in close proximity to the plane of the man-way opening. The track and supporting frame is attached to the sealing surface that is around the man-way opening in the same location the approximately 10.2 centimeters (four inches) thick steel cover that has to be removed from the opening in order to perform the required maintenance and/or inspection. Four of the approximately 20 available stud apertures are used to secure the track support frame to the surface around the man-way opening.
[0063] The man-way opening is tipped downward by approximately 25 degrees. The current system utilizes a hinged shield that swings to one side only. The process of opening requires that gravity must be overcome because of the downward tipping and when the shield is swung away from the opening the workers in the area receive a significant amount of radiation exposure. As stated previously, the amount of shielding is compromised in order to keep the weight at a manageable level.
[0064] The invention includes two rollers at the top of each half shield assembly that permits easy rolling, even with the necessary weight, on a track which is supported above the man-way opening. A single roller is located at the bottom corner of each shield halves and roll on the underside of the lower track member. All of the weight of each shield assembly halves is carried by the upper track and the two rollers. The lower roller and track simply maintains the shield halves at the approximately 25 degree angle and in close proximity to the face of the man-way opening.
[0065] The invention places the shielding halves on a level plain and therefore the amount of weight of the shielding does not impact the ability of a worker to move the shielding as needed for access. The invention reduces the radiation levels directly in front of the shield by a factor of approximately three (3) compared to the existing shielding due directly to the amount of mass in the path of the radiation. In addition, the shielding maybe moved in such as way that access to the man-way opening can often be accomplish while the worker remains behind one of the halves, this benefit cannot be accomplished with the swing door type shielding currently used.
[0066] Adding FIG. 1 to the consideration, the structure of radiation shield apparatus 100 can clearly be seen. Radiation shield apparatus 100 covers man-way 102 . Radiation shield apparatus 100 has a track support frame 140 (also referred to as a track system) onto which attaches a left half shield assembly 230 (also referred to as a left shield panel, a radiation shielding panel, or a left shield panel assembly) and a right half shield assembly (also referred to as a right shield panel, a radiation shielding panel, or right shield panel assembly) 232 which move across the man-way 102 of the steam generator. Left half shield assembly 230 and right half shield assembly 232 cooperate to open or close man-way 102 as desired.
[0067] Left half shield assembly 230 has a left adjustable secondary lower shield panel 220 (also referred to as the left lower hinged panel) which can be in the open adjustment 240 or the closed adjustment 242 . Right half shield assembly 232 has a right adjustable secondary lower shield panel 222 (also referred to as the right lower hinged panel) which can be in the open adjustment 240 or the closed adjustment 242 . Open adjustment 240 provides access for maintenance hoses 310 and other equipment to be used by worker 124 for maintenance or repair.
[0068] Adding FIG. 1 a to the consideration, a variation to radiation shield apparatus 100 can be clearly seen. In this embodiment, radiation shield apparatus 100 has a single shield assembly 228 which has a single adjustable secondary lower shield panel 219 . The structure and function of this embodiment are otherwise the same as that described in FIG. 1 .
[0069] Adding FIG. 2 , FIG. 3 , FIG. 4 , and FIG. 5 to the consideration, the problems and safety concerns of the prior art can be clearly seen. In the prior art, cover plate 104 is removed from man-way 102 and a typical shield 110 is installed. Typical shield 110 is attached to sealing surface 106 in much the same manner as seen in FIG. 7 , FIG. 15 , FIG. 16 , and FIG. 17 .
[0070] Typical shield 110 has swing door shield 114 . Swing door shield 114 is able to swing open through its interaction with hinge 112 . Swing door shield 114 swings out and away from man-way 102 .
[0071] However, swing door shield 114 does not provide adequate protection to workers 124 as discussed in the background of the invention. Thus, to prevent harmful exposure emanating from man-way 102 yellow lead blanket panels 120 and white lead blankets 122 are necessary.
[0072] Adding FIG. 6 to the consideration, the structure of radiation shield apparatus 100 which covers man-way 102 becomes clear. The man-way 102 is inclined up to 35 degrees from vertical, with the top portion 130 being outward by that amount relative to bottom portion 132 . More preferably, the incline is about 10 degrees to 30 degrees. Most preferably, the incline is 20 degrees to 30 degrees.
[0073] Radiation shield apparatus 100 has a left half shield assembly 230 and a right half shield assembly 232 . Left half shield assembly 230 and right half shield assembly 232 are attached to track support frame 140 through top support roller assembly 150 and bottom guide roller assembly 152 .
[0074] Maintenance hoses 310 can be inserted through radiation shield apparatus 100 once it is installed over man-way 102 . Maintenance hoses 310 are utilized to clean and perform routine maintenance.
[0075] Adding FIG. 7 , FIG. 8 , and FIG. 9 to the consideration, the structure of track support frame 140 becomes clear. Track support frame 140 is substantially rectangular in shape and has top cross member 160 which is oppositely disposed from bottom cross member 162 . Left standing member 164 and right standing member 166 are oppositely disposed from each other and join top cross member 160 and bottom cross member 162 . Track support frame 140 mounts over man-way 102 and attaches to sealing surface 106 . Track support frame 140 is secured to sealing surface 106 through stud bolts 144 .
[0076] Once cover plate 104 is removed from man-way 102 , stud bolts 144 are securely inserted into stud apertures 108 on sealing surface 106 . Track support frame 140 has top cross member 160 which has alignment slots 101 . Alignment slots 101 insert over stud bolts 144 to guide the correct and precise positioning of track support frame 140 . Once track support frame 140 is correctly positioned, stud bolts 144 are tightened in top cross member 160 . Stud bolts 144 are also inserted into bottom apertures 163 and tightened into bottom cross member 162 .
[0077] Top stud bolt assembly 148 has top cross member 160 and track member 142 . Top cross member 160 has track member 142 at a perpendicular plane to man-way 102 . Track member 142 has track roller stop 170 on each side to ensure that radiation shield apparatus 100 does not roll over the end of top cross member 160 . Upper track member also has push pull center stop lock 180 .
[0078] Bottom stud bolt assembly 147 had bottom cross member 162 and track member 142 at a perpendicular plane to man-way 102 . Bottom cross member 162 has bottom apertures 163 and stud bolts 144 . Stud bolts 144 are permanently affixed to bottom cross member 162 through bolt tethers 146 .
[0079] Now adding FIG. 10 to the consideration, the lock down configuration 179 of radiation shield apparatus 100 can clearly be seen. Lock down configuration 179 creates a lockable high radiation area, which is defined by the Nuclear Regulatory Commission as a high radiation area which is controlled through a locking system.
[0080] To establish the lock down configuration 179 , left half shield assembly 230 and right half shield assembly 232 are separated and push pull center stop lock 180 is moved from backward position and placed forward (also depicted in FIG. 27 and FIG. 28 ). Then, left half shield assembly 230 and right half shield assembly 232 are pushed together. Push pull center stop lock 180 has two cavities to accommodate the upper portion of left half shield assembly 230 and right half shield assembly 232 . Push pull center stop lock 180 stops the movement of left half shield assembly 230 and right half shield assembly 232 toward each other.
[0081] Center draw latch 182 (depicted in FIG. 17 ) has latch lock slot 172 . Lockable slide bolts 224 each have slide bolt lock slots 174 . Cable 178 threads through latch lock slot 172 and slide bolt lock slots 174 and the ends of cable 178 are securely locked together with pad lock 176 .
[0082] The workings of push pull center stop lock 180 and cable 178 with pad lock 176 establish lock down configuration 179 . Push pull center stop lock 180 prevents either left half shield assembly 230 or right half shield assembly 232 from being moved past the substantially center point on upper track 142 where push pull center stop lock 180 is located. Center draw latch 182 , cable 178 , and pad lock 176 prevent right half shield assembly 232 , left half shield assembly 230 from being opened or moving away from the center toward the left and right ends of upper track support bar 142 . Also, cable 178 and pad lock 176 prevent either left adjustable secondary lower shield panel 220 or right adjustable secondary lower shield panel 222 from being adjusted and thus exposing man-way 102 .
[0083] Now adding FIG. 11 and FIG. 12 to the consideration, top support roller assembly 150 and bottom guide roller assembly 152 can be clearly seen. Only top support roller assembly 150 is depicted in these figures but bottom guide roller assembly 152 functions in the same manner. Top support roller assembly 150 has two rollers 154 and track member 142 . Bottom guide roller assembly 152 has track member 142 and a single roller 154 .
[0084] Left half shield assembly 230 and right half shield assembly 232 travel, by means of or on upper and lower rollers 154 , on upper and lower track members 142 . For the lower track member 142 , a single roller 154 is attached to angle steel 194 (depicted in FIG. 13 , FIG. 14 , and FIG. 15 ) by roller bolt 156 . While a pair of rollers 154 is attached to each the upper portion of left half shield assembly 230 or right half shield assembly 232 by roller bolt 156 in top support roller assembly 150 .
[0085] Upper track member 142 and lower track member 142 are held perpendicular to man-way 102 . The upper portion of left primary shield panel 184 and right primary shield panel 186 are angled about upper track member 142 to allow for this perpendicular alignment. Angle steel 194 is also angled about lower track member 142 to allow for this perpendicular alignment.
[0086] Top support roller assembly 150 is designed to support the weight of left half shield assembly 230 and right half shield assembly 232 . Bottom guide roller assembly 152 is designed to guide and support the workings of top support roller assembly 150 , especially at the desired angle thereby facilitating movement and use of radiation shield apparatus 100 . Since the movement of left half shield assembly 230 and right half shield assembly 232 are not offset, the effects of gravity are not as great and thus, it is easier to move heavier shielding.
[0087] Now adding FIG. 13 and FIG. 14 to the consideration, the connection between right primary shield panel 186 and right adjustable secondary lower shield panel 222 can be clearly seen. While only the right side is depicted, the left primary shield panel 184 and the left adjustable secondary lower shield panel 220 function in the same manner.
[0088] Right adjustable secondary lower shield panel 222 has hinge sleeve 206 which cooperates with dove tail cavity 196 on right primary shield panel 186 . Right primary shield panel 186 is welded or otherwise suitably attached to angle steel 194 . Hinge sleeve 206 is aligned with hinge end aperture 208 and hinge pin 200 is slid through hinge sleeve 206 and hinge end aperture 208 on angle steel 194 to connect the right adjustable secondary lower shield panel 222 and right primary shield panel 186 .
[0089] Hinge pin 200 is secured in hinge sleeve 206 through different mechanisms on each end. Dove tail connector 198 cooperates with dove tail cavity 196 to form a secure and stable attachment. Dove tail connector 198 is designed to precisely fit in dove tail cavity 196 .
[0090] On the other end, hinge pin 200 is secured through the interaction of pin aperture 202 and pin clip 204 . Pin clip 204 inserts into pin aperture 202 to prevent hinge pin 200 from sliding horizontally in hinge sleeve 206 . Pin tether 201 permanently attaches pin clip 204 to right adjustable secondary lower shield panel 222 .
[0091] Now adding FIG. 15 to the consideration, the interaction of angle steel 194 and right side-panel 212 can be clearly seen. While only right side-panel 212 is depicted, left side-panel 210 attaches in the same fashion. Angle steel 194 is attached to right primary shield panel 186 through welding or any other suitable attachment mechanism. Angle steel 194 has upper key slot 216 and lower key slot 218 .
[0092] On right side-panel 212 , are a pair of carriage-type bolt heads 214 . Carriage-type bolt heads 214 are designed to cooperate with upper key slot 216 and lower key slot 218 to form a secure and releaseable connection between right side-panel 212 and angle steel 194 .
[0093] Now adding FIG. 16 to the consideration, the adjustability of secondary lower shield panels 220 and 222 can clearly be seen. Left adjustable secondary lower shield panel 220 and right adjustable secondary lower shield panel 222 can be adjusted at a variety of angles in relation to left primary shield panel 184 and right primary shield panel 186 .
[0094] A depiction of right adjustable secondary lower shield panel 222 is depicted in this figure but left adjustable secondary lower shield panel 220 functions in the same manner. Latch adjustment plate 188 is attached to angle steel 194 (as depicted in FIG. 13 ). Latch adjustment plate 188 can be welded to angle steel 194 or attached in any other suitable fashion. Lockable slide bolt 224 is attached to right adjustable secondary lower shield panel 222 through any suitable attachment mechanism. Latch adjustment plate 188 has a series of latch apertures 190 .
[0095] The user positions right adjustable secondary lower shield panel 222 at a desired angle relative to right primary shield panel 186 . Then, lockable slide bolt 224 and a desired latch aperture 190 are aligned and lockable slide bolt 224 cooperates to secure the connection. When the angle of right adjustable secondary lower shield panel 222 needs to be changed, lockable slide bolt 224 is removed.
[0096] Adding FIG. 17 to the consideration, the structure of radiation shield apparatus 100 becomes more clear. As previously stated ( FIG. 7 ), radiation shield apparatus 100 is mounted on sealing surface 106 through the interaction with track support frame 140 . Left half shield assembly 230 and right half shield assembly 232 are mounted in three pieces so that each half can provide additional protection (as described in the background of the invention). First, left primary shield panel 184 and right primary shield panel 186 are mounted on upper track member 142 . Then, left side-panel 210 is attached to left angle steel 194 and right side-panel 212 is attached to right angle steel 194 (as depicted in FIG. 15 ) and left adjustable secondary lower shield panel 220 is attached to left primary shield panel 184 and right adjustable secondary lower shield panel 222 is attached to right primary shield panel 186 (as depicted in FIG. 13 and FIG. 14 ).
[0097] Attaching the three pieces of left half shield assembly 230 and right half shield assembly 232 in this manner provides benefits. First, the entirety of left half shield assembly 230 or right half shield assembly 232 can have greater weight, since each individual piece (primary shield panel 184 or 186 , adjustable secondary lower shield panel 220 or 222 , or side-panel 210 or 212 ) can have greater weight. The worker only has to lift one individual piece at a time so each individual piece can be composed of thicker lead thus adding to additional shielding.
[0098] Secondly, the pieces can be installed at the outer edges of upper track member 142 and lower track member 142 so that the worker can install the pieces away from the man-way and the radiation exposure. Once, the left half shield assembly 230 and the right half shield assembly 232 are installed they can be rolled along upper track member 142 and lower track member 142 to cover man-way 102 and the worker can be shielded from the radiation from behind left half shield assembly 230 or right half shield assembly 232 .
[0099] Left half shield assembly 230 and right half shield assembly 232 slide along track member 142 in either direction until their movement is stopped by the opposing half, push pull center stop lock 180 (as depicted in FIG. 11 ), or a track roller stop 170 . On lower track member 142 is release clip 158 which further prevents left half shield assembly 230 or right half shield assembly 232 from sliding off of track member 142 . Release clips 158 also function to guide and support shield assembly halves 230 and 232 in case a worker 124 (as depicted in FIG. 1 ) applies too much force in sliding either along track member 142 .
[0100] Release clips help to ensure that either right half shield assembly 232 or left half shield assembly 230 maintain their secure and stable position in track member 142 .
[0101] Left adjustable secondary lower shield panel 220 and right adjustable secondary lower shield panel 222 are secured in the desired angle through their interactions with lockable slide bolt 224 and latch apertures 190 on latch adjustment plate 188 (as described in detail in FIG. 16 ).
[0102] Right half shield assembly 232 and left half shield assembly 230 can be securely but releaseably locked together through center draw latch 182 . Center draw latch 182 pulls right half shield assembly 232 and left half shield assembly 230 together and locks them in place.
[0103] Left primary shield panel 184 has high efficiency particulate arrestance (hereinafter “HEPA”) port opening 250 . As shown in FIG. 17 , port cover plug 252 covers HEPA port opening 250 . Port cover plug 252 is securely but releaseably held in place through cover plug securing bolt 254 .
[0104] Adding FIG. 18 , FIG. 19 , FIG. 20 , FIG. 21 , FIG. 22 , and FIG. 23 to the consideration, the flexibility of radiation shield apparatus 100 is seen through the adjustability of secondary lower shield panels 220 and 222 and left half shield assembly 230 and right half shield assembly 232 . As depicted in FIG. 11 and FIG. 12 , left half shield assembly 230 and right half shield assembly 232 move through top support roller assembly 150 and bottom guide roller assembly 152 . As depicted in FIG. 13 and FIG. 16 , left adjustable secondary lower shield panel 220 and right adjustable secondary shield panel 222 rotate through its interactions hinge pin 200 and hinge sleeve 206 with and lock through its interactions with latch adjustment plate 188 , latch apertures 190 , and lockable slide bolt 224 .
[0105] Referring specifically to FIG. 18 , FIG. 19 , and FIG. 20 , the left half shield assembly 230 and right half shield assembly 232 can be moved into a variety of positions relative to each other. In FIG. 18 , left half shield assembly 230 is open 244 exposing man-way 102 while right half shield assembly 232 is closed 246 covering man-way 102 . Left primary shield panel 184 travels with left half shield assembly 230 as right primary shield panel 186 remains in place with right half shield assembly 232 . Left adjustable secondary lower shield panel 220 is in open adjustment 240 while right adjustable secondary lower shield panel 222 is in closed adjustment 242 .
[0106] Because left primary shield panel 184 travels with left half shield assembly 230 as right primary shield panel 186 remains in place with right half shield assembly 232 , a half slideability is produced. Left primary shield panel 184 may travel independently of right half shield assembly 232 . Thus, access is provided to the nuclear reactor 128 for repair or maintenance.
[0107] In FIG. 19 , both left half shield assembly 230 and right half shield assembly 232 are open 244 , fully exposing man-way 102 . Left primary shield panel 184 travels with left half shield assembly 230 and right primary shield panel 186 travels with right half shield assembly 232 . Left adjustable secondary lower shield panel 220 is in open adjustment 240 while right adjustable secondary lower shield panel 222 is in closed adjustment 242 .
[0108] In FIG. 20 , FIG. 21 , FIG. 22 , and FIG. 23 , both left half shield assembly 230 and right half shield assembly 232 are closed 246 fully covering man-way 102 . Left primary shield panel 184 remains in place with left half shield assembly 230 while right primary shield panel 186 remains in place with right half shield assembly 232 .
[0109] Referring specifically to FIG. 20 , FIG. 21 , FIG. 22 , and FIG. 23 , the adjustability of left adjustable secondary lower shield panel 220 and right adjustable secondary lower shield panel 222 can be clearly seen. These panels can be individually or jointly opened or closed through their adjustable interactions as seen in FIG. 13 , and FIG. 16 .
[0110] In FIG. 20 left adjustable secondary lower shield panel 220 is in open adjustment 240 while right adjustable secondary lower shield panel 222 is in closed adjustment 242 . In FIG. 21 , both right adjustable secondary lower shield panel 222 and left adjustable secondary lower shield panel 220 are in open adjustment 240 . In FIG. 22 , left adjustable secondary lower shield panel 220 is in closed adjustment 242 while right adjustable secondary lower shield panel 222 is in open adjustment 240 . In FIG. 23 , both left adjustable secondary lower shield panel 220 and right adjustable secondary lower shield panel 222 are in closed adjustment 242 .
[0111] Open adjustment 240 permits limited access to man-way 102 . This limited access permits the worker to manipulate maintenance and/or inspection equipment to access man-way 102 (as depicted in FIG. 6 ) and still remain completely or partially behind the protective radiation shield. Adjustable secondary lower shield panels 220 and 222 direct the escaping radiation downward while left side-panel 210 and right side-panel 212 block radiation from escaping from the sides. This combination of limited access, guiding, and blocking significantly reduces the amount of radiation exposure to worker (as depicted in FIG. 1 ).
[0112] Left side-panel 210 and right side-panel 212 may end up as installed in the pieces. Assembling by pieces greatly facilitates the installation of the radiation shield apparatus 100 . The combination for the left-side panel 210 and right side panel 212 forms radiation shield apparatus 100 .
[0113] Now adding FIG. 24 and FIG. 25 to the consideration and also considering FIG. 17 , various features of radiation shield apparatus 100 can be clearly seen. In FIG. 24 , left primary shield panel 184 has HEPA port opening 250 and safety bars 251 . HEPA port opening 250 allows radiation and harmful matter to be released from man-way 102 . While, safety bars 251 ensure that worker 124 (as depicted in FIG. 1 ) does not place his hands in the HEPA port opening 250 .
[0114] In FIG. 25 , left primary shield panel 184 has HEPA port shield adapter 256 and flexible ducting 262 . These structures are useful in drawing off dangerous radiation while allowing accessibility to the man-way 102 . Once radiation passes through HEPA port shield adapter 256 and flexible ducting 262 , it safely vents to the environment. HEPA port shield adapter 256 is attached to left primary shield panel 184 through cover plug securing bolt 254 .
[0115] Now adding FIG. 26 , FIG. 27 , and FIG. 28 to the consideration, the original version 300 of radiation shield door system can be seen. The major modifications between the present radiation shield apparatus 100 and the original version 300 are latch apertures 190 and right side-panel 212 and left side-panel 210 . Latch apertures 190 provide adjustability for adjustable secondary lower shield panels 220 and 222 .
[0116] First, latch apertures 190 are replaced with outside latch apertures 304 . In the embodiment depicted in FIG. 26 , FIG. 27 , and FIG. 28 , outside latch apertures 304 appear in the form of tubes, that are secured to the outer perimeter of right side-panel 212 and left-side panel 210 . Whereas in radiation shield apparatus 100 , latch apertures 190 are holes that are bored into or otherwise formed in the outer rim of latch adjustment plate 188 (as depicted in FIG. 13 and FIG. 16 ).
[0117] Second, upper key slot 216 and lower key slot 218 are replaced with side mounts 302 . In radiation shield apparatus 100 , upper key slot 216 and lower key slot 218 are located on the back of right side-panel 212 and left side-panel 210 . Where as in the original version 300 , the side mounts are located on the inner side of right side-panel 212 and left side-panel 210 . The inner side is the side that faces left adjustable secondary lower shield panel 220 or right adjustable 20 secondary lower shield panel 222 once right side-panel 212 and left side-panel 210 are in place. The back mounting of upper key slot 216 and lower key slot 218 makes the left side-panel 210 and right side-panel 212 more flexible in that either left side-panel 210 and right side-panel 212 can be inserted into either side of radiation shield apparatus 100 .
[0118] This application—taken as a whole with the abstract, specification, claims, and drawings—provides sufficient information for a person having ordinary skill in the art to practice the invention disclosed and claimed herein. Any measures necessary to practice this invention are well within the skill of a person having ordinary skill in this art after that person has made a careful study of this disclosure.
[0119] Because of this disclosure and solely because of this disclosure, modification of this tool can become clear to a person having ordinary skill in this particular art. Such modifications are clearly covered by this disclosure.
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The invention places adequate and useable shielding in the path of the radiation that exists when nuclear workers perform maintenance and inspection of the Pressure Water Reactor Steam Generator component at a nuclear electric generating plant. The shielding has an upper and a lower track member that permit the two shield assembly halves to roll easily and be manipulated so that access and the associated work to be performed will result in significant reduction to the typical radiation dose that the nuclear workers receive during this work when compared with the current shielding approach. The shielding includes rollers that roll on track members that are located above and below the man-way opening.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is related to Japanese application No. 63/164,298 filed June 30, 1988, the entire specification of which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a non-woven fabric material useful in preparing cushions, conveyer belts, bag filters, sealing materials, etc. which can be used at elevated temperatures.
TECHNOLOGY REVIEW
Heat resistant materials used for the above mentioned-products are known and include both non-woven material formed of a single fiber, and layered non-woven materials of at least two fibers.
Non-woven materials may be formed exclusively of asbestos fiber, stainless steel fiber and like heat resistant fibers. Asbestos material has been heretofore widely used since it is low-priced and has excellent heat resistivity. However, the use of asbestos is now strictly regulated in view of environmental and public health concerns because filaments of asbestos floating in air are now known to have adverse effects on human health.
Although the stainless steel fabrics are excellent in heat resistance, flexibility, springiness or cushioning property, etc., the high cost thereof poses a difficulty in wide use in various fields.
Unexamined Japanese Patent Publication No. 24572 of 1975 discloses a layered fabric material comprising a compacted mass of metal fibers such as stainless steel fibers or the like and a compacted mass of inorganic fibers such as rockwool fiber, glass fiber, asbestos fiber or the like. This material is produced by bonding the fiber masses with needle punching and firing the bonded fiber masses to form an interlocked layer at the interface of the fiber masses.
In the case of a layered material comprising a rockwool fiber or asbestos fiber and a metal fiber, the firing step is required to firmly hold the two layers together since the bonding force formed between the interlocked layers by needle-punching alone is too weak to keep the layers integral. However, the need to use a firing step makes this whole manufacturing process complicated, and the product obtained shows lowered springiness or cushioning property.
When the layered material is formed of a glass fiber and a metal fiber, its use is limited because the heat conductivity of glass fiber is low.
SUMMARY OF THE INVENTION
The present invention provides a composite non-woven fiber material comprising at least one stainless steel fiber layer and at least one carbon fiber layer, the stainless steel layer and the carbon fiber layer being intimately interlocked to form integrated composite, bonded therebetween, at least one exposed surface layer of the composite material being a stainless steel fiber layer.
An object of the invention is to provide a composite non-woven fabric material which can be easily produced at a reasonable cost.
Another object of the invention is to provide a composite non-woven fabric material which exhibits strong bonding between the different fabric layers.
Another object of the invention is to provide a composite non-woven fabric material which is stable at high temperatures.
Another object of the invention is to provide a composite non-woven fabric material which has good lubricating properties.
Other objects and features of the invention will become apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a cross section of the composite non-woven fabric material according to the invention.
FIG. 2 shows use of the composite material of the invention as cushioning element.
FIG. 3 shows use of the composite material of the invention as sealing element.
DETAILED DESCRIPTION OF THE INVENTION
Carbon fibers to be used in the invention may be selected from those produced from pitch materials and from organic polymers such as polyacrylonitrile (PAN), etc. The ratio of weight per area of a single carbon fiber layer is not critical, but it is usually from about 30 to about 2500 g/m 2 , preferably from about 50 to about 2300 g/m 2 . If the ratio is less than 30 g/m 2 , the amount of carbon fiber layer is greatly reduced and the advantage in cost of using carbon fiber layer together with stainless steel layer is lost. If the ratio exceeds 2500 g/m 2 , the filaments positioned at the intermediate portions of the carbon fiber layer cannot interlock intimately with the filaments of the stainless steel fiber layer and the composite is prone to separate at the intermediate of the carbon fiber layer when a shearing force is applied to the composite. In order to improve the resistance to separation of composite material, a thin stainless steel fiber layer may be incorporated within the carbon fiber layer.
The ratio of weight per area of a single stainless steel layer is also not critical, but it is usually from about 50 to about 2500 g/m 2 , preferably from about 120 to about 2000 g/m 2 . When the ratio is less than 50 g/m 2 , a uniform stainless steel fiber layer is difficult to prepare and an uneven fiber layer exhibits poor heat resistance and abrasion resistance. When the ratio is over 2500 g/m 2 , the relative amount of expensive stainless steel fiber is increased and the cost effectiveness of the invention will be reduced. The diameter of the filaments forming the stainless steel fiber is usually from about 2 to about 50 μm. When the composite material of the invention is used as heat resistant cushioning material, the diameter of stainless steel fiber preferably is from about 5 to about 20 μm. When the stainless steel fiber is formed of filaments with a small diameter of less than 2 μm, the fiber is prone to fracture. With the diameter of filaments of more than 50 μm, needle-punching step becomes difficult because needles used are easily broken.
The number of each of layers of the stainless steel fibers and the carbon fibers are not limited and variable as required. For example, the composite material according to the invention may have a two layer-structure of a single carbon fiber layer and a single stainless steel fiber layer, or a three layer-structure of two stainless steel layers and a carbon fiber layer interposed therebetween, or a multi-layer-structure wherein at least two carbon fiber layers and at least two stainless steel layers are alternately laminated. The composite material of the invention may include an intermediate layer or layers between the carbon fiber layer and the stainless steel fiber layer in order to improve tensile strength of the composite. The intermediate layer may be glass fiber cloth, stainless steel fiber cloth, etc.
It is essential for the composite material of the invention to have a stainless steel fiber layer on at least one exposed surface of the composite. The upper limit of the temperature at which the carbon fiber may be used in air is about 400 to about 450° C. whereas stainless steel fibers are useful at temperatures up to about 600° C. Thus, the composite of the invention can contact hot articles or interrupt or shut off hot air with the stainless steel fiber layer exposed to the hot article or hot air. The composite with the surface stainless steel fiber layer is also useful in cases where it is used at temperatures below 400° C. but the carbon fiber layer has to be mechanically reinforced.
The stainless steel fiber layer and the carbon fiber layer are integrated into a composite through the interlocking of filaments of both layers. If the both layers are bonded with an inorganic adhesive which is stable at high temperatures over 400° C., the resultant product is low in flexibility and the product application will therefore be limited. When an organic adhesive is used, the bonded product cannot be used at elevated temperatures.
Various method for integrating the stainless steel fiber layer and the carbon fiber layer by interlocking filaments of both layers may be used. Preferably, both layers are combined by needle punching. The integrated product obtained by needle punching shows high resistance to separation of layers due to intimate interlocking of filaments of both fiber layers and good springiness or cushioning properties. The composite of the invention may also be produced by interlocking the filaments of both fiber layers with use of a water jet loom.
The composite material of the invention is not limited in thickness. Products with about 3 to about 50 mm in thickness can easily be prepared.
The composite non-woven fiber material of the invention has a wide variety of uses which include: heat resisting cushioning material useful, for example, for supporting and relieving mechanical and/or thermal shock to glass products such as cathode ray tube processed at high temperatures; conveyer belt for carrying heated articles; sealing material for shutting off extremely hot gases; filter material used at high temperatures, etc.
The total heat conductivity of the composite can be varied when required by changing the relative thicknesses of the stainless steel fiber layer and the carbon fiber layer.
The stainless steel fiber layer formed on at least one exposed surface of the composite material of the invention functions as a heat insulator and can protect a carbon fiber layer integrated therewith against oxidation due to hot atmosphere over 400° C. Thus, the composite of the invention can, at high temperatures, replace the expensive non-woven fabric made of stainless steel fiber alone. Even at lower temperatures, the composite of the invention economically replace non-woven fabric of stainless steel fiber alone which is used for its excellent chemical resistance, flexibility, springiness, bending property, abrasion resistance, etc.
In addition, when the carbon fiber layer comes into contact with a moving article or element, it ensures a high abrasion resistance because of its good lubricating property.
In sum, the composite material of the invention shows an excellent durability under differing conditions resulting from the various improved properties mentioned above.
Given below are examples to illustrate the invention with reference to the accompanying drawings, without limiting the scope of the invention.
EXAMPLE 1
FIG. 1 is a cross section of a composite material of the invention.
The composite material 1 was prepared by placing on both sides of a carbon fiber layer 2 two stainless steel fiber layers 3, 3' and then needle-punching (925 punches/inch 2 ) the layers together to form the integrated composite.
The carbon fiber layer 2 was formed by a non-woven fabric prepared from pitch carbon fibers (13 μm in diameter, specific gravity=1.65, tensile strength=70 kg/mm 2 , elastic modulus=3.5 ton/mm 2 ) using a carding machine. The ratio of weight per unit are was 260 g/m 2 .
The stainless steel fiber layer 3 was a web formed from stainless steel fiber (trade mark "Nasron", product of Nihon Seisen Kabushiki Kaisha, Japan: 12 μm in diameter, specific gravity=7.9, elastic modulus=20000 kg/mm 2 ). The ratio of weight per unit area was 500 g/m 2 .
The characteristics of the composite material 1 were as follows:
ratio of weight per unit area; 900 g/m 2
thickness; 5-5.5 mm
bulk density; 0.18 g/cm 3
COMPARISON EXAMPLE 1
A non-woven fabric was prepared by needle punching (766 punches/inch 2 ) a fiber layer formed of stainless steel fiber alone.
The characteristics of the non-woven fibric obtained were as follows.
ratio of weight per unit area; 1500 g/m 2
thickness; 5-5.5 mm
bulk density; 0.3 g/cm 3
Evaluation of properties
(1) Flexibility
Each of the products obtained in Example 1 and Comparative Example 1 was tested for bending resistance in accordance with JIS(Japanese Industrial Standards)-L-1096 6-20-1.
The bending resistance of material of Example 1 was 6220 mg while the value for the material of Comparative Example 1 was found to be 6800 mg.
Thus, it was confirmed that the product of Example 1 was substantially similar to the product of Comparison Example 1 in flexibility.
(2) Heat conductivity
Each of the products of Example 1 and Comparative Example 1 was placed on a plate kept at 300° C. and was checked for the rise of temperature at the surface of the product after 3 minutes.
The temperature of the product of Example 1 was 190° C. whereas the temperature of product of Comparative Example 1 was 195° C.
It was confirmed from the results of these tests that both products were substantially the same in heat condictivity.
(3) Cushioning property at elevated temperature
The product 1 of Example 1 was used for supporting cathode ray tubes 4 at 600° C. in a step of glass processing as shown in FIG. 2.
After 6 weeks, it was found that the product of Example 1 showed little change in thickness and shape and had a similar properties as the product of Comparative Example 1 in heat resistance and was capable of effectively protecting fragile cathode ray tubes from mechanical and thermal shocks.
(4) Abrasion resistance
Each of the products obtained in Example 1 and Comparative Example 1 was tested for abrasion resistance in accordance with JIS-L-1021-612 using an abrasion ring of H38 and a load of 500 g.
The results after 1000 rotations were 705 for the product of Example 1 and 980 for Comparative Example 1. These values are expressed with the amount of weight loss multiplied by 1000.
The results indicate that the product of Example 1 has substantially the same abrasion resistance as the product of Comparative Example 1.
The smaller weight loss of the product of Example 1 than that of Comparative Example 1 may be attributable to the higher number of punches/inch 2 employed in Example 1.
(5) Durability
The composite material obtained in Example 1 was evaluated for durability as the sealing elements 7, 7' of an annealing furnace 6 kept at 900° C. into which a sheet of stainless steel 5 was continuously introduced at a speed of 200 m/min as shown in FIG. 3. The non-woven fabric obtained in Comparative Example 1 was also used as the sealing elements under the same conditions as the product of Example 1.
Each sealing element 7 or 7' was 1700 mm×300 mm in size and lightly pressed against the stainless steel sheet 5 to hermetically close the furnace.
The sealing elements 7, 7' prepared from the product of Comparative Example 1 had to be replaced only after 2 months because filaments of the stainless steel fiber were gradually broken and lost due to high abrasion thereof in contact with the stainless steel sheet 5.
In contrast, the sealing elements 7, 7' prepared from the product of Example 1 could be used for 4 months without any difficulty. The remarkable result may be attributable to the fact that the product of Example 1 has the carbon fiber layer 2 exposed at the end portion which exhibits a good lubricating property against the stainless steel sheet 5.
It is understood that various other modifications will be apparent to and can readily be made by those skilled in the art without departing from the scope and spirit of this invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the description as set forth herein, but rather that the claims be construed as encompassing all the features of patentable novelty that reside in the present invention, including all features that would be treated as equivalents thereof by those skilled in the art to which this invention pertains.
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The present invention provides a composite non-woven fiber material comprising at least one stainless steel fiber layer and at least one carbon fiber layer, the alternating stainless steel fiber layers and carbon fiber layers being intimately interlocked to form integrated composite material, at least one exposed surface layer of the composite material being a stainless steel fiber layer.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation, under 35 U.S.C. §120, of copending international application No. PCT/EP2011/060290, filed Jun. 21, 2011, which designated the United States; this application also claims the priority, under 35 U.S.C. § 119, of German patent application No. DE 10 2010 030 773.4, filed Jun. 30, 2010; the prior applications are herewith incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0002] The present invention concerns a thread or a sewing thread, and also a method for producing a thread or a sewing thread. The present invention concerns in particular a sewing thread of the type of a staple fiber thread of carbon, and in particular an appropriate production method. In addition the present invention also concerns measures for improving the properties of CF rovings and CF staple fiber threads, in particular for deployment in an embedding matrix of elastomers, thermoplastics and/or thermosetting plastics, such as phenolic resins.
[0003] In the production, processing and use of threads, and in particular of sewing threads, that is to say of threads that are deployed and used in sewing processes, limitations and other problems that cannot be tolerated often occur as a result of the underlying source materials and their properties.
[0004] These relate to aspects of static and/or dynamic load-bearing capacity and internal and external friction, and also in the context of consequential symptoms, e.g. effects on the thread or sewing thread itself ensuing as a result of internal and external friction in terms of structure and properties, and also aspects of contamination of the thread or the application environment in the context of the friction as a result of abrasion and similar.
SUMMARY OF THE INVENTION
[0005] It is accordingly an object of the invention to provide a thread, sewing thread or a staple fiber thread and a production method which overcome the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and which provides, in a simple and nevertheless reliable manner, in particular with simple processability, a property profile of the thread or sewing thread that is ensured to be as constant as possible.
[0006] With the foregoing and other objects in view there is provided, in accordance with the invention, a sewing thread, comprising:
[0007] a staple fiber thread formed as a spun fiber thread from a staple fiber material with or from staple fibers; and
[0008] consisting of or containing carbon fiber materials.
[0009] In a preferred embodiment, a proportion or all of said staple fibers are wholly or partially coated or impregnated as individual fibers, as groups of individual fibers, or as a whole, with one or a plurality of coating materials and/or impregnation materials respectively.
[0010] In accordance with a first aspect of the present invention a thread, and in particular a sewing thread, is created, which is designed as a staple fiber thread, or in the manner of the latter—in particular as a spun fiber thread of a staple fiber material with or from staple fibers - and which is designed with or from one or a plurality of carbon fiber materials.
[0011] Thus it is a first aspect of the present invention to design a thread or a sewing thread with a particularly constant property profile, such that this is or will be designed on the basis of a staple fiber thread, or in the manner of the latter, wherein this staple fiber thread and finally the thread of the sewing thread itself is or will be designed with or from one or a plurality of carbon fiber materials.
[0012] In chemical and physical process engineering and in many technical fields of application carbon fibers have proven to be particularly advantageous, because their property profile can be adjusted in a particularly suitable and constant manner, and as such are of particular advantage in many areas of deployment in terms of their mechanical, thermal, chemical and electrical properties.
[0013] In accordance with an alternative procedure the present invention creates a thread, and in particular a sewing thread, which is designed as a staple fiber thread, or in the manner of the latter - in particular as a spun fiber thread of a staple fiber material with or from staple fibers- and in which a proportion or all of the fibers of the fiber material(s) are wholly or partially coated or impregnated respectively with one or a plurality of coating materials and/or impregnation materials, either as individual fibers, as groups of individual fibers, or as a whole.
[0014] In accordance with the said alternative aspect the design of a thread or a sewing thread is therefore likewise focused on one staple fiber thread, or the manner of one staple fiber thread, wherein the latter and thus the thread or sewing thread itself is or will be designed with or from one or a plurality of fiber materials. A limitation to carbon fiber materials does not occur here in the first instance. In contrast, for purposes of improving and maintaining the property profile constant, in particular in terms of static and dynamic load bearing capacity, and/or in terms of internal and external friction, there is an additional focus such that a coating and/or impregnation is or will be provided with a coating material or an impregnation material. Through the selection of the respective materials for the coating and/or impregnation, the properties of the individual filaments, the interactions between the individual filaments, and thus the properties of the end product, namely the thread or sewing thread, both in terms of the internal interactions between the fibers and also in terms of the external interactions between individual fiber strands, that is to say, sections of the thread or sewing thread, and also with the environment, can be designed, adjusted and held constant in an advantageous manner.
[0015] It will be understood, of course, that the two inventive aspects can be combined with one another.
[0016] On the one hand this means that in the context of the carbon fiber material based staple fiber thread for the sewing thread recourse can likewise be made to a partial or complete coating and/or impregnation, namely in individual filaments or individual filaments sections, in their groups, or in the whole structure, the thread or roving.
[0017] On the other hand this means that the generally held thread or sewing thread on the basis of one or a plurality of fiber materials can or will be designed in the context of a coating and/or impregnation on the basis of carbon fiber materials.
[0018] The staple fiber thread can or will be extracted wholly or partially from a multi-filament thread or roving, in particular from a multi-filament carbon roving.
[0019] The staple fiber thread can thereby in particular be wholly or partially extracted from a stretch-broken and/or cut multi-filament thread or roving, in particular from a stretch-broken multi-filament carbon roving.
[0020] Furthermore the staple fiber thread can also be extracted wholly or partially from a textile surface structure, a multi-layer mat, in particular a carbon multi-layer mat, a woven fabric, in particular a carbon woven fabric, and/or combinations of these.
[0021] Here the use of recycled materials is particularly conceivable.
[0022] In addition the staple fiber thread can be formed from filaments, or filament sections with a length in the range from approximately 10 mm to approximately 250 mm.
[0023] Various possibilities therefore present themselves, on the basis of which the underlying staple fiber thread for a thread or a sewing thread can be developed.
[0024] All aspects can, of course, also be applied to multi-filament threads and or multi-filament rovings and their reconfiguration, e.g. their introduction into an enveloping matrix material, e.g. of an elastomer, a thermoplastic, and/or a thermosetting plastic, e.g. a phenolic resin, wherein in particular an impregnation and/or coating, e.g. by means of sizing, or in the manner of sizing, are suitable so as to develop advantageously aspects of the static and/or dynamic loading, of the internal and/or external friction, and/or from the embedding process, and also interaction with the embedding matrix material, and thus the transfer of force, thrust and pressure.
[0025] The staple fiber thread can or will be designed with or from filaments of filament sections on the basis of glass material fibers, acrylic material fibers, polyester fibers, polyamide fibers, basalt material fibers, and/or combinations of these, in particular as a hybrid, or in the manner of the latter, preferably with a carbon fiber proportion of more than 10%.
[0026] The coating and/or the impregnation with the coating material or the impregnation material respectively can or will be formed by means of sizing, and in particular as a size.
[0027] The inventively provided basic principles can also be applied to other types of fibers other than carbon fibers and staple fibers, in particular in terms of the coating and/or impregnation.
[0028] In accordance with further aspects of the present invention the principles underlying the invention are also introduced in appropriate production methods in an advantageous manner.
[0029] The present invention therefore also creates on the one hand a method for the production of a thread or a sewing thread, in which the thread or sewing thread is designed as a staple fiber thread, or in the manner of the latter—in particular as a spun fiber thread from a staple fiber material with or from staple fibers—and in which the thread or sewing thread is designed with or from one or a plurality of carbon fiber materials.
[0030] A proportion or all of the fibers of the one or more carbon fiber materials can thereby be wholly or partially coated or impregnated with one or a plurality of coating materials and/or impregnation materials, as individual fibers, as groups of individual fibers, or as a whole.
[0031] In accordance with a further aspect of the present invention a method for the production of a thread, or sewing thread, is also created, in which the thread, or sewing thread, is designed as a staple fiber thread, or in the manner of the latter—in particular as a spun fiber thread of a staple fiber material with or from staple fibers—in which the sewing thread is designed with or from one or a plurality of fiber materials, and in which a proportion or all of the fibers of the one or more fiber materials is wholly or partially coated or impregnated with one or a plurality of coating materials and/or impregnation materials, as individual fibers, as groups of individual fibers or as a whole.
[0032] Thereby one or a plurality of fiber materials can be designed with or from one or a plurality of carbon fiber materials, e.g. in the manner of a hybrid.
[0033] In accordance with the method the staple fiber thread can be wholly or partially extracted from a multi-filament thread or roving, in particular from a multi-filament carbon roving.
[0034] The staple fiber thread can thereby in particular be wholly or partially extracted from a stretch-broken and/or cut multi-filament thread or roving, in particular from a stretch-broken multi-filament carbon roving, wherein the process of the stretch-breaking and/or cutting can be designed into the method in an integrated manner.
[0035] On the other hand the staple fiber thread can also be extracted wholly or partially from a textile surface structure, a multi-layer mat, in particular a carbon multi-layer mat, a woven fabric, in particular a carbon woven fabric, and/or combinations of these, e.g. also within the framework of a recycling process.
[0036] The filaments or filament sections for the staple fiber thread can be designed with a length in the range from approximately 10 mm to approximately 250 mm.
[0037] The staple fiber thread can—in addition to the carbon-based materials—be designed with or from filaments or filament sections on the basis of glass material fibers, acrylic material fibers, polyester fibers, polyamide fibers, and/or combinations of these, in particular as a hybrid, or in the manner of the latter, preferably with a carbon fiber component in the range of more than 10%.
[0038] In accordance with the method the coating and/or the impregnation with the coating material or the impregnation material respectively can be formed by means of sizing, and in particular as a size.
[0039] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0040] Although the invention is illustrated and described herein as embodied in a thread or a sewing thread, and a method for producing a thread or a sewing thread, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0041] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0042] FIGS. 1A-1D are schematic and sectioned cross-sectional views of various embodiments of the thread or sewing thread according to the invention;
[0043] FIG. 2 is a schematic block diagram illustrating an exemplary embodiment of a process according to the invention for the production of an inventive thread or sewing thread;
[0044] FIGS. 3 and 4 are schematic block diagrams that explain the detailed aspects of exemplary embodiments of a process according to the invention for the production of an inventive thread or sewing thread.
DETAILED DESCRIPTION OF THE INVENTION
[0045] The following is a description of a variety of exemplary embodiments of the invention. All of the embodiments of the invention, and also their technical features and properties, can be individually isolated or combined with one another in any manner and without limitation, as required.
[0046] First, reference is made to the drawings in general, where a thread is identified with numeral 10 and individual filaments are identified with numeral 20 .
[0047] The present invention also concerns in particular staple fiber threads of carbon and their production, and also a method and possibilities for the improvement of the properties of CF rovings and CF staple fiber threads, in particular for deployment in elastomers, thermoplastics and thermosetting plastics, e.g. phenolic resins.
[0048] In the process this leads to tensile forces, which can have a negative effect on the finished product. As a result of the loads the filaments 20 can be damaged, and thus the mechanical strengths can be reduced. Disruptions to the process can also occur, e.g. in the context of thread tearing or similar.
[0049] With the aid of a rotation in the thread 10 the surface area can be increased, this rotation serves to protect the compound thread. However, here too processing is only possible to a limited extent. The filament threads have a very high strength, but a low extensibility. If on the other hand a staple fiber thread, i.e. a spun fiber thread of staple fibers 20 , is produced with a limited length, it is possible to produce a thread 10 with a higher extensibility.
[0050] For the stretch-broken staple fiber thread a carbon roving with a high number of filaments can be used as the raw material. On the other hand, the production of a 1 K roving with a filament diameter of or less than 6 μm is very cost-intensive.
[0051] Carbon fibers have a high strength, but also a low ductility, unfortunately. For this reason carbon fibers can only be processed comparatively slowly and with a comparatively high level of effort in textile processes.
[0052] Inter alia it is also an objective of the invention to specify a coating for carbon fibers 20 , threads 10 of stretch-broken fibers 20 or fire-retardant textile fibers 20 (e.g., Panox® available from SGL Carbon, Germany), and also other brittle fibers, which improve the processing properties.
[0053] The improvement can inter alia also be measured in terms of the fiber abrasion, the number of fiber fractures, and also the speed of the process. As a consequence an improvement is then also hereby achieved in the sewing and operational processes. Threads sized in this manner can be woven more effectively, which inter alia results in a higher productivity.
[0054] One exemplary embodiment of a possible inventive production method can have the following steps:
A. Stretch-breaking and/or cutting of a multi-filament roving, e.g. a roving of more than 48 K, or from textile surface structures, e.g. recycled material from a carbon multi-layer mat or woven fabric, to form filaments, which have a length in the range from 10 mm to 250 mm. B. Untangling and parallelizing in a carding operation. C. Production of a strip in a stretching operation. D. If required, further processing to form a flyer roving, as a function of a spinning method to be deployed. E. Thread production by means of spinning, e.g. with the aid of a ring spinning machine, a rotor spinning machine, or a friction spinning machine. F. Twisted thread production, e.g. to form a two-ply thread. G. Optional treatment with a textile finishing agent so as to improve the stick/slip behavior, to reduce the static friction, to increase the dynamic friction, to improve thermal protection and also the fiber's frictional characteristics, and to increase its extensibility.
[0062] An exemplary embodiment of the surface treatment can inventively be based on the following aspects:
[0063] The use of an elastic size with a low glass transition temperature, for purposes of coating fibers 20 and threads 10 , leads to a more suitable surface, which ensures improved processability.
[0064] Inter alia, self-crosslinking carboxylated styrene-butadiene copolymers have proved to be particularly suitable, which crosslink in a thermal drying process.
[0065] In addition to a very smooth surface, the electrical contactability of the fibers represents an interesting property. Here deployment as a heating conductor in conveying equipment, as hoses or in hoses, conveyor belts, heatable surface structures, etc., is conceivable.
[0066] By virtue of the flexibility, a gentle transmission of thrust between the fibers 20 , and thus a good introduction of force into the whole strand 10 , or the whole thread 10 , is ensured.
[0067] This process is equally suitable for the treatment of all types of fibers, in particular, however, of carbon and ceramic fibers.
[0068] Furthermore, good compatibility with elastomer matrices can also be ensured in this manner.
[0069] In terms of the improvement of properties of CF rovings and CF staple fiber threads, in particular for deployment in elastomers or thermoplastics, the improvement of the process properties is in particular realized in terms of the reduction and/or avoidance of abrasion, in particular in structures that are created by means of braiding, sewing, weaving or similar.
[0070] The avoidance of friction between individual filaments, which is also designated as internal friction, is enabled by means of partial or complete coating, impregnation and/or enveloping of a particular individual filament, or a section of an individual filament, with a thermoplastic or another appropriate material that reduces friction. By this means improved stability is achieved, in particular in the event of dynamic loading. This can concern applications such as lift cables, drive belts, conveyor belts or similar.
[0071] Furthermore by the impregnation, coating and/or enveloping improved integration of a CF roving, CF staple fiber thread or of the particular individual filaments in matrix systems, e.g. of rubber, thermoplastics, and/or thermosetting plastics, is also possible. Furthermore, by means of such impregnation, embedding and/or coating, improvement of the transmission of force, thrust and/or pressure can also be achieved.
[0072] For this purpose appropriate inventive methods for the introduction of thermoplastic fibers 20 and/or materials into continuous rovings or filament threads are described. Since such processes can also be undertaken with the supply of heat, such forms of embodiment ensure that the thermoplastic melts and provides complete integration of the CF filaments. The complete integration and protection of the filaments 20 or filament sections 20 reduces the internal friction between the filaments and in this manner enhances the dynamic strength of the product.
[0073] Impregnation 40 and/or coating 30 of the fibers 20 , fiber groups 25 , or the thread 10 as a whole, on the one hand reduces or prevents the generation of dust as a result of abrasion, but on the other hand it also reduces or prevents the adhesion of dust generated or existing on the fibers 20 , the fiber groups 25 , or the thread 10 as a whole.
[0074] Referring now to the figures of the drawing in more detail and first, particularly, to FIGS. 1A to 1D thereof, there is shown a schematic cross-sectional view of various exemplary embodiments of an inventive thread 10 or sewing thread 10 .
[0075] In the exemplary embodiment of FIG. 1A a group 25 or a bundle 25 of individual filaments 20 or fibers 20 of a fiber material 20 ′ is represented in a schematic cross-sectional view; after an appropriate spinning process as a group 25 or bundle 25 these form a thread 10 and in particular a sewing thread 10 .
[0076] Here it is essential to the invention that the actual fibers 20 take the form of staple fibers, that is to say, fiber or filament sections of a finite length, which have been or will be spun together by way of a spinning process. The material 20 of the underlying fibers 20 or filaments 20 is preferably a carbon material, such that the filaments 20 or fibers 20 can be designated as carbon fibers to a greater or lesser degree.
[0077] In the exemplary embodiment of FIG. 1 B the individual fibers or filaments 20 on their surfaces 20 a, that is to say, the covering surfaces 20 a of the fibers 20 or filaments 20 are formed with a coating 30 of a coating material 30 ′.
[0078] In the exemplary embodiment of FIG. 1C the individual fibers 20 or filaments 20 over their surfaces 20 a , that is to say, over their covering surfaces 20 a , are designed with an impregnation 40 with an impregnation material 40 ′. This means that the impregnation material 40 ′ penetrates into, or is driven into the surfaces 20 a of the fibers 20 or filaments 20 , so as to effect a surface modification.
[0079] The representations of FIG. 1B with the coating 30 , and of FIG. 1C with the impregnation 40 , represent extreme views of the conditions that are to be anticipated in reality. As a rule mixing processes will start to occur as soon as a coating material 30 ′ or an impregnation material 40 ′ is applied onto the surface 20 a of any fiber 20 or any filament 20 . This means that the applied materials 30 ′, 40 ′ on the one hand will implement or promote a coating 30 , but on the other hand will also promote impregnation 40 .
[0080] In the exemplary embodiment of FIG. 1D the group 25 or bundle 25 of the majority of the fibers 20 or fiber segments 20 is embedded in an embedding matrix 50 with or from an embedding material 50 ′, such that the surfaces 20 a of the individual or single fibers 20 or fiber sections 20 can no longer be seen.
[0081] Needless to say the aspects discussed in the context of the forms of embodiment of FIGS. 1B and 1C can also be combined with the embedding matrix 50 , in that e.g. fibers 20 or fiber sections 20 designed with a coating 30 or impregnation 40 can be embedded as a group 25 in total in an embedding matrix 50 .
[0082] FIG. 2 shows, in the manner of a schematic block diagram, aspects of a exemplary embodiment of the inventive method for the production of an inventive thread 10 or sewing thread 10 .
[0083] After a preparatory step S 0 , staple fibers, or a staple fiber material, are prepared in a following step S 1 .
[0084] In an intermediate processing step S 2 the prepared staple fiber material is optionally intermediately processed, in order e.g. to resolve or produce a particular arrangement of the staple fibers, or to execute a surface treatment or similar. This intermediate processing step S 2 is, however, optional and is only to be provided in certain forms of embodiment of the inventive production method, i.e. it is not essential in every exemplary embodiment of the invention.
[0085] After this there follows the step of the actual production of the thread 10 or sewing thread 10 , namely a process of spinning S 3 of the prepared and, if required, intermediately processed, or intermediately treated, staple fibers.
[0086] A post-processing step can then follow, in which the thus ensuing product is seen as a pre-thread, which e.g. is still to be surface treated and/or introduced into an embedding matrix 50 .
[0087] The final step S 5 completes the process.
[0088] FIG. 3 shows sub-aspects of the step S 1 of the preparation of the staple fibers, or the staple fiber material.
[0089] In the exemplary embodiment presented here a roving, e.g. in the sense of a multi-filament roving, preferably on the basis of a carbon fiber material, if required, however, also on the basis of other fiber materials, is thereby firstly prepared in a first sub-step T 1 .
[0090] This is then followed by a process T 2 of so-called stretch-breaking and/or cutting, in which the intrinsically continuous individual filaments of the roving are subdivided in a more less defined manner into fiber or filament segments or sections. This subdivided material then forms the source material for the further processing processes.
[0091] Alternatively sections of fiber material that are already available can, for example, also be provided for this purpose; these originate, for example, from a recycling process and use fiber material waste, for example, in a felt-like manner.
[0092] FIG. 4 shows sub-aspects of the optional intermediate processing step S 2 .
[0093] In this exemplary embodiment the prepared basic staple fiber material is untangled and/or rendered parallel in a first sub-step U 1 , and in particular by means of a so-called carding operation.
[0094] This is then followed by a second sub-step U 2 of the production of a strip in a stretching operation.
[0095] In a third sub-step U 3 intermediate processing then follows to form a so-called roving or flyer roving.
[0096] As has already been described above, the actual production of the thread 10 or sewing thread 10 takes place within the framework of a spinning process for the underlying staple fiber material, e.g. using a ring spinning machine, a rotor spinning machine, or a friction spinning machine.
[0097] For purposes of improving the properties and in particular for purposes of increasing the stability of the thread 10 or sewing thread 10 , the fundamental thread obtained can be seen as a pre-thread and subjected to a twisting process, in order e.g. to create a two-ply thread or similar.
[0098] Before or after a finishing process can take place in the form of a coating, sizing, impregnation and/or an embedding process.
[0099] The following tables show properties of forms of embodiment of inventively produced threads 10 or sewing threads 10 .
EXAMPLE 1
[0100]
[0000]
Dimensional
Physical property
unit
Numerical average value
Tensile strength (impregnated)
MPa
2,750
Tensile strength (dry)
MPa
1,000
Thread strength
N
43
Young's modulus (tensile)
GPa
220
Extension (impregnated)
%
1.1
Density
g/cm 3
1.79
Knot tensile strength
N
2.2
Loop tensile strength
N
14.4
Electrical resistance
Ω/m
averaged 405
Specific electrical resistance
Ω/m
16.7
Staple fiber length
mm
average: 123
max: 220
min: 15
Twist
Tpm
310 S/230 T
EXAMPLE 2
[0101]
[0000]
Dimensional
Physical property
unit
Numerical average value
Tensile strength (impregnated)
MPa
2,950
Tensile strength (dry)
MPa
820
Thread strength
N
90
Young's modulus (tensile)
GPa
200
Extension (impregnated)
%
1.4
Density
g/cm 3
1.79
Knot tensile strength
N
2.7
Loop tensile strength
N
60
Electrical resistance
Ω/m
averaged 140
Specific electrical resistance
Ω/m
16.0
Staple fiber length
mm
average: 123
max: 220
min: 15
Twist
Tpm
310 S/230 T
[0102] In a further development of the inventive method a textile structure is designed with or from the thread 10 or sewing thread 10 , in particular by means of a web process, preferably as a two-dimensional textile, or in the manner of the latter, as a woven fabric, a multi-layer mat, a mesh, a knotted fabric, a knitted fabric, or in the manner of these, and/or in combinations of these.
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A sewing thread is formed as a staple fiber thread. The staple fiber thread is formed as a spun fiber thread from a staple fiber material with or from staple fibers. The staple fibers are or contain carbon fiber materials. A certain proportion or all of the staple fibers are wholly or partially coated or impregnated as individual fibers, as groups of individual fibers, or as a whole, with one or a plurality of coating materials and/or impregnation materials respectively.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 11/113,286, filed Apr. 21, 2005 now U.S. Pat. No. 7,120,079, which is a continuation of U.S. patent application Ser. No. 10/623,111, filed Jul. 17, 2003, now issued as U.S. Pat. No. 6,891,769 issue date May 10, 2005, all of which are hereby incorporated by reference as if set forth herein.
BACKGROUND
1. Field of the Invention
The present invention relates to memory cells in an integrated circuit. More specifically, the invention relates to using a standard transistor as a flash/dynamic random access memory (DRAM) in order to reduce the size of a gate oxide for a memory cell in an integrated circuit.
2. Background
FPGA integrated circuits are known in the art. Typically, an FPGA has an array of logic elements and wiring interconnections with many thousands of programmable interconnect cells so that the FPGA can be configured by the user into an integrated circuit with defined functions. Each programmable interconnect cell, or switch, can connect two circuit nodes in the integrated circuit to make or break a wiring interconnection or to set the function or functions of a logic element.
FPGA devices may be classified in one of two categories. One category of FPGA devices is one-time programmable and uses elements such as antifuses for making programmable connections. The other category of FPGA devices is reprogrammable and uses devices such as transistor switches as the programmable elements to make non-permanent programmable connections.
Reprogrammable FPGA devices include some means, such as static random access memory and dynamic random access memory, for storing programming information used to control the programmable elements. Non-volatile memory devices such as EPROMs, EEPROMs, non-volatile RAM, and flash memory devices have all been proposed for or used to store programming information in the class of FPGA applications.
An ideal memory device optimizes density, preserves critical memory in a nonvolatile condition, is easy to program and reprogram, and is read quickly. Some non-volatile memory devices meet more of the above requirements than others. For instance, EPROMS are high density, however, they have to be exposed to ultra-violet light for erasure. EEPROMS are electrically byte-erasable, but are less reliable and have the lowest density. Flash memory devices, however, are low-cost, high-density, low-power, high-reliability devices resulting in a high-speed architecture.
FIG. 1 is a simplified schematic diagram of a flash memory cell. Flash memory cell 100 comprises a sense transistor 102 and a switch transistor 104 . Sense transistor 102 is usually a smaller, minimum-geometry device used for programming. Switch transistor 104 is a larger-geometry device, a pass transistor switch element is used to selectively connect two nodes 116 and 118 in the integrated circuit. Electronically, floating gate 110 is shared by both programming transistor 102 and switch transistor 104 . Programming is accomplished with Fowler-Nordheim tunneling. Fowler-Nordheim tunneling is well known in the integrated circuit art and will not be discussed herein to avoid overcomplicating the disclosure and thereby obscuring the present invention.
FIG. 2 is a simplified top-level layout view of the flash memory cell of FIG. 1 . As in FIG. 1 , flash memory cell comprises a switch transistor 202 and a sense transistor 204 .
However, a flash memory transistor cannot be easily scaled with the rest of the process. As is well known to those of ordinary skill in the art, the gate oxide of a flash memory transistor is thick, on the average of 8.5 nm. The CMOS process technology to date provides a junction capacitance of not lower than 1 ff. A flash memory cell with a lower capacitance is impractical.
Hence, there is a need in the art for a memory cell that can scale with the rest of the integrated circuit. There is also a need for a memory cell that has a junction capacitance of lower than 1 ff.
SUMMARY OF THE INVENTION
The present invention addresses the above concerns by providing a flash memory cell using a standard MOS transistor as the switching element for the FPGA interconnect.
A standard MOS transistor is able to store a charge, but the charge decays due to the inability of gate capacitance to maintain the charge. Thus, the present invention uses a memory array to periodically provide a refresh charge to maintain the gate voltage of the transistor at a sufficient level, and thus provides a dynamic refresh to support the standard transistor flash memory cell.
A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description of the invention and accompanying drawings, which set forth an illustrative embodiment in which the principles of the invention are utilized.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified schematic diagram of a flash memory cell.
FIG. 2 is a simplified top-level view of the flash memory cell of FIG. 1 .
FIG. 3 is a simplified schematic diagram illustrating an embodiment of the memory circuit of the present invention.
FIG. 4 is a simplified block diagram illustrating one arrangement of the memory circuit of the present invention.
FIG. 5 is a simplified block diagram illustrating another arrangement of the memory circuit of the present invention.
DETAILED DESCRIPTION
Those of ordinary skill in the art will realize that the following description of the present invention is illustrative only and not in any way limiting. Other embodiments of the invention will readily suggest themselves to such skilled persons.
In this disclosure, various circuits and logical functions are described. It is to be understood that designations such as “1” and or “0” in these descriptions are arbitrary logical designations. In a first implementation of the invention, “1” may correspond to a voltage high, while “0” corresponds to a voltage low or ground, while in a second implementation, “0” may correspond to a voltage high, while “1” corresponds to a voltage low or ground. Likewise, where signals are described, a “signal” as used in this disclosure may represent the application, or pulling “high” of a voltage to a node in a circuit where there was low or zero voltage before, or it may represent the termination, or the bringing “low” of a voltage at the node, depending on the particular implementation of the invention.
FIG. 3 is a simplified schematic diagram illustrating an embodiment of the memory circuit 300 of the present system. Memory circuit 300 of the present invention comprises a memory array 302 having wordlines 304 for addressing the memory. Memory array 302 can be any kind of array known in the art, for example, a flash memory array. Sense amplifiers 306 sense the states of the memory cells addressed by the wordlines and level-shifting circuits 308 shift the output levels of the sense amplifiers as will be described herein. Sense amplifiers and level-shifting circuits are well known in the art.
The outputs of level-shifting circuits 308 drive bitlines or column lines for providing output from the memory. Standard minimum-sized MOS transistors shown at reference numerals 310 a , 310 b , and 310 c are used as refresh transistors and each have their sources coupled to one of the bitlines or column lines shown at reference numeral 312 . The transistors 310 a , 310 b , and 310 c each have a drain coupled to the control gate of a different one of switching transistors 314 a , 314 b , and 314 c . Each of the refresh transistors 310 a , 310 b , and 310 c has a control gate coupled to a different dynamic random access word line shown at reference numerals 316 a , 316 b , and 316 c . As persons of ordinary skill in the art will appreciate, dynamic random access word lines 316 a , 316 b , and 316 c are also coupled to the gates of refresh transistors coupled to switching transistors on other bitlines, since for each address provided to memory array 302 , a data bit output is provided on each bitline.
Each of the switching transistors 314 a , 314 b , and 314 c a source and a drain coupled, respectively to an interconnect node. The interconnect nodes will be connected together when the switching transistor is turned on. Thus switching transistor 314 a is shown having its source/drain terminals connected, respectively, to interconnect node “A” shown at reference numeral 316 and interconnect node “B” shown at reference numeral 318 . Similarly, switching transistor 314 b is shown having its source/drain terminals connected, respectively, to interconnect node “C” shown at reference numeral 320 and interconnect node “D” shown at reference numeral 322 , and switching transistor 314 c is shown having its source/drain terminals connected, respectively, to interconnect node “E” shown at reference numeral 324 and interconnect node “F” shown at reference numeral 326 . As will be appreciated by persons of ordinary skill in the art, nodes “A” through “F” may be used for all interconnect purposes in an FPGA, including interconnecting interconnect conductors and defining logic module functions.
Memory circuit 300 operates by first using addresses provided on wordlines 304 to access a selected memory cell in the array as is known in the art. The contents of the selected memory cells are provided to sense amplifiers 306 and then to level shifting circuits 308 . The outputs of level shifting circuits 308 are used to drive the bitlines, one of which is shown at reference numeral 312 . The operation of the switching transistors 314 a , 314 b , and 314 c coupled to bitline 312 will be disclosed in detail herein, and persons of ordinary skill in the art will appreciate that other such switching transistors are coupled to the other bitlines and will operate in the same manner as disclosed for switching transistors 314 a , 314 b , and 314 c.
In order to understand how switching transistors 314 a , 314 b , and 314 c are maintained in a desired state, assume in an illustrative example that the circuit to be implemented in the FPGA requires that interconnect nodes “A” and “B” be connected together, interconnect nodes “E” and “F” be connected together, but interconnect nodes “C” and “D” be unconnected. This means that switching transistors 314 a and 314 c must be maintained in an “on” state, and switching transistor 314 b must be maintained in an “off” state.
Addresses are applied to wordlines 304 from address decoder 328 driven by address counter 330 and clock 332 . Decoded drive signals from address counter 328 are also applied to dynamic random access word lines 316 a , 316 b , and 316 c in a synchronized manner. As will be appreciated by persons of ordinary skill in the art, this may be done by employing conventional address-counter circuits.
When the data bit needed to drive switching transistor 314 a (in this case a logic “1”) appears on bitline 312 in response to its address being asserted on wordlines 304 , a logic “1” is also asserted by the address decoder on dynamic random access word line 316 a , thus turning on transistor 310 a . After a period of time sufficient to charge the gate capacitance of switching transistor 314 a , (i.e., the RC time constant of the gate capacitance of the switching transistor 314 a and the on-resistance of transistor 310 a ), transistor 310 a is then turned off by returning the voltage on dynamic random access word line 316 a at the gate of transistor 310 a to zero. The logic-one voltage that was at the bitline 312 during the time transistor 310 a was turned on is stored at the gate capacitance of switching transistor 314 a , thus turning it on.
In the present example also assume that the data bits for driving switching transistors 314 a , 314 b , and 314 c are stored in consecutive addresses in memory 302 . The address counter driving wordlines 304 is incremented and the data bit needed to drive switching transistor 314 b (in this case a logic “0”) appears on bitline 312 in response to its address being asserted on wordlines 304 . A logic “1” is also asserted on dynamic random access word line 316 b , thus turning on transistor 310 b . Transistor 310 b is then turned off by returning the voltage on dynamic random access word line 316 b at the gate of transistor 310 b to zero. The logic-zero voltage that was at the bitline 312 during the time transistor 310 a was turned on is stored at the gate capacitance of switching transistor 314 b , thus leaving it turned off.
The address counter driving wordlines 304 is again incremented and the data bit needed to drive switching transistor 314 c (in this case a logic “1”) appears on bitline 312 in response to its address being asserted on wordlines 304 . A logic “1” is also asserted on dynamic random access word line 316 c , thus turning on transistor 310 c . Transistor 310 c is then turned off by returning the voltage on dynamic random access word line 316 c at the gate of transistor 310 c to zero. The logic-one voltage that was at the bitline 312 during the time transistor 310 a was turned on is stored at the gate capacitance of switching transistor 314 c , thus turning it on.
The above-described process increments the address counters driving the wordlines and the dynamic random access word lines until the address counters have addressed the data bits for driving each of the switching transistors and then repeats because the charge placed on control gate 306 lasts only a finite amount of time, which may, in a practical embodiment of the present invention, be approximately 1 millisecond. As persons of ordinary skill in the art will recognize, the length of time that the charge placed on the gates of switching transistors 314 a , 314 b , and 314 c will be sufficient to maintain the interconnection depends on the leakage of the circuit. In this regard, it is noted that the level shifting circuits 308 are employed to provide a voltage sufficient to overdrive the gates of the switching transistors to eliminate the Vth drop across the channels of the on-state switching transistors. In one example where the nominal logic-one voltage used in the FPGA logic circuits is about 1.5 volts, the gate-drive voltage placed on the bitlines may be about 3.3 volts. From this disclosure, persons of ordinary skill in the art will readily be able to specify the bitline voltage for a particular design given the operating voltages of the logic circuits and the refresh rate of the switching transistors.
According to one embodiment of the present invention, the temperature of the die containing the FPGA is sensed, e.g., by employing a temperature sensor 334 , such as a band-gap reference, and the refresh rate is adjusted as a function of that temperature to take advantage of the temperature-dependent nature of the junction leakage of the switching transistors. Specifically, a slower refresh rate may be employed at lower operating temperatures. As will be appreciated by persons of ordinary skill in the art this may be done by employing a temperature-dependent clock controller circuit 336 that uses the output of the temperature sensor to adjust the frequency of the clock 332 used to drive the address counter 330 for the wordlines and dynamic random access word lines. The temperature-to-refresh-rate transfer curve will be specific to the MOS technology employed. The concept of adjusting the parameters of a circuit based on temperature is well known. The particular circuit used will be dependent on the actual integrated circuit in which it will be used and design of a particular circuit 336 for an actual integrated circuit is a trivial exercise for persons of ordinary skill in the art.
Referring now to FIG. 4 , a simplified block diagram illustrates a first arrangement of the memory circuit of the present invention. As shown in FIG. 4 , an FPGA integrated circuit 400 and a separate memory array 402 may be provided as separate packaged integrated circuits or as separate integrated-circuit die that are interconnected using a plurality of interconnect wires (“n” such wires are shown in FIG. 4 ). The FPGA includes the refresh transistors and the switching transistors. While this arrangement may be used, it has the disadvantage of requiring the use of “n” I/O pads on the FPGA integrated circuit.
Referring now to FIG. 5 , an FPGA integrated circuit die 404 and a separate memory array die 406 may be provided and interconnected by employing face-to-face die mounting technology wherein the die are contacted with each other. Arrays of boding pads (shown generally at reference numeral 408 ) on the contacting faces of the two die are placed in alignment and are bonded together. The arrangement of FIG. 5 has the advantage of avoiding the use of the normal I/O pads on the FPGA die for interconnecting the memory array while at the same time providing a much-reduced capacitance at each of the connections between the FPGA die and the memory array die. This allows for higher speed clocking of the memory array, thus increasing the size of memory (and the number of interconnects) that can be used in this system at any given refresh rate.
It should be understood that various alternatives to the embodiments of the disclosed method and apparatus described herein maybe employed in practicing the disclosed method and using the disclosed apparatus. It is intended that the following claims define the scope of the disclosed method and apparatus and that methods and structures within the scope of these claims and their equivalents be covered thereby.
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A method for providing a circuit for selectively interconnecting N pairs of nodes in an integrated circuit device comprising: providing a memory array having a plurality of wordlines and a plurality of bitlines; providing a plurality of dynamic random access memory wordlines; providing a separate switch for each pair of nodes in the integrated circuit, each switch associated with a unique combination of one of the plurality of bitlines and one of the plurality of dynamic random access memory wordlines, each switch including a refresh transistor and a switching transistor; and providing an address decoder having at least N distinct states for supplying signals to the plurality of wordlines and the plurality of dynamic random access memory wordlines.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of 35 U.S.C. §120 as a Divisional Application of U.S. Ser. No. 10/666,294, filed Sep. 18, 2003 now U.S. Pat. No. 7,445,738.
This application is related to U.S. Pat. No. 6,986,812 entitled SLURRY FEED APPARATUS FOR FIBER-REINFORCED STRUCTURAL CEMENTITIOUS PANEL PRODUCTION and co-pending application U.S. Ser. No. 10/665,541 entitled EMBEDMENT DEVICE FOR FIBER-ENHANCED SLURRY, filed Sep. 18, 2003 and herein incorporated by reference.
FIELD OF THE INVENTION
This invention relates to a continuous process and related apparatus for producing structural panels using a settable slurry, and more specifically, to a process for manufacturing reinforced cementitious panels, referred to herein as structural cementitious panels (SCP) (also known as structural cement panels), in which discrete fibers are combined with a quick-setting slurry for providing flexural strength and toughness. The invention also relates to a SCP panel produced according to the present process.
Cementitious panels have been used in the construction industry to form the interior and exterior walls of residential and/or commercial structures. The advantages of such panels include resistance to moisture compared to standard gypsum-based wallboard. However, a drawback of such conventional panels is that they do not have sufficient structural strength to the extent that such panels may be comparable to, if not stronger than, structural plywood or oriented strand board (OSB).
Typically, the present state-of-the-art cementitious panels include at least one hardened cement or plaster composite layer between layers of a reinforcing or stabilizing material. In some instances, the reinforcing or stabilizing material is continuous fiberglass mesh or the equivalent, while in other instances, short, discrete fibers are used in the cementitious core as reinforcing material. In the former case, the mesh is usually applied from a roll in sheet fashion upon or between layers of settable slurry. Examples of production techniques used in conventional cementitious panels are provided in U.S. Pat. Nos. 4,420,295; 4,504,335 and 6,176,920, the contents of which are incorporated by reference herein. Further, other gypsum-cement compositions are disclosed generally in U.S. Pat. Nos. 5,685,903; 5,858,083 and 5,958,131.
One drawback of conventional processes for producing cementitious panels that utilize building up of multiple layers of slurry and discrete fibers to obtain desired panel thickness is that the discrete fibers introduced in the slurry in a mat or web form, are not properly and uniformly distributed in the slurry, and as such, the reinforcing properties that essentially result due to interaction between fibers and matrix vary through the thickness of the board, depending on the thickness of each board layer and a number of other variables. When insufficient penetration of the slurry through the fiber network occurs, poor bonding and interaction between the fibers and the matrix results, leading to low panel strength development. Also, in extreme cases when distinct layering of slurry and fibers occurs, improper bonding and inefficient distribution of fibers causes inefficient utilization of fibers, eventually leading to extremely poor panel strength development.
Another drawback of conventional processes for producing cementitious panels is that the resulting products are too costly and as such are not competitive with outdoor/structural plywood or oriented strand board (OSB).
One source of the relatively high cost of conventional cementitious panels is due to production line downtime caused by premature setting of the slurry, especially in particles or clumps which impair the appearance of the resulting board, and interfere with the efficiency of production equipment. Significant buildups of prematurely set slurry on production equipment require shutdowns of the production line, thus increasing the ultimate board cost.
Thus, there is a need for a process and/or a related apparatus for producing fiber-reinforced cementitious panels possessing structural which results in a board with structural properties comparable to structural plywood and OSB which reduces production line downtime due to prematurely set slurry particles. There is also a need for a process and/or a related apparatus for producing such structural cementitious panels which more efficiently uses component materials to reduce production costs over conventional production processes.
Furthermore, the above-described need for cementitious structural panels, also referred to as SCP's that are configured to behave in the construction environment similar to plywood and OSB, means that the panels are nailable and can be cut or worked using conventional saws and other conventional carpentry tools. Further, the SCP panels should meet building code standards for shear resistance, load capacity, water-induced expansion and resistance to combustion, as measured by recognized tests, such as ASTM E72, ASTM 661, ASTM C 1185 and ASTM E136 or equivalent, as applied to structural plywood sheets.
BRIEF DESCRIPTION OF THE INVENTION
The above-listed needs are met or exceeded by the present invention that features a multi-layer process for producing structural cementitious panels (SCP's or SCP panels), and SCP's produced by such a process. After one of an initial deposition of loosely distributed, chopped fibers or a layer of slurry upon a moving web, fibers are deposited upon the slurry layer. An embedment device mixes the recently deposited fibers into the slurry, after which additional layers of slurry, then chopped fibers are added, followed by more embedment. The process is repeated for each layer of the board, as desired. Upon completion, the board has a more evenly distributed fiber component, which results in relatively strong panels without the need for thick mats of reinforcing fibers, as are taught in prior art production techniques for cementitious panels.
More specifically, the invention relates to structural cementitious panels made by a multi-layer process, including: (a.) providing a moving web; (b.) one of depositing a first layer of loose fibers and (c.) depositing a layer of settable slurry upon the web; (d.) depositing a second layer of loose fibers upon the slurry; (e.) embedding said second layer of fibers into the slurry; and (f.) repeating the slurry deposition of step (c.) through step (d.) until the desired number of layers of settable fiber-enhanced slurry in the panel is obtained. Also provided is an apparatus suitable for producing structural cementitious panels according to the present process.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic elevational view of an apparatus which is suitable for performing the present process;
FIG. 2 is a perspective view of a slurry feed station of the type used in the present process;
FIG. 3 is a fragmentary overhead plan view of an embedment device suitable for use with the present process;
FIG. 4 is a fragmentary vertical section of a structural cementitious panel produced according to the present procedure; and
FIG. 5 is a diagrammatic elevational view of an alternate apparatus used to practice an alternate process to that embodied in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1 , a structural panel production line is diagrammatically shown and is generally designated 10 . The production line 10 includes a support frame or forming table 12 having a plurality of legs 13 or other supports. Included on the support frame 12 is a moving carrier 14 , such as an endless rubber-like conveyor belt with a smooth, water-impervious surface, however porous surfaces are contemplated. As is well known in the art, the support frame 12 may be made of at least one table-like segment, which may include designated legs 13 . The support frame 12 also includes a main drive roll 16 at a distal end 18 of the frame, and an idler roll 20 at a proximal end 22 of the frame. Also, at least one belt tracking and/or tensioning device 24 is preferably provided for maintaining a desired tension and positioning of the carrier 14 upon the rolls 16 , 20 .
Also, in the preferred embodiment, a web 26 of craft paper, release paper, and/or other webs of support material designed for supporting a slurry prior to setting, as is well known in the art, may be provided and laid upon the carrier 14 to protect it and/or keep it clean. However, it is also contemplated that the panels produced by the present line 10 are formed directly upon the carrier 14 . In the latter situation, at least one belt washing unit 28 is provided. The carrier 14 is moved along the support frame 12 by a combination of motors, pulleys, belts or chains which drive the main drive roll 16 as is known in the art. It is contemplated that the speed of the carrier 14 may vary to suit the application.
In the present invention, structural cementitious panel production is initiated by one of depositing a layer of loose, chopped fibers 30 or a layer of slurry upon the web 26 . An advantage of depositing the fibers 30 before the first deposition of slurry is that fibers will be embedded near the outer surface of the resulting panel. A variety of fiber depositing and chopping devices are contemplated by the present line 10 , however the preferred system employs at least one rack 31 holding several spools 32 of fiberglass cord, from each of which a cord 34 of fiber is fed to a chopping station or apparatus, also referred to as a chopper 36 .
The chopper 36 includes a rotating bladed roll 38 from which project radially extending blades 40 extending transversely across the width of the carrier 14 , and which is disposed in close, contacting, rotating relationship with an anvil roll 42 . In the preferred embodiment, the bladed roll 38 and the anvil roll 42 are disposed in relatively close relationship such that the rotation of the bladed roll 38 also rotates the anvil roll 42 , however the reverse is also contemplated. Also, the anvil roll 42 is preferably covered with a resilient support material against which the blades 40 chop the cords 34 into segments. The spacing of the blades 40 on the roll 38 determines the length of the chopped fibers. As is seen in FIG. 1 , the chopper 36 is disposed above the carrier 14 near the proximal end 22 to maximize the productive use of the length of the production line 10 . As the fiber cords 34 are chopped, the fibers 30 fall loosely upon the carrier web 26 .
Next, a slurry feed station, or a slurry feeder 44 receives a supply of slurry 46 from a remote mixing location 47 such as a hopper, bin or the like. It is also contemplated that the process may begin with the initial deposition of slurry upon the carrier 14 . While a variety of settable slurries are contemplated, the present process is particularly designed for producing structural cementitious panels. As such, the slurry is preferably comprised of varying amounts of Portland cement, gypsum, aggregate, water, accelerators, plasticizers, foaming agents, fillers and/or other ingredients well known in the art, and described in the patents listed above which have been incorporated by reference. The relative amounts of these ingredients, including the elimination of some of the above or the addition of others, may vary to suit the application.
While various configurations of slurry feeders 44 are contemplated which evenly deposit a thin layer of slurry 46 upon the moving carrier 14 , the preferred slurry feeder 44 includes a main metering roll 48 disposed transversely to the direction of travel of the carrier 14 . A companion or back up roll 50 is disposed in close parallel, rotational relationship to the metering roll 48 to form a nip 52 therebetween. A pair of sidewalls 54 , preferably of non-stick material such as Teflon® brand material or the like, prevents slurry 46 poured into the nip 52 from escaping out the sides of the feeder 44 .
An important feature of the present invention is that the feeder 44 deposits an even, relatively thin layer of the slurry 46 upon the moving carrier 14 or the carrier web 26 . Suitable layer thicknesses range from about 0.05 inch to 0.20 inch. However, with four layers preferred in the preferred structural panel produced by the present process, and a suitable building panel being approximately 0.5 inch, an especially preferred slurry layer thickness is approximately 0.125 inch.
Referring now to FIGS. 1 and 2 , to achieve a slurry layer thickness as described above, several features are provided to the slurry feeder 44 . First, to ensure a uniform disposition of the slurry 46 across the entire web 26 , the slurry is delivered to the feeder 44 through a hose 56 located in a laterally reciprocating, cable driven, fluid powered dispenser 58 of the type well known in the art. Slurry flowing from the hose 56 is thus poured into the feeder 44 in a laterally reciprocating motion to fill a reservoir 59 defined by the rolls 48 , 50 and the sidewalls 54 . Rotation of the metering roll 48 thus draws a layer of the slurry 46 from the reservoir.
Next, a thickness monitoring or thickness control roll 60 is disposed slightly above and/or slightly downstream of a vertical centerline of the main metering roll 48 to regulate the thickness of the slurry 46 drawn from the feeder reservoir 59 upon an outer surface 62 of the main metering roll 48 . Another related feature of the thickness control roll 60 is that it allows handling of slurries with different and constantly changing viscosities. The main metering roll 48 is driven in the same direction of travel ‘T’ as the direction of movement of the carrier 14 and the carrier web 26 , and the main metering roll 48 , the backup roll 50 and the thickness monitoring roll 60 are all rotatably driven in the same direction, which minimizes the opportunities for premature setting of slurry on the respective moving outer surfaces. As the slurry 46 on the outer surface 62 moves toward the carrier web 26 , a transverse stripping wire 64 located between the main metering roll 48 and the carrier web 26 ensures that the slurry 46 is completely deposited upon the carrier web and does not proceed back up toward the nip 52 and the feeder reservoir 59 . The stripping wire 64 also helps keep the main metering roll 48 free of prematurely setting slurry and maintains a relatively uniform curtain of slurry.
A second chopper station or apparatus 66 , preferably identical to the chopper 36 , is disposed downstream of the feeder 44 to deposit a second layer of fibers 68 upon the slurry 46 . In the preferred embodiment, the chopper apparatus 66 is fed cords 34 from the same rack 31 that feeds the chopper 36 . However, it is contemplated that separate racks 31 could be supplied to each individual chopper, depending on the application.
Referring now to FIGS. 1 and 3 , next, an embedment device, generally designated 70 is disposed in operational relationship to the slurry 46 and the moving carrier 14 of the production line 10 to embed the fibers 68 into the slurry 46 . While a variety of embedment devices are contemplated, including, but not limited to vibrators, sheep's foot rollers and the like, in the preferred embodiment, the embedment device 70 includes at least a pair of generally parallel shafts 72 mounted transversely to the direction of travel ‘T’ of the carrier web 26 on the frame 12 . Each shaft 72 is provided with a plurality of relatively large diameter disks 74 which are axially separated from each other on the shaft by small diameter disks 76 .
During SCP panel production, the shafts 72 and the disks 74 , 76 rotate together about the longitudinal axis of the shaft. As is well known in the art, either one or both of the shafts 72 may be powered, and if only one is powered, the other may be driven by belts, chains, gear drives or other known power transmission technologies to maintain a corresponding direction and speed to the driving roll. The respective disks 74 , 76 of the adjacent, preferably parallel shafts 72 are intermeshed with each other for creating a “kneading” or “massaging” action in the slurry, which embeds the fibers 68 previously deposited thereon. In addition, the close, intermeshed and rotating relationship of the disks 74 , 76 prevents the buildup of slurry 46 on the disks, and in effect creates a “self-cleaning” action which significantly reduces production line downtime due to premature setting of clumps of slurry.
The intermeshed relationship of the disks 74 , 76 on the shafts 72 includes a closely adjacent disposition of opposing peripheries of the small diameter spacer disks 76 and the During SCP panel production, the shafts 72 and the disks 74 , 76 rotate together about the longitudinal axis of the shaft. As is well known in the art, either one or both of the shafts 72 may be powered, and if only one is powered, the other may be driven by belts, chains, gear drives or other known power transmission technologies to maintain a corresponding direction and speed to the driving roll. The respective disks 74 , 76 of the adjacent, preferably parallel shafts 72 are intermeshed with each other for creating a “kneading” or “massaging” action in the slurry, which embeds the fibers 68 previously deposited thereon. In addition, the close, intermeshed and rotating relationship of the disks 74 , 76 prevents the buildup of slurry 46 on the disks, and in effect creates a “self-cleaning” action which significantly reduces production line downtime due to premature setting of clumps of slurry.
As the disks 74 , 76 rotate relative to each other in close proximity (but preferably in the same direction), it is difficult for particles of slurry to become caught in the apparatus and prematurely set. By providing two sets of disks 74 which are laterally offset relative to each other, the slurry 46 is subjected to multiple acts of disruption, creating a “kneading” action which further embeds the fibers 68 in the slurry 46 .
Once the fibers 68 have been embedded, or in other words, as the moving carrier web 26 passes the embedment device 70 , a first layer 77 of the SCP panel is complete. In the preferred embodiment, the height or thickness of the first layer 77 is in the approximate range of 0.05-0.20 inches. This range has been found to provide the desired strength and rigidity when combined with like layers in a SCP panel. However, other thicknesses are contemplated depending on the application.
To build a structural cementitious panel of desired thickness, additional layers are needed. To that end, a second slurry feeder 78 , which is substantially identical to the feeder 44 , is provided in operational relationship to the moving carrier 14 , and is disposed for deposition of an additional layer 80 of the slurry 46 upon the existing layer 77 .
Next, an additional chopper 82 , substantially identical to the choppers 36 and 66 , is provided in operational relationship to the frame 12 to deposit a third layer of fibers 84 provided from a rack (not shown) constructed and disposed relative to the frame 12 in similar fashion to the rack 31 . The fibers 84 are deposited upon the slurry layer 80 and are embedded using a second embedment device 86 . Similar in construction and arrangement to the embedment device 70 , the second embedment device 86 is mounted slightly higher relative to the moving carrier web 14 so that the first layer 77 is not disturbed. In this manner, the second layer 80 of slurry and embedded fibers is created.
Referring now to FIGS. 1 and 4 , with each successive layer of settable slurry and fibers, an additional slurry feeder station 44 , 78 followed by a fiber chopper 36 , 66 , 82 and an embedment device 70 , 86 is provided on the production line 10 . In the preferred embodiment, four total layers 77 , 80 , 88 , 90 are provided to form the SCP panel 92 . Upon the disposition of the four layers of fiber-embedded settable slurry as described above, a forming device 94 ( FIG. 1 ) is preferably provided to the frame 12 to shape an upper surface 96 of the panel 92 . Such forming devices 94 are known in the settable slurry/board production art, and typically are spring-loaded or vibrating plates which conform the height and shape of the multi-layered panel to suit the desired dimensional characteristics. An important feature of the present invention is that the panel 92 consists of multiple layers 77 , 80 , 88 , 90 which upon setting, form an integral, fiber-reinforced mass. Provided that the presence and placement of fibers in each layer are controlled by and maintained within certain desired parameters as is disclosed and described below, it will be virtually impossible to delaminate the panel 92 produced by the present process.
At this point, the layers of slurry have begun to set, and the respective panels 92 are separated from each other by a cutting device 98 , which in the preferred embodiment is a water jet cutter. Other cutting devices, including moving blades, are considered suitable for this operation, provided that they can create suitably sharp edges in the present panel composition. The cutting device 98 is disposed relative to the line 10 and the frame 12 so that panels are produced having a desired length, which may be different from the representation shown in FIG. 1 . Since the speed of the carrier web 14 is relatively slow, the cutting device 98 may be mounted to cut perpendicularly to the direction of travel of the web 14 . With faster production speeds, such cutting devices are known to be mounted to the production line 10 on an angle to the direction of web travel. Upon cutting, the separated panels 92 are stacked for further handling, packaging, storage and/or shipment as is well known in the art.
Referring now to FIGS. 4 and 5 , an alternate embodiment to the production line 10 is generally designated 100 . The line 100 shares many components with the line 10 , and these shared components have been designated with identical reference numbers. The main difference between the line 100 and the line 10 is that in the line 100 , upon creation of the SCP panels 92 , an underside 102 or bottom face of the panel will be smoother than the upper side or top face 96 , even after being engaged by the forming device 94 . In some cases, depending on the application of the panel 92 , it may be preferable to have a smooth face and a relatively rough face. However, in other applications, it may be desirable to have a board in which both faces 96 , 102 are smooth. Since the smooth texture is generated by the contact of the slurry with the smooth carrier 14 or the carrier web 26 , to obtain a SCP panel with both faces or sides smooth, both upper and lower faces 96 , 102 need to be formed against the carrier 14 or the release web 26 .
To that end, the production line 100 includes sufficient fiber chopping stations 36 , 66 , 82 , slurry feeder stations 44 , 78 and embedment devices 70 , 86 to produce at least three layers 77 , 80 and 88 . Additional layers may be created by repetition of stations as described above in relation to the production line 10 . However, in the production line 100 , in the production of the last layer of the SCP panel, an upper deck 106 is provided having a reverse rotating web 108 looped about main rolls 110 , 112 (one of which is driven) which deposits a layer of slurry and fibers 114 with a smooth outer surface upon the moving, multi-layered slurry 46 .
More particularly, the upper deck 106 includes an upper fiber deposition station 116 similar to the fiber deposition station 36 , an upper slurry feeder station 118 similar to the feeder station 44 , a second upper fiber deposition station 120 similar to the chopping station 66 and an embedment device 122 similar to the embedment device 70 for depositing the covering layer 114 in inverted position upon the moving slurry 46 . Thus, the resulting SCP panel 124 has smooth upper and lower surfaces 96 , 102 .
Another feature of the present invention is that the resulting SCP panel 92 , 124 is constructed so that the fibers 30 , 68 , 84 are uniformly distributed throughout the panel. This has been found to enable the production of relatively stronger panels with relatively less, more efficient use of fibers. The percentage of fibers relative to the volume of slurry in each layer preferably constitutes approximately in the range of 1.5% to 3% by volume of the slurry layers 77 , 80 , 88 , 90 , 114 .
In quantitative terms, the influence of the number of fiber and slurry layers, the volume fraction of fibers in the panel, and the thickness of each slurry layer, and fiber strand diameter on fiber embedment efficiency has been investigated and established as part of this invention. In the analysis, the following parameters were identified:
v T =Total composite volume
v s =Total panel slurry volume
v f =Total panel fiber volume
v f,l =Total fiber volume/layer
v T,l =Total composite volume/layer
v s,l =Total slurry volume/layer
N l =Total number of slurry layers; Total number of fiber layers
V f =Total panel fiber volume fraction
d f =Equivalent diameter of individual fiber strand
l f =Length of individual fiber strand
t=Panel thickness
t l =Total thickness of individual layer including slurry and fibers
t s,l =Thickness of individual slurry layer
n f,l , n f1,l , n f2,l =Total number of fibers in a fiber layer
s f,l P , s f,l P , s f2,l P =Total projected surface area of fibers contained in a fiber layer
S f,l P , S f1,l P , S f2,l P =Projected fiber surface area fraction for a fiber layer.
Projected Fiber Surface Area Fraction, S f,l P
Assume a panel composed of equal number of slurry and fiber layers. Let the number of these layers be equal to N l , and the fiber volume fraction in the panel be equal to V f .
Total composite volume=Total slurry volume+Total fiber volume
v T =v s +v f (1)
Total composite volume/layer=Total slurry volume/layer+Total fiber volume/layer
v T N l = v s N l + v f N l ( 2 ) v T , l = v s , l + v f , l ( 3 )
where, v T,l =v t /N l ; v s,l =v s /N t ; v f,l =v f /N l
Assuming that all fiber layers contain equal amount of fibers, the total fiber volume/layer, v f,l is equal to
v f , l = v T * V f N l ( 4 )
Assuming fibers to have cylindrical shape, total number of fiber strands/layer, n f,l is equal to:
n f , l = v T * V f N l π d 2 4 * l f = 4 v T V f π d f 2 l f N l ( 5 )
where, d f is the equivalent fiber strand diameter.
The projected surface area of a cylindrical fiber is equal to the product of its length and diameter. Therefore, the total projected surface area of all fibers contained in a fiber layer is equal to
s f , l P = n f , l * d f * l f = 4 v T V f N l π d f ( 6 )
Projected fiber surface area fraction, S f,l P is defined as follows:
S f , l P = Projected surface area of fibers / layer , s f , l P Projected surface area of the slurry layer , s s , l P S f , l P = 4 v T V f N l π d f v s , l t s , l = 4 v T V f N l π d f v T t ( = v s , l t s , l = v T , l t l ) = 4 V f t π N l d f ( 7 )
where, t s,l and v s,l are the thickness and volume of the individual slurry layer, respectively.
Thus, the projected fiber surface area fraction, S f,l P can be written as:
S f , l P = 4 V f t π N l d f ( 8 )
The projected fiber surface area fraction, S f,l P can also be derived in the following form from Equation 7 as follows:
S f , l P = 4 v T V f N l π d f v s , l t s , l = 4 v T V f N l π d f ( 1 - V f ) * v T N l * 1 t s , l = 4 V f * t s , l π d f ( 1 - V f ) = 4 V f * t l π d f ( 9 )
where, t s,l is the thickness of distinct slurry layer and t l is the thickness of the individual layer including slurry and fibers.
Thus, the projected fiber surface area fraction, S f,l P can also be written as:
S f , l P = 4 V f * t s , l π d f ( 1 - V f ) ( 10 )
Equations 8 and 10 depict dependence of the parameter projected fiber surface area fraction, S f,l P on several other variables in addition to the variable total fiber volume fraction, V f .
In summary, the projected fiber surface area fraction, S f,l P of a layer of fiber network being deposited over a distinct slurry layer is given by the following mathematical relationship:
S f , l P = 4 V f t π N l d f = 4 V f * t s , l π d f ( 1 - V f )
where, V f is the total panel fiber volume fraction, t is the total panel thickness, d f is the diameter of the fiber strand, N l is the total number of fiber layers and t s,l is the thickness of the distinct slurry layer being used. A discussion analyzing contribution of these variables on the parameter projected fiber surface area fraction, S f,l P is given below:
The projected fiber surface area fraction, S f,l P is inversely proportional to the total number of fiber layers, N l . Accordingly, for a given fiber diameter, panel thickness and fiber volume fraction, an increase in the total number of fiber layers, N l , lowers the projected fiber surface area fraction, S f,l P and vice-versa. The projected fiber surface area fraction, S f,l P is directly proportional to the thickness of the distinct slurry layer thickness, t s,l . Accordingly, for a given fiber strand diameter and fiber volume fraction, an increase in the distinct slurry layer thickness, t s,l , increases the projected fiber surface area fraction, S f,l P and vice-versa. The projected fiber surface area fraction, S f,l P is inversely proportional to the fiber strand diameter, d f . Accordingly, for a given panel thickness, fiber volume fraction and total number of fiber layers, an increase in the fiber strand diameter, d f , lowers the projected fiber surface area fraction, S f,l P and vice-versa. The projected fiber surface area fraction, S f,l P is directly proportional to volume fraction of the fiber, V f . Accordingly, for a given fiber panel thickness, fiber strand diameter and total number of fiber layers, the projected fiber surface area fraction, S f,l P increases in proportion to increase in the fiber volume fraction, V f and vice-versa. The projected fiber surface area fraction, S f,l P is directly proportional to the total panel thickness, t. Accordingly, for a given fiber strand diameter, fiber volume fraction and total number of fiber layers, increase in the total panel thickness, t, increases the projected fiber surface area fraction, S f,l P and vice-versa.
Experimental observations confirm that the embedment efficiency of a layer of fiber network laid over a cementitious slurry layer is a function of the parameter “projected fiber surface area fraction”. It has been found that the smaller the projected fiber surface area fraction, the easier it is to embed the fiber layer into the slurry layer. The reason for good fiber embedment efficiency can be explained by the fact that the extent of open area or porosity in a layer of fiber network increases with decrease in the projected fiber surface area fraction. With more open area available, the slurry penetration through the layer of fiber network is augmented, which translates into enhanced fiber embedment efficiency.
Accordingly, to achieve good fiber embedment efficiency, the objective function becomes keeping the fiber surface area fraction below a certain critical value. It is noteworthy that by varying one or more variables appearing in the Equations 8 and 10, the projected fiber surface area fraction can be tailored to achieve good fiber embedment efficiency.
Different variables that affect the magnitude of projected fiber surface area fraction are identified and approaches have been suggested to tailor the magnitude of “projected fiber surface area fraction” to achieve good fiber embedment efficiency. These approaches involve varying one or more of the following variables to keep projected fiber surface area fraction below a critical threshold value: number of distinct fiber and slurry layers, thickness of distinct slurry layers and diameter of fiber strand.
Based on this fundamental work, the preferred magnitudes of the projected fiber surface area fraction, S f,l P have been discovered to be as follows:
Preferred projected fiber surface area fraction, S f, l p
<0.65
Most preferred projected fiber surface area fraction,
<0.45
S f, l p
For a design panel fiber volume fraction, V f , achievement of the aforementioned preferred magnitudes of projected fiber surface area fraction can be made possible by tailoring one or more of the following variables—total number of distinct fiber layers, thickness of distinct slurry layers and fiber strand diameter. In particular, the desirable ranges for these variables that lead to the preferred magnitudes of projected fiber surface area fraction are as follows:
Thickness of Distinct Slurry Layers, t s, l
Preferred thickness of distinct slurry layers, t s, l
≦0.20 inches
More Preferred thickness of distinct slurry layers, t s, l
≦0.12 inches
Most preferred thickness of distinct slurry layers, t s, l
≦0.08 inches
Number of Distinct Fiber Layers, N l
Preferred number of distinct fiber layers, N l
≧4
Most preferred number of distinct fiber layers, N l
≧6
Fiber Strand Diameter, d f
Preferred fiber strand diameter, d f
≧30 tex
Most preferred fiber strand diameter, d f
≧70 tex
While a particular embodiment of the multi-layer process for producing high strength fiber-reinforced structural cement panels has been shown and described, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.
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A structural cementitious panel, produced by a multi-layer process including providing a moving web; b. one of depositing a first layer of loose fibers upon the web and c. depositing a layer of settable slurry upon the web; d. depositing a second layer of loose fibers upon the slurry; e. embedding said second layer of fibers into the slurry; and f. repeating steps c. through e. until the desired number of layers of settable fiber-enhanced slurry in the panel is obtained. Also provided are an apparatus suitable for producing structural cementitious panels according to the present process, and a structural cementitious panel having multiple layers, each layer created by depositing a layer of settable slurry upon a moving web, depositing fibers upon the slurry and embedding the fibers into the slurry such that each layer is integrally formed with the adjacent layers.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is the 35 U.S.C. §371 national stage of PCT Application No. PCT/FI2013/050201, filed Feb. 22, 2013, which is herein incorporated by reference in its entirety and which also claims priority to, and the benefit of, Finnish Patent Application No. 20125204, filed Feb. 22, 2012, which is herein incorporated by reference in its entirety.
FIELD OF THE INVENTION
The invention relates to a method for making of paper, tissue, board or the like, from recycled fibre material according to the preamble of the enclosed independent claim.
BACKGROUND
Recycled fibre material, such as old corrugated containerboard (OCC), is commonly used as raw material for paper or board. The recycled fibre material comprises in addition to the fibres a number of other substances. Particulate foreign material is separated from the pulp in the pulper or at the screening. Some substances are naturally retained on the fibres and do not disturb the process. Other substances, such as stickies, may be separated from the pulp at the screening and removed from the process.
Typically recycled fibre material comprises starch, which has low molecular weight. This starch originates from the surface sizing of the paper or board, and it retains poorly on the fibres as it typically has no charge at all or it has a slightly anionic charge. Due to its small size it is not effectively separated at the screening either. Thus the low molecular weight starch remains in the water circulation of the pulping and papermaking processes or it is removed together with the screen effluent to the wastewater treatment. In the water circulation the starch increases the risk for microbial growth, as it is suitable nutritive substance for various microbes. Microbes may affect both the functioning of the chemistry of papermaking and/or the quality of the end product. High microbial activity can lower the pH and have a marked effect on wet-end chemistry. High microbial activity can also create strong odours that may be a nuisance or even a danger to operating personnel, and also destructive for product quality in packaging grades. Slime formation, biofilms, on the surfaces of tanks and machine frames leads to paper defects, such as spots and holes, or web breaks when slime lumps are sloughing off.
In the wastewater treatment the low molecular weight starch increases the COD load of the water to be treated, i.e. it increases the wastewater treatment costs.
The amount of low molecular weight starch in the recycled fibre material may be relatively high, for example 1-3% of the total weight of the recycled fibre. When the starch is lost to the water circulation during pulp preparation process the yield of the process is naturally decreasing. Therefore a process that would prevent the starch enrichment to the water circulation and assist its retention to the recycled fibres would provide numerous advantages.
SUMMARY
An object of this invention is to minimise or even eliminate the disadvantages existing in the prior art.
An object of the invention is also to provide a method with which the amount of low molecular weight starch may be reduced in the water circulation when pulping recycled fibre material.
A further object of the invention is to provide a method with which the retention of starch, especially low molecular weight starch, is improved.
These objects are attained with the invention having the characteristics presented below in the characterising part of the independent claim.
Typical method according to the present invention for making of paper, tissue, board or the like, by using recycled fibre material as a raw material, the method comprising following steps:
pulping recycled paper, board or the like in a pulper and obtaining a pulp flow comprising (i) an aqueous phase and (ii) at least recycled fibres and starch having low molecular weight, which are dispersed in the aqueous phase; adding a coagulant agent to the pulp flow or to an aqueous process flow comprising starch having low molecular weight; allowing the coagulant agent to interact with the starch having low molecular weight and optionally forming aggregates; and adding at least one flocculating agent, after the addition of the coagulant agent, to any flow, which comprises interacted coagulant agent, and forming a treated flow with starch comprising agglomerate(s); retaining at least part of the said aggregates and/or the said agglomerates to the fibres or to a web, which is formed.
Now it has been surprisingly found out that low molecular weight starch in the recycled pulp may be agglomerated by addition of a coagulant agent followed by the addition of a flocculating agent. Thus the low molecular weight starch interacts first with the coagulant agent and then with the flocculating agent and forms agglomerates, or it is attached to agglomerates, which are large enough to be retained on the fibres or to the formed web. Furthermore, by selecting suitable coagulant agents and flocculating agents the agglomerates may even have surface charges that assist in their retention on the fibres. It has been noticed that the amount of low molecular weight starch in the circulating process water is clearly reduced, when the chemical additions according to the present invention is performed. Furthermore, the overall process yield is improved when more of the starch in the recycled fibre material can be retained to the fibres and consequently, to the formed board or the paper web. Still further, it may be possible to reduce the amount of surface sizing later in the production process, as the retained starch may improve the strength properties of the formed board or paper.
According to one preferred embodiment of the invention the COD value of the treated flow is reduced with at least 10%, preferably at least 20%, more preferably at least 40%, from the COD value of the aqueous phase of the pulp flow or from the COD value of the aqueous process flow before the addition of the coagulant agent.
In this application recycled fibre material means recycled paper, recycled board and/or old corrugated containerboard (OCC), which comprise fibres and starch, optionally also other constituents. Pulp and pulp flow is understood to comprise an aqueous phase and a solid material phase, which includes fibres and other possible solids. The method according to the present invention may be used in pulping recycled paper, board and/or old corrugated containerboard (OCC), comprising starch, whereby the typical COD value of the aqueous phase of the untreated pulp flow is >20 kg/ton, more typically >35 kg/ton, sometimes even >50 kg/ton, before the addition of the coagulant agent and the flocculating agent. COD value is determined by disintegrating recycled fibre material to water, centrifuging thus obtained pulp and determining COD value from the separated aqueous phase by using Hach Lange method, according to description in the Experimental part of this application. Preferably the recycled fibre material is recycled board and/or old corrugated containerboard, preferably comprising at least 20 kg/ton starch, more preferably at least 30 kg/ton starch, starch being determined with iodine method which is described in Tappi standard T419 om-11 (Starch in paper), and using surface sizing starch as reference.
One possible advantage, which is provided by the present invention, is that the ash content of the produced paper increases, while the bursting strength of the paper is also increasing or remains at least on the same level. Typically, in the prior art, an increase in ash content decreases the bursting strength of the paper. As the trend is typically opposite, when the present invention is employed, it can be concluded that the present invention provides possibilities to increase the ash content and, at least relatively, the bursting strength, too. Typical increase in the bursting strength is 3-15%, more typically 5-10%, calculated in relation to the bursting strength of corresponding paper manufactured without sequential addition of coagulant agent and flocculating agent. The ash content increase may be 5-25%, more preferably 10-20%, typically 15-20%, calculated in relation to the ash content of corresponding paper manufactured without sequential addition of coagulant agent and flocculating agent.
In this application the terms “low molecular starch”, “low molecular weight starch” and “starch having a low molecular weight” are interchangeable and they are used as synonyms to each other. The low molecular weight starch in the recycled pulp originates normally from surface sizing, and it is typically oxidised starch, acid degraded or enzyme degraded starch. The low molecular weight starch may be, for example, oxidized surface starch having a weight average in the range of 100 000-5 000 000 g/mol, more typically 200 000-4000 000 g/mol. Alternatively, the low molecular weight starch may be an acid degraded or enzyme degraded surface starch having a weight average in the range of 30 000-3 000 000 g/mol, more typically 40 000-2 000 000 g/mol. Typically pulp, which is obtained by pulping recycled fibre material, comprises low molecular starch from different sources. This means that the low molecular starch in process presently described may comprise oxidized surface starch as well as acid degraded and/or enzyme degraded surface starch.
Surface size starches may be specified based on the viscosity of the cooked starch, typical viscosity levels being between 15-400 mPas, more typically between 20-300 mPas at 70° C. at 10% concentration. Charge densities of enzyme degraded starches are very low, being quite near to zero at pH 7, e.g. between −0.05-0 meq/g absolute starch. Oxidized starches are typically more anionic compared to enzyme degraded starches, being about −0.3-−0.01 meq/g, more typically about −0.2-−0.02 meq/g calculated of absolute starch.
Advantageously the method according to the present invention may be used for paper, tissue or board production, where the fresh water consumption of the process is <10 m 3 /ton produced paper or board, preferably <5 m 3 /ton produced paper or board and/or the process water conductivity is at headbox >2500 μS/cm, preferably >3000 μS/cm, sometimes even >4000 μS/cm. In other words, the present method is especially suitable for pulping recycled fibre material in a process having a low fresh water consumption. Furthermore, the present invention is especially intended for retaining free low molecular weight starch in the aqueous phase of the pulp to the fibres, which originate from recycled paper, tissue and/or board.
The method according to the present invention is thus suitable for producing paper, tissue, board or the like from recycled fibre material.
A method according to one embodiment of the present invention for improving process of making paper, board or the like, the process employing recycled fibre material as raw material, comprises
pulping recycled paper, board or the like in a pulper and obtaining pulp comprising at least recycled fibres and starch having low molecular weight dispersed in an aqueous phase, screening the pulp and separating unwanted material from the pulp, adding a coagulant agent to the pulp and allowing the coagulant agent to interact with starch having low molecular weight, adding a flocculating agent after the addition of the coagulant agent to a process flow and forming a starch comprising agglomerate,
whereby COD value of the aqueous phase of the pulp is reduced at least 10° A) from the COD value of the aqueous phase before the addition of the coagulant agent and the flocculating agent.
The coagulant agent interacts, either chemically or physically, with the low molecular weight starch, whereby a coagulation, coagulum or a loose agglomerate is formed. According to one embodiment of the invention the pulp flow is screened and unwanted material from the pulp flow is separated. The screened pulp flow is thickened to a higher concentration, e.g. storage concentration by separating a part of the aqueous phase from the pulp flow as a discharge flow, and the coagulant agent is added to the pulp flow before the thickening step of the screened pulp or to the discharge water flow from the thickening step. In case the coagulant agent is added to the pulp flow before the thickening of the pulp flow it is possible to add the coagulant agent either immediately after the pulping step, before the screening step or after the screening step. Addition of the coagulant agent to the pulp before the thickening step is advantageous as the enrichment of the starch to the water circulation is effectively prevented in the most processes, and a large amount of starch is effectively retained on the fibres.
According to one embodiment, especially when the process has effective screening and thickening steps, the coagulant agent may be added after the thickening step, for example after the storage towers. The coagulant agent may be added to the short circulation pulp between the stock proportioning and the headbox. Even in this embodiment the flocculating agent is added to the process after the coagulant agent, to a flow, which comprises interacted coagulant agent.
According to one embodiment of the invention the coagulant agent is an inorganic coagulant agent. The coagulant agent may be selected from aluminium compounds, iron compounds, bentonite or colloidal silica. Especially the coagulant agent is selected from the group comprising aluminium sulphate, aluminium chloride, polyaluminium chloride (PAC), polyaluminium sulphate (PAS), polyaluminium silica sulphate, sodium aluminate, alum, ferric sulphate (Fe 2 (SO 4 ) 3 ), ferrous sulphate (FeSO 4 ), ferric ferrous sulphate, ferric chloride, ferrous chloride, ferric ferrous chloride, ferric chloride sulphate, ferric nitrate, ferric sulphate nitrate, ferric chloride nitrate, ferric hydroxide, bentonite, silicious material, such as colloidal silica, and any of their mixture. According to one embodiment the coagulant agent is selected from group consisting of bentonite, colloidal silica, aluminium compounds or iron compounds comprising Fe(III). Bentonite is here understood as montmorollonite clay mineral. Aluminium compounds and iron compounds comprising Fe(III) are preferred as coagulant agents.
The coagulant agent may be added in amount of
0.5-10 kg active aluminium/ton dry pulp, preferably 0.75-8 kg active aluminium/ton dry pulp, more preferably 1-5 kg active aluminium/ton dry pulp or 5-50 kg active Fe/ton dry pulp, preferably 6-40 kg active Fe/ton dry pulp, more preferably 8-20 kg active Fe/ton dry pulp or 0.5-10 kg dry bentonite/ton dry pulp, preferably 1-8 kg dry bentonite/ton dry pulp, more preferably 2-5 kg dry bentonite/ton dry pulp, or 0.1-1 kg dry silica/ton dry pulp, preferably 0.2-0.8 kg dry silica/ton dry pulp, preferably 0.25-0.5 kg dry silica/ton dry pulp,
depending on the active substance in the coagulant agent.
Bentonite is typically used as 1-5 weight-% slurry, and it may have a particle size in the range of 200-800 nm. Colloidal silica is typically used as 0.5-25 weight-% slurry, and it may have a particle size in the range of 1-50 nm. Bentonite and colloidal silica slurries may be further diluted before use, if need be.
According to one embodiment the coagulant agent is polyaluminium chloride. Polyaluminium chloride is an inorganic polymer and it is typically present in a solution as a highly charged aluminium complex Al 13 O 4 (OH) 24 (H 2 O) 12 7+ or AlO 4 Al 12 (OH) 24 (H 2 O) 24 7+ . In this application polyaluminium chloride is understood as polymerised aluminium substance, which may be presented also by the general formula Al 2 (OH) x Cl 6-x , where 0<x<6. The degree of neutralisation, i.e. the replacement of CI ions with OH ions, may be expressed by using the unit basicity. The basicity of polyaluminium compound may be generally expressed by the following formula
% Basicity=100×[OH]/3[Al]
The higher the basicity, the higher the degree of neutralisation. Depending on basicity of polyaluminum chloride fewer ions have a 3 + charge, and more ions are high charged, averaging 5 + to 7 + .
According to one preferred embodiment of the present invention the coagulant agent is polyaluminium chloride having an aluminium content of 4-20%, preferably 7-18%, and a basicity 20-80%, preferably 30-70%, more preferably 35-55%. Typically polyaluminium chloride may be used as 20-40 weight-%, more typically as 30-40 weight-% aqueous solution. pH of the polyaluminium chloride solution is typically 0.5-4.2.
The interaction between low molecular weight starch and the coagulant agent may be chemical and/or physical. For example, polyaluminium chloride, alum and iron sulphates interact chemically with the low molecular weight starch and form coagulations, coagula or loose agglomerates. It is assumed that bentonite and colloidal silica adsorb or physically bind the starch, whereby loose agglomerates are formed. In case the coagulant agent is a metal coagulant with high cationicity, such as polyaluminium chloride or polyaluminium sulphate, it may form an inorganic polymer, which attracts and interacts with low molecular weight starch, fines and possible filler particles. The size of the formed coagulation, coagulum or loose agglomerate is then further increased when it comes into contact with the flocculating agent.
Flocculating agent is added after the addition of the coagulant agent so that the flocculating agent comes into a contact with the coagulant agent or the coagulant, coagulum or loose agglomerate which is formed, when low molecular weight starch is bound or attached to coagulant agent or absorbed on the coagulant agent. In other words, the flocculating agent is added to a flow, which comprises interacted coagulant agent, e.g. pulp flow, preferably after pulp storage towers or silos and before the headbox of the paper, tissue or board machine. Thus flocculating agent is preferably added to the short circulation of a paper, tissue or board machine, however after the addition of the coagulant agent to a flow comprising interacted coagulant agent. Flocculating agent may be added at one feeding location or at several separate feeding locations. Flocculating agent may be added directly to the pulp flow, or it may be added first to an aqueous process flow, which is later combined with the pulp flow. It is possible to add flocculating agent both to the pulp flow and to one or several aqueous process flows. The flocculating agent(s) is typically added as aqueous dispersion in amount of 20-2000 g/ton paper or board, typically 50-1000 g/ton paper or board, preferably 100-500 g/ton paper or board, the values being given as amount of active flocculating agent(s).
According to one preferred embodiment several different flocculating agents may be added, such as two, three or four different flocculating agents, preferably at several separate feeding locations. If several flocculating agents are added, advantageously at least one of them is anionic. For example, anionic polyacrylamide may be added after the addition of cationic polyacrylamide. In any case, the first flocculating agent is preferably added to a flow comprising interacted coagulant agent.
Typically the flocculating agent is added after the coagulant agent to a flow comprising interacted coagulant agent, the reaction time for the interaction between the coagulant agent and low molecular starch being >1 min, preferably in the range of 2-30 min, more preferably in the range of 5-15 min. This means that the flocculating agent is added after the required reaction time has elapsed. For example, when polyaluminium chloride is used as the coagulant agent, it is added to the pulp flow or to a water flow comprising low molecular weight starch, and a typical reaction time for the interaction between polyaluminium chloride and low molecular weight starch, preceding the flocculating agent addition, is in the range of 7-12 min, more typically ca. 10 min.
According to one embodiment of the invention the flocculating agent is selected from the group comprising cationic polyacrylamide (C-PAM), anionic polyacrylamide (A-PAM), polyvinyl amine (PVAm), polyethylene oxide (PEO), polyethyleneimine (PEI) and their mixtures. According to one embodiment of the invention the flocculating agent is cationic polyacrylamide (C-PAM) and/or anionic polyacrylamide (A-PAM) and it has an average molecular weight (MW) in the range of 4 000 000-22 000000 g/mol, more preferably 6 000 000-20 000 000 g/mol, still more preferably 7 000 000-18 000 000 g/mol. According to one advantageous embodiment the flocculating agent is a polymer having an average molecular weight (MW) >8 000 000 g/mol, preferably 9 000 000-18 000 000 g/mol. In this application the value “average molecular weight” is used to describe the magnitude of the polymer chain length. Average molecular weight values are calculated from intrinsic viscosity results measured in a known manner in 1N NaCl at 25° C. by using an Ubbelohde capillary viscometer. The capillary selected is appropriate, and in the measurements of this application an Ubbelohde capillary viscometer with constant K=0.005228 was used. The average molecular weight is then calculated from intrinsic viscosity result in a known manner using Mark-Houwink equation [η]=K·M a , where [η] is intrinsic viscosity, M molecular weight (g/mol), and K and a are parameters given in Polymer Handbook, Fourth Edition, Volume 2, Editors: J. Brandrup, E. H. Immergut and E. A. Grulke, John Wiley & Sons, Inc., USA, 1999, p. VII/11 for poly(acrylamide-co-N,N,N-trimethyl aminoethyl chloride acrylate), 70% acrylamide. Accordingly, value of parameter K is 0.0105 ml/g and value of parameter a is 0.3. The average molecular weight range given for the parameters in used conditions is 450 000-2 700 000 g/mol, but the same parameters are used to describe the magnitude of molecular weight also outside this range. For polymers having a low average molecular weight, typically around 1 000 000 g/l or less, the average molecular weight may be measured by using HPLC size exclusion chromatography, using PEO for calibration. HPLC size exclusion chromatography is used especially if no meaningful results can be obtained by using intrinsic viscosity measurement.
Preferably, after the addition of the coagulant agent and the flocculating agent, in this order, and obtaining a starch comprising agglomerate, the agglomerate is retained on the recycled fibres in pulp or to the web which is formed.
It is also possible to add biocide and/or amylase enzyme inhibitor for microbe control in the process. Biocide and/or amylase enzyme inhibitor may be added to the pulper and/or to a flow in the process, such as the pulp flow or the aqueous process flow. Preferably biocide and/or amylase enzyme inhibitor is added to the process flow and/or pulp flow before the pulp storage towers or silos located after the pulp thickening step. Biocide/enzyme inhibitor may be added to the pulp in the pulper or before thickening of the screened pulp. According to one preferred embodiment of the present invention biocide and/or amylase enzyme inhibitor is added to the pulp flow within 2 hours from the moment when the pulp flow exits the pulper outlet. Further, the biocide or the amylase enzyme inhibitor may be added to the pulp between inlet of the pulper and thickening step of the screened pulp. Early addition of biocide or amylase enzyme inhibitor is preferred, as it minimises further degradation of low molecular starch, and may improve the coagulation and flocculation of the low molecular starch, and thereby retention of the starch to the recycled fibres. It is possible to add biocide and/or amylase enzyme inhibitor only at one biocide feeding location. Alternatively, biocide and/or amylase enzyme inhibitor may be added at several separate biocide feeding locations, spaced apart from each other, whereby the addition of biocide/enzyme may be targeted at known problem points of the process. It is also possible to add biocide at first biocide feeding location(s) and amylase enzyme inhibitor at different and separate second biocide feeding location(s).
Preferably the biocide and/or amylase enzyme are added as early as possible in order to minimise the further degradation of low molecular starch. Biocide and/or amylase enzyme may be added, for example, to the aqueous dilution flow, which is led to the pulper. For example, biocide and/or amylase enzyme may be added to storage tank of dilution water of the pulper.
The biocide may be any suitable biocide, which reduces the number of viable bacteria and/or microbes in the process at least 80%. Similarly the amylase enzyme inhibitor may be any substance that inhibits the formation of or deactivates the amylase enzyme, such as a zinc inhibitor. Preferably the amylase enzyme inhibitor may be any suitable inhibitor reducing amylase enzyme activity under process conditions at least 20%.
According to one embodiment of the invention the biocide may be selected from a group comprising oxidizing biocides, such as sodium hypochlorite, hypobromous acid, chlorine dioxide; halogenated hydantoins, such as bromochloro-dimethylhydantoin; partially halogenated hydantoins such as monochloro-dimethylhydantoin; haloamines, such as chloramines or bromamines; and their mixtures. A haloamine, which is suitable for use in one embodiment of the present invention, may be formed by combining an ammonium source, such as ammonium sulfate, ammonium chloride, ammonium bromide, ammonium phosphate, ammonium nitrate or any other ammonium salt, including urea, with an oxidant such as sodium hypochlorite. Biocide may be added continuously to provide a total active chlorine concentration of from about 0.1-5 ppm throughout the treated portions of the process. More preferably, the active chlorine concentration in these portions of the process is about 0.75-2 ppm. It is also possible to add biocide by using slug dosing, which refers to periodical, or batch, dosing of biocide into the process, as contrasted with a continuous dosing. Typically a slug dose is 1-10 ppm, preferably 3-7 ppm. The slugs would preferably be fed for about 3-30 minutes each about 6-24 times a day, and are more preferably fed for about 5-15 minutes each about 12-24 times a day.
Strengthening agents and/or flocculant additives may be added to the pulp flow. According to one embodiment of the invention the strengthening agent is selected from the group comprising starch, cationic polyacrylamide (C-PAM), anionic polyacrylamide (A-PAM), glyoxalated polyacrylamide (G-PAM), amphoteric polyacrylamide, polydiallyldimethylammonium chloride (poly-DADMAC), polyacrylic amide (PAAE), polyvinyl amine (PVAm), polyethylene oxide (PEO), polyethyleneimine (PEI), chitosan, guar gum, carboxymethyl cellulose (CMC) and their mixtures. Starch may be cationic, anionic or amphoteric. Starch may be non-degraded or high cationic degraded starch having DS>0.05, non-degraded starch being preferred. When the strengthening agent is a synthetic polymer it may have an average molecular weight in the range 100 000-20 000 000 g/mol, typically 300 000-8 000 000 g/mol, more typically 300 000-1 500 000 g/mol, provided that the molecular weight of the strengthening agent is lower than the molecular weight of the corresponding flocculating agent. The average molecular weights are measured by using an Ubbelohde capillary viscometer, as described above in this application.
Strengthening agent is typically added as aqueous dispersion in amount of 0.1-20 kg/ton paper or board, typically 0.3-5 kg/ton paper or board, preferably 0.5-3 kg/ton paper or board, given as amount of active substance. The addition of a strengthening agent may preferably be performed before the addition of the flocculating agent, and the addition of strengthening agent is preferably performed to the pulp flow, preferably to the thick stock flow, the thick stock consistency being 2-6 weight-%.
It is also possible to use a flocculant additive which is selected from the group comprising bentonite, colloidal silica and conventional papermaking fixatives, such as polydiallyldimethylammonium chloride (poly-DADMAC) or polyamines.
Flocculant additive is typically added to the process before or after the addition of the flocculating agent, but after the addition of the coagulant agent. Flocculant additive, especially fixative, which may be used as a flocculant additive, is added to the pulp flow, typically in amount of 50-4 000 g/ton paper or board, typically 100-2000 g/ton paper or board, preferably 200-800 g/ton paper or board, given as amount of active substance.
According to one embodiment of the invention the coagulant agent is added to the discharge water flow of the thickening step, i.e. to the discharge water flow of a thickener, at one feeding location or more feeding locations. In this embodiment, the discharge water flow from the thickening step may be led forward in the process and used as dilution water between the machine chest and the headbox. Coagulant agent is introduced to the discharge water flow comprising starch having a low molecular weight after the thickening step, but before the machine chest. Coagulant agent may be fed at one feeding location or simultaneously at two, three or more feeding locations. Starch interacts with the coagulant agent and forms loose coagulants, coagula or agglomerates. Flocculating agent is added to the pulp flow and/or to the discharge water flow at flocculation feeding locations after the addition of the coagulant agent. For example, it is possible to add also the flocculating agent to the discharge flow from the thickening step. However, flocculating agent is added after the addition of the coagulating agent at at least one of the coagulant feeding locations, but before the machine chest in order to guarantee the retention of the recycled starch to the fibres and/or to the web(s) to be formed.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The invention is described in more detail below with reference to the enclosed schematic drawings, in which
FIG. 1 shows a first embodiment of the present invention for manufacturing recycled board,
FIG. 2 shows a second embodiment of the present invention for manufacturing recycled paper, tissue or board, and
FIG. 3 shows still another embodiment of the invention for manufacturing recycled board.
DETAILED DESCRIPTION
In FIG. 1 is shown a first embodiment of the present invention for manufacturing recycled board. Recycled paper and/or board bales 20 are introduced to a pulper 1 through an inlet. In the pulper 1 the paper and/or board bales are disintegrated and a flow of pulp comprising recycled fibres and starch having a low molecular weight is led out of the pulper 1 to a pulper dump chest 2 . From pulper dump chest the pulp is led to fractionation screening 3 and further either to fine screening 4 or short fibre thickener 5 . From the fine screening 4 fibres are led to the long fibre thickener 6 and reject from the screening stage is led to the reject thickening 7 . At the reject thickening 7 particulate material and the like is separated from water, and led out of process as sludge reject 19 . Water is removed as effluent 18 to an effluent treatment (not shown). In conventional processes starch having low molecular weight has exited the process through these material flows, and burdened effluent 18 or sludge reject 19 .
Coagulant agent can be introduced to the pulp comprising recycled fibres and starch having a low molecular weight at plurality of alternative coagulant feeding locations 26 . It is possible to feed coagulant agent at one feeding location 26 or to feed coagulant at two or more feeding locations 26 simultaneously. Coagulant feeding locations 26 are situated, at the latest, before the short fibre thickener 5 and/or the long fibre thickener 6 . From these thickeners 5 , 6 separated water is led to white water storage 17 and further back to pulper 1 as pulper water 24 . Coagulant feeding locations 26 are situated so that the coagulant agent interacts with starch before the thickeners 5 , 6 . Thus starch is at least mainly progressing forward with the fibre phase in the process and not recirculated back to white whiter storage 17 or pulper 1 with the water phase.
From the short fibre thickener 5 short fibre pulp is led to short fibre storage tower 8 and correspondingly, long fibre pulp is led from the long fibre thickener 6 to long fibre storage tower 9 . From fibre storage towers 8 , 9 pulps are led to top ply machine chest 10 or back ply machine chest 11 and further to top ply headbox 12 or back ply headbox 13 . Paper or board webs for top ply or back ply are formed on top ply wire 14 or back ply wire 15 and reunited after their initial formation. Water which is removed from the web is either directly circulated back to the process or collected to a white water chest 16 . Finally, formed paper or board web 21 is transferred further to pressing and drying. Fresh water 22 is added to the process through shower pipes 23 .
Flocculating agent is added to the pulp at flocculation feeding locations 28 . The flocculating agent may be added only to the short fibre pulp from the short fibre storage tower 8 or only to the long fibre pulp from the long fibre storage tower 9 , or preferably both to the short fibre pulp from the short fibre storage tower 8 and to the long fibre pulp from the long fibre storage tower 9 . Flocculating agent is added after the addition of the coagulating agent at one of the coagulant feeding locations 26 , but before the headbox 12 , 13 in order to guarantee the retention of the recycled starch to the fibres and/or to the web(s) to be formed.
Biocide or amylase enzyme inhibitor is preferably added to the process at one or several of the biocide feeding locations 25 for microbe control. It is possible to add biocide only at one biocide feeding location or to add separate dosages of biocide/enzyme inhibitor at several feeding locations. It is also possible to add biocide at one feeding location and amylase enzyme inhibitor at different feeding location.
In one embodiment, it is also possible to add strengthening agent and/or flocculation additive to the process at additive feeding locations 27 . Typically strengthening agent and/or flocculation additive are added after the storage towers 8 , 9 but at the latest just before headbox 12 , 13 . Preferably strengthening agents and/or flocculation additives are added after the addition of the coagulating agent, but before the addition of the flocculating agent.
In FIG. 2 is shown a second embodiment of the present invention for manufacturing recycled paper, tissue or board. Recycled paper and/or board bales 20 are introduced to a pulper 1 through a pulper inlet. In the pulper 1 the paper and/or board bales are disintegrated and a pulp flow comprising recycled fibres and starch having a low molecular weight is led out of the pulper 1 to a pulper dump chest 2 . From pulper dump chest 2 the pulp is led to a flotation unit 31 (optional) and further to fine screening primary stage 41 . From the fine screening primary stage 41 fibres are led either to a thickener 61 or to a fine screening reject stage 51 . From fine screening reject stage 51 fibres are led to the thickener 61 and the reject is led to the reject thickening 7 . At the reject thickening 7 particulate material and the like is separated from water, and led out of process as sludge reject 19 . Water is removed as effluent 18 to an effluent treatment (not shown). In conventional processes starch having low molecular weight has exited the process through these material flows, and burdened effluent 18 or sludge reject 19 .
Coagulant agent may be introduced to the pulp comprising recycled fibres and starch having a low molecular weight at plurality of alternative coagulant feeding locations 26 . It is possible to feed coagulant agent at one feeding location 26 or to feed coagulant at two or more feeding locations 26 simultaneously. Coagulant feeding locations 26 are situated, at the latest, before the thickener 61 , from which separated water is led to white water storage 17 and further back to pulper 1 as pulper water 24 . Coagulant feeding locations 26 are situated so that the coagulant agent interacts with starch before the thickener 61 . Thus starch is at least mainly progressing forward with the fibre phase in the process and not recirculated back to white whiter storage 17 or pulper 1 with the water phase.
From the thickener 61 pulp is led to a fibre storage tower 81 . From the fibre storage tower 81 pulp is led to a machine chest 101 and further to a headbox 121 . Paper, tissue or board web is formed on a wire 141 . Water which is removed from the formed web is either directly circulated back to the process or collected to a white water chest 16 . Finally, formed paper, tissue or board web 21 is transferred further to pressing and drying. Fresh water 22 is added to the process through shower pipes 23 .
Flocculating agent is added to the pulp at flocculation feeding location 28 . Flocculating agent is added after the addition of the coagulating agent at one of the coagulant feeding locations 26 , but at the latest just before the headbox 121 in order to guarantee the retention of the recycled starch to the fibres and/or to the web to be formed.
Biocide or amylase enzyme inhibitor is preferably added to the process at one or several of the biocide feeding locations 25 . It is possible to add biocide only at one biocide feeding location or to add separate dosages of biocide/enzyme inhibitor at several feeding locations. It is also possible to add biocide at one feeding location and amylase enzyme inhibitor at different feeding location.
In one embodiment, it is also possible to add strengthening agent and/or flocculation additive to the process at additive feeding locations 27 . Typically strengthening agent and/or flocculation additive are added after the fibre storage tower 81 but before headbox 121 . Preferably strengthening agents and/or flocculation additives are added after the addition of the coagulating agent, but before the addition of the flocculating agent.
FIG. 3 shows still another embodiment of the invention for manufacturing recycled board. Recycled paper and/or board bales 20 are introduced to a pulper 1 through a pulper inlet. In the pulper 1 the paper and/or board bales are disintegrated and a flow of pulp comprising recycled fibres and starch having a low molecular weight is led out of the pulper 1 to a pulper dump chest 2 . From pulper dump chest 2 the pulp is led to fractionation screening 3 and further either to fine screening 4 or short fibre thickener 5 . From the fine screening 4 fibres are led to the long fibre thickener 6 and reject from the screening stage is led to the reject thickening 7 . At the reject thickening 7 particulate material and the like is separated from water, and led out of process as sludge reject 19 . Water is removed as effluent 18 to an effluent treatment (not shown).
Discharge water from the thickeners 5 , 6 is led forward in the process and used as dilution water between the machine chest 10 , 11 and headbox 12 , 13 . Coagulant agent is introduced to the discharge flow from the short fibre thickener or to the discharge flow of the long fibre thickener at coagulant feeding locations 26 . The discharge flow comprises starch having a low molecular weight and this starch interacts with the coagulant agent and forms loose coagulants or agglomerates. It is possible to feed coagulant agent at one feeding location 26 or to feed coagulant at two or more feeding locations 26 simultaneously. Coagulant feeding locations 26 are situated after the short fibre thickener 5 and/or the long fibre thickener 6 , but before the headbox 12 , 13 .
From the short fibre thickener 5 short fibre pulp is led to short fibre storage tower 8 and correspondingly, long fibre pulp is led from the long fibre thickener 6 to long fibre storage tower 9 . From fibre storage towers 8 , 9 pulps are led to top ply machine chest 10 or back ply machine chest 11 and further to top ply headbox 12 or back ply headbox 13 . Paper or board webs for top ply or back ply are formed on top ply wire 14 or back ply wire 15 and reunited after their initial formation. Water which is removed from the web is either directly circulated back to the process or collected to a white water chest 16 . Finally, formed paper, tissue or board web 21 is transferred further to pressing and drying. Fresh water 22 is added to the process through shower pipes 23 .
Flocculating agent is added to the pulp and/or to the discharge flows at flocculation feeding locations 28 . The flocculating agent may be added only to the short fibre pulp from the short fibre storage tower 8 or only to the long fibre pulp from the long fibre storage tower 9 , or preferably both to the short fibre pulp from the short fibre storage tower 8 and to the long fibre pulp from the long fibre storage tower 9 . It is also possible to add flocculating agent to discharge flow from the short fibre thickener 5 and/or to the discharge flow of the long fibre thickener 6 . Flocculating agent is added after the addition of the coagulating agent at one of the coagulant feeding locations 26 , but before the headbox 12 , 13 in order to guarantee the retention of the recycled starch to the fibres and/or to the web(s) to be formed.
Biocide or amylase enzyme inhibitor is preferably added to the process at one or several of the biocide feeding locations 25 for microbe control. It is possible to add biocide only at one biocide feeding location or to add separate dosages of biocide/enzyme inhibitor at several feeding locations. It is also possible to add biocide at one feeding location and amylase enzyme inhibitor at different feeding location.
In one embodiment, it is also possible to add strengthening agent and/or flocculation additive to the pulp at additive feeding locations 27 . . . Typically strengthening agent and/or flocculation additive are added to the pulp after the storage towers 8 , 9 but at the latest just before machine chest 12 , 13 .
Strengthening agents and/or flocculation additives may be added to the pulp before the addition of the coagulating agent and the flocculating agent.
EXPERIMENTAL
The some embodiments of the invention are further described in the following non-limiting examples.
Example 1
Test slurry is prepared by using bleached pine kraft pulp refined in a Valley Hollander to Schopper Riegler value of 25 and degraded starch (Perfectamyl A 4692, Avebe), which is oxidized, low-viscosity, weakly anionic potato starch. Measured starch content in the test slurry is 301 mg/l. Test slurry is diluted to 5 g/l consistency and adjusted to room temperature+23° C.
Used test chemicals are diluted to suitable concentration before addition to the test slurry. The dilution level is selected such that the dosage of a diluted test chemical is between 1-3 ml. They are added to the test slurry as shown in Table 1 and a dynamic drainage jar, DDJ (Paper Research Materials, Inc., Seattle, Wash.) is used to control the retention degree of starch to paper and how much starch remains in the filtrate.
Used test chemicals are:
Prod A: coagulant agent, polyaluminium silicate product, Al-content 7.8 weight-%, basicity 40%.
Prod B: strengthening agent, glyoxylated PAM product, co-polymer of acrylamide and diallyldimethylammonium chloride, which is treated with glyoxal, charge density 0.5 meq/g dry polymer product, MW average 200 000 g/mol, dry solids 7.5%.
Prod C: flocculating agent, anionic polyacrylamide strength resin product, aqueous solution of co-polymer of acrylamide and acrylic acid, charge density: −2.9 meq/g dry polymer product, MW average 400 000 g/mol, dry solids 20%, viscosity 6000 mPas at 25° C. measured with Brookfield DVI+, equipped with small sample adapter, and spindle 31 .
Prod D: flocculating agent, cationic polyacrylamide product, co-polymer of acrylamide and acryloyloxyethyltrimethylammonium chloride, charge density 1.0 meq/g dry polymer product, MW average 7 000 000 g/mol, dry solids 90%.
Prod E: coagulant agent, colloidal silica product, 15% solids content, particle size 5 nm, S-value 60.
The pulp slurry volume in DDJ is 500 ml, stirrer speed is 1000 rpm and wire type is M60. Test chemical addition times are indicated as negative time before the drainage starts in Table 1. Stirring is started 45 s before drainage and is continuing after drainage until sample volume is filtered. The sample is taken from the first 100 ml filtrate. Filtrate is centrifuged with speed 3000 rpm 4-5 hours after starch addition.
From the centrifuge supernatant COD is measured by using Hach Lange method LCK 1041 according to manufacturer's instructions. 2 ml supernatant is carefully pipetted to a sample cuvette, which is closed and thoroughly cleaned outside, and inverted. Sample cuvette is heated in a thermostat 15 min at 175° C. The hot sample cuvette is allowed to cool to temperature 80° C. in the thermostat, whereafter it is removed from the thermostat, carefully inverted twice, and allowed to cool to room temperature outside the thermostat. The outside of the sample cuvette is cleaned and the evaluation is carried out. According to the test method oxidizable substances react with sulphuric acid-potassium dichromate solution in the presence of silver sulphate as a catalyst. Chloride is masked by mercury sulphate. The green colouration of Cr 3+ is evaluated, it being indicator of the COD value of the sample. The evaluation being performed by using a spectrometer.
Starch is measured from the filtrate by using Hach Lange method LCK 357 according to manufacturer's instructions. 2.0 ml sample is pipetted into an open cuvette, Cuvette is closed and mixed, evaluated after 10 minutes. pH of the sample should be in the range of 4-7, temperature 22° C. The analysed sample should be colourless and free of turbidities. Slight colouration may be allowed for with the help of a sample specific blank value, prepared by using 0.4 ml distilled water and 2 ml sample. Turbidities may be eliminated by passing the sample through a membrane filter (LCW 904). The sample evaluation is performed by spectrophotometric measurement at 535 nm, factor 127, using photometer RD Lange, LASA 100 v. 1.20. Calibration curve for the measurement is prepared by using Cargill C*film TCF07312 starch, which is cooked at 94-98° C., ca. 30 min.
The results of Example 1 are shown in Table 1. From Table 1 it can be seen that the addition of coagulant agent and flocculating agent, in this order, clearly improve the starch retention, i.e. the amount of starch in the filtrate is decreased. Similarly the COD value of the filtrate is decreased. This indicates that the starch would be retained to the fibres at the thickening step or at the wire section of the paper machine.
TABLE 1
Retention test for starch with dynamic drainage jar (DDJ).
Test time, s
−40
−30
−25
−15
−10
Amounts of used test chemicals
Filtrate
Prod A,
Prod B,
Prod C,
Prod D,
Prod E,
Results
Test
kg/t
kg/t
kg/t
kg/t
kg/t
COD
Starch
No
prod.*
prod.*
prod.*
prod.*
prod.*
mg/l
mg/l
1
0
0
0
0
0
543
301
2
0
0
0
0.3
0
401
272
3
0
30
2
0.3
3
398
293
4
25.6
30
2
0.3
3
227
189
5
64.1
0
0
0.3
3
202
212
*dosage of product, not calculated as active substance
Example 2
Test slurry is prepared from liner board containing surface size starch. Dry board is cut into 2×2 cm pieces and a batch of disintegrated pulp is prepared by adding 30 g of cut board pieces into 1.5 liters tap water, temperature+45° C. After 5 min soaking, the board pieces are disintegrated in a britt jar (Paper Research Materials, Inc., Seattle, Wash.) for 50 000 rotations.
The obtained pulp slurry is diluted to reach consistency 0.5%. Total diluted pulp volume is 20 liters. 0.5 liters OCC-pulp with high bacterial number and amylase activity is used as dilution water, the rest of the dilution water being fresh water. Starch has been added in amount of 3 g/l to the OCC pulp, and in addition to the natural bacterial flora of the process water, two known amylase positive bacteria originating from paper machines, Deinococcus geothermalis Hambi 2411 and Meiothermus silvanus Hambi 2478, has been inoculated into the water. The water has been incubated at +45° C., under shaking 120 rpm, for 3 d.
Two 1 liter portions are removed as reference samples and the rest of the slurry is treated with monochloramine as biocide so that the measurable residual total chlorine is approximately 1.5 mg/l. In addition, 100 mg/l zinc, originating from zinc chloride, is added to the pulp slurry for microbe control. Temperature of the pulp slurry is adjusted to room temperature, +23° C.
Retention test is done 2-4 hours after biocide addition. Used test chemicals are added as shown in Table 2 to a dynamic drainage jar, DDJ (Paper Research Materials, Inc., Seattle, Wash.), to control the retention degree of starch to paper and how much starch remains in the filtrate. The volume of pulp slurry in DDJ is 500 ml, stirrer speed is 1000 rpm and wire type M60.
Used test chemicals are:
MCA: Biocide, monochloramine.
Prod F: coagulant agent, aluminium sulphate, Al-content 9%, dry powder.
Prod G: coagulant agent, bentonite, alkali activated, fine milled, dry solids 88%, dispersed to 3% slurry.
Prod H: coagulant agent, polyaluminium chloride, Al-content 9.3%, basicity: 43%.
Prod E: coagulant agent, colloidal silica.
Prod D: flocculating agent, cationic polyacrylamide product, co-polymer of acrylamide and acryloyloxyethyltrimethylammonium chloride, charge density 1.0 meq/g dry polymer product, MW average 7 000 000 g/mol, dry solids 90%.
Prod J: flocculating agent, anionic polyacrylamide product, co-polymer of acrylamide and acrylic acid, charge density −2.7 meq/g dry polymer product, MW average 15 000 000 g/mol, dry solids: 90%.
Prod C: flocculating agent, anionic polyacrylamide strength resin product, aqueous solution of co-polymer of acrylamide and acrylic acid, charge density −2.9 meq/g dry polymer product, MW average 400 000 g/mol, dry solids 20%, viscosity 6000 mPas at 25° C. measured with Brookfield DVI+, equipped with small sample adapter, and spindle 31 .
Prod K: flocculating agent, cationic polyacrylamide micropolymer aqueous dispersion product, active polymer content 22%, charge density 1.1 meq/g dry active polymer product, MW average of the polymer 5 000 000 g/mol.
Chemical addition times are indicated in Table 2 as negative time before the drainage starts. The sample is taken from the first 100 ml filtrate. Filtrate is centrifuged with 3000 rpm 4-5 hours after biocide addition. From the centrifuge supernatant COD is measured by using Hach Lange method LCK 1041 according to manufacturer's instructions, as described above. Starch is measured from the filtrate by using Hach Lange method LCK 357 according to manufacturer's instructions, as described above. The results are shown in Table 2.
From Table 2 it can be observed that the addition of coagulant agent and flocculating agent, in this order, clearly improve the starch retention, i.e. the amount of starch in the filtrate is decreased. Similarly the COD value of the filtrate is decreased. This indicates that the starch would be retained to the fibres at the thickening step or at the wire section of the paper machine.
TABLE 2
Results of Example 2
time, s
−345
Proc F
−45
−35
−20
−15
−15
−10
−5
Filtrate
Test
microbe
kg/t
Prod G
Prod H
Prod E
Prod D
Prod J
Prod C
Prod K
COD
Starch
No.
control
prod.*
kg/t abs.**
kg/t, prod.*
kg/t, prod.*
kg/t prod.*
kg/t prod.*
kg/t prod.*
kg/t prod.*
mg/l
mg/l
1
MCA + Zn
334
221
2
MCA + Zn
0
0.3
309
205
3
MCA + Zn
5
0.3
287
188
4
MCA + Zn
10
0.3
284
179
5
MCA + Zn
5
0.3
295
196
6
MCA + Zn
10
0.3
285
188
7
MCA + Zn
20
0.3
282
166
8
MCA + Zn
10
3
0.3
293
195
9
MCA + Zn
10
6
0.3
288
187
10
MCA + Zn
2
10
0.3
281
188
11
MCA + Zn
2
10
0.3
1
274
174
12
MCA + Zn
5
10
3
0.3
286
182
13
MCA + Zn
10
10
3
0.3
272
173
14
MCA + Zn
10
3
0.3
3
279
162
15
none
0.3
347
218
16
none
370
237
*dosage of product, not calculated as active substance
**dosage calculated based on dry active substance
Example 3
Test pulp slurry is prepared from old corrugated cardboard (OCC) based test liner packaging paper. Test liner paper is cut into 2×2 cm pieces. Dilution water comprises 50% test liner machine tray water and 50% tap water. Conductivity of tap water is adjusted to same level than in tray water by adding NaCl. Paper pieces are soaked in dilution water, which is heated to +50° C., for 10 min in 2% consistency. Wet disintegration is made in britt jar (Paper Research Materials, Inc., Seattle, Wash.) 50 000 rotations, 20 hours before the sheet preparation.
Monochloramine (MCA) and Zn is added to the dilution water of some of the samples. Zn is dosed as zinc chloride solution, dosage being 50 ppm. The MCA dosage is also 50 ppm, high enough to have residual chloride in the pulp slurry on following day. Test pulp slurry properties are shown in Table 3.
TABLE 3
Properties of test pulp slurry.
Property
Value
Measurement Device
pH
7.8
Knick Portamess Type 911pH
Turbidity (NTU)
660
WTW Turb 555IR
Conductivity (mS/cm)
2.3
Knick Portamess Cond Type 911
Cationic demand (μekv/l)
59
PCD 03 (Mütek)
Zeta-potential (mV)
−8.4
SZP 06 (Mütek Analytic GmbH)
Consistency (g/l)
20
Test pulp slurry is further diluted with conductivity adjusted tap water to 1% concentration 1-2 hours before the sheet preparation. Conductivity of tap water is adjusted to same level than in tray water by adding NaCl.
General principle of producing hand sheets with Rapid Kö then hand sheet former is as follows:
Sheets are formed with Rapid Kö then sheet former according to standard ISO 5269/2. The pulp suspension is stirred at a constant stirring rate and a dry strength additive is added into the suspension. Stirring of test furnish is performed at 1000 rpm with propeller mixer. All sheets are dried in vacuum dryers 5 min at 1000 mbar pressure and at 92° C. temperature. After drying sheets are pre-conditioned for 24 h at 23° C. in 50% relative humidity. Sheet basis weight is 113 g/m 2 in air conditioned state. Basis weight is adjusted by cationic polyacrylamide (C-PAM) retention polymer dosage, to keep the retention constant.
Test chemical properties are described in Table 4. Following abbreviations are used: G-PAM is glyoxalated polyacrylamide; C-PAM-S is cationic polyacrylamide strength polymer; PEI is cross-linked fixative polymer with ethylene imine groups in the polymer backbone; Silica is colloidal silica in water solution, 15% solids content, particle size 5 nm, S-value 60; Ret C-PAM in cationic polyacrylamide retention polymer; A-PAM-D is anionic polyacrylamide dispersion retention polymer; A-PAM-S is anionic acrylamide strength polymer in water solution.
TABLE 4
Properties of used test chemicals.
Charge
density
at pH 7
MW average
(meq/g
Chemical
solids
viscosity
by weight
active
name
(%)
(cP)
(g/l)
polymer)
Form
G-PAM
12.4
23
600 000
1.9
water solution
C-PAM-S
9.0
18700
700 000
1.1
water solution
A-PAM-S
20
6500
500 000
−1.1
water solution
PEI
25
300
300 000
7.6
water solution
Silica
15
colloidal silica
Ret
95
6 000 000
1.3
powder
C-PAM
A-PAM-D
20
5 000 000
−4.2
salt dispersion
Test chemical sequence is disclosed in Table 5. The sequence starts always with biocide addition if not otherwise stated.
TABLE 5
Test chemical sequence.
Sample
name
Test chemical sequence
Sample A
1 Flocculating agent, no Coagulant agent, no biocide
(reference)
Sample B
1 Flocculating agent, no Coagulant agent,
Sample C
1 Coagulant agent + 2 Flocculating agents
Sample D
1 Strengthening agent + 1 Coagulant agent + 1 Flocculating
agent
Sample E
1 Strengthening agent + 1 Coagulant agent + 2 Flocculating
agents
Sample F
1 Strengthening agent + 1 Coagulant agent + 1 Flocculating
agent + 1 Strengthening agent
Sample G
1 Flocculant additive (fixative) + 1 Coagulant agent + 2
Flocculating agents
Test program and addition times are shown in Table 6.
After hand sheet formation the obtained hand sheets are tested for various properties by using methods disclosed in Table 7. Starch content in the sheets is measured by slushing 4 g dried hand sheets into 200 ml water, to give 2° A) concentration, by using an immersion blender for 1 min. Slushed pulp slurry sample is then acidified to pH<3, typically to pH 2.5-2.9, with HCl, centrifuged 15 min, at 5 000 rpm, in a centrifuge (Megafuge 2.0, Heraeus Instruments) and filtered by 0.45 μm syringe filter (ACRODISC PSF Syringe Filters GxF/PVDF 0.45 μm, Pall). To a 50 ml flask is added 15 ml of filtrated sample, which is dyed with Iodine solution having 7.5 g/l of KI and 5 g/l I 2 . Dye dose is 2.5 ml/sample, and 6.5 ml of 1% HCl is added to flask and the flask is filled to 50 ml mark with water. Absorbance is measured at 583 nm with a UV-spectrophotometer (Shimadzu UV-1800). Calibration solutions for starch concentration versus absorbance determination are prepared from Cargill C*Film TCF 70325 starch. Linear fitting line is made to correlate absorbance to starch content.
TABLE 6
Test program and addition times
Test time
−120 s
−120 s
−120 s
−20 s
−10 s
−5 s
−5 s
−20 h
G-PAM
C-PAM-S
PEI
Silica
Ret C-PAM
A-PAM-D
A-PAM-S
Chemical
Bocide
(kg/t dry)
(kg/t dry)
(kg/t dry)
(kg/t dry)
(kg/t dry)
(kg/t dry)
(kg/t dry)
Ref. Sample A
none
0.15
Ref. Sample B
MCA + Zn
0.09
Sample C
MCA + Zn
0.4
0.15
0.15
Sample D
MCA + Zn
2
0.4
0.15
Sample E
MCA + Zn
2
0.4
0.09
0.15
Sample F
MCA + Zn
2
0.4
0.15
0.15
Sample G
MCA + Zn
0.8
0.4
0.09
0.15
TABLE 7
Measured handsheet properties and standard methods used.
Measured Property
Used Standard method & Device
Grammage
ISO 536, Mettler Toledo
Ash content
ISO 1762, Precisa PrepAsh 229
Tensile strength
ISO 1924-3, Lorentzen & Wettre Tensile tester
Bursting strength
Tappi T 569, Lorentzen & Wettre Bursting
strength tester
Results for measurements of hand sheet properties are shown in Table 8. It can be seen that the starch content in the hand sheet is increasing when the addition sequence according to the invention is used in comparison to Reference Samples A and B. Increased starch content in hand sheets indicates also that the COD value in process water, which is discharged in thickening step or at sheet preparation, is decreased.
TABLE 8
Results for measurements of hand sheet properties.
Starch in
Starch in
Tensile
Ash
Bursting
paper
paper
index
content
strength
(Abs. value)
(g/t)
(Nm/g)
(%)
(kPa)
Ref. Sample A
0.021
307
28.8
13.3
165
Ref. Sample B
0.031
480
29.4
14.1
196
Sample C
0.055
897
30.0
15.7
194
Sample D
0.045
733
30.3
17.2
194
Sample E
0.050
811
31.2
17.0
213
Sample F
0.053
870
32.5
16.4
207
Sample G
0.057
932
28.8
17.0
179
Even if the invention was described with reference to what at present seems to be the most practical and preferred embodiments, it is appreciated that the invention shall not be limited to the embodiments described above, but the invention is intended to cover also different modifications and equivalent technical solutions within the scope of the enclosed claims.
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The invention relates to a method for making of paper, tissue, board or the like by using recycled fiber material as a raw material. The method comprises following steps: pulping recycled paper, board or the like in a pulper and obtaining a pulp flow comprising (i) an aqueous phase and (ii) at least recycled fibers and starch having low molecular weight, which are dispersed in the aqueous phase; adding a coagulant agent to the pulp flow or to an aqueous process flow comprising starch having low molecular weight; allowing the coagulant agent to interact with the starch having low molecular weight and optionally forming aggregates; and adding at least one flocculating agent, after the addition of the coagulant agent, to any flow, which comprises interacted coagulant agent, and forming a treated flow with starch comprising agglomerate(s); retaining at least part of the said aggregates and/or the said agglomerates to the fibers or to a web, which is formed.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to antennas for multiple-input multiple-output (MIMO) wireless communications, particularly of the microstrip antenna type used, e.g., in handsets for mobile or cellular telephones, and more particularly to a high isolation multiband MIMO antenna system.
2. Description of the Related Art
The next generation of wireless systems will be capable of providing high throughputs, broader bandwidths, and better interference mitigation, thus providing multimedia services with peak data rates of more than 150 Mbps in the downlink and 50 Mbps in the uplinks. One of the key enabling technologies in such systems is the utilization of multiple-input-multiple-output (MIMO) antenna systems.
MIMO antenna systems have a group of antennas in the transmitter and receiver terminals of the wireless system. This will allow the communication system to achieve higher data rates, and thus provide better multimedia service. One of the major design challenges in MIMO antenna system design is its miniaturization and integration issues, especially in the small form factor user terminals (or handheld devices). Also, when integrating several antennas in a small area, the coupling between them increases, their diversity performance decreases, and thus the efficiency of the wireless communication system decreases so that high data rates are no longer achievable.
The new cellular and wireless systems are leaning towards the lower frequency bands of operation because of the extended coverage area and better in-building penetration of the electromagnetic waves. The antenna design for lower operating bands is a challenge by itself, since the antenna size is expected to be larger in size than the ones used in higher frequency bands (a fundamental law in electromagnetic theory).
Thus, a multiband multiple-input and multiple-output (MIMO) antenna system with improved isolation solving the aforementioned problems is desired.
SUMMARY OF THE INVENTION
The high isolation multiband MIMO antenna system includes several antenna geometries that will operate at much lower frequency bands than traditional designs known in the art, and thus cover a wide range of wireless standards, especially for the fourth generation cellular phone system and the next generation in wireless data networks (as well as any variations of the two where multiple operating frequencies and MIMO system operation is to be supported). The high isolation multiband MIMO antenna system includes antennas that cover from 800 MHz up to 5.8 GHz, based upon the parameters used (higher frequency bands are also supported, but no commercial applications exist at this time). Each MIMO antenna system can comprise two elements, four elements, or more elements, depending upon the standard covered and the area provided within the device, and thus cover at least three different bands of operation that can be as wide as from 800 MHz to 5.8 GHz.
The high isolation multiband MIMO antenna system relates to microstrip antennas that have a single sheet of dielectric material with strips of copper-clad material forming antenna radiating/receiving elements and strips of copper-clad material forming ground planes on opposite sides of the dielectric material in patterns that are shaped and configured in relation to one another in such a manner that coupling between the different antennas is reduced to improve diversity and maximize data throughput. The antennas are dimensioned and configured so that they may be used, e.g., in the handsets of mobile or portable radios or cellular telephones, or similar handheld MIMO devices.
In addition to the various geometries of the antennas, we propose several schemes to enhance the isolation between the adjacent antenna elements within the MIMO antenna system. This is done via a variety of techniques on the first and second sides of the substrate where the reference plane (ground plane) can be situated. All the geometries and isolation enhancement methods are confined to a very small area of 100×50 mm 2 , which is a typical size of a handheld device. This can be expanded to include more than four MIMO antennas if the size of the terminal allows that, and if the standard supports multiple elements on the user terminal side.
These and other features of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of an exemplary high isolation multiband MIMO antenna system according to the present invention, the ground plane on the opposite face of the dielectric substrate being shown in phantom.
FIG. 2A is a bottom view of the antenna board or system of FIG. 1 , shown rotated 90° clockwise from the orientation of FIG. 1 .
FIG. 2B is a top view of the antenna board or system of FIG. 1 , shown rotated 90° clockwise from the orientation of FIG. 1 .
FIG. 3A shows a plan view of an alternative embodiment of a ground plane face of the dielectric substrate that can be used opposite the top face of FIG. 2A in a high isolation multiband MIMO antenna system according to the present invention.
FIG. 3C shows a plan view of another alternative embodiment of a ground plane face of the dielectric substrate that can be used opposite the top face of FIG. 2A in a high isolation multiband MIMO antenna system according to the present invention.
FIG. 3C shows a plan view of still another alternative embodiment of a ground plane face of the dielectric substrate that can be used opposite the top face of FIG. 2A in a high isolation multiband MIMO antenna system according to the present invention.
FIG. 3D shows a plan view of yet another alternative embodiment of a ground plane face of the dielectric substrate that can be used opposite the top face of FIG. 2A in a high isolation multiband MIMO antenna system according to the present invention.
FIG. 3E shows a plan view of another alternative embodiment of a ground plane face of the dielectric substrate that can be used opposite the top face of FIG. 2A in a high isolation multiband MIMO antenna system according to the present invention.
FIG. 3F shows a plan view of yet another alternative embodiment of a ground plane face of the dielectric substrate that can be used opposite the top face of FIG. 2A in a high isolation multiband MIMO antenna system according to the present invention.
FIG. 4A is a plan view showing the bottom face of an alternative embodiment of an antenna board in a high isolation multiband MIMO antenna system according to the present invention.
FIG. 4B is a plan view showing the top face of the antenna board of FIG. 4A .
FIG. 5A is a plan view showing the bottom face of another alternative embodiment of an antenna board in a high isolation multiband MIMO antenna system according to the present invention.
FIG. 5B is a plan view showing the top face of the antenna board of FIG. 4A .
FIG. 6 is a plan view showing the top face of another alternative embodiment of an antenna board in a high isolation multiband MIMO antenna system according to the present invention, the ground plane on the opposite face of the antenna board being shown in phantom.
FIG. 7 is a plot showing the directivity in dB for the antenna board of FIGS. 5A-5B .
FIG. 8 is a plot showing directivity performance for the antenna element geometry shown in FIG. 6 using the operating band of 780 MHz.
FIG. 9 is a plot showing directivity performance for the antenna element geometry shown in FIG. 6 using the operating band of 2.8 GHz.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The high isolation multiband MIMO antenna system is exemplified by several different embodiments of MIMO antennas that are variations of microstrip antennas constructed of copper-clad strips on opposite faces of a dielectric substrate, such as a printed circuit board. The antennas are dimensioned and configured to fit within the housing of a handheld MIMO device, such as a mobile or portable radio or cellular telephone. Each embodiment is configured for communication on at least two different frequency bands, with each band having multiple transmit/receive antennas for MIMO wireless communication.
FIG. 1 shows an exemplary high isolation multiband MIMO antenna system 5 having four elements. The antennas of the system are printed on the top face 100 a of a dielectric material substrate (sometimes referred to herein as an antenna board). The thickness of the substrate is preferably 0.8 mm, but other thicknesses can be used given that the thicknesses and lengths of the antenna elements are adjusted to cover the bands of frequencies needed. Two F-shaped antenna elements 23 and two serpentine-shaped antenna elements 22 , are shown, where each two of the same type are printed in a diagonal way to reduce the coupling and thus increase the isolation, i.e., the F-shaped elements 23 are position in the upper right and lower left quadrants of the board 5 , and the two serpentine elements 22 are positioned in the upper left and lower right quadrants of the board, respectively. The two different antenna geometries (serpentine 22 and F-shaped) 23 are placed beside one another, since each antenna operates in a different band, thus reducing interference on its adjacent element. The pattern of the antenna radiating/receiving elements are shown more clearly in FIG. 28 , which shows the top face 100 a of the board rotated 90° clockwise from its orientation in FIG. 1 . The antennas are fed from feeding points 40 and 80 and are impedance-matched to the feeding cable or transmission line impedance.
Each antenna radiating/receiving element has a corresponding reference plane, i.e., a ground plane in its corresponding quadrant, each ground plane having a broad, rectangular central portion 60 disposed towards the middle of the board and a narrow elongate portion 50 or strip extending medially from the broad central portion 60 to the corresponding end of the board. There is a split portion 90 free of copper-clad tracing disposed between opposing elongate portions 50 and between opposing broad rectangular portions 60 . The elongate portions 50 and broad rectangular portions 60 are a metal layer, while the split part 90 is non-metallic, meaning that there is a gap between the metal ground plane sections on the bottom face of the substrate, as shown most clearly in FIG. 2A , which shows the bottom face of the antenna board rotated 90° clockwise from the orientation of the antenna in FIG. 1 .
The length and width of the dielectric substrate are shown as 10 and 20 , respectively. For a typical smart phone device, the lengths 10 and 20 are typically given by 100×50 mm 2 . The serpentine antenna elements 22 are tuned to operate in a low frequency band, as low as 780 MHz, with a bandwidth of at least 80 MHz. The “F” shaped antenna elements 23 can operate on two higher frequency bands by adjusting the lengths of the two arms of the letter F, and the operating frequency can be in the 1 GHz, 2 GHz or higher frequency bands and wireless standards. This can cover cellular phone operation (GSM, PCS), wireless local-area-networks (WLAN), Bluetooth, WiBro, WiMax, etc.
The extended ground plane arm 50 and the split 90 are utilized to increase the isolation between the antenna elements. A typical value of isolation between two adjacent and similar elements is approximately 13 dB. If two different elements are used, as in FIG. 1 , the isolation is approximately a minimum of −15 dB.
The substrate bottom face 100 b is most clearly shown in FIG. 2A . The substrate top face 100 a is most clearly shown in FIG. 2B . The four exemplary top face antennas 22 and 23 are designed to cover at least three different operating frequencies of various wireless standards. The diagonally opposed zigzag (serpentine) antennas 22 are capable of covering the lower frequency bands around 780 MHz. The diagonally opposed F-shaped antenna elements 23 can cover two higher frequency bands. The two sets of opposing reference plane extended arms 50 enhance the isolation between adjacent elements. The split 90 in the reference plane provides an additional isolating feature. The main broad, rectangular reference plane portions 60 are also shown in FIG. 2A . Each antenna element, along with its ground plane, occupies approximately twenty-five percent of the total area of the substrate. In the embodiment shown, this gives a total area of 25×50 mm 2 .
This embodiment of a MIMO antenna 5 may have alternative ground plane geometries that can be used on the bottom face 100 b of the dielectric substrate, as shown in FIGS. 3A through 3F . As shown in FIG. 3A , ground plane configuration 305 a has a copper-clad major arm 350 in the middle of each reference plane, i.e., the two ground planes in the upper left and lower left quadrants of FIG. 2A have been merged together medially, and the two ground planes in the upper right and lower right quadrants of FIG. 2A have been merged together medially. In FIG. 3A , the upper left, lower left, upper right, and lower right corners and the center strip between the upper and lower halves of the dielectric substrate are unclad, leaving the dielectric substrate exposed to air. The geometry of this configuration 305 a gives isolation for the worst case (two identical antenna elements adjacent to or beside one another) of −8 dB between adjacent antenna elements.
As shown in FIG. 3B , configuration 305 b introduces an elongate split to define bifurcated major arms 352 , which enhances the isolation by 2 dB. As shown in FIG. 3C , in configuration 305 c , the split is lengthened to form bifurcated major arms 354 in which the furcations are separated from each other from the central ground plane patch to the end of the substrate, which adds about 2 dB to the isolation. When the split goes all the way through the central ground plane patches 60 , as shown in FIG. 2A , the worse case isolation obtained will be around −13 dB.
As shown in FIG. 3D , in configuration 305 d , the pattern of the ground planes is similar to FIG. 2A , but a gap 370 that is about 1 mm in size breaks each of the arms of the reference or ground plane. This gap 370 enhances the isolation by approximately 1 to 2 dB. FIG. 3E shows a configuration 305 e similar to FIG. 3D , but two more gaps 370 are disposed in the middle of each arm to enhance isolation by yet an additional 1 to 2 dB. Thus, a total isolation enhancement of approximately 4 dB greater than the original ground plane configuration is achieved via the additional splits 370 . The total isolation between any two adjacent elements in the worse case will be on the order of −16 to −19 dB. This is a good performance metric in MIMO antenna systems that are confined to a very small area (in the device housing) and that cover very wide frequency ranges.
The antenna configurations described herein are able to cover a much lower frequency band (780 MHz) that will be fundamental in next generation wireless systems than conventional antennas. All geometries are printed on a dielectric substrate area of 100×50 mm 2 .
As shown in FIG. 3F , the split divides the ground plane into a four quadrant pattern 305 f of identical broad rectangular and narrow elongate ground planes. A slight improvement of about −1 dB in the 780 MHz frequency band was observed, but a much larger isolation enhancement was observed at higher frequency bands. Also, the isolation curve was much cleaner from ripple and showed much lower isolation values.
In the alternative embodiment shown in FIGS. 4A and 4B , the antennas and reference planes are split between the top face 100 a of the dielectric substrate and the bottom face 100 b of the dielectric substrate. The bottom face 100 b (shown in FIG. 4A ) has a serpentine antenna element 22 in the upper right quadrant, an F-shaped antenna element 23 in the lower right quadrant, and two reference planes, one in the upper left quadrant and one in the lower right quadrant, each of the reference planes having a broad, substantially rectangular central portion 60 and an elongate portion 50 or strip extending medially from the central portion 60 to the left end of the substrate. The top face 100 a (shown in FIG. 4B ) includes an F-shaped antenna element 23 in the upper left quadrant and a serpentine antenna element 22 in the lower left quadrant of the top face 100 a.
Reference planes are oriented in the upper right and lower right quadrants of the top face 100 a . This alternation between the two faces 100 a and 100 b reduces antenna coupling, and thus enhances isolation between the antenna elements. The dimensions of this configuration are also 50×100 mm 2 .
FIGS. 5A and 5B show an alternative embodiment of an antenna in which all of the radiator/receiver elements are the same type (serpentine elements 22 are shown in the exemplary configuration), thereby resulting in a larger MIMO system. The antenna elements 22 are of the same type, and are placed on a single face 100 a of the dielectric substrate. Thus, the top face 100 a has the four antenna elements printed thereon, while the bottom face has the corresponding reference planes, including the main ground planes 60 and the ground arms 50 . This can be done for other elements and configurations, e.g., F-shaped elements 23 , depending upon the requirements of the application. The antenna system is printed on a substrate area of 50×100 mm 2 . Plot 700 of FIG. 7 shows the directivity in dB for this antenna element geometry.
FIG. 6 shows a dual band antenna having a different geometry than the above-described antenna geometries. This MEMO antenna system is printed on the top face and the ground planes (shown in phantom) on the bottom layer. The ground planes each have a broad central portion 490 and an elongate portion 520 or strip extending from the central portion medially to the corresponding end of the dielectric substrate. The radiating/receiving elements of the four antennas on the front face of the dielectric substrate each have parallel radiating arms 500 and 510 . The variation in the length of the first elongate antenna radiating arm 500 and the second elongate antenna radiating arm 510 changes the resonant frequencies of the single antenna element. The single antenna element comprising members 500 and 510 can cover the lower frequency band of 780 MHz and the highest frequency band of 5.8 GHz (or any other band in this range) in a simple and straightforward manner. Antennas 3 and 4 are mirror images of antennas 1 and 2 , each antenna comprising the two main radiating arms 500 and 510 , a shortened arm 480 or stub, and feed point 470 . The ground plane can be modified according to the aforementioned designs shown in FIGS. 3A through 3F for enhanced isolation performance. The exemplary ground plane splits 530 shown in FIG. 6 are preferable. The length and width of the dielectric substrate are given by 450 and 460 , respectively, and they are given by an area of 100×50 mm 2 . This antenna configuration's directivity performance metrics in dB is shown in plots 800 and 900 of FIGS. 8 and 9 for the operating bands of 780 MHz and 2.8 GHz.
It should be understood that the antenna configurations described herein cover any variation or combination thereof, including variations or combinations of the herein described reference plane isolation enhancement techniques. Moreover, the antennas described herein also apply to any antenna geometry that falls within the range of frequencies and is based on printed elements in a small area for wireless systems with MIMO capability.
It is to be understood that the present invention is not limited to the embodiment described above, but encompasses any and all embodiments within the scope of the following claims.
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The high isolation multiband MIMO antenna system is a multi-band dual and quad antenna for multiple-input-multiple-output (MIMO) antenna systems. Element and ground plane geometries that can cover a wide range of frequency bands (780 MHz-5850 MHz) are based on the varying some simple geometrical lengths and widths of the elements and ground planes. The MIMO antenna systems can be used for next generation cellular and wireless MIMO communication systems. Several isolation enhancement schemes increase the isolation between adjacent antenna elements. Any combination of the isolation and MIMO antenna system geometries can be created to support different wireless system standards. The novel MIMO antenna systems are disposed within a dielectric substrate area of 50×100 mm 2 .
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to centering devices, and more particularly to devices adapted to be mounted on well casings, liners, tubings, and similar conduit strings, for the purpose of centering such strings in well bores.
2. Description of the Prior Art
Centering devices having outwardly bowed springs are mounted on casing strings, or similar conduit strings, disposed in well bores for the purpose of placing and maintaining the casing strings substantially coaxially in the well bores. In some instances, the parts of said centering devices have been permanently assembled to one another at the point of manufacture, requiring the shipment in an assembled condition. In view of the large space or volume occupied by an assembled centering device or centralizer, substantial labor and material costs are entailed in boxing or crating it for shipment. Moreover, shipping costs have been comparatively high because of the large bulk or volume presented by the completed centering device, whether shipped boxed or unboxed. The large volume of the centering device also requires correspondingly large storage or warehouse space, which is costly to provide.
Conduit string centering devices have included end collars or annular members to which outwardly bowed springs have been welded. The welding operation entails the majority of time utilized in construction of the centering device. In prior art devices which have welding operations as a step in the manufacturing procedure, the completed apparatus oftentimes has resulted in a product which will enable the spring to give way during the transmission of the centering device within the well bore on the tubing or other strings because of the exteriorally affixed spring in relation to the collar element. That is, the spring has been welded to the exterior of the collar. Because the spring is outwardly flexed, and stress is exerted on the spring at the so-called "stress point", a break in the weld and/or the spring itself at the stress point will necessarily entail a break in the spring and/or a separation of the collar and spring, resulting in the spring being normally urged outwardly and away from the collar to the bore of the well, thus interrupting comparatively free travel of the centralizer mechanism in the well for setting. Additionally, breakage of the weld will prevent effective centering operation of the centering device.
Although non-welded centering devices have been offered by the prior art which have some advantages, particularly in view of the comparatively small amount of time and component parts utilized to assemble the devices, welded centering devices generally afford the most durable apparatus. However, because of the additonal manufacturing step of welding, heretofore welded centering devices have not been entirely successful.
Accordingly, it is an object of the present invention to provide an improved centering device or centralizer for well conduits that can be shipped to the point of use in a disassembled and compact condition, and then readily assembled at such point of use or at any other desired place, thereby effecting substantial savings in labor, material and time necessary for boxing, and in transportation costs, as well as in storage costs.
Another object of the invention is to provide a centering device or centralizer for well conduit strings that requires no particularly special equipment for its assembly. In fact, the parts of the present centralizer can be assembled by one or more relatively unskilled personnel utilizing a minimum of equipment and machinery.
A further object of the invention is to provide a centering device or centralizer for a well conduit embodying outwardly bowed springs adapted to be attached to associated collars or annular members by spot welding or otherwise permanently securing the parts to one another.
Yet another object of the invention is to provide a centering device for a well conduit in which the centering spring members can be assembled to the collars during a comparatively easy manufacturing procedure, and in which the springs remain properly assembled to the collars during normal handling of the device, during its installation on the well conduit, and during its running in the well bore. In addition, the construction of the well conduit centering device is such that in the event of a break in the weld of the spring to the supporting member, the spring is held in position and will not "pop out" of the supporting member. Therefore, the spring always will be in position to afford centering of the well conduit.
An additional object of the invention is to provide a centering device for a well conduit, the springs of the device being assembled readily by easy manufacturing applications in self-locking relation to the collars of the device, whereby disassembly of the device cannot be accomplished inadvertently.
It is a further object of the present invention to afford a method of assuring easy construction of the springs to the supporting members by providing support members which can be affixed to an inwardly and circumferentially extending shoulder upon each supporting member for resting of the respective ends of the spring members to assure further permanent securement of the spring to the support members.
It is a further object of the present invention to provide a well conduit centering device which provides a spring member welded or otherwise permanently secured to upper and lower supporting members, the weld or other permanent securing means of the spring to the support members being away from the stress point of the spring to provide additional strength in the spring and avoid weakness thereof by improper welding or other permanent securement.
It is a further object of the present invention to provide a well conduit centering device which will, upon failure of the weld or welds or other permanent securement, entrap the spring within the support member.
It is a further object of the present invention to provide a well conduit centering device having a flexing spring element, the flexing force of the spring not being carriable by the weld or other permanent securing means of the spring to the respective supporting members.
It is a further object of the present invention to provide a centering device for a well conduit embodying springs attached to collars, in which inward force or load on the spring tends to retain the attachment and assembled relation of the springs to the collars.
It is a further object of the present invention to provide a centering device for a well conduit embodying springs capable of ready assembly to associated collars, the assembled device being economical to produce, and being of strong and sturdy construction.
Other objects of the present invention will be apparent from a reading of the Figs., the specification below, and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a centering device mounted on a conduit string and disposed in a well bore.
FIG. 2 is a cross-sectional view of the device of FIG. 1 taken along lines 2--2 of FIG. 1.
FIG. 3 is a side elevational view of the centering device of the present invention showing both half sections of the apparatus in its fully constructed form.
FIG. 4 is a view illustrating the initial assembly of the spring and supporting elements.
FIG. 5 is a side frontal view similar to that of FIG. 4 showing assembly of the support member to two spring elements during construction.
FIG. 6 is a side elevational view similar to that shown in FIGS. 4 and 5, showing particularly the welding step of the manufacturing of the apparatus.
FIG. 7 is a partial sectional view of the apparatus of FIG. 6 taken along line 7--7 of FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As illustrated in FIG. 1, a centering device A is mounted on a conduit string B, such as a string of well casing, that is run in a well bore C, and which is to be mounted in substantially a centered condition therewithin. The casing string includes an upper casing section D and a lower casing section E suitably secured to one another by a coupling collar F.
The centering device A includes upper and lower collar member 10 and 11 slidably mounted on the casing string B and intervening outwardly bowed springs 12 secured to the collars with their mid-portions 13 adapted to bear against the wall of the well bore C to hold the casing string centered or substantially centered therewithin. The upper and lower collars 10 and 11 are disposed on opposite sides of the coupling collar F, the latter funcitioning as a stop ring, being adapted to engage a lower collar 11 and pull the centering device downwardly in the wall casing, the coupling member F also being adapted to engage the upper collar 10 in pulling the centering device upwardly in the well casing upon upward movement of the casing string B therewithin. As is known in the art, in lieu of the mounting of the centering device A on opposite sides of the coupling member F the entire device could be mounted on a single section of casing B with a coupler F suitably secured to said section between the upper and lower collars 10 and 11 of the centering device of the present invention.
The centering device A consists of two main half sections that can be placed laterally around the conduit string B and then secured to one another. Each of the half sections are shown in FIG. 3, the half sections being separated by a hinge and pin combination, described below. The parts of each half section can be assembled to one another during an easy manufacturing process utilizing primarily hand labor and simple, readily available tools, including arc welding equipment. The respective half sections then are secured to one another, to complete the centralizer, upon placing of the half sections around the conduit string and then inserting hinge pins 14 through the interleaved hinged knuckles 15 on diametrically opposite sides of each of the collars 10 and 11.
The upper and lower collars or annular members 10 and 11 are duplicates of one another and are oppositely arranged. Thus, the upper collar 10 includes two half sections or segments 16 attached to one another by the diametrically opposite hinge pins 14, the half sections being the same. As shown particularly in FIG. 5, each section includes an outer sleeve section 17 having upper and lower inwardly directed flanges 18 and 19 integrally associated therewith. Such a sleeve section may be formed readily from sheet metal. The ends of each outer sleeve section terminate in the hinge knuckles 15, the hinge knuckles at one end being in staggered relation to the hinge knuckles at the other end, such that when the two outer sleeve sections 16 are placed against one another, the hinge knuckles 15 on one sleeve section will interleave with the hinge knuckles on the other section, whereby the sections 16 are in transverse alignment with one another, being held in assembled relation upon insertion of the hinge pins 14 through the interleaved hinge knuckles.
The upper and inwardly directed flange 18 serves the office of a shoulder element circumferentially extending inwardly and around the support members 10 and 11. Upon each of the respective flanges 18, securely rests the respective ends 25 of the spring elements 12 such that, even though the spring 12 is not yet welded to the respective support member, such as 10, the spring is prevented from shifting laterally out of the element 10. The shoulder 18, in combination with the spaced opening 21, described below, provides a snug fit of the spring 12 within the support member, such as 10.
The collar section 16 has circumferentially spaced openings 21 through which the ends 25 of the springs 12 can be inserted from the exterior of each collar section to its interior. Each of the openings 21 is preferably of window-like configuration and fit the spring element 12 snugly to avoid a lateral functional movement with relation to the support members 10 or 11, as the case may be. But, each of the openings 21 is designed such that the width of the portion of the spring 12 extending therethrough is accepted by its companion support member, to facilitate assembly of the springs 12 to the collar section or segment 16, as described hereinbelow.
An upper portion 23 of each spring 12 may be substantially parallel to the axis of the collar 10, serving as a heel or fulcrum bearing against the exterior of the outer sleeve member 17 below the opening 21. This heel or fulcrum 23 merges into an inclined spring portion 24 extending inwardly through the openings 21, such intersection portion merging into a terminal portion or end 25 which, when assembled to the collar section, is adapted to be substantially parallel to the axis of the collar and abuts the shoulder 18 on the support member 10 or 11. This terminal portion 25 is preferably curved, conforming to the curvature of the collar 10 so as not to project substantially inwardly of such sleeve.
The inclined spring portion 24 also defines the approximately "stress point" or "point of stress" along the outwardly bowed spring element 12 immediate to each of the sleeves 10 and 11, that is, the maximum load point on the spring when the spring is caused to flex inwardly upon insertion in the well bore and upon contact with the bore wall of the well.
It is to be noted that when the springs 12 are assembled through the openings 21 in the collars, and with their heads or ends 25 abuting the shoulder 18, such heads 25 are prevented from moving outwardly since they will engage the sleeve section 17 of the collar. Once the selected plurality springs 12 are assembled within the support members and within the shoulder 18 on each collar section, in both the upper and lower collars 10 and 11, one half of the centralizer has been assembled, as is shown in FIG. 5. The springs 12 cannot be removed inadvertently from assembled relation to the collars 10 and 11 without intentionally doing so. At this point during the manufacturing procedure, spot welding, as shown in FIG. 6 may be initiated to spot weld each of the spring elements 12 to its support members 10 and 11 and thus form spot weld W by applying a cathodic element to one side of the surface to be welded and an anodic element to the other of said surfaces and transmitting therethrough an electric current at a predetermined voltage and rate. Alternatively, each of said springs may be assembled circumferentially and selectively around the collar elements and thereafter the welding procedure as described above and shown in FIG. 6 may be initiated. The particular mode of welding the spring elements to the support members 10 and 11 is not critical to adaptation of the present invention, it being essential only to secure the spring element 12 within the support members 10 and 11 in manner such that the shoulder 10 in conjunction with the snug fit through the portals 21 securely engage the spring element within the support members 10 and 11. Thus, it can be seen that screws, bolts or other permanent securement elements may be utilized to secure the springs to the collars in place of welding.
The lower portion of the centering device is the same as the upper portion, except the parts are oppositely directed. The springs 12 fit through the openings 21 in the half section 16 of the lower collar 11.
Two completed half sections of the centering device are then placed laterally around the conduit string B, with the upper and lower collars 10 and 11 on opposite sides of the stop ring F. Hinge pins 14 are then inserted through the interleaved hinge knuckles 15 at diametrically opposite points of each collar, to complete the assembly and to retain the half sections connected to one another. These hinge pins 14 may, if desired, make a forced fit with the hinge knuckles 15, so as to remain secured thereto and to avoid inadvertent removal therefrom.
In the use of the centering or centralizer device A as illustrated above, it is mounted on the well casing B, as described, and the latter is then run in the well bore. During downward movement, the stop ring F engages the lower collar 11, the springs 12 being pulled downwardly through the well bore C, and past any obstructions or restrictions that might be encountered therewith. As described above, the terminal or end portions 25 of the spring elements 12 cannot shift from position within the interior of the respective support members 10 and 11 and upon placement upon circumferentially and inwardly extending shoulder 18 since any inward force on the intermediate portions of the spring 12 results in a tendency for the terminal portion 25 to shift outwardly against the outer sleeve sections 17, due to the fulcruming of the heel portions 23 on the exterior of the collar. The terminal or end portions 25 cannot shift inwardly of the collar or latitudinally therein in view of the welding of the spring element 12 immediate the terminal end portion 25 to the collar element, such as 10. Additionally, the end portions 25 are prohibited from latitudinal shifting within their respective openings 21 because of the sizing of the openings 21 in relation to the spring elements 12. Although not essential in the operation of the present invention, upon mounting of the centering device on the conduit string B, the perifery of the latter makes a fairly close fit with each collar 10 and 11, as well as with the terminal or end portions 25 of the spring elements 12, the latter being prevented by the conduit string itself from moving inwardly and out of the slots 21.
Thus, from the above, it can be seen that the centering device of the present invention affords an easily constructable apparatus whose respective parts are affixed one to another by hand operation in conjunction with procedures such as spot welding and the like. In addition, when a welding procedure is applied to affix the respective springs to the respective collar elements, the weld is applied in such a fashion that the weld spot or the securing point of the spring to the collar is away from the stress point of the spring, further assuring a secure assembly. In this regard, it can be seen from the above that the present apparatus has the tensile and/or load strength of a non-welded centralizer. Furthermore, in the event of a faulty or defective weld or other failure in the weld securement of the spring to the collar, the spring element is trapped within each of the respective collars, such that the spring ends will not fly out of and away from the respective collars and render the apparatus inoperable in the well bore. Furthermore, because the weld of the spring to the collar is away from the stress point, the force created by the flexing of the spring element is not carried immediately by the weld.
Despite the fact that the springs 12 cannot be readily disassembled from the collars 10 and 11, the assembly of the springs to the collars can occur in a comparatively easy manner by use of unsophisticated tooling and comparatively inexperienced personnel.
The mode of assembly is shown in FIGS. 4 thru 6, inclusive. In FIG. 4, the lower ends of the springs have been inserted within and through a lower collar section 16. This can occur easily because the upper ends of the springs are free at this time, and the springs can be moved readily to insure the assembly of the lower terminals or ends of the springs in their companion openings. An upper collar section 16 is then slipped over the upper ends of the springs 12 such as shown in FIG. 5. To enable the flipping of the upper ends of the springs 12 within the upper collar section 16 opening 21, the latter has a slightly greater width than the width of the spring, but this width is not sufficient enough to enable comparative lateral shifting of the spring elements within the opening 21, but only enables relative longitudinal movement of the spring element 12 for affixation within the upper end of the collar section 16 upon the shoulder 18.
Moving to FIG. 6, the spring elements 12 may be separately spot welded in position with the upper end 25 affixed to the shoulder 18 of each of the respective members 10 and 11. Alternatively, each of the spring elements 12 may be circumferentially inserted within their respective openings 21 within the collar elements 10 and 11, and thereafter spot welding of the upper portion 25 may be accomplished.
As described above, the spring element 12 will remain in the assembly in position with respect to the upper and lower collar sections because of the shouldering of the terminal or end portions 25 upon the circumferentially extending and inwardly protruding shoulder 18 in combination with the flex of the spring element 12 together with the size of the opening 21, which prevents latitudinal shifting of the spring element 12 within the members 10 and 11 respectively. The one half of the centering device can be moved around or handled normally, without the fear of disassembly of the springs from the collar section, before spot welding thereof. When the full centralizer is completed, the two halfs are placed laterally toward each other over the casing B, and on opposite sides of the stop ring F and the hinge pins 14 are inserted in place, as above described.
If desired, the parts need only be assembled when the centering device is to be mounted on the conduit string B and this can take place near the well site if desired, with proper safety precautions being taken for the application of the welding technique as described above. The springs 12 are readily mounted in the upper and lower collar sections 16 by hand, and as in the manner as described above, with the two centering device sections being placed on the conduit string B at the desired location and the lock pins 14 thereafter inserted in their proper places.
It is not critical to the present invention that the spot welding technique as described above and exemplified in FIG. 6, be utilized. Alternatively, the end members 10 and 11 may be affixed to the respective spring elements 12 by other means, such as by inserting a pin, bolt, screw, or other solid means insertable through the spring and the collar. However, spot welding of the spring 12 to the upper and lower collar members 10 and 11 is simple, not time consuming, and is applicable through use of relatively unskilled labor and affords a better securement of the spring 12 to the upper and lower collar members 10 and 11. For this reason, it is the preferred method of securing the springs 12 to each of the collar members 10 and 11.
Although the invention has been described in terms of specified embodiments which are set forth in detail, it should be understood that this is by illustration only and that the invention is not necessarily limited thereto, since alternative embodiments and operating techniques will become apparent to those skilled in the art in view of the disclosure. Accordingly, modifications are contemplated which can be made without departing from the spirit of the described invention.
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A centering device is provided which is adapted to be mounted on a running-in string for subsequent disposal in a well bore. Upper and lower companion supporting members having a plurality of circumferentially spaced openings therein and shoulders circumferentially extending around the uppermost interior of each of the supporting members are provided for receipt of circumferentially spaced and outwardly bowed springs having upper and lower ends overlying the lower portion of the exterior of the supporting members and extending inwardly through the openings. The springs have portions disposed in the openings with the upper and lower ends of the springs respectively engaging the upper and lower shoulder of the support members. The spring portions include extensions received in the openings whereby each of the spring extensions longitudinally overlaps that portion of the supporting member defining the opening to interlock the spring extension with the portion of the supporting member to prevent removal of the spring from the support upon permanent securement of the spring to the supporting member. The opening receives the spring without permitting lateral shifting of the spring within the supporting member.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 61/917,511, filed Dec. 18, 2013, and U.S. Provisional Application No. 61/950,252, filed Mar. 10, 2014.
Incorporation by Reference
[0002] The entire disclosures of U.S. Provisional Application No. 61/917,511, filed Dec. 18, 2013, and U.S. Provisional Application No. 61/950,252, filed Mar. 10, 2014, are incorporated herein by reference.
FIELD OF DISCLOSURE
[0003] The present disclosure generally relates to a slot die for electrospinning polymeric fiber.
BACKGROUND
[0004] The process of electrospinning is well known in the art as represented in U.S. Pat. Nos. 2,158,416; 4,043,331; 4,044,404; 4,143,196; 4,287,139; 4,323,525; 4,432,916; 4,689,186; 6,641,773; and 8,178,030, each of which is incorporated herein by this reference. Electrostatic spinning, also referred to in the art as electro spinning or espinning, involves a charged polymer moving towards a charged or grounded surface. The fibers produced by electrospinning have submicron or “nano” diameters and their resultant fabrics have been found to be useful in the filtration, medical, and textile areas. These fibers with their dense packed yet porous structure can effectively be used for gas or fluid separation or absorption.
[0005] Electrospun polymeric fiber can be derived from a melt, solution, or dispersion. For example, the melt, solution, or dispersion can be discharged through a small charged orifice, such as a needle, towards a target wherein the needle and target have opposing electrical charges. The target (also sometimes referred to as the collector) includes a collection surface, which may be of a variety of materials and shapes, as will be understood by those skilled in the art. When an electric potential is placed on the melt, solution, or dispersion, and as the charge attempts to move to ground (i.e., the target or collector), one or more jets can be produced from which the fiber is drawn. A needle or small orifice typically produces a single jet, which can produce fiber at a rate of about 0.1 g/hr. Throughput of this type of electrospinning apparatus is usually very low. This process produces long fibers with a relatively narrow range of fiber diameters in the micron to submicron range. When fibers are allowed to accumulate on the collection surface, they produce a nonwoven fabric, also referred as a mat. Such apparatus for electrospinning from a single orifice and producing a single jet are represented by U.S. Pat. No. 8,178,030B2, and U.S. Pub. Nos. 2003/0215624A1, 2009/0032475A1, 2010/0233812A1, and 2011/0082565A1, each of which is incorporated herein by this reference.
[0006] Additional orifices can be added and banks of orifices in two-dimensional blocks or single lines may be used. Such apparatuses for producing multiple jets from multiple orifices are represented by U.S. Pat. No. 7,980,838B2; U.S. Pub. Nos. 2007/022563A1; 2008/0241297A1; and 2008/0277836A1, and European Patents EP 1,967,617A1; 1,975,284A2; and 1,992,721, each of which is incorporated herein by this reference. However, one issue of the multiple orifices producing multiple jets is the repulsion between the multiple jets due to the jets having the same or similar electric charge. The repulsion between the jets can cause bending, as well as possible suppression of the jets; thus, jet stability suffers, resulting in one or more of erratic spinning, less uniform deposition of fibers, a wider range of fiber diameters, and fiber breakage.
[0007] One or more jets can also be generated from the same orifice by increasing the electrical potential between the charged source (dispersion, solution, or melt) and the collector. The increase in electric potential increases the throughput proportionately, but at the expense of jet stability since the jets are mutually repulsive.
[0008] Another technique in the art is to electrospin from a charged free surface. A charge is placed on the dispersion, solution, or melt and free surface electrospinning occurs from a wire, a cylinder turning in a trough, or the like. At points of perturbation on the surface of the dispersion, solution, or melt, jets may form. An advantage of this approach is that multiple stable jets may be formed so that higher, more uniform throughputs may be obtained.
[0009] For free surface electrospinning, the ejection volumes are dependent upon, for example, but not limited to: 1) the viscosity of the dispersion, solution, or melt; 2) the distance from the dispersion source to the collection surface; 3) solvent properties; 4) the rate of loading or covering of the wire or cylinder of the spinning apparatus; or 5) the voltage. These factors also affect the thickness of the mat and the desired fiber diameters, so optimization of these parameters is required. The equipment for free surface electrospinning from a trough or wire process has been commercially developed for solution and dispersion electrospinning and lab, pilot, and commercial sized units are available. Lab units have also been developed for melt electrospinning Apparatuses for electrospinning from free surfaces are known in the art and are represented by: US Pat. Nos. 7,967,588B2 and 8,231,822B2; U.S. Pub. Nos. 2009/014547A1 and 2010/0272847A1; European Patents EP 1,673,493B1 and 2,059,630B1; and International Patent Publications WO 2008/028428A1 and 2009/049566A2, each of which is incorporated herein by this reference.
[0010] Further exemplary discussion of materials and methods as disclosed herein is provided in U.S. provisional patent application No. 61/917,511, filed Dec. 18, 2013 and U.S. provisional patent application No. 61/950,252, filed Mar. 10, 2014, which are both incorporated herein by reference in their entireties.
[0011] While advancements in producing multiple stable jets from free surface electrospinning have been made, there are still several shortcomings, such as uniformity of the deposited fiber and the characteristics of the fiber and the derived nonwoven fabrics. Furthermore, being able to control a variety of compositions and allowing for different polymeric preparations (e.g., that may not be electrospun on other electrospinning apparatuses) would be very desirable attributes. Thus, a need exists for processes and apparatuses that address various deficiencies or that would create additional benefits, including the deficiencies and benefits described above.
SUMMARY
[0012] The present disclosure generally relates to processes and apparatuses for high-throughput electrospinning of nonwoven materials. One aspect of the present disclosure involves a process of generating a substantially uniform electric field along and about the slit of a slot die, and “electrospinning” a polymeric solution, dispersion, suspension, and/or melt (collectively and individually referred to herein as “polymeric preparation”) from the slit through the substantially uniform field to a collector. Another aspect involves purposeful generating of a non-uniform electric field along and about the slot die slit. According to another aspect of the present disclosure, an apparatus is provided, comprising a slot die having a spinning edge with a slit. The slot die can be shaped to generate, according to some embodiments, a uniform, and according to some embodiments a purposefully non-uniform, electric field along and about the spinning edge when voltage is applied to the polymeric preparation and/or slot die. According to one embodiment, the spinning edge can be curved, defining at least one arc. The curved spinning edge can have a radius of curvature of at least 1 cm, and in one embodiment, between 5 and 100 cm inclusive. According to one embodiment, the curved spinning edge comprises a slit having a width (e.g., 90° perpendicular to the direction of the slit) between 0.01 and 10 mm, inclusive. The apparatus can further comprise one or more of a reservoir for holding the polymeric preparation, a collector installed a distance away from the slot die, a power source to apply a voltage difference between the slot die and the collector, and a delivery mechanism or pathway to supply the polymeric preparation to the slot die.
[0013] Additional features, advantages, and embodiments of the disclosure may be set forth or may be apparent from consideration of the following detailed description, drawings, and claims. Moreover, it is to be understood that both the foregoing summary of the disclosure and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the disclosure as claimed.
BRIEF DESCRIPTION OF DRAWINGS
[0014] A full and enabling disclosure, including the best mode thereof, directed to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, which makes reference to the following figures.
[0015] FIG. 1 schematically represents an electrospinning apparatus used in accordance with the present disclosure.
[0016] FIG. 2 is an isolated illustration of the fluid delivery end of a slotted die having a straight spinning edge and orthogonal corners.
[0017] FIGS. 3 a - 3 f are illustrations of a representative segment of a first embodiment of a slot die in accordance with the disclosure.
[0018] FIGS. 3 g - 3 l are illustrations of an enclosed slot die according to FIG. 3 a.
[0019] FIGS. 4 a - 4 g are illustrations of a representative segment of a second embodiment of a slot die in accordance with the disclosure.
[0020] FIGS. 4 h - 4 m are illustrations of an enclosed slot die according to FIG. 4 a.
[0021] FIGS. 5 a - 5 f are illustrations of a representative segment of a third embodiment of a slot die in accordance with the disclosure.
[0022] FIGS. 5 g - 5 l are illustrations of an enclosed slot die according to FIG. 5 a.
[0023] FIG. 6 is an illustration of electrospinning fibers emanating from the first embodiment illustrated in FIG. 3 j.
[0024] FIG. 7 is an illustration of electrospinning fibers emanating from the third embodiment illustrated in FIG. 5 j.
[0025] FIGS. 8 a - 8 d are illustrations of a representative segment of a fourth embodiment of a slot die in accordance with the disclosure.
DETAILED DESCRIPTION OF INVENTION
[0026] The present disclosure will now be described more fully hereinafter with reference to the accompanying figures, in which some, but not all embodiments of the disclosure are shown. Similar or identical features of the embodiments are provided with like reference numbers. Indeed, the disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Each example is provided by way of explanation of the disclosure, and is not intended to be limiting of the disclosure. In fact, 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. For instance, features illustrated or described as part of one embodiment can be used in the context of another embodiment to yield a further embodiment. Thus, it is intended that the present disclosure covers modifications and variations that come within the scope of the disclosed embodiments and their equivalents.
[0027] The present disclosure is directed to an apparatus 11 and process for electrospinning polymeric preparation 9 (i.e., polymeric solution, dispersion, suspension, or melt) into fibers for the formation of non-woven sheets, membranes, tubes, and coatings with the potential for multiple other applications and forms. In particular, the present disclosure is directed to high throughput electrospinning of nanofibers formed from spinning a polymeric preparation 9 from a slot die 10 so shaped and configured as to result in a substantially uniform electric field formed along the spinning edge 12 when high voltage is applied across the slot die 10 or polymeric preparation 9 and collector 15 of the electrospinning apparatus 11 .
[0028] One aspect of the disclosure provides for an even distribution of polymeric preparation 9 to the edge of a slit 16 . Jet stability can be controlled by slit edge shape, gap width, applied voltage, or a combination of these parameters. Jet stability can be controlled and adjusted accordingly to produce espun sheets with different physical and mechanical properties. When a sufficiently strong electric field is formed when voltage is applied to the slot die and the sharpness of the die sharp edge 34 is sufficiently sharp to provide suitable perturbation, Taylor cones are formed and electrospinning jets 14 of the polymeric preparation 9 erupt from the slit 16 in the slot die 10 . The jets 14 travel from the slit 16 of the slot die 10 toward a grounded or oppositely charged collector 15 to form a solid nonwoven material. In one embodiment, the disclosure focuses on slot dies in general and, in particular, the impact of the slot die's shape on the electric field uniformity to optimize electrospinning output.
[0029] An electrospinning apparatus 11 is illustrated schematically in FIG. 1 . In FIG. 1 , a reservoir 17 can be loaded with a polymeric preparation 9 . A delivery mechanism or pathway network 19 delivers the polymeric preparation 9 from the reservoir to a slot die 10 . A power source 13 , such as a DC power supply may be used to supply power to the slot die 10 if the slot die is made of conductive material and/or directly to the polymeric preparation 9 if the slot die is made of nonconductive material. The power source 13 establishes a voltage difference of 10 to 300 kV between the slot die 10 and the collector 15 and maintains a certain voltage difference between 30 and 150 kV. In one embodiment, the electrospinning apparatus 11 may comprise a positive electrode from a high voltage power supply connected to the slot die 10 , while a collector 15 can be grounded (or oppositely charged) such that an electric potential is created between the slot die 10 and the collector 15 that are a given distance apart. The charge induced by the connection of the power supply repels the charged polymeric preparation 9 away from the charge source (slot die 10 /polymeric preparation 9 ) and attracts fibers of the polymeric preparation 9 to the collection surface of the collector 15 . In another embodiment, the collector 15 can be charged while the slot die 10 is grounded or oppositely charged. In yet another embodiment, the slot die 10 and/or the collector 15 may be negatively charged. In yet another embodiment, the collector 15 can be two points or planes that are separated and either grounded or oppositely charged from the slot die 10 . In an alternate embodiment, the polymeric preparation 9 (i.e., solution, dispersion, suspension, or melt) can be charged and the collector 15 is grounded or oppositely charged.
[0030] The polymeric preparation (i.e., solution, dispersion, suspension, and/or melt) used to produce fibers can have a viscosity of between 1 and 200,000 cP. This polymeric preparation can be pumped through a pathway network 19 such as a tube, hose, vessel or the like and provided to the slot die 10 and thus the spinning edge 12 at a rate of between 0.1 and 5000 milliliters per hour per centimeter length of slit, or at a rate of 10 and 500 milliliters per hour per centimeter length of slit. In one embodiment, the polymeric preparation 9 can be supplied to the spinning edge 12 in a uniform manner across the slit length pneumatically, hydraulically, mechanically, or by gravity. In order to encourage uniform fiber spinning in accordance with at least one embodiment of this disclosure, it is important to provide a uniform distribution of polymeric preparation 9 across the die spinning edge 12 , which will be discussed in more detail below.
[0031] Materials to be electrospun into fibers according to the methods disclosed herein include dextran, alginates, chitosan, polyvinylpyridine compounds, cellulosic compounds, cellulose ether, hydrolyzed polyacrylamides, polyacrylates, polycarboxylates, polyethylene oxide, polyethylene glycol, polyethylene imine, polyvinylpyrrolidone, polyacrylic acid, poly(methacrylic acid), poly(vinyl alcohol), poly(vinyl alcohol) 12% acetyl, hydroxylpropyl cellulose, cellulose acetate, cellulose nitrate, alginic ammonium salts, pullulan, xanthan gum, polyurethanes (DSM (Bionate, Carbosil, Pursil), Lubrizol® (TG-500, SP-93A-100, tecophilic product line), AdvanSource® (C55D, C80A, and Hydrothane)), polystyrene, polymethacrylates, Teflon®, polyvinylidene fluoride, perfluoroalkoxy, fluorinated ethylene propylene, polytetrafluoroethylene, polyacrylonitrile, nylons, PEBAX®, polycarbonates, polyethylene terephthalate, polyesters, polyamides, poly(amic acid), polyimide, polylactic acid, polyglycolic acids, blends or copolymers of polylactic acid and polycglycolic acid, polyvinyl chloride, polycaprolactone, polyaniline, and blends and copolymers thereof.
[0032] The above solutions and dispersions of polymers may be combined with various additives and modifiers such as silver, calcium carbonate, hyaluronic acid and the like to produce beneficial modifications and features in the electrospun fibers.
[0033] FIG. 2 illustrates a comparative example of an electrospinning slot die 22 with a flat spinning edge 24 . The flat spinning edge 24 has no radius of curvature. The flat slot die 22 has a slit 16 at the discharge end 38 of the slot die 22 . The corners 32 ′ of the slot die 22 generally define orthogonal or right angles. When an electric potential is applied to the slot die 22 or polymeric preparation 9 , an electric field is generated and intensifies generally at the corners 32 ′. The intensified electric field at the orthogonal corners creates a repulsive force and decreases the stability of the electrospinning jets 14 nearby (leading to a possible increase in fiber breakage, a lessening of uniform fiber disposition, and a widening range of fiber diameters).
[0034] As illustrated in FIGS. 3 a - 3 j, the slot die 10 of the present disclosure departs from traditional slot dies by inter alia departing from traditional straight (flat) edge 24 and straight/orthogonal (e.g. approximately 90°) corners 32 ′. Such traditional “straight” or orthogonal features are depicted in FIG. 2 . According to the present disclosure, the slot die 10 can be defined with substantially curved, including multiple radii curve or single radius arc, edges and/or curved, including multiple radii or single radius arc, corners at or about the discharge end 38 of the die. Some example embodiments depicting alternate edge designs (see FIGS. 4 a - 5 l ) are discussed herein.
[0035] In one embodiment, the slot dies 10 ( 10 , 10 ′, 10 ″) may be comprised of a conducting material such as gold, brass, copper, silver, steel, platinum or other metal and alloys thereof. In other embodiments, the slot dies 10 ( 10 , 10 ′, 10 ″) could be totally or partially comprised of non-metal or non-conducting materials such as plastics, ceramics, etc. As illustrated in FIGS. 3 h, 4 i , and 5 h, the slit width (“w”) or distance between the edges 34 of the slit 16 should be of sufficient width to allow for Taylor cone formation and stabilization, in general, and be between 0.01 mm and 10 mm, inclusive, or between 0.05 mm and 1 mm, inclusive. In one embodiment, as illustrated in FIGS. 3 a and 4 a, the arc length (“L”) or the length of the edge 34 of the slit 16 can be between 1 cm and 10 m, inclusive, or in one embodiment, between 5 cm and 1 m, inclusive.
[0036] FIGS. 3 a - 4 m illustrate electrospinning slot dies 10 ( 10 , 10 ′) unique to the present disclosure with a spinning edge 12 having a radius of curvature “r”. The spinning edge 12 may have a sharp edge 34 as shown in FIGS. 3 d, 4 e and 5 d. An angle (θ) defined by the sharp edge 34 provides suitable perturbation for Taylor cone formation. The angle (θ) of the sharp edge 34 may range from 1 degree to 90 degrees inclusive, or 1 degree to 45 degrees, inclusive. Each of the slot dies 10 ( 10 , 10 ′, 10 ″) has a fluid pathway network 21 that includes a flow channel 26 at the fluid entry end 37 , a cavity 28 , and a spinning edge 12 with a slit 16 at the discharge end 38 of the slot die. The cavity 28 (also, the entire fluid pathway network 21 ) may have a different shape depending on the polymeric preparation 9 used. For example, the cavity 28 may comprise straight walls 36 , as shown in FIGS. 3 a, 4 a, and 5 a, for creating a uniform flow and distribution. However, walls 36 may have curved, including without limitation arcuate, portions (see FIG. 8 a ) and the angle between the walls 36 may vary depending on the polymeric material 9 used without departing from the disclosure.
[0037] In one embodiment, the cavity 28 may comprise a divergent section 29 and convergent section 30 . The divergent section 29 expands from a smaller length (l′) beginning at the end of the flow channel 26 to a larger length (l), the cord length of the slit. The convergent section 30 narrows from a larger width (W) to a smaller slit width (w). The purpose of the fluid pathway network 21 of the present disclosure can be to provide the polymeric preparation 9 to the die slit with as much uniformity as possible along the length (L) of the slit, and a variety of other (non-depicted) pathway networks may be utilized as will be understood by those skilled in the art.
[0038] According to one embodiment of the present disclosure, as depicted by FIGS. 3 a - 3 f, the slot die 10 has a spinning edge 12 that can be curved along its length (L), the spinning edge thus defining at least one arc having a radius of curvature (r). In accordance with certain aspects of the present disclosure, the radius of the spinning edge 12 and size, sharpness, and shape of the slot die 10 affects the electrical field shape and the flow of the spinning material. The radius “r” can be optimized (as discussed below) to increase the yield and uniformity of both the fibers and the nonwoven material produced over a slot die 22 of traditional “straight” features.
[0039] One goal of the design of the slot die, in accordance with at least one embodiment of the present disclosure is to create, as much as possible, a uniform electric field along the spinning edge 12 . According to some embodiments of the present disclosure (see, e.g., FIGS. 3 a - 4 m ), to foster a uniform electric field, the spinning edge has a curvature (radius) along the arc length (“L”) of the spinning edge 12 . According to one exemplary embodiment, the curved spinning edge 12 defines a single arc having a radius of curvature “r” of 1 cm to 1 meter, or a radius of curvature “r” of 5 cm to 100 cm. The radius of curvature of the spinning edge 12 induces a substantially more uniform electrical field compared to the flat slot die 22 where the electric field intensifies at the corners 32 ′, repelling the jets 14 and causing jet instability. Thus, the slot die 10 with a curved spinning edge 12 can be capable of producing a higher throughput and a higher useable mat width than can be produced by the flat slot die 22 with a flat spinning edge 24 . The useable mat width is the width of the mat that is generally parallel to the length of the spinning edge and is defined as 20% or less variation of the mat thickness or mat depth (i.e., generally perpendicular to the mat width) measured from the center of the mat. When comparing a flat or non-radius slot die 22 with orthogonal corners to a slot die 10 , 10 ′ having an arcuate spinning edge 12 and the arcuate spinning edge having a radius of curvature defined in the aforementioned range, the useable width of the resultant non-woven mat product generated by the slot die having a curved spinning edge may be increased by 10 to 1000%, or by 25 to 250%.
[0040] In one embodiment, a die with multiple slits and/or multiple single slit slot dies either in series or in parallel may be used without departing from the disclosure.
[0041] Other properties of the non-woven mat can be controlled, altered, or improved in accordance with this disclosure. These include but are not limited to: fiber diameter, porosity, fiber uniformity, total spinning width, fiber quality, fiber orientation, air flow, air permeability, cellular ingrowth, cellular attachment, surface area, tensile strength, max load, elasticity, opacity, pore size, and bubble point. Various such properties of interest in a non-woven mat are described, for example, in U.S. Pat. No. 8,262,979 and U.S. Pat. Publication Nos. 2013/0268062 A1, 2013/0053948 A1, and 2013/0197664 A1, which are incorporated herein by reference in their entireties.
[0042] FIGS. 4 a - 4 g illustrate a slot die 10 ′ that has a spinning edge 12 with a smaller radius of curvature compared to the slot die 10 of FIG. 3 a. In another embodiment, the corners 32 (see FIGS. 4 a, 5 a, and 8 a ) can be generally curved, including rounded (i.e., arcuate), having a radius of sufficient curvature to foster a substantially uniform electrical field and, in general, can be between 1 mm and 1 m, inclusive, or between 1 mm and 100 mm, inclusive. The rounded corners 32 further distribute the induced electrical field, reducing the build-up and effect of the electrical field on the electrospinning jets 14 at the corners 32 compared to slot die 22 with a flat spinning edge 24 and corners 32 ′ generally defining right angles. The rounded corners 32 may be adjacent the spinning edge and extend outwardly therefrom. In one example, the rounded corner may be proximate the spinning edge and in another embodiment the slot die may have a shoulder section 20 between the spinning edge and the rounded corners.
[0043] In some embodiments, the slot dies 10 ( 10 , 10 ′, 10 ″) may comprise shoulder sections 20 that extend between and connect the edges of the slit 16 and the curved corners 32 . The shoulder sections 20 may be curved or straight and may range in length from 1 mm to 10 m, inclusive, from 1 cm to 1 m, inclusive, or in one embodiment, from 1 cm to 30 cm, inclusive. In accordance with alternative embodiments of the disclosure, the shoulder sections 20 can be otherwise shaped, positioned, arranged, and/or omitted without departing from the disclosure.
[0044] In some embodiments of the disclosure, the curved spinning edge 12 , the shoulder sections 20 , and curved corners 32 affect Taylor cone stability. Different spinning edge 12 , shoulder section 20 and corner 32 geometries can, according to the present disclosure, effect varying degrees of non-uniformity (and uniformity) of the electric field, thus affecting the Taylor cone stability differently. When a jet 14 is formed and spinning from a slot die 22 ( FIG. 2 ) with a flat spinning edge 24 and orthogonal corners 32 ′, there can be an instability that forms due to the non-uniformity of the electric field when a high voltage (e.g., a voltage above 80 kV) is applied to the slot die or polymeric preparation 9 . The instability from the non-uniform electric field causes the Taylor cones to “walk” or move across the die slit 16 . This movement of a jet 14 can cause the termination of the jet 14 once it reaches the end of the slit length. A new jet may form to replace the recently terminated jet; however, jet termination and reformation can cause fiber defects and breakage. In accordance with one embodiment of the present disclosure, the Taylor cones or jets are stabilized from moving by making the electric field more uniform across the arc length (“L”) of the slot die slit 16 , thus increasing the jet life and reducing the amount of defects and fiber breakage (e.g., by 10-1000% depending upon the characteristics of the electrospinning polymeric preparation 9 and uniformity of the electric field). Both the curved spinning edge 12 and curved corners 32 foster a uniform (or in some embodiments varying degrees of non-uniform) electric field by preventing or reducing the electric field from intensifying at orthogonal corners. Further, stability of the Taylor cones or jets also narrows fiber size distribution and increases non-woven mat uniformity. In addition to improved jet stability, the number of jets 14 increases with the decrease of the radius of curvature of the spinning edge. Decreasing the radius of curvature of the spinning edge increases the number of jets by 1 to 200% that will form in the same slit length. The increased number of jets can improve throughput by 5-200%.
[0045] In one embodiment, the slot dies 10 ( 10 , 10 ′, 10 ″) may comprise two half portions 54 with identical features illustrated in FIGS. 3 a - 5 l . The two half portions 54 may be held together by adhesive or mechanical fastening means 58 such as screws, bolts, or similar means as illustrated in FIGS. 3 j, 4 k, and 5 j. Alternatively, one half of the slot die could comprise fluid flowing features (i.e. flow channel, cavity, etc.) and the other half of the slot die may be a die cover plate (not shown) for closing the slot die. The die cover plate may or may not comprise fluid flowing features.
[0046] FIGS. 6-7 are illustrations of the discharge of the jets 14 during the process of electrospinning, wherein an electric field is applied across the polymeric preparation 9 causing jets 14 to erupt from the slot dies 10 and 10 ″. The jet number is affected by the type of polymeric preparation 9 used, the voltage, the collector height and viscosity of the polymeric preparation 9 . FIG. 6 illustrates a slot die 10 with an arcuate spinning edge 12 and rounded corners 32 , and FIG. 7 illustrates a slot die 10 ″ with a flat spinning edge 24 and rounded corners 32 . Further, as the radius of curvature “r” of the spinning edge 12 of the slot die decreases, the fiber defects decrease and fiber uniformity increases.
[0047] Table 1 below illustrates how certain properties can be affected in accordance with at least one embodiment of the present disclosure.
[0000]
TABLE 1
Fiber and fabric properties obtainable according to
certain embodiments
Property (unit of measure)
Range
Average fiber diameter (nm)
50-20,000
Porosity (%)
20-95
Mean pore size (um)
0.1-10
Bubble point (um)
0.1-20
Fiber uniformity around average (%)
±10-50%
Total spinning width increase (%)
5-1000
Air permeability (cfm)
1-100
Surface area (m{circumflex over ( )}2/g)
0.5-2000
Tensile strength (psi)
100-10000
Max load (lbf)
0.01-20
Throughput (%)
5-200
EXAMPLE 1
[0048] Polyurethane (PU) was electrospun using a flat slot die design similar to slot die 22 as illustrated in FIG. 2 . A solution containing 7.5 wt % of TG-500 (Lubrizol) in acetic acid was pumped using a syringe, to a flat (non-radius) slot spinning die, having a slit length of 1.187″ and a slit width of 0.008″ at a rate of 90 ml/hr. The voltage applied was 95 kV and the distance between the slot die and the collector 15 was 12 inches. The nonwoven mat produced had a useable mat width of 3 inches with an average fiber diameter of 0.824 um.
EXAMPLE 2
[0049] Polyurethane (PU) was electrospun using the radius slot die 10 as illustrated in FIG. 3 j, in accordance with the present disclosure. A solution containing 7.5 wt % of TG-500 (Lubrizol) in acetic acid was pumped at a rate of 90 ml/hr using a syringe to a radius slot die having a spinning edge with a 5.5 inch radius of curvature, a slit length of 1.187″ and a slit width of 0.006″. The voltage applied was 95 kV and the distance between the slot die 10 and the collector 15 was 12 inches. The nonwoven mat produced had a useable mat width of 4 inches with an average fiber diameter of 0.865 um. This demonstrates a 1 inch or 25% increase in useable width under the same spinning conditions as compared to the flat slot die of Example 1.
EXAMPLE 3
[0050] PU was electrospun using a die design incorporating a flat edge (with a spinning edge having no radius of curvature) and rounded/curved corners as shown in FIGS. 5 j and 8 a. A solution containing 9 wt % TG-500 in acetic acid was electrospun at a height of 12″, a voltage of 97 kV, and a flow rate of 90 mL/hr from both dies. The two dies differed in the slot gap (i.e. slit) width with Sample 3.1 being produced from the die 10 ″ shown in FIG. 8 a with a 0.012″ gap width while Sample 3.2 was produced from the die shown in FIG. 5 j with a 0.007″ gap width.
[0051] There were two noticeable differences between the two sheets produced by the dies with different gap widths. The 0.012″ gap die produced an espun PU sheet with 0.4 inches more usable width. However, this was also accompanied by significantly more surface defects. These types of surface defects are usually attributed to jet instability. It appears the larger gap width is responsible for both of these differences. The larger gap would allow for larger jets and/or more jets, depending upon the voltage which was set high for this example. The increased mat width is believed to be due to the greater number of jets and the increased number of jets would also lead to greater repulsion between the jets, and thus may lead to “walking” of the jets wherein the jets move along the spinning edge. This action causes entanglement between the jets as well as broken fibers that can both lead to surface defects. Controlling the spinning parameters in conjunction with the gap width can allow for various sheet widths and densities to be produced.
[0052] While in certain aspects of the current disclosure, the goal is to maximize the stability and control of the Taylor cones or jets in order to achieve more uniform fibers and electrospun fabric, certain embodiments of the present disclosure are for the control and utilization of induced instability for the purposes of creating fibers with lower aspect ratios or lengths, more broken fibers and surface defects on the electrospun fabric, as understood from the previous description, by manipulating various aspects of the slot die (e.g., the slit width, the curvature of the spinning edge and/or the corners) in accordance with principles described above. The ability to control the stability of the electric field and subsequently the stability of the Taylor cones or jets formed at the face of the slot die is key in controlling the uniformity of the fibers and resulting electrospun fabric. While most potential applications benefit from increased uniformity, there are certain applications where induced defects and differences in uniformity are important.
[0053] The foregoing description generally illustrates and describes various embodiments of the present disclosure. Regarding the values provided in the above discussions, those values may be approximate, such as in other embodiments that are like the above-disused embodiments. It will, however, be understood by those skilled in the art that various changes and modifications can be made to the above-discussed construction of the present disclosure without departing from the spirit and scope of the disclosure as disclosed herein, and that it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as being illustrative, and not to be taken in a limiting sense. Furthermore, the scope of the present disclosure shall be construed to cover various modifications, combinations, additions, alterations, etc., above and to the above-described embodiments, which shall be considered to be within the scope of the present disclosure. Accordingly, various features and characteristics of the present disclosure as discussed herein may be selectively interchanged and applied to other illustrated and non-illustrated embodiments of the disclosure, and numerous variations, modifications, and additions further can be made thereto without departing from the spirit and scope of the present disclosure as set forth in the appended claims.
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An improved process for forming a polymer mat is described. The process of electrospinning polymer fibers includes providing an apparatus having a charge source, a target a distance from the charged source and a slot die having a spinning edge with a slit. The spinning edge has a radius of curvature between 5 cm and 100 cm. The method further includes providing a polymeric preparation (solution, dispersion, suspension, or melt) to the slot die and applying an electric field to a part or the whole apparatus or polymeric preparation. When the electric field is applied, a plurality of Taylor cones are produced with jets that stretch the polymeric preparation into a fibrous structure that can be collected on a target surface.
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FIELD OF THE INVENTION
[0001] The present invention relates to a flame retardant composition for flammable plastics. It also relates to a flame retarded plastic composition containing said flame retardant composition.
BACKGROUND OF THE INVENTION
[0002] A variety of plastics or synthetic resins are used as parts or components of many electric and electronic devices and apparatus by virtue of their high insulating performance, high water resistance, high moldability, adequate mechanical strength, etc. They also find use in packaging materials and construction materials. However, the most of plastics are flammable and hence flame retarded for use in many applications for safety reasons. The level of flame retardancy required for plastic articles has been standardized in many applications and is becoming more stringent in recent years.
[0003] Conventionally plastics are rendered flame retardant by incorporating a brominated flame retardant and antimony trioxide into plastics. However, concern has arisen about carcinogenic dioxines and other compounds which are produced when combusting waste plastic articles containing the brominated flame retardant. Attempts have been made to replace the brominated flame retardant with halogen-free flame retardants such as phosphate esters or ammonium polyphosphate. However, the use of these halogen-free flame retardants in an amount sufficient to achieve a desired flame retardancy level necessarily compromises other requisite properties such as moldability and strength properties because the halogen-free flame retardants are far less effective than the brominate flame retardants. Consequently, a need exists for a flame retardant composition which enables the amount of brominated flame retardants needed for achieving a desired level of flame retardancy in plastic articles to be significantly reduced compared to the brominated flame retardant alone. Such a composition would be advantageous not only for environmental reasons but it enables molding scraps of flame retarded plastics to be recycled because of low contents of brominate flame retardants.
[0004] It has been known that thermoplastic polymers may be rendered flame retardant by incorporating a free-radical generator such as 2,3-dimethyl-2,3-diphenylbutane or dicumylperoxide. The free-radical generator selectively breaks the main chain of polymers and increases the flowability of molten-polymers to help the self-extinguishability thereof. Following this principle, it has been known to incorporate the free-radical generator into flammable plastics in conjunction with a brominated flame retardant and/or a phosphate ester flame retardant so as to enhance the flame retardancy or to reduce the amount of the brominated flame retardant needed. See, JP-A-11/199784, JP-A-2001/181433, JP-A-2002/322323; JP-A-2003/160705, JP-A-2003/321584 and WO 00/12593. However, these prior art methods are not versatile in respect to usable polymers and/or brominated flame retardants and a relatively large amount of the radical generator is required to achieve a desired level of flame retardancy.
[0005] Accordingly, a need remains existed for a flame retardant composition and a flame retarded plastic composition which can save the brominated flame retardants while retaining a flame retardancy level sufficient to meet various flame retardancy tests.
SUMMARY OF THE INVENTION
[0006] The above need may be met, in accordance with the present invention, by providing a flame retardant composition for flammable plastics comprising
[0000] (a) a brominated flame retardant having a bromine con-tent greater than 50 wt %;
[0000] (b) a free-radical generator selected from the group consisting of 2,3-dimethyl-2,3-diphenylbutone and its homologs; and
[0000] (c) a phthalocyanine complex or a naphthalocyanine complex with a metal selected from groups 7 to 10 of the IUPAC periodic chart; wherein
[0000]
the weight ratio (b):(c) is from 99:1 to 1:99 and the sum of (b)+(c) is from 0.01 to 50 parts by weight per 100 parts by weight of (a).
[0008] In a preferred embodiment, said free-radical initiator is 2,3-dimethyl-2,3-diphenylbutane (DMDPB), 3,4-dimethyl-3,4-diphenylhexane, 4,5-dimethyl-4,5-diphenyloctane, 3,4-diethyl-3,4-diphenylhexane, 4,5-diethyl-4,5-diphenyloctane, 2,3-dimethyl-2,3-di-p-tolylbutane or 3,4-dimethyl-3,4-di-p-tolylhexane; while said metal is Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd or Pt.
[0009] In another preferred embodiment, the flame retardant composition comprises
[0000] (a) a brominated flame retardant having a bromine content-greater than 50 wt. %;
[0000] (b) 2,3-dimethyl-2,3-diphenylbutane; and
[0000] (c) iron phthalocyanine; wherein the weight ratio (b):(c) is from 95:5 to 5:95, and wherein the sum of (b)+(c) is from 0.05 to 15 parts by weight per 100 parts by weight of (a).
[0010] In another aspect, the present invention provides a flame retarded plastic composition comprising a flammable plastic material and the flame retardant composition of the present invention in an amount corresponding to 0.5 to 25 parts by weight of said brominated flame retardant per 100 parts by weight of said flammable plastic material.
[0011] According to the present invention, the amount of brominated flame retardants needed to achieve a desired flame retardancy level may be significantly saved compared to that of the brominated flame retardant alone. By virtue of reduced quantity of the brominated flame retardant, many beneficial properties of plastic materials such as molding and mechanical properties may be less compromised and the environmental concern may be ameliorated. In addition, scraps produced in association with processing may be recycled.
DETAILED DESCRIPTION
[0012] The present invention utilizes a synergism of both of the free-radical generator and the phtolocyanine or naphthalocyanic complex to save the brominated flame retardant.
[0013] The term “2,3-dimethyl-2,3-diphenylbutane or its homologs, as used herein refers to 1,2-diphenyl-1,1,2,2-tetraalkylethane and derivatives thereof having one or more alkyl substituents on one or more benzene rings in which each alkyl contains 1 to 6 carbon atoms. These compounds, otherwise called free-radical initiator, are known to generate a free radical upon heating to a temperature above the process temperature of most of plastic materials. Therefore, they remain intact during the processing such as extrusion injection molding, compression molding, hot press lamination or the like.
[0014] Copper phthalocyanine complexe such as phthalocyanine blue and phthalocyanine green are known as a thermally stable pigment and used in the production of colored plastic articles. U.S. Pat. No. 3,825,520 teaches that Fe, Cu, Mn, V and Co phthalocyanines may reduce smoke when incorporating into a styrene polymer in conjunction with octabromobiphenyl fire-retardant.
[0015] To the best of our knowledge, however, it is not known that a metal phthalocyanine or naphthalocyanine is effective to save a brominated flame retardant when incorporating in conjuntion with a free-radical generator into flammable plastic materials.
[0000] (a) Brominated Flame Retardants Having a Bromine Content Greater than 50 wt. %
[0016] Brominated flame retardants are well known in the art. Non-limitative examples are as follows.
[0017] Brominated alycyclic hydrocarbons: hexabromocyclododecane (HBCD), tetrabromocyclooctane (TBCO), monochloropentabromocyclohexane, etc.,
[0018] Brominated aromatic hydrocarbons: pentabromotoluene, hexabromobenzene, decabromodiphenylethane, brominated polystyrene, octabromotrimethylindane, etc.,
[0019] Brominated phenyl ethers: decabromodiphenyl ether, octabromodiphenyl ether, hexabromodiphenyl ether, bis(tribromophenoxy)ethane, bis(pentabromophenoxy)ethane, poly(2,6-dibromophenyleneoxide), etc.,
[0020] Brominated bisphenols and derivatives thereof: tetrabromobisphenol A, tetrabromobisphenol S, tetrabromobisphenol F, tetrabromobisphenol A bis(2,3-dibromopropyl)ether, tertrabromobisphenol S bis(2,3-dibromopropyl)ether, tetrabromobisphenol F bis(2, 3-dibromopropyl)ether, tetrabromobisphenol A bis(2,3-dibromoisobutyl)ether, tetrabromobisphenol S bis(2,3-dibromoisobutyl)ether, tetrabromobisphenol F bis(2,3-dibromoisobutyl)ether, tetrabromobisphenol A diallyl ether, tetrabromobisphenol S diallyl ether, tetrabromobisphenol F diallyl ether, tetrabromobisphenol A dimethallyl ether, tetrabromobisphenol S dimethallyl ether, tetrabromobisphenol F dimethallyl ether, etc.,
[0021] Brominated isocyanurates: tri(2,3-dibromopropyl)isocyanurate, tri(2,3-dibromosiobutyl)isocyanurate, etc.,
[0022] Other brominated flame retardants: tetrabromophthalic anhydride, brominated. polycarbonate, brominated epoxy resins, poly(pentabromobenzyl acrylate), ethylenebis(tetrabromophthalimide), 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine, tris(tribromoneopentyl)phosphate, etc.,
[0000] (b) Free-Radical Generators
[0023] As described above, the free-radical generator used in the present invention is 2,3-dimethyl-2,3-diphenylbutane or a homolog thereof. Examples of homologs include 3,4-dimethyl-3,4-diphenylhexane, 4,5-dimethyl-4,5-diphenyloctane, 2,3-dimethyl-2,3-di-p-tolylbutane and 3,4-dimethyl-3,4-di-p-tolylhexane. 2,3-Dimethyl-2,3-diphenylbutane(dicumene) is preferable.
[0000] (c) Phthalocyanine Complex and Naphthalocyanine Complex
[0024] The metal phthalocyanine complex and the naphthalocyanine complex used in the present invention possesses the same or analogous ligand structure as the copper phthalocyanine pigment. However, their central atom is chosen from a metal element of groups 7 to 10 of the IUPAC periodic chart in place of copper. Typically the central atom is Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni or Pt. Co or Fe is particularly preferable. The central atom may also be coordinated with a halogen ion, typically chloride ion. The phthalocyanine or naphthalocyanine ligand may have a substituent such as Cl, Br, alkyl, alkoxy, carboxyl or amino on the benzene ring. Phthalocyanine complexes and naphthalocyanine complexes having a central metal other than the above-mentioned metal species such as Cu, Ti, Zn, V or Cr have no or little effect to save the brominated flame retardant when use alone or in conjuction with the free-radical generator.
[0025] The ratio of (b):(c) in the flame retardant composition is 99:1 to 1:99, preferably 90:10 to 10:90, most preferably 75:25 to 25:75 by weight. The proportion of the sum of (b) +(c) is 0.01 to 50, preferably 0.1 to 30 and most preferably 0.2 to 20 parts by weight per 100 parts by weight of (a).
[0026] The flame retardant composition of the present invention is incorporated into flammable plastic materials. The quantity of the composition to be incorporated may vary depending on the desired flame retardancy, the nature of particular components (a), (b) and (c) and the presence of auxiliary flame retardants such as antimony trioxide and/or halogen-free flame retardants such as phosphate esters. This quantity ranges generally from 0.5 to 25, preferably from 1.0 to 15 by weight in terms of (a) per 100 parts of weight of the flammable plastic material. As stated above, this quantity should not be excessive as far as the desired flame retardancy may be achieved.
[0027] The flammable plastic materials to be rendered flame retardant are mostly thermoplastics. Non-limitative examples thereof include polystyrene, high impact polystyrene (HI-PS), styrene-butadiene copolymer, styrene-acrylonitrile copolymers, acrylonitrile-butadiene-styrene copolymer (ABS), polyethylene tetraphthalate (PET), polybutylene terephthalate, liquid crystalline polyester, polycarbonate, polyamide, polyphenyleneoxide, modified polyphenyleneoxide, polyphenylenesulfide, polyacetal, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-propylene-non-conjugated diene copolymer, ethylene-ethyl acrylate copolymer, ethylene-glycidyl methacrylate copolymer, ethylene-vinyl acetate-glycidylmethacryalte copolymer, maleic anhydride-modified ethylene-propylene copolymer, polyester-polyether elastomer, polyester-polyester elastomer, polyamide-polyether-elastomer, polyamide-polyester elastomer, and polymer blends and polymer alloys thereof. Polystyrene, HI-PS, polypropylene, ABS, polycarbonate and polyamide are typical examples of plastics used for fabricating plastic articles in large quantities. The flame retardant composition of the present invention finds use in thermosetting plastics or resins. For example, the compostion may be incorporated into laminates of phenol, epoxy or unsaturated polyester resin having paper or glass fiber substrates.
[0028] A portion of the brominated flame retadant (a) in the flame retardant composition may be replaced by a halogen-free phosphorus-based flame retardant to further save the brominate flame retardant (a) as far as the desired flame retardancy is achieved. Non-limitative examples of the phosphorus-based flame retardants include triphenyl phosphate, tricreyl phosphate, trixylenyl phosphate, diphenylcresyl phosphate, trixylenyl phosphate, resorcinol-bis(diphenyl)phosphate, bisphenol A-bis(diphenyl)phosphate, resorcinol-bis(dicresyl) phosphate, bisphenol A-bis(dicresyl)phosphate, resorcinol-bis(di-2,6-xylenyl)phosphate, bisphenol A-bis(2,6-xylenyl)phosphate, phenoxyphosphazene, methylphenoxyphosphazene, xylenoxyphosphazene, methoxyphosphazene, ethoxyphosphazene, proxyphosphazene, melamine polyphosphate, and ammonium polyphosphate. The phosphorus-based flame retardant may generally replace for the brominated flame retardant up to about 50%.
[0029] The flame retarded plastic composition may optionally comprise other conventional additives. One such optional additive is an auxiliary antioxidant such as antimony trioxide, antimony pentaoxide, tin oxide, zinc stannate, zinc stannate hydroxide, molybdenum oxide, ammonium molybdate, zirconium oxide, zirconium hydroxide, zinc borate, zinc metaborate or barium metaborate. Antimony trioxide is most preferable. The quantity of the auxiliary flame retardant, if incorporate, may range from 0.1 to 10 parts by weight per 100 parts by weight of the flammable plastic material. Examples of other conventional additives include heat stabilizers, antioxidants, UV absorbers, UV stabilizers, impact strength enhancers, pigments, fillers, lubricants, dripp retardants, crystalline nuclei agents, mold release agents, antioxidants and compatibilizers. These conventional additives are well known in the plastic processing art and details thereof may be found in many handbooks relating to the plastic processing technology.
[0030] When foamed plastic articles are intended, a blowing agent is incorporated in the flame retarded plastic composition optionally in conjuction with a foam nuclei agent or foam conditioning agent. Examples of the blowing agent include volatile organic blowing agents such as propane, butane, pentane, hexane, 1-chloro-1,1-difluoroethane, monochlorodifluoromethane, monochloro-1,2,2,2-tetrafluoroethane, 1,1-difluoroethane, 1,1,1,2-tetrafluoroethane or 1,1,3,3,3-pentafluoropropane; inorganic blowing agents such as water, nitrogen or carbon dioxide; and chemical blowing agents such as azo compounds. Typical examples of foam nuclei agents or foam conditioning agents are talc and bentonite. The quantity of the blowing agent may vary depending on the desired properties of foams and generally ranges between 0.005 to 0.7 mole/100 g of the plastic material.
[0031] The flame retarded plastic composition of the present invention may be prepared by the known method. In case of thermoplastic polymers, the flame retardant composition and optional additives are melt-blended using known apparatus such as biaxial extruders, Barnbury mixer, laboplastomills or hot roll mills and then molded into a desired shape by extruding, injection molding or compression molding. The flame retardant composition and the optional additives may be blended together or separately. In case of foams, the blowing agent may be directly injected into the molten plastic composition in the extruder. Alternatively, plastic beads containing the flame retardant and optional additives may be impregnated with a liquid blowing agent such as pentane followed by heating the beads in a mold with steam.
[0032] In case of thermosetting plastics such as phenol resin, the flame retardant and optional additives may be incorporated into oligo-condensates or varnish in conjunction with a curing catalyst, if needed, and the mixture may be cast or lamination molded.
EXAMPLES
[0033] The following are examples of the present invention and are not to be construed as limiting. Unless otherwise indicated, all percentages and parts are by weight.
[0034] The materials used in Examples and Comparative Example are as follows.
[0000] A. Plastic Material
[0035] A-1: High impact polystyrene available from Toyo Styrene Co., Ltd. under the name of TOYO STYROL H450
[0036] A-2: High impact polystyrene available from Toyo Styrene Co., Ltd. under the name of TOYO STYROL H650
[0037] A-3: Polypropylene available from Sumitomo Chemical Co., Ltd. under the name of SUMITOMO NOBLEN Y101S.
[0038] A-4: A 70:30 blend of polycarbonate available from Idemitsu Petrochemical Co., Ltd. under the name of TARFLON A 2000 and ABS available Toray Industries, Inc. under the name of TOYOLAC
[0039] A-5: Polyamide available from Asahi Kasei Corporation under the name of REONA 1300S
[0040] A-6: High density polyethylene available from Idemitsu Petrochemical Co., Ltd. under the name of IDEMITSU HD130J
[0041] A-7: Polystyrene available from Toyo Styrene Co., Ltd. under the name of TOYO STYROL G220
[0042] A-8: Phenol resin varnish
[0000] B. Brominated Flame Retardant
[0043] B-1: Tetrabromobisphenol A-bis(2,3-dibromopropyl)ether
[0044] B-2: Tetrabromobisphenol A-bis(2,3-dibromoisobutyl)ether
[0045] B-3: Tris(2,3-dibromopropyl)isocyanurate
[0046] B-4: Tris(tribromoneopentyl)phosphate
[0047] B-5: 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine
[0048] B-6: Decabromodiphenylethane
[0049] B-7: Decabromodiphenyl ether
[0050] B-8: Poly(2,6-dibromophenylene oxide)
[0051] B-9: Hexabromocyclododecane (HBCD)
[0052] B-10: Tetrabromobisphenol A epoxy oligomer
[0000] C. Radical Generator
[0053] 2,3-dimethyl-2,3-diphenylebuthane
[0000] D. Phthalocyanine/Naphthalocyanine Complex
[0054] D-1: Iron phathalocyanine
[0055] D-2: Iron phathalocyanine chloride
[0056] D-3: Cobalt phalocyanine
[0057] D-4: Iron naphthalocyanine
[0058] D-5: Copper phthalocyanine(for comparison)
[0059] D-6: Titanium phthalocyanine (for comparison)
[0000] E. Heat Stabilizer/Antioxidant
[0060] E-1: Dioctyltin maleate polymer
[0061] E-2: Pentaerythritol tetrabis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate
[0062] E-3: Bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphite
[0000] F. Auxiliary Flame Retardant
[0063] Antimony trioxide
[0000] G. Blowing Agent
[0064] Pentane
[0000] H. Foam Nuclei Agent (Foam Conditioning Agent)
[0065] Talc available from Nippon Talc Kogyo Co., Ltd.
[0000] I. Phosphorus Flame Retardant
[0066] Triphenyl phosphate
Examples 1-20 and Comparative Examples 1-19
[0000] 1. Preparation of Test Specimen
[0067] According to the formulations shown in Tables 1-5, various materials were blended and extruded using a biaxial extruder to prepare pellets. The pellets were then injection molded into test specimens of predetermined size. The temperature of heat cylinders of the extruder and the injection molding machine was set at the following temperatures.
Heat cylinder temperature, ° C. Injection molding Extruder machine Plastic material Inlet Outlet Inlet Outlet Mold A-1, A-3, A-6 80 200 180 200 40 A-4 80 260 240 260 80 A-5 80 300 280 300 80
2. Flame Retardancy Test
[0068] The vertical combustion method according to UL-94 standard was followed in Examples 1-16 and Comparative Examples 1-15. The size of test specimen was 125 mm in length, 12.5 mm in width and 3.2 mm in thickness. NR indicates not rating.
[0069] In Examples 17-20 and Comparative Examples 16-18, oxygen index (LOI) was determined according to JIS K 7201 standard test.
[0000] 3. Flexural Strength
[0070] According to ASTM-D790, flexural stress was determined.
[0000] 4. Evaluation After Recycling
[0071] The pellets for making test specimens were aged in an oven kept at a constant temperature of 80° C. and at a constant himidity of 95% RH for one week. The aged pellets were extruded again into pellets and injection molded into the test specimens under the same conditions as above.
[0072] Darkening of the recycled specimen was evaluated in terms of color difference Δ E of the corresponding specimen used in the initial test. The above described flame retardancy test and the flexural strenght test were repeated for the recycled specimen. The flexural strength was represented as % retension relative to the corresponding test specimen used in the initial test.
[0073] The recycling test was not conducted for specimens of Comparative Examples.
[0074] The results are shown in Tables 1-6 below.
TABLE 1 EXAMPLE Formulation(parts) & Test results 1 2 3 4 5 6 Plastics A-1 100 100 100 — — — A-2 — — — 100 100 100 Brominated flame retardant B-1 B-3 B-4 B-5 B-6 B-7 2.6 2.8 2.8 12.0 9.0 10.0 Radical generator C 0.04 0.06 0.095 0.06 0.06 0.06 Phthalocyanine/naphthalocyanine D-1 D-2 D-1 D-1 D-3 D-4 complex 0.04 0.02 0.005 0.06 0.06 0.06 Heat stabilizer E-1 0.05 0.05 0.05 0.05 0.05 0.05 Antioxidant E-2 0.1 0.1 0.1 0.1 0.1 0.1 Antimony trioxide — — — 1.0. 1.0 1.0 Flame retardancy, UL-94 V-2 V-2 V-2 V-0 V-0 V-0 Flexural strength, Mpa 42 43 43 38 38 35 After recycling Color Difference, ΔE 0.4 0.5 0.8 0.9 0.8 1.1 Flame retardancy, UL-94 V-2 V-2 V-2 V-0 V-0 V-0 % retent of flexural strength 98 98 95 99 96 96
[0075]
TABLE 2
COMPARATIVE EXAMPLES
Formulation (parts) & Test results
1
2
3
4
5
6
Plastics
A-1
100
100
100
—
—
—
A-2
—
—
—
100
100
100
Brominate flame retardant
B-1
B-3
B-4
B-5
B-6
B-7
2.6
2.8
2.8
12.0
9.0
10.0
Radical generator C
—
0.08
0.04
—
0.12
0.06
Phthalocyanine/naphthalocyanine
D-1
—
D-5
D-1
—
D-6
complex
0.08
—
0.04
0.12
—
0.06
Heat stabilizer E-1
0.05
0.05
0.05
0.05
0.05
0.05
Antioxidant E-2
0.1
0.1
0.1
0.1
0.1
0.1
Antimony trioxide
—
—
—
1.0
1.0
1.0
Flame retardancy, UL-94
NR
NR
NR
V-2
V-2
V-2
Flexural strength, MPa
42
35
42
38
38
36
After recycling
Color difference, ΔE
—
—
—
—
—
—
Flame retardancy, UL-94
—
—
—
—
—
—
% retent of flexural strength
—
—
—
—
—
—
[0076]
TABLE 3
COMPARATIVE
EXAMPLE
EXAMPLE
Formulation (parts) & Test results
7
8
9
7
8
9
Plastics
A-3
100
100
100
100
100
100
Brominated flame retardant
B-1
B-3
B-4
B-1
B-3
B-4
2.6
2.0
2.2
2.6
2.0
2.2
Radical generator C
0.04
0.04
0.04
0.06
—
—
Phthalocyanine/naphthalocyanine
D-1
D-3
D-4
—
D-3
—
complex
0.02
0.12
0.12
—
0.12
—
Heat stabilizer E-3
0.05
0.05
0.05
0.05
0.05
0.05
Antioxidant E-2
0.1
0.1
0.1
0.1
0.1
0.1
Antimony trioxide
—
—
—
—
—
—
Flame retardancy, UL-94
V-2
V-2
V-2
NR
NR
NR
Flexural strength, Mpa
47
47
46
42
46
47
After recycling
Color difference, ΔE
0.5
0.6
1.0
—
—
—
Flame retardancy, UL-94
V-2
V-2
V-2
—
—
—
% retent of flexural strength
98
98
95
—
—
—
[0077]
TABLE 4
EXAMPLE
COMP. EXAMPLE
Formulation(parts) & Test results
10
11
12
13
10
11
12
Plastics
A-4
100
100
100
100
100
100
100
Brominated flame retardant
B-5
B-6
B-7
B-5
B-5
B-6
B-7
6.0
5.5
5.0
7.0
6.0
5.5
5.0
Radical generator C
0.475
0.040
0.3
0.03
—
0.025
0.5
Phthalocyanine/naphthalocyanine
D-1
D-2
D-3
D-4
D-1
D-5
—
complex
0.025
0.475
0.3
0.03
0.5
0.475
—
Heat stabilizer E-1
0.05
0.05
0.05
0.05
0.05
0.05
0.05
Antioxidant E-2
0.1
0.1
0.1
0.1
0.1
0.1
0.1
Antimony trioxide
0.5
0.5
0.5
1.0
0.5
0.5
0.5
Flame retardancy, UL-94
V-0
V-0
V-0
V-0
V-2
NR
V-2
Flexural strength, Mpa
78
70
73
74
78
72
74
After recycling
Color difference, ΔE
0.8
0.9
0.6
1.0
—
—
—
Flame retardancy, UL-94
V-0
V-0
V-0
V-0
—
—
—
% retent of flexural strength
98
98
95
87
—
—
—
[0078]
TABLE 5
EXAMPLE
COMP. EXAMPLE
Formulation(parts) & Test results
14
15
16
13
14
15
Plastics
A-5
100
100
100
100
100
100
Brominated flame retardant
B-7
B-8
B-8
B-7
B-7
B-8
12.0
12.0
6.0
12.0
12.0
12.0
Radical generator C
0.2
0.4
0.9
—
0.5
0.4
Phthalocyanine/naphthalocyanine
D-1
D-2
D-4
D-1
—
D-6
complex
0.1
0.4
0.9
0.5
—
0.4
Heat stabilizer E-1
0.05
0.05
0.05
0.05
0.05
0.05
Antioxidant E-2
0.1
0.1
0.1
0.1
0.1
0.1
Antimony trioxide
1.5
2.5
0.5
1.5
1.5
2.5
Flame retardancy, UL-94
V-0
V-0
V-1
V-2
V-2
V-2
Flexural strength, Mpa
99
105
108
100
84
106
After recycling
Color difference, ΔE
1.1
1.2
1.0
—
—
—
Flame retardancy, UL-94
V-0
V-0
V-1
—
—
—
% retent of flaxural strength
90
92
95
—
—
—
[0079]
TABLE 6
EXAMPLE
COMP. EXAMPLE
Formulation(parts) & Test results
17
18
19
20
16
17
18
Plastics
A-6
100
100
100
100
100
100
100
Brominated flame retardant
B-5
B-5
B-7
B-8
B-5
B-7
B-8
10.0
8.0
8.0
8.0
10.0
8.0
8.0
Radical generator C
0.04
0.04
0.04
0.04
—
0.04
0.04
Phthalocyanine/naphthalocyanine
D-1
D-2
D-3
D-1
D-4
—
D-5
complex
0.02
0.12
0.12
0.06
0.06
—
0.06
Heat stabilizer E-1
0.05
0.05
0.05
0.05
0.05
0.05
0.05
Antioxidant E-2
0.1
0.1
0.1
0.1
0.1
0.1
0.1
Antimony trioxide
3.0
2.0
2.0
2.0
3.0
2.0
2.0
Flame retardancy, L0I
27.5
26.4
27.0
27.2
23.8
23.5
23.8
Flexural strength, Mpa
20
21
18
20
After recycling
Color difference, ΔE
2.3
2.0
1.8
1.6
—
—
—
Flame retardancy, L0I
27.4
26.4
26.8
27.1
—
—
—
% retent of flaxural strength
90
92
90
94
—
—
—
[0080] As shown in Tables 1-6, the flame retardancy of the formulations of Examples 1-20 is enhanced compared to that of the formulations of Comparative Examples 1-19 by incorporating the brominated flame retardant into the plastic material in conjuction with the radical generator and the phthalocyanine/naphthalocyanine complex with a metal of groups 7-10 of the periodic chart.
Examples 21-26 and Comparative Examples 20-23
[0000] 1. Preparation of Foamed Plastic Specimen
[0081] According to the formulation shown in Tables 7-8, various materials excluding the blowing agent were fed to a two stage tandem extruder. The materials are heat blended in the first stage extruder having an inner diameter of 65 mm and then extruded to the second stage extruder having an inner diameter of 90 mm. A predetermined amount of the blowing agent was injected under pressure into the extrudate through a separate line at the forward end of the first stage extruder. The extrudate from the first stage extruder was cooled to 120° C. in the second stage extruder and extruded through a die into a ribbon having a width of 45 mm and a thickness of 2.5 mm.
[0000] 2. Visual Evaluation of Foamed Extrudate
[0082] The state of the resulting extrudate was visually evaluated in accordance with the following criteria.
[0083] Good: A foamed extrudate free of crackes or voids is stably obtained.
[0084] Not good: The foamed extrudate includes a number of cracks or voids, or stable extrusion is not possible due to blowing of gas from the die.
[0000] 3. Flame Retardancy Test
[0085] Oxygen index (LOI) was determined according to JIS K 7201 standard test.
[0000] 4. Self-Extinguishability
[0086] Yes=LOI equal to or greater than 26
[0087] No=LOI less than 26
[0000] 5. Evaluation After Recycling
[0088] The foamed extrudate produced in the initial extruding was crashed and aged in an oven kept at a constant temperature of 80° C. and at a constant humidity of at 95% RH for one week. The aged particles were blow-extruded again under the same conditions as above. The recycled extrudate was tested for the state, the oxygen index and self-extinguishability. The recycling test was not conducted for the extrudates of Comparative Examples. The results are shown in Tables 7-8 below.
TABLE 7 EXAMPLE Formulation(parts) & Test results 21 22 23 24 25 26 Plastics A-6 100 100 100 100 100 100 Brominated flame retardant B-9 B-2 B-1 B-3 B-4 B-2 1.0 1.3 3.5 3.5 2.5 0.8 Radical generator C 0.063 0.025 0.01 0.025 0.02 0.027 Phthalocyanine/naphthalocyanine D-1 D-3 D-4 D-1 D-2 D-6 complex 0.027 0.025 0.04 0.025 0.01 0.003 Heat stabilizer E-1 0.05 0.05 0.05 0.05 0.05 0.05 Antioxidant E-3 0.01 0.01 0.01 0.01 0.01 0.01 Blowing agent, mol/100 g 0.1 0.1 0.1 0.1 0.1 0.1 Talc 1.0 1.0 1.0 1.0 1.0 1.0 Triphenyl phosphate — — — — 0.8 0.4 Initial State Good Good Good Good Good Good Flame retardancy, L0I 27.1 27.5 26.8 26.9 27.4 26.5 Self-extinguishability Yes Yes Yes Yes Yes Yes After recycling State Good Good Good Good Good Good Flame retardancy, L0I 26.8 26.9 26.8 26.8 26.6 26.1 Self-extinguishability Yes Yes Yes Yes Yes Yes
[0089]
TABLE 8
COMP. EXAMPLE
Formulation (parts) % Test results
20
21
22
23
Plastic
100
100
100
100
A - 6
Brominated flame retardant
B-9
B-1
B-3
B-2
1.0
3.5
3.5
4.0
Radical generator C
—
0.09
0.025
—
Phthalocyanine/naphthalo-
D-4
—
D-5
—
cyanine complex
0.09
—
0.025
—
Heat stabilizer E-1
0.05
0.05
0.05
0.05
Antioxidant E-3
0.01
0.01
0.01
0.01
Blowing agent, mol/100 g
0.1
0.1
0.1
0.1
Talc
1.0
1.0
1.0
1.0
Triphenyl phosphate
—
—
—
0.8
Initial
State
Good
Good
Good
Not good
LOI
23.9
24.2
22.7
26.5
Self-extinguishability
No
No
No
Yes
[0090] As shown in Tables 7-8, the foamed extrudates of Examples 21-26 exhibited satisfactory results in the flame retardancy and the foamed state. The foamed extrudates of Comparative Examples 20-23 were not self-extinguishable although the foamed state was good. The foamed extrudate of Comparative Example 23 was self-extinguishable because of increased amount of brominated flame retardant in conjuction with a phosphate ester but observed a number of cracks and scorching.
Examples 27-30 and Comparative Examples 24-26
[0000] 1. Preparation of Test Specimen
[0091] According to the formulations shown in Table 9, all additives were mixtured with the phenol resin varnish. A sheet of kraft paper was impregnated with the resulting mixture and dried to prepare a prepreg. Then eight sheets of the prepreg were laminated in a hot press at a pressure of 150 kgf/cm 2 at 150° C. for one hour to prepare a paper-phenol resin laminate having a thickness of 1.6 mm.
[0000] 2. Flame Retardancy Test
[0092] The vertical combustion method according to UL-95 standard was followed using a test specimen of 125 mm length, 12.5 mm width and 3.2 mm thickness. The results are shown in Table 9.
TABLE 9 EXAMPLE COMP. EXAMPLE Formulation(parts) & Test results 27 28 29 30 24 25 26 Plastics A-7 (solids) 100 100 100 100 100 100 100 Brominated flame retardant B-10 6.0 6.0 7.0 8.0 8.0 7.0 7.0 Radical generator C 0.38 0.02 0.1 0.03 — 0.38 0.4 Phthalocyanine D-1 D-2 D-3 D-4 D-1 D-5 — naphthalocyanine complex 0.02 0.38 0.1 0.03 0.4 0.02 — Flame retardancy, UL-94 V-0 V-0 V-0 V-0 V-2 V-2 V-2
[0093] As shown in Table 9, the laminates of Examples 27-30 exhibited enhanced flame retardancy compared to the laminate of Comparative Examples 24-26.
|
A flame retardant composition for rendering flammable plastics flame retardant is provided. The composition comprises a brominated flame retardant, a free-radical generator selected from 2,3-dimethyl-2,3-diphenyl-butane or its homologs, and a phthalocyanine or naphthalocyanine complex with a metal of groups 7 to group 10 of the IUPAC periodic chart. The quantity of the brominated flame retardant may be saved when incorporating into flammable plastic materials in conjunct with the free-radical generator and the phathalocyanine or naphthalocyanine complex of the above type.
| 2
|
FIELD OF THE INVENTION
The present invention relates to the field of nonwoven fabrics and methods for making fibers using spunbond or meltblown processes.
BACKGROUND OF THE INVENTION
This invention relates to the field of nonwoven fabrics. The manufacture of nonwoven fabrics like meltblown and spunbond fabrics involves the attenuation of polymer streams, generally in a fluid such as air. In spunbond fiber production, for example, fibers are attenuated within a chamber called a drawing unit and deposited onto a moving conveyor belt called a forming wire. In meltblown fiber production the drawing unit usually consists of only a nozzle through which polymer flows and is then attenuated pneumatically before deposition onto the forming wire.
Self-crimping fibers are normally created using conjugate fiber construction, i.e., two or more different polymers, which are melted and spun together in a side-by-side or other arrangement. Crimping usually requires a post-fiber formation treatment step, or a heated draw unit, adding to the cost and time to produce the nonwoven fabric. It would be desirable to have a one step process for producing fibers exhibiting self-crimping characteristics in single polymer, or "homofiber", composition.
Fabrics composed of twisted fibers typically exhibit greater strength characteristics and higher loft than fabrics composed of untwisted fibers. Twisting is not commonly achieved. It would be desirable to have a process for producing twisted fibers that could be achieved during the fiber attenuation stage.
U.S. Pat. No. 3,754,694, issued to Reba, discloses a device for accelerating passage of filaments therethrough using at least two baffle means disposed in the fluid inlet portion of the device.
U.S. Pat. Nos. 4,102,662; 4,137,059 and 4,140,509, issued to Levecque et al., disclose the use of a pair of high velocity whirling currents or tornadoes of air, where each of the gases in the two tornadoes turns in opposite directions, imparting a twisting effect on the fibers produced.
U.S. Pat. Nos. 4,135,903, and 4,185,981, issued to Ohsato et al., disclose a method of producing fibers from a thermoplastic material extruded into fibers incorporating two high speed gas streams directed from opposite directions toward the fiber stream, each gas stream having a component in a direction tangential to the fiber flow. The effect is to impart a rotational force on the fiber.
U.S. Pat. No. 4,295,809, issued to Mikami et al., discloses a meltblowing die having a movable spacer in each of the gas slots to provide effective uniformity in the gas streams across the width of the die.
The effect on turbulence of grooves or ribs in certain applications has been investigated by Walsh and Lindemann in "Optimization and Application of Riblets for Turbulent Drag Reduction", American Institute of Aeronautics and Astronautics (AIAA) Paper 84-0347, January 1984, by Lazos and Wilkinson in "Turbulent Viscous Drag Reduction with Thin-Element Riblets", AIAA Journal vol. 26, no. 4, p. 486 (1988), in U.S. Pat. No. 5,445,095 issued to Helfrich which is directed to liquid turbulence and additionally uses a drag reducing polymer, and by Walsh in an article entitled "Riblets" in the book Viscous Drag Reduction in Boundary Layers, edited by Dennis M. Bushnell and Jerry N. Hefner, published by AIAA (1990), ISBN 0-930403-66-5, and by others. These references are directed to the reduction of drag in a fluid stream in the boundary layer by the use of riblets, ribs or grooves.
None of these references teaches or suggests the improvement in the loft of a nonwoven web which is the subject of this invention.
Accordingly, it is an object of the present invention to provide a nonwoven fabric which is produced in a novel way which increases web strength, softness and feel.
It is a further object of the present invention to provide an apparatus having a plurality of protrusions associated with the interior walls of the fiber draw unit, which protrusions cause turbulence of air passing thereover, imparting rotational stress on fibers passing through the unit.
It is another object of the present invention to provide a process for producing a twisted homofiber which crimps during the attenuation step.
SUMMARY OF THE INVENTION
The objects of the invention are provided by a nonwoven fabric or web which has been produced in a pneumatic chamber which has a plurality of protrusions over an effective amount of the interior walls of the fluid contacting surface.
Generally described, the present invention provides a first embodiment comprising a spunbond process in which the interior walls of the fiber draw unit, particularly at the nozzle end proximity, have a series of protrusions preferably spaced in staggered angled rows. The protrusions are preferably rounded hemispherical bumps protruding from the wall surface. The protrusions are either machined as part of the wall or attached thereto, such as a sheet of thin material containing the protrusions being adhered to the walls. Preferably, the rows of protrusions overlap and are at an angle from the vertical of from about 0° to about 45°, more preferably from about 10° to 30°. Preferably the rows on one wall are oriented in a direction opposite the rows of the opposing wall. As fluid, typically air, is passed through the fiber draw unit the protrusions cause controlled lateral turbulence in the airflow, in the areas near (local to) the protrusions. The lateral component of the turbulent flow field exhibits drag on the fibers, tangential to the radius, imparting rotational energy to the fibers. The fibers passing therethrough are imparted with rotational energy derived from the lateral component of the two turbulent airflow fields that oppose one another, and have a tendency to twist and crimp.
Fibers produced thereby exhibit a degree of self-crimping and twisting, which results in a stronger, softer fabric.
The protrusions of the present invention are also usable in the air jets of a meltblown process for creating similar turbulence.
Other objects, features, and advantages of the present invention will become apparent upon reading the following detailed description of embodiments of the invention, when taken in conjunction with the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated in the drawings in which like reference characters designate the same or similar parts throughout the figures of which:
FIG. 1 is a schematic view of a typical drawing unit for producing spunbond webs.
FIG. 2 is a schematic view of a typical apparatus for forming meltblown webs.
FIG. 3 is a detail schematic view of the meltblowing die shown as item 16 in FIG. 2.
FIG. 4 is a cross-sectional view of the die of FIG. 3 taken along line 3--3.
FIG. 5 is a detail schematic view of a section of the interior walls of the pneumatic chamber.
DEFINITIONS
As Used herein the term "nonwoven fabric or web" means a web having a structure of individual fibers or threads which are interlaid, but not in an identifiable manner as in a knitted fabric. Nonwoven fabrics or webs have been formed from many processes such as for example, meltblowing processes, spunbonding processes, and bonded carded web processes. The basis weight of nonwoven fabrics is usually expressed in ounces of material per square yard (osy) or grams per square meter (gsm) and the fiber diameters useful are usually expressed in microns. (Note that to convert from osy to gsm, multiply osy by 33.91).
As used herein the term "microfibers" means small diameter fibers having an average diameter not greater than about 75 microns, for example, having an average diameter of from about 0.5 microns to about 50 microns, or more particularly, microfibers may have an average diameter of from about 2 microns to about 40 microns. Another frequently used expression of fiber diameter is denier, which is defined as grams per 9000 meters of a fiber and may be calculated as fiber diameter in microns squared, multiplied by the density in grams/cc, multiplied by 0.00707. A lower denier indicates a finer fiber and a higher denier indicates a thicker or heavier fiber. For example, the diameter of a polypropylene fiber given as 15 microns may be converted to denier by squaring, multiplying the result by 0.89 g/cc and multiplying by 0.00707. Thus, a 15 micron polypropylene fiber has a denier of about 1.42 (15 2 ×0.89×0.00707=1.415). Outside the United States the unit of measurement is more commonly the "tex", which is defined as the grams per kilometer of fiber. Tex may be calculated as denier/9.
As used herein the term "meltblown fibers" means fibers formed by extruding a molten thermoplastic material through a plurality of fine, usually circular, die capillaries as molten threads or filaments into converging high velocity, usually hot, gas (e.g. air) streams which attenuate the filaments of molten thermoplastic material to reduce their diameter, which may be to microfiber diameter. Thereafter, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a web of randomly disbursed meltblown fibers. Such a process is disclosed, for example, in U.S. Pat. No. 3,849,241 to Butin et al. Meltblown fibers are microfibers which may be continuous or discontinuous, are generally smaller than 10 microns in average diameter, and are generally tacky when deposited onto a collecting surface.
As used herein the term "spunbonded fibers" refers to small diameter fibers which are formed by extruding molten thermoplastic material as filaments from a plurality of fine, usually circular capillaries of a spinneret with the diameter of the extruded filaments then being rapidly reduced as they are quenched, drawn, usually pneumatically, and deposited on a moving foraminous mat, belt or "forming wire" to form the nonwoven fabric. Examples of this process may be found, for example, in U.S. Pat. No. 4,340,563 to Appel et al., U.S. Pat. No. 3,692,618 to Dorschner et al., U.S. Pat. No. 3,802,817 to Matsuki et al., U.S. Pat. Nos. 3,338,992 and 3,341,394 to Kinney, U.S. Pat. No. 3,502,763 to Hartman, U.S. Pat. No. 3,542,615 to Dobo et al. and U.S. Pat. No. 5,028,375 to Reifenhauser. Spunbond fibers are quenched and, therefore, generally not tacky when they are deposited onto a collecting surface. Spunbond fibers are generally continuous and have average diameters (from a sample of at least 10) larger than 7 microns, more particularly, between about 10 and 40 microns.
As used herein "multilayer laminate" means a laminate wherein some of the layers are spunbond and some meltblown such as a spunbond/meltblown/spunbond (SMS) laminate and others as disclosed in U.S. Pat. No. 4,041,203 to Brock et al., U.S. Pat. No. 5,169,706 to Collier, et al, U.S. Pat. No. 5,145,727 to Potts et al., U.S. Pat. No. 5,178,931 to Perkins et al. and U.S. Pat. No. 5,188,885 to Timmons et al. Such a laminate may be made by sequentially depositing onto a moving forming belt first a spunbond fabric layer, then a meltblown fabric layer and last another spunbond layer and then bonding the laminate in a manner described below. Alternatively, the fabric layers may be made individually, collected in rolls, and combined in a separate bonding step. Such laminated fabrics usually have a basis weight of from about 0.1 to 12 osy (6 to 400 gsm), or more particularly from about 0.75 to about 3 osy (25 to 102 gsm). Multilayer laminates may also have various numbers of meltblown layers or multiple spunbond layers in many different configurations and may include other materials like films (F) or coform materials, e.g., SMMS, SM, SFS, etc.
As used herein, the term "coform" means a process in which at least one meltblown diehead is arranged near a chute through which other materials are added to the web while it is forming. Such other materials may be pulp, superabsorbent particles, cellulose or staple fibers, for example. Coform processes are shown in commonly assigned U.S. Pat. No. 4,818,464 to Lau and U.S. Pat. No. 4,100,324 to Anderson et al. Webs produced by the coform process are generally referred to as coform materials. An example of a product often made by the coform process is a baby wipe.
As used herein the term "polymer" generally includes but is not limited to, homopolymers, copolymers, such as for example, block, graft, random and alternating copolymers, terpolymers, etc., and blends and modifications thereof. Furthermore, unless otherwise specifically limited, the term "polymer" shall include all possible geometrical configurations of the molecule. These configurations include, but are not limited to isotactic, syndiotactic and random symmetries.
As used herein the term "conjugate fibers" refers to fibers which have been formed from at least two polymers extruded from separate extruders but spun together to form one fiber. Conjugate fibers are also sometimes referred to as multicomponent or bicomponent fibers. The polymers are usually different from each other though conjugate fibers may be monocomponent fibers. The polymers are arranged in substantially constantly positioned distinct zones across the cross-section of the conjugate fibers and extend continuously along the length of the conjugate fibers. The configuration of such a conjugate fiber may be, for example, a sheath/core arrangement wherein one polymer is surrounded by another or may be a side by side arrangement or an "islands-in-the-sea" arrangement. Conjugate fibers are taught in U.S. Pat. No. 5,108,820 to Kaneko et al., U.S. Pat. No. 5,336,552 to Strack et al., and U.S. Pat. No. 5,382,400 to Pike et al. For two component fibers, the polymers may be present in ratios of 75/25, 50/50, 25/75 or any other desired ratios.
As used herein the term "biconstituent fibers" refers to fibers which have been formed from at least two polymers extruded from the same extruder as a blend. The term "blend" is defined below. Biconstituent fibers do not have the various polymer components arranged in relatively constantly positioned distinct zones across the cross-sectional area of the fiber and the various polymers are usually not continuous along the entire length of the fiber, instead usually forming fibrils or protofibrils which start and end at random. Biconstituent fibers are sometimes also referred to as multiconstituent fibers. Fibers of this general type are discussed in, for example, U.S. Pat. No. 5,108,827 to Gessner. Bicomponent and biconstituent fibers are also discussed in the textbook Polymer Blends and Composites by John A. Manson and Leslie H. Sperling, copyright 1976 by Plenum Press, a division of Plenum Publishing Corporation of New York, IBSN 0-306-30831-2, at pages 273 through 277.
As used herein, the term "machine direction" or MD means the length of a fabric in the direction in which it is produced. The term "cross machine direction" or CD means the width of fabric, i.e., a direction generally perpendicular to the MD.
As used herein, the term "point unbonded" refers to the technique, similar to point bonding, in which a set of calendar niprolls are used with one roll having a flat surface (the anvil roll) and the other roll being substantially flat and having a series of spaced depressions on its surface so that when material is passed through the nip assembly the material is bonded except for the areas contacting the depressions. This technique is used to make loops of fabric on a flat background (the bonded area) of the fabric, such as for use as "hook and loop" material.
As used herein, the term "garment" means any type of non-medically oriented apparel which may be worn. This includes industrial work wear and coveralls, undergarments, pants, shirts, jackets, gloves, socks, and the like.
As used herein, the term "infection control product" means medically oriented items such as surgical gowns and drapes, face masks, head coverings like bouffant caps, surgical caps and hoods, footwear like shoe coverings, boot covers and slippers, wound dressings, bandages, sterilization wraps, wipers, garments like lab coats, coveralls, aprons and jackets, patient bedding, stretcher and bassinet sheets, and the like.
As used herein, the term "personal care product" means diapers, training pants, absorbent underpants, adult incontinence products, and feminine hygiene products.
As used herein, the term "protective cover" means a cover for vehicles such as cars, trucks, boats, airplanes, motorcycles, bicycles, golf carts, etc., covers for equipment often left outdoors like grills, yard and garden equipment (mowers, roto-tillers, etc.) and lawn furniture, as well as floor coverings, table cloths and picnic area covers.
DETAILED DESCRIPTION
The processes for which this invention may be useful are the meltblowing or spunbonding processes which are nonwoven fabric production methods which are well known in the art. These processes generally use an extruder to supply melted thermoplastic polymer to a die or spinneret where the polymer is fiberized to yield fibers which may be staple length or longer. The fibers are then drawn, usually pneumatically, and deposited on a moving foraminous mat or belt to form the nonwoven fabric. The fibers produced in the spunbond and meltblown processes are microfibers as defined above.
Nonwoven fabrics are used in the production of garments, infection control products, personal care products and protective covers.
Spunbond nonwoven fabric is produced by a method known in the art and described in a number of the references cited above. Briefly, the spunbond process generally uses a hopper which supplies polymer to a heated extruder. The extruder supplies melted polymer to a spinneret where the polymer is fiberized as it passes through fine openings usually arranged in one or more rows in the spinneret, forming a curtain of filaments. The filaments are usually quenched with air, drawn, usually pneumatically, and deposited on a moving foraminous mat, belt or "forming wire" to form the nonwoven fabric.
The fibers produced in the spunbond process are usually in the range of from about 10 to about 40 microns in diameter, depending on process conditions and the desired end use for the fabrics to be produced from such fibers. For example, increasing the polymer molecular weight or decreasing the processing temperature result in larger diameter fibers. Changes in the quench fluid temperature and pneumatic draw pressure can also affect fiber diameter.
Polymers useful in the spunbond process generally have a process melt temperature of between about 300° F. to about 610° F. (149° C. to 320° C.), more particularly between about 350° F. and 510° F. (175° C. and 265° C.) and a melt flow rate, as defined above, in the range of about 10 to about 150, more particularly between about 10 and 50. Examples of suitable polymers include polypropylenes, polyethylenes and polyamides.
Conjugate fibers may also be used in the practice of this invention. Conjugate fibers are commonly polypropylene and polyethylene arranged in a sheath/core, "islands in the sea" or side by side configuration. Biconstituent fibers may also be used in the practice of this invention. Blends of a polypropylene copolymer and polybutylene copolymer in a 90/10 mixture have been found effective. Any other blend would be effective as well provided it may be spun.
This invention pertains particularly to the process used to cool and attenuate the fibers after they are produced by the spinneret. The spunbonding patents cited above, though describing somewhat different processes, have in common that they provide a chamber for pneumatically attenuating the fibers prior to formation of a web. This chamber may be seen in FIG. 1 as item 32 and is sometimes referred to in the cited spunbond patents as a "draw-off tube" (Dorschner), a "sucker unit" (Matsuki), "filament passageway" (Kinney), "yarn passageway" (Kinney), "guide passageway" (Hartmann), "venturi nozzle" (Reifenhauser) and "aspirator" (Dobo). The combination of the quench chamber and drawing nozzle is referred to as the drawing unit.
When used in meltblowing the drawing unit usually includes only a drawing nozzle having chambers and gaps as shown in FIG. 4 as items 38, 40 and 42, 44 and which may have a series of spaced apart protrusions projecting from the interior walls in accordance with this invention, as will be described in greater detail hereinbelow. The instant invention is therefore, suitable for use in any fiber producing process which relies on pneumatically drawing fibers. Accordingly, this invention is specifically contemplated to encompass not only spunbond processes but also meltblown processes and others. In order to properly encompass these processes, the term "pneumatic chamber" as used herein means includes at least the spunbonding drawing unit and the meltblowing chambers and gaps.
In FIG. 1, an example of a spunbonding process, the spinneret 22 may be of conventional design and arranged to provide extrusion of filaments 20 from spin box 18 in one or more rows of evenly spaced orifices across the full width of the machine into the quench chamber 24. The size of the quench chamber will normally be only large enough to avoid contact between the filaments and the side and to obtain sufficient filament cooling. The filaments 20 simultaneously begin to cool from contact with the quench fluid which is supplied through inlet 26 in a direction preferably at an angle having the major velocity component in the direction toward the nozzle entrance. The quench fluid may be any of a wide variety of gases as will be apparent to those skilled in the art, but air is preferred for economy. A portion of the quenching fluid is directed through the filaments 20 and withdrawn through exhaust port 28.
Immediately after extrusion through the orifices, acceleration of the strand movement occurs due to tension in each filament generated by the aerodynamic drawing means. The filaments 20 accelerate between the walls 34, 36, particularly starting at the upper portion 33 and exit through nozzle 32 where they may be gathered onto foraminous mat or belt 38 to form a nonwoven web 40.
In the practice of this invention in spunbond applications, the series of protrusions should extend at least a major portion of the distance from the upper end 33 to the nozzle 32.
The manufacture of meltblown webs is discussed generally above and in the references and may also be accomplished according to the following general procedure.
Turning now to FIG. 2, it can be seen that an apparatus for forming meltblown web is represented by the reference number 10. In forming the nonwoven web of the present invention, pellets, beads or chips (not shown) of a suitable material are introduced into a hopper 12 of an extruder 14. The extruder 14 has an extrusion screw (not shown) which is driven by a conventional drive motor (not shown). As the material advances through the extruder 14, due to rotation of the extrusion screw by the drive motor, it is progressively heated to a molten state. Heating of the material may be accomplished in a plurality of discrete steps with its temperature being gradually elevated as it advances through discrete heating zones of the extruder 14 toward a meltblowing die 16. The die 16 may be yet another heating zone where the temperature of the thermoplastic resin is maintained at an elevated level for extrusion. The temperature which will be required to heat the material to a molten state will vary somewhat depending upon exactly which material is utilized and can be readily determined by those in the art.
FIG. 3 illustrates that the lateral extent 18 of the die 16 is provided with a plurality of orifices 20 which are usually circular in cross-section and are linearly arranged along the extent 18 of the tip 22 of the die 16. The orifices 20 of the die 16 may have diameters that range from about 0.01 of an inch to about 0.02 of an inch and a length which may range from about 0.05 inches to about 0.30 inches. For example, the orifices may have a diameter of about 0.0145 inches and a length of about 0.113 inches. From about 5 to about 50 orifices may be provided per inch of the lateral extent 18 of the tip 22 of the die 16 with the die 16 extending from abut 20 inches to about 60 inches or more. FIG. 2 illustrates that the molten material emerges from the orifices 20 of the die 16 as molten strands or threads 24.
FIG. 4, which is a cross-sectional view of the die of FIG. 3 taken along line 3--3, illustrates that the die 16 preferably includes attenuating gas sources 30 and 32 (see FIGS. 2 and 3). The heated, pressurized attenuating gas enters the die 16 at the inlets 26, 28 and follows a path generally designated by arrows 34, 36 through the two chambers 38, 40 and on through the two narrow passageways or gaps 42, 44 so as to contact the extruded threads 24 as they exit the orifices 20 of the die 16. The chambers 38, 40 are designed so that the heated attenuating gas passes through the chambers 38, 40 and exits the gaps 42, 44 to form a stream (not shown) of attenuating gas which exits the die 16 on both sides of the threads 24. It is the interior walls of the chambers 38, 40 and gaps 42, 22 which have the series of protrusions in the practice of this invention. The temperature and pressure of the heated stream of attenuating gas can vary widely. For example, the heated attenuating gas can be applied at a temperature of from about 220° to about 315° C. (425°-600° F.), more particularly, from about 230° to about 280° C. The heated attenuating gas may generally be applied at a pressure of from about 0.5 pounds per square inch gage (psig) to about 20 psig. More particularly, from about 1 to about 10 psig.
The position of the air plates 46, 48 which, in conjunction with a die portion 50 define the chambers 38, 40 and the gaps 42, 44, may be adjusted relative to the die portion 50 to increase or decrease the width of the attenuating gas passageways 42, 44 so that the volume of attenuating gas passing through the air passageways 42, 44 during a given time period can be varied without varying the velocity of the attenuating gas. Furthermore, the air plates 46, 48 may be adjusted to effect a "recessed" die tip 22 configuration as illustrated in FIG. 4, or a positive die tip 22 stick out configuration wherein the tip of the die portion 50 protrudes beyond the plane formed by the plates 48. Lower attenuating gas velocities and wider air passageway gaps are generally preferred if substantially continuous meltblown fibers or microfibers 24 are to be produced.
The two streams of attenuating gas converge to form a stream of gas which entrains and attenuates the molten threads 24, as they exit the orifices 20, into fibers or, depending on the degree of attenuation, microfibers of a small diameter which is usually less than the diameter of the orifices 20. The gas-borne fibers or microfibers 24 are blown by the action of the attenuating gas onto a collecting arrangement which, in the embodiment illustrated in FIG. 2, is a foraminous endless belt 52 conventionally driven by rollers 54. Other foraminous arrangements such as a rotating drum could be used. One or more vacuum boxes (not shown) may be located below the surface of the foraminous belt 52 and between the rollers 54. The fibers or microfibers 24 are collected as a coherent matrix of fibers on the surface of the endless belt 52 which is rotating as indicated by the arrow 58 in FIG. 2. The vacuum boxes assist in retention of the matrix on the surface of the belt 52. Typically, the tip 22 of the die 16 is from about 6 inches to about 14 inches from the surface of the foraminous belt 52 upon which the fibers 24 are collected. The thus collected, entangled fibers or microfibers 24 are coherent and may be removed from the belt 52 as a self-supporting nonwoven web 56.
FIG. 5 shows front schematic views of a portion of a pair of opposing interior walls 100 and 102. These walls are similar in general relative positioning inside the pneumatic chamber in the spunbond apparatus and chambers and gaps in the meltblown apparatus, i.e., they oppose each other, have a fluid passageway defined between the walls and may be either generally parallel, slightly converging, or slightly diverging. For the purposes of the present discussion, both walls 100 and 102 will incorporate the protrusions. It is to be understood that the present invention contemplates either one or both walls 100, 102 as incorporating the protrusions.
The protrusions will be discussed initially with respect to the walls of the pneumatic chamber as part of the spunbond apparatus. In a preferred embodiment the walls 100 and 102 have a series of angled rows 104, each row comprising a series of protrusions 110. The protrusion 110 is raised with respect to the wall surface and may be of any of a number of shapes, or of a variety of shapes and sizes, including, but not limited to, double sloped (two gradients on the same protrusion), rounded "U", pointed, squared "U", hemispherical, elongated, rounded "V" shaped, ridged (i.e., having grooves, ridges, depressions or valleys within the raised portion), crescent or "C" shaped, "I" shaped, or the like. All suitable geometric shapes or angles are contemplated as being within the scope of the present invention. It is preferable that the protrusions be shaped so that the fibers passing thereover do not catch or stick on the protrusions, which would cause clogging. Therefore, typically, it is preferable that the rounded protrusions be sufficiently raised as to create turbulence yet not so high or prominent as to catch the fibers as they pass thereover. Additional factors regarding the protrusions 110 include composition (e.g., hollow, solid, deformable, or rigid), size, length, height, spacing, distribution, geometry, and surface topography (e.g., protrusions 110 can have smooth, ridged, channeled, rough, perforated (i.e., spongelike) dimpled or otherwise textured surfaces). Moreover, the protrusions 110 can be of different shapes, such as random or rows of shaped protrusions, or even a gradient of sized protrusions.
The protrusions 110 can be associated with the walls 100 and 102 in a variety of different ways. The protrusions 110 can be cast or otherwise machined as part of the wall structure (if the walls 100 and 102 are formed in this manner). Alternatively, the protrusions 110 can be affixed to or integrated with a sheet of material, such as metal or plastic, for example, where the protrusions are indented through the sheet from the back side. The sheet can then be fastened to the wall 100 or 102, such as by an adhesive, welding, screws, bolts, mated tongue and groove construction (where the sheet would have at least one tongue which would slide within a mating groove in the wall), male and female mating snaps, electrostatic attraction, hook and loop tape, and the like. Several of these fastening means permit the removal of the sheets should they need to be replaced. It may be that a removable sheet of thin metal or plastic having the protrusions 110 therein is more cost effective than forming the protrusions 110 directly on the wall surface. Spacing of the walls apart from each other should be taken into consideration in designing the pneumatic chamber, since the sheet thickness may reduce the width of the fluid passageway.
The protrusions 110 can be arranged in any of a number of different spatial arrangements, or randomly. In a preferred embodiment, the protrusions 110 are arranged in a number of offset angled rows 104, as shown in FIG. 5. The rows 104 overlap and have an angle from the vertical of at least about 0° to 45°, more preferably from about 15° to about 35°.
FIG. 5 shows the walls 100 and 102 as both facing the observer. In a preferred embodiment the apparatus walls 100 and 102 face each other such that the rows 104 on wall 100 are preferably not parallel to the rows 104 on the opposing wall 102, i.e., the rows "cross" if viewed from the front or back, the significance of which is discussed in detail hereinbelow. Alternatively, it is possible for the rows 104 to be parallel.
The protrusions 110 are preferably disposed along the wall portion of the pneumatic chamber 24 between the upper portion 33 and the nozzle 32. While the protrusions can be placed further upward into the chamber 24, the effectiveness diminishes because of the enlarged chamber volume.
In a spunbond process, fluid, such as air, enters the inlet 26 and flows through to the narrower upper portion 33 and exits the nozzle 32. Filaments 20 are drawn through the chamber between the walls 34 and 36 and exit the nozzle 32. In the prior art, the walls 34 and 36 are substantially smooth and create minimal turbulence, which heretofore was considered desirable. The protrusions 110 of the present invention induce turbulence within the passageway among the air and fibers passing therethrough. It is believed that the turbulence occurs at two levels: microturbulence and macroturbulence. Microturbulence occurs as air passes over (and around) one and between two of the protrusions 110, creating a mini-disruption in airflow and a mini-vortex. Macroturbulence occurs as air is passed over the entire wall surface, with airflow disruption occurring between and among the rows 104.
Additionally, turbulence and shear is created by the interaction of air between the two walls, i.e., the tendency of the air passing over wall 100 to be shunted in an angle, while air passing over wall 102 is shunted at a complementary angle, thus the air "shears" the fibers in a circumferential direction, imparting rotation around their central axis. An analogy is that the walls 100 and 102 cause rifling of the air, like a bullet passing through a rifled gun barrel. The shearing action imparts a twist on the fibers passing through the passageway.
Fibers produced by one embodied process of the present invention exhibited crimping in the range of about 7-30 helical crimps per inch. It is believed that about 7-200 helical crimps per inch are possible by altering the protrusion 110 configuration and flow rate.
Twisted fibers produced by the above apparatus typically have certain improved characteristics as compared to untwisted fibers, such as a softer feel, improved drapability, improved strength (due to formation of twisted coils), and improved crimp. The fibers self-crimp, using the energy of the air shearing them in a circumferential (axial) direction. Normally, crimping requires conjugate fiber composition, whereas an advantage of the present invention is that a homofiber exhibits self-crimping.
The present invention can be incorporated into a meltblown apparatus as follows. FIG. 4 shows walls 200 and 202 as forming the passageway 38 and walls 204 and 206 as forming the passageway 40. The pairs of walls are generally the same as the walls 100 and 102 in surface and protrusion construction, however, each pair of walls preferably converges toward the tip 22. The protrusions 110 on the walls provide lateral momentum to the air flow field that is equal and opposite with respect to the opposing side. This lateral momentum is exerted on the fibers, and it ultimately changes the quench efficiency and hence the physical characteristics of the meltblown fibers.
Fabric produced according to the embodiments of the present invention can be further processed by point bonding or point unbonding procedures which post-treat the fabric to form either a flat or raised loop surface, for, for example, hook-and-loop type fasteners, depending on the characteristics desired.
A further advantage of the present invention is that the protrusion pattern could be used to impart rotational energy to the fibers, which may aid in splitting conjugate fibers. This reduces the overall fiber size which increases coverage, making material appear to have a higher basis weight than it actually does. Materials are made to appear heavier and are stronger when smaller fibers are used to make the material.
Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. In the claims, means plus function claims are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures.
It should further be noted that any patents, applications or publications referred to herein are incorporated by reference in their entirety.
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There is provided a fabric produced by a spunbond or a meltblown apparatus, wherein the apparatus has a pneumatic chamber having at least one wall containing a plurality of spaced protrusions. Preferably, both opposing walls contain protrusions aligned in staggered angled rows and the rows on one wall are angled opposite the rows on the opposing wall, thereby causing controlled lateral flow near the chamber walls. This lateral flow exhibits drag on the fibers, imparting rotational energy to the fibers. The fibers are imparted with rotational energy derived from the lateral component of the two turbulent airflow fields that oppose one another, and have a tendency to twist and crimp. Fabrics so produced have improved loft, drape, and feel and may be useable as a loop material for hook-and-loop type fasteners.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefits of U.S. Pat. Appln. Ser. No. 60/620,389 of the same title filed on 20 Oct. 2004.
FIELD OF THE INVENTION
[0002] The present invention relates, in general, to gutter brackets attachable to a roof rafter for the purpose of supporting a gutter.
BACKGROUND OF THE INVENTION
[0003] It has long been appreciated gutter brackets may be attached to a roof or a wall to support a gutter, such as described in U.S. Pat. No. 1,478,837.
[0004] In U.S. Pat. No. 5,687,936, which is hereby incorporated by reference in its entirety, a single piece gutter bracket has a gutter support arm that is connected to a centrally disposed web with two spaced apart flanges extending substantially perpendicularly from opposing edges of the central web, in the direction opposite the gutter support arm. The distance between the flanges is approximately equal to the thickness of a rafter extension and may be substantially parallel or slightly angled in order to provide a frictional fit on a rafter extension. The flanges are secured directly to the sides of the rafter extension. The central web covers a portion of the end surface of the rafter extension, providing some protection to the rafter extension. The front of the gutter support arm may lie lower than the back of the gutter support arm to inhibit the flow of water, thereby helping to preserve the dwelling's building materials. The gutter bracket need not be installed during construction, beneath the roof shingles or the like, but may be installed after construction is complete. Accordingly, it is easily removed and replaced, without the need to disturb the building's roof supports or other architecture.
[0005] Later, in U.S. Pat. No. 6,651,937, an expandable gutter bracket has a gutter support arm that is connected to a centrally disposed mounting portion, or web, with two spaced apart flanges extending substantially perpendicularly from opposing edges of the mounting portion, in the direction opposite the gutter support arm. The distance between the flanges is selectively provided by the mounting portion to be approximately equal to the thickness of a rafter extension and may be substantially parallel or slightly angled in order to provide a frictional fit on a rafter extension. Various configurations of the mounting portion are provided to select the appropriate thickness, including a plurality of attachments that pass through the gutter support arm and connect to each end of the flanges or two respective halves of a two-piece web.
[0006] While these gutter brackets have a number of advantages and applications, further features are desirable to increase the number of applications for gutter brackets and to provide additional improvements.
BRIEF SUMMARY OF THE INVENTION
[0007] The invention overcomes the above-noted and other deficiencies of the prior art by providing a gutter bracket assembly which includes a mounting bracket having a proximal portion that attaches to an exposed surface of a rafter extension and a distal portion that extends out beyond the rafter extension to support a gutter. An extension member is attached to the mounting bracket to adjust for variations in the shape of the rafter extension so that the gutter is supported horizontally and at the correct height above ground.
[0008] In one aspect of the invention, a gutter bracket assembly has a mounting bracket with a curved distal portion shaped to follow a contour of an undersurface of the gutter. A back clip is fastened to the curved distal portion to grip an inner lip of the gutter. Similarly, a front clip is fastened to the curved distal portion to grip an outer lip of the gutter. Thereby, the gutter is securely held to the mounting bracket even if spaced away from a distal end of a rafter extension that is not plumb. Spacing away may be desired even if plump to reduce trapped moisture on the rafter extension that may lead to deterioration. Further, having a detached back clip rather than a fix gripping feature enables greater installation flexibility. For instance, the front and back clips may be selected for a particular placement that holds a gutter transversely horizontal even if the mounting bracket differs in its installed angle from other rafter extensions.
[0009] In another aspect of the invention, a gutter bracket attaches to one lateral side of a rafter extension with a gutter bracket arm extending distally at an angle to accommodate variations in the angle of a distal end of the rafter extension as well as a pitch of the rafter extension.
[0010] These and other objects and advantages of the present invention shall be made apparent from the accompanying drawings and the description thereof.
DESCRIPTION OF THE FIGURES
[0011] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and, together with the general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the present invention.
[0012] FIG. 1 is a perspective disassembled view of a gutter bracket assembly with opposing lateral flanges for rafter dimensional flexibility and with attachable front and back clips for securely holding down of a gutter.
[0013] FIG. 2 is a perspective view of two dual arm gutter bracket assemblies having straight, proximal flange portions that attach to lateral sides of a rafter with lateral force distributing cylindrical spacers.
[0014] FIG. 3 is a perspective view of a dual arm gutter bracket similar to that shown in FIG. 2 but with a straight distal portion passing through the proximal and distal lips of a supported gutter.
[0015] FIG. 4 is a side view of a gutter bracket assembly with an increased vertical projecting flange with a plurality of attachment holes to increase vertical adjustment of an attached gutter bracket arm.
[0016] FIG. 5 is a side view of a gutter bracket assembly with a downwardly projecting lateral bracket and gutter bracket arm having a horizontal proximal attachment portion.
[0017] FIG. 6 is a side view of an increased strength gutter bracket assembly with an elongated proximal portion of a gutter bracket arm attached to a plurality of downwardly projecting lateral flanges.
[0018] FIG. 7 is a side view of a contoured gutter bracket assembly.
[0019] FIG. 8 is a perspective view of a disassembled gutter bracket assembly of FIG. 1 with back clips with a plurality of attachment holes in a triangular web that allows attachment to angled rafter ends.
[0020] FIG. 9 is a perspective view of an alternative pair of gutter bracket assemblies attached to respective exposed lateral sides of a rafter extension.
[0021] FIG. 10 is a perspective view of another alternative pair of gutter bracket assemblies with rotatably attachable gutter bracket arms and each mounted on respective exposed lateral sides of a rafter extension.
[0022] FIG. 11 is a perspective, exploded view of the alternative pair of gutter bracket assemblies of FIG. 10 .
[0023] FIG. 12A is a right side view in elevation of the gutter bracket assembly of FIG. 10 installed on a rafter extension having a 10/12 pitch.
[0024] FIG. 12B is a right side view in elevation of the gutter bracket assembly of FIG. 10 installed on a rafter extension having a 8/12 pitch.
[0025] FIG. 12C is a right side view in elevation of the gutter bracket assembly of FIG. 10 installed on a rafter extension having a 6/12 pitch.
[0026] FIG. 12D is a right side view in elevation of the gutter bracket assembly of FIG. 10 installed on a rafter extension having a 4/12 pitch.
DETAILED DESCRIPTION OF THE INVENTION
[0027] FIG. 1 depicts a gutter bracket assembly 10 formed from a pair of right and left lateral flanges 12 , 14 that are attachable to a rafter (not shown). Each presents opposing front webs 16 , 18 that come together at parallel and projecting tabs 20 , 22 respectively for being on each side of a proximal end 24 of a gutter bracket arm (“hook”) 26 . Fasteners (e.g., bolts and nuts) 28 , 30 pass through holes 32 , 33 and 34 , 35 respectively in the projecting tabs 20 , 22 and through holes 36 , 38 in the proximal end 24 .
[0028] Advantageously, a pair of back clips 40 each having a pair of holes 44 , 46 are also attached by fasteners 28 , 30 . A gutter (not shown) is set across gutter bracket arm 26 , as well as other gutter bracket arms, and is hooked on the backside under the back clips 40 , 42 . Then front clips 52 , 54 are attached with a fastener 56 to a distal end 58 of the bracket support arm 26 to engage the other lip of the gutter. The front clips 52 , 54 are advantageously stamped or molded with substantial strength and possibly decorative ornamentation to provide a more appealing installation over a spring clip or other attachment.
[0029] In FIG. 2 , a pair of rafters 70 , 72 each support a dual arm gutter bracket assembly 74 formed by a pair of gutter bracket arms 76 , 78 that have a straight, proximal flange portion 80 and a curved hook portion 82 . A pair of back clips 84 , 86 and a pair of front clips 88 , 90 are attached opposingly on each end of the curved hook portion 82 . Fasteners 92 , 94 pass through the flange portions 80 of both of the gutter bracket arms 76 , 78 , advantageously with cylindrical spacers 96 , 98 spacing the gutter bracket arms 76 , 78 as desired for aesthetics or load distribution at the hook portions 82 . In addition, each separate or integral cylindrical spacer 96 , 98 presents a larger surface for distributing loads to the side of the respective rafter 70 , 72 .
[0030] In FIG. 3 , a pair of straight gutter bracket assemblies 120 , 122 are attached to respective rafters 124 , 126 . Each lateral portion 142 is bolted by bolts 128 , 130 with cylindrical spacers 132 , 134 formed therein. Instead of a hooked distal portion, a straight support portion 136 of each gutter bracket support arm 138 , 140 passes through apertures formed in a gutter 142 .
[0031] In FIG. 4 , a gutter bracket assembly 200 provides additional fastener openings along a vertically extended projecting tab 202 of each lateral flange 204 providing additional vertical adjustment options for a gutter bracket arm 206 .
[0032] In FIG. 5 , a gutter bracket assembly 300 is adapted for a rafter 302 that presents a beveled lower surface 303 so that a vertically oriented lateral bracket 304 may present a downward attachment tab 306 to a gutter bracket arm 308 having a horizontal distal attachment portion 310 . The supported gutter 312 may be or may not be held down with back and front clips (not shown).
[0033] In FIG. 6 , a gutter bracket assembly 300 is adapted for a rafter 402 that presents an extended lower surface 403 so that a plurality of vertically oriented lateral brackets 404 , 405 may present a respective downward attachment tab 306 to horizontal distal attachment portions 408 , 410 of a proximal portion 412 of each gutter bracket arm 414 . Thereby, a gutter bracket assembly 300 may withstand greater loads.
[0034] In FIG. 7 , a gutter bracket assembly 400 includes a curved proximal portion 402 of a gutter bracket arm 404 shaped to underlie a contoured rafter 406 . A lateral flange 408 is attached to a generally downward portion 410 of the rafter 406 to attach to the curved proximal portion 402 . For additional support, an attachment tab 412 attaches to a more distal portion of a hook portion 414 of the arm 404 to a rafter end surface 414 .
[0035] In FIG. 8 , a gutter bracket assembly 500 is identical to that described in FIG. 1 . In this instance, back clips 502 , 504 form a triangular flange with a plurality of holes 506 - 508 that allow adjusting the angle of the gutter bracket arm 26 to advantageously be brought to horizontal, even if the rafter end is not cut plumb or varies from application to application. A plurality of economically fabricated back clips 502 , 504 thus provide additional installation flexibility. It should be appreciated that a back clip similar to that described may be used instead in combination with a separate triangular (or other shape) flange that only serves to pivot the orientation of a gutter bracket arm.
[0036] In FIG. 9 , a pair of identical gutter brackets 600 each include a proximal flange portion 602 fastened to a opposite, exposed lateral sides of a rafter extension 604 . The proximal flanges are dimensioned to provide fastener holes 605 spaced to provide enhanced strength. The thickness of the rafter extension 604 thus does not affect the ability to use one or two gutter brackets 600 , each extending a curved gutter bracket arm 606 with a fixed proximal hook 608 positioned to grip an inner lip of a gutter (not shown) and a clip recess 610 formed in a distal end for engaging an outer lip of the gutter.
[0037] It should be appreciated that paired gutter brackets 600 installed together for each rafter extension 604 advantageously increase the support strength and provide a balanced aesthetic look. In some applications consistent with the present invention, fasteners or attaching members that transversely pass through the rafter extension and attach at each end to respective gutter brackets of the paired assembly assist in avoiding an unbalanced torque on a fastener that could lead to bending.
[0038] In FIGS. 10-11 , a pair of mirror-image left and right bracket assemblies 700 each include a proximal flange 702 that attaches respectively to opposite exposed lateral sides of a rafter extension 704 . Each flange 702 presents a number of spaced apart fastener holes 705 to provide for secure attachment to the rafter extension 704 . A distal tab 707 extends from each proximal flange 702 , presenting top and bottom arm fastener apertures holes 709 , 711 . Each gutter bracket assembly 700 includes an attachable curved gutter bracket arm 706 with a fixed proximal hook 708 positioned to grip an inner lip of a gutter (not shown) and a clip recess 710 formed in a distal end for engaging an outer lip of the gutter. A proximal attachment tab 713 of the gutter bracket arm 706 includes a top hole 714 through which a fastener (not shown) may pivotally attach the gutter bracket arm 706 on an outer side of the respective distal tab 705 of the proximal flange 702 . Advantageously, a bottom slot 716 arcs in a fixed radius below the top hole 714 such that another fastener (not shown) may lock the gutter bracket arm 706 at a desired angle relative to the proximal flange 702 . Thereby, the gutter bracket arm 706 may be positioned horizontally without regard to whether a distal end of the rafter extension 706 is plumb, nor whether the pitch of the rafter extension varies from installation to installation (e.g., 10/12 in FIG. 12A , 8/12 in FIG. 12B , 6/12 in FIG. 12C , and 4/12 in FIG. 12D ). Depending upon the slope of the rafter extension.
[0039] While the present invention has been illustrated by description of several embodiments and while the illustrative embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications may readily appear to those skilled in the art.
[0040] For example, illustrative versions herein depict paired gutter brackets that form an assembly, perhaps even physically attached to each other. In addition, versions of a gutter bracket assembly shown herein include one gutter bracket arm sharing dual proximal flanges that attach to opposite lateral sides of a rafter extension. Thereby, an increased strength and aesthetically pleasing gutter bracket is realized. However, it should be appreciated with the benefit of the present disclosure that applications consistent with the present invention may include a single gutter bracket arm supported by attachment to only one lateral exposed surface of a wall or rafter extension due to user desires for reduced expense, reduced strength requirements, or personal preference. In particular, certain features disclosed herein for back clips, front clips, spacing lateral the proximal portion of a gutter bracket from the rafter extension, attaching to a bottom of a rafter extension, and/or adjusting to a pitch of a roof may be incorporated into such a single sided gutter bracket or gutter bracket assembly without the benefit of an identical or mirror-image portions on the other side of the rafter extension.
[0041] For another example, while a pivotally attached gutter bracket arm advantageously allows for setting a desired angle to compensate for roof pitch, alternatively a range of fixed angle attachments may be provided for the installer to select from.
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An improved gutter bracket assembly attached to exposed rafters for supporting a gutter provides increased strength as well as flexibility in attaching to various types of rafters by including a pair of flanges that attach to lateral sides of a rafter. Thereby, greater attachment strength is achieved than typical at the open grain of the rafter end. Attachable front and back clips provide secure attachment after initial placement of the gutter is made.
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This is a division of application Ser. No. 922,344, filed Oct. 23, 1986 now U.S. Pat. No. 4,877,470.
FIELD OF THE INVENTION
The present invention is directed to method and apparatus for forming bias laid, non-woven fabrics wherein, preferably, the yarns in at least two of the layers of fabric are laid at an angle of from 30° to 150° to the long axis of the fabric. In such fabrics, the yarns in the various layers are neither knitted, nor woven, but are held together by stitching through the layers, or by other external means, such as adhesive bonding.
THE PRIOR ART
The history of fabric formation is a long one. Most fabrics are made by the now traditional processes of knitting, weaving, etc., and sophisticated machinery has been developed for automatically manufacturing fabrics in accordance with these techniques.
For many modern usages, particularly in areas where structural strength and integrity are required, fabrics manufactured by the older techniques cannot be used. Such uses include structural parts for high speed airplanes where the fabric is to be impregnated with a curable resin system.
In the modern usages referred to, the traditional knitted or woven fabrics do not provide sufficient strength, even when impregnated with a curable resin system, following cure, to provide the necessary uniformity and strength. Accordingly, non-woven fabrics have been developed for such utilization.
The non-woven fabrics which have been developed for these structural uses involve a series of layers which are laid down, generally in a continuously formed fabric, and with at least the final width of the fabric during formation, the layers ultimately being held together by stitching through the layers, knitting with a loose stitch through the layers, or adhesively bonding threads of the layers at crossing points. The composition of the stitching material or of the adhesive material is not of critical importance, so long as the material has sufficient strength to hold the various layers together up to the time of resin impregnation, since the final strength of the part formed and the holding of the various yarns of the fabric in their proper position is accomplished by the cured resin.
The most desirable of the non-woven fabrics for structural purposes has been found to be those with at least two layers, the yarns of which are at an angle of approximately 45° to the long axis of the fabric direction, the two layers lying at 90° to each other. There can be more than two layers of yarns, depending upon the end use to which the fabric is to be put and either the first two layers, or any successive layers, can be placed at angles varying from 30° to 150° to the long axis of the fabric. If desired, a series of warp threads, lying parallel to the long axis of the fabric, a series of weft threads, lying at approximately 90° to the long axis of the fabric, or both, can be included. Once all of the fabric layers have been placed, the fabric is held together for storage, shipment, and ultimate impregnation, by one of the referenced methods, i.e., stitching, loose weave knitting, or adhesive bonding.
Among patents showing the formation of similar types of fabric are Eaton, U.S. Pat. No. 3,607,565; Smith, U.S. Pat. No. 3,765,893; and Campman et al U.S. Pat. No. 4,325,999.
The Campman et al patent particularly describes a number of methods for forming bias laid, non-woven fabrics, as generally referred to in the present patent application. However, as will be observed from a review of Campman et al, successive courses of each set of yarns there are laid in a pattern such that each course is angled at 90° to the previous course. For purposes of this invention, a course is defined as the plurality of yarns laid together in traversing the distance from one side of the fabric being formed to the opposite side; when the plurality of yarns reverses directions, and returns from the second side to the first side, that is a second course.
In Campman et al, prior to the reversal of direction of the yarns, so as to lay a second course, the yarns are wrapped around a series of pins, the number of pins corresponding to the number of yarns being laid. When the plurality of yarns is returned to the first side of the forming fabric, the yarns are wrapped about a set of pins formed on the conveyor on the first side, and, again, direction reversed by 90° so as to be returned to the second side for a fourth course. Campman et al do show one embodiment in which the courses of yarns formed by a single set of moving yarns are parallel to each other. That is, essentially, shown in FIG. 10 of the Campman et al patent, and the portion of the disclosure relating to that figure. However, a relatively complex mechanism is necessary to accomplish this parallelism between courses, the complex mechanism including two sets of pins on each side of the fabric being formed to allow the second, or return course, to be parallel to the first. None of the other automatic types of bias fabric formation machinery known to applicant provides even a mechanism of this complexity for forming parallel courses, except for applicant's patent, referred to below.
The inability to provide parallel courses results, in many instances, in a diminution of strength of the structural member being formed from these bias laid, non-woven fabrics. Further, because there is a waste of yarn due to the 90° return angle, which causes the second course to partially overlie the first course, the expense of the bias laid, non-woven fabric is greater than it would be if parallel courses were possible.
In my prior U.S. Pat. No. 4,556,440, a method and apparatus are shown for forming bias laid, non-woven fabrics, in parallel based, in part, on the speed of the yarn carrying means being diminished near the ends of its travel and possible movement of those means in a direction opposite the direction of fabric travel at a point where the yarns being conveyed are to be placed onto or between the needles of the continous conveyors. That patent also describes the possibility of some overlap of a returning course over a course already laid from the same group of yarns. However, as that patent stated, when such an overlap is created, there is also a slight angle between the course first laid and the return course.
In Klaeui, U.S. Pat. No. 3,564,872, an apparatus and process for laying parallel courses of yarn is also taught, employing a rake. However, the disclosure of the Klaeui patent is limited to yarns laid at a 90° angle to the direction of movement of the conveyors; there is no provision for an overlapping of a return course, the courses in Klaeui being laid adjacent each other; and all of the operating systems, including the conveyors, the yarn carriers, and the rakes, are driven from the same system of gears and pulleys, so that no variation is possible between the various operating systems, once a machine is constructed.
Further, Klaeui does not teach the possibility of impaling the yarns on either the rake or on the means formed on the conveyors for holding the yarns.
The prior art has not shown a process or apparatus which allows fully parallel courses of bias laid, non-woven fabrics to be placed on moving conveyors where partial overlapping of return courses is provided for and where the yarns being laid onto the conveyor can be either placed between holding means, such as needles, or impaled on them. Because of the greater control of strength and uniformity provided by either or both of these steps, such apparatus and process have been ardently sought.
BRIEF DESCRIPTION OF THE INVENTION
In accordance with the present invention, it has unexpectedly been discovered that if a rake mechanism, synchronized with, but driven separately from, the conveyors, yarn carrying means, and bonding mechanism, is associated with the needles formed on the conveyors, greater assurance of parallelism of the yarns is achieved. Further, employing this rake mechanism, successive courses of yarn can overlie a portion of an already laid course so as to better control the strength and thickness of the resulting layer, the overlying portions being parallel to the first courses. As with the invention set forth in my prior patent, it is not important whether the individual yarns fall between the needles or are impaled on the needles, and that is true with regard to both the needles of the conveyor and the needles of the rake system.
Preferably, the needles on the rake system are formed at an angle to correspond to and supplement the angle of the approaching yarns being fed by the yarn carrying means, at each end of the travel limits of the yarn carrying means. Thus, for example, if the yarn carrying means is angled at 45° to the angle of travel of the fabric being formed, then the needles of the rake mechanism beyond one of the conveyors is formed at 45° and the needles of the rake mechanism beyond the opposite conveyor are formed at 135°. Similarly, when the yarn carrying means is at an angle of 30°, then the needles of the rake mechanism beyond the first conveyor are at an angle of 30°, while the needles on the rake mechanism beyond the opposite conveyor are at an angle of 150°. The rakes, themselves, to which the needles are attached, are always parallel to the belt conveyor system.
The purpose of the rake mechanism is to accept and retain the yarns being carried by the yarn carrying means at either end of the extremities of travel of the yarn carrying means. Thus, the yarns being carried by the yarn carrying means are accepted between the needles of the rake mechanism on the appropriate side of the fabric forming apparatus, either by being placed between adjacent needles, or by being impaled by one of the needles. The rake mechanism, through a movement opposed to the direction of travel of the conveyors on the fabric forming mechanism, and in conjuction with the return travel of the yarn carrying means, places the yarns onto or between the appropriate needles on the conveyors of the fabric forming mechanism. Again, the yarns can be placed between adjacent needles on the conveyors, or can be impaled on those needles. As explained in my prior patent, the impaling of yarns on the needles frequently provides for a more uniform product.
In order to make certain that the yarns are appropriately held within or on the needles of the rake mechanism, when the yarn carrying means is travelling in, essentially, the same direction as the fabric forming mechanism, the rakes must first be moved a slight distance in the same direction as the conveyors, whereby the yarns are trapped by the rake mechanism, and then the rake mechanism will move backward, against the direction of travel of the conveyor, in order to release the yarns to the conveyor needles. When the direction of travel of the yarn carrying means is, essentially, against the direction of travel of the fabric forming mechanism, this double motion of the rake mechanism is not required, and the rake mechanism need merely move opposite the direction of travel of the fabric forming mechanism. When the rakes are moved a slight distance in the same direction as the conveyors, the movement is sufficient to place the yarns over the needles of the rake, generally a movement of at least one needle space, and preferably two or three needles spaces. The amount of movement of the rake in this additional direction does tend to vary with the thickness of the yarn being employed.
Two different modes of operation are possible for the rake mechanism. In its travel opposite the direction of movement of the fabric forming mechanism, the rake system may either move a distance which is the same as the width of the yarns being carried by the yarn carrying means, i.e., a full course, or may move a distance equivalent to only a portion of the width of the yarns, i.e., a fraction of a full course. When only a fraction of a complete course is traversed by the rake mechanism, obviously, there is some overlap of the return course onto the course first laid. The desired width of this overlap is determined, not by the construction of the apparatus or any limitation on the process, but rather by the requirements of the use to which the ultimately formed fabric is to be put. Obviously, the less the amount of travel of the rake system, the greater will be the overlap of successive courses, and the denser will be the fabric formed; conversely, when the rake system travels a substantial percentage of the width of a course, there will be relatively little overlap of successive courses, and a lesser density of that layer in the finally formed fabric.
Because of the use of the rake system, particularly when used in conjunction with the slowing of the movement of the yarn carrying means near the extremities of travel, as set forth in my prior patent, complete parallelism within each layer is attained, with or without overlap. When there is overlap, the overlapped portions are parallel with the yarns of the first course, unlike the fabric construction set forth in my prior patent.
While my prior patent set forth the possibility of a movement of the yarn carrying means in a direction opposite that of the travel of the fabric forming mechanism, in addition to movement of the carrier back and forth between the conveyor, that is not required in accordance with the present invention to achieve parallelism of successive courses. It may be used as an additional means of achieving parallelism in accordance with the present invention, but is not required.
While the disclosure of the present invention primarily describes the use of a sewing machine to bind together the various layers of a bias laid, non-woven fabric, it will be appreciated that other methods of bonding the layers to each other can be employed, including knitting, adhesive application, etc.
In accordance with the present invention, the apparatus for stitching the various layers of the bias laid, non-woven fabric together can be any of the machines presently employed in the textile industry for such a purpose. For example, the machine presently sold by Liba Maschinenfabrik GmbH of West Germany, under the designation Copcentra-HS, is suitable for formation of fabrics in accordance with the present invention. Both because this machine is known to the trade, and because the present invention does not include, as novel subject matter, the method of stitching the various layers together, this specification will not include a detailed description of the sewing mechanism. The Liba Copcentra-HS machine is provided, in its operative gearing, with an oscillating crank mechanism. Because of the inherent nature of the operation of such a crank, the oscillating drive shaft controlled by the mechanism moves more slowly before its direction is reversed. By keying the movement of the yarn carrying means to this oscillating drive shaft, movement of the yarn carrying means is slowed at the end of each course, which allows the conveyor mechanisms to move relatively further forward than would otherwise be true, and aid in gaining parallelism of the various courses. The operation and construction of this portion of the Copcentra-HS machine is fully set forth in my prior patent, U.S. Pat. No. 4,556,440, and that portion of that patent is herein incorporated by reference.
In accordance with the present invention, a pair of parallel conveyors is formed, the front supports of the conveyors being at the head of a bonding mechanism, such as a Liba Copcentra-HS stitching machine. Each conveyor carries a series of equidistantly spaced needles which extend outwardly from the space between the conveyors. The fabric to be formed is placed on these conveyors and, more particularly, the individual yarns are placed around or on the individual needles. In general terms, each conveyor is comprised of an endless chain to which are attached members on which the individual needles are formed, the members, on the operating portion of the conveyor belt, forming a continuous, moving bar. The drive mechanism for the conveyors is independent of the drive mechanism for the yarn carriers, at least in the sense that the conveyors are moved at a constant speed.
Yarn carriers move back and forth between the moving conveyors. Each yarn carrier carries a plurality of individual, equally spaced yarns. The yarn carriers are caused to move beyond each conveyor and its associated rake system, as the yarn carrier passes beyond the rake system, it moves downwardly, so as to place the individual yarns which are carried around the needles on the rake system, or to cause the needle on the rake system to impale one of the yarns. Thus, it will be recognized that the number of yarns in a given linear dimension need not equal the number of needles in the same linear dimension. When number of yarns in a given linear dimension is greater than the number of needles in the same linear dimension, some of the yarns will be impaled by the needles, providing for a more uniform coverage. In this way, the density of each layer can be controlled, as desired.
The number of yarn carriers employed, and thus the number of individual layers, is determined by the end use of the bias laid, non-woven fabric being produced. The angle at which the yarn carriers place the courses of yarn on the moving conveyors is, likewise, determined by the end use to which the final fabric is to be put. While for many uses, angles of 45° to the long axis of the fabric, for each of two courses, is preferred, it will be apparent that other angular settings can be employed and that more than two layers can be placed on the moving conveyors. Generally, the bias laid layers are at angles of between 30° and 150° to the long axis of the fabric. In addition to the bias laid layers, however, a warp layer can be included in the fabric being formed, the yarns in the warp layer being placed in the standard manner essentially parallel to the moving conveyors. Similarly, one of the yarn carriers can be angled so as to place a weft layer onto the fabric being formed, the angle of the weft layer being the standard, essentially 90°, to the long axis of the fabric.
As previously indicated, the two conveyors move at a constant speed toward the bonding mechanism where the fabric layers are bound together. The yarn carrying means, while moving at a generally constant speed across the fabric being laid, can be slowed down in their travel across the fabric at the end of each course. Because the movement of the yarn carrier can be keyed to an oscillating crank mechanism, and because that crank mechanism slows down near the end of each stroke, movement of the yarn carrying mechanism is also slowed near the end of the stroke, which is keyed to correspond with the end of the course.
Thus, the present invention provides for the formation of bias laid fabrics where all of the yarns in a given layer are parallel to each other. The parallelism in a given layer is achieved without complex machinery. Further, because the number of yarns need not equal the number of needles over a given linear dimension, greater density and uniformity are provided. Use can be made of the mechanism of the bonding portion of the apparatus to aid in the laying of the yarns so as to achieve these advantages.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a plan view of one preferred form of bias fabric in accordance with the present invention;
FIG. 2 is a plan view of a second form of bias fabric in accordance with the present invention;
FIG. 3 is a perspective view, partly representational, showing the mechanism for placing the bias laid yarns on the conveyors;
FIG. 4 is a top plan view showing the conveyor, conveyor needles, rake system, and yarn carrier in accordance with the present invention along the line 4--4 of FIG. 3;
FIG. 5 is a sectional view showing a single needle of the conveyor system and a single needle of the rake system, with the yarn carrier beyond, and below, the rake system; and
FIG. 6 is a sectional view along the line 6--6 of FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, FIG. 1 illustrates a layer of yarns laid with the process and apparatus of the present invention, including a first course C and a second course C'. As will be apparent, each of the courses is laid at an angle of approximately 45° to the direction of the fabric forming mechanism shown by the arrow A. The apparatus and process of the present invention are so adjusted in forming the fabric of FIG. 1, that course C' is laid adjacent course C, without any overlap; however, as will be apparent, the two courses are parallel to each other.
In FIG. 2, a fabric is formed in accordance with a second embodiment of the present invention where the process and apparatus are adjusted to provide for an overlap of yarns in successive courses. Thus, with a fabric forming direction illustrated with the arrow B, a first yarn course D is laid at approximately a 45° angle to the fabric forming mechanism. A second course D' is then laid parallel to course D, and overlying approximately one-half of the width of course D. It will be appreciated that FIG. 2 is merely one illustration of the amount of overlap which can be achieved employing the process and apparatus of the present invention, more or less overlap being possible and being dictated by the requirements of the finished fabric.
An overview of the placement of the bias laid yarns in accordance with the present invention is shown in FIG. 3. The system is similar to that described in my U.S. Pat. No. 4,556,440. Two endless conveyors 30 and 31 are shown, respectively, on the left and right hand sides. These conveyors 30 and 31, which are of the same length, are driven at the same speed by forward pulleys 32 and 33 and are suspended on rearward pulleys 34 and 35. Forward pulleys 32 and 33 are connected by axial member 36, while rearward pulleys 34 and 35 are connected by axial member 37. Each conveyor includes a plurality of blocks 40. Formed onto, or from, each block are a series of sharp needles 42 best illustrated in FIG. 4.
Formed across, but slightly above, the conveyors 30 and 31 are a plurality of guide arms 50, 51, 52. Three such arms are illustrated for laying of three layers of yarn, but it will be appreciated that additional guide arms and complete yarn laying assemblies can be provided, depending upon the number of layers of yarn to be incorporated into the bias laid fabric. Similarly, the number of such guide arms can be reduced to two. Moving along each of the guide arms is a member 53 to which is attached a yarn carrier 54, each yarn carrier being employed for laying a plurality of yarns 55. It will be appreciated, from a review of FIG. 3, that regardless of the angling of the guide arms 50, 51, 52, the yarn carrier 54 is placed in a direction parallel to the movement of the conveyors 30, 31.
As illustrated in my prior patent, U.S. Pat. No. 4,556,440, the yarn carriers are mounted in a slot so that they dip down below the level of the needles 42, and similar needles formed on the rake systems, to be described, in order to allow the yarns 55 being carried to be caught in the rake system at either end of the travel of the carriers 54. As also set forth in that patent, each of the carriers 54 may be mounted on a pneumatic cylinder attached to a source of air or other gas under pressure to allow movement of the carrier 54 rearwardly as the yarns are caught on the rake system.
While not illustrated, a device having means to hold the individual yarns in the fabric 60 together is placed at the end of the mechanism illustrated in FIG. 3, just before the pulleys 32, 33. This device can be a stitching machine; such as the previously described Liba Copcentr-HS, can be a different type of stitching machine, a knitting machine, or a device which applies an adhesive at selected points along the fabric length and width in order to hold the yarns together, prior to impregnation.
Through a driving means the yarn carriers are moved back and forth across the short axis of the fabric being formed. Either the bonding mechanism contains a driving means, such as an oscillating crank mechanism, which causes the speed of the yarn carrier to be reduced near the end of its travel, or such an oscillating crank mechanism can be provided, separate and apart from the bonding unit, in order to accomplish the same results. While the slowing down of the carriers 54 near the end of travel, beyond the conveyors, can be omitted when the rake system is employed, this slowing down is an aid to attaining parallelism of the yarns, even with the rake system.
In addition to being slowed down by this mechanism at either end of its travel, it is necessary to cause the yarn carrier to drop down below the level of the needles 42, when the carrier has passed beyond those needles and the associated conveyor. This dropping down is required in order to allow the yarns to be wrapped around the needles, or to be impaled by them. This is accomplished by mounting the yarn carrier on a guide pin which travels in a horizontal slot in a guide arm, that slot being angled downwardly beyond the conveyor and the rake system, so as to cam the yarn carrier downwardly, and move the yarns below the horizontal level of the needles. On the return stroke, the yarn carrier moves upwardly, completing the operation of wrapping the yarns around the needles, or impaling them; and then returns across the fabric being formed.
The particular improvement of the present invention involves the rake systems illustrated, on the left hand side of the machine, as numbers 70, 71, and 72 and, on the right side of the machine, as 80, 81, and 82. While the general structure of each of these rake mechanisms, and their method of operation, is the same, there are some variations, as will be detailed below. The rake systems and their operation are best illustrated in FIGS. 4, 5, and 6.
As illustrated in FIGS. 3 and 4, the conveyors 30 and 31 have a number of blocks 40 formed on an endless chain. Extending from each of the blocks 40 are sharp needles 42 which are spaced equidistantly. As best seen in FIG. 4, the needles extend at, essentially, right angles to the blocks 40 and conveyor 31. As best illustrated in FIG. 5, the needles 42 are angled slightly upwardly from the blocks 40. This slight angling upwardly is provided to allow grabbing of the threads and proper interaction of the needles 42 with the rake systems 70, 71, 72, 80, 81, and 82, and the carriers 54. The amount of angling should be from 10° to 40°, preferably from 20° to 30°.
The rake system illustrated in FIG. 4 is, essentially, the one shown in FIG. 3 as 80. While the guide member 50 is, essentially, at a 45° angle to the conveyor 31, the carrier 54 is, essentially, parallel to that conveyor. The needles 100 formed on rake 80 are at approximately a 45° (135°) angle so as to supplement the angle of the guide member 50 and provide the proper interaction with the yarns being carried by the carrier 54. The angling of the needles 100 on the rake system should correspond, roughly, to the supplement of the angle of the particular guide member in association with which they are used. Thus, if the guide member is at 30°, the needles on the rake system should be at 150°; if the guide member is at 45°, the needles on the rake system should be at 135°; if the guide member is at 60°, the needles on the rake system should be at 120°; if the guide member is at 90° to the direction of travel of the fabric being formed, the needles 100 on the rake system should be at 90°. It has been found, however, that the 45° rake system can be employed with both the 30° and 60° guide members.
As best illustrated in FIG. 5, the needles 100 on the rake system have an essentially vertical portion 101, extending upwardly from the rake system 80, and are then bent over at 102, so that the point of the needle 103, is angled downwardly. Generally, the angle E between the upstanding vertical portion 101 and the portion of needle 100 on which the point 103 is formed is the same as the angle F between the needle 42 and the block 40. The angle E may be greater than the angle F, but the point 103 must lie below the needle 42. Preferably, the angle E is approximately 55°. This is to prevent the yarn from escaping from the rake as the carrier is raised, and then travels back across the conveyor system. The alignment, bending, and angling of the needles 100 from the rake system 80 is best illustrated in FIG. 6. It will be appreciated, as just described, that the angling of the needles 100 on the rake system 82 will be exactly opposite that shown in FIGS. 4 and 6, and the angling of the needles 100 on the rake systems 71 and 81 will be at essentially right angles to the rake systems 71 and 81 and, therefore, at, essentially, right angles to the conveyors 30 and 31. The angling of the needles on the rake system 70 will be essentially the same as those on the rake system 82, while the angling of the needles on the rake system 72 will be essentially the same as those on the rake system 80.
In operation, and referring, particularly, to the rake system 80 of FIG. 4, as the conveyor 31 moves in the direction indicated by the arrow G, and the carrier 54 moves in the direction indicated by the arrow H, the yarns 55 are moved to a point beyond the rake system 80 and below the points 103 of the needles, as best illustrated in FIG. 5. The rake system 80 then moves in the direction indicated by the arrow I in FIG. 4 so as to firmly grasp the yarns 55 which are in the vicinity of the needles 100 formed on the rake system 80. As previously indicated, the individual yarns 55 may either fall between adjacent needles 100, or may be impaled on an individual needle 100. Obviously, with certain types of yarns, such as carbon fibers, the sizing and spacing of the yarns 55 and the carrier 54 would be such that none of these yarns would be impaled.
As the carrier 54 is raised upwardly, away from the rake system 80, it begins to move in a direction opposite the arrow H and, because of the tension in the yarns, pulls the yarns off of the rake needles and places them, firmly, on the needles 42 formed on the conveyor 31, as illustrated by the yarn 55' in FIG. 4.
When the conveyor 54 has completed its travel across the fabric being formed, to the opposite conveyor 30, the process is repeated, with one exception. In returning across the fabric being formed to the conveyor 30, the yarns are beyond, and below, rake system 70, when the conveyor 54 dips down. In order to assure retention of the yarns 55 in the needles 100 of the rake system 70, the rake system 70 must first move slightly forward, i.e., in the same direction as the conveyor 30 is travelling, before it is moved rearwardly for depositing of the yarns 55 on and within the needles 42 of the conveyor 30. Only a slight movement of the rake 70 in a forward direction, i.e., a distance sufficient to place the yarn over the needles 42 formed on the conveyors 30 and 31. Generally, the forward movement of the rake system 70 is approximately the distance between two of the needles 100, preferably the distance between two to three of the needles 100. The amount of movement required tends to vary with the thickness of the yarn.
The operation of the rake systems 71 and 81, and of the rake system 72 is the same as that described for the rake system 80. This is because the carrier 54 is moving either at right angles, or in a direction opposite the direction of travel of the fabric being formed. The operation of the rake system 82 is the same as that of the rake system 70, since the carrier 54, at that point, is moving in the same direction as the direction of travel of the fabric being formed.
While the means for moving the various rake systems are not illustrated, any convenient means can be employed. Thus, the rakes may be moved pneumatically, mechanically, or by a solenoid movement.
As previously indicated, the density of the fabric can be controlled by overlapping of return courses on first courses. This is accomplished without loss of parallelism. Further, this increased density is accomplished without requiring too high a concentration of yarns in each carrier, a situation which could lead to difficulty in operation of the mechanism. Without the rake systems of the present invention, this overlapping with paralellism could not be accomplished. The amount of overlap accomplished is, generally, based upon the width of the yarns 55 in the carrier. Obviously, this width has nothing to do with the denier of the yarns, but rather refers to the dimension W shown in FIG. 3. As this width increases, with the same travel of the rake system, there is a greater overlap of yarns, while as the width W is decreased, with the same movement of the rake system, there is less of an overlap of yarns.
The amount of movement of the rake systems 70, 71, 72, 80, 81, and 82, and of the carriers 54, in a direction opposite the direction of fabric formation is dependent upon the speed of the conveyor. The speed of the conveyor is dependent upon the number of stitches per inch being placed by the needling machine, when one is used, i.e., the fewer the number of stitches, the faster can be the fabric formation.
As indicated in my prior patent, the number of yarns in the carrier 54 need not correspond to the spacing of the needles 42 formed on the conveyors. Similarly, the number of yarns in the carrier 54 need not correspond to the number of needles 100 on the rake system in the same linear dimension, nor do the number of needles 100 in the rake system have to correspond with the number of needles 42 on the conveyor in the same linear dimension. As previously indicated, the ability to impale some yarns aids in control of density uniformity.
As indicated, the fabric formed in accordance with the present process is generally used in the formation of structural parts, as in airplanes, and in such a use is wrapped around a mold, or laid into a particular position, after which, or prior to, being impregnated with a resin. When the fabric is fully in place and impregnated, the resin is cured to complete formation of the part.
While the description of the present invention has involved a stitching of the various fabric layers together, it will be appreciated that other methods for holding the non-woven fabric in place can be employed. For example, a loose knitting operation, as is known in the art can be employed. Further, a light resin spray can be applied to bond the fibers at their crossing points. Again, the material which is employed for this bonding, or the materials used, are not of critical importance, as the ultimate strength of the bias laid non-woven fabric comes from the resin which is finally used for impregnation and which is cured with the fabric in place. If the bonding mechanism used for the fabric does not have a device, such as the oscillating crank of the Liba Copcentra-HS, then such a mechanism can be independently provided for driving of the yarn carriers in order to provide for their reduced speed of motion near the ends of the travel paths.
No mention has yet been made in this specification of the loops which are obviously formed, either by the yarns wrapping around the various needles or by being impaled on them. As is apparent, these loops are at the extremities of the width of the fabric being formed. After stitching or other methods of bonding, so that the fabric is generally held together, the loops can be cut away by any known mechanism. Once the other bonding means have been put into place, the loops, which had served only the function of holding the fabric in place up until that time, are no longer required.
While the invention has been illustrated and described in accordance with the particular embodiments, it will be apparent to those skilled in the art that variations are possible within the spirit and scope of the invention. Accordingly, the invention is not to be considered as limited except as set forth in the appended claims.
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Non-woven, bias laid fabrics, where the various fabric layers are held together by external means, such as stitching, and wherein, preferably, at least two of the layers are formed at an angle of from 30° to 150° relative to the long axis of the fabric, are formed by directing at least two pluralities of yarns back and forth across the width of the forming fabric, to be wrapped around or mounted on a series of needles formed on a moving conveyor, one conveyor being placed on either side and moving in the direction of the long axis of the fabric. Speed of movement of the yarns can be determined by the speed of movement of the mechanism for the machine operated to hold the various fabric layers together; preferably said machine mechanism moves more slowly near the ends of each cycle, so that yarn carriers are similarly slowed at either end of the forming fabric width, aiding in making successive courses of yarn lie parallel to each other without the necessity for extra equipment. A second series of needles is provided beyond each moving conveyor, in association with each plurality of yarns being directed back and forth across the width of the forming fabric, to accept the plurality of yarns and place them onto or into the needles on the moving conveyor, the additional series of needles providing for parallelism in each plurality of yarns, with or without overlap of each plurality of yarns.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a divisional application of co-pending application Ser. No. 404,333 now U.S. Pat. No. 4,502,103, filed July 30, 1982, for LIGHT WITH MOUNT FOR PLURAL LAMP BULBS.
BACKGROUND OF THE INVENTION
The invention relates generally to lights that have a dual function, operating as a flood light or as a spot light. One such Combined Flood and Spot Light is described in U.S. patent application Ser. No. 285,944, filed July 23, 1981, by the Applicant herein. More particularly, the invention relates to lamp bulb mounts, which support and align two lamp bulbs to achieve the dual function light. The invention also relates to lamp bulb sockets that are capable of accepting different types of lamp bulbs. The invention is particularly well suited for portable lights and driving lights.
Separate units for flood or fog lighting and for spot lighting have been available for many years. Campers, police officers and fire fighters have used separate units without great inconvenience. The separate units are hung from belts, and whichever unit is desired can be taken in hand when needed. However, it is apparent that a single unit having both capabilities would be highly desirable in any case and particularly so when the lights are mounted on motor vehicles where the space for attachment is more restricted as vehicles become smaller.
The present invention is particularly useful in association with a Combined Flood and Spot Light of the type described in Applicant's copending U.S. patent application Ser. No. 285,944, referenced above. Such a light, as described in the copending application, utilizes two bulbs in axial alignment with each other and positioned relative to each other and to a forwardly facing and a rearwardly reflecting reflecting member of the light. A mount that will align and position a pair of light bulbs, while maintaining easy access to both light bulbs for replacement, has not been previously available. Neither has there been available a mount for use with a light which was versatile enough to accept the different types of halogen lamp bulbs which are widely used in automobile driving lights and other high intensity requirements, such as police and fire work.
DESCRIPTION OF THE PRIOR ART
Combined flood and spot lights utilizing two distinct lamp bulbs as separate light sources in a single unit, are known. Dual lamp bulbs mounted within separate reflectors of a single driving light for automobiles are seen in U.S. Pat. Nos. 3,622,778 to T. Cibie and 3,870,876 to O. Puyplat. In both of these patent references, the lamp bulbs are offset with respect to a longitudinal axis of the light and to each other.
A pair of separate light bulbs that are mounted in an axial relationship to each other, along the longitudinal axis of a driving light of generally circular transverse cross section, are seen in A. Kush, U.S. Pat. No. 1,148,101 and A. Plewka, U.S. Pat. No. 3,759,084. Both Kush and Plewka rely on the concept of a pair of forwardly diverging and projecting reflective members or surfaces spaced along the longitudinal axis a slight distance away from each other. One of the lamp bulbs is mounted at each of the reflecting members at the rearmost concave position. Special provision must be made, as by removing one of the reflecting surfaces, in order to gain access to the rearwardmost lamp bulb for replacement.
Of particular interest in driving lights and portable lights, because of their relatively high intensity, are halogen lamp bulbs. Such lamp bulbs come in two main configurations. Axial filament halogen lamp bulbs, having wattages between fifty-five and eighty-six watts, are known as type H2. These axial filament lamp bulbs mount into a lamp socket through a pair of outwardly directed flange portions. A second type of halogen lamp features a filament transverse to a longitudinal axis of the lamp bulb. These transverse filament lamp bulbs are known by type T 21/2 or T 23/4 and have a wattage range of between six and fifty watts. A pair of twin leads or pins, parallel to a longitudinal axis of the lamp bulb, are the means through which connection to a lamp socket are made. No known devices possess the capability of connectably accepting, in a single socket, either the flange type or twin lead type of the halogen lamp bulbs.
It is known that to cool the lamp bulbs themselves can increase the endurance and the useable lifetime of the lamps. Increasing the endurance and useable lifetime of portable light units is particularly important because such units are usually employed in special or emergency situations where ultimate performance and longevity are required, or may even be critical.
OBJECTS AND SUMMARY OF THE INVENTION
It is the principal object of the present invention to provide a new and improved light that can function as a flood light or a spot light.
It is a related object of the present invention to provide a mount for a pair of axially aligned lamp bulbs of a light, which mount aligns and positions the lamp bulbs to advantageously achieve the desired flood and spot lighting functions.
It is a further related object of the invention to provide a lamp bulb support for axially aligned lamp bulbs that is easily removable from the light to replace either a forward or a rearwardly mounted lamp bulb.
It is another object of the present invention to provide a mount capable of accepting either or both of a flanged type or a twin pin type of a halogen lamp bulb.
It is still another object of the invention to provide a portable light powered by a rechargable battery and a control circuit in which the battery and control circuit are cooled to increase performance efficiency, prolong life and achieve reliability.
In accordance with these and other objects of the invention, a combination flood and spot light uses a pair of axially aligned lamp bulbs to function as a flood light or a spot light. A mount of the lamp bulbs aligns and positions the lamp bulbs relative to a forwardly directed reflecting member or surface of the light.
The lamp mount includes a generally cylindrical forward base with a forwardly divergent surface geometrically formed to matingly conform to the forwardly divergent reflecting member at a rearmost termination thereof. The forward base is releasably connected to a rearward base. The rearward base has a width approximately equal to that of the forward base and each base supports a lamp bulb of the light. The forward and rearward bases are received in a tubular support of the light. The lamp bulb of the rearward base projects through the forward base, while the lamp bulb of the forward base forwardly extend from the forward base a preselected distance. The preselected distances are established to achieve spot and flood reflection patterns from the reflecting member. The forward lamp bulb gives a spot light function to the light rays emanating therefrom, while the rearward bulb achieves the flood light function.
A socket adapted to receive either a flange type or a twin lead type halogen lamp bulb is connected both the forward and rearward bases. In order to achieve interchangeable acceptance, each of the sockets includes a pair of spring mounting means, each of which have the capability of accepting either type of halogen lamp bulb. Convenience is inherent because only one lamp bulb type may be available to a user. In an emergency situation, as may be encountered in police and rescue work, any bulb is better than none. Flexibility with respect to the flood and spot light configurations is available because the wattage specifications and light emission pattern will vary depending on the lamp bulb chosen.
The light includes a forwardly diverging housing into which the rear reflector member is mounted. Across the forwardmost termination of the housing a glass lens is secured. The housing is connected to the hollow tubular support, which support has fins formed on the outer surface thereof to effectuate cooling of the mount. The tubular support is connected to a handle of the light through a pivotal connection. The handle is hollow and, in turn, connects to a case. An outlet of the case registers with a fan driven by a motor which is contained within the case. Air moved by the fan enters an inlet of the case, moves past the battery and control circuit through the handle and pivotal connection into the tubular support, cooling the mount and lamp bulb, and exhausts through air holes in the housing.
Cooling of the entire light can increase endurance and therefore overall battery life, particularly a rechargable battery, since excess heat is deleterious to battery life. Maintaining a lower ambient temperature around the battery and control circuitry increases the efficiency and maximizes the lifetime of those components.
The invention is defined by the scope of the appended claims. A greater appreciation of the objects, improvements and features of the present invention can be obtained from the following detailed description and drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view of a light of the invention secured to a handle and a case, certain portions of the light being broken away and shown as section views for clarity, wherein a motor, control circuit and rechargable battery are shown in diagrammatic form.
FIG. 2 is an exploded perspective view of a lamp mount and reflector of the invention, certain portions being broken away for clarity.
FIG. 3 is a sectional view taken in the plane of line 3--3 of FIG. 1.
FIG. 4 is an exploded side elevation of the mount shown in FIG. 2, certain portions of the mount being removed for clarity and shown as section views.
FIG. 5 is a section view taken in the plane of line 5--5 of FIG. 4.
FIG. 6 is an exploded perspective view of one terminal of a socket of the mount seen in FIG. 2.
FIG. 7 is an exploded perspective view of another terminal of the socket of the mount seen in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A mount 10 for a pair of lamp bulbs 11 and 12 insertable into a multiple function light 22 is seen in FIGS. 1, 2 and 4. The mount 10 is insertable into the light 22 (FIG. 1) in a predetermined orientation so that the bulbs 11 and 12 are aligned along an axis 24, which axis is a longitudinal axis of the light 22.
The mount 10 is formed from two releasably connected pieces, a forward base 14 and rearward base 16. (FIGS. 2 and 4) A socket 19 of the forward base 14 accepts lamp bulbs having either the connection seen in lamp 11 or the connection seen in lamp 12. Similarly, a socket 20 of the rearward base 14 is adaptable for either type of lamp bulb 11 or 12.
The light 22 includes, at a forward end 26 thereof, an outwardly or forwardly divergent frustoconical housing 29 and at a rearward end 28 a hollow tubular support 30 within which the mount 10 is inserted from the rearward end 28. Hereinafter, reference will be made to forward and rearward in relation to the forward and rearward ends 26 and 28 of the assembled light 22, including the mount 10. The axis 24 is the longitudinal axis of the housing 29 and the tubular support 30, both the housing 29 and tubular support 30 presenting circular perpendicular cross sections relative to the axis 24. The housing 29 surrounds and retains therein a reflector member 32. The lamp bulbs 11 and 12 project through a central opening 34 in a concave recess 33 of the reflector member 32.
The relative dimensions and locations of the components of the light 22 with respect to each other are chosen so that light rays emanating from the forward lamp 11 will strike the forwardly divergent, preferably parabolic, reflector member 32 of the light 22, which reflector 32 will reflect the rays forwardly in a substantially parallel array, providing a spot light effect. The rearward lamp 12 is mounted in the concave recess 33 of the reflector 32 so that the light rays emitted are not focused by the parabolic reflector 32, instead travelling in a random array, providing a flood light effect. A double pole, double throw switch 23 is mounted on a handle 36 of the light 22 to separately actuate the forward lamp 11 or the rearward lamp 12.
A fan 40 is mounted within a case 38, which case is connected to the tubular support 30 by the handle 36 and a pivotal connection 37 (FIG. 3), and which fan 40 provides air movement means for cooling of the light 22. The fan is turned by a motor 41, the motor being actuated by a thermostat 43 connected to a battery 42, upon excess heat in the case 38. The battery 42 powers the lamp bulbs 11 and 12 and drives the motor 41. The battery is turned on by, switching takes place through, and the thermostat 43 is actuated through a control circuit 44.
The entire light 22 is maintained at an optimum temperature by air movement from the fan 41, which air movement passes by the battery 42, the control circuitry 44, the motor 41 and the lamp bulbs 11 and 12, before exiting or exhausting the light 22 through air holes 46 formed in the housing 29.
The forward base 14 of the mount 10 is of generally cylindrical shape (FIGS. 2 and 4). A slot or opening 47 is formed therethrough, which slot 47 is centered along the axis 24 when the forward base 14 is inserted into the tubular support 30. The opening 47 allows for passage of the rearward lamp bulb 12 through the forward base 14 and into a position between posts or terminals 17a and 17b of the socket 19 upon the connection of the rearward base 16 to the forward base 14 (FIG. 1).
To permit the connection between the rearward base 16 and the forward base 14 and to align the mount 10 with the reflector 32, the forward base 14 includes a pair of alignment pins 48 which project rearwardly and forwardly from the upper base 14 in parallel alignment with the axis 24, upon insertion of the forward base 14 into the tubular support 30. A forward surface 49 of the forward base 14 is forwardly concave or projecting. Upon insertion of the mount 10 into the tubular support 30, the surface 49 contacts and conformably mates to the concave recess 32, on the rearward side thereof in the area of the central opening 34. The alignment pins 48 pass through corresponding alignment holes 50 in the reflector 32 (FIG. 2).
A pair of contact notches 51 (FIG. 4) are formed in one half of the forward base 14, which branch to the side of the opening 47. The contact notch 51 allows for connection of the posts 17a and 17b to the forward base 14. A foot pad 41 (FIGS. 6, 7) of each of the posts 17a and 17b is threadably connected to the forward base 14 at the contact notch 51 by a nut and bolt, which defines a contact point 52. The contact point 52 is also connected to a like contact point 54 on the rearward base 16 by electrical conductors 21. (FIG. 2) A longitudinal groove 53 is formed in the forward base 14 between the contact notches 51. It is noted in FIG. 4 that the groove 53 is positioned ninety degrees away from a plane containing the posts 17a and 17b. This positioning of the groove 53 allows clearance of posts 18a and 18b of the rearward base 16 of the socket 20 as the rearward base is connected to the forward base 14. It is therefore seen that the mount 10, as assembled, includes the posts 17a and 17b containing the lamp bulb 11 and, in a plane perpendicular to the plane containing the posts 17 a and 17b, the posts 18a and 18b.
The rearward base 16 (FIGS. 2 and 4) has a pair of alignment holes 55 formed along bores having axes parallel to the axis 24, the holes 55 therefore being provided to receive the alignment pins 48 of the forward base 14. The rearward base 16 is of a U-shaped configuration including parallel arms 56 and an interconnecting cross piece 57. The posts 18a and 18b are connected to the base 16 by the contact points 54, which are bolts with nuts threaded thereon, to the cross piece 57. The forward and rearward bases 14 and 16 are formed from injection molded high temperature plastic (polyphenylene sulfide) sold under the trademark RYTON (R4).
The posts or terminals 17a and 18a of the sockets 19 and 20 are substantially identical, as are posts 17b and 18b. (FIGS. 6 and 7) The following description will first focus on the guide posts 17a and 18a. Each guide post 17a and 18a includes the foot pad 41 (FIG. 5), which foot pad and contacts 52 and 54 are connected to the battery 42. Each guide post 17a and 18a also includes a rectangular upright 61 having a longitudinal axis parallel to the longitudinal axis 24, which upright 61 is of substantially rectangular plate construction. At the forwardmost terminal end of the guide posts 17a and 18a is located a small nipple 62. Intermediate the foot pad 41 and the small nipple 62, but nearer the small nipple 62 is a larger nipple 64. The nipples 62 and 64 are both integrally formed. An arm 66 extends laterally away from the upright 61 toward the opposite or alignment posts 17b and 18b. (FIG. 4) A small channel 67 is formed along an axis parallel to axis 24 near the distal end of the arm 66.
The posts 17a and 18a each include one upright 61, as well as a spring retainer 68 and spring plate 69 which are connected to the upright by a rivet 70. The spring plate 69 is of L-shaped configuration having a vertical leg 71 and a horizontal leg 72 (FIGS. 5 and 6). The vertical leg 71 is connected by the rivet 70 to the upright 61. The horizontal leg 72 extends laterally along and adjacent to the arm 66. A clasp 74 of the spring plate 69 secures the horizontal leg 72 to the arm 66.
The spring retainer 68 superimposes the spring plate 69 and includes a flat portion 75 through which the rivet 70 passes, connecting the spring retainer 68 to the upright 61. A step 76 (FIG. 5) raises a main body 77 of the spring retainer 68 to a slightly raised position relative to the vertical leg 71 of the spring plate 69. A second downward step 78 places the spring retainer 68 into contact with the upright 61 at 79 (FIG. 5). A thumb clip 80 angles away from the upright 61. The spring retainer 68 can be moved away from the upright 61 by pressure against the thumb clip 80.
The alignment posts 17b and 18b (FIG. 7) are of virtually identical construction to the guide posts 17a and 18a (FIG. 6). The same reference numbers have been incorporated in the drawing relating to posts 17b and 18b. The posts 17a and 17b and 18a and 18b are essentially mirror images of each other across a plane perpendicular to opposing post containing the axis 24. The alignment posts 17b and 18b have a tab 81 rather than the large nipple 69.
There are two types of lamp bulbs 11 and 12 to which the sockets 19 and 20 can adapt (FIGS. 3 and 4). Both the lamp bulbs 11 and 12 are halogen bulbs widely used in motor car applications and available from the North American Phillips Lighting Corporation of Hightstown, N.J. Referring to FIG. 4, the lamp bulb 11 is known as an H-2 type halogen lamp. It includes an axial filament 85 which is aligned along the axis 24. The lamp bulb 11 also includes a pair of laterally directed flanges 86a and 86b. The flange 86a includes a hole 87 formed therethrough which hole is received by the large nipple 64 of the guide posts 17a or 18a. The flange 86b includes a notch 88, which notch receives the tab 81 of the alignment posts 17b and 18b.
The lamp bulb 11 is fitted into one of the sockets 19 or 20 by actuation of the thumb clips 80 of the spring retainers 68, sliding the flanges 86a and 86b of the lamp bulb 11 downwardly until the hole 87 fits over the nipple 64 and the notch 88 fits over the tab 81. Releasing the thumb clips 80 applies a spring pressure against the flanges 86a and 86b holding the lamp bulb in place. The nipples 62 make the contact essentially a point contact between the nipples and the upright 61, increasing the frictional hold therebetween to secure the lamp bulb 11 into the socket 19 or 20.
The other type of lamp bulb 12 to which the sockets 19 and 20 are convertible is a halogen type T-23/4 bulb. The lamp bulb 12 has a filament 89 that is transverse to the axis 24 and a pair of twin leads 90a and 90b which connect to the sockets 19 and 20. The twin leads 90a and 90b are therefore fit into the lead receiving channels 67 and are retained therein by the spring plate 69. It is therefore seen that the lead receiving channels 67 are spaced a set distance apart corresponding to the manufactured distance between the leads 90a and 90b.
If the lamp bulb 11 is used, then the sockets 19 and 20 retain the lamp bulb through the spring retainer 68 in associated parts. If the lamp bulb 12 is used, then leads 90a and 90b are received in the lead receiving channel 67 and held in place by the spring plates 69.
Electrical current to operate the lamp bulbs 11 and 12 is supplied by the battery 42, which battery is a nickel cadmium rechargeable type supplying approximately 13.2 volts. Current is supplied through the control circuit 44 and electrical conductors 91 to the toggle switch 23, three electrical conductors 92 pass through the pivotal connection 37, one common ground and two positive conductors, the positive conductors attaching to one of the contacts 52 and 54, the other contacts 52 and 54 attaching to the common ground, which contacts are in electrical contact with the lamp bulbs 11 and 12. The rear base 16 is seen to be automatically aligned to a position allowing the conductors 92 to enter the interior of the tubular support 30 (FIG. 1). In a conventionally wired manner, the toggle switch 23 completes a circuit including either lamp 12 or lamp 11, giving either a flood or a spot light effect.
The entire mount 10 is received in axial alignment with axis 24 by the tubular support 30, which support 30 also acts as a heat sink. The tubular support 30 is of cylindrical construction having axial fins 94, for radiating heat, formed along the outer surface, and a hollow interior opening dimensioned so as to matingly receive the forward base and rearward base 14 and 16 in free sliding contact. Once the mount 10 is inserted into the tubular support 30, a threaded end cap 95 having an axial spring 96 is connected to the tubular support 30 at the rearward end 28. An elongated opening 108 (not specifically shown) allows for connection to the pivotal connection 37 and for passage of air into the tubular support 30.
The frustoconical shaped housing 29 (FIG. 1) is press fitted into the forward end 26 of the tubular support 30 through a tapered opening 109. The housing 29 surrounds the reflector member 32 and has a retainer ring 97 essentially coterminous with the associated free edge of the reflector member 32. An open tapered portion 98 matingly fits within the tapered opening 109 of the tubular support 30 and are secured together by any suitable means such as soddering, braising, welding or the like. The lamp bulbs 11 and 12 extend through the central opening 34 and opening 98 in the reflector member and housing 29, respectively, to a preselected distance forward of the central opening 34.
A circular transparent glass plate or lens 98 extends across the open ends of the first reflector member 32. A circular rim or frame 99 serves as a closure for the light 22 and holds the housing 29, reflector member 32 and lens 98 in fixed relationship to each other at the edge 97.
An integral support U-joint 100 (FIG. 3) is press fit and spot welded to tubular support 30 in the opening 105 and forms a portion of the pivotal connection 37. The U-joint 100 is hollow, allowing for passage of conductors 92, as well as the passage of air. Holes 101 are formed therethrough to receive a pin 103 for pivotal connection to ears 102 of the handle 36, through like holes 107 in the ears 102. Ends 104 of the pin are splayed to define rivet-like connections. The U-joint 100 connects in an offset manner to the same side of each ear 102. Wave washers 105 of circular plan view are interposed between each ear 102 and the U-joint 100, providing a spring biased force that will retain the housing 29 and tubular support 30 in a set position relative to the case 38. A rubber boot 106 covers the entire pivotal connection to both seal against air flow when the light 22 is being cooled, as well as to prevent catching a finger or piece of clothing in the connection 37 and to waterproof the light 22.
The handle 36 includes a grip 110 having finger indentations 111 formed therealong. A panel 112 allows for monitoring of the condition of the battery 42, and through control circuitry not specifically shown, and is the location of the switch 23. A generally hollow frustoconical portion 114 extends from the grip 110 to connect to the case 38 in a conventional manner, as by screws. A passage 115 is formed through the frustoconical portion 114 through the handle 36 to the pivotal connection 37.
The case 38 includes an open inlet 116 and outlet 117. Ambient air is brought into the inlet 116 past the battery 42, control circuit 44 and motor 41 by the fan 40. The fan 40 is positioned in the outlet 116 to force air into the passage 115.
Air cooling of the light 24 is thus provided by the movement of air by the fan 40 from the inlet 116, through the outlet 117, down the passage 115, through the opening 105. The entire mount 10 is therefore air cooled upon excessive heat occurring at the thermostat 43. The mount 10 allows air to pass into the interior of the housing 29 and in the area between the reflector member 32 and housing. Air finally exhausts the light 22 through the air holes 46.
Although the present invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made by way of example and that changes in details and structure may be made without departing from the spirit thereof.
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A portable light including at least one lamp bulb, a battery and a control circuit for conducting electrical current from the battery to the lamp bulb comprising in combination:
an airflow passageway in which said battery, said control circuit, and said lamp bulb are serially mounted, said airflow passage defined at one end by an inlet in airflow communication with the atmosphere and defined at another end by an outlet in airflow communication with the atmosphere, and means for moving air between the inlet and outlet along said air passageway mounted in said air passageway and actuated by said control circuit.
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BACKGROUND
[0001] 1. Technical Field
[0002] The embodiments herein generally relate to head supporting mechanisms, and, more particularly, to an infant head cradle.
[0003] 2. Description of the Related Art
[0004] Infants are recommended to be placed on their backs (i.e., face up) when they are sleeping in cribs, cradles, bassinets, and other places. One cause of Sudden Infant Death Syndrome (SIDS) is suffocation caused by infants who are either positioned on their stomachs when sleeping or infants who somehow turn their body/head over while sleeping and are unable to lift their heads in order to breathe.
SUMMARY
[0005] In view of the foregoing, an embodiment herein provides an assembly comprising a platform; a base positioned on the platform, wherein the base comprises a groove comprising a generally curved track; a rotatable arcuately-shaped head cradle positioned within an open region of the base, wherein the head cradle comprises a protruding belt portion dimensioned and configured to slide within the groove of the base; and at least one ball bearing positioned between the belt portion of the head cradle and the base, wherein the at least one ball bearing slides in the curved track of the base.
[0006] The platform may comprise an upper surface comprising a pair of guides and a receptacle; a front wall; a back wall positioned opposite to the front wall; and a pair of side walls positioned between the front wall and the back wall. The front wall may be dimensioned and configured to be approximately one-half in length compared to the back wall. The base may further comprise a top region comprising a recessed saddle-shaped central surface; and a pair of raised side surfaces positioned on lateral sides of the central surface, wherein each side surface comprises a hole disposed therein. The base may further comprise a front region comprising at least one slot configured in a front wall of the base, wherein the front wall of the base is positioned transverse to the central surface and the pair of raised side surfaces, wherein the groove and the track extend from a first side surface through the central surface and to the second side surface of the top region.
[0007] Additionally, the base may further comprise a bottom region comprising a pair of generally cylindrical legs having concave ends that are dimensioned and configured to accept a ball bearing, wherein the legs rest in the pair of guides of the platform; and a boss feature dimensioned and configured to rotationally connect to the receptacle of the platform. The boss feature may comprise a neck portion; and an enlarged lip that snaps into the receptacle of the platform. The head cradle may comprises an anterior surface comprising an inner area of the belt portion that is generally centrally positioned on the U-shaped anterior surface, wherein the inner area of the belt portion comprises at least one semi-spherical bump outwardly extending from the belt portion; and a posterior surface comprising a concave socket positioned on an opposite side of the at least one semi-spherical bump, wherein the concave socket is dimensioned and configured to accept the at least one ball bearing.
[0008] The assembly may further comprise a neck roll operatively connected to the base, wherein the neck roll comprises a tube member having a substantially curved front, top, and bottom end and a substantially flat back end, wherein the back end comprises at least one attachment mechanism, wherein the attachment mechanism engages the at least one slot of the base. Moreover, the assembly may further comprise a blanket system comprising a fastening mechanism that attaches the blanket system to any of the platform, the base, and the head cradle; a first blanket operatively connected to the fastening mechanism; and a second blanket operatively connected to the first blanket. The second blanket may comprise a pair of holes aligned with one another; and an attachment mechanism to attach opposite ends of the second blanket to one another.
[0009] Another embodiment provides a head-restraint system comprising a base portion; a platform positioned underneath the base portion, wherein the platform supports the base portion; a head cradle positioned within an open region of the base portion; means for pivoting the head cradle with respect to the base portion; and means for pivoting the base portion with respect to the platform. The means for pivoting the head cradle with respect to the base portion may comprise a groove comprising a generally curved track dimensioned and configured on the base portion; a protruding belt portion dimensioned and configured on the head cradle to slide within the groove of the base portion; and at least one ball bearing positioned between the belt portion of the head cradle and the base portion, wherein the at least one ball bearing slides in the curved track of the base portion.
[0010] The means for pivoting the base portion with respect to the platform may comprise a pair of guides and a receptacle dimensioned and configured on an upper surface of the platform; a pair of legs dimensioned and configured on a lower surface of the base portion, wherein the legs comprise concave ends that are dimensioned and configured to accept a ball bearing, wherein the legs rest in the pair of guides of the platform; and a boss feature dimensioned and configured on the lower surface of the base portion, wherein the boss feature rotationally engages the receptacle of the platform.
[0011] Additionally, the means for pivoting the head cradle with respect to the base portion may comprise a pivot mechanism rotationally connecting the base portion to the head cradle; and a friction reducing mechanism positioned between the base portion and the head cradle. Furthermore, the means for pivoting the base portion with respect to the platform may comprise a pivot mechanism rotationally connecting the base portion to the platform; and at least one ball bearing positioned between the base portion and the platform. The system may further comprise a cushioning mechanism positioned on the base portion. Also, the system may further comprise an audio signal mechanism that generates audio signals and outputs the audio signals, wherein the audio signal mechanism is positioned adjacent to any of the platform, the base portion, and the head cradle. The audio signal mechanism may comprise a programmable sound card; a speaker; and a power supply unit. Moreover, the system may further comprise a dual component blanket system connected to any of the platform, the base portion, and the head cradle, wherein the dual component blanket system comprises an outer blanket portion and an inner blanket portion.
[0012] Another embodiment provides an apparatus comprising a stationary platform; a base rotationally connected to the platform; a head cradle rotationally connected to the base; a first pivot mechanism rotationally connecting the base to the head cradle; and a second pivot mechanism rotationally connecting the base to the platform.
[0013] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The embodiments herein will be better understood from the following detailed description with reference to the drawings, in which:
[0015] FIG. 1 illustrates a schematic diagram of an infant headrest assembly according to an embodiment herein;
[0016] FIGS. 2 and 3 illustrate exploded diagrams of the infant headrest assembly of FIG. 1 according to an embodiment herein;
[0017] FIG. 4 illustrates a front view of the infant headrest assembly of FIG. 1 according to an embodiment herein;
[0018] FIG. 5 illustrates a rear view of the infant headrest assembly of FIG. 1 according to an embodiment herein;
[0019] FIG. 6 illustrates a side view of the infant headrest assembly of FIG. 1 according to an embodiment herein;
[0020] FIG. 7 illustrates a top view of the infant headrest assembly of FIG. 1 according to an embodiment herein;
[0021] FIG. 8 illustrates a schematic diagram of the platform of the infant headrest assembly of FIG. 1 according to an embodiment herein;
[0022] FIG. 9 illustrates a top view of the base of the infant headrest assembly of FIG. 1 according to an embodiment herein;
[0023] FIG. 10 illustrates a bottom view of the base of the infant headrest assembly of FIG. 9 according to an embodiment herein;
[0024] FIG. 11 illustrates a front view of the base of the infant headrest assembly of FIG. 9 according to an embodiment herein;
[0025] FIG. 12 illustrates an anterior view of the cradle of the infant headrest assembly of FIG. 1 according to an embodiment herein;
[0026] FIG. 13 illustrates a posterior view of the cradle of the infant headrest assembly of FIG. 1 according to an embodiment herein;
[0027] FIG. 14 illustrates schematic diagram of the neck roll of the infant headrest assembly of FIG. 1 according to an embodiment herein;
[0028] FIG. 15 illustrates a top view of a blanket system according to an embodiment herein;
[0029] FIG. 16 illustrates a cross-sectional side view of an infant headrest assembly according to an embodiment herein; and
[0030] FIG. 17 illustrates a cross-sectional view cut along line A-A′ of the infant headrest assembly of FIG. 16 according to an embodiment herein.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0031] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0032] The embodiments herein provide a polyaxial infant head cradle that rotates in two dimensions thereby allowing a baby to turn its head in a “no” motion as well as side-to-side motion (i.e., head-to-shoulders). Referring now to the drawings, and more particularly to FIGS. 1 through 17 , where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments.
[0033] FIGS. 1 through 7 illustrate schematic diagrams of an infant headrest assembly 1 according to a first embodiment herein. The assembly 1 comprises a platform 10 that holds a base 20 , which connects to a neck roll 40 . A generally U-shaped cradle 30 sits in the base 20 . A plurality of ball bearings 50 are also included in the assembly 1 and are positioned between the platform 10 and base 20 , as well as between the base 20 and the cradle 30 .
[0034] FIG. 8 illustrates a schematic diagram of the platform 10 of the infant headrest assembly 1 of FIG. 1 according to an embodiment herein. The platform 10 comprises an upper surface 11 , a front wall 12 , and a back wall 13 positioned opposite to the front wall 12 . The front wall 12 is generally configured approximately one-half in length compared to the back wall 13 . A pair of curved side walls 14 , 15 are positioned between the front wall 12 and back wall 13 . Disposed in the upper surface 11 is a generally circular receptacle 16 . A pair of generally curved guides 17 , 18 are further disposed in the upper surface 11 . The receptacle 16 and guides 17 , 18 generally provide supporting means for the base 20 as it rests on the platform 10 as well as providing rotational means for the base 20 to rotate with respect to the platform 10 . The platform 10 may be dimensioned and configured to attach or hold/clasp a securing a blanket 70 (of FIG. 15 ) that may be further attached into the U-shaped cradle 30 .
[0035] FIGS. 9 through 11 illustrate the base 20 of the infant headrest assembly 1 of FIG. 1 according to an embodiment herein. The base 20 comprises a recessed central surface 21 . Positioned on lateral sides of the central surface 21 are two raised side surfaces 22 a , 22 b that are generally flat. The side surfaces 22 a , 22 b each have a hole 26 disposed therein. Extending from one lateral side 22 a through the central surface 21 onto the other lateral side 22 b is a groove 65 comprising a generally curved track 23 positioned therein. A pair of slots 25 are positioned in the front of the base 20 . The undersurface 27 of the base 20 comprises a pair of generally cylindrical legs 28 having concave ends 60 that are dimensioned and configured to accept a ball bearing 50 (as indicated in FIG. 3 ), which then rest in the guides 17 , 18 of the platform 10 . Furthermore, the undersurface 27 of the base 20 comprises a generally cylindrical boss 29 dimensioned and configured to fit in the receptacle 16 of the platform 10 . The curved configuration of the guides 17 , 18 allow the ball bearings 50 to slide therein, and the receptacle 16 is configured to allow the boss 29 to rotate therein, thus permitting the base 20 to rotate with respect to the platform 10 . Accordingly, this rotation of the base 20 allows an infant positioned in the head cradle 30 to comfortably move its head 90 (shown in FIG. 16 ) towards each of its shoulders. The boss 29 preferably comprises a neck portion 61 and an enlarged lip 62 that snaps into the receptacle 16 to prevent separation of the base 20 from the platform 10 once assembled.
[0036] FIGS. 12 and 13 illustrate the cradle 30 of the infant headrest assembly 1 of FIG. 1 according to an embodiment herein. The cradle 30 comprises a generally U-shaped anterior surface 31 comprising a generally centrally positioned belt portion 34 having semi-spherical bumps 33 outwardly extending from the surface 32 of the belt portion 34 . The edge 35 of the cradle 30 is preferably configured having a thicknesses no greater than half the thickness of the semi-spherical bumps 33 . The opposite side of each semi-spherical bump 33 is a correspondingly configured concave socket 36 that is dimensioned and configured to accept a ball bearing 50 (as indicated in FIGS. 2 and 3 ). The belt portion 24 is dimensioned and configured to slide within the groove 65 of the base 20 with the ball bearings 50 positioned in the concave sockets 36 configured to slide in the track 23 configured in the groove 65 of the base 20 (as indicated in FIGS. 2 and 3 ). This rotational movement allows the head cradle 30 to rotate with respect to the base 20 , which permits an infant positioned in the head cradle 30 to comfortably move its head from side-to-side (i.e., in a “no” motion). A blanket, foam insert, or other cushioning mechanism 80 (shown in FIGS. 16 and 17 ) may be removably attached to the U-shaped anterior surface 31 of the cradle 30 to facilitate enhanced comfort for the infant's head 90 (as shown in FIG. 16 ) that is resting in the cradle 30 . The cradle 30 comprises a radius of curvature sufficiently large so that the infant's head 90 is not held snug within the cradle 30 in order to prevent unintended suffocation or neck pain or injury. Once the baby's head 90 begins to become snug against the cradle 30 , then the parent/guardian is put on notice that the baby has outgrown the assembly 1 and should no longer be used for that particular baby.
[0037] FIG. 14 illustrates schematic diagram of the neck roll 40 of the infant headrest assembly 1 of FIG. 1 according to an embodiment herein. The neck roll 40 is generally cylindrical in shape having a curved surface 41 with a front end 42 and an oppositely positioned back end 43 . The back end 43 is preferably flat and comprises at least one attachment mechanism 44 , which may be configured as clips, for example, or other appropriate attachment mechanism. The attachment mechanisms 44 engage the slots 25 located at the front of the base 20 to allow the neck roll 40 to attach to the base 20 .
[0038] The offset single center of rotation of the base 20 provides for proper anatomically correct head movement/tilting, and the ball bearing track 23 and groove 65 allow the cradle 30 to rotate freely yet remain attached to the base 20 . The assembly 1 may further include means (e.g., a snap, etc.) (not shown) for securing various thickness memory foam 80 (shown in FIGS. 16 and 17 ) for cushioning and comfort and to allow for different-sized baby heads 90 and to accommodate growth of the baby's head 90 . The various components of the assembly 1 may comprise plastic, foam, memory-shaping alloy, or any other type of material that is easily manufactured, economical, hypoallergenic, and eco-friendly.
[0039] FIG. 15 , with reference to FIGS. 1 through 14 , illustrates a top view of a blanket system 70 according to an embodiment herein. The blanket system 70 includes at least one fastener 74 that attaches to the assembly 1 . For example, the blanket system 70 may attach to the platform 10 , base 20 , cradle 30 , or neck roll 40 , or some combination thereof. The blanket system 70 further comprises an outer blanket 71 , and inner blanket 72 , which may be joined together through the fastener(s) 74 . Additionally, the inner blanket 72 comprises a pair of arm holes 73 a , 73 b to allow the infant's arms (not shown) to be inserted therethrough. Furthermore, the inner blanket 72 comprises an attachment mechanism 75 , 76 (such as a Velcro® fasteners, for example) to allow the infant to be swaddled by the inner blanket 72 . The outer blanket 71 may further be used to swaddle the infant or to simply act as a means for the infant to lie upon or the edges may be tucked under the sides of a crib, cradle, or bassinet mattress. The outer blanket 71 and inner blanket 72 may comprise soft cloth material, wool, plastic, etc. for example.
[0040] FIG. 16 illustrates a cross-sectional side view of an infant headrest assembly 100 according to a second embodiment herein, and FIG. 17 illustrates a cross-sectional view cut along line A-A′ of the infant headrest assembly 100 of FIG. 16 . In this embodiment, a first pivot mechanism 82 is connected to the base 20 and head cradle 30 to facilitate the rotation of the head cradle 30 with respect to the base 20 . This rotational movement allows an infant positioned in the head cradle 30 to comfortably move its head 90 from side-to-side (i.e., in a “no” motion). A friction reducing mechanism 85 (for example, a wheel) positioned between the base 20 and the cradle 30 further allows the head cradle 30 to smoothly rotate with respect to the base 20 . Furthermore, a second pivot mechanism 84 is connected to the platform 10 and base 20 to facilitate the rotation of the base 20 with respect to the platform 10 . Accordingly, this rotation of the base 20 allows an infant positioned in the head cradle 30 to comfortably move its head 90 towards each of its shoulders.
[0041] In this alternative embodiment, the number of ball bearings 50 in the assembly 100 is reduced compared with assembly 1 because the rotation of the head cradle 30 with respect to the base 20 is facilitated by the first pivot mechanism 82 and the friction reducing mechanism 85 . Additionally, absent from this embodiment is a separately attached neck roll; rather the foam insert 80 may be configured to have a neck roll portion 83 configured thereon to reduce the number of separately connected components in the assembly 100 . Additionally, an audio signal mechanism 86 that generates audio signals and outputs the audio signals is positioned in the assembly 1 such that it may be adjacent to either the base 20 , the platform 10 , or the head cradle 30 . The audio signal mechanism 86 comprises a programmable sound card or chip 88 , a speaker 89 , and a power supply unit 87 . The power supply unit 87 may include batteries or may be powered using a cord/adapter system or may use other power supply means such as ambient radio frequency power harvesting. The programmable sound card or chip 88 may be configured to play “soothing sounds” for the infant or may be configured to allow recording thereon using a built-in microphone (not shown) that plays back a recording (such as a parent's voice). Furthermore, the programmable sound card or chip 88 may be configured as a two-way communication device to allow for radio transmission of audio signals back and forth to/from a remotely-located transceiver (not shown) to facilitate remote baby monitoring. The audio signal mechanism 86 may be included in either assembly 1 or assembly 100 .
[0042] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.
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A head-restraint system includes a rotatable base portion; a stationary platform positioned underneath the base portion, wherein the platform supports the base portion; a rotatable head cradle positioned within an open region of the base portion; a first pivoting mechanism that allows the head cradle to rotate with respect to the base portion; and a second pivoting mechanism that allows the base portion to rotate with respect to the platform.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 12/826,187, filed Jun. 29, 2010, which itself is a continuation of U.S. patent application Ser. No. 11/383,233 filed May 15, 2006, now U.S. Pat. No. 7,792,526, issued Sep. 7, 2010, both of which are incorporated by reference in their entirety.
BACKGROUND
In a Wireless Local Area Network (WLAN) comprising a number of access points (APs), mobile stations (STAs) roam from one AP to another as they change locations with their users. There are two ways for a mobile station to discover available access points to roam to. Either it can search periodically for alternatives, so that it has a list ready when it is ready to roam, or it can wait until it is necessary to roam to search for other access points. In the first approach, called pre-emptive discovery, a station periodically scans the WLAN channels to learn about its neighboring access points, in a process usually referred to as background scanning. This process may be either active, where the station sends probes out on all its channels to detect neighboring access points, or passive, where the station listens on all its channels for access point beacons. The frequency of background scans directly impacts the roaming performance of a WLAN device. If background scans are not performed frequently enough, the device may fail to pick the optimal access point while roaming, or even fail to find a neighbor and disconnect.
Decreasing the background scanning interval improves network connectivity performance; however, it also degrades battery life, because scanning is a process that consumes a significant amount of power. In selecting a scanning interval, a compromise is made between preserving battery power, and providing adequate roaming capabilities.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like reference numerals indicate corresponding, analogous or similar elements, and in which:
FIG. 1 is an illustration of an exemplary deployment of a wireless local area network (WLAN) in a building, according to an embodiment of the invention. The WLAN includes access points (APs) and a switched, routed fabric including a server;
FIG. 2 is a flowchart of an exemplary method implemented by a mobile station to conserve battery power while roaming, according to an embodiment of the invention; and
FIG. 3 is a block diagram of an exemplary mobile station compatible with the method shown in FIG. 2 .
It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity.
DETAILED DESCRIPTION
In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of embodiments. However it will be understood by those of ordinary skill in the art that the embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the embodiments.
While decreasing the background scanning interval improves seamless roaming capabilities, it degrades battery life, since scanning is a process that consumes a significant amount of power. It is necessary, therefore, to trade off network connectivity performance against battery conservation. Typically, the background scanning interval for a STA is set to a constant value by the device manufacturer. However, using a single background scanning interval that stays constant over time may not be ideal. The need for network connectivity performance is not constant over time, but rather, varies with how the STA is being used with respect to its network connection.
A mobile station that may be used with a WLAN may support various types of network-related activity. For example, the mobile station may be equipped for any of the following activities or any combination thereof: Internet browsing, sending and receiving e-mail, conducting VoIP conversations, and the like. These activities have different needs for network connectivity. A VoIP application, for example, has a significant need for uninterrupted network connectivity during an active call.
Different network usage modes may be defined for a STA according to the activities' needs for uninterrupted WLAN access and bandwidth. The usage modes may be defined based on: (A) which applications are currently active (i.e., which applications are actively consuming CPU time, or are in the foreground of the STA's screen), (B) how the applications are being used with respect to network connectivity, or (C) through direct monitoring of the STA's network traffic.
A non-exhaustive list, Set A, of exemplary network usage modes based on applications includes:
Disconnected: STA is not connected to the WLAN;
Connected Idle: STA is connected to the WLAN, but the only network activity of the STA is that which is required to maintain a connection to the WLAN;
Connected with User Interface Activity: STA is connected to the WLAN and an application or applications that do not require a network connection are active, e.g., calculator, task list, calendar, address book etc.;
Connected Email: STA is connected to the WLAN, and an email application in the STA is active (e.g. the user is actively typing, reading, sending, and/or receiving email);
Connected Instant Messaging: STA is connected to the WLAN and an instant messaging application in the STA is active (e.g., the user is actively typing, reading, sending and/or receiving instant messages);
Connected Browsing: STA is connected to the WLAN and a network browsing application in the STA is active;
Connected Media Streaming: STA is connected to the WLAN and a media streaming application in the STA is active;
Connected in a Phonecall: STA is connected to the WLAN and a telephone application in the STA is active and a call is established via the network (e.g. a VoIP call).
This list of usage modes is in order of increasing network connectivity performance requirements, i.e., the network connectivity performance requirements of a phone call are higher than for instant messaging or email activities. For activities which have higher requirements for network usage, roaming performance is considered more critical, and a shorter background scanning interval is preferred. In the “Connected in a Phone Call” mode, roaming performance is preferred over power consumption, so the background scanning interval may be reduced. In the “Connected Idle” mode, the power consumption becomes more important than the roaming performance, and the background scanning interval may be increased. In the “Disconnected” mode, background scanning is turned off (i.e. the background scanning interval is infinite). For intermediate network usage modes, such as email or instant messaging applications, roaming performance and power conservation may have similar weight, and the background scan interval may be set at a median level. Other network usage modes may be defined and included in such a list where appropriate according to their anticipated network connectivity performance requirements.
A non-exhaustive list, Set B, of example network usage modes based on how the applications are being used with respect to network connectivity includes:
Disconnected: STA is not connected to the WLAN;
Connected Idle: STA is connected to the WLAN, but the only network activity of the STA is that which is required to maintain a connection to the WLAN. There is either no user interface activity, or there is user interface activity that is not likely to result in the need to transmit or receive data to/from the network, e.g. calculator, task list, calendar;
Connected with User Interface Activity: STA is connected to the WLAN and there is user interface activity that is likely to result in network activity, e.g., looking up a contact in an address book, composing an email. No network transmission or reception is taking place;
Connected Email: STA is connected to the WLAN, and email is being sent and/or received via the WLAN;
Connected Instant Messaging: STA is connected to the WLAN and the user is actively typing, reading, sending and/or receiving instant messages, so that instant messages and/or notifications about instant message activities and statuses are being sent and/or received via the WLAN;
Connected Browsing: STA is connected to the WLAN and a network browsing application in the STA is active;
Connected Media Streaming: STA is connected to the WLAN, a media streaming application in the STA is active and an audio and/or video streaming session (e.g. podcast) is in progress;
Connected in a Phonecall: STA is connected to the WLAN and a telephone application in the STA is active and a call is established via the network (e.g. a VoIP call).
This list of usage modes is also in order of increasing network connectivity performance requirements. Usage modes having higher network connectivity performance requirements may be associated with shorter background scanning intervals. Other network usage modes may be defined and included in such a list where appropriate according to their anticipated network connectivity performance requirements.
In this method, each application may periodically or occasionally send information about the user's activities to a centralized network usage application. The network usage application may then determine which of the usage modes is appropriate, and may determine a minimal background scanning interval from the usage mode.
It may also be possible to determine the requirements for network connectivity performance of the STA by monitoring the actual network traffic characteristics and deducing the current applications status. A non-exhaustive list, Set C, of exemplary network usage modes based on network traffic includes:
Disconnected: STA is not connected to the WLAN;
Connected Idle: STA is connected to the WLAN, with sporadic, intermittent network activity (for example, usually 3 frames or less per IEEE 802.11 beacon);
Connected Email: STA is connected to the WLAN, with medium-sized packets (e.g., packets between 200-600 bytes in length), sent within a pre-defined packet rate (e.g., 10 at least 10 packets in 20 seconds);
Connected Instant Messaging: STA is connected to the WLAN, with small (e.g., less than 200 bytes in length) intermittent packets from/to the same destination with inter-packet spacing of approximately one to five seconds;
Connected Browsing: STA is connected to the WLAN, and medium to large (e.g., 600-1500 bytes in length) packets are being continuously transmitted and received for longer than a few seconds;
Connected Phonecall and/or Media Streaming: STA is connected to the WLAN, and there are periodic incoming and/or outgoing medium-size high-priority packets with inter-packet spacing of less than 100 ms.
In addition, it is possible to combine, either wholly or partially, sets A to C in order to determine the network connectivity requirements of the STA. For example, using set A, a STA may have an email application that is currently in the foreground, resulting in the selection of the “Connected e-mail” mode, whereas using set C, monitoring the traffic directly determines that the STA's mode is “Connected Idle”. To select the most appropriate background scanning interval, a rule may be defined such that the mode that corresponds to the shorter background scanning interval will be selected.
To better balance the requirements of roaming performance and battery conservation, the background scanning interval may be changed dynamically according to the current network usage mode of the STA. This may be done automatically, without any need for user intervention. The STA itself may monitor the user's activities and adjust the background scanning interval according to the current WLAN requirements. In one example, network usage modes such as defined above may be used to characterize the STA's current network needs, and the background scanning interval may be adjusted on the basis of the current network usage mode. The background scanning may be active or passive or any combination thereof.
FIG. 1 is an illustration of an exemplary deployment of a wireless local area network (WLAN) in a building, according to an embodiment of the invention. The WLAN includes APs 102 , 103 , 104 and 105 in a switched, routed fabric including a server 106 .
A mobile station 110 may be active in the WLAN. A non-exhaustive list of examples for mobile station 110 includes a wireless-enabled laptop, a wireless-enabled cellphone, a wireless-enabled PDA, a wireless-enabled smartphone, a wireless-enabled video camera, a wireless-enabled gaming console, a wireless Voice over Internet Protocol (VoIP) phone and any other suitable wireless-enabled mobile station.
In the example of FIG. 1 , APs 102 , 103 , 104 and 105 , server 106 and mobile station 110 are compatible with a wireless networking standard, such as the Institute of Electrical and Electronic Engineers (IEEE) 802.11 standard for Wireless LAN Medium
Access Control (MAC) and Physical layer (PHY) specifications. However, it will be obvious to those of ordinary skill in the art how to modify the following for other existing WLAN standards or future related standards.
Mobile station 110 may roam, for example, from the coverage area of AP 102 , to the coverage area of AP 103 during a single conversation. To maintain the quality of the conversation, the roaming must happen seamlessly and must be transparent to the user of the station. During a conversation, then, a shorter background scanning interval is desirable in order to maintain at all times a current list of available APs. On other occasions, when mobile station 110 is not currently in use for a conversation or another activity requiring continuous data streaming, a short interruption to service may not be noticeable to the user. During these times, a longer background scanning interval may be used to conserve battery power.
FIG. 2 is a flowchart of a method implemented by a mobile station 110 , according to an embodiment of the invention. At 202 , mobile station 110 monitors its own network usage. This may be accomplished either at the STA application level by monitoring the user's activities, or at a lower level by directly monitoring the STA's own network traffic, or by some combination of these approaches. For example, separate applications that are being run on the STA, including for example, an email application, and/or a VoIP application, may send alerts about the user's activities to a network usage application. A network usage application may classify the current state of the STA according to a list of network usage modes, by monitoring which applications are active, or by using the alert messages from the other applications. Alternatively or additionally, the station may deduce directly from the characteristics of the network traffic which of the list of network usage modes reflects its current state. For example, medium to large sized packets back-to-back are characteristic of a browsing session, medium-sized, high-priority packets at a constant rate are characteristic of a telephone VoIP call, and e-mail may have similar characteristics to browsing, but with less data and in shorter periods of time. The station may then determine its immediate requirement for network connectivity performance from the usage mode.
The usage mode represents the station's immediate requirement for network connectivity performance. At 204 , a background scanning interval is determined on the basis of the station's immediate requirement for network connectivity performance. At 206 , the background scanning interval may be adjusted at the WLAN control level to the interval determined at 204 .
Computer-executable instructions for implementing a power management scheme such as the above-described method in a mobile station may be stored on a form of computer readable media. Computer readable media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer readable media includes, but is not limited to, random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory or other memory technology, compact disk ROM (CD-ROM), digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired instructions and which can be accessed by internet or other computer network forms of access.
FIG. 3 is a block diagram of an exemplary mobile station, according to some embodiments of the invention. Mobile station 110 includes at least one antenna 300 coupled to a radio 302 , which in turn is coupled to a WLAN controller 304 . WLAN controller 304 may be coupled to a memory 306 storing firmware 308 to be executed by WLAN controller 304 . Mobile station 110 includes a processor 310 and a memory 312 coupled to processor 310 . Memory 312 may store executable application code modules 314 to be executed by processor 310 . Application code modules 314 , when executed by processor 310 , may perform network functions such as internet browsing, email, or telephony applications. Memory 312 may store a network usage application code module 315 , which when executed by processor 310 , may use information about the user's activities to determine the immediate networking connectivity performance requirements, and determine an appropriate background scanning interval. Alternatively, or in addition, network usage application code module 315 may inspect the network traffic of mobile station 110 in order to deduce its immediate networking connectivity performance requirements. Alternatively, WLAN controller 304 may itself inspect the network traffic of mobile station 110 in order to deduce the immediate network connectivity performance requirements of mobile station 110 and to adjust the background scanning interval accordingly. If the method of direct monitoring of network traffic is used exclusively, network usage application 315 would be unnecessary, as the WLAN controller has the ability to monitor traffic directly, and to control the background scanning interval itself.
Processor 310 may be coupled to WLAN controller 304 and may be able to control, at least in part, the operation of WLAN controller 304 . Mobile station 110 includes a battery 316 to provide power to radio 302 , WLAN controller 304 , processor 310 and memories 306 and 312 . Mobile station 110 may include other components that, for clarity, are not shown.
Radio 302 , WLAN controller 304 , processor 310 and memories 306 and 312 are functional blocks and may be implemented in any physical way in mobile station 110 . For example, radio 302 , WLAN controller 304 , processor 310 and memories 306 and 312 may be implemented in separate integrated circuits, and optionally in additional discrete components. Alternatively, some of the functional blocks may be grouped in one integrated circuit. Furthermore, the functional blocks may be parts of application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or application specific standard products (ASSP).
A non-exhaustive list of examples for processor 310 includes a central processing unit (CPU), a digital signal processor (DSP), a reduced instruction set computer (RISC), a complex instruction set computer (CISC) and the like.
Memories 306 and 312 may be fixed in or removable from mobile station 110 . A non-exhaustive list of examples for memories 306 and 312 includes any combination of the following:
a) semiconductor devices such as registers, latches, read only memory (ROM), mask ROM, electrically erasable programmable read only memory devices (EEPROM), flash memory devices, non-volatile random access memory devices (NVRAM), synchronous dynamic random access memory (SDRAM) devices, RAMBUS dynamic random access memory (RDRAM) devices, double data rate (DDR) memory devices, static random access memory (SRAM), universal serial bus (USB) removable memory, and the like; b) optical devices, such as compact disk read only memory (CD ROM), and the like; and c) magnetic devices, such as a hard disk, a floppy disk, a magnetic tape, and the like.
A non-exhaustive list of examples for antenna 300 includes a dipole antenna, a monopole antenna, a multilayer ceramic antenna, a planar inverted-F antenna, a loop antenna, a shot antenna, a dual antenna, an omnidirectional antenna and any other suitable antenna.
Application code modules 314 , when executed by processor 310 , may monitor current user activities. The network applications may send information about the user's activities to another application that determines an appropriate background scanning interval, or may themselves determine a background scanning interval. Assigning a usage status mode such as described above may be performed as an intermediate step to determining a background scanning interval. The background scanning interval is then updated at WLAN controller 304 , which controls the background scanning performed by radio 302 .
Alternatively, mobile station 110 may periodically monitor its own network traffic in order to determine its current network access needs and an appropriate background scanning interval.
Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.
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In a Wireless Local Area Network (WLAN), roaming from one access point to another by a mobile station without interruption to network service may be facilitated by frequently performing background scans to find neighboring access points while the mobile station is associated to the WLAN. Frequent background scanning, however, depletes battery life. By dynamically adjusting the background scanning interval during the mobile station's association to the WLAN, the mobile station's immediate need for network connectivity performance may be met, while simultaneously prolonging battery life. For example, by using a shorter background scanning interval during a telephone conversation, network connectivity performance may be maintained throughout the call. Longer background scanning intervals may be used during periods when interruptions to network connectivity may be better tolerated.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims the benefit of and priority to U.S. Provisional Application Ser. No. 61/175,924 filed on May 6, 2009, the entire contents of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to surgical devices and, more particularly, relates to a seal assembly for use with a surgical access device during a minimally invasive surgical procedure, for example, in both laparoscopic and endoscopic procedures.
DESCRIPTION OF ART
[0003] Minimally invasive surgical procedures avoid open invasive surgery in favor of closed or local surgery with less trauma. These procedures involve use of laparoscopic devices and remote-control manipulation of instruments with indirect observation of the surgical field through an endoscope or similar device, and are carried out through the skin or through a body cavity or anatomical opening. Laparoscopic and endoscopic procedures generally require that any instrumentation inserted into the body be sealed, i.e. provisions must be made to ensure that gases do not enter or exit the body through the incision as, for example, in surgical procedures in which the surgical region is insufflated. These procedures typically employ surgical instruments which are introduced into the body through a cannula. The cannula has a seal assembly associated therewith and provides a substantially fluid tight seal about the instrument to preserve the integrity of the established air or gas within the surgical region.
[0004] Minimally invasive procedures have several advantages over traditional open surgery, including less patient trauma, reduced recovery time, reduced potential for infection, etc. However, minimally invasive surgery, such as laparoscopy, has several disadvantages. In particular, the frictional forces exerted on surgical instruments inserted through it, has proved to be difficult in procedures requiring extensive manipulation of the long narrow endoscopic instruments within a remote site because of the restricted mobility. In addition, known seal devices are deficient in resilience and in rigidity for affixing the seal within a cannula or trocar housing.
SUMMARY
[0005] The present disclosure relates to a surgical access apparatus for passing through tissue to an underlying surgical area. The apparatus includes an access member defining a longitudinal axis and having a longitudinal channel for reception of a surgical object, a seal member mounted to the access member and positioned to intersect the longitudinal channel, and having internal seal surfaces defining a passage and being dimensioned to establish a substantial sealing relation with a surgical object inserted therethrough and a substantially annular element mounted to the seal member and at least partially circumscribing the passage. The annular member is rigid relative to the seal member and defines an opening to permit passage of the object. The annular element is dimensioned to minimize offset manipulation of the surgical object relative to the longitudinal axis.
[0006] The annular element may be at least partially embedded within the seal member. The annular element is mounted in a radial outward relation to the internal seal surfaces of the seal member whereby the internal seal surfaces engage the surgical object in substantial sealed relation therewith. The annular element may be substantially planar and arranged in general transverse relation to the longitudinal axis.
[0007] The seal member may define a generally tapered configuration. In this embodiment, the seal member may define a proximal seal face and a distal seal face with the proximal seal face at least partially defining the internal seal surfaces. The annular element may be mounted between the proximal seal face and the distal seal face. In the alternative, the seal member may define a substantially planar configuration. The seal member may comprise an elastomeric material and a fabric material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Various embodiments of the present disclosure will be described hereinbelow with reference to the figures wherein:
[0009] FIGS. 1 is a perspective views of an access assembly and a seal assembly in accordance with the principles of the present disclosure;
[0010] FIG. 2 is a side cross-sectional view of the seal assembly;
[0011] FIG. 3 is an isolated cross-sectional view of the seal member of the seal assembly;
[0012] FIG. 4 is a cross-sectional view taken along the lines 4 - 4 of FIG. 3 ; and
[0013] FIG. 5 is a side cross-sectional view of an alternate embodiment of the seal member of the seal assembly.
DETAILED DESCRIPTION
[0014] The seal assembly of the present disclosure, either alone or in combination with a seal system internal to a cannula assembly, provides a substantial seal between a body cavity of a patient and the outside atmosphere before, during and after insertion of an object through the cannula assembly. Moreover, the seal assembly of the present disclosure is capable of accommodating objects of varying diameters, e.g., instruments from about 4.5 mm to about 15 mm, while maintaining a fluid tight interface about the instrumentation adapted for insertion through a trocar and/or cannula assembly to prevent gas and/or fluid leakage so as to preserve the atmospheric integrity of a surgical procedure. The flexibility of the present seal assembly greatly facilitates endoscopic and/or laparoscopic surgery where a variety of instruments having differing diameters are often needed during a single surgical procedure. Specifically, the surgical device includes a seal assembly which permits and limits some lateral and/or angular manipulation of the surgical instrument while also maintaining a seal about the instrument. The seal assembly is further adapted to substantially close in the absence of a surgical instrument to maintain the integrity of the insufflated peritoneal cavity.
[0015] The surgical seal assembly of the present disclosure is additionally adapted to decrease the frictional forces exerted on surgical instruments inserted through it which has proven to be difficult in procedures requiring extensive manipulation of the long narrow endoscopic instruments within a remote site because of the restricted mobility.
[0016] Examples of surgical instrumentation include clip appliers, graspers, dissectors, retractors, staplers, laser probes, photographic devices, endoscopes and laparoscopes, tubes, and the like. Such instruments will be collectively referred to herein as “instruments” or “instrumentation”.
[0017] The seal assembly may also be adapted dimensionally to receive and form a seal about a physician's arm or hand during a hand-assisted laparoscopic procedure. In this application, the seal assembly is a component of an access member which is introduced within the body to provide access to underlying tissue in, e.g., the abdominal cavity.
[0018] Moreover, the seal assembly may be readily incorporated into an access device, such as a conventional trocar device or cannula housing to provide the device with zero-closure and/or sealing around an instrument or other object.
[0019] In the following discussion, the term “proximal” or “trailing” will refer to the portion of the surgical device nearest to the clinician during operation while the term “distal” or “leading” will refer to that portion of the portal apparatus most remote to the clinician.
[0020] Referring now to the drawings, in which like reference numerals identify identical or substantially similar parts throughout the several views, FIGS. 1-2 illustrate one embodiment of a seal assembly, i.e. seal assembly 100 of the present disclosure mounted to an access device such as cannula or trocar assembly 200 . Cannula assembly 200 may be any conventional cannula suitable for the intended purpose of accessing a body cavity and typically defines a passageway permitting introduction of instruments therethrough. Cannula assembly 200 is particularly adapted for use in laparoscopic surgery where the peritoneal cavity is insufflated with a suitable gas, e.g., CO 2 , to raise the cavity wall from the internal organs therein. Cannula assembly 200 is typically used with an obturator assembly (not shown) which may be blunt, a non-bladed, or a sharp pointed instrument positionable within the passageway of the cannula assembly 200 . The obturator assembly is utilized to penetrate the abdominal wall or introduce the cannula assembly 200 through the abdominal wall, and then subsequently is removed from the access device to permit introduction of the surgical instrumentation utilized to perform the procedure through the passageway. Cannula assembly 200 includes cannula sleeve 202 and cannula housing 204 mounted to an end of the sleeve 202 . Any means for mounting cannula sleeve 202 to cannula housing 204 are envisioned including threaded arrangements, bayonet coupling, snap-fit arrangements, adhesives, etc. Cannula sleeve 202 and cannula housing 204 may be integrally formed. Cannula sleeve 202 defines a longitudinal axis “k” extending along the length of sleeve 202 . Sleeve 202 further defines an internal longitudinal passage 206 dimensioned to permit passage of surgical instrumentation. Sleeve 202 may be formed of stainless steel or other rigid materials such as a polymeric material or the like. Sleeve 202 may be clear or opaque. The diameter of sleeve 202 may vary, but, typically ranges from about 10 mm to about 15 mm for use with the seal assembly 100 of the present disclosure.
[0021] Cannula housing 204 includes luer connector 208 . Luer connector 208 is adapted for connection to a supply of insufflation gaseous is conventional in the art and incorporates valve 210 to selectively open and close the passage of the luer connector 208 . Cannula housing 204 may further include a duckbill or zero closure valve (not shown) adapted to close upon exposure to the forces exerted by the insufflation gases in the internal cavity. Other zero closure valves are also contemplated including single or multiple slit valve arrangements, trumpet valves, flapper valves, etc.
[0022] With reference to FIGS. 2-3 , seal assembly 100 will be discussed in detail. Seal assembly 100 may be a separate component from cannula assembly 200 and, accordingly, adapted for releasable connection to the cannula assembly 200 . Alternatively, seal assembly 100 may be incorporated as part of cannula assembly 200 . Seal assembly 100 includes a seal housing, generally identified as reference numeral 102 , and seal member 104 which is disposed within the seal housing 102 . Seal housing 102 houses the sealing components of the assembly and defines the outer valve or seal body of the seal assembly 100 . Seal housing 102 defines central seal housing axis “b” which is preferably parallel to the axis “k” of cannula sleeve 202 and, more specifically, coincident with the axis “k” of the cannula sleeve 202 . Seal housing 102 incorporates three housing components, namely, first, second and third housing components 106 , 108 , 110 , respectively, which, when assembled together, form the seal housing 102 . Assembly of housing components 106 , 108 , 110 may be affected by any of the aforementioned connection means discussed with respect to cannula housing 204 .
[0023] Seal member 104 may be mounted within seal housing 102 by any conventional means. In one embodiment, seal member 104 includes an outer peripheral segment 112 which is otherwise attached, mounted or connected to seal housing 102 . Outer peripheral segment 112 may or may not have an undulation to permit lateral movement of seal member 104 within the seal housing 102 . Outer peripheral segment 108 may be secured to seal housing 102 by any conventional means.
[0024] Seal member 104 defines a general tapered configuration having a longitudinal component of direction with respect to seal axis “b”. Seal member 104 may include an elastomeric material 114 having one or more fabric layers 116 impregnated or mounted to the elastomeric material. A suitable seal 104 is the seal disclosed in commonly assigned U.S. Pat. No. 6,702,787 to Racenet, the entire contents of which are incorporated herein by reference. Fabric layer or material 116 may be, for example, a SPANDEX material containing 20% LYCRA available from Milliken. The elastomeric material may be polyisoprene or a natural rubber. In the embodiment shown in FIG. 2 , two fabric layers 116 are arranged to enclose elastomeric material 114 . Other arrangements are also envisioned.
[0025] Seal member 112 has inner seal surfaces 118 which define a passage 120 for passage of the surgical object. The passage 120 may be normally closed or may be in the form of an aperture which is open in at rest condition. Inner seal surfaces 118 adjacent passage 120 may be elastomeric to facilitate formation of the seal about the inserted object. Seal member 112 defines proximal seal face 122 , distal seal face 124 and intermediate seal face 126 disposed between the proximal and distal seal faces 122 , 124 . Inner seal surfaces 118 establish a seal about the inserted object. Inner seal surfaces 118 may include portions of proximal seal face 122 and intermediate seal face 126 .
[0026] Seal member 112 has a substantially annular element or ring 128 mounted to or embedded within the seal member 112 adjacent passage 120 . Annular element 128 may be formed from any suitable material which is rigid relative to the elastomeric material of inner surfaces 118 . Suitable materials include polymeric materials, steel, titanium, etc. Annular element 128 defines an opening 130 for passage of the surgical object. Opening 130 generally defines an internal dimension or diameter which is greater than the diameter of the surgical object or instrument to be positioned within cannula sleeve 202 . Annular element 128 may further include anchoring elements 132 depending from the proximal face of the annular element 128 . Anchoring elements 132 may be embedded within seal member 112 to secure annular element 128 to the seal member 112 . Anchoring elements 132 may be embedded during a molding process utilized in manufacturing seal member 112 . In the alternative, annular element 128 may be devoid of anchoring elements 132 , and secured to seal member 112 through adhesives, cements, etc.
[0027] In the embodiment of FIGS. 2-4 , annular element 128 is mounted to intermediate end face 126 of seal member 112 . The width “w” of annular element 128 may be less than the corresponding width of intermediate end face 126 of seal member 112 . With this arrangement, the inserted instrument will contact the seal member 112 , e.g., the elastomeric material and/or the fabric material, at inner seal surfaces 112 whereby a seal is formed about the instrument. The instrument or object may move in a lateral direction however, the presence of annular element 128 will ensure that the passage does not open beyond a predetermined inner diameter, e.g., corresponding to the internal dimensions “m” of the annular element 128 . This minimizes the potential of “cat-eyeing”, which is the establishment of a gap between the object and the seal.
[0028] Seal assembly 100 , either alone or in combination with a seal unit/seal assembly internal to cannula assembly 200 , provides a substantial seal between a body cavity of a patient and the outside atmosphere both during and subsequent to insertion of an instrument through the cannula. In this manner, insufflation gases are prevented from escaping through the trocar assembly to the outside environment. Seal assembly 100 is preferably detachably mountable to cannula housing 204 . Thus, the surgeon can remove the seal assembly 100 from the cannula assembly 200 at any time during the surgical procedure and, similarly, mount the seal assembly 100 to the cannula when desired in order to provide a sealing engagement with an instrument to be inserted through the cannula. In addition, seal assembly 100 may be readily adapted for mounting to conventional cannulas of differing structures. The detachability of seal assembly 100 from cannula assembly 200 facilitates specimen removal through cannula assembly 200 .
[0029] Referring to FIG. 5 , an alternate embodiment of seal member 150 for use with the seal assembly 100 is illustrated. Seal member 150 is substantially similar to seal member 104 of the embodiment of FIGS. 1-4 . Seal member 150 includes inner planar seal segment 152 and outer segment 154 . Inner planar segment 152 has inner seal surfaces 156 defining slit 158 for reception of an object whereby the inner seal surfaces 156 establish a seal about the object. Slit 158 may open for reception of the object and may close in the absence of the object. Thus, seal member 150 also may function as a zero closure valve for maintaining the integrity of the underlying insufflated body cavity. Seal member 150 may, in the alternative, have an aperture in lieu of slit 158 . Inner planar segment 152 has proximal and distal faces 160 , 162 .
[0030] Seal member 150 further includes annular element 164 mounted to distal face 162 . Annular element 164 may be substantially similar to the annular element 128 discussed hereinabove in connection with the embodiment of FIGS. 1-4 . Annular element 164 defines an internal dimension “t” greater than an internal dimension of slit 158 . Annular element 164 restricts lateral movement of the surgical object thereby assisting in maintaining the integrity of the seal about the object by, e.g., minimizing “cat-eyeing”. In addition, in the event the object is moved laterally or in a radial direction, the forces associated with this movement are transferred to the outer peripheral segment of seal member 150 . This may preserve the integrity of inner seal surfaces 156 defining slit 158 .
[0031] It will be understood that various modifications may be made to the embodiments shown herein. Therefore, the above description should not be construed as limiting, but merely as exemplifications of preferred embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the presently disclosed seal assemblies.
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A surgical access apparatus for passing through tissue to an underlying surgical area includes an access member defining a longitudinal axis and having a longitudinal channel for reception of a surgical object, a seal member mounted to the access member and positioned to intersect the longitudinal channel, and having internal seal surfaces defining a passage and being dimensioned to establish a substantial sealing relation with a surgical object inserted therethrough and a substantially annular element mounted to the seal member and at least partially circumscribing the passage. The annular member is rigid relative to the seal member and defines an opening to permit passage of the object. The annular element is dimensioned to minimize offset manipulation of the surgical object relative to the longitudinal axis.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to devices that contain multiple antennas.
BACKGROUND
[0002] Modern mobile computing devices are typically capable of carrying out communications using a plurality of different wireless protocols. Different types of wireless communication require separate antennas. These different types of antennas each take up space within the mobile computing device. Since mobile computing devices have a limited amount of space, the addition of more wireless communications protocols becomes difficult because of space constraints.
SUMMARY OF THE INVENTION
[0003] The present invention relates to reduced volume antennas. The antenna device includes (a) a first wireless communications arrangement which is capable of at least one of transmitting and receiving. In addition, the device includes (b) a first antenna coupled to the first wireless communications arrangement and (c) a second wireless communications arrangement which is capable of at least one of transmitting and receiving. Furthermore, the device includes (d) a second antenna coupled to the second wireless communications arrangement. The second antenna acts as a parasitic element for the first antenna.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 shows a first device including an exemplary antenna according to the present invention.
[0005] FIG. 2 shows a second device including an exemplary antenna according to the present invention.
[0006] FIG. 3 shows a third device including an exemplary antenna according to the present invention.
DETAILED DESCRIPTION
[0007] The exemplary embodiments of the present invention may be further understood with reference to the following description and the appended drawings, wherein like elements are referred to with the same reference numerals. The exemplary embodiments of the present invention describe devices that minimize the space requirements of multiple antennas.
[0008] A “device,” as used in this disclosure, may refer to any type of device that may send or receive signals through the use of an antenna. For example, the device may be a handheld computer, a notebook computer, a personal digital assistant (“PDA”), a scanner, a mobile telephone, a data acquisition device, a camera, a pager, etc. Though the exemplary embodiments of the present invention may refer specifically to mobile computing devices, as such devices may greatly benefit from reducing the overall amount of space devoted to antennas, the broader principles of the present invention are equally applicable to any other type of device that may include a plurality of antennas.
[0009] An “antenna” is a transducer used to transmit and receive radio waves. Though the exemplary embodiments described below will refer to specific types of antennas, those of skill in the art will understand that the same principles are applicable to antennas used for any purpose. Many types of antennas use “parasitic elements,” which are antenna elements that do not have any wired input or output, but either reflect or absorb and re-radiate radio waves sent to or from an active antenna element in proximity to the parasitic element. The use of parasitic elements improves the performance of antennas. The same effect can be achieved by the addition of lumped elements (e.g., capacitors or inductors) to the antenna, but this can result in losses. However, the use of parasitic elements and lumped elements takes up additional space within a device.
[0010] Modern mobile computing devices may communicate wirelessly using a plurality of communication protocols. For example, a mobile device may be able communicate with a wireless local area network (“WLAN”), a wireless wide area network (“WWAN”), one or more peripherals using the Bluetooth protocol, a global positioning system (“GPS”), a radio frequency identification (“RFID”) protocol, etc. In prior embodiments of such devices, the antennas for each of these are separated from each other and occupy considerable volume within the device. This is challenging given the small form factor of mobile devices, and makes it difficult to further decrease the size of such devices.
[0011] FIG. 1 shows a first exemplary embodiment of a device 100 according to the present invention. The device 100 may be, for example, a mobile computing device of the types described above, but may also be any other type of device that may include two or more antennas. The device 100 includes one or more wireless transceivers/receivers (not shown), which may include, for example, an 802.11 transceiver, a Bluetooth transceiver, a GPS receiver, etc. The exemplary device 100 also includes a display 120 and an input means 130 (e.g., a keypad, etc.). Those of skill in the art will understand that other exemplary devices may lack one or both of these components and may also include other types of components. The device 100 also includes an antenna housing 140 .
[0012] FIG. 1 also shows a detailed view of the antenna housing 140 of the device 100 . The antenna housing 140 contains a pair of antennas 150 and 160 . The antennas 150 and 160 are located proximately to one another; the exact proximity may vary among embodiments of the present invention depending on the purposes for which the antennas 150 and 160 are being used. Those of skill in the art will understand that while FIG. 1 illustrates an antenna housing 140 and antennas 150 and 160 of specific shapes and in specific locations, these shapes and locations are only illustrative and the shapes and locations may vary among embodiments of the present invention. Further, those of skill in the art will understand that while FIG. 1 illustrates an exemplary embodiment with antennas 150 and 160 within a housing 140 , other embodiments of the present invention may lack a dedicated antenna housing. FIG. 2 illustrates such an embodiment.
[0013] By locating the antennas 150 and 160 proximately to one another, the antenna 160 may act as a parasitic element for the antenna 150 , and vice versa. In other words, as described above, the antenna 160 may act as a capacitive element to reflect or absorb and re-radiate radio waves that have been sent to or from the antenna 150 , while the antenna 150 does the same for radio waves sent to or from the antenna 160 . Those of skill in the art will understand that the radio waves may interfere with one another if they are transmitted on similar frequency bands; thus, acceptable isolation may be achieved by using the antennas 150 and 160 for communication on frequency bands that are suitably different from one another. Meeting the technical specification for an acceptable isolation is an important factor for practical implementation of the exemplary embodiments of the present invention. This ensures reduced interference between the antennas 150 and 160 (in this case, working at different frequencies) connected to their respective transceivers/receivers.
[0014] Those of skill in the art will understand that the antennas 150 and 160 must be located close enough to one another that they are capable of acting as parasitic elements for one another, providing the right amount of coupling. The precise proximity required will depend on the amount of coupling required between the antennas 150 and 160 and depends on the individual designs of the antennas 150 and 160 . For example, if the antenna 150 is a Bluetooth antenna operating in a frequency range appropriate for Bluetooth functionality (e.g., 2.4 GHz to 2.4835 GHz), and the antenna 160 is a GPS antenna operating on a frequency appropriate for GPS functionality (e.g., 1176.45 MHz, 1227.60 MHz, 1379.913 MHz, 1381.05 MHz or 1575.42 MHz), they may be placed a first distance from one another, while if the antenna 150 is an 802.11 antenna operating in a frequency band appropriate for 80:2.11 communication (e.g., 2.4 GHz to 2.5 GHz) and the antenna 160 is an WWAN antenna operating at a frequency appropriate for WWAN communication (e.g., 850 MHz, 900 MHz, 1800 MHz, 1900 MHz), they may be placed a second distance from one another. The first and second distances may or may not be the same.
[0015] FIG. 2 illustrates a second exemplary embodiment of a device 300 according to the present invention. Like the device 100 of FIG. 1 , the device 300 may be, for example, a mobile computing device of the types described above, but may also be any other type of device that may include two or more antennas. The device 300 includes one or more wireless transceivers/receivers (not shown), which may include, for example, an 802.11 transceiver, a Bluetooth transceiver, a GPS receiver, etc. The exemplary device 300 also includes a display 320 and an input means 330 (e.g., a keypad, etc.), but as above, those of skill in the art will understand that other exemplary devices may lack one or both of these components, and may include other types, of components.
[0016] FIG. 2 also illustrates a detailed cutaway view of a portion of the device 300 . The device 300 , like the device 100 , includes two antennas 340 and 350 that are located proximately to one another. However, the device 300 lacks a dedicated antenna housing; rather, the antennas 340 and 350 are located within the main housing of the device 300 . As discussed above with reference to the exemplary embodiment of FIG. 1 , those of skill in the art will understand that the specific shapes and locations of the antennas 340 and 350 shown in FIG. 2 are only exemplary, and that the precise shapes and locations of the antennas may vary among embodiments of the present invention.
[0017] FIG. 3 illustrates another exemplary device 500 according to the present invention. The exemplary device 500 is similar to the device 100 of FIG. 1 and includes one or more wireless transceivers/receivers (not shown), a display 510 and an input means 520 . However, the device 500 includes two antenna housings 530 and 540 . Each of the antenna housings 530 and 540 contains a pair of antennas selected and disposed to act as parasitic elements for one another, as described above.
[0018] FIG. 3 also illustrates a detailed view of the antenna housing 530 , which contains antennas 550 and 560 . As discussed above with reference to FIGS. 1 and 2 , the illustrated designs and positions of the antennas 550 and 560 are only exemplary, and may vary among embodiments of the present invention. The antenna housing 540 contains antennas 570 and 580 (not shown in expanded detail). The antennas 570 and 580 , as illustrated in FIG. 3 , may be substantially similar in design (though tuned to different frequencies) to the antennas 550 and 560 , or may be dissimilar to the antennas 550 and 560 . Those of skill in the art will understand that the antennas 570 and 580 may be used for different purposes and thus may differ in both design and orientation from the antennas 550 and 560 .
[0019] FIGS. 1-3 illustrate various exemplary embodiments including a device 100 including two antennas within a separate antenna housing, a device 300 including two antennas within the main housing of the device, and a device 500 including two pairs of antennas within two separate antenna housings. However, those of skill in the art will understand that other potential embodiments of the present invention may include a device with two pairs of antennas disposed within the main housing of the device; a device with one pair of antennas disposed within the main housing of the device and one pair of antennas disposed within a separate antenna housing; and devices with more than two pairs of antennas disposed within the main housing of the device, within separate antenna housings, or a combination of the two.
[0020] The exemplary embodiments of the present invention aid in the design of devices including multiple antennas by making it possible to simultaneously improve the performance of the antennas and conserve space within the devices. As discussed above, conserving space is of particular importance in modern mobile computing devices. By the implementation of these exemplary embodiments, multiple antennas can be located in close proximity to one another, improving the performance of both in confined space while eliminating the need for passive elements that serve no other function.
[0021] The above described exemplary embodiments refer specifically to devices using exactly two antennas acting as parasitic elements for one another. However, those of skill in the art will understand that other embodiments that incorporate antennas configured in groups of more than two are also possible. For example, in another exemplary embodiment, an antenna housing may contain three antennas, all of which operate on frequencies that differ sufficiently so as to not interfere with one another, and all of which are spaced at appropriate distances from one another to act as parasitic elements for one another as described above. Other exemplary embodiments may include differing numbers of antennas selected and placed in similar manners.
[0022] The present invention has been described with reference to the above specific exemplary embodiments. However, those of ordinary skill in the art will recognize that the same principles may be applied to other embodiments of the present invention, and that the exemplary embodiments should therefore be read in an illustrative, rather than limiting, sense.
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A device includes (a) a first wireless communications arrangement which is capable of at least one of transmitting and receiving. In addition, the device includes (b) a first antenna coupled to the first wireless communications arrangement and (c) a second wireless communications arrangement which is capable of at least one of transmitting and receiving. Furthermore, the device includes (d) a second antenna coupled to the second wireless communications arrangement. The second antenna acts as a parasitic element for the first antenna.
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TECHNICAL FIELD
[0001] This invention relates to a method and a device for the treatment of aortic arch disease and more particularly to the treatment of a form of aortic aneurysm known as an aortic dissection.
BACKGROUND OF THE INVENTION
[0002] An aortic dissection is a form of aneurysm to the descending aorta in which the wall of the aorta is damaged to such an extent that blood under pressure can get between inner and outer layers of the wall of the aorta to expand part of the wall into an inflated sac of blood which is referred to as a false lumen. The inflated sac of blood or false lumen so formed may extend some distance down the descending aorta and open out into the aorta again further down.
[0003] It is the object of this invention to provide a device and a method of treatment of such an aortic dissection.
[0004] Throughout this specification the term proximal with respect to both human or animal vasculature and the deployment device and prosthesis will be used to refer to the region closest to the heart or that part of the deployment device or of the prosthesis which when in use is closest to the heart and the term distal will be used for regions of the human or animal vasculature further from the heart and those parts of the deployment device or prosthesis which in use are further from the heart.
SUMMARY OF THE INVENTION
[0005] In one form therefore the invention is said to reside in a prosthesis adapted for inter-luminal placement by endovascular deployment, the prosthesis comprising a plurality of self expanding stents together defining an elongate substantially cylindrical lumen wall engaging surface and at least one of the stents having a bio-compatible graft material cover whereby the cover is adapted to close off a rupture in the wall of the lumen and the stents are adapted to provide pressure on the wall of the lumen adjacent to and extending away from the rupture.
[0006] Preferably the cover portion encompasses two or three stents and the cover is stitched or otherwise fastened to the stents in the covered portion.
[0007] Preferably the covered portion of the prosthesis is at the proximal end of the plurality of stents.
[0008] The uncovered other stents preferably extend away from the covered portion and may be linked by suitable flexible links. Alternatively the uncovered stents may be linked by a thread or fibre such as a suture threaded through the bends of the zig-zag stents. The thread or fibre such as a suture may be connected to each bend by a knot such as for example, a half hitch, a thumb knot, two half hitches, a clove hitch or a similar knot.
[0009] The proximal end of the covered portion of the prosthesis may include barbs extending from the stents through the cover to engage with the wall of the lumen when deployed.
[0010] In one preferred embodiment of the invention there may be three covered stents each of the zig-zag type and constructed from stainless steel or nitinol and up to eight or ten uncovered stents formed from stainless steel or nitinol.
[0011] The uncovered stents may be of the Gianturco type zigzag stent and constructed so that in their expanded state they provide a low but useful radial force on the aorta wall.
[0012] Alternatively the uncovered portion may be in the form of a self expanding spiral of zig-zag configuration.
[0013] In a further form the invention may be said to reside in a prosthesis for treatment of an aortic dissection comprising a substantially cylindrical body in the expanded state having at least one self expanding stent covered by a bio-compatible graft material and a self expanding stent assembly extending from a distal end thereof.
[0014] There may be included barbs extending from the proximal end of the graft.
[0015] In one embodiment the self expanding stent assembly extending from a distal end of the biocompatible graft material may be formed from a biocompatible and biodegradable mesh material so that after it has performed its work of providing a radial pressure onto the wall of the aorta it can biodegrade in the bloodstream.
[0016] The stents in these embodiments of the invention may be made MRI (Magnetic Resonance Imaging) compatible.
[0017] In one form the stent may be in the form of a Gianturco style zig zag Z stent. Alternatively the stent may be a Nitinol™ self expanding stent of the type known as a Zilver™ stent sold by Cook Incorporated.
[0018] The bio-compatible graft material may be either on the inside or the outside of the covered portion of the prosthesis.
[0019] In a further form the invention may be said to reside in a deployment device and prosthesis for treatment of an aortic dissection, the prosthesis comprising a substantially cylindrical body in the expanded state having at least one self expanding stent covered by a bio-compatible graft material and a self expanding stent assembly extending from a distal end thereof, and the deployment device comprising an elongate catheter adapted to be deployed over a guide wire, a nose cone at the proximal end of the elongate catheter, a trigger wire arrangement adapted to retain a proximal end of the prosthesis in a retracted state, a sheath arrangement over the elongate catheter adapted to retain the prosthesis in a contracted state around the elongate catheter, means at the distal end of the elongate catheter to release the trigger wire arrangement and means to withdraw the sheath arrangement.
[0020] Preferably the elongate catheter includes means to supply an angiographic contrast medium at a distal end thereof through the catheter and the nose cone includes discharge ports for the angiographic contrast medium.
[0021] In an alternative form the invention is said to reside in a method of treatment of aortic dissection disease comprising the steps of loading a prosthesis onto a deployment device, the prosthesis comprising a plurality of self expanding stents together defining an elongate substantially cylindrical lumen wall engaging surface and at least one of the stents having a bio-compatible graft material cover whereby the cover is adapted to close off a rupture in the wall of the lumen, the deployment device including means to retain the proximal end of the prosthesis in a retracted state and a trigger wire arrangement to release the proximal end of the prosthesis, a sheath to retain the entire prosthesis in a retracted state and means to withdraw the sheath, endovascularly deploying the deployment device with the prosthesis loaded thereon to the site of the aortic dissection, checking by radiographic techniques that the covered stent or stents are at the site of the aortic dissection, withdrawing the sheath to expose the covered stent or stents of the prosthesis, releasing the proximal end of the prosthesis by means of releasing the trigger wire arrangement, withdrawing the sheath to deploy the other stents of the prosthesis along the wall of the lumen such that they provide pressure against the wall of the lumen, and withdrawing the deployment device.
[0022] Preferably the covered stent or stents are at the proximal end of the prosthesis.
[0023] The bio-compatible material may be dacron, expanded polytetrafluoroethylene or other synthetic bio-compatible material.
[0024] While Dacron, expanded polytetrafluoroethylene (ePTFE), or other synthetic biocompatible materials can be used to fabricate the coverings for the stent graft and the tubular extension, a naturally occurring biomaterial, such as collagen, is highly desirable, particularly a specially derived collagen material known as an extracellular matrix (ECM), such as small intestinal submucosa (SIS). Besides SIS, examples of ECM's include pericardium, stomach submucosa, liver basement membrane, urinary bladder submucosa, tissue mucosa, and dura mater.
[0025] SIS is particularly useful, and can be made in the fashion described in Badylak et al., U.S. Pat. No. 4,902,508; Intestinal Collagen Layer described in U.S. Pat. No. 5,733,337 to Carr and in 17 Nature Biotechnology 1083 (November 1999); Cook et al., WIPO Publication WO 98/22158, dated 28 May 1998, which is the published application of PCT/US97/14855. Irrespective of the origin of the material (synthetic versus naturally occurring), the material can be made thicker by making multilaminate constructs, for example SIS constructs as described in U.S. Pat. Nos. 5,968,096; 5,955,110; 5,885,619; and 5,711,969. Animal data show that the SIS used in grafts can be replaced by native tissue in as little as a month's time. In addition to xenogenic biomaterials, such as SIS, autologous tissue can be harvested as well. Additionally Elastin or Elastin-Like Polypetides (ELPs) and the like offer potential as a material to fabricate the graft to form a device with exceptional biocompatibility. Another alternative would be to use allographs such as harvested native tissue. Such tissue is commercially available in a cryopreserved state.
[0026] U.S. Pat. No. 5,387,235 entitled “Endovascular Transluminal Prosthesis For Repair Of Aneurysms” discloses apparatus and methods of retaining grafts onto deployment devices. These features and other features disclosed in U.S. Pat. No. 5,387,235 could be used with the present invention and the disclosure of U.S. Pat. No. 5,387,235 is herewith incorporated in its entirety into this specification.
[0027] U.S. Pat. No. 5,720,776 entitled “Stent Barb” discloses improved barbs with various forms of mechanical attachment to a stent. These features and other features disclosed in U.S. Pat. No. 5,720,776 could be used with the present invention and the disclosure of U.S. Pat. No. 5,720,776 is herewith incorporated in its entirety into this specification.
[0028] PCT Patent Publication No. WO98/53761 entitled “A Prosthesis and a Method of Deploying a Prosthesis” discloses an introducer for a prosthesis which retains the prosthesis so that each end can be moved independently. These features and other features disclosed in PCT Patent Publication No. WO98/53761 could be used with the present invention and the disclosure of PCT Patent Publication No. WO98/53761 is herewith incorporated in its entirety into this specification.
[0029] U.S. Provisional Patent Application No. 60/392,667, now Ser. Nos. 10/609,846 filed Jun. 30, 2003, and PCT Patent Application No. PCT/US03/204963 filed Jun. 30, 2003, entitled “Thoracic Deployment Device” discloses introducer devices adapted for deployment of stent grafts particularly in the thoracic arch. This feature and other features disclosed in U.S. Provisional Patent Application No. 60/392,667 could be used with the present invention and the disclosure of U.S. Provisional Patent Application No. 60/392,667 is herewith incorporated in its entirety into this specification.
[0030] U.S. Provisional Patent Application No. 60/391,737, now Ser. Nos. 10/602,930, filed Jun. 24, 2003, and PCT Patent Application No. PCT/US03/19997, filed Jun. 24, 2003, entitled “Stent-Graft Fastening Arrangement” discloses arrangements for fastening stents onto grafts particularly for exposed stents. This feature and other features disclosed in U.S. Provisional Patent Application No. 60/391,737 could be used with the present invention and the disclosure of U.S. Provisional Patent Application No. 60/391,737 is herewith incorporated in its entirety into this specification.
[0031] U.S. utility patent application Ser. No. 10/647,642 entitled “Asymmetric Stent Graft Attachment” discloses retention arrangements for retaining onto and releasing prostheses from introducer devices. This feature and other features disclosed in U.S. utility patent application Ser. No. 10/647,642 could be used with the present invention and the disclosure of U.S. utility patent application Ser. No. 10/647,642 is herewith incorporated in its entirety into this specification.
[0032] PCT Patent Publication No. WO03/053287 entitled “Improving Graft Adhesion” discloses arrangements on stent grafts for enhancing the adhesion of such stent grafts into walls of vessels in which they are deployed. This feature and other features disclosed in PCT Patent Publication No. WO03/053287 could be used with the present invention and the disclosure of PCT Patent Publication No. WO03/053287 is herewith incorporated in its entirety into this specification.
BRIEF DESCRIPTION OF THE DRAWING
[0033] This then generally describes the invention but to assist with understanding reference will now be made to the drawings which show a preferred embodiment of the invention.
[0034] In the drawings:
[0035] FIG. 1 shows a schematic view of an aorta with an aortic dissection;
[0036] FIG. 2 shows the aorta shown in FIG. 1 with a deployment device inserted therein;
[0037] FIG. 3 shows the first stage of deployment of the prosthesis;
[0038] FIG. 4 shows the fully deployed prosthesis;
[0039] FIG. 5 shows a prosthesis according to one embodiment of this invention;
[0040] FIG. 6 shows an alternative embodiment of the prosthesis according to the invention; and
[0041] FIG. 7 shows a still further embodiment of the prosthesis according to the invention.
DETAILED DESCRIPTION
[0042] Looking more closely to the drawings and in particular FIG. 1 it will be seen that the aorta comprises an ascending aorta 1 which receives blood from the heart though an aortic valve 2 . At the upper end of the ascending aorta there are branches for the innominate artery 3 the left common carotid artery 4 and the subclavian artery 5 . The aorta after these is referred to as the descending aorta 6 and it is in this region that an aortic dissection can occur. In an aortic dissection the wall of the descending aorta can be injured such as by a traumatic injury so that a partial rupture or tear 7 occurs and the wall of the descending aorta splits so that there is an outer wall 8 and an inner wall 9 between which a false lumen 10 occurs. At some distance down the false lumen 10 the false lumen may again open out into the aorta 6 such as at 11 . The dotted line 12 shows the normal position of the wall of the aorta.
[0043] Treatment of the aortic dissection requires that the rupture 7 be closed off and the false lumen deflated.
[0044] As can be seen in FIG. 2 a deployment device 15 with a nose cone 16 has been advanced over a guide wire 17 through the true lumen 18 of the descending aorta 6 . Preferably the deployment device is inserted through a femoral artery and up through the iliac arteries into the aorta.
[0045] Once the deployment device is in substantially the correct place angiographic fluids may be supplied through a hollow elongate catheter 20 in the deployment device to exit through apertures 22 in the nose cone so that with the angiographic contrast medium the region can be visualised by radiographic techniques.
[0046] When the deployment device is found to be in the correct position the sheath 24 of the deployment device is withdrawn to the position as shown in FIG. 3 at which stage the covered portion 25 of the prosthesis is exposed except that the proximal end 27 is retained by a trigger wire mechanism to the central catheter 20 . The sheath is withdrawn until the first of the uncovered stents 29 of the prosthesis are exposed. At this stage the pressure of blood flow from the heart will still tend to cause blood flow around the prosthesis.
[0047] Next the trigger wire mechanism is released so that the proximal end 27 of the prosthesis 25 is allowed to open as shown in FIG. 4 and the barbs 30 on the proximal end of 27 of the prosthesis engage against the wall of the aorta to securely fix the covered portion 25 of the prosthesis in the upper end of the descending aorta with the covered portion 25 of the prosthesis covering the rupture 7 and essentially closing it off so that blood can no longer flow into the false lumen 10 . Blood can then flow through the covered portion of the prosthesis and exit out the end of the covered portion at the first stent 29 and then as the sheath 23 is continued to be withdrawn the remaining self expanding stents are allowed to engage against the wall of the true lumen 18 and provide pressure onto the wall particularly where the false lumen occurs to gradually deflate and close off the false lumen as finally shown in FIG. 4 . At this stage the sheath 23 is advanced to the nose cone 16 and the deployment device is withdrawn.
[0048] FIG. 5 shows a prosthesis for use with the method of the present invention. The prosthesis has three stents 35 under a biocompatible graft material cover 36 which provides the covered portion 25 of the prosthesis and a number of uncovered stents 38 each of which are linked to the next stent up or down by flexible links 37 . The covered portion is joined to the uncovered portion by links. The flexible links enable each stent to expand separately as the false lumen is deflated which may occur over a period of several days or weeks. The stents provide gradual pressure on the wall of the lumen to close the false lumen and open up the true lumen.
[0049] It will be realised that different numbers of covered stents and uncovered stents may be used depending upon the nature of the aortic dissection and the length of aorta to be opened and the dimensions of the rupture in the wall of the aorta.
[0050] Barbs 30 are provided at the proximal end 39 of the prosthesis.
[0051] The stents 35 may be Gianturco zigzag Z stents or any other form of self expanding stent. Alternatively the stents 35 may be balloon expanded stents.
[0052] The prosthesis may have a total length of from 100 to 300 mm and a diameter when expanded of 22 to 45 mm. The covered portion may have a length of from 50 to 150 mm and a diameter when expanded of 22 to 45 mm.
[0053] As discussed earlier the stents 38 and the links 37 may be in the form of a mesh and formed from a biocompatible and biodegradable mesh material so that after it has performed its work of providing a radial pressure onto the wall of the aorta it can biodegrade in the bloodstream.
[0054] FIG. 6 shows a further embodiment of a prosthesis according to the present invention.
[0055] In this embodiment the covered portion is the same as in the previous embodiment shown in FIG. 5 but the uncovered self expanding stents 40 are linked by means of a fibre or thread 42 such as a suture so that each self expanding stent can act independently of its neighbours. Where each fibre or suture 42 passes a bend 41 of a stent there may be a knot 43 such as a clove hitch to assist with the controlled linking of adjacent stents. Threads or sutures 44 join the proximal uncovered stents 40 to the covered portion 25 of the prosthesis.
[0056] FIG. 7 shows a still further embodiment of the prosthesis of the invention.
[0057] In this embodiment the covered portion is the same as in the previous embodiment shown in FIG. 5 but the uncovered portion is formed from a continuous spiral of zig-zag stent 45 with again loops in adjacent spirals joined by a thread 47 such as a suture. Again suitable knots may be used to assist with the controlled linking of adjacent portions of the spiral stent. Threads or sutures 49 join the uncovered spiral stent 45 with the covered portion 25 of the prosthesis.
[0058] Throughout this specification various indications have been given as to the scope of the invention but the invention is not limited to any one of these but may reside in two or more of these combined together. The examples are given for illustration only and not for limitation.
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A prosthesis adapted for inter-luminal placement by endovascular deployment for the treatment of vascular dissection, the prosthesis has a self expanding stents ( 38 ) connected together to define an elongate lumen wall engaging surface. At least one of the stents has a bio-compatible graft material cover ( 36 ) to define a covered portion ( 25 ). The cover is adapted to close off a rupture ( 7 ) in the wall of the lumen ( 6 ) and the stents are adapted to provided pressure on the wall of the lumen adjacent to and extending away from the rupture.
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This application relates to novel glass fiber articles of manufacture useful as insulation and to a process of manufacture of glass fiber insulating material. More particularly, this application relates to glass fibers bound by a thin coating of an aluminum phosphate ionic polymer converted to an amorphous polymer after application to the fiber.
BACKGROUND OF THE INVENTION
Coatings for glass articles are numerous in both kind and purpose. The versatility of glass in recent years has caused the industry to apply coatings to glass, particularly in the form of fibers, to impart a particular physical property to the fiber. Protective coatings for glass fibers are disclosed in U.S. Pat. No. 2,444,347 to Greger et al. providing resistance to alkaline environment and to bond the fiber together. Of particular interest were glass fibers of very small diameter, termed therein "glass wool". In this form there is a large surface to volume ratio. The coating imparts some protection to the surface exposed to hostile environments. Colloidal solutions of aluminum phosphates are employed to mold glass-wool into shaped articles. The aluminum phosphates employed in the coating process are prepared in accordance with U.S. Pat. No. 2,405,884 to Greger.
Technical Bulletin I-236 published by Monsanto Company also suggests the use of colloidal aluminum phosphates as binding agents for glass fiber mats and insulation referring to the above-mentioned patent to Greger et al.
Glass fiber structures having superior heat resistance are described in Japanese Kokai No. 48 92690. According to this publication, glass fiber especially useful under elevated temperatures is provided by coating the glass fiber with a solution of aluminum phosphate or aluminum phosphate-chrome oxide complex to a thickness of from 0.1 to 10 microns. The coated fiber is heated to at least 150° C. to form a uniform crystalline coating on the surface of the fiber.
Water-soluble solid aluminum phosphate complexes and binder compositions for refractory compositions or alumina are disclosed in U.S. Pat. No. 3,899,342 to Birchall et al. The complex is provided by mixing a solution of aluminum orthophosphate having an Al:P molar ratio of substantially 1:1 with anions of a carboxylic acid or a mineral oxy-acid and curing the phosphate binder at a temperature of from 80° C. to 200° C. or higher. Also disclosed are cold curing methods which employ a curing agent such as magnesium oxide. Cast articles are formed wherein the refractory is placed in a mold. Oxy-acids, such as citric and oxalic acids, are suggested for complexing agents with the orthophosphate.
In U.S. Pat. No. 4,147,823 to Lavalee, an ink for glass and ceramic substrates can be formulated by reacting an aluminum salt of a weak organic acid such as a stearate or palmitate with phosphoric acid to provide a matrix of insoluble aluminum phosphate cement. The complex contains filler and color pigment components which are caused to adhere to glass surfaces such as electric light bulbs. The bonding agent is heat cured at about 300° C. to form an adhesively bonded mark on the glass.
Low density, high heat resistant glass fiber insulation is prepared according to Kokai No. 60-209067 to Suganuma et al. by impregnating a glass fiber needle mat with a slurry comprising an aqueous solution of an aluminum or magnesium phosphate and one or more refractory compositions such as alumina, kaolin, feldspar, etc. The glass fiber, in the form of a needle mat, is impregnated with the slurry and dried at 120° C. for about one hour followed by two additional hours at 320° C. to provide a molded refractory article.
A broad range of inorganic fibers are treated with a biphosphate to provide heat and flame resistance, durability and adhesion on the surface of the fibers according to Japanese Kokai No. 2-149453. Metals employed to form the biphosphate in aqueous solution are metals of Groups I, II and III of the periodic table with aluminum and magnesium preferred. The biphosphate is sprayed onto fibers, such as glass fibers, whereupon the fiber surface is partially dissolved so that the fibers are bonded in block form or bonded together providing a non-woven cloth with superior heat resistance. The biphosphate is said to be polymerized and solidified on the surface of the fiber.
Modern glass fiber insulation materials comprise very small diameter filaments and are commonly provided with organic resin coatings for several purposes. First, the brashness of glass fiber is reduced so that the amount of dust and breakage of filaments during shipping and handling is reduced. Further, glass fiber insulation is commonly supported on a substrate, such as paper or aluminum which provides, in addition to support, also insulating value. The insulation is usually prepared in a certain thickness thereby providing a desired amount of insulating value. During packaging and shipping the insulation is compressed to conserve space but when unpackaged at the location of use, the insulating material on the substrate is expected to expand so as to provide insulating value to the degree required. Another function of the organic resin coating on the glass fiber is to provide sufficient flexibility of the glass filaments such that the filaments regain most of the original thickness needed to provide the expected insulating value after packaging and unpackaging. While providing the above-described desirable results, organic resins have the possibility of contributing to environmental problems in waste disposal and in the event of combustion in the structure being insulated may emit undesired fumes. Organic resins are also combustible.
There is needed a more environmentally advantageous and effective coating for glass fiber, particularly in the insulation function where substrate support is employed. There is desired, for environmental reasons, a suitable replacement for the organic resins in glass fiber insulation.
BRIEF DESCRIPTION OF THE INVENTION
In accordance with this invention, there is provided novel glass fiber articles suitable for insulating purposes and a process for preparing such articles. In accordance with this invention, glass fibers are treated with an aqueous acid aluminum phosphate solution. The aqueous solution is prepared by combining Al 2 O 3 , orthophosphoric acid and water in a molar ratio of Al 2 O 3 /P 2 O 5 of less than 1 and preferably in the range of from 1 to 2 to 1 to 4, more preferably from 1 to 3. Sufficient water is included to provide a free flowing solution and may be up to about 95% by weight. The amount of water referred to is both combined and free water. An ionic polymer is formed in aqueous solution.
The treatment provides a small amount of solution on the fiber surface which is then converted to a water insoluble, amorphous polymer by the application of heat and removal of water. Prior to conversion of the solution to the amorphous state the glass fibers are compiled onto a substrate causing the fibers to form a lattice like structure wherein numerous fiber-fiber contact points are established. Because the aqueous solution is very fluid, it flows along the surface of the fibers and collects at fiber-contact contact points due to surface tension. The fiber lattice is then subjected to heat treatment to remove water and to form the amorphous polymer. It has been found that when the fiber lattice is formed in this manner there is provided a resilient lattice structure. In accordance with this invention, there is provided an excellent tacking agent for the glass fibers which allows the glass fiber article to substantially recover its shape and size after compaction. Generally, the amount of amorphous polymer needed to tack the glass fiber satisfactorily is in the range of from about 1% to about 5% of the total weight of the glass fiber.
Polymerization of the acid phosphate is achieved by heating the treated fiber whereby water is removed to form an amorphous, non-hygroscopic polymer. Typical means to remove water from the ionic polymer may be employed such as electric or gas fired waffle ovens, infrared or microwave ovens.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing the ratios of Al 2 O 3 , P 2 O 5 and water in the solutions employed to treat the glass fiber in accordance with this invention. The preferred composition of the ionic aluminum phosphate polymer solution of this invention to be applied to the fiberglass fibers is shown by the shaded area in FIG. 1. Lines A, B, C and D indicate solutions containing Al:P molar ratios of 1:1, 1:2, 1:3 and 1:4 respectively.
FIG. 2 is a greatly enlarged portion of a photomicrograph showing a segment of fiberglass which has been treated in accordance with this invention. There is shown in FIG. 2 the accumulation of amorphous polymer at the intersection of the fibers whereby the fibers are resiliently held together.
DETAILED DESCRIPTION OF THE INVENTION
The water soluble ionic aluminum phosphate polymer is prepared by combining aluminum oxide, such as Al 2 O 3 .3H 2 O, with ortho-phosphoric acid and water in the molar ratio noted above. In practice the aluminum oxide is added to the water-phosphoric acid mixture which has been heated to a temperature above about 100° C. A clear viscous solution results which can be diluted with water to provide a solution easily applied to glass fibers such as by spraying the fibers at a convenient location after filament formation and preferably before combination into an article for use as insulating material. As will be shown in the Examples below, the viscosity of the coating solutions of this invention can be adjusted by the amount of water included therein. One advantage of such adjustment is to provide a suitable viscosity for the particular means employed to apply the coating solution to the fiber glass. It is not important as to the exact time or location for the application of the aqueous solution.
After application of the aqueous solution to the glass fiber, the treated fiber is subjected to polymerization condition(s) wherein the soluble acid aluminum phosphate is converted to a water insoluble, amorphous polymer by removal of water.
As noted above, the removal of water is performed by any suitable means such as by heating the treated fiber. It is important to control the removal of water whether conducted by air convection, furnace, oven or microwave, so as to produce the amorphous polymer. If the removal of water is insufficient, the desired phase change does not occur and the residue may be hygroscopic. If the removal of water is accompanied by excessive heat and water removal, an undesired crystalline aluminum phosphate is produced. In either of the above cases, the desired amorphous polymer is not formed in sufficient amounts to impart the desired properties in the glass fiber article.
It has been found that the desired water insoluble amorphous polymer is formed by heating the treated glass fiber to a temperature in the range of from about 350° C. to about 400° C. for about 45 to about 90 seconds. The relationship of time and temperature is regulated so as to remove the above-noted amount of water from the solution so as to form the desired amorphous polymer.
Treatment of the glass fibers in accordance with this invention does not necessarily entail the complete coating of the fiber with the ionic polymer. However, there should be a sufficient amount of solution on the cross-over points of the very fine fibers with each other to provide a resilient tacking force by the amorphous polymer of sufficient strength to hold the shape of the article into which it has been formed prior to heating. That is, the shape of the article is resumed after compaction and to the approximate original size.
In addition, other inorganic acids may also be included in minor amounts. Inorganic acids may include, for example, boric acid, which is added for the purpose of preventing the components of the aqueous solution from salting out and may be added in amounts of from about 0.06% to about 0.5 percent, by weight, based upon amount of Al 2 O 3 /P 2 O 5 included therein. As will be shown below in the preferred embodiments, the aqueous solution is usually provided by combining aluminum oxide (including the various hydrates) in water with orthophosphoric acid. Following addition, the solution is formed upon heating to a temperature in the range of from about 105° C. to about 120° C. for a period of from about 30 to about 40 minutes. The concentration of the aqueous solution can be provided over a broad range and is mainly determined by the equipment employed in its application to the glass fiber. When the solution is desirably sprayed onto the glass fiber an aqueous solution may be prepared over a broad range of from about 5% to about 30%, by weight, although there is no intention of limiting this invention by such concentration as there are several suitable means for applying the solution to the fiber.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following examples illustrate the preparation of compositions useful in the process of this invention. In these examples percent is expressed as percent by weight unless otherwise noted.
EXAMPLE 1
Into a 2 L ceramic container there were placed phosphoric acid and distilled water. This solution was heated to approximately 80° C. and then aluminum oxide trihydrate was added slowly. The mixture was stirred while heating to a temperature in the range of from 105° C. to about 110° C. until a clear solution was obtained. The stock solutions prepared by this procedure were diluted to 13.25% concentration by addition of distilled water to render them less viscous before spraying onto the glass fiber as described in Example 2 below. Three stock solutions were prepared by the above procedure as noted below. To one stock solution a small amount of boric acid was added for the purpose of preventing precipitation due to salting out. The stock solutions contained the following ingredients:
______________________________________Ingredient a b c______________________________________Al.sub.2 O.sub.3 3H.sub.2 O 155.42 g 155.42 g 155.42 gH.sub.3 PO.sub.4 -85.9% 689.75 g 710.44 g 710.44 gBH.sub.3 O.sub.3 0.75 gH.sub.2 O 161.88 g 161.88 g 161.88 g______________________________________
EXAMPLE 2
Viscosity measurements were made with solutions a,b and c of Example I. Water was added to reduce the concentration of the solution for the purpose of observing the effect of concentration upon viscosity. The ionic aluminum phosphate polymer content for each test solution is given in weight percent in Table I below. The measurements were made with a Brook-Field viscometer Model RVT and the results summarized in Table I wherein the viscosity is reported in centipoise units.
TABLE I__________________________________________________________________________Temp a a a b b b c c°C. 73.98% 63.10% 50.48% 71.20% 63.10% 50.48% 63.10% 50.48%__________________________________________________________________________23 4950 210 32 1810 225 36 180 3654 600 65 35 475 80 33 60 39__________________________________________________________________________
EXAMPLE 3
Standard commercial glass fiber insulation having a combination paper/aluminum backing and an insulation value rating of R-11 was obtained and stripped of its organic coating by heating 5 inch by 4 inch segments in a muffle furnace at 450° C.-470° C. for a period of from 45 minutes to 1 hour. After removal and cooling, the segments were weighed and then compressed evenly over their upper surface under a weight of 50 gms. for 5 seconds. The weight was removed and the thickness of the sample immediately measured. The layers of glass fiber were pulled apart and sprayed with the above-described solutions so as to provide sufficient material to enhance the recovery of the segment to its original size after compression as noted below. The segments were weighed immediately after spraying and then heated in a muffle furnace set at about 400° C. for a period of from 45 to 90 seconds. The segments were again removed from the furnace and cooled to room temperature. To test the ability of the segments to regain their original size after compression and release, the thickness of each segment was measured and then compressed evenly over their upper surfaces under a weight of 887 g for a period of 5 minutes. The compressed thickness was measured and, after removal of the weight, the thickness of each segment was again measured to determine the percentage regain of thickness according to the equation: ##EQU1## wherein t o is the original thickness and t f is the thickness of the segment after compression and regain of thickness. In Table II below, there is presented test data obtained wherein the above-described segments were weighed and then treated with ionic polymeric aluminum phosphate solution (compositions a-c above). In Table II the following abbreviated notations have the following meanings:
I=initial weight of the segment before treatment.
T=weight of the treated segment.
C=weight of the segment after heating.
T 1 =initial thickness of the segment before treatment.
T 2 =thickness of the segment under compression after heat treatment.
T 3 =thickness of the segment after compression release.
Also included in Table II below is the weight percent of the amount of ionic aluminum phosphate applied to the segment and the percent regain of thickness calculated as shown above.
TABLE II______________________________________Weight RegainSegment I T C % T.sub.1 T.sub.2 T.sub.3 %______________________________________Solution a:1 10.73 15.40 11.1 3.54 7.2 2.45 7.1 982 7.77 10.83 8.04 3.47 7.1 2.0 6.9 973 11.83 16.53 12.27 3.72 7.3 2.9 7.1 974 9.7 13.53 10.01 3.2 6.65 2.4 6.5 98Solution b:1 7.64 10.54 7.72 1.05 6.4 1.6 6.1 952 8.18 12.25 8.49 3.79 7.2 2.1 6.95 963 12.86 16.29 13.11 1.94 7.9 2.9 7.80 98Solution c:1 10.62 14.72 10.88 2.45 7.4 2.65 7.2 972 13.52 16.62 13.9 2.81 7.3 2.8 7.1 973 12.01 16.87 12.63 5.16 7.1 3.0 7.0 98Control - no resin:1 6.8 2.1 5.7 842 7.2 -- 6.3 87.51 7.2 -- 7.0 98______________________________________
The data in Table II above indicates the ability of the amorphous aluminum phosphate polymer to provide glass fiber insulating structures with regain ability equal to the organic resin now generally employed in commerce. Because the viscosity of the ionic phosphate polymer solution of this invention can be adjusted by varying the water content as shown in Table I above, the viscosity of previously employed organic coating solutions may be matched by the compositions of this invention. The amount of ionic polymer employed to treat the glass fibers to provide this result is generally in the range of above 1 percent, by weight of the fiber, while it is shown that amounts of up to about 5%, by weight of the fiber are also effective.
Increased amounts of the ionic polymer may be employed, but would not significantly improve the regain of thickness because lower amounts are shown to be effective to the extent of 98%. In addition to providing the above-noted resilience of the insulating articles, the coating of this invention is also capable of reducing the brashness of the protruding glass fibers. It has been noted that the treated fibers are substantially dust free during movement of the coated fibers. Because of the inorganic nature of the herein disclosed coating for glass fibers, there is offered the possibility of recycling cut ends of glass fiber articles which result from the forming and shaping operations during manufacture of insulating members containing said fibers. Further, the heating of the fibers treated in accordance with this invention, providing an amorphous polymer, results in the loss of water which is relatively benign to the environment. Structures containing the insulation treated in accordance with this invention are less likely to emit obnoxious fumes when subjected to high intensity heat such as when such structures catch fire, whereas the organic resins of current commerce are undesirable because of the fumes produced under such circumstances. The amorphous polymer produced in accordance with this invention is stable up to about 1300° C.
While the illustrative embodiments of the invention have been described with particularity, it will be understood that various other modifications will be apparent to and can readily be made by those skilled in the art without departing from the scope and spirit of the invention.
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There is disclosed novel glass fiber particularly useful for preparing formed insulating articles having on the surface of the fibers an amorphous aluminum phosphate polymer wherein the polymer resiliently tacks the glass fibers together so as to provide regain of shape after deformation of the fibers as by compression. Also disclosed is a process for preparing glass fiber articles wherein the fibers are contacted with an ionic polymer which is then dehydrated to form an amorphous non-hygroscopic polymer.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Application No. 62/149,195, filed on Apr. 17, 2015, entitled “FILTERING DEVICE WITH GEARED FLOW REDUCTION WITH FLOW BY-PASS,” the disclosure of which is hereby incorporated herein by reference in its entirety.
BACKGROUND OF THE DISCLOSURE
[0002] The present disclosure is generally related to a filtration system, more specifically, to a filtration system that includes one or more systems configured to reduce, stop or otherwise alter fluid flow. The water flow is altered to indicate expiration of a filter unit after the filtration system's useful life has passed. The filtration system is typically a water filtration system, more typically a water filtration systems used in connection with an appliance. The appliance is typically a refrigerator.
[0003] Gearing systems have been contemplated to be used in connection with measuring water flow through a water filter. However, these systems have been, prior to the various solutions of the present disclosure, impractical when used in connection with refrigerator filter systems because the gear train mechanism would require fine tolerance on the gear train stack and it would be difficult to manufacture a system for the large volume of water to be measured by a refrigerator water filter, approximately 600 US gallons. Prior faucet based gearing systems for totaling water flow measure a volume, which is typically a maximum of up to 25 US gallons.
SUMMARY
[0004] An aspect of the present disclosure is generally directed to a method of indicating to a user of an appliance that a water filter unit operably connected to the appliance has passed its useful life. The method typically includes the steps of: providing a filter unit that includes a fluid flow impeding system within a housing of the filter unit; engaging the filter unit with the appliance in a manner such that water received into the appliance from an exterior water source from the appliance enters the filter unit through an inlet aperture and filtered water is delivered out an outlet aperture; measuring the volume of water treated by the filter unit using an end of life measuring system positioned within the filter unit where the end of life measuring system includes a by-pass water line that diverts a minority portion of the water received by the filter unit from the exterior water source into engagement with a gear train system that is operably engaged with a fluid flow impeding device; and activating the fluid flow impeding device contained within the housing of the filter unit after a maximum volume of water the filter unit has been designed to treat has been surpassed.
[0005] Yet another aspect of the present disclosure is generally directed to a filter unit that includes: a substantially cylindrically shaped main body portion having a distal end portion and an engaging end portion configured to engage a water source and receive water from the water source through a water inlet aperture and deliver treated water out of the filter unit through a water outlet aperture; and a fluid flow impeding system positioned in at least one of (1) the distal end portion or (2) the engaging end portion of filter unit; and where the fluid flow impeding system is spaced within the main body portion such that water passing from the water inlet aperture and out the water outlet aperture passes through the fluid flow impeding system. The fluid flow impeding system is configured to be activated after a predetermined volume of water has passed through the fluid flow impeding system and thereafter position a fluid flow impeding object into the water flow and thereby slow the flow of water through the water impeding valve to a rate less than the normal flow rate and after the predetermined volume of water has passed through the fluid impeding system. The fluid flow impeding system includes a gear based flow totaler assembly having a gear stack in operable connection with a diverted water flow within a diverted water flow pathway that is a minority of the water flowing through the main water flow pathway in the filter where the minority of water flowing through the main water flow pathway and the gear stack are configured to measure when the effective useful life of the filter unit has been surpassed.
[0006] Yet another aspect of the present disclosure is generally directed to an appliance that includes: at least one freezer compartment; at least one fresh food compartment; an exterior water connection that provides water from outside the appliance to the appliance; a filter unit; and a filter head assembly configured to receive a filter unit wherein the filter unit is configured to be engaged and disengaged with the filter head assembly by hand and without the use of tools. The filter unit includes: a main body portion having a distal end portion and an engaging end portion configured to engage a water source and receive water from the water source through a water inlet aperture and deliver treated water out of the filter unit through a water outlet aperture; and a fluid flow impeding system positioned in at least one of (1) the distal end portion or (2) the engaging end portion of filter unit. The fluid flow impeding system is typically engaged with an interior wall of the main body portion such that water passing from the water inlet aperture and out the water outlet aperture passes through the fluid flow impeding system. The fluid flow impeding system includes a gear based flow totaler assembly that includes a gear stack in operable connection with a diverted water flow within a diverted water flow pathway that is a minority of the water flowing through the main water flow pathway in the filter where the minority of water flowing through the main water flow pathway and the gear stack are configured to measure when the effective useful life of the filter unit has been surpassed. The water filter has a useful life capacity such that the filter is able to filter greater than 200 gallons of unfiltered municipal water prior to losing its efficacy and the water filter includes an activated carbon filtration media that reduces chlorine, taste and odor components (CTO) per NSF 42 and NSF Standard 53 to a minimum of 200 gallons. The fluid flow impeding system and the gear based flow totaler are each typically free of any electronically powered component.
[0007] These and other features, advantages, and objects of the present disclosure will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] In the drawings:
[0009] FIG. 1 is an elevated front view of an exemplary filter unit according to an aspect of the present disclosure;
[0010] FIG. 2 is an exploded view of the structural components of the filter unit of FIG. 1 ;
[0011] FIG. 3 is an elevated end view of the filter unit of FIG. 1 ;
[0012] FIG. 4 is a cross-sectional view of the filter unit taken along the line IV-IV in FIG. 3 ;
[0013] FIG. 5 is an exploded view of a fluid flow impeding system according to an aspect of the present disclosure;
[0014] FIG. 6 is a dual cut away view of the fluid flow impeding system as shown in FIG. 5 in an assembled form;
[0015] FIG. 7 is a cross-sectional view of the fluid flow impeding system within the filter unit without the protective material over the electronic components of the system;
[0016] FIG. 8 is a cross-sectional view of the fluid flow impeding system within the filter unit with the protective material over the electronic components of the system;
[0017] FIG. 9 is a cross-sectional bottom view of the fluid flow impeding system including the electrical components of the system;
[0018] FIG. 10 is a cross-sectional top view of the fluid flow impeding system according to an aspect of the present disclosure;
[0019] FIG. 11 is a perspective view of an electrical system according to an aspect of the present disclosure;
[0020] FIG. 12 is a perspective view of an electrical system according to an aspect of the present disclosure;
[0021] FIG. 13 is an elevated front view of the electrical system of FIG. 12 ;
[0022] FIG. 14 is a perspective view of the impeller according to an aspect of the present disclosure;
[0023] FIG. 15 is a front elevational view of the impeller of FIG. 14 ;
[0024] FIG. 16 is a perspective view of an impeller according to another aspect the present disclosure;
[0025] FIG. 17 is a front perspective view of an impeller according to another aspect of the present disclosure;
[0026] FIG. 18 is a front perspective view of the impeller of FIG. 16 ;
[0027] FIGS. 19A-D are each a front perspective view of different configurations of valve feed inserts with various by-pass configurations that allow some amount of flow to continue through the filter unit, but at a reduced rate;
[0028] FIG. 20A is a cross-sectional perspective view of a fluid flow impeding system according to an aspect of the present disclosure prior to the expiration of the useful life of the filter unit;
[0029] FIG. 20B is a cross-sectional perspective view of a fluid flow impeding system according to an aspect of the present disclosure after the useful life of the filter unit showing impeded or stopped flow of water through the filter unit;
[0030] FIG. 21A is a cross-sectional perspective view of an alternative fluid flow impeding system according to an aspect of the present disclosure prior to the expiration of the useful life of the filter unit;
[0031] FIG. 21B is a cross-sectional perspective view of an alternative fluid flow impeding system according to an aspect of the present disclosure prior to expiration after the useful life of the filter unit showing impeded or stopped flow of water through the filter unit;
[0032] FIG. 22 is a dual cut away perspective view of a fluid flow impeding system according to an aspect of the present disclosure generally showing water flow into and out of the system;
[0033] FIG. 23 is a dual cut away perspective view of a fluid flow impeding system and according to an aspect of the present disclosure generally showing water flow into and out of the system showing a more detailed view of water flow as it passes through the fluid flow impeding system, through the filter and out the center outlet;
[0034] FIG. 24 is a cross-sectional view of a filter unit according to an aspect of the present disclosure with the small black arrows showing the water flow path through the system;
[0035] FIG. 25 is a bottom left perspective view of an embodiment of a fluid flow impeding system according to an aspect of the present disclosure;
[0036] FIG. 26 is a front elevational view of the housing of FIG. 25 showing the electronic component insulated by a waterproof insulated material;
[0037] FIG. 27 is a front elevational view of the housing of FIG. 25 showing the circular water flow direction through an impeller if it were inserted into the system;
[0038] FIG. 28 is a perspective view of the housing shown in FIG. 27 with an impeller, according to an aspect of the present disclosure, fitted within the housing;
[0039] FIG. 29 is a front left perspective view of the housing of FIGS. 25-28 with an impeller cover cap positioned over the impeller;
[0040] FIG. 30A is a cross-sectional perspective view of a fluid impeding system according to another aspect of the present disclosure prior to the expiration of the useful life of the filter unit using a flap valve to initially permit water flow;
[0041] FIG. 30B is a cross-sectional perspective view of a fluid impeding system according to another aspect of the present disclosure after the expiration of the useful life of the filter unit using a flap valve showing the valve in the closed position to inhibit water flow;
[0042] FIG. 31A is a cross-sectional perspective view of a fluid impeding system according to another aspect of the present disclosure prior to the expiration of the useful life of the filter unit using a plurality of beads suspended in strands;
[0043] FIG. 31B is a cross-sectional perspective view of a fluid impeding system according to another aspect of the present disclosure prior to the expiration of the useful life of the filter unit where the suspended strands of beads shown in FIG. 31A have been released to inhibit water flow;
[0044] FIG. 32A is a cross-sectional perspective view of a fluid impeding system according to another aspect of the present disclosure prior to the expiration of the useful life of the filter unit using magnetic beads, typically metallic spherical beads, or other debris engaged to a magnet to initially permit water flow;
[0045] FIG. 32B is a cross-sectional perspective view of a fluid impeding system according to another aspect of the present disclosure prior to the expiration of the useful life of the filter unit where the magnetic beads or debris have been released to inhibit water flow;
[0046] FIG. 33 is a circuit design according to an aspect of the present disclosure where the solenoid may be used without a capacitor.
[0047] FIG. 34 is an enlarged cross-sectional view of a fluid impeding system according to another aspect of the present disclosure employing a solenoid and plunger/peg system to restrict flow through the filter;
[0048] FIG. 35 is a cross-sectional view of the fluid impeding system shown in FIG. 34 spaced within the filter with the arrows showing general water flow through the filter;
[0049] FIG. 36 is a cross-sectional view of the fluid impeding system shown in FIGS. 34 and 35 with the plunger triggered and seated inside a raised ring thereby restricting water flow through a small (about 0.5 mm diameter) hole in the plunger;
[0050] FIG. 37 is schematic cut-away view of a refrigerator filter with a gear-based flow totaler in place showing a balancing restriction on the by-pass line;
[0051] FIG. 38 is a schematic cut-away view of a refrigerator water filter with gear-based flow totaler in place and a venturi-driven pressure differential;
[0052] FIG. 39A shows a schematic view of a shape memory alloy in a relaxed state in the water flow/inactivated position;
[0053] FIG. 39B shows a shape memory alloy in the activated/deployed position impeding water flow through the water path;
[0054] FIG. 40A shows an alternative embodiment where the shape memory alloy is the relaxed state and the perforated plate is in the retracted position;
[0055] FIG. 40B shows the shape memory alloy in the trained shape state/activated state and the perforated plate in the water impeding position.
[0056] FIG. 41 is a cross-sectional top view of a filter showing a fuse system that is isolated from water flow but in the water flow pathway;
[0057] FIG. 42 is a cross-sectional bottom view of the aspect of the present disclosure shown in FIG. 41 and FIG. 43 ; and
[0058] FIG. 43 is a front, elevated, cross-sectional view taken along lines XLIII in FIG. 41 .
DETAILED DESCRIPTION
[0059] Before the subject disclosure is described further, it is to be understood that the disclosure is not limited to the particular embodiments of the disclosure described below, as variations of the particular embodiments may be made and still fall within the scope of the appended claims. It is also to be understood that the terminology employed is for the purpose of describing particular embodiments, and is not intended to be limiting. Instead, the scope of the present disclosure will be established by the appended claims.
[0060] Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range, and any other stated or intervening value in that stated range, is encompassed within the disclosure. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, and are also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure.
[0061] In this specification and the appended claims, the singular forms “a,” “an” and “the” include plural reference unless the context clearly dictates otherwise.
[0062] Referring to FIGS. 1-43 , a filtration system is generally employed. The filtration system typically includes a filter unit 10 (see FIG. 1 ). The filter unit typically includes a cylindrical body portion 12 with a water receiving and emitting end 14 and a distal end 16 . The filter unit defines an interior volume within the cylindrical body portion between the water receiving and emitting end and the distal end. The filter unit includes a filter media portion 20 disposed within the interior volume 18 (see FIGS. 2-4 ). The filter media portion has a permeable media wall 22 is spaced away from the body portion 12 and defines an exterior passage 24 between the permeable media wall 22 and the body portion 12 . The permeable media wall 22 typically surrounds the central axis of the filter media portion 20 and defines an interior passage 26 . A filter media engaging cap 28 is typically coupled between the water receiving and emitting end 14 of the filter unit and the body portion 12 . The filter media engaging cap 28 typically has a cylindrical filter media engaging trough portion defined by an outer wall 30 and an upwardly extending central axis channel 32 . The upwardly extending central axis channel 32 is typically cylindrically shaped in size to matingly engage the interior passage of the filter media portion 20 . A second cap 34 also typically contains a filter media engaging portion trough section. The second cap 34 is typically spaced at the opposing end of the filter media portion. The interior passage 26 extends through the filter media engaging cap 28 and operably couples with the outlet aperture 36 to dispense filtered liquid, typically filtered water.
[0063] An inlet aperture 38 is operably coupled with the fluid flow impeding system 40 and the exterior passage 24 to deliver unfiltered (unfiltered by the filter unit 10 ) water into the interior volume of the filter unit 10 . The water in the exterior passage passes through and is treated by the filter media portion 20 . The filter media engaging cap 28 and the second cap 34 prevent unfiltered from passing from the exterior passage 24 to the interior passage 26 without passing through the filter media portion 20 .
[0064] The fluid flow impeding system 40 operates to measure the amount (volume) of water passing through the filter unit 10 being delivered as filtered water to the end user. Upon passing of the service life of the filter media portion 20 or the approximate service life of the filter media portion 20 , the fluid flow impeding system 40 operates to impede (reduce the flow rate) or stop the flow of fluid through the system. A fluid flow impeding system, according to the present disclosure, may operate to allow some flow of unfiltered water to flow at a normal rate followed by an impeded or stopped flow shortly thereafter to repeatedly demonstrate to the user upon each use that the filter media portion has passed its service life to effectively filter unwanted material from the fluid/water. In this manner, the user is repeatedly notified that the filter has expired while not believing that there is a problem with the system, such as a clogged water conduit in the appliance or other overall problem with the appliance engaged with the filter unit.
[0065] As shown in various figures, O-rings 122 are used in various locations of the filter unit to ensure a sealing connection between components.
[0066] The filter unit 10 is typically positioned within a refrigerator appliance according to one aspect of the present disclosure. The refrigerator appliance typically includes an insulated cabinet forming at least one interior freezer compartment and at least one interior refrigerator compartment cooled with at least one refrigeration circuit. The freezer compartment may be arranged below and be separate from the refrigerator compartment and enclosed with a slidable drawer having an insulated door. The freezer compartment may also alternatively be arranged relative to the refrigerator compartment in a side-by-side configuration or with the freezer compartment on top of the refrigerator compartment. In any configuration, the compartments may be accessible by opening and closing hinged doors by hand without use of tools by a person grasping and pulling on a handle on each of the doors. The refrigerator compartment may be enclosed with two hingeable doors in a side-by-side style door arrangement. The left refrigerator door may also include an interactive display, a water dispenser, and an ice dispenser that receives ice from an ice maker positioned somewhere within the appliance or proximate the appliance. The right refrigerator door is also capable of being positioned in an open position when the door is pivoted away from the side wall of the insulated cabinet to expose the interior refrigerator compartment. The refrigerator compartment may also include an alternative enclosure and an alternative location configuration relative to the freezer compartment. It is also conceivable that the refrigerator appliance may alternatively be an appliance with one or more refrigerator compartments and no freezer compartments or only one or more freezer compartments and no refrigerator compartments.
[0067] In each embodiment, the appliance may or may not have an ice dispenser or water dispenser, but typically the appliance will have both an ice dispenser and water dispenser. The filter unit 10 is typically operably connected to the appliance to receive water from a water distribution system of the appliance. The water distribution system typically includes a connector on a rear surface of the insulated cabinet of the appliance that couples the appliance with an external water source to supply a water flow to the filter unit 10 . Typically, the water supply is a municipal water source or well water source. While the water supply supplied to the appliance prior to being treated by the filter unit 10 may be filtered prior to being treated by the filter unit 10 , the water source typically provides unfiltered water to the filter unit 10 .
[0068] The filter unit typically engages the appliance via a filter head assembly in either a lower grill area on the bottom typically the bottom right below the freezer compartment or an upper panel area above the refrigerator compartment, most typically on the top interior surface of the refrigerator compartment. However, it is conceivable that the filter unit may engage the appliance at any location within or on the exterior surface of the appliance. Further, the filter unit 10 may be used in other applications including other appliances that store, use or dispense any liquid in need of filtration. The liquid to be treated is typically drinking water or water used to form ice. Additionally, the filter unit 10 may be used in connection with a household or standard tap water faucet. When engaged with such a faucet, the engagement is typically at or proximate the faucet outlet or other domestic water source. However, it is conceivable that the filter could be installed intermediate within the water piping of the faucet line between the faucet outlet and the water source.
[0069] The body portion 12 of the filter unit 10 is typically cylindrically shaped with a diameter that is capable and configured to be grasped by a hand of a user. Often one or more grasping cutouts or protrusions 42 are included on the exterior surface of the body portion 12 . Most typically, the grasping cutouts or protrusions are proximate the distal end 16 (see FIG. 2 ). This provides a gripping surface for the user to engage and disengage the filter unit from the filter head assembly, which is typically done by rotational and longitudinal movement of the filter unit relative to the filter head assembly.
[0070] The filter head assembly typically includes a filter receiving end and water receiving end. The filter receiving end typically has a cylindrical receiver adapted to receive all or at least a portion of the water receiving and emitting end 14 of the filter unit 10 . The cylindrical receiver may include an electrical connector that is adapted to engage with and provide electricity and data communication with at least one electronic device that communicates with the filter unit. The cylindrical receiver of the filter head assembly may also include a securing clip that couples with the exterior surface of the body portion 12 of the filter unit 10 .
[0071] The water receiving end of the filter head assembly typically includes an inlet and an outlet laterally extending on opposite sides of the filter head assembly. The inlet generally couples with the water source via at least one water line that receives water flow from outside the appliance, typically unfiltered water from outside the appliance. In addition, the outlet generally couples with the water dispenser and/or the ice maker within the appliance via at least one water conduit line, typically unfiltered water to the ice maker or for consumption or use by the user. The inlet and outlet of the filter head assembly can be at any angle relative to one another and disposed at any location on the filter head assembly to connect the inlet aperture and the outlet aperture of the filter unit 10 .
[0072] The filter unit 10 may have a single engagement protrusion that is typically an oval cross-sectional shape (not shown in the drawings). The engagement protrusion extends longitudinally from the water receiving and emitting end in general alignment with the longitudinal extent of the body portion 12 . The engagement protrusion is generally disposed at an offset location on the water receiving and emitting end according to this embodiment of the present disclosure, substantially aligning the outlet aperture with the central axis of the body portion 12 . The body portion 12 , in this embodiment, typically includes a laterally extending key member that is configured to slidably engage a helical shaped slot on the interior surface of the cylindrical receiver of the filter head assembly to engage the filter unit therewith. Similarly, the body portion includes a helically shaped retention slot to slidably engage a retention member on the filter head assembly. The entire disclosure of U.S. Pat. No. 8,580,109 is incorporated by reference.
[0073] In the embodiment shown in FIGS. 1-4 , the filter unit 10 includes an outlet engagement protrusion 44 longitudinally extending away from the water receiving and emitting end 14 of the filter unit 10 . The outlet engagement protrusion 44 has the outlet aperture 36 therein. The water receiving and engagement end 14 also includes an inlet engagement protrusion 46 extending away from the water receiving and emitting end 14 at a location offset from the outlet engagement protrusion 44 . The inlet engagement protrusion 46 includes the inlet aperture 38 therein. The inlet and outlet engagement protrusions 44 , 46 are configured to engage the inlet and outlet members of the filter head assembly upon longitudinal insertion of the filter unit into the filter head assembly. As such, it is conceivable that other embodiments may include alternative arrangements of the filter unit that are configured to engage with alternative filter head assemblies.
[0074] The filter media portion 20 is typically configured to filter and purify water that passes through the media wall 22 . The media filter portion 20 may include one or more filter media such as carbon (e.g., activated carbon particles, such as mesoporous activated carbon, carbon powder, particles sintered with a plastic binder, carbon particles coated with a silver containing material, or a block of porous carbon); ion exchange material (e.g., resin beads, flat filtration membranes, fibrous filtration structures, etc.); zeolite particles or coatings (e.g., silver loaded); polyethylene; charged-modified, melt-blown, or microfiber glass webs; alumina; aluminosilicate material; and diatomaceous earth. The media material may also be impregnated or otherwise disposed on a porous support substrate, such as a fabric material, a paper material, a polymer screen, or other conceivable porous structures that may be contained in the permeable media wall 22 to filter and purify water. It is also conceivable that the filter media portion 20 may be configured to treat water that passes through the media wall 22 , whereby the filter media portion may include a treatment media material configured to add a descaling agent to the water, add a vitamin to the water, add a mineral to the water, add a pharmaceutically active agent to the water, and add a color to the water, or mixtures thereof.
[0075] The filter media portion 20 is configured to include a service life based upon the types of media material contained therein. The service life may be quantified in the amount of water flow that optimally passes through the filter media portion 20 before the filtration, purification, and/or treatment effects of the media material deteriorate or no longer perform as desired or to the extent desired. The amount of time a filter media may deteriorate either prior to or after being initially exposed to any water flow may also be a factor in the service life of the filter unit. The service life of the filter unit configured to filter and purify water is typically at least about 50 to about 500 gallons, more typically about 100 to about 300 gallons and, even more typically 100 to 200 gallons, depending upon the frequency of use and the source water quality. The filter life may be up to about 500 gallons or 600 gallons depending largely on size of the filter and the nature of the filter media as well as the level of impurities in the water to be treated.
[0076] The filter unit 10 , also typically includes a circular support structure 48 that is positioned in engagement with the second cap 34 to provide structural support. The second cap 34 typically includes a downwardly extending nozzle 50 that engages the interior passage 26 . The distal end cap 52 engages the distal end of the body portion 12 . The distal end cap 52 may threadably engage or permanently be bonded to the distal end of the body portion 12 . Most typically, the distal end cap will be engaged to the body portion in manner that would be tamper evident, i.e. if one were to remove the distal end cap, it would be apparent to an end consumer. Alternatively, if one were to remove the distal end cap, the distal cap and/or body portion may be damaged, such that the distal end cap may not be reattached to the body portion 12 . In this manner, it prevents tampering with the filter and identifies to the user whether or not tampering has occurred and/or whether or not the filter material may have been altered or replaced.
[0077] As shown throughout the figures, the present disclosure also generally includes a fluid flow impeding system 40 that may be placed at either end of the filter unit 10 . As shown in FIG. 2 , the fluid flow impeding system is positioned proximate the water receiving and emitting end 14 , while FIG. 5 shows the fluid flow impeding system 40 positioned at the distal end of the filter unit 10 .
[0078] Generally speaking, according to an aspect of the present disclosure, the fluid flow impeding system 40 includes the filter media engaging top cap 28 (shown in FIG. 2 ). The filter media engaging cap 28 engages one end of the filter media 20 , but in FIG. 5 , the filter media engaging top cap engages the second cap. In the case of FIG. 5 , while not shown, a similar structure that engages the end of the filter media portion 20 proximate the water receiving and emitting end 14 typically would be utilized. The filter media engaging top cap 28 typically includes an upwardly extending nozzle 54 when the filter media engaging top cap engages the filter media; however, when positioned at the distal end, the nozzle 54 may be removed. The filter media engaging cap also typically includes a downwardly extending channel 56 that extends through a center aperture 58 of an impeller 60 . The impeller 60 is typically seated within an impeller receiving cavity of an impeller housing 62 . The impeller housing 62 also typically has an electronics receiving cavity 64 on a first side 66 and an impeller receiving cavity on a second, opposite side that is opposite the first side. The first side 66 and the second, opposite side 70 are typically divided by a dividing wall. The electronics assembly 72 is typically seated within the electronics receiving cavity 64 and any exposed electronic or power system information is typically encased within a non-toxic, water impermeable material 74 . The electronics are “potted”, which is a process of filling an electronic assembly with a solid or gelatinous compound to exclude moisture. Thermosetting plastic, silicone or rubber gels may be used. Projecting downward and allowing water there through is a water impeding valve 76 .
[0079] FIGS. 25-29 show an exemplary impeller housing 62 according to an aspect of the present disclosure. FIG. 27 shows the water flow path through the impeller receiving cavity. Water typically flows out of a side aperture 118 . FIG. 28 shows the impeller positioned within the impeller receiving cavity 68 of the impeller housing 62 . FIG. 29 shows an end cap 120 positioned over the impeller receiving cavity 68 .
[0080] The water impeding valve 76 of the fluid flow impeding system 40 typically has an inlet side 78 and an outlet side 80 and is typically positioned in parallel with the central axis of the filter unit; however, numerous shapes and configurations of the valve 76 may be used. Within the water impeding valve is typically a water impeding object 82 . A spherical member may be the water impeding object, but the water impeding object, for example, may also be one or more of the following: an impeller 60 held stationary by a signal activated breaking mechanism such as a solenoid driven pin driven in between that radially outwardly extending water engaging water engaging fins 94 ; a plurality of metal debris or metal beads ( FIGS. 32A and 32B ); a flap valve ( FIGS. 30A and 30B ); a plurality of beads ( FIGS. 31A and 31B ) and/or a spring-biased stop or other spring-biased water impeding object ( FIGS. 21A and 21B ). When the water impeding object is a spherical member as shown in FIGS. 6-10 , the sphere is typically retained by the retaining member 84 , which is typically a retractable pin. The retractable pin is operably associated with a solenoid 86 .
[0081] FIGS. 6-10 and 22-24 show the embodiment employing a solenoid and retaining member. In operation, water flows from the water within the impeller housing inlet aperture 38 , past the spherical member and into engagement with the impeller 60 thereby spinning the impeller. The impeller 60 typically has one or more magnets 88 enclosed within or positioned on a portion of the impeller. The magnet or magnets 88 operate to communicate with a reed switch that is a component of the electronic's assembly 72 to count or track each time the magnet(s) pass over the reed switch. This allows the filter unit 10 to determine how much (the volume of water) water follows through the filter unit 10 .
[0082] When the volume of water following through the filter unit 10 surpasses or is approximately the maximum volume capable of being effectively treated by the filter media portion 20 , typically a sufficient charge has accumulated in a capacitor 90 of the electronic assembly such that the solenoid is activated or the solenoid itself is activated without the use of a capacitor and the retaining member 84 is retracted by the solenoid. Once the retaining member has been retracted, the water impeding object 82 (spherical member) is allowed to flow along with the water flow flowing through the water impeding valve and moves into engagement with an internal bottleneck portion 92 of the typically hourglass-shaped water impeding valve. As a result, the water flowing through the filter unit 10 is slowed or stopped. Typically, water is allowed to flow through at an approximately 75 to 80% reduced rate from the water flow rate prior to activation of a solenoid and the retracting of the retaining member 84 .
[0083] The impeller 60 typically has a plurality of water engaging fins 94 that radially extend away from a central hub 96 . The water engaging fins are typically curved to capture water flowing through the filter 10 and allow for rotational movement of the impeller in the cylindrical housing of a cylindrically shaped impeller housing 62 . Essentially the fins are arcuate wall members. While not shown, the fluid flow impeding system shown in FIGS. 6-10 and 22-24 may include one or more water flow channels that are not a water impeding valve. When used, the water flow channels that are not in the water flow path of the water impeding valve ensure that the entire flow of water is not blocked by the spherical member. Rather, depending on the size of the aperture(s) of the water channel(s), a regulated percentage of water less than the normal flow rate will still flow through the filter unit 10 .
[0084] As discussed above, one or more magnets 88 communicate with a reed switch, which is part of a single sided surface mount circuit board, which is typically approximately 0.032 inches thick. A reed switch should be in signal communication with the magnet such that the reed switch reads each time the magnet passes over the read switch. As a result, an accurate assessment of the volume of water passing through the filter unit 10 may be made by the filter unit.
[0085] As shown in FIGS. 7 and 8 , the impeller housing 62 typically has an integral polypropylene “V” seal 97 that creates an interference seal between the interior side of the body portion 12 and the impeller housing. The “V” seal operates to force water to pass through the impeller. As also shown in FIGS. 7 and 8 , a quattro seal 98 is employed to engage the downwardly extending channel 56 to the body portion 12 of the filter unit 10 . A quarto seal is a four-lobbed seal with a geometry that provides twice the number of sealing surfaces than a standard O-ring. The quarto seal utilizes squeeze and deflection to affect a seal. The second cap 34 also typically includes integral “V” sealing members 97 positioned circumferentially about the perimeter of the second cap 34 .
[0086] As shown in FIG. 9 , the electronic assembly 72 of the present disclosure typically includes at least one battery 100 . The battery or batteries operate to provide power to the printed circuit board processor and the capacitor. Alternatively, a turbine may be used instead of or in addition to a battery and capacitor to provide the activating electrical power to the other component of the systems of the present disclosure such as the solenoid. Preferably, all of the electrical components are kept on one side of the printed circuit board.
[0087] The water impeding valve 76 (see FIG. 10 ) is typically positioned in between a plurality of ribs 102 . The ribs 102 provide structural support. The water impeding valve may also be a funnel shape that fits between the ribs. As shown in the drawings, the water impeding valve is typically substantially hourglass-shaped.
[0088] As shown in FIGS. 14-18 , the impeller 60 can have various configurations. As shown in FIG. 16 , the impeller may be molded such that the magnets are molded within the impeller when the impeller is made of one or more plastic materials. As shown in FIG. 17 , the impeller may include a low friction axle 102 . FIG. 17 shows magnet receiving apertures 104 . The magnets are affixed or molded into the magnet receiving aperture(s) 104 . The magnets may be attached via an appropriate adhesive.
[0089] As shown in FIGS. 19A-D , various valve seats may be used in connection with the systems of the present disclosure. The valve seats may receive the spherical member or other water impeding object(s) and are typically designed to have the spherical member block the majority of the water flow while allowing some water flow to continue through the valve seats. As shown in FIG. 19A , the spherical member 82 would eventually be seated within the funnel portion 106 b of the valve seat inserts 108 a . Similarly, the spherical member would be received into the funnel portion 106 of the valve seat 108 b shown in FIG. 19B . The valve seat 108 c and 108 d have a substantially planar spherical member receiving surface 110 . As can be seen, there are typically alternative water flow paths that would not be blocked if a spherical member were brought into engagement with the planar surfaces. For example, in FIG. 19C the peripheral water channels 112 would not be blocked by the spherical members when brought into engagement with the primary center channel 114 . Water flow would still be permitted through the valve seat insert. However, a majority of the water flow would be blocked thus slowing the flow of water through the filter assembly and the flowed water being dispensed to the user.
[0090] In another aspect of the present disclosure shown in FIGS. 20A and 20B , the electronic assembly 72 operates in the same manner as discussed above. Mainly, the impeller communicates with the reed switch. The capacitor charges to a predetermined level. Once the predetermined level of charge is reached, which corresponds the useful life of the filter media portion of the filter unit, the capacitor discharges and breaks the wire connection (see FIG. 20A ) such that the spherical member 82 is allowed to be forced by water flow into engagement with a water flow aperture (see FIG. 20B ) and block one of a plurality of such water flow apertures. In this manner, while a majority of water is blocked, some water is still permitted to flow thereby creating a slowed water flow rate.
[0091] Yet another aspect of the present disclosure is shown in FIGS. 21A and 21B . These figures show a spring biased impeding object 116 that is biased toward an engaged position and held in a disengaged position with a wire engagement in a similar manner as shown in FIGS. 20A-B . Again, once a predetermined electrical change has been reached after the volume of water that may be effectively treated by the filter unit has passed through the filter unit, the capacitor discharges and releases the spring bias member to block the water passage.
[0092] FIGS. 31A and 31B show an alternative fluid impeding system employing utilizing a plurality of suspended strands of beads 218 prior to release ( FIG. 31A ) and after triggering of the fluid impeding system ( FIG. 31B ), which results in a slowed water flow through the filter. Once triggered after a predetermined electrical charge has been reached and after the volume of water that may be effectively treated by the filter unit has passed through the filter unit, the capacitor discharges and releases the strands of beads and water flow is inhibited.
[0093] FIGS. 32 and 32B show yet another fluid impeding system. The system shown uses a plurality of magnetic beads 250 , typically metallic, spherical beads, or other debris that engages a magnet to permit initial “normal” water flow ( FIG. 32A ) and are disenganged/released form the magnet to inhibit water flow ( FIG. 32B ). The magnet holding the spherical beads may be an electromagnet that is deactivated once a predetermined electrical change has been reached after the volume of water that may be effectively treated by the filter unit has passed through the filter unit. The deactivation releases the magnetic beads.
[0094] FIG. 33 shows how the S-t-F circuit shown might utilize a “3 volt” solenoid. The components in the step-up circuit (boxed) can be removed, and the battery connected directly to the energy storage capacitor, C 2 , through a current limiting resistor, R 6 . C 2 is now charged to 3V (instead of something more than 5V) and may need to change in value, depending on the energy required to activate the 3V solenoid. If the battery is capable of supplying the necessary current (this translates to the battery's internal resistance being low enough), it may be possible to eliminate C 2 , and use the battery to activate the solenoid directly. The purpose of R 6 is to prevent the solenoid (or step-up circuit, if used) from dropping the battery voltage to zero, which would reset the microprocessor.
[0095] FIGS. 34-36 show another fluid impeding system that uses a solenoid 220 that releases the plunger/peg 222 once a predetermined electrical change has been reached after the volume of water that may be effectively treated by the filter unit has passed through the filter unit, the capacitor discharges and releases the plunger 222 . The plunger sits inside a raised ring 224 . Water is then restricted via a small (0.5 mm diameter) hole in the plunger. Prior to the seating of the plunger, water is allowed to freely flow underneath the plunger. FIG. 34 shows an enlarged view of the fluid impeding system of this embodiment. Water flows through the system in the direction of the arrows 268 , FIG. 34 , and the arrows shown in FIGS. 35-36 . The core 270 , magnet 272 , bobbin 274 and winding 276 are shown.
[0096] As shown in FIGS. 37-40B , an alternative flow by-pass and triggering mechanism is shown. Gearing systems within water filters with a capacity of greater than about 50 gallons where the gearing system measures or approximates filter life have generally not been employed due to the tremendous complexity of such systems. However, the present disclosure incorporates, as shown in FIGS. 37-38 , a flow by-pass system. A significant amount of water by-passes the impellers of a gear-based flow totaler assembly. This allows the gear assembly to turn much slower compared to a configuration utilizing the total water flow. This reduces the number of gears in the total gear assembly, which simplifies the design, increases reliability, and reduces cost. This configuration also reduces the volume of internal space within the filter utilized by the gear assembly.
[0097] A manifold with more than one outlet is employed where the outlet is at a given hydraulic system static pressure. The manifold would not have to have a balanced flow but merely consistent flow where, for example, 90% of the water flow could travel a main water flow path 300 and 10% would travel a secondary flow path 302 , which is rotated through the turbine wheel of the flow totaler 304 . The secondary flow path will have a minority of the water flow flowing through it, but more typically significantly less than 50%, as discussed above. This reduces the gear train stack 306 required to count the total flow of the water filter to only a small percentage. This reduces the number of stages and fineness of the gear teeth required for approximately 10× flow volume if the total flow has to be directed entirely through the flow totaling mechanism.
[0098] FIG. 37 shows a cut-away of a refrigerator water filter with the gear-based flow totaler in place. The water inlet flows through a turbine wheel that drives the timing and gear train. In turn, the gear train, as the flow total is achieved, closes off a discharge port to stop or reduces total flow in order to signal to a user that the end of the filter life has been reached. The schematic view shows a flow by-pass of the flow totaling mechanism. The by-pass allows a range of total flow coming into the filter inlet from about 5% to about 85% with the intent that the majority of flow would by-pass the flow totaler. However, a certain amount of flow may be required to drive the totaler mechanism and, as such, a balancing restriction 308 could be set into the by-pass as indicated by the narrowing in the by-pass flow cross-section. This restriction could be accomplished in a variety of ways by simply choosing an appropriate length and diameter of the by-pass, by introducing a flow washer or other flow restrictor or by pinching of the tube diameter as shown in FIG. 37 . Additionally, to assist in more consistent flow regulation over a range of inlet pressures, the by-pass could employ a venturi 310 in the mechanism flow path that would set up a pressure differential for the by-pass (see FIG. 38 ).
[0099] In addition to using the by-pass totaling mechanism to calculate when to initiate a flow restriction mechanism, the disclosure contemplates the use of a shape memory plunger as a flow restriction mechanism. As shown in FIGS. 39A-40B , the shape memory plunger changes the water filter flow resistance by employing a shape memory component in one state not imposing any geometry that would impede water flow and in a deployed state (energized to go to a trained shape) the component would provide a pinch point or move a plug or plunger to the flow stream thereby increasing flow resistance. Care is typically needed to ensure the shape memory alloy is out of the water flow so that heat required to activate the trained state is not excessive in order to overcome the cooling effect of any water. Thus, the shape memory alloy could be encased in a loosely fitting membrane cloak or bag (not shown). Additionally, the force of the shape memory alloy needs to be minimal and the force generated is primarily used to provide total or substantial blockage of the main flow path. As shown FIGS. 39A-40B , a plug 400 or gate 402 could be moved into the flow path but consideration needs to be made to ensure the force does not have to overcome substantial fluid flow or restriction forces. To avoid fluid momentum forces, the trigger could be fired once flow has stopped or the plug shaped so that initial flow impingement would aid to drive the flow blocking plug into place in the main flow path. Thus, instead of being streamline such as the plug shown in FIGS. 39A and 39B , instead the plug could be a perforated plug. As shown in FIGS. 40A and 40B , once tipped into the flow field by the deployed shape memory alloy 404 , is then driven by the flow into a blockage position held lightly in place by the deployed shape memory alloy, but firmly by water flow during water filter dispensing. The shape memory alloy 404 would typically require a one-time firing of a power circuit upon the determination of the appropriate flow volume for the filter. Once the total capacity of treated water has been reached, the triggering mechanism fires and the shape memory alloy moves the water flow impingement mechanism into position. This slows the flow of the water being dispensed to the user out of the appliance, typically a refrigerator, and indicates to the user that the useful life of the filter has been reached.
[0100] The shape memory alloy may be a shape memory alloy produced by Dynalloy, Inc. of Irvine, Calif. The shape memory alloy is typically a wire capable of repeatable motion. The wire can typically contract from about 3% to about 5% of its length upon activation, which is achieved by heating the wire with electricity.
[0101] The shape memory alloy would typically need to be sealed from contact with water due to the fact that the action of the shape memory alloy is driven by heat, which would be dissipated by water contacting the alloy. As such, the system of the present disclosure would have the alloy link sealed on at least one end of a water tight enclosure. The seal on the end is typically constructed to be breakable when the alloy is activated. A cap made of a folded membrane such as a thin silicone sheet material might be used. The silicone sheet would typically be constructed to unfold upon breakage of the link occurring on activation of the alloy. Alternatively, a very low durometer material may be applied to the system such that it slides or extends when the link breaks.
[0102] In another system, a water flow reduction system might employ a dissolvable material, such as a polymer that is NSF 61 safe and typically would not add taste, color or odor to the drinking water, and a non-dissolvable plastic part. As the dissolvable material gradually erodes, the non-dissolvable material/plastic would be release to block or slow the flow of water through the system/filter.
[0103] In yet another aspect of the present disclosure shown in FIGS. 41-43 , a fuseable underwater valve actuator is shown. This aspect incorporates an elongated chamber that insulates a portion of the fuse wire from the flow of water, which operates to lower the level of power that needs to be supplied to break the fuse wire after the useful life of the filter has passed. The fuse may be actuated during a period of water flow, but could also be actuated during a period of non-water flow. The figures, a clam shell housing 500 encases the fuse 502 in a watertight manner. The fuse 502 is typically surrounded by a low thermal mass, non-electrically conductive, thermally insulation material 504 , which is most typically air, but could also be a solid material such as a plastic or a foam insulation material. The fuse wire extends through an end 506 of the housing 500 . The end 506 is proximate the plug ball 508 and has an easily rupturable plug 510 . The fuse wire extends through the plug 510 and engages the plug ball 508 to retain the plug ball in the disengaged position that does not slow or stop the flow of water. As in previous embodiments, once the useful life of the filter has passed, the electrical charge, which can be significantly less than in other embodiments where the fuse is in contact with water that acts as a heat sink, breaks the fuse wire. When the fuse wire breaks, the plug ball 508 is released and settles into contact with the valve seat 512 . The valve seat typically has a plurality of radially inwardly extending support spokes 514 that define a series of water flow segment 516 . The plug ball 508 is of sufficient size to substantially impede, but typically not completely block water flow through the water flow segments 516 after the plug ball 508 is released by the fuse wire.
[0104] The clam shell housing is typically mounted and engaged with a series of support spokes 518 . A ring-shaped base 520 and anchor legs 522 extending therefrom may be used to further support the clam shell housing in position. These components may be affixed or molded into the plastic components of the system. Conceivably, the clam shell housing could be other shapes than the elongated tubular shape as shown, including cuboid-shaped, and spherical. Additionally, other anchoring elements (not shown) may be used in connection with this aspect of the present disclosure such as anchoring systems that engage a distal end 524 of the housing 500 and/or along the middle portion of the housing 500 . This aspect of the present disclosure does not require and typically does not use a solenoid or other electrically powered component to trigger the fuse wire.
[0105] It will become apparent to those skilled in the art that various modifications to the preferred embodiment of the disclosure as described herein can be made without departing from the spirit or scope of the disclosure as defined by the appended claims.
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A method of indicating to a user of an appliance that a water filter unit operably connected to the appliance has passed its useful life that includes the steps of: providing a filter unit and wherein the filter unit comprises a fluid flow impeding system within a housing of the filter unit; engaging the filter unit with the appliance; measuring the volume of water treated by the filter unit using an end of life measuring system positioned within the filter unit; and activating the fluid flow impeding device contained within the housing of the filter unit after a maximum volume of water the filter unit has been designed to treat has been surpassed.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to a video game control adapter apparatus, and more particular, to a video game control adapter apparatus that displays a video game image on an associated video display in response to a control signal transmitted without a cable.
[0003] 2. Description of the Related Art
[0004] The typical home video game device has an output terminal that is connected to a display unit such as a television set and an input terminal that accommodates a cable from a controller. The video game device itself is equipped with both a disk drive unit with a turntable that rotatably drives a disk (such as a CD-ROM) on which is recorded the game software that animates the device as well as a pick-up unit (an optical pick-up unit) that reads the data recorded on the game software disk.
[0005] The video game device generates image data from the data read from the device and displays the image on the video display. Additionally, the video game device also generates image data in response to a control signal input thereto in response to the operation of control buttons provided on the controller.
[0006] Accordingly, a video game player can participate in the game displayed on the video display by manipulating the buttons on the controller while watching the video display on which the game image data is displayed. Moreover, depending on the type of game activity (fishing and shooting are typical examples), it is possible to purchase special dedicated controllers designed specifically for that game. In such a case, by connecting the special controller cable to the video game device, the game player can get a more realistic feel for the game activity (fishing, shooting, etc) than is possible with the ordinary general-purpose controller.
[0007] However, the conventional arrangement described above has a disadvantage in that, although the special controller gives the game player a more realistic feel for the game than is possible with the ordinary controller, the game player must nevertheless purchase the special controller separately, thereby incurring additional costs which are not insubstantial.
[0008] Additionally, both the ordinary controller and the special controller require the use of a cable to connect the controller to the input terminal of the video game device. The range of movement of the game player is thus restricted by the length of the cable, which is undesirable. Thus, in a shooting game in which the controller is formed into the shape of a pistol, for example, the game player cannot take the pistol in hand and wield it freely but must instead remain close to the video display or to the video game device, as the case may be.
[0009] As a result of such a drawback, the game player cannot fully enjoy the video game because the freedom of movement of the game player is restricted by the control cable connecting the controller and the video game device.
BRIEF SUMMARY OF THE INVENTION
[0010] Accordingly, it is a general object of the present invention to provide an improved and useful video game control adapter apparatus in which the drawbacks described above are eliminated.
[0011] The above-described object of the present invention is achieved by a video game control adapter apparatus that includes a reception adapter that attaches to a connector of a video game device that displays a game image on a video display as well as a transmission adapter that transmits a control signal toward the reception adapter when a switch built into a toy to which the transmission adapter attaches is switched ON.
[0012] According to this aspect of the present invention, any toy with a built-in switch can be used as a controller instead of the ordinary video game controller, which increases the range of choices of controllers as well as the pleasure gained from using a controller adapted to a particular game.
[0013] Additionally, according to the above-described aspect of the present invention, control signals can be transmitted to the video game device in response to a manipulation of the toy without a cable by using radio waves, light or sound, so the movements of the game player are not restricted by the cable.
[0014] Additionally, the above-described object of the present invention is also achieved by the video game control adapter apparatus as described above, wherein the reception adapter includes a reception sensor that has directivity.
[0015] According to this aspect of the present invention, the range within which signals transmitted from the transmission adapter attached to the toy can be restricted to a predetermined range. Thus, signals outside the predetermined range constitute “misses” and signals within the range constitute “hits”, thereby enabling the video game to function as a game.
[0016] Additionally, the above-described object of the present invention is also achieved by the video game control adapter apparatus as described above, wherein the transmission adapter is substantially card-shaped.
[0017] According to this aspect of the present invention, the card-like shape of the transmission adapter enables the transmission adapter to be fitted to a wide variety of toy shapes, such shapes including, but not limited to, toy pistols, toy swords, toy cosmetic compacts, and so forth.
[0018] Additionally, the above-described object of the present invention is also achieved by the video game control adapter apparatus as described above, wherein the transmitting part of the transmission adapter that transmits the control signal is provided on a projecting portion that projects from the toy.
[0019] According to this aspect of the invention, the placement of the transmitting part of the transmission adapter on a projecting portion that projects from the toy allows the transmission of control signals from the transmission adapter to the reception adapter to proceed without interference from the toy, which may be of irregular shape.
[0020] It should be noted that a receiving part of the reception adapter need not necessarily project from the reception connector. Instead, it is sufficient that such receiving part be externally exposed so as to be able to receive transmission of control signals from the transmission adapter.
[0021] Additionally, the above-described object of the present invention is also achieved by the video game control adapter apparatus as described above, wherein the control signal is a radio wave, an optical signal, or an audio signal.
[0022] According to this aspect of the present invention, the use of a cable to connect the toy with the video game device is no longer required, thereby increasing the freedom of movement of the game player and enhancing the pleasure of the video game activity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] These and other objects, features, aspects and advantages of the present invention will become better understood and more apparent from the following description, appended claims and accompanying drawings, in which:
[0024] [0024]FIG. 1 is a perspective view of a video game system employing a video game control adapter apparatus according to one embodiment of the present invention;
[0025] [0025]FIG. 2 is a lateral view of the video game control adapter apparatus in use;
[0026] [0026]FIG. 3 is a block diagram of a state of attachment of the transmission adapter of the video game control adapter apparatus of the present invention to a toy pistol;
[0027] [0027]FIG. 4 is a block diagram of a state of attachment of the reception adapter of the video game control adapter apparatus of the present invention to a video game device;
[0028] [0028]FIG. 5 is a plan view of a video game device fitted with the reception adapter of the video game control adapter apparatus of the present invention;
[0029] [0029]FIG. 6 is a perspective view of a first variation of the video game control adapter apparatus of the present invention; and
[0030] [0030]FIG. 7 is a perspective view of a second variation of the video game control adapter apparatus of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0031] A description will now be given of a video game control adapter apparatus according to one embodiment of the present invention, with reference to the accompanying drawings. It should be noted that identical or corresponding elements in all drawings are given identical or corresponding reference numbers, with a detailed description thereof given once and thereafter generally omitted for brevity of explanation.
[0032] [0032]FIG. 1 is a perspective view of a video game system employing a video game control adapter apparatus according to one embodiment of the present invention.
[0033] As shown in FIG. 1, the video game system comprises a television set as a video display 10 , to which a video game device 12 is attached by a cable 18 , and a controller 14 . The game player enjoys the game by manipulating the controller 14 in response to the images shown on the video display 10 .
[0034] A front of the television set that functions as the video display 10 includes a power switch 16 and a jack 20 to which a plug end of the cable 18 from the video game device 12 is fitted. A rear surface of the video game device 12 has an output terminal (not shown in FIG. 1 because not viewable from the angle shown in FIG. 1) to which the other end of the cable 18 is fitted, thus connecting the video game device 12 to the television set that functions as the video display 10 .
[0035] Additionally, an upper surface of the video game device 12 has a disk holder portion 22 that accommodates a CD-ROM (not shown in FIG. 1) on which the game software is recorded, a power switch 24 , and an eject switch 26 . A front surface of the video game device 12 is provided with a connector 32 to which a terminal 30 of the cable 28 of the controller 14 is connected.
[0036] Ordinarily, the game player can cause a character displayed on the screen of the video display 10 to move, for example, or can attack an enemy character so displayed by manipulating switches 34 , 36 on the controller 14 connected to the connector 32 of the video game device 12 via the cable 28 .
[0037] However, when using the controller 14 , the length of the cable 28 limits the positioning of the game player so that the game player cannot move freely. In the case of a shooting game, for example, the game player cannot take cover and shoot at the opposing character from behind such cover, which takes some of the fun out of the game.
[0038] In contrast to such types of cable-type controllers 14 , there are radio-type controllers that are sold separately. However, such radio-operated controllers represent an additional cost to the consumer as compared to the ordinary cable-type controller 14 .
[0039] In the present embodiment, a reception adapter 40 that is designed to be attached to the connector 32 of the video game device 12 is attached to the connector 32 , and a transmission adapter 44 that is designed to be attached to a control unit 42 is attached to a control unit 42 which, in this case and for illustrative purposes only, happens to be a toy pistol. The toy pistol 42 is configured so that whenever the game player pulls the trigger 42 a a switch signal or volume signal is output, with the transmission adapter 44 being attached to a grip portion 42 b of the toy pistol 42 .
[0040] [0040]FIG. 2 is a lateral view of the control adapter in use.
[0041] As shown in FIG. 2, a control adapter apparatus 46 comprises the above-described reception adapter 40 and the transmission adapter 44 , the latter formed into substantially the shape of a card. As noted above, the reception adapter 40 is designed to be inserted into the connector 32 in the front surface of the video game device 12 . The transmission adapter 44 is designed to be inserted into the handle 42 b of the toy pistol 42 .
[0042] When the game player aims the toy pistol 42 at the video game device 12 and pulls the trigger 42 a, a control signal in the form of a radio wave is transmitted from the transmission adapter 44 , as indicated by the arrow in FIG. 2. When the video game device 12 receives the control signal transmitted from the transmission adapter 44 at the reception adapter 40 , it makes a determination that the enemy character in the display has been hit. With two hits, for example, the enemy character falls dead.
[0043] A description will now be given of the toy pistol 42 .
[0044] [0044]FIG. 3 is a block diagram showing the attachment of the transmission adapter of the present invention to the toy pistol.
[0045] As shown in FIG. 3, the toy pistol 42 comprises a connector 48 to which the transmission adapter 44 is connected, a battery 50 , a switch 52 that turns ON and OFF with each revolution of the trigger 42 a, a light emitting diode (LED) 54 that emits light in a direction toward which the toy pistol 42 is pointed when the switch 52 is turned ON, and a buzzer 56 that supplies an acoustic effect when the switch 52 is turned ON.
[0046] As noted previously, the transmission adapter 44 is formed into a substantially card-like shape, and comprises a signal data processor 58 for controlling the signals input and output via the connector 48 , and a transmitter 60 that transmits control signal radio waves according to instructions from the signal data processor 58 .
[0047] Accordingly, when the game player pulls the trigger 42 a of the toy pistol 42 , the transmission adapter 44 transmits a control signal and, at the same time, the LED 54 of the toy pistol 42 emits light and the buzzer 56 emits sound.
[0048] It should be noted that the toy pistol 42 is not something originally made specifically for use as a controller for this video game device 12 but is instead simply a commonly sold item. The only difference between the toy pistol 42 described here and an ordinary toy pistol is that the toy pistol 42 described here has a connector 48 to which the transmission adapter 44 can be adapted.
[0049] Accordingly, the game player does not need to purchase a special controller for the video game device 12 . Instead, a previously purchased toy pistol, for example, can be used as the controller, that is, the toy described in the claims, of the video game device 12 simply by attaching the above-described transmission adapter 44 , provided, of course, that the toy pistol has a switch, the connector 48 and a power supply.
[0050] [0050]FIG. 4 is a block diagram showing the attachment of the reception adapter of the present invention to a video game device.
[0051] As shown in FIG. 4, the video game device 12 comprises a motor 64 that rotatably drives a CD-ROM 62 contained in the disk holder portion 22 , an optical pick-up 66 that reads the software data recorded on the CD-ROM 62 , a control circuit 68 to which data signals output from the optical pick-up 66 are inputted, the connector 32 to which the reception adapter 40 is attached, a video/audio processor 72 that generates video and audio signals from the signals output from the control circuit 68 and outputs those signals to the television set 10 . Additionally, the control circuit 68 arbitrarily selects data from among the data recorded on the CD-ROM 62 in response to the presence and absence of a control signal received at the reception adapter 40 , and outputs the selected video and audio data to the video/audio processor 72 .
[0052] Accordingly, when a signal transmitted from the toy pistol 42 is received at the reception adapter 40 , the television set used as the video display 10 shows a bullet hitting the enemy character, and when such a signal transmitted from the toy pistol 42 is not received at the reception adapter 40 , the bullet is shown missing the enemy character.
[0053] The reception adapter 40 comprises a connector 74 that is connected to the video game connector 32 , a signal data processor 75 for controlling signals input and output via the connector 74 , an optical sensor 76 that receives light as the control signal, an audio sensor 78 , and a receiver 80 that receives control signals transmitted from the transmitter 60 of the transmission adapter 44 .
[0054] Accordingly, the reception adapter 40 outputs a reception signal to the control circuit 68 via the signal data processor 75 and the connector 74 when either the receiver 80 of the reception adapter 40 receives a control signal transmitted from the toy pistol 42 , or the optical sensor 76 of the reception adapter 40 receives light transmitted from the LED 54 , or the audio sensor 78 of the reception adapter 40 receives the sound of a gunshot transmitted from the buzzer 56 . As a result, the control circuit 68 determines that the bullet fired from the toy pistol 42 has scored a hit on the enemy character.
[0055] [0055]FIG. 5 is a plan view of a video game device fitted with the reception adapter of the present invention.
[0056] As shown in schematic form in FIG. 4, the receiver 80 , optical sensor 76 and audio sensor 78 are provided on the front of the reception adapter 40 so as to face the game player and thus improve reception of the radio waves, light and/or sound emitted from the toy pistol 42 . Additionally, the receiver 80 , optical sensor 76 and audio sensor 78 are provided on the reception adapter 40 . Additionally, the receiver 80 , optical sensor 76 and audio sensor 78 provided on the reception adapter 40 each have a directivity varying laterally from a centerline by a predetermined angle θ such as, for example, 20-30 degrees. As a result, whenever the game player pulls the trigger 42 a on the toy pistol 42 within the angle 2 θ as shown in FIG. 5, the game player scores a hit on the enemy character because the transmitted signal is received at the reception adapter 40 . However, if the game player pulls the trigger 42 a on the toy pistol 42 when positioned outside the range 2 θ as shown in FIG. 5, then the game player does not score a hit on the enemy character because the transmitted signal is not received at the reception adapter 40 .
[0057] A description will now be given of a first variation of the present invention, and more specifically, of a variation of the control unit.
[0058] [0058]FIG. 6 is a perspective view of a first variation of the present invention.
[0059] As shown in FIG. 6, a toy cosmetics compact is used as a control unit 82 . The toy compact control unit 82 has a pad switch 84 that the game player touches provided on a top surface of a lower case half 86 , and an upper case half or cover 88 hinged along one side of the lower case half 86 . The toy compact control unit 82 functions as a controller used with game software targeting young female consumers, for example, so that, by touching the pad switch 84 , the appearance of the character displayed on the video display 10 can be changed.
[0060] Additionally, a lower surface of the cover 88 is fitted with either a mirror or another control switch. A slot 90 for inserting the above-described transmission adapter 44 is provided along a lateral edge of the lower case half 86 .
[0061] After inserting the transmission adapter 44 into the slot 90 , the game player can then press the pad switch 84 to transmit a radio wave, light or sound control signal to the reception adapter 40 attached to the video game device 12 . When such a signal is received at the reception adapter 40 , the character displayed on the screen television set used as the video display 10 changes appearance or position.
[0062] As shown in FIG. 6, the transmission adapter 44 is shaped like a card. The advantage of the card-like shape is that it allows the transmission adapter to be used not only in the toy pistol 42 described above but also in a thin, flat control unit such as the toy compact control unit 82 described here.
[0063] A description will now be given of a second variation of the present invention, and more specifically, of a variation of the control unit.
[0064] [0064]FIG. 7 is a perspective view of a second variation of the present invention.
[0065] As shown in FIG. 7, a toy sword 92 is used as the control unit, with a grip portion 94 of the toy sword provided with switches 96 , 98 . By pressing the switches 96 or 98 and wielding the toy sword, the enemy character can be vanquished. Also, as shown in the diagram, a slot 100 for inserting the card-shaped transmission adapter 44 described above is provided at an end surface of the grip portion 94 of the toy sword 92 .
[0066] After inserting the transmission adapter 44 into the slot 100 , the game player can then press either of the two switches 96 and 98 to transmit a radio wave, light or sound control signal to the reception adapter 40 attached to the video game device 12 . When such a signal is received at the reception adapter 40 , the enemy character displayed on the screen television set used as the video display 10 is considered by the video game device 12 to have been cut down and is so displayed on the screen.
[0067] Thus, by attaching the transmission adapter 44 to in one case a toy pistol 42 , in another case a toy compact 82 , and in a third case a toy sword 92 , items which are not originally designed as controllers for the video game device 12 can be made to act as such. The advantage is that it becomes possible to select a controller having a shape suited to the game software. Moreover, the reception adapter 40 and transmission adapter 44 can be used as a set, and as a set are less expensive than the special controllers sold separately.
[0068] It should be noted that although the embodiments described above make reference to control units in the form of toy pistols 42 , toy compacts 82 and toy swords 92 , the control unit is not limited to such forms but may consist of any toy to which the transmission adapter 44 can be successfully attached.
[0069] As can be appreciated by those of ordinary skill in the art, additional variations and embodiments of the invention are possible.
[0070] In one variation, the video game control adapter apparatus can be configured so that the adapters mounted on both the control unit (that is, the toy) and the video game device can both transmit and receive signals.
[0071] According to such a configuration, signals can be sent from the video game device to the toy gun of the present invention, thus triggering the LED of the gun and/or the buzzer and therefore providing a more realistic feel to the game.
[0072] In another variation, the adapter fitted to the control unit (that is, the toy) may further have a built-in LED and buzzer.
[0073] According to such a configuration, even toys which do not have an LED and buzzer, such as cosmetic compacts and swords, can be made to have the same effects as those described above with respect to the toy gun.
[0074] Additionally, by providing the toy with an adapter with transceiver capabilities, it becomes possible to play among a plurality of such toys without the need for the video game device.
[0075] The above description is provided in order to enable any person of ordinary skill in the art to make and use the invention and sets forth the best mode contemplated by the inventor of carrying out the invention.
[0076] The present invention is not limited to the specifically disclosed embodiments and variations, and modifications may be made without departing from the scope and spirit of the present invention.
[0077] The present application is based on Japanese Priority Application No. 2000-246493, filed on Aug. 15, 2000, the entire contents of which are hereby incorporated by reference.
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A video game control adapter includes a reception adapter that attaches to a connector of a video game device that displays a game image on a video display; and a transmission adapter that transmits a control signal toward the reception adapter when a switch built into a toy to which the transmission adapter attaches is switched ON.
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The present invention is directed to a method for producing nonwoven, nonbiodegradable tissue ingrowth inducing, tissue interfacing substrates.
BACKGROUND OF THE INVENTION
Infection is a major concern associated with percutaneous and implant devices and an approach to such problem has recently focused on development of composite collagen-polymer matrices which can accommodate antimicrobial factors and which are compatible with the tissue. One of the problems is to enhance or impart tissue ingrowth properties to the non-degradable polymer matrix of such devices. In a collagen-polymer matrix, the collagen portion is naturally reabsorbed into the host tissues, therefore a viable environment for tissue interfacing with the device substrate (the polymer) is desired. However, if the epithelial tissues do not interface to the implant device, they will begin to propagate toward areas which may increase the chances of infection. For example, if a percutaneous device is an elastomeric cuff around a catheter, if the epithelial tissues do not adhere to the percutaneous cuff, they will begin to propagate down the catheter conduit, forming a sinus tract which may form a pathway for bacterial contamination and potentially serious infection.
It is therefore important to develop methods for creating controlled porosity for the elastomeric substrate which form a component of such percutaneous or implant devices, which improve or impart tissue ingrowth-inducing and tissue-interfacing properties and encourage epithelial growth into the device.
We have found that size, and in particular the shape, of pores on the surface of the elastomeric substrate are important in inducing tissue ingrowth properties. Imperfect pores, i.e. those which may form a circumferential mushroom on the surface surrounding the pore or which do not have smooth flat or slightly domed flat bottom surfaces, are undesirable. It is therefore important to devise a method to form the pores at the desired predetermined pore densities, sizes, and depths in an efficient manner which also achieve the desired pore shapes.
It is therefore an object of the present invention to provide a method for manufacturing a nonwoven, non-degradable tissue ingrowth-inducing, tissue-interfacing substrate with predetermined oriented sizes, pore densities and pore depths.
This and other objects of the invention will be apparent from the following description and from practice of the invention.
SUMMARY OF THE INVENTION
The present invention provides a process for manufacturing a nonwoven, non-degradable tissue ingrowth-inducing, tissue-interfacing substrate with predetermined uniform pore size, pore density and pore depth comprising steps of
(a) providing a thermoplastic substrate;
(b) contacting at least a portion of one surface of the substrate with a heated surface for a sufficient period of time and at temperature sufficient to soften the substrate without deformation;
(c) while the substrate is in a softened state, inserting perpendicularly into the surface of the substrate a plurality of pins, which are at a lower temperature than the substrate, of sufficient external diameter to achieve a predetermined pore size in a pattern sufficient to achieve the predetermined pore density and with sufficient force and displacement to achieve the predetermined pore depth;
(d) removing the substrate from the heated surface to allow the substrate to cool;
(e) removing the pins from the substrate;
(f) optionally, repeating steps (b), (c), (d) and (e) on a different portion of the substrate surface.
In a second embodiment a process for manufacturing a nonwoven, non-degradable tissue ingrowth-inducing, tissue-interfacing substrate with predetermined oriented, uniform pore size, pore density and pore depth is provided comprising the steps of:
(a) providing a thermoplastic substrate;
(b) inserting perpendicularly into at least a portion of the substrate heated pins for a period of time for said pins to soften and penetrate the substrate, the pins being of sufficient external diameter to achieve the predetermined pore size in a predetermined pattern sufficient to achieve the predetermined pore density and with sufficient force and displacement to achieve the predetermined pore depth;
(c) removing the pins from the substrate;
(d) optionally repeating steps (b) and (c) on a different portion of the substrate.
The preferred thermoplastic substrate produced by these methods is a polyurethane or polyethylene terephthalate having, on the surface or surfaces to be exposed to the tissue, a pore density in the range of about 20 to 10,000 pores per square centimeter; with uniform pores of diameter in the range of about 50 to 500 microns, with the pores characterized by a substantially cylindrical shape. The pores have substantially smooth flat or slightly curved bottom surfaces.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows a preferred embodiment apparatus for performing a method according to the present invention.
FIG. 2 shows a second embodiment of an apparatus for performing a method according to the present invention.
FIGS. 3A and 3B are SEM micrographs of pores made according to the invention at 120× and 500× magnification, respectively, viewed from a 45° tilt.
FIGS. 4A and 4B are SEM micrographs of pores made according to the invention at 130× and 500× magnification, respectively, cross-sectional views.
FIGS. 5A and 5B are SEM micrographs of a pore made according to the invention at 1200× and 800× magnification, respectively, at 0° and 45° tilts, respectively.
FIGS. 5C and 5D are SEM micrographs of a pore made according to the invention with slight imperfections (extrusions) at 800× magnification, viewed at 0° and 45° tilts, respectively.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, there is shown a preferred apparatus for performing the method in accordance with the present invention. Preferably a stationary pin clamp 10 is utilized having a preselected number of pins 11 of sufficient diameter to produce pores of the desired diameters when perpendicularly pressed into a softened elastomeric substrate 12, fed across the pins by feed roller 13 and take-up roller 14. The pins 11 and substrate 12 are juxtaposed so that the pins will form essentially perpendicular pores on the substrate. A heated anvil 15, is mounted parallel to the pins 11. The anvil 15 contains a heating element 16 and a thermocouple 17 used with temperature controller 18 to, in turn, control the heater power source 19. The substrate 12 (shown as a sheet) is pulled along between, but not in contact with either the anvil face 16A or the pins 11, using a precision advancing mechanism (not shown), such as a lead screw assembly. To perform the process, the heated anvil face 16A (heated to a temperature to achieve softening of the substrate without deforming the substrate) is brought into contact with the substrate 12 by lowering shaft 20. Depending upon the chemical nature of the substrate and the thickness of the substrate, the period of time of this contact will be determined so that the substrate is sufficiently softened to receive the pins. This means that the substrate will be heated to a temperature of about 10° F. or less above its softening point, provided that the temperature is also maintained at least about 5° F. below the melting point of the substrate. This period of time, for a polyurethane sheet of about a thickness of about 0.010 to 0.015" is typically in the range of about 0.5 to 2.5 seconds at a temperature in the range of 170° to 300° F. When the substrate is sufficiently softened, the cool pins 11 are pressed into the opposite surface of the substrate by further lowering of shaft 20 where the depth of the imprint of the pins is controlled by a stop on the press (not shown). Then the anvil is released from the substrate, with the pins 11 still in place, thereby allowing the substrate to cool, and fixing the pore size and shape. This prevents heat buildup which would cause nonuniform pores. The pins 11 remain in the substrate 12 (dwell time) on an average of about 2 seconds and then are withdrawn. The substrate 12 is then moved so that pores may be imprinted on a different area.
If desired, the pins may be used to puncture almost entirely through the substrate, but it is preferred that the pores penetrate to a depth of about 5× to 20× the pore diameter.
In an alternate embodiment of the invention, referring to FIG. 2, a heated head 30 accommodating a plurality of pins 31 is utilized. The head 30 and pins 31 are heated with an internal heating element 32 located within the head controlled by a thermocouple 33 (or other suitable means of temperature control), which is electrically connected to a temperature controller 34, which, in turn, controls the heater power source 35. A clamping plate 36 fixes the pins in place. The head is used with any appropriate automatic displacement device, such as a linearly controlled shaft 37, to automatically lower it toward the surface of the cool substrate 38 and unheated anvil 39 to form imprints of the pins at a predetermined depth for a predetermined dwell time, then withdrawn. The heated pins 31, while made of a smooth metal, such as stainless steel, are preferably coated with a smooth, heat impervious coating such as a high temperature silicone, so that as the pins are withdrawn they do not extrude unduly large threads of elastomeric material from the pores, thereby changing the pore size and/or shape. The pins should be at a temperature sufficient to soften the substrate, i.e., about 10° F. or less above the softening point. For a polyurethane sheet of 0.015" thickness, the pins should be at a temperature in the range of about 170° to 300° F. and the dwell time should be about 0.5 to 2 seconds.
For tissue ingrowth and tissue implant properties, polyurethanes are the preferred substrates, particularly polyurethane sold under the trade names TECOFLEX (Thermedics, Inc.), BIOMER (Ethicon) and PELLATHANE (Dow Plastics). A second class of preferred elastomeric materials are polyethylene terephthalates, particularly sold under the trade names KODAPAK, TENITE and VALOX by Eastman and GE Plastics. Other suitable thermoplastic materials include, but are not limited to, acrylic and methacrylic polymers or copolymers, acetal homopolymers, acetal copolymers of trioxane and ethylene oxide, epoxy resins, phenylene oxide-based resins (such as, polyphenylene oxide and blends of polyphenylene oxides and styrene resins), polyaryl ethers, polyesters, polyethylene, polypropylene, polysulfones, ethylene polymers (such as ethyl vinyl acetates), and other thermoplastics which are non-degradable and nonwoven.
A useful pore density is in the range of about 20 to 10,000 pores per square centimeter, with the greater number of pores the better. A typical uniform pore diameter with typical tissue ingrowth properties is from about 50 to about 500 microns, but there may be useful pores outside of this range.
Utilizing the device shown in FIG. 1, a set of samples (polyurethane sheets, 0.3 mm thick) were fabricated having a pore size from 50 to 75 microns and a density of about 1430 pores pre square centimeter. (Anvil temp. 225° F.; softening contact time 1 sec.; pin dwell time 2 sec.) One set was at pore depths about halfway through the polymer and another set had depths nearly all the way through the polymer. The samples were examined by a scanning electron microscope, the results of which are shown in FIGS. 3A, 3B, 4A, 4B. There are practically 100% good pores shown (FIGS. 3A and 3B), with the cross-sections of the pore samples having nearly straight cylindrical walls with nearly flat floors which in some cases were slightly curved upwards and radiused topped edges (FIGS. 4A and 4B).
Pores made using the device in FIG. 2 are shown in FIGS. 5A-5D, with sample pore sizes 280 microns, 220 microns and 160 microns, on polyurethane sheets. Half-depth pores were formed (pin temp. 200° F., dwell time 2 sec). About 28% of the pores were perfect pores (FIGS. 5A and 5B). Many of the pores showed some melted polymer material adhering to the imprinting pin and extruded back to the pore (FIGS. 5C and 5D).
The following examples are provided by way of illustration and are not intended to limit the invention in any way.
EXAMPLE 1
Flat sheets of polyurethane in five different porosity configurations were made using the device of FIG. 2, using pin temperature of 200° F. and dwell time of 2 sec. The configurations are as follows: two systems with a pore size of 280 μ, one with a density of pores of 36 cm -2 and the other of 320 cm -2 ; one system with a pore size of 220 μ and a density of 220 pores cm -2 ; and two systems with a pore size of 160 μ, one with a density of 120 pores cm -2 and the other a density of 1000 pores cm -2 .
Two 1 cm×2 cm polyurethane sheets (0.3 mm thick) of each porosity configuration were implanted in six white New Zealand rabbits, for a total of ten implants per animal. Four incisions were made into the dorsum of each rabbit (two on each side). Underneath each of the incisions, two or three separate subcutaneous pockets were created allowing for a total of five implants per side. Three rabbits were sacrificed at 2 weeks and three rabbits at 4 weeks. Implants were removed taking care not to damage the fibrous capsule, by cutting a thick slice of skin and subcutaneous tissue around the implant. These samples were fixed in formalin, histologically processed, embedded in paraffin, sectioned 5u thick and placed on microscope slides. All sections were stained with H&E, PAS, trichrome, nonspecific esterase, and acid phosphates. Two sections of each type of stain were prepared for light microscopic evaluation.
In order to achieve the most efficient evaluation of each implant, the capsule was divided into 3 layers--inner, middle, and outer. The inner layer is the inflammatory layer of cells immediately surrounding the implant. The middle layer is the center of the capsule which consists mainly of collagen and fibroblasts. The outer layer is the area farthest from the implant usually dominated by blood vessels.
During microscopic observation, the thickness of the capsule and inner inflammatory layer were measured around the entire perimeter of the implant. Measurements of the distance from implant to the closest blood vessels were obtained. Quantitative measurements of enzyme, macrophage, and fibroblast activity, as well as blood vessel population, were taken at randomly chosen areas in each of the 3 capsule layers. Using polarized light, each of the capsule layers was inspected for collagen fiber quantity, orientation and density.
Tables I, II, and III are qualitative comparisons of the inner, middle and outer layers of each capsule surrounding their respective implant. A scale of 0-5 was used with a 5 indicating the most, thickest, or densest of the characteristic being compared.
Using the qualitative data for each of the five implant types, a ranking of implants was determined based on the most beneficial characteristics for a percutaneous tissue-interfacing material to exhibit. In Table IV, implants are ranked from the porosity configuration with the most to the one with the least desirable behavior for the characteristics of capsule thickness, vascularity, macrophage and fibroblast content, and collagen density and orientation. Similar to the other tables, each capsule layer is compared separately.
TABLE 1______________________________________INNER-INFLAMMATORY LAYER +Capsule Blood Macro- Fibro-Implant Thickness Vessel phages blasts Collagen______________________________________4075-36 4 0 1 2 44075-36 5 0 4-5 2 14074-120 1 0 2 3-4 14075-120 4 0 3-4 1 04071-225 2 0 3-4 3 14074-225 3 0 5 1 14071-320 1 0* 4 3-4 24075-320 3 0 1 2 14071-1000 1 0* 4 3-4 04074-1000 2 0 1 3-4 1______________________________________ *Possible thin layer near the surface +Thickness of inflammatory laher
TABLE II______________________________________MIDDLE-COLLAGEN LAYER +Capsule Blood Macro- Fibro-Implant Thickness Vessel phages blasts Collagen______________________________________4075-36 3 0 1 3 44075-36 1 0 1 3-4 34074-120 2 2 1 3-4 24075-120 1 0 2 2-3 24071-225 4 4 3-4 1 34074-225 5 5 1 2 24071-320 3 4 3-4 2 34075-320 4 1 2 2 34071-1000 2-3 4 2 2 14074-1000 5 2 1 1 2______________________________________ +Density of collagen in the middle layer
TABLE III______________________________________OUTER-BLOOD VESSEL LAYER +Capsule Blood Macro- Fibro-Implant Thickness Vessel phages blasts Collagen______________________________________4075-36 0 1 4 1 54075-36 0 1 4 1 44074-120 1 3 4 1 44075-120 0 2 3 1 44071-225 3 3 3-4 2 44074-225 5 5 3 4 44071-320 2 2 4 2 34075-320 0 3 2 2 34071-1000 2 3 2 2 24074-1000 5 3 2 4-5 4______________________________________ +Thickness of blood vessel layer
TABLE IV______________________________________RANCKING OF IMPLANTS ACCORDING TO MOSTDESIRABLE CHARACTERISTICS IN EACH OF THETHREE LAYERS OF THE CAPSULE Capsule Blood Macro- Fibro- Collagen/Pore Size Thickness Vessel phages blasts Orient______________________________________1000 1,3,2 1,2,1 1,2,1 1,3,1 2,5,4320 2,3,3 1,3,3 1,5,2 2,4,3 3,2,4225 3,5,1 5,1,1 5,4,2 3,5,1 1,3,2120 3,1,4 5,4,3 1,2,4 3,1,4 3,3,2 36 5,1,5 5,5,5 1,1,5 3,1,4 3,1,1______________________________________ Under each column, the three numbers represent the ranking of each implan in the inner, middle, outer layer. A "1" signifies the implant with the highest ranking and "5" the implant with the lowest ranking.
EXAMPLE 2
Flat sheets of TECOFLEX polyurethane in 2 different porosity configurations were made using a device as shown in FIG. 1 (anvil temp. 225° F., contact time 1 sec, pin dwell time 2 sec). Both had pores of 50-75 μ at a density of 1430/cm 2 . The only difference between the two different implant types is their pore depth, one with half depth pores and the other with full depth pores.
Six 1 cm×3.5 cm sheets of each porosity configuration were implanted in two white New Zealand rabbits, for a total of twelve implants per animal. Four incisions were made into the dorsum of each rabbit (two on each side). Underneath each of the incisions, three separate subcutaneous pockets were created allowing for a total of six implants per side. One rabbit was sacrificed at 17 days and one rabbit at 32 days. Implants were removed taking care not to damage the fibrous capsule, by cutting a thick slice of skin and subcutaneous tissue around the implant.
The histological portion of each implant was infiltrated in a vacuum at 37° C. with a graded series of gelatin solution, up to 25%, at which time they were embedded in 25% gelatin. The embedded samples were frozen in liquid nitrogen and sectioned on a cryostat. Because the polymer never became frozen like the surrounding tissue, rarely was the implant itself kept in the sections.
Two sections of each sample have been stained with H&E and trichrome and microscopically analyzed. During microscopic observation, the thickness of the capsule was measured. Quantitative measurements of macrophage and fibroblast activity, as well as blood vessel population, were taken at randomly chosen areas in both the capsule and pores. Using polarized light, the capsule and pores were inspected for collagen fiber quality, orientation and density.
After cryostat sectioning was complete, a portion of the implant was left uncut. A few of these leftover samples were stained with tolulene blue and viewed under a stereomicroscope to try and observe the ingrowth of collagen into the pores.
Histological slides of the 17 day samples show areas of what appears to be ingrowth. The half depth pore samples of this time period have an average capsule thickness of 125-175 um, little macrophage response near the implant, approximately 18% volume percentage of fibroblasts, and a neutrophil and macrophage response on the outer radius of the capsule. The full pore samples had capsule thicknesses that ranged from 50-175 um, approximately 15% volume percentage of fibroblasts, little macrophage response near the implant, but heavy neutrophil and macrophage response on the outer radius of the capsule. Both the full depth and half depth pore samples seemed to have vessels running parallel to the implant as close as 25 um and less.
On the 32-day samples, the half depth pore samples have an average capsule thickness of 150 um, approximately 25% volume percentage of fibroblasts, and the same type of neutrophil and macrophage response on the outer radius of the capsule. The full depth pore samples had average capsule thicknesses of 175 μ on one side and 250 μ on the other side. There was an approximately 33% volume percentage of fibroblasts, and the same type of neutrophil and macrophage reaction on the outer perimeter of the capsule. Both the full and half depth pore samples had the same type of parallel vessels as the 17 day samples with a heavier vessel population. These 32 day samples also seemed to have a denser, more mature collagen matrix than that of the 17 day samples.
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A process is provided for manufacturing nonwoven, nonbiodegradable tissue ingrowth-inducing, tissue-interfacing substrates with predetermined oriented uniform pore diameter, pore density and pore depth. The substrates have pores which have advantageous tissue ingrowth-inducing properties.
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BACKGROUND OF THE INVENTION
Diesel engines, particularly those intended for propelling industrial vehicles, use a fuel obtained from the distillation of oil incorporating a fairly high proportion of paraffin products. At temperatures lower than 0° these products have a tendency to form paraffin crystals at a temperature known as the Trouble Point. Then at a lower temperature, generally at about -7°, the concentration and size of the crystals becomes such that filters of normal-sized mesh are blocked, which causes the engine to stop. At temperatures lower than -10° a freezing phenomenon can occur, causing seizure of the valve of the supply pump.
The invention proposes devices for heating the fuel by the transfer of external heat energy, consisting essentially of exchangers using water, electrical resistances, or an oil circuit, or a combination of these means. The invention proposes means enabling the thermal exchange to be improved by a mechanical stirring effect, which in itself already has a fluidizing effect and the thermal transfer of which enables the result obtained to be increased to such an extent that the limit of operation is lowered for example from -7° to -20° for a device having a capacity of 150 W, that is a downward offset of 13°, but it is possible to reach temperatures of -40° to -50°.
SUMMARY OF THE INVENTION
According to the invention, the heating device essentially incorporates, in a block, a central tube, for transmitting heat energy, inside a concentric bore in which the fuel circulates, the space between the two tubes defining a chamber which is made helical by the arrangement of a spiral bulkhead which imposes on the fuel a rotary path. The normal fuel flow rate is preferably chosen to be at the limit of laminar flow and turbulent flow.
In addition, when the heating device utilizes the cooling water of the heat engine, the internal tube in which it circulates is itself preferably subdivided into two equal volumes by a spiral bulkhead which enables thermal exchange between the water and the wall of the tube to be increased.
From a modular exchanger unit it is possible to combine a number of such units in honeycombs, parallel to one another, or to arrange that the circulation of the fluids is always in series. At the ends, the circulation tubes are preferably put into communication by manifolds, which are independent, firstly, for the fuel and, secondly, for the heating fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described below with reference, by way of example, to embodiments shown in the accompanying drawings and in which:
FIG. 1 is plan view partially sectioned of a heating device using water circulation;
FIG. 2 is an end view in the direction of the arrow F1 shown in FIG. 1;
FIG. 3 is a plan view in partial section of a device for mixed heating by electricity and water circulation; and
FIG. 4 is an end view in elevation in the direction of the arrow F3 shown in FIG. 3.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
According to a first embodiment shown diagrammatically in FIGS. 1 and 2, the exchanger device is supplied with heat from the cooling water of the engine. It consists of a body 1 having four bores 2 one above the other, two being arranged so as to be parallel in an upper row, the other two being arranged vertically below the two first bores in a a lower row. These bores house internal concentric tubes such as tubes 3, 4 leaving a free space 5, 6 intended for the circulation of the fuel. At the ends, manifolds 7, 8, 9 have suitable holes passing through which, in the manifold 7, enable water to enter and to leave through the holes 10, 11; the manifold 8 enables the two chambers 5 and 6 of the upper row to communicate with one another for fuel to pass through, and likewise the two chambers of the lower row, through passages such as 12. The passage 13 enables water to flow towards the tube of the lower bore after having circulated in the tube 4. The manifold 9 enables water to flow at the other end from one tube of a row to the other tube of the same row.
According to one of the characteristics of the invention, each water tube is surrounded externally with a helical bulkhead 14, so that the annular chambers for fuel circulation are defined in such a way as to constrain the fuel to follow a helical path along the exchanger tubes. Lastly, a fuel inlet is provided laterally at 15, whereas the outlet takes place through a hole which is situated underneath and which communicates with the chamber of the lower row. Helical bulkheads 20 within tubes 3, 4 cause the water to follow a spiral path within the tubes.
In this way, the water coming from the cooling circuit of the engine enters the block through the inlet 10, passes through the tube 3 to the opposite manifold 9 where it passes through the passage 16 to the adjoining tube 4, and passes through the tube 4 to the passage 13 through which it reaches the lower tube where it follows a similar path at the lower level, so as to leave through the outlet 11.
For its part, the fuel arriving through the inlet 15 circulates helically in the chamber 5 around the tube 3. It reaches the manifold 8 where, through the passage 12, it arrives in the adjoining chamber 6 where it circulates helically as far as a passage 17, where it flows into the chamber situated immediately below. From there it returns towards the manifold 8 and, through a passage similar to the passage 12, it flows into an adjoining chamber where it circulates helically so as to reach an outlet situated vertically below the inlet 15.
Suitably spaced Teflon seals provide perfect sealing over a wide range of temperatures. The body 1 and the different manifolds are assembled by means of tie rods 18 and nuts. Spacing plates 19 are inserted between the manifolds and the body and between the manifolds themselves, so that in the case of damage the water is prevented from mixing with the fuel.
In such a device, heating by convection and stirring due to the helical circulation co-operate so as to allow faster and more efficient exchange.
It is of course understood that at the same time the circulation pumps and the filters are arranged to provide sufficient circulation during the time required to heat the cooling water to the required temperature.
When sufficient electrical energy is available, heating can be obtained at least partially from electrical resistances. Such a mixed device is shown in FIGS. 3 and 4.
The general arrangement is the same as for the device described above, but two water tubes have been replaced by armoured electrical resistances 21, situated in two bores above one another. The two other bores have water tubes 22 passing through them.
The annular chambers 23 formed between the bores and the water tubes or the resistances form passages for the fuel, which enters the device at one end through an inlet 24 in the manifold 25.
As in the previous example, the chambers between the water tubes and the resistances are provided with helical windings 26 which completely close the annular passage and thus cause the fuel to circulate along a helical path, which causes stirring at the same time as turbulence in the flow.
After having entered at inlet 24, the fuel circulates along the electrical resistance 21, then flows through the passage 27 so as to enter the passage surrounding the water tube as far as the other end where, through a passage 28 in the manifold 25, it descends into the lower bore then returns through the second lower bore to an outlet 29 situated below the inlet 24.
The water tubes which pass through the end manifolds 25 and 30 from one side to the other are separately connected to inlet and outlet passages which are not shown.
It is also possible to achieve heat transfer by electrical resistances alone. Such a device is easily derived from the previous example and does not require a special description.
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A device for heating fuel for engines. A block (1) has a number of bores (2) through which pass thermal transfer tubes (3, 4) whose diameter is smaller than that of the bores so as to provide annular chambers (5, 6) for the fuel to flow through. Helical bulkheads are arranged inside the chambers (5, 6) between the tubes and the walls of the bore, causing the fuel to follow a helical path around the heating tubes (3, 4).
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CROSS REFERENCES TO RELATED APPLICATIONS
The present invention contains subject matter related to Japanese patent application JP 2007-292495 filed in the Japanese Patent Office on Nov. 9, 2007, the entire contents of which being incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a data recording apparatus writing data on/reading data from a hard disk drive in response to a command received from an upper control device.
2. Description of the Related Art
Apparatuses with redundant array of inexpensive disks (RAID), or RAID apparatuses, are those in which a RAID technology is used to record AV data (i.e., video data and audio data) on a plurality of hard disk drives. Such RAID apparatuses have been widely used as data recording apparatuses for business and professional purposes. In general, such RAID apparatuses carry out write/read operations of AV data in response to commands transmitted from upper control devices.
Hard disk drives have restrictions on access time (i.e., time before actually carrying out a data-write/read operation after receiving a data-write/read command) due to seek time of a head or rotational delay of a target sector.
Therefore, a system continuously reproducing AV data without interruption has been designed to use a specific format to appropriately arrange AV data on hard disks in a RAID apparatus, thereby assuring a high data rate at the time of reading/writing operation (see, for example, Japanese Unexamined patent application Publication No. 2000-076021).
SUMMARY OF THE INVENTION
Specific formats may not be used for hard disks in a RAID apparatus when AV data is written on or read from the RAID apparatus using application software running on a universal OS (e.g., when the AV data is written on or read from the RAID apparatus by operating a personal computer). In this case, the hard disks may be managed using a universal file system with a universal OS to allow the hard disks to be more easily handled with application software.
However, the management of the hard disks in the RAID apparatus using the universal file system leads to segmentation of a request for writing/reading AV data with a large data size through the application software into commands with small data sizes because of a small memory unit being managed by the universal OS. These small commands are then transmitted to a control part that carries out the internal control of the RAID apparatus.
For executing one received command, the control part carrying out the internal control of the RAID apparatus issues commands for the respective hard disk drives in the RAID apparatus. Thus, if a large number of commands with small data sizes are consecutively received, then commands for the respective hard disk drives may be issued up to the number obtained by multiplying the number of the received commands by the number of the hard disk drives. As a result, the control part shows a considerable amount of overhead.
In this way, the more the overhead of the control part increases, the more the throughput of reading/writing AV data in the RAID apparatus decreases.
It is desirable to reduce the overhead of a control part. The control part carries out the internal control of a data recording apparatus writing data on/reading data from a hard disk drive in response to a data-write/read command received from an upper control device when the hard disk in such an apparatus is managed using a universal file system.
According to an embodiment of the present invention, there is provided a data recording apparatus writing data on/reading data from a hard disk drive in response to a data-write/read command received from an upper control device. The data recording apparatus includes a command-aggregating device and a command-issuing device. The command-aggregating device is configured to generate an aggregate command by aggregating contents of a plurality of commands under the conditions that the plurality of commands are of the same kind continuously received from the control device and logical block addresses designated by the plurality of commands are consecutive addresses. The command-issuing device is configured to issue the aggregate command generated by aggregating the plurality of commands to a hard disk drive controller that controls the hard disk drive.
According to another embodiment of the present invention, there is provided a method for internal control of a data recording apparatus writing data on/reading data from a hard disk drive in response to a data-write/read command received from an upper control device. The method includes:
generating an aggregate command by aggregating contents of a plurality of commands under the conditions that the plurality of commands are of the same kind continuously received from the control device and logical block addresses designated by the plurality of commands are consecutive addresses; and
issuing the aggregate command generated by aggregating the plurality of commands to a hard disk drive controller that controls the hard disk drive.
According to the embodiments of the data recording apparatus and the method for internal control thereof, a command may not be issued to a hard disk drive controller immediately after receiving one command from an upper control device. According to the embodiments of the data recording apparatus and the method for internal control thereof, there is generated one aggregate command in which contents of a plurality of commands are aggregated under the conditions that the plurality of commands are of the same kind continuously received from the upper control device and logical addresses designated by the respective commands are consecutive addresses.
Subsequently, such a command in which the contents of the plurality of commands are aggregated is issued to the hard disk drive controller.
The upper control device may manage data in the data recording apparatus using a universal file system and transmit a write/read command to the data recording apparatus in response to a write/read request for a large data size received from an outside apparatus. In this case, such a write/read request is divided into a plurality of commands and then transmitted to the data recording apparatus. In general, these commands continuously received by the data recording apparatus are of the same kind and designate consecutive logical block addresses, respectively.
Therefore, in that case, only one command obtained by aggregating contents of a plurality of divided commands is issued to the hard disk drive controller. Thus, the number of commands issued to the hard disk drive controller corresponds to the number of the hard disk drives. In the related art, if the number of commands divided in the upper control device is defined as “N”, then the number of issued commands is obtained by multiplying the number of the hard disk drives by “N”. Thus, according to an embodiment of the present invention, the number of commands issued may be 1/N commands of the related art.
Therefore, it leads to reduce the overhead of the control part that carries out the internal control of the data recording apparatus when the hard disks thereof are managed using the universal file system.
Furthermore, according to the embodiments of the data recording apparatus or the method for the internal control thereof, for example, the contents of a plurality of commands may be aggregated under the further condition that the total number of sectors requested by the plurality of commands is not more than a predetermined maximum number of sectors.
Therefore, the number of sectors requested per command issued to the hard disk drive controller may not exceed the maximum sector number. Thus, write/read efficiency can be prevented from lowering due to issuing commands requesting an excessive number of sectors. In addition, data with an amount exceeding the capacity of a memory in the data recording apparatus, which is provided for temporarily storing data received together with a data-write command until a command is issued to the hard disk drive controller, is prevented from being written on the memory.
Furthermore, according to the embodiments of the data recording apparatus or the method for the internal control thereof, for example, the contents of a plurality of commands may be aggregated under the further condition that the plurality of commands are received within a predetermined time.
In this way, by only aggregating the contents of commands received within a predetermined time period, the time until a command corresponding to the received command is issued to the hard disk drive controller may not exceed a predetermined time. Thus, data may be recorded/reproduced in real time without a break.
According to further another embodiment of the present invention, there is provided a data recording system. The system includes a data recording apparatus and an upper control device. The upper control device transmits a data-write/read command to the data recording apparatus. The data recording apparatus writes data on/reads data from a hard disk drive in response to the data-write/read command received from the upper control device. The data recording apparatus includes a command-aggregating device and a command-issuing device. The command-aggregating device is configured to generate an aggregate command by aggregating contents of a plurality of commands under the conditions that the plurality of commands are of the same kind continuously received from the control device and logical block addresses designated by the plurality of commands are consecutive addresses. The command-issuing device is configured to issue the aggregate command generated by aggregating the plurality of commands to a hard disk drive controller that controls the hard disk drive.
The data recording system includes the data recording apparatus according to the embodiment of the present invention and an upper control device. Therefore, the overhead in the control part carrying out the internal control of the data recording apparatus can be reduced when the hard disk in the data recording apparatus is managed using a universal file system.
According to embodiments of the present invention, there is provided a data recording apparatus writing data on/reading data from a hard disk drive in response to a data-write/read command received from an upper control device. The overhead of a control part carrying out the internal control of the apparatus can be reduced when the hard disk in the data recording apparatus is managed using a universal file system.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram illustrating the entire configuration of a digital cinema screening system in accordance with an embodiment of the present invention.
FIG. 2 is a diagram illustrating a circuit provided in the digital cinema server shown in FIG. 1 .
FIG. 3 is a schematic diagram illustrating the manner of dividing an AV data write/read request into a plurality of commands, using a universal file system.
FIG. 4 is a block diagram illustrating the configuration of the data recording apparatus shown in FIG. 1 .
FIG. 5 is a flow chart representing command aggregating processing executed by an internal control part shown in FIG. 4 .
FIG. 6 is a schematic diagram illustrating the manner of aggregating AV data write/read commands by the command aggregating processing shown in FIG. 5 .
FIGS. 7A and 7B are schematic diagrams illustrating the manner of aggregating commands to reduce the write-processing time.
FIG. 8 is a diagram illustrating a specific example of the aggregating of commands.
FIG. 9 is a diagram illustrating another specific example of the aggregating of commands.
FIG. 10 is a diagram illustrating a still another specific example of the aggregating of commands.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. In the following description, a digital cinema screening system will be described as an embodiment of the present invention. First, the general configuration of the digital cinema screening system will be described.
FIG. 1 is the general configuration of the digital cinema screening system in accordance with the embodiment of the present invention. The digital cinema screening system includes a data recording apparatus 1 using a RAID technology, a digital cinema server 2 , a projector (projection-type display device) 3 , and a personal computer 4 .
A housing (not shown) houses the data recording apparatus 1 , the digital cinema server 2 , and the projector 3 . The digital cinema server 2 is connected to the personal computer 4 via a high speed network (e.g., using such standard as 1000BASE-T)
The digital cinema screening system records AV (audio and/or video) data of a movie to be screened (the video data has been compressed by an image compression standard such as JPEG 2000) in advance on the data recording apparatus 1 from the personal computer 4 through the digital cinema server 2 . Subsequently, the recording apparatus 1 reproduces the AV data and the digital cinema server 2 then supplies the AV data to the projector 3 to project the AV data on a screen.
The personal computer 4 stores programs for allowing the user to carry out recording AV data, screening a movie, and managing data other than AV data on a GUI screen. Here, the data other than AV data may include, for example, log information about the operation of the data recording apparatus 1 , information about the file systems of AV data in the data recording apparatus 1 , and movie caption data. Based on the user's operation on the GUI screen, a request for writing/reading AV data, a request for writing/reading log information, file system information, and caption data, or the like is transmitted from the personal computer 4 to the digital cinema server 2 via the high-sped network 5 .
FIG. 2 is a diagram illustrating main circuits in the digital cinema server 2 . As shown in the figure, the digital cinema server 2 includes a CPU 11 and a decoder 20 for decompressing the compressed AV data. The CPU 11 is connected to the high-speed network 5 shown in FIG. 1 and connected to the data recording apparatus 1 shown in FIG. 1 via a PCI-X bus. The decoder 20 is connected to the data recording apparatus 1 and the projector 3 shown in FIG. 1 .
A universal operating system (OS), such as Linux, runs on the CPU 11 . Thus, the CPU 11 manages hard disks in the data recording apparatus 1 using a universal file system, such as XFS, on the OS. The CPU 11 stores the following three programs (a) to (c), which run on the universal OS:
(a) “internal-control application”, an internal-control program for the data recording apparatus 1 ;
(b) “digital cinema application”, a program for transmitting an AV data write/read command to the “internal-control application” in response to an AV data write/read request received from the personal computer 4 ; and
(c) “management application”, a program for transmitting write/read commands for log information, file system information, and caption data to the “internal-control application” in response to requests therefor received from the personal computer 4 .
Here, an AV data write/read command transmitted from the personal computer 4 to the CPU 11 may request AV data having a much larger amount of data than that of other data (including the log information, file system information, and caption data). Therefore, the data size (the number of sectors requested) per AV data write/read request may be extremely large in comparison with a small data size per request for writing/reading log information, file system information, or caption data.
The CPU 11 manages hard disks in the data recording apparatus 1 using the universal file system on the universal OS. Thus, if the CPU 11 receives from the personal computer 4 a request for writing/reading AV data with a large data size, the universal file system divides the write/read request into a large number of commands with small data sizes as schematically illustrated in FIG. 3 . It is due to a small memory unit managed by the universal OS. Therefore, as schematically illustrated in FIG. 3 , the “internal-control application” receives a large number of write/read commands with small data sizes each time the AV data write/read request is transmitted from the personal computer 4 .
Furthermore, the CPU 11 functions as an upper control device of the digital recording apparatus 1 by executing the “digital cinema application” or the “management application”. Here, the upper control device is one transmitting a data-write/read command to the data recording apparatus 1 . In addition, the CPU 11 also has a function of carrying out the internal control of the recording apparatus 1 by executing the “internal-control application”.
Hereinafter, for clear explanations, the CPU 11 will be divided into two parts in terms of functions. One part of the CPU 11 configured to function as an upper control device in the CPU 11 is referred to as an upper control part 11 - 1 . The other part of the CPU 11 configured to carry out the internal control of the data recording apparatus 1 is referred to as an internal control part 11 - 2 .
FIG. 4 illustrates the configuration of the data recording apparatus 1 with the upper control part 11 - 1 , the internal control part 11 - 2 , and a decoder 20 . Here, the figure illustrates the internal control part 11 - 2 as a part of the data recording apparatus 1 because of its function. Double-lined arrows represent the flows of data (e.g., AV data, log information, file system information, and caption data), respectively. Single-lined arrows represent the flows of commands transmitted and received by the upper control part 11 - 1 and the internal control part 11 - 2 and the responses therefrom, respectively.
The data recording apparatus 1 includes an ECC/DMA part 12 including a field programmable gate array (FPGA), a cache memory 13 , seven hard disk drives (HDDs) 15 ( 15 - 1 to 15 - 7 ), and HDD controllers (e.g., SAS controllers) 14 ( 14 - 1 to 14 - 7 ) controlling the HDDs. Among the seven HDDs 15 ( 15 - 1 to 15 - 7 ), four HDDs 15 - 1 to 15 - 4 are provided for data storage, two HDDs 15 - 5 to 15 - 6 are provided for error correction, and the remaining one HDD 15 - 7 is provided for spare or backup.
When recording is carried out, the ECC/DMA part 12 generates an error-correction code based on the data sent from the upper control part 11 - 1 in the digital cinema server 2 . The data with the error-correction code is stripped and then fed into the HDDs 15 - 1 to 15 - 6 via the HDD controllers 14 - 1 to 14 - 6 , respectively.
When reproduction is carried out, the ECC/DMA part 12 uses the cache memory 13 to destripe data received from HDDs 15 - 1 to 15 - 6 through the HDD controllers 14 - 1 to 14 - 6 and the destripped data is then subjected to error correction, thereby reconfiguring the data to its original state.
During the reproduction of video data, data reconfigured at the ECC/DMA part 12 is sent to the decoder 20 . The baseband video data decompressed by the decoder 20 is sent to the projector 3 shown in FIG. 1 and then displayed on a screen from the projector 3 .
During the reproduction of audio data, data reconfigured at the ECC/DMA part 12 is output from an audio output terminal (not shown) provided to a housing, to the outside thereof. The data recording apparatus 1 , the digital cinema server 2 , and the projector 3 are housed in the housing.
During the reproduction of log information and file system information, the information data reconfigured at the ECC/DMA part 12 are supplied to the upper control part 11 - 1 and then transmitted from the upper control part 11 - 1 to the personal computer 4 as shown in FIG. 1 . Subsequently, such information is displayed on a GUI screen in the display of the personal computer 4 .
During the reproduction of caption data, the data reconfigured at the ECC/DMA part 12 is transmitted to a mixing circuit (not shown) in the digital cinema server 2 and then combined with the baseband video data decompressed by the decoder 20 .
The internal control part 11 - 2 executes the “internal-control application” as described above to control both the ECC/DMA part 12 and the HDD controllers 14 . Here, FIG. 5 illustrates the flowchart of command aggregating processing, which is a part of the processing carried out by the “internal-control application”.
First, the internal control part 11 - 2 is kept in a standby mode until it receives one command from the upper control part 11 - 1 (Step S 1 ). If it receives one command, then a timer (installed in the CPU 11 shown in FIG. 2 ) is set (Step S 2 ).
Subsequently, the timer started at the immediately preceding step (step S 2 ) is used for determining whether a previously defined time limit T is over (Step S 3 ). The setting value of the time limit T may be determined considering the continuous recording of AV data or the continuous reproduction of AV data for a movie displayed on a screen.
If it is “No” in step S 3 , then whether a subsequent command is newly received or not is determined (Step s 4 ). If it is “No” in step S 4 , then the processing returns to step S 3 .
If it becomes “Yes” in step S 4 , then whether two commands, a command received in the present step S 4 and a command received in the immediately preceding step are of the same kind is determined (whether they have the same kind of data and two of them are write commands or read commands) (Step S 5 ). Here, the command received in the immediately preceding step may be one received in the immediately preceding step S 1 when the processing proceeds to step S 4 for the first time. Alternatively, it may be the command received in the immediately preceding step S 4 when the processing proceeds to step S 4 for the second time or more.
If it is “Yes” in step S 5 , whether logical block addresses (LBAs) specified by these two commands are continuous is determined (Step S 6 ).
If it is “Yes” in step S 6 , then whether the total number of sectors requested by the command received in the immediately preceding step S 1 and all the commands received in the subsequent step 4 exceeds the predetermined maximum number of sectors Smax is determined (Step S 7 ). The setting value of the maximum sector number Smax may be determined considering the following two points:
One is to prevent a decrease in write/read efficiency due to an excessive number of sectors requested per command issued to the ECC/DMA part 12 and the HDD controllers 14 - 1 to 14 - 6 .
The other is to prevent writing an excessive volume of data to the cache memory 13 over the capacity thereof. Here, data is written in the cache memory 13 until commands are issued to the ECC/DMA part 12 and the HDD controllers 14 - 1 to 14 - 6 when receiving a data-writing command.
If it is “No” in step S 7 , then a command obtained by aggregating contents of the command received in the immediately preceding step S 1 and all the commands received in the subsequent step S 4 is generated (Step S 8 ), followed by returning to step S 3 .
If it is “Yes” in step S 3 , “No” in step S 5 or S 6 , or “Yes” in step S 7 , then commands are issued to the ECC/DMA part 12 and the HDD controllers 14 - 1 to 14 - 6 (Step S 9 ). Here, the commands correspond to those generated in the immediately preceding step S 8 (or those received in the immediately preceding step S 1 when the processing has not proceeded to the step S 8 ) subsequent to receiving commands in the immediately preceding step S 1 . Subsequently, the timer is reset (Step S 10 ) and the processing returns to the step S 1 .
As described above, if the upper control part 11 - 1 allows the “digital cinema application” to transmit AV data write/read commands to the internal control part 11 - 2 , a request for writing/reading AV data from the personal computer 4 with comparatively large data size is divided into a plurality of commands. Subsequently, these commands are transmitted to the internal control part 11 - 2 . Thus, these commands continuously received by the internal control part 11 - 2 are those of the same kind and generally designate consecutive logical block addresses.
Therefore, if the AV data write/read commands are transmitted from the upper control part 11 - 1 , then aggregating occurs until it becomes “Yes” in step S 3 or step S 7 in the command aggregating processing shown in FIG. 5 (until passing the time limit T or exceeding the maximum sector number Smax). That is, the internal control part 11 - 2 aggregates contents of the AV data write/read commands from the upper control part 11 - 1 into one command as schematically illustrated in FIG. 6 . Here, the write/read commands are a large number of divided commands supplied from the upper control part 11 - 1 . Subsequently, commands corresponding to the aggregated command are issued to the respective HDD controllers 14 - 1 to 14 - 6 and then executed therein.
In this way, if a command is divided into “N” commands in the upper control part 11 - 1 , then the number of commands issued from the internal control part 11 - 2 may be one Nth compared to the related art. The overhead of the internal control part 11 - 2 carrying out the internal control of the data recording apparatus 1 can be reduced while managing the hard disks therein using the universal file system.
In this way, furthermore, the number of commands executed by the respective HDD controllers 14 - 1 to 14 - 6 can be reduced by aggregating the contents of the commands. Thus, the throughput of writing/reading AV data can be substantially improved. When writing AV data, as shown in FIGS. 7A and 7B that are schematic diagrams, the write-processing times in the respective HDD controllers 14 - 1 to 14 - 6 when issuing the aggregated commands ( FIG. 7B ) are shortened in comparison with the write-processing times in the respective HDD controllers 14 - 1 to 14 - 6 without aggregating the contents of commands ( FIG. 7A ).
The aggregated command allows the internal control part 11 - 2 to reduce its overhead, thereby shortening the write-processing time. In addition, the write-processing time can also be shortened by reducing the number of times that the HDD controllers 14 - 1 to 14 - 6 wait for rotational latency with respect to the desired sectors. Therefore, the throughput of writing AV data can be improved greatly.
Furthermore, when aggregating contents of a plurality of commands, the command aggregating processing is carried out under the condition that the plurality of commands are received within a predetermined time limit T (Step S 3 in FIG. 5 ). Thus, real-time screening of a movie can be carried out by continuous reproduction of AV data or real-time recording of AV data can be carried out without a break.
Furthermore, when aggregating contents of a plurality of commands, the command aggregating processing is carried out under the condition that the total number of sectors requested by the plurality of commands is not more than the maximum number of sectors Smax (Step S 7 in FIG. 5 ). Thus, it becomes possible to avoid a decrease in write/read efficiency due to an excessive number of sectors requested per command issued to the ECC/DMA part 12 and HDD controllers 14 - 1 to 14 - 6 and to prevent the data exceeding the volume of the cache memory 13 from being written therein.
FIGS. 8 to 10 are specific examples of the commands aggregated by the command aggregating processing, respectively. In these examples, the time limit T is set to one second and the maximum sector number Smax is set to 100. Note, however, that these values T and Smax are examples for explanation purpose only. Thus, these values may be set in view of the real-time recording/reproduction and the write/read efficiency as described above.
In the example shown in FIG. 8 , eleven write commands (the same kind of data) are received at a time period from 10:00:00.100 to 10:00:00.200. These eleven write commands specify logic block addresses (LBAs) with a value of 10 displaced from each other, while the length (LEN) of each LBA corresponding to the number of request sectors is 10. Thus, the LBAs are consecutive.
However, the total number of request sectors reaches the maximum sector number Smax=100 by the tenth write command. Thus, the first to tenth write commands can be aggregated to one command “WRITE LBA1000 LEN100”.
In the example shown in FIG. 9 , five write commands (the same kind of data) are received at a time period from 10:00:00.100 to 10:00:00.140 and four write commands (the same kind of data as that of the aforementioned five write commands) are then received after an interval, or at a time period from 10:00:05.100 to 10:00:05.130. These eleven write commands specify logic block addresses (LBAs) with a value of 10 displaced from each other, while the length (LEN) of each LBA corresponding to the number of request sectors is 10. Thus, the LBAs are consecutive.
However, the time limit T=1 second has passed when the sixth write command is received. Thus, the first to fifth write commands can be aggregated to one command, “WRITE LBA1000 LEN50”.
In the example shown in FIG. 10 , the manner of dividing the request from the personal computer 4 is also illustrated. The upper control part 11 - 1 receives a request for writing AV data from the personal computer 4 at time 10:00:00.000. This write request specifies LBA1000. In addition, LEN (the number or request sectors) is 200.
The upper control part 11 - 1 divides such a write request into twenty commands each having LEN=10. The internal control part 11 - 2 receives these twenty commands at a time from 10:00:00.010 to 10:00:00.200.
Up to the 10th write command among them, the total number of request sectors reaches the maximum sector number Smax=100 (also the time limit T reaches one second). Thus, the first to tenth write commands are aggregated to one command, “WRITE LBA1000 LEN100”.
In addition, the 11th to 20th write commands allows the total number of request sectors to reach the maximum sector number Smax=100 (also the time limit T reaches one second). Thus, the 11th to 20th write commands are aggregated to another command, “WRITE LBA1100 LEN100”.
In the above-described embodiment, a single CPU 11 in the digital cinema server 2 functions as the upper control device of the data recording apparatus 1 and as the device carrying out the internal control of the data recording apparatus 1 . In an alternative example, the CPU 11 in the digital cinema server 2 may have only a function as an upper control device of the data recording apparatus 1 (may execute only a “digital cinema application” and a “management application”). In addition, another CPU dedicated to carry out the internal control of the data recording apparatus 1 (execute the “internal-control application”) may be installed within the data recording apparatus 1 .
Furthermore, a digital cinema screening system is described as an embodiment of the present invention. Alternatively, the present invention may be applied to any data recording apparatus writing data on/reading data from a hard disk drive in response to a command supplied from an upper control device, where a hard disk can be managed using a universal file system.
It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.
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A data recording apparatus that writes data on/reads data from a hard disk drive in response to a data-write/read command received from an upper control device is provided. The data recording apparatus includes a command-aggregating device and a command-issuing device. The command-aggregating device is configured to generate an aggregate command by aggregating contents of a plurality of commands under the conditions that the plurality of commands are of the same kind continuously received from the control device and logical block addresses designated by the plurality of commands are consecutive addresses. The command-issuing device is configured to issue the aggregate command generated by aggregating the plurality of commands to a hard disk drive controller that controls the hard disk drive.
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This application is a continuation of patent application Ser. No. 07/600,418, filed Oct. 19, 1990, abandoned.
BACKGROUND OF TEE INVENTION
The present invention relates generally to improved means and methods for automatically recognizing data on documents, and more specifically to improved means and methods for automatically recognizing amount information on financial documents, such as checks, invoices and remittance documents.
Today's financial services industry is facing the immense challenge of processing huge amounts of documents efficiently. Predictions that document payment methods would decline have not been realized. In fact, document payment methods have grown worldwide and are expected to continue increasing. There is thus a vital need to devise improved methods for processing such documents.
The use of imaging technology as an aid to document processing has been recognized as one way of significantly improving document processing, as disclosed, for example, in U.S. Pat. Nos. 4,205,780; 4,264,808; 4,672,186; and 4,888,812. Generally, imaging involves optically scanning documents to produce electronic images that are processed electronically and stored on high capacity storage media (such as magnetic disc drives and/or optical memory) for later retrieval and display. It is apparent that document imaging provides the opportunity to reduce document handling and movement, since these electronic images can be used in place of the actual document. For example, document images can be retrieved from storage and displayed on workstations where operators can enter amount data and other information based on the observed images, instead of having to view the documents directly.
Although the use of imaging in a document processing system can provide significant improvements, the need for operator viewing and entry of data from the documents continues to limit the attainable document processing speed and efficiency.
SUMMARY AND OBJECTS OF THE INVENTION
In accordance with the present invention, a further extension of the speed and efficiency of document processing is made possible by providing improved methods for automatically locating, extracting and recognizing data on documents, and most particularly to improved methods which can advantageously operate at the high speeds required for use in financial document processing systems, such as those involving checks, invoices and remittance documents
U.S. Pat. Nos. 4,449,239; 4,201,978; 4,468,808; 4,918,740; 4,523,330; 4,685,141; 3,832,682; and European patent EP-0,111,930 disclose various automatic data recognition approaches known in the art.
The specific nature of the invention as well as objects, features, advantages and uses will become evident from the following detailed description along with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a typical check of a type widely used in the United States.
FIG. 2 generally illustrates a document processing system in which the present invention may be incorporated.
FIG. 3 is a flow chart generally illustrating the various operational steps performed by an automatic courtesy amount reader in accordance with the invention.
FIG. 4 is a flow chart illustrating a preferred manner for accomplishing the "Locate $" Step 102 of FIG. 3.
FIG. 5 is a typical gray level image provided by the image module 14 of FIG. 2.
FIG. 6 is a block diagram illustrating apparatus for the parallel generation and storage of seed and mask binary images from the gray level image represented on FIG. 5.
FIG. 7 illustrates a typical "$" seed search area $SA established by Step 102B in FIG. 4.
FIG. 8 illustrates a typical "$" mask search area $MA established by Step 102B in FIG. 4.
FIG. 9 is a flow chart illustrating a preferred manner for accomplishing the "Extract Courtesy Amount" Step 104 of FIG. 3.
FIG. 10 illustrates a typical courtesy amount seed search area C.A.SA established by Step 104B in FIG. 9.
FIG. 11 illustrates a typical courtesy amount mask search area C.A.MA established by Step 104B in FIG. 9.
FIG. 12 is a flow chart illustrating a preferred manner for accomplishing the "separate ¢ portion and categorize" Step 110 of FIG. 3.
FIG. 13 illustrates a typical extracted courtesy amount (prior to clean-up in Step 104J in FIG. 9) containing extraneous connected component groups 62 and 63.
FIGS. 14-16 illustrate typical extracted courtesy amounts after clean-up in Step 104J in FIG. 9.
FIGS. 17-18 illustrate how "¢" characters are extracted from a "¢" field comprised of underlined double figures.
FIGS. 19-22 illustrate how "¢" characters are extracted from a "¢" field comprised of a fraction.
DETAILED DESCRIPTION
Like numerals and characters refer to like elements throughout the figures of the drawings.
For the purposes of this detailed description, the present invention will be illustrated as applied to automatically recognizing the dollar amount (typically referred to as the "courtesy amount") on a check in a document processing system for processing financial documents. However, it is to be understood that the present invention is also applicable to other types of documents, as well as to other types of data recognition applications, financial and otherwise.
Reference is initially directed to FIG. 1, which illustrates a check 10 of a type widely employed in the United States. The check 10 has a "$" currency symbol 10a, and an associated amount 10b, which is typically referred to in the banking industry as a "courtesy amount." A reader which recognizes this courtesy amount is typically referred to as a courtesy amount reader (CAR). The courtesy amount 10b may be machine printed or handwritten, as shown in FIG. 1.
The typical check 10 shown in FIG. 1 also includes encoded machine readable data 10c at the bottom-left of the check, which serves to provide identifying information such as the identity of the bank on which the check is drawn, the customer's account number, and the check number. Typically, this encoded machine readable data 10c is provided in magnetic ink and is referred to by the acronym "MICR" (magnetic ink character recognition).
FIG. 2 generally illustrates a document processing system in which the present invention may be incorporated. The documents to be processed are typically financial documents, including checks of the type illustrated in FIG. 1. As illustrated in FIG. 2, these financial documents 10 are applied to a document processor 12, which, in a conventional manner, machine reads encoded data from the documents, captures and processes images of the documents, and sorts the documents into pockets (not shown).
The document processor 12 in FIG. 2 includes an imaging module 14 for capturing images of documents, processing and compressing the captured document images, and then transmitting the compressed document images to storage apparatus 16, such as disk drives. Workstations 19 receive document images from the storage apparatus 16 for display and entry of data by workstation operators, such as courtesy amounts from the viewed images. A computer processing unit (CPU) 20 provides for overall control of the system, and also for maintaining a data base for document information transmitted thereto by the document processor 12 and workstations 19 (via the storage apparatus 16).
The document processor 12 of FIG. 2 additionally includes a courtesy amount reader 18 coupled to the imaging module 14 for automatically recognizing courtesy amounts on checks, such as illustrated in FIG. 1. An important advantage of providing such a courtesy amount reader 18 in the document processing system of FIG. 1 is that those checks whose amounts are successfully read need not have their courtesy amounts read and entered by viewing their images at the workstations 18.
The courtesy amount reader (CAR) 18 typically comprises a plurality of microprocessors, RAMs, ROMs and other associated circuitry, along with appropriate programming, for operating on document images applied thereto from the image module 14, in order to provide for automatic recognition of the courtesy amounts in accordance with the invention. The manner in which such may be provided for the CAR 18 will become evident from the disclosure herein.
FIG. 3 is a flow chart generally illustrating the various operational steps performed by the CAR 18 in FIG. 2 in recognizing a courtesy amount on a check. It is to be understood that this flow chart is presented by way of example, and should not be considered as limiting the scope of the invention. For example, certain steps shown herein may be omitted, other steps may be added, and/or the arrangement of the steps may be modified.
As indicated by Step 100, the CAR 18 receives a gray level image of a check from the imaging module 14 in FIG. 2. The CAR locates the "$" 10a in FIG. 1 (Step 102), and then extracts the associated courtesy amount 10b (Step 104). A determination is then made as to whether the extracted courtesy amount is machine printed or handwritten (Step 106). If machine printed, a relatively simple recognition of the courtesy amount is performed (Step 108) and the result outputed (Step 118).
If the extracted courtesy amount is determined to be handwritten (Step 106), a more complex analysis is required. In such case, the "¢" portion 10b-1 (FIG. 1) is first separated and categorized (Step 110), and the "¢" characters then extracted based on the categorization (Step 112). The resulting extracted "¢" characters are then "¢" recognized (Step 114).
After the "¢" characters have been successfully recognized (Step 114), the dollar characters are recognized (Step 116). The CAR 18 (FIG. 2) then outputs the recognized courtesy amount, or a reject signal (Step 118). In the system of FIG. 2, this CAR output is sent to the CPU 20. If a reject condition is detected during any of the steps in FIG. 3, a reject output is immediately provided and the remaining steps aborted. As shown in FIG. 3, extraction and recognition of the "¢" portion of the courtesy amount are performed prior to the dollar portion, since it is more likely to produce a reject. It will be understood that the recognized courtesy amount output provided by the CAR can be accompanied by a confidence value based on confidence indications produced during the recognition process. It will also be understood that the recognition Steps 106, 108, 114 and 116 in FIG. 3 can be provided using known recognition techniques, such as disclosed in the aforementioned patents.
A description of each of the steps illustrated in FIG. 3 is set forth below.
Step 100 (FIG. 3)
During this step, the imaging module 14 in FIG. 2 provides a gray scale image (such as illustrated in FIG. 5) to the CAR 18 of at least the portion of a check containing the "$" character 10a and the associated courtesy amount 10b. It is to be understood that the size illustrated in FIG. 5 is by way of example only.
Step 102 (FIG. 3)
During this step, the "$" character 10a (FIG. 5) is located. Obviously, a currency character other than the "$" could be used as a location character, such as an asterisk "*" or other appropriate symbols.
Step 104 (FIG. 3)
During this step, the courtesy amount 10b (FIG. 5) is extracted using the previously located "$" character 10a as a location guide.
Step 106 (FIG. 3)
During this step, a determination is made as to whether the extracted courtesy amount is machine printed or handwritten. If it is machine printed, operation proceeds to Step 108. If it is handwritten, operation proceeds to Step 110.
Step 108 (FIG. 3)
If the courtesy amount is determined to be machine printed, a relatively simple recognition is made based on the type of machine printing recognized.
Step 110 (FIG. 3)
If the courtesy amount is determined to be handwritten, a more complex analysis is required, which begins with the separation of the "¢" portion 10b-1 (FIG. 5) from the dollar portion 10b-2. The separated "¢" portion is then categorized.
Step 112 (FIG. 3)
During this step the "¢" characters are extracted based on the categorization made in Step 110.
Step 114
During this step the extracted "¢" characters are recognized.
Step 116 (FIG. 3)
During this step, the "$" characters 10b-2 (FIG. 5) of the courtesy amount are recognized to complete recognition of the courtesy amount.
Step 118 (FIG. 3)
During this step, the CAR 18 outputs (to the CPU 20 in FIG. 2) the recognized courtesy amount, or a reject signal. A reject signal is provided by the CAR if a reject condition is detected during any of the previous steps, in which case subsequent steps are aborted. A recognized courtesy amount may also be accompanied by a confidence value.
Various ones of the steps shown in FIG. 3 will now be considered in detail.
Detailed Description of Step 102
A preferred manner for accomplishing Step 102 in FIG. 3, in accordance with the invention, will next be considered with reference to steps 102A through 102H in FIG. 4. It will be remembered that the purpose of Step 102 is to locate the "$" character 10a on the check 10 in FIG. 5.
Step 102A (FIG. 4)
During this step, a thresholding is used to derive a plurality of binary images from the gray level image (FIG. 5) provided by the image module 14 in FIG. 2. The derivation of these binary images will be understood by noting that a gray level image may typically be represented electronically as an X-Y matrix of pixels (picture elements), where each pixel has one of a plurality of gray level values. For example, each pixel could be provided with sixteen gray level values represented by 4 bits corresponding to the binary numbers 0 to 15, where 15 is black and 0 white. Each derived binary image is produced by employing a different one of these gray level values as a threshold in converting the gray level image to the binary image. For example, if a threshold of eight is used for producing a particular binary image, then that binary image will have black pixels for those pixels whose gray level values are eight or greater, all other pixels of the binary image being white.
For the particular embodiment of the invention being considered herein, three binary images are derived from the gray level image (FIG. 5) using three different thresholds, high, intermediate and low. The high threshold binary image will be referred to as the "$" seed image, the intermediate binary image will be referred to as the courtesy amount seed image, and the low threshold binary image will be referred to as the mask image. As will hereinafter be explained, the "$" seed image is used for locating the "$" character 10a (FIG. 5), the courtesy amount binary image is used for extracting the courtesy amount 10b, and the mask image is used for both purposes.
As illustrated in FIG. 6, in order to increase recognition speed, the seed and mask images can be generated in parallel by respective converters 34, 36 and 38 as the gray level image is received from the image module 14 in FIG. 2, the resulting binary images being retrievably stored in respective random access memories (RAMs) 44, 46 and 48.
Step 102B (FIG. 4)
During this step, search areas on the "$" seed and mask images are established for use in locating the "$" character. FIG. 7 illustrates an example of a "$" seed image search area $SA for the seed image, and FIG. 8 illustrates an example of a "$" mask search area $MA for the mask image. FIGS. 7 and 8 also illustrate the effects produced by using different thresholds for deriving the seed and mask images. In this regard, note that the "$" mask search area $MA in FIG. 8 (because of the lower threshold used) contains many more extraneous black pixels (noise) than does the "$" seed search area $SA in FIG. 7.
For the purpose of the particular embodiment being considered, it will be assumed that the desired "$" seed search area $SA in FIG. 7 is known. For example, its location could be previously stored in the CPU 20 (FIG. 2), or could be derived from reading the machine-readable line 10c on the check 10 (FIG. 1). Alternatively, provision could be made for searching the entire image until the "$" character is located.
Steps 102C, 102D and 102E (FIG. 4)
During step 102C, the "$" seed search area $SA in FIG. 7 is scanned for a "new" black pixel. As will be explained, hereinafter, a "new" black pixel is one which has not yet been accounted for in the seed search area $SA. Typically, vertical column-by-column scanning is employed, since it is advantageous in locating the "$" character that it be encountered before the amount characters. If, during a scan, a new black pixel is not found (Step 102D), then a determination is made (Step 102E) as to whether the last vertical column of the "$" seed search area $SA in FIG. 5 has been scanned. In such case, a reject is produced. It is also to be understood that a reject could also occur if the maximum time alloted for the recognition process has expired. This is done in order to prevent the recognition process for any one check from exceeding a time which would be inconsistent with check processing speed requirements.
If during Step 102E it is determined that vertical scanning has not been completed, operation returns to Step 102C to continue the search for a new black pixel in the scan direction of the "$" seed search area $SA.
Steps 102F, 102G and 102H (FIG. 4)
If a new black pixel is found during Step 102D, operation proceeds to Step 102F. During Step 102F, the found seed black pixel (Step 102D) in the "$" seed search area $SA (FIG. 7) is propagated using the "$" mask search area $MA (FIG. 8) to generate a connected group of pixels which will hereinafter be referred to by the symbol CC. The manner in which a CC is generated will next be explained.
Reference is first directed to the "$" seed search area $SA in FIG. 7. It will be seen that the "$" character 10a is approximately complete, but with various breaks, such as illustrated at 10'a, while the adjacent "8" numeral of the courtesy amount 10b has more and wider breaks 10'b. This is to be expected since the "$" character normally has a significantly higher contrast than the courtesy amount characters and is produced using a higher quality printing process. Also note that, because of the relatively high threshold used to derive the "$" seed image (as described previously), the "$" seed search area $SA in FIG. 7 contains only a few widely spaced extraneous black pixels such as 32s.
Reference is next directed to the "$" mask search area $MA in FIG. 8, which is derived using a lower threshold (as described previously). It will be seen that, because of the lower thresholding, the "$" character 10a is complete, while the adjacent "8" of the courtesy amount 10b still contains some breaks 10"b. Also, there are significantly more extraneous black pixels such as 32m in the "$" mask search area $MA in FIG. 8 than in the "$" seed search area $SA in FIG. 7. In addition the "$" mask search area $MA contains black pixels from the courtesy amount border 33.
Steps 102D and 102F in FIG. 4 take advantage of both of the "$" seed and mask search areas $SA and $MA (FIGS. 7 and 8, respectively) to locate and recognize the "$" character. More specifically, when a new black pixel is found in the "$" seed search area $SA in FIG. 7 (Step 102D), the pixel having a corresponding location in the "$" mask search area $MA in FIG. 8 is located. For example, if 34s in FIG. 7 is the new black pixel found in the "$" seed search area $SA (Step 102D), then the correspondingly located black pixel 34m in the "$" mask search area $MA in FIG. 8 is located. This can be implemented using the seed and mask images stored in the respective "$" seed and mask RAMs 44 and 48 in FIG. 6, which may be organized for example, so that corresponding seed and mask pixels have corresponding addresses.
The next operation which takes place in the performance of Step 102F is to propagate the black pixel 34m (FIG. 8) in the "$" mask search area $MA so as to generate a CC comprised of all black pixels connected to 34m. This may be accomplished, for example, using the mask RAM 48 in FIG. 6. Starting with the black pixel 34m (FIG. 8), a determination is made as to whether there are any black pixels at addresses corresponding to pixel locations immediately adjacent the black pixel 34m (FIG. 8). A like determination is made for each newly determined black pixel, and then repeated again and again until all connected black pixels forming the CC have been identified. The addresses of these identified black pixels then constitute the CC generated from the black pixel 34m. The mask RAM 46 in FIG. 6 may, for example, be used to store the addresses of the identified black pixels forming a CC.
Still with reference to FIGS. 7 and 8, it will be understood that, if the new pixel found in the "$" seed search area $SA in FIG. 7 (Step 102D) is the black pixel 34s of the "$" character 10a, then the resulting CC produced by propagation of the corresponding black pixel 34m in the "$" mask search area $MA in FIG. 8 (Step 102F) will be CC-1, which is the "$" character 10a. This will be the case since all pixels of the "$" character in the "$" mask search area $MA in FIG. 8 are connected.
On the other hand, if it were to be assumed that the "$" character was absent and the new black pixel found in the "$" seed search area $SA (FIG. 7) was the pixel 36s of the numeral "8," then propagation of the corresponding black pixel 36m in FIG. 8 would generate CC-2, which will be seen to merely be the upper portion of the "8" because of the breaks 10"b.
Following generation of a CC in Step 102F, operation proceeds to Step 102G where the size, geometry, and location of the generated CC are used to make a relatively fast determination of whether it is an appropriate candidate for the "$" character, or should be rejected, thereby avoiding the relatively more time consuming recognition process.
Only if a CC is determined to be a "$" candidate (Step 102G) will operation proceed to Step 102H where conventional character recognition is performed to determine whether the CC is the "$" character. For example, the classifier approach described in the aforementioned U.S. Pat. No. 4,449,239 may be employed for recognition. If the CC is not determined to be an appropriate "$" candidate in Step 102G, or if the CC is not recognized to be the "$" in Step 102H, then operation returns to Step 102C to continue scanning for a new black pixel in the "$" seed search area $SA in FIG. 7. However, if the CC is recognized to be the "$" character in Step 102H, then the "$" character has been located. In such a case, no further scanning occurs, and operation proceeds to Step 104 in FIG. 3 to extract the courtesy amount.
As mentioned previously in connection with Step 102E, if no recognition of the "$" character is made when the end of the scan is reached, then a reject occurs. If it is desired that an additional search area be scanned for the "$" character, then, instead of producing a reject at the end of the scan, operation would proceed back to step 102B in FIG. 4 to establish the new seed and mask search areas. This scanning of additional search areas may be repeated as many times as desired, or until time out occurs.
From the foregoing description of Step 102F, it will be understood that the "new" black pixel referred to in Step 102C is one that was not previously found as a result of propagation in the "$" mask search area during Step 102F, since there is no need to propagate previously identified black pixels. There are various possible ways of preventing such previously identified seed pixels from being propogated in the "$" mask search area. In the embodiment being described, it has been found advantageous to accomplish this purpose by deleting seed pixels from the "$" seed image (stored in the "$" seed image RAM 44 in FIG. 6) upon identification of the corresponding pixel in the "$" mask search area $MA during mask propagation in Step 102F in FIG. 4. Accordingly, black pixels which were identified during previous propogations in Step 102F are not seen during scanning in Step 102C, thereby reducing the time required to locate the "$" character. This savings is in addition to the time saved because the seed image contains relatively few "noise" black pixels as a result of the high threshold used in its derivation.
It will also be understood that the above described seed/mask propagation approach for generating a CC is additionally advantageous for locating the "$" character 10a on a check 10 (FIG. 1), since the "$" character is normally printed with high quality and high contrast, and is unlikely to produce breaks in the "$" mask search area $MA (FIG. 8). Thus, submitting each generated CC for recognition, as described above (Steps 102G and 102H), makes it highly likely that the "$" character will be recognized, as compared to other markings or characters (such as the numeral "8" considered previously).
It is further to be understood that the seed/mask propagation approach for generating a CC is subject to many variations within the scope of the invention. For example, the definition of "connectivity" used for generating a CC could be changed in various ways to accommodate the recognition of particular types of characters under differing circumstances. For example, the definition of "connectivity" could be changed so that connectivity would be restricted to one or more particular directions (such as vertical, horizontal and/or particular diagonals). Another possible change in the definition of connectivity could permit a one (or more) pixel break to occur between "connected" pixels in particular circumstances.
Detailed Description of Step 104
A preferred manner for accomplishing Step 104 in FIG. 3 will next be considered with reference to Steps 104A through 104J in FIG. 9. It will be remembered that the purpose of Step 104 is to extract the courtesy amount 10b shown in FIG. 1.
Step 104A (FIG. 9)
During this step, operation switches to extracting the courtesy amount 10b (FIG. 5), the location of the courtesy amount having been determined based on having successfully located the "$" character 10a in Step 102 (FIGS. 3 and 4). It will become evident as the description of Step 104 progresses that the basic seed/mask approach described for locating the "$" in Step 102 is also used for courtesy amount-extraction, but in a somewhat different manner.
Step 104B (FIG. 9)
During this step, seed and mask search areas are established for extraction of the courtesy amount based on having determined the location of the "$" character in Step 102 of FIG. 3. FIG. 10 illustrates an example of a courtesy amount seed search area C.A.SA, while FIG. 11 illustrates an example of a somewhat larger courtesy amount mask search area C.A.MA. Note that C.A.MA in FIG. 11 is of sufficient size to include courtesy amount portions which might project beyond the courtesy amount border 33. Also note in this regard that, even though the "7" of the courtesy amount is not fully contained in the courtesy amount search area C.A.SA in FIG. 10, the "7" will be fully extracted as a result of seed/mask propagation in the larger courtesy amount mask search area C.A.MA in FIG. 11.
In the preferred embodiment being described herein, the same mask image (stored in RAM 48 in FIG. 6) is used for amount extraction as is used for location of the "$;" however, the courtesy amount seed image (stored in RAM 46 in FIG. 6) is used for amount extraction instead of the "$" seed image (in RAM 44) used for locating the "$" character. This is done because the "$" seed image threshold is chosen to be high to take advantage of the high contrast "$" character, as explained previously, and would not be appropriate for the courtesy amount characters which have a greater range of contrast variations. FIG. 10 illustrates an example of a possible choice of a threshold for the courtesy amount seed search area C.A.SA, wherein the border 33 (FIG. 5) as well as low contrast extraneous pixels (noise) do not appear. In this regard, it is to be understood that all parts of the courtesy amount need not be included in the courtesy amount search are C.A.SA IN FIG. 10. It is merely required that sufficient portions of the courtesy amount be included in C.A.SA in FIG. 10 to provide for adequate extraction of the courtesy amount as a result of seed/mask propagation in C.A.MA in FIG. 11.
Steps 104C, 104D, 104E and 104F (FIG. 9)
These steps may be generally the same as previously described for respective Steps 102C, 102D, 102E and 102F, in FIG. 4, except that for a normal courtesy amount, there is no reject after the end of the scan (Step 102E), operation instead proceeding to Step 106 (FIG. 3). Steps 104C, 104D, 104E and 104F will thus not be considered in detail. It will be sufficient to note that, each time a "new" black pixel is found during scanning of the courtesy amount seed search area C.A.SA (FIG. 10), propagation in the courtesy amount mask search area C.A.MA (FIG. 11) generates a CC (as previously defined).
Step 104G (FIG. 9)
Similar to Step 102G in FIG. 4, this step tests whether the CC generated in Step 104F is appropriate based on the size, geometry and location of the CC. For the purposes of courtesy amount extraction, this test in Step 104G determines-whether the generated CC is likely to be a part of the courtesy amount. For example, a useful basis for determining whether a generated CC is a likely part of the courtesy amount is to determine whether it extends to the border 52 (FIG. 11) of the courtesy amount mask search area C.A.MA as, for example, line 55 in FIG. 11. Such a generated CC is most unlikely to be a part of the courtesy amount.
Step 104H (FIG. 9)
If a generated CC is determined as not likely to be a part of the courtesy amount in Step 104G, then operation proceeds to Step 104H which discards the generated CC; operation then returns to Step 104C to continue scanning for a new black pixel in the courtesy amount seed search area C.A.SA in FIG. 10.
Step 104I (FIG. 9)
If a generated CC is determined to likely be a part of the courtesy amount in Step 104G, then operation proceeds to Step 104I which stores the generated CC (e.g. in RAM memory 46 in FIG. 6) for later use. Operation is then returned to Step 104C to continue scanning for a new black pixel in the courtesy amount seed search area C.A.SA in FIG. 10.
Before leaving Step 104I, it will be helpful to note the difference between the way generated CCs are used for locating the "$" character (Step 102, FIGS. 3 and 4), and for courtesy amount extraction and recognition. It will be remembered that, for locating the "$" character, each generated CC is considered as an entity for recognition purposes, since the "$" character is provided with high quality printing and normally has a high contrast and no breaks. However, a CC generated for courtesy amount extraction may be only a fragmentary portion of a character because courtesy amount characters may have several breaks, particularly when handwritten. Thus, a courtesy amount character may be comprised of a plurality of generated CCs. Accordingly, in extracting and recognizing the courtesy amount, no attempt is made to recognize a generated CC, as is done when locating the "$" character (Step 102H in FIG. 4). Instead, each CC which is determined as likely to be part of a courtesy amount is stored Step (104I) until the entire courtesy amount area has been scanned, at which time all generated CCs which are likely to be part of the courtesy amount will have been stored. These stored CCs then constitute the extracted courtesy amount. FIG. 13 is an example of such a stored courtesy amount extracted as described above. Thus, with respect to the courtesy amount, the seed/mask propagation approach for generating CCs primarily serves as a particularly advantageous way of extracting and storing the courtesy amount for recognition.
Step 104J (FIG. 9)
Typically, Step 104J is reached, via Step 104E (which tests for end of scan), after scanning of the courtesy amount seed search area C.A.SA (FIG. 10) has been completed and all generated CCs likely to be a part of the courtesy amount are stored. The purpose of Step 104J is to clean up this stored extracted courtesy amount (FIG. 13) by removing extraneous CCs, such as exemplified by 62 and 63. One approach used is to delete extraneous CCs, such as 62, if they are spaced a predetermined amount above and below the courtesy amount region. This may be accomplished, for example, by projecting the entire amount field horizontally to define a region having upper and lower boundaries. CCs, such as 62 in FIG. 13, above or below these boundaries are then deleted. If the projection creates a plurality of regions, the appropriate upper and lower boundaries are those corresponding to the region which includes the "$" character.
The removal of extraneous CCs, such as 63 in FIG. 13, located to the right of the courtesy amount, present a more difficult problem, since they may be a part of the courtesy amount. A particularly advantageous method for determining whether these CCs are extraneous is based on the condition that the horizontal spacing between the rightmost CC and the nearest black pixel to the left of the CC be a predetermined amount greater than the horizontal width of the CC. If this condition is met, then the CC is considered to be extraneous and is deleted. An example of how this condition may be implemented will be explained with respect to FIG. 13. For the purpose of this example, the courtesy amount region will be considered to be divided into columns, numbered from left to right, each column having a width equal to one pixel. First, the locations of the following columns are determined from the extracted courtesy amount:
C1=The rightmost column having a black pixel.
C2=The rightmost column of the next area of white columns with minimum width W left of C1.
C3=The next column to the left of C2, having a black pixel.
If the following condition is met:
(C2-C3)>K(C1-C2)
then all black pixel elements 63 which are deposed between C1 and C3 are deleted. Typically, W may have a width corresponding to the width of three columns, the choice of W being such that the above condition will not be met by portions of a single character. K may typically have a value of 1.5. These values of W and K are chosen to assure that the courtesy amount will not be mistaken for an extraneous CC. The above is iteratively repeated so long as the condition continues to be met. When the condition fails to be met, the testing terminates and operation proceeds to the next Step 106 in FIG. 3.
Detailed Description of Step 110 (FIG. 12)
It will be understood from FIG. 3, that Step 110 is reached if the courtesy amount extracted during Step 104 is determined to be handwritten. The purpose of Step 110 is to separate the "¢" portion 10b-1 (FIG. 1) from the dollar portion 10b-2 of the courtesy amount 10b. A preferred manner for accomplishing Step 110, in accordance with the invention, will next be considered with reference to Steps 110A through 110H in FIG. 12. The "$" portion and "¢" portion of the courtesy amount will hereinafter be referred to as the "$" field and "¢" field, respectively.
Step 110A (FIG. 12)
During Step 110A, the extracted courtesy amount is searched for the presence of a period or decimal point ("."). Such a period or decimal point is, of course, indicative of the separation between "$" and "¢" fields of the courtesy amount, and its detection can therefore be used as a basis for separating these fields.
A preferred method for detecting the presence of a period will be described with respect to FIG. 14. For this purpose, the extracted courtesy amount is investigated from left to right, such as by using column-by-column scanning of the image of the extracted courtesy amount stored in RAM memory 46 in FIG. 6.
If a potential period candidate is found, such as PC in FIG. 14, an upper line UL and lower line LL (FIG. 14) are determined for the courtesy amount portion (such as the numeral "9" in FIG. 14) immediately to the left of PC. The lines are numbered from top to bottom. A potential period candidate PC is considered to be an actual period candidate if the following conditions are satisfied:
(1) The potential period candidate PC has a height which is no greater than 1/2 (UL-LL).
(2) The potential period candidate PC has a width W which is less than a prescribed amount.
(3) The average line number of the potential period candidate PC is less than 1/2(UL+LL).
Typically, up to three period candidates are permitted to be identified based on the above measurements. Operation then proceeds to Step 110B in FIG. 12.
Step 110B (FIG. 12)
During Step 110B, the up to three period candidates determined in Step 110A are investigated using well known statistical classification techniques, as disclosed, for example, in the aforementioned patents. If more than one period candidate is found to be acceptable, the rightmost one is chosen as a separator of the "$" and "¢" fields, and operation then proceeds to Step 110G in FIG. 12.
However, if no period at all is identified, then operation proceeds to Step 110C to try to separate the "$" and "¢" fields on another basis.
Step 110C (FIG. 12)
During Step 110C, superscripting of the "¢" field of a courtesy amount, such as illustrated in FIG. 15, is investigated as a basis for separation of the "$" and "¢" fields of the courtesy amount. For this purpose, the extracted courtesy amount is again investigated from left to right to detect the start of a superscripted character SC (for example, the numeral "5" in FIG. 15).
Similar to Step 110B, which describes the search for a potential period candidate, the upper line UL and lower line LL (FIG. 15) are determined for the courtesy amount portion (such as the numeral "7" in FIG. 15) immediately to the left of the candidate superscripted character SC. Again the lines are numbered from top to bottom. A candidate superscripted character SC is considered to be an actual superscripted character if the following conditions are satisfied:
(1) the bottom line number of the candidate superscripted courtesy amount character is no greater than 1/3(2LL+UL).
(2) the height of the candidate superscripted character SC is at least 1/3(LL-UL).
(3) the candidate superscripted character SC is separated from the courtesy amount portion immediately to the left (such as the numeral "7" in FIG. 15) by at least one white column. A white column is a column having no black pixels.
(4) courtesy amount portion SC' (the numeral "0" in FIG. 14) immediately to the right of the candidate superscripted courtesy amount character SC has a lower line number of no greater than the lower line number of SC plus half its height.
The first candidate which satisfies the above conditions is considered to be the start of a superscripted "¢" field.
Operation then proceeds to Step 110D in FIG. 12.
Step 110D (FIG. 12)
Step 110D receives the results of the search for a superscripted "¢" field performed in Step 110C. If a superscripted character was found, a basis for separation of the "$" and "¢" fields will have been determined, and operation proceeds to Step 110G.
However, if a superscripted "¢" field is not found, then operation proceeds to step 110E in FIG. 12 to find another basis for separation of the "$" and "¢" fields.
Step 110E (FIG. 12)
During Step 110E, the presence of a complex "¢" field, such as illustrated in FIGS. 16 and 17, is investigated as a basis for separation of the "$" and "¢" fields. It will be seen that FIG. 16 shows a first type of complex "¢" field comprised of two superscripted numerals having an underline. FIG. 17 shows a second type of complex "¢" field in which the "¢" amount is provided as a fraction.
To determine whether a complex "¢" field is present, the extracted courtesy amount is again investigated from right to left, as in previously described Steps 110A and 110C. In searching for a complex "¢" field, the following are determined (see FIGS. 16 and 17).
(1) The last occupied column C1 of the extracted courtesy amount.
(2) The first white column C2 to the left of the last occupied column C1.
(3) The first line L1 occupied by a courtesy amount portion located to the right of the white column C2.
As illustrated in FIGS. 16 and 17, the values of C1, C2 and L1 delineate a particular portion of the extracted courtesy amount for testing as to whether it is a suitable candidate for a complex "¢" field. Testing is accomplished using statistical classification techniques which are specifically designed to recognize various possible "¢" field types and, in particular, the complex "¢" field types illustrated in FIGS. 16 and 17. The manner in which such statistical classification techniques may be implemented will be evident from the abovementioned patents.
If a complex "¢" field is recognized, such as shown in FIGS. 16 and 17, then column C2 is-considered to be the separating column between the "$" and "¢" fields. It will be remembered that C2 is the first white column to the left of the last occupied column C1.
The results of operation in Step 110E are then passed to step 110F in FIG. 12.
Step 110F (FIG. 12)
Step 110F receives the results of the search for a complex "¢" field performed in Step 110E. If a complex "¢" field was found, then column C2 serves as a-basis for separation of the "$" and "¢" fields, and operation proceeds to Step 110G in FIG. 12.
However, if a complex "¢" field is not found, then a reject occurs, since no basis has been found for separating the "$" and "¢" fields of the courtesy amount, and no further basis for separation. In this regard it is to be understood that additional bases for providing separation may also be provided.
Step 110G (FIG. 12)
It will be understood from the foregoing description of FIG. 12, that operation proceeds to Step 110G as a result of having found a basis for separating the "¢" and "$" fields of the courtesy amount, either based on finding the period (Steps 110A and 110B), finding a superscripted "¢" field (Steps 110C and 110D), or finding a complex "¢" field (Steps 110E and 110F).
Accordingly, Step 110G provides for separating the "¢" field using the particular basis found for separation (period, superscript or complex "¢" field).
Also during Step 110G, the separated "¢" field is categorized as being one of several types using statistical classifying techniques, such as disclosed in the aforementioned patents. Categories which may be provided by Step 110G for the preferred embodiment being described are double zeroes; double figures, underlined double figures and fraction. Other categories could also be provided.
If an acceptable category is determined in Step 110G, Operation proceeds to Step 112 in FIG. 12; otherwise a reject occurs.
Detailed Description of Step 112 (FIG. 3)
A preferred manner for accomplishing Step 112, in accordance with the invention, will next be considered. It will be remembered that the purpose of Step 112 is to extract the "¢" characters based on the category determined for the "¢" field.
Operation in Step 112 for the various categories provided in the preferred embodiment being described is explained below:
Double Zeroes
For this category, it is immediately known that the value of the "¢" field is zero, and thus operation proceeds to Step 116 in FIG. 3 without further processing. Typically, this category is used only where the basis for separation is detection of a period or superscripted "¢" field.
Double Figures
For this category, the "¢" field figures are directly available so that operation proceeds to Step 114 in FIG. 3 for their recognition without further processing. As for the "Double Zero" category, this category is typically used only where the basis for separation is detection of a period or a superscribed "¢" field.
Underlined Double Figures
For this category, operations are directed to removing the underline so that only the "¢" characters remain, as illustrated in FIGS. 18 and 19 for a "¢" field comprised of an underlined "36". A preferred implementation for accomplishing this purpose is described below.
First, the slope of the underline is determined as follows. For each column of the "¢" field, the number of white pixels to the first black pixel is counted from the lower edge. If the difference of these numbers for two successive columns is greater in terms of amount than 4, then a position of discontinuity is present. All positions of discontinuity and the greatest column range between two positions of discontinuity in the "¢" field are determined. In this greatest column range, the underline is also expected. Two image coordinates points (x1, y1) and (x2, y2) are defined as follows:
x1=Start column of the column range.
y1=Number of white pixels from the lower edge to the first-black pixel in column x1.
x2=End column of the column range.
y2=Number of white pixels from the lower edge to the first black pixel in column x2.
The slope SL of the underline is then determined by the following equation:
SL=(y2-y1)/(x2-x1)
In order to delete the underline found, a family of n straight-lines-of-the slope SL and vertical spacing of 1 is formed. The number n of straight lines is dependent upon the slope of the underline and is established as follows:
n=11 for 0 ≦|su|<0.5
n=14 for 0.5≦|su|<1
n=25 for 1≦|su|<2
n=32 otherwise
Furthermore, starting points are established on these straight lines for the scanning of the "¢" field from the right and from the left with the scanning step width 1 along the straight lines:
In the case of scanning from the left:
x1 (i)=first column of the "¢" field (for all straight lines) y1 (i)=y -- start+i-1 (for the ith straight line)
In this case, y -- start is established so that (x1 y1) occurs under the scanning points of the first straight line.
In the case of scanning from the right:
xr (i)=Last column of the "¢" field (for all straight lines)
yr (i)=y -- start+i-1 (for the ith straight line)
In this case, y -- start is established so that (x2, y2) occur under the scanning points of the first straight line.
The "¢" field is scanned along these straight lines, with the objective of determining that straight line below which no useful information, occurs. For this purpose, the number of scanning points as far as the scanning point with the first black pixel in the "¢" field is counted for all scanning straight lines in the scanning from the right and from the left. Then, the straight lines with the maximum number of counted scanning points in the course of the scanning from the right and in the course of the scanning from the left are determined. From this range of straight lines, that one is selected which is lowest. All portions of the extracted "¢" fields below this lowest straight line are deleted, producing the result shown in FIG. 19. The above procedure also handles the situation where the "¢" characters intercept the underline.
After elimination of the underline (FIG. 19) the remaining "¢" field components ("36" in FIG. 19) are again examined using statistical classification techniques to determine whether it is in a double zero or double figures category. If the category is double zero, operation proceeds to Step 116, since the value of the "¢" field is known to be zero. If the category is double figures, operation proceeds to Step 114 for recognition of the double figures. If neither category is found, a reject occurs.
Fraction
For this category, operation is directed to first removing the denominator, and then removing the fraction line, as illustrated in FIGS. 20, 21 and 22 for a "¢" field comprised of a fraction having a numerator "80" and a denominator "100." A preferred implementation for accomplishing this purpose is described below.
First, the field is investigated to a column range within which the fraction line is expected. This may be accomplished, for example, by determining the connected component group CC having the greatest width. Once the fraction line has been found, its slope is determined by finding the coordinates x1, y1, x2, y2 and calculating the slope in the same manner as previously described for the underlined complex "¢" field.
A straight dividing line is now established, above which as far as possible only the numerator and the fraction line are situated. This straight dividing line is determined by the slope and by the coordinates (x1, y1+offset) with
offset=2 for 0≦|sb|<0.5
offset=3 for 0.5≦|sb|<1
offset=7 for 1≦|sb|<2
offset=10 otherwise.
Having thus established the straight dividing line, the "¢" field components below this dividing line are deleted, which for the fraction example illustrated in FIG. 19 will result in the denominator "100" being deleted. Thus, the "¢" field components remaining will be the underlined "80" shown in FIG. 21.
Accordingly, since the fraction operations so far should have resulted in underlined double zeroes or double figures, as illustrated in FIG. 21, the remaining "¢" field components are examined using statistical classification techniques to determine whether these remaining components, in fact, correspond to this underlined double zeroes or underlined double figures. If so, operation continues as previously described above for the underlined complex "¢" field category to extract the "¢" characters (FIG. 22); if not, a reject occurs.
While the invention has been described herein with respect to particular preferred embodiments, it is to be understood that many modifications and variations in implementation, arrangement and use are possible within the scope of the invention. For example, the number and type of seed and mask images and search areas employed may be varied, as well as the number and types of classification categories. Furthermore, it is to be understood that the seed and mask images need not be limited to binary (two-level) images. For example, a mask image might itself be a gray level (multiple level) image in order to provide additional information useful for courtesy amount extraction, "¢" field separation and/or recognition. Also, processing steps may be added to provide additional features, or described steps removed or rearranged. In addition, the invention can be adapted to a wide variety of applications besides those described herein. Accordingly, the claims following are to be considered as including all possible modifications and variations coming within the scope defined thereby.
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A method for separating integer and fractional portions of a financial amount preparatory to recognition of the financial amount. This separating is accomplished based on determining the presence of at least one of a plurality of possible distinguishing separation characteristics, such as the presence of a period (decimal point), superscripted characters, or a fraction. The separated fractional portion is then categorized into one of a plurality of categories based on the nature of the fractional portion representation. The characters making up this fractional portion are then extracted based on this categorizing.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method, apparatus, and medicine for clogging blood vessels of an eye fundus.
2. Description of the Prior Art
There is known a method for clogging blood vessels of an eye fundus. There is also known a photocoagulator used as an apparatus for clogging blood vessels of an eye fundus. In the photocoagulator, an infrared fluorescent agent, called indocyaninegreen, is injected into a subject. When the infrared fluorescent agent circulates through the blood vessels of the eye fundus of the subject, infrared rays of light for excitation are projected onto the eye fundus and, as a result, the infrared fluorescent agent is excited to emit fluorescence. While a region emitting the fluorescence is being observed, a diseased part, such as neovascular vessels of a choroid, in the depth of the eye fundus is specified. After that, a near-infrared semiconductor laser beam is projected onto the diseased part so as to coagulate and treat the diseased part.
In this conventional method and apparatus, however, injury to normal tissues is unavoidable during the treatment because of photocoasulation. Therefore, it is expected to develop a fundus treating method by which a diseased part only is treated to the utmost without injury to normal tissues, and develop an apparatus and a medicine used for the treatment.
SUMMARY OF THE INVENTION
The present invention was made in view of the foregoing. It is therefore an object of the present invention to provide a fundus vessel clogging method by which only a diseased part of an eye fundus is treated to the utmost without injuring normal tissues, an apparatus used for clogging the blood vessels, and a medicine to clog them.
In order to achieve the object, a fundus vessel clogging method according to an aspect of the present invention includes the steps of furnishing a subject with a photosensitive substance which remains in a diseased part in the depth of the eye fundus where an infrared fluorescent agent remains and which undergoes a photosensitive change in the diseased part by the use of a laser beam with a specific wavelength as well as furnishing the subject with the infrared fluorescent agent, specifying the diseased part in accordance with emission of infrared fluorescence, and projecting the laser beam with the specific wavelength onto the diseased part so that the photosensitive substance will produce a photochemical change, thereby clogging blood vessels of the diseased part in the depth of the eye fundus.
In order to achieve the object, a fundus vessel clogging apparatus according to an aspect of the present invention includes an illuminating optical system for illuminating an eye fundus of a subject, who has been furnished with an infrared fluorescent agent, with infrared rays of light so as to excite the infrared fluorescent agent and emit infrared fluorescence, a photographic optical system for observing and photographing the eye fundus, and a projecting optical system for projecting a laser beam with a specific wavelength onto the subject who has been furnished with a photosensitive substance which undergoes a photochemical change by means of the laser beam. In the apparatus, the laser beam is projected onto the photosensitive substance and thereby blood vessels of the diseased part in the depth of the eye fundus are selectively clogged while a region emitting the infrared fluorescence is being observed.
In order to achieve the object, a medicine according to an aspect of the present invention includes a mixture containing an infrared fluorescent agent and a photosensitive substance of the following general formula (CHEMICAL FORMULA 3):
{CHEMICAL FORMULA 3}
where n is 1 or 2.
In order to achieve the object, a medicine according to another aspect of the present invention includes a mixture containing an infrared fluorescent agent and a photosensitive substance of the following general formula (CHEMICAL FORMULA 4):
{CHEMICAL FORMULA 4}
where n is 1 or 2.
A fundus vessel clogging apparatus according to another aspect of the present invention is characterized in that a diseased part in the depth of an eye fundus is specified by infrared fluorescence, and a laser beam with a specific wavelength is projected onto a photosensitive substance which accumulates in the diseased part and undergoes a photochemical change by means of the laser beam for the purpose of treatment for the diseased part.
It is preferable to project an aiming laser beam which serves to distinguish a part where the laser beam is projected from a part where the infrared fluorescence emits in such a way as to superimpose the aiming laser beam upon the laser beam. More preferably, the aiming laser beam is intermittently projected.
According to the present invention, the infrared fluorescent agent and the photosensitive substance remain in the diseased part. In this situation, the remaining of the photosensitive substance in the diseased part is larger than that of the infrared fluorescent agent therein. Therefore, the diseased part is observed and specified by the infrared fluorescent agent, and thereafter a laser beam with a wavelength by which the photosensitive substance produces a photochemical change is projected. Thereby, since only the photosensitive substance produces a photochemical change, an influence on normal tissues is avoided as much as possible, and accordingly the diseased part only can be treated. In this case, if a mixture containing an infrared fluorescent agent and a photosensitive substance is used as a medicine, intravenous injection into the subject can be given at a time.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing showing optical systems of a fundus blood vessel clogging apparatus according to a first embodiment of the present invention.
FIG. 2 is a schematic sectional view showing the tissue structure of an eye fundus according to the present invention.
FIG. 3 is a schematic drawing showing optical systems of a fundus blood vessel clogging apparatus according to a second embodiment of the present invention.
FIG. 4 is a plan view showing a pattern plate of FIG. 3 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
FIG. 1 shows an embodiment of a method for clogging blood vessels of an eye fundus and an apparatus, which is applied to a fundus camera, for clogging the blood vessels. In FIG. 1 , a reference numeral 1 designates an illuminating optical system of the fundus camera, and reference numeral 2 designates a photographic optical system thereof. The illuminating optical system 1 includes a halogen lamp 3 and a xenon tube 4 . The halogen lamp 3 is conjugate to the xenon tube 4 with respect to a condenser lens 5 . The illumination light of the halogen lamp 3 and that of the xenon tube 4 are condensed by a condenser lens 6 and then are guided to a reflecting mirror 8 through an annular diaphragm 7 . A laser diode may be used instead of the halogen lamp 3 .
The illumination light reflected by the reflecting mirror 8 passes through a relay lens 9 , is then reflected by a perforated mirror 10 , is guided to the eye fundus R of a subject through an objective lens 11 , and illuminates the eye fundus R. The light beam from the eye fundus R passes through the objective lens 11 and is then guided to a focusing lens 13 through a hole 12 of the perforated mirror 10 . A quick return mirror 14 is disposed behind the focusing lens 13 . When a photograph is taken with a film (i.e., when a still image is recorded), the quick return mirror 14 is removed from the optical path of the photographic optical system 2 . An image of the fundus is formed on a film 15 by the focusing lens 13 . On the other hand, during observation, the light beam from the fundus R is reflected by the quick return mirror 14 , and the fundus image is formed on a CCD 16 . A signal output of the CCD 16 is converted into an image signal by an image processing circuit (not shown), and the fundus image is formed on a TV monitor (not shown). A surgeon performs an operation, mentioned later, while observing the TV monitor. In the case of visible fluorescence, a fundus image may be observed by the use of a finder optical system 16 ′ which is made up of a quick return mirror 14 ′ and an eyepiece 15 ′. When the finder optical system 16 ′ is not used, the quick return mirror 14 ′ is placed out of the optical path of light reflected by the quick return mirror 14 .
In accordance with a photographic mode, an exciter filter 17 for visible fluorescence and an exciter filter 18 for infrared fluorescence are inserted into the optical path between the annular diaphragm 7 and the condenser lens 6 . Correspondingly to the insertion of the exciter filter 17 for visible fluorescence and the exciter filter 18 for infrared fluorescence into the optical path of the illuminating optical system 1 , a barrier filter 19 for visible fluorescence and a barrier filter 20 for infrared fluorescence are inserted into the optical path between the perforated mirror 10 and the focusing lens 13 of the photographic optical system 2 . When the exciter filter 17 for visible fluorescence is inserted into the optical path of the illuminating optical system 1 , green illumination light is guided to the fundus R, and the fundus R is illuminated with the green illumination light. On the other hand, when the exciter filter 11 for infrared fluorescence is inserted into the optical path of the illuminating optical system 1 , red and infrared illumination light is guided to the fundus R, and the fundus R is illuminated therewith. In a color photographic mode except the fluorescence photographic mode, the exciter filters 17 , 18 are placed out of the optical path of the illuminating optical system 1 , and the barrier filters 19 , 20 are placed out of the optical path of the photographic optical system 2 .
In the optical path of the illuminating optical system 1 , there is disposed a reflecting optical member 22 which serves as a constituent part of a laser projection optical system 21 used for photocoagulation between the reflecting mirror B and the relay lens 9 . In this embodiment, a half mirror is used as the reflecting optical member 22 . The laser projection optical system 21 includes a laser light source 23 . Herein, a source for emitting a laser beam having a wavelength range of visible light (wavelength of 664 nm) is used as the laser light source 23 . A selective diaphragm 24 is disposed in front of the laser light source 23 . The selective diaphragm 24 is conjugate to the fundus R with respect to the objective lens 11 . When a blood vessel clogging treatment is conducted, a shutter 25 is inserted between the CCD 16 and the quick return mirror 14 in accordance with the power of a laser beam. The shutter 25 has a function of preventing the CCD 16 from being burned by the reflection of a laser beam having a high power. Likewise, a shutter 25 ′ is inserted into the finder optical system 16 ′. The laser projection optical system 21 includes a light laser source 27 used for aiming. The laser light source 23 is conjugate to the laser light source 27 with respect to a half mirror 28 . Relay lenses 29 , 30 are disposed between the half mirror 28 and the reflecting optical member 22 .
The selective diaphragm 24 consists of diaphragms 31 , 32 which differ in aperture diameter from each other. Either of the selective diaphragms 31 , 32 is inserted between the relay lens 29 and the relay lens 30 . When a treatment for clogging blood vessels of a diseased part is conducted, a laser spot is formed on the fundus R in accordance with the diameter of an aperture of the selective diaphragm 24 . A laser beam emitted by the laser light source 27 is designed to have a wavelength range within which the laser beam can pass through the barrier filter 20 . In this embodiment, the wavelength of the laser light source 27 is of a green range.
Since color photography and visible fluorescence photography are not directly relevant to the present invention, an explanation thereof is omitted. Thus, infrared fluorescence photography will be explained.
When the infrared fluorescence photography is carried out, an infrared fluorescent agent, called indocyaninegreen, of the following chemical formula (CHEMICAL FORMULA 5) is injected into the veins of the subject or is taken by the subject in advance.
{CHEMICAL FORMULA 5}
The infrared fluorescent agent circulates through the fundus and is then illuminated with excitation light having a specific wavelength which has passed through the exciter filter 18 for infrared fluorescence. Thereby, infrared fluorescence is emitted. If the fundus R has a diseased part K 1 , such as neovascular vessels, as shown in FIG. 2 , the infrared fluorescent agent remains in the diseased part K 1 . Thereby, the amount of fluorescence from the diseased part K 1 becomes larger than that of fluorescence from around the diseased part K 1 . Therefore, the diseased part K 1 shining brightly on a TV monitor can be located. Conventionally, an infrared laser beam has been projected, taking careful aim, onto the diseased part K 1 , and thereby the diseased part K 1 has been coagulated. However, disadvantageously, this conventional photoagulation method brings about an injury to normal tissues therearound. In the present invention, therefore, a photosensitive substance of the following constitutional formula (CHEMICAL FORMULA 6) is injected into the veins of the subject or is taken by the subject.
{CHEMICAL FORMULA 6}
where n is 1 or 2.
This photosensitive substance is a tetrapyrrole derivative, Mono-L-aspartiru chlorin/e6/4 sodium salt Mono- L - aspartyl chlorin e 6 tetrasodium salt (Abbreviated Npe6), one of the tetrapyrrole derivatives, is accumulated together with the infrared fluorescent agent in the endothelium of blood vessels of the diseased part K 1 such as neovascular vessels. Active oxygen is then generated by the projection of a laser beam having the wavelength of 664 nm thereonto, and thereby the blood vessels of the diseased part K 1 are clogged.
The following formula (CHEMICAL FORMULA 7) is a stereoisomer of CHEMICAL FORMULA 6. It is preferable to use a chemical compound of this formula instead of CHEMICAL FORMULA 6.
{CHEMICAL FORMULA 7}
where n is 1 or 2.
The photosensitive substances are mixed with the infrared fluorescent agent, and advantageously a mixture containing them is given to the subject by intravenous injection at a time.
As described above, the laser light source 23 emits a laser beam having the wavelength of 664 nm in order to cause the photosensitive substance to generate a photochemical change. When the diseased part K 1 is treated, a laser spot is formed on the fundus R in accordance with the diameter of an aperture of the selective diaphragm 24 . The laser power of the laser light source 23 can be regulated by a power regulator (not shown). It is desirable that the laser light source 23 is capable of making the laser oscillation with the projection intensity of 20 to 500 mW/cm 2 and with the full power of at least 500 mW.
In the laser projection optical system 21 , a laser beam is projected by aiming at a marker which is a region of infrared fluorescence shining brightly in the fundus R. Thereby, the photosensitive substance is caused to generate a photochemical change. Consequently, neovascular vessels can be clogged without injuring normal tissues to the utmost.
FIG. 3 shows a second embodiment of a fundus camera to which the present invention is applied. The fundus camera of the second embodiment is constructed such that a pattern plate 33 is disposed between the laser light source 27 for aiming and the half mirror 28 , and the relay to the eye fundus R is made through relay lenses 34 , 35 . As shown in FIG. 4 , for example, a star-shaped aiming pattern is projected onto the pattern plate 33 . Thereby, a distinction can be easily drawn between a part where the laser beam is projected and a part where infrared fluorescence is emitted. In order to distinguish the two parts more easily, a construction may be employed in which the laser light source 27 for aiming is intermittently driven to flicker the aiming pattern.
According to the present invention, the method for clogging blood vessels of an eye fundus and the apparatus and medicine used for clogging the blood vessels have the advantage that only the blood vessels of a diseased part are clogged for a surgical treatment almost without injury to normal tissues.
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An apparatus for clogging blood vessels of an eye fundus includes an illuminating optical system ( 1 ) for illuminating an eye fundus of a subject, who has been given an injection of an infrared fluorescent agent, with infrared rays of light and exciting the infrared fluorescent agent so as to generate infrared fluorescence, a photographic optical system ( 2 ) for observing and photographing the eye fundus, and a projecting optical system ( 21 ) for projecting a laser beam of light having a specific wavelength onto the subject who has been also given an injection of a photosensitive substance which undergoes a photochemical change by the laser beam. In the apparatus, while a region which emits infrared fluorescence is being observed, the laser beam is projected onto the photosensitive substance so as to clog blood vessels of a diseased part in the depth of the eye fundus.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional application No. 61/385,009 filed Sep. 21, 2010 entitled “DEVICE AND METHODS FOR INHIBITING SQUIRRELS”, the entire disclosure of which is incorporated herein.
FIELD OF THE INVENTION
[0002] This invention generally relates to a device for inhibiting access by squirrels, for example, to birdhouse and bird feeders.
BACKGROUND OF THE INVENTION
[0003] The fight against squirrels in bird feeders is a never-ending challenge for some bird lovers. Squirrels are notorious for gaining access to bird feeders and to birdhouses no matter what type of preventative device is tried. Numerous attempts have been made to discourage squirrels from accessing elevated bird feeders and birdhouses, such as saucer-shaped plates positioned either below or above the feeder or house, and domes positioned above the feeder or house. Intricate designs that include a plurality of sliding nested pipes have been attempted. Greasing the wire or pole supporting the feeder or house is also known to not always be successful.
[0004] Various attempts have also been made to inhibit squirrels from accessing the bird feed, once the bird feeder has been reached. Many bird feeder designs utilize a spring-loaded perch, which can support the weight of a bird, but collapses under the weight of a squirrel. Some bird feeders provide an electric shock to the squirrel or spin after access has been gained, providing a great source of amusement for any onlooker.
[0005] There has to be a better way to inhibit squirrels from gaining access to bird feeders and to birdhouses.
BRIEF SUMMARY OF THE INVENTION
[0006] This invention is directed to a device and methods of using the device to inhibit, deter, and preferably prevent, squirrels from accessing an elevated location such as a bird feeder or birdhouse. The device includes an exposed coiled spring that is attached to the support mechanism of the location, the support mechanism usually being a pole, stick, wire or string. When installed properly, the coiled spring surrounds the support mechanism. The coil is exposed, with no structure (e.g., a tube, cylinder, etc.) covering at least the bottom of the coil, and preferably the entire length of the coil.
[0007] When the coil device is hung on around pole supporting a bird feeder and a squirrel jumps on it as it attempts to climb, the coiled spring collapses under the weight of the squirrel, dropping it back to the ground. When the coiled device is hung above a bird feeder around the support mechanism and a squirrel attempts to descend to the feeder, the coiled spring collapses under the squirrel's weight, stretching the squirrel's body and causing it to pull itself back up to the tree branch. In both embodiments, the recoil action of the coiled spring device frightens the squirrel to further avoid the bird feeder.
[0008] In one particular embodiment, this disclosure provides a kit for deterring squirrels and other critters. The kit includes a coil and an attachment mechanism. In some embodiments, the attachment mechanism is one or two zip-ties. The coil may be metal.
[0009] In another particular embodiment, this disclosure provides a method of inhibiting or deterring access to an elevated location mounted on a pole. The method includes providing a coil having a first end and a second end, mounting the first end below the elevated location with the coil exposed around the pole, and letting the coil hang in a relaxed state around the pole with at least the second end of the coil exposed. The first end of the coil may be attached to the location being protected or to the pole. The second end of the coil may hang freely. In some embodiments, the entire coil may be exposed.
BRIEF DESCRIPTION OF THE DRAWING
[0010] The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawing, in which:
[0011] FIG. 1 is a schematic illustration of a birdhouse positioned on a pole with the squirrel inhibiting device operably mounted on the pole;
[0012] FIG. 2 is a schematic illustration of two bird feeders positioned on a Shepard's hook with the squirrel inhibiting device operably mounted on the Shepard's hook;
[0013] FIG. 3 is a schematic illustration of a bird feeder suspended by a wire from a tree with the squirrel inhibiting device operably mounted on the wire; and
[0014] FIG. 4 is a schematic illustration of a kit including the squirrel inhibiting device and at least one mounting mechanism.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The present invention is a device to deter or inhibit access to an elevated location (such as a bird feeder, birdhouse or bird bath) to vermin such as squirrels. Although the description of this invention is directed to inhibiting access to squirrels, it is understood that this device can also be used to inhibit access by cats, skunks, opossums, raccoons, rats, mice, and other smaller vermin. Overall, it could be said that this invention is directed to deterring access to an elevated location to critters.
[0016] In the following description, reference is made to the accompanying drawing that forms a part hereof and in which are shown by way of illustration various specific embodiments. The description provides additional specific embodiments. It is to be understood that other embodiments are contemplated and may be made without departing from the scope or spirit of the present invention. The following Detailed Description, therefore, is not to be taken in a limiting sense. While the present invention is not so limited, an appreciation of various aspects of the invention will be gained through a discussion of the examples provided below.
[0017] Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties are to be understood as being modified by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein.
[0018] As used herein, the singular forms “a”, “an”, and “the” encompass embodiments having plural referents, unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.
[0019] FIG. 1 illustrates a birdhouse 1 mounted in an elevated position (i.e., above the ground) via pole 2 . A coiled squirrel inhibiting device 10 is attached below birdhouse 1 around pole 2 . Device 10 has a first end 12 and a second end 14 that have therebetween a plurality of coils. Device 10 is mounted to pole 2 below birdhouse 1 , in the illustrated embodiment just below the level of birdhouse 1 . In other embodiments, device 10 may be connected to birdhouse 1 . Device 10 is positioned around pole 2 so that pole 2 extends through device 10 and the coils spirally wrap around pole 2 . At least second end 14 is exposed; that is, at least second end 14 is not covered by any structure (e.g., a tube, cylinder, sleeve, etc.). Preferably, at least the lower half of device 10 is exposed, more preferably at least the lower three-quarters of device 10 . In some embodiments, at least the lowest 6 inches of device 10 is exposed, and in other embodiments at least the lowest 12 inches of device is exposed. As illustrated in FIG. 1 , the entire length of device 10 is exposed.
[0020] In its compressed state, that is, with ends 12 , 14 pushed together to minimize the distance between adjacent coils, device 10 has a length usually about 2 to 3 inches (e.g., about 2.5 inches) but may be about 1 to 5 inches. In its relaxed extended state (i.e., extended merely due to gravity, with no other forces extending device 10 ), device 10 may be about 2 feet to 4 feet, although the extended length is highly dependent on the spring constant of device 10 , which is a function of the material of device 10 , the thickness of the material, the number of coils, the diameter of the coils, etc. The diameter of device 10 , in its compressed state is usually about 2 to 3 inches (e.g., about 2.5 inches), although larger or smaller devices 10 would be useful, depending on the support (e.g., pole 2 ) around which device 10 is positioned. In an extended state (either a relaxed extended state or a forced extended state), the diameter will be generally the same as in its compressed state, but may decrease slightly due to elongation of the coil. In most embodiments, the diameter of device 10 is constant from first end 12 to second end 14 when device 10 is in its compressed state.
[0021] Device 10 may be made from any suitable material such as metal, plastic, composite materials, or the like, although metal is the preferred material as it will withstand the rigors of being installed outdoors in extreme temperatures (cold and hot), is resistant to UV degradation, and depending on the specific metal, may be resistant to rusting. A metal device 10 is also preferred as it will typically be free of minute topography onto which a squirrel could cling.
[0022] Device 10 inhibits access to birdhouse 1 via pole 2 by multiple manners. When installed to protect a location, device 10 hangs in a relaxed extended state, preferably with second end 14 unconnected and hanging freely above the ground. Further, at least second end 14 and in most embodiments the entire length of device 10 is exposed. Upon a squirrel touching device 10 , device 10 will move, often scaring the squirrel away or at least away from device 10 . The contact by the squirrel will cause device 10 to swing, rotate, and/or stretch. Additionally, if the movement of device 10 does not sufficiently deter the squirrel and the squirrel attempts to climb up device 10 , device 10 stretches under the squirrel's weight to a forced extended state, both scaring the squirrel and deterring vertical climbing by the squirrel. As the squirrel attempts to climb higher up device 10 , the coils of device 10 continue to stretch, inhibiting vertical progress by the squirrel. Further, when the squirrel gives up and releases device 10 , device 10 will recoil, hopefully again scaring the squirrel.
[0023] The following procedure may be used to install device 10 to protect an elevated location (e.g., birdhouse 1 ) that is supported via its bottom, e.g., by pole 2 , by attaching device 10 to the bottom of the location.
[0024] (1) Remove birdhouse 1 or other object from support pole 2 and set aside.
[0025] (2) Place the birdhouse's mounting element (e.g., support wire or rod) through the center of the coils of device 10 . This is easiest done with device 10 in a compressed state.
[0026] (3) Attach upper end 12 of device 10 to the mounting element so that device 10 hangs securely therefrom.
[0027] (4) Let lower end 14 of device 10 hang loose around pole 2 . With device 10 in its relaxed extended state, lower end 14 preferably does not contact the ground.
[0028] (5) Remount birdhouse 1 onto support pole 2 .
[0029] In an alternate method, step (2) may be to wrap device 10 onto the mounting element until the entire device 10 surrounds it.
[0030] Device 10 may be utilized with various arrangements and with various locations to be protected. FIGS. 2 and 3 illustrate alternate arrangements that benefit having a squirrel inhibiting device.
[0031] FIG. 2 illustrates two bird feeders 4 A and 4 B suspended above the ground on a Shepard's hook 3 . A coiled squirrel inhibiting device 20 is attached to and around Shepard's hook 3 , which has two separate and spaced apart hanging hooks supported by a pole portion. Device 20 has a first end 22 and a second end 24 that have therebetween a plurality of coils. Device 20 is generally the same as device 10 described above.
[0032] The following procedure may be used to install device 20 to protect an elevated location (e.g., bird feeders 4 A, 4 B) by attaching device 20 to the support that does not have an upper end over which device 20 can be fed (e.g., hook 3 ).
[0033] (1) Manually wind device 20 around Shepard's hook 3 until the entire device 20 surrounds hook 3 ;
[0034] (2) Attach upper end 22 of device 20 to Shepard's hook 3 , either on the pole portion or at the joint between the pole portion and the hanging hooks, so that it hangs securely.
[0035] (3) Let lower end 24 of device 20 hang loose. With device 20 in its relaxed extended state, lower end 24 preferably does not contact the ground.
[0036] In an alternate method, step (1) may be to remove Shepard's hook 3 from the ground and slide device 20 upward around hook 3 so that device 20 surrounds the pole portion of hook 3 .
[0037] FIG. 3 illustrates a bird feeder 6 suspended and depending from a tree branch 7 via wire 5 . A coiled squirrel inhibiting device 30 is attached around wire 5 . Device 30 has a first end 32 and a second end 34 that have therebetween a plurality of coils. Device 30 is generally the same as device 10 , 20 described above. When device 30 is suspended above the location to be protected, second end 34 is above the level of bird feeder 6 , preferably a distance that is uncomfortable for the squirrel to jump, for example, at least 12 inches, such as at least 24 inches.
[0038] FIG. 4 illustrates a critter (e.g., squirrel) deterring kit. The kit includes a coiled device 40 and an attachment mechanism 48 . Coiled device 40 has first end 42 , a second end 44 and a plurality of coils 46 therebetween. Device 40 is generally the same as device 10 , 20 , 30 described above.
[0039] As indicated above, the coiled animal deterrent device 40 may be made from any suitable material such as metal, plastic, composite materials, or the like, although metal is the preferred material as it will withstand the rigors of being installed outdoors in extreme temperatures (cold and hot), is resistant to UV degradation, and may be resistant to rusting. In its compressed state, device 40 has a length (or height, when set on a surface) of about 1 to 5 inches, usually about 2 to 3 inches (e.g., about 2.5 inches), and a diameter of about 2 to 3 inches (e.g., about 2.5 inches), although larger or smaller devices 40 would be useful. In its relaxed expanded state, device 40 has a length of about 2 feet to 4 feet, although the extended length is highly dependent on the spring constant of device 40 , which is a function of the material of device 40 , the number of coils, the diameter of the coils, etc. One or both ends 42 , 44 may include a feature to facilitate connecting attachment mechanism 48 thereto, a feature such as an eyelet, a hook, a slit, a protrusion, or a stop.
[0040] Attachment mechanism 48 may be any device suitable for attachment of device 40 to pole 2 , Shepard's hook 3 , wire 5 , or even to birdhouse 1 or a feeder. The attachment mechanism may be, for example, a zip-tie (e.g., plastic zip-tie), metal wire, string, pressure sensitive adhesive, a screw, a nail, or a clip. Mechanism fasteners, such as a nail, screw, clip, are particularly suitable for attaching device 40 (e.g., end 42 ) directly to the bottom of a metal or wooden structure, such as a birdhouse. Wire or zip-ties are particularly suitable for attaching device 40 to an attachment point such as a joint in a multiple-hook Shepard's hook. Tape or a clip may be best suited for attaching device 40 to a suspended wire. The user of device 40 will be able to determine the best or most convenient attachment mechanism 48 for the application. The particular kit of FIG. 4 includes two plastic zip-ties as attachment mechanism 48 . One or both zip-ties may be used to attach device 40 .
[0041] Thus, embodiments of DEVICE AND METHODS FOR DETERRING SQUIRRELS are disclosed. Various modifications and alterations of this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention, and it should be understood that this invention is not to be unduly limited to the illustrative embodiments set forth herein. One skilled in the art will appreciate that the present invention can be practiced with embodiments other than those disclosed. The disclosed embodiments are presented for purposes of illustration and not limitation, and the present invention is limited only by the claims that follow.
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A device and methods of using the device to deter squirrels from accessing an elevated location such as a bird feeder or birdhouse. The device includes an exposed coiled spring that surrounds the supporting pole, stick, wire or string. The coil is exposed, with no structure (e.g., a tube, cylinder, etc.) covering at least the bottom of the coil, preferably the entire length of the coil. When the device is on pole and a squirrel jumps on it as it attempts to climb, the coiled spring collapses under the weight of the squirrel, dropping it back to the ground. When the device is hung above a bird feeder around the support and a squirrel attempts to descend to the feeder, the coiled spring collapses under the squirrel's weight, stretching the squirrel's body and causing it to pull itself back up to the tree branch.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a supporting assembly which is mounted to a vehicle chassis adjusting device to support and hold the vehicle chassis to be adjusted.
2. Description of Related Art
A seriously damaged, especially twisted, vehicle chassis is generally placed on an adjusting device which is installed on the ground for repair. A number of members are used to support and hold the chassis to be adjusted by the adjusting device, such as a combination base or a lattice-like track installed on a concrete ground and in cooperation with a so-called "drag tower" as well as chains. During adjustment, the most stable fixing points locate on the supporting members. Various types of clamping devices (responsive to different types of U.S.-made, Europe-made, and Japan-made chassis) are developed to securely clamp the supporting members and the chassis together. However, another problem arises in actual practice, that is, when adjusting chassis of different sizes, the result is unsatisfactory as the deformation situations of the damaged chassis differ from one another, i.e., the adjusting orientations required for the damaged chassis vary in a large extent. Furthermore, the force applied by the drag tower to the chassis may reach several tonnes and the supporting members must have opposite supporting force for accurate adjustment of the chassis. Although both the drag tower and the combination base are adjustable to respond to the change in the adjusting orientation, the supporting members lack appropriate arrangements and thus cause problems as they are only adjustable in height and fail to provide strong structural support.
Therefore, there has been a long and unfulfilled need for an improved supporting assembly which is not only adjustable in height but also adjustable in angular position and in lateral direction so as to suit chassis of different sizes.
SUMMARY OF THE INVENTION
A supporting assembly for a vehicle chassis provided by the present invention includes a base plate mounted to a vehicle adjusting device, a rotational device mounted on the base plate and rotatable along a vertical axis, a track device includes a fixed plate securely mounted on the rotational device to rotate therewith, a fixed track securely mounted on the fixed plate and extending in a horizontal direction, and a movable block slidably mounted in the fixed track, a height-adjustable device mounted on the movable block to move therewith and being adjustable in a height thereof, and a clamping device mounted on the height adjusting device and adapted to engage with and support a vehicle chassis.
The base plate further includes a plurality of legs extending radially and outwardly from an outer periphery thereof, each leg being securely mounted to a base frame of a chassis adjusting device by a second clamping device. The second clamping device includes a substantially U-shaped stationary member which defines a space, a movable clamping plate which is restrained in the space, and a bolt having a lower end securely attached to the movable clamping plate and an upper end to which an operative handle is attached.
The rotational device includes a fixed lower member securely mounted to the base plate and an upper member rotatably mounted on the fixed lower member. The fixed lower member has a central through hole and the upper member is substantially T-shaped in section with a longitudinal portion thereof received in the central through hole. A bearing ring with an annular groove is provided between the fixed lower member and the rotatable upper member, a bearing being received in the annular groove, thereby providing a smooth rotational movement. Preferably, the lower member includes a recess in a lower end thereof, and a plate is securely attached to a lower distal end of the longitudinal portion of the rotatable upper member and is located in the recess to provide a stable rotational movement.
The fixed plate has a plurality of rings formed along a perimeter thereof through which a chain is passable for operation of a drag tower during adjustment of a vehicle chassis. The movable block of the track device includes a mount plate, at least one substantially M-shaped member securely attached to an underside of the mount plate and including two opposite limbs and a middle section therebetween, a groove being formed between each of the limbs and the middle section for engaging with the fixed track.
The middle section of the M-shaped member further comprises a first roller plate securely mounted to a bottom side thereof. The first roller plate rests on an inner bottom surface of the slot of the fixed track and includes at least one roller rotatably mounted therein to provide a smooth sliding movement between the fixed plate and the movable block.
Each of the limbs of the M-shaped member further comprises a second roller plate securely mounted to an underside thereof. The second roller plate rests on the fixed plate and includes at least one roller rotatably mounted therein to provide a smooth sliding movement between the fixed plate and the movable block.
The middle section of the M-shaped member further includes a recess in each of two opposite sides thereof which faces the associated limb, each recess having a roller rotatably mounted therein for a smooth contact with an associated inner surface of the fixed track. A third roller plate is securely mounted in each slot between the middle section and the limb and rests on the associated second roller plate and includes at least one roller rotatably mounted therein to provide a smooth sliding movement between an associated outer surface of the fixed track and the movable block.
The height-adjustable device includes an outer tube securely mounted on the movable block to move therewith, a middle tube mounted in the outer tube, and an inner tube mounted in the middle tube. The inner tube includes a plurality of vertically spaced holes in a periphery thereof. The middle tube also includes a plurality of vertically spaced holes in a periphery thereof. A positioning pin is passable through two aligned holes respectively in middle and inner tubes after a desired height of the inner tube is reached.
The inner tube further includes inner threadings in an inner periphery of an upper end thereof and an adjusting bolt is received in the upper end of the inner tube. The adjusting bolt includes a flange on an upper portion thereof which has a plurality of radial holes in a periphery thereof. The adjusting bolt further includes an annular groove in an upper end thereof, a bearing ring with a bearing therein being mounted around the upper portion of the adjusting bolt above the flange and further comprising a retainer ring mounted in the annular groove to retain the bearing ring. The first clamping device is securely mounted on the bearing ring such that the first clamping device does not rotate when the adjusting bolt is operated to change the height thereof by means of a tool passing through one of the radial holes in the periphery of the flange. A sleeve is rotatably mounted around a lower section of the outer tube and includes a ring formed in a periphery thereof. A second sleeve is rotatably mounted around an upper end of the upper tube and includes a ring formed in a periphery thereof. A chain is passable by a through the rings, said chain is used for cooperating with a drag tower for adjusting a twisted frame of a vehicle chassis.
Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a supporting assembly for a vehicle chassis in accordance with the present invention;
FIG. 2 is a partial perspective view showing a base plate, a rotational device, a track device, and part of a supporting device of the supporting assembly in accordance with the present invention;
FIG. 3 is a perspective view of a clamping device for fixing the base plate of the supporting assembly to a vehicle chassis adjusting device;
FIG. 4 is a cross-sectional view of the clamping device in FIG. 3.
FIG. 5 is an exploded view of the rotational device of the supporting assembly in accordance with the present invention;
FIG. 6 is an exploded view illustrating the track device;
FIG. 7 is another exploded view which illustrates the details of the movable block of the track device;
FIG. 8 is a cross-sectional view of the track device;
FIG. 9 is a perspective view of a height adjusting device and a clamping device of the supporting assembly in accordance with the present invention; and
FIG. 10 is an exploded view of the height adjusting device and the clamping device in FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings and initially to FIG. 1, a supporting assembly in accordance with the present invention generally includes a base plate 10, a rotational device, a track device, a height adjusting device, and a clamping device 60.
Referring to FIGS. 1 and 2, the base plate 10 is a substantially circular plate with a plurality of legs 11 extending radially and outwardly from an outer periphery thereof. A plurality of holes 12 are formed in the circular plate for mounting the rotational device. Each leg 11 is fixed to a base frame of a chassis adjusting device (not shown) by means of a second clamping device. As clearly shown in FIGS. 3 and 4, the second clamping device includes a substantially U-shaped stationary member 13, a movable clamping plate 16 which is restrained in a space defined by the stationary member 13, and a bolt 14 with a lower end thereof securely attached to the movable clamping plate 16 by means of a fixing bolt 17 and with an upper end thereof attached to an operative handle 15. Operation of such a clamping device is conventional and therefore is not redundantly described herein.
Referring to FIGS. 1 and 5, the rotational device includes a fixed lower member 20 with a central through hole 21 and an upper member 24 which is substantially T-shaped in section and which is rotatably mounted on the fixed lower member 20 with its longitudinal portion received in the central through hole 21. The fixed lower member 20 includes a flange with a plurality of annularly aligned holes 23 formed therein and is securely mounted to the base plate 10 by bolts passing through holes 23 in the flange and corresponding holes 12 in the base plate 10. Preferably, between the fixed lower member 20 and the rotatable upper member 24, a bearing ring 27 with an annular groove 28 therein is provided for receiving a bearing 29 in the annular groove 28, thereby providing a smooth rotational movement therebetween. Preferably, the lower member 20 includes a recess 22 in a lower end thereof, and a plate 26 is located in the recess 22 and is secured to the lower distal end of the longitudinal portion of the rotatable upper member 24, thereby providing a stable rotational movement, as clearly shown in FIG. 1.
Referring to FIGS. 1, 2, and 6, the track device includes a fixed plate 30 with a plurality of holes 31 therein by means of which the fixed plate 30 is securely mounted on the upper rotatable member 24 to rotate therewith. A plurality of spaced rings 32 are formed along a perimeter of the fixed plate 30 through which a chain (not shown) is passable for operation of a drag tower during adjustment of a vehicle chassis. A fixed track 33 is securely mounted to the fixed plate 30 and has a slot 331 which extends along a horizontal direction and which is substantially of an inverted T-shape cross section. The track device further includes a movable block 34 which includes a middle section 35 correspondingly formed to the T-shaped slot 331 and is therefore movable along the longitudinal direction of the fixed track 33.
Referring to FIGS. 1 and 6 through 8, the movable block 34 includes a mount plate 341 with a plurality of holes 36 therein for mounting the height adjusting device, a plurality of substantially M-shaped members 342 securely attached to an underside of the mount plate 341 and each including two limbs 343 and an above-mentioned section 35, a slot 351 is defined between each of the limbs 343 and the section 35 for engaging with the fixed track 33. As shown in FIGS. 6 through 8, a first roller plate 37 is securely mounted to bottom sides of said sections 35 of the M-shaped members 342 and rests on an inner bottom surface of the slot 331 of the fixed track 33 and includes a plurality rows of rectangular holes 371 each having a roller 372 rotatably mounted therein by a pin 373, providing a smooth sliding movement between the fixed plate 30 and the movable block 34. A second roller plate 38 is securely mounted to an underside of each limb 343 of the M-shaped member 342 and rests on the fixed plate 30 and is adjacent to the fixed track 33, each second roller plate 38 includes a row of rectangular holes 381 each having a roller 382 rotatably mounted therein by a pin 383, providing a smooth sliding movement between the fixed plate 30 and the movable block 34.
As shown in FIG. 7, the middle section 35 of each M-shaped member 342 further includes a recess 352 in each of two opposite sides thereof which faces an associated limb 343, the recess 352 having a roller 353 rotatably mounted therein by a pin 354 for a smooth contact with an associated inner surface of the fixed track 30. As shown in FIG. 8, a third roller plate 39 is securely mounted in each slot 351 (the slot 351 is sufficiently large to accommodate one side wall of the track and the third roller plate 39) and rests on an associated second roller plate 38 and is adjacent to associated lateral side of fixed track 33. Each third roller plate 39 includes a row of rectangular holes 391 each having a roller 392 rotatably mounted therein by a pin 393, providing a smooth contact between the outer surfaces of the side walls of fixed track 33 and associated side walls of the limbs 343 of the M-shaped members 342 thereby providing a smooth sliding movement therebetween.
Referring to FIGS. 1, 9, and 10, mounted on the mount plate 341 of the track device is a height adjustable device which includes an outer tube 40, a middle tube 43 mounted in the outer tube 40, and an inner tube 45 mounted in the middle tube 43. The outer tube 40 includes a flange 41 on a lower end thereof which has a plurality of holes 42 therein whereby the outer tube 40 is mounted on the mount plate 341 by bolts passing through holes 42 and holes 36 in the mount plate 341. A sleeve 48 is rotatably mounted around a lower section of the outer tube 40 and includes a ring (not labeled) formed in a periphery thereof through which a chain (not shown) is passable so as to be operated by a drag tower during adjustment of a vehicle chassis.
The inner tube 45 includes a plurality of vertically spaced holes 46 in a periphery thereof. The middle tube 43 also includes a plurality of vertically spaced holes 44 in a periphery thereof, and a positioning pin 50 is provided to pass through two aligned holes 44 and 46 respectively in middle and inner tubes 43 and 45 after a desired height of the inner tube 45 is reached, i.e., the height of the inner tube 45 is adjustable by pulling it upwardly and then positioning it by means of the positioning pin 50.
The inner tube 45 further includes inner threadings in an inner periphery of an upper end thereof and an adjusting bolt 51 is received in the upper end of the inner tube 45 for micro-adjustment of the height of the previously-mentioned clamping device 60 which will be explained hereinafter. The adjusting bolt 51 includes a flange 52 on an upper portion thereof which has a plurality of radial holes 53 in a periphery thereof. The adjusting bolt 51 further includes an annular groove 55 in an upper end 54 thereof. A bearing ring 57 with a bearing 58 therein is mounted around the upper portion of the adjusting bolt 51 above the flange 52 and is retained in position by means of a retainer ring 59 mounted in the annular groove 55. A second sleeve 49 is rotatably mounted around the upper end of the inner tube 45 and includes a ring (not labeled) formed in a periphery thereof through which a chain (not shown) is passable so as to be operated by a drag tower during adjustment of a vehicle chassis.
The first clamping device 60 is securely mounted on the bearing ring 57 by means of passing bolts through holes 61 therein and corresponding holes 56 in the bearing ring 57. The height of the first clamping device 60 is primarily determined by the inner tube 45 and is micro-adjustable by the adjusting bolt 51 by passing a suitable tool through one of the holes 53 to rotate the adjusting bolt 51, thereby raising or lowering the first clamping device 60. The first clamping device 60 in this embodiment is chosen to mate with a vehicle chassis of the type having screw holes therein. It is appreciated that the first clamping device 60 can be replaced by other types of clamping devices so as to mate with different vehicle chassis.
In operation, the base plate 10 is secured to a chassis adjusting device by the second clamping devices shown in FIGS. 3 and 4 or other suitable clamping devices. Then, the rotatable member 24 of the rotational device is rotated to a desired orientation for adjustment. Thereafter, the movable block 34 is moved to a position where the first clamping device 60 is below the vehicle chassis to be adjusted. The inner tube 45 is raised to a height close to the vehicle chassis and the first clamping device 60 is adjusted to the desired height under operation of the adjusting bolt 51 and is then secured to the vehicle chassis by bolts. The vehicle chassis is thus stably supported by a plurality of supporting assemblies. Thereafter, the sleeves 48 and 49 are rotated to a desired orientation such that chains may be passed through for operation during adjustment of the vehicle chassis under operation of a drag tower or other suitable means for stretching the twisted frame of the vehicle chassis. Since the twisted frame may be stretched in various orientations in order to completely reshape the structure, positions and orientations of the supporting assembly must be adjustable responsive to the change in the point of the force applied by the drag tower, so as to obtain accurate adjustment effect in the chassis, and such object is satisfactorily achieved under the provision of the supporting assembly of the present invention.
Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.
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A supporting assembly for a vehicle chassis includes a base plate securely mounted to a vehicle chassis adjusting device, a rotational device mounted on the base plate and rotatable along a vertical axis, a track device including a fixed plate securely mounted on the rotational device to rotate therewith, a fixed track securely mounted on the fixed plate and extending along a horizontal direction, and a movable block slidably mounted in the fixed track, a height-adjustable device mounted on the movable block to move therewith and being adjustable in a height thereof, and a clamping device mounted on the height- adjusting device and adapted to engage with and support a vehicle chassis.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This divisional application claims priority to U.S. Non-Provisional Application Ser. No. 11/746,706 filed on May 10, 2007 and U.S. Provisional Application No. 60/747,061 filed on May 11, 2006, entitled “Antibiotic-Bound Poly(Caprolactone) Polymer”.
STATEMENT OF GOVERNMENT INTEREST
[0002] This invention was made with Government support under Grant No. RO1 A1 51351 awarded by the National Institutes of Health. The Government has certain rights in the invention.
FIELD OF INVENTION
[0003] This invention relates to attaching one or more bioactive molecules to the same polymer, and also for attachment before or after polymerization
BACKGROUND OF THE INVENTION
[0004] The delivery of water-insoluble drugs to targets within the human body is a challenge that presently places strict limitations on what drugs can be applied clinically. The need for methods which overcome this is of high priority in the development of new therapeutics for treatment of human disease.
[0005] The development of antibiotics for control of pathogenic bacteria has been of pressing need in this era of drug resistant infections. N-Methylthiolated b-lactams have been identified as a new family of antibacterial agents active against Staphylococcus bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). (See Turos, E.; Konaklieva, M. I.; Ren, R. X. F.; Shi, H.; Gonzalez, J.; Dickey, S.; Lim, D. Tetrahedron 2000, 56, 5571; Bart Heldreth, Timothy E. Long, Seyoung Jang, Suresh K. R. Guntireddygari, Edward Turos, Sonja Dickey, Daniel V. Lim, “N-Thiolated b-Lactam Antibacterials: Effects of the N-Organothio Substituent on anti-MRSA Activity,” Bioorganic and Medicinal Chemistry 14, 3775-3784 (2006); and Edward Turos, Jeung-Yeop Shim, Yang Wang, Kerriann Greenhalgh, G. Suresh Kumar Reddy, Sonja Dickey, Daniel V. Lim, “Antibiotic-Conjugated Polyacrylate Nanoparticles: New Opportunities for Development of Anti-MRSA Agents,” Bioorganic and Medicinal Chemistry Letters 16, in press (2006); which are incorporated herein by reference).
[0006] The compounds have also displayed promising anticancer properties. These lactams exert their growth inhibitory effects on bacteria through a mode of action that is distinctively different to that of other b-lactam antibiotics, and possess structure-activity patterns unlike those already mapped for other b-lactam antibacterials such as the penicillins. One of the major limitations in the potential application of these N-thiolated b-lactam compounds, however, is their exceedingly low water solubility.
[0007] Drug delivery vehicles such as liposomes and gold nanoparticles have been developed to improve bioavailability, efficacy, and specificity of pharmaceutical compounds, particularly for anticancer agents, but nanoparticles have received surprisingly little attention in the antibiotic and infectious disease area. Some of the few notable examples have included antibiotic-encapsulated polymeric nanoparticles and liposomes, biodegradable nanospheres and surface-coated gold and silver nanoparticles.
SUMMARY OF INVENTION
[0008] In one embodiment, the invention provides an effective drug delivery platform that would enhance the water solubility of the lactams, without sacrificing inherent bioactivity.
[0009] In another embodiment, the invention provides for the development of antibacterial polyacrylate nanoparticles based on well-precedented emulsion polymerization procedures.
[0010] This invention addresses this need, and demonstrates the use of antibiotic-bound poly (caprolactone) polymers as anti-infective materials for biomedical applications in the prevention of bacterial infections.
[0011] In a first embodiment, the invention includes a functionalized compound comprising at least one caprolactone ring with an appended functional group. A plurality of methylene groups act as a spacer between the lactone ring and the functional group. In a preferred embodiment, the functional group is an antibiotic, such as a N-thiolated β-lactam. The functional group is preferably covalently bonded.
[0012] In an alternate embodiment, a method is provided for producing the functionalized compound of the previous embodiment. The method includes providing a at least one caprolactone ring with a protecting group spaced apart from the caprolactone ring by a plurality of methylene groups. The protecting group is then cleaved from the caprolactone ring and replaced by bonding a functional group to the caprolactone ring. Illustrative reagents for cleaving the protecting group include 10% pd/C as a catalyst in the presence of H 2(g) and ethyl acetate (EtOAc). The protecting group is selected from the group consisting of alcohol protecting groups, amine protecting groups, carbonyl protecting groups and carboxyl protecting groups. In a preferred embodiment, the protecting group is selected for the group consisting of a benzel ester and a tert-butyl ester. As with the previous embodiment, the functional group is an antibiotic such as a N-thiolated β-lactam.
[0013] In another embodiment, the invention includes the compound represented by the formula:
[0000]
[0014] or a pharmaceutically acceptable salt or ester thereof, wherein is selected from the group consisting of water-insoluble drugs, antibiotics, lactams, β-lactams, N-thiolated β-lactams and protecting groups. The protecting group is selected from the group consisting of alcohol protecting groups, amine protecting groups, carbonyl protecting groups and carboxyl protecting groups.
[0015] In yet another embodiment, the invention includes the compound represented by the formula:
[0000]
[0016] or a pharmaceutically acceptable salt or ester thereof.
[0017] In another embodiment, the invention includes the compound represented by the formula:
[0000]
[0018] or a pharmaceutically acceptable salt or ester thereof.
[0019] In still another embodiment, the invention includes the compound represented by the formula:
[0000]
[0020] or a pharmaceutically acceptable salt or ester thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which:
[0022] FIG. 1 shows the polymerization of a caprolactone monomer to polycaprolactone (PCL).
[0023] FIG. 2 shows the functionalized caprolactone polymer can be used for covalent binding of drug molecules.
[0024] FIG. 3 shows examples of functionalized caprolactones from the literature.
[0025] FIG. 4 shows the functionalized lactone of present invention.
[0026] FIG. 5A shows drug appendage before polymerization.
[0027] FIG. 5B shows drug appendage after polymerization.
[0028] FIG. 6 shows lactone resynthesis.
[0029] FIG. 7 shows ylide synthesis.
[0030] FIG. 8 is an image showing results of biological testing of the lactam-containing monomer vs. MSSA.
[0031] FIG. 9 demonstrates the anti-Bacillus activity of the β-lactam containing copolymer.
[0032] FIG. 10 shows the invention employing an alternate carboxyl protecting group.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0033] In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings, which form a part hereof, and within which are shown by way of illustration specific embodiments by which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the invention.
[0034] N-Thiolated β-Lactams
[0035] New family of anti-MRSA and anti-Bacillus agents that have recently been reported by our laboratory. Extensive SAR studies have shown that changing the N-thioalkyl substituent has a large effect on the bioactivity and that changes at the other positions of the ring exert a more subtle effect. Recent research in our group has been focused on covalent attachment of these and other antibiotics to polymers for drug, delivery and for new biomaterials.
[0000]
[0036] As used herein, the term “drug” to any therapeutic or prophylactic agent other than food which is used in the prevention, diagnosis, alleviation, treatment, or cure of disease in man or animal.
[0037] As used herein, the term “antibiotic” refers to any natural, synthetic, and semi-synthetic compound that has been identified as possessing antibacterial, antifungal, antiviral, or antiparasitic activity.
[0038] Polycaprolactones
[0039] Polycaprolactone (PCL) is a biodegradable polyester which can be prepared by ring opening polymerization of ε-caprolactone using a catalyst such as stannous octanoate, as shown in FIG. 1 . PCL is degraded by hydrolysis of its ester linkages in physiological conditions (such as in the human body) and is therefore useful as a biomaterial. PCL has been approved by the Food and Drug Administration (FDA) for use in the human body as (for example) a suture (sold under the brand name Monocryl™ or generically). In particular, PCL has been used in long term implantable devices, owing to its degradation which is relatively slow. (See V. R. Sinha, K. Bansal, R. Kaushik, R. Kumria and A. Trehan; Poly-ε-caprolactone microspheres and nanospheres: an overview, International Journal of Pharmaceutics , Volume 278, Issue 1, 18 Jun. 2004, Pages 1-23; which is incorporated herein by reference.)
[0040] The characteristics of PCL make it useful as a delivery mechanism for antibiotics. For example PCL is biodegradable (bulk hydrolysis of ester bonds), the byproducts of degradation are non-toxic (biocompatible), it is FDA approved and displays high permeability to many drugs. Therefore, the invention provides a functionalized caprolactone polymer can be used for covalent binding of drug molecules ( FIG. 2 ).
[0041] The functionalized caprolactones of the prior art (Detrembleur et al Macromolecules, 2000, 33, 14-18 and Trollsas et at Macromolecules, 2000, 33, 4619-4627) are shown in FIG. 3 . In contrast, the functionalized lactone 10 of present invention is shown in FIG. 4 . Lacton 10 comprises at least one lactone ring 12 , functional group 16 and at least one spacer 14 . As it can be seen, functional group 16 is placed away from site of polymerization. Moreover, an additional methylene spacer 14 between functional group 16 and lactone ring 12 enhances further functionalization.
[0042] In another embodiment, the invention provides a method of producing an antibiotic-conjugated functionalized caprolactone ( FIG. 5A and FIG. 5B ). In Step 1 includes providing a caprolactone comprising lactone ring 12 , methylene spacer 14 and protecting group 18 . In Step 2 , protecting group 18 is cleaved, preferably under mild conditions. Finally, in Step 3 , drug of interest 20 is covalently bonded to the finished compound. FIG. 5A illustrates the method of appending a drug of interest to the functionalized lactone before polymerization. FIG. 5B illustrates the method of appending a drug of interest to the functionalized lactone after polymerization. Lactone retrosynthesis is shown in FIG. 6 and Ylide synthesis is shown in FIG. 7 .
Example 1
[0043] The following represents an embodiment of the invention wherein 1,4-dioxaspiro[4.5]decan-8-one is used to synthesize a functionalized lactone bearing a pendent benzyl ester as the protecting group.
[0000]
[0044] Reagents and conditions: (a) 2 eq. ylide, C 6 H 6 , 12 h, reflux; (b) 60 psi H 2(g) , cat. 10% Pd/C, MeOH, 12 h; (c) 3LiOH, MeOH, 12 h, rt; 1M HCl; (d) 3K 2 CO 3 , 1.1 BnBr, MeCN, 12 h, reflux; (e) 70% AcOH, 12-24 h, rt; (f) 1.5mCPBA, CHCl 3 , 3-5 h, reflux.
[0045] Next the functionalized lactone is coupled with an antibiotic, here N-thiolated β-lactam, after deprotection of benzyl ester. FIG. 8 shows the results of biological testing of the lactam-containing monomer vs. MSSA.
[0000]
[0046] Reagents and conditions: (a) cat. 10% Pd/C, 60 psi H 2(g) , EtOAc, 12 h; (b) 1.5 eq. EDCl, cat. DMAP, dry CH 2 Cl 2 , 12 h, rt.
Example 2
[0047] In another embodiment, the invention provides a PCL derived from copolymerization of a functionalized lactone monomer with caprolactone. Copolymers containing 10%, 15%, 20%, 25% and 30% of the substituted lactone were prepared and characterized by TLC, 1 H, NMR, 13 C NMR and MALDI-TOF. The Copolymers displayed low molecular, between about 1000 and 4000.
[0000]
[0048] Deprotection of the copolymer and coupling with the antibiotic, β-lactam, is shown below and was achieved using the following reagents and conditions: (a) cat. 10% Pd/C, H 2(g) , EtOAc, 12-24 h. (b) 15 EDCI, cat. DMAP, dry CH 2 Cl 2 , 12 h. rt. The antibiotic activity of the completed PCL against Bacillus is shown in FIG. 9 .
[0000]
Example 3
[0049] In yet another embodiment, the functionalized lactone comprises a carboxyl protecting group, as shown in FIG. 10 . Ylide synthesis is shown below using the reagents and conditions: (a) PPh 3 , C 6 H 6 , 12 h, rt; (b) 20% NaOH (aq) , 5 h, rt.
[0000]
Example 4
[0050] The following demonstrates the synthesis of lactone bearing pendant tert-butyl ester using the reagents and conditions: (a) 1.5 eq. ylide C 6 H 6 . 12 h, reflux, (b) H 2(g) , cat. 10% Pd/C, EtOAC, 24 h; (c) 0.1 eq. I 2 , dry acetone, 1 hr, rt; (d) 1.5mCPBA CHCl 3 , 3 h, reflux.
[0000]
[0051] Copolymerization with caprolactone was achieved as shown below. Copolymers containing 10%, and 20% of the substituted lactone were prepared and characterized by TLC, 1 H NMR and 13 C NMR.
[0000]
[0052] Functional caprolactone monomers have been synthesized and characterized. The monomers were further copolymerized with caprolactone. Caprolactone monomers and polymers with covalently bound N-thiolated β-lactams have been prepared and shown to possess bioactivity against MSSA and Bacillis respectively.
[0053] It will be seen that the advantages set forth above, and those made apparent from the foregoing description, are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
[0054] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. Now that the invention has been described,
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This invention is the design and synthesis of a caprolactone monomer which bears a pendant protected carboxyl group. This monomer has been copolymerized with caprolactone in varying ratios. After polymerization, the protecting group can be removed and an antibiotic can be attached as a new pendant group. The bioactivity of the antibiotic-bound poly(caprolactone) polymer is described.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation in part of parent application Ser. No. 07/879,808, filed May 7, 1992, now U.S. Pat. No. 5,282,370, issued Feb. 1, 1994.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to accumulator devices, particularly for vehicular air-conditioning systems, for separating moisture-laden, partially vaporized refrigerant fluid into a moisture-free refrigerant vapor having a predetermined, specific lubricating oil content.
2. Description of the Prior Art
The use of accumulators in air-conditioning systems, particularly vehicular air-conditioning systems, is well known. One is placed downstream of the evaporator, which cools the passenger compartment air as it is passed over and through the evaporator, and therefore takes in partially or completely vaporized refrigerant fluid which may or may not have a relatively small amount of condensation created water, and which will also have a small amount of lubricating oil necessary to the functioning of the compressor. The partially vaporized refrigerant fluid, being on the downstream end of the evaporator, is at a relatively low pressure, in the order of 40 psig and a raised but relatively low temperature in the order of 60° F. (there being a modest temperature rise through the evaporator of about 10° F.). The accumulator is upstream of the condenser and its purpose is to assure that only refrigerant vapor fluid passes to the compressor and that this vapor be moisture-free and include a prescribed amount of lubricating oil, and that the oil-laden vapor be free of particulates that might otherwise harm the compressor.
Thus the known accumulators basically accomplish five functions: (i) completely vaporize the refrigerant fluid, (ii) remove all water vapor, (iii) screen all particulates, (iv) inject into the outgoing vapor stream a predetermined amount of lubricating oil, and (v) act as a reservoir for the refrigerant when system demand is low. Typical examples of accumulators accomplishing these functions are shown in U.S. Pat. Nos. 3,798,921; 4,111,005; 4,291,548; 4,496,378 and 5,052,193.
The major challenges in designing such an accumulator are to provide one which is efficient, one which fits well within the system packaging--in other words, fits within the engine compartment and is easily accessible for maintenance--and one which is inexpensive to manufacture.
Of particular interest with regard to operation efficiency and manufacturing cost is the design and placement of the baffle within the interior of the accumulator which serves the purpose of separating pure vapor from liquified vapor, passing the former through the outlet and recirculating the latter until it completely vaporizes and it passes through the outlet. From the foregoing examples, those shown in U.S. Pat. Nos. 4,291,548 and 5,052,193 show a baffle which is a separate member or component designed to be placed within the system in some convenient manner, with the newer designs tending towards easily insertable, plastic, self-positioning members.
It is a purpose of the present invention to improve upon these known designs and their method of manufacture.
SUMMARY OF THE INVENTION
The present invention contemplates an accumulator design for an air-conditioning system which is efficient in its operation, includes a minimum number of parts and is less expensive to manufacture relative to known commercial designs.
The invention further contemplates integrating the accumulator housing and baffle structure to thereby reduce the overall number of parts in the accumulator and facilitate its most efficient manufacturing and assembly. The internal baffle member is formed to be an inwardly extending annular flange having a major diameter equal to the housing's diameter and a minor diameter which is between fifty and ninety-five percent that of the major diameter. Additionally, the end of the baffle member defining the minor diameter is extended toward the bottom of the accumulator.
The invention further contemplates an accumulator, as above described, wherein the incoming partially vaporized refrigerant is discharged through the inlet port below the integrated baffle whereby the refrigerant has the maximum amount of time in which to vaporize before it passes through the outlet port.
The invention further contemplates an accumulator, as above described, wherein all of the incoming, partially vaporized, moisture-laden refrigerant is caused to flow through the desiccant material provided for removing moisture from the refrigerant, and preferably forced to do so at the first point of entering the accumulator interior chamber.
The invention also contemplates an accumulator design, as above described, which readily facilitates, with no change in the interior structure and components, top-mounted inlet and outlet tubes and side-mounted inlet and outlet tubes or any combination of the above, thus facilitating the packaging of the accumulator within the engine compartment. These above objects, features and advantages of the present invention will become readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a typical vehicular air-conditioning system incorporating use of an accumulator as may be designed pursuant to the present invention;
FIG. 2 is an elevational view shown partially in cross section of a first embodiment of the present invention;
FIG. 3 is a plan view taken along section lines 3--3 of FIG. 2;
FIG. 4 is an elevational view shown partially in cross section of a second embodiment of the present invention;
FIG. 5 is a plan view taken along section lines 5--5 of FIG. 4 of the second embodiment of the present invention;
FIG. 6 is an elevational view shown partially in cross section of a third embodiment of the present invention;
FIG. 7 is a plan view taken along section lines 7--7 of FIG. 6 of the third embodiment of the present invention;
FIG. 8 is an elevational view shown partially in cross section of a fourth embodiment of the present invention;
FIG. 9 is a plan view taken along section lines 9--9 of FIG. 8 of the fourth embodiment of the present invention;
FIG. 10 is an elevational view shown partially in cross section of a fifth embodiment of the present invention;
FIG. 11 is a plan view taken along section lines 11--11 of FIG. 10 of the fifth embodiment of the present invention;
FIG. 12 is an elevational view shown partially in cross section of a sixth embodiment of the present invention; and
FIG. 13 is a plan view taken along the section lines 13--13 of FIG. 12 of the sixth embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is a generally conventional vehicular air-conditioning system including a compressor 12, condenser 14, expansion device in the form of an orifice tube 16, evaporator 18 and an accumulator generally designated 20. A refrigerant fluid, such as Freon-12 or the like, is circulated through the system beginning as a high temperature/high pressure vapor on the outboard side of the compressor, then passing through the condenser, during which time additional heat is taken out of the vapor forming a high temperature/high pressure liquid, then passing through the orifice tube, causing thermal expansion of the refrigerant and thereby producing a low temperature/low pressure vapor/liquid stream passing through the evaporator which takes in heat from the heated vehicular passenger compartment and thereby transforms the refrigerant to a low temperature/low pressure vapor. At this stage, the vapor temperature is generally in the order of 64° F. and at approximately 40 psig pressure.
A first embodiment of an accumulator constructed in accordance with the present invention is shown in FIGS. 2 and 3 wherein the accumulator 20 has a housing composed of two cup-shaped shells 22 and 24, joined as by welding, brazing or soldering at their open end indicated at 26. The housing thereby defines an internal chamber having an upper portion 30 and a lower portion 32, generally coinciding to the boundaries of the respective cup-shaped members 22 and 24. The open, upper end of the housing member 24 is formed with a radially, inwardly directed flange or baffle member 34, which may be stamped, roll formed or spun. As described in greater detail below, the flange 34 functions as a baffle member interrupting the flow of refrigerant vapor being received within the accumulator from the evaporator or inlet end of the accumulator.
The accumulator 20 further includes an inlet tube 36 and an outlet tube 38. The inlet tube is centrally disposed off-center as viewed in the plan view of FIG. 3, i.e., its axis is parallel but not coincident with the vertical axis of the accumulator. The outlet tube 38 is a generally U-shaped member embodying two vertically oriented legs 40 and 42, with a U-shaped bight portion 44 located at a predetermined distance from the bottom of the member 24. The bight portion includes a hole 45 for allowing lubricating oil, generally found in the incoming vapor stream and collecting at the bottom of the accumulator in a manner which is well-known, to be recirculated within the outgoing vapor stream.
The hole may be capped with an orifice filter (not shown) to act as a large particle trap and to precisely meter the amount of oil flowing downstream to the compressor.
Both the inlet tube 36 and the outlet tube 38 extend through holes drilled in the top closed end of the cup-shaped member 22 and are brazed or welded thereto as indicated at 46.
It will be noted that the inlet tube 36 and the legs 40 and 42 of the outlet tube will clear an inner annular edge or rim 48 of the flange or baffle member 34. The outlet tube 38 includes an inlet end 50 located at a predetermined distance from the top wall of the cup-shaped member 22.
The inlet tube 36 includes an unrestricted, open discharge end 52 located in the chamber lower portion 32 and below the baffle member 34, at the end of an angular elbow 53. As seen in FIG. 3, the discharge end 52 is directed generally tangential to the housing wall so that, at least initially, the discharged refrigerant will assume a circumferential flow path around the circumference of the housing. A desiccant material containing member 60 such as a cylindrically-shaped flexible bag member having tightly packed silica gel particles is disposed in the lower central region of the housing member 24 and may be fixed to one or the other of the inlet and outlet tubes 36 and 38 or both, or simply rest on the bight portion 44 of the outlet tube 38. Preferably, the baffle member 34, as viewed in FIG. 2, will be located within the middle two-thirds of the length of the accumulator, i.e. the length of the lower housing member 24 will be anywhere from one-half to twice the length of the upper housing member 22.
Also, regardless of the location of the baffle member 34 along the accumulator axis, the inlet tube's discharge end 52 is preferably located above the level of any refrigerant fluid collected within the housing member 24 when it functions as a lower reservoir for refrigerant fluid, i.e. when system demand is low or the system is inoperative.
In operation, the inlet tube 36 receives a low temperature, low pressure refrigerant mixture of liquid, vapor and oil as it has passed through the evaporator 18. The refrigerant mixture will exit from the discharge end 52 of the inlet tube 36 and flow partially upward under pressure and impinge upon the baffle member 34 which will re-direct the flow downward, thus interrupting any direct flow of liquid refrigerant into the outlet tube 38 and thereby ensuring sufficient vapor flow activity within the accumulator to cause the liquid/vapor mixture to completely vaporize prior to collecting at the top of the chamber, i.e. the upper portion 30 of the cup-shaped housing 22, at which point it is caused to flow through the inlet end 50 of the outlet tube 38.
All of the refrigerant mixture is caused to flow through or about the desiccant bag member 60 whereby any moisture content is removed. The desiccant material containing member may also function as a filter for particulates, as is well-known in the art.
A mixture of lubricating oil and liquid refrigerant will precipitate out of the moisture-free, particulate-free vapor or liquid/vapor mixture and collect at the bottom of the cup-shaped lower housing 24 to be adjusted at a controlled rate through the lubricating oil orifice or hole 45 of the outlet tube 38.
The method of manufacturing the above-described accumulator includes the step of forming, as by drawing, the cup-shaped members 22 and 24. The inlet and outlet ports in the upper cup-shaped member 22 are then formed by stamping to receive the pre-formed inlet and outlet tubes 36 and 38, and upon inserting the pre-formed inlet and outlet tubes in the cup-shaped member 22, each tube is brazed or welded to the top wall as indicated at 46 in FIG. 2. Further, the bottom cup-shaped member 24 is provided with the flange or baffle member 34 by roll forming, or any other suitable process, and the open end receiving portion of the upper cup-shaped member 22 is concentrically flared as by rolling or forming at 70, sufficiently to snugly receive the flanged end of lower cup-shaped member 24. Then the desiccant containing member 60 is positioned about the inlet and outlet tubes or secured thereto as previously described, and the cup-shaped members are axially slipped together in telescopic relationship until the flange 34 of the lower housing member 24 abuts against the internal shoulder formed at the flare 70. The two cup-shaped members are then welded around the entire circumference of the flare 70 as indicated at 26.
Regarding the geometry of the baffle member 34, in all embodiments it is believed the best results are obtained where its minor diameter to major diameter ratio ranges from about 0.5:1 to 0.95:1, and preferably where the ratio equals about 0.8:1. It is also preferred that the baffle member be convex with the convex surface presented towards the bottom portion 32 of the lower housing member 24. The degree of convexity will be such as to impart good circulatory action to the refrigerant mixture being circulated past the baffle member 34.
In addition to the above described preferred embodiment it should be noted that it is also possible to form the baffle member 34 in the open end of the upper cup-shaped member 22 as shown in FIGS. 12 and 13. The baffle member 34, again, can be roll formed, or made by any other suitable process. In the embodiment in which the baffle member 34 is formed in the upper cup-shaped member 22, the bottom cup-shaped member's 24 open end is concentrically flared, as by rolling or forming, sufficiently to snugly receive the upper cup-shaped member 22 having the baffle member 34 formed therein. In this embodiment, with the baffle member 34 formed in the upper cup-shaped member 22, it is still preferable to form the baffle member 34 with a convex cross section pointed toward the bottom portion 32 of the lower housing member 24 in order to impart a circulatory action to the refrigerant mixture being circulated past the baffle member 34. Additionally, it is preferable to extend the baffle member at its end 35 in a downward direction toward the bottom portion 32. This helps to direct the circulating liquid refrigerant back into the desiccant bag member 60 thereby ensuring that all of the moisture is removed from the refrigerant.
In FIGS. 4 and 5 there is shown a second embodiment of the present invention. In this and other embodiments discussed below, like numerals are maintained where the elements are identical to those described in connection with the first embodiment of FIGS. 2 and 3. The primary difference in structure with that described in connection with the first embodiment is the structure of the baffle member 34. It will be noted from FIGS. 4 and 5 that the outlet tube legs 40 and 42 are nearly adjacent the housing members 22 and 24 and to accommodate this, it is necessary to provide diametrically opposed cut-out portion 72 and 74 in the baffle member 34 as shown in FIG. 5, which receive and locate the outlet tube relative to the accumulator housing. Preferably these cut-out portions are stamped prior to the rolling of the flange or baffle member 34. Also, the inlet tube 36 is centrally disposed coincident to the vertical axis of the accumulator, is closed at the bottom by a cap member 54 and includes a plurality of passages or holes 56 to allow the incoming refrigerant mixture to pass through the desiccant material containing member 60 and then to the lower portion 32 of the chamber. A further difference lies in the desiccant material containing member 60 which is constructed as a saddlebag, as shown generally in U.S. Pat. No. 4,291,548, the description of which is incorporated herein by reference.
A third embodiment is shown in FIGS. 6 and 7 wherein the inlet and outlet tubes 36 and 38 respectively, are "side-mounted", i.e., the inlet and outlet ports 76 and 78 are located in the cylindrical side wall of the upper housing member 22. Further, it will be noted that the inlet tube 36 is located radially off-center of the axis of the accumulator and disposed near the wall of the housing as with the outlet tube 38. Because of this the baffle member 34 will include a respective cut-out and locating slot or scallop 80 similar to those described in connection with the embodiment of FIGS. 4 and 5.
It will be noted that the desiccant containing member 60 is cylindrical, as was shown in the first embodiment, and remains vertically disposed in the radial center of the accumulator, adjacent to the discharge end 52 of the inlet tube 36, as seen clearly in FIG. 7. Also, the discharge end 52 of the inlet tube 36 includes no outlet holes other than being completely open at its end 52 as shown, i.e. the cap 54 of the previously described embodiment is omitted and the open discharge end 52 is positioned adjacent the desiccant member 60 and directed to the side as with the first embodiment described.
Yet another embodiment of the present invention is shown in FIGS. 8 and 9. The primary difference in this embodiment with respect to those previously described is in the structure of the outlet tube 38, which it will be noted is relatively shorter in overall length than those previously described. In this embodiment, the bight portion 44 of the outlet tube 38 is located above the baffle member 34, and an oil pick-up tube 82 extends from the downstream end of the bight portion 44 to the bottom of the chamber. A screen member 84 is connected to the oil pick-up tube 82 and will filter any particulates which may be lying at the bottom of the accumulator. The rate of flow of lubricating oil is controlled by the diameter of the internal flow passage of the oil pick-up tube 82. This construction also makes possible the use of a cylindrical cartridge-type desiccant containing member 60. Its particular structure is not a part of the present invention, and any appropriate cartridge may be used, or in the alternative, a conventional saddle-bag type desiccant material containing member, as previously described, may be used. The inlet tube may be generally of the type as described in either FIGS. 2 or 4, with the latter alteration being shown. As seen in FIG. 9, the outlet tube may be disposed off-center of the accumulator axis, such that the leg members 40 and 42 are located nearest the internal wall of the accumulator. The inner annular rim 48 of the baffle member 34 is uninterrupted as is the case in the embodiment shown in FIGS. 2 and 3.
Finally, in FIGS. 10 and 11 there is shown yet another embodiment of the present invention. Like the immediately preceding embodiment, the outlet tube 38 is disposed completely within the upper portion 30 of the chamber above the baffle member 34. In this case, the outlet tube 38 is centrally disposed, as seen in the plan view of FIG. 11, such that it passes through the vertical axis of the accumulator. As with the embodiment of FIGS. 8 and 9, the outlet tube 38 is connected to the elongated oil pick-up tube 82, extending to the bottom of the lower portion 32 of the chamber. The primary difference between this embodiment and that of FIGS. 8 and 9 is the location of the inlet tube 36 which is located off-center as with the embodiments of FIGS. 6 through 9, such that the baffle member 34 must include the cut-out and locating portion 80. The desiccant material containing member 60 used with this embodiment will be similar to that shown in connection with the embodiment of FIGS. 6 and 7, or in light of the lower chamber portion 32 being entirely free of the inlet tube and oil pick-up tube, a cartridge unit such as described in connection with the embodiment immediately preceding, may be utilized.
However, as with each embodiment, other than that of FIGS. 2 and 3, the baffle member 34 turns down at the annular rim or edge 48 toward the lower portion 32 of the lower cup-shaped housing 24. In FIG. 2, it is to be noted the flange 34 is not so completely developed such that the inner annular rim 48 projects radially inward approximately perpendicular to the vertical axis of the accumulator. This difference in the degree the flange is turned is not believed to materially affect the refrigerant mixture circulation, but rather accommodates the fabrication of the unit.
Although particular embodiments of the present invention have been illustrated in the accompanying drawings and described in the foregoing detailed description, it is to be understood that the present invention is not to be limited to just the embodiments disclosed. For example, it is possible to have the baffle member 34 of the embodiment shown in FIGS. 12 and 13 extend closer to the center axis of the cylinder housing and to have scallops cut into the baffle member 34 which have the inlet tube 36 and outlet tube 38 passing through the scallops, similar to the embodiment in FIG. 7. Additionally, numerous rearrangements, modifications and substitutions are possible, without departing from the scope of the claims hereafter.
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An accumulator for use in an air-conditioning system wherein a refrigerant fluid is circulated. The accumulator embodies an enclosed housing defining an internal vapor chamber, an inlet tube, an outlet tube having a vapor inlet end in an upper portion of the vapor chamber, and a baffle member located within the housing between the upper and lower portions and within the vapor chamber to impede the flow of incoming partially vaporized fluid causing it to circulate within the chamber and allowing the refrigerant vapor to rise to the upper portion of the vapor chamber and to flow through the outlet tube. The baffle member is an integral part of the housing, being formed at the open end of one of two cup-shaped housing members and turning inwardly to provide a generally ring-shaped baffle member, with the cup-shaped members being joined at their open ends to complete the enclosed housing.
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TECHNICAL FIELD
[0001] This patent relates generally to computer software and more particularly to business application software using the Internet.
BACKGROUND
[0002] Modern day businesses cannot function efficiently without use of state of the art technology. Specifically, computers and software are an almost essential part of most of the businesses in developed economies. Typically, businesses use a number of off the shelf business applications, such as Excel® as well a number of custom applications specifically designed for a particular aspect of the business. There are a number of industry specific software applications that are developed by software companies to be used in a particular type of businesses, such as financial services, medical services, etc.
[0003] While such industry specific software applications are generally designed with specific characteristics of particular type of business in mind, they still need to be modified to be more suitable for use by the end user. Customer relationship management (CRM) software is one such example of a business application that is often modified by either the end user or by an independent software vendor specializing in this particular type of software.
[0004] Since the development of the Internet, businesses typically use web based applications to provide distributed business solution on the Internet. In a typical web based application, a three-tier platform is used to implement the business application, wherein a web browser is the client tier, a database containing various business data used by the application is the back-end tier, and a web server and its extensions became the middle tier. The middle tier, often also known as the middleware, is responsible for a number of functionalities including, but not limited to, reading data, writing data, data access authorization, relationship validation, etc.
[0005] Middleware used for business applications demand highly customizable solutions for managing business data. Typical processes in such an application include various processes for authorization, maintaining data integrity, applying business rules, etc. Business applications also requires enforcing various relationship constraints amongst business entities during various cascading operations for security, reorganization of business divisions, updates/deletes to heterogeneous objects hierarchies, etc. As referred to in here, an entity is a metadata description of a real world concept, such as a customer or a product. The term entity and the term class can be used interchangeably to mean such definition or description of such real world concepts. An entity instance, or just an instance, is the physical data describing a particular member of the set of such entities. Similarly, a relationship constraint is a set of rules that govern how a particular relationship between two entities is traversed while performing business logic. On the other hand, cascading operations are operations related to business logic that automatically traverse various entity relationship constraints.
[0006] All cascading operations can occur on both connected and disconnected clients. However, the subset of cascading operations which change data are only trusted when they occur on the central application server. Thus, allowing customization of business processes and entity schema creates several challenges with respect to cascading operations. Therefore, there is a need to provide better middle tier platform for providing customizable business solution for managing business data.
SUMMARY
[0007] A metadata driven system for supporting business application software required in the middle tier for a line of business applications includes a process metadata module adapted to store a process in metadata format, wherein the process object contains logic related to an entity of the application software. The system allows for persistence of various entities like accounts, incidents, etc., and allows an end user of the business application software to create new types of entities. The system also allows the end user to perform critical business logic operations even on the new entities defined by the end user after the deployment of the business application without requiring recompilation of the business application software. The metadata driven approach allows to easily make changes to business applications and to automate quality assurance of objects built on top of the business applications.
[0008] An implementation of the metadata driven system allows representing a business entity, such as a business account, contact, etc., having a database schema defining the business entity, in a metadata format. The system may be adapted to define a plurality of properties of the business entity in metadata format as an entity metadata module, to serialize the entity metadata module to the application platform, to de-serialize the serialized entity metadata module and to store the de-serialized entity metadata module on the application platform. The system may be further adapted to define a process object in metadata format as a process metadata module, wherein the process object contains logic for the business entity. The system may also include a serialization module for serializing the process metadata module to the application platform, a de-serialization module for de-serializing the serialized process metadata module, and a storage module for storing the de-serialized process metadata module on the application platform.
[0009] An alternate implementation of the system may also be adapted to define an operation performed on the entity in metadata format as an operation metadata module, to serialize the process metadata module to the application platform, to de-serialize the serialized process metadata module, and to store the de-serialized process metadata module on the application platform.
BRIEF DESCRIPTION OF DRAWINGS
[0010] FIG. 1 is a block diagram of a network interconnecting a plurality of computing resources;
[0011] FIG. 2 is a block diagram of a computer that may be connected to the network of FIG. 1 ;
[0012] FIG. 3 illustrates a block diagram of a metadata driven system that may be used for managing applications on the network of FIG. 1 ;
[0013] FIG. 4 illustrates a block diagram of an entity metadata module that may be used by the metadata driven system of FIG. 3 ;
[0014] FIG. 5 illustrates a flowchart for generating a metadata module to be used by the metadata driven system of FIG. 3 ; and
[0015] FIG. 6 illustrates a flowchart for using the metadata driven system of FIG. 3 .
DESCRIPTION
[0016] Although the following text sets forth a detailed description of numerous different embodiments, it should be understood that the legal scope of the description is defined by the words of the claims set forth at the end of this patent. The detailed description is to be construed as exemplary only and does not describe every possible embodiment since describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims defining the invention.
[0017] It should also be understood that, unless a term is expressly defined in this patent using the sentence “As used herein, the term ‘______’ is hereby defined to mean . . . ” or a similar sentence, there is no intent to limit the meaning of that term, either expressly or by implication, beyond its plain or ordinary meaning, and such term should not be interpreted to be limited in scope based on any statement made in any section of this patent (other than the language of the claims). To the extent that any term recited in the claims at the end of this patent is referred to in this patent in a manner consistent with a single meaning, that is done for sake of clarity only so as to not confuse the reader, and it is not intended that such claim term by limited, by implication or otherwise, to that single meaning. Finally, unless a claim element is defined by reciting the word “means” and a function without the recital of any structure, it is not intended that the scope of any claim element be interpreted based on the application of 35 U.S.C. § 112, sixth paragraph.
Network
[0018] FIG. 1 illustrates a network 10 that may be used to implement an XML versioning system described herein. The network 10 may be the Internet, a virtual private network (VPN), or any other network that allows one or more computers, communication devices, databases, etc., to be communicatively connected to each other. The network 10 may be connected to a personal computer 12 and a computer terminal 14 via an Ethernet 16 and a router 18 , and a landline 20 . On the other hand, the network 10 may wirelessly connected to a laptop computer 22 and a personal data assistant 24 via a wireless communication station 26 and a wireless link 28 . Similarly, a server 30 may be connected to the network 10 using a communication link 32 and a mainframe 34 may be connected to the network 10 using another communication link 36 . As it will be described below in further detail, one or more components of the dynamic software provisioning system may be stored and operated on any of the various devices connected to the network 10 .
Computer
[0019] FIG. 2 illustrates a computing device in the form of a computer 110 that may be connected to the network 10 and used to implement one or more components of the dynamic software provisioning system. Components of the computer 110 may include, but are not limited to a processing unit 120 , a system memory 130 , and a system bus 121 that couples various system components including the system memory to the processing unit 120 . The system bus 121 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus also known as Mezzanine bus.
[0020] Computer 110 typically includes a variety of computer readable media. Computer readable media can be any available media that can be accessed by computer 110 and includes both volatile and nonvolatile media, removable and non-removable media. By way of example, and not limitation, computer readable media may comprise computer storage media and communication media. Computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can accessed by computer 110 . Communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, radio frequency, infrared and other wireless media. Combinations of the any of the above should also be included within the scope of computer readable media.
[0021] The system memory 130 includes computer storage media in the form of volatile and/or nonvolatile memory such as read only memory (ROM) 131 and random access memory (RAM) 132 . A basic input/output system 133 (BIOS), containing the basic routines that help to transfer information between elements within computer 110 , such as during start-up, is typically stored in ROM 131 . RAM 132 typically contains data and/or program modules that are immediately accessible to and/or presently being operated on by processing unit 120 . By way of example, and not limitation, FIG. 1 illustrates operating system 134 , application programs 135 , other program modules 136 , and program data 137 .
[0022] The computer 110 may also include other removable/non-removable, volatile/nonvolatile computer storage media. By way of example only, FIG. 1 illustrates a hard disk drive 140 that reads from or writes to non-removable, nonvolatile magnetic media, a magnetic disk drive 151 that reads from or writes to a removable, nonvolatile magnetic disk 152 , and an optical disk drive 155 that reads from or writes to a removable, nonvolatile optical disk 156 such as a CD ROM or other optical media. Other removable/non-removable, volatile/nonvolatile computer storage media that can be used in the exemplary operating environment include, but are not limited to, magnetic tape cassettes, flash memory cards, digital versatile disks, digital video tape, solid state RAM, solid state ROM, and the like. The hard disk drive 141 is typically connected to the system bus 121 through a non-removable memory interface such as interface 140 , and magnetic disk drive 151 and optical disk drive 155 are typically connected to the system bus 121 by a removable memory interface, such as interface 150 .
[0023] The drives and their associated computer storage media discussed above and illustrated in FIG. 1 , provide storage of computer readable instructions, data structures, program modules and other data for the computer 110 . In FIG. 1 , for example, hard disk drive 141 is illustrated as storing operating system 144 , application programs 145 , other program modules 146 , and program data 147 . Note that these components can either be the same as or different from operating system 134 , application programs 135 , other program modules 136 , and program data 137 . Operating system 144 , application programs 145 , other program modules 146 , and program data 147 are given different numbers here to illustrate that, at a minimum, they are different copies. A user may enter commands and information into the computer 20 through input devices such as a keyboard 162 and pointing device 161 , commonly referred to as a mouse, trackball or touch pad. Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, or the like. These and other input devices are often connected to the processing unit 120 through a user input interface 160 that is coupled to the system bus, but may be connected by other interface and bus structures, such as a parallel port, game port or a universal serial bus (USB). A monitor 191 or other type of display device is also connected to the system bus 121 via an interface, such as a video interface 190 . In addition to the monitor, computers may also include other peripheral output devices such as speakers 197 and printer 196 , which may be connected through an output peripheral interface 190 .
[0024] The computer 110 may operate in a networked environment using logical connections to one or more remote computers, such as a remote computer 180 . The remote computer 180 may be a personal computer, a server, a router, a network PC, a peer device or other common network node, and typically includes many or all of the elements described above relative to the computer 110 , although only a memory storage device 181 has been illustrated in FIG. 1 . The logical connections depicted in FIG. 1 include a local area network (LAN) 171 and a wide area network (WAN) 173 , but may also include other networks. Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets and the Internet.
[0025] When used in a LAN networking environment, the computer 110 is connected to the LAN 171 through a network interface or adapter 170 . When used in a WAN networking environment, the computer 110 typically includes a modem 172 or other means for establishing communications over the WAN 173 , such as the Internet. The modem 172 , which may be internal or external, may be connected to the system bus 121 via the user input interface 160 , or other appropriate mechanism. In a networked environment, program modules depicted relative to the computer 110 , or portions thereof, may be stored in the remote memory storage device. By way of example, and not limitation, FIG. 1 illustrates remote application programs 185 as residing on memory device 181 . It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used.
Metadata Driven Business Logic Processing
[0026] FIG. 3 illustrates a block diagram of a metadata driven system 200 that may be used for managing various applications on the network 10 of FIG. 1 . The system 200 may include an entity metadata module 202 , a process metadata module 204 , a base process metadata module 206 , a serialization module 208 and a de-serialization module 210 . The system 200 may communicate with a server database 212 , a remote database 214 , a graphical user interface (GUI) 216 and a browser 218 . Various modules of the system 200 may be implemented on any of the various computing devices, such as the server 30 , the desktop computer 12 , etc., of the network 10 . When implemented on the computer 110 , the system 200 may be stored on the ROM 131 , on the RAM 132 , or any other similar location.
[0027] The system 200 may be used to implement a middleware for an application, such as a customer relation management (CRM) application that accesses various data on the server database 212 and on the remote database 214 . While the system 200 is illustrated in here to implement a CRM application, any number of alternate applications can be implemented using the system 200 . For example, in an alternate implementation, the system 200 may be used to implement a human resource management application on a network, such as the network 10 . Other examples of applications that may be implemented using the system 200 include various business applications, such as an enterprise resource planning (ERP) system, a distributed accounting system, a material requirement planning (MRP) system, a project management system, etc.
[0028] The system 200 may use the GUI 216 and browser 218 to communicate with users of the system 200 . Moreover, one or more application programs, such as the application program 135 stored on computer 110 , may interact with the system 200 . The system 200 may communicate with the various devices on the computer 110 using the system bus 121 , or any other manner well known to those of ordinary skill in the art. Similarly, the system 200 may communicate with various devices on the network using the local area network 171 , the wide area network 173 , etc.
[0029] Now referring to the specific components of the system 200 , the entity metadata module 202 may define various properties of an entity used by an application. Such an entity may be, for example, an account table for customer account data of a CRM application, a sales table for sales data in an inventory management application, etc. As it is well known to those of ordinary skill in the art, metadata in general represents information about entities and their relationships. The entity metadata module 202 may include properties of various entities, including properties for various entities created by an end user or by an independent software vendor (ISV). Examples of some of the properties that may be represented by the entity metadata module 202 may be the data type of the entity, the size of the entity, security information regarding the entity, relationship of the entity with other entities, etc. Whereas, the block diagram in the FIG. 3 illustrates only one block for entity metadata module 202 , it is to be understood that in an implementation of the system 200 , the structure of the entity metadata module 202 may be highly complex, including different entity metadata modules for different entities, where one or more of such plurality of entity metadata modules may be interrelated to each other.
[0030] The process metadata module 204 may represent various processes related to an entity. For example, when an entity represents a contract, that provides information regarding a sales contract, a process related to the contract entity may be a contract renewal process, which may involve business logic and may be implemented by a ContractProceeObject.Review( ) method. In this case, the process metadata module 204 may represent the ContractProceeObject.Review( ) method. If a process represented by the process metadata module 204 needs one or more sub-processes, such sub processes may also be provided within the process metadata module 204 .
[0031] The process metadata module 204 may include various processes developed by an original developer of an application using the entity and supplied with the initial implementation of the application. However, a user, an ISV, etc., also may develop and provide additional processes that may be added to the process metadata module 204 . In such a situation, the process metadata module 204 may include metadata representing information about the additional processes and other information which may be necessary to create and/or invoke instances of such additional business processes.
[0032] Allowing a third party vendor to develop and provide one or more processes using the process metadata module 204 allows adding different functionalities to an application without having to compile and deploy such added functionalities into the application. Moreover, if an ISV adds an entity to an application, while the properties of such added entity are stored in the entity metadata module 202 , various processes to be performed upon such added entity may be stored in the process metadata module 204 .
[0033] The base process metadata module 206 stores various basic processes that may be used by various processes of an application, including the processes stored in the process metadata module 204 . For example, the base process metadata module 206 is shown to include a create process, a read process, an update process and a delete process, are shown in FIG. 3 . However, many more base processes related to security, data persistence, etc., may also be stored in the base process metadata module 206 . Thus for example, the ContractProceeObject.Review( ) method stored on the process metadata module 204 may call an update process from the base process metadata module 206 to update a contract entity, where the properties and relationships of such contract entity may be stored on the entity metadata module 204 .
[0034] The serialization module 208 may include processes for converting an in-memory object representation of an entity into a format that can be sent over a network or saved to be disk or other storage media. Similarly, the de-serialization module 210 may include a de-serialization process for converting data from a memory or data received from a network into an in-memory object representation, which can be used by one or more processes stored on either of the process metadata module 204 and the base process metadata module 206 .
[0035] FIG. 4 illustrates a detailed block diagram of various components that may be stored in the entity metadata module 202 of FIG. 3 . As discussed above, the entity metadata module may be used to store information about various entities created during the original design of the application as well as information about various entities that may be added by an ISV or a user of the application. While FIG. 4 illustrates various information stored in the entity metadata module in different blocks, a person of ordinary skill in the art would recognize that one or more of these blocks may be merged together or one or more of these blocks may be further divided into various sub-blocks. Moreover, each of these blocks may access information from the other blocks by using a common communication bus such as the system bus 121 of the computer 110 .
[0036] More specifically, the entity metadata module 202 may include a physical shape block 232 , an attribute block 234 including various attributes of the various entities, a bound processes block 236 including various processes bound to the various entities, a relationship block 238 including various relationships of—and between—the various entities, a maps block 240 including entity maps for the various entities, a user interface block 242 including various user interfaces used with the various entities and a rules block 244 including various rules regarding one or more of the various entities.
[0037] The physical shape block 232 may store definitions of various entities' physical database shape such as table definitions, view definitions, etc, in the metadata format. For example, when for a customer entity related to a CRM application, the physical shape block 232 may store information regarding the number of columns in a customer table, the memory address for the customer table, etc.
[0038] The attributes block 234 may store various information related to the attributes of the entities in the metadata format. For example, a security attribute of an entity may specify whether a user or a process has a security privilege to view or change information about the entity. One or more attributes of an entity may be specified by the original designer of an application and/or by an ISV. Moreover, for certain entities such attributes may be changed by a user and for other entities such attributes may not be changed by the users.
[0039] The bound processes block 236 may specify processes bound to various entities in the metadata format, where such processes may be stored in the process metadata module 204 , the base process metadata module 206 , or in some other format. An example of a process bound to a customer entity may be a “generate e-mail” process that causes the application to generate an e-mail at every fixed period. Another example of a process bound to a sales person entity may be an “update location” process that updates a local phone number of a sales person every time the application receives travel information related to the sales person.
[0040] The relationships block 238 may specify, in the metadata format, various relationships between the various entities related to the application. For example, in a human resource application implemented by the system 200 , the relationship block 238 may specify that a relation between a manager and an employee is one-to-many, whereas a relation between a manager and a secretary is one-to-one. The relationship block 238 may also specify relationships for entities added by an ISV or by a user.
[0041] The maps block 240 may specify, in the metadata format, various rules for constructing other entities based on various existing entities in an application. For example, the maps block 240 of an accounting system may specify rules for creating an invoice entity based on a customer entity, a product entity, a sales tax entity, etc.
[0042] The user interface block 242 may specify, in the metadata format, various layouts, views, pick-lists, etc., for entities related to an application. For example, the user interface block 242 related to a particular raw material entity in a MRP application may specify that the pick-list for that particular raw material should list the most commonly used materials at the top of a pick-list or that the most cost effective shipping alternative for that material at the top of a pick-list, etc.
[0043] The rules block 244 may specify, in the metadata format, various rules related to one or more entities in an application, such as a validation rule, a cardinality rule, etc. For example, the rules block 244 of a CRM application may specify that any update to a customer refund entity higher than a first amount must be validated by a manger entity. As another example, a validation rule stored in the metadata format in the rules block 244 for a human resources application may specify that any update to an employee bonus entity must be validated by two manager entities.
[0044] Furthermore, the entity metadata module 202 may also include an operations block 246 describing various operations related to entities of the target application. For example, the operations block 246 may store a create operation including requirements for offline playback support, offline transaction support, etc. Similarly, the operations block 246 may also store a retrieve operation including information that the retrieve operation does not need offline playback support, offline transaction support, etc.
[0045] Now referring to FIG. 5 , a program 250 illustrates a method of generating various metadata modules to be used by the metadata driven system of FIG. 3 . Specifically, the program 250 illustrates adding a new entity to an existing application and adding a process related to the newly added entity. At a block 252 the program 250 may receive an entity that needs to be added to the application. For example, if an existing application is a CRM application, an ISV may be interested in adding a housing status entity representing customer's housing information, i.e., whether the customer is an owner or a renter, etc.
[0046] At a block 254 , the program 250 serializes the newly received object/entity so that it may now be stored on the memory. At a block 256 , the program 250 stores the newly received entity into the entity metadata module 204 . Note that the program 250 may also store various properties and relationships defining the newly created housing status entity into the entity metadata module 204 . For example, one of such property may be that the housing status can take only one of four different statuses (such as: own, rent, dependent and other). Similarly, another property of the newly added entity may be the relational key of the newly created entity.
[0047] Subsequently, at a block 258 , the program 250 receives and serializes various processes related to the newly created housing status entity. For example, one such process may be to update the housing status. However, it may be that updating the status may be connected to a number of other processes based on a number of different rules, such as: upon a change of housing status from rent to own, initiate a review of the credit status, generate a first set of marketing material, etc. As the entity metadata module 202 may already have information regarding relationships and properties of other entities affected by such process, it is easy to implement such new processes without having to compile the entire application. Moreover, as the properties of the newly added housing status entity are added to the entity metadata module 202 , the newly added entity also is accessible by the other processes.
[0048] Subsequently, at a block 260 , the program 250 determines if any of the processes related to the newly created entity requires any of the base processes such as create, read, update, delete, etc. If it is determined that one or more such base processes are necessary, at the block 260 the program 250 ensures that all such base processes are available in the base process metadata module 206 . If it is determined that one or more base processes are not available in the base process metadata module 206 , at a block 262 the program requests, receives and stores such base processes into the base process metadata module 206 .
[0049] Now referring to FIG. 6 , a program 300 illustrates a method of using the metadata driven system 200 . For illustration purposes, the program 300 only illustrates using the metadata driven system 200 for executing an insert request, however, other requests or complex processes may also be implemented using the metadata driven system 200 . Such a request may be performed by a business process defined using the process metadata module 204 , wherein the business process requires a create operation to be performed on a business entity stored on the entity metadata module 202 to create a query on the business entity. The program 300 uses various base processes stored on the base process metadata module 206 to perform the business process. The program 300 may use various extensions of the entities for which the insert request is to be executed, wherein the such extensions may also be stored in the entity metadata module 202 related to that entity. Generally, the extensions of an entity may be implemented during the design of an application or by ISVs or users of the application.
[0050] At a block 302 , the program 300 may send a PreCreate request to a Validate base process stored on the base process metadata module 206 to validate various attributes of an entity instance on which the create process is to be performed.
[0051] Next, at a block 304 , the program 300 may send another PreCreate request to an InjectDefaults base process stored on the base process metadata module 206 to set customer defined values for various attributes of the entity instance. For example, the default value of the home status may be “rent,” and if no value is assigned to the entity instance, the InjectDefaults base process may add such default value to the entity instance.
[0052] Subsequently, at a block 306 , the program 300 may send a PreCreate request to a Security base process stored on the base process metadata module 206 to obtain security permissions for the entity on which the create process is to be performed. The program 300 may use a security extension of the entity to validate that a user has appropriate permission to perform the create process.
[0053] While in the present case for the create process, the program 300 performs only a single level security check, in an alternate case, a two level security check may be performed where the program 300 first may check that a user has a permission to perform a requested process against a class of instances defined by the entity and subsequently, the program 300 may perform an entity instance specific check to ensure whether the user has a permission to perform the requested process on the particular instance of the entity. Note that in the case of a create process, there is no existing instance of the entity, and therefore, only one level of security check may be sufficient.
[0054] At a block 308 , the program 300 may send a BuildCreate request to a QueryBuilder process stored on the process metadata module 204 to create an instance of the entity.
[0055] Subsequently, at a block 310 , the program 300 may send a PostCreate request to the Security base process stored on the base process metadata module 206 to store security permissions for the entity on which the create process is to be performed.
[0056] At a block 312 , the program 300 may send a PostCreate request to a Workflow base process stored on the base process metadata module 206 to allow various customer defined business processes to run outside the scope of the current operation. The Workflow base process is an example of a process that allows an ISV or a user of an application to develop business rules/actions to be taken in response to certain events related to the system containing the entity. For example, a user of a sales force management system can create a workflow process that triggers sending an e-mail every time a new sales opportunity or sales lead is entered into the sales force management system.
[0057] Subsequently, at a block 314 , the program 300 may send a PostCreate request to a Callout base process stored on the base process metadata module 206 to notify other systems which have subscribed to the Create process execution allowing them to execute any existing or new business logic.
[0058] At a block 316 , the program 300 may send a PostCreate request to an Offline base process stored on the base process metadata module 206 to store the request, if required by the system's current connection state, for subsequent playback to the central server when a reliable connection is reestablished. Note, that the step 316 allows storing the request when the create operation is performed on a disconnected client for later playback when a connection to a central application server is established, such storing may not be necessary in case of an operation being performed at the central application server.
[0059] A person of ordinary skill in the art would appreciate the advantages of the metadata driven system 200 described above for a business application that may need frequent updating and custom development capabilities. Making the business application metadata driven provides tremendous value in terms of allowing customization and support for customization, without having to perform compilation of the business application after each customization. Specifically, by making various processes, such as validation, authorization, persistence, etc., metadata driven, the metadata driven system 200 described in here makes it extremely easy to customize business applications, thus reducing cost of development and maintenance of business applications.
[0060] The metadata driven system 200 also makes internal development of new entities with business logic easier. Because updating metadata via some tools is much easier than updating and compiling code for a business application and deploying the updated code on a cluster of servers and clients, the metadata driven system 200 allows making design changes to business applications easier. Similarly, because it is easier to use metadata to automate tests and compare outcome of tests with desired results, automated test processes for quality assurance of business applications can be easily added to the process metadata module 204 .
[0061] Although the forgoing text sets forth a detailed description of numerous different embodiments of the invention, it should be understood that the scope of the invention is defined by the words of the claims set forth at the end of this patent. The detailed description is to be construed as exemplary only and does not describe every possible embodiment of the invention because describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims defining the invention.
[0062] Thus, many modifications and variations may be made in the techniques and structures described and illustrated herein without departing from the spirit and scope of the present invention. Accordingly, it should be understood that the methods and apparatus described herein are illustrative only and are not limiting upon the scope of the invention.
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A metadata driven system for supporting business application software required in the middle tier for a line of business applications includes a process metadata module adapted to store a process in metadata format, wherein the process object contains logic related to an entity of the application software. The system allows for persistence of various entities like accounts, incidents, etc., and allows an end user of the business application software to create new types of entities. The system also allows the end user to perform critical business logic operations even on the new entities defined by the end user after the deployment of the business application without requiring recompilation of the business application software. The metadata driven approach allows to easily make changes to business applications and to automate quality assurance of objects built on top of the business applications.
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BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a ring spinning machine in which conveyor belts drivable for delivering empty tubes and removing cops are disposed along spindle rows present on both sides of the machine, the conveyor belts having openings at half the spindle spacing for receiving arbors for cops and empty tubes in alternation.
A ring-spinning machine of this generic type is known for example from German published, non-prosecuted application DE-OS 20 45 263. An essential characteristic of such a ring-spinning machine is that conveyor belts are disposed on both sides of the machine along the rows of spindles. The conveyor belts deliver empty tubes to the spinning machine and remove cops therefrom. The conveyor belts have openings at half the spindle spacing at which alternatingly arbors for cops and for empty tubes are secured. Typically, the arbors are secured in these openings by screw fastening means. One advantage of this is that in doffing, an intermediate position for the empty tubes is not required. Thus the full cops are first removed from the spindles by the doffer and placed directly on the arbors, intended for that purpose, between the empty tubes that are located on the respectively other arbors. Immediately after that, by indexing the conveyor belts onward by one-half the spindle spacing, the empty tubes are positioned under the grippers of the respective doffer. The doffer can then immediately grasp these empty tubes and place them on the empty ring spindles. This doffing process can be achieved very reliably and quickly. However, in this embodiment, the transport path of the cops and tubes is bound to the transport path of the respective conveyor belts.
To overcome that bound condition, it has heretofore been proposed in European patent publication EP 0 410 121 B1 to provide slideways all around the ring-spinning machine, on which, by means of a conveyor chain having drivers, caddies independent of one another (transport plates) can be displaced. These caddies can be spun out of this transport loop along with the cops or tubes placed on them. The center spacing of the caddies is equivalent to the spindle spacing. To enable carrying out the doffing operation, additional spindles are also present on the drivers. In the doffing process, the tubes first removed from the caddies have to be transferred to this intermediate position so that the arbors of the caddy will be freed for mounting the removed cops on them. Then the doffer must take over the "temporarily stored" empty tubes and mount them on the ring arbors. This doffing operation is more complicated than the one described in the above-noted German publication 20 45 263.
European published, non-prosecuted application EP 0 355 887A1 describes a spinning machine in which the intermediate position is avoided by using caddies with two arbors. These caddies are coupled to one another, resulting in one coherent train. However, that cancels out the mutual independence of the caddies. Above all, it becomes problematic to control this coherent caddy train if it is used in ring-spinning machines with more than 40 spinning stations, as in the exemplary embodiment of EP 0 355 887 A1, as for example 1000 or more. Above all, because dimensional deviations add up, by the end of the train there can be such a difference in spindle spacing that major damage can occur in the doffing process.
The same problem arises if, as in the example in Japanese patent application 64-28175, a pusher unit of caddies coupled together in pairs is formed.
The Japanese patent abstract JP 62-257429 pertains to a conveyor belt with entraining members 12 which engage in relatively large openings at the bottom of peg trays. The spindle spacing of the spinning machine corresponds to the diameter of the peg trays. Accordingly, the transport system cannot be utilized in doffing systems without intermediate storage of the empty tubes.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a transport system in a ring-spinning machine for transporting empty tubes to and cops from a row of spindles, which overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and which further develops the above-noted generic ring-spinning machine in such a way that a more-flexible transport system is created. It is moreover an object of the invention to provide an assembly which is applicable to retrofitting conventional transport systems of ring-spinning machines in which conveyors are provided with openings to which arbors for the tubes and the cops are directly attached.
With above and other objects in view there is provided, in accordance with the invention, an assembly for transporting empty tubes and cops in a ring-spinning machine having rows of spindles disposed on both sides thereof at a given spindle spacing. The assembly comprises driven conveyor belts disposed alongside the rows of spindles of the ring-spinning machine, the conveyor belts being drivable for delivering empty tubes to and removing cops from the spindles, the conveyor belts having openings formed therein at a mutual spacing approximately corresponding to half the given spindle spacing; a plurality of caddies each carrying an arbor for receiving an empty tube and an arbor for receiving a cop; each of the caddies having a length being less than the given spindle spacing; and each of the caddies having an indentation formed in a bottom surface thereof; guide tracks extending along the conveyor belts for guiding the caddies on the conveyor belts; driver members secured in at least every other one of the openings of the conveyor belts, the driver members engaging in the indentations formed in the bottom surface of each of the caddies for transporting the caddies in a form-locking manner. The openings formed in the conveyor belts are openings which receive arbors for cops and empty tubes in alternation in the original configuration. Additionally, the arbors removed from the conveyor belts may be reused in the retrofitted assembly and secured to the caddies.
The novel invention described herein makes it possible to retrofit generic ring-spinning machines with a more flexible transport system, having mutually independent caddies, at reasonable expense. The conveyor belts, on which the openings for securing the arbors are present at half the spindle spacing, can remain together with their drive in the ring-spinning machine. The only additional requirement includes guideways or guide tracks for guiding the caddies along the conveyor belts. These guides have a C-shaped cross sections whose openings face one another. The openings in the conveyor belts, which are adapted in their spacing precisely to the spindle spacing, are used to receive drivers or entraining members. As a result, without further provisions, the drivers likewise have precisely the spindle spacing relative to one another. At the maximum length of the caddies according to the invention, which is less than the spindle spacing, the respective disposition of the caddies along the spindle rows is determined solely by the spacing among the drivers. Dimensional deviations in the caddies from soiling, deformation or the like remains without any influence on adhering to the spacing. Above all, dimensional deviations are prevented from adding up.
Although it is not precluded that caddies may be provided alternatingly for cops and empty tubes, and that drivers are disposed for that purpose in all the openings of the conveyor belts, this would make the stability of such caddies extremely low. Their base plates could then, given a spacing of 70 mm, have a maximum diameter of less than 35 mm, for instance, and would thus even be less than the winding diameter of the cops. By comparison, larger caddies with both types of arbors do provide for major advantages in terms of stability.
By disposing the drivers in accordance with the spindle spacing, in combination with the fact that the caddies do not strike one another during transport, it is also possible to use one and the same caddy size for different spinning machine spacings. For instance, caddies with a length of 69 mm are usable for spinning machines with a spindle spacing of 70 and 75, without further ado. All that needs to be done is to take care so that the further indexing of the conveyor belts during the doffing operation after placement of the cops can be done only by an amount that is equivalent to the center spacing between the arbors on the caddies which deviates from the otherwise usual half spindle spacing.
In accordance with another feature of the invention, the assembly includes transverse transport paths extending between the guide tracks and joining together the guide tracks for forming a closed loop.
To enable fully exploiting the advantages of flexibility of the transport system, the transport path should be embodied completely as a closed loop. This makes it possible to exchange cops for empty tubes at a transfer region, for example a region of contact with transport paths of the bobbin winding machine. In this way, at the same time, the removal of the cops from the ring-spinning machine and resupplying it with empty tubes are attained. Compared with the method that is usual for the generic ring-spinning machines, the initially complete doffing of all the cops and subsequent delivery of the empty tubes to the same end of the machine after a reversal of the direction of motion of the conveyor belts produces a considerable time saving. The known method, particularly at small cop dimensions (higher exchange frequency), can lead to considerable time problems.
It has already been attempted, for instance in German published application DE-OS 28 15 105, to bypass this disadvantage by transporting the empty tubes across the entire ring-spinning machine to its other end, to enable delivering them simultaneously with the cop removal that takes place at the opposite end. However, this empty tube transport path extending across the spinning machine is difficult to monitor and can lead to considerable problems, because of poor accessibility, in the event of trouble such as backups, seizing and the like. Conversely, in the present invention, the accessibility of the transport paths of the cops and tubes is assured continuously.
In accordance with an added feature of the invention, the driver members each have a driver member length defined along a transport direction of the conveyor belts and the indentations formed in the caddies have an indentation length defined along the transport direction, the driver member length and the indentation length being adapted to one another so as to ascertain proper engagement of the driver members in the indentations. Preferably, the driver member length is slightly less than the indentation length.
The play between drivers and indentations in the caddies that is averted in the context of the invention means not only that the spacing accuracy is adhered to exactly, but an arbitrary transport direction of the caddies is also permitted. This further increases the flexibility of the system.
In accordance with an additional feature of the invention, the caddies comprise substantially rectangular base plates, the base plates having bores formed therein for receiving the arbors, the bores corresponding to the openings in the conveyor belts.
In accordance with a further feature of the invention, the assembly includes means disposed at one of the crosswise transport paths for exchanging cops against empty tubes, such as for instance a change-over device.
In accordance with again a further feature of the invention, the assembly further includes storage belts for cueing caddies. The storage belts, which preferably transport the caddies by slaving friction, are disposed between an end of a respective one of the conveyor belts and the transverse transport path at which the cops are exchanged for empty tubes.
In accordance with a concomitant feature of the invention, the assembly includes pusher means disposed at respective ends of the transverse transport paths for displacing the caddies onward in a transport direction by a distance corresponding to a width and to the length, respectively, depending on the required transport direction.
The expense for retrofitting a generic ring-spinning machine in accordance with the present invention can be reduced markedly still further by reusing the arbors, which were previously secured to the conveyor belts, for the caddies. All that needs to be done then is to expand the base plates of the caddies.
In order to dissolve the form-locking and thus forced driving of the caddies, as caused (at least in the region in which the exchange between cops and empty tubes takes place) by the entraining drivers, storage conveyor belts that adjoin the existing conveyor belts are provided. The storage conveyor belts transport the caddies solely by frictional engagement. As a result, their mutual spacing is no longer fixed, and the drive of the conveyor belts can take place continuously, or in other words not intermittently.
Displacement devices or change-over devices at the ends of the transverse transport paths are advantageous because the direction of caddy transport is changed by 90° without changing the orientation of the caddies.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a transport assembly in a ring-spinning machine with driven conveyor belts for delivering empty tubes and removing cops disposed along spindle rows at the spinning machine, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic top-plan view of a transport loop for the caddies in a ring-spinning machine, including an exchange region for the cops and empty tubes, to a bobbin winder machine loop;
FIG. 2 is a side view of a detail of a transport path in the region where a transition occurs from the form-locking transport of the caddies to the frictional transport in which the caddies are transported by slaving friction;
FIG. 3 is a side view of the opposite transition region, in which the caddies are taken over from the frictional transport means to the form-locking transport means, in one embodiment of the invention; and
FIG. 4 is a top-plan view corresponding to FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the figures of the drawing in detail and first, particularly, to the essentially schematic illustration of FIG. 1 and to FIG. 2, there is seen the entire transport loop of a ring-spinning machine 1 according to the invention. The various stages in the transport sequence are synchronized with one another by a central control unit 2. The conveyor belts 3 and 4 are those that were already originally present in the ring-spinning machine now retrofitted according to the invention. The spindles or arbors 11 for cops 14 and arbors 12 for empty tubes 13, which arbors were originally secured in openings 45 and 45' (FIG. 2), are now secured on caddies 10. The base plates 10' of the caddies 10 have bores 11" and 12" through which screws 11' and 12' can be passed in order to secure the arbors 11 and 12, respectively. This securing of the arbors 11 and 12 is accordingly essentially equivalent to how they were secured previously in the respective conveyor belt 3 or 4.
The bore 11" for the screw 11' of the arbor 11 is widened toward the bottom in the form of a rounded-off indentation. This widening serves the purpose of receiving entrainers or drivers 43, which are secured to the conveyor belt 3 by means of screws 44. The screws 44 are passed through the openings 45, which were used originally to secure the arbors 11 directly. The openings 45, and thus the drivers 43, are disposed at a distance from one another which corresponds to a spindle spacing S of spindle row of the ring-spinning machine The openings 45', which served originally to secure the arbors 12, are not used in this exemplary embodiment, because the guidance of the caddies is intrinsically adequately assured by one driver 45 each. However, it is not precluded by the invention that the openings 45' may also be occupied with drivers which could engage suitably embodied bores 12" for the arbors 12.
The engagement of the drivers 43 in the indentations 11" is a form-locking engagement. A form-locking connection is herein defined as one which connects two elements together due to the shape of the elements themselves, as opposed to a force-locking connection, which locks the elements together by force external to the elements. Force-locking, in this context, is also referred to as frictional engagement or friction slaving.
The arbors 11 are provided with resilient knobs 11'" for securingly holding the cops 14. For the tubes 13, which have a substantially lower weight, simple arbors 12 are considered to be adequate. However, as already noted, the embodiment of the arbors 11 and 12 is equivalent to their usual embodiment, because they can be re-used when the transport system is refitted according to the invention.
As also seen in FIG. 2, a guide track 49 provides exact guidance of the caddies 10 and in particular their base plates 10'. The guide track 49 extends along the conveyor belts 3. This guide track 49 has an essentially rectangular channel cross section, which is open at the top and on the bottom has a groove 49'. The opening 49" on the top serves to allow the passage of the arbors 11 and 12 of the caddies 10, while the groove 49' is required for the free passage of the heads of the screws 44. The cover plate of the guide track 49, interrupted by the opening or slit 49" serves essentially to prevent tilting of the caddies 10. The parts of the guide track 49 disposed on the underside on either side of the groove 49' serve as a bearing surface for the conveyor belt 3.
The conveyor belt 3 is deflected by a deflection roller 46 that is driven by a motor 15 (FIG. 1) via a drive shaft 47. Analogously to the guide track 49, the deflection roller 46 has a groove 48, which permits the free passage of the heads of the screws 44.
In the transport direction, the conveyor belt 3 is adjoined by a further conveyor belt 7, which is deflected by a deflection roller 50 that in turn is supported by a bearing axle 51. The conveyor belt 7 is continuously driven by a motor 18 (FIG. 1), while the conveyor belt 3 and the conveyor belt 4 on the opposite side of the ring-spinning machine 1 are driven discontinuously. The belt 7 may be referred to as a storage belt which cues up the caddies (10) until they are received at a platform 6'.
In the region of the conveyor belt 7, there is also a guide track 52, which with its underside supports the upper run of the conveyor belt 7 and with its top, forming a guide slit 52' for the passage of the arbors 11 and 12, prevents tilting of the caddies 10.
In FIG. 2, a tube 13 mounted on an arbor 12 is shown in dash-dotted lines between two cops. This is merely intended to demonstrate that the spacing of the arbors must be chosen such that a tube 13 can be positioned between the cops 14 without contacting them. As already described above, this is a requirement for the doffing operation, since the cops 14 are mounted by the doffer between the tubes 13 that are still located on their arbors 12. In the transport phase, which is illustrated in FIG. 2, naturally there are no longer any tubes 13 on the arbors 12.
In FIGS. 3 and 4, the transfer of the caddies 10 from a continuously transporting conveyor belt 8 onto the discontinuously transporting conveyor belt 4 is shown. The conveyor belt 4 is embodied analogously to the conveyor belt 3 and is therefore shown in simplified form. Only the drivers, here identified by reference numeral 53, can be seen. Here, a guide track 59 has a groove 59' on its underside and guide slit 59" on the top as well as cover plates for preventing tilting of the caddies 10. It should also be emphasized that the mutual spacing of the caddies is chosen to be greater than in the view of FIG. 2. Accordingly, this example, unlike the view of FIG. 2, involves a spinning machine having a larger spindle spacing. The spindle 63, spacing could be 70 mm in FIG. 2 for instance while in the example of FIGS. 3 and 4 it is 75 mm. Nevertheless, caddies 10 having the same dimensions, such as 68 mm or 69 mm, are used.
This is unproblematic with respect to the doffing operation, since the drivers 53 and the arbors 11 for the cops 14, the arbors being located with their center axis vertically above the drivers, are positioned identically. Compared with the original spacing of the arbors 12 (half the spindle spacing), this spacing here is shortened by a few millimeters. Nevertheless, this can easily be compensated for by correspondingly shortening the transport paths during the doffing operation (position of the tubes under the grippers of the doffer after the removal of the cops). This can be achieved by the drive of the motor 16 or on the opposite side of the motor 15, both of which are controlled with the central control unit 2.
The spacing among the caddies 10 on the side of their removal from the conveyor belt 3 is unproblematical, especially if the conveyor belt 7 is driven somewhat faster than the conveyor belt 3. On the opposite side, care must be taken to assure that the corresponding spacings are brought about upon transfer to the conveyor belt 4 if the caddies 10 directly abut the conveyor belt 8. To that end, stoppers 56 and 60 are provided, which are likewise triggered by the central control unit 2, via control lines 56' and 60'. The stoppers are activated once the end faces of two successive caddies 10 are positioned precisely at the level of these stoppers. In that position, it is advantageous to stop the conveyor belt 4. With the penetration of beveled rams or push rod stops 56" and 60" between the successive caddies 10, a spacing is initially created that is equivalent to the thickness of the rams. Immediately thereafter, the conveyor belt 4 is restarted, and the rams 56" and 60" are retracted, in a manner adapted to the requisite spacing among the caddies 10. This position must be chosen such that the arriving driver 53 can unproblematically penetrate into the bore 11', which is embodied as a round indentation. It should be noted that the driver 53 and the indentation have only such slight differences in dimension that unhindered penetration of the driver 53 into the indentation is assured. Any play that goes beyond that might possibly cause inaccuracies.
In addition to the fact that in the present example the penetration of the rams between the caddies is made easier by rounding of the edges thereof, it is also advantageous to round these edges off for overall purposes of manipulating the caddies. It is moreover possible to chamfer the lower edges of the caddies, so that at the transition of the caddies from one transport segment to another any steps that might be present can be unproblematically overcome. This provision is readily understood and has therefore not been specifically illustrated in the drawing.
The use of the same caddies for different spinning machine spacings provides corresponding advantages in manufacture and in spare parts warehousing, since only one, or in the case of major spacing differences at most two, different caddy sizes need to be available.
It can also be seen in FIGS. 3 and 4 that a guide track 61, which has a guide slit 61' on its top, is also disposed in the region of the continuously driven, supplying conveyor belt 8.
FIG. 1 shows a situation in which the ring-spinning machine 1 has had half its cops removed or has been half re-supplied with its empty tubes. By the intermittently driven conveyor belt 3, the caddies 10 are successively supplied to the conveyor belt 7 that is driven continuously at a somewhat higher speed. This conveyor belt 7 transports the caddies 10 as far as the platform 6' of the transverse transport path 6. The frontmost caddy 10 at a given time is pushed all the way onto this platform 6' by the pressure from behind of the following caddies. A sensor 24 detects this arrival and via a control line 24 switches a ram 23, which is operated by means of a fluid cylinder, for instance. By means of this ram 23, the caddy 10 standing on the platform 6' is displaced by one caddy spacing onto a conveyor belt of the transverse transport path 6, which is driven in the direction of the arrow by means of a motor 19. This conveyor belt feeds this caddy against a stopper 29 that stops it. The stopper 29 may be coupled with non-illustrated sensor, in order to check whether a caddy has arrived.
Disposed next to the stopper is a change-over device 33 whose gripper head 34 engages the cop 14 positioned on the caddy 10 and moves it to a caddy 62 of the bobbin winding machine loop. Change-over devices of this kind are well-known and so a more-detailed description thereof can be dispensed with for the purpose of this disclosure. The now empty caddy 10 is transported by the aforementioned conveyor belt along the transverse transport path 6 up to a further stopper 30 where it is stopped. With its gripper head 32, a change-over device 31 located at that point takes an empty tube 13 from a caddy 62 of the bobbin winding machine and places it onto the corresponding arbor 12 on the caddy 10 located at the stopper 30. The configuration and dimensioning of the change-over 31 and in particular the swivel radius of the gripper head 32 is chosen accordingly, as can be seen from FIG. 1.
On the bobbin winding machine side, the caddies 62 are delivered to the transport path 9 located parallel to the transverse transport path 6 of the ring-spinning machine loop by a conveyor belt 41, which is driven by a motor 22. A conveyor belt extending along this transport path 9 is driven continuously by a motor 20. First, the caddies 62 with empty tubes 13 are backed up by a stopper 27. The first caddy 62 at a given time at the stopper 27 is ready for removal of the empty tube 13 positioned at it, which as already noted is engaged by the gripper head 32 of the change-over device 31. The caddies 62 released by the stopper 27 are then ready for receiving a cop 14. To that end, they are stopped by a stopper 28 in a position in which the gripper head 34 of the change-over device 33 can mount a cop 14 that has been taken over from the ring-spinning machine 1. Once the cop 14 is in place, the stopper 28 releases the caddy 62, which is then delivered to a transport path 42 whose conveyor belt is driven by a motor 21 in the direction of the arrow. The transport path 42 merges with a delivery path to the bobbin winding machine.
The caddies 10 released by the stopper 30 along the crosswise transport path 6 travel until they enter the region of a ram 25, where they are stopped by a non-illustrated stop. A sensor 26 detects the arrival of the caddy 10 and transmits the information to the ram actuator 25 via an information line 26'. This pusher 25 becomes active and displaces the caddy 10 onto the conveyor belt 8, which is continuously driven by a motor 17. The conveyor belt 8 feeds the caddies 10 as far as the conveyor belt 4. The transfer of the caddies 10 to this conveyor belt 4 has already been described above.
A platform 37 is provided at the end of the conveyor belt 4 as seen in the transport direction. The caddies 10 are pushed onto the platform 37. The length of the platform 37 and the pulsed operation of the conveyor belt 4 should be adapted to one another such that one caddy 10 at a time is pushed all the way onto the platform 37 once the conveyor belt 4 is stopped again. Although intrinsically this assures secure positioning of the respective caddy 10 on the platform 37, a sensor 36 may also be provided at that point. The sensor 36 is connected to a ram 35 via an information line 36'. After the arrival of the caddy 10 in the appropriate position on the platform 37, the ram 35 is actuated and displaces this caddy 10 onto the conveyor belt of a transverse or crosswise transport path 5. This conveyor belt is driven in the direction of the arrow by a motor 38. On this crosswise transport path 5, the caddies 10 are transported until they reach a non-illustrated stop next to a ram 39. Here as well, a sensor 40 detects the arrival of a caddy 10 and reports that to the ram 39 via an information line 40'.
By means of the central control unit 2, the motor 15 and thus the intermittent drive of the conveyor belt 3 should be adapted to the activity of the ram 39 in such a way that the caddy 10 to be displaced onto the conveyor belt 3 is displaced so exactly onto this conveyor belt 3 that a driver precisely meets the indentation intended for it in the caddy 10. In the event that a new caddy 10 has not yet arrived at the ram 39, which the sensor 40 has detected, then the drive of the motor 15 must also be suppressed until a new caddy 10 arrives.
Because of the continuous drive of the conveyor belts 7 and 8 among others, the compulsory cadence of the intermittent drive in the region of the conveyor belts 3 and 4 is interrupted, so that it is unnecessary to adapt all the motions in the entire loop to one another.
As will be appreciated, the motors 15 and 16 are coupled to the central control unit 2 by control lines 15' and 16', respectively. The rams are likewise coupled to the center control unit 2, that is, ram 23 via a control line 23' ram 25 via a control line 25' ram 35 via a control line 35' and ram 39 via a control line 39'. As a result, the possibility exists of varying the transport loop and fully adapt each of the steps.
The stoppers 27 and 28 of the bobbin winding machine loop are likewise connected to the central control unit 2 via control lines 27' and 28', and the stoppers 29 and 30 are so connected via control lines 29' and 30, as are the change-over lifters 31 and 33 via control lines 31' and 33'. As a result, the activity of the stoppers at a given time for positioning the various caddies can be adapted to the activity of the change-over lifters. Instead of the connection with the central control unit, it is also possible, however, for each of the two change-over lifters to be coupled to the immediately adjacent stoppers for coordinating these stoppers.
In the event that the ring-spinning machine 1 is to be coupled with a different bobbin winding machine, in which the transport loop is in the opposite direction, the possibility also exists of changing the transport direction in the loop of the ring-spinning machine, by making only a few changes relative to the configuration shown in the drawings. The driving direction is of no particular significance because of the slight play of the drivers relative to the indentations of the caddies 10. The arrangement of displacement devices and stoppers must merely be changed, and the directions of rotation of the motors reversed. The spatial orientation of the caddies does not change anyway, and so here as well no additional provisions are necessary.
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An assembly for transporting empty tubes and cops in a ring-spinning machine. Driven conveyor belts are disposed alongside rows of spindles disposed on both sides of the ring-spinning machine. The conveyor belts are driven for delivering empty tubes to and removing cops from the spindles, and the conveyor belts have openings formed therein at a mutual spacing approximately corresponding to half the given spindle spacing for securing arbors for alternatingly supporting empty tubes and cops. Instead of the arbors, however, at least every other opening supports a driver which engages one of a plurality of caddies at an indentation formed in a support surface thereof and entrains it along the conveyor belt. Each of the caddies carry an arbor for an empty tube and for a cop. The caddies have a length which is less than the given spindle spacing. Guide tracks extend along the conveyor belts and they guide the caddies along the conveyor belts.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application No. 09/004,106, filed Jan. 7, 1998 (now U.S. Pat. No. 6,073,023), which is hereby incorporated by reference and which claims the benefit of U.S. provisional application No. 60/037,634, filed Jan. 15, 1997.
BACKGROUND OF THE INVENTION
The present invention relates generally to a communications system having pre-defined restricted user groups. More particularly, the present invention relates to a cellular telephone system wherein at least some group members within such a pre-defined group are restricted to making telephone calls to and receiving telephone calls from other group members only.
Many organizations have work forces spread out over a relatively wide geographic area. Such work forces and organizations may for example be: drivers for a hauling concern, an ambulance company, a courier company, or the like; work crew members for an electric, cable, or water utility or the like; salespersons for a sales company or the like; service technicians for a copier repair firm, computer repair firm, or the like; repair and maintenance technicians for a climate control service firm, a plumbing or electrical service firm, or the like; roving laborers for a contractor or the like; or security officers for a security firm, private security force, or the like, among others. In most if not all cases, the organizations would prefer to be in close communication with such work force workers.
Previously, such organizations could only maintain such close contact by building and operating their own private radio communications systems or by contracting with radio communications system service providers. As should be understood, such private systems are quite costly. With the advent of widely available cellular telephone service, however, many organizations have found it advantageous to provide at least some of their work force workers with cellular telephones (“cell phones”). Accordingly, workers, dispatchers, supervisors, and other appropriate personnel can conveniently and easily contact one another, as the case may be. Moreover, such organizations need not expend the costs associated with maintaining or contracting for private radio communications systems.
As should be evident, with the provided cell phone, each worker can make calls to and receive calls from work-related individuals for work-related purposes. However, each worker may also use the provided cell phone to contact non-work-related individuals for non-work-related purposes. As should be understood, such non-work-related uses may prove to be quite costly and are at any rate considered undesirable. A need exists, then, for a cellular telephone system that prevents at least some workers from using provided cell phones for non-work-related uses.
BRIEF SUMMARY OF THE INVENTION
In a preferred embodiment of the present invention, the aforementioned need is satisfied by a communications system having a pre-defined calling group with a plurality of members. In particular, in the present invention, a plurality of personal communication devices (PCDs) each have a system ID and a group ID, and each member of the group is assigned one of the PCDs. The system ID and the group ID both have a predetermined characteristic, where each system ID has a first variation with respect to the characteristic and each group ID has a second variation with respect to the characteristic. A first member of the group having a first PCD, then, attempts to contact a second member of the group having a second PCD by entering into the first PCD the group ID of the second PCD.
A communications switch allows the first PCD to access the communications system thereby. The first PCD transmits information to the communications switch, where the transmitted information includes the system ID of the first PCD and the group ID of the second PCD. A switch database is in communication with the communications switch, and includes a record for the first PCD. The record includes information that the first PCD is assigned to a member of the group. The communications switch locates the record for the first PCD based on the system ID of the first PCD, and determines based on the record for the first PCD that the first PCD is allowed to contact the second PCD by way of the group ID of the second PCD.
A group database is in switchable communication with the communications switch. The group database has the system ID and the group ID for the PCD of each member of the group. The communications switch forwards the attempted contact and the group ID of the second PCD to the group database for further processing. The group database determines that the group ID of the second PCD is located therein, locates the system ID of the second PCD based on the group ID of the second PCD, and forwards the attempted contact and the system ID of the second PCD to an appropriate communications switch for further processing.
In a preferred embodiment of the present invention, the calling group has a plurality of members including restricted members and non-restricted members. Each restricted member is restricted to contacting non-restricted members and other restricted members within the group. Each non-restricted member is able to contact restricted members, other non-restricted members, and non-group individuals. The record for the first PCD includes a first designator designating that the first PCD is assigned to a member of the group and a second designator indicating whether the first PCD is assigned to a restricted member or a non-restricted member.
If the communications switch determines based on the record for the first PCD that the first PCD is assigned to a restricted member, the communications switch allows the attempted contact to proceed if the number of the communications device has the second variation. If the communications switch determines based on the record for the first PCD that the first PCD is assigned to a non-restricted member, the communications switch allows the attempted contact to proceed if the number of the communications device has the first or the second variation. If the communications switch determines based on the record for the first PCD that the first PCD is assigned to a non-restricted member and if the number of the communications device has the first variation, the communications switch forwards the attempted contact and the number of the communications device to an appropriate communications switch for further processing. If the communications switch determines based on the record for the first PCD that the first PCD is assigned to a restricted member or a non-restricted member and if the number of the communications device has the second variation, the communications switch forwards the attempted contact and the number of the communications device to the group database for further processing.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The foregoing summary, as well as the following detailed description of a preferred embodiment of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings an embodiment which is presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:
FIG. 1 is a block diagram of a cellular telephone communications system employed in the preferred embodiment of the present invention;
FIG. 2 is a block diagram of a cellular switch shown in FIG. 1;
FIG. 3 is a block diagram of a group organized in accordance with the preferred embodiment of the present invention;
FIG. 4 is a block diagram of the cellular switches shown in FIGS. 1 and 2 and a group database in accordance with the preferred embodiment of the present invention;
FIG. 5 is a block diagram of a home location record (HLR) or a visitor location record (VLR) in a switch database associated with one of the cellular switches shown in FIGS. 1 and 2 in accordance with the preferred embodiment of the present invention; and
FIG. 6 is a block diagram of the group database shown in FIG. 4 in accordance with the preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Certain terminology may be used in the following description for convenience only and is not limiting. The words “left”, “right”, “upper”, and “lower” designate directions in the drawings to which reference is made. The words “inwardly” and “outwardly” are further directions toward and away from, respectively, the geometric center of a referenced object. The terminology includes the words above specifically mentioned, derivatives thereof, and words of similar importance.
Referring to FIG. 1, there is shown a cellular telephone communications carrier system 11 in accordance with a preferred embodiment of the present invention. In the carrier system 11 , and as should be understood, a plurality of cell phone users each have a cell phone 10 (i.e., a ‘personal communications device (PCD)), and each cell phone 10 is assigned a unique ten-digit cell phone number (three-digit area code+seven-digit number starting with a three-digit exchange) (i.e., a ‘system ID’ with a first variation of a length characteristic). The carrier system 11 is geographically divided into a plurality of regions, where each region has a cell facility or cell 12 , and each cell 12 is assigned to a cellular switch 14 .
Each cell 12 includes a cellular telephone radio transceiver for establishing two-way cellular communication with any cell phone 10 within the region of such cell 12 . Each cell 12 also includes additional communication facilities for maintaining communications with one of the cellular switches 14 . Such communications with the cellular switch 14 may be by land line, RF, microwave, or any other appropriate communications medium. Typically, a plurality of the cells 12 are assigned to one cellular switch 14 .
Referring now to FIG. 2, each cellular switch 14 typically includes or is in communication with a switch database 16 , and the switch database 16 includes a home location register (HLR) 18 for each of a plurality of cell phones 10 . For any one cell phone 10 in the carrier system 11 , only one cellular switch 14 in the carrier system 11 has a corresponding HLR 18 . Accordingly, the cellular switch 14 with the HLR 18 for the cell phone 10 is the ‘home’ switch for that cell phone 10 , and each cell phone 10 has only one home switch 14 . The home switch 14 of the cell phone 10 is the cellular switch 14 that is contacted to determine which cellular switch 14 the cell phone 10 is registered at.
When a cell phone user first turns on his or her cell phone 10 , the cell phone 10 registers with one of the cells 12 . Typically, such cell 12 is the cell for the region in which the cell phone 10 is physically located, or the cell for an adjacent region if circumstances so require. As part of such registration, the cell 12 checks with its assigned cellular switch 14 to determine if the switch database 16 of such cellular switch 14 has an HLR 18 for the cell phone 10 . If so, and as discussed above, such cellular switch 14 is the home switch for the cell phone 10 .
If no HLR 18 for the cell phone 10 is present in the switch database 16 , the cell phone 10 is a ‘visitor’ to such ‘visited’ cellular switch 14 , and a visitor location register (VLR) 20 is created for the cell phone 10 in the switch database 16 of the visited switch 14 . Preferably, the visited switch 14 communicates with the home switch 14 for the visiting cell phone 10 , the HLR 18 for the visiting cell phone 10 is substantially copied from the switch database 16 of the home switch 14 , the VLR 20 for the visiting cell phone 10 is formed in the switch database 16 of the visited switch 14 substantially based on the copied HLR 18 , and the HLR 18 for the visiting cell phone 10 in the switch database 16 of the home switch 14 is updated to reflect that the cell phone 10 is registered at the visited switch 14 .
Once registered with a cell 12 and a cellular switch 14 , a telephone call (i.e., an attempted contact) is normally made by sending a ten-digit destination phone number from the cell phone 10 (in addition to other information) to the communications switch 14 by way of the cell 12 . This assumes the call is to a U.S. or similar destination. Of course, if the call is to a non-U.S. or similar destination, the destination phone number will likely have more than ten digits. Nevertheless, the term ‘ten-digit call’ and the like will be used below for convenience only.
Typically, and absent any other restrictions, the ten-digit call is passed from the cellular switch 14 and through a number of other switches (not shown) until a connection is made and the call is completed between the cell phone 10 and the destination telephone corresponding to the destination telephone number, be it another cell phone 10 or a land line phone. For example, if the destination telephone number is a land line number local to the cellular switch 14 , the cellular switch 14 may contact a local telephone company switch to complete the call. Correspondingly, if the destination number is a long-distance land line number, the cellular switch 14 may connect with a long-distance telephone company switch to complete the call. Of course, the cellular switch 14 need not contact any other switches if the destination telephone number is for a cell phone 10 that is home to the cellular switch 14 . Typically, and as seen in FIG. 2, each cellular switch 14 (as well as every other non-cellular switch) has a number of input ports 26 and output ports 28 through which connections with other switches are achieved, and trunk lines (not shown) interconnect the communications switches by way of the input ports and output ports 26 , 28 .
When a call is made from the outside world to one of the cell phones 10 in the carrier system 11 , the call upon reaching the carrier system 11 is initially switched to the home switch 14 for the cell phone 10 . If the HLR 18 for the cell phone 10 indicates that the cell phone 10 is ‘at home’, the home switch 14 completes the call by way of an appropriate cell 12 . Otherwise, if the HLR 18 for the cell phone 10 indicates that a VLR 20 has been created for the cell phone 10 at a visited switch 14 , the home switch 14 forwards the call to the visited switch 14 for further processing and completion.
In the preferred embodiment of the present invention, and referring now to FIG. 3, at least one group 22 is formed with regard to a particular organization, where each member of the group is designated as a basic member having a basic member cell phone 10 b or an enhanced member having an enhanced member cell phone 10 e . Additionally, the group 22 may include one or more dispatcher members, where each dispatcher member can access any other member 10 b , 10 e within the group by way of a dispatcher land line phone 24 .
Preferably, each member 10 b , 10 e , 24 of the group 22 has a pre-defined shortened number (i.e., a ‘group ID’ with a second variation of a length characteristic) that is used by others in the group 22 to make contact therewith. Preferably, the shortened number is a four-digit number, although one skilled in the art will recognize that other variations of number length may be employed without departing from the spirit and scope of the present invention.
Moreover, one skilled in the art will recognize that variations of other characteristics besides length may be used to differentiate system IDs from group IDs without departing from the spirit and scope of the present invention. For example, group IDs may be defined as all IDs having a pre-defined beginning or end portion, or as all IDs having a ‘*’ or ‘#’ as a digit, among other things. Nevertheless, the terms ‘four-digit number’, ‘ten-digit number’, and the like will be used below for convenience only.
Preferably, each basic member 10 b may only make a call to a pre-defined four-digit number, and may only receive a call from an authorized inbound group member 10 b , 10 e , 24 . Also preferably, each enhanced member 10 e may make and receive four-digit (i.e., group) and ten-digit (i.e., non-group) calls. As should be understood, a basic member having a basic member cell phone 10 b would typically be a worker who need only be able to communicate with other group members 10 b , 10 e , 24 . Correspondingly, an enhanced member having an enhanced member cell phone 10 e would typically be a worker who needs access to other group members 10 b , 10 e , 24 , and also to the outside world, or should otherwise be allowed to have such access. Presumably, the enhanced member 10 e can be trusted to not misuse his or her cell phone 10 .
Referring now to FIG. 4, there is shown an example that will be useful in describing the preferred embodiment of the present invention. As seen, a first basic member BM 1 is registered to a first cellular switch SW 1 , a second basic member BM 2 is registered to a second cellular switch SW 2 , and a dispatcher member DISP 1 is at a land line phone available by way of a land line switch LL-SW. As also seen, the first cellular switch SW 1 is the home switch for both the first basic member BM 1 and the second basic member BM 2 , as shown by the HLR for BM 1 and the HLR for BM 2 in the switch database DB 1 associated with the first cellular switch SW 1 , and the second cellular switch SW 1 is the visited switch for the second basic member BM 2 , as shown by the VLR for BM 2 in the switch database DB 2 associated with the first cellular switch SW 2 .
One skilled in the art will appreciate that no cells 12 are shown in or discussed in connection with FIG. 4 since such cells 12 are not necessary for purposes of describing the preferred embodiment of the present invention. However, such cells 12 are still necessary in the carrier system 11 . One skilled in the art will also appreciate that although direct connections are shown between the first and second cellular switches SW 1 , SW 2 and between other switches in FIG. 4, such connections may in fact be indirect by way of other switches (not shown) without departing from the spirit and scope of the present invention.
With reference to the example shown in FIG. 4, then, a group telephone call from BM 1 to BM 2 is completed as follows. Preliminarily, BM 1 enters the pre-defined four-digit number for BM 2 into his or her cell phone 10 , and then enters ‘send’ or the equivalent to initiate the group call. Thereafter, the cell phone 10 sends to SW 1 the four-digit number for BM 2 and the ten-digit number for BM 1 .
Based on the ten-digit number for BM 1 , SW 1 locates the HLR 18 for BM 1 in DB 1 . SW 1 then checks such HLR to determine the kind of access that BM 1 is permitted. Preferably, and referring now to FIG. 5, each HLR 18 or VLR 20 in any database 16 for any cellular switch 14 includes a primary dialing class (PDC) designator (“first designator”), and a secondary dialing class (SDC) designator (“second designator”). Additionally, the HLR 18 includes an immediate call forwarding (ICF) designator, a visited switch designator, and a home system only designator. Further, the HLR 18 or VLR 20 for any group member 10 b , 10 c preferably includes the ten-digit number for the group member 10 b , 10 e , among other information (not shown). Of course, one skilled in the art will realize that the elements included in the HLR 18 or VLR 20 may vary without departing from the spirit and scope of the present invention so long as the HLR 18 or VLR 20 provides the information necessary for the operability of the present invention, as described below.
The PDC for the HLR 18 or VLR 20 for any group member 10 b , 10 e is set to indicate that the group member 10 b , 10 e is indeed a member of a group 22 . The SDC for the HLR 18 or VLR 20 for any group member 10 b , 10 e is set to indicate whether a group member is a basic member 10 b or an enhanced member 10 e . When the SDC is set to indicate that a group member is a basic member 10 b , calls made from the basic member 10 b are forwarded to a group database 30 (shown in FIG. 4) for further processing. The ICF for the HLR 18 for any basic member 10 b is set to indicate that calls made to the basic member 10 b are to be forwarded to the group database 30 for further call processing. The visited switch designator for the HLR 18 for any group member 10 b , 10 e indicates whether a VLR 20 exists at a visited cellular switch 14 , and which cellular switch 14 . The home system only designator for the HLR 18 for any group member 10 b , 10 e indicates whether the group member 10 b , 10 e can visit at cellular switches 14 at other carrier systems 11 . Preferably, the home system only designator for each basic member 10 b is set to prevent a VLR 20 from being created for the member 10 b outside the carrier system 11 . Accordingly, a basic member 10 b is prevented from using the cell phone 10 outside the carrier system 11 . As should be understood, by referring to the HLR 18 or VLR 20 for any group member 10 b , 10 e , a cellular switch 14 determines how to handle any call involving such group member 10 b , 10 e.
Since the HLR for BM 1 by definition includes an SDC designator that indicates that BM 1 is a basic group member 10 b , the communications switch SW 1 only allows BM 1 to make four-digit (group) calls. That is, if BM 1 were to attempt to make a ten-digit (non-group) call, SW 1 would prevent the call from being further processed and completed.
Additionally, since the HLR for BM 1 by definition includes the PDC designator set to indicate that BM 1 is a member of a group 10 b and since the call is a four-digit call, the communications switch SW 1 forwards the BM 1 to BM 2 four-digit (group) call to the group database 30 for further call processing. Preferably, the group database 30 is associated with a group switch 32 such that the group switch 32 facilitates call switching for the group database 30 . Preferably, as part of forwarding the group call from SW 1 , the group database 30 receives the ten-digit number of BM 1 plus the four-digit number of BM 2 .
Preferably, and referring now to FIG. 6, the group database 30 includes a partition 34 for each group 22 in the cellular telephone system, and each partition 34 includes information on each group member 10 b , 10 e , 24 in the respective group 22 . As seen in FIG. 6, partitions 34 exist for groups A and B, and BM 1 , BM 2 , and DISP 1 are all in group A. Preferably, and as seen, the group database 30 has the ten-digit number and the four-digit number for each group member 10 b , 10 e , 24 in each group 22 . Accordingly, from the received ten-digit number of BM 1 , the group database 30 can determine that BM 1 is in group A, and from the four-digit number of BM 2 , the group database can locate the ten-digit number of BM 2 within group A.
Since the group database 30 can determine that BM 1 is in group A, the group database preferably only allows BM 1 to make four-digit (group) calls to other group members 10 b , 10 e , 24 in group A. That is, if BM 1 were to attempt to make a four-digit (group) call to a group member 10 b , 10 e , 24 in group B or any other group, the group database 30 preferably would prevent the call from being further processed and completed.
Based on the located ten-digit number for BM 2 , the group switch 32 associated with the group database 30 forwards the call to the home switch for BM 2 for further processing in accordance with the ten-digit number for BM 2 . This is necessary since the home switch for BM 2 (SW 1 in this example) maintains the HLR 18 which includes the visited switch designator that indicates whether BM 2 is registered at its home cellular switch 14 or is visiting another cellular switch 14 .
Preferably, and as seen in FIG. 6, each cellular switch 14 is home to a number of cell phone exchanges, and the group database 30 includes an exchange-switch table 36 that lists a home cellular switch 14 for each area code and exchange in the group database 30 . Accordingly, based on the area code and exchange in the ten-digit number for BM 2 , the group database 30 can determine that the home switch for BM 2 is SW 1 . Preferably, when the group call for BM 2 is forwarded to SW 1 , appropriate call information is also forwarded to SW 1 , including the ten-digit number for BM 2 .
Based on the ten-digit number for BM 2 , switch SW 1 looks at the HLR 18 for BM 2 in DB 1 . Since BM 2 is a basic member 10 b of the group 22 , the HLR 18 for BM 2 by definition has the ICF designator set to forward all calls to BM 2 to the group database 30 for further processing. Accordingly, the forwarded call from the group database 30 would normally be switched by SW 1 back to the group database 30 . As should be understood, this is undesirable since the call to BM 2 has already been processed by the group database 30 . Accordingly, in the preferred embodiment of the present invention, once the group database 30 processes and forwards a call to a basic member 10 b , the group switch 32 must notify the receiving cellular switch 14 (SW 1 in this example) to suspend immediate call forwarding for this call only.
Referring again to FIG. 4 and the four-digit (group) call from BM 1 to BM 2 , since the HLR for BM 2 indicates that BM 2 is visiting SW 2 , switch SW 1 forwards the call to SW 2 for further completion. Once SW 2 receives the call, the call is completed in the normal fashion.
If BM 2 makes a four-digit (group) call to BM 1 , the call will be handled in the same manner as stated above. However, in such a situation, SW 2 must refer to the VLR for BM 2 to determine the PDC and SDC designators for BM 2 .
If in the above scenario BM 1 were instead an enhanced member EM 1 (not shown), a four-digit (group) call from EM 1 to BM 2 would cause SW 1 to forward the call to the group database 30 for completion in the same manner as stated above. Likewise, if BM 2 were instead an enhanced member EM 2 (also not shown), a fourdigit (group) call from BM 1 to EM 2 would cause SW 1 to forward the call to the group database 30 for completion in the same manner as stated above. However, it should be noted that the ICF designator is not set for an enhanced member 10 e and that immediate call forwarding therefore need not be suspended at any time. If EM 1 calls a ten-digit (non-group) number or receives a call from a ten-digit (non-group) number, SW 1 would preferably recognize from the HLR. 18 for EM 1 that EM 1 is an enhanced member 10 e , would not block the call, and would not forward the call to the group database 30 . In such an instance, SW 1 would preferably complete the call as if EM 1 were not in a group 22 .
However, if anyone, group or non-group, employs a communications device to call basic member BM 2 by way of the ten-digit number for BM 2 , the call would be routed to SW 1 , the home switch for BM 2 ; SW 1 would determine that the HLR for BM 2 has the ICF designator set; and SW 1 would therefore forward the call to the group database 30 for further processing. Preferably, the group database 30 would complete the call in the manner set forth above only if an appropriate security code were entered or if the caller's ten-digit number were recognized as a number of a group member. As should be evident, if the group database 30 can recognize a caller's ten-digit number, a security code need not be required.
Accordingly, a dispatcher member 24 or the like with the security code and/or a recognized ten-digit number would be able to access any basic member 10 b of the group 22 , but an inappropriate third party without the security code would not be able to access the any such basic member 10 b of the group 22 . Preferably, any dispatcher can call a group member either directly by dialing the ten-digit number for the group member and then a security code, or by dialing a telephone access number and the four-digit number for the group member.
In a situation where BM 1 makes a four-digit call to dispatcher member DISP 1 , the call is forwarded to the group database 30 in the manner explained above. Thereafter, the group database 30 preferably forwards the call to the land line telephone number for DISP 1 by way of the group switch 32 and land line switch LL-SW. As should be understood, since DISP 1 is not a cell phone 10 and is not registered with a cellular switch 14 , no incoming call forwarding suspension is required.
In the preferred embodiment of the present invention, each cellular switch 14 in a carrier system 11 must be able to recognize that four-digit calls are handled differently than ten-digit calls. Moreover, since multiple carrier systems 11 may have common four-digit numbers for different cell phones 10 , it is preferable that each cell phone 10 be assigned to a ‘home’ carrier system 11 , and that four-digit calls from a cell phone 10 be prevented from being completed through cellular switches 14 not associated with the home carrier system 11 of the cell phone 10 . Also preferably, and as stated above, by setting the home system only designator in the HLR 18 for each basic member 10 b , such basic member 10 b is prevented from visiting a cellular switch outside the ‘footprint’ of the carrier system 11 and obtaining service. However, one skilled in the art will recognize that allowing a basic member 10 b to visit a cellular switch outside the ‘footprint’ of the carrier system 11 may be desirable under certain circumstances, and that such an action is therefore within the spirit and scope of the present invention.
As should be understood, since the code assigned to each group member 10 b , 10 e , 24 is preferably four digits, a maximum of ten thousand group members spread across multiple groups 22 are allowed per carrier system 11 . Of course, one skilled in the art will recognize that if the code is five digits, one hundred thousand group members in the carrier system 11 are allowed, that if the code is three digits, one thousand group members in the carrier system 11 are allowed, etc.
In a preferred embodiment of the present invention, each cellular switch 14 is preferably a Lucent Technologies 5 E switch, the group database 30 is an ORYX database designed by Priority Call Management of Wilmington, Massachusetts, and the group switch 32 is an Excel LNX switch from Excel Inc. of Hyannis, Mass. As one skilled in the art will recognize, however, other switches and databases may be employed without departing from the spirit and scope of the present invention.
From the foregoing description, it can be seen that the present invention comprises a new and useful cellular telephone system with pre-defined restricted groups. It will be appreciated by one skilled in the art that changes can be made to the embodiment described above without departing from the broad inventive concepts thereof. For example, in addition to a cellular telephone system, the present invention may also be deployed in other switched communications systems, including wireless systems such as PCS and SMR and wired systems such as the classic land line telephone system. As should be understood, deploying the present invention in such other systems would require minor variations that would be evident to one skilled in the art. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed but is intended to cover modifications within the spirit and scope of the present invention.
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A communications system having a pre-defined calling group with a plurality of members is disclosed. A plurality of personal communication devices (PCDs) each have a system ID and a group ID, and each member of the group is assigned one of the PCDs. The system ID and the group ID both have a predetermined characteristic, where each system ID has a first variation thereof and each group ID has a second variation. A first group member having a first PCD contacts a second member having a second PCD by entering into the first PCD the second PCD group ID. The first PCD transmits the first PCD system ID and the second PCD group ID to a communications switch. Based on the first PCD system ID, the communications switch locates a record for the first PCD in a switch database and determines therefrom that the first PCD can contact the second PCD by way of the second PCD group ID. A group database in switchable communication with the communications switch has the system ID and group ID for each group member PCD. The communications switch forwards the contact and the second PCD group ID to the group database for further processing. The group database determines that the second PCD group ID is located therein, locates the second PCD system ID based on the second PCD group ID, and forwards the attempted contact and the second PCD system ID to an appropriate communications switch for further processing.
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CROSS-REFERENCE TO RELATED APPLICATION(S)
This application is a continuation-in-part of U.S. patent application Ser. No. 10/871,554, filed Jun. 17, 2004 now abandoned, which claims the benefit of U.S. Provisional Application No. 60/479,549, filed Jun. 18, 2003, both of which disclosures are incorporated herein by this reference.
BACKGROUND AND SUMMARY OF THE INVENTION
The invention relates to welding backup systems for heat-sink or purge purposes as for application to welding construction of pipelines or tanks and the like.
A number of additional features and objects will be apparent in connection with the following discussion of the preferred embodiments and examples with reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
There are shown in the drawings certain exemplary embodiments of the invention as presently preferred. It should be understood that the invention is not limited to the embodiments disclosed as examples, and is capable of variation within the scope of the skills of a person having ordinary skill in the art to which the invention pertains. In the drawings,
FIG. 1 is a perspective view of a tank in accordance with the prior art;
FIG. 2 is a perspective view of a given tile unit in accordance with the invention for chaining together indefinitely with other like tile units, a few dissimilar units aside, and producing an internal ring assembly in accordance with the invention for welding backup;
FIG. 3 is an enlarged scale section view taken along line III-III in FIG. 1 , showing an example operative use environment for such an internal ring assembly in accordance with the invention for welding backup, as for example and without limitation utilization in connection with butt welds of hoop sections;
FIG. 4 is an enlarged scale view of DETAIL IV-IV in FIG. 3 ;
FIG. 5 is a perspective view comparable to FIG. 2 except showing not only given tile units as better shown by FIG. 2 but also at least one embodiment of dissimilar tile units in accordance with the invention;
FIG. 6 is an enlarged scale section view taken along line IV-IV in FIG. 3 ;
FIG. 7 is an enlarged scale perspective view, partly broken away, of the jamming or wedging tile unit in accordance with the invention and as previously shown in FIGS. 3 and 4 ;
FIG. 8 is an elevational view of an active length of tile units in accordance with the invention for constructing an alternate embodiment of an internal ring backup assembly in accordance with the invention, wherein some portions are broken away to foreshorten the section and others are removed from view;
FIG. 9 is a top plan view thereof;
FIG. 10 is an elevational view of an alternative embodiment of an actuator for the FIGS. 8 and 9 embodiment, and which actuator provides a user with a mechanical advantage for foreshortening the active length of tiles therein;
FIG. 11 is a perspective view of a further embodiment of linked together tiles in accordance with the invention;
FIG. 12 is an elevational view of the embodiment of FIG. 11 ;
FIG. 13 is a reduced scale top plan view, the tank wall being shown in section, showing an example operative use environment for the linked together tile units in accordance with the embodiment of FIGS. 11 and 12 in combination with an active length of tile units comparable to the embodiment of FIGS. 8 and 9 , partly broken away;
FIG. 14 is an enlarged scale top plan view comparable to FIG. 13 except showing a further embodiment of an actuator in accordance with invention for foreshortening the active length of tile units;
FIG. 15 is an enlarged scale section view taken along line XV-XV in FIG. 1 , except including illustration of an additional embodiment in accordance with the invention for welding backup, as more particularly for the weldment joining a nozzle to the domed cap of the tank;
FIG. 16 is an enlarged scale perspective view of the annulus backup plate in FIG. 15 ;
FIG. 17 is an enlarged scale section view showing another embodiment in accordance with the invention for welding backup, as more particularly showing a purge arrangement for creases;
FIG. 18 is an enlarged scaled elevational view of the ventilated tube and its sheath in FIG. 17 ;
FIG. 19 is a perspective view of the spaced end portions of a belt for pipe welding backup in accordance with the invention, wherein middle portions are broken away to foreshorten the illustration;
FIG. 20 is a reduced scale perspective view showing one end of the belt of FIG. 19 lapped externally over the outboard course of a hoop seam for the tank of FIG. 1 ; and
FIG. 21 is an enlarged scale sectional view of the tank, with portions broken away, including illustration of portions of the belt FIGS. 19 and 20 , as well as a clamp and come-along device in accordance with the invention for cinching tight and clamping the belt in a use position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a tank T in accordance with the prior art. Briefly, the tank T has a domed top-end or cap E outfitted with various access fixtures or nozzles N. This type of tank is conventional in process industries for the production of pharmaceutical products, whether that be end-products or, more typically, intermediate products. The prior art prefers such tanks to be welded up out of stainless steel components. The prior art also prefers stainless steel weldments to be backed up by heat sinks as well as purged of oxidizing gases to the extent practical. The longstanding problem has been, naturally, to what extent is practical under the circumstances.
FIG. 2 shows a given tile unit 20 in accordance with the invention for chaining together indefinitely with other like tile units, a few dissimilar units aside. As more particularly shown by FIG. 3 , a chain of like tile units 20 allows production of an internal ring assembly 10 in accordance with the invention for welding backup. In FIG. 2 , the given tile unit 20 comprises a tile 21 mated to a discrete cell of a roller chain, including pins 22 , bushings 23 , rollers 24 , roller-link plates 25 , and pin-link plates 26 . FIG. 6 better shows that between either the roller-link plates 25 or the pin-link plates 26 , preferably at least one of such plate pairs 25 or 26 are fixed to a mounting fixture (eg., base plate) 27 for fastening tight to the tile 21 .
FIG. 3 shows an example operative use environment for such the internal ring assembly 10 in accordance with the invention. For example and without limitation, the tank T might have a six foot (˜1.8 m) outside diameter, and even if the top end cap E is welded in place, it will include a manhole for worker access in and out of the tank. In use, a worker constructs a chain assembly 10 of the target inside circumference for a match as close as possible. Then the worker temporarily hangs the chain assembly 10 on the inside wall of the tank T at a seam for butt welding. One way to do this is by progressively working around in a circle and taping the chain assembly 10 to the tank T's wall at angularly spaced locations by vertically-arranged strips of aluminum tape or the like. The aluminum tape just provides temporary holding power. Regardless if it takes one, two or more workers to hang the chain assembly 10 , this step of the workflow is readily aided by the tape (whether it be simply duct tape) temporarily holding the chain assembly 10 at its elevation in the tank T on the seam.
FIG. 4 shows better what is encircled by detail IV-IV in FIG. 3 . Plural (eg., three in this view) tile units (eg., 30 , 40 , 50 ) differ from the given tile units 20 as follows, wherein preferably the given tile units 20 proceed uninterrupted by any other dissimilar tile units until meeting at the opposite ends of the circle (or hoop of whatever geometry). The lever unit 30 has a handle-lever 32 for causing a jamming or wedging action among tile units 30 , 40 , 50 in order to apply an expansion force on the chain assembly 10 as a whole comprising substantially a chain of the given tile units 20 . As shown better by FIG. 7 , the lever tile unit 30 has its lever pivoting on chosen pin 22 , the lever has a tool end forming dual forks 34 for engaging the pin ends of succeeding tile unit 40 as well as has a concave, spring-biased pressure applicator 36 for engaging the rounded lobes of the dual roller-link plates 25 of succeeding tile unit 40 .
Returning to FIG. 4 , tile unit 40 proceeds to terminate in dual forks 44 for engaging the pin ends 22 of mosaic link plates 46 , which in turn proceed to terminate in forks 48 for engaging the pin ends 22 of the next successive tile plate 50 , which has like mosaic link plates 56 having fork ends 58 for engaging the pin ends 22 of the first-in-line given tile unit 20 . Mosaic link plates 46 and 56 are characterized as having roller-gripping origins and flaring out to (or otherwise changing into) pin-gripping terminations. As can be reckoned by FIGS. 3 and 4 , operating the lever 32 counterclockwise causes the tiles of tile units 30 , 40 and perhaps 50 to lift away from flush contact with the wall of the tank T, and thereby release or break the application of an expansion force. In FIG. 3 , the lever 32 is depicted by solid lines to show the lock or jamming position, and is depicted in dashed lines to show the release or break position. In reverse, operation of the lever 32 to the jamming or wedging position shown by FIG. 4 achieves the requisite jamming or wedging force on the chain assembly 10 as a whole to expand it snugly in good thermal contact with the wall of the tank T.
FIG. 5 shows not only given tile units 20 as better shown by FIG. 2 but also at least one embodiment of dissimilar tile units 60 in accordance with the invention. These dissimilar tile units 60 have smaller tile-footprints than other tile units in order to allow assembly of a chain 10 made of fractionally smaller units. This provides modularity when it comes to building a chain 10 of a selected length. Adding or subtracting the small tiles 60 provides finer granularity in achieving the desired length nearly exactly. Put differently, this allows allow formation of a chain hoop 10 of fairly precise measure. The chain hoop 10 's final measure is not limited to integer multipliers of the standard tile footprint of tile units 20 . These tile units 20 might measure four to six inches (˜10 to 15 cm) in span. In contrast, the dissimilar tile units 60 are about half the size of the other tile units (eg., two to three inches, or ˜5 to 7½ cm, in span). The dissimilar tile units 60 also feature mosaic-style link plates 66 having fork ends 68 as described more particularly above.
To return back briefly to FIG. 3 , among other things, it shows the internal ring 10 expansively forced tight against the tank T's inside wall. Moreover, FIG. 3 shows that adjacent tiles 21 are scalloped alternately concave and convex to abut one another more compactly. This provides several advantages. The tiles 21 adapt better to use on tanks having a wide range of inside diameters. That way, an internal ring 10 can be formed of larger or smaller overall diameters with the tiles 21 still compactly mating each other because each relatively pivots at its edges relative its neighbors. Also, the mating concave-convex edges narrow the gap between adjacent tiles 21 , which provide better thermal coverage over the whole circumference of the seam.
FIGS. 8 and 9 show an alternative strategy for achieving the application of the jamming or wedging force preferred for the invention. That is, FIGS. 8 and 9 show an “active” length 70 of tile units in accordance with the invention for constructing an alternate embodiment of an internal ring backup assembly in accordance with the invention (compare, eg., internal ring backup assembly 270 in FIG. 13 ). To turn briefly to FIG. 13 , it shows an internal ring backup assembly 270 comprised of an active length 70 and, in contrast, a “passive” length 200 . The “passive” length 200 forms the greater fraction of the overall length of the internal ring 270 's circumference. In contrast, the “active” length 70 forms only a minor fraction thereof. The “active” length 70 functions like a coil compression spring, which acts against the two ends of the “passive” length 200 . The “passive” length 200 , as is true with chains of tile units 20 , has practically no compressibility. Hence whatever compressive force is applied to the ring 270 as a whole by the “active” length 70 is of course carried and held by the “passive” length 200 as well.
To turn back to FIGS. 8 and 9 , the active length 70 is serviced by an optional embodiment of a jamming or wedging force applicator 72 in accordance with the invention. The active length 70 is produced from a series of tile units 74 the bottom out in tiles 71 . Tiles 71 , as well as tiles 21 , are preferably produced of a high conductivity metal, such as copper, and more preferably of high-conductivity oxygen-free copper. The remainder of the construction materials may comprise any various materials including steel, aluminum, stainless steel, spring steel (ie., for springs), steel cable and so on.
In the active length 70 , the tiles 71 are held together by a tether. In FIGS. 8 and 9 , one embodiment of a tether includes for example and without limitation a looped steel cable 75 . The cable 75 passes relatively freely through apertured mounting blocks 76 , and adjacent tile units 74 are biased apart by compression springs 77 . A T-headed actuator 78 operates to allow a worker to manually acuate the actuator 72 (which is in the “up” direction in FIG. 8 ) to shorten the length of the active length 70 . That way, a worker can insert the foreshortened active length 70 between the ends of a passive length (eg., 200 in FIG. 13 ). Once inserted, the worker can relax his or her squeeze on the actuator 72 and thereby obtain an expansion force on the chain assembly 270 as whole. The expansion force naturally forces the tiles 71 and 220 against an inside wall of a hoop section (see FIG. 13 ).
FIG. 10 shows an alternative embodiment of an actuator 172 for the FIGS. 8 and 9 embodiment of an active length 70 of tile units. This actuator 172 provides a user with a mechanical advantage for foreshortening the active length 70 . The actuator 172 comprises a standard 174 , a trigger-actuated traveler 176 , and a pair of pull rods 178 (near side only in view) secured to the traveler 176 and flanking the standard 174 . Each pull rod 178 terminates in a lugged-end formed with lugs over which the centers of the cables 75 are looped. A user operates this actuator 172 as follows. Squeezing the trigger of the trigger-actuated traveler 176 causes a mechanism (not shown) inside the traveler 176 comprising a ratchet and drive gear (again, not shown) to drive the traveler 176 up the standard 174 (eg., “up” given the orientation of FIG. 10 ). The effect this has on the pull rods 178 is to exert a pulling force on the cables 75 , causing the cable centers to pull out as indicated by direction arrow 180 , which in consequence foreshortens the active length 70 .
The traveler 176 's internal ratchet mechanism locks the travel of the traveler 176 on the standard 174 after each squeeze of the trigger. The user can therefore squeeze the trigger several times in a row and successively tighten the foreshortening of the active length 70 until all the slack is squeezed out between adjacent tiles 71 . Since the ratchet locks the foreshortening of the active length 70 after each squeeze of the trigger of actuator 172 , the active length 70 remains compressed in its compact-most state until the ratchet is let off. That way, a user can leisurely squeeze down the active length 70 in one place and then carry it over to another place where it inserts between the ends of a passive length 200 . The worker can therefore do the following. The worker might squeeze out the slack in the active length 70 by doing so with the tiles 71 laying flat on the floor. Then, with the active length 70 locked down by the traveler 174 , the user lifts the active length 70 up off the floor and places it in its use position against the tank T's wall. The locked down active length 70 is released from being locked down by the ratchet, and spread apart, by the user releasing the traveler 176 on the standard 174 as including by a release button 182 .
FIGS. 11 and 12 show better the “passive” length 200 of linked together tiles 220 in accordance with the invention. The passive length 200 comprises tiles 220 linked together by a flexible band 250 of woven copper filaments. The band 250 is indeed flexible but little else. It affords only minimal stretch or foreshortening, and is considered not resilient for application of a compressive force. The band 250 fairly much has a fixed length, plus or minus a small fractional percentage of stretch or compaction due to the weave. Each tile 220 is shown allowing up to four (4) rivet connections 228 to the overlying flexible band 250 . The overall length 200 of tiles 220 linked together this way is termed a “passive” length for convenience sake in this description, but also in recognition that, in contrast to an “active” length 70 , each tile 220 is situated fairly tightly-abutted next to its neighbors. Consequently, passive lengths 200 do not contribute to the jamming or wedging action as does a compressively-biased active length 70 . Additionally, the “overall length” of a passive length 200 might be produced as an assembly of sub-assemblies, each sub-assembly comprising a dozen or dozens of discrete tiles 220 or so.
FIG. 13 shows the passive length 200 deployed in combination with the active length 70 in order to obtain internal ring assembly 270 for welding backup. The passive length 200 forms the greater fraction of the overall length of the internal ring assembly 270 's circumference. In contrast, the active length 70 is only a minor fraction thereof. During set-up, a worker would tape up the passive length 200 in place separately. What that accomplishes is the passive length 200 being temporarily stabilized in place over the seam except for a gap of twelve to twenty inches or so (˜30 to 50 cm). The gap is naturally defined between the opposite ends of the passive length 200 . It is this gap which is to be filled by the active length 70 .
The factors which determine the selected “length” of the active length 70 includes the following. One factor is the linear measure of the active length 70 in its relaxed state, ie., whether it measures considerably longer than the gap it has to fill. Another factor is contrasting factor. That is, the linear measure of the active length 70 in its compact-most state because of course it has to insert within the gap. That way, when the compression is released, the active length 70 spreads apart and forcibly provides the wedging or jamming action for the overall internal ring 270 . When this is done, all the tiles 71 and 220 alike are forced into good thermal contact with the tank T's inside wall.
FIG. 14 shows a further embodiment of an actuator 272 in accordance with invention for foreshortening an active length 70 of tile units 71 . This actuator 272 comprises a bar 274 carrying a stationary bracket 275 on one end. The stationary bracket 275 has a pair of hooks 278 for hooking on the lugs of an end mounting block 76 . The bar 274 further carries a trigger-actuated traveler 276 which also has a pair of hooks 278 for hooking on the lugs of the opposite end's mounting block 76 .
A user operates this actuator 272 as follows. Squeezing the trigger of the trigger-actuated traveler 276 causes a mechanism (not shown) inside the traveler 276 comprising a ratchet and drive gear (not shown) to drive the traveler 276 inwards on the bar 274 (eg., “left” given the orientation of FIG. 10 ). The effect this has on active length 70 is to foreshorten it. As described more particularly above, the user can shorten the active length 70 in a series of squeezes because of the locking action of the ratchet, and do so on the floor until ready to place in the gap. Once inserted in the gap, the foreshortened active length 70 is allowed to spread apart again by the user releasing the traveler 276 on the bar 274 as including by the release button 282 .
FIG. 15 shows a welding backup arrangement 80 in accordance with the invention for the weldment that joins a nozzle N to the domed cap E of the tank T. This welding backup arrangement 80 comprises an annulus backup plate 82 , a stemmed lid 84 that includes a stem portion 86 , an actuator 87 , and a purge fitting 88 for supply of a purge gas. It is an aspect of the invention that the welding backup arrangement 80 operates to clamp annulus backup plate 82 by virtue of the lid 84 and actuator 87 opposite the weld seam for at least purge purposes, and perhaps light-duty heat-sink purposes. The lid 84 operates not only as a heat sink but the stem portion 86 is sized for closely fitting inside the top end of the nozzle N and thereby assist in maintaining the roundness of the nozzle N's top end during the welding operation. That way, this helps prevent the nozzle N's top end from distorting into an ovoid shape or the like.
As FIG. 16 shows better, preferably the annulus backup plate 82 is slotted as shown to allow flexure and conformance to complexly-warped geometries of a domed structure. Preferably the annulus backup plate 82 is produced of a high conductivity metal such as copper, and more preferably of high-conductivity, oxygen-free copper.
FIGS. 17 and 18 show another embodiment in accordance with the invention, as for more particularly achieving a purge arrangement 90 for both creases (as shown) and cylindrical seams (not shown) or the like. In FIG. 17 , this crease may be typical of—and only as an example and without limitation—being formed between a nozzle N and end cap E. The crease can be serviced by purge arrangement 90 which comprises a seal of metallic tape 91 (aluminum is suitable) having an adhesive layer 92 for sealing in a ventilated tube 93 and its porous sheath 94 . Preferably the ventilated tube 93 is formed of copper as well, and is perforated regularly with vents 95 . Preferably the sheath comprises a woven copper-filament flexible conduit. In use, the ventilated tube 93 is preferably serviced by a metered gas source 96 .
This purge arrangement 90 can be comparable adapted for other uses than besides with creases alone. That is, purge arrangement 90 can be satisfactorily strung around an inside diameter or an outside diameter to provide purge service welding a seam from the opposite side of the tank wall as the purge arrangement 90 .
FIG. 19 shows at least the spaced end portions of a belt 100 for pipe welding backup in accordance with the invention, as for lapping externally over the outboard course of a hoop seam for the tank T (see, eg, FIG. 20 ). Preferably the belt 100 of FIGS. 19 through 21 comprises a copper braided construction. One end 102 is formed as a mated, hard-metal loop end such as of brass, bronze, beryllium or like metals amenable to a brazing, soldering or fusion mating. The terminating end 104 can be simply a cut-off end as shown in either of FIG. 19 or 20 .
FIG. 21 shows a minor section of the tank T with the belt 100 girdling it in order to better show a clamp 106 and come-along device 110 in accordance with the invention. The come-along device 110 has a lever actuator 112 which when actuated in the clockwise direction (as reckoned by FIG. 21 ) causes its pin connection 114 with the belt 100 's loop end 102 to be forced apart from a clamped connection 116 with a marginal end-portion 104 ′ of the belt 100 's blank end 104 . To fully tighten the belt 100 , operation of the lever actuator 112 preferably takes several strokes. Preparatory to each spreading stroke, the come-along 110 's clamp 114 is tightened and the belt 100 's clamp 106 is relaxed. A stroke of the come-along 110 cinches the belt 100 incrementally, which slips through the belt 100 's relaxed clamp 106 , which at the end of the stroke is tightened. The come-along 110 's clamp 114 is released, manually slid along the belt 100 in the direction of the loop end 102 , during while the lever 112 is being pivoted fully counterclockwise, then clamp 114 is re-tightened. Belt-clamp 106 is next relaxed so that a successive stroke of the lever 112 further tightens the girdle force of the belt on the tank T. Once the desired girdle compression for belt 100 is achieved, the come-along device 110 may be removed and a worker is then preferably afforded an inventive opportunity to weld and inside weldment to the seam of the tank T with the heat-sink service of cinched-tight belt 100 on the outboard side of the seam.
The invention having been disclosed in connection with the foregoing variations and examples, additional variations will now be apparent to persons skilled in the art. The invention is not intended to be limited to the variations specifically mentioned, and accordingly reference should be made to the appended claims rather than the foregoing discussion of preferred examples, to assess the scope of the invention in which exclusive rights are claimed.
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A welding apparatus is disclosed for use during welding of a tubular metal nozzle to a tank's metal domed cap. The nozzle extends longitudinally between a base end for mating to the tank's cap at an aperture therein and a spaced-away terminal free end. Typically, the nozzle's longitudinal axis is aligned oblique to a normal axis for the domed cap through the aperture thereof. Such welding apparatus involves a clamping arrangement having an actuator extending between a lid and a spaced, opposed backup plate. The backup plate seats against at least a marginal periphery of the domed cap's inner concave surface surrounding the aperture thereof. The lid covers the nozzle's terminal free end. Releasably actuating the actuator increases clamping pressure between the lid and backup plate, thereby clamping the backup plate opposite the weld seam for at least purge purposes, and perhaps light-duty heat-sink purposes.
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FIELD OF THE INVENTION
The present invention relates to a method designed to produce and treat wood fibers.
BACKGROUND OF THE INVENTION
One problem which is generally encountered in connection with plants for producing and treating wood fibers is the emission to the surrounding atmosphere of volatile organic substances, i.e. Volatile Organic Compounds (VOC), as well as formaldehyde from the raw wood, and from the size which is used in the process. One object of the present invention is to solve this problem. Another object of the present invention is to recover thermal energy in these processes.
SUMMARY OF THE INVENTION
These and other objects have now been accomplished by the invention of apparatus for the treatment of wood chips comprising a preheater for preheating the wood chips in the presence of steam thereby producing volatile organic substances from the wood chips therein, a beater for mechanically processing the wood chips whereby wood fibers are released from the wood chips and the steam and the volatile organic substances are contained therein, a cyclone for separating the wood fibers from the steam and the volatile organic substances, the cyclone including an inlet, an upper outlet and a lower outlet, a blower line for transporting the wood fibers, the steam and the volatile organic substances from the beater to the inlet of the cyclone, a drying conduit connected to the lower outlet of the cyclone for carrying the wood fibers therefrom, a sluice valve associated with the lower outlet of the cyclone for controlling the removal of the wood fibers from the cyclone, and a processing conduit connected to the upper outlet of the cyclone for the steam and the volatile organic substances whereby the volatile organic substances separated in the cyclone can be separated and heat associated with the steam separated in the cyclone can be recovered. In a preferred embodiment, the apparatus includes a scrubber for separating the volatile organic substances from the steam separated in the cyclone, and a heating coil for recovering heat from the steam separated in the scrubber.
In accordance with a preferred embodiment of the apparatus of the present invention, the apparatus includes a steam ejector associated with the lower outlet of the cyclone for transporting the wood fibers in the dryer conduit, and a mixing chamber attached to the steam ejector for mixing flue gas and drying air and supplying the mixture of flue gas and drying air to the steam ejector.
In accordance with one embodiment of the apparatus of the present invention, the apparatus includes an injector associated with the lower outlet of the cyclone, and an air compressor for supplying compressed air to the injector for transporting the wood fiber, the steam and the volatile organic substances in the drying conduit.
In accordance with another embodiment of the apparatus of the present invention, the preheater includes an upper portion including a wood chip entrance and an outlet, a lower portion, and a steam inlet for supplying steam to the lower portion of the preheater whereby the steam can countercurrently contact the wood chips entering the wood chip entrance in the preheater and the volatile organic substances and steam can exit from the outlet from the preheater, and a scrubber connected to the outlet from the preheater whereby the volatile organic substances can be separated from the steam and additional heat can be recovered from the steam.
In accordance with another embodiment of the apparatus of the present invention, the apparatus includes a heat exchanger connected to the outlet from the cyclone and a condensate tank connected to the heat exchanger whereby the volatile organic substances can be separated in the gaseous state for incineration and the heat can be recovered from the steam. Preferably, the heat exchanger comprises a first heat exchanger, and the apparatus includes a second heat exchanger and a third heat exchanger connected to the condensate tank for providing heat for drying the wood fibers and for cooling the condensate in the condensate tank. Preferably, the apparatus includes at least one mixing chamber whereby the drying conduit supplies drying air to at least one of the second and third heat exchangers.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more fully appreciated with reference to the following detailed description, which, in turn, refers to the attached drawings in which:
FIG. 1 a is schematic representation of the process performed in a portion of a plant designed in accordance with the present invention;
FIG. 1 b is a schematic representation of another portion of the process performed in a plant designed in accordance with the present invention;
FIG. 2 is a top, elevational, partial view of a portion of the plant shown in FIG. 1 a in an enlarged scale and in an alternative embodiment;
FIG. 3 is a top, elevational, partial view of the same part of the plant shown in FIG. 2 with yet another embodiment shown therein; and
FIG. 4 is a schematic representation of the process performed in an alternative embodiment of a plant designed in accordance with the present invention.
DETAILED DESCRIPTION
The plant shown in FIGS. 1 a and 1 b comprises a number of parts, including a fiber production part A, a steam separator part B, two fiber drying stages, C 1 and C 2 , and an energy subplant D. The plant will be described with regard to its design/construction while simultaneously explaining its operation in order to avoid needless repetition.
In fiber-production part A, the wood chips are preheated in an alkalinizing bin 1 , preferably using steam at atmospheric pressure. From bin 1 , the chips are fed by a plug-type screw conveyor 2 which compresses and dewaters the chips as they are conveyed to chip preheater 3 . Chip preheater 3 heats the chips with heat obtained from condensing steam that is supplied through steam inlet 50 located in the lower part of the preheater, the pressure, temperature and time having been present and adapted to the raw wood chips. Preheater 3 has a top outlet 56 where released organic emissions are degassed from the wood along with air during heating, thereby improving heat transfer between the steam and the chips. The greater part of the emissions, i.e. volatile organic substances (VOC and formaldehyde), is released in the preheater and separated at a high concentration in the top of the preheater and conveyed together with steam and air through line 57 to scrubber 11 where solid particles are separated along with certain condensable organic substances and volatile waste gases, and where heat is recovered from the steam. Since the steam is supplied through inlet 50 at a low level the chips, which enter from the top of the preheater, can be washed in counterflowing steam during condensation.
The electrical energy that is added in order to free fibers from the chips in beater 4 is converted, for the most part, to steam in connection with the mechanical processing of is the preheated chips to produce free fibers or fiber bundles. During processing, a certain amount of organic emissions are released from the wood, and they are conveyed forward in blower line 5 in the gaseous state together with the steam. In blower line 5 the fibers, fiber bundles and steam are conveyed at high speed to inlet 52 of cyclone separator 6 . If size is to be used, it is added in blower line 5 at 51 thereby sizing the fiber. Emissions of volatile organic substances are also released from the size, and together with the fiber and the steam, they are conveyed to cyclone separator 6 for separation from the fiber. Bottom outlet 53 on cyclone separator 6 is connected, by means of sluice valve 7 , to conveyance line 55 in which the fiber is sent to a fiber drier. However, drying of the fiber can also take place in line 55 due to the fact that the transport medium is drying air (see especially FIGS. 2 and 4 ). Consequently, line 55 will hereinafter be called conveyance/drying line 55 . Upper connection 54 on the cyclone separator is connected to scrubber 10 that separates the fibers and organic substances from the steam obtained from the cyclone separator.
Cyclone separator 6 can be included in several alternative basic embodiments. In alternative embodiment 1 , which is shown in FIG. 1 a , steam ejector 8 is connected downstream from sluice valve 7 . Steam ejector 8 , which is supplied with steam at 67 , handles further conveyance of the fiber together with preheated drying air and flue gases that are sucked from mixing chamber 9 . This mixing chamber 9 receives flue gases through line 66 , which runs from energy subplant D in the plant and also receives drying air through valve 58 . In this alternative embodiment, the fiber is already being dried while it is being conveyed to drier stage C 1 .
In an alternative embodiment 2 , which is shown in FIG. 2, conveyance/drying line 55 is connected directly to sluice valve 7 so that hot air is supplied directly to the drier line at 59 . In an alternative embodiment 3 , which is shown in FIG. 3, the fiber is transported to the drier stage by means of compressor 31 which is supplied with conveyance air at 60 and feed injector 32 .
In drier stage C 1 , the drying air is heated as indicated by arrows 61 in air/hot-water coil 18 and in air/steam coils, 19 and 20 , and also in mixing chamber 21 used for flue gas obtained from energy subplant D. The suspension of steam, air and volatile organic substances (VOC and formaldehyde) that arrives at scrubber 11 from preheater 3 is washed free of solid particles in scrubber 11 using condensate pumped from condensate tank 26 by means of pump 28 . Parts of released emissions from the wood are condensed and leave scrubber 11 together with the scrubber water. Steam leaving scrubber 11 is used during condensation to heat the drying air in air/steam coil 20 . Condensate from coil 20 leaves separator 14 where volatile organic emissions proceed by means of regulator valve 15 , suction fan 22 (FIG. 1 b ) and duct 30 to incinerator 62 in energy subplant D.
Steam obtained from cyclone separator 6 that contains organic emissions released in connection with fiber production and sizing is washed free of solid particles in scrubber 10 using condensate from condensate tank 26 . Parts of the aforesaid emissions are condensed and leave scrubber 10 together with the scrubber water. The washed steam from scrubber 10 is sent to heating coil 19 where it is used to heat drying air 61 . In heating coil 19 the steam is condensed, and the condensate is sent to separator 16 from which volatile non-condensable emissions are sent to incinerator 62 for incineration by means of regulator valve 17 , suction fan 22 and duct 30 .
The condensate in condensate tank 26 is transported by pump 27 to heat the drying air in heating coil 18 . The condensate leaves coil 18 at a temperature of about 40° C. by means of separator 12 where the remaining emissions of volatile organic gases are sent to incinerator 62 by means of valve 13 , suction fan 22 and duct 30 .
Condensate from separator 12 is sent to tank 23 , which contains a decanter insert. Condensate consisting of emission remnants (terpenes) released from the wood substance is decanted and transported by pump 24 and pipe 29 to incinerator 22 where it is used to moisten solid fuel 63 and grindings 64 , which are also transported here.
The level in condensate tank 23 is regulated by means of pump 25 . Water that proceeds by means of pump 25 is a) used if so desired to heat drying air, as indicated by arrows 65 , in drier stage C 2 by means of heating coil 40 , or b) used in the rest of the process wherever needed, or c) sent out directly for purification. Drying air 61 and drying air 65 in drier stages C 1 and C 2 are heated to the final temperature together, if so desired, with flue gas from the energy subplant by means of mixing chambers 21 and 41 , or using some other heating medium.
FIG. 4 shows an alternative embodiment of the plant, which is somewhat simplified relative to the previously described alternative embodiments. Here, fiber-production part A is the same as in the embodiments previously described. In steam separator part B, on the other hand, the emissions released in preheater 3 are sent together with steam and air through line 70 to heat exchanger 73 and condensate tank 76 in order to separate condensable organic substances and volatile waste gases and recover heat from the steam. Bottom outlet 53 on cyclone separator 6 is connected, by means of sluice valve 7 , to injector 32 which is located in conveyance/drying line 55 that runs to the first drier stage C 1 . Upper connection 54 on cyclone separator 6 is also connected to heat exchanger 73 in order to heat the drying air.
In drier stage C 1 , the drying air is heated, as indicated by arrows 87 , in the following manner: a) heat exchanger 75 , b) mixing chamber 74 together with mixed-in drying air leaving cyclone separator 83 in drier stage C 2 , c) heat exchanger 73 together with steam from cyclone separator 6 and preheater 3 and d) mixing chamber 72 using the necessary supplementary drying energy introduced at 85 . In drier stage C 2 , the drying air is heated in heat exchanger 78 and also by means of heating coil 84 , alternatively using a heating medium supplied at 86 .
An alternative to the aforesaid drying air heating arrangement can be provided by eliminating mixing chamber 74 , where mixed-in drying air from drier stage C 2 is used. Another alternative can be provided by eliminating heat exchangers 75 and 78 which are intended for cooling condensate sent from condensate tank 76 to condensate tank 79 and replacing them with some other form of cooling.
The suspension of steam, air and volatile organic substances (VOC and formaldehyde) which arrives at heat exchanger 73 from preheater 3 and cyclone separator 6 is condensed and sent out as condensate to tank 76 , where volatile organic emulsions in the gaseous state are sent to the energy subplant for incineration through 93 . Parts of the emulsions mentioned above are condensed and transported together with the condensate by pump 77 to heat exchanger 75 used for drier stage C 1 and also to heat exchanger 78 used for drier stage C 2 and they transfer parts of their heat content to the drying air. Transport to cyclone separator 83 is provided by fan 82 .
Condensate from heat exchanger 78 is sent at a temperature of about 40° C. to condensate tank 79 , from which remaining emulsions of volatile organic gases are sent by means of 93 to the energy subplant for incineration. The level in condensate tank 79 is regulated by means of pump 80 . If so desired, water from pump 80 is used, by means of 89 , in the rest of the process wherever needed or is sent out directly for purification.
Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.
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Method is disclosed for treating wood chips including a heater for preheating the wood chips in the presence of steam, a beater to mechanically process the wood chips into wood fibers, a cyclone for separating the wood fibers from steam and volatile organic substances produced in the beater, a blower line for transporting the wood fibers, steam and volatile organic substances from the beater to the inlet of the cyclone, a drying conduit connected to the lower outlet of the cyclone for carrying wood fibers therefrom, a sluice valve associated with the lower outlet of the cyclone for controlling the removal of the wood fibers from the cyclone, and a processing conduit connected to the upper outlet of the cyclone for the steam and the volatile organic substances whereby the volatile organic substances separated in the cyclone can be separated and heat associated with the steam separated in the cyclone can be recovered.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims benefit under 35 U.S.C. § 119 from Korean Patent Application No. 2005-06283, filed on Jan. 24, 2005, the entire content of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of manufacturing a micro electro mechanical system structure, a cantilever-type micro electro mechanical system structure, and a sealed fluidic channel. More particularly, the present invention relates to a method of manufacturing a micro electro mechanical system structure, a cantilever-type micro electro mechanical system structure, and a sealed fluidic channel that eliminates the necessity of using a sacrificial layer provided at a predetermined interval from a substrate.
2. Description of the Related Art
According to a surface micro-machining technology which is based on a semiconductor integrated circuit manufacturing process for machining a thin film element, it is possible to manufacture a minute structure on a silicon substrate and to couple it with semiconductor circuitry, so that a micro electro mechanical system (hereinafter, referred to as “MEMS”) element such as a micro-sensor can be manufactured. Here, in the remaining portion of the minute structure, excepting one side or both sides thereof, it is necessary to form a space so as to float the minute structure over the substrate. Therefore, in order to form the minute structure, a method of using a sacrificial layer has been adopted, and materials which have a good etching selectivity to the structure material have been used as the sacrificial layer.
U.S. Pat. No. 6,762,471 discloses an example of forming a minute structure by using a sacrificial layer as discussed above.
FIG. 1 shows a known minute thin film resonator, which illustrates the construction of the thin film resonator disclosed in U.S. Pat. No. 6,762,471.
In its construction, the thin film resonator 100 is provided with a supporting member (e.g. supporting layer) 155 , posts 140 and 141 , a first electrode 165 , an insulating film 175 , and a second electrode 185 . The thin film resonator 100 is formed with a predetermined gap (e.g., air gap) on the substrate 110 . On the substrate 110 , a circuit 105 is present, to which the second electrode 175 and the circuit 105 are connected through a connecting member 220 .
FIGS. 2A to 2G illustrate the process used to form the thin film resonator shown in FIG. 1 with a predetermined gap on the substrate, in which a first electrode 165 , an insulating film 175 , and a second electrode 185 forming a floating structure with a predetermined gap D will be discussed.
Referring to FIG. 2A , the sacrificial layer 120 is deposited on the substrate 110 , and then holes 130 and 131 are formed. Next, referring to FIG. 2B , a BPSG (borophosphosilicate glass) layer 135 is deposited. Here, the BPSG layer 135 is embedded through holes 130 and 131 to form posts 140 and 141 , which support the thin film resonator 100 that will be formed in the subsequent step. As shown in FIG. 2C , BPSG layer 135 , which is deposited on the sacrificial layer 120 , is polished. Subsequently, referring to FIG. 2D , in the upper side of the sacrificial layer 120 in which posts 140 and 141 are embedded via holes 130 and 131 , a silicon nitride layer 150 is deposited, which becomes a support layer 155 . Next, a first metal layer 160 which forms the first electrode 165 is deposited, and a second metal layer 180 which forms the second electrode 185 is deposited. Referring to FIG. 2E , the second metal layer 180 , the insulating layer 170 , and the first metal layer 160 are patterned sequentially in a shape of the thin film resonator 100 . Referring to FIG. 2F , a silicon nitride film 150 is patterned in a shape of the support layer 155 , in which openings 195 and 196 are formed. Referring to FIG. 2G , an etching solution containing a hydrofluoric (hereinafter, referred to as “HF”) acid solution moves through the openings 195 and 196 to remove the sacrificial layer 120 . Thereafter, washing and drying steps are carried out to form the thin film resonator 100 .
The sacrificial layer is generally removed by a wet etching process, i.e., the process of etching after immersing the wafer into a chemical solution containing a HF solution, and then washing and drying.
However, in the above-mentioned conventional method, an undesirable stiction phenomenon occurs, in which the minute structure (e.g., thin film resonator 100 ) moves down in a space C from which the sacrificial layer is removed due to a capillary force as a result of surface tension during the drying step after washing.
Such stiction phenomenon deteriorates the performance of the minute structure, which leads to a decrease in yield due to failure of the element during manufacturing.
SUMMARY OF THE INVENTION
In order to overcome the problems described above, a primary object of the present invention is to provide a method of manufacturing the minute structure without using a sacrificial layer.
Another object of the present invention is to provide a method of manufacturing a cantilever-type MEMS structure based on the manufacturing process of a minute structure.
Still another object of the present invention is to provide a method of manufacturing a sealed fluidic channel based on the above-mentioned manufacturing process of a minute structure.
In order to accomplish the objects described above, according to a first aspect of the present invention, a method of manufacturing a MEMS structure is provided which comprises: forming a trench in a P-type silicon substrate; forming an oxide film (e.g., SiO 2 ) on a P-type silicon substrate to form a barrier by embedding the trench with the oxide film; removing the oxide film formed on the substrate, except for the barrier embedded in the trench; forming a mask layer on the substrate where the oxide film has been removed and removing a portion corresponding to an inside of the barrier; forming a porous layer having a predetermined thickness on the upper side of the substrate corresponding to the inside of the barrier; removing the substrate corresponding to the lower area of the porous layer to form a cavity; removing the mask layer formed outside the barrier, sealing the upper side of the cavity with a membrane layer; and then forming a structure on the upper side of the membrane layer.
In a preferred embodiment, the trench is formed by deep reactive ion etching (deep RIE).
In another preferred embodiment, the oxide film is formed by thermal oxidation of the silicon substrate or by thin film deposition on the silicon substrate.
The step of removing the oxide film formed on the substrate except for the barrier embedded in the trench is preferably carried out by chemical mechanical polishing.
In another preferred embodiment, the mask layer is preferably formed of a silicon nitride film, the deposition of the mask layer is performed by chemical vapor deposition, and the etching of the mask layer is performed by reactive ion etching.
In the step of forming the porous layer, preferably the P-type silicon substrate is immersed into a chemical solution to treat it electrochemically, in which an electric current lower than a critical current value is applied.
In the step of forming the cavity, preferably the P-type silicon substrate is immersed into a chemical solution to treat it electrochemically, in which an electric current larger than a critical current value is applied.
In the step of forming the membrane layer, the membrane layer is preferably formed of an insulating material, and the insulating material includes an oxide film such as SiO 2 , a silicon nitride film such as Si 3 N 4 , and a polysilicon film.
Here, the oxide film can be formed by thermal oxidation or thin film deposition such as chemical vapor deposition; and the silicon nitride film can be formed by thin film deposition such as chemical vapor deposition.
The polysilicon film can be deposited by physical vapor deposition, and the like.
According to a second aspect, the present invention provides a method of manufacturing a MEMS structure which comprises depositing a mask layer for cavity formation on an N-type silicon substrate and removing an area where a cavity is to be formed; doping a P-type material on the substrate where the mask layer has been removed to form a P-type silicon layer; forming a porous layer having a predetermined thickness on the upper side of the P-type silicon layer; removing the P-type silicon layer corresponding to the lower area of the porous layer to form a cavity; removing the mask layer formed on the substrate; sealing the upper part of the cavity with a membrane layer; and forming a structure on the upper side of the membrane layer.
In a preferred embodiment, the mask layer is preferably formed of silicon nitride, and the etching of the mask layer is formed by reactive ion etching.
In the step of forming the porous layer, preferably the silicon substrate is immersed into a chemical solution to treat it electrochemically, in which an electric current smaller than a critical current value is applied.
In the step of forming the cavity, preferably the silicon substrate is immersed into a chemical solution to treat it electrochemically, in which an electric current larger than a critical current value is applied.
In the step of forming the membrane layer, the membrane layer is preferably formed of an insulating material, and the insulating material may include an oxide film such as SiO 2 , a silicon nitride film such as Si 3 N 4 , and a polysilicon film.
Here, the oxide film can be formed by thermal oxidation or thin film deposition such as chemical vapor deposition.
The silicon nitride is preferably formed by thin film deposition such as chemical vapor deposition.
The polysilicon film can be formed by, for example, chemical vapor deposition or physical vapor deposition, and the like.
The doping of a P-type material can be performed by ion implantation or thermal diffusion.
According to a third aspect, the present invention provides a method of manufacturing a cantilever-type MEMS structure which comprises forming a trench in a P-type silicon substrate; forming an oxide film (e.g., SiO 2 ) on the P-type silicon substrate to form a barrier by embedding the trench with the oxide film; removing the oxide film formed on the substrate except for the barrier embedded in the trench; forming a mask layer on the substrate where the oxide film has been removed and removing a portion corresponding to an inside of the barrier; forming a porous layer having a predetermined thickness on the upper part of the substrate corresponding to the inside of the barrier; etching the substrate corresponding to the lower area of the porous layer to form a cavity; removing the mask layer formed outside the barrier; forming a membrane layer on the substrate and the porous layer; forming a cantilever-type structure on the upper side of the membrane layer and patterning it in a shape of the cantilever-type structure; and etching the membrane layer including the porous layer so as to float one end of the cantilever-type structure over the cavity.
According to a fourth aspect, the present invention provides a method of manufacturing a cantilever-type MEMS structure which comprises forming a trench in a P-type silicon substrate; forming an oxide film (e.g., SiO 2 ) on the P-type silicon substrate to form a barrier by embedding the trench with the oxide film; removing the oxide film formed on the substrate except for the barrier embedded in the trench; forming a mask layer on the substrate where the oxide film has been removed and removing a portion corresponding to an inside of the barrier; forming a porous layer having a predetermined thickness on the upper part of the substrate corresponding to the inside of the barrier; etching the substrate corresponding to the lower area of the porous layer to form a cavity; removing the mask layer formed outside the barrier; forming a cantilever-type structure on the substrate and the porous layer, and patterning it in a shape of the cantilever-type structure; and etching the porous layer so as to float one end of the cantilever-type structure over the cavity.
According to a fifth aspect, the present invention provides a method of manufacturing a cantilever-type MEMS structure which comprises depositing a mask layer for cavity formation on a N-type substrate and removing an area where the cavity is to be formed; doping a P-type material into the substrate where the mask layer has been removed, to form a P-type silicon layer; forming a porous layer in a predetermined thickness on the upper part of the P-type silicon layer; removing the P-type silicon layer corresponding to the lower area of the porous layer to form a cavity; removing the mask layer formed on the substrate; forming a membrane layer on the substrate and the porous layer; forming a cantilever-type structure on the upper side of membrane layer and patterning it in a shape of the cantilever-type structure; and etching the membrane layer including the porous layer to float one end of the cantilever-type structure on the cavity.
According to a sixth aspect, the present invention provides a method of manufacturing a cantilever-type MEMS structure which comprises depositing a mask layer for cavity formation on an N-type silicon substrate and removing an area where the cavity is to be formed; doping a P-type material into the substrate in those areas where the mask layer has been removed to form a P-type silicon layer; forming a porous layer having a predetermined thickness on the upper part of the P-type silicon layer; removing the P-type silicon layer corresponding to the lower area of the porous layer to form a cavity; removing the mask layer formed on the substrate; forming a cantilever-type structure on the substrate and the porous layer, and patterning it in a shape of the cantilever-type structure; and etching the porous layer so as to float one end of the cantilever-type structure on the cavity.
According to a seventh aspect, the present invention provides a method of manufacturing a sealed fluidic channel which comprises forming a trench in a P-type silicon substrate; forming an oxide film (e.g., SiO 2 ) on the P-type silicon substrate to form a barrier by embedding the trench with the oxide film; removing the oxide film formed on the substrate except for the barrier embedded in the trench; forming a mask layer on the portion of the substrate where the oxide film has been removed and removing a portion corresponding to the inside of the barrier; forming a porous layer having a predetermined thickness on the upper part of the substrate corresponding to the inside of the barrier; etching the substrate corresponding to the lower area of the porous layer to form a cavity; removing the mask layer formed outside the barrier; forming a membrane layer on the substrate and the porous layer; and forming at least one inlet hole for inflow of the fluid and at least one outlet hole for discharge of the fluid in the porous layer and the membrane layer.
According to an eighth aspect, the present invention provides a method of manufacturing a sealed fluidic channel which comprises depositing a mask layer for cavity formation on an N-type silicon substrate and removing an area where the cavity is to be formed; doping a P-type material into the substrate in those areas where the mask layer has been removed to form a P-type silicon layer; forming a porous layer having a predetermined thickness on the upper part of the P-type silicon layer; removing the P-type silicon layer corresponding to the lower area of the porous layer to form a cavity; removing the mask layer formed on the substrate; forming a membrane layer on the substrate and the porous layer; and forming at least one inlet hole for inflow of the fluid and at least one outlet hole for discharge of the fluid in the porous layer and the membrane layer.
According to the method of manufacturing the MEMS structure, in fabricating a cantilever-type MEMS structure and a fluidic channel, by previously forming the cavity before manufacturing the structure and forming the membrane layer for sealing the cavity, an unnecessary process for forming and removing the sacrificial layer can be eliminated.
Also, according to the present invention, since the structure protection apparatus is not necessary, it is possible to prevent breakdown of the structure.
Further, according to the present invention, a MEMS element based on a new concept can be designed.
BRIEF DESCRIPTION OF THE DRAWINGS
The above aspects and features of the present invention will be more apparent by describing certain embodiments of the present invention with reference to the accompanying drawings, in which:
FIG. 1 shows a thin film resonator disclosed in U.S. Pat. No. 6,762,471, as a minute resonator in the prior art;
FIGS. 2A to 2G show the process used to form the thin film resonator shown in FIG. 1 with a predetermined gap on the substrate, more particularly, a process in which a first electrode, an insulating film, and a second electrode form a floating structure with a predetermined gap, together;
FIGS. 3A to 3G show a process for forming a resonator, more particularly, a process in which a minute structure is formed so as to float from the substrate according to one embodiment of the present invention;
FIGS. 4A to 4E show a process for forming the resonator, more particularly, a process in which a MEMS structure is formed so as to float from the substrate according to another embodiment of the present invention;
FIGS. 5A to 5C show a process in which a cantilever-type structure is formed on the membrane based on the process shown in FIGS. 3A to 3F ;
FIGS. 6A to 6C show a process in which a cantilever-type structure is formed on the porous layer based on the process shown in FIGS. 3A to 3D ;
FIGS. 7A to 7C show a process in which a cantilever-type structure is formed on the membrane based on the process shown in FIGS. 4A to 4D ;
FIGS. 8A to 8C show a process in which a cantilever-type structure is formed on the porous layer based on the process shown in FIGS. 4A to 4D ;
FIG. 9A shows an example in which a sealed fluidic channel is formed based on FIGS. 3A to 3F ; and
FIG. 9B shows an example in which the sealed fluidic channel is formed based on FIGS. 4A to 4D .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Certain embodiments of the present invention will be described in greater detail with reference to the accompanying drawings. However, the present invention should not be construed as being limited thereto.
In the following description, the same reference numerals are used for the same elements in different drawings. The following detailed description of construction and elements is provided to assist in a comprehensive understanding of the invention. Thus, it is apparent that the present invention can be carried out in various embodiments without being limited thereto. Also, well-known functions of constructions are not described in detail since they would obscure the invention in unnecessary detail.
Example 1
FIGS. 3A to 3G show a process used for forming the resonator, more particularly, the process in which a minute structure is formed so as to float from the substrate according to one embodiment of the present invention.
Referring to FIG. 3A , a trench 1 a is formed in a P-type silicon substrate 1 and an oxide film 3 such as SiO 2 is formed therein. The trench 1 a is etched by a deep reactive ion etching technique. Deep RIE is used to etch deep cavities in substrates with a relatively high aspect ratio. Often, a fluoropolymer is used to passivate the etching of the sidewalls. Also, the oxide film 3 can be formed by thin film deposition or thermal oxidation to the P-type silicon substrate 1 . As the thin film deposition, chemical vapor deposition (hereinafter, referred to as “CVD”) or physical vapor deposition (hereinafter, referred to as “PVD”), and the like can be performed. Then, the oxide film 3 is embedded into the trench 1 a, in which a barrier 5 for forming a cavity 4 (not shown), which will be discussed later, can be formed. According to another embodiment, Ta 2 O 5 and Al 2 O 3 may be used as the oxide film instead of SiO 2 . Another insulating material such as SiN may also be used instead of the oxide film.
Referring to FIG. 3B , the oxide film 3 formed on the P-type silicon substrate 1 is removed, leaving only the barrier 5 embedded in the trench 1 a. The oxide film 3 can be removed by, for example, chemical mechanical polishing using a planarization method.
Referring to FIG. 3C , a silicon nitride layer 7 is deposited on the upper side of the P-type silicon substrate from which the oxide film 3 has been removed. A mask to form the cavity 4 (as shown in FIG. 3E ), in the central portion of silicon nitride layer 7 , opening 7 a is etched to expose an internal area defined by the barriers 5 . Then, the silicon nitride layer 7 is formed by, for example, CVD, particularly low pressure chemical vapor deposition, and etched by reactive ion etching.
Referring to FIG. 3D , the upper side of the P-type silicon substrate 1 exposed via the opening 7 a of silicon nitride layer 7 is electrochemically treated to form a silicon porous layer 9 having a predetermined thickness t. Then, the silicon porous layer 9 is subjected to a moderate electrochemical treatment after immersing the P-type silicon substrate 1 into a chemical solution, for example, HF solution, at an applied current which is lower than a critical current value. Also, the thickness can be controlled by adjusting the time of the applied current. Porous Si manufacturing technology is also described in U.S. Pat. Nos. 6,355,498 and 6,060,818, incorporated herein by reference.
A hole is an important factor in manufacturing the porous Si (2hole + +6HF+Si→SiF 6 2− +H 2 +4H + ). More specifically, a hole is supplied by applying +bias to a Si substrate and a polishing mode changes according to a current density J. If a small amount of hole is supplied (low J), there is a limitation to amount of hole required for a polishing and thus the polishing proceeds to form pores (porous Si), and, if a large amount of hole is supplied (high J), a polishing actively proceeds so that an electrochemical polishing occurs. If the current density reaches a certain value, a polishing rate abruptly increases. The certain value is referred to as a critical current density. The polishing mode changes from the critical current density. The critical current density is different depending on a doping material and density. The above-described porous Si manufacturing technology is a well-known technology and is disclosed in U.S. Pat. Nos. 6,355,498 and 6,060,818.
Referring to FIG. 3E , a portion corresponding to the lower area of silicon porous layer 9 is removed to form the cavity 4 . Then, the cavity can be treated electrochemically after immersing into the chemical solution, for example, a HF solution, similar to the step of forming the silicon porous layer 9 . The applied current is larger than a critical current value. Accordingly, the silicon porous layer 9 formed at the upper side of the substrate remains without etching.
Referring to FIG. 3F , a membrane layer 11 for sealing the cavity 4 is formed, in which the membrane layer 11 is preferably formed of an insulating material, such as an oxide film (e.g., SiO 2 ), silicon nitride film (e.g., Si 3 N 4 ), and polysilicon film. Then, the oxide film is formed by thermal oxidation. In the oxidation process, since the oxide film is formed while consuming the porous silicon, the silicon porous layer 9 is changed into an oxide film. Also, the oxide film and nitride film are formed by thin film deposition. The thin film deposition can be performed by, for example, CVD, while the polysilicon can be formed by CVD or PVD. FIG. 3F shows an example for forming membrane layer by a thermal oxidation process. If a deposition method is used, a thin film such as silicon nitride film or polysilicon film is mainly deposited on the silicon porous layer to form a membrane layer (not shown) which is comprised of the dual film of thin film/polysilicon porous layer 9 .
Referring to FIG. 3G , a structure 12 is formed on the membrane layer 11 . Then, the resulting structure 12 forms a resonator and includes a first electrode layer 12 a, a piezoelectric layer 12 b, and a second electrode layer 12 c.
Example 2
FIGS. 4A to 4E show the process for forming the resonator, more particularly, the process in which a MEMS structure is formed so as to float from the substrate according to another embodiment of the present invention.
Referring to FIG. 4A , an N-type silicon substrate 31 is provided, and a mask layer 35 to form the cavity, which will be described later, is deposited thereon. Then, the mask layer 35 is formed with an opening 35 a to expose the central portion of the N-type silicon substrate 31 . The mask layer 35 is formed of an insulating material, for example, silicon nitride (e.g., Si 3 N 4 ), and is deposited by CVD. Also, etching can be performed by reactive ion etching (RIE).
Next, a P-type material is diffused into the central portion of the N-type silicon substrate 31 exposed via the opening 35 to form a P-type silicon layer 37 .
Referring to FIG. 4B , a porous layer 38 is formed on the upper side of the P-type silicon layer 37 having a predetermined thickness. Here, since the porous layer 38 (the embodiment 1) is formed in the same manner as described in FIG. 3D , its detailed explanation will be omitted.
Referring to FIG. 4C , the lower area of the P-type silicon layer 37 , wherein the porous layer 38 is formed, is electrochemically polished to form a cavity 33 . Since the cavity 33 is formed in the same manner as shown in FIG. 3E , its detailed explanation will be omitted.
Referring to FIG. 4D , after removing the mask layer 35 , the membrane layer 39 is formed, and the cavity 33 can be sealed in this step. The membrane layer 39 is preferably formed of an insulating material such as an oxide film, silicon nitride film, polysilicon film, and the like, in the same manner as in embodiment 1. Here, since the step for forming the oxide film is the same as that shown in FIG. 3 , its detailed explanation will be omitted. Note that FIG. 4C and FIG. 4D show that the porous layer 38 is oxidized and then changed to the membrane layer 39 , such as an oxide film.
Referring to FIG. 4E , the structure 12 is formed at the upper side of the membrane layer 39 .
The above described embodiment 2 has an advantage in being capable of eliminating the process which forms the barrier 5 for limiting an area in which silicon porous layer 9 and cavity 4 are to be formed in the embodiment 1 (e.g., the step of forming a trench 1 a, and the step of etching and removing the oxide film 3 ), thereby reducing the number of steps in the total process.
In the above explanations, the structure 12 has been described as the resonator, however, the structure 12 is not limited thereto. For instance, the structure 12 may be a pressure sensor or an actuator, as well as, a cantilever-type structure where only one end thereof is supported, or a fluidic channel, and the like.
FIGS. 5A to 5C show a process where a cantilever-type structure is formed on the membrane based on the embodiment 1. In FIGS. 5A to 5C , as the same members as in the embodiment 1 have identical reference numerals, description thereof will thus be omitted.
In this case, the steps of forming the cavity 4 on the substrate 1 and sealing the membrane layer 11 are identical with those shown in FIGS. 3A to 3F .
Thereafter, as shown in FIG. 5A , the cantilever structure layer is formed on the upper side of the membrane 11 , and then patterned in a cantilever-type structure 50 shape. In the drawing, reference numeral 61 designates the mask layer for forming the cantilever-type structure 50 , and it is formed of, for example, photoresist.
Then, as shown in FIG. 5B , the membrane layer 11 is removed to float one end of the cantilever-type structure over the cavity 4 . That is, a projection portion of one end of the cantilever structure projects as an overhang over the cavity. Here, if the membrane layer 11 is made of an oxide film, it is possible to remove the oxide film by vapor phase HF etching, which is a type of dry etching.
Subsequently, as shown in FIG. 5C , the photoresist layer 61 serving as the mask layer is removed, thereby fully forming the cantilever-type structure 50 .
FIGS. 6A to 6C show a process where the cantilever-type structure is formed on the porous layer based on the embodiment 1.
In FIGS. 6A to 6C , the cantilever-type structure is directly formed on the porous layer, in which the process for forming the cantilever-type structure is similar to the process shown FIGS. 5A to 5C , except for the step for forming the membrane layer 11 . The difference between FIGS. 6A to 6C and FIGS. 5A to 5C is that the steps in FIGS. 6A to 6C are performed by an isotropic etching method to remove the porous layer 9 .
FIGS. 7A to 7C show a process where the cantilever-type structure 50 is formed based on the process of embodiment 2, in which the cantilever-type structure 50 is formed on the membrane 39 . Here, the cantilever-type structure 50 is formed based on the embodiment 2. Since the same members as in the embodiment 2 have identical reference numerals, description thereof will thus be omitted.
In this case, the steps for forming the membrane layer 39 are performed in accordance with FIGS. 4A to 4D . Thereafter, since the process for forming the cantilever-type structure shown in FIGS. 7A to 7C is identical to the process shown in FIGS. 5A to 5C , descriptions thereof will be omitted.
Then, FIGS. 8A to 8C show a process where the cantilever-type structure 50 is formed based on the process shown in the embodiment 2, in which the cantilever-type structure 50 is formed on the porous layer 38 .
In this case, the steps for forming the porous layer 38 on the substrate 31 and forming the cavity 33 are identical with those steps in FIGS. 4A to 4C . Thereafter, after removing the mask layer 35 formed on the substrate 31 , the cantilever-type structure 50 is formed on the porous layer 38 . The cantilever-type structure 50 is formed in accordance with the steps shown in FIGS. 6A to 6C .
The cantilever-type structure 50 formed as described above can be applied to any storage apparatus such as a STM probe, an AFM probe, and the like.
FIG. 9A shows an example in which a sealed fluidic channel is formed based on the embodiment 1, while FIG. 9B shows an example in which the sealed fluidic channel is formed based on the embodiment 2. Since the fluidic channel is also formed based on the embodiments 1 and 2, the same members as in the embodiments 1 and 2 have identical reference numerals, and description thereof will be omitted.
Referring to FIGS. 9A and 9B , cavities 4 , 33 are formed in the substrates 1 , 31 , respectively, in accordance with the steps shown in FIGS. 3A to 3F and FIGS. 4A to 4D , and then cavities 4 , 33 are sealed by membrane layers 11 , 39 . Thereafter, at least one inlet hole 11 a, 39 a and at least one outlet hole 11 b, 39 b is formed into membrane layer 11 , 39 including porous layer 9 , 38 , respectively.
A typical process of manufacturing the sealed fluidic channel used in a BIO MEMS, and the like comprises forming a trench serving as a fluid passage on the substrate, and coupling it with the other substrate at its upper side, or in the case of forming the trench by wet etching a channel of undercut shape, where the channel is sealed by a thin film deposition technique. As described above, according to such conventional method, a problem resides in that the process for forming the fluidic channel is complicated.
Therefore, according to the present invention, it is possible to more simply produce the fluidic channel in comparison with the conventional technique.
The foregoing embodiment and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teachings can be readily applied to other types of apparatuses. Also, the description of the embodiments of the present invention is intended to be illustrative, and not to limit the scope of the claims, and many alternatives, modifications, and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.
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A method of manufacturing a MEMS structure including forming a porous layer having a predetermined thickness on the top surface of a substrate over an area where a cavity is to be formed; forming the cavity by etching the substrate below the porous layer; forming a membrane layer on the top surface to seal the cavity; and forming a structure on the upper side of the membrane layer. After forming a cantilever structure on the membrane layer and etching the membrane layer, a cantilever structure is produced in a floating state over the cavity. Also, at least one inlet hole and outlet hole can be formed in the porous layer and the membrane, thereby providing a sealed fluidic channel.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to license plate fasteners. More particularly, the invention concerns license plate fasteners that comprise a threaded fastener for securing the license plate to the vehicle and a decorative cover that is removably connected to the threaded fastener.
2. Discussion of the Prior Art
A number of different types of license plate fasteners have been suggested in the past for interconnecting license plates to the front and rear of vehicles. Exemplary of such license plate fasteners is the fastener disclosed in U.S. Pat. No. 4,890,967 issued to Rosenbaum. The Rosenbaum invention concerns a bolt cap cover that comprises a locking retainer member that fits over the flats of a standard hex-headed bolt and a cap having a generally cylindrical inner surface that fits over the retainer. The retainer is made of a resilient material such as nylon and is designed such that it abuts the lateral flats of the bolt head when the cap is installed. The cap itself may be of various designs and materials, thereby permitting a variety of decorative appearances to be achieved. The cylindrical inner surface of the cap compresses the retainer against the flats of the bolt head as the cap is installed over the retainer, thereby securing both the cap and retainer to the bolt head.
Another type of prior art license plate fastener is disclosed in U.S. Pat. No. 6,964,549 issued to Fallon. The Fallon fastener comprises a generally tubular insert or adaptor made of a resilient material structure like Nylon that includes an annular first end surface surrounded by a peripheral skirt. The annular first end surface is engageable in the manner of a washer by the head of a license plate fastener that is otherwise surrounded by the skirt with the free edge of this skirt provided with an exterior peripheral bead shaped for radial capture in an interior recess formed in a domed, decorative covering cap. A circular seat provided on the domed cap exterior is then useful and conformed to receive one of variously marked plugs to match the logo, style or mark of the vehicle manufacturer or any other style or symbol.
A typical component of the prior art license plate fasteners is some type of retainer member that fits over the head of the fastener used to connect the license plate to the vehicle. The retainer member of the prior art devices constitutes the means by which the decorative cover portion of the device is affixed. In other words, the prior art devices consist of three parts, namely the threaded connector for connecting the license plate to the vehicle, the retainer member that fits over the threaded connector and the decorative head cover that is held in position by the retainer member. In sharp contradistinction, the novel apparatus of the present invention comprises only two components, namely a threaded fastener used to interconnect the license plate to the vehicle and a decorative cover that is removably interconnected directly with the head of the threaded fastener.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a two-piece, decorative fastener assembly for securing a license plate to a vehicle. The decorative fastener uniquely includes a threaded fastener for securing the license plate to the vehicle and a decorative cover that is connected directly to the head portion of the threaded fastener.
Another object of the invention is to provide a fastener assembly of the aforementioned character which is of a two-piece construction comprising a threaded fastener and a decorative cover that can be quickly and easily connected directly to the head portion of the threaded fastener.
Another object of the invention is to provide a two-piece fastener assembly in which the face of the decorative cover is provided with decorative symbols that match the logo, style or mark of the vehicle manufacturer.
Another object of the invention is to provide a fastener assembly of the character described in which the configuration of the decorative cover is indicative of the logo associated with the vehicle.
Another object of the invention is to provide a fastener assembly as described in the preceding paragraphs in which the decorative cover is provided with a plurality of circumferential spaced-apart, resiliently deformable gripping segments for gripping the head portion of the threaded fastener.
Another object of the invention is to provide a faster assembly of the type described in which the upper surface of the head portion of the threaded fastener is provided with a plurality of circumferentially spaced, radially extending striations for resisting rotation of the decorative cover relative to the threaded fastener.
Another object of the invention is to provide a two-piece fastener assembly for securing a license plate to a vehicle that is of simple design, is highly attractive in appearance, is easy to use and can be manufactured inexpensively in substantial quantities.
By way of summary, these and other objects of the invention are accomplished by a decorative, two-piece fastener assembly for use in mounting a license plate onto a vehicle that includes a threaded fastener for securing the license plate to the vehicle, the threaded fastener including a head portion having a diameter and a threaded shank portion, the head portion having a top wall, a bottom wall and a sidewall interconnecting said top and bottom wall; and a decorative cover connected to the head portion of said threaded fastener, the decorative cover comprising a body portion having a front face, a rear face and a counter-bore having a diameter larger than said diameter of said head portion of the threaded fastener, the body portion further including gripping means disposed within said bore for gripping the head portion of said threaded fastener. In the preferred form of the invention the gripping means comprises a plurality of circumferentially spaced-apart, resiliently deformable gripping segments, each said gripping segment terminating in a gripping protuberance for engagement with a circumferentially extending shoulder provided on the head portion of the threaded fastener.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a generally perspective, front view of one form of the decorative fastener of the invention for use in mounting a license plate onto a vehicle.
FIG. 2 is a generally perspective, exploded view of the decorative illustrated in FIG. 1 .
FIG. 3 is a generally perspective, exploded, rear view of the form of decorative illustrated in FIG. 1 .
FIG. 4 is a generally perspective, rear view, similar to FIG. 3 , but showing the threaded fastener component of the decorative fastener interconnected with the head portion thereof.
FIG. 5 is a generally perspective, rear view of an alternate form of the decorative fastener of the invention in which the threaded fastener is integrally formed with the head portion.
FIG. 6 a greatly enlarged, cross-sectional view taken along lines 6 - 6 of FIG. 3 .
FIG. 7 is a generally perspective, front view of the threaded fastener component of the decorative fastener of the invention.
FIG. 8 is a greatly enlarged, generally perspective view of the area designated in FIG. 4 as “ 8 - 8 ”.
FIG. 9 is an exploded, generally perspective front view of still another form of the decorative fastener of the invention for use in mounting a license plate onto a vehicle.
DESCRIPTION OF THE INVENTION
Referring to the drawings and particularly to FIGS. 1 through 4 , one form of the two-piece, decorative fastener of the invention for use in mounting a license plate onto a motor vehicle is there shown and generally designated by the numeral 14 . In this form of the invention the fastener assembly comprises a stainless steel threaded fastener 16 for securing the license plate to the vehicle and a decorative cover 18 that can be releasably affixed to the threaded fastener. In this regard, vehicle license plates are typically formed from a thin metal stamping that is provided with fastener openings along the edges thereof. Similarly, the vehicle is provided with a plurality of apertures that are designed to receive threaded fasteners, such as fastener 16 , that can be used to attach the license plate to the vehicle.
In the present form of the invention fastener, or screw, 16 has a threaded shank portion 20 and a head portion 22 having a hexagonal wrench-receiving aperture 23 , a diameter “D- 1 ” and a height “H” ( FIG. 3 ). As best seen in FIG. 3 of the drawings, head portion 22 also has a top wall 22 a , a bottom wall 22 b and a tapered sidewall 22 c interconnecting the top and bottom wall. As indicated in FIG. 3 , tapered sidewall 22 c terminates in a circumferentially extending shoulder 22 d.
The second component of the two-piece decorative fastener of the invention comprises the previously identified decorative cover 18 that can be releasably connected to head portion 22 of the threaded fastener in the manner illustrated in FIG. 4 of the drawings. Decorative cover 18 , which is preferably formed from a moldable plastic such as acrylonitrile butadiene styrene (ABS), comprises a generally shield-shaped body portion 24 having a front face 24 a , a rear face 24 b and a generally cylindrical, centrally located first cavity 24 c . Cover 18 can be formed in various configurations identifiable with the logos of a particular motor vehicle and the front face 24 of the cover can be provided with indicia representative of a particular motor vehicle or representative of the owner of the vehicle.
Disposed within first cavity 24 c of the cover 18 are novel gripping means for gripping the head portion 22 of the threaded fastener 20 when the head portion of the fastener is inserted into the cavity 24 c in the manner illustrated in FIG. 4 of the drawings. These important gripping means here comprise a plurality of circumferentially spaced-apart, resiliently deformable gripping segments 26 that cooperate to define a tapered second cavity 27 . As best seen in FIGS. 6 and 8 of the drawings, each of the gripping segments 26 terminates in a rounded-gripping protuberance 28 for gripping engagement with the circumferentially extending shoulder 22 d of the head portion of the fastener 20 when the head portion of the fastener is inserted into second cavity 27 in the manner illustrated in FIG. 8 of the drawings. As indicated in FIGS. 3 and 6 of the drawings, gripping protuberances 28 cooperate to define an opening having a diameter “D- 2 ” that is slightly smaller than the diameter “D- 1 ” of the head portion 22 of the threaded fastener 16 .
With the construction described in the preceding paragraphs and as illustrated in the drawings, the threaded fasteners 16 of the invention that are provided with self-tapping threads 16 a , can be used in a conventional manner to interconnect a license plate with the particular vehicle the logo of which matches the logo of the decorative cover of the decorative cover. When the license plate is attached to the vehicle, the head portions 22 as well as the circumferentially spaced shoulders 22 d of the fasteners 16 are exposed so that the decorative covers can be expeditiously interconnected with the threaded fasteners in the manner next to be described.
Although the diameter “D- 2 ” of the opening defined by the gripping segments 26 is slightly less than the diameter “D- 1 ” of the head portion 22 of the threaded fasteners, because of the resilient nature of the gripping segments 26 , a inward force exerted on the head portion 22 of a decorative cover will cause the gripping segments to spread apart a sufficient distance to permit the head portion of the threaded fastener to be received within and seat against the lower surface 27 a of the cavity 27 . As the head portion 22 of the cover seats against the lower surface of the cavity, the gripping segments 26 will return to their initial configuration and the gripping protuberances 28 will seat against the circumferentially extending shoulder 22 d in the manner illustrated in FIG. 8 of the drawings. With the gripping protuberances 28 in engagement with the circumferentially extending shoulders 22 d of the head portions of the fasteners 16 , the decorative cover will be securely held in position on the threaded fasteners 16 . To further secure the cover 18 to the screw head, 22 , the taper of the cavity 27 and the taper of the head portion 22 of the screw 16 are strategically sized so that the cover is press-fit over the head portion of the screw.
Turning now to FIG. 7 of the drawings, it is to be noted that in one form of the invention the upper surface 22 a of the threaded fastener 16 is provided with a plurality of circumferentially spaced, radially extending protuberances, or striations, 33 that are engageable with the generally planar surface 27 a of second cavity 27 when the cover 18 is in position over the head portion of the threaded fastener. These important radially extending protuberances 33 function to grip the generally planar surface 27 a of second cavity 27 to resist rotation of the cover relative to the threaded fastener when the cover is in position over the threaded fastener in the manner illustrated in FIG. 1 of the drawings.
Referring next to FIG. 5 of the drawings, another form of the decorative fastener of the invention is there shown and generally designated by the numeral 35 . This form of the invention is similar in many respects to that illustrated in FIGS. 1 through 4 of the drawings. However, in this latest form of the invention the decorative fastener 35 is molded in a single piece and comprises a threaded fastener portion 35 a , which is of similar construction to threaded fastener 16 and a decorative cover 35 b , which is of similar construction to the previously described cover 18 . As before, cover 35 b , while shown as being generally shield-shaped, can be of various shapes and various types of indicia can be imprinted on the front face 35 c of the cover. Fasteners 35 , which include self-tapping threads 35 d , can be used in the same manner as a conventional threaded screw to interconnect a vehicle license plate to a motor vehicle.
Referring next to FIG. 9 of the drawings, still another form of the decorative fastener of the invention is there shown and generally designated by the 37 . This form of the invention is similar in many respects to that illustrated in FIGS. 1 through 4 of the drawings and like numerals are used in FIG. 9 to identify like components. Like the earlier described fastener of the invention, fastener 37 is of a two-part construction comprising a threaded fastener 16 that is substantially identical in construction and operation to that previously described, and a decorative cover 39 that is substantially identical to the previously described cover 18 , save that the configuration of cover 39 is generally hexagonal in shape. Additionally, the upper face 39 a of the cover is provided with fanciful indicia 41 that can be representative of the vehicle owner or of the company that owns the vehicle. In this regard, it is to be understood that the cover of the decorative fastener can be of any desired shape and can exhibit various types of indicia has maybe desired by the vehicle owner.
Having now described the invention in detail in accordance with the requirements of the patent statues, those skilled in this art will have no difficulty in making changes and modifications in the individual parts or their relative assembly in order to meet specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention, as set forth in the following claims:
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A two-piece, decorative fastener assembly for securing a license plate to a vehicle. The decorative fastener uniquely includes a threaded fastener for securing the license plate to the vehicle and a decorative cover that can be quickly and easily connected directly to the head portion of the threaded fastener.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to x-ray diagnostic imagining contrast formulations for imaging the gastrointestinal (hereinafter sometimes referred to as GI) tract. The formulations described herein have enhanced utility as oral/rectal GI diagnostic contrast agents.
This invention also relates to improved formulations of gastrointestinal therapeutic agents.
2. Reported Developments
It is a common medical practice to employ barium sulfate formulations to image the gastrointestinal tract of patients. Barium sulfate can be given either orally to visualize the stomach and upper GI tract or rectally to visualize the colon and lower GI tract. Barium sulfate is usually administered as a suspension that has limited stability even with the addition of stabilizers, it is often too opaque to visualize all segments of the GI tract, it often forms clumps that yield resultant radiopaque areas on x-ray films and has poor patient acceptability characteristics. Poor patient acceptability characteristics include palatability, patient discomfort during and after administration and constipation of the patient. Barium sulfate also shows poor affinity for coating the GI mucosa and consequently the patient is often needed to be manipulated or even rotated to ensure that the barium sulfate suspension coats the gastric mucosa. Nevertheless, segments of the GI tract are often either obscured or are not adequately coated to be visualized. It is not uncommon for the patient to undergo repeated examinations to achieve satisfactory imagining results.
The most serious failings of currently available formulations of barium sulfate are that they do not adequately coat the entire GI tract, requiring subsequent examination, and they pose safety concerns especially with patients that are suspected of having intestinal perforations or obstructions. Perforations of the upper GI tract or small bowel occurs with sufficient frequency that the risk of localized tissue injury is present. It is also not uncommon for orally administered barium sulfate to accumulate proximally to an obstruction in the bowel causing impaction that can lead to eventual perforation of the GI tract. In addition, aspiration of barium sulfate in the lungs may cause occlusion of the bronchioli and resultant pulmonary sequela.
Aqueous barium sulfate formulations are less constipating than non-aqueous barium sulfate formulations, however, they are often hypertonic, and consequently are irritating to the gastric mucosa.
Another class of compounds that have been investigated for imaging the GI tract are oil based emulsions of iodinated organic substances. Emulsions that have particle sizes of <0.3 microns have been reported to image the small intestines of dogs but 50-70% of the oil based emulsions are reported to be absorbed from the intestine. Oily emulsions also appear to coat to some extent both the upper and lower segments of the GI tract as compared with non-oil based contrast agents. Oily emulsions are not usually contraindicated for patients with intestinal perforations or with intestinal obstructions. The major problems associated with these oil based emulsions is their tendency to be absorbed from the GI tract and the inherent toxicity that may be associated with the absorption of these agents. Emulsions such as PANTOPAQUE, i.e., ethyl iodophenylundecylate, adhere to the gastric mucosa, have low viscosity, low surface tension, are miscible with tissue fluids and exhibit good radiopacity. However, the emulsions of these organic iodinated substances suffer from their undesirable toxic effects.
Accordingly, there is a need to provide oral GI diagnostic x-ray contrast agents that enable the visualization of both the upper and lower GI tract following a single administration, that is safe and efficacious and is not contraindicated for GI tract perforations and/or obstructions. Such an agent should have excellent mucosal coating properties for both the upper and lower GI tract, i.e. it should have mucoadhesive or bioadhesive properties that enable the entire GI tract to be visualized. The object of the present invention is to provide a formulation that enhances the imaging of the GI tract that takes into consideration the physical-chemical properties of the imaging agents, surface stabilizers and viscosity modifiers. There is a need to provide in such a formulation primary surface stabilizers with appropriate mucoadhesive properties and secondary excipients that provide for a marked improvement in imaging quality as compared with existing products and formulations. The identification of surface active stabilizers with bioadhesive or mucoadhesive properties that enable the imaging of the entire GI tract has not been reported to date. This represents a difficult technical problem that requires the application of mucoadhesive technology to develop appropriate surface active agents that will enable the entire GI tract to be visualized. Bioadhesion is usually achieved by interaction of either a synthetic or natural polymeric substance with the mucosal membranes of the GI tract. Such technology has been employed to enhance drug delivery by decreasing the transit time of a drug substance in the GI tract and hence promote an opportunity for enhanced absorption. With regards to the development of safe and effective x-ray contrast agents for visualizing the GI tract, it is important to identify mucosal adhesives that coat the GI surfaces and visualize diseased or abnormal tissues. Highly charged carboxylated polyanions are good candidates for use as bioadhesives in the GI tract. See, for example: Park, K. and Robinson, J. R., Bioadhesion: Polymers and Platforms for Oral-Controlled Drug Delivery; Method to Study Bioadhesion. Int. J. Pharm., 19, 107 (1984). The formation of a bioadhesive bond between a polymeric substance and the mucosal lining of the GI tract can be visualized as a two step process, i.e., initial contact between the two surfaces and the formation of secondary bonds due to non-covalent interactions. Bioadhesives specific for the GI tract must interact with the mucus layer during attachment. Mucus, a general term for the heterogenous secretion found on the epithelial surfaces of the GI tract, is made of the following components: glycoprotein macromolecules, inorganic salts, proteins, lipids and mucopolysaccharides. These glycoproteins typically consist of a protein core with carbohydrate side chains. This forms a network of mucus that is a continuous layer covering the GI tract. From a bioadhesive perspective, mucus consists of highly hydrated, crosslinked linear, flexible yet random coiled glycoprotein molecules with a net negative charge. Understanding the principles of bioadhesion is the basis for formulating an oral contrast x-ray agent for GI tract visualization. Bioadhesion accounts for the interaction between a biological surface and a biomaterial substance. As noted previously., bioadhesive agents are usually polymeric substances that adhere to tissues by ionic or covalent bonds or by physical attachment. Several theories of bioadhesion have been published including electronic, adsorption, wetting, diffusion and fracture theories. Bioadhesives bind to membrane surfaces and are retained for variable periods of time.
Crystalline x-ray contrast agents do not inherently adhere to the mucosal surfaces of the GI tract. It has now been discovered that crystalline x-ray contrast agents modified by the addition of surfactants, however, can be rendered so that they adsorb onto the GI mucosal surface. This is achieved by the use of mucoadhesive surfactants. The primary difficulty with previously reported mucoadhesive surfactants is that they do not interact effectively with both the particles and GI tract uniformly so that both the upper and lower GI tract can be visualized by a single agent during one examination. The surfactants used for this purpose must adsorb sufficiently to the different regions of the GI tract to enhance visualization by the contrast agent. In practice, surfactants tend to be adsorbed at some biological surfaces differentially than at others due to a variety of complex reasons. There is a need for contrast agents that are adsorbed sufficiently over the entire GI tract to allow adequate and uniform visualization of the different regions of the GI tract.
In accordance with the invention there is further provided a method for x-ray diagnostic imaging of the GI tract which comprises orally or rectally administering to the patient an effective amount contrast producing amount of the above-described x-ray contrast compositions.
A method for diagnostic imagining of the GI tract for use in medical procedures in accordance with this invention comprises orally or rectally administering to the mammalian patient in need of x-ray examination, an effective contrast producing amount of a composition of the present invention. After administration, at least a portion of the GI tract containing the administered composition is exposed to x-rays to produce an x-ray image pattern corresponding to the presence of the contrast agent, then the x-ray image is visualized and interpreted using techniques known in the art.
In another embodiment the present invention relates to improved formulations of gastrointestinal therapeutic agents. These formulations possess the benefit of providing prolonged local contact of the therapeutic agents with the mucosal layer of the gastrointestinal tract.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided an orally/rectally administrable gastrointestinal diagnostic x-ray contrast formulation comprising:
of from about 4 to about 45% w/v, and preferably of from about 15 to about 25% w/v, of an essentially water insoluble or poorly water-soluble particulate radiopaque crystalline material having an effective average particle size of less than about 2,000 nm, more preferably an effective average particle size of less than about 1,000 nm, and most preferably an effective average particle size of less than about 400 nm;
of from about 0.5 to about 10% w/v, and preferably of from about 2 to about 6% w/v of a bioadhesive or mucoadhesive surfactant stabilizer (hereinafter sometimes referred to as "primary stabilizer"); and
water to make 100% w/v.
Secondary stabilizers may also be used in the x-ray contrast formulation up to about 1% w/v, preferably up to about 0.2% w/v, and most preferably up to about 0.1% w/v. Secondary stabilizers include dioctylsulfosuccinate (DOSS) and sodium lauryl sulfate (SLS).
Other ingredients customarily used in oral pharmaceutical formulations may also be included, such as flavorants, colorants and preservatives to provide pharmaceutically acceptable and palatable formulations without such additional ingredients affecting the gastrointestinal imaging efficacy of the formulations.
The particulate radiopaque material used in the present invention includes: barium salts and crystalline organic compounds known for use in diagnostic imaging formulations.
The surfactants found to have bioadhesive or mucoadhesive properties include:
1) Poloxamers having an average molecular weight of from about 1,000 to 15,000 daltons;
2) Polyvinyl alcohol;
3) Polyvinyl pyrrolidone,
4) Hydroxypropyl methylcellulose; and
5) Polyoxyethylene sorbitan mono-oleate (Tween 80).
Poloxamers are polyethylene-polypropylene glycol block polymers containing ethylene oxide (PEO) and propylene oxide (PPO) moles according to the formula (PEO)a-(PPO)b-(PEO)c wherein
a is 46, 52, 62, 75, 97, 98, 122 and 128;
b is 16, 30, 35, 39, 47, 54 and 67; and
c is 46, 52, 62, 75, 97, 98, 122 and 128.
Table 1 shows the various poloxamers by manufacturer-designated number.
TABLE 1______________________________________Molecular Weights of PoloxamersPoloxamer Av. ValuesNo. Pluronic Av. Mol. Wt. a b c______________________________________401 4,400 6 67 6402 5,000 13 67 13403 5,750 21 67 21407 F127 12,000 98 67 98331 3,800 7 54 7333 4,950 20 54 20334 5,850 31 54 31335 6,000 38 54 38338 F108 15,000 128 54 128282 3,650 10 47 10284 4,600 21 47 21288 F98 13,500 122 47 122231 2,750 6 39 6234 4,200 22 39 22235 4,600 27 39 27237 F87 7,700 62 39 62238 F88 10,800 97 39 97212 2,750 8 35 8215 4,150 24 35 24217 F77 6,600 52 35 52181 2,000 3 30 3182 2,500 8 30 8183 2,650 10 30 10184 2,900 13 30 13185 3,400 19 30 19188 F68 8,350 75 30 75122 1,630 5 21 5123 1,850 7 21 7124 2,200 11 21 11101 1,100 2 16 2105 1,900 11 16 11108 F38 5,000 46 16 46______________________________________
Certain number of these surfactants are also known as Pluronic, which is a brand name of BASF Corporation.
Preferred surfactants for use in the present invention are:
Pluronic F127
Pluronic F108
Pluronic F98
Pluronic F87
Pluronic F88
Pluronic 77
Pluronic F68 and
Pluronic F38.
In another embodiment of the invention, there is provided an orally/rectally administrable therapeutic composition comprising:
of from about 0.1% to about 45% w/v, and preferably of from about 5% to about 25% w/v, of an essentially water insoluble or poorly water-soluble particulate crystalline material having an effective average particle size of less than about 2,000 nm, more preferably an effective average particle size of less than about 1,000 nm, and most preferably an effective average particle size of less than about 400 nm;
of from about 0.1% to about 10% w/v, and preferably of from about 1% to about 6% w/v of a bioadhesive or mucoadhesive surfactant stabilizer (hereinafter sometimes referred to as "primary stabilizer"); and
water to make 100% w/v.
Secondary stabilizers may also be used in the therapeutic composition up to about 1% w/v, preferably up to about 0.2% w/v, and most preferably up to about 0.1% w/v. Secondary stabilizers include dioctylsulfosuccinate (DOSS) and sodium lauryl sulfate (SLS).
Other ingredients customarily used in oral pharmaceutical formulations may also be included, such as flavorants, colorants and preservatives to provide pharmaceutically acceptable and palatable formulations.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is based on the discovery that particulate crystalline materials can be rendered mucoadhesive or bioadhesive in the gastrointestinal tract when the particulate crystalline material is combined with certain surface active agents in a suspension.
The invention can be practiced with a wide variety of crystalline materials that are water-insoluble or poorly soluble in water. As used herein "poorly soluble" means that the material has a solubility in aqueous medium of less than about 10 mg/ml, and preferably of less than about 1 mg/ml. Examples of preferred crystalline materials follow.
Drugs
Suitable drug substance can be selected from a variety of known classes of drugs including, for example, antacids, anti-inflammatory agents, antibiotics (including penicillins), antimycobacterial agents, antiviral agents, corticosteroids, parasympathomimetics, radio-pharmaceuticals, sympathomimetics, demulcents, emollients, gastrointestinal protectives and adsorbents, antifungals, H2-blocking agents, proton pump inhibitors, muscarinic antagonists, bismuth compounds, sucralfate, carbenoxolone, prostaglandins, digestants, bile acids, laxatives, antiparasitic agents, anthelmintics, antiprotozoal agents, antimicrobial agents, vitamins, immunologic agents, vaccines, anesthetics, lipid-regulating agents and bile acid sequestrants. Preferred drug substances include those intended for oral administration and rectal administration. A description of these classes of drugs and a listing of species within each class can be found in Martindale, The Extra Pharmacopoeia, Twenty-Ninth Edition, The Pharmaceutical Press, London, 1989, the disclosure of which is hereby incorporated by reference in its entirety. The drug substances are commercially available and/or can be prepared by techniques known in the art.
Radiopaque Materials
A preferred x-ray contrast agent utilized in the present invention is barium sulfate which is a white, radiopaque, crystalline powder that is essentially insoluble in water. It is commercially available in the particle size range of 0.001 to 0.1 micron diameter. Smaller particle size may also be obtained with techniques known in the prior art such as described in U.S. Pat. No. 5,145,684 which is incorporated herein by reference, or analogously, as described herein with respect to other crystalline radiopaque compounds. However, good results are obtainable with other finely-divided, inorganic, essentially water-insoluble salts of barium including barium hexaboride, barium chromite, barium fluogallate, barium tri-ortho phosphate, barium metasilicate, barium titanate and barium zirconate.
Preferred organic radiopaque crystalline compounds of the present invention include, but are not limited to the following compounds.
EXAMPLE 1
3,5-Bis-acetylamino-2,4,6-triiodo-benzoic acid ethyl ester (WIN 59316) ##STR1## Molecular Wt.: 657 Melting Point: 219°-220° C.
EXAMPLE 2
2-(3,5-Bis-acetylamino-2,4,6-triiodo-benzyloxy)-2-methyl malonic acid(WIN 67975) ##STR2##
Preparation of WIN 67975 (described in U.S. Pat. No. 5,264.610)
A solution of sodium hypaque (50 g, 79 mmole) in 150 ml of dry DMF was treated with 16.6 ml (87 mmole) of diethyl 2-bromo-2-methylmalonate and the reaction mixture was heated for 12 hrs on a steam bath. After cooling, the solution was added to ice water and the resulting precipitate was collected by filtration, rinsed with water, ethyl acetate and dried under vacuum. The product was recrystallized from DMF-water to give 48.4 g (69%) of pure material, mp 268°-269° C. (dec.); CI-MS: MH + 787. The 1 H-NMR (300 MHz) spectral data was consistent with the desired material. Calculated for C 19 H 21 I 3 N 2 O 8 : C 29.03, H 2.69, N 3.56, I 48.43; Found C 28.82, H 2.56, N 3.57, I 48.83.
EXAMPLE 3
Propanedioic Acid, [[3,5-bis-(acetylamino)-2,4,6-triiodo-benzoyl]oxy]-bis(1-methylethyl) ester (WIN 68165) ##STR3## Molecular Wt.: 800.12 Melting Point: 252°-253° C.
EXAMPLE 4
Diethyl 5-acetylamino-2,4,6-triiodo-isophthalate (WIN 59316)
3.91 g (0.17 mol) of sodium was dissolved in 500 ml of ethanol. Then, 50 g (0.083 mol) of 5-acetylamino-2,4,6-triiodo-isophthalic acid was added and the solution was stirred for half hour. The solvent was stripped to yield an intermediate, disodium 5-acetylamino-2,4,6-triiodoisophthalate. 250 ml of dry N,N-dimethylformamide was added. The contents did not dissolve completely. 15 ml (29.2 g, 0.187 mol) of ethyl iodide was added and the solution was heated on stem bath for 2 hrs. The solution was poured into 4 liters of water, filtered and rinsed with cold water. Solid was dried in a vacuum oven over the weekend. Yield--52.18 g. MS results, MW=657 a.m.u. This product and 5.0 g prepared using a small scale identical procedure was combined, total weight--57.2 g. It was dissolved in 120 ml of N,N-dimethylformamide. The solution was filtered into 2 liters of filtered and distilled water. The contents were swirled by hand. White solid was filtered and dried at 110° C., 0.2 mm Hg for 20 hrs. Recovered 56.27 g, melting point, 219°-220° C., MS results, MW=656.98 a.m.u.
Elemental analysis: Calculated for C 14 H 14 I 3 NO 5 : C 25.54, H 2.15, N 2.13, I 57.95. Found C 25.80, H 2.06, N 1.99, 157.77.
EXAMPLE 5
Ethyl 3,5-bis(acetylamino)-2,4,6-triiodobenzoate (WIN 8883) ##STR4##
Synthesis of Ethyl 3,5-bis(acetylamino)-2,4,6-triiodobenzoate (WIN 8883)
To 8.11 L of dry N,N-dimethylformamide was added 1.01 kg (1.65 mol) of diatrizoic acid. To the vigorously stirred suspension was carefully added 274 g (1.99 mol) of milled potassium carbonate. During the addition there was significant gas evolution. Before all of the suspended solid had gone into solution, a second solid began to form toward the end of the carbonate addition. The mixture was stirred for 30 min. at room temperature. Ethyl iodide (608 g, 3.90 mmol) was added dropwise and the mixture was stirred overnight at room temperature at which point the reaction mixture was nearly homogeneous. The reaction mixture was poured into 25 L of water, filtered and the solid washed with water and dried at reduced pressure at 60° C. to afford 962 g (91% yield) of a white solid, mp 280°-290° C. (dec.). Analysis for C 13 H 13 I 3 N 2 O 4 : Calculated: C 24.32, H 2.05, N 4.36. Found C 24.27, H 1.93, N 4.28.
EXAMPLE 6
Bis-[1-(ethoxycarbonyl)propyl]-2,4,6-triiodo-5-acetylamino-isophthalate (WIN 68183) ##STR5##
Bis-[1-(ethoxycarbonyl)propyl]-2,4,6-triiodo-5-acetylamino-isophthalate (WIN 68183) was prepared as follows.
Sodium metal (1.9 g, 82.6 mmol) was dissolved in 500 ml of absolute ethanol followed by the addition of 25 g (42 mmol) of 5-substituted-2,4,6-triiodoisophthalic acid. After stirring for 30 minutes the solvent was removed under vacuum to give 36.1 g of the di-sodium salt which was dried under high vacuum and used without further purification.
To a suspension of the sodium salt (10 g, 15.5 mmol) described above in 50 ml of DMF was added ethyl 2-bromobutyrate and the mixture was stirred at ambient temperature for 6 hrs at which point solution was observed. After heating for 1 hr on a steam bath, the solution was cooled and added to a mixture of ice and water. The desired product crystallized from the aqueous solution overnight and was collected by filtration and dried under vacuum to give an essentially quantitative yield of white solid, mp 195°-205° C.; CI-MS: MH + 830. The 1 H-NMR (300 MHz) spectral data was consistent with the desired material. Calculated for C 22 H 26 I 3 NO 9 : C 31.87, H 3.16, I 45.92, N 1.69; Found: C 31.81, H 3.17, I 45.94; N 1.64.
EXAMPLE 7
1,3,5-Triethyl-2,4,6-triiodobenzene (WIN 68756) ##STR6##
1,3,5-Triethyl-2,4,6-triiodobenzene was prepared in 56% yield from triethylbenzene (5.0 g, 31.4 mmol), [bis(trifluoroacetoxy)iodo]benzene (21.2 g, 49.2 mmol), and iodine (12.5 g, 47.2 mmol) in 50 ml of CCl 4 . Recrystallization from cyclohexane gave 9.5 g of pure material.
Title Compound: 1 H (300 MHz) and 13 C (75 MHz) NMR spectra were consistent With the desired product. Calculated for C 12 H 15 I 3 : C 26.69, H 2.80, I 70.51; Found: C 26.84, H 2.54, I 70.39.
EXAMPLE 8
3,5-Bis-acetylamino-2,4,6-triiodo-benzoic acid 4-methoxy-benzyl ester (WIN 67754) ##STR7##
3,5-Bis-acetylamino-2,4,6-triiodo-benzoic acid 4-methoxy-benzyl ester (WIN 67754) was prepared as follows.
To a stirred solution of sodium diatrizoate (25 g, 39 mmol) in 200 ml of DMF was added 4-methoxybenzyl chloride (5.8 ml, 42 mmol) over a 30 minute period. The resulting mixture was stirred overnight at ambient temperature. Additional 4-methoxybenzyl chloride (1 ml) was then added and the mixture was stirred for 24 hrs. The solvent was removed under reduced pressure leaving a white solid residue which was slurried in 300 ml of distilled water. The crude product was collected, washed with water and dried at 70°-75° C. to give a solid which was then digested with 400 ml of chloroform-isopropanol (1:1). Upon cooling, the solid was collected and dried under vaccuum at 80°-85° C. to give the product (24.3 g, 85% yield) as a white granular solid, mp 244°-246° C.; CI-MS: MH + 735. The 1 H-NMR (300 MHz) spectral data was consistent with the desired product. Calculated for C 19 H 17 I 3 N 2 O 5 ; C 31.09, H 2.33, I 51.86, N 3.82; Found: C 31.05, H 2.23, I 51.84, N 3.84.
EXAMPLE 9
3,5-Bis-acetylamino-2,4,6-triiodo-benzoic acid 4-isopropyl benzoate ester (WIN 67956) ##STR8##
3,5-Bis-acetylamino-2,4,6-triiodo-benzoic acid 4-isopropyl benzoate ester (WIN 67956) was prepared in a manner similar to Example 8.
EXAMPLE 10
6-Ethoxy-6-oxohexyl 3,5-bis(acetylamino)-2,4,6-triiodobenzoate (WIN 67722) ##STR9##
6-Ethoxy-6-oxohexyl 3,5-bis(acetylamino)-2,4,6-triiodobenzoate (WIN 67722) was prepared as follows.
Sodium diatrizoate (16.1 g, 25.3 mmol) was dissolved in 180 ml of dry dimethylformamide and to this solution was added, in one portion, ethyl 6-bromohexanoate (4.5 ml, 25.3 mmol). The reaction mixture was stirred for 12 hrs at ambient temperature and then poured into 1.6 liter of ice-water with stirring. The resulting white precipitate was collected by filtration, dissolved in 1:1 ethanol-ethyl acetate and the solution was treated with magnesium sulfate, decolorizing charcoal and then filtered through a short pad of silica gel. The filtrate was concentrated to dryness and dried to give 16 g (84%) of the desired product. Recrystallization from methanol-water gave analytically pure material, mp 235°-238° C. (decomp. at 275° C.); MS:M + 756. The 1 H-NMR (300 MHz) spectral data was consistent with the desired product. Calculated for C 19 H 23 I 3 N 2 O 6 ; C 30.18, H 3.07, I 50.35, N 3.70; Found: C 30.26, H 2.88, I 50.40, N 3.65.
EXAMPLE 11
3,5-Bis-acetylamino-2,4,6-triiodo-benzoic acid 5-isopropoxycarbonyl-pentylester (WIN 67995) ##STR10##
3,5-Bis-acetylamino-2,4,6-triiodo-benzoic acid 5-isopropoxycarbonylpentylester (WIN 67995) was prepared in a manner similar to Example 10.
Method of Preparing the Radiopaque Particulates
The radiopaque particulates were prepared by milling the large radiopaque particles mixed with an appropriate surface active agent to obtain the desired particle size. Alternatively, the large radiopaque particulates may be comminuted to the desired particle size and subsequently intimately mixed with the appropriate surface active agent. The milling technique is described in U.S. Pat. No. 5,145,684, which is incorporated herein by reference.
As used herein, particle size refers to a number average particle size as measured by conventional particle size measuring techniques well known to those skilled in the art, such as sedimentation field flow fractionation, photon correlation spectroscopy, or disk centrifugation. By "an effective average particle size of less than about 400 nm" for example, it is meant that at least 90% of the particles have a weight average particle size of less than about 400 nm when measured by the above-noted techniques. With reference to the effective average particle size, it is preferred that at least 95% and, more preferably, at least 99% of the particles have a particle size less than the effective average, e.g., 400 nm. In particularly preferred embodiments, essentially all of the particles have a size less than 400 nm.
The particles of this invention can be prepared in a method comprising the steps of dispersing a radiopaque substance in a liquid dispersion medium and applying mechanical means in the presence of grinding media to reduce the particle size of the radiopaque substance to an effective average particle size of less than about 400 nm. The particles are reduced in size in the presence of the surface active agent. Alternatively, the particles can be intimately mixed with a surface active agent after attrition.
A general procedure for preparing the particles of this invention is set forth below. The radiopaque substance selected is obtained commercially and/or prepared by techniques known in the art in a conventional coarse form. It is preferred, but not essential, that the particle size of the coarse radiopaque substance selected be less than about 100 μm as determined by sieve analysis. If the coarse particle size of the radiopaque substance is greater than about 100 μm, then it is preferred that the particles of the radiopaque substance be reduced in size to less than 100 μm using a conventional milling method such as airjet of fragmentation milling.
The mechanical means applied to reduce the particle size of the radiopaque substance conveniently can take the form of a dispersion mill. Suitable dispersion mills include a ball mill, an attritor mill, a vibratory mill, and media mills such as a sand mill and a bead mill. A media mill is preferred due to the relatively shorter milling time required to provide the intended result, i.e., the desired reduction in particle size.
The grinding media for the particle size reduction step can be selected from rigid media preferably spherical or particulate in form having an average size less than about 3 mm and, more preferably, less than about 1 min. Such media desirably can provide the particles of the invention with shorter processing times and impart less wear to the milling equipment. The selection of material for the grinding media is not believed to be critical. We have found that zirconium oxide, such as 95% ZrO stabilized with magnesia, zirconium silicate and glass grinding media provide particles having levels of contamination which are believed to be acceptable for the preparation of pharmaceutical compositions. However, other media, such as stainless steel, titania, alumina, and 95% ZrO stabilized with yttrium, are expected to be useful. Preferred media have a density greater than about 3 g/cm 3 .
The attrition time can vary widely and depends primarily upon the particular mechanical means and processing conditions selected. For ball mills, processing times of up to five days or longer may be required. On the other hand, processing times of less than 1 day (residence times of one minute up to several hours) have provided the desired results using a high shear media mill.
The particles must be reduced in size at a temperature which does not significantly degrade the radiopaque substance. Processing temperatures of less than about 30°-40° C. are ordinarily preferred. If desired, the processing equipment can be cooled with conventional cooling equipment. The method is conveniently carried out under conditions of ambient temperature and at processing pressures which are safe and effective for the milling process. For example, ambient processing pressures are typical of ball mills, attritor mills and vibratory mills. Processing pressures up to about 20 psi (1.4 kg/cm 2 ) are typical of media milling.
Nanosuspension particle size was determined during the milling process and again immediately before the nanosuspensions were administered to rodents. Particle size was determined on the Coulter Model N4MD Submicron Particle Analyzer (Coulter Corp.; Miami Lakes, Fla.); and using the Microtrac Ultrafine Particle Analyzer (Leeds and Northrup Co.; St. Petersburg, Fla.).
The following formulation examples will further illustrate the present invention.
EXAMPLE 12
______________________________________WIN 68183 20 gPluronic F127 4.0 gBenzoate Sodium 0.2 gSaccharin Sodium 0.1 gFD&C Red No. 40 0.03 gWater, qs 100 ml______________________________________
EXAMPLE 13
______________________________________WIN 68183 15 gPluronic F127 4.0 gBenzoate Sodium 0.2 gSorbate Potassium 0.15 gSaccharin Sodium 0.1 gFD&C Red No. 40 0.03 gWater, qs 100 ml______________________________________
EXAMPLE 14
______________________________________WIN 68183 25 gPluronic F88 5.0 gBenzoate Sodium 0.2 gSaccharin Sodium 0.1 gFD&C Red No. 3 0.03 gWater, qs 100 ml______________________________________
EXAMPLE 15
______________________________________WIN 8883 19 gSucrose 10 gPluronic F77 4.0 gDioctylsulfosuccinate 0.1 gMethylparabens 0.2 gPropylparabens 0.07 gFD&C Yellow No. 5 0.03 gWater, qs 100 ml______________________________________
EXAMPLE 16
______________________________________WIN 68756 15 gPluronic F127 5 gSorbitol 5 gBenzoate Sodium 0.2 gWater, qs 100 ml______________________________________
EXAMPLE 17
______________________________________WIN 8883 22 gHPMC (2% = 100 cps) 2 gSteam sterilized by autoclaving at 120° C. 0.2 gfor 21 minutes & 5 psigWater, qs 100 ml______________________________________
EXAMPLE 18
______________________________________WIN 67754 20 gPluronic F127 4.0 gBenzoate Sodium 0.2 gSorbate Potassium 0.15 gSaccharin Sodium 0.1 gWater, qs 100 mlHydrochloric Acid adjust to pH 4.0______________________________________
Determining Imaging Efficacy
X-ray diagnostic imaging was performed in anesthetized rats with the exception of G05-R1 samples which were imaged in fasted and anesthetized ferrets. Images were obtained using the Siemens C-Arm Siremobil 3U x-ray unit. The imaging dose was 10 ml/kg administered via gastric intubation to the anesthetized animal. X-rays were taken at 15, 30, 45 and 60 minutes and at 1, 2, 5 and 24 hours post-dose. A 10-15 ml volume of air was introduced to the animal at 30 minutes to produce a double contrast image.
Images were evaluated by the criteria of coating, homogeneity, rate of gastric emptying and the total transit time. These are considered to be a measure of the stability of the nanosuspension during transit down the GI tract and the ability of the formulation to image the lower gastrointestinal tract. Nanosuspensions were rated excellent when there was a uniform coating with transradiation of long intestinal segments, sufficient radiodensity to delineate anatomical structure, rapid emptying and transit, and stability and homogeneity during GI transit. A plus sign (+) was assigned when imaging in the lower GI was exceptional, a minus sign (-) as given when it was not. The nanosuspension of WIN 8883 milled in Pluronic F127, was considered to be excellent for both upper and lower GI imaging in both rats and ferrets. All other nanosuspensions were compared with this formulation.
The various polymeric surfactants and additional excipients used to prepare nanosuspensions are listed in Table 2. Nanosuspensions of WIN 8883 were milled at 20% weight per volume in presence of 4% w/v solutions of stabilizers unless specified otherwise.
TABLE 2______________________________________Surfactants Used for the Preparationof Nanoparticulate FormulationsSURFACTANT GRADE SOURCE______________________________________PLURONIC F127 NF BASFPLURONIC F68 NF BASFPLURONIC F77 NF BASFPLURONIC F87 NF BASFPLURONIC F88 NF BASFPLURONIC F98 NF BASFPLURONIC F108 NF BASFTETRONIC T908 PRILL BASF (RM)TYLOXAPOL RM SIGMAPOLYVINYL ALCOHOL RM SIGMAAvg. MW 30-70KPOLYVINYL PYRROLIDONE RM SIGMA(PVP 40) MW 40KHYDROXYPROPYLMETHYL RM SIGMACELLULOSE (HPMC:2% SOLUTION = 100 CPS)POLYOXYETHYLENE SORBITAN RM SIGMAMONO-OLEATE (TWEEN 80)DIOCTYLSULFOSUCCINATE, DOSS RM SIGMA______________________________________ RM = Commercial Grade Raw Material NF = National Formulary
The efficacy of the nanoparticulate formulations to image the GI tract is shown in Table 3. Overall, compounds with the lowest aqueous solubility were often the most efficacious. WIN 68183 and WIN 68756 were considered to be excellent imaging agents as compared with WIN 8883, however, lower GI imaging was not as definitive as with WIN 8883. WIN 67754 was scored as good overall and exhibited exceptional lower GI imaging. Initially WIN 67956 showed very rapid gastric emptying and therefore was repeated with air given at 15 minutes to induce double contrast. No improvement in coating was seen with this compound and it was rated as good. WIN 67722 and WIN 67995 were rated as good in the upper GI, however, imaging efficacy in the lower GI was poor. WIN 59316, WIN 68165 and WIN 67975 were rated as fair, with only WIN 59316 imaging well in the lower GI tract.
TABLE 3__________________________________________________________________________Imaging Efficacy of Nanoparticulate Formulations Prepared with PluronicF127 Aqueous Particle Solubility Days Milling Size ImagingCode WIN No. (μg/ml) Milled Process.sup.(a) (nm).sup.(b) Range.sup.(c) Efficacy.sup.(d,e)__________________________________________________________________________GO5 8883 <5 1.8 P 186/ND Narrow ++++(*)GO5 R2 8883 <5 5 JM 135/ND 80-230 ++++(*)GO9 68183 <1 9 JM 139/ND 95-169 ++++(*)G10 68756 <1 <1 P3R 165/154 94-395 ++++GO6 67754 15 9 JM 152/ND 95-300 +++(*)GO8 67956 1 14 JM 221/ND 125-478 +++GO8 R167956 1 7 JM 241/223 130-686 +++G11 67722 2 <1 P3R 150/146 84-442 +++(-)G16 67995 1 4 JM 156/171 97-253 +++(-)GO7 59316 1 14 JM 678/ND 185-900 ++(*)G12 67975 8 <1 P3R 211/206 93-910 ++(-)G13 68165 1 <1 P6R 742/1060 527-1704 ++__________________________________________________________________________ .sup.(a) P = Planetary Mill, JM = Jar Mill, P(N)R = 18 hour planetary mil and N = number of days Jar Mill. .sup.(b) Postmilling/pre-dose particle size; ND = Not Determined. .sup.(c) Range(nm) = Size Distribution for 10 to 99% of the particles by weight. .sup.(d) Imaging efficacy is indicated as follows: Excellent++++ Good+++ Fair++ Poor .sup.(e) Formulations with efficacy followed by (*) signs indicate exceptional lower GI imaging while those with (-) sign were found to be unacceptable in the lower GI.
Efficacy of Nanoparticulate Formulations Prepared with Alternate Surfactants as X-Ray Contrast Agent
The imaging efficacy of nanosuspension formulations with alternate surfactants are shown in Table 4.
Excellent imaging was obtained from nanosuspensions of WIN 8883 stabilized with Pluronic F77 with 0.1% DOSS added (G29) and with Pluronic F88 (GO4), however, these nanosuspensions did not image the lower GI as effectively as GO5.
Good imaging was obtained from nanosuspensions of WIN 8883 stabilized with polyvinyl alcohol (PVA) (G21), tyloxapol (G20), tyloxapol with 0.1% w/v DOSS (G37), hydroxypropyl methylcellulose (G22), F88 with 0.1% DOSS (G27), and F87 (G26). Good upper GI imaging was obtained from nanosuspensions of WIN 8883 stabilized with F98 (G14), F108 (G15) and F68 with 0.1% w/v DOSS (G23). Fair imaging was obtained from the WIN 8883 nanosuspensions stabilized with T908 (GO1), Tween 80 (G3), 1% w/v DOSS (G18), polyvinyl pyrrolidone, (PVP 40) (G19) and F87 with 1% w/v DOSS (G25). Poor imagining was obtained when no stabilizer was used (GO2) and the formulation with F77 alone (G28) gelled during milling and therefore was not imaged. Nanosuspension G18, prepared in 1.0% w/v DOSS was foamy, and G19, 4% PVP 40 milled to a thick foam.
DOSS and HPMC were found to be fair in regard to their stabilizing effect on imaging efficacy. DOSS itself was found to be fair (G18) while HPMC was rated as good, even with particle sizes greater than 700 rim. DOSS was needed to stabilize the nanosuspension prepared in 4% w/v Pluronic F77 (G29). The same formulation without DOSS could not be imaged due to gelling during the milling process.
DOSS had variable effects when used in conjunction with other stabilizers. The nanosuspension stabilized with F88 (GO4) was rated as excellent. When 0.1% w/v DOSS was used as a secondary stabilizer (G24), the imaging efficacy was rated only as good. A similar result was noted with nanosuspensions stabilized with F87. The suspension without DOSS (G26) was rated higher in imaging efficacy than did the same suspension with 0.1% w/v DOSS (G25). Nanosuspensions stabilized with 4% w/v tyloxapol plus 0.1% w/v DOSS (G27) or without DOSS (G20) were both rated good. Milling time, however, was reduced and overall particle size was smaller with the DOSS-added suspension.
TABLE 4______________________________________Imaging Efficacy of Diagnostic Agents Preparedwith Alternative Surfactants Mill- Par- ing ticle Imaging Stabilizer Days Proc- Size Effi-I.D. (w/v) Milled ess (nm).sup.(b) Range.sup.(c) cacy.sup.(d,e,f)______________________________________GO2 None 6 JM 1000/ Broad + NDGO5 4% F127 1.8 P 186/ Narrow ++++(*) NDG29 4% F77/ 5 JM 146/ 66-243 ++++ 0.1% 187 DOSSEGO4 4% F88 1.8 P 183/ Narrow +++(-) NDG21 4% PVA 6 JM 204/ 134-405 +++(*) 199G26 4% F87 5 JM 155 55-265 +++G20 4% 6 JM 180/ 137-521 +++ Tyloxapol 262G22.sup.(f) 2% 6 JM 334/ 350-2596 +++ HPMC 700G24 4% F88/ 5 JM 160 146-265 +++ 0.1% DOSSG27 4% 5 JM 140 66-315 +++ Tyloxapol/ 0.1% DOSSG23 5% F68/ 4 JM 147/ 108-602 +++(-) 0.1% 170 DOSSGO3 4% 6 JM 161/ Narrow ++ Tween 80 NDG18.sup.(f) 1% 4 JM 119/ 85-247 ++ DOSS 130G19.sup.(f) 4% PVP 5 JM 673/ 620-1265 ++ 823G25 4% F87/ 5 JM 150 66-243 ++ 0.1% DOSS______________________________________ .sup.(a) P = Planetary Mill, JM = Jar Mill, P(N)R = 18 hour planetary mil and N = number of days Jar Mill .sup.(b) Postmilling/pre-dose particle size; ND = Not Determined. Formulations G24 through G28, G30 and G32 were sized within 24 hours of milling; others were sized when the milling was terminated. .sup.(c) Range(nm) = Size Distribution for 10 to 99% of the particles by weight. .sup.(d) Imaging efficacy is indicated as follows: Excellent++++ Good+++ Fair++ P .sup.(e) Formulations with efficacy followed by (*) signs indicate exceptional lower GI imaging while those with (-) signs were found to be unacceptable in the lower GI. .sup.(f) Foaming was eviident in G18 (1% DOSS), very thick foam was found in G19 (4% PVP) and in G22 (2% HPMC).
Comparison of Pluronic F127 vs. F88 Surfactants
The two alternate compounds stabilized with Pluronic F127 and which demonstrated excellent imaging efficacy in the rat (WIN 68183 and WIN 68756), were subsequently milled with F88 with a resultant loss of efficacy as shown in Table 5.
TABLE 5__________________________________________________________________________Comparison of Efficacy Between Pluronic F88 and Pluronic F127 Particle Days Milling Size ImagingI.D. WIN No Pluronic Milled Process.sup.(a) (nm).sup.(b) Range.sup.(c) Efficacy.sup.(d,e,f)__________________________________________________________________________GO5 8883 F127 1.8 P 186/ND Narrow ++++(*)GO9 68183 F127 9 JM 139/ND 95-169 ++++GO10 68756 F127 P3R -- 165/154 94-395 ++++GO4 8883 F88 1.8 P 183/ND Narrow ++++(-)G31 68756 F88 3 JM 209 118-578 +++G17 68183 F88 8 JM 146/125 77-237 +++(-)__________________________________________________________________________ .sup.(a) P = Planetary Mill, JM = Jar Mill, P(N)R = 18 hour planetary mil and N = number of days Jar Mill .sup.(b) Postmilling/pre-dose particle size; ND = Not Determined. .sup.(c) Range(nm) = Size Distribution for 10 to 99% of the particles by weight (preimage where indicated) .sup.(d) Imaging efficacy is indicated as follows: Excellent++++ Good+++ Fair++ P .sup.(e) Formulations with efficacy followed by (*) signs indicate exceptional lower GI imaging while those with (-) signs were found to be unacceptable in the lower GI. .sup.(f) G31 was imaged within 24 hours of milling.
Summarizing the above-described test results, twenty different stabilizers were examined using nanosuspensions of WIN 8883, of these, Pluronic F127 was considered excellent for imaging both the upper and lower GI. A nanosuspension stabilized with F88 was judged as excellent but for the upper GI only. Twenty compounds gave acceptable results as oral GI x-ray imaging agents. Three compounds (WIN 8883, WIN 68183 and WIN 68756) and one stabilizer, Pluronic F127, was recognized as an excellent oral GI x-ray imaging agent. When nanosuspensions of these same three compounds were stabilized with F88, only the WIN 8883 nanosuspension produced excellent imaging, and then only in the upper GI.
The dosages of the contrast agent used according to the method of the present invention will vary according to the precise nature of the contrast agent used. Preferably, however, the dosage should be kept as low as is consistent with achieving contrast enhanced imaging. By employing as small amount of contrast agent as possible, toxicity potential is minimized. For most contrast agents of the present invention dosages will be in the range of from about 0.1 to about 16.0 g iodine/kg body weight, preferably in the range of from about 0.5 to about 6.0 g iodine/kg of body weight, and most preferably, in the range of from about 1.2 to about 2.0 g iodine/kg body weight for regular x-ray visualization of the GI tract. For CT scanning, the contrast agents of the present invention will be in the range of from about 1 to about 600 mg iodine/kg body weight, preferably in the range of from about 20 to about 200 mg iodine/kg body weight, and most preferably in the range of from about 40 to about 80 mg iodine/kg body weight.
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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Nanoparticulate crystalline x-ray contrast agents are formulated with stabilizers to enhance contact between the crystalline x-ray contrast agents and the gastrointestinal tract.
Nanoparticulate crystalline therapeutic substances also formulated with stabilizers to enhance contact between the crystalline therapeutic substances and the gastrointestinal tract and to provide extended therapeutic effect.
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This application is a national stage completion of PCT/EP2004/010296 filed Sep. 15, 2004 which claims priority from German Application Serial No. 103 47 492.7 filed Oct. 13, 2003.
FIELD OF THE INVENTION
The invention concerns a shifting device.
BACKGROUND OF THE INVENTION
For the shifting of a transmission, especially where vehicles are concerned, a shifting device is provided in the transmission with the aid of which the individual gear stages can be engaged. As this is done, it is possible that parts of the shifting device can be moved manually by the vehicle driver or, alternating, this function may be carried out by actuators which are energized by at least one auxiliary power medium to execute the necessary movements required by the shifting mechanism.
Customarily, the expended forces which are sufficient for the selection of the individual gear stages are less than those forces to be exerted upon the shifting of the selected gear stage, which has a result that the elements of the selection apparatus on the shifting device can be otherwise dimensioned than are those of the necessary components, which are intended for the execution of the shifting.
The costs for a shifting device of this kind for a transmission are essentially dependent upon the complexity of the employed installed components, upon the materials thereof, upon the required expense for the mechanical working of the components and further upon manufacturing costs for the machining, shaping and heat treatment.
DE A1 198 43 584 makes known a shifting apparatus for a multistage shifting transmission wherein, on a single shifting shaft, a multiplicity of shifting forks are placed. A selection mechanism enables the choice of one of the shifting forks by way of the turning of a shifting shaft. Alternately, if the shifting shaft is axially displaced, then the respectively selected shifting fork is activated to carry out the intended shifting action. A blocking shaft, placed parallel to the shifting shaft, is likewise rotated upon the turning of the shifting shaft and thereby, employing, in its function as a blocking shaft, the movement of such shifting forks which were not chosen as indicated above. The components for this construction must be manufactured in a complex manner and at high cost. Following the assembly of the components, the co-action of the functioning parts generates noise and frequently leads to critical noise problems.
EP-B1 0 633 412 teaches of an actuator for a sliding collar enclosed in a shifting transmission, having a shifting rod located and slidable in the direction of its longitudinal axis on which a shifting fork, as well as a ring-shaped engagement unit, are rigidly affixed. The actuation apparatus is constructed as a combined plastic-metal component, where a metal part, which serves as the ring-shaped engagement unit as well as a core for the shifting rod, is sprayed with a plastic material and the shifting fork consists exclusively of plastic. In this assembly, simply a combination of plastic and metal must be created as a component, in order to assure the required stability of a component necessary for the shifting of a gear stage.
The purpose of the invention is to demonstrate a shifting device, which can be economically manufactured and can operate at a low noise level without containing a complex binding construction.
SUMMARY OF THE INVENTION
According to the invention, a shifting device for the shifting of a transmission possesses a shifting shaft upon which a multiplicity of shifting forks or shifting rockers (hereinafter referred to as “shifting forks”) are placed in an axial, slidable alignment for the execution of shifting procedures. Provided are: a) a selection apparatus for the choice of one of the shifting forks out of the multiplicity of shifting forks and b) blocking disks for the prevention of an axial motion of the non-chosen shifting forks. For the carrying out of shifting procedures, these elements are being constructed of a material of greater structural strength while, contrarily, the elements of the selection apparatus are being made from a material of lower grade.
In an advantageous embodiment, the elements of the selection apparatus make use of ring-shaped engagement units, specifically for each shifting fork. The ring-shaped engagement units are axially affixed and slidable along the shifting shaft to enable the execution of the shifting procedure. The ring-shaped engagement units are rotatable about the shifting shaft for the selection of one of the shifting forks and possess elements of a come-along apparatus, which enable an axial sliding of the ring-shaped engagement unit because of the axial motion of the shifting shaft in the shifting procedure.
Another advantageous embodiment demonstrates, that the ring-shaped engagement units on the shaping fork, coact with a blocking means for prevention of axial motion of non-chosen shifting forks on the shifting shaft.
In a particularly advantageous embodiment, elements of the blocking means incorporate rotatable blocking disks, the circumferences of which extend into an axial movement area of the ring-shaped engagement units. The contour of a blocking disk is designed in such a manner that the eliminated zone of the blocking disks, which is in segmental shape, allow an axial movement of the ring-shaped engagement units on the shifting shaft, while other areas of the blocking disks are appropriate for preventing an axial movement of the ring-shaped engagement units.
Advantageously, recesses are present on the ring-shaped engagement units, which recesses co-act with projections on the shifting shaft. The projections penetrate the recesses, if the associated shifting forks are not engaged and further the projections slide the ring-shaped engagement units axially if the selected shifting fork is in a displaced position in order to change the gear stage.
The elements of the selection apparatus exhibit advantageously, exhibit complementary toothings which mesh and enable a rotation of the elements of the selection apparatus in relation to one another. In this operation, due to their formation, only parts of the ring-shaped engagement unit possess toothing.
Representing one embodiment, an area of a section in the blocking disks can exhibit a toothing, which can mesh into the toothing of a ring-shaped engagement unit.
An inventive embodiment would be especially advantageous, if the elements for the carrying out shifting procedure were made of steel or aluminum, while the elements of the selection apparatus and of the blocking disks are constructed of aluminum or plastic or, again, from a combined compounding.
In the case of a particularly advantageous design of the invention, an actuator can be provided for the axial displacement of the shifting shaft, while an additional actuator governs the elements of the selection apparatus as well as those of the of the blocking disks. In this way, a transmission becomes available for ratio control of rotation of the shifting shaft actuator in an axial movement thereof.
Advantageously, at least one actuator is provided, which is designed to operate electromechanically, pneumatically or hydraulically.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described, by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a first shifting device with individual elements, and
FIG. 2 is a second presentation of detailed elements of a second embodiment of the shifting device.
DETAILED DESCRIPTION OF THE INVENTION
According to FIG. 1 , four shifting forks, namely 8 , 10 , 12 and 14 are placed on a shifting shaft 2 . Shifting shaft 2 is axially slidably supported in bearings 4 and 6 which, in turn, are affixed in a housing (not shown) of the shifting transmission. The shifting forks are installed so as to be moveable in relation to the shifting shaft 2 . For the purposes of clarity of illustration and better understanding, not all possible shifting forks are shown on the shaft 2 . Further, individual elements of the shifting device are presented in a somewhat exploded view separate from the shifting shaft. In a completed assembly, however, all shifting forks are located in a manner similar to that of shifting fork 12 , which is shown on the shifting shaft 2 . Presented in FIG. 1 is an arrangement of the three shifting forks 8 , 10 and 12 of the shifting shaft 2 , while the shifting fork 14 is placed underneath the shifting shaft 2 in this arrangement. The following components, described here, serve analogously for every shifting fork, if these also can be described and explained by a single typical shifting fork, because of their common characteristics.
The shifting shaft 2 possesses projections in the form of two pins 16 , 18 on the shifting fork 10 , which enclose the shifting fork 10 between them. Between pins 16 and 18 and the shifting fork 10 is to be found at each side of the shifting fork 10 , one sheet metal, contoured disk 20 , 22 . The contoured disks 20 , 22 are bounded on their inner circumference, similar openings 24 through which, respectively, the pins 16 and 18 can be axially inserted. The remaining area between each of the openings 24 , bounded by the inner circumference of a contoured disk 20 and 22 is able, by a mutual turning of a contoured disk 20 and 22 on the shifting shaft 2 , with the aid of the pins 16 and 18 , to make a mutual overlap. Thereby, in a case of an axial movement of the shifting shaft 2 over the pin 16 and 18 and the contoured disk 20 and 22 even the shifting fork 10 is axially displaced and a gear stage can be engaged in the transmission.
In order to turn the contoured disk 20 and 22 on the shifting shaft 2 , the contoured disk 20 and 22 possesses a contoured surface (hereinafter “contour 26 ”) on its outer circumference, which co-acts with a complementary contour on a ring-shaped engagement unit 28 and/or 30 and forms a turn-fast connection between the contoured disk 20 and 22 and the ring-shaped engagement unit 28 and 30 ( FIG. 2 ).
Such a device, basically including a ring-shaped engagement unit 32 is pictured in its location on the shifting fork 12 , wherein currently two single, ring-shaped engagement units are combined to form one component. In order to enable a rotation of the ring-shaped engagement unit 32 on the shifting shaft 2 , without interfering with the arms of the shifting fork 12 , the ring-shaped engagement unit 32 is furnished with a recess 34 . On the outer circumference of the ring-shaped engagement units 28 , 30 , 32 is provided a toothing 36 , which can stand in engagement with corresponding toothing 38 , 40 on gears 42 and 44 . This is correspondingly valid for all shifting forks 8 , 10 , 12 and 14 . The gears 42 and 44 are turn-fast affixed on a shaft 46 , which is essentially aligned parallel to shifting shaft 2 . The shaft is rotated by an actuator 48 such as, for example, an electric motor through a ratio train with a toothing 50 . The arrangement however, can also be so designed that the actuator 48 is directly bound to the shaft 46 without the ratio train. Laterally located to the gears 42 and 44 is respectively a blocking disk 52 of a blocking apparatus, which does not possess a complete, circular circumference, but has a recess in the form of a circular segment 54 .
The blocking disks 52 of the differing shifting forks 8 , 10 , 12 , 14 also exhibit such segmental cutoffs at various positions on their circumferences, so that the two blocking disks 52 always present the same cutoffs to one shifting fork, while otherwise, the cutoffs on the blocking disks 52 of the other shifting forks are provided for rotation about the axis of the common shaft 46 . The blocking disks 52 act together with the ring-shaped engagement units 28 , 30 , 32 for the formation of the blocking apparatus, for example by the edges of the toothings of the ring-shaped engagement unit 28 , 30 , 32 . In this way, the blocking disks 52 hold the ring-shaped engagement units 28 , 30 32 and therewith also hold the shifting forks in their axial position on the shifting shaft 2 and only permit an axial movement of the currently selected shifting fork in the area of the segment 54 on the blocking disk 52 .
The shifting shaft 2 is connected to an actuator 60 by way of a transfer block 56 with a ball-joint drive 58 which is, in turn, connected to an actuator 60 , for instance, an electric motor. Instead of the ball drive 58 , this power transfer can be accomplished by a gear drive (not shown). The illustrated actuators 48 and 60 are shown in FIG. 1 as being co-axial or axis parallel to the shaft 2 and 46 which is to be placed in motion. By way of an appropriate directive gear drive, the possibility exists that an assembly, which stands at an angle to the shaft, may also be installed at a right angle, for instance.
In order to shift the gear stage, it is necessary that the shifting forks 8 , 10 , 12 or 14 be pushed axially. The shifting forks 8 , 10 , 12 and 14 are freely supported on the shifting shaft 2 and for engagement, these must be axially shape-fit with the shifting shaft 2 by the pins 16 , 18 and the contoured disk 20 , 22 . The toothed ring-shaped engagement units 28 , 30 , 32 are rotated by the shaft 46 , which shaft is provided with gears 42 , 44 . The shifting shaft 2 moves itself for the engagement of the gear stages only in the axial direction. The selective preliminary choice of the gear stage to be shifted is carried out in that the contoured disk 20 , 22 are rotated by the ring-shaped engagement units 28 , 30 , 32 which encompass them and thereupon close a discrete angle. Analogous to this angle, the cutouts 24 in the contoured disks 20 , 22 are provided which, by way of the non-shifted gear stages, as soon as the shifting shaft moves itself, lead to an engagement of the pins 16 and/or 18 and thereby to no correspondingly movement contoured disk of the corresponding shifting fork. In the case of the fork to be shifted which is in this position, its necessary contoured disk 20 and 22 lacks an internal opening 24 , so that the fork undergoes an axial movement and the desired gear stage is engaged. In each of the different selection positions, there is always one contoured pair 20 , 22 without internal cutouts 24 in overlap with the rods 16 , 18 so that an action can be initiated. All of the rest of the ring-shaped engagement units are coinciding with the internal cutouts 24 with the appropriate rods 16 , 18 and no axial motion can occur.
FIG. 2 shows a shifting device in accord with FIG. 1 in a partially released condition. In this case, the segments 54 on the blocking disks 52 are provided with a toothing, so that the blocking disks in the non-blocking angular position can mesh into the outer toothing of the appropriate ring-shaped engagement unit 28 , 30 . The ring shaped engagement units 28 , 30 are designed here as separate components so that the necessity of the formation of toothing 36 , as is required with the ring-shaped engagement unit 32 , is eliminated.
Since the elements taking part in the selection of the shifting fork to be shifted are exposed only to comparatively small forces, the design of these elements finds that a construction material of a lesser structural strength will suffice. Such a material would be plastic or a metal other than steel, but possibly including aluminum. Aluminum, in comparison to steel, is a low strength metal and plastic, both in comparison to steel and aluminum, in turn, is a material of lesser strength.
Appropriate for a plastic construction, in the present embodiment, is the ratio determining stage with the toothing 50 to which can be added the shaft 46 and all gears 42 , 44 and blocking disks 52 which are on the shaft 46 . Likewise, the ring-shaped engagement units 28 , 30 , 32 can be made of plastic both in the assembled state as well as in the separate part versions. The elements of plastic can be pre-manufactured and require no or only minuscule reworking. This is essentially cheaper than the construction materials for systems built of greater structural strength. A further advantage can be found with elements made of plastic producing a lesser generation of noise, since plastic possesses, essentially, a noise dampening function. Known at the present time and generally criticized noise problems, such as rattling in the transmission and scraping of gears, can be avoided by the above system.
REFERENCE NUMERALS
2 shifting shaft
4 bearing
6 bearing
8 shifting fork
10 shifting fork
12 shifting fork
14 shifting fork
16 pin
18 pin
20 contoured disck (externally)
22 contoured disk (externally)
24 internal opening of 20 , 22
26 contour at outer circumference
28 rich-shaped engagement unit
30 ring-shaped engagement unit
32 ring-shaped engagement unit
34 cutout
36 toothing
38 toothing
40 toothing
42 gear
44 gear
46 shaft
48 actuator
50 toothing
52 blocking disk
54 segment
56 transfer block
58 universal ball joint
60 actuator
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A shifting device for the shifting of a transmission with a shifting shaft ( 2 ), having a multiplicity of shifting forks or shifting levers ( 8, 10, 12, 14 ) placed in an axial slidable manner for the carrying out of a shifting procedure with a selection apparatus ( 28, 30, 32, 42, 44, 46 ) for the choice of a shifting fork ( 8, 10, 12, 14 ) from the multiplicity of shifting forks for the carrying out of the shifting procedure and with blocking disk ( 52 ) for the prevention of the movement of non-chosen shifting forks ( 8, 10, 12, 14 ). The elements ( 2, 8, 10, 12, 14, 20, 22 ) for the carrying out of the shifting procedure are made from a material of high structural strength and the elements of the selection apparatus ( 28, 30, 32, 42, 44, 46 ) and the blocking apparatus ( 52 ) are constructed from a material of lesser structural strength.
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This is a continuation of application Ser. No. 07/698,618, filed May 10, 1991 now abandoned.
FIELD OF THE INVENTION
The present invention relates to the field of power line communications wherein communication signals are transmitted over signal lines normally used for power transmission. More specifically, the present invention relates to the field of reducing power line communication signal attenuation caused by the various elements and devices which comprise and connect to power lines within a plane, boat, house (or other structure), etc.
BACKGROUND OF THE INVENTION
It has become common in the computing industry to transfer data and commands between data processing devices such as computers, printers, displays, terminals, etc., commonly referred to as "nodes" or network resources. Interconnection of computers and other devices has been achieved via a variety of different networks. One such network is known as a Local Area Network (LAN).
It is predicted that LAN's will be used for many applications in the future. Some of these applications will undoubtedly eliminate the costly and complicated wiring commonly used today. These future applications include automotive, domestic, aviation and ship-borne applications, among others. In these future applications each device may include a specialized unit which provides communication for that device in order to send and receive messages transmitted over the communications medium. In this way, a single medium may be used for multiple purposes such as power transmission to devices connected to a power line as well as communications between these devices connected to the power line. One example of such multiple use network communications is that of a home management system as is described in more detail with reference to FIG. 1. Please note that the same basic issues arise in other situations such as in an office building or storage warehouse.
As can be seen in FIG. 1, a house 100 is shown having a number of devices each coupled via a single communications medium which, in this case, is the standard electrical power line which exists in most houses. These devices can have intelligence so that if a particular device is appropriately signalled it will perform a predefined operation.
Using standard house wiring as the communication medium has the advantage of avoiding the high costs of installing dedicated communication wiring to new or existing buildings. Additionally, using standard house wiring as the communication medium has the advantage of ease of use in that connection to the network is a simple and familiar process for anyone who has ever plugged in a home appliance.
One difficulty in using house wiring for the communication medium is the large amount of noise which exists on the house wiring due to the large variety of pre-existing appliances connected to the wiring network. A further difficulty is caused by all of the attenuation which exists in the house wiring due to a variety of sources as is discussed more fully below. This attenuation of the communications signal may be 40 decibals (dB) or more. Under these conditions it can be very difficult for a communication device to properly receive such an attenuated signal while an adjacent appliance is producing large amounts of noise.
SUMMARY AND OBJECTS OF THE INVENTION
One objective of the present invention is to provide a coupling circuit with minimal attenuation at its output terminals.
Another objective of the present invention is to provide a coupling circuit with minimal attenuation at its output terminals when connected to a wall outlet of a typical house.
These and other objects of the present invention are provided for by a circuit for coupling a signal source to a signal line having a given impedance. The circuit comprises a resistor having sufficient resistance to limit the current of the signal source if the signal line is shorted to thus prevent the signal source from saturating, a capacitor having sufficient impedance to limit the current in the signal line at a first frequency wherein the signal line may also be carrying current at the first frequency, and an inductive element having sufficient impedance to substantially cancel out the impedance of the capacitor and the impedance of the signal line at a second frequency wherein the signal source outputs the second frequency.
Other objects, features, and advantages of the present invention will be apparent from the accompanying drawings and from the detailed description which follows below.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements, and in which:
FIG. 1 is a simplified example configuration of the power line communication apparatus as used in the present invention;
FIG. 2 is a prior art power line coupling network and transmit amplifier;
FIG. 3 is a reduced circuit of the prior art power line coupling network and transmit amplifier of FIG. 2;
FIG. 4 is a reduced circuit of the prior art power line coupling network and transmit amplifier of FIG. 3;
FIG. 5 is a reduced circuit of the prior art power line coupling network and transmit amplifier of FIG. 3 further including a local receptacle impedance voltage divider;
FIG. 6 is a reduced circuit of a series resonant power line coupling network;
FIG. 7 is a transmit amplifier and power line coupling network of the present inventions.
FIG. 8 illustrates another embodiment of the transmit amplifier and power line coupling network of the present invention that includes the use of a leakage transformer.
DETAILED DESCRIPTION
A power line communication (PLC) apparatus is described which enables communications over power lines between devices. In the following description numerous specific details are set forth, such as specific frequencies, component values, etc. These details are provided to enable one to fully appreciate and understand the present invention. It will be obvious to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known circuits have been shown in block diagram form in order not to unnecessarily obscure the present invention in detail.
Referring again to FIG. 1, a portion of a typical household configuration using the transmitter/receivers of the present invention can be seen. PLC apparatus 60 is plugged into one receptacle of wall outlet 52 (alternatively, wall outlet 52 may itself incorporate the communications intelligence of PLC apparatus 60). Also shown in FIG. 1, household appliance 56 is also plugged into wall outlet 52. Wall outlet 52 is connected by house wiring 53 to a main circuit breaker panel of the dwelling. Other wall outlets, such as outlet 54, are also connected to circuit breaker panel 50 via house wiring 53 in parallel with wall outlet 52. Another PLC apparatus 62 is shown plugged into one receptacle of wall outlet 54 of FIG. 1. Also shown in FIG. 1, household appliance 58 is also plugged into wall outlet 54.
PLC apparatus 60 can send a command signal through wall outlet 52 across the house wiring 53 to circuit breaker panel 50 then across the house wiring 53 to wall outlet 54 and on to PLC apparatus 62. This command signal may indicate to PLC apparatus 62 to take some action such as turning on a light which is connected to PLC apparatus 62. Of course, because PLC apparatuses can transmit as well as receive communication signals, transmitter/receiver 62 can equally signal PLC apparatus 60 to take some action.
Because of the large amount of noise down at the power transmission frequency level of 60 hertz (the standard frequency level in the U.S.), or 50 hertz (commonly used in foreign countries), when it is desired to transmit data on a power line it is common to modulate a carrier signal and transmit data at some higher frequency. In the preferred embodiment of the present invention this higher frequency is approximately 100-150 kilohertz. Note that higher frequencies encounter higher attenuation while lower frequencies encounter greater noise.
Unfortunately, because power lines (and appliances connected to them) weren't designed to allow operation of a communication network, there are few standards and controls in place to limit the impedance of the appliances which may be connected to the receptacles of the various wall outlets in a house. While some appliances and devices may have very large impedances others may have impedances of only one ohm or less. If an appliance with a low impedance is connected to one receptacle of a wall outlet when a PLC apparatus is connected to the other receptacle of the same wall outlet then there is an attenuation of the signal output from the PLC apparatus which can occur even before the signal is placed on the wiring going to the circuit breaker panel. This attenuation is due to a voltage divider effect between the output impedance of the PLC apparatus and the impedance of the appliance when both are connected to the same ,wall outlet. This voltage divider effect is discussed more fully below with reference to FIG. 5.
Further, due to the impedance of house wiring 53 between wall outlet 52 and circuit breaker panel 50, there is a series inductance the impedance of which in conjunction with the collective line to neutral impedance at panel 50 further attenuates the signal from PLC apparatus 60 which is connected to wall outlet 52. In a typical house the length of wiring 53 between a wall outlet and a circuit breaker panel is typically 40 feet or more which results in approximately 10 ohms of impedance in the 100-150 kilohertz range. Please note that with the frequencies used in the preferred embodiment of the present invention it is not necessary to view this as a transmission line because the distance between a wall outlet and a circuit breaker in a typical home is less than one quarter of a wave length. Note also the house wiring is terminated (at panel 50) in something less than its characteristic impedance. Therefore, it is the inductance of the house wiring and not the capacitance which is the critical element.
Then, when all of the lines going into circuit breaker panel 50 are connected in parallel, the impedance at circuit breaker panel 50 forms another impedance. This circuit breaker parallel impedance can be as low as one ohm. Thus the impedance of wiring 53 and the impedance of panel 50 function as a voltage divider attenuating signals transmitted by PLC 60. Also, there can be additional attenuation of the signal from one PLC apparatus to another when they reside on the opposing two phases of power in a household. Note: while there is a measure of signal coupling between the two phases it is typically with an attenuation of 15-20 dB.
Still further, due to the impedance of house wiring 53 between circuit breaker panel 50 and outlet 54 there is a series inductance the impedance of which in conjunction with the collective line to neutral impedance at outlet 54 further attenuates the signal from PLC apparatus 60. As stated above, this series impedance is approximately 10 ohms in the 100-150 kilohertz range.
And finally, when a household appliance 58 is coupled in parallel to the same wall outlet 54 as PLC apparatus 62 another voltage divider effect is formed between the impedance of wiring 53, from panel 50 to outlet 54, and the impedance of appliance 58.
In total, the attenuation in a typical household may be greater than 40 dB. To repeat, this is caused by the voltage divider effect of the PLC apparatus when another device is also connected to the same wall outlet, the high series impedance of the house wiring, the low parallel impedance of the circuit breaker panel, the imperfect coupling between the two phases of household power, a second series impedance of house wiring, and the parallel impedance of appliance 58. Further, it is estimated that approximately 20-40% of this attenuation can occur right at the wall outlet due to the voltage divider effect.
FIG. 2 depicts a simplified diagram of a transmit amplifier 68 and a prior art power line coupling network containing a series resistor 70, a coupling transformer 72 and a series capacitor 74. Transmit amplifier 68 increases the transmit signal to enough power to get it out onto the power line while the coupling transformer 72 electrically isolates the power line communication apparatus from direct connection with the power line.
Series resistance 70 limits the drive current of transmit amplifier 68 should there be a low impedance across the output terminals. Typical series resistance in the prior art is in the range of 5 to 20 ohms (Ω).
Series capacitor 74 limits the power line current at the power transmission frequency (e.g., 60 Hz). The size of capacitor 74 must be chosen properly in order to accomplish this. If capacitor 74 is too small, it becomes a problem to the transmit circuit because a smaller capacitor would provide a larger impedance to the communications signal frequencies (i.e., 100-150 KHz) which thus causes greater attenuation of the transmit signal. Conversely, if capacitor 74 is too large the impedance drops in which case more low frequency power transmission current will flow and thus coupling transformer 72 is more likely to saturate. Therefore, typical series capacitance in the prior art is in the range of 0.10 to 0.47 microfarads (μF).
Referring now to FIG. 3, when one wishes to analyze operation primarily at communication signal frequencies a reduced Thevenin equivalent circuit of the circuit of FIG. 2 can be drawn wherein transmit amplifier 68 and coupling transformer 72 have been replaced with a voltage source 73 in series with a resistor 76 and capacitor 74. This reduction technique is well known in the art.
This circuit can be further reduced, as shown in FIG. 4, when the impedance is of primary interest, thus leaving merely a voltage source 73 and the complex impedance 78 of the power line coupling network itself as the sole elements. This reduction technique is also well known in the art.
Impedance 78 is a function of the impedance of resistor 76 and the impedance of capacitor 74 of FIG. 3. Again, as stated above, this is one prior art approach to implementing a power line coupling network.
However, the prior art power line coupling network of FIG. 3 incurs further difficulties, as was referred to above. If the output terminals of the power line coupling network of FIG. 3 are connected to a wall outlet receptacle when another device is connected to another receptacle of the same wall outlet, a voltage divider effect occurs which can substantially attenuate the output signal from the power line coupling network.
FIG. 5 depicts the voltage divider effect of a prior art power line coupling network connected in parallel with another device plugged into the same wall outlet. The impedance of the power line coupling network is depicted as Z out 78 while the impedance of the device coupled in parallel is depicted as Z outlet 80. In this situation, the voltage which the power line coupling network actually places on the line (V outlet ) is attenuated and is therefore equal to the open circuit output voltage of the power line coupling network itself (V out 73) multiplied by the impedance Z outlet 80 divided by the sum of the impedances Z outlet 80 and Z out 78 (V outlet =V out (Z outlet/Z outlet +Z out )).
Because it is generally impractical to build this type of power line coupling network with less than five ohms of output impedance (Z out 78) and because the impedance of a device connected in parallel to the power line coupling network (Z outlet 80) can be an ohm or less, the signal attenuation through the power line coupling network can be 16 decibals or more:
Attenuation=10 log(V.sub.outlet.sup.2 /V.sub.out.sup.2)=20 log(V.sub.outlet /V.sub.out)=20 log(Z.sub.outlet /(Z.sub.outlet +Z.sub.out))=20 log 1/(1+5)=16).
Another prior art approach to power line coupling networks is the use of a series resonant coupling network as is shown in FIG. 6. In a series resonant coupling network, as compared to the power line coupling network of FIG. 2, the size of capacitor 82 is reduced (which thus lowers its cost) and a series inductor 84 is added. The inductor value is chosen so that at the carrier frequency the inductor's inductive reactance (2πƒ c L)cancels out the capacitor's capacitive reactance (-1/2πƒ c C). In this way, the impedance Z out 78 at the carrier frequency is merely the resistance 76 of the power line coupling network. Of course, in this idealized environment the power line coupling network is only connected to resistive loads.
Unfortunately, when this series resonant coupling network is connected to power lines which consist of other than pure resistive loads this offset of a positive reactance with a negative reactance at a given frequency can be lost. And in reality there is rarely just a resistive load in power lines and hence the reactance of these real world power lines can, in effect, "detune" the resonant circuit. Thus, although no reactance may be seen in an idealized environment, once reactances of a real world power line are connected to the resonant circuit of the power line coupling network these other reactances can still cause attenuation of the output signal.
For example, if a 0.047 microfarad coupling capacitor 82 is placed in series with a 39 microhenry inductor 84 then, in an idealized world, the -29 ohms reactive impedance of capacitor 82 (at 118 kHz) would be offset by the +29 ohms reactive impedance of inductor 84 (at 118 kHz). However, once the series resonant power line coupling network is connected to a wall outlet which is connected to a 40 foot length of house wiring then (because house wiring has an inductance of approximately 0.25 microhenries per foot) an additional 12.5 microhenries is added in series to the circuit which is enough to detune the resonant circuit.
Further, if a still smaller capacitor 82 were used in an attempt to offset the additional inductance of the house wiring, then very high attenuation would occur if the transmit receptacle capacitance were primarily capacitive in nature (in which case the resonance would occur above the carrier frequency and the attenuation would be caused by a capacitive divider).
Because it is important in the present invention to provide suitable power signals with minimal power loss/attenuation for a large percentage of households, it is desirable that a minimal percentage of households have an overall attenuation of ≧55 decibals (dB). The following table shows the results of tests and simulations in the communication signal frequency range of 100-150 kHz of the prior art conventional power line coupling network, the prior art series resonant power line coupling network, and various values of inductors 84 of the series resonant power line coupling network of the present invention each showing an improvement over the prior art series resonant power line coupling network.
______________________________________ % of householdsPower Line with ≧55 dBCoupling Network Source Impedance attenuation______________________________________conventional 5Ω + .27 μF .88%reduced cap only 5Ω + .047 μF 6.05%std. series resonant 5Ω + .047 μF + 39 μH 2.94%improved ser. res. 5Ω + .047 μF + 33 μH 1.40%improved ser. res. 5Ω + .047 μF + 27 μH .79%improved ser. res. 5Ω + .047 μF + 22 μH .70%improved ser. res. 5Ω + .047 μF + 18 μH .93%______________________________________
The above table shows that the series resonant L/C coupling circuit of the present invention achieves better performance than either the prior art conventional power line coupling network or the prior art series resonant circuit and is accomplished by adjusting the resonant elements to account for the realities of the typical power line which is being connected to. The above table further shows that there is an optimal amount of inductive reactance to offset the capacitive reactance of both the coupling network and a typical house and therefore merely using the smallest value of series inductor does not provide the best results. Therefore, in the preferred embodiment of the series resonant power line coupling network of the present invention a 0.047 microfarad capacitor is placed in series with a 22 microhenry inductor to best offset the reactances when connecting to a real world power line having more than just resistive elements.
It is important to note that the only component variation between the prior art series resonant power line coupling network and the preferred embodiment of the power line coupling network of the present invention is changing the 39 microhenry inductor to a 22 microhenry inductor. It is believed that this difference of approximately 17 microhenries is the proper value to compensate for the de-tuning effect of the typical power line being coupled to. Therefore, while in the preferred embodiment a 22 microhenry inductor is used, this particular value is optimized for a 100-150 kHz communication signal frequency with a 0.047 microfarad capacitor. However, if the communication signal frequency and the capacitor are chosen to be different values than in the preferred embodiment of the present invention, then the inductor value would also have to be adjusted so as to maintian the above-explained approximately 17 microhenry difference.
Referring now to FIG. 7, transmit amplifier 68 is shown coupled to the preferred embodiment of the power line coupling network of the present invention. More specifically, transmit amplifier 68 is coupled through series resistance 70 (approximately 5-20 ohms, as explained above) to coupling transformer 72. Coupling transformer 72 is coupled through series inductor 82 of approximately 22 microhenries and series capacitor 84 of approximately 0.047 microfarads to the hot lead of a wall receptacle.
In an alternative embodiment, the separate inductor element could be replaced by L utilizing a transformer having the appropriate leakage inductance, such as leakage transformer 92 shown in FIG. 8. More specifically, by using a transformer wherein the flux from the winding on one side does not fully couple to the winding on the other side, in this way the desired series inductance can be created in the transformer itself. Stated differently, by using a transformer with a leakage inductance of 22 microhenries no discrete inductive component is needed which thus simplifies, and lowers the cost of, the power line coupling circuit.
An additional benefit of the present invention is the avoidance of coupling transformer saturation from low frequency power line noise. The problem with the coupling transformer saturating with low frequency noise is that the shape of the noise impulses is modified (by the transformer's saturation) to have a faster falling edge than rising edge. Then the adaptive snubber incorrectly snubs on the tail edge of some of the noise when it should not be snubbed at all. The series resonant circuitry of the power line coupling network of the present invention prevents this from occuring because the power line coupling network of the present invention does not allow as much low frequency current to flow in the coupling transformer and thus the transformer does not saturate from low frequency noise and thus the impulse waveform is not distorted and thus the snubber can operate properly.
In the foregoing specification, the invention has been described with reference to the presently preferred embodiment thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specifications and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.
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An apparatus for reducing power line communication signal attenuation is disclosed. This apparatus provides for reduction of power line communication signal attenuation by balancing reactance between chosen circuit elements and the typical impedances found in a house, structure, or similar entity. The present invention uses a series resonant circuitry to couple the communication signal to the power line. The inductance in the series resonant circuitry is chosen to compensate for the de-tuning effect of the typical power line to which it's coupled in the communication system.
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This application is a continuation of Ser. No. 08/540,525 filed Oct. 10, 1995, abandoned.
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to a numerical control (“NC”) system for a five-axis precision positioning and support of a machine tool with respect to a workpiece surface in a work envelope.
2. Background Art
The precision machining of large workpieces requires the use of a wide array of expensive machine tools such as full size models and gauges, templates, fixtures, and drill-sets. These tools have a substantial acquisition and maintenance costs, as well as costs related to their storage, property management, inspection, reinspection, and accountability. In addition, the manufacturing tolerances and repeatability achievable with these tools is limited.
For example in the aerospace industry, large airframe components such as fuselage sections can be precision machined only with the use of very costly full size models and gauges. A typical series of models needed to drill precision holes is shown in FIGS. 1A-1B. As shown in FIG. 1A, the first step in this process is to fabricate a male master model 100 of a fuselage section, which model is made of metal or plaster and has projections 105 of the size and at the locations required for the holes to be drilled in the fuselage section. A female plaster cast 110 is formed over the model 100 , which cast has apertures 115 formed over the projections 105 . As shown in FIG. 1B, a male cast back 120 is formed from the plaster cast 110 , which cast back is also made from plaster. Again, projections 125 are formed by the plaster flowing into the apertures 115 in the cast 110 . Finally, a drill bonnet 130 made of a composite material, such as fiberglass or graphite composite, is formed over the cast back 120 . The bonnet 130 has apertures 135 of the correct size and at the correct locations where holes are required to be drilled.
The first step in using the bonnet 130 is to fasten a fuselage section into an assembly jig using bracing means, or “details”, and locator pins to provide a reference position for the fuselage. The bonnet 130 is then secured adjacent the fuselage section and aligned with the section using the locator pins. The bonnet 130 then serves as a drilling template through which holes are drilled into the fuselage section.
The cost to fabricate a typical drill bonnet 130 can average $1 million and take from one to 12 weeks. For the F-18 aircraft, 900 bonnets are needed to drill all the fuselage holes. Thus, the total cost for the drill bonnet tool family for the F-18 is approximately $1 billion. Full scale interior models, called master gages, are also required to precisely locate and drill holes in details which are attached to interior structures of the assembly jig. These details are used to locate the bulkheads, frames and ribs of the aircraft. Such master gages can cost between $5-10 million each and the F-18 requires 33 such master gages, for a total master gage tool family cost of approximately $250 million.
One object of the invention is to eliminate the need for these costly tool families and replace them with a machine tool locating system made from standardized parts to reduce cost and fabrication time. Another object of the invention is to improve the accuracy of hole location by eliminating the cumulative tolerance resulting from the use of multiple master models and gages, and related molds.
Another object of the invention is to increase the speed with which an assembly jig can be prepared to machine a new workpiece, or implement engineering changes to an existing workpiece design. Previously, new master models and gages would have to be fabricated for either a new aircraft component or changes to an existing one, requiring from four to 24 weeks to prepare. A positioning system of invention can locate machine tools directly from machine design software, reducing this aircraft change time to one or two days.
SUMMARY OF THE INVENTION
The present invention is embodied in an automated system for the positioning and support of a machine tool within a workpiece supporting assembly, comprising a pair of generally parallel, planar longitudinal translation modules affixed to the assembly and having sliding pads and a movement means, a transverse translation module affixed to the longitudinal sliding pads in a generally perpendicular orientation to the longitudinal modules and having sliding pads and a movement means. The system also includes a vertical translation module affixed to the transverse sliding pads in a generally perpendicular orientation to the longitudinal and transverse translation modules and having sliding pads and a movement means, the vertical translation module further comprising a mounting means for the machine tool and a means to rotate the machine tool about a vertical axis and a means to pivot the machine tool about any axis orthogonal to the vertical axis, and a control means.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are perspective views prior art molds used to fabricate a drill positioning bonnet.
FIG. 2 is a perspective view of a positioning system of the invention.
FIG. 3 is a perspective view of a portion of the system of FIG. 2 showing a translation module.
FIG. 4 is a block diagram of a control means for the system of FIG. 2 .
FIG. 5 is a perspective view of a portion of a second embodiment of the system of FIG. 2 showing a ballrail and pad assembly.
FIG. 6 is a perspective view of the positioning system of the present invention within a jig assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 2, a system 200 of the invention uses two longitudinal translation modules 201 positioned parallel to an x axis. The function and construction of these modules 201 is similar to other translation modules used in the invention for transverse and vertical movement as explained below. The modules 201 may be temporarily or permanently attached to a jig frame 202 having a workpiece within the jig frame 202 , as shown in FIG. 6 and located with conventional locator pins in reference positions 203 of the frame 202 , as shown in FIG. 6 .
Sliding pads 205 translate along each module 201 in response to synchronized servo motors 210 , by means described below. The sliding pads 205 are similar to sliding pads used on other translation modules used in the invention. The pads 205 will be of an appropriate size depending on the size of the structure being translated and the distance of travel. The modules 201 also include linear sensors 212 along the length of the module. The sensors 212 are of a conventional design such as glass scales or digital strips. Again, the sensors 212 are similar to sensors used on other translation modules and will generally have a length of approximately the same length as the translation module on which it is mounted.
Removable mounting bases 215 are fastened to the pads 205 and support bridge members 220 . Members 220 support a transverse translation module 225 , parallel to the y axis and driven by a servo motor 230 , which combined structure forms a bridge 231 over the work envelope with modules 201 on either side of the bridge. The motor 230 may be connected to the module 225 either by a belt reduction drive 232 , gear drive, or a direct drive. The sliding pads 205 support and translate a z axis structure 240 along the y axis and the sensor 212 is mounted along the length of the module 225 .
The z axis structure 240 includes two vertical translation modules 245 and sliding pads 205 driven by a single servo motor 250 . Two vertical translation modules 245 provide additional strength to support the weight of the structure 240 and prevent the back pressure from a machining operation from displacing the structure, which could cause machining errors. The modules 245 also include sensors 212 along their length. Again, the motor 250 may be connected to modules 245 either by a belt reduction drive 280 , gear drive, or a direct drive. The belt reduction drives 232 , 280 or gear drives provide increased accuracy in translational movement of the sliding pads 205 .
The modules 245 translate a carriage 255 along the z axis, on which a rotation motor 260 is mounted in order to rotate a machine tool 265 about the z axis. In accordance with one preferred embodiment of the invention, the machine tool 265 will be an electric drill for forming apertures in the workpiece. A pivot motor 270 is also mounted on the carriage 255 and the pivot motor rotates the machine tool 265 about all axes perpendicular to the z axis, depending on the position of the rotation motor 260 . Rotational sensors 272 are mounted on each of the rotational motor 260 and pivot motor 270 to measure the angular rotation of the motors.
The translation modules 201 , 225 and 245 use conventional ballscrew drive construction, which provides accurate control at a minimum cost. As shown in FIG. 3, each module 201 , 225 and 245 consists of guide rails 300 and a ball lead screw 310 mounted in a parallel position between the rails. The ball lead screw 310 is supported at both ends of the module by bearings 315 , which are mounted on a support plate 305 that also supports the rails 300 . The pad 205 includes a threaded guide 320 which is positioned adjacent between the rails 300 and engages the screw 310 . As the screw 310 turns, the sliding pad 205 translates along the direction of the rails 300 . The screw 310 can be coupled directly to a servo motor, such as the motor 210 in FIG. 2, or by means of the belt reduction drives 232 , 280 or gear drives, to servo motors 230 and 250 , respectively (also in FIG. 2 ).
The positioning system 200 of FIG. 1 is controlled by the NC devices illustrated in FIG. 4. A conventional servo control module 350 , such as a UMH Series, High-Frequency Type, DC Servo Control, made by Baldor of Berne, Switzerland, sends translation signals 355 to the motors 210 , 230 and 250 (shown in FIG. 2 ), rotation signals 360 to the motors 260 and 270 (shown in FIG. 2) and operation signals 365 to the machine tool 265 (shown in FIG. 1 ). The module 350 receives sensor signals 370 from the linear sensors 212 mounted on each of the modules 201 , 225 , and 245 and rotational sensors 272 (shown in FIG. 2 ). The sensor signals 370 measure the proximity of (a) the initial machining part of the machine tool 265 (e.g. the tip of a drill) to a desired set of x, y and z coordinates (referred to as the “vector”), and (b) the orientation of the tool path (e.g. the drill centerline) to the contour of the workpiece surface (referred to as the “normal”) as defined by rotation and pivot angles. The module also receives task signals 375 from a conventional industrial controller 380 , such as a Delta Tau Controller (made by Data Systems Inc., of Northridge, Calif.) and sends task completion signals 385 to the controller 380 . The controller 380 generates the task signals 375 from a workpiece database 390 that is sent to the controller 380 . The workpiece database 390 comprises a set of task signals 375 and defines the work to be performed on workpiece, such as the location, orientation and depth of holes.
The operation of the system 200 begins by the mounting of the translation modules 201 , as shown in FIG. 2, in a parallel relation on a jig frame 202 , as shown in FIG. 6. A bridge 231 of a suitable height and length to access those portions of the workpiece on which the work is to be performed is attached by the bases 215 to the pads 205 . A conventional laser alignment tool is used to locate the machine tool 165 with respect to a reference datum of the workpiece.
As shown in FIG. 4., each task signal 375 defines a task to be performed on the workpiece and is generated by the controller 380 . For example if the task is to drill a hole in the workpiece, a basic data item in the task signal 375 would be the location of the drill tip, i.e. the vector, and is defined by x, y and z coordinates in relation to the workpiece reference datum used to locate the modules 201 (as shown in FIG. 2 ). Another data item is the normal, which is defined by angles about the rotation and pivot axes at a selected vector. Other data to be defined could include the speed of the drill, the feed rate at which the drill moves with respect to the workpiece, and the distance that the drill is to travel (which determines the depth of the hole).
The controller 380 holds in memory each task signal 375 in the workpiece database 390 . This workpiece database 390 could be provided by a computer aided design (“CAD”) program defining a finished workpiece and could be entered in the controller 380 by manual or magnetic means.
In addition, the controller 380 determines when a task signal 375 (e.g. comprising the vector, normal, drill rates and distance) is sent to the control module 350 . For example, the controller 380 could be programmed to send the task signal 375 to the module 350 only after a hole drilled pursuant to a previous task signal has been finished, i.e., a “when done” command.
When a task signal 375 is sent to the control module 350 , it sends translation signals 355 and rotation signals 360 to move the machine tool 265 (shown in FIG. 2) to the desired vector and normal. If the desired vector or normal of the task signal 375 is not reached by means of the translation signals 355 or rotation signals 360 , one or more sensor signals 370 proportional to the error in coordinates or angles will be sent to the module 350 . The module 350 then generates appropriate revised translation signals 355 or rotation signals 360 in order to make the correction in vector or normal. The translation signals 355 and rotation signals 360 also include a velocity command that directs the speed of the motors 210 , 230 and 250 (shown in FIG. 2) in order to control the time at which the desired vector will be reached.
After the desired position is reached, the module 350 sends the operation signal 365 (i.e. the remaining information from the task signal 375 ) to accomplish the desired work. For example when a drill reaches a desired vector and normal, the module 350 sends to a drill the operation signal 365 , comprising a drill speed, drill feed rate, and a drill distance. After this operation signal 365 has been sent, module 350 sends the completion signal 285 to the controller 355 , which then sends a subsequent task signal 375 to the module 350 and the operation is repeated until all the tasks in the workpiece database 390 have been completed.
In a second preferred embodiment, the cost and expense of the linear sensors 212 and rotational sensors 272 (shown in FIG. 2) may be eliminated without adversely affecting the performance of the system 200 . This result can be a significant savings because sensors such as digital strips can cost as much as 20 percent of the cost of the system 200 .
This embodiment is achieved by using conventional laser measuring means to measure the vector of the machine tool 265 at maximum travel positions of each translation module 201 , 225 and 245 (shown in FIG. 2 ), and at several commanded intermediate positions. These vectors are compared with the location signals 355 (shown in FIG. 4) sent to reach each of the measured positions, and vector errors are determined for each module. This set of vector errors is programmed into the memory of the controller 380 . After this calibration procedure, when the workpiece database 390 requires movement to a set of coordinates, the controller 380 corrects the task signal 375 by the amount of the vector errors. A similar calibration procedure is used to measure normal errors and to eliminate the need for rotational sensors 272 .
In another preferred embodiment of the invention, a ballrail 400 is mounted on the bridge member 220 and parallel to the transverse module 225 . Further, the ballrail 400 is positioned on the opposite side of the module 225 from the z axis structure 240 and is connected to the z axis structure by a modified sliding pad 405 , which translates along the module 225 (i.e. y axis) in a manner identical to sliding pad 205 (shown in FIG. 2 ). The pad 405 is operatively connected to the ballrail 400 at a semicircle 410 whose ballrail facing surface is covered with ball bearings 415 . The ballrail 400 and pad 405 assembly (a “ballrail and pad assembly”) allows translation along the y axis, but prevents motion of the pad 405 is the z direction. The advantage of the ballrail and pad assembly is to offset the lever arm produced by the z axis structure about the module 225 , thus improving stability of the machine tool 265 (shown in FIG. 2) during machine operations. For example during a drilling operation, a resistance force (“drill-back”) may develop that can displace the drill and reduce the hole accuracy. The effect of drill-back is substantially reduced by the ballrail and pad assembly.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
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The present invention is embodied in an automated system for the positioning and support of a machine tool within a workpiece supporting assembly, comprising a pair of generally parallel, planar longitudinal translation modules affixed to the assembly and having longitudinal sliding pads and a longitudinal movement device, a transverse translation module affixed to the longitudinal sliding pads in a generally perpendicular orientation to the longitudinal modules and having transverse sliding pads and a transverse movement device. The system also includes a vertical translation module affixed to the transverse sliding pads in a generally perpendicular orientation to the longitudinal and transverse translation modules and having vertical sliding pads and a vertical movement device, the vertical translation module further comprising a mounting device for the machine tool and a device to rotate the machine tool about a vertical axis and a device to pivot the machine tool about any axis orthogonal to the vertical axis, and a control device.
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TECHNICAL FIELD
This invention relates to combustion in internal combustion engines and more particularly to a combustion method which I have named delayed reaction stratified combustion.
BACKGROUND
Among various types of stratified charge or stratified combustion engines are those of ignition chamber or prechamber design wherein a small prechamber is fed a rich mixture that is subsequently ignited and a connecting main chamber is supplied with air or very lean mixture. The stratified combustion process in such engines may be considered as instantaneous reaction since, upon ignition, the products of rich combustion issuing from the prechamber immediately mix and react with unreacted constituents of the main chamber.
The consequence of this sequence of reactions in terms of formation of nitrogen oxides (NO x ) is not optimum since the products in the main chamber always pass through the slightly lean air-to-fuel ratio (approximately 16:1) in which maximum NO x is produced. Further, the effect of injecting the burning charge of rich mixture into the cold main body of lean mixture or air is to cool or quench the combustion reaction so that the combustion event and the time occupied in burning in the region of maximum NO x are extended, increasing the total NO x formation. An example of the air/fuel ratios present in the main chamber of an engine of this type during combustion is shown in FIG. 1 wherein the ratios begin at infinity and are subsequently enriched during combustion to approximately a stoichiometric air/fuel ratio of 14.7:1.
SUMMARY OF THE INVENTION
The present invention utilizes an open chamber stratified charge engine and proposes a method of combustion therein that avoid excessive quenching of burning mixture and eliminates or minimizes the effects of combustion of air-fuel mixture in the region of maximum NO x formation. The method provides for the injection of supplemental air into a rapidly burning rich main chamber mixture during an intermediate portion of the combustion event in a manner that avoids quenching the burning mixture and instead aids its rapid combustion so that the time of combustion in a region of maximum NO x production is minimized. Further, if the overall air/fuel ratio is limited to stoichiometric, the region of maximum NO x formation is never traversed. Such a combustion reaction in accordance with the invention is shown, for example, in FIG. 2.
The consequence of a combustion method in accordance with the invention, which I have termed a delayed reaction stratified combustion method, is the ability to operate at reduced levels of NO x formation for the same amount of exhaust gas recirculation or at the same levels of NO x formation with far less exhaust gas recirculation than with homogeneous or conventional stratified charge combustion methods thereby permitting higher mean effective pressures and, thus, improved power and stability of combustion.
The delayed reaction stratified combustion engine concept may be carried out by adding a small third valve to the conventional engine cylinder arrangement and providing a small compressor for supplying air, or air and ricirculated exhaust gases, to the combustion chambers at specifically controlled points of the combustion cycle. The cylinders are metered rich having for example, a 10.5:1 air/fuel ratio, which provides easy ignition with rapid combustion at a relatively low rate of production of nitrogen oxides. A diluent, such as air, or preferably air plus recirculated exhaust gas, is compressed in the compressor and injected into the cylinder through the third valve during an intermediate portion near the middle third of the combustion event so that the overall mixture products are diluted by the added air to a desired air/fuel ratio, such as stoichiometric, while an additional desired amount of recirculated exhaust gas is also included.
Computer simulated comparisons of my delayed reaction stratified combustion method with the conventional homogeneous combustion and instantaneous reaction stratified combustion methods have shown the capability of my method to provide more efficient rapid and stable combustion with equivalent levels of exhaust gas recirculation and NO x production or reduced levels of either or both of the latter. These and other features and advantages of the invention will be more fully understood from the following description of certain preferred embodiments taken together with the accompanying drawings.
BRIEF DRAWING DESCRIPTION
In the drawings:
FIG. 1 is a graphical presentation of air/fuel ratio versus time during combustion in the main combustion chamber of an exemplary conventional instantaneous reaction stratified combustion engine;
FIG. 2 is a graphical presentation of air/fuel ratio versus time in an exemplary combustion event of a delayed reaction stratified combustion engine in accordance with the invention;
FIG. 3 is a graphical presentation of computer simulated combustion results for both conventional engines and engines in accordance with the invention, and
FIG. 4 is a partially schematic representation of an engine arrangement suitable for practicing the delayed reaction stratified combustion method of the present invention.
DETAILED DESCRIPTION
FIGS. 1 and 2 of the drawings are comparative graphical presentations of the combustion chamber air/fuel ratios during exemplary combustion events in the main chambers respectively of a conventional instantaneous reaction stratified combustion engine and a delayed reaction stratified combustion engine according to the invention.
In FIG. 1, line 10 illustrates the increasing enrichment versus time of the mixture in the main chamber, from undiluted air at the beginning of the combustion event to a stoichiometric ratio, as burning mixture from the stratified charge engine prechamber is injected into the main chamber during the combustion event. It is seen that, at the indicated elapsed time of about 4 milliseconds into the combustion event, the air/fuel ratio passes through the slightly lean air/fuel ratio of about 16:1 which is in the region of maximum formation of nitrogen oxides. Note that this air/fuel ratio occurs relatively early in the combustion event, when combustion is occurring at a maximum rate. Further, the overall rate of combustion is somewhat slowed by the quenching effect on the injected burning mixture of the body of relatively cool air or lean mixture into which the burning fuel elements are injected.
In comparison, line 12 of FIG. 2 illustrates the air/fuel ratio versus time for an exemplary combustion event of an engine practicing the delayed reaction stratified combustion method of the present invention. Here the initial air/fuel ratio in the main chamber is rich having, specifically a 10.5:1 air/fuel ratio, which may alternatively be expressed as a fuel/air equivalence ratio of substantially 1.4.
In this example, combustion is initiated and takes place at the initial rich air/fuel ratio for about the first third of the combustion event, or for not less than the first thirty percent thereof. Thereafter, a diluent such as air, or preferably air mixed with recirculated exhaust gases, is injected into the main combustion chamber during a period occupying about the middle third of the combustion event, or over a period occupying at least 25 but not more than about 60 percent of the time of the combustion event.
In the illustrated example, the injection of air starts shortly before the 4 millisecond point and is substantially completed at about 7 milliseconds after the beginnning of combustion. During this period, the air/fuel ratio within the main combustion chamber is made increasingly leaner to a predetermined end point which, in the illustrated example, is approximately stoichiometric, that is 14.7:1 air/fuel ratio or a fuel/air equivalence ratio of 1.
Injection of the elements of air into the hot mass of rapidly burning rich mixture does not have the same quenching effect as the reverse process in the conventional stratified combustion cycle previously described, since the mass of the body of burning gas is so great compared to the relatively small elements of cooler diluent injected therein that these elements of injected diluent are rapidly heated to take their place in the combustion reaction as further elements of diluent continue to be injected. It can be seen that, in the illustrated example, combustion in the main chamber never reaches the point of lean combustion at the approximately 16 to 1 air/fuel ratio level wherein maximum NO x production is experienced. Instead combustion is completed at approximately a stoichiometric ratio with burning being substantially complete at 10 milliseconds after the initiation of combustion.
It should be understood, however, that the delayed reaction combustion method may be practiced with varying amounts of diluent which may include air and a desired amount of recirculated exhaust gases from zero to any practical amount. Thus, if desired, the method may provide for the initial rich combustion mixture to be diluted beyond stoichiometric to a selected level of lean combustion. In such an event, combustion in the main chamber may pass through the 16 to 1 air/fuel ratio at which maximum NO x is formed. However, this condition will be reached at a substantially later point in the combustion cycle wherein the combustion reaction is much more fully complete than the comparative point in the conventional instantaneous reaction stratified combustion method so that a lower level of NO x formation is anticipated.
Reviewing the important aspects of the present combustion cycle, it should be noted that a substantial portion of the initial combustion in the main chamber occurs at a predetermined level of rich air/fuel ratio sufficient to provide rapid combustion with relatively low production of nitrogen oxides. Subsequently, during an intermediate portion of the combustion event, a diluent such as air or air and exhaust gases is introduced which provides the necessary oxygen to complete combustion and dilutes the burning mixture to a stoichiometric air/fuel ratio or, if desired, a leaner ratio. Injection of the air further accelerates combustion by providing the needed oxygen for burning the excess fuel supplied with the initial rich mixture as well as by creating turbulence in the burning mixture which increases the combustion rate. Subsequently, combustion of the mixture is completed at the final air-fuel mixture reached upon completion of injection of the timed controlled quantity of diluent, combustion of the diluted mixture being completed during the latter portion not exceeding 70 percent of the respective combustion event.
Referring now to FIG. 3 of the drawings, there are shown the results of computer assisted calculation of comparative operating conditions for comparable engines operating with conventional homogeneous combustion, conventional instantaneous reaction stratified combustion and the present invention of delayed reaction stratified combustion. The figure plots percent indicated efficiency at maximum indicated mean effective pressure against indicated specific NO x in grams per indicated horsepower-hour under various operating conditions considered. These conditions are shown at the various data points by legends listing the overall exhaust air/fuel ratio/the percent recirculated exhaust gas/and the maximum indicated mean effective pressure in psi. In these calculations, the delayed reaction stratified combustion method was performed according to the example given in FIG. 2. From the data indicated in FIG. 3, it may be seen that the delayed reaction stratified combustion method of the present invention is capable of providing higher indicated efficiencies and/or lower levels of recirculated exhaust gas and NO x formation than comparable conditions of conventional homogeneous combustion or instantaneous reaction stratified combustion.
In FIG. 4, there is illustrated an exemplary engine, generally indicated by numeral 15, capable of providing operation according to the delayed reaction stratified combustion method of the present invention. Engine 15 includes a cylinder block 16 having a plurality of cylinders 17, only one of which is shown. Pistons 19 are reciprocably disposed in the cylinders and connected by connecting rods 20 with a crankshaft, not shown. The upper end of each cylinder 17 is closed to form a variable volume combustion chamber 22.
An inlet port 23 and inlet valve 24 provide means for admitting to the combustion chamber 22 a primary charge of rich air-fuel mixture supplied by suitable means such as a carburetor, not shown. An exhaust port 26 and exhaust valve 27 provide means for exhausting burned products from the combustion chamber in conventional manner. A spark plug 28 provides means for igniting the rich primary mixtures delivered to the combustion chamber through the inlet port.
The engine also includes means to provide secondary inlet charges to the combustion chamber including a secondary inlet port 30 controlled by a secondary inlet valve 31 and connected by a conduit 32 with a compressor 34. The compressor is operated by the engine or otherwise to supply the secondary inlet port with compressed diluents such as air or air plus recirculated exhaust gas (egr) a pressure regulator 35 in the line 32 controls the pressure of the diluent supplied to the secondary inlet port. Suitable means, not shown, are provided for actuating the valves and the spark plug in timed relation to provide in the engine combustion chamber 22 a combustion cycle in accordance with the delayed reaction stratified combustion method previously described.
In operation, the engine piston reciprocates in the cylinder on a 4 stroke cycle including intake compression, expansion and exhaust strokes. On the intake stroke, a primary charge of rich air-fuel mixture having a predetermined fuel/air equivalence ratio which is preferably 1.4 is drawn into the main combustion chamber 22. This mixture is compressed on the piston compression stroke and ignited by the spark plug near the end of the compression stroke.
Rapid combustion then begins during which a substantial portion of the fuel is burned in a very short interval occupying approximately the first third of the total elapsed time of the combustion event. During this event the valve 31 is actuated, causing the injection of supplemental air or air and exhaust gas during an intermediate portion occupying approximately the central third of the elapsed time of the total combustion event. The amount of air injected is controlled to provide a final overall air/fuel ratio within the combustion chamber of a desired fuel/air equivalence ratio which may preferably be one.
Combustion continues and is completed in a relatively short time interval during which the piston begins to move downwardly on its expansion stroke developing power. Thereafter, the exhaust valve opens and the piston moves upwardly expelling the burned gases in conventional manner.
The practice of the present invention, involving the time injection of controlled amounts of diluents including air into a rich main cylinder charge during an intermediate portion of each combustion event, provides advantages over known combustion methods as has been described in the foregoing specification. While the invention has been described by reference to certain preferred embodiments, it should be understood that numerous changes could be made within the scope of the inventive concepts disclosed. Accordingly it is intended that the invention not be limited except in accordance with the language of the following claims.
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A method of delayed reaction stratified combustion for internal combustion engines comprising burning a compressed fast burning rich air-fuel mixture during an initial portion of a combustion event, adding supplemental diluting air optimally with recirculated exhaust gas (EGR) during an intermediate portion of such combustion event and completing combustion during latter portions of the combustion event. Suggested timing and mixture ratios may be chosen to obtain improved efficiency, reduced NO x formations and/or reduced requirement for egr.
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REFERENCE TO PRIOR APPLICATION
This is a division of application Ser. No. 854,909 filed Nov. 25, 1977, now U.S. Pat. No. 4,132,832 which in turn is a continuation-in-part of U.S. application Ser. No. 731,212, filed Oct. 12, 1976, now U.S. Pat. No. 4,136,216, which is a divisional application of U.S. application Ser. No. 607,506, now U.S. Pat. No. 3,993,799 which is a continuation-in-part of U.S. application Ser. No. 512,224 filed Oct. 4, 1974, now abandoned.
BACKGROUND OF THE INVENTION
Electroless or autocatalytic coating of dielectric surfaces is a well known process finding wide-spread utility in the preparation of such diverse articles as printed circuits, automotive trim, mirrors, etc.
Normal commercial electroless coating processes generally involve an initial cleaning and etching of the dielectric substrate by physical or chemical means to improve adherence of the metallic coating. The etched surface is then catalyzed by suitable catalytic compositions and processes to provide a surface capable of electroless plating initiation. In the prior art, the catalytic treatment generally encompassed the use of precious metals. More recently, compositions and processes utilizing non-precious metals have been disclosed suitable for electroless plating of dielectrics. U.S. Pat. Nos. 3,993,491, 3,993,801, 3,993,799, 3,958,048, 4,048,354, and Ser. No. 645,198 now U.S. Pat. No. 4,087,586 and Ser. No. 720,588 now U.S. Pat. No. 4,082,899 which are included herein by reference disclose the prior art as well as the recent advancements in which non-precious metals have been reported.
In reviewing the teachings disclosed in U.S. Pat. Nos. 3,993,799 and 3,958,048 it is evident that colloids or either hydrous oxides, metals (elemental state) and alloys (phosphides, borides, nitrides, etc.) are useful in the catalytic treatment either as a two step or a single step activation treatment. Generally speaking, preferred metals in the above colloids are cobalt, copper, iron and nickel, although as suggested in U.S. Pat. No. 3,993,799 other non-precious metals may be used. It is recognized that it is generally desireable to have suspensions (dispersions) of very fine particulate matter for both stability (i.e., against precipitation), reactivity, and adhesion to the substrate. Accordingly, it is highly desirable to prepare such suspensions under conditions which would yield finely divided and highly stable colloids.
It is also well recognized in the art of electroless plating that for effective electroless plating onto catalytically treated non-conductors at least one of the following requirements must be met:
Case I: The catalytic surface may react chemically with the reducing agents present within the electroless plating bath. More than one chemical reaction may take place.
Case II. The catalytic surface may react chemically with the metallic ions present within the electroless plating bath in a galvanic type replacement reaction.
In Case I, the chemical reactions may range from chemical reduction of the catalytic components present on the dielectric, and/or decomposition of the reducing agent at the interfere ultimately yielding hydrogen gas via an active reducing agent intermediate. In Case II, to permit a galvanic replacement reaction, it is recognized that some of the metal ions present in solution must be more noble with respect to the metal and metal ions present on the treated non-conductor surface. Such relationship is well recognized from the EMF series. Thus, while metals like copper, cobalt, nickel and iron may be preferred as recognized in U.S. Pat. No. 3,993,799, yet other non-precious metals may also be of potential use (e.g., zinc, manganese, etc.). It is further recognized that it is highly desireable to have catalysts which when contacted with the chemical (electroless) plating bath will yield short induction times. Generally speaking it is recognized that whenever the induction time is short, the probability for complete metallic coverage is excellent and thus eliminates the problem of skip plating.
SUMMARY OF THE INVENTION
It is the principle object of the present invention to provide an effective and economical process and compositions for preparing dielectric substrates for electroless coating or plating of a metallic surface thereon, and to provide an electroless coating process including such preparation.
It is a particular object of the present invention to provide improved compositions through which the catalytic activity would be increased. Other objectives of the present invention, if not specifically set forth herein, will be apparent to the skilled artisan upon the reading of the detailed description of the invention which follows.
Suprisingly, it has been discovered that the aforesaid objectives may be achieved by a process and composition which render the colloidal composition a greater reactivity and hence provide a greater catalytic activity for the colloid when adsorbed onto the non-conductors. The improved compositions incorporate the addition of metallic ions (e.g., nickel) subsequent to the nucleation of the colloidal dispersion comprising copper.
DETAILED DESCRIPTION OF THE INVENTION
The process of the present invention is applicable to metallic plating of a wide variety of dielectric (non-conductor) substrates. Dielectric substrates described in the prior art, including thermoplastic and thermosetting resins and glass, may also be suitably plated in accordance with the present invention. Normally, these substrates will be cleaned and surface treated prior to plating in order to improve adherence of the metallic coating. The present invention is an improvement to the processes and compositions disclosed in the above cited references.
The colloids of the present invention are generally prepared by adding the selected compound of a catalytic metal or a salt thereof, e.g., the sulfate, nitrate, chloride, bromide or acetate salts, to an aqueous medium to produce an aqueous solution and reacting the above solution with a chemical agent which will yield by precipation (nucleation) either a reduced metal, compound or an alloy of same metal. The precipitation reaction is generally carried forth in the presence of at least one colloid stabilizer thereby stabilizing the resulting colloid formed and insuring good dispersion for the medium.
Although there are various methods for the production of colloids, e.g., U.S. Pat. No. 2,438,230, such approaches, while simple to implement, do not provide as great a freedom with respect to selectivity of colloids formed and their properties as those produced by the precipitation technique. U.S. Pat. No. 3,635,668 describes a process for the production of copper hydrate suitable for use as a fungicide. U.S. Pat. No. 3,082,103 demonstrates a universal milling technique by which finely divided oxides may be formed. It should also be noted that while most of the examples in the present invention are directed to formation of the colloidal solutions via precipation techniques, the present invention is not limited to this approach. Specifically, catalytic colloidal composition may also be prepared by the dissolution and stabilization of properly prepared powders. Hence, the manner by which the chemical components are used in preparing said colloidal catalytic composition is a matter of convenience, e.g., shipping costs. The precipitation technique for producing the catalytic medium is believed however to possess certain advantages. Specifically, this technique is potentially capable of producing colloids of varied size, shape, and chemical make-up. This freedom is especially useful with respect to desired subsequent catalytic properties. Furthermore, such technique is also useful in the preparation of reduced metal or metal-alloys or compounds by adding a suitable precipitating agent (e.g., reducing agent), which can form the reduced metallic state or the alloys or the resulting compound(s) through its chemical interaction with the metal ion(s). Typical reducing agents are tannic acid, hydrazine, amineboranes, hypophosphites, borohydrides, sulfur types, etc. In the event that the colloids are prepared by a precipation technique it may further be recommended that after preparation, centrifugation, washing and redispersion in pure water be undertaken thereby removing extraneous ionic species and insuring a medium with low ionic strength.
The stability of the above colloidal compositions may be enhanced by various techniques, e.g., dialysis, repetitive centrifugation and washings, as well as by the addition of various materials, referred to herein as stabilizers. The term "stabilizer" is used herein to generally describe chemicals believed to be adsorbed onto the colloids thereby altering the charge characteristics of said colloids and thus preventing their coagulation. Such stabilizers may be of organic or inorganic nature.
Stabilizers contemplated by the present invention include secondary colloids, polyalcohols, sugars, dispersants and surfactants, which while by themselves do not serve to catalyze the dielectric substrate in this process, they are believed to stabilize the active colloid by an encapsulation (or adsorption) mechanism. It is noted that for a specific composition more than one stabilizer may be present. Stabilizers may also be chemicals which take part within the colloidal double layer structure.
Typical secondary colloids are gum arabic, gelatin, agar agar, starch, albumin, hemoglobin, cellulose derivatives such as carboxymethyl cellulose and hydroxypropyl cellulose, N-alkylbeta-aminopropionic acid, carboxymethyl dextran, and the like. Typical sugars include mannitol, sorbitol, dulcitol maltose, and arbinose raffinose.
Surfactants may also be suitably employed as a stabilizer for the colloids. The surfactant, or surface active agent, as used herein generally refers to substances which are capable of lowering the surface tension of a liquid or the interfacial tension between two liquids. All such substances possess the common feature of a water-soluble (hydrophillic) group attached to an organic (hydrophobic) chain. Surfactants as used herein are also intended to encompass detergents, dispersants and emulsifying agents regardless of whether they are capable of lowering the interfacial surface tension. The surfactants used are not limited to the hydrocarbon type and they can be fluorocarbon or silicon bearing type.
It is also contemplated that a mixture of surfactants or surfactants with other stabilizers may be used. Care should be exercised (e.g., excess concentration) in the use of surfactants in the preparation of the present colloids, as would be noted by anyone skilled in the art.
The term "precipitation agent" as used herein is generally intended to encompass those chemical compounds which when contacted with metallic ions (with or without added energy) cause the onset (nucleation) of the secondary phase (insoluble phase). Typical materials may be reducing agents, hydroxides, sulphides and others. At times, depending on the chemical nature of the precipitation agents, codeposits within the resulting colloids are noted.
In general, the electroless coating process of the present invention comprises contacting (e.g., by immersion) the dielectric substrate, preferably previously etched with the colloid, i.e., the colloidal catalytic composition, washing the substrate and then contacting the colloid adsorbed substrate with a composition comprising an activating agent, (e.g., reducing agent) to form an activated state (e.g., reduced oxidation state) on the surface of the substrate, thus forming the catalytic nuclei active effective for the electroless build-up process upon subsequent immersion of the substrate in an appropriate electroless plating bath. Alternatively, the second step may be deleted.
Activation may also encompass a selective dissolution of the colloidal stabilizer(s) when present on the substrate.
For the sake of convenience, certain examples hereinafter will not refer to the intermediate rinsing step, but the need for such step should be recognized.
The following examples are illustrative of the present invention and are not to be taken in limitation thereof.
EXAMPLE 1
An ABS substrate was etched in a solution comprised of 400 g/l chromium oxide, 350 g/l concentrated sulfuric acid, and a flourocarbon surfactant for several minutes at a temperature of 70° C. Thereafter, the etched substrate was immersed in the colloidal dispersions for five minutes. Plating evaluation was carried out at room temperature using a typical commercial electroless copper bath. The colloidal compositions were as follows:
______________________________________Cu(NO.sub.3).sub.2 0.1MNi(NO.sub.3).sub.2 0.04MNaBH.sub.4 0.019MNaOH 0.19MOrzan S 12 g/lDaxad 11 1.35 g/l______________________________________ Orzan S is predominantly sodium lignosulfate. Daxad 11 is predominantly sodium salts of polymerized alkyl naphthalene sulfonic acids.
Test 1A: In this case the nickel and copper were admixed as above prior to the colloidal nucleation step.
Test 1B: Same as 1A, however, NaBH 4 and NaOH were reduced by 20% and nickel ions via the inorganic nickel compound were added post the copper colloid post nucleation to yield a 0.04 M concentration level. Induction times were found to be 20 sec and 10 sec for tests 1A and 1B, respectively. It is also noted that after the colloidal compositions, immersion into a 0.3 g/l dimethylamine borane solution at 49° C. for 3 minutes took place. Furthermore, in preparing the above colloids, nucleation, preferably above room temperature, took place. It is further noted that though the present colloids are derived using cupric ions, cuprous ions (Cu(I)) may be substituted and hence their incorporation falls within the spirit of this invention.
It is interesting to note that repeating the procedure of Example 1, however substituting cobalt, copper or iron for the nickel, did not reveal the unusual effect(s) encountered for nickel. It is further noted that though in this example certain specific nickel and copper salts were selected other salts or inorganic compounds of these metals may be substituted in a manner obvious to one skilled in the art. Further investigation of the unexpected results have demonstrated that the concentration of added nickel ions may be varied over a wide range while providing the noted improvement. In addition, examinations by electron microscopy using composition similar to 1A and 1B have shown marked differences, specifically the diffraction pattern (plates 7315 and 7317) for 1B showed a greater degree of amorphous nature in comparison to 1A. Also the transmission mode showed 1B to contain an extremely fine grained background.
While I do not wish to be bound by theory it would appear that the addition of nickel post the copper colloid nucleation is placed around the copper colloid and thereby the resulting adduct has a greater catalytic activity.
It should also be obvious that various approaches may be taken in the charging of such colloids, e.g., controlled addition of compound with specific anions such as hydroxyl ions and/or controlled addition of suitable surfactants and/or secondary colloids. In addition, the reference to catalytic metal in this invention is intended to encompass various colloidal end-products (e.g., metals, alloys, oxides, compounds, and mixtures thereof) bearing the catalytic metal(s) in any of several oxidation states which are non-noble. The catalytic composition may be the colloidal product as prepared or the colloidal product derived after further cleaning of the colloid has been made to remove extraneous (undesired) chemical species.
It will further be obvious to one skilled in the pertinent art that many modifications and variations may be made in the preceding description without departing from the spirit and scope of the present invention. For example, it will be apparent that mixtures of reducing agents may be used in a single solution or may be used in successive steps. Furthermore, it is within the scope of the present invention to delete the use of a separate reducing solution and directly immerse the substrate (contacted previously with the colloidal catalytic composition) in an electroless plating formulation containing one or more reducing agents.
It should also be recognized by those skilled in the art that, from the present teachings, multiple combinations of materials shown in separate examples are possible and such combinations fall within the spirit of the invention. It is understood that the term copper colloid encompasses colloids whose nucleus is of either elemental copper, compounds of copper or alloy of copper and mixtures thereof.
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Metallic surfaces are imparted to non-conductive or dielectric substrates by an electroless (chemical) coating process comprised of coating the surface of the substrate with colloids of catalytic non-precious metals wherein the metals are either part of an alloy or in the elemental state or a compound and wherein the colloidal compositions are prepared by a special method which renders the colloids a greater catalytic activity when used in the plating process.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ophthalmic apparatus, and more particularly to an alignment mechanism of the ophthalmic apparatus for aligning an operation apparatus and a measuring apparatus with a patient's eye.
2. Description of Related Art
FIG. 1 shows a typical alignment mechanism used in a known ophthalmic operation apparatus and a known measuring apparatus.
In the alignment mechanism, which provides a light source 2 arranged at the oblique above position of an examinee's eye 1, lenses 3, 4 and a light detector 5, a light beam emitted from the light source 2 is condensed through the lens 3 on an apex of cornea of the examinee's eye 1, and reflected thereon. The reflected light is again focused through the lens 4 toward the light detector 5 arranged at a focus position of the lens 4, and detected thereby.
This alignment method, although being able to obtain satisfactory alignment precision thereby, has only a very limited detectable scope. Accordingly, the alignment light may be focused out of the light detector 5 if the position (of the apparatus) is even slightly dislocated.
In addition to the above problem, this alignment method needs a display means to display a detected result by the light detector 5 on an observing system including a microscope or a TV monitor or the like, whereby the alignment mechanism may become complicated.
Another alignment mechanism shown in FIG. 2 has also been proposed. In the alignment mechanism, lasers 6a and 6b are arranged respectively at right and left oblique above positions of an examinee's eye 1. The respective laser beams emitted from the two lasers 6a and 6b irradiate the examinee's eye 1 and form laser spots thereon, the laser spots are then observed through an observing system 7 arranged on the optical axis of the examinee's eye 1. Thus, the alignment is adjusted so as to correspond the laser spots each other on the examinee's eye 1, namely, the focus position (alignment) is correct when laser spots by the two lasers 6a and 6b become one laser spot 8 as shown in FIG. 3(a), the examinee's eye 1 is too near than a proper focus position when two laser spots 8a and 8b are separate spots as shown in FIG. 3(b), and the examinee's eye 1 is too far than a proper focus position when two laser spots 8a and 8b are changed places with each other as shown in FIG. 3(c).
The alignment method needs corresponding two small laser spots formed on the examinee's eye, however, the reflected plane on which the light beams are reflected toward the observing system is the curved cornea surface of the examinee's eye. Accordingly the small spots are even difficult to observe. And further, when the examinee's eye 1 is positioned either too near (b) or far (c) than a proper focus position, the operator may observe the two spots in a same view, thereby can not judge whether a distance between the examinee's eye and the apparatus is too short or long to determine an alignment direction to which the apparatus should be moved.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above circumstances and has an object to overcome the above problems and to provide an ophthalmic apparatus provided with an alignment mechanism capable of easily aligning the apparatus with the examinee's eye by a simple construction.
Additional objects and 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 objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, an ophthalmic apparatus of this invention comprises an alignment mechanism including a slit image projecting system for projecting an alignment slit image on the subject's eye, a slit image observing system for observing the slit image projected on the subject's eye, wherein a plurality of the slit image projecting system are arranged so as to project the slit image from at least two directions on the subject's eye, the directions putting the optical axis of the slit image observing system therebetween, and an alignment moving means for moving an apparatus body comprising the slit image observing system, relatively to the subject's eye, in three-dimensional direction.
In the second aspect of the present invention, an ophthalmic operation apparatus comprises an operation laser source, an operation laser optical system for projecting an operation laser beam emitting from the laser source on the patient's eye, a pair of slit image projecting systems, each for projecting an alignment slit image on the patient's eye, a slit image observing system for observing a slit image projected on the patient's eye through the slit image projecting system, and an alignment moving means for moving the operation laser optical system, relative to the patient's eye, in three-dimensional direction, based on the slit image on the patient's eye observed through the slit image observing system.
According to the present invention, an alignment for the apex of a cornea can be easily achieved with a simple mechanism in which two slit light beams are projected from oblique above positions on the cornea and the operator adjusts the alignment based on the slit image observed by the observing system.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this specification illustrate an embodiment of the invention and, together with the description, serve to explain the objects, advantages and principles of the invention. In the drawings,
FIG. 1 is a schematic diagram of explaining an alignment mechanism of a prior art;
FIG. 2 a schematic diagram of explaining an alignment mechanism of another prior art;
FIGS. 3(a) through 3(c) are diagrams of showing various alignment conditions in a case of using the alignment mechanism of FIG. 2;
FIG. 4 is a perspective view of a cornea operation apparatus according to the present invention;
FIG. 5 is an arrangement diagram of laser transmitting optical system of the apparatus of FIG. 4;
FIG. 6 is a schematic diagram of explaining an alignment mechanism of the present invention;
FIGS. 7(a) through 7(c) are diagrams of showing various alignment conditions in the optical axis direction according to the present invention;
FIGS. 8(a) and 8(b) are diagrams of showing various alignment conditions in the longitudinal direction according to the present invention;
FIGS. 9(a) and 9(b) are diagrams of showing various alignment conditions in the lateral direction according to the present invention;
FIG. 10 is a diagram of showing an alignment condition with another slit diaphragm according to the present invention; and
FIGS. 11(a) and 11(b) are diagrams of showing each alignment condition with another slit diaphragms according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A detailed description of one preferred embodiment of an ophthalmic apparatus embodying the present invention will now be given referring to the accompanying drawings.
In FIG. 4, a cornea operation apparatus for correcting refractive error of a patient's eye is shown. The laser transmitting optical system of the apparatus has little relation to the present invention, accordingly the detail description thereof, having been mentioned in Japanese Patent Appl. No. HEI 2(1990)-416767 which corresponds to U.S. Appl. No. 812,819, is omitted in this specification. The only brief explanation thereof will be here described referring to FIG. 5.
As shown in FIG. 5, an optical system includes an ablating laser source 20 (preferably an excimer laser), plane mirrors 21, 22, 24, 25 and 27 for deflecting the laser beam emerging from the laser source 20, an aperture 23 located in the optical path between the mirrors 21, 22, 24, 25 and a projection lens 26, the projection lens 26 which is arranged in the optical path and for projecting the laser beam passing through the aperture 23 to a cornea of the examinee's eye 1 via mirror 27. The aperture 23 has a variable diameter which is changed by an aperture drive motor 29 in accordance with an instruction signal of a control device 28.
The projection lens 26 is conjugated with the aperture 23 and the cornea of the examinee's eye 1, and the laser beam passing through the aperture 23 in a confined space is projected on the surface of the cornea through the lens 26 such that an ablation area of the cornea is restricted. Then, the laser beam passing through the projection lens 26 is deflected toward the examinee's eye 1 by the mirror 27.
The examinee's eye 1 is provided at a position having a predetermined positioning relation for the apparatus.
In an alignment driving mechanism of the optical system of the cornea operation apparatus shown in FIG. 5, the optical system including the aperture 23, the plane mirrors 24, 25, 27 and the projection lens 26 is movable parallel to the x-axis by a driving motor 30, the above optical system including further the plane mirror 22 is movable parallel to the y-axis by a driving motor 31. In this moving operation, the projection lens 26 keeps a conjugating relation with the aperture 23 and the examinee's eye 1.
The optical system including the plane mirror 25, the projection lens 26 and the plane mirror 27 is movable parallel to the z-axis by a driving motor 32, then the aperture 23 is moved according to the movement of the optical system by a link device 33 so that the projection lens 26 may keep as always a conjugating relation with the aperture 23 and the eye 1.
FIG. 6 shows an optical arrangement of an alignment light projecting system and an alignment observing system provided in relation with the alignment driving mechanism shown in FIG. 5.
The alignment observing system provides a microscope 10 for observing the cornea 11 of the examinee's eye.
The alignment light projecting optical systems 12a and 12b are disposed symmetrically at both sides of the optical axis of the microscope 10, which are provided respectively with illumination lamps 13a, 13b, condenser lenses 14a, 14b for condensing the light emerging from the illumination lamps 13a, 13b, linear slit diaphragms 15a, 15b, and projection lenses 16a, 16b for projecting the light beam passing through the slit diaphragms 15a, 15b to the cornea 11. The projection lenses 16a, 16b are conjugated with the respective slit diaphragms 15a, 15b and the cornea 11.
The light beam passing through the slit diaphragm 15a in the slit space is projected on the surface of the cornea 11 such that the slit image by the slit diaphragm 15a is always formed at a focus point on the optical axis of the microscope 10. The light beam passing through the slit diaphragm 15b is similarly projected to the cornea 11.
The alignment operation with the apparatus including the above optical system will be explained as below.
For the alignment in the optical axis direction, the slit light beam emerging from the slit projecting optical system 12a (left side system in FIG. 6), although substantially passes through the cornea 11, is partially diffused by the cornea 11 toward the microscope 10, and thereby a slit line image 17a of circular arc shape is observed through the microscope 10 as shown in FIGS. 7(a) through 7(c). Similarly, the light beam emerging from the slit projecting optical system 12b (right side system in FIG. 6) is observed as a slit line image 17b of circular arc shaped through the microscope 10.
When the apex of the cornea 11 is placed at a focus position of the microscope 10, as shown in FIG. 7(a), the slit line image 17a and the slit line image 17b partially overlap each other at the apical point of the cornea. But then, when the cornea 11 is positioned below the position shown in FIG. 6, that is, far from the microscope 10 than the focus position of the microscope 10, two slit line images 17a and 17b are apart from each other as shown in FIG. 7(b). When the cornea 11 is positioned above the position shown in FIG. 6, that is, near the microscope 10 than the position on which the microscope 10 is focused, two slit line images 17a and 17b intersect as shown in FIG. 7(c).
Accordingly, when the two slit line images 17a and 17b are observed as FIG. 7(b), the apparatus is moved downward (to the z-axis direction in FIG. 5) or the cornea 11 upward so that a distance between the microscope 10 and the cornea 11 is made shorter, and, when the two slit line images 17a and 17b are observed as FIG. 7(c), the apparatus 10 is moved upward or the cornea 11 downward so that the distance is made longer. Thus, if adjusting the distance between the apparatus 10 and the cornea 11 such that the two slit line images 17a and 17b may be observed as FIG. 7(a), the alignment to focus the microscope 10 on the cornea 11 is accordingly completed.
Next, in the alignment operation in the longitudinal and lateral directions, the two slit line images 17a and 17b are observed as in either FIG. 8(a) or FIG. 8(b) when the apex of the cornea is dislocated in the longitudinal direction of the visual field, and the two slit images 17a and 17b are observed as in either FIG. 9(a) and FIG. 9(b) when dislocated in the lateral direction. For this alignment, the cornea 11 and the optical axis of the microscope 10 are relatively moved so that the two slit line images 17a and 17b are placed at respective correct positions in the visual field as shown in FIG. 7(a).
More specifically, when the apex of cornea is dislocated in the longitudinal direction of the visual field, the apparatus is moved parallel to the y-axis of FIG. 5 or the cornea is moved in the longitudinal direction thereof. When the apex of cornea is dislocated in the lateral direction of the visual field, the apparatus is moved parallel to the x-axis of FIG. 5 or the cornea is moved in the lateral direction thereof.
The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. For instance, although the slit diaphragms 15a, 15b each provides a linear slit therein in the above embodiment, at least either slit diaphragm may further provide an across line in the center, referring to FIG. 10, which make the recognition which portion should be adjusted to a center of the visual field clearly and accordingly the alignment between the visual field and the cornea easily. Additionally, if the observing system is given a reticle indicating a position at which the across line should be placed, the alignment is made more easily.
If, in addition to two linear slit line images, one or more slit line images are provided so as to overlap each other at a point as shown in FIGS. 11(a) and 11(b), the alignment can be easy achieved.
And further, the slit diaphragm in the present invention can have various slit forms without limited to a linear slit form.
The foregoing description of the preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiment chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto, and their equivalents.
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An ophthalmic apparatus for measuring and operating a subject's eye, which includes an ophthalmic operation apparatus, provides an alignment mechanism including a slit image projecting system for projecting an alignment slit image on the subject's eye, a slit image observing system for observing the slit image projected on the subject's eye, wherein a plurality of the slit image projecting system are arranged so as to project the slit image from at least two directions on the subject's eye, the directions putting the optical axis of the slit image observing system therebetween, and an alignment moving device by which an apparatus body including the slit image observing system is moved relatively to the subject's eye in three-dimensional direction.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The present invention relates to structural reinforcement in general and in particular to reinforcing adjacent wall studs to each other.
[0003] 2. Description of Related Art
[0004] In the field of construction, it is often desirable to make a structure as strong as possible. The strength of a building is desirable for the purposes of load bearing ability as well as resistance to outside loads such as earthquakes, wind and other environmental loading.
[0005] Building construction typically includes a plurality of elongate members connected each other to form walls, ceilings, floor and the like. In the case of walls, such elongate wall members are often referred to as studs while in ceilings and roofs, they may be referred to as joist.
[0006] One difficulty that exists is the tendency of relatively long structural members to lose strength and rigidity as their length increases. This is particularly a difficulty for relatively long slender members such as wall studs and the like. Such wall studs may commonly be subject to buckling failure. Another difficulty that exists with wall studs is that walls formed by conventional wall studs is that such construction techniques may be less resistant to shear loads than they are to compressive loads. Under such loads, wall studs may be prone to rotate about their end connections to the top and bottom plate. The resulting deflection of the entire load above such a wall may contribute to an entire building failing or collapsing.
SUMMARY OF THE INVENTION
[0007] According to a first embodiment of the present invention there is disclosed an apparatus for reinforcing a plurality of adjacent parallel spaced apart wooden structural members to each other. Each of the structural members extends between first and second ends and has first and second edges. The apparatus comprises a ridged member extending between first and second ends and having a length sufficient to extend between two adjacent structural members. The apparatus further comprises a socket at each of the first and second ends of the rigid member. Each socket has a central axis therethrough and is formed of a base panel and first and second side panels. The socket is adapted to engage with a socket of an adjacent rigid member so as to interlink successive rigid members across a plurality of structural members.
[0008] The base panel of each socket may be abuttable at against a corresponding base panel wherein the first and second side panels are engagable with corresponding first and second side panels of the adjacent socket. The side panels of the socket may overlap the side panels of the adjacent socket when the socket is engaged therewith.
[0009] The base panel may extend between first and second edges wherein one of the first or second edges abuts against a corresponding first or second edge of the adjacent socket. The one of the first or second edge may be angularly oriented relative to the central axis.
[0010] The first and second panels may include fastener bores therethrough adapted to align with corresponding bores in the first and second panels of the adjacent socket. The central axes of the first and second sockets may be substantially parallel to each other.
[0011] The rigid member may extend diagonally between the first and second sockets, such that the rigid member is angularly oriented relative to the central axis of the first and second socket. The first and second side panels may be co-formed with the base panel. The base panel may be co-formed with the rigid member. The apparatus may be formed of a material selected from the group consisting of metal, plastic, wood and composite materials.
[0012] The first and second side panels may include end tabs connectable to adjacent end tabs of an corresponding socket of an adjacent rigid member.
[0013] According to a further embodiment of the present invention there is disclosed a kit for reinforcing a plurality of adjacent parallel spaced apart wooden structural members to each other. Each of the structural members extends between first and second ends and has first and second edges. The kit comprises a plurality of apparatuses each comprising a ridged member extending between first and second ends and having a length sufficient to extend between two adjacent structural members. Each apparatus further comprises a socket at each of the first and second ends of the rigid member. Each socket has a central axis therethrough and is formed of a base panel and first and second side panels. The socket is adapted to engage with a socket of an adjacent rigid member so as to interlink successive rigid members across a plurality of structural members.
[0014] Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In drawings which illustrate embodiments of the invention wherein similar characters of reference denote corresponding parts in each view,
[0016] FIG. 1 is a perspective view of a plurality of apparatuses according to a first embodiment of the present invention for reinforcing structural members located across wall studs.
[0017] FIG. 2 is a front perspective view of one of the apparatuses of FIG. 1 .
[0018] FIG. 3 is a rear perspective view of one of the apparatuses of FIG. 1 .
[0019] FIG. 4 is a front profile view of two of the apparatuses of FIG. 2 applied to a wall stud.
[0020] FIG. 5 is a cross-sectional view of the two apparatus of FIG. 4 as taken along the line 5 - 5 .
[0021] FIG. 6 is a plan view of a cut sheet for forming the apparatus of FIG. 2 .
[0022] FIG. 7 is a plan view of a cut sheet for forming an apparatus for reinforcing structural members located across wall studs according to a further embodiment of the present invention.
[0023] FIG. 8 is a front profile view of an apparatus for reinforcing structural members according to a further embodiment of the present invention.
[0024] FIG. 9 is a detailed perspective view of one of the sockets of the apparatus of FIG. 8 .
DETAILED DESCRIPTION
[0025] Referring to FIG. 1 , an apparatus for stabilizing adjacent wall studs 6 according to a first embodiment of the invention is shown generally at 20 . The wall studs 6 may be of any conventional type, such as by way of non-limiting example dimensioned lumber, engineered studs, composite material studs or metal studs and extend between top and bottom ends, 8 and 10 , respectively. It will also be appreciated that the present apparatus may be useful for stabilizing any other type of wall structural member, such as, by way of non-limiting example, floor joists roof trusses or the like. The wall studs 6 as illustrated have front and rear surfaces, 12 and 14 , respectively, as are conventionally known.
[0026] With reference to FIGS. 2 and 3 , the apparatus 20 comprises a rigid member 22 extending between first and second ends, 24 and 26 , respectively. The first and second ends have first and second sockets 30 and 50 , respectively extending therefrom. As illustrated in FIG. 1 , the first and second sockets are adapted to receive one of the front or rear surfaces 12 or 14 of the wall studs 6 therein. As further illustrated in FIG. 1 , the first socket 30 of one apparatus is engagable with a second socket 50 of an adjacent apparatus so as to be interlocked therewith as will be more fully described below.
[0027] The rigid member 22 may be formed of any known shape. As illustrated, the rigid member 22 may be formed of a substantially planar member, although it will be appreciated that other shapes may be useful as well, such as, by way of non-limiting example, a tube, a bar, a box section, an I-beam, a c-shaped channel, an L-shaped channel or a triangular cross section beam. It will also be appreciated that the rigid member 22 may also include strengthening flanges or ribs extending therefrom as are commonly known. The rigid member 22 may be formed of any suitable material, such as, by way of non-limiting example, metal, plastic, ceramics or the like. It will also be appreciated that although the apparatus 20 may be formed of bent sheet metal, it may also be formed by other means such as an extruded, cast or welded structure.
[0028] The first socket 30 is formed of a base panel 32 having first and second side panels, 34 and 36 , respectively extending therefrom. The first and second side panels 34 and 36 extend substantially perpendicularly from the base panel 32 so as to form a u-shaped socket along a central axis 42 for receiving the wall stud 6 therein. It will be appreciated that the width of the base panel may be selected to space the first and second side panels apart by a distance corresponding to the width of the wall stud such as approximately 1.5 inches (38 mm) for use with a conventional 2×4 dimension lumber wall stud, by way of non-limiting example. Each of the first and second side panels includes fastener bores 38 and 40 , respectively, therethrough sized to receive fasteners, such as, by way of non-limiting example, screws or nails therethrough as will be more fully described below.
[0029] The base plate comprises a substantially planar member extending between top and bottom edges, 44 and 46 , respectively. As illustrated, the bottom edge 46 may be substantially perpendicular to the central axis 42 of the socket while the top edge 44 is angularly oriented relative to the central axis 42 . As illustrated in FIG. 6 , the top edge may have a top incline angle, generally indicated at 48 of between 0 and 60 degrees relative to a plane perpendicular to the central axis. As illustrated, the first side panel 34 may have a length selected to extend above and below the top and bottom edges 44 and 46 of the base panel 32 while the second side has a length selected to extend above the top edge 44 of the base panel 32 .
[0030] The second socket 50 is formed of a base panel 52 having first and second side panels, 54 and 56 , respectively extending therefrom. The first and second side panels 54 and 56 extend substantially perpendicularly from the base panel 52 so as to form a u-shaped socket along a central axis 62 for receiving the wall stud 6 therein. It will be appreciated that the width of the base panel may be selected to space the first and second side panels apart by a distance corresponding to the width of the wall stud such as approximately 1.5 inches (38 mm) for use with a conventional 2×4 dimension lumber wall stud, by way of non-limiting example. Each of the first and second side panels includes fastener bores 58 and 60 , respectively, therethrough sized to receive fasteners, such as, by way of non-limiting example, screws or nails therethrough. As will be more fully described below the fastener bores 38 , 40 , 58 and 60 may be located such that a common fasteners may be passed through a pair of corresponding bores when adjacent apparatuses are secured together.
[0031] The base panel 52 comprises a substantially planar member extending between top and bottom edges, 64 and 66 , respectively. As illustrated, the top edge 64 may be substantially perpendicular to the central axis 42 of the socket while the bottom edge 66 is angularly oriented relative to the central axis 42 . As illustrated in FIG. 6 , the bottom edge may have a bottom incline angle, generally indicated at 68 of between 0 and 60 degrees relative to a plane perpendicular to the central axis. The top and bottom incline angles 48 and 68 will be selected to correspond to each other such that when sockets of adjacent apparatuses 20 are located adjacent to each other, they may be abutted against each other as illustrated in FIGS. 1 and 4 . As illustrated, the first side panel 34 may have a length selected to extend above and below the top and bottom edges 44 and 46 of the base panel 32 while the second side has a length selected to extend above the top edge 44 of the base panel 32 . In such a manner, the first and second side plates of such abutted sockets may be overlapped with each other as will be more fully described below.
[0032] With reference to FIG. 4 , in operation, a first apparatus 20 a may be located on a wall stud 6 with the front edge 12 of the wall stud received within a first socket 30 . Thereafter, a second apparatus 20 b, may be located on the same wall stud 6 with front edge 12 of the wall socket being received within the second socket 50 at a position above the first socket 30 of the first apparatus 20 a. Thereafter, the second apparatus 20 b may be moved in a downward direction so as to engage the bottom edge 66 of the second socket 50 of the second apparatus 20 b against the top edge 44 of the first socket 30 of the first apparatus 20 a. In such a position, the first and second side panels 54 and 56 of the second socket on the second apparatus will overlap the first and second side panels 34 and 36 of the first socket of the first apparatus. Thereafter, fasteners 70 may be passed through corresponding sets of bores 38 and 60 and 58 and 40 as illustrated in FIG. 5 . Optionally, the sockets 30 and 50 may include barbs, spikes or other suitable projections from an interior surface thereof so as to engage the wall stud when the apparatus 20 is secured thereto.
[0033] The rigid member 22 has a length selected to extend between adjacent wall studs 6 . By way of non-limiting example, the rigid member has a length sufficient to space the central axes 42 and 62 of the first and sockets apart by a distance corresponding to the distance between the wall studs. Such spacing will be dictated by the wall construction type and may therefore be of any suitable range, such as by way of non-limiting example, 16 inches (406 mm) for 16 inch on center construction walls. It will be appreciated that other distances may be suitable as well. As illustrated, the rigid member extends away from each socket so as to form an incline angle, generally indicated at 72 between the rigid member 22 and the central axes 42 and 62 of the first and second sockets. The incline angle 72 is selected to permit the apparatus to extend diagonally between adjacent wall studs and may have an angle of between 30 and 60 degrees with an angle of 45 degrees having been found to be particularly useful.
[0034] As illustrated, the base panels 32 and 52 may be formed of a continuation of the rigid member 22 or may be a separate member secured thereto by fasteners, adhesives or the like. It will be appreciated that in embodiments where the base panels are co-formed with the rigid member, that the rigid member and base panels 32 and 52 will be co-planar with the rigid member 22 .
[0035] With reference to FIG. 6 , the apparatus 20 may be cut from a single sheet of metal, such as, by way of non-limiting example, steel, stainless steel, aluminium or galvanized steel. The sheet metal may be cut into a blank according to known methods and thereafter bend into the desired shape as illustrated and described above. Any thickness of metal as required to provide the necessary strength may be utilized such as between 12 and 22 gauge. In particular, it has been found that sheet metal of between 16 and 20 gauge has been useful. It will also be appreciated that the apparatus 20 —may also be formed of non-metal materials, such as, by way of non-limiting example, carbon fibre, fibreglass, plastics, ceramics and composite materials. It will also be appreciated that although elongate, substantially straight members are shown, non-straight members may also be utilized, such as, by way of non-limiting example, arcuate, space frame, plates or any other shape as long as the sockets 24 and 26 are rigidly translationally fixed relative to each other so as to securely locate the adjacent structural member relative to each other.
[0036] The sheet metal may be cut into a blank according to known methods and thereafter bend into the desired shape as illustrated and described above. In particular, the blank may include a central portion 102 which forms the rigid member 22 , top and bottom portions, 102 and 104 , respectively having an outline sufficient to be bent along bend lines 108 to form the top and bottom sockets 30 and 50 as described above. Thereafter, the blank 100 may be folded along the fold lines 108 to form the desired final apparatus.
[0037] With reference to FIG. 7 , a blank for forming an optional embodiment of the present invention is illustrated having extension tabs 110 extending from the second side panels 36 and 56 of the first and second sockets. The extension tabs 110 may include additional bores 112 therethrough sized to pass fasteners therethrough as described above. The extension tabs 110 may have a length sufficient to extend to and engage with a socket applied to a rear edge 14 of the wall stud when the socket is applied to a front surface of the wall stud wherein a single fastener may be passed through both bores 112 . Optionally, the extension tab 110 may have a length sufficient to pass around the rear edge 114 of the wall stud to permit wrapping of the wall stud within the socket.
[0038] Turning now to FIGS. 8 and 9 , an optional embodiment of the present invention is illustrated generally at 150 having a rigid member 152 with end sockets 154 at each end thereof. The end sockets are formed of base panels 156 having first and second side panels, 158 and 160 , respectively extending therefrom. The first and second side panels 158 and 160 extend substantially perpendicularly from the base panel 156 so as to form a u-shaped socket along a central axis 162 for receiving the wall stud 6 therein. As described above, the width of the base panel may be selected to space the first and second side panels apart by a distance corresponding to the width of the wall stud such as approximately 1.5 inches (38 mm) for use with a conventional 2×4 dimension lumber wall stud, by way of non-limiting example. Each of the first and second side panels includes fastener bores 164 and 166 , respectively, therethrough sized to receive fasteners, such as, by way of non-limiting example, screws or nails therethrough as will be more fully described below. The base panel 156 may also optionally include a fastener bore 168 therethrough.
[0039] Each of the first and second side panels 158 and 160 includes an end tab, 170 and 172 , respectively extending therefrom away from the central axis 162 of the socket 154 . Each end tab 170 and 172 includes a connection bore, 174 and 176 therethrough. The apparatuses 150 as illustrated in FIGS. 8 and 9 may be applied to the wall studs 6 such that a socket of one apparatus is adjacent to and abuts against a corresponding socket of an adjacent apparatus wherein the end tabs 170 and 172 of the sockets will abut against each other. Thereafter fasteners, such as, bolts screws and the like may be passed through the connection bores 174 and 176 so as to secure the sockets 154 to each other.
[0040] While specific embodiments of the invention have been described and illustrated, such embodiments should be considered illustrative of the invention only and not as limiting the invention as construed in accordance with the accompanying claims.
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An apparatus for reinforcing a plurality of adjacent parallel spaced apart wooden structural members to each other. Each of the structural members extends between first and second ends and has first and second edges. The apparatus comprises a ridged member extending between first and second ends and having a length sufficient to extend between two adjacent structural members. The apparatus further comprises a socket at each of the first and second ends of the rigid member. Each socket has a central axis therethrough and is formed of a base panel and first and second side panels. The socket is adapted to engage with a socket of an adjacent rigid member so as to interlink successive rigid members across a plurality of structural members.
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TECHNICAL FIELD
The present invention relates to a portable blending and mixing plant or "pugmill" that provides an homogenous blending and mixture of various aggregates and additives.
BACKGROUND OF THE INVENTION
Known portable mixing plants for producing asphalt and the like do not consistently obtain a homogenous mixture of aggregate and additives in the blending and mixing process. These problems arise from inconsistent flow of the aggregate, dry additives and liquid additives into the mixing chamber as well as changes in the mass balance of the mixing chamber. Resulting mixtures are not homogenous, thereby producing an undesirable finished product. In part, the inconsistent flow can be attributed to the difficult process of dispensing solid matter in a steady-state fashion. The discrepancies in the mixtures are accentuated in the portable mixing plant by the rugged nature of the terrain where the plant is normally used. The general presumption in the present versions of the portable mixing plant is of a steady-state model in the mixture process, but the present day control systems are not designed to handle the transient dynamic models that constitute the actual mixing process.
Prior art attempts to solve this problem have involved volumetric metering of the aggregate or the additives. One such device is a plant made and sold by Aran of Wacol, Brisbane, Australia under the name Aran ASR Continuous Mixing 280C. Although such techniques provide some improvement in the final product consistency, they are difficult to use in practice and are quite cumbersome to transport. There thus remains a long-felt need to overcome these and other problems associated with such plants.
BRIEF SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to provide a mobile pugmill that consistently produces a homogenous product.
It is another more general object of the invention to provide a transportable vehicle for blending and mixing aggregate and additives with a high degree of accuracy.
It is still another object to provide a highly portable, unitized pugmill that mixes products using a specialized weight-dependent metering system instead of known volumetric metering systems.
It is a further object of the invention to provide a vehicle that includes a feeder, mixer, silo, metering system and discharge conveyor all mounted on a tandem axis chassis. A programmable logic controller cooperates with weigh belt feeders to continuously measure and selectively control the amounts of feed material, additive and water that are combined in the mixer.
The present invention overcomes the inconsistencies of prior art plants by incorporating changes in gauging the mass flow rate of the aggregate and the dry additive feeders. Belt scales are used to obtain a more accurate reading of the mass of solids. A signal containing the present aggregate mass flow rate is then fed into a process control system that regulates the aggregate mass flow rate. The dry additive mass flow is based on the same system but is integrally linked to the weight percentage of the current aggregate flow rate instead of the ideal aggregate selected set point. A liquid flow meter is installed to measure the fluid flow of the liquid additive used. A proportional controller is used to control the fluid flow to the weight percentage amount of the actual aggregate flow as specified by the liquid set point. This ensures that the proper proportion of additives will be mixed with the aggregate even if the aggregate flow rate suffers from peaks or drops that will eventually be compensated by the aggregate controller.
The foregoing has outlined some of the more pertinent objects of the present invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention as will be described. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the following Detailed Description of the preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and the advantages thereof, reference should be made to the following Detailed Description taken in connection with the accompanying drawings in which:
FIG. 1 is an elevational view of the inventive pugmill supported on a vehicle frame;
FIG. 2 is a more detailed view of the various components of the pugmill of FIG. 1; and
FIG. 3 is a diagram illustrating the metering control system of the inventive.
DETAILED DESCRIPTION
Referring to FIG. 1, the inventive vehicle 10 includes an elongated vehicle frame 12. Transport wheels 14 are provided at one end of the frame, typically the back end, to enable the vehicle to be transported. The opposite end, typically the forward end, includes a hitch 16 that is connectable to a conventional hitch structure at the rear of a drawing vehicle or tractor (not shown) to ready the vehicle for transport over a road. Although not meant to be limiting, the frame is approximately 50 feet in length and is a tandem axis chassis with an air ride suspension (not shown).
The pugmill includes several main components: a mixer 20, an aggregate feed system 22, a dry additive feed system 24, a liquid feed system 26 and a front discharge conveyor 28. In operation, aggregate supplied from the aggregate feed system 22 is mixed in the mixer 20 with a dry additive supplied from the dry additive feed system 24 and a liquid supplied from the liquid feed system 26. The resulting product is then removed from the plant via the front discharge conveyor 28. Conveyor 28 includes a foldable end portion 30 to reduce the length thereof during transportation of the vehicle. Thus, the inventive pugmill includes two different feed systems (one for the aggregate and one for the dry additives) on the same chassis, as well as a novel weighing system for controlling the metering of the various feeds into the mixer 20.
Referring now to FIG. 2, a more detailed description of the pugmill feed and mixing operations can be seen. Aggregate feed system 22 comprises a variable speed aggregate feeder 32 supported adjacent an aggregate scale 34. The relative positions shown are merely exemplary, and other orientations may be used. Aggregate supported in the feeder 32 is supplied onto the scale 34 where it is weighed and also conveyed toward the mixer 20, which in the preferred embodiment is located in the approximate center of the pugmill. Dry additive feed system 24 comprises an additive silo 36 having an output that feeds into an upwardly-inclined variable speed additive auger 38. Again, the particular orientation of these devices is merely exemplary. Additive supplied from the silo 36 is delivered along the auger 38 and deposited on an additive belt scale 40, where it is weighed. From the additive belt scale 40, the additive is delivered into the mixer. The mixer also receives a liquid from the liquid feed system 26 comprising a conduit 44, liquid flow meter 46 and liquid flow control valve 48. Liquid is delivered from a source (not shown) connected to the conduit 44.
As will be appreciated, each of the component feed systems includes some means for varying the rate at which the constituent supplied thereby is metered into the mixing chamber. Thus, the aggregate feed system includes the variable speed feeder, the dry additive system includes the variable speed auger, and the liquid feed system includes a liquid flow control valve. Other equivalent flow rate metering devices or apparatus may be substituted within the spirit and scope of the invention. Thus, as one example, the aggregate feed system could incorporate a hopper that deposits the aggregate onto a variable speed auger that in turn deposits the aggregate onto a weigh scale. Each of aggregate and additive metering devices is selectively controlled by the weight of material being supplied (as opposed to its volume) using a metering control system that receives inputs from the belt scales. This operation is now described.
Turning to FIG. 3, the inventive control system 50 includes an input device 52, such as a touch screen having a display and keyboard, and a programmable logic controller 54. The touch screen 52 allows the user to establish a number of "set" points including an aggregate set point 56, a dry additive set point 58, and a liquid additive set point 60. Aggregate set point 56 establishes the mass flow rate (lbs/hr) for the aggregate. Dry additive set point establishes the mass flow rate (lbs/hr) for the additive, and the liquid set point establishes the liquid flow rate for the liquid. The programmable logic controller 54 continually monitors the set points and compares them with actual flow conditions to provide real-time control over mixing conditions by selectively varying one or more of the flow rate variables.
In particular, the aggregate set point is monitored in the programmable logic controller ("PLC") 54 by an aggregate proportional-integral-derivative ("PID") loop 62. The loop 62 monitors an electrical signal from the aggregate belt scale sensor means 66 to thereby gauge the flow rate of aggregate from the feeder. To adjust the flow of the aggregate, the aggregate PID loop 62 sends a first control signal to a variable speed driver device 64 that controls the aggregate feeder.
The dry additive also includes its own PID loop 68 that receives two inputs, an electrical signal proportional to flow rate of the dry additive through the additive feed system (as determined by the weight of the additive on the belt scale 40), and a dry additive rate calculation 70 based on the dry additive set point 58 and a value derived from the aggregate flow rate. For example, if the signal from the aggregate belt scale indicates a mass flow rate of 200,000 lbs/hr. and the percentage is set at 2.5% (0.025 * 200,000 lbs/hr=5000 lbs/ hr of dry additive), the dry additive flow rate will be 5000 lbs/hr. This calculation is controlled by the dry additive PID loop 68 that monitors signals from the dry additive belt scale sensor means 74 to determine any necessary control process changes to implement in the flow. If such a change is calculated, a signal 72 is sent to the variable speed screw auger to increase or decrease speed to reach the desired additive flow.
The liquid additive set point 60 is established at a weight percentage selection of the aggregate flow rate. The calculation of the liquid flow rate 76 is conducted by determining the weight percentage of the aggregate flow. The aggregate flow per time segment is determined from a calculation covering the aggregate flow rate and a weight of liquid per time segment which is then divided by the density of the liquid to determine a liquid measure per time segment flow for the liquid additive (for example, the aggregate flow rate is 200,000 lbs/hr., the liquid set point is 5.0%, 5% of 200,000 is 10,000, the liquid being used weighs 8.3 lbs/gal, 10,000/8.3 equals 1205 gal/hr, 1205/60=20 gal/min., this is recalculated every program scan). This set point rate is then compared 78 to the actual flow rate from the liquid flow meter 84. If the actual rate is less than the desired rate the PLC will adjust the rate flow valve in the open direction 80, or if the actual rate is higher than the desired rate, the liquid flow control valve will be adjusted in the closed direction 82.
One skilled in the art will appreciate that the above-described control system is flexible and may easily be adapted to handle several dry and at least two liquid additive sources. Thus, for example, where a second dry additive is used, an auxiliary silo is provided along with an additional weigh scale. The onboard PLC controller is then adapted to use a PID loop as previously described to facilitate control over the amount of the second dry additive metered into the mix.
Although the present invention is preferably implemented with the programmable logic controller, it should be appreciated that the metering control system may be hardwired or implemented as a computer program running on a personal computer or the like. One of ordinary skill in the art would also recognize that all or parts of such methods may be carried out in hardware, in firmware, or in more specialized apparatus constructed to perform the required method steps.
The present invention is especially advantageous for the production of soil remediation, stabilized soils, roller compacted concrete and cold mix asphalt. The device is a highly portable, unitized pugmill that is capable of mixing products with a high degree of accuracy. The mill includes a feeder, mixer, solo, measurement system and discharge conveyor all mounted on a single tandem axis chassis. All that is needed for the operation is water and a source of power for the control system. The programmable logic controller and weigh belt feeders measure and control the amounts of feed material, additive and water.
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A mobile pugmill accurately mixes an aggregate, an additive and a liquid supplied to a mixing chamber. The pugmill includes a first scale for weighing the aggregate being supplied to the mixing chamber and producing a signal proportional to aggregate weight as the aggregate is being continually conveyed to the mixing chamber. The pugmill also includes a second scale for weighing the additive being supplied to the mixing chamber and producing a signal proportional to additive weight as the additive is being continually conveyed to the mixing chamber. The pugmill further includes a programmable logic controller responsive to the signals proportional to aggregate and additive weights for selectively controlling flow rates into the mixing chamber of the aggregate, the additive and the liquid.
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FIELD OF THE INVENTION
This invention relates to a duplicating machine for security keys and more particularly for keys for use in security cylinder locks of MEDECO™ type.
BACKGROUND OF THE INVENTION
The general principle of operation of cylinder locks is known. In these, the bolt is usually operated by a cylinder (or plug) rotated within a corresponding cylindrical seat provided in the lock body. The cylinder is rotated by a cut key previously inserted into it, and is made possible by correctly arranging a plurality of pins housed partly in radial seats provided in the plug and partly in the extension of said seats provided in the cylindrical cavity housing it. As each pin is divided into two parts, the plug can be rotated only if the separation surface between the two parts of each pin coincides with the surface of discontinuity between the plug and relative seat. This state is achieved by correct cutting of the key which is inserted into the plug, to release it before rotating it.
The degree of reliability of a lock of this type corresponds to the number of variable factors which participate in forming that "combination" which enables the lock to be operated, and in particular the cross-section of the key and of the corresponding insertion seat in the plug, the number of pins and the number of positions which each pin can assume.
The possibility of finding two different locks operable by the same key is currently very remote, and hence the degree of reliability of such security locks is fairly high. However a wrongdoer expert in security locks can insert special tools into the opening in the plug and position the various pins in the same manner in which they would be positioned by the corresponding cut key, to hence succeed in rotating the key.
In order to prevent this tampering a security lock has been proposed in which the plug can be rotated only if the various pins are correctly positioned both axially and rotationally, in such a manner as to deactivate a special rake element which in addition to the pins also prevents the plug rotating within its seat.
In this known type of lock, known as a MEDECO™ lock, the notches are cut in the key by a cutter which instead of being positioned only perpendicular to the key to be cut can also be positioned inclined by ±20° to the horizontal, and hence able to form inclined notches in the key. If in addition that end of the pins in contact with the key is of dihedron shape, inserting the key into the plug results not only in axial displacement but also rotation of the pins, corresponding to the inclination of the notches present in said key.
In this manner the double result is obtained of increasing the number of variable parameters which define a lock, and of making it practically impossible to operate the pins from the outside, so substantially increasing the degree of reliability of the lock.
In order to define the cutting code for the key, there is associated with the code defining the axial position of each pin a letter which can either be C (in the case of a perpendicular cut--Central), or R (in the case of a cut rotated through 20° clockwise--Right), or L (in the case of a cut rotated through 20° anticlockwise--Left).
In order to still further increase the number of variable parameters in a MEDECO™ lock, it has been proposed to also vary the shape of the wedge-shaped end of each pin, in the sense that besides being of symmetrical dihedron shape it can also be of asymmetrical dihedron shape with the sharp edge either forward or rearward of its position on the pin axis. The three forward positions are conventionally indicated by a letter, namely K, B or Q, preceding the letter identifying the three corresponding centered positions by one place, whereas the three rearward positions are conventionally indicated by a letter, namely M, D or S, following the letter identifying the three centered positions by one place.
The aforedescribed MEDECO™ locks have a very high degree of reliability, however they suffer from a serious problem relating to code-cutting the relative key, ie cutting keys from the identifying code for each pin of the corresponding key. In this respect, each notch key has to be cut with a cutter which not only forms the notch in the key to the required depth but also takes account of the particular shape of the pin, ie it must be able to be positioned perpendicular to the key axis or rotated through 20° or -20° from it, and must also be able to be shifted axially along the key shank by an amount corresponding to the particular asymmetry of the tip of the pin.
Machines currently exist for code-cutting (ie without using a key to be duplicated but knowing only the cutting code), both for MEDECO™ keys with a symmetrical wedge pin and for MEDECO™ keys with an asymmetrical wedge pin, but there are no machines able both to cut keys of one type, and to cut keys of the other type.
In addition, in known code-duplicating machines for MEDECO™ keys, the cutting involves a series of difficult, slow and non-instinctive operations, which are therefore subject to error.
Again in these known machines the key to be cut is generally positioned with that edge to be cut facing upwards with the cutter descending vertically onto it, to hence create a notch the cut of which is not perfectly rectilinear but instead is curved in accordance with the radius of the cutter. The result is that the engagement between the notch and relative pin is not perfect.
Finally, known duplicating machines for MEDECO™ keys have all their members accessible from the outside and hence subject to inevitable errors due to the presence and accumulation of swarf originating during cutting.
SUMMARY OF THE INVENTION
The main object of the invention is to cut security keys for MEDECO™ locks with both symmetrical and asymmetrical pins.
A further object of the invention is to code-cut MEDECO™ keys in a rigorously precise and repeatable manner.
A further object of the invention is to effect this cutting in very simple and fast manner.
A further object of the invention is to enable this cutting to be effected by non-specialized personnel.
These and further objects which will be apparent from the description given hereinafter are attained according to the invention by a duplicating machine for security keys and more particularly for keys for use in security cylinder locks of MEDECO™ type.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the present invention is further clarified hereinafter by way of non-limiting example with reference to the accompanying drawings, in which:
FIG. 1 is partly sectional plan view of a duplicating machine according to the invention; and
FIG. 2 is a partly sectional side view thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The duplicating machine according to the invention comprises on a base 2 a motor 4 which via a belt transmission system drives a cutter 6 for cutting a key 8. The unit comprising the motor 4, belt transmission system and cutter 6 is slidable vertically along two guides 10, its vertical movements being controlled by a lever 12.
The duplicating machine is also provided with a clamp 14 the purpose of which is to maintain the key 8 in a position facing the cutter 6. The clamp 14 is mounted on a first slide 16 slidable parallel to the axis of the key 8 on an underlying rockable support 18. The rockable support 18 is mounted on a slide 20 slidable horizontally on the base 2 in a direction perpendicular to the axis of the cutter 6.
The slide 16 is moved along the rockable support 18 by a handwheel 22, mounted on the rockable support 18 and provided with a threaded shaft 24 engaging in a threaded bush 26 rigid with the rockable support 18. This movement, which by its nature should be continuous, takes place in reality in steps because of the presence of a spring device 28 which snap-halts the handwheel 22 at each revolution to preferentially position the key 8 relative to the cutter 6 in those positions in which the notches are to be cut. These positions are expressly displayed by a number which appears through an aperture 30 provided in the rockable support 18.
The rockable support 18 is mounted on the slide 20 such as to be able to rotate on it about a horizontal axis 32 lying in the vertical plane of the cutter 6 and perpendicular to the axis of the key. 8. The rockable support 18 is provided with a cylindrical seat having its axis positioned above the axis of rotation 32 and parallel to it. This seat houses a cylindrical bar 33 which can move axially under the control of a lever 34, the lower end of which engages in a cavity provided in the bar.
Said bar 33 is provided at one end with a peg 36 engaging in a slotted guide 38, visible in FIG. 1 and formed in three parts which are parallel to the axis 32 and are slightly displaced from each other in the horizontal plane by a distance corresponding to the axial offset of the end of the three different types of pin of the security lock.
The cylindrical bar 33 comprises three longitudinally aligned notches elastically engagable by a ball 42 constrained to the seat of the bar so as to predetermine the three positions which this is able to assume by operating the lever 34 and corresponding to the engagement of the peg 36 in three portions of the slotted guide 38.
The lever 34 is pivoted on a pin 44 rigid with the rockable support 18 and can hence be made to rotate about this latter to generate the axial movements of the bar 33 as stated. At the same time the lever can be operated in a transverse direction perpendicular to the preceding, to cause the support 18 to rock in the two directions about the axis 32.
These overall movements of the lever 34 are guided and displayed by a template 45 rigid with the machine base 2.
The movements of the slide 20 along the machine base 2 are enabled by the engagement of said slide in guides 46 provided in said base and are generated by the counteraction between the lateral surface of a roller 48 rigid with the slide and a multi-lobed wheel 50 rigid with a control knob 52 applied to the base.
More specifically, the wheel 50 comprises on its lateral surface a plurality of concave lobes all of the same radius, equal to that of the roller 48, and a spring, not visible on the drawings, urged by the slide 22 to maintain said roller 48 elastically adhering to one of the lobes of the wheel 50. The distance of each of said lobes from the axis of rotation of the wheel 50 is determined in such a manner as to position the key 8 with respect to the cutter 6 to correspond to the different depths required for the cut notches.
The angular position of the knob 52 and hence of the multi-lobed wheel 50 is indicated by a number through an aperture 54 provided in a fixed cover 56 embracing said knob 52.
The operation of the duplicating machine according to the invention is as follows:
the blank key 8 to be cut is firstly mounted in the clamp 14 in such a manner as to respect the traditional location points for correct cutting. The handwheel 22 is then operated until the number corresponding to the first notch to be cut appears in the aperture 30. The machine is set such that when the lever 34 is in the central position of the aperture provided in the guide template 45 (position C), the vertical plane of the cutter 6 coincides with the plane in which the first notch is to be cut in the key 8.
If this notch is to be perfectly perpendicular to the key and has to correspond to a symmetrical lock pin, the lever 34 is maintained in this position so that on operating the lever 12, the cutter is lowered and acts on the key 8 to form therein a notch having a depth related to the position of the control knob 52. It is apparent that to set the depth of said notch the knob 52 is firstly operated so as to vary the position of the key 8 relative to the cutter 6 in the horizontal plane and hence the depth of the notch, in accordance with the chosen lobe of the wheel 50 as displayed through the aperture 54.
If however the notch to be cut is again perpendicular to the axis of the key 8 but is to be provided for engaging as asymmetrical pin (coded D or B instead of C), the lever 34 has to be moved forwards or backwards before operating the lever 12. In this manner the bar 33 is moved axially and, by virtue of the engagement of its peg 36 in the slot 38, displaces the threaded bush 26 to the right or left relative to the rockable support 18 by a small distance related to the asymmetry of the lock pin.
Clearly, the axial displacement of the threaded bush 26 results in a like displacement of the threaded shaft 24, of the slide 16, of the clamp 14 and of the key 8. In FIG. 1 the control lever 34 is shown in position B.
If instead a notch inclined for example in the anticlockwise direction is required, before operating the lever 12, the lever 34 is moved towards the left (position L) to rotate the rockable support 18 and hence the key 8 about the axis 32. The subsequent operation of the lever 12 then results in the formation of the inclined notch in the key 8.
If the cut notch, in addition to being inclined, also has to be arranged for engagement by an asymmetrical pin, the lever 34 has to be shifted both towards the left and forwards (position M) or backwards (position K).
The commands to be used for the key cutting are basically as follows:
the handwheel 22 is operated to axially move the key to position it for effecting the successive notches,
the knob 52 is operated to adjust the depth of each notch,
the lever 34 is operated in a direction parallel to the key axis to set the notch angle (perpendicular, or rotated through 20° anticlockwise, or rotated through 20° clockwise),
the lever 34 is operated in a direction perpendicular to the key axis to form the notch in relation to the type of pin which is to interact with it (symmetrical pin or asymmetrical pin with its end displaced towards the head of the key, or asymmetrical with its end displaced towards the tip of the key).
From the aforegoing it is apparent that the duplicating machine according to the invention completely attains the stated objects, and in particular:
it enables any key of MEDECO™ type to be code-cut in rigorously precise form,
it allows very fast and simple cutting, with instinctive operations,
it can be used by non-specialized personnel,
it enables the resultant notches to present a perfectly rectilinear cut.
Although the present invention has been shown and described with respect to a preferred embodiment thereof, it should be understood by those skilled in the art that other various changes in the form and detail thereof may be made without departing from the spirit and scope of this invention.
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A code-duplicating machine for security keys usable in cylinder locks with a bolt operable by a plug and with a plurality of pins operable axially and rotataby by a cut key inserted into said plug to release it and enable it to rotate. The machine comprises a cutter (6), a clamp (14) for a key (8) to be cut, and means for causing said clamp (14) and said cutter (6) to undergo mutual movement resulting in said key being cut in accordance with a predetermined code.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to a handle for concrete and other heavy nonmetallic covers that are buried below grade, such as covers and inspection lids for septic tanks, wells, and concrete and plastic liquid distribution boxes, that provides means for indication of the location of the cover.
2. Description of the Prior Art
The need for marking the location of subterranean structures in the field of building and construction is well recognized, resulting in many designs.
U.S. Pat. No. 3,568,626, patented by Hamilton Southworth, Jr., Mar. 9, 1971, describes a ribbon of infrangible, stretchable strips which are buried in the soil over buried utilities such as electric lines, gas lines, or water lines, to provide warning of the existence of the utilities to a worker excavating over the utilities. The warning is provided when the excavating machinery catches and draws up a portion of the strip and it is seen by the worker. Coding means of a magnetic or radioactive type are applied to the strip before burial of the strip so that once the strip is discovered at the point of excavation, the worker can then determine the subterranean location or run of the utility line by following above ground with suitable sensors, the path of the underground ribbon.
U.S. Pat. No. 3,916,821, patented by Othmar W. Pies, Nov. 4, 1975 discloses a marker assembly comprising a permanent magnet surrounded by a housing having an upright socket for receiving a stake. When the stake is driven into the ground with the housing below the surface of the ground, the stake can be found from above the ground by a magnetic dipping needle.
U.S. Pat. No. 4,699,838, patented by Ronald E. Gilbert, Oct. 13, 1987, describes a reinforced metallic tape marker which is buried over underground plastic, ceramic, concrete, and other nonmetallic utilities, that resists tearing during backfilling of the trench in which the utility with overlaying tape are buried.
SUMMARY OF THE INVENTION
It is one object of the invention to provide means for marking the location of a subterranean structure.
It is another object that the means for marking comprise an element of the structure.
It is another object that the means for marking be light in weight for shipping and storage.
It is another object that the means for marking can be made in part from material which is ordinarily discarded at a construction job site.
It is another object that the means for marking comprise a plastic handle for a cover of a subterranean structure, and that steel rebar commonly found at a construction job site can be used to complete construction of the plastic handle means for marking.
Other objects and advantages will become apparent to a reader of the following description of the invention.
A plastic handle for a nonmetallic cover of an element of subterranean installment includes means for receiving by way of insertion a metal marker of substantial mass.
Preferably the means for receiving includes means for holding the metal so that is removable, and the means for receiving has a shape that closely receives rebar.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention be more fully comprehended, it will now be described, by way of example, with reference to the accompanyiny drawings, in which:
FIG. 1 is a vertical perspective view of a handle according to the present invention.
FIG. 2 is a view of a portion of a handle showing a retaining means.
FIG. 3 is a vertical perspective view of another handle according to the present invention.
FIG. 4 is a vertical perspective view of a handle and cover according to the present invention.
FIG. 5 is a vertical perspective of a handle and cover according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before explaining the invention in detail, it is to be understood that the invention is not limited in its application to the detail of construction and arrangement of parts illustrated in the drawings since the invention is capable of other embodiments and of being practiced or carried out in various ways. It is also to be understood that the phraseology or terminology employed is for the purpose of description only and not of limitation.
Referring to FIG. 1, body 14 of handle 10 is constructed throughout of engineered plastic such as Dupont 801 (tm). It is designed to be gripped by hand, but can be engaged by cable or other lifting means, as the handle can be manufactured to a 2,000 pound rating.
Legs 18 are designed to be inserted into a concrete, plastic or other nonmetallic cover for an element of construction such as a septic tank, pump chamber, distribution box, and well, that are buried in the ground, in which the cover is buried below grade or below the soil and is out of sight.
Often after below ground installation of the element of construction and cover, a lawn or other valuable overlying surface is developed. When it is time to inspect, clean or otherwise access the interior of the element of construction, it is desirous to find the exact location of the cover and dig straight down so as to disturb as little of the overlying development as possible.
The handle of the present invention is designed to provide a mark of the location of the cover through use of a metal detector. Many metal detector designs which can detect the fully assembled handle below ground are presently available on the market, such as from Radio Shack (tm), a division of Tandy Corp., Fort Worth, Tex.
Handle 10 includes slot 24 in top 26 of the handle, for receiving a metal bar. In a preferred embodiment of the invention, slot 24 is shaped to receive rebar 32 that is commonly used in construction. Preferably slot 24 is shaped to receive the rebar by insertion of the rebar from one end of the slot axially into the slot, and to prevent withdrawal of the rebar radially from the slot. A portion of the top therefor extends over each side of the rebar.
Portions of rebar often abound as scrap on construction sites. Cutting tools for quickly cutting the rebar are also commonly available on construction sites. A portion of rebar is cut preferably to about the length 36 of slot 24, and is inserted into slot 24 at the construction site.
The handle with rebar provides a high quality marker for detection equipment because the rebar presents to the metal detector a substantially large ferrous mass that is easy to detect for most detectors.
The handle can be economically molded without the cost in dies and labor of molding-in a remotely detectable marker of the quality of rebar.
In FIG. 2, top 40 of a handle of the present invention includes slot 44 which is shaped to receive rebar 32 axially or radially, and to cradle rebar selected from several diameters normally used in construction. Retainer means such as rotary catch 46 prevents radial removal of the rebar when the catch is rotated on pivot 48 to a position over the rebar in the slot.
Handle 50 in FIG. 3 includes retainer pegs 54 which are inserted into slots 56 in side wall 60 of the handle after rebar piece 62 is inserted obliquely into slot 66 in side wall 60.
Holes 70 in legs 72 hold rebar 76 pieces which increase retention strength of the legs in a cover. Stops 80 help set the depth to which the legs are inserted into the cover when the handle is inserted into the cover material for molding or casting it into the cover.
In FIG. 4, handle 84 is mounted in inspection lid 86, and holds rebar 88 behind protrusions 90 of the handle. Protrusions 90 yield sufficiently to permit radial insertion of the rebar past the protrusions, into a depression 92 in the handle, and to resist removal of the rebar once so installed.
In FIG. 5, handle 94 is bolted to top 96 of cover 98 from below the cover. The other cover on the handle is installed in the cover without rebar, as a second handle, as a second marker was needed.
Although the present invention has been described with respect to details of certain embodiments thereof, it is not intended that such details be limitations upon the scope of the invention. It will be obvious to those skilled in the art that various modifications and substitutions may be made without departing from the spirit and scope of the invention as set forth in the following claims.
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A concrete cover for a subterranean construction includes a cast-in plastic handle which holds a piece of rebar in the cover and removably holds a piece of rebar externally of the cover.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a computer controlled cleaning tool. More specifically, the present invention relates to a cleaning tool for automatically cleaning a preheater rotor used in electrical power plants.
2. Description of the Related Art
Using high pressure water which is forced through a preheater rotor is well known. Typically, after prolonged use the preheater rotor or rotors of an electrical power plant become coated and clogged with debris such as coal ash. This occurs when hot gases from a plant's combustion process are routed to a preheater rotor, which transfers heat to fresh air routed back to the combustion process to increase the burning efficiency. When the rotors become coated with debris the heat transferring efficiency is reduced and therefore the rotors need to be cleaned periodically.
Typically the preheater rotors are up to twenty feet in diameter and a high pressure water stream of approximately 0.25 inches is applied to the rotor. It can easily be seen that this cleaning process takes a long time, anywhere from 25 to 50 hours depending on the width of the water stream and the rate at which the rotor is rotated past the stream.
There have been attempts made in the past to increase the efficiency and ease of this cleaning. One such attempt includes using programmable logic control (PLC) to move a high pressure water nozzle along a bar extending radially from a hub of the rotor.
This system required an operator to compute how long it would take a rotor to make a complete revolution based on a rotor rotation rate which the operator would independently set. The operator would then compute how long the cleaning would take based on how much of the rotor was to be cleaned and the width of the water nozzle spray. All of the computed parameters would then be entered into the PLC which would then set a timer and move the spray nozzle by an amount equal to the nozzle spray width when the timer indicated the rotor had completed a revolution.
It is therefore desirable to provide a system which would enable only basic direct information, such as inner and outer radii of the rotor, spray width, and the rotor rotation rate or the time to complete the cleaning to be entered and have the cleaning tool automatically clean the area of the rotor bounded by the inner and outer radii.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an easy-to-use, compact, computerized cleaning tool.
It is a further object of the present invention to provide a cleaning tool which decreases: tool setup time, the number of personnel needed, and the operating steps required of an operator.
It is a still further object of the present invention to provide a cleaning tool wherein an operator simply enters parameters of the cleaning operation and the computer calculates the required information based on the parameters and automatically controls the cleaning operation.
Yet another object of the present invention is to provide a cleaning tool where the cleaning operation can be interrupted and parameters needed to be changed can be entered wherein the computer recalculates the required information based on the change in parameters.
These and other objects are met by the air preheater cleaning tool and method of the present invention and also, in large measure, solves the problems outlined above. A method for automatically cleaning a preheater rotor used in an electrical power plant, comprises the steps of:
(a) providing a computer for controlling the cleaning, the computer includes user interface means;
(b) entering parameters into the computer defining an area of the rotor to be cleaned and one of a rate at which the rotor is to be rotated and a time to complete the rotor cleaning;
(c) calculating with the computer the other of the rotor rotation rate and the time to complete the cleaning;
(d) moving cleaning means operably coupled to the computer to a starting position in response to a signal from the computer;
(e) activating cleaning means wherein the cleaning means produces a predetermined track width;
(f) rotating the rotor at a predetermined speed in response to a signal from the computer such that the cleaning means cleans a predetermined width of the rotor thereby making a clean track on the rotor;
(g) determining with the computer when a complete clean track has been made on the rotor;
(h) moving the cleaning means in response to a signal from the computer so that a portion of the rotor adjacent the previously cleaned portion is cleaned; and
(i) repeating steps f, g, and h until the area defined by step b is cleaned.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a preheater rotor in a power plant;
FIG. 2 is a side elevation of the rotor with a pair of cleaning tools attached;
FIG. 3 is a partial view of FIG. 2 showing one of the cleaning tools;
FIG. 4 is a top view of the rotor with the pair of cleaning tools attached wherein the rotor is shown in broken-line;
FIG. 5 is a block diagram of the computer and associated components of the cleaning tools for automatically controlling the cleaning of the rotor;
FIGS. 6A-6C are a flow chart of software used by the computer for automatically controlling the cleaning of the rotor;
FIG. 7 is a flow chart of a calculate and display subroutine of FIGS. 6A-6C;
FIG. 8 is a flow chart of a main input subroutine of FIGS. 6A-6C;
FIGS. 9A and 9B are a flow chart of an indexing subroutine of FIGS. 6A-6C; and
FIGS. 10A and 10B are a flow chart of a move subroutine of FIGS. 6A-6C.
FIG. 11 is an illustration of a preferred operator terminal in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 an electrical power plant's combustion process is shown generally at 10. The process works by fire 12 heating air which causes boiler 14 to produce steam to the power plant's turbines for producing electricity. The hot area is then circulated through at least one preheater rotor 16. Heat is then transferred to rotor 16 and the now somewhat less hot air which has passed through rotor 16 is exhausted at 18.
Rotor 16 is rotated by a high torque motor and as rotor 16 is rotated fresh, cool air is forced through rotor 16 at an inlet 22. The rotor 16 warms the cool air as the air passes through rotor 16. By warming the fresh air before introducing it to the fire 12 the efficiency of the combustion process is increased by decreasing the fuel needed to heat the air to produce steam for the turbines. The fire 12 is typically fueled by coal or oil that produce debris in the heated air which collects on the rotor 16 as the air passes through rotor 16.
The accumulation of debris on the rotor 16 decreases heat transfer efficiency of the rotor 16. In order to maintain acceptable heat transfer efficiency it is desirable to clean the rotor 16 periodically. The cleaning is best accomplished by the cleaning tool shown in FIGS. 2-5. The major mechanical components are shown in FIGS. 2-4 and the electronic components shown in FIG. 5. FIG. 2 shows two cleaning assemblies 24 and 26 which are attached to hub 20 adjacent opposite sides of the rotor 16. Cleaning assemblies 24 and 26 are identical and include power heads 28 and 30, nozzle blocks 32 and 34, nozzles 36 and 38, beams 40 and 42, and chains 48 and 50. The power heads 28 and 30 include trolley assemblies (not shown) which are adaptable move along different size beams 40 and 42.
As shown in FIG. 3, a water hose 44 is attached to nozzle 36 in nozzle block 32. Preferably, nozzle block 32 has structure allowing up to 4 hoses 44 to be attached to 4 nozzles 36. Also, power head 28 is connected to a control/power line 46 and uses a chain 48 to move along beam 40. As those skilled in the art are aware beams 40 and 42 are attached to hub 20 and a wall 52 of the preheater. The cleaning assembly 26 also includes a water hose connected to nozzle 38 and a power/control line connected to power head 30 (shown in FIG. 5 at 47).
Preferably, the lower cleaning assembly 26 is positioned so that spray from nozzle 38 will force debris up through rotor 16 before spray from nozzle 36 forces debris back down through rotor 16, as shown in FIG. 4. The beams 40 and 42 should be parallel to rotor 16 to ensure that the maximum force of the spray from nozzles 36 and 38 is applied to rotor 16.
Referring now to FIG. 5, a computer control 54 is shown and includes an operator terminal 56, a parallel input/output interface 58, a digital-to-analog converter 60, a power supply 62, and a computer 64. Control 54 also includes relays 66-72 and terminal 56 preferably includes a keyboard, as shown in FIG. 11, and a display screen 57.
Computer 64 is preferably, a single pc board containing a central processing unit, random access memory, read only memory, and three, eight bit bi-directional parallel ports. The operator terminal is an integrated key input pad for entering parameters into computer 64 defining a cleaning operation, as detailed below. The parallel input/output interface converts higher voltage and current external signals to computer levels and vice versa.
The digital-to-analog converter converts computer information into zero to ten volts for controlling a variable speed motor drive (VSMD) 74. VSMD 74, then causes a high torque motor 76 to rotate rotor 16 at a rate determined by computer 64. VSMD 74 is the power source for a redundant 30 volt power supply 62 from a 480 VAC main supply.
Connected to computer control 54 are an optional infrared sensor 78, limit switches 80-86, and power heads 28 and 30 which include reverse switches 88 and 90. Infrared sensor 78, which includes a sensor and a reflector (not shown) attached to the rotor 16, performs two functions. The main function is for sensor 78 to inform computer 64 when a complete revolution of rotor 16 has occurred. The other function of sensor 78 is to allow computer 64 to calculate a ratio between the motor 76 revolutions per minute and the rotor 16 revolutions per minute. This ratio is typically close to 1750:1.
The limit switches 80-86 are preferably magneticly mounted at inner and outer most points on beams 40 and 42 to indicate to computer 64 when power heads 28 and 30 have reached the end of travel and to protect the power heads 28 and 30 from being damaged.
Once all connections to computer control 54 have been made as shown in FIG. 5 and the power heads 28 and 30 are placed on beams 40 and 42 the rotor is ready to be cleaned. The use of cleaning assemblies 24 and 26 will be explained with reference to assembly 24 in conjunction with the flow charts of FIGS. 6A-10B. The cleaning assembly 26 will move exactly as cleaning assembly 24 because they are aligned to clean the same area of the rotor 16 at any given time.
The cleaning operation begins at step 600 of FIG. 6A where computer 64 sets the input/output options as shown. Next, step 602 loads the keyboard array and default ratios. Step 604 determines if rotor sensor 78 is connected; if it is not step 606 causes "Rotor Sensor Not Connected" to be displayed on display 57. The program then proceeds to step 608 which displays "Enter Existing Rotor Ratio ".
Next, step 610 determines if the entered rotor ratio, as explained above is within acceptable limits; if not step 612 causes "Ratio Should Be 875 To 3500" to be displayed and loops back to step 608 until an acceptable ratio has been entered. Step 614 then causes display 57 to tell the operator to "Enter Driver-Rotor Ratio" and step 616 determines if the ratio between the revolutions per minute of the VSMD 74 and the rotor 16 are within acceptable limits. If the ratio is not acceptable step 618 causes the message "Ratio Should Be > & <5" to be displayed and loops back to step 616 until an acceptable ratio is entered.
The program then calls a calculate and display subroutine at step 620. The subroutine is shown at FIG. 7 and at step 700 causes computer 64 to compute the current circumference of rotor 16 relative to the position of nozzles 36 and 38, a proper DAC 60 voltage (BM), and a time required to complete the cleaning of rotor 16 (TOJ) based on existing default values. Step 702 then causes display 57 to display:
______________________________________TRK FPM RAD TOJ______________________________________(N) (F) (R) (T)______________________________________
where TRK is a track or spray width produced by nozzles 36 and 38 on rotor 16 and N is a number in inches; FPM is the linear feet per minute at which the rotor is rotating and F is a number in feet; RAD is the outer radius of the rotor 16 and R is a number in feet; and TOJ is the time of job and T is a number in hours.
Step 702 will initially display values such as N=0.250, F=20.0, R=20.0, and T=25.0. The program then returns to step 622 which clears and resets all program interrupts. Next, step 624 calls a main input subroutine which is shown in FIG. 8.
Step 800 of FIG. 8 then determines if the T.O.J. key of operator terminal 56 has been pressed. If YES step 802 causes "Time Of Job? (T)?" to be displayed. Once a value T has been entered step 804 causes computer to calculate the required feet per minute at which rotor 16 must be rotated in order to finish the cleaning based on the entered value T and also the required BM (digital to analog voltage) to cause motor 76 to rotate rotor 16 at the required rate. The program the loops back to step 800 where if the T.O.J. key has not been pressed step 806 determines if a F.P.M. key has been pressed.
If the F.P.M. key was pressed step 808 causes "Feet Per Minute? (F)?" to be displayed. Step 810 then causes the T.O.J. and BM to be calculated based on the F input. As can be readily determined if either the F.P.M. or the T.O.J. change the other must necessarily change. The program the loops to step 800 where as above and if the answer to both steps 800 and 806 is NO step 812 determines if a Radii key has been pressed.
If YES step 814 causes "Outside Radius? (R)?" to be displayed and then step 816 calls a move subroutine shown in FIGS. 10A and 10B. Step 1000 determines if the move is part of an indexing routine of FIGS. 9A and 9B. If NO step 1002 causes computer 64 to move power heads 28 and 30 by an amount equal to a calculated new radius based on the present radius and an amount B by which the power heads 28 and 30 are to move. B should be in inches and is typically the track width of the spray from nozzles 36 and 38. Because B is in inches and R is in feet B is divided by 12. Step 1004 then releases the reverse relays 68 and 70 and step 1006 clears a counter used to determine the distance power heads 28 and 30 have moved.
After the program returns from the move routine step 818 causes "Inside Radius? (H)?" to be displayed. This radius is the inner most radius which is to be cleaned and is typically the hub 20 radius (hence the letter H) but can be any number greater than the hub radius and less than the outside radius. Computer 64 at step 820 then calculates the circumference (C) of the rotor 16 and the T.O.J. The program then loops back to step 800 and if the answers to steps 800, 806, and 812 are NO the program proceeds to step 822 which determines if a Move key has been pressed.
If the Move key has been pressed step 824 calls the move subroutine as explained above and then loops to step 800 again where the programs proceeds to step 826 if the answers to steps 800, 806, 812, and 822 are NO. Step 826 determines if a restart key has been pressed and if YES step 828 causes the computer to restart and the program returns to step 600. If the answer to step 826 is NO step 830 then determines if an Index key has been pressed if YES the routine returns to step 626 and if NO the program loops to step 800 and proceeds as above until the Index key is pressed.
Once the Index key is pressed step 626 causes "Rotor Start: 5 seconds. Press a Key To Stop" to be displayed. Step 628 then activates a 5 second timer and step 630 determines if the timer has timed out. If NO step 632 determines if a key has been pressed. If a key is pressed the program loops to step 620 if not the program loops to step 630 until the timer has timed out. Once the timer has timed out step 634 starts the rotation of the rotor 16.
Next, step 636 causes "When Indexing Is To Start Press Index" to be displayed. Step 638 then determines if the Index key has been pressed; if NO the program loops to step 636 until it is pressed. Step 640 then calls an indexing routine which can be either timing or sensor driven, as explained below. Before the Index key is pressed an operator must activate the cleaning assemblies 28 and 30 by turning on a high pressure water supply.
Step 900 of the indexing routine of FIG. 9A determines if sensor 78 is connected if YES the routine will be sensor driven and proceeds to step 902 and determines if a sensor interrupt has occurred. If no sensor interrupt has occurred step 904 causes display 57 to indicate that cleaning is occurring by displaying something such as a spinning star symbol. Step 906 then determines if any key of operator terminal 56 has been pressed. If NO the program loops to step 902, if YES step 906 call the main input subroutine of FIG. 8 as explained above. When step 902 detects a sensor interrupt the program jumps to step 920 explained below.
On the other hand if sensor 78 is not connected at step 900 the indexing routine will be timing driven and step 908 causes computer 64 to calculate the spray time at the current radius. Step 910 then sets a timer to the calculated spray time and step 912 determines if the timer has timed out. If NO step 914 causes a star to spin on display 57 as a step 904. Step 916 then determines if a key has been pressed. If YES the program proceeds to step 906 and if NO loops back to step 912.
If a key is not pressed before the timer of step 912 times out step 918 stops the timing and step 920 sets a value B equal to the track width N, where B is an amount by which the power heads 28 and 30 are to move. Step 922 then calls a move subroutine, shown in FIGS. 10A and 10B, with the + and - signs indicating whether power heads are to be moved in or out.
In this case the answer to step 1000 will be YES and step 1008 will read the limit switches 80-86. Step 1010 then determines if the power heads 28 and 30 are at their limits. If YES step 1012 displays "Limits Detected Before Move" and step 1014 sets B equal to zero and the program returns to step 924 after steps 1004 and 1006. If the power heads 28 and 30 are not at their limits at step 1010 step 1016 moves power heads 28 and 30 and starts a counter to determine how far the power heads 28 and 30 have moved. Step 1018 causes a bell to ring to indicate to the operator that the power heads 28 and 30 are moving.
Next, step 1020 determines if a key has been pressed; if YES the program returns to step 924 after steps 1004 and 1006. If the answer to step 1020 is NO step 1022 reads the limit switches 80-86 to determine if the power heads 28 and 30 have reached their limits. Step 1024 then determines if the counter equals B which has been set to the track width N. If YES step 1026 stops the power heads 28 and 30 and the cleaning continues. If the answer to step 1024 is NO step 1028 determines if the power heads 28 and 30 are at any of their limits. If step 1028 is NO the program loops to step 1022 but if the answer is YES step 1030 causes "Limits Detected During Move" to be displayed and the power heads 28 and 30 are stopped and after steps 1004 and 1006 the program returns to step 924.
After the program returns from the move subroutine step 924 calls the calculate and display subroutine explained above to determine the circumference of the present radius and the require DAC voltage and FPM. Next, step 926 determines if this is the end of the job by determining if R≦H or B=0 and if the answer to either is YES the cleaning is end if NO the program loops to step 900.
The indexing routine will continue uninterrupted until the entire area of the rotor 16 defined by the inner and outer radii has been cleaned. While the indexing routine is running step 642 determines if the move or erase keys of terminal 56 have been pressed. If the erase key is pressed the program returns to the beginning at step 600.
If, however, the move key is pressed step 644 determines how far the power heads 28 and 30 are to move by the formula shown in step 644, where B=the distance to be moved, R=a new radius to which the power heads are to be moved, and RM=the radius at which the power heads are currently located. Step 646 then calls the move routine of FIGS. 10A and 10B as explained above. Next, step 648 sets the values of H, N, and F into memory which are then used to calculate new parameters when there is a change in any one parameter. The program the loops back to step 636 and proceeds as explained until the cleaning is completed or aborted.
As those skilled in the art will appreciate, it is noted that substitutions may be made for the preferred embodiment and equivalents employed herein without departing from the scope of the present invention as recited in the claims. For example, other types of ways to move the power heads 28 and 30 may be employed as well as various types of sensors and switches.
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A method for automatically cleaning a preheater rotor used in an electrical power plant is disclosed. The method includes controlling with a computer the cleaning of the rotor as well as calculating parameters such as a rate at which the rotor is to be rotated and a time to complete the rotor cleaning based on parameters entered by an operator. The method also controls the movement of a cleaning assembly along the radius of the rotor. An associated apparatus is also disclosed.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and hereby claims priority to PCT Application No. PCT/GB2005/000697 filed Feb. 24, 2005, Great Britain Application No. 0405389.8 filed on Mar. 11, 2004 and Great Britain Application No. 0414717.9 filed on Jul. 1, 2004, the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates to a method of packet switched handover in a mobile communication system, in particular for 2nd and 3rd generation mobile phone systems, using general packet radio service (GPRS).
[0003] Packet Switched (PS) handover is a relatively new topic in Global System for Mobile communications (GSM) /Enhanced Data rates for GSM Evolution (EDGE) Radio Access Network (GERAN) requiring new mechanisms in the RAN and Core Network. PS handover requires low PS service interruption times, preferably less than 200 ms. In the case of inter-SGSN handover the new SGSN (serving general packet radio service (GPRS) support node) may not be able, or may not want, to support the same set of parameters for the data protocols. In the case of GERAN, these are the Sub-network Dependent Convergence Protocol (SNDCP) and logical link control (LLC) protocols. In this case, a negotiation procedure takes place between the mobile and the SGSN after it establishes itself in the new cell after handover. During this procedure PS data cannot be received by the mobile thus increasing the PS service interruption time.
[0004] If new LLC/SNDCP parameters need to be negotiated for the mobile in the new cell, the target SGSN must initiate the procedure by sending an exchange identification (XID) command to the mobile. This can only be carried out when the SGSN knows that the mobile has successfully made access in the target cell by receiving the PS handover complete message as shown in FIG. 1 . At this point the target SGSN can send the XID command to the mobile which in turn sends an XID response back to the target SGSN. Only when the XID response is received can the target SGSN start to relay downlink protocol data units (PDUs) to the mobile. This procedure causes a further two round trip times (mobile to SGSN and back) to be added to the service interruption time, which is undesirable.
SUMMARY OF THE INVENTION
[0005] The inventor proposes a method of packet switched handover in a mobile communication system comprising a terminal, a source node and a destination node comprises negotiating protocol parameters for the destination node on behalf of a new network entity, by communicating with an old network entity whilst the terminal is still connected to the source node; and completing the packet switched handover, such that service interruption on handover is reduced.
[0006] According to the method most, if not all, of the negotiation procedure is conducted before the mobile moves to the new cell, thus considerably reducing the service interruption time.
[0007] Preferably, the negotiation of protocol parameters comprises including an exchange identification data command in a packet switched handover request.
[0008] Preferably, the exchange identification data command is packed in a target to source transparent container at a target base station, transferred to a source base station, unpacked and sent in a packet switched handover command to the terminal.
[0009] As a packet switched handover request is not always present, alternatively, the negotiation of protocol parameters comprises including an exchange identification data command in a packet switched handover command and continuing downlink data transfer before the packet switched handover is complete.
[0010] Preferably, a packet switched exchange identification response is sent from the terminal to a source base station and thence to the source node; and relayed to the destination node, such that downlink data transfer continues. Typically, the source node is an SGSN.
[0011] Preferably, a start time for the terminal to access a target cell in the packet switched handover command is delayed. This has the effect of further reducing the down time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] These and other objects and advantages of the present invention will become more apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings of which:
[0013] FIG. 1 shows an example of conventional packet switched handover in a mobile communication system;
[0014] FIG. 2 illustrates a first example of a method of packet switched handover in accordance with one embodiment of the present invention; and,
[0015] FIG. 3 illustrates a second example of a method of packet switched handover in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.
[0017] FIG. 1 illustrates the conventional steps for inter-SGSN packet switched (PS) handover XID procedure after access to a target cell. A source base station 1 sends a PS handover command 2 to a mobile station 3 . The mobile station (MS) replies with a PS handover access message 4 to a target base station system (BSS) 5 which sends physical information 6 back to the MS. The MS then sends a PS handover complete message 7 to the target BSS, which sends this message on to a new serving GPRS support node (SGSN) 8 . Only once the PS handover is complete does a procedure for negotiating new parameters begin. This is done by the new SGSN 8 sending an exchange identification (XID) command 9 to the MS and an update packet data protocol (PDP) context request 10 to a gateway GPRS support node (GGSN) 11 . The MS sends back an XID response 12 and the GGSN sends back an update PDP context response 13 . The new SGSN starts to relay downlink logical link protocol data units (PDU's) 14 to the MS 3 after having received the XID response, so that downlink data transfer can continue.
[0018] The method addresses the problem of the delays caused by having to wait until after the handover is complete to start the protocols set up, by carrying out the negotiation steps, at least partially, while the terminal is still connected to the source cell. An example of a network entity is the SGSN for inter-SGSN handover in 2G systems, but more generally for both 2G and 3G systems, the network entity is any core network end-point that requires different protocol parameters. One option for achieving the negotiation steps for the 2G example is for a target SGSN to pass XID information to a target BSS packed in a target BSS to source BSS transparent container. An XID command is included in a PS handover request from the target SGSN to the target BSS, then packed into the target to source transparent container which is passed via messages to the source BSS where it is unpacked and sent in the PS handover command.
[0019] This is explained in more detail with reference to FIG. 2 . A decision is made by a source BSS 20 to perform A/Gb mode PS handover (where an MS 21 is connected to a core network via GERAN and the Gb interface). A PS handover required message 22 is sent to an old SGSN 23 which passes on a prepare PS handover request message 24 to a new SGSN 25 which transfers the PDP contexts. The new SGSN sends a PS handover request 26 to a target BSS 27 including an XID command, which has the effect of reserving radio resources in the target base station controller (BSC). The target BSS 27 returns a PS handover request acknowledge 28 to the new SGSN 25 with the XID command packed in a target to source transparent container which is passed via a new SGSN to old SGSN prepare handover response message 29 and an old SGSN to a source BSS PS handover command 30 to the source BSS 20 . Here the XID command is unpacked and sent to the MS in the PS handover command 31 . On receipt of the prepare PS handover response message 29 , the old SGSN 23 may start bi-casting of data to the new SGSN.
[0020] A further optimisation is possible by providing a mechanism for the XID response message to be sent to the target SGSN whilst the mobile station (MS) is still in the source cell. The MS responds to the XID command sent in the PS handover command by sending a new message on the radio interface called “PS XID Response”. This message is passed on to the source SGSN in a new BSS GPRS protocol (BSSGP) message also called “PS XID Response” and then relayed back to target SGSN via a new GPRS tunnelling protocol (GTP) message called “Relay XID Response”. Once the target SGSN has a satisfactory XID response, downlink LLC PDUs that may have been relayed from the source SGSN can be sent towards the target cell. By delaying the start time for the MS to access the target cell in the PS handover command, the extra PS service interruption time caused by the XID negotiation procedure can be reduced to less than one round trip time (MS to SGSN and back) and possibly reduced to zero depending on how long the MS is able to remain in the source cell.
[0021] An example of this optimisation is described with respect to FIG. 3 . In this case an XID response message is sent to the target SGSN 25 whilst the MS 21 is still in the source cell. GPRS tunnelling protocol (GTP) packets are sent from a GGSN 32 to the old SGSN 23 and from there the packets are relayed to the new SGSN 25 . The relayed packets are sent over allocated logical link control (LLC) and radio link control/medium access control (RLC/MAC) entities. When a handover is required, the old SGSN 23 sends a PS handover command 33 to the source BSS 20 and the source BSS sends on a PS handover command 34 to the MS 21 . The PS handover command 34 includes an XID command with LLC and SNDCP parameters. The MS sends back a PS XID response 35 to the source BSS, which sends the response on to the old SGSN, including XID responses. The old SGSN 23 forwards a relay XID response 36 to the new SGSN 25 , so that downlink data transfer can continue. The remainder of the PS handover steps continue in the usual way, i.e. the MS 21 sends a PS handover access message 37 to the target BSS 27 , the target BSS sends back physical information 38 to the MS and the MS indicates to the target BSS that the PS handover is complete. The PS handover complete message 39 is send on to the new SGSN 25 to finish the procedure.
[0022] The invention has been described in detail with particular reference to preferred embodiments thereof and examples, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention covered by the claims which may include the phrase “at least one of A, B and C” as an alternative expression that means one or more of A, B and C may be used, contrary to the holding in Superguide v. DIRECTV, 358 F3d 870, 69 USPQ2d 1865 (Fed. Cir. 2004).
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A method of packet switched handover in a mobile communication system comprising a terminal, a source node and a destination node comprises negotiating protocol parameters for the destination node on behalf of a new network entity, by communicating with an old network entity whilst the terminal is still connected to the source node; and completing the packet switched handover, such that service interruption on handover is reduced.
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TECHNICAL FIELD
[0001] The present invention relates generally to a container for brewing material and more particularly relates to a pod for use in the automatic brewing of coffee, tea, and other beverages.
BACKGROUND OF THE INVENTION
[0002] Various types of automatic coffee and tea dispensers are known. Generally described, these dispensers hold a measure of ground coffee, tealeaves, or other type of brewable material in a container of some sort. Hot water generally is added to the material so as to brew the beverage. The material is generally held in some sort of disposable container that must be opened or penetrated so as to allow the hot water to pass therethrough.
[0003] One drawback with these known brewing devices, however, is that the elements of the device that come into contact with the brewing material generally must be cleaned. Further, the container for the material must be inserted and aligned in the dispenser for each beverage. As a result, the beverage dispenser as a whole may be somewhat slow between beverage cycles as the container is inserted, aligned, removed and/or the dispenser elements are cleaned.
[0004] There is a desire therefore, for a device that brews a beverage with a quick cycle time. The device preferably should be relatively inexpensive and easy to use and produce a high quality beverage. Likewise, the device preferably should be adaptable for different types of brewing materials and amounts.
SUMMARY OF THE INVENTION
[0005] The present invention thus may provide for a container for holding ground coffee or tealeaves. The container may include a body and a lip extending from the body. The lip may include a top substantially flat surface and a width of no more than about 2.6 millimeters (about 0.1 inch).
[0006] The body may include a sidewall and a base. The base may include a number of apertures therein, a number of support ribs thereon, and a number of spikes thereon. Each of the spikes may include a base surrounded by a number of blades.
[0007] The lip may include a flange extending from the flat surface. The flange may extend downwardly at an angle so as to form a pocket with the body. The pocket may include an upper curved radius.
[0008] The container also may include a lid positioned within the body. The lid may include a concave shape and a number of apertures therein. The body may include one or more over-cuts therein for the lid.
[0009] The container also may include one or more layers of filter paper positioned within the body. A foil envelope for holding the ground coffee or the tealeaves also may be used. The container may be made of polystyrene, polyethylene, or polypropylene.
[0010] A further embodiment of the present invention may provide for a container for holding ground coffee or tealeaves. The container may include a base with a number of apertures therein, a circular sidewall extending from the base, and a lip extending from the sidewall. The lip may include a top substantially flat surface and a flange extending downwardly from the flat surface. The flange may include a width of no more than about 2.6 millimeters (about 0.1 inch). The base may include a number of spikes thereon.
[0011] A further embodiment of the present invention may provide for a dispenser for brewing a beverage from a beverage material. The dispenser may include a pod with the beverage material therein, a pod holder, and an injection head. The pod may include a lip extending from a body. The pod holder may be adapted to receive the pod therein and support the lip of the pod. The injection head may include about 136 to 160 kilograms (about 300 to 350 pounds) of force applied to the lip of the pod. The dispenser further may include a number of pods.
[0012] The pod may include about five (5) to about eight (8) grams of a plastic material. The dispenser further may include a turret assembly such that the turret assembly may include the pod holder and an injector assembly such that the injector assembly may include the injection head. The injector assembly may include a drive mechanism so as to maneuver the injection head. The drive mechanism may maneuver the injection head about 6.4 to about 12.7 millimeters (about one-quarter to about one-half inches) in a substantially vertical direction. The lip may include a substantially flat top surface and the injection head may include a sealing ring sized to accommodate the flat top surface. The injection head provides water pressurized at about 1.4 to 14 kilograms per square centimeter (about 20 to about 200 pounds per square inch) to the pod. The body may include a number of spikes therein.
[0013] A method of the present invention may provide for preparing a beverage from a beverage material. The method may include placing the beverage material within a container, tamping the beverage material down with a lid of the container, positioning the lid into the container, and injecting the container with water pressurized water at about 1.4 to 14 kilograms per square centimeter (about 20 to about 200 pounds per square inch).
[0014] These and other features of the present invention will become apparent upon review of the following detailed description of the preferred embodiments when taken in conjunction with the drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a perspective view of one embodiment of a beverage dispenser system for use with the present invention.
[0016] FIG. 2 is a top plan view of the beverage dispenser system of FIG. 1 .
[0017] FIG. 3 is a perspective view of a turret system of the beverage dispenser system of FIG. 1 .
[0018] FIG. 4 is a perspective view of an injector assembly of the beverage dispenser system of FIG. 1 , with the guide wheels and the return spring of the support plate shown in phantom lines.
[0019] FIG. 5 is a rear perspective view of the injector assembly of the beverage dispenser system of FIG. 1 , with the idler wheel and the limit switch shown in a cut away view.
[0020] FIG. 6 is a side cross-sectional view of a configuration of brewing material for use with the present invention.
[0021] FIG. 7 is a side cross-sectional view of an alternative configuration of brewing material for use with the present invention.
[0022] FIG. 8 is a top perspective view of a pod of the present invention.
[0023] FIG. 9 is a bottom perspective view of the pod of FIG. 8 .
[0024] FIG. 10 is a side plan view of the pod of FIG. 8 .
[0025] FIG. 11 is a bottom plan view of the pod of FIG. 8 .
[0026] FIG. 12 is a side cross-sectional view of the pod of FIG. 8 .
[0027] FIG. 13 is a side cross-sectional view of the lip of the pod of FIG. 8 .
[0028] FIG. 14 is a side cross-sectional view of an alternative embodiment of a pod of the present invention with a lid thereon
[0029] FIG. 15 is a side cross-sectional view of the interior wall of the pod of FIG. 14
[0030] FIG. 16 is a perspective view of an alternative embodiment of a pod of the present invention.
[0031] FIG. 17 is a top plan view of the pod of FIG. 16 .
[0032] FIG. 18 is a side cross-sectional view of the pod of FIG. 16 .
[0033] FIG. 19 is a perspective view of a spike used in the pod of FIG. 16 .
DETAILED DESCRIPTION
[0034] Commonly owned U.S. patent application Ser. No. 10/071,643, entitled “COFFEE AND TEA DISPENSER”, is incorporated herein by reference.
[0035] Referring now to the drawings, in which like numerals refer to like elements throughout the several views, FIGS. 1 and 2 show one application of a beverage dispenser system 100 . In these figures, a pod brewing apparatus 300 is shown. The pod brewing apparatus 300 may include a heat exchanger 150 positioned within a hot water reservoir 160 and in communication with an injection nozzle 200 as is shown. In this embodiment, the elements of the beverage dispenser system 100 as a whole are mounted onto a dispenser frame 305 . The dispenser frame 305 may be made out of stainless steel, aluminum, other types of metals, or other types of substantially noncorrosive materials.
[0036] The injection nozzle 200 may interact with one or more pod cartridges 210 so as to produce the desired beverage in a cup 230 or any other type of receptacle. The pod cartridges 210 may be positioned in the beverage dispenser system 100 within a turret assembly 310 . The turret assembly 310 may be fixedly attached to the dispenser frame 305 . As is shown in FIG. 3 , the turret assembly 310 may include a turret plate 320 positioned within a turret frame 325 . The turret frame 325 may be made out of stainless steel, aluminum, other types of conventional metals, or similar types of substantially noncorrosive materials. The turret plate 320 may be substantially circular. The turret plate 320 may include a number of pod apertures 330 . The pod apertures 330 may be sized to accommodate the pod cartridges 210 . The turret plate 320 may spin about a turret pin 340 . A turret motor 350 may drive the turret assembly 310 . The turret motor 350 may be a conventional AC motor or a similar type of device. The turret motor 350 may drive the turret assembly 310 at about six (6) to about thirty (30) rpm, with about twenty-five (25) rpm preferred.
[0037] The turret plate 320 also may have a number of detents 360 positioned about its periphery. The detents 360 may be positioned about each of the turret apertures 330 . The detents 360 may cooperate with one or more limit switches 365 so as to control the rotation of the turret plate 320 . The rotation of the plate 320 may be stopped when the limit switch 360 encounters one of the detents 360 .
[0038] Positioned adjacent to the turret assembly 310 may be an injector assembly 400 . The injector assembly 310 may be fixedly attached to the dispenser frame 305 . The injector assembly 400 also may include an injector frame 410 extending above the turret assembly 310 . The injector frame 410 may be made out of stainless steel, other types of metals, or similar types of substantially noncorrosive materials.
[0039] As is shown in FIGS. 4 and 5 , the injector assembly 400 may include the injection nozzle 200 as described above. The injection nozzle 200 may have a narrow tip so as to penetrate the pod cartridge 210 if needed or a wide mouth to accommodate the entire pod cartridge 210 . The injector assembly 400 may include an injector head 420 that cooperates with the injection nozzle 200 . The injector head 420 may be slightly larger in diameter than the pod cartridges 210 . The injector head 420 also may be made out of stainless steel, plastics, or similar types of substantially noncorrosive materials. The injector head 420 may include a sealing ring 430 positioned about its lower periphery. The sealing ring 430 may be made out of rubber, silicone, or other types of elastic materials such that a substantially water tight seal may be formed between the injector head 420 and the pod cartridge 210 . The heat exchanger 150 may be in communication with the injector head 420 so as to provide hot, pressurized water to the pod cartridges 210 .
[0040] The injector head 420 may be moveable in a substantially vertical plane via a cam system 440 . (The terms “vertical” and “horizontal” are used as a frame of reference as opposed to absolute positions. The injector head 420 and the other elements described herein may operate in any orientation.) A cam system drive motor 450 may drive the cam system 440 . The drive motor 450 may be a conventional AC motor similar to the turret motor 350 described above. The drive motor 450 also may be a shaded pole or a DC type motor. The drive motor 450 may rotate an eccentric cam 460 via a drive belt system 470 ; The drive motor 450 and the gear system 470 may rotate the eccentric cam 460 at about six (6) to about thirty (30) rpm, with about twenty-five (25) rpm preferred. The eccentric cam 460 may be shaped such that its lower position may have a radius of about 4.1 to about 4.8 centimeters (about 1.6 to 1.9 inches) while its upper position may have a radius of about 3.5 to 4.1 centimeters (about 1.3 to about 1.7 inches).
[0041] The eccentric cam 460 may cooperate with an idler wheel 480 . The idler wheel 480 may be in communication with and mounted within a support plate 490 . The support plate 490 may maneuver about the injector frame 410 . The support plate 490 may be made out of stainless steel, other types of steel, plastics, or other materials. The support plate 490 may be fixedly attached to the injector head 420 . The support plate 490 may have a number of guide wheels 500 positioned thereon such that the support plate 490 can move in the vertical direction within the injector frame 410 . A return spring 520 also may be attached to the support plate and the injector frame 410 . A limit switch 530 may be positioned about the cam 460 such that its rotation may not exceed a certain amount.
[0042] The injector head 420 thus may maneuver up and down in the vertical direction via the cam system 440 . Specifically, the drive motor 450 may rotate the eccentric cam 460 via the gear system 470 . As the eccentric cam 460 rotates with an ever-increasing radius, the idler wheel 480 pushes the support plate 490 downward such that the injector head 420 comes in contact with a pod cartridge 210 . The eccentric cam 460 may lower the injector head 420 by about 6.4 to about 12.7 millimeters (about one-quarter to about one-half inches). Once the injector head 420 comes into contact with the pod cartridge 210 , the eccentric cam 460 may continue to rotate and increases the pressure on the pod cartridge 210 until the cam 460 reaches the limit switch 530 . The injector head 420 may engage the pod cartridge 210 with a downward force of about 136 to 160 kilograms (about 300 to 350 pounds). The sealing ring 430 thus may form a substantially airtight and water tight seal about the pod cartridge 210 . The drive motor 450 may hold the cam 460 in place for a predetermined amount of time. The cam system 440 may then be reversed such that the injector head 420 returns to its original position.
[0043] Once the injection nozzle 200 of the injector head 420 is in contact with the pod cartridge 210 , the hot, high pressure water may flow from the heat exchanger 150 into the injector head 420 . The water may be at about 82 to about 93 degrees Celsius (about 180 to about 200 degrees Fahrenheit). The incoming water flow may be pressurized at about 11 to about 14 kilograms per square centimeter (about 160 to 200 pounds per square inch). The pressure of the water passing through the pod cartridge 210 may be about 1.4 to about 14 kilograms per square centimeter (about 20 to about 200 pounds per square inch). The pressure of the water flowing through the pod cartridge 210 may vary with the nature of the beverage.
[0044] As is shown in FIGS. 6 and 7 , the pod cartridges 210 may be filled with different types of grinds, leaves, or other types of a brewing material 550 . In the case of a single serving sized espresso beverage of about thirty (30) milliliters, about six (6) to about eight (8) grams of espresso grinds may be placed in the pod cartridge 210 . Likewise, about six (6) to about (8) grams of coffee grinds may be added to the pod cartridge 210 to produce about a 240 milliliter (about eight (8) ounce) cup of coffee. About three (3) to about five (5) grams of tealeaves may be added to the pod cartridge 210 in order to make about a 150 milliliter (about five (5) ounce) cup of tea.
[0045] The brewing material 550 may be positioned within one or more layers of filter paper 560 . The filter paper 560 may be standard filter paper used to collect the brewing material 550 while allowing the beverage to pass therethrough. The pod cartridge may have an upper filter layer 570 and a lower filter layer 580 . The brewing material 550 itself may be positioned directly between the upper and lower filter layers 570 , 580 . Alternatively, the brewing material 550 may be placed within a foil envelope 590 . The foil envelope 590 may serve to keep the brewing material 550 therein fresh and out of contact with the ambient air. Alternatively, the entire pod cartridge 210 may be placed within a foil envelope, either individually or as a group, until the pod 210 is ready for use.
[0046] FIGS. 8-12 show an embodiment of the pod cartridge 210 that may be used with the beverage dispenser system 100 or in other types of beverage systems. The pod cartridge 210 may be substantially in the shape of a cup 600 . The cup 600 may be made out of a conventional thermoplastic such as polystyrene, polyethylene, or polypropylene. Alternatively, stainless steel or other types of substantially non-corrosive materials also may be used. The cup 600 may be substantially rigid.
[0047] The cup 600 may include a substantially circular sidewall 610 and a substantially flat base 620 . The sidewall 610 and the base 620 of the cup 600 may be molded and form a unitary element or a separate sidewall 610 and a separate base 620 may be fixedly attached to each other. The sidewall 610 and the base 620 , as well as the cup 600 as a whole, may have any convenient diameter so as to accommodate the pod apertures 330 of the turret plate 320 of the turret assembly 310 and the injector head 420 of the injector assembly 400 . Alternatively, the sidewall 610 and the base 620 of the cup 600 may have any convenient diameter so as to accommodate other any type of beverage dispenser system 100 .
[0048] The sidewall 610 of the cup 600 may have any convenient depth so as to accommodate an appropriate amount of the brewing material 550 . In this embodiment, the sidewall 610 may have an inside diameter of about 3.9 centimeters (about 1.535 inches), an outside diameter of about 4.03 centimeters (about 1.586 inches) and a wall thickness of about 1.295 millimeters (about 0.051 inches). The sidewall 610 also may have a depth of about 2.43 centimeters (about 0.955 inches) with the base 620 having an additional depth of about 0.318 centimeter (about 0.125 inches). Such a configuration of the sidewall 610 and the base 620 of the cup 600 may hold about six (6) to about sixteen (16) grams of the brewing material 550 , depending upon the size of the desired beverage, i.e., eight (8), twelve (12), or sixteen (16) ounces. These dimensions are for purposes of example only. The sidewall 610 and the base 620 of the cup 600 may take any desired or convenient size or shape. For example, the sidewall 610 may be straight, tapered, stepped, or curved if desired.
[0049] The base 620 also may include a bottom floor 630 . The bottom floor 630 may include a number of apertures 640 formed therein. The apertures 640 may extend through the width of the floor 630 . In this embodiment, the apertures 640 may be largely circular in shape with a diameter of about 1.6 millimeters (about 0.063 inches). Any desired shape or size, however, may be used. In this embodiment, about 54 apertures 640 are used herein, although any number may be used. The base 620 also may include a number of support ribs 650 supporting the floor 630 . An inner circular rib 660 , an outer circular rib 670 , and a number of radial ribs 680 may be used. Any design or number of ribs 660 may be used. In this embodiment, the ribs 650 may have a depth of about 2.54 millimeters (about 0.1 inch) and the floor 630 may have a depth of about 1.78 millimeters (about 0.07 inches), although any desired thickness may be used.
[0050] The sidewall 610 of the cup 600 also may include an upper lip 700 . The upper lip 700 may include a substantially flat top portion 710 and a downwardly angled flange 720 extending from the top portion 710 . The flange 720 may extend downwardly so as to form a pocket 730 with the sidewall 610 . The top of the pocket 730 may form a curved inner radius 735 . As is shown in FIG. 13 , the sidewall 610 may or may not include an outer step 740 within the pocket 730 .
[0051] In this embodiment and by way of example only, the flat top portion 710 of the upper lip 700 may have width of about 2.54 millimeters (about 0.01 inch) extending in the horizontal direction. The flange 720 may have the length of about 2.2 millimeters (about 0.087 inch). The flange 720 and the pocket 730 of the lip 700 are sized to accommodate the size of the pod apertures 330 . Specifically, the lip 700 is configured to accommodate the size of the pod apertures 330 and the expected force of the injector head 420 while using as little material as possible.
[0052] FIGS. 14 and 15 show a further embodiment of the cup 600 . In this embodiment, the sidewall 610 of the cup 600 may include a number of over-cuts 760 formed therein. In this embodiment, a first over-cut 770 and a second over-cut 780 may be used. Any number of over-cuts 760 , however, may be used. The over-cuts 760 may be continuous around the inner circumference of the side wall 610 or the over-cuts 760 may be intermittent. The over-cut 760 may cooperate with a lid 790 . The lid 790 may have edges 800 that are substantially wedge shaped to fit and remain within the over-cut 760 . The use of the wedge shaped edge 800 ensures that the lid 790 remains in place. The edges 800 may be continuous or intermittent so as to mate with the over-cut 760 . The lid 790 preferably is bowed inward or largely concave in shape.
[0053] The lid 790 may be placed in the first or second over cut 770 , 780 depending upon the amount of brewing material 550 that is desired to be placed within the cup 600 . The lid 790 is bowed downward so as to tamp the brewing material 550 down under pressure and to keep the brewing material 550 therein from shifting. The lid 790 may compact the brewing material 550 with at least about nine (9) kilograms of compressive force (about twenty (20) pounds of force). The lid 790 also may have a number of apertures 810 therein so as to permit water from the injector head 420 to pass therethrough. Depending on the nature of the injector head 420 , the use of the lid 790 may not be necessary. Instead, a foil wrapper or any other covering may be used. Likewise, the over-cuts 760 also may be eliminated or modified as desired.
[0054] FIGS. 16-19 show a further embodiment of the present invention, a spiked pod 850 . The spiked pod 850 may use the cup 600 , the side wall 610 , the base 620 , the lip 700 , and the elements thereof as described above with the pod cartridge 210 . The spiked pod 850 also may include a number of spikes 860 positioned along the floor 630 of the base 620 . The spikes 860 may serve to puncture a package for the brewing material 550 as will be described in more detail below. In this embodiment, about eighteen (18) spikes 860 may be used. Any desired number of spikes, however, 860 may be used. The spikes 860 may be aligned along the radial ribs 680 of the base 620 or elsewhere along the floor 630 .
[0055] As is shown in, for example, FIG. 19 , the spikes 860 may include three (3) triangular blades 870 surrounding a base 880 . The tips of the blades 870 may form a puncture area 890 . The blades 860 may have any desired shape. The blades 870 may have a height of about 6.35 millimeters (about 0.25 inch) and the base 880 may have a height of about 3.8 millimeters (about 0.15 inches) such that the puncture area 890 may be about 2.54 millimeters (about 0.1 inches) in length above the base 880 . Any desired size, however, may be used.
[0056] In use, the lower layer 580 of filter paper may be placed with the cup 600 of the pod cartridge 210 . The lower layer 580 may be positioned along the floor 630 of the base 620 . An amount of the brewing material 550 then may be positioned therein. The upper layer 570 of the filter paper then may be placed on the brewing material 550 if desired. The lid 790 then may be placed within the cup 600 so as to tap down the brewing material 550 . Once the lid 790 has compacted the brewing material 550 , the edge 800 of the lid 790 is positioned within the appropriate over-cut 760 within the side wall 610 of the cup 600 . The pod 210 then may be sealed or otherwise shipped for use with the beverage dispenser system 100 or otherwise.
[0057] The pod 210 may be positioned within one of the pod apertures 330 in the turret assembly 310 . Specifically, the outer edge of the pod aperture 330 aligns with the flange 720 of the lip 700 of the cup 600 . A pod or other device with a convention square lip would extend too far out of the pod aperture 330 to function with the injection head 420 of the injector assembly 310 . The injector head 420 then may be positioned about the pod 210 . The sealing ring 630 of the injector head 420 may seal about the top portion 710 of the lip 700 of the cup 600 . The use of a rounded lip or a lip with a non-flat shape may cause damage to the sealing ring 430 given the amount of pressure involved, i.e., as described above, the injector head 420 may engage the pod cartridge 210 with a downward force of about 136 to about 160 kilograms of force (about 300 to about 350 pounds) and the incoming water flow may be pressurized at about eleven (11) to about fourteen (14) kilograms per square centimeter (about 160 to 200 pounds per square inch (psi)). The pressure of the water flowing through pod cartridge 210 may vary with the nature of the brewing material 550 from about 1.4 to about 14 kilograms per square centimeter (about twenty ( 20) to about 200 pounds per square inch).
[0058] The water passing through the injection head 420 may spread out over the lid 790 and the apertures 810 thereof and into the brewing material 550 . The brewed beverage may then pass through the apertures 640 in the base 620 of the cup 600 .
[0059] The lip 700 as well as the base 620 of the cup 600 are designed to use as little material as possible while being able to withstand the water pressures described above with out deformation. The cup 600 as a whole may have about five (5) to about eight (8) grams of plastic material therein when using, for example, polypropylene homopolymer. The configuration of the lip 700 may save about 0.4 to about 0.6 grams or about ten percent (10%) of the plastic required.
[0060] In the embodiment of the spiked pod 850 , the brewing material 550 may be positioned within the foil envelope 590 . At least the lower filter layer 580 also may be placed within the cup 600 . The injection nozzle 200 may penetrate the foil envelope 590 or water may otherwise flow into the cup 600 with the water pressure described above. This water pressure may force both the lower filer layer 580 and the foil envelope 590 against the spikes 860 of the spiked pod 850 . This pressure may allow these spikes 860 to penetrate both the lower filter area 580 and the foil envelop 590 . The punctures caused by the spikes 860 may allow the brewed beverage to pass therethrough while substantially maintaining the remaining brewing material 550 therein. The spikes 860 may provide substantially uniform penetration of the foil envelope 590 . The brewing material 590 also may be contained within other types of structures that may be penetrated by the spikes 860 .
[0061] It should be apparent that the foregoing relates only to the preferred embodiments of the present invention and that numerous changes and modifications may be made herein without departing from the spirit and scope of the invention as defined by the following claims and the equivalents thereof.
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A container for holding ground coffee or tealeaves. The container may include a body and a lip extending from the body. The lip may include a top substantially flat surface and a width of no more than about 2.6 millimeters (about 0.1 inch).
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of co-pending U.S. patent application Ser. No. 13/036,435 to Claude Leonard Beckenstein, Jr. et al., filed on Feb. 28, 2011, and entitled “Method for Determining Power Supply Usage,” which is a continuation of U.S. Pat. No. 7,917,315 to Claude Leonard Benckenstein, Jr. et al., filed on Aug. 13, 2008, and entitled “Method for Determining Power Supply Usage,” which are hereby incorporated by reference.
TECHNICAL FIELD
[0002] The present embodiments relate to a method for measuring electron flow to determine remaining capacity of a power supply, such as a lithium primary battery, a lithium ion battery, a lead-acid battery, a fuel cell, a solar panel system, or other power supply.
BACKGROUND
[0003] A need exists for a method that accurately measures and tracks electron flow that is portably usable in many environments, easy to undertake, and inexpensive to operate.
[0004] A further need exists for a method that can be installed on a wide variety of power supplies for remote and close proximity monitoring of electron usage by a customer, a user, and an administrator simultaneously, that does not require measurement of time to determine remaining capacity.
[0005] The present embodiments meet these needs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The detailed description will be better understood in conjunction with the accompanying drawings as follows:
[0007] FIG. 1 is a depiction of an amplitude signal for use herein according to one embodiment of the disclosure.
[0008] FIG. 2 is a flow chart of the method according to one embodiment of the disclosure.
[0009] FIG. 3 is a diagram of a fuel gauge usable in the method according to one embodiment of the disclosure.
DETAILED DESCRIPTION
[0010] Before explaining the present embodiments in detail, it is to be understood that the invention is not limited to the particular embodiments and that it can be practiced or carried out in various ways.
[0011] The present embodiments relate to a method for tracking electron flow from a power supply using a networked system. The system can utilize alarms and/or meters when electron flow is at a reduced level by accurately and with high precision tracking the electron flow.
[0012] Typically, remaining capacity of a power source is measured by recording the amount of current maintained per a unit of time. In extreme conditions, such as the high temperatures and pressures encountered within a wellbore, the accurate tracking of the passage of time, such as through use of a processor-based clock, is not possible.
[0013] The present method enables measurement of the capacity of a power source independent of elapsed time by tracking electron flow, rather than current per unit time. During operation of a power source, current is measured and converted to a voltage proportional to the current. The voltage proportional to current is converted and recorded as a monotonic uni-polar representation of an aggregate number of electrons. Subsequent representations are accumulated until this value reaches a calibration constant, at which time a known quantity of current has been maintained, such as one mA/hour, enabling capacity of the power source to be calculated in standard engineering units. The accumulated value can then be reset, allowing further accumulation until the calibration constant is again reached.
[0014] The method relates to counting electrons from a power supply.
[0015] First, a current from a power source is measured which is then termed “a measured current.”
[0016] The power supply can be a lithium primary battery, a lithium-ion battery, a lead acid battery, a fuel cell, or another source of electrical energy that provides a flow of electrons in a direct current, such as electrons generated by an alternator of a car, or a generator of a boat or RV.
[0017] Next, the measured current is converted to a voltage. The conversion occurs, in an embodiment, using a current sense resistor, such as a model WSL2512RI000FEA resistor made by Vishay of the state of Pennsylvania. The current sense resistor can handle between about 0 amps and about 6 amps. This current sense resistor is placed in series with the load, the load being the device powered by the power supply. In this configuration the current at the current sense resistor is the same at the current drawn off the power supply.
[0018] The current can be a pulsed current or a constant current. In an embodiment, if the current is pulsed, is can be pulsed at about 2 amps every one second or about 1 amp every 2 seconds, or other variations of pulsed current. If the current is constant, for example, it can be about 100 mA.
[0019] The converted current is integrated into a monotonic uni-polar representation of an aggregate number of electrons through a Deboo integrator. The amplitude of the voltage is representative of the aggregate number of electrons flowing through a current sense resistor after integration using a Deboo (non-inverting) integrator with a capacitor.
[0020] The Deboo integrator is a non-inverting uni-polar integrator that forms a monotonic, unidirectional signal, wherein the amplitude represents the number of electrons flowed, similar to a trip odometer tracking mileage of a car. Other integrators can be usable herein, such as passive integrators generally known in the field of electrical engineering.
[0021] When the integrator output voltage reaches a preset limit, or a threshold, then the monotonic uni-polar representation of the aggregate number of electrons is “read” by the microprocessor forming a reading internal to the microprocessor. This reading is representative of the fact the preset limit has been reached and a corresponding number of electrons have passed through the current sense resistor.
[0022] Using an analog-to-digital converter, such as a AD7819 made by Analog Devices, the monotonic uni-polar representation of the number of aggregate electrons is identified and stored in memory of the microprocessor. Additionally, in an embodiment it is contemplated that the reading is formed using an analog to digital converter within the microprocessor.
[0023] Prior to electron saturation, the reading can be made by the microprocessor, which can be a model MC908QBMDTE, made by Freescale of Austin, Tex. The microprocessor has a processor and data storage containing computer instructions for instructing the processor to accumulate the amplitude each time the output of the integrated reaches a preset limit. Each reading is added to a memory location in the data storage where it is combined with previous readings forming a summation.
[0024] The microprocessor contains instructions for storing the value of the amplitude voltage and for adding each value to a previous sum forming a running summation. The summation, being representative of the number of times the output of the integrator has reached the preset limit, which is also proportional to the total charge which has passed from the power source.
[0025] Additionally, the microprocessor contains instructions for resetting the integrator, or discharging the integrator, once the voltage of the amplitude signal reaches a preset limit. Once this occurs, the amplitude signal will be reset, and will generally increase as a function of the signal input into the integrate as previously described.
[0026] The readings are repeated by actuating of the microprocessor before the integrator reaches the preset limit. With each reading, the accumulator value is transmitted to the accumulator, and the summation continues, causing the accumulator value to increase or remain constant, but never decrease.
[0027] The summation is then compared to a calibration value stored on the microprocessor for the particular fuel gauge. The calibration value is preloaded in the data storage. The calibration value is unique to each designated fuel gauge circuit. An example of a calibration value is 14,000. It should be noted that when the accumulator reaches the calibration constant, a known quantity of power has flowed, such as 1 mAH, enabling accurate electron tracking and determination of power source capacity.
[0028] The comparison can then be recorded as an established standard engineering unit of capacity, such as Amp Hours, when the summation of accumulator values meets or exceeds the calibration value.
[0029] In an additional embodiment, the fuel gauge can monitor and record ambient temperature, that is the temperature surrounding the power supply using a temperature sensor. After the temperature is read, then the established standard engineering unit of capacity is adjusted based on the ambient temperature.
[0030] In the fuel gauge, the current sense resistor is a sensor that determines current 15 proportional to voltage. An example of such a current sense resistor is model WSL2512RI000FEA made by Vishay of Pennsylvania.
[0031] The microprocessor used in the method enables the sensing of electron flow at temperatures ranging from about −40 degrees Centigrade to about 150 degrees Centigrade.
[0032] It should be noted that the established standard engineering unit of capacity, from the microprocessor, can be determined using a reader in a manner known to those in the field of electrical engineering.
[0033] In one embodiment, the fuel gauge can have a reader that communicates the established standard engineering unit of capacity to a user who is using at least one light emitting diode.
[0034] The communication from the reader can be over a wireless network, a hard wired network, a satellite network, or combinations thereof. The user can be connected to a website, or be connected to a graphical user interface display directly for viewing electron flow, and the fuel usage occurring to the power supply.
[0035] When the reader is in communication with a network, the fuel gauge permits continuous and automatic remote monitoring of power supply capacity.
[0036] An example of automatic, and continuous, real time monitoring is with an executive dashboard that is continually pushing the data to the user, rather than the user asking for the data. This push enables better and more accurate monitoring of the fuel use.
[0037] Monitoring using an executive dashboard enables a user to view that constant status of multiple power supplies, such as batteries, each connected via the network for constant and highly accurate measurement, such within 1 mV. Monitoring using an executive dashboard also allows for less waste of fuel, particularly in a remote environment, such as a recharging station for military radios in the middle of a barren arctic wasteland.
[0038] In an embodiment it is contemplated that the capacitor of the integrator has at least two miniature 0.01 microfarad value capacitors, each having a low loss, high temperature rating, such as 125 Centigrade, with a moderately high capacitance.
[0039] It is contemplated that a moderately high capacitance would be equivalent to about 0.22 microfarads for each capacitor.
[0040] The two capacitors can be contemplated to be connected in parallel and therefore provide a capacitance of about 0.44 microfarads. An example of such a miniature 0.01 microfarad value capacitor would be a high tech plastic fill capacitor made by Fujitsu.
[0041] A different embodiment contemplates that the capacitor can be a precision capacitor, which would have a capacity of about 0.02 microfarads.
[0042] In an embodiment the preset limit of aggregate electrons can be no more than three volts using a 12 bit converter.
[0043] Turning now to the figures, FIG. 1 illustrates a representative amplitude signal produced by the integrator for use in the invention herein. The voltage ( 60 ) produced by the integrator is a function of the voltage of the current sense resistor. The signal produced in FIG. 1 represents a generally linear increase in the voltage output by the integrator as a result of a generally constant input voltage. FIG. 1 also illustrates the saturation point V 1 ( 62 ) of the integrator. It can be seen once the integrator becomes saturated, the output voltage no longer increases regardless of the input voltage. FIG. 1 illustrates a preset limit ( 64 ) at V 2 , which is selected at a voltage below the saturation point V 1 ( 62 ) of the integrator. In the operation of the device a reading will be taken when the preset limit ( 64 ) is reached and the integrator will be discharged. The amplitude signal can vary based upon the input signal in a predictable way known to those in the art based on the configuration of the integrator.
[0044] FIG. 2 shows a method for counting electrons from a power supply, the method comprising the following steps: measuring a current of a power supply forming a measured current ( 100 ); converting the measured current to a voltage ( 102 ); integrating the voltage into a monotonic uni-polar representation of an aggregate number of electrons having an amplitude representative of the aggregate number of electrons flowing through a current sense resistor using an integrator having a capacitor ( 104 ); actuating a microprocessor in communication with a data storage just before the integrator reaches a preset limit of aggregate electrons ( 106 ); reading the amplitude representative of the aggregate number of electrons from the integrator with the microprocessor forming a reading ( 108 ); transmitting the reading to an accumulator formed in the data storage forming an accumulator value ( 110 ); resetting the integrator after transmitting the reading ( 112 ); repeating the actuation of the microprocessor before the integrator reaches the preset limit, making additional readings and repeating the transmission to the accumulator and repeating the formation of a summation of accumulator values using the additional readings ( 114 ); compare the summation of accumulator values to a calibration value; wherein the calibration value is unique to a designated fuel gauge circuit and when the summation of accumulator values reaches the calibration value, 1 mA/hour has flowed ( 116 ) and recording an established standard engineering unit of capacity when the summation of accumulator values meets or exceeds the calibration value ( 118 ). A second accumulator can be used to record quantities of battery usage.
[0045] FIG. 3 shows the fuel gauge usable in this method. The fuel gauge has, in an embodiment, a voltage pre-regulator ( 10 ) for receiving current and providing a preset voltage. The voltage pre-regulator ( 10 ) is designed for 10-80V applications to provide 6 Volts. In an embodiment, the voltage pre-regulator can be resistant to extreme temperature, high pressure, shock and vibration.
[0046] Additionally, the fuel gauge has a main voltage regulator ( 12 ) in communication with the voltage pre-regulator for receiving the preset voltage and providing power to other components of the fuel gauge. The regulator can be a band gap device, designed for precision measurement applications, and is contemplated to be precise to within about 1 percent. In an embodiment, the main voltage regulator can have a maximum voltage tolerance of about 80V. In one embodiment the main voltage regulator can contain a temperature sensor ( 48 ).
[0047] An example of the voltage pre-regulator would be one such as LT3014BES5 made by Micropower. An example of the main voltage regulator would be one such as those produced by Analog Devices.
[0048] A current sense resistor ( 14 ), such as a model WSL2512RI000FEA resistor made by Vishay, is in communication with the main voltage regulator for converting the current to a voltage proportional to the current.
[0049] In an embodiment, the main voltage regulator can be a precision regulator, and the current sense resistor can be a precision resistor.
[0050] An integrator ( 16 ) is shown, comprising an op amp ( 18 ) such as a LTC2054HS5 made by Linear Technologies and a capacitor ( 20 ). The integrator ( 16 ) receives power ( 22 ) from the main voltage regulator, and an input voltage proportional to current ( 24 ) from the current sense resistor. In an embodiment, the integrator can have a saturation voltage ranging from about 0 volts to about 3 volts.
[0051] A microprocessor ( 26 ) with data storage ( 28 ), such as a MCQB8DTE made by Freescale, can be used in combination with a hysteresis circuit ( 30 ). Those of ordinary skill in the art can appreciate that the hysteresis circuit can be either be an external component for conditioning the amplitude signal of the integrator, or the hysteresis circuit can be contained within the microprocessor. The microprocessor is contemplated to remain in a low power state until activated. In one embodiment, the microprocessor can consume from one to three microwatts of power in the low power state.
[0052] The data storage, which can be fixed, removable, or remote data storage, can include computer instructions ( 32 ) for instructing the microprocessor to convert the voltage across the current sense resistor to a monotonic uni-polar representation of an 15 aggregate number of electrons ( 34 ).
[0053] A resistor ( 36 ) is disposed between the integrator and the microprocessor for activating the microprocessor from the low power state prior to saturation of the integrator with the voltage proportional to current.
[0054] A reset circuit ( 38 ) is disposed between the microprocessor and the integrator for resetting the monotonic uni-polar representation of an aggregate number of electrons to zero. In an embodiment, the reset circuit resets the integrator to zero in less than three microseconds for ensuring accuracy.
[0055] In an embodiment, the fuel gauge has a modem ( 40 ) for providing a communication signal ( 42 ) over power lines of the fuel gauge. A switch ( 44 ) can be used for controlling power to the modem.
[0056] In an embodiment, the op amp can be a low power and low drift device. The op amp can be one such as model LTC2054HS5 from Linear Technology which provides a low pollution due to noise. The op amp can receive power from the main voltage regulator. The op amp operates using a logic input that cycles to activate and deactivate the op amp.
[0057] The hysteresis circuit provides a discrete rapid output in response to a slowly changing input. The output of this circuit can be either logic 0 or 1, but input must change significantly for output to change.
[0058] While these embodiments have been described with emphasis on the embodiments, it should be understood that within the scope of the appended claims, the embodiments might be practiced other than as specifically described herein.
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The remaining capacity of a power source, such as a battery, may be monitored with a microprocessor by integrating data received from a current sensor. The microprocessor may measure electrons passing through the battery by sampling the integrator and summing the values recorded from the integrator. Each time the integrator is sampled, the microprocessor may reset the integrator to prevent the integrator from saturating. The microprocessor may sample the integrator when the integrator approaches a predetermined value. The remaining capacity of the battery may be calculated based on calibration values and the sum of electrons measured by the integrator. The remaining capacity may be communicated to remote users through a network and displayed in an executive dashboard.
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REFERENCE TO RELATED APPLICATIONS
This Patent Application is being filed as a Continuation-in-Part application of Ser. No. 11/761,010, filed 11 Jun. 2007, currently pending.
FIELD OF THE INVENTION
The present invention relates generally to inline skates, and particularly to inline skates that combining a one-way roll stop device and a cushion device for providing the inline skates with superior braking effect during sliding as well as with more forceful acceleration holds. Thereby, a structure of inline skates with ergonomics, exercise-injury prevention, and comfort is provided.
BACKGROUND OF THE INVENTION
Inline skating is a rising roller-skating exercise. To date a variety of types has developed including mainly recreational, figure, cross-country, acrobatic, and speed. Special structures are designed for cross-country and speed inline skates to meet their speed demands or requirements by special environments. In addition, user needs to receive extraordinary and long-term trainings to handle or use them appropriately. The basic structure and function thereof similar to recreational inline skates, details of the inline skates of these types are not described here. In the following, recreational, figure, and acrobatic inline skates are described in detail.
First, for a recreational inline skate, the structure thereof includes a boot, a base under the boot, and a plurality of wheels adapted on the base. There is no front brake pad. When the left leg slides, it is necessary to use the right leg for pressing the ground and pushing backwards in the direction slightly deviating from the direction of sliding, and then a forward force for the left leg is given. Owing to the larger wheel diameter with the longer span, it is laborious for both legs to alternatingly press down and push angularly to maintain a sliding motion over a long time period. In addition, it violates ergonomics as well. Besides, recreational inline skates do not provide effective braking arrangement. Some brands add rear brake pads behind the roller skates. While braking, the player has to put forth his strength to raise his feet upwards with his ankles pushed downwards so that the rear brake pads under the ankles can produce friction with the ground. By doing this, slight braking effect is attained. However, the braking effect is very poor, and the braking action violates ergonomics as well. Furthermore, the rear brake pads tend to make both legs stuck with and bump against each other and consequently make the player stumble when he alternates his legs to slide or when he corners (forward or backward crossovers). Thereby, most players disassemble the rear brake pads by themselves, which makes the rear brake pads exist in name only.
Moreover, for a figure inline skate, a front brake pad is adapted at the first-wheel position of a recreational inline skate, and all wheels are shrunk and arranged behind the front brake pad. Hence, the figure inline skate slides slower and unstable. When sliding forward, the center of gravity leans forward. Slight incaution results in touch of the front brake pad on the sliding leg on the ground, which is very dangerous because it will cause the player trip forward.
As for an acrobatic line skate, no brake is adapted thereon because a brake device that is like the one on a recreational or a figure inline skate obstructs absolutely acrobatic movements and thereby results in danger. However, it does not mean that an acrobatic inline skate need not a brake device. In fact, tumbles when wearing acrobatic inline skates occur frequently. Some severe injuries even happened.
To sum up, various current inline skates cannot provide an effective and safe brake device. A special braking skill, that is, T-stop, refers to turning aside and opening both legs abruptly during sliding to make both legs perpendicular to the direction of sliding for attaining braking effect. However, this skill needs long-term practices. Slight incaution tends to result in tumble and accidental injuries such as scrapes, collision injuries, and sprains. Besides, the skill violates ergonomics. In addition to ease of wear on the inline skates, T-stop is not applicable in all fields. If the field is slightly slippery, unsmooth, or has too much grip, falling over tends to happen. Thereby, improved brake device of inline skates is desired for solving inconveniences in operations and problems of frequent exercise injuries.
Owing to the drawbacks and imperfections of inline skates described above, the present invention provides inline skates complying with ergonomics, being exercise-injury preventive, shock absorptive, and comfortable. In addition, the inline skates according to the present invention provide multiple brakes as well as providing more powerful acceleration. By supporting upright automatically, the inline skates according to the present provide active safety for players.
SUMMARY
An objective of the present invention is to provide a structure of inline skates, which can achieves superior braking effect in a manner complying ergonomics. In addition, the inline skates according to the present invention can support upright automatically on the go for preventing tumbles. Thereby, exercise injuries are reduced or avoided accordingly, and active safety is provided.
Another objective of the present invention is to provide a structure of inline skates, which can provide effectively more forceful acceleration holds as well as shock-absorbing capability for comfort. Thereby, the operation quality of the inline skates is improved.
In order to achieve the objectives and effects described above, the present invention provides a structure of inline skates, which includes a base, a wheel set, at least one one-way roll stop device, and at least one cushion device. The base includes at least one connection member and an orientation member. Two side plates are disposed on the both sides of the connection member. A plurality of pivotal hole are disposed on the side plates. A long pivotal bore is disposed on the front end or the rear end of the least one side plate. The wheel set includes a front wheel and a rear wheel. The front wheel and the rear wheel are pivoted on the side plates. The front wheel and the rear wheel includes at least one bearing, respectively. The one-way roll stop device includes an annular ratchet wheel and a pawl assembly. The annular ratchet wheel is disposed on the side of the front wheel or the rear wheel of the wheel set. The annular ratchet wheel has a hole to form an annular shape. The diameter of the hole is greater than the diameter of the bearing, and the hole of the annular ratchet wheel is opposite to the bearing.
The pawl assembly is disposed on the base, the annular ratchet wheel is disposed opposite to the pawl assembly. The annular ratchet wheel and the pawl assembly are spaced from one another. The orientation member is utilized to orientate the pawl assembly for making the pawl assembly space from the annular ratchet wheel when the position of the base corresponding to the front wheel or the rear wheel is not pressed. The cushion device includes a sliding block and sleeve assembly and a spring. The sliding block and sleeve assembly includes a sleeve, which has a trough to be used for accommodating the spring. A pivotal hole is disposed at the lower end of the sleeve. The rear side of the sleeve has a sliding block corresponding to the long pivotal bore of the side plate with a shorter length. The sliding block is inset the long pivotal bore.
One end of the cushion device is disposed on the base, and the other end of the cushion device is connected with the front wheel or the rear wheel by passing a screw bolt assembly through the pivotal hole of the sliding block and sleeve assembly, the long pivotal bore of the side plate, and the front wheel or the rear wheel. The front wheel or the rear wheel can roll in two direction when the position of the base corresponding to the front wheel or the rear wheel is not pressed. When the position of the base corresponding to the front wheel or the rear wheel is pressed, the front wheel or the rear wheel of the wheel set is pressed accordingly. The cushion device eases the stress through compression thereof. When the cushion device compresses, it drives the annular ratchet wheel of the one-way roll stop device to contact with the pawl assembly to stop the front wheel or the rear wheel from rolling in one direction, and the front wheel or the rear wheel can roll in another direction. Thereby, braking effect and an acceleration hold are provided. In addition, shock-absorbing effect is provided as well by the cushion.
In order to make the structure and characteristics as well as the effectiveness of the present invention to be further understood and recognized, the detailed description of the present invention is provided as follows along with preferred embodiments and accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a three-dimensional schematic diagram according to a first preferred embodiment of the present invention;
FIG. 2 shows an explosion view according to the first preferred embodiment of the present invention;
FIG. 3 shows a side view according to the first preferred embodiment of the present invention;
FIG. 4 shows an action schematic diagram of a front wheel according to the first preferred embodiment of the present invention;
FIG. 5 shows a resistive action schematic diagram of a front wheel according to the first preferred embodiment of the present invention;
FIG. 6 shows a schematic diagram according to a second preferred embodiment of the present invention;
FIG. 7 shows a schematic diagram according to a third preferred embodiment of the present invention;
FIG. 8 shows a schematic diagram of another preferred embodiment of the cushion device according to the present invention;
FIG. 9 shows a schematic diagram according to a fourth preferred embodiment of the present invention;
FIG. 10 shows a schematic diagram according to a fifth preferred embodiment of the present invention;
FIG. 11 shows a schematic diagram of stopping a front wheel according to a fifth preferred embodiment of the present invention;
FIG. 12 shows a schematic diagram of the orientation member according to the present invention;
FIG. 13 shows a schematic diagram of the orientation member disposed on the pawl assembly and the side plate according to the present invention;
FIG. 14 shows a schematic diagram according to a sixth preferred embodiment of the present invention;
FIG. 15 shows a schematic diagram according to a seventh preferred embodiment of the present invention;
FIG. 16 shows a schematic diagram according to a eighth preferred embodiment of the present invention;
FIG. 17 shows a schematic diagram according to a ninth preferred embodiment of the present invention;
FIG. 18A shows a schematic diagram of conventional pawl stopping the ratchet wheel according to prior art; and
FIG. 18B shows a schematic diagram of conventional pawl separated from the ratchet wheel according to prior art.
DETAILED DESCRIPTION
FIGS. 1 to 3 show a structure of inline skates according to a first preferred embodiment of the present invention. The inline skate 100 includes a boot 10 , a base 20 , a wheel set 30 , an one-way roll stop device 40 , and a cushion device 50 .
The boot 10 is disposed on the base 20 , and the base 20 comprises at least one connection member. The connection member is a connection plates 21 according to this embodiment. Two side plates 22 is disposed under both sides of the connection plate 21 , respectively. At the front end of the side plates 22 , a long pivotal bore 221 is disposed. Behind and above the long pivotal bore 221 , two orientation holes 222 are disposed on the side plates 22 . In addition, behind the long pivotal bore 221 , three pivotal holes (not shown in the Figures) are disposed for mounting the wheel set 30 . The wheel set 30 includes a front wheel 31 , two intermediate wheels 32 , and a rear wheel 33 . The front wheel 31 includes a hole 311 and a plurality of fixed holes 315 , and at least one bearing 36 is set in the hole 311 . The front wheel 31 is adapted between the two long pivotal bores 221 by means of a screw bolt assembly 34 . The intermediate wheels 32 and the rear wheel 33 are adapted between pivotal holes of the side plates 22 behind the long pivotal bores 221 by means of screw bolt assemblies 35 , respectively. In the present invention, It can also be that the wheel set 30 includes only one intermediate wheel 32 , or the wheel set 30 only includes the front wheel 31 and the rear wheel 33 without any intermediate wheel 32 disposed therein.
The one-way roll stop device 40 includes an annular ratchet wheel 41 and a pawl assembly 42 . The annular ratchet wheel 41 and the pawl assembly 42 serve as a roll member and an one-way brake member respectively. The annular ratchet wheel 41 has a hole 413 and is an annular-shaped slice and is smaller slightly in diameter than the front wheel 31 . It is manufactured integrally and is mounted pivotally at the center on the side of the front wheel 31 . Alternatively, the annular-shaped slice can be fixedly coupled to the center on the side of the front wheel 31 . As shown in FIG. 2 , the annular ratchet wheel 41 has a plurality of fixed holes 415 . The annular ratchet wheel 41 is fixed on the side of front wheel 31 by passing a plurality of fixing members 37 through the fixed holes 415 and 315 . First ratchet teeth 411 with one-way hook-shaped teeth are disposed on the periphery of the annular ratchet wheel 41 . The diameter of the hole 413 of the annular ratchet wheel 41 is greater than the diameter of the bearing 36 , and the hole 413 is opposite to the bearing 36 . It is not necessary to remove the annular ratchet wheel 41 when the bearing 36 is needed to change. It will be convenient to change the bearing 36 . Otherwise, the weight of the annular ratchet wheel 41 is reduced while the annular ratchet wheel 41 has the hole 413 .
The pawl assembly 42 includes an elastic plate 421 and pawls 422 disposed on both sides under the elastic plate 421 . The elastic plate 421 is roughly a U-shaped plate. The shape here according to a preferred embodiment is used for description but not for limiting its scope. On both ends of the elastic plate 421 , two wing plates 423 , which extend upwards and outwards, are adapted. At least one second ratchet teeth 425 is disposed on the pawl 422 , which has two long bores 424 . The pawl assembly 42 is orientated on the orientation holes 222 by passing at least one orientation member 426 through the long bores 424 and the orientation holes 222 , the ratchet wheel 41 and the pawl assembly 42 are spaced from one another (shown in FIG. 3 ), and the orientation member 426 here according to one embodiment is a screw bolt assembly.
The wing plates 423 of the elastic plate 421 connect against the underside of the connection plate 21 while making the second ratchet teeth 425 of the pawls 422 correspond to the first ratchet teeth 411 of the annular ratchet wheel 41 . Thereby, the pawl assembly 42 can move up and down due to the orientation member 426 can move up and down in the long bores 424 . Moreover, because the elastic plate 421 has elasticity and can extend and compress, the pawl assembly 42 can have elastic cushion effect accordingly, which occurs when the ratchet wheel 41 is not locked but can slide freely. Furthermore, the pawl assembly 42 has the two pawls 422 without requiring the elastic plate 421 and the wing plates 423 disposed thereon. The pawls 422 are disposed on the side plates 22 of the base 20 by passing the orientation member 426 through the long bores 424 of the pawls 422 and the orientation holes 222 .
The cushion devices 50 are disposed on one side of the side plates 22 , respectively, including two sliding block and sleeve assemblies 51 , two springs 52 , two adjustment shafts 53 , and at least one nut 54 . The sliding block and sleeve assembly 51 is an assembly with a sleeve 511 and a sliding block 512 , and the sliding block 512 is disposed on the rear side of the sleeve 511 . The sliding block 512 is a long block corresponding to the long pivotal bore 221 with a shorter length. A pivotal hole 514 is adapted at the lower end of the sliding block and sleeve assembly 51 . The sliding block and sleeve assembly 51 is disposed on the side of the front wheel 31 by passing the screw bolt assembly 34 through the pivotal hole 514 , the long pivotal bore 221 and the front wheel 31 . The sliding block 512 insets the long pivotal bore 221 .
A trough 513 is disposed on the top of the sleeve 511 (as shown in FIG. 3 ), and is used for accommodating the spring 52 . The spring 52 is put around the adjustment shaft 53 , whose top end is fixedly coupled to the side plate 22 of the base 20 . The top end of the adjustment shaft 53 also can be fixedly coupled to the connection plate 21 of the base 20 . In addition, threads are adapted on the adjustment shaft 53 with nuts 54 thereupon for confining the spring 52 between the trough 513 and the nut 54 . By adjusting the threading locations of the nuts 54 , the compression force of the spring 52 can be adjusted accordingly. Hence, requirements by players with different weights or by various cushioning conditions can be met by adjustments at any time.
Please refer to FIG. 3 . The first ratchet teeth 411 on the annular ratchet wheel 41 of the one-way roll stop device 40 protrude opposite to the second ratchet teeth 425 on the pawl 422 of the pawl assembly 42 , and the first ratchet teeth 411 on the annular ratchet wheel 41 and the second ratchet teeth 425 on the pawl 422 are spaced from one another. Besides, when the annular ratchet wheel 41 contacts with the pawl assembly 42 , according to the rolling direction of the annular ratchet wheel 41 , two statuses result including an occlusion and cease-rolling status, and a free-sliding and maintain-rolling status. When the one-way roll stop device 40 is disposed on the front wheel 31 , it is installed to make the annular ratchet wheel 41 and the pawl assembly 42 in the free-sliding and maintain-rolling status when the annular ratchet wheel 41 rolls forwards, and in the occlusion and cease-rolling status when the annular ratchet wheel 41 rolls backwards. Thereby, when the one-way roll stop device 40 is disposed on the front wheel 31 , it can stop the front wheel 31 from rolling if the front wheel 31 rolls backwards.
Please refer to FIG. 4 . In general, when the inline skates slide forward, the weight of the player is distributed evenly on the front wheel 31 , the two intermediate wheels 32 , and the rear wheel 33 . In this scenario, the front wheel 31 maintains common operation condition. The pawl assembly 42 is orientated on the base 20 by the means of the orientation member 426 , and therefore the annular ratchet wheel 41 and the pawl assembly 42 are spaced from one another. Thus, the annular ratchet wheel 41 and the pawl assembly 42 are not contacted each other and does not affect the roll of the front wheel 31 . Therefore, the front wheel 31 can roll forwards or backwards. Even if the player pushes downwards the front wheel 31 , the front wheel 31 will not stop rolling forward. This is because when the inline skates move forwards, the front wheel 31 , and hence the annular ratchet wheel 41 , roll forwards as well. Thereby, the annular ratchet wheel 41 and the pawl assembly 42 are not occlusive. Through the elastic cushioning function of the pawl assembly 42 , the annular ratchet wheel 41 and the pawl assembly 42 will be in the free-sliding and maintain-rolling status.
Please refer to FIG. 5 . The braking function of the one-way roll stop device 40 disposed on the front wheel 31 is similar to the ratchet wheel in front of a general figure skate or to the brake pad in front of a conventional four-wheel skate, and is done by tipping toes while sliding backwards. If acceleration is desired, the back propelling leg uses the front wheel 31 to propel backwards. At the instant of propelling, the front wheel 31 rolls backwards. Thereby, when the player needs braking or acceleration, the front wheel 31 is pressed downwards. At this moment, the front wheel 31 rolls backwards. Because of downward pressure on the cushion device 50 by weight, the annular ratchet wheels 41 on sides of the front wheel 31 engage with the pawl assemblies 42 and rolling is stopped. Hence, the rolling of the front wheel 31 is stopped in one direction. Thereby, braking effect or a hold for forward acceleration is provided. Consequently, when the front wheel 31 rolls forwards, if pressure is exerted downwards, the annular ratchet wheel 41 and the pawl assembly 42 are in the free-sliding and maintain-rolling status. On the other hand, when the front wheel 31 rolls backwards, if pressure is exerted downwards, the annular ratchet wheel 41 and the pawl assembly 42 are in the occlusion and cease-rolling status. It is to say, when the front wheel 31 is pressed downward, the annular ratchet wheel 41 and the pawl assembly 42 are engaged to stop the front wheel 31 from rolling in one direction, but the front wheel 31 can be rolled in another direction.
FIG. 6 shows a schematic diagram of a structure of inline skates according to a second preferred embodiment of the present invention, and is used for describing that an one-way roll stop device 40 ′ and a cushion device 50 ′ are disposed on the rear wheel 33 . The difference between the present embodiment and the previous embodiment is that the one-way roll stop device 40 ′ is disposed as stopping rolling while rolling forwards. That is, the directions of the first ratchet teeth 411 ′ of an annular ratchet wheel 41 ′ and the second ratchet teeth 425 ′ of a pawl assembly 42 ′ are opposite to the directions of those disposed on the front wheel 31 . Thereby, when a player needs braking or is about to fall down faceup carelessly, by pressing the rear wheel 33 downwards by his weight to some extent, the annular ratchet wheel 41 ′ on the side of the rear wheel 33 contacts the pawl assembly 42 ′, and thus ceasing the rear wheel 33 from rolling forwards in one direction. Accordingly, a braking force is attained for braking and a forward supporting reaction force is provided for avoiding falling down backwards.
In addition, the baking effect according to the present embodiment is far superior to the braking effect of the rear brake pad in a recreational inline skate according to the prior art without the drawbacks and danger brought about by the latter. Moreover, as same as above description of the first preferred embodiment, the annular ratchet wheel 41 ′ and the pawl assembly 42 ′ are spaced from one another and the annular ratchet wheel 41 ′ does not contact with the pawl assembly 42 ′ when the player does not press the rear wheel 33 . In this scenario, the roll of the rear wheel 33 is not affected and the rear wheel 33 can roll forwards or backwards. Otherwise, a long pivotal bore is disposed on the rear end of the side plate 22 according to this embodiment for disposing the cushion device 50 ′. The side plate 22 has an orientation hole according to this embodiment. The pawl assembly 42 ′ is orientated by passing the orientation member 426 ′ through the orientation hole. At least one bearing is disposed on the rear wheel 33 according to this embodiment.
FIG. 7 shows a schematic diagram of a structure of inline skates according to a third preferred embodiment of the present invention. The third preferred embodiment is provided on the basis of the first preferred embodiment described above. The annular ratchet wheel 41 and the pawl assembly 42 are disposed likewise. The difference is the cushion device 60 of this embodiment. The side plates 22 of the base 20 are further divided into connection side plates 23 on both sides. The back end of the connection side plate 23 connects with the side plate 22 , and the front end thereof is used for pivoting the front wheel 31 . In addition, the cushion device 60 includes a sleeve assembly 61 , a spring 62 , an adjustment shaft 63 and at least one nut 64 . The sleeve assembly 61 includes a sleeve 611 , and a pivotal hole 614 is disposed under the sleeve 611 . The pivotal hole 614 is provided for fixing the sleeve assembly 61 on the side of the front wheel 31 and the side of the connection side plate 23 by means of the screw bolt assembly 34 .
A penetrating trough 615 is disposed in the sleeve 611 of the cushion device 60 and is used for accommodating the spring 62 . Inside the penetrating trough 615 , a ring-stop surface 616 , which is used for stopping the spring 62 . The spring 62 is putted around the adjustment shaft 63 , and the top end of the adjustment shaft 63 is fixed on the side plate 22 of the base 20 . Otherwise, the top end of the adjustment shaft 63 is fixed on the connection plate 21 of the base 20 . Threads are adapted on the adjustment shaft 63 with the nut 64 thereupon for confining the spring 62 between the trough 615 and the nut 64 . When the adjustment shaft 53 is passed through the penetrating trough 615 , a nut 617 or a C type ring is used for securing under the lower end of the adjustment shaft 53 . Thereby, the position of the front wheel 31 can be orientated by means of the connection side plate 23 , the sleeve 611 , and the adjustment shaft 53 . Besides, the compression force of the spring 62 can be adjusted by adjusting the nuts 54 . Furthermore, the connection side plate 23 also can be connected with the rear wheel 33 , and the cushion device 60 is disposed on the rear wheel 33 .
FIG. 8 shows a schematic diagram of another preferred embodiment of the cushion device according to the present invention. The cushion device 65 includes a sliding block and sleeve assembly 66 , a spring 67 , and an upper sleeve 68 . The sliding block and sleeve assembly 66 includes a sleeve 661 , a sliding block 662 and a pivotal hole 664 . The sliding block 662 is disposed on the rear side of the sleeve 661 , and is corresponding to the long pivotal bore 221 of the base 20 with a shorter length (as shown in FIG. 2 ). The pivotal hole 664 is disposed at the lower end of the sleeve 661 . The screw blot assembly 34 passes through the pivotal hole 664 , the long pivotal bore 221 and the front wheel 31 , and the sliding block 662 is inset the long pivotal bore 221 to fixing the sliding block and sleeve assembly 66 and the front wheel 31 on the base 20 .
A trough 663 is disposed at the top end of the sleeve 661 and is used for accommodating the spring 67 . The upper sleeve 68 is disposed on the side plate 22 or the connection plate 21 of the base 20 by means of a fixed member (not shown in the Figures). The upper sleeve 68 includes an upper trough 683 , which is corresponding to the sleeve 661 of the sliding block and sleeve assembly 66 . The spring 67 is confined between the trough 663 and the upper trough 683 . Otherwise, by adding spacers to the trough 663 and/or the upper trough 683 , the compression force of the spring 67 can be adjusted accordingly. Hence, requirements by players with different weights or by various cushioning conditions can be met by adjustments at any time. The cushion device 65 according to this embodiment also can be disposed on the rear wheel 33 , and the rear end of the base 20 also includes a long pivotal bore for insetting the sliding block 662 of the sliding block and sleeve assembly 66 .
FIG. 9 shows a schematic diagram of a structure of inline skates according to a fourth preferred embodiment of the present invention. The cushion device 70 of this preferred embodiment is different from the cushion device 65 of the FIG. 8 . The cushion device 70 includes a sleeve assembly 71 , a spring 72 and an upper sleeve 73 . The sleeve assembly 71 includes a sleeve 711 and a pivotal hole 714 . The pivotal hole 714 is disposed at the lower end of the sleeve 711 . The sleeve assembly 71 is fixed on the side of the front wheel 31 and the side of the connection side plate 23 by passing the screw bolt assembly through the pivotal hole 714 . A trough 713 is disposed on the sleeve 711 and is used for accommodating the spring 72 . The upper sleeve 73 is disposed on the side plate 22 or the connection plate 21 of the base 20 by means of a fixed member 38 . The upper sleeve 73 includes an upper trough 733 . The spring 72 is confined between the trough 713 and the upper trough 733 . Otherwise, the side plate 22 further includes an arc trench 223 , and the connection side plate 23 further includes a pillar 233 . The pillar 233 is inset the arc trench 223 , and the pillar 233 is movable in the arc inset 223 .
FIG. 10 shows a schematic diagram of a structure of inline skates according to a fifth preferred embodiment of the present invention. The pawl assembly 75 of this preferred embodiment is different from the pawl assembly 42 of the previous embodiment. The pawl assembly 75 is disposed between the inside of the side plate 22 of the base 20 and the front wheel 31 . One end of the pawl assembly 75 is disposed on the side plate 22 of the base 20 , and another end of the pawl assembly 75 includes at least one second ratchet tooth 751 . A long bore 76 is disposed on the pawl assembly 75 . An orientation member 77 is disposed on the base 20 by passing through the long bore 76 . The pawl assembly 75 is orientated by the orientation member 77 , and therefore the pawl assembly 75 and the annular ratchet wheel 41 are spaced from one another. The orientation member 77 is movable in the long bore 76 . The pawl assembly 75 and the annular ratchet wheel 41 are not contacted each other when the position of the base 20 corresponding to the front wheel 31 is not pressed. Thereby, the front wheel 31 can roll forward or backward.
As shown in the FIG. 11 , when the position of the base 20 corresponding to the front wheel 31 is pressed, the front wheel 31 will move up to make the pawl assembly 42 engage the annular ratchet wheel 41 thereby stopping, the front wheel 31 from rolling in one direction, and rolling in another direction. In this embodiment, the front wheel 31 can rolls forwards, nor rolls backwards. The pawl assembly 75 and the annular ratchet wheel 41 also can be applied to the rear wheel 33 according to this embodiment. When the position of the base 20 corresponding to the rear wheel 33 is pressed, the pawl assembly 75 and the annular ratchet wheel 41 are engaged thereby stopping the rear wheel 33 from roll in one direction, and rolling in another direction. The directions of the annular ratchet wheel 41 and of the pawl assembly 75 disposed on the rear wheel 33 are opposite to the directions of those disposed on the front wheel 31 . Thereby, the rear wheel 33 could roll forwards or backwards when player does not press the rear wheel 33 , and when the player press the rear wheel 33 , the annular ratchet wheel 41 and the pawl assembly 75 are engaged, so as to stop the rear wheel 33 from rolling forwards, but rolling backwards.
According to a preferably embodiment of the present invention, the inner diameter of the annular ratchet wheel 41 is 16-30 mm, and the outer diameter of the annular ratchet wheel 41 is 30-46 mm. The annular ratchet wheel 41 has 12-32 first ratchet teeth 411 , and the pawl assembly 75 has 1-6 second ratchet teeth 751 . According to a preferably embodiment, the engagement perimeter of the first ratchet teeth 411 of the annular ratchet wheel 41 and the second ratchet teeth 751 of the pawl assembly 75 is not over than three sixteenth of the peripheral of the annular ratchet wheel 41 .
FIG. 12 shows a schematic diagram of the orientation member 77 of the FIGS. 10 and 11 . The orientation member 77 includes a flange 771 , a orientation shaft 773 and a fixing shaft 775 . The flange 771 is disposed on the upper end of the orientation shaft 773 , and the fixing shaft 775 extends from the lower end of the orientation shaft 773 . The diameter of the flange 771 is greater than the diameter of the orientation shaft 773 , and the diameter of the orientation shaft 773 is greater than the diameter of the fixing shaft 775 . As shown in FIG. 13 , when the orientation member 77 is disposed on the side plate 22 of the base 20 by passing through the long hole 76 of the pawl assembly 75 , the fixing shaft 775 is fixedly coupled to the side plate 22 of the base 20 , and the flange 771 and the side plate 22 of the base 20 would stop the pawl assembly 75 . Thereby, the pawl assembly 75 would be orientated on the orientation shaft 773 to be opposite to the annular ratchet wheel 41 accurately.
Otherwise, the pawl assembly 75 would not be shake or wobble to contact the front wheel 31 or the rear wheel 33 for preventing the rolling of the front wheel 31 or the rear wheel 33 from the influence of the pawl assembly 75 . Hence, when the base 20 is pressed, it would be ensure that the annular ratchet wheel 41 and the pawl assembly 75 are engaged. the orientation member 77 is a rivet according to a preferably embodiment.
FIG. 14 shows a schematic diagram of a structure of inline skates according to a sixth preferred embodiment of the present invention. The pawl assembly 80 of this preferred embodiment does not include long hole 76 of the FIG. 10 . The orientation member 87 is used for stopping the pawl assembly 80 , and therefore the pawl assembly 80 and the annular ratchet wheel 41 are spaced from one another. Thereby, when the position of the base 20 corresponding to the front wheel 31 is not pressed, the pawl assembly 80 and the annular ratchet wheel 41 are not contacted with each other, therefore the front wheel 31 can roll forwards or backwards. When the position of the base 20 corresponding to the front wheel 31 is pressed, the front wheel 31 is moved up to make the pawl assembly 80 engage the annular ratchet wheel 41 , thereby the front wheel 31 is stopped from rolling in one direction, and rolling in another direction.
According to above embodiment and description, the pawl assembly and the annular ratchet wheel are spaced from one another. Therefore, the front wheel or the rear wheel can roll forwards or backwards. However, when the position of the base corresponding to the front wheel or the rear wheel is pressed, the front wheel or the rear wheel will be moved up so as to make the pawl assembly engage the annular ratchet wheel. Thereby, the front wheel or the rear wheel is stopped from rolling in one direction, and being able to roll in another direction. The structure of the pawl assembly and he annular ratchet wheel of the present invention is different from the conventional structure of the pawl and the ratchet wheel, which is used for rolling in one direction only.
As shown in FIG. 18A , in conventional concept, a ratchet wheel 90 and a pawl 95 are kept in contact with each other generally. The ratchet wheel 90 has an axle hole 93 for pivoting a shaft 94 to be disposed on a wheel 92 . One end of the pawl 95 is disposed on a shaft 96 , and a spring (not shown in Figures) is disposed on the shaft 96 , and the pawl 95 is always contacted with the ratchet wheel 90 since the elastic force of the spring affects to the pawl 95 . Thereby, the ratchet wheel 90 and the pawl 95 would be contacted with each other to limit the wheel 92 to rolling in one direction, nor rolling forwards or backwards. If the conventional ratchet wheel 90 is spaced from the pawl 95 , the pawl 95 is rotated by the elastic force of the spring. Therefore, the pawl 95 contacts against the base plate 96 , as shown in FIG. 18B . Therefore, the pawl 95 can be not used for engaging the ratchet wheel 90 again.
Although the pawl assembly is separated from the annular ratchet wheel according to the present invention, but these would not occur above problem of the ratchet wheel 90 and the pawl 95 . The present invention is to use the orientation member orientating the pawl assembly for making the pawl assembly and the annular ratchet wheel be spaced from one another and disposed on the most appropriate position to be in engagement. When the position of the base corresponding to the front wheel or the rear wheel is not pressed, the front wheel or the rear wheel is moved up to make the pawl assembly engage the annular ratchet wheel. Thereby, the front wheel or the rear wheel is stopped from rolling in one direction, but the front wheel or the rear wheel can be rolled in another direction.
Accordingly, the design concept of the pawl assembly and the annular ratchet wheel according to present invention is different from the design concept of the conventional pawl and the conventional ratchet wheel. Otherwise, the conventional ratchet wheel has a axis hole for pivoting on the shaft, so that the wheel with the conventional ratchet wheel cannot be convenient for changing the bearing of the wheel. However, the present invention has a hole whose diameter is greater than the diameter of the bearing, nor axis hole. Thereby, it is convenient to change the bearing of the wheel and is effect to reduce the weight of the annular ratchet wheel.
FIG. 15 shows a schematic diagram of a structure of inline skates according to a seventh preferred embodiment of the present invention. A base 25 of this preferred embodiment is different from the base 20 of FIG. 2 . The base 25 includes at least one connection block 26 and two side plates 22 , preferably the base 20 has two connection blocks 26 according to this preferred embodiment. The connection block 26 serves as a connection member to connect the two side plates 22 . A plurality of fixing member (no shown in Figures) are passed through the two side plates 22 and the two connection blocks 26 to dispose the two side plates 22 on the both sides of the two connection blocks 26 . A orientation trench 261 is disposed on at least one side of the connection block 26 corresponding to the front wheel 31 , preferably two orientation trenches 261 are disposed on both sides of the connection block 26 . The two orientation trenches 261 serve as two orientation members to orientate the two pawl assemblies 89 for making the two pawl assemblies 89 and the two annular ratchet wheels 41 are spaced from one another, and the two pawl assemblies 89 are corresponding to the two annular ratchet wheels 41 , respectively.
One end of the pawl assembly 89 is disposed on the orientation trench 261 by the fixing member (not shown in Figures). The pawl assembly 89 is inset the orientation trench 261 , and the orientation trench 261 is larger than the pawl assembly 89 . The pawl assembly 89 is orientated on the orientation trench 261 since the side wall of the orientation trench 261 and the side plate 22 stop the pawl assembly 89 . As shown in FIG. 16 , the pawl assembly 89 is opposite to the annular ratchet wheel 41 accurately, and the pawl assembly 89 would be wobbled to contact with the front wheel 31 for preventing the rolling of the front wheel 31 from the influence. Hence, when the base 25 is pressed, it is ensure that the pawl assembly 89 engages the annular ratchet wheel 41 .
FIG. 17 shows a schematic diagram of an improved structure of inline skates according to a ninth preferred embodiment of the present invention. The ninth preferred embodiment is provided on the basis of the above preferred embodiment described above. The ninth preferred embodiment adopts different device for embodying at least one one-way roll stop device 40 A. The adjustment shaft 63 of the cushion device 60 is disposed on a pivotal hole 24 in front side of the side plate 22 . The cushion device 60 is connected with the front wheel 31 and the connection side plate 23 by means of a screw bolt assembly 34 . However, a different device is adopted for embodying said at least one one-way roll stop device 40 A. First, a plurality of surrounding arc-shaped holes 230 is disposed on the connection side plate 23 , and a pivotal hole 231 is disposed on the center of said plurality of surrounding arc-shaped holes 230 .
Besides, the one-way roll stop device 40 A includes a side ratchet wheel 401 and a side pawl 402 , and the side ratchet wheel 401 and the side pawl 402 are defined as a roll member and a brake member respectively. The side ratchet wheel 401 is disposed inside the front wheel 31 . At least one bearing 26 is disposed on the front wheel 31 , and the side ratchet wheel 401 includes a hole whose diameter is greater than the diameter of the bearing 26 . The side pawl 402 has an annular body 402 A, one side of the annular body 402 A has at least one ratchet tooth 402 B. The ratchet tooth 402 B correspond to the side ratchet wheel 401 , and can engage with each other or slide freely, and the annular body 402 A has a plurality of the ratchet teeth 402 B according to the embodiment. When the front wheel 31 rolls forwards, the ratchet teeth 402 B slides freely with the side ratchet wheel 401 . On the contrary, when the front wheel 31 rolls backwards, the ratchet teeth 402 B engages with the side ratchet wheel 401 . On the other side of the annular body 402 A, a plurality of first stick-like parts 402 D and a plurality of second stick-like parts 402 E are both distributed annularly. The first stick-like parts 402 D are thicker than the second stick-like parts 402 E, and a trench 402 C is disposed on the end of each second stick-like part 402 E. The plurality of surrounding arc-shaped holes 230 is larger than the plurality of first stick-like parts 402 D and second stick-like parts disposed on one side of the annular body 402 A of the side pawl 402 . In addition, each second stick-like part 402 E of the side pawl 402 is passed through the plurality of surrounding arc-shaped holes 230 disposed on the connection side plate 23 , as same as above description of the first preferred embodiment, the side ratchet wheel 401 and the side pawl 402 are spaced from one another.
A second compression spring 407 , a spacer 406 , a first compression spring 405 , a special-shaped spacer 404 , and a hook ring 403 are slip on sequentially thereon. The hook ring 403 clips on a trench 402 C. The inner radius of the spacer 406 is smaller than the outer radius of the circle surrounded by the first stick-like parts 402 D, and the elastic force of the second compression spring 407 is smaller than that of the first compression spring 405 . Thereby, a driving apparatus is defined to include a driver 408 , the second compression spring 407 , the spacer 406 , the first compression spring 405 , the special-shaped spacer 404 , and the hook ring 403 . Owing to the functions of the first compression spring 405 and the second compression spring 407 , the annular body 402 A of the side pawl 402 maintains tight contact with the connection side plate 23 under normal conditions. Therefore, the side ratchet wheel 401 and the side pawl 402 are spaced from one another.
In addition, the driver 408 is disposed on the side plate 22 and is disposed the upper side of the special-shaped spacer 404 . When weight presses the connection plate 21 , the cushion device 60 is compressed accordingly, which makes the driver 408 close and contact the special-shaped spacer 404 . Because the contact surface between the driver 408 and the special-shaped spacer 404 is an inclined plane 408 A, when the driver 408 is pressed down, it will produce a pressing force on the special-shaped spacer 404 towards the connection side plate 23 . Nevertheless, because the inner radius of the spacer 406 is smaller than the outer radius of the circle surrounded by the first stick-like parts 402 D, and the elastic force of the second compression spring 407 is smaller than that of the first compression spring 405 , said pressing force towards the connection side plate 23 will not compress the first compression spring 405 , but, instead, will force the spacer 406 to compress the second compression spring 407 and thereby make the side pawl 402 move towards the side ratchet wheel 401 . At this moment, if the front wheel 31 rolls backwards, the side ratchet wheel 401 will engage the side pawl 402 and the rolling of the front wheel 31 is stopped in one direction. However, the front wheel 31 can roll in another direction. On the contrary, if the front wheel 31 rolls forwards at the moment, due to deployment of the first compression spring 405 , the side ratchet wheel 401 and the side pawl 402 slide freely. In addition, the driver 408 does not contact the special-shaped spacer 404 and the side ratchet wheel 401 and the side pawl 402 are spaced from one another when the player does not press the front wheel 31 . Therefore, the side ratchet wheel 401 does not contact the side pawl 402 and the roll of the front wheel 31 is not affected, and therefore the front wheel 31 can roll forwards or backwards. From the description above, it is known that the present has at least the following effects and features:
1. If the cushion device and the one-way roll stop device according to the present invention are disposed on the front wheel, when the front wheel is pressed to some extent while rolling backwards, the front wheel has the capability of stopping rolling backwards and in one direction. If the cushion device and the one-way roll stop device according to the present invention are disposed on the rear wheel, when the rear wheel is pressed to some extent while rolling forwards, the rear wheel has the capability of stopping rolling forwards and in on direction. 2. According to the present invention, if forward propelling is desired by pressing backwards, because the propelling leg is pressed downwards by weight and the front wheel is pushed backwards, which is in a back-rolling status, thereby, back-rolling is stopped in one direction. Consequently, a hold for propelling forward that is more powerful and more ergonomic is given. 3. The operation of the braking function on the front wheel according to the present invention is similar to the ratchet wheel in front of a general figure skate or to the brake pad in front of a conventional four-wheel skate, and is done by tipping toes while sliding backwards. At this moment, the front wheel is pressed while rolling backwards, thereby, a braking function that is more ergonomic and safe is given. The braking effect of the rear wheel is similar to the braking effect of the rear brake pad in a recreational inline skate. When the player slides forwards, if he puts forth his strength to raise his feet upwards with his weight pushed downwards the rear wheel, at which moment the rear wheel is pressed to some extent and rolling forward, a braking effect that stops rolling forwards is attained. The baking effect is far superior to the braking effect of the rear brake pad in a recreational inline skate according to the prior art without the drawbacks and danger brought about by the latter. 4. As provided in the front and the rear wheels according to the present invention, when the player steps forward, because of the cushion devices disposed thereon, tiptoes and ankles are cushioned and shock-absorbed. Thereby, ergonomic effect is attained. 5. When the players is about to fall down forwards carelessly, because the front wheel is pressed by weight while rolling backwards, a braking force is given for stopping rolling backwards and in one direction. Thereby, the player is supported upright automatically. When the players is about to fall down faceup carelessly, because the rear wheel is pressed by weight while rolling forwards, a braking force is given for stopping rolling forwards. Thereby, the player is supported by the reaction force upright automatically. Hence, the present invention can provide a function of automatically support upright before falling down faceup carelessly or falling down forwards carelessly.
Accordingly, the present invention conforms to the legal requirements owing to its novelty, non-obviousness, and utility. However, the foregoing description is only a preferred embodiment of the present invention, not used to limit the scope and range of the present invention. Those equivalent changes or modifications made according to the shape, structure, feature, or spirit described in the claims of the present invention are included in the appended claims of the present invention.
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A structure of inline skates is provided, the structure of inline skates includes a cushion device, a wheel with an annular ratchet wheel on its side, and a pawl assembly. By using the user's weight to press down the structure of present invention, the wheel with the annular ratchet wheel on its side engages the pawl assembly, which stops the wheel with the annular ratchet wheel on its side from rolling in one direction, and the wheel with the annular ratchet wheel on its side can roll in another direction. Thereby, the structure of inline skates is more ergonomic and exercise injuries can be prevented. In addition, a brake is provided for providing shock absorption and as a fulcrum to make more powerful acceleration. Besides, automatic support upright is also provided for avoiding tumbles.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to an automotive engine coolant temperature determination method. More particularly, the present invention relates to a method using a cylinder head temperature sensor to infer such a temperature.
2. Disclosure Information
It is well known that malfunctions of engine cooling systems, such as a leak, will generally cause damage to the engine due to excessive engine overheating. To indicate such an event, a temperature sensing system for an internal combustion engine may include an engine coolant temperature (ECT) sensor, a cylinder head temperature (CHT) sensor, or a combination of the two. The temperature sensors record a temperature and relay the information to an electronic engine controller, which, in turn, relays the information to an operator, typically via an instrument display panel.
In ECT sensor equipped vehicles the sensor typically communicates with a coolant passage in a cylinder head. The problem with ECT sensor equipped vehicles is that an accurate reading of the CHT can not be obtained. Having an accurate CHT reading is important with respect to fuel economy and emissions.
In CHT sensor equipped vehicles the sensor typically communicates with the cylinder head at a location adjacent the combustion chamber of the engine. A problem with CHT sensor equipped vehicles is that the ECT can not be accurately calculated. For example, the CHT can be up to 70 degrees Fahrenheit hotter than the ECT and the temperature gauge would read hot when the system is really operating within a normal temperature range, thereby giving a "false reading".
To combat these problems many vehicles are equipped with both ECT and CHT sensors. A problem with a two sensor system is that it is more costly than the single sensor systems. A further problem is that the algorithm programmed into the engine controller is more complex because of the need to receive information from two sensors.
It would therefore be desirable to provide a method of accurately inferring ECT in CHT sensor equipped vehicles that overcomes the deficiencies associated with previous systems.
SUMMARY OF THE INVENTION
The present invention overcomes the disadvantages of the prior art approaches by providing a method of inferring ECT in CHT sensor equipped vehicles including the steps of measuring the CHT, calculating the ECT from the measured CHT as a function of at least one vehicle operational state, generating a signal for the calculated ECT, and sending the generated signal to a display.
It is an object and advantage of the present invention to calculate ECT as a function of the vehicle operational state. Calculation in this fashion prevents "false readings" which may arise when CHT is running hotter then ECT, but still within an acceptable operational range.
A feature of the present invention is to filter the calculated ECT to prevent inaccurate display readings resulting from sudden changes in vehicle operational states, the filter step being performed prior to the step of generating a signal.
These and other advantages, features and objects of he invention will become apparent from the drawings, detailed description and claims which follow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an automotive vehicle according to the present invention;
FIG. 2 is a partial cross-sectional view of an internal combustion engine having a temperature sensing system according to the present invention; and
FIG. 3 is a flow chart showing a method for inferring ECT in CHT sensor equipped vehicles according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, FIG. 1 shows an automotive vehicle 10 having an internal combustion engine 12 and a dashboard 14 housing an instrument display panel 16. As known in the art, the display panel 16 has a variety of gauges which communicate various vehicle operational states such as vehicle speed, engine revolutions per minute, and engine temperature for example.
A temperature sensing system 11, shown in FIG. 2, infers ECT from a measured CHT. The engine 12 includes a cylinder block 18 having a cylinder 20 formed therein and a piston 22 reciprocally housed within the cylinder 20. A cylinder head 24 is mounted to the cylinder block 18, with a cylinder head gasket 26 disposed therebetween, such that the cylinder head 24 closes the outer end of the cylinder 20, thereby defining a combustion chamber 28 between the top of the piston 22 and an insulation deck 30 of the cylinder head 24. A sparkplug 32 is fastened to the cylinder head 24 to communicate with the combustion chamber 28. A cooling system 34 of the engine 12 is generally provided by a coolant passage 36 formed in the cylinder head 24. A coolant 38 circulates in coolant passage 36 to cool the engine 12.
According to the present invention, a temperature sensor 42 communicates with the insulation deck 30 in the cylinder head 24 adjacent the combustion chamber 28. Preferably, the temperature sensor 42 is a thermistor as is known in the art. The temperature sensor 42 senses the cylinder head 24 temperature and relays the information to an electronic engine controller (EEC) 44 having a keep alive memory (KAM) storage device 46.
Referring now to FIG. 3, according to the present invention, a method of inferring ECT from a CHT sensor is described. At step 50, the process is initiated. At step 52, it is determined whether a CHT is available from the EEC. If not, then at step 54 the engine temperature signal generated and sent to the display 16 (ECT DISPLAY) is set equal to a failure mode value of ECT (ECT FMEM). Generally, the engine temperature signal generated and sent to the display 16 at step 54 equals the combustion chamber air charge temperature during a cold start, and ramps to a calibratible constant whose value is typical for a warm engine.
If a valid CHT is available, then at step 56, it is determined whether the initial pass through this process has been completed (INIT FLG). The initial pass completed is indicated by a 1 as discussed below.
If the initial pass was completed, then at step 58, a temporary ECT value is determined. This temporary value is equal to the CHT value minus a first function (F1(RPM, LOAD)) plus a second function (F2(CHT)). The first function is derived from a calibratible look up table showing the deviation of ECT from CHT as a function of revolutions per minute (RPM) and cylinder air charge temperature (LOAD). Both RPM and LOAD values may be derived from the EEC. The second function is to account for the difference between ECT and CHT increases for very high values of CHT.
At step 60, the engine temperature signal generated and sent to the display 16 (ECT DISPLAY) is set equal to a rolling average function (ROLAV) used to filter out noise. The rolling average function is determined as a function of the temporary ECT value and a calibratible time constant (RUN TC) that takes into consideration the fact that CHT heats faster than the engine coolant.
At step 62, the temperature difference (DELTA) is determined and stored. The DELTA is the difference between the CHT and the engine temperature signal generated. The DELTA is sent to the display 16 and is stored in KAM, so that the DELTA at power-down is available during the next power-up. At step 64, the process ends.
If the pass at step 56 was not completed, then the process flow moves to step 66, where DELTA is determined as a function of the last DELTA stored in KAM multiplied by an exponential decay function (EXP). The EXP is a function of the number of minutes the engine 12 has been powered down (SOAKTIME) divided by a calibratible time constant (SOAK TC), which determines the rate at which DELTA decays during a soak. This information is available from the EEC 44. The EXP is equal to 1 if SOAKTIME equals zero and decays to zero as SOAKTIME approaches infinity. At step 68, the engine temperature signal generated and sent to the display 16 is equal to the difference between the CHT and the DELTA from step 66. At step 70, INIT FLG is registered as 1 indicating that the initial pass has been completed. At step 64, the process ends.
The present invention is advantageous for a number of reasons. First, because ECT is calculated as a function of the vehicle operational state "false readings" are avoided. For example, "false readings" which may arise when CHT is running hotter then ECT, but still within an acceptable operational range. Further, filtering the calculated ECT prevents inaccurate display readings resulting from sudden changes in vehicle operational states. More specifically, because ECT is being inferred by CHT as a function of RPM and LOAD, anomalous readings for RPM and LOAD need to be taken out of the calculation as they tend to change faster than actual CHT and ECT. In other words, if ECT is being inferred at a time when there is a sudden spike in RPM, with the RPM then returning to normal running, without filtering, the ECT calculation would indicate being out of control limits when that is not actually the case. It is an important aspect of the invention, therefore, that not only is ECT inferred from CHT as a function of vehicle operational states, but also that the ECT sent to the display is filtered to eliminate noise resulting from the various operational states.
Various other modifications to the present invention will, no doubt, occur to those skilled in the art to which the present invention pertains. It is the following claims, including all equivalents, which define the scope of the present invention.
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The present invention provides a method of inferring the engine coolant temperature in cylinder head temperature sensor equipped vehicles including the steps of measuring the cylinder head temperature, calculating the engine coolant temperature from the measured cylinder head temperature as a function of at least one vehicle operational state, generating a signal for the calculated engine coolant temperature, and sending the generated signal to a display.
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